Effect of infarct artery patency on prognosis after acute myocardial infarction. The Survival and Ventricular Enlargement Investigators

In this study, adult male rats were injected intraperitoneally with a single dose of serotonin (5-hydroxytryptamine, 5HT; 10 mg kg-1 bodyweight) for 2 h or 18 h, or daily with graded doses of 5HT (0.1-10 mg kg-1) for four days before being killed. Serum and testicular interstitial fluid (IF) concentrations of luteinizing hormone (LH), follicle-stimulating hormone (FSH), testosterone and immunoreactive-inhibin were measured by radioimmunoassay, and one testis was removed for histological examination. At 2 h after a single injection, 5HT caused a significant inhibition of serum concentrations of LH and inhibin, recovered IF volume and intratesticular testosterone concentrations; testis weight and serum concentrations of testosterone and FSH were unaffected. At 18 h after injection, all parameters had returned to normal, with the exception of intratesticular testosterone concentration which remained lower than normal. The lowest 5HT dose (0.1 mg kg-1) had no effect on any parameter following four daily injections. At a dose of 1.0 mg kg-1 5HT, there was a four-fold increase in the concentration of serum LH, but testis weight, recovered IF volume, testosterone and inhibin concentrations and serum concentrations of FSH were not significantly affected. At the highest dose of 5HT (10 mg kg-1) after four daily injections, testis weight decreased, and IF volume increased nearly three-fold. Testis concentrations of inhibin and serum testosterone were reduced, whereas serum concentrations of both LH and FSH were elevated; intratesticular testosterone concentrations did not differ from controls. Only at the highest dose of 5HT was disruption to the seminiferous epithelium observed, with focal damage ranging in severity from increased degeneration of spermatogenic cell profiles, to complete loss of the germinal epithelium; however, many tubule profiles displayed completely normal spermatogenesis. The acute IF volume reduction and spermatogenic disruption in 5HT-treated rats were consistent with localized ischaemia due to constriction of the testicular arterial supply. The eventual increase in IF volume observed after 5HT treatment appeared to be secondary to the loss of germ cells. Although 5HT also inhibited pituitary LH release and Leydig cell steroidogenesis, these effects appeared to play only a minor role in the induction of spermatogenic damage.     

Mapping the locus of the H-Y gene on the human Y chromosome

The H-Y locus is on the short arm of the human Y chromosome in most individuals but on the long arm in at least one of 17 individuals with structural abnormalities of the Y.     

Methods of transfemoral lumbar epidural venography in the diagnosis of lumbar disc herniation

This article outlines several ways of achieving adequate visualization of the epidural venous plexus in the diagnosis of lumbar disc herniation. Preference is expressed for simultaneous injection of contrast medium via two catheters selecttively introduced into the lateral sacral segmental veins or into the left and right internal iliac veins. For visualization of the epidural veins, the investigator has a choice of over 20 different procedures. The position of choice of the catheter tip(s) can vary during the examination, dependent on diagnostic problems or technical catheterization problems. Epidural venography should be regarded as a very accurate, relatively simple method of demonstrating disc herniations in the lumbar region. This method is especially recommendable in cases that are clinically suspect but have a negative or dubious caudogram. The risk of complications is very small. It is also a good method for azygography. It is possible to perform the examination on outpatients.