Academic literature on the topic 'Bovine retina'
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Journal articles on the topic "Bovine retina"
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Saari, John C., Robert J. Champer, Mary Ann Asson-Batres, Gregory G. Garwin, Jing Huang, John W. Crabb, and Ann H. Milam. "Characterization and localization of an aldehyde dehydrogenase to amacrine cells of bovine retina." Visual Neuroscience 12, no. 2 (March 1995): 263–72. http://dx.doi.org/10.1017/s095252380000794x.
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AbstractAn enzyme of bovine retina that catalyzes oxidation of retinaldehyde to retinoic acid was purified to homogeneity and a monoclonal antibody (mAb H-4) was generated. MAb H-4 recognized a single component (Mr = 55,000) in extracts of bovine retina and other bovine tissues. The antibody showed no cross-reactivity with extracts of rat, monkey, or human retinas. A 2067 bp cDNA was selected from a retina cDNA expression library using mAb H-4. The cDNA hybridized with a similarly sized, moderately abundant mRNA prepared from bovine retina. Nucleotide sequence analysis indicated that the cDNA contained a single open reading frame encoding 501 amino acids that have 88% sequence identity with the amino-acid sequence of human hepatic Class 1 aldehyde dehydrogenase. Amino-acid sequence analysis of purified enzyme demonstrated that the cDNA encodes the isolated enzyme. MAb H-4 specifically labeled the somata and processes of a subset of amacrine cells in bovine retinal sections. Labeled amacrine somata were located on both sides of the inner plexiform layer, and their processes ramified into two laminae within the inner plexiform layer. The inner radial processes of Müller (glial) cells were weakly reactive with mAb H-4. Weak immunostaining of amacrine cells was found in monkey retina with mAb H-4, but no signal was detected in rat or human retina. The results provide further evidence for metabolism and function of retinoids within cells of the inner retina and define a novel class of retinal amacrine cells.
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Sitaramayya, Ari, Lorraine Lombardi, and Alexander Margulis. "Influence of dopamine on cyclic nucleotide enzymes in bovine retinal membrane fractions." Visual Neuroscience 10, no. 6 (November 1993): 991–96. http://dx.doi.org/10.1017/s0952523800010099.
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AbstractDopamine is a major neurotransmitter and neuromodulator in vertebrate retina. Although its pharmacological and physiological actions are well understood, the biochemical mechanisms of its signal transduction are less clear. Acting via D1 receptors, dopamine was shown to increase cyclic AMP levels in intact retina and to activate adenylate cyclase in retinal homogenates. The action via activation of D2 receptors is controversial: it was reported to decrease cyclic AMP levels in intact retina but inhibition of cyclase could not be demonstrated in retinal homogenates; also it was reported to activate rod outer segment cyclic GMP phosphodiesterase in vitro but did not decrease cyclic GMP levels in aspartate-treated retinas. We made an attempt to fractionate bovine retinal membranes and to investigate the effects of dopamine, via Dl and D2 receptors, on the synthesis and hydrolysis of cyclic AMP and cyclic GMP. Activation of cyclic AMP synthesis was noted in all fractions, but no effects were evident on cyclic nucleotide hydrolysis or cyclic GMP synthesis in any fraction. Also, D2 agonist did not inhibit cyclic AMP synthesis. These observations suggest that D2 receptors may not be directly coupled to cyclic nucleotide metabolizing enzymes in bovine retina.
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Yan, Qi, E. Helene Sage, and Anita E. Hendrickson. "SPARC Is Expressed by Ganglion Cells and Astrocytes in Bovine Retina." Journal of Histochemistry & Cytochemistry 46, no. 1 (January 1998): 3–10. http://dx.doi.org/10.1177/002215549804600102.
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SPARC (secreted protein, acidic and rich in cysteine)/osteonectin is a matricellular, counteradhesive glycoprotein that disrupts cell-matrix interactions, interacts with growth factors and components of extracellular matrix, and modulates the cell cycle, but appears to subserve only minor structural roles. SPARC is expressed in a variety of tissues during embryogenesis and remodeling and is believed to regulate vascular morphogenesis and cellular differentiation. Although usually limited in normal adult tissues, SPARC is expressed at significant levels in the adult central nervous system. Using a monoclonal antibody against bovine bone osteonectin, we have determined the localization of SPARC in newborn (3-day-old) and adult (4–8-year-old) normal bovine retinas. SPARC was present in the soma of ganglion cells and strong reactivity was found in ganglion cell axons. Muller cells displayed no immunoreactivity, but SPARC was present in retinal astrocytes that were identified by the astrocyte marker glial fibrillary acidic protein (GFAP). Newborn calf retina showed a staining pattern similar to that of adult retina but exhibited significantly reduced levels of SPARC. Minimal levels of SPARC protein were also detected in some capillaries of the inner retina of both newborn and adult animals, whereas large vessels were negative. The presence of SPARC in the retina was confirmed by Western blotting of retinal extracts. These data indicate that SPARC originating from both neurons and glia of the inner retina may be an important modulator of retinal angiogenesis. The increased expression of SPARC in adult relative to newborn retinal tissue also indicates that SPARC has an ongoing role in the maintainance of retinal functions.
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Koscielniak, A., M. Serafin, M. Duda, T. Oles, A. Zadlo, A. Broniec, O. Berdeaux, et al. "Oxidation-Induced Increase In Photoreactivity of Bovine Retinal Lipid Extract." Cell Biochemistry and Biophysics 75, no. 3-4 (November 2, 2017): 443–54. http://dx.doi.org/10.1007/s12013-017-0832-3.
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Abstract The mammalian retina contains a high level of polyunsaturated fatty acids, including docosahexaenoic acid (22:6) (DHA), which are highly susceptible to oxidation. It has been shown that one of the products of DHA oxidation—carboxyethylpyrrole (CEP), generated in situ, causes modifications of retinal proteins and induces inflammation response in the outer retina. These contributing factors may play a role in the development of age-related macular degeneration (AMD). It is also possible that some of the lipid oxidation products are photoreactive, and upon irradiation with blue light may generate reactive oxygen species. Therefore, in this work we analysed oxidation-induced changes in photoreactivity of lipids extracted from bovine neural retinas. Lipid composition of bovine neural retinas closely resembles that of human retinas making the bovine tissue a convenient model for studying the photoreactivity and potential phototoxicity of oxidized human retinal lipids. Lipid composition of bovine neural retinas Folch’ extracts (BRex) was determined by gas chromatography (GC) and liquid chromatography coupled to an electrospray ionization source-mass spectrometer (LC-ESI-MS) analysis. Liposomes prepared from BRex, equilibrated with air, were oxidized in the dark at 37 °C for up to 400 h. The photoreactivity of BRex at different stages of oxidation was studied by EPR-oximetry and EPR-spin trapping. Photogeneration of singlet oxygen (1O2, 1Δg) by BRex was measured using time-resolved detection of the characteristic phosphorescence at 1270 nm. To establish contribution of lipid components to the analysed photoreactivity of Folch’ extract of bovine retinas, a mixture of selected synthetic lipids in percent by weight (w/w %) ratio resembling that of the BRex has been also studied. Folch’s extraction of bovine neural retinas was very susceptible to oxidation despite the presence of powerful endogenous antioxidants such as α-tocopherol and zeaxanthin. Non-oxidized and oxidized BRex photogenerated singlet oxygen with moderate quantum yield. Blue-light induced generation of superoxide anion by Folch’ extract of bovine neural retinas strongly depended on the oxidation time. The observed photoreactivity of the studied extract gradually increased during its in vitro oxidation.
