Peak Expiratory Flow Rate in Normal Hausa-Fulani Children and Adolescents of Northern Nigeria

Background: Peak expiratory flow rate (PEFR) is a useful parameter for assessing respiratory function in health and disease. However there are few studies reporting normal values of this parameter in Northern Nigeria in general and the North western zone in particular. Also prediction formulae for predicting PEFR from anthropometric parameters are not available for this population. The present study was therefore designed to measure Peak expiratory flow rate (PEFR) in normal Hausa-Fulani children and adolescents in Sokoto and to derive prediction formulae for this population. Methods: Apparently healthy boys (n=376) and girls (n=240) aged between 6 and 18 years were randomly selected and their height, weight and chest circumference determined. PEFR was measured at ambient temperature and pressure saturated with water vapour (ATPS) in the erect position. Regression analyses were carried out on the relationship between PEFR and each anthropometric parameter and prediction formulae with the least standard error of estimates chosen. Data obtained in this study were also subjected to prediction formulae derived from Nigerian populations elsewhere. Results: PEFR (L/min) was significantly (P<0.001) higher in boys (382.5 \ub1 118.3) than in girls (332.6 \ub1 88.3). It correlated positively and significantly with age, height, weight and chest circumference in both sexes. The prediction formulae derived from the present data in boys and girls respectively are: PEFR (L/min) = 85.83 + 8.25 x weight (kg) (\ub1 3.15) and PEFR (L/min) = 3.67 + 28.15 x age (years) (\ub1 3.51). The predicted PEFR values obtained using earlier formulae were generally lower than the observed values. Conclusion: PEFR has been obtained in normal healthy Hausa-Fulani children and adolescents in Sokoto and prediction formulae derived for use in this population. The results of this study suggest that the usefulness of prediction formulae may be limited to the ethnic group or locality from which they were derived.Fond : Le d\ue9bit expiratoire maximal (DEM) est un param\ue8tre utile pour \ue9valuer la fonction respiratoire dans la sant\ue9 et la maladie. Cependant, il y a peu d'\ue9tudes indiquant des valeurs normales de ce param\ue8tre au nord du Nig\ue9ria en g\ue9n\ue9ral et la zone occidentale du nord en particulier. En outre les formules de pr\ue9vision pour pr\ue9voir le DEM des param\ue8tres anthropom\ue9triques ne sont pas disponibles pour cette population. La pr\ue9sente \ue9tude a \ue9t\ue9 donc con\ue7ue pour mesurer le d\ue9bit expiratoire maximal (DEM) dans les enfants et les adolescents normaux de hausa-Fulani-Fulani \ue0 Sokoto et pour d\ue9river des formules de pr\ue9vision \ue0 cette population. M\ue9thodes : Les gar\ue7ons apparent en bonne sant\ue9 (n=376) et les filles (n=240) \ue2g\ue9s entre 6 et 18 ans ont \ue9t\ue9 al\ue9atoirement choisis et leur circonf\ue9rence de taille, de poids et de coffre ont \ue9t\ue9 d\ue9termin\ue9es. Le DEM a \ue9t\ue9 mesur\ue9 \ue0 la temp\ue9rature ambiante et \ue0 la pression satur\ue9es avec la vapeur d'eau (TAPS) en position droite. Des analyses de r\ue9gression ont \ue9t\ue9 effectu\ue9es sur le rapport entre le DEM et chaque param\ue8tre anthropom\ue9trique et formules de pr\ue9vision avec la moindre erreur type des \ue9valuations choisies. Des donn\ue9es obtenues dans cette \ue9tude ont \ue9t\ue9 \ue9galement soumises aux formules de pr\ue9vision d\ue9riv\ue9es des populations nig\ue9rianes ailleurs. R\ue9sultats : Le DEM (L/min) \ue9tait de mani\ue8re significative (P<0.001) plus haut dans les gar\ue7ons (382,5 \ub1 118,3) que dans les filles (332,6 \ub1 88,3). Il s'est corr\ue9l\ue9 positivment et de mani\ue8re significative avec l'\ue2ge, la taille, et la circonf\ue9rence de poids et de coffre dans les deux sexes. Les formules de pr\ue9vision d\ue9riv\ue9es des donn\ue9es actuelles dans les gar\ue7ons et dans les filles respectivement sont : DEM (L/min) = 85,83 + 8,25 x poid (kilogramme) (\ub1 3,15) et DEM (L/min) = 3,67 + 28,15 x \ue2ge (ann\ue9es) (\ub1 3,51). Les valeurs du DEM pr\ue9vues obtenues en utilisant des premi\ue8res formules \ue9taient g\ue9n\ue9ralement inf\ue9rieures aux valeurs observ\ue9es. Conclusion : Le DEM a \ue9t\ue9 obtenu dans les enfants et les adolescents de sant\ue9 normale d' Hausa-Fulani \ue0 Sokoto et les formules de pr\ue9vision d\ue9riv\ue9es pour l'usage dans cette population. Les r\ue9sultats de cette \ue9tude sugg\ue8rent que l'utilit\ue9 des formules de pr\ue9vision puisse \ueatre limit\ue9e au groupe ou \ue0 la localit\ue9 ethnique desquels ils ont \ue9t\ue9 d\ue9riv\ue9s

Genome-wide analysis identifies 12 loci influencing human reproductive behavior.

