Hypotensive activity of the ethanol extract of Pavetta crassipes leaves

Pavetta crassipes leaf is routinely used locally in Nigeria for the management of respiratory disorders and hypertension. The hypotensive and other cardiovascular effects of Pavetta crassipes were investigated in cats and rats. The effects of the extract on rat and cat blood pressures, isolated rat atria, rat portal vein, isolated rat aorta and rat vas deferens were studied. Specific receptor antagonists (atropine, mepyramine, phentolamine, propranolol) were used to elucidate the underlying mechanism(s) involved in the cardiovascular changes induced by P. crassipes. The results revealed that the ethanolic extract of Pavetta crassipes lowered the blood pressures of cats and rats in a dose dependent manner. The extract also caused a concentration-dependent decrease in the force of contraction of the isolated rat atria and rat portal vein. The decreases in blood pressure values were attenuated in the presence of a beta-adrenoceptor antagonist, propranolol. The extract also attenuated isoprenaline-induced contraction of the rat atria. However, the extract did not affect contractions evoked by KCl, norepinephrine and 5-HT on the rat aorta. Pavetta crassipes contains biologically active substances that may be useful in the management of hypertension.     

Contrasting associations between aldosterone synthase gene polymorphisms and essential hypertension in blacks and in whites

BACKGROUND: Genetic variability in the gene for aldosterone synthase--a key enzyme in the production of aldosterone--can affect sodium homeostasis and thereby blood pressure. The possibility of impaired aldosterone production for the development of hypertension is of particular relevance in black Afro-Caribbeans exposed to a high dietary sodium intake. OBJECTIVES: To compare the frequency of three variants (-344C/T, intron 2 conversion, and the K173R polymorphism) of the aldosterone synthase gene in blacks and whites, and to determine any association of the variants with hypertension. DESIGN AND METHODS: We made case-control comparisons of the three gene variants in relation to ethnic background and to essential hypertension in 193 white (51% hypertensive) and 245 black individuals (59% hypertensive) living in south London. RESULTS: The frequency of each of the variants was significantly different between the two ethnic groups. The T and the K alleles were more frequent in the black participants (79 compared with 50% for the -344T allele and 81 compared with 50% for K173 allele), whereas the frequency of the intron 2 conversion allele was much lower in that group (8 compared with 38%). None of these variants was associated with essential hypertension in the black participants. In contrast, in the white participants there was a significant and graded association between the intron 2 conversion allele and essential hypertension (odds ratio 1.86, 95% confidence interval 1.16 to 2.98; = 0.01). Moreover, among the white population, the presence of homozygosity both of the T allele and of the intron 2 conversion alleles was associated with a much greater frequency of hypertension (71 compared with 43%; chi(2) = 0.03). CONCLUSIONS: The contrasting associations between these variants and essential hypertension do not necessarily exclude the possibility that other, as yet undefined, variants of the aldosterone synthase gene could be linked with hypertension in black people. Nonetheless, the strong association between the intron 2 conversion allele and essential hypertension in the white population reinforces the view that the increased blood pressure may be due, at least in part, to abnormal expression of enzymes involved in the metabolism of adrenal mineralocorticoids.     

Association of malarial parasitaemia with dehydrating diarrhoea in Nigerian children

Records of 402 children--216 (53.7%) males and 186 (46.3%) females--aged 1-36 month(s), admitted to the Diarrhoea Treatment and Training Unit of the University of Benin Teaching Hospital, Benin city, Nigeria, during July 1993-June 1996, were reviewed to document the relationship between dehydration and malaria parasitaemia. There was a significant association between severity of dehydration and malaria parasitaemia (p < 0.0001). Association of parasitaemia (p < 0.006) with dehydration (p < 0.0001) was significantly more marked in patients with acute watery diarrhoea than in those with persistent and bloody diarrhoea. Parasitaemia was demonstrated in 50.5% of those not initially suspected to have malaria. Parasitaemia was also significantly associated with fever (p < 0.001) and fever coexisting with vomiting (p < 0.01). The prevalence of malaria-associated diarrhoea was 61.7%. More infants (75.6%) than older children had diarrhoea. It was concluded that the prevalence of malaria-associated diarrhoea was high and that children with dehydration are more likely to manifest malaria parasitaemia.     

