摘要:

Two major intrinsic membrane polypeptides of molecular weights 22K and 26K have been isolated and antisera for each prepared against highly purified preparations. The lack of reactivity of these antibodes in several other tissues suggests that they are unique to the lens. These antisera were used for localization of these polypeptides in adult human lenses by indirect immunofluorescent staining. Neither of the polypeptides is found in the epithelial cells; however those cells commencing differentiation show some fluorescent staining. The elongating fiber cells of the bow region show cytoplasmic staining for both 22K and 26K. This may reflect their sites of synthesis. In this region the species of 22K studied showed no localization in the membrane; however, 26K is concentrated at the membrane as evidenced by the intense band of fluorescent staining in this region. In the lens inner cortical region, there is a loss of cytoplasmic staining and both polypeptides appear to be membrane bound. This redistribution of the membrane polypeptides occurring in the inner cortex is at the site of considerable lens fiber contour alterations.

ISSN:0271-3683    

DOI:10.3109/02713688208997680

出版商:Taylor&Francis    

年代:1982

数据来源: Taylor

摘要:

The effect of topical 2.5% phenylephrine hydrochloride, an alpha adrenergie agonist, on the rate of aqueous humor flow was studied in the eyes of 22 normal human subjects. The drug and a placebo were administered by random assignment from coded containers with the fellow eye serving as the control. Intraocular pressure, anterior chamber volume, corneal thickness and the rate of clearance of topically applied fluorescein from the anterior chamber were measured. Four of the 22 subjects underwent a study of the effect of phenylephrine on the permeability to fluorescein of the blood-aqueous barrier. No statistically significant effect of the drug was found on the rate of aqueous humor flow, intraocular pressure, anterior chamber volume, corneal thickness or permeability of the blood-aqueous barrier.

ISSN:0271-3683    

DOI:10.3109/02713688208997681

出版商:Taylor&Francis    

年代:1982

数据来源: Taylor

摘要:

An unusual group of high molecular weightω-hydroxy fatty acids have been identified in the lipids of the meibomian glands of steer and humans. These acids comprise about 10% of all the acids of the steer lipid, are primarily monoenoic, and constitute three homologous series with members ranging from C30to C36. They could be important in helping to spread other meibomian gland lipids over the tear film.

ISSN:0271-3683    

DOI:10.3109/02713688208997682

出版商:Taylor&Francis    

年代:1982

数据来源: Taylor

摘要:

Spatial and temporal tuning were examined for both retinal and cortical signals using low contrast sinusoidol gratings. Maximum PERR and VECP responses occurred at the 4 Hz alternation rate and at 0.68 and 2.2 cpd, respectively. A 25% low spatial frequency attenuation (LSFA) was observed for the PERR. To test the possibility that prior inability to detect LSFA of the PERR was due to the masking of a pattern contrast response by a large amplitude local luminance response, mean luminance and optical power were varied in separate experiments. Greater relative LSFA was observed with a lower mean luminance and defocus differentially affected responses elicited by high and low spatial frequency gratings. In addition greater relative LSFA was observed when power at the second harmonic rather than amplitude was the dependent measure.We conclude that LSFA may be observed. The absence of spatial tuning in previous reports is explained by the masking of pattern contrast by local luminance responses. Detection of LSFA in the present experiments is attributed to use of stimulus conditions which minimize local luminance responses and the use of an objective response measure with a high signal-to-noise ratio, i.e., power at the second harmonic of the stimulation frequency.

ISSN:0271-3683    

DOI:10.3109/02713688208997683

出版商:Taylor&Francis    

年代:1982

数据来源: Taylor

摘要:

A new mutant line (delayed amelanotic-DAM) of domestic chicken shows an early progressive loss of choroidal and pigment epithelial melanin which leads to visual impairment, blindness and severe retinal dystrophy. Ocular amelanosis begins with an initial destruction of choroidal melanocytes, usually accompanied by choroidal inflammation. Following complete loss of chor oidal melanocytes, RPE shows a variety of pathological changes which appear to represent successive stages and include thinning, retraction, clumping, and destruction of apical processes and RPE cells. Retinal detachment, loss of cells and retinal laminar organization occur in the inner retinal layers in advanced cases of ocular amelanosis.

ISSN:0271-3683    

DOI:10.3109/02713688208997684

出版商:Taylor&Francis    

年代:1982

数据来源: Taylor

摘要:

We report here that cortisol induction of glutamine synthetase in the chick embryo retina is maximal when the glucose concentration in the culture medium is 0.2 g/1, rather than the 1 g/1 (0.1%, or 6 mM) customarily found in many commercially available media; induction is a factor of 2.1 higher at 0.2 g/1. Glutamine synthetase is known to be localized within retinal Müller cells. The pH of the medium at the end of a 24-hr culture period is generally higher (approximately 7.2) in the low-glucose medium than that found in the standard maintenance medium (pH approximately 6.8), probably indicating decreased metabolism at the lower sugar concentration. Manipulation of the culture medium components may provide a method to monitor metabolic stress responses of Müller cells.

ISSN:0271-3683    

DOI:10.3109/02713688208997685

出版商:Taylor&Francis    

年代:1982

数据来源: Taylor

摘要:

Histological evidence of retinal damage associated with the clinical observation of Retinopathy of Prematurity (ROP) grade III was documented in preterm infants receiving the minimum dosage of vitamin E recommended by the American Academy of Pediatrics (5 mg/kg/day), and exposed to high concentration/duration of oxygen at birth. Matched infants that were provided a higher oral dosage of vitamin E (100 mg/kg/day) did not develop the serious grade of retinopathy (grade III) (1,2). In this paper cytological correlates are described which substantiate pre-existing theories concerning the pathological changes associated with the development of the disease at a light microscopic level. Moreover, observations made at the elec tronmicroscopic level permit distinctions to be made concerning the newly formed retinal vessels, in treated versus non-treated infants, that have not been noted in the history of this disease. These retinal distinctions suggest that vitamin E may be efficacious in reducing the severity of ROP. Lastly, a mechanism is suggested for the action of vitamin E in reducing the severity of ROP.

ISSN:0271-3683    

DOI:10.3109/02713688208997686

出版商:Taylor&Francis    

年代:1982

数据来源: Taylor

摘要:

Three commercially available ocular decongestant products which contain varying concentrations of a vasoconstrictor (naphazoline hydrochloride) and an antihistamine (antazoline phosphate or pheniramine maleate) were tested for comfort and therapeutic efficacy. Three separate studies were performed: 1) a comfort comparison, 2) a vasoconstrictive efficacy test using anin vivomodel of allergic conjunctivitis Induced by compound 48/80, and 3) a clinical trial of therapeutic efficacy In patients with allergic/hay fever conjunctivitis. The three preparations were found to vary greatly In patient comfort and acceptability, but were not different in their ability to amellorate the itching, tearing, redness, edema, and discomfort that occur In human allergic conjunctivitis.

ISSN:0271-3683    

DOI:10.3109/02713688208997687

出版商:Taylor&Francis    

年代:1982

数据来源: Taylor