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PubMed1982

T and B lymphocytes in the aqueous humor of patients with uveitis.

Sixteen patients with different types of uveitis (ocular toxoplasmosis, chronic cyclitis, Vogt-Koyanagi-Harada syndrome, Behçet's syndrome, ocular herpes, and a probable nematode) had the aqueous humor withdrawn and had the number of T, B, and null lymphocytes assessed. T and B lymphocytes were identified by rosette formation with sheep erythrocytes and with human erythrocytes sensitized with IgM antibody and complement or zymosan-C3 complexes, respectively. A much higher number of T lymphocytes than B lymphocytes was observed in all cases. The results were not influenced by treatment with steroids or immunosuppressive drugs for local, periocular, or systemic effects.

Aqueous Humor↗
PubMed2004

Aqueous humor dynamics in monkeys after topical 8-iso PGE(2).

PURPOSE: To determine in normotensive cynomolgus monkeys, the effects of topical 8-iso prostaglandin (PG)E(2) on intraocular pressure (IOP), aqueous humor formation (AHF), uveoscleral outflow (Fu), and total and trabecular outflow facility. METHODS: IOP was measured by Goldmann applanation tonometry under ketamine anesthesia after single or twice-daily topical treatments with 8-iso PGE(2). With animals under pentobarbital anesthesia, AHF and flow to blood (equated to trabecular outflow) were determined by anterior chamber perfusion with radioactively labeled albumin solution. Fu and trabecular outflow facility were calculated from these measurements. Total outflow facility was measured by two-level, constant-pressure perfusion. RESULTS: IOP was not significantly changed after single or multiple 10- micro g doses of 8-iso PGE(2). The 25- micro g dose significantly decreased IOP by 2 to 3 mm Hg compared to the contralateral vehicle-treated control 4 to 6 hours after a single dose and by 3 to 5 mm Hg within 1.5 hours after twice-daily treatments for 4 to 5 days. Total outflow facility corrected for control eye washout was increased by an apparent 37% (P < 0.02, n = 7) from 2 to 3.5 hours after the ninth dose, largely due to outlier values obtained in one monkey. Isotope studies performed after twice-daily treatments totaling 9 to 29 doses showed no change in AHF, trabecular outflow facility, or total outflow facility. Relative to AHF, trabecular outflow was significantly decreased, and the calculated Fu was significantly increased when all data were analyzed. CONCLUSIONS: The present findings are consistent with lowering of IOP by 8-iso PGE(2), primarily by increasing Fu. A direct effect on the trabecular meshwork was not indicated by these in vivo studies.

Administration, Topical↗
PubMed2006

Regulation of connective tissue growth factor expression in the aqueous humor outflow pathway.

PURPOSE: Connective Tissue Growth Factor (CTGF) is an inducible secretory protein known to regulate proliferation and extracellular matrix production in various cell types. We hypothesize that CTGF plays a critical role in the physiological regulation of aqueous humor outflow through the trabecular meshwork (TM) by influencing extracellular matrix synthesis and organization. METHODS: To determine the expression of CTGF in tissues of the aqueous outflow pathway, cells obtained from human TM and Schlemm's Canal (SC) were analyzed by PCR and western blot analysis. To understand the regulation of CTGF expression in TM cells, TM cells were either treated with various physiologic factors or subjected to cyclical stretch prior to analysis of CTGF expression by RT-PCR and western blot analysis. To study the effect of increased intraocular pressure on CTGF production, we perfused porcine eyes at high pressure (50 mm Hg) for 5 h, followed by analysis of CTGF expression by RT-PCR and western blotting. RESULTS: Treatment of human TM cells treated with either serum or transforming growth factor-beta 1 led to a robust stimulation, compared to thrombin, lysophosphatidic acid (LPA), and dexamethasone, which elicited a relatively moderate induction of CTGF expression. Both high pressure perfusion and mechanical stretch were associated with increases in the levels of CTGF at the protein and transcript levels. CONCLUSIONS: This study demonstrates that CTGF expression in TM cells is modulated by several physiological agonists and by increased ocular pressure and mechanical stretch. These results suggest that the regulation of CTGF expression within tissues of the outflow pathway may play a role in the homeostasis of intraocular pressure, possibly by modulation of ECM production in these tissues.

