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Abhijith K. Anil - One of the best experts on this subject based on the ideXlab platform.
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Proteomics of human Aqueous Humor.
Omics : a journal of integrative biology, 2015Co-Authors: Krishna R Murthy, Pavithra Rajagopalan, Sneha M. Pinto, Jayshree Advani, Praveen R. Murthy, Renu Goel, Yashwanth Subbannayya, Lavanya Balakrishnan, Mahashweta Dash, Abhijith K. AnilAbstract:The Aqueous Humor is a colorless, transparent fluid that fills the anterior chamber of the eye. It plays an important role in maintaining the intraocular pressure and providing nourishment to the lens and cornea. The constitution of the Aqueous Humor is controlled by the blood-Aqueous barrier. Though this ocular fluid has been extensively studied, its role in ocular physiology is still not completely understood. In this study, Aqueous Humor samples were collected from 250 patients undergoing cataract surgery, subjected to multiple fractionation strategies and analyzed on a Fourier transform LTQ-Orbitrap Velos mass spectrometer. In all, we identified 763 proteins, of which 386 have been identified for the first time in this study. Sorbitol dehydrogenase (SORD), filensin (BFSP1), and phakinin (BFSP2) are some of the proteins that have not been previously reported in the Aqueous Humor. Gene Ontology analysis revealed 35% of the identified proteins to be extracellular, with a majority of them involved in cell communication and signal transduction. This study comprehensively reports 386 novel proteins that have important potential as biomarker candidates for future research into personalized medicine and diagnostics aimed towards improving visual health.
Otto Closs - One of the best experts on this subject based on the ideXlab platform.
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Quantitation of alpha crystallin in human Aqueous Humor by radioimmunoassay.
Acta Ophthalmologica, 2009Co-Authors: Hans Otto Sandberg, Ivar Folling, Otto ClossAbstract:A method for quantitation of alpha crystallin in individual samples of human Aqueous Humor by radioimmunoassay is described. The concentration of alpha crystallin in Aqueous Humor from 48 eyes with cataract and three eyes with clear lenses was at or below 0.006 μg/ml. Two samples from eyes with heterochromic cataract contained 0.011 and 0.012 μg/ml, respectively. Alpha crystallin is probably not among those lens proteins described earlier in normal human Aqueous Humor.
Robert N Weinreb - One of the best experts on this subject based on the ideXlab platform.
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Aqueous Humor dynamics in mice
Investigative Ophthalmology & Visual Science, 2003Co-Authors: Makoto Aihara, James D Lindsey, Robert N WeinrebAbstract:PURPOSE: To assess Aqueous Humor dynamics in mouse eyes. METHODS: Aqueous Humor dynamics of NIH Swiss White mouse were assessed with an injection and aspiration system, using fine glass microneedles. Intraocular pressure (IOP) was measured by a microneedle connected to a pressure transducer. Episcleral venous pressure (EVP) was measured by gradually lowering intracameral pressure until blood reflux into Schlemm's canal was observed. Outflow facility (C) was determined based on constant pressure perfusion measurements obtained at two different IOPs. Aqueous volume (V(a)) was determined by direct measurement of aspirated Aqueous Humor. Aqueous Humor production (F(a)) was measured by the dilution method with rhodamine-dextran. Conventional and uveoscleral outflow (F(c) and F(u), respectively), as well as the turnover rate of Aqueous Humor, were also calculated. RESULTS: IOP and EVP were 15.7 +/- 2.0 and 9.5 +/- 1.2 mm Hg, respectively (n = 20). F(a) was 0.18 +/- 0.05 microL/min (mean +/- SD; n = 8). C was 0.0051 +/- 0.0006 microL/min per mm Hg (n = 8). Estimated F(c) and F(u) were 0.032 and 0.148 microL/min, respectively. F(c) was 18% of F(a). F(u) was 82% of F(a). V(a) was 5.9 +/- 0.5 microL (n = 8). The calculated turnover rate of Aqueous Humor was 2.5%. CONCLUSIONS: The mouse eye has similar Aqueous production and Aqueous Humor turnover rate as the human eye. The presence of both conventional and uveoscleral outflow suggests that the mouse is a useful model system for further investigations of the biology of Aqueous dynamics.
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Physiological factors in the circadian rhythm of protein concentration in Aqueous Humor.