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Rodriguez, K. A., and A. T. Tsin. "Retinyl esters in the vertebrate neuroretina." American Journal of Physiology-Regulatory, Integrative and Comparative Physiology 256, no. 1 (January 1, 1989): R255—R258. http://dx.doi.org/10.1152/ajpregu.1989.256.1.r255.
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High-performance liquid chromatography (HPLC) was employed to measure retinyl esters in the vertebrate retina. Both retina and retinal pigment epithelium (RPE) from frog, chicken, and bovine eyes were studied. In comparison to the RPE, the retina possessed a significant level of 11-cis and all trans retinyl palmitate. Using a sensitive radioassay, we also detected the presence of retinyl ester hydrolase (REH) activity in homogenates prepared from both retina and RPE. The rate of retinyl ester hydrolysis in these retinas was sufficiently high to supply retinal chromophores for the metabolic renewal and for the regeneration of visual pigments. In comparison to retinyl esters in the RPE, retinyl esters in the retina are located much closer to the sites of visual pigment synthesis and regeneration. Hence it is possible that these retinyl esters play a more important role in the visual cycle than those in the RPE.
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Milam, Ann H., Daniel E. Possin, Jing Huang, Robert N. Fariss, John G. Flannery, and John C. Saari. "Characterization of aldehyde dehydrogenase-positive amacrine cells restricted in distribution to the dorsal retina." Visual Neuroscience 14, no. 3 (May 1997): 601–8. http://dx.doi.org/10.1017/s0952523800012256.
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AbstractA class 1 aldehyde dehydrogenase (ALDH) catalyzes oxidation of retinaldehyde to retinoic acid in bovine retina. We used immunocytochemistry and in situ hybridization to localize this enzyme in adult and fetal bovine retinas. Specific ALDH immunoreactivity was present in the cytoplasm of wide-field amacrine cells restricted in distribution to the dorsal part of the adult retina. The somata diameters ranged from ∼8 μ to ∼15 μ, and the cells increased in density from ∼125 cells/mm2 near the horizontal meridian to ∼425 cells/mm2 in the superior far periphery. The ALDH-positive cells had somata on both sides of the inner plexiform layer (IPL) and processes in two IPL strata. The majority of ALDH-positive cells were unreactive with antibodies against known amacrine cell enzymes and neurotransmitters, including GABA and glycine. The ALDH-positive amacrine cells also did not react with anti-cellular retinoic acid-binding protein, which was present in a subset of GABA-positive amacrine cells. In flat-mounted retinas processed by in situ hybridization, the larger ALDH-positive amacrine cells tended to be more heavily labeled. In addition to amacrine cells, Müller cell processes in the inner retina were weakly immunoreactive for ALDH; however, these glial cells did not contain ALDH mRNA. The pattern of ALDH expression in fetal bovine retinas was documented by immunocytochemistry. No ALDH reactivity was found before 5.5 months; for the remainder of the fetal period, ALDH immunoreactivity was present in amacrine cells similar to those in adult retina. The ALDH-positive amacrine cells in bovine retina are novel, being limited in distribution to the dorsal retina and unlabeled with other amacrine cell-specific markers. Identification of ALDH in amacrine cells provides additional evidence that cells of the inner retina are involved in retinoid metabolism.
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Das, S. R., N. Bhardwaj, H. Kjeldbye, and P. Gouras. "Muller cells of chicken retina synthesize 11-cis-retinol." Biochemical Journal 285, no. 3 (August 1, 1992): 907–13. http://dx.doi.org/10.1042/bj2850907.
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The amounts of endogenous retinyl palmitate, retinol and retinaldehyde were measured in the neural retina and retinal pigment epithelium (RPE) of predominantly cone (chicken), rod (rat) and more mixed (cat, human) retinae. The ratio of 11-cis to all-trans isomers of retinyl palmitate and retinol in the neural retina and the RPE increases progressively with the increase in diurnality of the species from rat to chicken. The membrane fractions of both chicken and bovine RPE enzymically isomerize all-trans retinol to 11-cis-retinol. Chicken neural retina membranes enzymically form 11-cis-retinol and all-trans-retinyl palmitate from all-trans-retinol. Light and electron microscopy revealed no contamination of chicken neural retina by RPE. Muller cells from chicken retina were isolated, cultured and characterized by immunocytochemical localization of cellular retinaldehyde-binding protein. Cultured chicken Muller cells form all-trans-retinyl palmitate, 11-cis-retinol and 11-cis-retinyl palmitate from all-trans-retinol and release most of the 11-cis-retinol into the medium. The results indicate that chicken neural retina and Muller cells in particular synthesize 11-cis-retinoids from all-trans-retinol.
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Dejda, Agnieszka, Izabela Matczak, and Wojciech A. Gorczyca. "p19 detected in the rat retina and pineal gland is a guanylyl cyclase-activating protein (GCAP)." Acta Biochimica Polonica 49, no. 4 (December 31, 2002): 899–905. http://dx.doi.org/10.18388/abp.2002_3749.
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The Ca(2+)-dependent activation of retina-specific guanylyl cyclase (retGC) is mediated by guanylyl cyclase-activating proteins (GCAPs). Here we report for the first time detection of a 19 kDa protein (p19) with GCAP properties in extracts of rat retina and pineal gland. Both extracts stimulate synthesis of cGMP in rod outer segment (ROS) membranes at low (30 nM) but not at high (1 microM) concentrations of Ca(2+). At low Ca(2+), immunoaffinity purified p19 activates guanylyl cyclase(s) in bovine ROS and rat retinal membranes. Moreover, p19 is recognized by antibodies against bovine GCAP1 and, similarly to other GCAPs, exhibits a Ca(2+)-dependent electrophoretic mobility shift.
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Smith, J. D., J. J. Greenlee, A. N. Hamir, J. A. Richt, and M. H. West Greenlee. "Retinal Function and Morphology Are Altered in Cattle Infected with the Prion Disease Transmissible Mink Encephalopathy." Veterinary Pathology 46, no. 5 (May 9, 2009): 810–16. http://dx.doi.org/10.1354/vp.08-vp-0206-w-fl.
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Transmissible spongiform encephalopathies (TSEs) are a group of diseases that result in progressive and invariably fatal neurologic disease in both animals and humans. TSEs are characterized by the accumulation of an abnormal protease-resistant form of the prion protein in the central nervous system. Transmission of infectious TSEs is believed to occur via ingestion of prion protein–contaminated material. This material is also involved in the transmission of bovine spongiform encephalopathy (“mad cow disease”) to humans, which resulted in the variant form of Creutzfeldt-Jakob disease. Abnormal prion protein has been reported in the retina of TSE-affected cattle, but despite these observations, the specific effect of abnormal prion protein on retinal morphology and function has not been assessed. The objective of this study was to identify and characterize potential functional and morphologic abnormalities in the retinas of cattle infected with a bovine-adapted isolate of transmissible mink encephalopathy. We used electroretinography and immunohistochemistry to examine retinas from 10 noninoculated and 5 transmissible mink encephalopathy–inoculated adult Holstein steers. Here we show altered retinal function, as evidenced by prolonged implicit time of the electroretinogram b-wave, in transmissible mink encephalopathy–infected cattle before the onset of clinical illness. We also demonstrate disruption of rod bipolar cell synaptic terminals, indicated by decreased immunoreactivity for the alpha isoform of protein kinase C and vesicular glutamate transporter 1, and activation of Müller glia, as evidenced by increased glial fibrillary acidic protein and glutamine synthetase expression, in the retinas of these cattle at the time of euthanasia due to clinical deterioration. This is the first study to identify both functional and morphologic alterations in the retinas of TSE-infected cattle. Our results support future efforts to focus on the retina for the development of new strategies for the diagnosis of TSEs.
