Reversible cerebral vasoconstriction syndrome is a rare clinical syndrome characterized by sudden thunderclap headache often an under diagnosed neurological emergency. It is often provoked by ...postpartum state or exposure to provocative drugs. We report a rare case of Rizatriptan-induced reversible cerebral vasoconstriction syndrome presenting with thunderclap headache and paraparesis with complete recovery of neurological and imaging findings.
The mutagenic activities of the enantiomers of the diastereomeric pair of bay-region 10,11-diol-8,9-epoxides of dibenza,hacridine (DBa,hACR) were evaluated in histidine-dependent strains of ...Salmonella typhimurium and in cultured Chinese hamster V79 cells. In strains TA98 and TA100 of S.typhimurium, the (-)-8S,9R,10R,11S diol-epoxide was the most mutagenic compound, inducing 1200 and 6900 His+ revertants/nmol respectively. The mutagenic activity of each of the remaining three isomers was essentially independent of the bacterial strain used and had 14-72% of the activity of the S,R,R,S isomer. However, in Chinese hamster V79 cells, the (+)-8R,9S,10S,11R diol-epoxide was the most mutagenic compound (68 8-azaguanine resistant variants/nmol/10(5) cells), inducing from 2 to 11 times as many mutations as the other three isomers. These results are analogous to previous studies with the bay-region diol-epoxides of other polycyclic hydrocarbons in that the isomer with R,S,S,R absolute configuration has had variable activity in the bacterial assays, but has generally been the most active in the mammalian cells. Furthermore, this isomer has almost always been highly tumorigenic in the mouse.
The melanocortin 4 receptor (MC4R) plays an important role in body weight regulation and energy homeostasis. Administration of peptidic MC4R antagonists (usually by intracerebro ventricular ...injection) has been shown in the literature to increase body weight and/or food intake in several rodent models. We report here the identification of a novel nonpeptidic MC4R antagonist and its effects on tumor-induced weight loss in mice following peripheral administration.
L-689,502 is a potent inhibitor of HIV-1 protease activity in vitro. Microbial biotransformations of L-689,502 by cultures belonging to the genus Streptomyces sp. were performed. Extracts of culture ...broths were examined for the production of metabolites of L-689,502 that could inhibit HIV-1 protease activity. One culture, MA 6804 (Streptomyces lavendulae, ATCC 55095), produced L-694,746 that, while being structurally related to L-689,502, is a novel metabolite and a potent inhibitor of HIV-1 protease.
The absolute configurations of the enantiomeric 5,6-arene oxides of 7,12-dimethylbenzaanthracene (DMBA) were recently assigned such that the late eluting enantiomer from a chiral HPLC column has ...5R,6S absolute configuration. Mushtaq et al. (1984) BBRC 125, 539. The authors further concluded that the 5R,6S-enantiomer predominates on metabolism of DMBA by cytochrome P450c in liver microsomes from 3-methylcholanthrene-treated rats. Their chemical assignment of absolute configuration is incorrect. Thus, metabolism of DMBA by these microsomes as well as by homogeneous cytochrome P450c produces 5,6-oxide highly enriched (95%) in the 5S,6R-enantiomer in accord with theoretical predictions.