Investigative ophthalmology & visual science, 1998Co-Authors: John H.k. Liu, James D Lindsey, Robert N WeinrebAbstract:PURPOSE. The authors addressed three questions concerning the circadian rhythm of Aqueous Humor protein concentration in rabbits. First, is there an endogenous oscillator for this circadian rhythm? Second, does a circadian rhythm occur for individual Aqueous Humor protein components? Third, what is the role of ocular sympathetic nerves, which are more active in the dark phase, in this circadian rhythm? METHODS. Adult New Zealand albino rabbits were entrained to a daily 12-hour light/12-hour dark cycle. Under a constant dark environment for 24 hours, rabbits were killed at 4-hour intervals, beginning at 2 hours before the onset of the subjective light phase. Eight rabbits were used for each of the six time points. Aqueous Humor and vitreous Humor were collected, and their protein concentrations were determined. Major Aqueous Humor protein components were resolved by polyacrylamide gel electrophoresis (PAGE), stained with silver reagent, and analyzed using densitometry. Another group of eight light-dark- entrained rabbits underwent unilateral transection of the cervical sympathetic trunk. Three weeks after the operation, the circadian elevation of intraocular pressure (IOP) at 2 hours into the dark phase was determined for both eyes. Rabbits were later killed at this time point, and total protein concentrations in Aqueous Humor and vitreous Humor were determined in both eyes. Major Aqueous Humor protein components in both eyes were resolved by PAGE and were compared. REsuLTs. In light-dark-entrained rabbits, a circadian rhythm of protein concentration appeared in the Aqueous Humor under a constant dark environment. Total protein concentration in Aqueous Humor increased sharply in the early subjective light phase, remained relatively high during the remainder of the subjective light phase, and decreased in the subjective dark phase. Analyses of albumin and other abundant proteins in the Aqueous Humor showed that all of them varied similarly in a circadian pattern. In contrast, total protein concentration in the vitreous Humor remained unchanged. In rabbits with unilaterally decentralized ocular sympathetic nerves, total protein concentrations in the Aqueous Humor and the vitreous Humor in the early dark phase showed no difference between the two eyes. In addition, there was no difference in individual Aqueous Humor protein concentration between the two eyes. However, the nocturnal IOP elevation in the decentralized eye was less than that in the contralateral, intact eye. CoNcLUsioNs. The circadian rhythm of Aqueous Humor protein concentration in rabbits can continue without an external signal of dark-light change, indicating the existence of an endogenous oscillator. A similar circadian rhythm occurs for various major Aqueous Humor protein components. The nocturnal increase in ocular sympathetic activities plays a limited role in the circadian rhythm of Aqueous Humor protein concentration.
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Lysosomal enzyme activity in human Aqueous Humor
Clinica chimica acta; international journal of clinical chemistry, 1991Co-Authors: Robert N Weinreb, Shyun Jeng, Arnold L. MillerAbstract:Abstract Activity of the lysosomal enzymes N-acetyl-β-D-hexosaminidase, α-D-mannosidase, β-D-glucuronidase, and β-D-galactosidase was detected in Aqueous Humor from eyes undergoing intraocular surgery. There was no correlation between lysosomal enzyme activity and age. Lysosomal enzyme activity in human Aqueous Humor most likely reflects the total amount of lysosomal enzyme activity released by ocular tissues surrounding the anterior chamber including the cornea, trabecular meshwork, ciliary body, iris, and lens. Their release into Aqueous Humor may have a role in regulating Aqueous outflow in normal and glaucomatous eyes.
Richard F. Brubaker - One of the best experts on this subject based on the ideXlab platform.
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Aqueous Humor dynamics in patients with diabetes mellitus
American Journal of Ophthalmology, 1995Co-Authors: Lillinger Larsson, John M Pach, Richard F. BrubakerAbstract:Purpose We measured Aqueous dynamic variables in subjects with diabetes mellitus and correlated them with severity of retinopathy and metabolic control to determine whether diabetes affects the anterior circulation of the eye as it affects the posterior (retinal) circulation. Methods Sixty-one subjects with diabetes mellitus type 1 and 60 subjects with diabetes mellitus type 2 were recruited from the active practice of the Mayo Clinic. Thirty-two normal subjects, divided by age into two overlapping groups of 20 each, served as contemporaneous control subjects. The diabetic subjects were stratified into four groups according to severity of retinopathy. Aqueous Humor flow was measured by clearance of topically applied fluorescein with a spectrofluorophotometer; outflow facility was measured by tonography; and intraocular pressure was measured by applanation tonometry. Results In type 1 diabetics, the mean intraocular pressure was slightly greater (14 ± 3 mm Hg), compared with control subjects (12 ± 2 mm Hg [P = .002]), while Aqueous Humor flow was slightly less (2.5 ± 0.6 μl/min), compared with control subjects (2.9 ± 0.5 μl/min [P = .023]). In type 2 diabetics, the intraocular pressure was 14 ± 3 mm Hg, which did not differ from that of control subjects (14 ± 3 mm Hg [P = .258]). Aqueous Humor flow in type 2 diabetics (2.5 ± 0.7 μl/min) did not differ significantly from that of the control group (2.5 ± 0.7 μl/min [P = .961]). Tonographic facility of outflow was not significantly different in type 1 and type 2 diabetics and the control subjects. There was no significant correlation in Aqueous Humor flow, intraocular pressure, or tonographic facility of outflow to severity of retinopathy or hemoglobin A 1c in either type 1 or type 2 diabetics. Conclusion The dynamics of Aqueous Humor are not affected to any clinically significant extent in the early or middle stages of diabetic retinopathy. However, there is a tendency toward less Aqueous Humor flow in the advanced stages of retinopathy.