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MARGULIS, ALEXANDER, NIKOLAY POZDNYAKOV, LOAN DANG, and ARI SITARAMAYYA. "Soluble guanylate cyclase and nitric oxide synthase in synaptosomal fractions of bovine retina." Visual Neuroscience 15, no. 5 (May 1998): 867–73. http://dx.doi.org/10.1017/s0952523898155098.
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Cyclic GMP has been shown in recent years to directly activate ion channels in bipolar and ganglion cells, and to indirectly regulate coupling between horizontal cells, and between bipolar and amacrine cells. In all of these cases, the effects of cyclic GMP are mimicked by nitric oxide. An increase in calcium concentration stimulates the production of nitric oxide by neuronal and endothelial forms of nitric oxide synthase, which in turn activates soluble guanylate cyclases, enhancing the synthesis of cyclic GMP. Though some effects of nitric oxide do not involve cyclic GMP, the nitric oxide-cyclic GMP cascade is well recognized as a signaling mechanism in brain and other tissues. The widespread occurrence of nitric oxide/cyclic GMP-regulated ion channel activity in retinal neurons raises the possibility that nitric-oxide-sensitive soluble guanylate cyclases play an important role in cell–cell communication, and possibly, synaptic transmission. Immunohistochemical studies have indicated the presence of soluble guanylate cyclase in retinal synaptic layers, but such studies are not suitable for determination of the density or quantitative subcellular distribution of the enzyme. Microanalytical methods involving microdissection of frozen retina also showed the presence of cyclase activity in retinal plexiform layers but these methods did not permit distinction between nitric oxide-sensitive and insensitive cyclases. In this study, we fractionated retinal homogenate into the cytosolic and synaptosomal fractions and investigated the specific activity and distribution of soluble guanylate cyclase and nitric oxide synthase. The results show that both enzymes are present in the synaptosomal fractions derived from inner and outer plexiform layers. The synaptosomal fraction derived from inner retina was highly enriched in cyclase activity. Nitric oxide synthase activity was also higher in the inner than outer retinal synaptosomal fraction. The results suggest that the nitric oxide-cyclic GMP system is operational in both synaptic layers of retina and that it may play a more significant role in the inner retina.
Dissertations / Theses on the topic "Bovine retina"
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Tretiach, Marina Louise. "Bovine Models of Human Retinal Disease: Effect of Perivascular Cells on Retinal Endothelial Cell Permeability." Thesis, The University of Sydney, 2005. http://hdl.handle.net/2123/1153.
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Background: Diabetic vascular complications affect both the macro- and microvasculature. Microvascular pathology in diabetes may be mediated by biochemical factors that precipitate cellular changes at both the gene and protein levels. In the diabetic retina, vascular pathology is found mainly in microvessels, including the retinal precapillary arterioles, capillaries and venules. Macular oedema secondary to breakdown of the inner blood-retinal barrier is the most common cause of vision impairment in diabetic retinopathy. Müller cells play a critical role in the trophic support of retinal neurons and blood vessels. In chronic diabetes, Müller cells are increasingly unable to maintain their supportive functions and may themselves undergo changes that exacerbate the retinal pathology. The consequences of early diabetic changes in retinal cells are primarily considered in this thesis. Aims: This thesis aims to investigate the effect of perivascular cells (Müller cells, RPE, pericytes) on retinal endothelial cell permeability using an established in vitro model. Methods: Immunohistochemistry, cell morphology and cell growth patterns were used to characterise primary bovine retinal cells (Müller cells, RPE, pericytes and endothelial cells). An in vitro model of the blood-retinal barrier was refined by coculturing retinal endothelial cells with perivascular cells (Müller cells or pericytes) on opposite sides of a permeable Transwell filter. The integrity of the barrier formed by endothelial cells was assessed by transendothelial electrical resistance (TEER) measurements. Functional characteristics of endothelial cells were compared with ultrastructural morphology to determine if different cell types have barrier-enhancing effects on endothelial cell cultures. Once the co-culture model was established, retinal endothelial cells and Müller cells were exposed to different environmental conditions (20% oxygen, normoxia; 1% oxygen, hypoxia) to examine the effect of perivascular cells on endothelial cell permeability under reduced oxygen conditions. Barrier integrity was assessed by TEER measurements and permeability was measured by passive diffusion of radiolabelled tracers from the luminal to the abluminal side of the endothelial cell barrier. A further study investigated the mechanism of laser therapy on re-establishment of retinal endothelial cell barrier integrity. Müller cells and RPE, that comprise the scar formed after laser photocoagulation, and control cells (Müller cells and pericytes, RPE cells and ECV304, an epithelial cell line) were grown in long-term culture and treated with blue-green argon laser. Lasered cells were placed underneath confluent retinal endothelial cells growing on a permeable filter, providing conditioned medium to the basal surface of endothelial cells. The effect of conditioned medium on endothelial cell permeability was determined, as above. Results: Co-cultures of retinal endothelial cells and Müller cells on opposite sides of a permeable filter showed that Müller cells can enhance the integrity of the endothelial cell barrier, most likely through soluble factors. Low basal resistances generated by endothelial cells from different retinal isolations may be the result of erratic growth characteristics (determined by ultrastructural studies) or the selection of vessel fragments without true â barrier characteristicsâ in the isolation step. When Müller cells were co-cultured in close apposition to endothelial cells under normoxic conditions, the barrier integrity was enhanced and permeability was reduced. Under hypoxic conditions, Müller cells had a detrimental effect on the integrity of the endothelial cell barrier and permeability was increased in closely apposed cells. Conditioned medium from long-term cultured Müller cells and RPE that typically comprise the scar formed after lasering, enhanced TEER and reduced permeability of cultured endothelial cells. Conclusions: These studies confirm that bovine tissues can be used as a suitable model to investigate the role of perivascular cells on the permeability of retinal endothelial cells. The dual effect of Müller cells on the retinal endothelial cell barrier under different environmental conditions, underscores the critical role of Müller cells in regulating the blood-retinal barrier in health and disease. These studies also raise the possibility that soluble factor(s) secreted by Müller cells and RPE subsequent to laser treatment reduce the permeability of retinal vascular endothelium. Future studies to identify these factor(s) may have implications for the clinical treatment of macular oedema secondary to diseases including diabetic retinopathy.
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Tretiach, Marina Louise. "Bovine Models of Human Retinal Disease: Effect of Perivascular Cells on Retinal Endothelial Cell Permeability." University of Sydney, 2005. http://hdl.handle.net/2123/1153.
