Effect of Tripterigium wilfordii Hook. f. on the fertility of rats

Studies were undertaken to assess the effect of the total glycosides extracted from Tripterigium wilfordii Hook. f. (GTW), a ready-made Chinese herb medicine, on the fertility of both male and female rats. In male rats, GTW was given by gastric gavage at a dose of 10 mg/kg per day, 6 days a week for 8 weeks. All the treated animals became infertile. The body weight growth was normal and the mating behavior was present. There was a drastic decrease in the viability of the epididymal spermatozoa, while the decrease in the sperm density, though significant, was far less marked. Seminiferous tubular damage was minimal and no perceptible change was observed in the Leydig and the Sertoli cells. All other parameters examined, including the serum testosterone level and the histology of various organs, were normal. In female rats, GTW given orally at a dose of 50 mg/kg per day on days 1-4 or 7-9 of pregnancy did not significantly affect the fertility. It is thus concluded that non-toxic dose of GTW can cause infertility in male rats, the mechanism of which may involve and interference in the function of the epididymal and/or testicular spermatozoa; in female rats, the dose regimens employed do not have significant anti-implantation or early-pregnancy termination effect.

Effect of intra-epididymal injection of copper particles on fertility, spermatogenesis, and tissue copper levels in rats

In male rats, a single injection of 10 mg metallic copper particles in oil into each caput epididymidis induced infertility, whilst leaving mating behaviour and blood testosterone levels unchanged. Fertility tended to recover 5.5 months after the copper treatment. Although the copper content of the caput epididymidis reached a level of around 100 times higher than control values, the serum copper concentration did not rise significantly. This finding and the observation that treated animals gained weight as fast as the controls suggest a low systemic toxicity of this method. The testicular copper concentration was significantly higher than that in controls and different degrees of damage, including vacuolation, karyorrhexis, pyknosis, and cytolysis, were seen mainly in pachytene spermatocytes and early spermatids. Clumps of foreign particles, apparently metallic copper, were found in the interstices of the caput epididymidis together with degenerative changes in the epithelial cells of the caput, suggesting a possible effect of copper on the epididymal epithelium. The viability of epididymal sperm decreased more markedly than the decrease in sperm density. It is therefore most likely that the major cause of infertility after copper injection into the caput epididymidis is a direct inhibitory effect of copper on the sperm, whilst damage to the seminiferous and epididymal epithelial may contribute.

Histochemical demonstration of guanase in human liver with guanine in bicine buffer as substrate

Histochemical studies of human guanase (guanine deaminase) have seldom been undertaken, in part because of technical difficulties which result in heavy background staining. In this report, we describe a modified procedure in which the methodological inadequacies have been overcome. The modified technique has been applied to determine the intracellular and lobular distribution of guanase in normal human liver and in cases of primary biliary cirrhosis and alcoholic cirrhosis. Guanase was present within the cytoplasm of hepatocytes throughout the entire lobule. Enzyme activity was stronger on the sinusoidal side of the hepatocytes and in the periportal area. The reaction was weaker in perivenular hepatocytes. Portal components (bile ducts and veins), fibrous tissue and inflammatory cells were non-reactive, and the enzyme was absent from hepatocyte nuclei and membranes. Sections of skeletal muscle contained no guanase. The specificity of the reaction was confirmed by control tests on liver tissue and by the use of a specific inhibitor of guanase. It is concluded that the modified procedure overcomes the disadvantages inherent in the original method for guanase demonstration, allows the examination of fine cellular detail and should become a valuable histochemical tool with which to study diseases of the liver.

Holographic interferometry used to demonstrate a theory of pattern formation in animal coats

Time-average holographic interferometry has been used to observe modal patterns of acoustically excited thin plates and shells having shapes which are schematically related to shapes occurring in the coats of animals. These modal patterns are related by a reaction-diffusion model to animal coat markings found in nature.

Plasmid deoxyribonucleic acid replication in Streptomyces griseus

A series of electron micrographs showing the presence of different molecular forms representing various replication stages of plasmid deoxyribonucleic acid from Streptomyces griseus was obtained. Based upon an analysis of these electron micrographs, a tentative model for plasmid deoxyribonucleic acid replication in S. griseus is proposed.