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Effect of Desmopressin on Aqueous Humor Flow in Humans
American Journal of Ophthalmology, 1993Co-Authors: Suzanne R. Viggiano, Charles F. Abboud, Richard F. BrubakerAbstract:The rate of Aqueous Humor flow was studied in 17 human subjects with neurogenic diabetes insipidus. Flow was measured by fluorophotometry on two consecutive afternoons. The first day, subjects used desmopressin to control their diuresis; on the second day, subjects did not use desmopressin and had uncontrolled diuresis. On both days, one eye was created with the beta-adrenergic antagonist, timolol. With desmopressin, the rate of Aqueous Humor flow in the untreated eye was 2.53 ± 0.79 ul/min (mean ± standard deviation) and in the timolol-treated eye was 1.69 ± 0.40 ul/ min. Without desmopressin, the rate of Aqueous Humor flow in the untreated eye was 2.34 ± 0.69 ul/min and in the timolol-treated eye was 1.53 ± 0.43 ul/min. Thus, the use of desmopressin was associated with a slightly higher rate of Aqueous Humor flow in both the normal and the beta-adrenergically inhibited eye (P = .05), and the suppression of Aqueous Humor flow associated with beta-adrenergic inhibition occurred with and without antidiuretic hormone (P The observed differences in Aqueous Humor flow on the two days could have been caused by a direct effect on the eye or to indirect effects, such as the change in plasma osmolality, which changed from 291 ± 6 mOsm on the desmopressin day to 299 ± 8 mOsm on the desmopressin-abstention day (P
Joao Antonio Prata - One of the best experts on this subject based on the ideXlab platform.
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Aqueous Humor dynamics in rats
Graefes Archive for Clinical and Experimental Ophthalmology, 1996Co-Authors: Andre Mermoud, George Baerveldt, Donald S. Minckler, Joao Antonio PrataAbstract:• Background: In order to determine normal outflow facility and Aqueous Humor production values in Lewis rats, we established methods of measuring Aqueous Humor dynamics in this animal. • Methods: Outflow facility was determined using anterior chamber infusion with constant pressure. Aqueous Humor production was determined by a technique of dilution with FITC-albumin. • Results: The mean outflow facility was 0.044±0.01 μl/min/mmHg. Rats weighing less than 300 g had lower values than did rats weighing more than 300 g (0.034±0.006 μl/min/mmHg vs 0.050±0.015 μl/min/mmHg,P=0.009). The mean Aqueous Humor production was 0.350±0.110 μl/min. The turnover rate of Aqueous Humor production per minute was 2.23%. • Conclusions: Anterior chamber infusion with constant pressure and the FITC-albumin method allow measurement of the outflow facility and Aqueous Humor production in Lewis rats. These methods may be useful in assessing Aqueous Humor dynamics when rats are used as a glaucoma model.
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Aqueous Humor dynamics in rats.
Graefe's archive for clinical and experimental ophthalmology = Albrecht von Graefes Archiv fur klinische und experimentelle Ophthalmologie, 1996Co-Authors: Andre Mermoud, George Baerveldt, Donald S. Minckler, Joao Antonio PrataAbstract:In order to determine normal outflow facility and Aqueous Humor production values in Lewis rats, we established methods of measuring Aqueous Humor dynamics in this animal. Outflow facility was determined using anterior chamber infusion with constant pressure. Aqueous Humor production was determined by a technique of dilution with FITC-albumin. The mean outflow facility was 0.044 +/- 0.01 microliter/min/mmHg. Rats weighing less than 300 g had lower values than did rats weighing more than 300 g (0.034 +/- 0.006 microliter/min/mmHg vs 0.050 +/- 0.015 microliter/min/mmHg, P = 0.009). The mean Aqueous Humor production was 0.350 +/- 0.110 microliter/min. The turnover rate of Aqueous Humor production per minute was 2.23%. Anterior chamber infusion with constant pressure and the FITC-albumin method allow measurement of the outflow facility and Aqueous Humor production in Lewis rats. These methods may be useful in assessing Aqueous Humor dynamics when rats are used as a glaucoma model.
