Academic literature on the topic 'Retrograde protein 1'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the lists of relevant articles, books, theses, conference reports, and other scholarly sources on the topic 'Retrograde protein 1.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Journal articles on the topic "Retrograde protein 1"
1
Blacque, Oliver E., Chunmei Li, Peter N. Inglis, Muneer A. Esmail, Guangshuo Ou, Allan K. Mah, David L. Baillie, Jonathan M. Scholey, and Michel R. Leroux. "The WD Repeat-containing Protein IFTA-1 Is Required for Retrograde Intraflagellar Transport." Molecular Biology of the Cell 17, no. 12 (December 2006): 5053–62. http://dx.doi.org/10.1091/mbc.e06-06-0571.
Full textAbstract:
The assembly and maintenance of cilia require intraflagellar transport (IFT), a microtubule-dependent bidirectional motility of multisubunit protein complexes along ciliary axonemes. Defects in IFT and the functions of motile or sensory cilia are associated with numerous human ailments, including polycystic kidney disease and Bardet–Biedl syndrome. Here, we identify a novel Caenorhabditis elegans IFT gene, IFT-associated gene 1 (ifta-1), which encodes a WD repeat-containing protein with strong homology to a mammalian protein of unknown function. Both the C. elegans and human IFTA-1 proteins localize to the base of cilia, and in C. elegans, IFTA-1 can be observed to undergo IFT. IFTA-1 is required for the function and assembly of cilia, because a C. elegans ifta-1 mutant displays chemosensory abnormalities and shortened cilia with prominent ciliary accumulations of core IFT machinery components that are indicative of retrograde transport defects. Analyses of C. elegans IFTA-1 localization/motility along bbs mutant cilia, where anterograde IFT assemblies are destabilized, and in a che-11 IFT gene mutant, demonstrate that IFTA-1 is closely associated with the IFT particle A subcomplex, which is implicated in retrograde IFT. Together, our data indicate that IFTA-1 is a novel IFT protein that is required for retrograde transport along ciliary axonemes.
2
Schafer, Jenny C., Courtney J. Haycraft, James H. Thomas, Bradley K. Yoder, and Peter Swoboda. "XBX-1 Encodes a Dynein Light Intermediate Chain Required for Retrograde Intraflagellar Transport and Cilia Assembly in Caenorhabditis elegans." Molecular Biology of the Cell 14, no. 5 (May 2003): 2057–70. http://dx.doi.org/10.1091/mbc.e02-10-0677.
Full textAbstract:
Intraflagellar transport (IFT) is a process required for flagella and cilia assembly that describes the dynein and kinesin mediated movement of particles along axonemes that consists of an A and a B complex, defects in which disrupt retrograde and anterograde transport, respectively. Herein, we describe a novel Caenorhabditis elegans gene, xbx-1, that is required for retrograde IFT and shares homology with a mammalian dynein light intermediate chain (D2LIC). xbx-1 expression in ciliated sensory neurons is regulated by the transcription factor DAF-19, as demonstrated previously for genes encoding IFT complex B proteins. XBX-1 localizes to the base of the cilia and undergoes anterograde and retrograde movement along the axoneme. Disruption of xbx-1 results in cilia defects and causes behavioral abnormalities observed in other cilia mutants. Analysis of cilia in xbx-1 mutants reveals that they are shortened and have a bulb like structure in which IFT proteins accumulate. The role of XBX-1 in IFT was further confirmed by analyzing the effect that other IFT mutations have on XBX-1 localization and movement. In contrast to other IFT proteins, retrograde XBX-1 movement was detected in complex A mutants. Our results suggest that the DLIC protein XBX-1 functions together with the CHE-3 dynein in retrograde IFT, downstream of the complex A proteins.
3
Anderson, Nadine S., Indrani Mukherjee, Christine M. Bentivoglio, and Charles Barlowe. "The golgin protein Coy1 functions in intra-Golgi retrograde transport and interacts with the COG complex and Golgi SNAREs." Molecular Biology of the Cell 28, no. 20 (October 2017): 2686–700. http://dx.doi.org/10.1091/mbc.e17-03-0137.