Animals↗
PubMedDate not supplied

Penetration of amikacin into aqueous humor of rabbits.

Amikacin is an aminoglycoside antibiotic that has poor corneal penetration due to its hydrophilic properties. The purpose of this study was to compare and evaluate the penetration of amikacin sulfate into aqueous humor of the rabbit eye when applied by different routes and concentrations, namely 100 or 250 mg/ml topical fortified amikacin eye drops, 100 or 250 mg/ml amikacin-embedded soft contact lenses and 25 mg subconjunctival amikacin injection. One hour after application, amikacin was not detectable in any of the 100 mg/ml concentration groups. High levels of amikacin above the minimum inhibitory concentration for susceptible bacteria were detected when applied subconjunctivally and by 250 mg/ml topical fortified routes. Topical fortified amikacin 250 mg/ml reached the highest value in the aqueous (p < 0.05). Our results point out the poor corneal penetration of amikacin in standard concentrations from the intact rabbit cornea and that subconjunctival injections might provide satisfactory penetration.

Administration, Topical↗
PubMed1984

Effect of antineoplastic drugs on fibroblast proliferation in rabbit aqueous humor.

An assay is described to test the ability of antineoplastic agents to slow fibroblast growth. The effect of bleomycin sulfate, cytosine arabinoside (cytarabine), and 5-fluorouracil on suppression of fibroblast proliferation in 20% rabbit aqueous humor was studied in vitro. All of the drugs exhibited some suppression of fibroblast proliferation at differing doses. The choice of target cell, however, was an important factor in the dose responses obtained.

Animals↗
PubMed2005

Effects of dinucleoside polyphosphates on trabecular meshwork cells and aqueous humor outflow facility.

The most important risk factor for the development of glaucoma is elevated intraocular pressure (IOP). Hypotensive drugs decrease IOP, preventing optic nerve damage and further vision loss. The balance between aqueous humor (AH) production and drainage determines IOP, and problems in AH outflow pathways are associated with open-angle glaucoma development. Previous studies have shown the presence of diadenosine tetraphosphate (Ap(4)A) and pentaphosphate (Ap(5)A) in the AH. Topic application of Ap(4)A to the cornea decreased IOP, whereas Ap(5)A increased it. Because dinucleoside polyphosphates stimulate P2Y purinergic receptors, we studied their presence in trabecular meshwork (TM) cells. Additionally, the effects of diadenosine polyphosphates (Ap(n)As; n = 3-5) and Up(4)U (P(1),P(4)-(diuridine 5')-tetraphosphate; INS365) in outflow facility were tested. P2Y(1), P2Y(2), and P2Y(4) receptors were detected in TM cells by Western blot and immunocytochemistry. In TM cells, Ap(3)A, Ap(4)A, and Ap(5)A induced discrete intracellular calcium concentration ([Ca(2+)](i)) mobilizations compared with higher and more sustained [Ca(2+)](i) mobilizations after Up(4)U application. In bovine ocular anterior segments perfused at constant pressure, 1 microM Ap(3)A or Ap(4)A increased outflow facility, whereas Up(4)U or Ap(5)A did not modify it. 2-MeSADP, a selective P2Y(1) agonist, induced outflow facility increases similar to those obtained after Ap(3)A and Ap(4)A, and these were prevented by addition of the selective P2Y(1) receptor antagonist MRS-2179 (2'-deoxy-N(6)-methyladenosine-3',5'-diphosphate). Our results demonstrate that the hypotensive effect of Ap(4)A and other dinucleotides is mediated, at least in part, by increasing trabecular outflow facility through activation of P2Y(1) receptors. The latter would seem to be an interesting target in the development of antiglaucomatous drugs to selectively increase AH outflow.

Animals↗
PubMed1984

Comparative anesthetic effects on aqueous humor dynamics in the cynomolgus monkey.