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Doctor of Philosophy (Medicine)Background: Diabetic vascular complications affect both the macro- and microvasculature. Microvascular pathology in diabetes may be mediated by biochemical factors that precipitate cellular changes at both the gene and protein levels. In the diabetic retina, vascular pathology is found mainly in microvessels, including the retinal precapillary arterioles, capillaries and venules. Macular oedema secondary to breakdown of the inner blood-retinal barrier is the most common cause of vision impairment in diabetic retinopathy. Müller cells play a critical role in the trophic support of retinal neurons and blood vessels. In chronic diabetes, Müller cells are increasingly unable to maintain their supportive functions and may themselves undergo changes that exacerbate the retinal pathology. The consequences of early diabetic changes in retinal cells are primarily considered in this thesis. Aims: This thesis aims to investigate the effect of perivascular cells (Müller cells, RPE, pericytes) on retinal endothelial cell permeability using an established in vitro model. Methods: Immunohistochemistry, cell morphology and cell growth patterns were used to characterise primary bovine retinal cells (Müller cells, RPE, pericytes and endothelial cells). An in vitro model of the blood-retinal barrier was refined by coculturing retinal endothelial cells with perivascular cells (Müller cells or pericytes) on opposite sides of a permeable Transwell filter. The integrity of the barrier formed by endothelial cells was assessed by transendothelial electrical resistance (TEER) measurements. Functional characteristics of endothelial cells were compared with ultrastructural morphology to determine if different cell types have barrier-enhancing effects on endothelial cell cultures. Once the co-culture model was established, retinal endothelial cells and Müller cells were exposed to different environmental conditions (20% oxygen, normoxia; 1% oxygen, hypoxia) to examine the effect of perivascular cells on endothelial cell permeability under reduced oxygen conditions. Barrier integrity was assessed by TEER measurements and permeability was measured by passive diffusion of radiolabelled tracers from the luminal to the abluminal side of the endothelial cell barrier. A further study investigated the mechanism of laser therapy on re-establishment of retinal endothelial cell barrier integrity. Müller cells and RPE, that comprise the scar formed after laser photocoagulation, and control cells (Müller cells and pericytes, RPE cells and ECV304, an epithelial cell line) were grown in long-term culture and treated with blue-green argon laser. Lasered cells were placed underneath confluent retinal endothelial cells growing on a permeable filter, providing conditioned medium to the basal surface of endothelial cells. The effect of conditioned medium on endothelial cell permeability was determined, as above. Results: Co-cultures of retinal endothelial cells and Müller cells on opposite sides of a permeable filter showed that Müller cells can enhance the integrity of the endothelial cell barrier, most likely through soluble factors. Low basal resistances generated by endothelial cells from different retinal isolations may be the result of erratic growth characteristics (determined by ultrastructural studies) or the selection of vessel fragments without true âbarrier characteristicsâ in the isolation step. When Müller cells were co-cultured in close apposition to endothelial cells under normoxic conditions, the barrier integrity was enhanced and permeability was reduced. Under hypoxic conditions, Müller cells had a detrimental effect on the integrity of the endothelial cell barrier and permeability was increased in closely apposed cells. Conditioned medium from long-term cultured Müller cells and RPE that typically comprise the scar formed after lasering, enhanced TEER and reduced permeability of cultured endothelial cells. Conclusions: These studies confirm that bovine tissues can be used as a suitable model to investigate the role of perivascular cells on the permeability of retinal endothelial cells. The dual effect of Müller cells on the retinal endothelial cell barrier under different environmental conditions, underscores the critical role of Müller cells in regulating the blood-retinal barrier in health and disease. These studies also raise the possibility that soluble factor(s) secreted by Müller cells and RPE subsequent to laser treatment reduce the permeability of retinal vascular endothelium. Future studies to identify these factor(s) may have implications for the clinical treatment of macular oedema secondary to diseases including diabetic retinopathy.
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Chittock, R. S. "GTP metabolism in vertebrate retinal receptors." Thesis, University of Bristol, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.356119.
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Reid, K. "Biochemical and histochemical studies of the photoreceptor cells and the interphotoreceptor matrix of the bovine retina." Thesis, University of Edinburgh, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.661009.
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Mice immunised with partially purified surface molecules of photoreceptor outer segments or with a synthetic peptide corresponding to the N-terminus of a cone-specific rhodopsin-like protein, gave rise to the production of monoclonal antibodies with only general immunoreactivity against the retina. Immunisation with interphotoreceptor matrix or crude photoreceptor outer segment preparations resulted in the production of hybridomas which secreted monoclonal antibodies 1001.A1 and 1001.A3. 1001.A1 binds to the interstitial retinol-binding protein (IRBP), associated with the rod photoreceptor cells and the IPM, as demonstrated by immunohisto chemistry and by Western blotting and dot blotting of IPM and purified IRBP. 1001.A3 binds a soluble high molecular weight chondroitin sulphase proteoglycan. Immunohistochemistry indicated the antigen to be present in the form of distinct sheath-like structures surrounding the photoreceptor cells. Gel filtration chromatography both in native conditions and in the presence of guanidinium chloride showed the antigen to have an apparent molecular mass of greater than 2000kDaltons and indicated the antigen was not a loosely associated aggregate of smaller components. Binding of 1001.A3 to fixed tissue sections of the bovine retina was completely abolished by their prior treatment with either chondroitinase ABC, chondroitinase AC, hyaluronidase (testicular) or trypsin. Prior treatment of tissue sections with either heparinase or neuraminidase had no effect on binding. Treatment of tissue sections with hyaluronidase (Streptomyces) had no effect on the ability of 1001.A3 to bind, but the structure of the antigen was altered. The sheath-like structure surrounding the photoreceptors was broken down and immunoreactivity was seen in the same area of the IPM, adjacent to the photoreceptors but with no defined structure. In conclusion, the antigen is a chondroitin sulphate molecule which is associated with hyaluronic acid molecules and which together form a defined sheath-like structure surrounding the photoreceptor cells.
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Boukra, Nouara. "Structure de la rhodopsine bovine : analyse par microscopie electronique et essai de cristallisation en trois dimensions." Université Louis Pasteur (Strasbourg) (1971-2008), 1987. http://www.theses.fr/1987STR13126.
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Mascarelli, Frédéric. "Purification et mode d'action des facteurs de croissance de type fgfs d'origine nerveuse." Paris 6, 1988. http://www.theses.fr/1988PA066402.
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La purification des facteurs de croissance du fibroblaste (fgf) acide et basique chez le poulet au cours du developpement embryonnaire a permis de confirmer la grande conservation des fgf au cours de l'evolution. Le photorecepteur est la cellule qui contient la plus grande activite mitogenique specifique en fgf
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Chrysina, Evangelia D. "Structural studies on α-lactalbumin and retinol binding protein." Thesis, University of Bath, 2000. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.323727.
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Wong, Simon Yuk Chun. "A spectrin-like protein in bovine retinal rod photoreceptor outer segments as defined by monoclonal antibodies." Thesis, University of British Columbia, 1988. http://hdl.handle.net/2429/29217.
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Biochemical and immunological studies indicate that rod outer segments (ROS) of bovine photoreceptor cells contain a Mr 240,000 polypeptide related to the ∝-subunit of red blood cell (RBC) spectrin. With the use of sodium dodecyl sulfate gel electrophoresis in conjunction with the immunoblotting technique, monoclonal antibody 4B2 was found to bind to a Mr 240,000 polypeptide in ROS that is distinct from the prominent Mr 220,000 concanavalin A binding glycoprotein. The Mr 240,000 polypeptide is highly susceptible to degradation by endogenous proteases. It does not appear to be an integral membrane protein but is tightly membrane associated since it can be partially extracted from ROS membranes with urea in the absence of detergent.
The 4B2 antibody cross-reacted with RBC ghost membranes and bovine brain microsomal membranes. Radioimmune assays and immunoblotting analysis of purified bovine RBC spectrin further revealed that the 4B2 antibody predominantly labelled the ∝-chain of RBC spectrin having an apparent Mr of 240,000. Monoclonal antibody 3A6 was found to bind to a polypeptide with a slightly lower Mr than the 4B2-specific polypeptide. It is also highly susceptible to degradation by endogenous proteases, but unlike the 4B2 antibody, it predominantly labelled the β-chain of RBC spectrin having an apparent M of 220,000. Polyclonal anti-spectrin antibodies that bound to both the ∝ - and β-chain of RBC spectrin predominantly labelled a Mr 240,000 polypeptide of ROS membranes. Two faintly labelled bands in the Mr range of 210,000-220,000 were also observed. These components may represent variants of the β -chain of spectrin that are weakly cross-reacting or present in smaller quantities than the ∝-chain.
Immunocytochemical labelling studies using the 4B2 antibody and immunogold-dextran markers indicated that the ROS spectrin-like protein is preferentially localized in the region where the discs come in close contact to the plasma membrane of ROS. Immunoblotting analysis indicated that rhodopsin and peripherin which constitute over 90% of total disc membrane proteins were selectively solubilized in Triton X-100, whereas a set of polypeptides including the 4B2-specific polypeptide and the Mr 220,000 concanavalin A-binding glycoprotein was only partially soluble. Electron microscopy of a negatively stained Triton-extracted ROS pellet revealed a filamentous network.