Full textAbstract:
Extended coiled-coil proteins of the golgin family play prominent roles in maintaining the structure and function of the Golgi complex. Here we further investigate the golgin protein Coy1 and document its function in retrograde transport between early Golgi compartments. Cells that lack Coy1 displayed a reduced half-life of the Och1 mannosyltransferase, an established cargo of intra-Golgi retrograde transport. Combining the coy1Δ mutation with deletions in other putative retrograde golgins (sgm1Δ and rud3Δ) caused strong glycosylation and growth defects and reduced membrane association of the conserved oligomeric Golgi (COG) complex. In contrast, overexpression of COY1 inhibited the growth of mutant strains deficient in fusion activity at the Golgi (sed5-1 and sly1-ts). To map Coy1 protein interactions, coimmunoprecipitation experiments revealed an association with the COG complex and with intra-Golgi SNARE proteins. These physical interactions are direct, as Coy1 was efficiently captured in vitro by Lobe A of the COG complex and the purified SNARE proteins Gos1, Sed5, and Sft1. Thus our genetic, in vivo, and biochemical data indicate a role for Coy1 in regulating COG complex-dependent fusion of retrograde-directed COPI vesicles.
4
Hollenbeck, P. J., and D. Bray. "Rapidly transported organelles containing membrane and cytoskeletal components: their relation to axonal growth." Journal of Cell Biology 105, no. 6 (December 1, 1987): 2827–35. http://dx.doi.org/10.1083/jcb.105.6.2827.
Full textAbstract:
We have examined the movements, composition, and cellular origin of phase-dense varicosities in cultures of chick sympathetic and sensory neurons. These organelles are variable in diameter (typically between 0.2 and 2 microns) and undergo saltatory movements both towards and away from the neuronal cell body. Their mean velocities vary inversely with the size of the organelle and are greater in the retrograde than the anterograde direction. Organelles stain with the lipophilic dye 1, 1'-dioctadecyl-3,3,3',3'-tetramethyl-indocarbocyanine and with antibodies to cytoskeletal components. In cultures double-stained with antibodies to alpha-tubulin and 70-kD neurofilament protein (NF-L), approximately 40% of the organelles stain for tubulin, 30% stain for NF-L, 10% stain for both tubulin and NF-L, and 40% show no staining with either antibody. The association of cytoskeletal proteins with the organelles shows that these proteins are able to move by a form of rapid axonal transport. Under most culture conditions the predominant direction of movement is towards the cell body, suggesting that the organelles are produced at or near the growth cone. Retrograde movements continue in culture medium lacking protein or high molecular mass components and increase under conditions in which the advance of the growth cone is arrested. There is a fourfold increase in the number of organelles moving retrogradely in neurites that encounter a substratum-associated barrier to elongation; retrograde movements increase similarly in cultures exposed to cytochalasin at levels known to block growth cone advance. No previously described organelle shows behavior coordinated with axonal growth in this way. We propose that the organelles contain membrane and cytoskeletal components that have been delivered to the growth cone, by slow or fast anterograde transport, in excess of the amounts required to synthesize more axon. In view of their rapid mobility and variable contents, we suggest that they be called "neuronal parcels."
5
Buser, Dominik P., Kai D. Schleicher, Cristina Prescianotto-Baschong, and Martin Spiess. "A versatile nanobody-based toolkit to analyze retrograde transport from the cell surface." Proceedings of the National Academy of Sciences 115, no. 27 (June 18, 2018): E6227—E6236. http://dx.doi.org/10.1073/pnas.1801865115.
Full textAbstract:
Retrograde transport of membranes and proteins from the cell surface to the Golgi and beyond is essential to maintain homeostasis, compartment identity, and physiological functions. To study retrograde traffic biochemically, by live-cell imaging or by electron microscopy, we engineered functionalized anti-GFP nanobodies (camelid VHH antibody domains) to be bacterially expressed and purified. Tyrosine sulfation consensus sequences were fused to the nanobody for biochemical detection of trans-Golgi arrival, fluorophores for fluorescence microscopy and live imaging, and APEX2 (ascorbate peroxidase 2) for electron microscopy and compartment ablation. These functionalized nanobodies are specifically captured by GFP-modified reporter proteins at the cell surface and transported piggyback to the reporters’ homing compartments. As an application of this tool, we have used it to determine the contribution of adaptor protein-1/clathrin in retrograde transport kinetics of the mannose-6-phosphate receptors from endosomes back to the trans-Golgi network. Our experiments establish functionalized nanobodies as a powerful tool to demonstrate and quantify retrograde transport pathways.