Cynomolgus monkeys were anesthetized with either intravenous (IV) ketamine hydrochloride, IV ketamine and intramuscular (IM) diazepam, IM methohexital sodium and IM pentobarbital sodium, or endotracheal halothane. Intraocular pressure, aqueous humor flow rate (F), anterior chamber volume, corneal endothelial transfer coefficient (Ka), and anterior chamber elimination coefficient (Ke) were determined noninvasively, using applanation tonometry, keratometry, pachymetry, and fluorophotometry. Arterial blood gases (ABG), acid-base balance, and mean arterial pressure (MAP) were monitored. The IOP was highest with ketamine and lowest with pentobarbital. The F and Ke were about 30% lower with halothane than with the other regimens, while Ka was highest with ketamine. The ABG and MAP were within normal physiologic limits with the three noninhalation regimens; pH was within normal limits with all four regimens. The MAP was lowest and PO2 highest with halothane, while pH was highest with pentobarbital.

Acid-Base Equilibrium↗
PubMedDate not supplied

Elevated soluble Fas in aqueous humor of patients with Behcet's uveitis: correlation with uveitis severity.

PURPOSE: To examine the role of soluble Fas (sFas) in patients with Behcet's uveitis. METHODS: We measured the sFas levels in both sera and aqueous humor (AH) of patients (n = 40) with uveitis and of non-uveitis controls (n = 27) using an enzyme-linked immunosorbent assay. The patients with uveitis comprised 24 with Behcet's disease, 6 pan-uveitis, 5 anterior uveitis, 2 lens-induced uveitis, 1 Vogt-Koyanagi-Harada disease, 1 sarcoidosis, and 1 retinal vasculitis. The severity of uveitis was determined by the Hogan grading method (0--4 grade) at the time of sampling. RESULTS: The concentration of aqueous sFas in uveitis patients was significantly higher than that in non-uveitis controls, while there was no difference in the serum concentration of sFas between the two groups. In the paired samples of serum and AH, obtained simultaneously, the aqueous sFas levels were higher than serum Fas levels in patients with uveitis, whereas the non-uveitis controls displayed significantly lower sFas levels in AH than in the serum. The sFas levels in AH or serum were not different between Behcet's uveitis patients and non-Behcet's uveitis patients. However, in patients with Behcet's uveitis, circulating sFas strongly correlated with aqueous sFas, which was not so in those with non-Behcet's uveitis. Patients (n = 29) with more active (grade greater-than-or-equal 2) uveitis had significantly higher levels of aqueous sFas than those (n = 11) with less active (grade < 2) uveitis. After treatment with steroids and/or immunosuppressive agents, aqueous sFas levels decreased in parallel with a reduction in the number of inflammatory cells. CONCLUSIONS: The levels of sFas were elevated in patients with Behcet's uveitis and correlated well with the uveitis severity in these patients.

Adolescent↗
PubMed1994

Immunoreactive vasoactive intestinal peptide contributes to the immunosuppressive activity of normal aqueous humor.

Suppression of immune-mediated inflammation within the normal anterior chamber (AC) of the eye is in part the result of active suppression of effector T cell activities by immunosuppressive cytokines found in aqueous humor (AqH), the fluid filling the AC. There are immunosuppressive factors found in the low m.w. fraction (< 5 kDa) of AqH, including the neuropeptide alpha-melanocyte-stimulating hormone (alpha-MSH). In seeking other factors, we now report that the neuropeptide vasoactive intestinal peptide (VIP) is also present in normal AqH. VIP immunoreactivity was found in normal rabbit eyes at a concentration of 12 +/- 1 nM. At this intraocular concentration, VIP suppressed Ag-stimulated lymph node cell (LNC) proliferation and IFN-gamma production in vitro. Although suppression of LNC proliferation was not neutralized by absorption of VIP from the low m.w. fraction of AqH, removal of VIP did neutralize suppression of IFN-gamma production by this fraction of AqH. Absorption of both VIP and alpha-MSH from this fraction of AqH permitted production of IFN-gamma by Ag-stimulated LNC that was no different than absorbing VIP alone. The low m.w. fraction of AqH absorbed of either alpha-MSH and VIP lost its ability to suppress local adoptive transfer of delayed-type hypersensitivity. The results suggest that VIP is an important immunosuppressive neuropeptide in AqH. Neuropeptides play an important role in ocular immune privilege and creation of an intraocular immunosuppressive microenvironment.

Animals↗
PubMed2006

Measuring triamcinolone acetonide in aqueous humor by gas chromatography-electron-capture negative-ion mass spectrometry.