These studies indicate that ROS contain a protein related to RBC spectrin, which may constitute a major component of a filamentous network lining the inner surface of the ROS plasma membrane as previously seen by electron microscopy. This membrane skeletal system may serve to stabilize the ordered ROS structure and maintain a constant distance between the rim region of the discs and the plasma membrane.Medicine, Faculty of
Biochemistry and Molecular Biology, Department of
Graduate
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Fritze, Olaf. "Der Aktivierungsmechanismus von Rhodopsin." Doctoral thesis, Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät I, 2006. http://dx.doi.org/10.18452/15566.
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Rhodopsin, der Rezeptor der visuellen Kaskade, gehört zu größten Klasse A der G-Protein-koppelnden Rezeptoren (GPCRs) und gilt als Modell-Rezeptor in der GPCR-Forschung. Über 3 % des humanen Genoms kodieren für GPCRs, doch trotz der physiologischen Bedeutung dieser Proteinfamilie sind die fundamentalen Mechanismen, mit denen diese Rezeptoren extrazelluläre Signale in das Zellinnere weiterleiten noch nicht verstanden. In der vorliegenden Dissertation werden Aspekte des Aktivierungsmechanismus von Rhodopsin sowie der Kopplung und Aktivierung des G-Proteins Transduzin untersucht. Die Arbeit ist in drei Schwerpunkte unterteilt: I. Es wurde ein in GPCR’s hochkonserviertes NPxxYx(5,6)F Motiv (Aminosäuresequenz Asn-Pro-x-x-Tyr-x(5,6)-Phe) in der siebten und achten Helix charakterisiert. In diesem konservierten Motiv sind mehrere für die Ausbildung der aktiven Rezeptorkonformation wichtige Funktionen vereint: Verknüpfung zu einem Wasserstoffbrückennetzwerk, Helixflexibilität sowie die exakte Positionierung der achten Helix. Letzteres hat nicht nur bei der Rezeptoraktivierung sondern auch bei der nachfolgenden Interaktion mit dem G-Protein eine Bedeutung. II. Anhand von chimären Rezeptoren, bei denen Teile der achten Helix durch homologe Sequenzen des beta2-adrenergen Rezeptors ausgetauscht wurden, wurde die Rolle der achten Helix bei der Rezeptor-Aktivierung und Bindung des G-Proteins untersucht. Auch bei dieser Studie wurde gezeigt, dass die exakte Positionierung der achten Helix essentiell für die Interaktion mit dem G-Protein ist. Zudem wurde ein bezüglich der G-Protein-Aktivierung funktionsfähiger chimärer Rezeptor gefunden, was auf einen übergeordneten Mechanismus bei der Aktivierung von G-Proteinen durch GPCRs hindeutet. III. Die Funktion des ß-Ionon-Rings des Retinals beim Aktivierungsmechanismus von Rhodopsin wurde an einem Retinal studiert, bei welchem Teile des Retinal-Rings fehlten (azyklisches Retinal). Auch diesem azyklischen Retinal können Eigenschaften eines partiellen Agonisten zugeschrieben werden. Beim Vergleich zu Pigmenten mit dem nativen 11-cis-Retinal wurden starke Analogien bei der initialen Energieaufnahme durch die Retinal-Isomerisierung sowie bei der Weiterleitung der Lichtenergie ins Protein gefunden. Allerdings wird die Energie schlechter auf das Protein übertragen, wodurch wesentlich weniger der aktiven G-Protein bindenden Rezeptorkonformation gebildet wird. Als wichtigste Funktion des Retinal-Rings wurde die Aufrechterhaltung der aktiven Meta-II-Konformation identifiziert.Rhodopsin, the receptor of the visual cascade, belongs to the largest group A of G-protein coupled receptors (GPCRs) and can be seen as a model receptor in GPCR research. More than 3 % of the human genome code for GPCRs. But despite their physiological relevance, the detailed mechanism of signal transduction from extra cellular signal to different cellular pathways remains to be fully understood. Different aspects of receptor activation and the coupling and activation of the G-protein transducin are investigated in this dissertation. The thesis focuses on the following three subjects: I. A NPxxYx(5,6)F motif (amino acid sequence Asn-Pro-x-x-Tyr-x(5,6)-Phe) has been characterized for rhodopsin. It is localized in helix VII and VIII and is highly conserved throughout the GPCR family. Various roles for rhodopsin activation are combined in this motif: linkage to a hydrogen-bond network, helix flexibility and the exact positioning of helix VIII. The latter is not only relevant for the activation of the receptor but also for interaction with its G-protein. II. The role of helix VIII for receptor activation and G-protein coupling was studied on chimeric receptors, in which parts of helix VIII were exchanged against homologous sequences of the beta2 adrenergic receptor. This study confirmed the importance of helix VIII’s position for G-protein coupling. Furthermore, a chimeric receptor was found, which was fully functional concerning G-protein activation. This indicates that GPCRs might use a single, generic mechanism for G-protein activation. III. The role of the ß-ionone-ring for the activation mechanism of rhodopsin was studied by means of an acyclic retinal, which lacks four carbon atoms of the ß-ionone-ring. This modified retinal could be classified as a partial agonist for rhodopsin. Energy input by retinal isomerization and formation of the G-protein binding Meta-II conformation were found to be very similar to rhodopsin when bound to its native 11-cis-retinal. However, the lack of the ring structure resulted in a lower amount of Meta-II and a fast decay of activity. It was concluded that the main role of the ring structure is to maintain the active state of rhodopsin.
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TORRIGLIA, SMATI ALICIA. "Isolement et immunolocalisation d'un recepteur des fgfs acide et basique a partir de la retine neurale bovine." Paris 5, 1993. http://www.theses.fr/1993PA05W086.
Full textBooks on the topic "Bovine retina"
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Rundle, Dana. Identification of n-terminal myristoyltransferase enzymes in bovine retina: Determination of kinetic parameters of type I and type II enzymes using multiple substrates. [s.n.], 2000.
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Pool, Robert. Beyond Engineering. Oxford University Press, 1997. http://dx.doi.org/10.1093/oso/9780195107722.001.0001.
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We have long recognized technology as a driving force behind much historical and cultural change. The invention of the printing press initiated the Reformation. The development of the compass ushered in the Age of Exploration and the discovery of the New World. The cotton gin created the conditions that led to the Civil War. Now, in Beyond Engineering, science writer Robert Pool turns the question around to examine how society shapes technology. Drawing on such disparate fields as history, economics, risk analysis, management science, sociology, and psychology, Pool illuminates the complex, often fascinating interplay between machines and society, in a book that will revolutionize how we think about technology. We tend to think that reason guides technological development, that engineering expertise alone determines the final form an invention takes. But if you look closely enough at the history of any invention, says Pool, you will find that factors unrelated to engineering seem to have an almost equal impact. In his wide-ranging volume, he traces developments in nuclear energy, automobiles, light bulbs, commercial electricity, and personal computers, to reveal that the ultimate shape of a technology often has as much to do with outside and unforeseen forces. For instance, Pool explores the reasons why steam-powered cars lost out to internal combustion engines. He shows that the Stanley Steamer was in many ways superior to the Model T--it set a land speed record in 1906 of more than 127 miles per hour, it had no transmission (and no transmission headaches), and it was simpler (one Stanley engine had only twenty-two moving parts) and quieter than a gas engine--but the steamers were killed off by factors that had little or nothing to do with their engineering merits, including the Stanley twins' lack of business acumen and an outbreak of hoof-and-mouth disease. Pool illuminates other aspects of technology as well. He traces how seemingly minor decisions made early along the path of development can have profound consequences further down the road, and perhaps most important, he argues that with the increasing complexity of our technological advances--from nuclear reactors to genetic engineering--the number of things that can go wrong multiplies, making it increasingly difficult to engineer risk out of the equation. Citing such catastrophes as Bhopal, Three Mile Island, the Exxon Valdez, the Challenger, and Chernobyl, he argues that is it time to rethink our approach to technology. The days are gone when machines were solely a product of larger-than-life inventors and hard-working engineers. Increasingly, technology will be a joint effort, with its design shaped not only by engineers and executives but also psychologists, political scientists, management theorists, risk specialists, regulators and courts, and the general public. Whether discussing bovine growth hormone, molten-salt reactors, or baboon-to-human transplants, Beyond Engineering is an engaging look at modern technology and an illuminating account of how technology and the modern world shape each other.
