The quantity of rhodopsin in human eyes

The content of rhodopsin in the eyes of 15 donors (30 eyes) was determined. Both retinal and pigment epithelial fractions were collected from each globe, extracted using 1% CTAB, and the rhodopsin difference spectrum of each fraction was obtained separately. The total amount of rhodopsin, obtained by summing the amounts recovered from the retinal and PE fractions, ranged from 2.00 to 11.94 (median: 6.40) nmoles/eye. Previously reported mean values of about 3.5 to 4.0 nmoles per retina have been obtained using a variety of methods. The present higher values, perhaps largely dependent on procedural details described herein, appear plausible given the known concentrations of rhodopsin in rod outer segments, rod outer segment volumes, and number of rods in the human retina.     

Relaxing retinotomies. Analysis of anatomic and visual results

The authors analyzed 100 consecutive eyes undergoing relaxing retinotomies to determine the anatomic and visual results associated with the use of this procedure. With a minimum follow-up of 6 months, 58 eyes were completely attached, 8 were partially attached (macula on), and 34 were detached. Thirty-four percent of all eyes and 50% of attached eyes obtained a visual acuity of 5/200 or greater at 6 months. At last examination, 29% of all eyes and 43% of attached eyes had a visual acuity of at least 5/200. Eyes that had circumferential relaxing retinotomies involving the entire temporal quadrant generally had lower visual acuities when compared with eyes that had relaxing retinotomies sparing the entire temporal quadrant. The use of a radial relaxing retinotomy also was associated with lower final visual acuity. The length of the relaxing retinotomy or the placement of the relaxing retinotomy either anterior or posterior to the encircling scleral buckle did not appear to influence the anatomic or visual results. Hypotony (intraocular pressure less than 5 mmHg) was seen in 43% of reattached eyes.     

Intraocular pressure and axial length in children

The intraocular pressure and the anteroposterior length of the eye are of great clinical importance for the diagnosis and management, before and after surgery, of congenital glaucoma. It is well-known that normal intraocular pressure in children is different from the normal levels in adults. We performed measurements of intraocular pressure and axial length in 141 children who had been admitted for eye problems other than glaucoma. The intraocular pressures were measured with the Perkins hand-held applanation tonometer at the beginning of general anesthesia. Simultaneously, A-scan ultra-sound measurements of the axial lengths of the eyes were made. In 10 children under the age of two years, the intraocular pressure was 11.85 +/- 1.35 mmHg. In 79 children from two to seven years, the intraocular pressure was 12.80 +/- 1.73 mmHg. In 52 children from seven to 15 years, the intraocular pressure was 13.31 +/- 1.79 mmHg. The axial lengths of the eyes in children under the age of two years, from two to seven years, and from seven to 15 years, were 21.31 +/- 0.97 mm, 22.04 +/- 0.92 mm, and 23.22 +/- 1.00 mm, respectively. These results were considered to be guidelines for measuring intraocular pressure and axial length in children suspected of having congenital glaucoma. The differences of intraocular pressures stated by other authors are due to early measurement of the intraocular pressure at the beginning of general anesthesia.     

Brightness discrimination and contrast sensitivity in chronic glaucoma--a clinical study.

The visual acuity, the difference in sensitivity of the two eyes to light (brightness ratio), and contrast sensitivity were assessed in 28 patients with chronic open angle glaucoma and compared with those of 41 normal controls of similar ages and visual acuity. The results obtained were related to the results of Tübingen visual field analysis in patients with glaucoma. Twenty-four of the 28 glaucoma patients (86%) had a significant disparity in brightness ratio between the two eyes. This was found to match the frequency of visual field loss. Moreover, there was a significant relationship between the interocular differences in brightness sense and the difference in the degree of visual field loss between the two eyes. Of the glaucoma patients 39% had sum contrast sensitivities outside the normal range for age-matched normal controls. No significant correlation was found between the interocular difference in brightness sense and the visual acuity or the interocular difference in sum contrast sensitivity. It is concluded that, in the presence of a normal visual acuity, the brightness ratio test warrants evaluation as a potential screening test for chronic open angle glaucoma.     

The effect of concomitant disorders in childhood depression on predicting treatment response

Children with pure depression or depression plus an anxiety-related disorder (n = 14) had a higher drug response rate (57%) and a lower placebo response rate (20%) when compared to children with depression plus a concomitant conduct or oppositional disorder (n = 17) (33% drug response rate and 67% placebo response rate). These findings could explain why studies of prepubertal-onset depression found no differences between drug and placebo treatment assuming that a large percentage of the studies' subjects had concomitant conduct or oppositional disorders. The children with pure depression or depression plus an anxiety-related disorder had different symptom clusters from those with depression plus a concomitant conduct or oppositional disorder. The former had more severe CDRS ratings on sleep, appetite disturbance, depressed feelings, and psychomotor retardation. In contrast, those with a concomitant conduct or oppositional disorder had shorter attention spans and were more likely to disturb other children (based on Conners scale scores).     

Distribution and disposition of trospectomycin sulfate in the in vivo rat, perfused rat liver, and cultured rat hepatocytes

Trospectomycin sulfate is an experimental, aminocyclitol antibiotic. It has been shown in preclinical, chronic safety studies in the dog and rat to elicit a reversible, lysosomal phospholipidosis in liver. The present experiments were conducted to characterize the tissue distribution and disposition of 3H]trospectomycin sulfate in the male rat, perfused rat, perfused rat liver, and cultured rat hepatocytes. Following a 5 mg/kg iv dose to four rats, approximately 70% of the dose was recovered within 24 hr primarily in urine as unchanged drug, and the remainder was eliminated with a terminal phase half-life in blood and tissues of 3 days. Fecal excretion was relatively minor (16% of the dose recovered in feces in 7 days) until later timepoints, when it was the principal pathway of terminal phase elimination. The liver sequestered approximately 10% of the dose and had the highest tissue levels of drug at all times measured. Liver perfusion experiments indicated that trospectomycin accumulated in a hepatic depot compartment as parent drug by a first-order process which was nonsaturable up to a 1 mM concentration of drug. Biliary excretion of unchanged trospectomycin by the perfused liver was slow (approximately 3% of the dose in 2 hr) and occurred by both paracellular and transcellular mechanisms. The hepatic depot compartment appeared to be responsible for transcellular biliary excretion, and thus for the sustained fecal excretion observed in vivo. Subcellular distribution experiments indicated that at least 50% of the drug in the hepatic depot was sequestered in organelles having a broad density range. The existence of a trospectomycin depot compartment was also demonstrated in cultured hepatocytes.(ABSTRACT TRUNCATED AT 250 WORDS)     

Immunogold localisation of laminin in normal and exfoliative iris.

Immunoelectron microscopic studies of exfoliative iris tissue (seven specimens) revealed the presence of laminin in the fibrillar component of exfoliation material. The immunogold label was uniformly distributed on the exfoliation fibres. Deposition of laminin labelled exfoliation material in the dilator muscle was a noteworthy feature, as was an apparent depletion of laminin in the basement membranes of ostensibly unaffected vessels. In control iris tissue (five enucleated eyes) laminin was identified in the basement membrane round vascular contractile cells, but not beneath the endothelium.