Dissertations / Theses on the topic 'Ultrastructure analysis'
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1
Taylor, Wilson A. "Comparative analysis of sporoderm ultrastructure in fossil and extant lycopods /." The Ohio State University, 1989. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487599963591563.
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Pratelli, Ambra. "Ultrastructural and immunolocalization studies on the interactions occurring between IntraFlagellar Transport components and the ciliary tip structures during IFT trains turnaround in Chlamydomonas flagella." Doctoral thesis, Università di Siena, 2021. http://hdl.handle.net/11365/1143888.
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Cilia and flagella are dynamic organelles of the eukaryotic cell that undergo cycles of assembly/disassembly, in a manner that is coordinated in time with the cell cycle. Cilia are composed by more than 600 peptides and their turnover occurs at the plus distal end of the axoneme; since these organelles lack the machinery required for protein synthesis, a bidirectional transport process known as the IntraFlagellar Transport (IFT) is required to provide flagellar precursors and remove turnover products.
IFT is carried on by macromolecular complexes (the IFT particles) which are arranged in polymers (the IFT trains) in the space between the microtubular doublets and the flagellar membrane. IFT trains operate as platforms for cargoes and are moved bidirectionally by specific molecular motors, kinesin-2 as the anterograde motor and dynein-1b as the retrograde motor. Anterograde and retrograde IFT trains possess distinct architectures but, up to now, a high-resolution 3D-model is available only for the anterograde trains, while much less is known on the ultrastructure of retrograde trains.
At the distal tip of the organelle, the anterograde transport (from the cell body up to the ciliary distal end or tip) is converted into the retrograde transport (from the tip back to the cell body). Such a turnaround process is strictly required for the correct functioning of the IFT process. So far, however, very little is known about the morpho-functional organization of the tip district, where IFT turnaround takes place. In particular, nothing is known on the interactions that might occur between IFT proteins and the distal tip structures.
This doctoral work has been aimed at contributing new information for the comprehension of the IFT turnaround process in the model organism Chlamydomonas reinhardtii.
We started our studies from the observation that thin sections of flat-embedded flagella often show anterograde IFT trains that contact the distal end of the central pair microtubules (CP), suggesting the direct involvement of CP capping structures (terminal plates and the ring above) in the IFT turnaround process. We confirmed the interaction of anterograde trains with the CP distal end by electron-tomographic reconstruction of flat-embedded flagellar tips. This approach revealed that anterograde trains split into three components after having reached the end of the A tubule, with the outer part of the train that remains associated with the membrane, the inner part, closer to the microtubule surface, that continues its travel and bends to contact the CP plates, and an intermediate part that stops before reaching the tip. The latter region was interpreted as the part of the train consisting of inactive dynein-1b, which is known to dissociate from the anterograde train before its activation and recruitment for the retrograde transport.
Then, we sought to obtain further information on the ultrastructural organization of the distal CP segment. We were able to identify a ladder-like structure (LLS) which is distinctive of this region, is intercalated between the two CP tubules, and is resistant to the cold treatments used to depolymerize tubulin.
In order to confirm the association between IFT anterograde trains and the capping CP structures, whole cells were treated with inhibitors of Ca++-dependent protein kinases before flagellar demembranation and negative staining. These inhibitors block the release of kinesin-2 from the anterograde trains and, consequently, IFT turnaround at the tip. As expected, we observed a massive accumulation of IFT particles around the CP terminus.
Successively, we analyzed by immunoelectronmicroscopy the specific distribution of the three protein complexes present within the IFT particles. At this purpose, we carried out a series of immunolabeling experiments on grid-absorbed demembranated cells or on sections of resin-embedded samples, using antibodies directed against subunits of the IFT-A complex (IFT139), and of the two IFT-B subcomplexes IFT-B1 (IFT74 and IFT81) and IFT-B2 (IFT172 and IFT57).
Our findings suggest that at the tip the IFT-A complex is closely associated with the membrane. On the contrary, both IFT-B1 and IFT-B2 antibodies labelled the distal CP region, though, interestingly, with distinct spatial distributions. IFT-B2 labeling was restricted to approximately the distal 200 nm-segment of the CP, which contains the LLS, and gold particles were never found more distally, above the terminal plates, while IFT-B1 labeling extend also to the ring. The whole set of immunoelectronmicroscopy data indicates that the IFT-B1 and IFT-B2 subcomplexes differentially interact with the distal CP region and its capping structures, and suggests that the IFT-B1 subcomplex might be a main component of the CP capping structures. Accordingly, in our negatively stained samples the cap was shown to consist of thin elongated elements, frequently with a sort of small knob at their mid region; these elements fit quite well with the available IFT-B 3D model. The possibility that IFT-B1 proteins are involved in the formation of the CP cap was confirmed by the analysis of a series Chlamydomonas mutants with defective IFT, which related the presence of the CP cap to the establishment of a fully cycling IFT process.
Our data sustain a model of IFT turnaround in which i) the IFT-A complex turns around quickly, remaining associated with the membrane, ii) IFT-B1 and IFT-B2 follow a more complex pathway, during which they separate and differentially interact with the CP distal segment, iii) IFT-B1 directly contribute to the formation of the CP cap. The LLS component, which is ectopically assembled also in mutant strains devoid of the CP tubules, is likely to act as an anchoring structure for IFT-B2 during IFT turnaround.
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Axelsson, Maria. "Image analysis for volumetric characterisation of microstructure /." Uppsala : Centre for Image Analysis, Swedish University of Agricultural Sciences, 2009. http://epsilon.slu.se/200919.pdf.
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Johnstone, Andrew Fredericks Moser. "PHYSIOLOGICAL AND ANATOMICAL ASSESSMENT OF SYNAPSES AT THE CRAYFISH NEUROMUSCULAR JUNCTION." UKnowledge, 2006. http://uknowledge.uky.edu/gradschool_diss/274.
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The crayfish, Procambarus clarkii, has a multitude of ideal sites in which synaptic transmission may be studied. Its opener muscle, being innervated by a single excitatory neuron is a good model for studying the structure/function of neuromuscular junctions since the preparation is identifiable from animal to animal and the nerve terminals are visible using a vital dye. This allows ease in finding a suitable site to record from in each preparation and offers the ability to relocate it anatomically. Marking a recorded site and rebuilding it through electron microscopy gives good detail of synaptic struture for assesment.In the first of these studies, low output sites known as stems (which lie between varicosities) were used to reduce n (number of release sites) in order to minimize synaptic complexity so individual quantal events could be analyzed by their unique parameters (area, peak, tau, rise time and latency). This was in attempt to uncover specific quantal signatures that could be traced back to the structure of the area recorded. It was found that even at stem regions synaptic structure is still complex having multiple synapses each of which could harbor a number of AZs. This gives insight as to how quantal analysis should be treated. Even low output synapses n must be treated at the AZ level.Synaptic depression was studied at the crayfish extensor muscle. By depressing the phasic neuron and recording from the muscle it appears thatdepression is a presynaptic phenomenon. The use of 5-HT gave insight to vesicular dynamics within the nerve terminal, by delaying depression and increasing maximum EPSP amplitude. TEM of phasic nerve terminals reveals no change in numbers of dock or RRP vesicles. Short term facilitation and vesicular dynamics were studied with the use of 5-HT and a neurotoxin TBOA, which blocks the glutamate transporter. In this study I showed differential mechanisms that control RRP and RP vesicles. By blocking glutamate reuptake, the RRP is depleted as shown by reduced EPSPs, but recovered with 5-HT application. The understanding of vesicle dynamics in any system has relevance for all chemical synapses.
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Gogoli, Komlavi. "Contribution à l'étude des faisceaux de fibres de lin : analyse des relations morphologie-comportement mécanique-ultrastructure." Thesis, Normandie, 2022. https://tel.archives-ouvertes.fr/tel-03789637.
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Afin de réduire l’impact écologique des processus industriels, on assiste à un intérêt croissant dans l’industrie pour les fibres végétales. En effet, en plus d’être biodégradables, ces fibres possèdent des propriétés mécaniques capables de concurrencer celles des fibres synthétiques. Cependant, leur usage est limité notamment par la variabilité de leurs propriétés mécaniques. De plus, ces fibres présentent un comportement mécanique non-linéaire qu’il convient d’élucider. Dans ce contexte, cette thèse se propose dans une première partie d’étudier l’influence de la morphologie des faisceaux de fibres de lin sur leur comportement mécanique. Les résultats révèlent une forte hétérogénéité de la morphologie et une dépendance du comportement mécanique par rapport aux paramètres morphologiques comme le vrillage des échantillons, l’état des lamelles mitoyennes ou la section transversale. Dans une deuxième partie, il est proposé une caractérisation par diffraction des rayons X de l’ultrastructure du lin afin d’améliorer la compréhension du comportement mécanique non-linéaire des fibres de lin. Le traitement des mesures de diffraction par la technique d’analyse combinée << structure/microstructure/texture >> a rendu possible, entre autres, la détermination de la distribution de l’Angle Micro-Fibrillaire et la forme des cristallites de cellulose. Cette méthode a ensuite permis de suivre l’évolution sous traction de l’ultrastructure de la fibre de lin. Nous avons pu ainsi proposer un scénario susceptible d’expliquer le comportement mécanique non-linéaire des fibres de linIn order to reduce the ecological impact of industrial processes, there is a growing interest in the industry for plant fibres. Indeed, in addition to being biodegradable, these fibres have remarkable mechanical properties, making them very competitive with synthetic fibres. However, the use of plant fibres is currently limited, in particular by the variability observed in their mechanical properties. In addition, these fibres have a non-linear mechanical behaviour that needs to be elucidated. In this context, this work proposes in a first part to study the influence of the morphology of flax fibre bundles on their mechanical behaviour. The results reveal a strong heterogeneity in the morphology and a dependence of the tensile mechanical behaviour on morphological parameters such as the twisting of the samples, the state of the middle lamellae or the cross-section. In a second part, an X-ray diffraction characterisation of the flax ultrastructure is proposed to improve the understanding of the non-linear mechanical behaviour of flax fibres. The use of the so-called combined analysis << structure/microstructure/texture >> approach for the X-ray diffraction data fit allows the determination of the Micro-Fibrillar Angle distribution and the shape of the cellulose crystallites. This method then made it possible to follow the evolution of the ultrastructure of flax fibres under tensile loading. Finally, this allowed us to propose a scenario that could explain the non-linear mechanical behaviour of flax fibres
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Cappello, V. "ANALYSIS OF NEUROMUSCULAR JUNCTIONS AND EFFECTS OF NANDROLONE ADMINISTRATION IN A MOUSE MODEL FOR ALS." Doctoral thesis, Università degli Studi di Milano, 2012. http://hdl.handle.net/2434/170264.
