DNA damage, prophage induction and mutation by furazolidone

Ultraviolet absorption data and thermal chromatography through hydroxyapatite (HAP) column revealed that furazolidone treatment of Vibrio cholerae cells produced more than 80% of DNA reversibly bihelical due to the formation of interstrand cross-links and the reaction obeyed a first order relation. Sensitivities of the Escherichia coli strains to the lethal action of the drug were in the order: AB 2480(uvr- rec-) greater than AB 2463(rec-) greater than AB 1886(uvr-) greater than AB 1157(repair proficient) or AB 4401(wild type). Furazolidone was 'Rec test' positive, produced dose-dependent prophage induction in E. coli cells and also dose-dependent streptomycin-resistance forward mutation in V. cholerae cells. The quantitative aspect and also the mode of furazolidone action on DNA were discussed.

A probe into the possible mechanism underlying the interceptive action of aristolic acid

Oral administration of aristolic acid (90 mg/kg body weight) on day 6 pregnant and pseudopregnant mice resulted in the termination of pregnancy with in utero fetal death but the length of pseudopregnancy remained unaffected. Peripheral level of progesterone remained statistically uninfluenced in both conditions and exogenous progesterone failed to prevent aristolic acid-induced pregnancy loss, both of which rule out the involvement of luteolysis as the causal factor for the termination of pregnancy. In another experiment, aristolic acid was found to have no inhibitory effect over the maintenance of decidual cell reaction which indicates no inhibitory influence of the compound on uterine utilization of progesterone but points to the fact that presence of concepts is an essential component in the array of mechanism(s) leading to the termination of pregnancy. Probable toxic effect of aristolic acid on the concepts is discussed.

Induction of implantation in the rat by iproniazid

Rats were bilaterally ovariectomized on Day 3 post coitum and treated daily with progesterone. Iproniazid, an inhibitor of monoamine oxidase, on Day 8 induced implantation in all rats. Indomethacin treatment prevented this effect.

The pathology and pathogenesis of fatal hepatic amoebiasis--A study based on 79 autopsy cases

The present study is based on a retrospective analysis of 79 autopsy cases of hepatic amoebiasis. An attempt has been made to reconstruct the sequence of events starting from intestinal infection to invasion and transport of amoebae along the radicles of the portal veins, the formation of early Zahn's infarct and the proliferation of amoebae in such foci leading to the formation of small abscesses. The coalescence of small abscesses gives rise to the apparently large abscesses. Apart from direct contiguity, more distant extension leading to a satellite abscess is due to involvement of the hepatic and/or portal venous radicles. It seems that obstruction of the hepatic vein contributes substantially towards the enlargement of the liver and its exaggerated nutmeg appearance. Signs and symptoms of hepatic vein obstruction sometimes overshadow the abscess pathology. Thrombosis or pressure of a neighbouring abscess over the portal vein obstruction sometimes overshadow the abscess pathology. Thrombosis or pressure of a neighbouring abscess over the portal vein and bile-duct lead to development of portal hypertension and jaundice. Both cell-mediated and humoral immunity are depressed in fatal cases of hepatic amoebiasis.

Seminal vesicles and its importance in the regulation of male fertility

During experimental studies on the physiological significance of accessory sex glands, it was documented that excision of prostate in rats did not affect fecundity; conversely, surgical removal of seminal vesicles or its plasma consistently made the animals infertile. However, fertility of the plasma-removed animals was found to return to normalcy after 3 weeks following the surgical manipulation. Human chorionic gonadotropin or testosterone treatment starting immediately after surgical manipulation of the vesicular plasma retained fertility throughout the test period. The importance of seminal vesicular plasma in terms of male fertility has been discussed.

Pregnant mare's serum gonadotropin. III. Hemispaying and the reversal of the antifertility faculty of pregnant mare's serum gonadotropin

A single injection of 10 IU of pregnant mare's serum gonadotropin (PMSG) on day 5 of pregancy caused wastage of the fetoplacental unit by day 16 of pregnancy. Semispaying, which seems to subtract approximately 50% of the ovarian steroid contribution, at 24, 48, and 72 hours following the PMSG schedule prevented the antifertility faculty of the hormone preparation. However, hemicastration at 96 hours following the gonadotropin regimen was found to be ineffective, and 100% of the test animals showed complete termination of pregnancy. Experimental data collectively tempt us to propose that an estrogen excess, particularly of follicular origin in both ovaries, is essential for more than 72 hours following gonadotropin sensitization before the antifertility faculty of PMSG can be demonstrated.

Cyproterone acetate: I. Microquantity releasing device of cyproterone acetate and its failure in inducing functional sterility in male rats

Prasad and his coworkers emphasized that microquantities of cyproterone acetate (CPA) when continuously available developed functional sterility in male rats by interfering the epididymal physiology. In our experimental rats either 2 or 3 capsules containing CPA as per the specification of Prasad were implanted subcutaneously and left for 300 and 250 days, respectively. Fertility test was made every month and it was observed that all the experimental animals were able to impregnate female rats throughout the experiment. Excepting the epididymis the weight of testes and other accessory glands did not differ from the controls in the animals which had 2 CPA capsules for 300 days; On the other hand, the animals which received 3 CPA capsules for 250 days showed significant reduction in weight of all the acessory glands including the testes.

Pregnant mare's serum gonadotrophin. I. Progesterone or prolactin and the reversal of antifertility efficacy of pregnant mare's serum gonadotrophin

A single consistent luteolytic dose of 10 IU PMSG given on day 5 of pregnancy caused complete resorption of foetuses and placentae associated with a polyfollicular ovarian state in rats. Concomitant treatment with progesterone or prolactin given concurrently with PMSG was found to overcome the antifertility efficacy of PMSG and maintained the endocrine balance favouring pregnancy maintenance. It was postulated that the PMSG-induced ovarian polyfolliculogenesis might be responsible for luteolysis of the corpus luteum gravidarum.