6
Shimizu, Takayuki, Sylwia M. Kacprzak, Nobuyoshi Mochizuki, Akira Nagatani, Satoru Watanabe, Tomohiro Shimada, Kan Tanaka, et al. "The retrograde signaling protein GUN1 regulates tetrapyrrole biosynthesis." Proceedings of the National Academy of Sciences 116, no. 49 (November 15, 2019): 24900–24906. http://dx.doi.org/10.1073/pnas.1911251116.
Full textAbstract:
The biogenesis of the photosynthetic apparatus in developing seedlings requires the assembly of proteins encoded on both nuclear and chloroplast genomes. To coordinate this process there needs to be communication between these organelles, but the retrograde signals by which the chloroplast communicates with the nucleus at this time are still essentially unknown. The Arabidopsis thaliana genomes uncoupled (gun) mutants, that show elevated nuclear gene expression after chloroplast damage, have formed the basis of our understanding of retrograde signaling. Of the 6 reported gun mutations, 5 are in tetrapyrrole biosynthesis proteins and this has led to the development of a model for chloroplast-to-nucleus retrograde signaling in which ferrochelatase 1 (FC1)-dependent heme synthesis generates a positive signal promoting expression of photosynthesis-related genes. However, the molecular consequences of the strongest of the gun mutants, gun1, are poorly understood, preventing the development of a unifying hypothesis for chloroplast-to-nucleus signaling. Here, we show that GUN1 directly binds to heme and other porphyrins, reduces flux through the tetrapyrrole biosynthesis pathway to limit heme and protochlorophyllide synthesis, and can increase the chelatase activity of FC1. These results raise the possibility that the signaling role of GUN1 may be manifested through changes in tetrapyrrole metabolism, supporting a role for tetrapyrroles as mediators of a single biogenic chloroplast-to-nucleus retrograde signaling pathway.
7
Signor, Dawn, Karen P. Wedaman, Jose T. Orozco, Noelle D. Dwyer, Cornelia I. Bargmann, Lesilee S. Rose, and Jonathan M. Scholey. "Role of a Class Dhc1b Dynein in Retrograde Transport of Ift Motors and Ift Raft Particles along Cilia, but Not Dendrites, in Chemosensory Neurons of Living Caenorhabditis elegans." Journal of Cell Biology 147, no. 3 (November 1, 1999): 519–30. http://dx.doi.org/10.1083/jcb.147.3.519.
Full textAbstract:
The heterotrimeric motor protein, kinesin-II, and its presumptive cargo, can be observed moving anterogradely at 0.7 μm/s by intraflagellar transport (IFT) within sensory cilia of chemosensory neurons of living Caenorhabditis elegans, using a fluorescence microscope–based transport assay (Orozco, J.T., K.P. Wedaman, D. Signor, H. Brown, L. Rose, and J.M. Scholey. 1999. Nature. 398:674). Here, we report that kinesin-II, and two of its presumptive cargo molecules, OSM-1 and OSM-6, all move at ∼1.1 μm/s in the retrograde direction along cilia and dendrites, which is consistent with the hypothesis that these proteins are retrieved from the distal endings of the cilia by a retrograde transport pathway that moves them along cilia and then dendrites, back to the neuronal cell body. To test the hypothesis that the minus end–directed microtubule motor protein, cytoplasmic dynein, drives this retrograde transport pathway, we visualized movement of kinesin-II and its cargo along dendrites and cilia in a che-3 cytoplasmic dynein mutant background, and observed an inhibition of retrograde transport in cilia but not in dendrites. In contrast, anterograde IFT proceeds normally in che-3 mutants. Thus, we propose that the class DHC1b cytoplasmic dynein, CHE-3, is specifically responsible for the retrograde transport of the anterograde motor, kinesin-II, and its cargo within sensory cilia, but not within dendrites.
8
Cavolo, Samantha L., Chaoming Zhou, Stephanie A. Ketcham, Matthew M. Suzuki, Kresimir Ukalovic, Michael A. Silverman, Trina A. Schroer, and Edwin S. Levitan. "Mycalolide B dissociates dynactin and abolishes retrograde axonal transport of dense-core vesicles." Molecular Biology of the Cell 26, no. 14 (July 5, 2015): 2664–72. http://dx.doi.org/10.1091/mbc.e14-11-1564.