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Several lines of evidence indicate that neuromuscular junction (NMJ) destruction and disassembly is an early phenomenon in the amyotrophic lateral sclerosis (ALS) neurodegenerative disease. Here we analyzed by confocal and electron microscopy the NMJ structure in the diaphragm of Superoxide dismutase (SOD)1 G93A mice at symptom onset and we compared these observation with animals sacrificed at the pathological end stage. In young transgenic mice, which provide a model for familial ALS, the present findings showed marked denervation both in the diaphragm and in the gastrocnemius, which partially spares soleus muscle. At the clinical end stage even the soleus is slight denervated, but less severely than other muscles. In addition, the size of the synaptic vesicle (SV) pool was found reduced and alterations of mitochondria were observed in approximately 40% of the remaining presynaptic terminals. Treatment of SOD1 G93A mice with the anabolic steroid nandrolone during the presymptomatic stage preserved the diaphragm muscle mass and features indicative of synaptic activity, represented by the number of vesicles docked within 200 nm from the presynaptic membrane and area of acetylcholine receptor clusters. Furthermore, structural preservation of mitochondria was documented in presynaptic terminals, but innervation of diaphragm muscle fibers was only slightly increased in nandrolone-treated SOD1-mutant mice. Altogether the results point out and define fine structural alterations of diaphragm NMJs in the murine model of familial ALS at symptom onset, and indicate that nandrolone may prevent or delay structural alterations in NMJ mitochondria and stimulate presynaptic activity but does not prevent muscle denervation in the disease.
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Strassert, Jürgen F. H. [Verfasser]. "The symbioses of termite gut flagellates and their bacterial endo- and ectosymbionts : analysis of ultrastructure, phylogeny, and cospeciation / Jürgen F. H. Strassert." Berlin : Freie Universität Berlin, 2010. http://d-nb.info/1024105148/34.
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Nordin, Anders. "Buellia species with pluriseptate spores and the Physciaceae (Lecanorales, Ascomycotina) : Taxonomic, phylogenetic and ultrastructural studies." Doctoral thesis, Uppsala : Acta Universitatis Upsaliensis : Univ.-bibl. [distributör], 2001. http://publications.uu.se/theses/91-554-4879-8/.
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Lima, Bruna de Araujo 1985. "Análise dos mecanismos da atividade antimicrobiana da violaceína sobre Staphylococcus aureus = Analysis of antimicrobial activity mechanisms of violacein against Staphylococcus aureus." [s.n.], 2013. http://repositorio.unicamp.br/jspui/handle/REPOSIP/317022.
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Orientador: Marcelo BrocchiTese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia
Made available in DSpace on 2018-08-23T15:34:06Z (GMT). No. of bitstreams: 1 Lima_BrunadeAraujo_D.pdf: 3794605 bytes, checksum: 178a4bf447e5292f789a4713d5500b38 (MD5) Previous issue date: 2013
Resumo: A violaceína é um pigmento violeta produzido por algumas espécies bacterianas de origem ambiental, tais como Chromobacterium violaceum e Janthinobacterium lividum. Esta molécula apresenta várias propriedades biológicas incluindo antibacteriana, antifúngica, antiviral, antiprotozoária e antitumoral, apesar de sua função exata na fisiologia dos micro-organismos que a produz, ainda é desconhecido. No presente trabalho, a atividade antimicrobiana da violaceína produzida comercialmente, o extrato semi purificado e nanopartículas de vanadato de prata foram avaliados contra espécies de bacterianas gram-positivas e gram-negativas. A violaceína exibiu efeito antimicrobiano contra Staphylococcus aureus resistente à meticilina (MRSA) e Enterococcus resistente à vancomicina (VRE), que são micro-organismos frequentemente relacionados com infecções adquiridas em hospitais. Os valores de MIC (concentração inibitória mínima) e MBC (concentração bactericida mínima) da violaceína produzida comercialmente foram de 0,625 ?M e 1,25 ?M respectivamente e, análise de curvas de crescimento e tempo-morte revelaram um efeito antibacteriano durante 12 horas contra MRSA. A microscopia eletrônica de transmissão mostrou os efeitos da violaceína com alterações morfológicas e ultra estruturais, incluindo alterações na parede celular e formação de septos de divisão anormais. Nos resultados obtidos das análises de proteômica e transcriptoma a violaceína afetou a expressão de várias classes funcionais de proteínas e genes em MRSA, incluindo processos biológicos em biossíntese da parede celular e divisão celular que corroboram as alterações ultra estruturais visualizadas. Em conclusão, a violaceína produzida comercialmente demonstrou atividade antimicrobiana para S. aureus MRSA e pela primeira vez, os efeitos da violaceína sobre o metabolismo de S. aureus foram descritos, indicando possíveis alvos e vias metabólicas afetadas por esta droga. No seu conjunto, estes dados indicam a violaceína como uma droga potencial para o tratamento de infecções provocadas por MRSA
Abstract: Violacein is a violet pigment produced by some bacterial species of environmental source, such as Chromobacterium violaceum and Janthinobacterium lividum. This molecule has numerous biological properties including antibacterial, antifungal, antiviral, antiprotozoal and antitumor activity, although the exact role in the physiology of producing microorganisms is still unknown. In this study, the antimicrobial activity of violacein produced commercially, semi purified extract and silver vanadate nanoparticles were evaluated against several species of gram-positive and gram-negative bacteria. Violacein exhibited antimicrobial activity against methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus (VRE), microorganisms that are often related to hospital-acquired infections. MIC (minimum inhibitory concentration) and MBC (minimum bactericidal concentration) values of violacein produced commercially were 1.25 ?M mM and 0.625 ?M respectively, and analysis of growth and time-kill curves showed an antibacterial effect against MRSA for 12 hours. The transmission electron microscopy showed the effects of violacein with morphological and ultra-structural changes, including changes in cell wall formation and abnormal division septum. The results obtained from the analysis of proteomic and transcriptomic revealed that violacein affects the expression of several functional classes of proteins and genes in MRSA, including biological processes in cell wall biosynthesis and cell division, supporting ultra-structural changes. In conclusion, violacein produced commercially demonstrated antimicrobial activity against S. aureus MRSA and the effects on the metabolism of S. aureus have been described, indicating possible targets and pathways affected by this drug. These data indicate violacein as a potential drug for the treatment of infections caused by MRSA
Doutorado
Microbiologia
Doutora em Genética e Biologia Molecular
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Moore, Wendy Ann Louise. "The effect of age and caloric restriction on the ultrastructure and pattern of lipofuscin accumulation in granule cells of the dentate gyrus of the hippocampus of C3B10RF1 female mice, a morphometric analysis." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape10/PQDD_0027/MQ40691.pdf.
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Morell, Ybarz Maria. "Ultrastructural analysis of odontocete cochlea." Doctoral thesis, Universitat Politècnica de Catalunya, 2012. http://hdl.handle.net/10803/125113.
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The morphological study of the Odontocete organ of Corti including possible pathological features resulting from sound over-exposure, represent a key conservation issue to assess the effects of acoustic pollution on marine ecosystems. Through the collaboration with stranding networks belonging to 26 countries, 150 ears from 13 species of Odontocetes were processed. In this dissertation, we present a standard protocol to 1) compare the ultrastructure of the cochlea in several Odontocete species and 2) investigate possible damage as a consequence of sound exposure, using scanning (SEM) and transmission (TEM) electron microscopy, and immunohistochemistry.
In a preliminary study, computerized tomography scans were performed before decalcification with ears of 15 odontocete species, proposing a set of standard measurements which classified very well the species. In addition, the constant ratio between measurements of inner and middle ear structures contributed to confirm the active role of the odontocete middle ear in sound reception mechanism.
We established a decalcification protocol using the fast commercial decalcifier RDO® and EDTA (Ethylendiaminetetraacetic acid). Although further experiments should be conducted to assess the suitability of using one or the other method (because the number of samples treated with EDTA was comparatively small), RDO® at specific dilutions decreased the decalcification time of cetacean ear bones with control of the decalcification endpoint, helping a faster access to inner structures.
The complementary use of electron microscopy and immunofluorescence allowed the description in odontocetes of new morphological features of tectorial membrane, spiral limbus, spiral ligament, stria vascularis, hair cells and their innervation. Furthermore, this study revealed qualitative and quantitative morphological characteristics of the organ of Corti in high-frequency hearing species, including 1) an outer hair cell (OHC) small length, 2) a thick cuticular plate in OHC, and a thick reticular lamina, 3) robust cup formation of the Deiters cell body, 4) the high development of cytoskeleton in Deiters and pillar cells and 5) the basilar membrane high stiffness. Interestingly, all these features, including a common molecular design of prestin, are also shared by echolocating bats, suggesting a convergent evolution in echolocating species.
The presence of scars among hair cell rows, the pattern of stereocilia imprints in the tectorial membrane and the condition of fibrocytes II and IV were criteria suitable to determine or discard possible acoustic trauma, despite the numerous artefacts that rapidly develop as a consequence of tissue autolysis.
Consequently, matching the preliminary approximation of the cochlear frequency map with the damaged region would bring information on the sound source that would have triggered a possible lesion.
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Harper, John D. I. "Genetical and ultrastructural analysis of the Chlamydomonas cell cycle." Thesis, Queen's University Belfast, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.236312.
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Solé, Carbonell Marta. "Statocyst sensory epithelia ultrastructural analysis of Cephalopods exposed to noise." Doctoral thesis, Universitat Politècnica de Catalunya, 2012. http://hdl.handle.net/10803/84184.
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Controlled Exposure Experiments revealed lesions in the statocysts of four cephalopod species
of the Mediterranean Sea (Sepia officinalis, Loligo vulgaris, Illex coindetii and Octopus
vulgaris), when exposed to relatively low intensity low frequency sounds. The analysis was
performed through: scanning (SEM) and transmission (TEM) electron microscopy techniques of
the whole inner structure of the cephalopod statocysts, especially on macula and crista; SEM of
the epidermal lines of cephalopod hatchlings; and proteomic studies (2DE/MALDI –MS) of the
statocyst’s endolymph. All exposed adult individuals presented the same lesions and the same
incremental effects over time, consistent with a massive acoustic trauma observed in land
species that were exposed to much higher intensities of sound. Immediately after exposure, the
damage was observed in the macula statica princeps (msp) and in the crista sensory epithelium.
Kinocilia on hair cells were either missing or were bent or flaccid. A number of hair cells
showed protruding apical poles and ruptured lateral plasma membranes, most probably resulting
from the extrusion of cytoplasmic material. Hair cells were also partially ejected from the
sensory epithelium, and spherical holes corresponding to missing hair cells were visible in the
epithelium. The cytoplasmic content of the damaged hair cells showed obvious changes,
including the presence of numerous vacuoles and electron dense inclusions not seen in the
control animals. The appearance of these lesions became gradually more pronounced in
individuals after 12, 24, 48, 72, and 96 hours. Special attention was given to validate these
findings with control animals that were caught, maintained and sequentially sacrificed following
the same protocol as the exposed individuals. The statocyst ultrastructure was therefore revisited
and a comparative analysis was carefully conducted to assess the lesions triggered by the
exposure to noise
This study also presents preliminary results of the sound effects on epidermal lines of
cephalopod hatchlings. The lesions, consistent with an acoustic trauma, were identic in the three
species that were exposed, but their evolution over time, in opposition with what was observed
in the statocysts, were different, suggesting that the animal size and metabolic response might
play a role in a possible recovery process.
