Irradiance Readings of Phototherapy Equipment: Nigeria

Phototherapy devices (n = 63) at twelve nurseries in Nigeria were evaluated. Irradiance was measured using the BiliBlanket Meter II. Irradiance readings ranged from 0.5 to 18.4 μW/cm²/nm; phototherapy units varied widely, including locally made units, reconditioned machines, and modern equipment. Imported “intact” machines with all blue bulbs had higher irradiance readings than locally made devices using primarily daylight bulbs (2.5–18.4 μW/cm²/nm vs 0.5–4.2 μW/cm²/nm). The distance between infant and phototherapy units ranged from 45 to 60 cm, far exceeding the recommended distance of about 10 cm. Only 6% of the machines provided irradiance of >10 μW/cm²/nm. None delivered intensive phototherapy (irradiance ≥ 30 μW/cm²/nm). Phototherapy devices in developing countries should be assessed for irradiance, and the infant be placed at a distance of about 10 cm from the device. Phototherapy devices with adequate irradiance would reduce the need for exchange blood transfusion and the burden of acute bilirubin encephalopathy in developing countries.     

Prevalence of overweight and obesity in Eti-Osa LGA, Lagos, Nigeria

In many of the urban centres of the developing countries, a change in lifestyle due to increased affluence has been observed. It has been shown that change in lifestyle is an important factor in the global epidemic of overweight and obesity. The aim of this study was to assess the influence of lifestyle and socioeconomic class on the prevalence of overweight and obesity amongst adolescents from rural and urban centres in Lagos, Nigeria. This is a cross-sectional prospective survey carried out on a sample of 1504 randomly selected adolescents, aged between 10 and 19 years, from six public secondary schools located in urban and rural areas of the Eti-Osa local government area of Lagos State, Nigeria. A self-designed completed questionnaire was used to determine the participants' socio-demographic characteristics. Anthropometric measurements were taken to calculate their body mass index (BMI). The overall prevalence rates of overweight and obesity in the urban and rural areas, respectively, were 3.7% and 0.4%, and 3.0% and 0.0%. Socioeconomic class did not significantly affect the BMI values. Overweight is an evolving problem, while obesity is seemingly not a problem yet in adolescent school-aged children in Lagos State, Nigeria.     

Determination of in vivo velocity and endothelial shear stress patterns with phasic flow in human coronary arteries: a methodology to predict progression of coronary atherosclerosis

Background Although the coronary arteries are equally exposed to systemic risk factors, coronary atherosclerosis is focal and eccentric, and each lesion evolves in an independent manner. Variations in shear stress elicit markedly different humoral, metabolic, and structural responses in endothelial cells. Areas of low shear stress promote atherosclerosis, whereas areas of high shear stress prevent atherosclerosis. Characterization of the shear stresses affecting coronary arteries in humans in vivo may permit prediction of progression of coronary disease, prediction of which plaques might become vulnerable to rupture, and prediction of sites of restenosis after percutaneous coronary intervention. Methods To determine endothelial shear stress, the 3-dimensional anatomy of a segment of the right coronary artery was determined immediately after directional atherectomy by use of a combination of intracoronary ultrasound and biplane coronary angiography. The geometry of the segment was represented in curvilinear coordinates and a computational fluid dynamics technique was used to investigate the detailed phasic velocity profile and shear stress distribution. The results were analyzed with several conventional indicators and one novel indicator of disturbed flow. Results Our methodology identified areas of minor flow reversals, significant swirling, and large variations of local velocity and shear stress—temporally, axially, and cirumferentially—within the artery, even in the absence of significant luminal obstruction. Conclusions We have described a system that permits, for the first time, the in vivo determination of pulsatile local velocity patterns and endothelial shear stress in the human coronary arteries. The flow phenomena exhibit characteristics consistent with the focal nature of atherogenesis and restenosis. (Am Heart J 2002;143:931-9.)     