Full textAbstract:
Axonal transport is critical for maintaining synaptic transmission. Of interest, anterograde and retrograde axonal transport appear to be interdependent, as perturbing one directional motor often impairs movement in the opposite direction. Here live imaging of Drosophila and hippocampal neuron dense-core vesicles (DCVs) containing a neuropeptide or brain-derived neurotrophic factor shows that the F-actin depolymerizing macrolide toxin mycalolide B (MB) rapidly and selectively abolishes retrograde, but not anterograde, transport in the axon and the nerve terminal. Latrunculin A does not mimic MB, demonstrating that F-actin depolymerization is not responsible for unidirectional transport inhibition. Given that dynactin initiates retrograde transport and that amino acid sequences implicated in macrolide toxin binding are found in the dynactin component actin-related protein 1, we examined dynactin integrity. Remarkably, cell extract and purified protein experiments show that MB induces disassembly of the dynactin complex. Thus imaging selective retrograde transport inhibition led to the discovery of a small-molecule dynactin disruptor. The rapid unidirectional inhibition by MB suggests that dynactin is absolutely required for retrograde DCV transport but does not directly facilitate ongoing anterograde DCV transport in the axon or nerve terminal. More generally, MB's effects bolster the conclusion that anterograde and retrograde axonal transport are not necessarily interdependent.
9
Ramos-García, Silvia L., Robert W. Roberson, Michael Freitag, Salomón Bartnicki-García, and Rosa R. Mouriño-Pérez. "Cytoplasmic Bulk Flow Propels Nuclei in Mature Hyphae of Neurospora crassa." Eukaryotic Cell 8, no. 12 (August 14, 2009): 1880–90. http://dx.doi.org/10.1128/ec.00062-09.
Full textAbstract:
ABSTRACT We used confocal microscopy to evaluate nuclear dynamics in mature, growing hyphae of Neurospora crassa whose nuclei expressed histone H1-tagged green fluorescent protein (GFP). In addition to the H1-GFP wild-type (WT) strain, we examined nuclear displacement (passive transport) in four mutants deficient in microtubule-related motor proteins (ro-1, ro-3, kin-1, and a ro-1 kin-1 double mutant). We also treated the WT strain with benomyl and cytochalasin A to disrupt microtubules and actin microfilaments, respectively. We found that the degree of nuclear displacement in the subapical regions of all strains correlated with hyphal elongation rate. The WT strain and that the ro-1 kin-1 double mutant showed the highest correlation between nuclear movement and hyphal elongation. Although most nuclei seemed to move forward passively, presumably carried by the cytoplasmic bulk flow, a small proportion of the movement detected was either retrograde or accelerated anterograde. The absence of a specific microtubule motor in the mutants ro-1, ro-3, or kin-1 did not prevent the anterograde and retrograde migration of nuclei; however, in the ro-1 kin-1 double mutant retrograde migration was absent. In the WT strain, almost all nuclei were elongated, whereas in all other strains a majority of nuclei were nearly spherical. With only one exception, a sizable exclusion zone was maintained between the apex and the leading nucleus. The ro-1 mutant showed the largest nucleus exclusion zone; only the treatment with cytochalasin A abolished the exclusion zone. In conclusion, the movement and distribution of nuclei in mature hyphae appear to be determined by a combination of forces, with cytoplasmic bulk flow being a major determinant. Motor proteins probably play an active role in powering the retrograde or accelerated anterograde migrations of nuclei and may also contribute to passive anterograde displacement by binding nuclei to microtubules.
10
Giannotta, Monica, Giorgia Fragassi, Antonio Tamburro, Capone Vanessa, Alberto Luini, and Michele Sallese. "Prohibitin: A Novel Molecular Player in KDEL Receptor Signalling." BioMed Research International 2015 (2015): 1–13. http://dx.doi.org/10.1155/2015/319454.