The analysis of noise effects in the statocyst endolymph by proteomic techniques was only
conducted on Sepia officinalis. The presence of differential staining of gels from control and
subjected to sound exposure individuals demonstrate that the injuries could be related to a
possible physiological imbalance that would affect the protein levels of the endolymph.
The lesions and findings described here are new to cephalopod pathology. Given that lowfrequency
noise levels in the ocean are increasing (e.g. due to shipping, offshore industry, and
naval maneuvers), that the role of cephalopods in marine ecosystems is only now beginning to
be understood, and that reliable bioacoustic data on invertebrates are scarce, the present study
and future investigations will bring an important contribution to the sustainable use of the
marine environment.Després de sotmetre'ls a experiments d'exposició controlada a sons de baixa intensitat i baixa freqüència es van observar lesions en els estatocists de quatre espècies de cefalòpodes de la mar Mediterrània (Sepia officinalis, Loligo vulgaris, Illex coindetii i Octopus vulgaris). L'anàlisi es va realitzar per mitjà de de microscòpia electronica d'escombratge (SEM) i de transmissió (TEM) de tota l'estructura interna de l'estatocist dels cefalòpodes, especialment en la màcula i en la crista, per SEM de les línees epidèrmiques de les larves dels cefalòpodes i per tècniques de proteòmica (2DE/MALDI-MS), de l'endolimfa de l'estatocist. Tots els estatocists d'individus adults de cefalòpodes exposats presentaven les mateixes lesions i aquests efectes eren més greus a mesura que passava el temps després de l'exposició als sons. Tots els animals exposats al soroll van mostrar lesions consistens amb trauma acústic massiu observat en altres espècies terrestres que havien estat exposades a intensitats molt més altes de so. Immediatament després de l'exposició, es van observar danys a la macula statica princeps (msp) i en l'epiteli sensorial de la crista. Els quinocilis de les cèl·lules ciliades desapareixien o es doblegaven i es tornaven flàccids. Un nombre important de cèl·lules ciliades mostraven els pols apicals sobresortint de l'epiteli sensorial, així com el trencament de les membranes plasmàtiques laterals, molt probablement com a resultat de l'extrusió de material citoplasmàtic. Les cèl·lules ciliades també van ser parcialment expulsades de l'epiteli sensorial deixant visibles forats esfèrics en el mateix. El contingut citoplasmàtic de les cèl·lules ciliades danyades va mostrar canvis obvis, com ara la presència de nombrosos vacúols i inclusions electrodenses que no es veien en els animals control. L'aparició d'aquestes lesions es va tornar gradualment més pronunciada en els individus analitzats després de 12, 24, 48, 72 i 96 hores. Es van validar curosament aquests resultats per mitjà de la comparació amb els animals control que van ser capturats, mantinguts i sacrificats de forma seqüencial seguint el mateix protocol que els individus exposats. La ultraestructura de l'estatocist va ser revisada i es va dur a terme un curós anàlisi comparatiu per tal d'avaluar les lesions provocades per l'exposició al soroll. Aquest estudi també presenta els resultats preliminars dels efectes del so en les línies epidèrmiques de cefalòpodes recent nascuts. Les lesions, consistens amb trauma acústic, eren idèntiques en les tres espècies que van ser exposades, però la seva evolució en el temps, en oposició amb el que es va observar en els estatocists, era diferent, cosa que suggereix que la grandària dels animals i la resposta metabòlica podria tenir influència en un possible procés de recuperació. L'avaluació dels efectes en l'endolimfa de l'estatocist per tècniques de proteòmica es va dur a terme només en Sepia officinalis. La presència de taques diferencials en els gels dels individus control i els sotmesos a exposició a so demostren que les lesions podrien estar relacionades amb un possible desequilibri fisiològic que tindria repercusions en els nivells proteics de l'endolimfa. Les lesions descrites aquí són noves pel que fa a la patologia dels cefalòpodes. Atès que els nivells de soroll de baixa freqüència a l'oceà estan augmentant (per exemple, a causa del transport, la indústria petrolera i les maniobres navals), que el paper dels cefalòpodes en els ecosistemes marins només ha començat a ser entès recentment, i que les dades bioacústiques fiables sobre els invertebrats són escasses, el present estudi i les investigacions futures aportaran una important contribució a l'ús sostenible del medi marí.
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De, Lange Albe Carina. "Ultrastructural analysis of platelets and fibrin networks in stroke patients." Diss., University of Pretoria, 2010. http://hdl.handle.net/2263/30763.
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Ischaemic stroke represent more than 80% of the total stroke instances. The location of the occlusion and the amount of brain tissue involved determines the effect of the stroke. Stroke can result in paralysis, memory loss, speech impairment and even a “lock-in” state. The amount of neuronal damage will determine whether these symptoms will be temporary or permanent. Stroke is deemed the second leading cause of death for individuals over the age of 60. According to the World Stroke Organization (WSO) every six seconds stroke claims a life, regardless of age or gender. Stroke is a global burden and the medical costs and disability related to stroke in America for 2010 was projected at almost $73.7 billion. The morphology of platelets, fibrin networks and erythrocytes as well as the differential white blood cell counts of 20 thrombo-embolic ischaemic stroke patients were investigated. Internal and external alterations were revealed in the platelets of stroke patients when compared to healthy controls. The decreased numbers of alpha granules in the platelets of the stroke patients indicated these platelets to be activated. Substances released by activated platelets promote fibrin network structure, specifically the formation of fibrin strands and accumulation of additional platelets. The fibrin network of healthy individuals consists of major, thick fibers with minor, thin fibers distributed between them. The fibrin network of stroke patients exhibited an abnormally layered and matted ultrastructure comprising of mainly thin, minor fibrin fibers packed closely together. An uncharacteristic circular morphology was also observed. These alterations in the fibrin network indicate the activated platelets to be actively involved in the thrombotic event. Neuronal damage related to stroke is also advanced by the vasoactive substances released by activated platelets. It can therefore be deduced that the morphology of the fibrin network is altered long before the concrete thrombotic event transpire. Large numbers of abnormal erythrocytes were distinguished in the blood of stroke patients. Among these abnormal forms of erythrocytes specifically codocytes, knizocytes, stomatocytes and echinocytes were identified. Abnormal erythrocyte forms were significantly increased in hypertensive patients and females independently. Alterations in the ultrastructure of erythrocytes disturb blood flow in the microcirculation and could possibly augment the ischaemic event. Inflammation is closely related to ischaemic stroke. An increased monocyte count and a reduced number of neutrophils were a significant feature among all the stroke patients of this study. Patients with hypertension as well as patients consuming aspirin on a daily basis showed the greatest influence on the observed differential white blood cell counts. These morphological alterations observed in the platelets, fibrin network and erythrocytes as well as the differential white blood cell count could be incorporated in an analysis regime that could probably indicate an impending thrombotic event. Therefore treatment could be initiated before the ischaemic event to possibly prevent the stroke. For future studies a larger study population, a more refined patient enrolment as well as the analysis of follow-up blood samples from patients could substantiate the above-mentioned findings and provide additional information concerning the thrombotic event and the effectiveness of treatment procedures.Dissertation (MSc)--University of Pretoria, 2010.
Anatomy
Unrestricted
15
Bannister, Lee-Jay. "An ultrastructural and molecular analysis of neuronal degeneration in Huntington's disease." Thesis, University College London (University of London), 2004. http://discovery.ucl.ac.uk/1446715/.
Full textAbstract:
Huntington's disease (HD) is an inherited, progressive, neurodegenerative disorder for which there is no effective treatment. It is one of nine disorders known to be caused by the expansion of a genomic CAG repeat sequence, producing a protein with an expanded array of polyglutamine residues. The mechanisms underlying the degeneration and death of neurons in HD remain unclear, and are the subjects of this investigation. Several animal models have been generated to investigate the pathogenic mechanisms underlying HD, of which this thesis uses two: the Bates R6/2 mouse, which has the affected region of the human gene inserted into its genome; and the Shelboume Hdh 'knock-in' mice, in which the CAG repeat sequence of the murine huntingtin gene homologue has been expanded into the pathogenic range. Ultrastructural analyses have been undertaken on the CNS from each of the mouse models, detailing the subcellular changes that occur. This has been furthered by analyses of the molecular machinery of apoptosis in an attempt to identify factors involved in neurodegeneration. Affected neurons in each of the HD models, and in aged wild-type mice, exhibit very similar morphologies: a condensation of cytoplasm and nucleoplasm, disturbances in the nuclear membrane, dilation and disruption of cell organelles and increased autophagic activity. These morphologic changes do not correlate with those reported to occur during apoptosis. Furthermore, molecular analyses reveal the involvement of none of the components of apoptosis. In relating each of the mice, it is clear that neurodegenerative changes do not correlate with phenotypic changes; rather the early and most pronounced symptoms of HD are a result of neuronal dysfunction. It is also concluded that the increased autophagic activity and cell condensation occur in adult neurons under stress and thus may be indicative of a common process by which adult neurons die.
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Zhao, Liming. "Ultrastructural analysis of stomatal development in wild type and mutant Arabidopsis /." The Ohio State University, 1999. http://rave.ohiolink.edu/etdc/view?acc_num=osu1488190595940653.
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Peddie, Chris. "Serotonin and glutamate receptors in the hippocampus : an ultrastructural analysis of colocalisation." Thesis, Open University, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.412507.
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Kwapinska, Magdalena. "Taxonomic Review and Ultrastructural Analysis of the Commensal Amphipod genus Paraleucothoe (Crustacea: Amphipoda)." NSUWorks, 2009. http://nsuworks.nova.edu/occ_stuetd/233.
Full textAbstract:
A re-examination of the genera Leucothoe and Paraleucothoe through a literature review was performed. Specimens of a suspected invasive amphipod initially identified as Paraleucothoe flindersi collected from a host sponge Mycale sp. Gray, 1867, in Hawaiian coastal waters by D.G. Muir (Bishop Museum, Honolulu, Hawai’i) (Muir, 1997) were also examined for the purpose of their proper identification and to determine whether they are native or invasive to Hawai’i.
Published research suggests that, L. novaehollandiae Haswell, 1880, L. brevidigitata Miers, 1884, and P. flindersi (Stebbing, 1888) appear to be the same species, although their exact taxonomic placement remains uncertain. Careful reexamination revealed each to be distinct, all differing from the Hawaiian species examined here.
