Prevention of cadmium-induced effects on regional glutathione status of rat brain by vitamin E

The effect of vitamin E on the cadmium-induced changes of glutathione metabolism was investigated in different brain regions. Daily intraperitoneal injection of cadmium (0.4 mg/kg) for 30 days significantly decreased the concentration of reduced glutathione (GSH), and the activities of glutathione reductase (GR) and glucose-6-phosphate dehydrogenase (GPDH) in the cerebellum, cerebral hemispheres and brain stem of rats. Cadmium elevated the levels of oxidized glutathione (GSSG) in cerebellum and cerebral hemisphere regions only, while the GSH/GSSG ratio decreased in all three brain regions. The only effect of intramuscular injections of vitamin E (5 mg/kg) given on alternate days for 30 days was a slight increase in GSH and GR in the cerebral hemispheres. The simultaneous administration of vitamin E and cadmium prevented cadmium-induced changes in GSH and GSSG levels and in the GSH/GSSG ratio, but the cerebellar GSH remained lowered. Furthermore, vitamin E, with the exception of GR in the cerebral hemispheres, did not prevent cadmium-induced changes in enzyme activities. As the simultaneous injections of vitamin E reduced cadmium-induced alterations in glutathione concentration without having any appreciable effect on the activity of related enzymes, it is suggested that the preventive effect of vitamin E is mediated through its antioxidative effect, saving GSH from oxidative destruction in the brain of cadmium-exposed rats.     

Chorioretinal and choriovitreal neovascularization after photocoagulation for proliferative diabetic retinopathy. A clinicopathologic correlation

A patient with proliferative diabetic retinopathy was treated by panretinal and focal photocoagulation. Later, he developed one area of clinically diagnosed chorioretinal and choriovitreal neovascularization (CNV), neovascular glaucoma, and a blind painful eye necessitating enucleation. Clinicopathologic correlations of this eye including fundus photography, fluorescein angiography, light and electron microscopy are reported. Histopathologic examination revealed three areas of CNV, suggesting that some CNV may go undetected clinically also in other cases and thus may occur more frequently than evident from the literature. Our CNV occurred at sites of focal treatment. Retreatment of one area was unsuccessful. Choriovitreal neovascularization passed through discontinuities of Bruch's membrane into the retina and showed fenestrae of the endothelial cells. Endothelial fenestrae may account for the profuse fluorescein leakage seen clinically in CNV.     

Flow cytometric evaluation of the effect of various doses of vindesine sulphate on mouse spermatogenesis

Spermatogenesis, a rapidly proliferating cell system, is highly susceptible to damage by radiotherapy and/or chemotherapy. Vindesine, a semisynthetic vinca alkaloid, was given as a single injection to adult male Swiss albino mice to study its effects on testicular weight and male germ cell turnover pattern using flow cytometry. Testicular weight declined significantly at Day 7 to 14 and from Day 14 to 35 after administration of 1 and 2 mg/kg b wt vindesine, respectively. Flow cytometric evaluation of various testicular cell types after the administration of 2 mg/kg b wt vindesine revealed a significant increase in the relative percentage of spermatogonial cells at Day 21 and 35 posttreatment. In contrast, the relative percentage of primary spermatocytes declined significantly at Day 7 and 14 posttreatment. Similarly, a significant reduction in the relative percentage of round spermatids was observed from Day 7 to 35 posttreatment. The relative percentage of elongated spermatids declined significantly at day 35 post-treatment. These changes are reflected in the transformation ratios. While the 4C:2C ratio did not exhibit any significant change below 1 mg/kg vindesine, it declined significantly after 1 mg/kg (Day 14) and 2 mg/kg (Day 7 to 35, except Day 28 posttreatment) vindesine treatment. Treatment of male mice with 2 mg/kg vindesine resulted in a significant decline in 1C:2C ratio from 7 to 35 d post-treatment. The 4C:S-phase ratio decreased significantly at Day 7 and 14 posttreatment for all the drug doses above 0.05 mg/kg. A significant reduction in the 1C:4C ratio was observed at day 21 to 35 posttreatment as a result of 2 mg/kg vindesine administration.     

Amniotic membrane is an effective burn dressing material

Human amniotic membrane is a readily available biological dressing material used to treat burns. It not only prevents oozing of plasma from burn wounds but also relieves pain and controls sepsis. We used human amniotic membrane to treat fifteen burn patients, and this material was effective. The application of this cost-free dressing material warrants further study as it can be made use of in areas where expensive and specialized equipment is not available.     

Anaphylactoid reaction to methylprednisolone pulsed therapy for multiple sclerosis

A further case of anaphylactoid reaction to methylprednisolone is reported. The occurrence of allergic reactions to steroids is reviewed, and suggestions for management of pulsed IV methylprednisolone therapy are made.     

Involution of thymic epithelium and low serum thymulin bioactivity in weanling mice subjected to severe food intake restriction or severe protein deficiency

The volume of epithelium in the cortex and in the medulla of the thymus was compared in four groups of weanling male and female CBA/J mice. Well-nourished controls (C), food intake restricted (R), and animals given a low-protein diet ad libitum (LP) were fed from 23 to 37 days of age. Baseline controls (B) were studied at 23 days of age. Epithelial volume fraction was estimated for each group by point-counting morphometry on electron micrographs. Other mice were used to obtain group mean estimates of thymic index (mg/g live weight) and volume fraction of cortex and medulla (light microscope-level point-counting morphometry). Cortical and medullary epithelial volumes were calculated for each animal examined by electron microscopy by obtaining the live weight and applying, in sequence, the group mean thymic index, an assumed thymic density of 1.0 mm3/mg, the group mean cortical or medullary volume fraction, and the measured cortical or medullary volume fraction for that animal. Serum thymulin bioactivity was also measured in C, R, and LP mice. The results reveal thymic epithelial involution in the two most common rodent models of malnutrition, and suggest that this may contribute to the low serum thymulin levels found in malnourished experimental animals and humans.