Full textAbstract:
The KDEL receptor (KDELR) is a seven-transmembrane-domain protein involved in retrograde transport of protein chaperones from the Golgi complex to the endoplasmic reticulum. Our recent findings have shown that the Golgi-localised KDELR acts as a functional G-protein-coupled receptor by binding to and activating Gs and Gq. These G proteins induce activation of PKA and Src and regulate retrograde and anterograde Golgi trafficking. Here we used an integrated coimmunoprecipitation and mass spectrometry approach to identify prohibitin-1 (PHB) as a KDELR interactor. PHB is a multifunctional protein that is involved in signal transduction, cell-cycle control, and stabilisation of mitochondrial proteins. We provide evidence that depletion of PHB induces intense membrane-trafficking activity at the ER–Golgi interface, as revealed by formation of GM130-positive Golgi tubules, and recruitment of p115,β-COP, and GBF1 to the Golgi complex. There is also massive recruitment of SEC31 to endoplasmic-reticulum exit sites. Furthermore, absence of PHB decreases the levels of the Golgi-localised KDELR, thus preventing KDELR-dependent activation of Golgi-Src and inhibiting Golgi-to-plasma-membrane transport of VSVG. We propose a model whereby in analogy to previous findings (e.g., the RAS-RAF signalling pathway), PHB can act as a signalling scaffold protein to assist in KDELR-dependent Src activation.
Dissertations / Theses on the topic "Retrograde protein 1"
1
Overeem, Kathie. "Retrograde signalling within fear neurocircuitry: Nitric oxide signalling from the lateral nucleus of the amygdala regulates thalamic EGR-1 mediated alterations of presynaptic protein levels during auditory fear conditioning." Thesis, University of Canterbury. Psychology, 2009. http://hdl.handle.net/10092/3212.
Full textAbstract:
Previous research has shown that nitric oxide signalling in the lateral nucleus of the amygdala is required for the consolidation of Pavlovian conditioned fear. Given the evidence that nitric oxide can act as a retrograde signalling molecule in in vitro models of memory consolidation the question arises whether this is also occurring within behavioural memory models? Using auditory fear conditioning this research shows that nitric oxide does indeed act as retrograde signalling molecule in the fear system. Its synthesis in the lateral nucleus of the amygdala regulates conditioning induced expression of the immediate early gene early growth response gene 1 (EGR-1) in cells of the auditory thalamus that project to the lateral nucleus of the amygdala. The regulation of EGR-1 expression by the lateral nucleus of the amygdala was proven to be dependent on amygdala-based cellular excitation, nitric oxide synthesis and NR2B-NMDA receptor activation but not ERK/MAPK activity. Using an EGR-1 antisense oligonucleotide to prevent training induced EGR-1 expressions in the auditory thalamus it was shown that this gene upregulation is necessary for the consolidation of conditioned fear. Finally, inhibition of EGR-1 upregulation in the auditory thalamus was proven to impair conditioning induced increases in the presynaptic proteins synaptophysin, and synapsin II and II back in the lateral nucleus of the amygdala. Overall, the results of this dissertation have shown that nitric oxide acts as a retrograde messenger in a mammalian memory system by modulating gene expression in presynaptic cells. This modulation of gene expression serves to increase levels of presynaptic proteins back at the origin of nitric oxide synthesis. This supports the long standing doctrine that nitric oxide acts as a retrograde signalling molecule to coordinate presynaptic changes associated with memory formation.
2
Hwang, Christine. "The Presynaptic F-box Protein FSN-1 Regulates Synapse Development via Retrograde Insulin Signaling in Caenorhabditis elegans." Thesis, 2010. http://hdl.handle.net/1807/24582.
Full textAbstract:
Synaptogenesis entails the development and establishment of functional synapses, which form the fundamental unit of communication in the nervous system. Initially identified in Caenorhabditis elegans (C. elegans), the FSN-1, F-box protein family has emerged as evolutionarily conserved binding partners of PHR family proteins, which regulate synaptogenesis. Previously, we have shown that FSN-1 and RPM-1 form a SCF/FSN-1/RPM-1 ubiquitin ligase complex that negatively regulates synapse growth by downregulating presynaptic targets, like the MAP kinase pathway. For my master’s thesis, I used a combination of both candidate and forward genetic approaches to identify additional components of signaling pathways that are regulated by FSN-1 during synaptogenesis. Our studies are among the first to suggest diverging roles for these partners and provide the first evidence for a mechanism through which the F-box protein regulates synaptogenesis via retrograde insulin/IGF/FOXO signaling and glucosaminidase/O-GlcNAc modifications.
3
Dey, Trishna. "Studies on the post-transcriptional regulation of genes of glutamate utilization pathway in Pichia pastoris and a role for Retrograde regulation protein 1." Thesis, 2020. https://etd.iisc.ac.in/handle/2005/4923.