Detailed examination using both light and scanning electron microscopy and comparison with P. flindersi P. spinicarpus (Abildgaard, 1789), P. commensalis (Haswell, 1879 a), L. novaehollandiae, L. brevidigitata, and L. lihue Barnard, 1970, determined that the Hawaiian specimens represent a new undescribed species of Leucothoe.
19
Suzuki, Kiyoshi. "Ultrastructural Analysis of Plant Cell Walls by Using Deep-Etching and Immunolabeling Techniques." Kyoto University, 2000. http://hdl.handle.net/2433/151626.
Full textAbstract:
Kyoto University (京都大学)0048
新制・課程博士
博士(農学)
甲第8631号
農博第1158号
新制||農||814(附属図書館)
学位論文||H12||N3476(農学部図書室)
UT51-2000-R37
京都大学大学院農学研究科森林科学専攻
(主査)教授 伊東 隆夫, 教授 藤田 稔, 教授 東 順一
学位規則第4条第1項該当
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Piatkowski, Bryan. "Axillary hair developmental ultrastructure and mucilage composition in the moss Physcomitrella patens: Microscopic and bioinformatic analyses." OpenSIUC, 2015. https://opensiuc.lib.siu.edu/theses/1841.
Full textAbstract:
Physcomitrella patens, a haploid-dominant land plant, has increasingly become useful in molecular genetic studies and is a model for early land plant evolution. This thesis work explores the mucilage secretory hair ontology, development, and ultrastructure with microscopic methods. Axillary hair development parallels that of secretory tissues found in other mosses and ultrastructure shares important similarities with liverwort mucilage papillae. These mucilage secretory structures cover the developing apex and young leaves with mucilage for protection. Changes in the hair cell wall and mucilage secretion are mediated by pectin and wall modification. Using bioinformatic methods, this thesis also investigates protein-protein interactions in Physcomitrella to understand the molecular mechanisms governing pectin biosynthesis and modification.
21
Castro, Michele Garcia Medeiros Teotônio de [UNESP]. "Avaliação seminal e testicular de cães submetidos à administração de cisplatina." Universidade Estadual Paulista (UNESP), 2010. http://hdl.handle.net/11449/91676.
Full textAbstract:
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A correta orientação do Médico Veterinário, aos proprietários de cães, usados com finalidades reprodutivas, submetidas à quimioterapia com cisplatina, é importante na medida que este agente citostático age nas células em constante divisão, podendo ser citotóxico para as células germinativas testiculares. O objetivo desse trabalho foi avaliar a qualidade espermática através do espermograma, ultra-som e avaliação de ultraestruturas do testículo de cães que receberam cisplatina em diferentes momentos de análise espermática. A dose utilizada foi de 70 mg/m², dose terapêutica, em intervalos de 21 dias, totalizando 4 infusões. Os cães foram divididos em dois grupos de 4 animais cada, sendo que um dos grupos recebeu a quimioterapia e o protocolo de diurese para proteção renal, já o grupo controle não recebeu a cisplatina, estando sujeito apenas aos fatores ambientais e ao tratamento suporte. Os resultados obtidos demonstraram que a cisplatina influenciou na qualidade espermática de cães, pois elevou as patologias maiores e totais acima do aceitável para cães aptos a reprodução, além de alterações de volume testicular observados pelo exame ultra-sonográfico ao longo dos tratamentos e constatação da degeneração testicular em variados graus observados pela análise ultraestrutural. Portanto, infere-se que este citostático possa acarretar alterações morfofuncionais nos túbulos seminíferos
The Veterinary Doctor's correct orientation, to the proprietors of dogs, used with reproductive purposes, submitted to the chemotherapy with cisplatin, it is important in the measure that this citostatic agent acts in the cells in constant division, could be toxicity for the testicle germ cells . The objective of that work was to evaluate the spermatic quality through the spermogram, ultra-sound and evaluation of ultrastructures of the testicle of dogs that received cisplatin in different moments of spermatic analysis. The used dose was of 70 mg/m², therapeutic dose, in intervals of 21 days, totaling 4 infusions. The dogs were divided in two groups of 4 animals each, and one of the groups received the chemotherapy and the diuresis protocol for renal protection, the group control didn't already receive the cisplatin, being just subject to the environmental factors and the treatment supports. The obtained results demonstrated that the cisplatin influenced in the spermatic quality of dogs, because it elevated the larger and total pathologies above the acceptable for capable dogs the reproduction, besides alterations of volume testicular observed by the ultra-sound exam along the treatments and verification of the degeneration testicular in varied degrees observed by the analysis ultrastructural. Therefore, it is inferred that this citostatic agent can cart alterations morphofunctional in the seminiferous tubules
22
Yang, Yang. "Ultrastructural analysis of internal limiting membrane removed during vitrectomy with and without dye assistance." Diss., lmu, 2011. http://nbn-resolving.de/urn:nbn:de:bvb:19-143739.
Full text
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Smith, Heidi Lynn. "Mechanisms of nurse egg formation in the spionid polychaete Boccardia proboscidea, an ultrastructural analysis." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp01/MQ37808.pdf.
Full text
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Hase, Manuela. "Molecular and ultrastructural analysis of Tpr, a nuclear pore complex-attached coiled-coil protein /." Stockholm, 2003. http://diss.kib.ki.se/2003/91-7349-525-5/.
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Daniels, Alison. "Microscopic and computer analysis of ultrastructural changes accompanying isolation and manipulation of tobacco protoplasts." Thesis, University of Nottingham, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.278755.
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Wawrzyniak, Louise Ann. "Combined Ultrastructural Examination and Cinephotomicroscopic Analysis of a Motile, Colonial Green Alga, Stephanosphaera pluvialis." The Ohio State University, 1986. http://rave.ohiolink.edu/etdc/view?acc_num=osu1392045026.
Full text
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Bladon, Trevor Scott Carleton University Dissertation Biology. "A biochemical, ultrastructural and immunocytochemical analysis of nuclear matrix in concanavalin A - stimulated lymphocytes." Ottawa, 1986.
Find full text
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Patrone, Laura May. "Ultrastructural Analysis of Vegetative and Mitotic Cells of the Unicellular Red Alga Rhodella violacea." W&M ScholarWorks, 1988. https://scholarworks.wm.edu/etd/1539625447.
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Collevecchio, Violetta <1978>. "Diencephalic asymmetries: morphological, immunohistochemical and ultrastructural analysis of habenular nuclei in elasmobranchs and teleosts." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2008. http://amsdottorato.unibo.it/654/1/Tesi_Collevecchio_Violetta.pdf.
Full textAbstract:
The habenular nuclei are diencephalic structures present in Vertebrates and they form, with the
associated fiber systems, a part of the system that connects the telencephalon to the ventral
mesencephalon (Concha M. L. and Wilson S. W., 2001). In representative species of almost all classes
of Vertebrates the habenular nuclei are asymmetric, both in terms of size and of neuronal and
neurochemical organization, although different types of asymmetry follow different evolutionary
courses. Previous studies have analyzed the spread and diversity of the asymmetry in species for which
data are not clear (Kemali M. et al., 1980). Notwithstanding that, it’s still not totally understood the
evolution of the phenomenon, and the ontogenetic mechanisms that have led to the habenular
asymmetry development are not clear (Smeets W.J. et al., 1983).
For the present study 14 species of Elasmobranchs and 15 species of Teleostean have been used.
Brains removed from the animals have been fixed using 4% paraformaldehyde in phosphate buffer;
brains have been analyzed with different tecniques, and I used histological, immunohistochemical and
ultrastructural analysis to describe this asymmetry.
My results confirm data previously obtained studying other Elasmobranchs species, in which the left
habenula is larger than the right one; the Teleostean show some slightly differences regarding the size
of the habenular ganglia, in some species, in which the left habenular nucleus is larger than the right.
In the course of studies, a correlation between the habits of life and the diencephalic asymmetry seems
to emerge: among the Teleostean analyzed, the species with benthic life (like Lepidorhombus boscii,
Platichthys flesus, Solea vulgaris) seem to possess a slight asymmetry, analogous to the one of the
Elasmobranchs, while in the other species (like Liza aurata, Anguilla anguilla, Trisopterus minutus)
the habenulae are symmetrical. However, various aspects of the neuroanatomical asymmetries of the
epithalamus have not been deepened in order to obtain a complete picture of the evolution of this
phenomenon, and new searches are needed to examine the species without clear asymmetry, in order to
understand the spread and the diversity of the asymmetry among the habenulae between the
Vertebrates.
30
Collevecchio, Violetta <1978>. "Diencephalic asymmetries: morphological, immunohistochemical and ultrastructural analysis of habenular nuclei in elasmobranchs and teleosts." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2008. http://amsdottorato.unibo.it/654/.
Full textAbstract:
The habenular nuclei are diencephalic structures present in Vertebrates and they form, with the
associated fiber systems, a part of the system that connects the telencephalon to the ventral
mesencephalon (Concha M. L. and Wilson S. W., 2001). In representative species of almost all classes
of Vertebrates the habenular nuclei are asymmetric, both in terms of size and of neuronal and
neurochemical organization, although different types of asymmetry follow different evolutionary
courses. Previous studies have analyzed the spread and diversity of the asymmetry in species for which
data are not clear (Kemali M. et al., 1980). Notwithstanding that, it’s still not totally understood the
evolution of the phenomenon, and the ontogenetic mechanisms that have led to the habenular
asymmetry development are not clear (Smeets W.J. et al., 1983).
For the present study 14 species of Elasmobranchs and 15 species of Teleostean have been used.
Brains removed from the animals have been fixed using 4% paraformaldehyde in phosphate buffer;
brains have been analyzed with different tecniques, and I used histological, immunohistochemical and
ultrastructural analysis to describe this asymmetry.
My results confirm data previously obtained studying other Elasmobranchs species, in which the left
habenula is larger than the right one; the Teleostean show some slightly differences regarding the size
of the habenular ganglia, in some species, in which the left habenular nucleus is larger than the right.
In the course of studies, a correlation between the habits of life and the diencephalic asymmetry seems
to emerge: among the Teleostean analyzed, the species with benthic life (like Lepidorhombus boscii,
Platichthys flesus, Solea vulgaris) seem to possess a slight asymmetry, analogous to the one of the
Elasmobranchs, while in the other species (like Liza aurata, Anguilla anguilla, Trisopterus minutus)
the habenulae are symmetrical. However, various aspects of the neuroanatomical asymmetries of the
epithalamus have not been deepened in order to obtain a complete picture of the evolution of this
phenomenon, and new searches are needed to examine the species without clear asymmetry, in order to
understand the spread and the diversity of the asymmetry among the habenulae between the
Vertebrates.
