摘要:

The uric acid peak among the compounds in aqueous humor separated by high pressure liquid chromatography was identified by its retention time, the UV absorbance characteristics, and the effect of uricase. The uric acid concentration in the aqueous humor of normal monkey, human eyes with cataract, and human eyes with glaucoma are<0.05, 1.7±0.3, and 3.8±0.4 respectively. The significance of high uric acid concentration in glaucoma is discussed.

ISSN:0271-3683    

DOI:10.3109/02713688209019992

出版商:Taylor&Francis    

年代:1982

数据来源: Taylor

摘要:

In designing ester prodrugs to improve corneal drug bioavailability, it is important to consider the influence of chain length on both corneal permeation and hydrolysis of the prodrug. However, the second factor has received relatively little attention. The purpose of this study was to evaluate whether the ocular hydrolysis of a homologous series ofα-andβ-napthyl esters was influenced by chain length. Solutions of each ester were incubated with selected ocular tissues and fluids of adult albino rabbits. For theα-series peak hydrolytic rate was reached at the caproate (C6) ester, coinciding with minimization in the value of the Michaelis-Menten constant (Km) and maximization in the value of maximum velocity (Vmax). For theβ-series peak hydrolytic rate was reached at the valerate (C5) ester. In contrast to theα-series this was primarily due to a large increase in value for Km. These findings indicate that the rate of ocular esterase-mediated hydrolysis varies within a homologous series of esters, and that this chain length dependency is influenced by the chemical nature of the parent compound.

ISSN:0271-3683    

DOI:10.3109/02713688209019993

出版商:Taylor&Francis    

年代:1982

数据来源: Taylor

摘要:

A technique for measuring the increase in conjunctival thickness which accompanies a clinically relevant, topically induced model of ocular anaphylaxis was developed and was compared with the determination of an increase in percent of degranulated mast cells in affected tissue. Twenty rats immunized with egg albumin were topically challenged with egg albumin solution applied to one eye and with phosphate-buffered saline applied to the other eye. Clinical signs of edema and erythema were not seen in ocular tissues undergoing anaphylaxis. However, both conjunctival thickness and percent of degranulated mast cells were significantly greater in antigen-challenged tissues than in buffer-challenged tissues. Amount of edema correlated significantly with amount of mast cell degranulation. Conjunctival thickness served as a reliable indicator of anaphylaxis. The measurement of topically induced anaphylaxis by evaluating the increase in conjunctival thickness was simpler, faster, and less expensive than the evaluation of anaphylaxis by the increase in the percent of degranulated mast cells in the same tissues.

ISSN:0271-3683    

DOI:10.3109/02713688209019994

出版商:Taylor&Francis    

年代:1982

数据来源: Taylor

摘要:

The ontogeny ofα-,β-, andδ-crystallin antigens in the developing lens of mallard(Anaa platyrhynchos)was investigated by indirect immunofluorescence using specific antibodies to mallardα-,β-, andδ-crystallins raised in rabbits.The IgG fraction from each antiserum was isolated by affinity chromatography usign Protein A Sepharose CL-4.B. Fluoresceine (FITC) or rhodamine (TRITC) conjugated goat anti rabbit (GAR)γ-globulin was used as the secondary antibody.The results show thatα-,β-, andδ-crystallins appear simultaneously in the developing mallard lens and are detectable from 66 hr (stage 15/16). This situation is different from the chick whereδ-is known to appear first followed byβ-, andα-. This could be due to species variation.In the epithelium, however, as in the chick,δ-emerges first followed byβ-, andα-but rather late when compared with the chick and this seems probably due to a difference in the incubation time between the two species.Results from immunofluorescence and Tris-SDS gel electrophoresis demonstrate thatαA subunit of theα-crystallin appears much earlier than theαB subunit.We also found that the newly discoveredε-crystallin (18) appears long after the three major crystallin classes.

ISSN:0271-3683    

DOI:10.3109/02713688209019995

出版商:Taylor&Francis    

年代:1982

数据来源: Taylor

摘要:

The intracellular pathway by whichβ-adrenergic agonists and antagonists affect aqueous humor dynamics involves the intracellular mediator, cyclic AMP. We have therefore tested the activity of forskolin, a direct activator of adeny-late cyclase, in rabbits.Following a 15 minin vitroincubation in the presence of forskolin (15μM) and isobutylmethylxanthine, a 10 fold increase in cyclic AMP was found in both rabbit iris-ciliary body and scleral-trabecular rings relative to controls.Following an intracameral injection of forskolin (10μg) a time-dependent decrease in intraocular pressure was observed, which reached a mean decrease of 5 mm Hg at 4 hr in unanesthetized rabbits. Outflow facility was measured in anesthetized rabbits by constant pressure perfusion before injection and 1 hr after injection of either forskolin (10μg) or control vehicle. Forskolin caused an approximate doubling of outflow facility (0.41μl/min/mm Hg) compared to the preinjection mean value. Control vehicle, ethyl alcohol, caused a statistically insignificant increase in outflow facility. At this concentration of forskolin, the integrity of the blood-aqueous barrier was normal as measured by protein and fluorescein entry into the aqueous humor.These results indicate that agents which directly activate adenylate cyclase are effective at increasing outflow facility and decreasing TOP.

