Differences in body composition of black and white girls

Adults have racial differences in body composition that may modulate risks resulting from obesity. Although black and white children have been shown previously to have differences in bone mineral density and subcutaneous body fat, differences in visceral adipose tissue have not been evaluated. We studied 20 black and 20 white normal-weight girls aged 7-10 y, who were matched for weight, body mass index (BMI), bone age, chronological age, Tanner breast stage, and socioeconomic status. Each underwent anthropometric measurements, bioelectrical impedance analysis, dual-energy X-ray absorptiometry (DXA), and abdominal magnetic resonance imaging (MRI) for determination of total (TAT), visceral (VAT), and subcutaneous (SAT) adipose tissue. Serum lipids and fasting and 2-h oral-glucose-tolerance test (OGTT) glucose and insulin concentrations were also measured. There were no differences between groups in absolute waist circumference or waist-to-hip ratio, but waist-to-thigh ratio was smaller in black than in white girls. Black girls had greater bone mineral density and less TAT, VAT, and SAT than whites. VAT was not significantly correlated with any measure of insulin, or with serum lipids. However, both basal and 2-h OGTT serum insulin were significantly correlated with SAT as assessed by MRI in black girls (r2 = 0.46 for basal insulin, P = 0.001: r2 = 0.31 for 2-h insulin, P = 0.01) but not in white girls (r2 < 0.05, for basal and 2-h insulin, NS). We conclude that there are significant racial differences in body composition and differences in the strength of association between abdominal adipose tissue depots and insulin sensitivity in black and white girls.     

A redox-based mechanism for the neuroprotective and neurodestructive effects of nitric oxide and related nitroso-compounds

Congeners of nitrogen monoxide (NO) are neuroprotective and neurodestructive. To address this apparent paradox, we considered the effects on neurons of compounds characterized by alternative redox states of NO: nitric oxide (NO.) and nitrosonium ion (NO+). Nitric oxide, generated from NO. donors or synthesized endogenously after NMDA (N-methyl-D-aspartate) receptor activation, can lead to neurotoxicity. Here, we report that NO.- mediated neurotoxicity is engendered, at least in part, by reaction with superoxide anion (O2.-), apparently leading to formation of peroxynitrite (ONOO-), and not by NO. alone. In contrast, the neuroprotective effects of NO result from downregulation of NMDA-receptor activity by reaction with thiol group(s) of the receptor's redox modulatory site. This reaction is not mediated by NO. itself, but occurs under conditions supporting S-nitrosylation of NMDA receptor thiol (reaction or transfer of NO+). Moreover, the redox versatility of NO allows for its interconversion from neuroprotective to neurotoxic species by a change in the ambient redox milieu. The details of this complex redox chemistry of NO may provide a mechanism for harnessing neuroprotective effects and avoiding neurotoxicity in the central nervous system.     

Electroencephalographic changes in rats received antigens of different parasites

The prevalence of epilepsy in developing countries is much higher than in developed ones. Some of the highest prevalence rates in developing countries have been reported from tropical Africa where parasitic infections are endemic. This work was carried out to assess the effect of different parasitic antigens on the activity of cerebral cortex in rats. Nine crude antigens were used: Adult Fasciola, adult S. mansoni, hydatid cyst, T. spiralis, E. histolytica, Acanthamoeba spp. G. lamblia, Cryptosporidium spp. and crude antigen of T. gondii. All the parasitic antigens induced electroencephalographic changes compared with baseline tracings.     

Is routine pathological evaluation of pediatric hernia sacs justified?

BACKGROUND/PURPOSE: Herniorrhaphy is the most common general surgical procedure performed on children, and hernia sac material is one of the most common tissue specimens microscopically examined in the authors' surgical pathology laboratory. The risk of accidental vas deferens ligation has prompted the recommendation that all hernia sacs be examined pathologically. The authors hypothesized that the incidence of unrecognized vas deferens or epididymis ligation is actually very low and may not warrant routine pathological examination of all pediatric hernia sacs. METHODS: Over a 3-year period (1994 to 1996), pathology reports from all hernia repairs at the authors' institution were reviewed. A total of 1,494 inguinal hernia sacs were pathologically evaluated from 1,077 pediatric patients (417 were bilateral). Pathological diagnoses not affecting clinical management (ie, chronic inflammation, irritated hernia sacs, embryonal remnants, adrenal cortical rests) were classified as incidental findings. Identification of true vas deferens was classified as a positive finding. RESULTS: The study population had a mean age of 3.9 +/- 0.1 years and 963 (89%) were boys. The incidence of vas deferens injury from herniorrhaphy was found to be 0.13% (2 of 1,494), and these were recognized by the pediatric surgeon in the operating room. CONCLUSIONS: When vas deferens injury is suspected, the sample should always be sent to the pathology department for confirmation. However, no occult carcinoma or other pathology was identified, and the remainder of the histological findings did not change the clinical treatment of any child. Given a fixed cost of pathological analysis, elimination of routine hernia sac examination may result in substantial annual savings. Therefore, in the current era of cost containment, recommendations for routine pathological examination of excised pediatric hernia sacs should be reevaluated.     