31
Miller, Aaron. "Stress Response in Montastraea cavernosa as a Result of Sediment Loading: Quantitative Histological and Ultrastructural Analysis." NSUWorks, 2006. http://nsuworks.nova.edu/occ_stuetd/270.
Full textAbstract:
This study investigates the effects of sediment stress on tissue and cellular structure in the cultured coral Monastraea cavernosa. The goal of this research is to quantify fine and ultrastructural data and examine potential correlation between sediment stress and changes in coral tissues and associated zooxanthellae dinoflagellate cells. An experiment in which colonies of this species were exposed to sediment stress provided the samples for this study (Vargas-Angel et al., in press). In that experiment, sediment stress was induced by the application of sediment (approximately 200-225 mg/cm2) twice daily over a four-week period. At the end of each week, a colony from each experimental tank was sacrificed and prepared for histological analysis. In the present study the paraffin blocks from this experiment were re-sectioned and stained for additional analysis. The sections were then examined for variability in the following stress parameters: 1) Symbiotic zooxanthellae and mucosecretory cell size (coenosarc, oral disk, and the middle polyp), 2) Epithelium thickness (coenosarc and oral disk), and 3) Zooxanthellae mitotic index (cell doublets) of cells (coenosarc and oral disk). Transmission electron microscopy (TEM) was also utilized for an ultrastructural study of coenosarc tissue and associated zooxanthellae. These included: 1) Zooxanthellae size comparisons with cells assessed using histological measurements, 2) Zooxanthellae accumulation vacuole size, and 3) Zooxanthellae nuclei chromosome bundle number. Significant differences were found in the tissues and cells examined from different areas of the polyp as well as with duration of sanding treatment. In sanded corals, zooxanthellae, mucosecretory cell sizes, and the mitotic index increased significantly through week three, and decreased significantly in week four. In addition, the epithelium thickness decreased significantly throughout the study and indicates that sedimentation causes atrophy (thinning) of the epithelium. Sediment stress related increase in mucosecretory cell (MSC) size indicates that coral mucus production increased under sediment stress. This increase in MSC cell size is correlated with subsequent increase in both zooxanthellae size and mitotic index. These effects may be a result of nutrient enrichment due to the chemistry of the mucus. In addition, this study also demonstrates that zooxanthellae sizes are distinct in different areas of the polyp and may respond differently to sanding stress. Therefore, current protocols for extracting zooxanthellae from corals, which results in combining cells from several sections of the polyp, may not discriminate tissue-specific zooxanthellae characteristics. Future culture-work in which examination of mucus related nutrient enrichment effects, and ultrastructural/ biochemical tissue-specific characteristics of the zooxanthellae are proposed.
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Lee, Sengyong. "Analyses of mutants in the 33 kDa manganese stabilizing protein of photosystem II and construction of a deletion mutant in synechococcus PCC 7942." Virtual Press, 1993. http://liblink.bsu.edu/uhtbin/catkey/865930.
Full textAbstract:
The 33 kDa manganese stabilizing protein (MSP) has been proposed to provide ligands to stabilize Mn ions in the water lysis reaction of photosystem II of photosynthesis. In previous research site-directed mutagenesis had been performed on regions of the psbO gene encoding two aspartic acid residues of MSP which were thought to have the potential to form carboxyl bridges with Mn ions. The purpose of this research was to analyze these mutants. Plasmids pUC120-33 (#1,3,5,7,9,11,15) containing mutant psbO genes could not be isolated from E.coli because the expressed MSP was toxic to the cells. However, a psbO mutant gene carried in pPGV5-33 (#7) was isolated from E.coli and transformed into cyanobacterium Svnechococcus PCC 7942. Cyanobacterial cells carrying the MSP mutant showed a susceptibility to intensive light (100 footcandles) with a decrease of 30% in the growth rate within the first 100 hours after inoculation. This result suggested a possible function of the MSP in protecting the oxygen evolving complex from intensive light exposure. However, the mutant appeared to revert after this time probably due to homologous gene recombination with the wild type gene. In order to further analyze the function of mutants without recombination occurring, the construction of an MSP deletion was attempted using insertion of a kanamycin cartridge into the middle of the psbO gene. The inactivated psbO gene was transformed into E.coli and transformants were selected by kanamycin resistance. However, plasmid DNA carrying the interrupted genes could not be isolated, probably due to toxicity of the expression product in E.coli cells. Thus, future studies should be directed to reconstruction of a deletion mutant by direct transformation into cyanobacterial cells. Once a deletion mutant has been constructed analyses of the site-directed mutations could be performed in cyanobacteria.Department of Biology
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Shen, Ying. "Analysis of optical properties of paracrystalline ultrastructures in human oocytes by PolScope microscopy correlated to embryo quality and viability." Giessen : VVB Laufersweiler, 2007. http://geb.uni-giessen.de/geb/volltexte/2007/4832/index.html.
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Raschdorf, Oliver [Verfasser], and Dirk [Akademischer Betreuer] Schüler. "Genetic and ultrastructural analysis of magnetosome membrane biogenesis and biomineralization in Magnetospirillum gryphiswaldense / Oliver Raschdorf ; Betreuer: Dirk Schüler." München : Universitätsbibliothek der Ludwig-Maximilians-Universität, 2016. http://d-nb.info/1156533732/34.
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Baptista, Josemberg da Silva. "Repercussões morfológicas no timo de ratos jovens submetidos à desnutrição proteíca e à renutrição precocemente corrigida." Universidade de São Paulo, 2008. http://www.teses.usp.br/teses/disponiveis/42/42131/tde-13032009-093222/.
Full textAbstract:
Verificou-se o metabolismo e as repercussões morfológicas no timo de forma qualitativa e quantitativa através de morfometria e estereologia.Utilizaram-se 30 ratos wistar () nos grupos Nutrido (N=10), Desnutrido (D=10) e Renutrido (R=10). O peso corporal e a ingestão foi maior no N, menor no D, e os R apresentaram valores médios em relação a estes grupos. Todos os outros parâmetros (ingestão de água, excreção de fezes e urina, %ingestão/peso corporal, %fezes/ingestão, água/peso corporal, %urina/água consumida e peso tímico) não obtiveram diferença estatística entre o N e R. O grupo D mostrou exuberante alteração nos componentes elásticos e fibrosos, menor calibre dos seus vasos, atrofia dos lóbulos tímicos (com limite córtex-medular muitas vezes indefinido), e grande quantidade de timócitos em apoptose no córtex e na medula. Poucos corpúsculos tímicos foram verificados no grupo D, diferindo dos animais N e R. Deste modo, afirma-se que os animais R conseguiram restituir a morfologia da glândula após intervenção nutricional.The Metabolism and morphologic repercussions on thymus were verified in a qualitative and quantitative way by morfometric and stereologycal assessment. 30 wistar rats were used () in the Nourishment (N=10), Undernourishment (UN=10) and Re-nourishment (RN=10) groups. The body weight and ingestion were higher in N, lower in UN, and RN presented medium values in relation to the others groups. All the addicional parameters as water ingestion, faeces and urine excrecion, %ingestion/corporal weigh, %faeces/ingestion, water/corporal weight, %urine/water consumed and thymic weight, had no statistics difference between N and RN. The UN group showed exuberant modification on elastic and fibrous components, smaller caliber of their vessels, thymic lobule atrophy (with many times indefinite cortex-medular limit), and apoptose of timocytes in the cortex and medulla. Few thymic corpuscles were verified in UN group differing of the N and RN. Therefore, after nutricional intervencional, the gland morphology was reestablished.
36
Yang, Yang [Verfasser], and Gandorfer [Akademischer Betreuer] Arnd. "Ultrastructural analysis of internal limiting membrane removed during vitrectomy with and without dye assistance / Yang Yang. Betreuer: Gandorfer Arnd." München : Universitätsbibliothek der Ludwig-Maximilians-Universität, 2011. http://d-nb.info/1022791249/34.
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Castro, Michele Garcia Medeiros Teotônio de. "Avaliação seminal e testicular de cães submetidos à administração de cisplatina /." Jaboticabal : [s.n.], 2010. http://hdl.handle.net/11449/91676.
Full textAbstract:
Orientador: Wilter Ricardo Russiano VicenteBanca: Márcia Rita Fernandes Machado
Banca: Andrigo Barboza De Nardi
Resumo: A correta orientação do Médico Veterinário, aos proprietários de cães, usados com finalidades reprodutivas, submetidas à quimioterapia com cisplatina, é importante na medida que este agente citostático age nas células em constante divisão, podendo ser citotóxico para as células germinativas testiculares. O objetivo desse trabalho foi avaliar a qualidade espermática através do espermograma, ultra-som e avaliação de ultraestruturas do testículo de cães que receberam cisplatina em diferentes momentos de análise espermática. A dose utilizada foi de 70 mg/m², dose terapêutica, em intervalos de 21 dias, totalizando 4 infusões. Os cães foram divididos em dois grupos de 4 animais cada, sendo que um dos grupos recebeu a quimioterapia e o protocolo de diurese para proteção renal, já o grupo controle não recebeu a cisplatina, estando sujeito apenas aos fatores ambientais e ao tratamento suporte. Os resultados obtidos demonstraram que a cisplatina influenciou na qualidade espermática de cães, pois elevou as patologias maiores e totais acima do aceitável para cães aptos a reprodução, além de alterações de volume testicular observados pelo exame ultra-sonográfico ao longo dos tratamentos e constatação da degeneração testicular em variados graus observados pela análise ultraestrutural. Portanto, infere-se que este citostático possa acarretar alterações morfofuncionais nos túbulos seminíferos
Abstract: The Veterinary Doctor's correct orientation, to the proprietors of dogs, used with reproductive purposes, submitted to the chemotherapy with cisplatin, it is important in the measure that this citostatic agent acts in the cells in constant division, could be toxicity for the testicle germ cells . The objective of that work was to evaluate the spermatic quality through the spermogram, ultra-sound and evaluation of ultrastructures of the testicle of dogs that received cisplatin in different moments of spermatic analysis. The used dose was of 70 mg/m², therapeutic dose, in intervals of 21 days, totaling 4 infusions. The dogs were divided in two groups of 4 animals each, and one of the groups received the chemotherapy and the diuresis protocol for renal protection, the group control didn't already receive the cisplatin, being just subject to the environmental factors and the treatment supports. The obtained results demonstrated that the cisplatin influenced in the spermatic quality of dogs, because it elevated the larger and total pathologies above the acceptable for capable dogs the reproduction, besides alterations of volume testicular observed by the ultra-sound exam along the treatments and verification of the degeneration testicular in varied degrees observed by the analysis ultrastructural. Therefore, it is inferred that this citostatic agent can cart alterations morphofunctional in the seminiferous tubules
Mestre
38
Oh, Jae-Ho. "Etude structurale de la graphitation naturelle : exemples de bassins sud-coreens." Orléans, 1987. http://www.theses.fr/1987ORLE2043.
