Mammary tumorigenesis in chemical carcinogen-treated mice. VII. Prolactin and progesterone levels in BALB/c mice.

Pituitary and serum levels of prolactin (PRL) and serum levels of progesterone (P) were determined by polyacrylamide gel electrophoresis and radioimmunoassays in BALB/c female mice, 15-17 or 44 weeks old, treated with chemical carcinogens. Neither 1.5 mg 3-methylcholanthrene (MCA) nor 1.5-6 mg 7,12-dimethylbenz(a)anthracene (DMBA) markedly altered pituitary or serum levels of PRL in the younger mice, though DMBA increased the total pituitary content of PRL by about 33% in the 44-week-old mice. However, this increase was not correlated with the incidence of mammary tumors in the group or individuals. MCA increased serum P levels by about 22% within 50 days of the last treatment. This increase was attributable to higher serum levels of P during the diestrous and proestrous phases of the cycle. Adrenalectomy reduced serum P levels by about 60%, wheras ovariectomy had no effect. Serum P levels in 44-week-old rats were not affected by DMBA. The results fail to support the notion that MCA and DMBA promote murine mammary tumorigenesis by increasing pituitary and serum prolactin concentrations.     

An analysis of theα-adrenoceptor modulation of vasomotor tone at the level of lateral medullary pressor area (LMPA)

Summary Microinjection of noradrenaline and clonidine into lateral medullary pressor area (LMPA) of chloralose anaesthetized cats produced dose dependent decrease in blood pressure without affecting heart rate, while phenylephrine did not elicit any cardiovascular response. Selective ₂-adrenoceptor, antagonists idazoxan and piperoxan, microinjected locally, blocked the effects of the agonists but prazosin and phenoxybenzamine, which are relatively selective for ₁-adrenoceptors, failed to do so. Clonidine did not elicit any response in guanethidine pretreated cats but noradrenaline microinjected into LMPA of these animals induced a pressor response which was blocked by prazosin pretreatment. It is concluded that catecholaminergic fibres impinging upon this are inhibit the activity of the inhibitory second order baroreceptor neurone by activating ₁-adrenoceptors while ₂-adrenoceptors situated presynaptically on these inhibitory catecholaminergic nerve terminals are responsible for the manifestation of the hypotensive effect of clonidine and exogenously administered noradrenaline.     

Efficacy and safety of mycophenolate mofetil versus levamisole in frequently relapsing nephrotic syndrome: an open-label randomized controlled trial

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New forensic challenges and detection of snake venom

Forensic Toxicology -     

The Status of Stereotactic Radiosurgery for Cerebral Metastases in 1998

The last decade has witnessed an exponential proliferation of radiosurgery facilities in the United States and around the globe, and consequently, several tens of thousands of patients have undergone this procedure for a variety of intracranial and skull-base abnormalities. Since brain metastases represent the most common intracranial neoplasm, these have become a common target for radiosurgery. We present a review paper summarizing the major issues surrounding the management of brain metastases as well as an English-language literature review of 20 independent reports, using either -knife or linear accelerator-based radiosurgery, with >1250 patients and >2100 lesions available for analysis. Variable reporting in the studies precludes a definitive analysis and comparison of all factors in a rigorous statistical fashion, but the composite data reveal an average local control rate of 83% and a median survival of 9.6 months, which are comparable to those in recent surgical reports. Prognostic factors for survival are beginning to be unraveled, and the most important ones appear to be the presence of fewer than three lesions, controlled extracranial disease, and Karnofsky performance score. The exact impact of dose has not been clarified, but a dose–response relationship, especially for 18 Gy, is emerging. The role of whole-brain radiotherapy remains unresolved; it may enhance local control but does not convincingly improve survival and, in some series, is associated with an increased risk of late complications, which appear to be less than 5% on average. The concerns regarding chronic steroid dependance and increased intracranial edema do not appear to be a common problem. With such a large base of uncontrolled evidence, this is an opportune time for conducting and completing randomized trials to validate these observations.