Book chapters on the topic "Bovine retina"
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Blankenship, Elise, and David T. Lodowski. "Rhodopsin Purification from Dark-Adapted Bovine Retina." In Methods in Molecular Biology, 21–38. New York, NY: Springer New York, 2015. http://dx.doi.org/10.1007/978-1-4939-2330-4_2.
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Kean, Edward L., Jermin Ju, and Naiqian Niu. "Regulatory Influences on the Glycosylation of Rhodopsin By Human and Bovine Retinas." In Degenerative Diseases of the Retina, 139–47. Boston, MA: Springer US, 1995. http://dx.doi.org/10.1007/978-1-4615-1897-6_16.
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Aymerich, Maria S., Alfredo Martinez, and S. Patricia Becerra. "Characterization and Localization of Pigment Epithelium-Derived Factor Binding Sites in the Bovine Retina." In New Insights Into Retinal Degenerative Diseases, 127–33. Boston, MA: Springer US, 2001. http://dx.doi.org/10.1007/978-1-4615-1355-1_15.
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Gerding, H., E. Vollmer, G. Cremer-Bartels, H. Rokos, K. Krause, and H. Busse. "Immunoenzymatic Labeling of Biopterin and Neopterin in the Pigment Epithelium of Bovine Retina." In Advances in Experimental Medicine and Biology, 347–50. Boston, MA: Springer US, 1993. http://dx.doi.org/10.1007/978-1-4615-2960-6_72.
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Kanan, Yogita, Robert A. Hamilton, Kevin L. Moore, and Muayyad R. Al-Ubaidi. "Protein Tyrosine-O-Sulfation in Bovine Ocular Tissues." In Retinal Degenerative Diseases, 835–41. Boston, MA: Springer US, 2011. http://dx.doi.org/10.1007/978-1-4614-0631-0_107.
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Smine, Abdelkrim, and James J. Plantner. "Purification and Characterization of Matrix Metalloproteinase-3 (Stromelysin-1) from Bovine Interphotoreceptor Matrix." In Degenerative Retinal Diseases, 399–407. Boston, MA: Springer US, 1997. http://dx.doi.org/10.1007/978-1-4615-5933-7_43.
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Primo, Vincent A., and Joseph F. Arboleda-Velasquez. "Isolation and Transfection of Primary Culture Bovine Retinal Pericytes." In Methods in Molecular Biology, 107–17. New York, NY: Springer New York, 2016. http://dx.doi.org/10.1007/978-1-4939-3628-1_7.
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Kothary, Piyush C., Rhonda Lahiri, Lynn Kee, Nitin Sharma, Eugene Chun, Angela Kuznia, and Monte A. Del Monte. "Pigment Epithelium-Derived Growth Factor Inhibits Fetal Bovine Serum Stimulated Vascular Endothelial Growth Factor Synthesis in Cultured Human Retinal Pigment Epithelial Cells." In Retinal Degenerative Diseases, 513–18. Boston, MA: Springer US, 2006. http://dx.doi.org/10.1007/0-387-32442-9_71.
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Hoste, A. M., L. J. Andries, and S. U. Sys. "The Ca2+ Channel Blocking Action of β-Blockers in Bovine Retinal Microartery." In Glaucoma: Decision Making in Therapy, 307–12. Milano: Springer Milan, 1996. http://dx.doi.org/10.1007/978-88-470-2196-9_49.
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Stiemer, R., H. Gausepohl, M. Mirshahi, Y. Kozak, M. Kraft, J. P. Faure, and R. Frank. "Localization of an Immunopathologically Important Epitope in the Bovine Retinal S-Antigen by the Pepscan Method." In Molecular and Cell Biology of Autoantibodies and Autoimmunity. Abstracts, 88–91. Berlin, Heidelberg: Springer Berlin Heidelberg, 1989. http://dx.doi.org/10.1007/978-3-642-46681-6_78.
Full textConference papers on the topic "Bovine retina"
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Durig, B. R., W. H. Peters III, and M. E. Hammer. "Digital Image Correlation Measurements Of Strain In Bovine Retina." In SPIE International Symposium on Optical Engineering and Industrial Sensing for Advance Manufacturing Technologies, edited by Chander P. Grover. SPIE, 1989. http://dx.doi.org/10.1117/12.947619.
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Liu, Changgeng, and Myung K. Kim. "In Vitro Bovine Retina Imaging by Digital Holographic Adaptive Optics." In Frontiers in Optics. Washington, D.C.: OSA, 2012. http://dx.doi.org/10.1364/fio.2012.fw5a.2.
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Miranda, Vanessa Regina, and Nelson Henrique Morgon. "Estudo Teórico in silico da Interação entre Geraniol e o Sítio Ativo da Opsina Bovina." In VIII Simpósio de Estrutura Eletrônica e Dinâmica Molecular. Universidade de Brasília, 2020. http://dx.doi.org/10.21826/viiiseedmol202053.
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The bovine opsin protein, 6PGS, is present in the eye of the Bos taurus species, and has activity throughout the period of development of the retina, remaining until its adult stage. The interaction of the geraniol ligand, which has anti-inflammatory, antimicrobial and antioxidant activities, with the active site of the protein was studied through theoretical calculations using Density Functional Theory. The molecular structure results show that in the interaction process of geraniol with the active site of 6PGS there is a distortion in the geometry of the ligand. Through the UV-Vis spectra, a shift of the wavelength maximum value in relation to the free geraniol is observed, of the order of 50 nm.
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Myers, Kristin M., and Thao D. Nguyen. "The Bulge Inflation Response of Bovine Sclera." In ASME 2009 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2009. http://dx.doi.org/10.1115/sbc2009-204250.
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Glaucoma is one of the leading causes of blindness in the United States and in the world [1]. It is caused by damage to the retinal ganglion cells (RGC), a type of neuron that transmits visual information to the brain. Despite therapeutic efforts to reduce the rate of vision loss in glaucoma patients, the rate of blindness remains high [2]. There is evidence that elevated intraocular pressure (IOP) plays an important role in the damage to RGCs [3–5], but the relationship between the mechanical properties of the connective tissue and how it affects the cellular function is not understood. The load-bearing eye wall consists of the cornea and the sclera. Both tissues are collagen rich structures with preferentially aligned collagen lamellae dictating its mechanical response. Previous studies have shown that the viscoelastic material response of the eye wall differs between normal and glaucoma animal tissues [6]. However, these previous studies relied on strip testing of tissue samples.
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Gnoatto, Eduarda Socovoski, Vitoria Karolini Betim Fieldkircher Caus, Cristian Ferreira Corona, Letiére Cabreira Soares, and Dalila Moter Benvegnú. "EFEITO ANTIMICROBIANO DE COMPOSTOS TRIAZÓLICOS EM CEPAS DE Staphylococcus aureus ISOLADAS DE CASOS DE MASTITE EM BOVINOS." In I Congresso Nacional de Microbiologia Clínica On-Line. Revista Multidisciplinar em Saúde, 2021. http://dx.doi.org/10.51161/rems/1198.