Full textAbstract:
On etudie la formation du graphite naturel. On compare les carbones issus de series nturelles soumises a un metamorphisme croissant a des carbones traites exprimentalement. Leur texture et leur micro-structure sont analysees par microscopie electronique par transmission, par microspectrometrie raman et diffraction rx. La graphitation des carbones issus de vegetaux superieurs est comparable a la graphitation sous pression des carbones vitreux. Les materiaux d'origine algaire sont comparables aux carbones issus de la pyrolyse experimentale sous pression des parois d'algues
39
Martini, Maria Helena. "Caracterização das sementes de seis especies de theobroma em relação ao theobroma cacao L." [s.n.], 2004. http://repositorio.unicamp.br/jspui/handle/REPOSIP/256114.
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Orientador : Debora de Queiroz TavaresTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos
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Resumo: Nos estudos sobre as reservas do mesofilo cotiledonar do gênero Theobroma destacam-se os trabalhos sobre sementes de T. cacao, fonte única da matéria prima do chocolate. Estas pesquisas preferenciam as mudanças ocorridas na estrutura celular durante a fermentação, secagem, torração; etapas do processo de produção do chocolate. Mais recentes são os trabalhos com sementes de T. grandiflorum utilizadas na elaboração do cupulate, produto com características semelhantes ao chocolate. O presente trabalho analisa as células de reserva lípide-proteicas e idioblastos de polifenóis de T. cacao, T. grandiflorum, T. subincanum, T. bicolor e T. speciosum. Em T. obovatum e T. microcarpum o estudo apresentou apenas as células polifenólicas. A distribuição dos glóbulos lipídicos nas células são análogas nestas espécies, isto é, localização periférica e extrema susceptibilidade ao calor, coalescendo sob condições térmicas acima de 30°C. A proteína de reserva apresenta-se entremeada com os glóbulos lipídicos e alguns grãos de amido. As células polifenólicas, em T. bicolor e T. speciosum, localizam-se na região do feixe vascular e parênquima da radícula e nas outras espécies estudadas estão dispersas pelo mesofilo e próximas ao feixe vascular. A mucilagem é uma secreção celular constante em cinco espécies estudadas, não se acumulando dentro das células, porém com raras exceções ocorrem células com mucilagem na epiderme do mesofilo (T. subincanum). T. speciosum caracteriza-se por efetivamente apresentar células de mucilagem. Estas células são abundantes no mesofilo e cerca de 10% alcançam grandes dimensões sem rompimento do tecido. As células polifenólicas apresentam características histoquímicas semelhantes a mucilagem, porém sua estreita relação com os feixes vasculares direciona seu desenvolvimento para a síntese de polifenóis. O tecido do mesofilo cotiledonar é semelhante em todas as espécies aqui estudadas devido a predominância de reserva lípide-proteica. Células imaturas de sementes verdes demonstram capacidade para sintetizar todas as reservas; na maturidade celular demonstram predominância de reservas lípide-proteicas ou de mucilagem ou de polifenóis. A distribuição das reservas no mesofilo aproximam T. grandiflorum à T. subincanum. A maior quantidade de proteínas está em T. bicolor. Esta espécie apresenta menor quantidade de lipídeos e de células polifenólicas
Abstract: Many investigations on the cellular reserves within the cotyledon mesophyll of the Theobroma have been carried out on Theobroma cacao seeds, the source of raw for the production of chocolate. These studies demonstrated structural cellular changes due to fermentation, drying, and roasting processes during chocolate production. Recently the seeds of the T. grandiflorum have been analyzed due to their importance in the production of ¿cupulate¿, a new product similar to chocolate. In the present work, we analyze the lipid-protein reserve cells and polyphenolic idioblasts derived from T. cacao, T. grandiflorum, T. subincanum, T. bicolor, T. speciosum and T. obovatum. Only phenolic cells were studied in T.obovatum and T. microcarpum.The distribution of lipid bodies was similar in all the species studied; that is, they were located at the periphery of the cell wall and demonstrated extremely susceptibly to heat, coalescing at temperatures above 30°C. The reserve protein was interspersed with lipid bodies and some starch granules. The polyphenolic cells were dispersed throughout the mesophyll and around the vascular bundles in all the species studied. In T. bicolor and T. speciosum the polyphenolic cells were only observed around the vascular bundle and radicle parenchyma. Mucilage is a cellular secretion in the five species studied. Mucilage does not accumulate intracellularly; however, rarely we did observe mucilage in the cells of the mesophyll epidermis of T. subincanum. In T. speciosum, mucilage cells were abundant in the mesophyll and about 10% reached large dimensions without tissue disruption. The polyphenolic cells presented characteristic mucilage histochemistry, however their strict association with vascular bundles should direct their development towards polyphenol synthesis. Cotyledon mesophyll tissue is similar in all the species studied with respect to lipid-protein reserve. Immature cells demonstrated the capacity to synthesize all the reserves, but this capacity is not retained in the mature cell. The distribution of reserves in the mesophyll are most similar in T. grandiflorum and T. subincanum. T. bicolor showed a high protein content, lower lipid levels and low levels of polyphenolic cells
Doutorado
Doutor em Alimentos e Nutrição
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Shen, Ying [Verfasser]. "Analysis of optical properties of paracrystalline ultrastructures in human oocytes by PolScope microscopy correlated to embryo quality and viability / vorgelegt von Ying Shen." Giessen : VVB Laufersweiler, 2007. http://d-nb.info/988724464/34.
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Hirunagi, Kanjun. "Immunocytochemical and Ultrastructural Analysis of Opsin- and Vasoactive Intestinal Peptide (VIP)- like Immunoreactive Neurons in the Lateral Septum of the Pigeon." 名古屋大学博物館, 2003. http://hdl.handle.net/2237/7284.
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Bautista, Melissa A. "Ultrastructural Analysis of Excitatory and Inhibitory Synapses within the Medial Nucleus of the Trapezoid Body of Normal Hearing and Congenitally Deaf Mice." Wright State University / OhioLINK, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=wright1229722450.
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Matak, Andrija. "Synthesis and spectroscopic analysis of 4'-amino and 4'-sulfonamide chalcone derivatives and ultrastructural effects of 4'-sulfonamide boronic acid chalcone on Eimeria papillata sporozoites in vitro /." Link to Theses, 2008. http://eprint.cc.andrews.edu/38/.
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Küffner, Mercedes [Verfasser], and Michael [Akademischer Betreuer] Frotscher. "Ultrastructural analysis of spine apparatus in CA3 pyramidal neurons following single cell electroporation in Synaptopodin Knockout - mice = Elektronenmikroskopische Untersuchung des Spine-Apparats in CA3 Pyramidenzellen mittels Einzelzell-Elektroporation in Synaptopodin-defizienten Mäusen." Freiburg : Universität, 2013. http://d-nb.info/1115495283/34.
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Vieira, Moema Queiroz. "Análise ultraestrutural de células-tronco mesenquimais humanas derivadas de tecido adiposo (hADSC) durante a diferenciação adipogênica : interações entre as gotas lipídicas citoplasmáticas e outras organelas." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2013. http://hdl.handle.net/10183/107632.
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As células-tronco mesenquimais humanas derivadas de tecido adiposo, do inglês human adipose-derived stem cells (hADSC), são células progenitoras que residem entre adipócitos e armazenam lipídios neutros, principalmente triglicerídeos e ésteres de colesterol (TG e EC), em gotas lipídicas citoplasmáticas (GLC), contribuindo para o turnover do tecido adiposo. As GLC são organelas que desempenham um papel crucial na homeostasia energética e no metabolismo dessas células. Caveolas são invaginações de 50-100 nm que foram inicialmente caracterizadas por microscopia eletrônica. A forma e a organização estrutural das caveolas deve-se a proteínas especificas da família das caveolinas (caveolina-1, -2 e -3) que se associam em oligômeros para formar cavidades/invaginações na membrana plasmática. A função das caveolinas na formação das GLC está relacionada com a captação de ácidos graxos e seu metabolismo, e a relação existente entre estes dois componentes celulares parece ser crucial para manutenção da homeostasia celular. Muitas organelas que são funcionalmente conectadas ao metabolismo de lipídeos são encontradas justapostas as GLC. Distinções morfológicas observadas reforçam diferenças que podem existir na maneira pelas quais as GLC interagem com outras organelas em adipócitos. Sítios de contatos entre membranas, do inglês membrane contact sites (MCS), são descritos para muitas organelas e parecem funcionalmente importantes nos processos de interações entre as GLC e outras organelas celulares. O presente trabalho avaliou as diferenças ultraestruturais entre hADSC diferenciadas ou não para pré-adipócitos, comparando com células 3T3-L1. Também foram avaliadas, através de microscopia eletrônica de transmissão, as interações das GLC com outras organelas celulares durante a diferenciação adipogênica, pois apesar de sua importância no metabolismo energético e em várias doenças, as GLC são pouco compreendidas como organelas celulares. De fato, o tamanho, a composição e a regulação das GLC variam consideravelmente entre organismos e tipos celulares. A complexidade das interações das GLC com outras organelas também varia consideravelmente em adipócitos e não adipócitos. Este trabalho mostrou a importância de estudos que visam esclarecer como as GLC são formadas, modificadas e reguladas. Através destes estudos poderemos ter uma melhor compreensão acerca da relação existente entre o acúmulo excessivo de lipídios no organismo e a chamada síndrome metabólica (obesidade, diabetes e aterosclerose).Human adipose-derived stem cells (hADSC) are progenitor cells that reside between adipocytes, store neutral lipids, especially triglycerides and cholesterol esters (TG and CE) into cytoplasmic lipid droplets (CLD), contributing to the turnover of the adipose tissue. The CLD are organelles that play a crucial role in energy homeostasis and cell metabolism. Caveolae are invaginations of 50-100 nm that were initially characterized by transmission electron microscopy. The shape and structural organization of caveolae are held by specific proteins of the family of caveolinas (caveolin-1, -2 and -3) that associate to form oligomers in cavities/invaginations on the plasma membrane. The caveolin functions on the CLD development are related to the fatty acid uptake and its metabolism. The relationship between these cell components seems to be pivotal for the cellular homeostasis maintenance. Many organelles that are functionally connected to lipid metabolism are found juxtaposed to the CLD. Morphologic distinctions reveal the differences that may exist in the way through which the CLD interact with other organelles within adipocytes. The membrane contact sites (MCS) have been described for many organelles and seems to be functionally important in the interaction processes with CLD. This work evaluated the ultrastructural differences between hASDC differentiated or not to pre-adipocyte compared to the 3T3-L1 cells. It was also evaluated through transmission electron microscopy, the CLD interactions to the others cellular organelles in hASDC during adipogenesis induction because, despite its importance in energy metabolism and in various diseases, the CLD are poorly understood as cell organelles. Indeed, the size, composition and regulation of GLC vary considerably between organisms and cell types. The complexity of CLD interactions with other organelles also ranged considerably between adipocytes and undifferentiated. This work showed the importance of studies that aim the clarify how the CLD are formed, modified and regulated. Through these studies it is possible to get a better understanding of the relationship between the excessive accumulation of body lipids and the metabolic syndrome (obesity, diabetes and atherosclerosis).
