Hemodynamic and endocrine effects of acute and chronic administration of nifedipine

Although it is well known that calcium channel blockers can influence contraction of vascular smooth muscle, there is less knowledge on its effect on excitation contraction coupling in the endocrine glands and more specifically on insulin and glucagon release. In this study, nifedipine was administered in doses of 40 to 80 mg/day to 14 patients with essential hypertension, and its hemodynamic effects were evaluated by non-invasive methods, and its effect on glucose metabolism by an arginine infusion test. Nifedipine produced a significant reduction in systolic and diastolic blood pressure, both after the first dose (30/12 mm Hg) and after 8 weeks of administration (19/12 mm Hg). There were no significant changes in cardiac output (5.1 to 4.9 L/min), muscle (2.4 to 3.2 mL/sec/min) or cutaneous basal flow (9.8 to 8.6 mL/100 mL) as measured non-invasively by echocardiogram and by plethysmography. Insulin and glucagon release were evaluated by the arginine infusion test. Nifedipine produced a tendency toward an increase in glucagon release and a reduction in insulin release although these changes did not reach statistical significance. In this group of patients, nifedipine produced a significant reduction in systolic and diastolic pressure, but no significant changes in insulin or glucagon plasma levels.     

Phenotypical manifestations of partial trisomy 9 and monosomy 4 in two siblings

In this case report, we describe two siblings with a previously unreported partial monosomy 4q and partial trisomy 9q. The sibling karyotypes were determined to be 46,XX,der(4)t(4;9)(q33;q33)pat and 46,XY,der(4)t(4;9)-(q33;q33)pat. The siblings share several common pathological features, including VSD, PDA, low-set ears and digit anomalies as well as features consistent with Pierre-Robin syndrome and hydrocephalus. We review previously reported phenotypes associated with monosomy 4q and partial trisomy 9q and discuss potential mechanisms for these morphological insults with particular emphasis on neuropathology.     

Gene mutation assay of acrolein in the CHO/HGPRT test system

The mutagenic potential of acrolein has been studied with a wide range of in vitro and in vivo genetic toxicity assays. The data often have been conflicting, especially with the Ames assay. This study was undertaken to assess the mutagenic potential of acrolein using the CHO/HGPRT assay, both with and without metabolic activation. This assay system was chosen because it provides eukaryotic DNA as the target and is capable of detecting a range of mutational events. Because of its considerable toxicity, acrolein was tested over a very narrow dose range of 0.2-2 nl ml-1 without exogenous activation and 0.5-8 nl ml-1 with rat S-9 activation. Multiple assays were performed under both conditions. The results indicated that while acrolein was clearly very cytotoxic, it did not induce a significant mutagenic response in the presence or absence of metabolic activation.     

Neuronal activity of identified posterior hypothalamic neurons projecting to the brainstem peribrachial area of the cat

Following horseradish peroxidase injections in the brainstem peribrachial (PB) area, massive retrograde labeling was found in the posterior hypothalamic region. Single-unit recordings posterior hypothalamic neurons with antidromically identified projections to the PB area revealed that these neurons have higher firing rates in waking than in slow-wave sleep and dissimilar discharge patterns as compared with intralaminar thalamic neurons. The results are discussed in the context of reciprocal hypothalamo-brainstem circuits.     

Rhythmical myoclonus and tremor at rest disclosing mesencephalic metastasis

We report a case in which rhythmical myoclonus and tremor at rest revealed a thalamo-subthalamic metastasis from a bronchial carcinoma. Tremor of the upper limbs and face (4 Hz) disappeared with sustained posture and action. A cogwheel phenomenon, hypotonia and disorders of automatic and voluntary movements were also present. Surface electromyographic recordings showed a rhythmical, synchronous activity of the biceps brachialis and triceps muscles at rest. Pathology disclosed lesions of the red nucleus and neighbouring area and severe compression of the substantia nigra which were likely to be the cause of the signs and symptoms.     

At-risk behaviors with regard to HIV and addiction among women in prison.

The bulk of studies pertaining to addiction among delinquents have been conducted on male subjects. However, the few studies examining female inmates show that a significant proportion of them present an addictive disorder. Furthermore, the HIV infection rate is higher among these women than among incarcerated men. This study attempts to verify if women presenting a combination of criminal and addictive behaviors are at a higher risk of developing an earlier and a more severe delinquency than other delinquent women. Another goal is to determine whether women showing this comorbidity present a higher incidence of HIV-related risk behaviors. The study was conducted on a sample of 210 women from the Montreal detention center. It shows that addicted inmates present earlier onsets of both drug use and criminal behaviors compared to other female inmates. Addicted women also exhibit significantly more HIV-related risky behaviors, both in their drug use and in their sexual practices.