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Introdução: A mastite bovina é a principal enfermidade da indústria leiteira mundial, a qual desencadeia um processo inflamatório na glândula mamária de bovinos. Esta doença é causada principalmente por bactérias, que predominam devido às más condições higiênico-sanitárias no ambiente e péssimas condições de saúde dos animais. O uso indiscriminado de antibióticos em rebanhos leiteiros tem gerado aumento da resistência bacteriana, dificultando o tratamento dessa doença, o que por sua vez acaba prejudicando o bem-estar do animal e a qualidade do leite produzido. E, dentre as diversas bactérias pode ser citado o Staphylococcus aureus, que se destaca devido á sua resistência. À vista disso, pesquisas têm buscado alternativas para tratamento desta doença, os quais não acarretem mais resistência bacteriana. Um exemplo disto é a utilização de compostos triazólicos e seus derivados, que se destacam na área de química medicinal e podem ser usados para a síntese de vários compostos heterocíclicos com diferentes atividades biológicas como: antiviral, antibacteriana, antifúngica e antituberculose. Objetivo: Realizar uma revisão da literatura sobre ação antimicrobiana de compostos triazólicos sobre S. aureus. Métodos: Foi realizada uma revisão bibliográfica no banco de dados Scholar Google no qual foram selecionados trabalhos entre os anos de 2008 e 2020 com um nº de 16, cujos termos utilizados foram: "triazol", "antimicrobial" e "S. aureus". Resultado: Os métodos mais utilizados para avaliação da atividade antimicrobiana foram Difusão em poço e Concentração Inibitória Mínima. Os compostos derivados de triazol, em todos os estudos apresentaram efeito antimicrobiano significativo em relação às cepas de S. aureus. Alguns trabalhos relataram que geralmente a presença de qualquer substituinte no anel benzeno presente no composto levou ao aumento da atividade antimicrobiana frente a todas as cepas bacterianas testadas. Além disso, foi demonstrado que a presença de átomos ou grupos que retiram ou doam elétrons nas posições orto ou para em relação à fenila ligada ao triazol é capaz de aumentar a atividade antibacteriana desses compostos. Conclusão: Por meio da revisão bibliográfica deste estudo, observou-se que os compostos derivados de triazol têm sido relatados por apresentarem notável efeito antimicrobiano em cepas de S. aureus.
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Panazzolo, Roberta de Cassia, Larissa Lara Voigt, Jennyfer Júlia Da Silva Sá, Adrielli Rauen Santos, and Paulo Henrique Alcantara Gomes Silva. "RELATO DE CASO: ROMPIMENTO DA VEIA MAMÁRIA EM VACA HOLANDESA EM TANGARÁ SANTA CATARINA." In I Congresso Brasileiro Online de Práticas Veterinárias: Uma abordagem para animais de grande porte e produção Animal. Revista Multidisciplinar em Saúde, 2022. http://dx.doi.org/10.51161/granvet-35.
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Introdução: Edema de úbere é uma das enfermidades mais recorrentes em vacas leiteiras, sendo descrita por acúmulo de líquido no espaço intracelular, podendo ser causado por distúrbios circulatórios, dieta, herdabilidade e traumas. Esta enfermidade causa grandes prejuízos econômicos, visto que tem alta incidência e durante o período de acometimento dos animais a produção de leite diminui consideravelmente, uma vez que altera sua fisiologia. Esse inchaço pode estar associado à ruptura da veia mamária, condição pouco descrita na literatura que tem como sinais clínicos o aumento de volume na região abdominal juntamente com mucosas pálidas e taquicardia. Normalmente quando ocorre o traumatismo a hemorragia é interna e o diagnóstico é difícil, no entanto pode ser facilmente identificado através da necropsia, pela visualização de edema e hemorragia no tecido subcutâneo, hemorragia no úbere e rompimento da veia mamária. Objetivo: O objetivo deste relato é descrever o caso clínico de ruptura de veia mamária em bovino, acompanhado durante a rotina do laboratório de patologia veterinária UFSC, visto que a literatura referente a este tema é escassa. Relato de caso: O caso ocorreu em bovino fêmea, de cinco anos, da raça holandesa, na cidade de Tangará em Santa Catarina. Conforme o histórico clínico, o animal amanheceu com edema no úbere, com mucosas pálidas e taquicardia, foi coletado sangue e estava com aspecto líquido, vindo a óbito no início da tarde. No exame clínico, o úbere estava inflamado e edemaciado, o animal apresentava temperatura normal. Discussão: Ao realizar a necropsia foi constatado após a abertura do úbere intensa hemorragia com presença de edema. Ao retirar o sangue e coágulos, observou-se ruptura da veia mamária. O diagnóstico foi baseado em achados macroscópicos, dispensando análise microscópica. A lesão relatada é pouco descrita na literatura, devido aos sinais clínicos, alterações e achados macroscópicos citadas na necropsia. Conclusão: Portanto, o animal veio a óbito por rompimento da veia mamária, associado ao quadro de anemia por hemorragia.
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Santos, Sâmia Melo, and Alana Rayssa Oliveira Mendes. "RELAÇÃO HOMEM – NATUREZA: FATOR DE CAUSALIDADE DA CRISE AMBIENTAL." In II Congresso Brasileiro de Ciências Farmacêuticas On-line. Revista Multidisciplinar em Saúde, 2021. http://dx.doi.org/10.51161/rems/1039.
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Introdução: O meio ambiente é fonte de sobrevivência para o homem desde os primórdios, o mesmo retira dele seu sustento, extraindo riquezas naturais como: água, alimentos (frutos, legumes, carne bovina, carne suína, peixes, ovinos etc.). Para melhoramento da agricultura ao longo dos anos, o homem passou fazer o uso de substâncias químicas para acelerar processo de amadurecimento das frutas, evitar pragas e estimular o crescimento. A interferência do homem no meio ambiente acabou por prejudicar sua própria existência, os danos são tão grandes que interferem no processo saúde-doença. Objetivo: Portanto, o objetivo deste trabalho é realizar uma revisão de literatura acerca da relação homem – natureza e como a mesma pode afetar a agricultura e interferir no processo saúde-doença. Material e métodos: Para isto, foi realizada uma revisão de literatura nos bancos de dados Scielo e Pubmed. Resultados: Portanto a necessidade humana de desenvolvimento capitalista transformou o meio ambiente em uma moeda de troca levando a uma crise ambiental, na qual a sua própria existência passa a ser questionada. Segundo alguns autores como Balim, o homem primitivo não interferia na natureza sem cautela, sempre tentava manter o equilíbrio, mas ao modernizar seu modo de pensar, começou a estar no centro de tudo, sempre extraindo bens da natureza como se estes não fossem finitos. Conclusão: Esta forma de agir se encaixa em uma perspectiva simplista onde o meio ambiente é apenas um objeto para uso humano, necessitando assim de uma nova visão de mundo para entender que os recursos do planeta são finitos.
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Kitajima, Y., S. Sugino, T. Sanada, Y. Sawae, T. Murakami, and M. Watanabe. "Transport Phenomena in Engineered Cartilage With Tissue Development in Agarose Gel." In ASME/JSME 2007 5th Joint Fluids Engineering Conference. ASMEDC, 2007. http://dx.doi.org/10.1115/fedsm2007-37465.