裸眼取换套管工艺的研究及应用

裸眼取换套管工艺是随着油水井老井及腐蚀损坏而开展的一项新的工艺技术。钻井二公司运用该项技术成功地取换修复了因套管腐蚀老化而停产的５口油水井。在取换套管施工过程中，对工具的配套准备、套管割铣工艺及套管回接技术等进行了应用研究，取得了良好的效果。５口井经试压达到了甲方设计要求的，均已恢复了注水及采油生产。     

Heterogeneity of human platelet density subpopulations in aggregation, secretion of ATP, and cytosolic-free calcium concentration

AIM: To investigate thrombin (500 U.L-1)-, ADP (0.1-30 mumol.L-1)-, and 5-hydroxytryptamine (5-HT, 3 mumol.L-1)-induced aggregation, secretion of ATP and cytosolic-free calcium mobilization in density subpopulations of human washed platelets. METHODS: Using Percoll discontinuous gradient. RESULTS: The human platelets were separated into high density (HD), intermediate density (ID), and low density (LD) subpopulations, and their sizes were diminished with decreasing density (r = 0.978, P < 0.01). The magnitude of aggregations by thrombin, ADP, and 5-HT was more significant in HD platelets than that in LD platelets (P < 0.01). The amount of secretion of ATP induced by thrombin and ADP in HD platelets was also much higher than that in LD platelets (P < 0.01), except for 5-HT which did not cause the ensuring release reaction in any subpopulation of human platelets. Thrombin (1500 U.L-1)-, ADP (mumol.L-1)-, and 5-HT (3 mumol.L-1)-induced cytosolic-free calcium mobilization was evaluated as well. Results showed that the resting level of cytosolic-free calcium concentration ([Ca2+]i) was the same in all subpopulations, about 80-90 nmol.L-1. However, the level of [Ca2+]i mobilization was entirely different, heightened with increasing density. CONCLUSION: The function of HD platelets was much stronger and more active than that of LD platelets in human.     

Vitamin E protects human skeletal muscle from damage during surgical ischemia-reperfusion

Idiopathic epidural spinal lipomas are rare: only 13 cases have been described in the literature. We report a further case in an obese patient without known etiological factors. Diagnosis of epidural lipomatosis was performed by MRI. Weight reduction was obtained by conservative treatment, reserving surgery in case symptoms did not disappear. Of the 8 obese patients with idiopathic epidural spinal lipomatosis described in the literature, 3 were treated conservatively, with complete regression of symptoms in 2 cases, partial in the other one. In our patient, the radicular symptomatology disappeared once he had lost weight.     

Colonic strictures in children with cystic fibrosis

PURPOSE: To determine the radiographic, clinical, surgical, and histologic findings in children with cystic fibrosis who develop strictures of the colon. MATERIALS AND METHODS: Ten children (five boys, five girls; age range, 2.5-9.0 years; mean age, 5.5 years), who were treated at the practices of the authors, were retrospectively identified and their medical records reviewed. RESULTS: Radiographic manifestations of the colonic disease included mucosal irregularity and spiculation with nodular thickening of the colonic wall and loss of normal colonic haustration. Luminal narrowing involved long segments of the colon. Longitudinal shortening of the colon was also a prominent feature. The decrease in caliber of the bowel ranged from mild narrowing to complete occlusion of the lumen. Histologic examination revealed severe submucosal fibrosis and fatty infiltration with transmural extension of the fibrosis to involve the serosa in some cases. Unlike in Crohn disease, however, acute inflammatory changes were minimal or absent. CONCLUSION: Colonic stricture in children with cystic fibrosis is due to irreversible and frequently progressive narrowing of the colonic lumen.