Full textAbstract:
The methylotrophic yeast, Pichia pastoris can utilize compounds such as glucose, glycerol, methanol, acetate, amino acids, or oleic acid as the sole source of carbon. However, the regulation of synthesis of key enzymes of these metabolic pathways is not well understood. Unlike Saccharomyces cerevisiae, P. pastoris can utilize amino acids not only as a nitrogen source but also a carbon source. The prime focus of this work is to understand the regulatory mechanisms involved in the synthesis of two key enzymes of glutamate utilization pathway, glutamate dehydrogenase (GDH2) and phosphoenolpyruvate carboxykinase (PEPCK) in P. pastoris. We demonstrate that:
i) P. pastoris basic, helix-loop-helix, leucine zipper protein known as PpRtg1p functions as a nuclear transcription factor in Saccharomyces cerevisiae and cytosolic post-transcriptional regulator in P. pastoris.
ii) PpRtg1p regulates the translation of GDH2 and PEPCK mRNAs when glutamate is the sole source of carbon.
iii) GDH2 and PEPCK regulate each other's protein levels via PpRtg1p-independent mechanism when glutamate is the sole source of carbon.
iv) Translation of GDH2 and PEPCK mRNAs is induced by metabolites generated during prolonged carbon starvation.
Book chapters on the topic "Retrograde protein 1"
1
Cottage, Amanda J., Ellie K. Mott, Jun-Hui Wang, James A. Sullivan, Dan MacLean, Linh Tran, Mun-Kit Choy, et al. "GUN1 (GENOMES UNCOUPLED1) Encodes a Pentatricopeptide Repeat (PPR) Protein Involved in Plastid Protein Synthesis-Responsive Retrograde Signaling to the Nucleus." In Photosynthesis. Energy from the Sun, 1201–5. Dordrecht: Springer Netherlands, 2008. http://dx.doi.org/10.1007/978-1-4020-6709-9_261.
Full text
2
Cevher-Keskin, Birsen. "Endomembrane Trafficking in Plants." In Electrodialysis. IntechOpen, 2020. http://dx.doi.org/10.5772/intechopen.91642.
Full textAbstract:
The functional organization of eukaryotic cells requires the exchange of proteins, lipids, and polysaccharides between membrane compartments through transport intermediates. Small GTPases largely control membrane traffic, which is essential for the survival of all eukaryotes. Transport from one compartment of this pathway to another is mediated by vesicular carriers, which are formed by the controlled assembly of coat protein complexes (COPs) on donor organelles. The activation of small GTPases is essential for vesicle formation from a donor membrane. In eukaryotic cells, small GTP-binding proteins comprise the largest family of signaling proteins. The ADP-ribosylation factor 1 (ARF1) and secretion-associated RAS superfamily 1 (SAR1) GTP-binding proteins are involved in the formation and budding of vesicles throughout plant endomembrane systems. ARF1 has been shown to play a critical role in coat protein complex I (COPI)-mediated retrograde trafficking in eukaryotic systems, whereas SAR1 GTPases are involved in intracellular coat protein complex II (COPII)-mediated protein trafficking from the endoplasmic reticulum (ER) to the Golgi apparatus. The dysfunction of the endomembrane system can affect signal transduction, plant development, and defense. This chapter offers a summary of membrane trafficking system with an emphasis on the role of GTPases especially ARF1, SAR1, and RAB, their regulatory proteins, and interaction with endomembrane compartments. The vacuolar and endocytic trafficking are presented to enhance our understanding of plant development and immunity in plants.
3
Davenport, Andrew. "Clinical investigation of renal disease." In Oxford Textbook of Medicine, edited by John D. Firth, 4781–806. Oxford University Press, 2020. http://dx.doi.org/10.1093/med/9780198746690.003.0476.