Intravitreal triamcinolone acetonide (IVTA) injection has been used in the treatment of various posterior segment diseases. One of the side effects of IVTA is raised intraocular pressure, which may be secondary to triamcinolone acetonide (TAA)'s effects on the trabecular meshwork that affects aqueous outflow. In order to study the biological effects of TAA on the trabecular meshwork, we firstly need to reliably and accurately detect the concentration of TAA in tissue cells or fluids. In this study we have described a technique of using gas chromatography-electron-capture-negative-ion mass spectrometry (GC-NCI-MS) to develop a simple, sensitive, selective and validated method to detect TAA in aqueous humor (AH) of rabbits following IVTA and subconjunctival TAA injections. We derivatized TAA from extracted aqueous sample by acetic anhydride and BSTFA, respectively, and analyzed by GC-NCI-MS. The detection limit was 0.3ng/ml, linearity over 0.995 from 0 to 300ng/ml. The reproducibility ranged from 10.4 to 3.9 for concentrations from 3 to 300ng/ml, and recovery was over 95% for the concentrations 10, 60, and 200ng/ml. No interference was found from 159 aqueous samples. There was no TAA residue carried to the next injection from previously high concentration injection, 10,000ng/ml. We have provided an alternative, rapid, and robust method other than LC-MS-MS for TAA detection in AH.

Animals↗
PubMed1984

[Passage of ceftriaxone in the aqueous humor and tears. Comparison with other beta-lactams].

The intraocular distribution of ceftriaxone (a new cephalosporin of the third generation) was studied in 33 patients undergoing cataract surgery. The mean level of antibiotic in the aqueous humor was of 0,53 micrograms/ml (1.25% of the serum level), in the tears show an average rate of 5.75 micrograms/ml (13% of the serum level) was found. A study of the kinetics in the tears shows increasing levels for the first 18th hours.

Adult↗
PubMed2006

Multiplex cytokine detection versus ELISA for aqueous humor: IL-5, IL-10, and IFNgamma profiles in uveitis.

PURPOSE: The purpose of this study was to determine levels of IL-2, -4, -5, -10, TNF-alpha, and IFN-gamma in aqueous humor (AH) from patients with active panuveitis, anterior uveitis (AU), and noninflammatory controls by using a flow cytometric mutiplex array (CBA) and to compare with results from ELISA. METHODS: Pooled normal AH was spiked with six cytokines at decreasing concentrations for evaluating the CBA. AH was also obtained from 10 controls (cataract patients) and 36 patients with active uveitis. Cell-free supernatants were added to a cocktail of capture beads and detector antibodies or to antibody-coated wells for CBA and ELISA determination, respectively. RESULTS: CBA demonstrated greater sensitivity for detecting IL-4, IL-10, and TNF-alpha than with ELISA. Increased IFN-gamma was detected in both AU and panuveitis groups compared with controls (P < 0.01). IL-10 was higher in the panuveitis group on steroids (P < 0.01). IL-5 was detected in the control (P < 0.01) and AU groups (P < 0.05) but was undetectable in the panuveitis group (n = 10). Correlations between IFN-gamma and IL-10 were found in all uveitis groups (P < 0.01) but not in controls, whereas TNF-alpha correlations with IL-4/IFN-gamma were obtained in controls but not in the uveitis groups (P < 0.01). CONCLUSIONS: It was possible to measure cytokines titrated into normal AH specimens by CBA, and a greater number of cytokines were detected with increased sensitivity than with ELISA. Elevated IFN-gamma in active uveitis and decreased IL-5 in posterior uveitis suggest Th1 polarity is more marked, with greater uveal tract involvement. The increased IL-10 in the steroid treated group suggests glucocorticoid-induced IL-10 upregulation.

Adult↗
PubMed1984

Effect of topically applied forskolin on aqueous humor dynamics in cynomolgus monkey.

Topical administration of a 1% forskolin suspension significantly reduced intraocular pressure in cynomolgus monkey eyes. The fall in intraocular pressure was associated with a significant (P less than 0.01) decrease in aqueous humor flow measured by a fluorophotometric technique. No significant change was found in tonographic outflow facility or pupillary diameter. A loss of effect on intraocular pressure to subsequent doses of 1% forskolin suspension occurred in cynomolgus monkeys by the third day of twice-a-day treatment.

Administration, Topical↗