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Almeida, Marcos dos Santos de 1980. "Análise de diferentes protocolos de acupuntura nos aspectos bioquímicos, ultraestruturais e organizacionais de tendões de ratos em processo de cicatrização = Analysis of different acupuncture protocols on biochemical, ultrastructural and organizational aspects of rats tendons in healing process." [s.n.], 2015. http://repositorio.unicamp.br/jspui/handle/REPOSIP/317345.
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Orientador: Edson Rosa PimentelTese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia
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Resumo: Vários estudos indicam que a acupuntura (AC) tem efeito anti-inflamatório (AI) sistêmico e mecanotransdutor local. Estes efeitos podem potencialmente acelerar o processo de cicatrização. Portanto, o objetivo deste estudo foi analisar o efeito de diferentes protocolos de AC nas características bioquímicas, organizacionais e ultraestruturais de tendões de ratos durante o processo de cicatrização. Ratos Wistar machos com 60 dias de idade foram divididos nos seguintes grupos: grupo não tenotomizado ou normal (N), grupo tenotomizado (T), tenotomizado e submetido à AC no ponto E-36 (E36), tenotomizado e submetido à AC no B-57 (B57), tenotomizado e submetido à AC manual no ponto E-36 e B-57 (EB) e tenotomizado e submetido à eletroacupuntura (EA) nos dois pontos citados. Os animais foram submetidos à eutanásia nos dias 7, 14 e 21 após a lesão. Em seguida, os tendões calcâneos foram coletados, processados e analisados para quantificação de proteínas não colagênicas através do método de Bradford. Para a análise organizacional, foi utilizada a quantificação da birrefringência das fibras de colágeno através da microscopia de polarização. Na analise ultraestrutural foram mensurados os diâmetros das fibrilas de colágeno e em seguida foram construídos histogramas de distribuição destes diâmetros assim como foi calculado o diâmetro da massa-média - MAD - das fibrilas de colágeno. Os resultados mostraram que o uso associado dos pontos E-36 e B-57 aumenta tanto a birrefringência das fibras de colágeno nos dias 14 e 21 após a lesão quanto o MAD nos três períodos analisados. A reorganização das fibrilas de colágeno também aumentou no dia 21 após a lesão com a aplicação dos dois pontos citados. No entanto, a aplicação da EA não promoveu aumento da birrefringência ou da reorganização das fibrilas assim como diminuiu o MAD no dia 21 após a lesão. Desta forma, concluímos que o uso da AC manual nos pontos E-36 e B-57 tem efeito no restabelecimento das propriedades estruturais e ultraestruturais do colágeno de tendões durante o processo de cicatrização. Estes resultados sugerem o fortalecimento da estrutura tendínea com consequente aumento da resistência a re-ruptura e o potencial uso da AC em protocolos de reabilitação
Abstract: Several studies indicate that acupuncture (AC) has both local mechanotransductor and systemic anti-inflammatory (AI) effects. These effects could potentially accelerate the healing process. Therefore, the aim of this study was to analyze the effect of different protocols of AC on the biochemical, organizational and ultrastructural aspects of rat tendons during the healing process. Male Wistar rats at 60 days of age were divided into the following groups: not tenotomized or normal group (N), tenotomized group (T), tenotomized and submitted to AC at ST-36 point (ST36), tenotomized and submitted to AC at BL-57 point (BL57), tenotomized and submitted to manual AC at ST-36 and BL-57 points (SB) and tenotomized and submitted to electroacupuncture (EA) on the two points mentioned. The animals were euthanized on 7th, 14th and 21th days after injury. Thereafter, the Achilles tendons were collected, processed and analyzed to quantify non-collagenic proteins using the method of Bradford. For organizational analysis, it was quantified the collagen fibers birefringence by polarizing microscopy. In the ultrastructural analysis were measured the diameters of collagen fibrils and then histograms of distribution of these diameters were built as well as mass-average diameter - MAD - of collagen fibrils was calculated. The results showed that the associated use of ST-36 and BL-57 points increases both the birefringence of collagen fibers at 14th and 21th days and the MAD at the three periods analyzed. The reorganization of collagen fibrils also increased at 21th day with the application of the two points mentioned. However, the application of EA did not increase the birefringence or the reorganization of fibrils as well as decreased the MAD of fibrils at 21th after injury. Thus, we conclude that the use of manual AC at ST-36 and BL-57 points is effective in restoring the structural and ultrastructural properties of the collagen of tendons during the healing process. These results suggest strengthening the tendon structure with consequent increased resistance to re-rupture and the potential use of AC in rehabilitation protocols
Doutorado
Anatomia
Doutor em Biologia Celular e Estrutural
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Oliver, Fojkar. "Azotofiksirajuće cijanobakterije u zemljištima Vojvodine i njihova ultrastrukturna i genetička karakterizacija." Phd thesis, Univerzitet u Novom Sadu, Poljoprivredni fakultet u Novom Sadu, 2016. https://www.cris.uns.ac.rs/record.jsf?recordId=101459&source=NDLTD&language=en.
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U radu je ispitana zastupljenost azotofiksirajućih cijanobakterija, ukupnog broja algi i ukupnog broja bakterija u različitim tipovima zemljišta na jedanaest lokaliteta u Vojvodini, od čega se sedam nalaze u zaštićenim prirodnim dobrima. Ispitana je brojnost u zavisnosti od dubine pedološkog profila, kao i od godišnjeg doba. Izvršena je izolacija sojeva azotofiksirajućih cijanobakterija, određena njihova taksonomska pripadnost i osnovne citološke karakteristike. Ispitana je ultrastruktura vegetativnih ćelija, heterocista i spoljnih struktura na ćelijama fimbrije i pili, transmisionim elektronskim mikroskopom. Izvršena je genetička karakterizacija izolovanih sojeva azotofiksirajućih cijanobakterija PCR metodom analizom STRR fragmenata DNA.Brojnost azotofiksirajućih cijanobakterija i ukupna brojnost algi je bila znatno veća kod hidromorfnih i halomorfnih zemljišta, nego kod automorfnih zemljišta. Najveća prosečna godišnja brojnost azotofiksirajućih cijanobakterija, u površinskom sloju 0-5cm, je utvrđena kod zemljišta fluvisol u SRP “Koviljsko petrovaradinskom ritu”, 150864 jedinki po gramu apsolutno suvog zemljišta. Zemljište sa najnižom brojnošću azotofiksirajućih cijanobakterija, je gajnjača u NP Fruška gora, 1582 jed./gr zemljišta u površinskom sloju.Kod svih ispitivanih zemljišta brojnost azotofiksirajućih cijanobakterija je bila najveća u površinskom sloju zemljišta, 0-5 cm dubine, opadala je sa dubinom zemljišta i bila najmanja u najdubljem sloju, 30 - 60 cm. Kod najvećeg broja ispitivanih zemljišta brojnost azotofiksirajućih cijanobakterija je bila najveća tokom zimskog perioda. Azotofiksirajuće cijanobakterije su dominantne u našim zemljištima i zastupljene sa 56.27% u odnosu na druge grupe algi.Izolovano je 30 sojeva azotofiksirajućih cijanobakterija: 19 sojeva Nostoc-a, 4 soja Anabaena, 4 Cylindrospermum, i po jedan soj Calothrix, Tolypothrix i Phormidium. Prosečna zastupljenost heterocista, ćelija koje vrše azotofiksaciju, kod roda Nostoc je iznosila 8.28%, Anabaena 4.25%, Cylindrospermum-a 2.93%, Calotrix elenkinii 6.19% i Tolypothrix 7.76%.Ultrastrukturnim ispitivanjem, TEM mikroskopom, vegetativnih ćelija azotofiksirajućih cijanobakterija uočili smo inkluzije redovnog pojavljivanja: karboksizome (Cs), cijanoficinkse granule (CG), polifosfatne granule (PG), ribozome (R), lipidne granule (ß –granule) i tilakoide (T), kao i inkluzije neredovnog pojavljivanja: membranom ograničene kristalne inkluzije.Koristeći TEM i tehniku bojenja ćelija sa RR i ultratankih preseka utvrdili smo prisustvo omotača od fimbrija kod tri soja (A.314, A.azollae i N.302) i tipične fimbrije kod dva soja (N.311 i N.9229). Metodom negativnog bojenja NS PTA uočili smo takođe tipične fimbrije, igličastog-dlakastog izgleda, jasnih granica niti kod tri soja (N.302, N.7901 i N.9229), međutim uočili smo i atipične sluzne fimbrije, koje nemaju jasno izražene granice, ali su veoma moćno raširene oko vegetativnih ćelija, kod tri soja (A.314, A.azollae, N.311).Kod simbiotskih-infektivnih sojeva N.7901 i N.9229 javljaju se samo tipične fimbrije iz prve klase, a kod diazotofnih sojeva i simbiotskog - neinfektivnog soja A.azollae javljaju se atipične-sluzne fimbrije iz druge klase.Za ispitivanje sličnosti cijanobakterija metodom PCR-a pomoću STRR konzervativnih sekvenci DNA genoma korišćeno je 39 sojeva azotofiksirajućih cijanobakterija i kod 38 je utvrđeno njihovo prisustvo. Svi sojevi se mogu podeliti u tri grupe, klastera. Prvi klaster je najveći i obuhvata 24 soja i deli se na dva podklastera: Ia koji obuhvata 12 sojeva gde dominiraju sojevi Nostoc-a (8), i podklaster Ib koji obuhvata takođe 12 sojeva, od čega 6 sojeva pripada rodu Anabaena. Podklaster Ia i podklaster Ib pokazuju različitost od 90%. Sva tri simbiozna, infektivna, soja Nostoc-a se nalaze u klasteru I: N.7901, N.9229 i N. 8001. Svaki simbiozni soj Nostoc-a ima genetske sličnosti sa po jednim diazotrofnim sojem Nostoc-a izolovanim iz zemljišta Vojvodine.Klaster II obuhvata sedam (7) sojeva među kojima dominiraju sojevi Cylindrospermum-a, dok klaster III obuhvata 7 sojeva od čega 6 pripadaju rodu Nostoc, a jedan rodu Rivularia.Detaljno poznavanje svojstava izolovanih azotofiksirajućih cijanobakterija doprineće njihovoj budućoj primeni kako u proizvodnji ratarskih i povrtarskih kultura, tako i u biotehnološkoj proizvodnjiIn this study examined is the frequency of nitrogen-fixing cyanobacteria, total number of algae and total number of bacteria in different soil types on eleven localities in the Vojvodina Province. Seven out of those eleven localities are found in protected nature reserves. Actually, studied was the number of the cyanobacteria and algae depending on the depth of pedological characterization as well as on season. First, isolated were the types of nitrogen-fixing cyanobacteria, determined was their taxonomic origin and basic cytological characteristics. Also examined was the ultrastructure of vegetative cells, heterocysts and other outer structures on fimbriae and pili cells using TEM, transmission electron microscope. Finally, performed was the genetic characterization of isolated types of nitrogen-fixing cyanobacteria using the PCR method and analyzing STRR fragments of DNA.The presence of nitrogen-fixing cyanobacteria and total number of algae was significantly higher with hydromorphic and halomorphic soils than with authomorphic ones. Highest annual average number of nitrogen-fixing cyanobacteria in the topsoil (0-5 cm) was reported with fluvisol soil in Special Nature Reserve „Koviljsko petrovaradinski rit” (Swamp) and there were 150864 units of bacteria per gram of absolutely dry soil. The soil with the lowest presence