Full textAbstract:
An accurate history and careful examination will determine the sequence and spectrum of clinical investigations required to make a diagnosis or decide on prognosis or treatment for renal disease. Midstream urine (MSU) sample—this standard investigation requires consideration of (1) macroscopic appearance, (2) stick testing, and (3) microscopy. Quantification of proteinuria—this is important because the risk for progression of underlying kidney disease to endstage renal failure is related to the amount of protein in the urine. Low molecular weight proteinuria is caused by proximal tubular injury and can be detected with markers. Knowledge of the glomerular filtration rate (GFR) is of crucial importance in the management of patients, not only for detecting the presence of renal impairment, but also in the monitoring of all patients with or at risk of renal impairment, and in determining appropriate dosing of those drugs cleared by the kidney. Measurement of plasma creatinine remains the standard biochemical test used to assess renal function. The simplified Modification of Diet in Renal Disease (sMDRD) formula is explained, along with a revised version (CKD-EPI). Investigations of tubular function, including the proximal tubule, distal tubule, and renal-induced electrolyte and acid–base imbalances are discussed in this chapter. Renal imaging covered in this chapter includes ultrasonography, ultrafast multislice CT scanning, magnetic resonance imaging, nuclear medicine scanning, and fluorodeoxyglucose positron emission tomography. Invasive techniques including antegrade or retrograde ureteropyelography and angiography are discussed. A renal biopsy should be considered in any patient with disease affecting the kidney when the clinical information and other laboratory investigations have failed to establish a definitive diagnosis or prognosis, or when there is doubt as to the optimal therapy.
4
Emmett, Stevan R., Nicola Hill, and Federico Dajas-Bailador. "Gastroenterology." In Clinical Pharmacology for Prescribing. Oxford University Press, 2019. http://dx.doi.org/10.1093/oso/9780199694938.003.0014.
Full textAbstract:
Nausea and vomiting can be defined, respectively, as the urge to or the actual act of expelling undigested food from the stomach. It is thought to be an evolutionary defence mechanism to protect against toxic insult (drugs or microbes) and over- eating, while it can also be triggered during pregnancy, or by unpleasant sights or smells. In some instances, it may be the symptom of a more severe underlying pathology. Severity of nausea and vomiting varies considerably between individuals exposed to the same stimulus and symptoms can be highly detrimental to patient quality of life affecting not only their nutritional intake, but also mood and well- being. Although nausea itself is a subjective term, vomiting is a pathophysiological reflex triggered by the vomiting centre located in the medulla. The vomiting centre receives signals from a number of afferent inputs, i.e. the chemoreceptor trigger zone (CTZ), vestibular nucleus, abdominal and cardiac vagal afferents, and cerebral cortex (Table 6.1). It may also be activated by hormonal triggers, which accounts for hyperemesis in pregnancy, and the increased incidence of nausea and vomiting associated with the female gender. As the vomiting centre is located close to centres responsible for salivation and breathing, vomiting is often associated with hypersalivation and hyperventilation. The CTZ is highly vascularized and located at the floor of the fourth ventricle, just outside the blood– brain barrier and, therefore, is itself directly sensitive to chemical stimuli. Afferent inputs activate the vomiting centre through several known neurotransmitter pathways; dopamine (D<sub>2</sub>), serotonin (5- HT<sub>3</sub>, 5- HT<sub>4</sub>), acetylcholine (ACh), and substance P (neurokinin 1; NK<sub>1</sub>). Each of which provides a potential pharmacological target in the management of nausea and vomiting, once the cause has been established. Efferent pathways from the vomiting centre induce autonomic changes, including vasoconstriction, pallor, tachycardia, salivation, sweating, and relaxation of the lower oesophagus and fundus of the stomach. In vomiting, oesophageal relaxation leads to contraction of the pyloric sphincter, thereby emptying the contents of the jejunum, duodenum, and pyloric stomach into the relaxed fundus. Coordination of muscle contraction occurs within the diaphragm and abdomen, and retrograde contractions from the intestine then expel the contents of the fundus.
Conference papers on the topic "Retrograde protein 1"
1
Kuznetsov, Ivan A., and Andrey V. Kuznetsov. "Modeling of Tau Protein Transport in Axons." In ASME 2013 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/imece2013-62430.
Full textAbstract:
This paper develops a simplified analytical solution for the slow axonal transport of tau proteins. A six kinetic state model developed in Jung and Brown [1] was used to simulate transport of tau. The model was extended by accounting for tau degradation and diffusion in the off-track kinetic states. The analytical solution was obtained by assuming that transitions between anterograde and retrograde states are infrequent. This assumption was validated through an analysis of the sensitivity of the solution to changes in the values of the two kinetic constants that describe the transition rates between the anterograde and retrograde states, and by a comparison with the experimentally measured tau distributions reported in Konzack et al. [2]. The predicted average transport velocity of tau was also in the experimentally reported range.