ISSN:0271-3683    

DOI:10.3109/02713688209019996

出版商:Taylor&Francis    

年代:1982

数据来源: Taylor

摘要:

It has been shown that illumination of rod outer segment suspension in the presence of photosensitizers (methylene blueλ≥620 run; retinal 370≥λ≥390 nm) results in chemical modification of the lipid and protein components of the photoreceptor membranes. This modification can be registered by accumulation of lipid peroxidation (LPO) products as well as oligomerisation of rhodopsin and a decrease of rhodopsin thermal stability. These effects are prevented by′02-quenchers and free radical scavengers. It has been found that the electric activity (ERG) of isolated frog retina is inhibited due to photosensitized generation of′02 which can be overcome by preliminary addition of′03-quenchers and free radical scavengers to the incubation medium. The LPO products are accumulated in the retinae of rats exposed to high intensity lightin vivo.It is concluded that′02 and LPO are involved in light-induced damage of the retina.

ISSN:0271-3683    

DOI:10.3109/02713688209019997

出版商:Taylor&Francis    

年代:1982

数据来源: Taylor

摘要:

Herpes simplex virus Type 1 (HSV-1) inoculated intracamerally (IC) into the anterior chamber of BALB/c eyes induces anterior chamber associated immune deviation (ACAID) in which T cell-mediated delayed type hypersensitivity (DTK) responses to HSV-1 are impaired while B cell-mediated anti-HSV neutralizing antibody responses are intact or enhanced.

ISSN:0271-3683    

DOI:10.3109/02713688209019998

出版商:Taylor&Francis    

年代:1982

数据来源: Taylor

摘要:

Artifacts related to the wave-spreading phenomenon of fluorescent structures within the eye interfere with interpretation of vitreous fluorophotometric data. A standardized protocol which minimizes such artifacts is desirable in order to reveal actual changes in vitreous fluorescence. We have devised a protocol which reduces artifacts of crystalline lens autofluorescence and“tailing”from both lens and retina by the subtraction of preinjection data from measurements taken one hour after intravenous injection of fluorescein. A method of calculation is presented, performed automatically when programmed into a computerized fluorophotometer. Distinctions among healthy subjects and different kinds of ocular pathology are sharper when artifacts are reduced and the data are normalized to plasma fluorescein concentration. Examples of data from subjects with diabetes and no retinopathy, hypertension, cystoid macular edema, panuveitis and pars planitis are presented.

ISSN:0271-3683    

DOI:10.3109/02713688209019999

出版商:Taylor&Francis    

年代:1982

数据来源: Taylor

摘要:

Pneumolysin, a cytolytic toxin fromStreptococcus pneumoniae, has previously(1) been shown to interactin vitrowith polymorphonuclear leukocytes in a variety of ways behaving as a chemotactic, lethal or lytic agent, depending on its concentration. In this study we examined the effect of leukopenia induced by administration of nitrogen mustard on the response of the rabbit to conjunctival instillation and intracorneal injection of pneumolysin. Control animals responded to instillation of crude and pure toxin with intense erythema and chemosis, and production of a thick discharge. No discharge and only traces of erythema and chemosis were noted in leukopenic animals. Leukopenic rabbits also showed a decreased capacity to respond to intracorneal injection of the toxin, particularly striking in the first 48 hours following pneumolysin injection, when opacification, discharge formation, chemosis, and erythema were found to be markedly less than in control animals. We conclude that the polymorphonuclear leukocyte plays a key role in the response of the rabbit eye to pneumococcal toxin. This system appears to be a good model for study of the inflammatory response to microbial products.

ISSN:0271-3683    

DOI:10.3109/02713688209020000

出版商:Taylor&Francis    

年代:1982

数据来源: Taylor

摘要:

Acute administration of non-selective and relatively selectiveβ-adrenoceptor agonists elicit a monophasic fall in IOP. The present study indicates that unilateral application of certainβ-agonists on consecutive days can result in marked ocular hypertension. 1-Epinephrine, reproterol and 1-isoproterenol evoked an elevation of IOP on the second and third day after topical administration of a 2% solution in normal rabbits and in rabbits with surgically transected extraocular muscles. In contrast, the same concentration of d-isoproterenol produced hypotensive responses only when administered once daily for three consecutive days. Since d-isoproterenol did not cause a rise in IOP during chronic administration, the mechanism involved in the hypertensive response appears to be more sensitive to the levorotatory form. Administration of timolol inhibited the ocular hypertensive effect of epinephrine and reproterol. Since timolol lowers IOP by depressing formation of aqueous, it is suggested that the rise in IOP following chronic administration ofβ-agonists possibly involves an increase in aqueous humor production.

ISSN:0271-3683    

DOI:10.3109/02713688209020001

出版商:Taylor&Francis    

年代:1982

数据来源: Taylor