Higher Levels of Alanine Aminotransferase Within the Reference Range Predict Unhealthy Metabolic Phenotypes of Obesity in Normoglycemic First-Degree Relatives of Patients With Type 2 Diabetes Mellitus

J Clin Hypertens (Greenwich). Obesity is a heterogeneous disorder with metabolically healthy and unhealthy phenotypes and varying degrees of cardiometabolic complications. To evaluate whether alanine aminotransferase (ALT) could be used for identification of obese phenotypes, the authors measured ALT, adiponectin, leptin, leptin receptor, free leptin index, high-sensitivity C-reactive protein, fasting insulin, glucose, and full lipid profile in 486 (176 men and 310 women) normoglycemic first-degree relatives of patients with type 2 diabetes mellitus with negative medication history and hepatitis screen. Patients were classified into obesity phenotypes on the basis of the degree of adiposity and the International Diabetes Federation criteria for the metabolic syndrome. One hundred and thirty-seven (28%) patients were positive for the metabolic syndrome, 32 (7%) had normal weight but metabolically unhealthy phenotype, and 201 (41%) were obese but metabolically healthy. ALT showed significant positive correlations with body mass index, waist circumference, beta-cell function, insulin, homeostasis model assessment for insulin resistance, high-sensitivity C-reactive protein, total cholesterol, and triglycerides and increased with increasing number of metabolic syndrome components. Binary logistic regression analyses showed that higher ALT levels within the normal range were significantly associated with the metabolic syndrome. ALT could be used for identification of the metabolically obese phenotype. Lowering the ALT upper normal reference limit will facilitate earlier detection of risky phenotypes of obesity.     

Growth hormone and insulin-like growth factor-I alter hippocampal excitatory synaptic transmission in young and old rats

In rats, as in humans, normal aging is characterized by a decline in hippocampal-dependent learning and memory, as well as in glutamatergic function. Both growth hormone (GH) and insulin-like growth factor-I (IGF-I) levels have been reported to decrease with age, and treatment with either GH or IGF-I can ameliorate age-related cognitive decline. Interestingly, acute GH and IGF-I treatments enhance glutamatergic synaptic transmission in the rat hippocampus of juvenile animals. However, whether this enhancement also occurs in old rats, when cognitive impairment is ameliorated by GH and IGF-I (des-IGF-I), remains to be determined. To address this issue, we used an in vitro CA1 hippocampal slice preparation and extracellular recording techniques to study the effects of acute application of GH and IGF-I on compound field excitatory postsynaptic potentials (fEPSPs), as well as AMPA- and NMDA-dependent fEPSPs, in young adult (10 months) and old (28 months) rats. The results indicated that both GH and IGF-I increased compound-, AMPA-, and NMDA-dependent fEPSPs to a similar extent in slices from both age groups and that this augmentation was likely mediated via a postsynaptic mechanism. Initial characterization of the signaling cascades underlying these effects revealed that the GH-induced enhancement was not mediated by the JAK2 signaling element in either young adult or old rats but that the IGF-I-induced enhancement involved a PI3K-mediated mechanism in old, but not young adults. The present findings are consistent with a role for a GH- or IGF-I-induced enhancement of glutamatergic transmission in mitigating age-related cognitive impairment in old rats.     

Postsynaptic Adenosine A2A Receptors Modulate Intrinsic Excitability of Pyramidal Cells in the Rat Basolateral Amygdala

Background:

The basolateral amygdala plays a critical role in the etiology of anxiety disorders and addiction. Pyramidal neurons, the primary output cells of this region, display increased firing following exposure to stressors, and it is thought that this increase in excitability contributes to stress responsivity and the expression of anxiety-like behaviors. However, much remains unknown about the underlying mechanisms that regulate the intrinsic excitability of basolateral amygdala pyramidal neurons.

Methods:

Ex vivo gramicidin perforated patch recordings were conducted in current clamp mode where hyper- and depolarizing current steps were applied to basolateral amygdala pyramidal neurons to assess the effects of adenosine A_2A receptor modulation on intrinsic excitability.

Results:

Activation of adenosine A_2A receptors with the selective A_2A receptor agonist CGS-21680 significantly increased the firing rate of basolateral amygdala pyramidal neurons in rat amygdala brain slices, likely via inhibition of the slow afterhyperpolarization potential. Both of these A_2A receptor-mediated effects were blocked by preapplication of a selective A_2A receptor antagonist (ZM-241385) or by intra-pipette infusion of a protein kinase A inhibitor, suggesting a postsynaptic locus of A_2A receptors on basolateral amygdala pyramidal neurons. Interestingly, bath application of the A_2A receptor antagonist alone significantly attenuated basolateral amygdala pyramidal cell firing, consistent with a role for tonic adenosine in the regulation of the intrinsic excitability of these neurons.

Conclusions:

Collectively, these data suggest that adenosine, via activation of A_2A receptors, may directly facilitate basolateral amygdala pyramidal cell output, providing a possible balance for the recently described inhibitory effects of adenosine A₁ receptor activation on glutamatergic excitation of basolateral amygdala pyramidal cells.