The effect of local chemical sympathectomy of the rat uterus on its sensitivity to sex hormones

Chemical sympathectomy of the rat uterus did not alter the main metabolic processes maintaining the uterus weight even though it changed its response to sex steroids. Sensitivity of endo- and myometrium to progesterone significantly decreased thus inducing a relative increase in the estradiol action.     

A preclinical trial of iodoantipyrine safety

Intraluminal coagulation of a ventricular catheter followed by its removal and replacement is a technique used for proximal shunt revision. The authors describe experience leaving the original catheter in place when flow of CSF is established by the coagulation. Advantages of this modification include maintenance of ventricular access when the ventricles are small and the possibility of reducing the incidence of subsequent shunt obstruction by mitigating intraventricular hemorrhage caused by catheter removal.     

Malignant hepatic tumours associated with previous exposure to Thorotrast: four cases

This report concerns four patients in a district general hospital who died from malignant liver tumours associated with Thorotrast (thorium dioxide) deposits in the liver. Three were known to have had diagnostic angiographic studies performed 36 to 43 years previously using Thorotrast as the contrast agent. In the fourth case no previous relevant information could be obtained. There were two men and one woman with hepatocellular carcinoma and one woman with cholangiocarcinoma. In one of the hepatoma cases there was associated hypercalcaemia of malignancy. Reported latency intervals suggest that cases of Thorotrast-related hepatic malignancy may present up to the second decade of the twenty-first century.     

Regional distribution of dopamine D4 receptors in rat forebrain

Binding of the D2-like (D2/D3/D4) radioligand [3H]nemonapride under selective conditions (with 300 nM S[-]-raclopride and other masking agents to occlude D2/D3 receptors and non-specific binding sites) revealed a subset of raclopride-insensitive binding sites considered D4-like receptors. These sites were stereoselective to R(-)-N-n-propylnorapomorphine (NPA) over its S(+)-NPA in a similar fashion to cloned D4 receptors expressed in cell lines. In addition, the highly D4-selective agent L-745,870 displaced 74-83% of these sites in rat brain regions, suggesting that most were D4 receptors. These apparent D4 receptors represented a relatively high proportion of D2-like receptors in hippocampus, dorsolateral frontal, medial prefrontal and entorhinal cortex, but fewer in caudate-putamen and nucleus accumbens.     

Evaluation of [11C]RTI-121 as a selective radioligand for PET studies of the dopamine transporter

The cocaine analogue RTI-121 (3 beta-(4-iodophenyl)tropane-2 beta-carboxylic acid isopropyl ester), when labeled with carbon-11, was evaluated in rats as a potential PET ligand for the dopamine transporter. The compound gave in vivo striatum:cerebellum ratios that were similar to those obtained with the related ligand [11C]RTI-55 (2 beta-(4-iodophenyl)tropane-2 beta-carboxylic acid methyl ester) but showed a much greater selectivity for the dopamine compared with the 5-HT uptake site. The results indicate that [11C]RTI-121 could be used in preference to [11C]RTI-55 in man. Experimentally, [11C]RTI-121 has potential in the quantification of dopamine terminal function in rat models of disease, using a combination of autoradiography, postmortem sampling, and in vivo tomography.     

Studies on human sexual development. V. Concentrations of testosterone, 17-hydroxyprogesterone and progesterone in human amniotic fluid throughout gestation

Concentrations of unconjugated testosterone, 17-hydroxyprogesterone (170HP) and progesterone were measured by radioimmunoassay in amniotic fluid (AF) specimens from normal pregnancies of 9-40 weeks gestation. In two-thirds of samples from pregnancies with male fetuses. AF testosterone exceeded the upper limit found in female samples, with minimal overlap in the 12-18 week period of gestation. Although AF testosterone levels associated with male and female fetuses were both significantly lower toward term, the sex-difference persisted. Between 9-19 weeks gestation, fetal sex was also found to influence AF 170HP, a steroid thought to be predominantly of placental and fetal adrenal origin; in this case, female levels exceeded male. Awareness of the influence of sex and gestation upon AF concentrations of these steroids is an important prerequisite for their application to the prenatal diagnosis of endocrine disease (e.g., congenital adrenal hyperplasia). There was no sex difference in AF progesterone concentrations at 12-18 weeks gestation. The median progesterone concentration at 34-40 weeks was higher with female fetuses, but this difference may be related to a difference in gestational age between AF samples obtained from male and female fetuses.     

Numerical and physical modeling of turbulent flow around a plate with two transverse ribs

Results are presented of a numerical and experimental investigation of turbulent incompressible fluid flow near a horizontal plate on which one and two interceptors are installed.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 52, No. 1, pp. 43–51, January, 1987.     

Emotional stress and blood melatonin levels

Blood serum melatonin concentrations were measured in male Wistar rats exposed to acute water-immersion emotional stress (ES) during intraperitoneal injections of physiological saline or different doses of melatonin. ES increased blood melatonin levels in rats receiving physiological saline 1 hour before or just after ES. When physiological saline was administered just ES, blood melatonin concentrations remained unchanged. The blood levels of melatonin both in control and stressed animals injected with exogenous melatonin were higher than those in rats given physiological saline alone. Immersion ES decreased blood melatonin concentrations in rats receiving different exogenous melatonin doses just before ES. However, in rats given melatonin, 1.0 mg/kg, after ES, its blood levels after ES was higher than those in the animals unexposed to stress. The findings suggest that it is just exogenous rather than endogenous melatonin that is consumed in rats injected with its different doses just prior to immersion ES.