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The primary function of articular cartilage is to absorb impact in life cycle, however once cartilage is damaged, it has poor ability to recover. And then transplant of engineered cartilage tissue is considered as the promising measure for the therapeutic approach, since it is free from immune reaction. Articular cartilage consists of 2% chondrocyte and 98% extra-cellar-matrix (ECM), which is made by chondrocyte’s metabolic action. ECM shows high osmotic pressure, mainly due to highly negative charged proteoglycan, and hence retain large amount of water. The most characteristic nature of cartilage tissue is avascularity, hence materials, such as nutrition and wastes, are transported from connective tissue or periosteum by mainly diffusion. One of the most significant key factors to control the development of the engineered cartilage is this transport phenomenon, which is, on the other hand, strongly affected by the tissue development. Therefore we study transport processes as ECM development. In this study, we selected ultra-low gelling temperature agarose gel, of different types and weight percent, as the scaffold, and chondrocytes were isolated from the bovine metacarpal-phalangeal joint. Engineered cartilage was obtained by incubating cell-agarose compounds for ECM to be produced. Engineered cartilage tissue specimens were soaked with fluorescent labeled dextran of prescribed molecular weight to observe the diffusion transport process. We evaluated diffusion coefficients by two different methods, namely, global observation in specimen by using flow chamber and local observation diffusion using FRAP method. We compare coefficients of dextran molecules both in engineered cartilage and cell-free agarose gel. First we investigate the effects of tissue development on diffusion coefficients. We observe the effects of incubation periods on the diffusion coefficients of engineered cartilage. And then we investigate the charge effects on the transport phenomena, by comparing the transport processes of charged and uncharged dextran. We also investigate the effects of scaffold type on tissue development.
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Liu, Chung Y., Per Wallen, Dean Handley, and Jena Smith. "FIERIN POTENTIATING THE ACTIVATION OF FIBRINOLYTIC SYSTEM ON THE ENDOTHELIAL CELL SURFACE: FORMATION OF THE SURFACE-BOUND TRIMOLECULAR COMPLEX OF FIBRIN, PLASMINOGEN, AND PLASMINOGEN ACTIVATOR." In XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1643318.
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Previous reports have shown that f ibrin (Fn), plasminogen (Pig), and tissue plasminogen activator (tPA) can bind to bovine aortic endothelial cell (BAEC) respectively. The present studies are to examine the formation of the trimolecular complex of Fn, Pig, and tPA on the BAEC surface. BAEC monolayers were first incubated with one of the three components in buffer (pH 7.5, 25 C) and washed, and then incubated with the second component and washed. Finally, the BAEC monolayers after the first and second incubations were incubated with the third component in the presence of plasmin substrate S-2251. Plasminogen activation rates (PAR)(pM/min) were measured. The results (TABLE) show that Pig and tPA retain their respective activities after their binding to BAEC surface, either Pig or tPA as the first bound component. These results suggest that the formation of Plg-tPA complex can occur after their binding to the BAEC surface. With Fn as the second binding component, BAEC monolayers show higher PAR values (138 & 187, pM/imin) than those without Fn (34.5 & 59.1 pM/min), suggesting Fn potentiation of tPA-induced Pig activation on the BAEC surface. Since the reaction of Fn with the Plg-tPA complex is required for the expression of fibrin potentiation, the present results suggest that the formation of trimolecular complex can occur on the BAEC surface. Further, when Fn was the first bound component and Pig or tPA was the second or third bound component, the BAEC rmonolayers show the highest PAR values (353 & 331 nVrmin), suqqestinq that both Plq and tPA can bind not only to BAEC surface but also to Fn which was already first bound to BAEC surface. Thus, trimolecular complex may have multiple binding sites on BAEC surface and anyone of the three binding sites (Fn, Pig, and tPA) may act as the binding site for the trimolecular couplex on the BAEC surface.
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Holmes, W. E., H. R. Lijnen, and D. Collen. "CHARACTERIZATION OFα2-ANTIPLASMIN.REACTIVE SITE VARIANTS PRODUCED BY SITE-DIRECTED MUTAGENESIS." In XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1644766.
Full textAbstract:
α2-Antiplasmin (α2AP) is the primary physiological plasmin inhibitor in human plasma. The inhibition is rapid (second order rate constants (k1) are expressed as M−1 s−1 ) (k1 = 2 × 107) and occurs as the consequence of an irreversible 1:1 stoichiometric complex formation; the exact nature of and the forces involved in complex formation are not fully understood. In fact, what makes α2AP an inhibitor, rather than simply a substrate remains unresolved. Recently, we deduced the primary structure of α2 AP from the sequence of its cDNA. 95%of this sequence was confirmed by amino acid (aa) sequence analysis of naturalα2 AP (α2 AP)? The 452 aa molecule contains 2 disulfide bonds and 4 glycosylated Asn residues, aa sequence alignment confirmed α2AP's membership in the Serpin family. The reactive site sequence as determined by NH2 - and COOH-terminal aa sequence analysis of the plasmin-modified inhibitor and the released M−r ∼ 8000 peptide is Met362-Ser363-Arg364-Met365-Ser366, P3-P2-P1-P'1-P'2, respectively.Natural and engineered P1 residue substitutions in the Serpin α2 -antitrypsin ( α2 AT) have shown altered specificities and efficiencies. To further examine the role of P and P' residues in determining Serpin specificity, in the present study we have by site-directed mutagenesis, deleted (△) the P'l-Met365 residue of a AP thereby producing a recombinant (r) inhibitor (r α2 AP△Met365) whose putative new reactive site mimics that of antithrombin III (ATIII) and a AT-Pittsburgh (Pl-Arg-P'1-Ser). A second variant was constructed (ra2AP△Arg364) in which the Pl-Arg364 residue was deleted, producing the new sequence Met362-Ser363-Met364-Ser365, containing 2 potential sites analogous to the Pl-P'l, Met-Ser reactive site of α2 AT. The variants and r α2 AP were expressed in CH0 cells, purified and compared with n α2 AP, α2AT and ATIII for the ability to inhibit plasmin, thrombin, trypsin and elastase. n α2 AP and r α2 AP had nearly identical inhibition constants and like ATIII did not inhibit neutrophil elastase. Without heparin both α2 APs and ATIII inhibited thrombin moderately (k1 = 2 to 4× 103 ). Bovine trypsin was neutralized by the α2 APs with k1 = 3 × 106 and by ATIII with k1 = 1 × 105. The α2APs inhibited plasmin (k1 = 2 ×107 ) much more efficiently than ATIII (K1 =2 × 103 ). In contrast, was a highly effective antielastase (k1 = 1 × 107 ), a poor plasmin and thrombin inhibitor ancl inhibited bovine trypsin with = 2 × 10. As reported by others, α2 AT-Pittsburg has greatly reduced antielastase activity and greatly enhanced antithrombin activity. Analysis of ra APAMet365 revealed little change in activity toward plasmin, trypsin and elastase. Thus, α2 AP has no absolute requirement for Met .in the P'l position in order to effectively inhibit plasmin and trypsin. The other P^ subsites appear to be spatially flexible as deletion of the natural P'l residue must displace them. Contrary to prediction a 20-fold decrease in antithrombin activity was observed rather than an enhanced activity. Analysis of rα2 AP△Arg364 showed that it is unreactive with plasmin, trypsin and thrombin, but that it has acquired a significant antielastase activity (k1 = 1.5 × 105). The exact PI residue(s) has not been determined but removal of the bulky basic Arg364 may have resulted in accessibility of the predicted reactive site(s) peptide bond(s) Met362-Ser363 or Met364-Ser365 to the active site cleft of elastase. α2AP'Enschede', a natural mutant with deficient antiplasmin activity, was shown to contain an Ala insertion between aa 353 and 357, 7 to 10 positions NH2-terminal to its reactive site (Holmes et al., this meeting). This mutation results in conversion of α2 AP'Enschede' from an inhibitor to a substrate that retains a high affinity for the active site of plasmin.