of nitrogen-fixing cyanobacteria recorded was cambisol in National Park “Fruska gora” with 1582 units per gram of soil in the topsoil.With all the researched types of soils the number of nitrogen-fixing cyanobacteria was in the topsoil, 0-5 cm of depth and decreased in line with the depthof soil and lowest was at the deepest layer, 30-60cm. The highest frequency of nitrogen-fixing cyanobacteria was found during the winter season with most of the examined soils. Nitrogen-fixing cyanobacteria are the dominant type of bacteria in our soils and are presented with 56, 27% compared to other types of algae.30 strains of nitrogen-fixing cyanobacteria were isolated: 19 types of Nostoc sp., 4 of Anabaena sp. and one in each genus of Calothrix, Tolypothrix and Phormidium.Using ultrastructural examination and TEM microscope when studying vegetative cells of nitrogen-fixing cyanobacteria observed were the inclusions of regular frequency: carboxysomes (Cs), cyanophycin granules (CG) , polyphosphate granules (PG), ribosomes (R), lipid granules (SS -granule ) and thylakoids ( T ) as well as the inclusion of irregular occurrence: a membrane-bound crystal inclusions.Using TEM technique and staining the cells with the RR and ultra thin cross section, we determined the presence of depletion of the fimbriae with three strains (A.314, A.azollae and N.302) and typical fimbriae with the two strains (N.311 and N.9229). Applying the method of negative staining NS PTA also noticed were a typical fimbriae, needle-hairy like looks with clear boundaries with the three strains (N.302, N.7901, N.9229). However, also observed were atypical mucous fimbriae, which do not have clearly expressed borders, but they are very strongly spread around the vegetative cells, with the three strains (A.314, A.azollae, N.311).With symbiotic - infective strains N.7901 and N.9229 only typical fimbriae of first class occurred, and in diazotroph strains and symbiotic – non infectious strain A. azollae found were atypical mucous fimbriae of second class.To test the similarity of cyanobacteria by PCR method and using a STRR - conservative DNA sequence of the genome used were 39 strains fixing cyanobacteria and with 38 established was their presence. All strains can be divided into three groups of clusters. The first cluster is the largest and covers 24 strains, and is divided into two subclusters: Ia which includes 12 strains,where predominant are Nostoc strains ( 8 ) , and subcluster Ib , which also implies 12 strains , out of which 6 strains belong to the genus Anabaena. Subcluster Ia and Ib show a difference of 90 %. All three symbiotic , infectious Nostoc strains are classified in a cluster I: N.7901, N.9229 and N. 8001. Each symbiotic Nostoc strain has a genetic similarity with one di-nitrogen Nostoc strain isolated from a lot of different soils in Vojvodina.Cluster II includes seven (7) strains , including strains among which the predominant are Cylindrospermum ones , while cluster III includes 7 strains of which 6 belong to the genus Nostoc and one to genus Rivularia.Detailed knowledge of the properties of isolated fixing cyanobacteria could contribute to their future application both in the production of field crops and vegetables, as well as in biotechnological production.
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Stevenson, James Ware. "A morphometric analysis of ultrastructural dynamics in the murine glomerulus following surgically-induced renal hypertension." Thesis, 2016. https://hdl.handle.net/2144/17039.
Full textAbstract:
Chronic kidney disease (CKD) and end stage renal disease (ESRD) are significant causes of adult morbidity and mortality worldwide. Though these conditions are common, the mechanisms of pathogenesis in kidney disease are poorly understood. Genetic predisposition has been established in the African American population; however this does not explain the ubiquity of CKD in the United States and abroad. Diabetes and hypertension are the two most frequently occurring co-morbidities in kidney disease and both have been identified as putative sources of injury to the delicate filtering structures of the kidney. Furthermore, the intrinsic functional relationship between the cardiovascular and renal organ systems adds to the plausibility of a hemodynamic cause. In light of this knowledge, we aim to explore the roles of genetic predisposition and hypertension in the pathogenesis and progression of CKD.
The filtering apparatus of the kidney, the glomerulus, is a looping tuft of capillaries specialized to allow the passage of water and certain substances from the blood while restricting others. Glomeruli at the corticomedullary boundary of the kidney experience blood pressures closer to those in systemic arterioles and are subject to similar hemodynamic stresses. To evaluate the role of hypertension in CKD, we employed a well-known model of hypertensive kidney disease in mice involving uninephrectomy (UNX), subcutaneous implantation of a timed-release pellet containing the active aldosterone precursor deoxycorticosterone acetate (DOCA), and a high-salt diet. Given the role of heritability in human CKD pathogenesis, we applied the DOCA-UNX model in two strains of mice with differing susceptibility to kidney damage, the 129S6 and C57BL/6 strains, to evaluate the effects of genetic predisposition. Mice were subjected to varying lengths of hypertension exposure and their kidneys were subsequently examined by transmission electron microscopy (TEM). Ultrastructural lesions of glomeruli were evaluated by a renal pathologist and assigned subjective pathology scores based on the extent and severity of involvement.
We hypothesized that certain glomerular lesions, particularly those involving the podocytes of the visceral epithelium, would increase in severity in mice with heritable susceptibility (129S6) as well as those with longer exposure to glomerular hypertension. Our observations demonstrate these hypotheses are partially correct. By TEM histopathology, mouse strain was found to have a significant effect on the severity of certain epithelial lesions while duration of hypertension had a significant effect on the overall morphological pathology of the podocytes, glomerular basement membrane, and glomerulus as a whole. These results provide a promising foundation for further investigation of the pathogenesis of CKD in mice.
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Jeffery, Jennifer L. "Carotenoid In Planta Development, Storage, and Bioaccessibility: A Comprehensive Approach to Nutrient Analysis." 2008. http://hdl.handle.net/1969.1/ETD-TAMU-2008-12-198.
Full textAbstract:
Plants contain a host of secondary metabolites that may be of dietary use to man. A comprehensive approach to plant-based nutrition would include investigating all aspects of a nutrient, from creation through storage and consumption. Here, experiments address each of these facets for a group of important antioxidant and pigment compounds, the carotenoids.
The carotenoid biosynthetic pathway regulatory mechanisms leading to lycopene accumulation are well defined in the model fruit, tomato. Those leading to accumulation of other carotenoids and flesh colors, however, are poorly understood. The variety of flesh colors available in watermelon fruit (red, orange, salmon yellow, and canary yellow) makes it an ideal candidate for investigating the regulation of the full pathway. Carotenoid accumulation was measured in ten watermelon varieties, representing the four flesh colors and three ploidy levels, throughout fruit maturation. It was found that the putative regulatory mechanisms controlling lycopene accumulation in red-fleshed fruit may be applied in a generalized fashion to each flesh color in respect to the major carotenoid accumulated at maturity. Additionally, triploid varieties were generally found to have higher accumulation levels than diploids, and tetraploids were intermediate to both. In addition to total carotenoid content, many factors are important in determining perceived benefit. Several of these factors involve components of the food matrix, cellular and subcellular species-specific characteristics of the food which act as barriers to nutrient release. Cell size, cell wall, and chromoplast (the carotenoid storage organelle) characteristics were observed in nine fruits and vegetables using light and transmission electron microscopy. Watermelon, tomato, and melon have the largest cells. Sweet potato, butternut squash, carrot, and mango have the most fibrous cell walls; mango and papaya additionally had the thickest walls. Chromoplast globular, tubular, crystalline, and membranous substructures were described for each food. These food matrix factors may be related to differences in carotenoid bioaccessibility between food sources. An in vitro digestion experiment was used to determine carotenoid bioaccessibility for each of these foods. Per serving, grapefruit yielded the most lycopene while carrot gave the most ?-carotene, ?-carotene, lutein, and phytoene, and mango proved a good source of violaxanthin.
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Weiser, Novak Samuel. "Ultrastructure and morphometric analysis of hippocampal synapses in the Fmr1-/y mouse model of fragile X syndrome." Thesis, 2015. http://hdl.handle.net/1828/6052.
Full textAbstract:
Fragile X Syndrome (FXS) is a prevalent monogenic disease, often presenting with cognitive and neurological disorders including autism and epilepsy. The Fmr1 gene - transcriptionally silenced in FXS - normally encodes the Fragile X Mental Retardation Protein (FMRP), which acts as an activity dependent translational regulator at the base of dendritic spines. In an attempt to understand its role, dendritic spines in the dentate gyrus (DG) and cornu ammonis 1 (CA1) hippocampal regions of three-week old Fmr1- mice were analyzed and compared to wildtype (WT) littermate controls using electron microscopy. Dendritic spines with a continuous profile of the parent dendrite, spine neck, and spine head complete with synaptic components (presynaptic vesicles and postsynaptic densities) were included in our morphological analyses. We observed no changes in postsynaptic density length (DG: 5.69±0.30/6.18±0.85; SR: 7.55±0.87/6,96±0.33 µm/100 µm2; p=0.627/0.620), synapse density (DG: 32.3±3.8/30.3±1.9; SR: 34.4±1.8/30.7±0.5 synapses/100 µm2; p=0.655/0.270), spine head diameters (DG: 0.524±0.016/0.529±0.014; SR: 0.524±0.014/0.515±0.014 µm; p=0.098/0.20) or spine neck lengths (DG: 0.457±0.016/0.485±0.019; SR: 0.421 ± 0.015/0.425±0.017 µm; p=0.14/0.26), but found that in the DG spine necks were significantly narrower in the Fmr1- mice (0.193±0.0062/0.167±0.0064 µm; p=0.0002), whereas there were no changes in CA1 spine neck widths (0.162±0.0049/0.161±0.0061 µm; p=0.073). Estimated resistance calculated from spine necks morphologies revealed a ~1.7 fold increase in the Fmr1- DG compared to WT DG. These findings support that FMRP plays a role in granule cell spine neck structure and may influence synaptic signal compartmentalization and propagation in a regionally dependent manner.Graduate