Differential effects of prednisolone and indomethacin on zymosaninduced inflammation in a modified murine tissue-chamber model

A tissue-chamber model of inflammation in mice has been modified and used to investigate the kinetics of zymosan-induced inflammatory mediators such as tumour necrosis factor (TNF), interleukin-1 (IL-1) and prostaglandin E₂ (PGE₂). In addition, the influx of polymorphonuclear leukocytes (PMN) into the chamber fluid and the granuloma surrounding the chamber was measured by myeloperoxidase (MPO) activity using a new microtitre plate assay. TNF and IL-1 reached peak concentrations at 3 and 6 h respectively after zymosan injection. Intermediate high concentrations of IL-1 were observed until the end of the experiment at 72 h, but TNF concentrations decreased from 24 h to biologically insignificant values. In contrast, exudate PGE₂ and MPO activity increased up to 24 h after zymosan injection and remained high until 72 h. At 6h after zymosan challenge, oral pre-treatment with prednisolone (3 to 30mg/kg) dose-dependently reduced TNF, IL-1 and PGE₂ concentrations while indomethacin (0.3 to 3 mg/kg) significantly attenuated PGE₂, slightly enhanced TNF and had no effect on IL-1 concentrations in the exudate. Both drugs had similar potencies against exudate and tissue MPO activities. Prednisolone inhibited IL-1 at 72 h post-zymosan. Indomethacin was more potent than prednisolone against PGE₂ (ID₅₀ of <0.3 versus 0.6mg/kg). The data obtained confirm the usefulness and reliability of this model in evaluating the effects of anti-inflammatory agents on inflammatory mediators induced by zymosan.     

Report of two cases: Rattlesnake venom-induced thrombocytopenia

We report 2 patients who presented with vasomotor symptoms and severe thrombocytopenia following rattlesnake bites. These symptoms persisted in spite of treatment with antivenin and transfusion of multiple doses of platelets. Thrombocytopenia is a common occurrence in moderate to severe crotaline envenomation. Algorithms suggested for the treatment of rattlesnake envenomation with crotaline-specific antivenin may not reverse the associated thrombocytopenia. The precise mechanism of venom-induced thrombocytopenia (VIT), even in the absence of significant coagulopathy, is unknown. Our experience suggests that, unless spontaneous bleeding occurs, repeated transfusion of fresh frozen plasma and/or platelets may not be indicated.     

Antiinflammatory and antibacterial activities of C-methylflavonols from Piliostigma thonningii

Newly described C-methylflavonols, 6,8-di-C-methylquercetin 3-methyl ether, 6-C-methylquercetin 3,7-dimethyl ether, 6,8-di-C-methylquercetin 3,7-dimethyl ether together with the known compounds quercetin, quercitrin, 6-C-methylquercetin 3-methyl ether, 6-C-methylquercetin 3,7,3′-trimethyl ether, 6,8-di-C-methyl- kaempferol 3-methyl ether and 6,8-di-C-methylkaempferol 3,7-dimethyl ether isolated from the leaves of Piliostigma thonningii, were tested for their ability to inhibit prostaglandin synthesis in vitro and antibacterial activity against Staph. aureus. The influence of the B ring 3′,4′ diol group on the activity of C-methylflavonols in the inhibition of prostaglandin synthesis differ from that observed for a series of flavonoids without C-methyl groups. The antibacterial activity in the series mirror those of methylated antimicrobial flavonoids. The traditional uses of the plant in infections and inflammatory conditions were rationalized on the basis of the activities of these compounds. © 1997 John Wiley & Sons, Ltd.     

Female adolescents and the future of female genital mutilation/cutting: a report from an endemic area

BackgroundDespite collaborative efforts aimed at its eradication, Female Genital Mutilation/Cutting (FGM/C) continues in endemic areas.ObjectiveTo evaluate the experience and preparedness of female adolescents to protect their future daughters from FGM/C.MethodsA cross-sectional survey involving adolescent secondary school girls in North Central Nigeria. Participants were secondary school students who completed the study''s self-administered questionnaire after informed parental or participant''s consent. Data management was with SPSS 20.0 (IBM, USA), P-value <0.05 was significant.ResultsThere were 2000 participants aged 13–19 years (mean 15.56±1.75), prevalence of FGM/C was 35.0%, awareness was 86.1%, mutilation was performed between infancy and eight years of age (mean 3.85±3.24 years), 644(32.2%) desire to mutilatetheir future daughters, 722(36.1%) expressed support for FGM/C and 63.1% of victims of FM/C reported adverse post-mutilation experiences. Support for FGM/C was associated with low social class (P0.0010), opinion that FGM/C has benefit (P0.001) and desire to mutilate future daughters (P0.001) while awareness of efforts to eradicate FMG/C was 813(40.7%).ConclusionFGM/C remains prevalent with potential support for its continuation among female adolescents despite reported adverse post-mutilation experiences. The multi-pronged approach to eradicate FGM/C should prioritize re-orientation for adolescent girls, rehabilitation of mutilated girls and girl child formal education.     

Prevalence and correlates of dysmenorrhea among Nigerian college women

The study assessed first year students in a Nigerian university (n = 409) for dysmenorrhea. The prevalence of dysmenorrhea was 53.3% and most students experienced pain at onset of menses. About half of the students reported that menstrual pain interferes with their normal daily activity. The independent predictors of dysmenorhea were longer days of menstrual flow, younger age at menarche and lower scores on extraversion scale. College health-care providers should screen routinely for dysmenorrhea among students and offer treatment. As dysmenorrhea reportedly affects school performance and attendance, more attention should be devoted to providing health education on this topic to students.