The genetic architecture of human reproductive behavior-age at first birth (AFB) and number of children ever born (NEB)-has a strong relationship with fitness, human development, infertility and risk of neuropsychiatric disorders. However, very few genetic loci have been identified, and the underlying mechanisms of AFB and NEB are poorly understood. We report a large genome-wide association study of both sexes including 251,151 individuals for AFB and 343,072 individuals for NEB. We identified 12 independent loci that are significantly associated with AFB and/or NEB in a SNP-based genome-wide association study and 4 additional loci associated in a gene-based effort. These loci harbor genes that are likely to have a role, either directly or by affecting non-local gene expression, in human reproduction and infertility, thereby increasing understanding of these complex traits

Iron Behaving Badly: Inappropriate Iron Chelation as a Major Contributor to the Aetiology of Vascular and Other Progressive Inflammatory and Degenerative Diseases

The production of peroxide and superoxide is an inevitable consequence of aerobic metabolism, and while these particular "reactive oxygen species" (ROSs) can exhibit a number of biological effects, they are not of themselves excessively reactive and thus they are not especially damaging at physiological concentrations. However, their reactions with poorly liganded iron species can lead to the catalytic production of the very reactive and dangerous hydroxyl radical, which is exceptionally damaging, and a major cause of chronic inflammation. We review the considerable and wide-ranging evidence for the involvement of this combination of (su)peroxide and poorly liganded iron in a large number of physiological and indeed pathological processes and inflammatory disorders, especially those involving the progressive degradation of cellular and organismal performance. These diseases share a great many similarities and thus might be considered to have a common cause (i.e. iron-catalysed free radical and especially hydroxyl radical generation). The studies reviewed include those focused on a series of cardiovascular, metabolic and neurological diseases, where iron can be found at the sites of plaques and lesions, as well as studies showing the significance of iron to aging and longevity. The effective chelation of iron by natural or synthetic ligands is thus of major physiological (and potentially therapeutic) importance. As systems properties, we need to recognise that physiological observables have multiple molecular causes, and studying them in isolation leads to inconsistent patterns of apparent causality when it is the simultaneous combination of multiple factors that is responsible. This explains, for instance, the decidedly mixed effects of antioxidants that have been observed, etc...Comment: 159 pages, including 9 Figs and 2184 reference

ENDOTHELIUM-DEPENDENT AND -INDEPENDENT RELAXATIONS IN AORTIC RINGS OBTAINED FROM HYPERTENSIVE HOODED (AGUTI) RATS.

Experimental hypertension studies are few in the hooded (Aguti) rat. The present study was designed to investigate the usefulness of this rat strain for experimental hypertension studies and to test the hypothesis that the hypertension may be associated with a diminution of endothelium dependent and independent relaxations. Hypertension was induced in inbred hooded rats (n=8 each) by administering 8% salt in the diet and /or 100 mg/kg/day Nω-nitro-L-arginine-methyl-ester (L-NAME) in the drinking water for six and/or four weeks respectively. The rats were anaesthetized using a 25% urethane and 1% chloralose mixture given intraperitoneally at a dose of 5mg/kg. Their blood pressure was measured invasively. Thereafter, relaxations of rat aortic preparations to acetylcholine, histamine and sodium nitroprusside (SNP) were assessed using standard organ bath conditions. P<0.05 was taken as statistically significant. The mean arterial pressure (MAP;mm Hg) rose significantly in all test groups (Salt: 148.3±4.6; L-NAME: 181.7±8.3; Salt+L-NAME:154.9±8.7) compared with control (94.2±6.8; P<0.05). The MAP was significantly (P<0.05) higher in the L-NAME group than in all the other groups. The heart rate fell significantly in the salt + L-NAME group compared to control (P<0.05).The IC50 of acetylcholine in aortic rings from L-NAME rats (7.9 x 10-1 ± 6.0 x 10-3) was significantly higher than in rings from control (9.4 x 10-8 ± 2.8 x 10-8), salt (7.8 x 10-7 ± 4.7 x 10-7) and salt + L-NAME (3.3 x 10-7 ± 2.1 x 10-7) rats (P<0.05). The IC50 of histamine and SNP in the rings from the test groups of rats showed no significant difference from control. These results suggest that the hooded rat may be useful for experimental hypertension studies. Also, endothelium dependent and independent relaxations were preserved in the various forms of hypertension studied except in chronic NOS inhibition where the former was attenuated in response to acetylcholine

The Vasorelaxant Effect Of Viscum album Leaf Extract Is Mediated By Calcium-Dependent Mechanisms

Viscum album leaf extract has a folk reputation as an antihypertensive agent in Nigeria. Evidence suggests that it has a relaxant effect on smooth muscle. The present study was designed to investigate the role of calcium in the vasorelaxant effect of this extract. Concentration response studies to noradrenaline, KCl and CaCl2 were carried out in rat aortic rings with and without the extract in physiological salt solution (n=6 each). Also the role of intracellular calcium mobilisation was studied by measuring the phasic response to noradrenaline in Ca2+-free EGTA physiological salt solution (n=6). The contractile responses to noradrenaline or KCl were attenuated (P<0.05) and shifted to the right in the presence of the extract. Also the contractile response to CaCl2 in the presence of noradrenaline or KCl was attenuated (P<0.05) and shifted to the right, while the phasic response to noradrenaline was significantly (P<0.05) diminished These results suggest that the vasorelaxant effect of Viscum album extract may be mediated by a non-specific non-competitive inhibition of Ca2+ influx as well as inhibition of Ca2+ mobilization from intracellular stores. This implies that it may contain vasorelaxant agents that may have calcium antagonistic potential