Ascorbic acid during cerebral ischemia in newborn piglets

We measured ascorbic acid (reduced and oxidized) in brain, CSF and blood, before, during and after cerebral ischemia in newborn piglets. Bilateral carotid ligation induced a 54% decrease in cerebral blood flow (p < 0.01) and a 43% decrease in the cerebral metabolic rate of oxygen (p < 0.01). After ischemia and reperfusion, we obtained a 60% decrease (p < 0.01) in total brain ascorbic acid content. CSF ascorbic acid increased during reperfusion:+60% at 30min (p < 0.001) and +160% at 120min (p < 0.05). Blood ascorbic acid content did not change. These changes and the absence of massive oxidation of ascorbic acid in brain tissue suggest release of ascorbic acid by the brain during ischemia.     

Proliferative activity and characteristics of the structural-functional organization of the chromosomes in cells of the developing brain, related to the genetically determined excitability of the nervous system in rats

This report describes the results of a comparative genetic analysis of the proliferation activity, level of chromosomal aberrations, and the state of interphase chromatin in nerve cells from the developing brains of rat embryos from lines with nervous systems of different excitation thresholds. A relationship between the basal level of nervous system excitability and these cytogenetic characteristics was found. Higher values were seen in embryos of the high-threshold line VP1, as compared with the low-threshold line NP1. The role of the cytogenetic characteristics of the embryo brain in the processes of CNS development and function are discussed in relation to the genetically determined level of nervous system excitability. Translated from Rossiskii Fiziologicheskii Zhurnal imeni I. M. Sechenova, Vol. 85, No. 1, pp. 93–98, January, 1999.     

TGF-β2对树突状细胞表型和功能的影响

目的: 研究转化生长因子-β2 (TGF-β2)对树突状细胞(dendritic cells, DC)表型和功能的影响. 方法: 体外培养骨髓来源的DC(BMDC)及TGF-β2诱导的DC(TGFβ2-DC). 采用双色免疫荧光化学染色或流式细胞仪(FCM)分析DC的细胞表型. 分离纯化脾脏来源的同种异体T细胞和CD4+ T细胞. 用BMDC及TGFβ2-DC刺激T细胞增殖,并用混合淋巴细胞反应(MLR)测定其能力. 在CD4+ T细胞与BMDC或TGFβ2-DC共培养5 d后,用FCM检测CD4+ T细胞表型的变化. 结果: BMDC表现为CD11c, CD86, MHC class II+和CD8а-的髓系DC. TGF-β2的诱导抑制了DC表面协同刺激分子、MHC classII的表达(P<0.01),并抑制其刺激同种异体T细胞增殖的能力. 与BMDC诱导的CD4+ T细胞相比,TGFβ2-DC诱导的CD4+ T细胞CD152(细胞毒T淋巴细胞相关分子4, CTLA-4)表达上升(P<0.01). 结论: TGF-β2的诱导促使DC表面协同刺激因子表达下降,T细胞合成CTLA-4增加,T细胞的活化和增殖受到明显抑制.     

Giant prostatic utricle (utriculus masculinis): diagnostic imaging and surgical implications

The prostatic utricle is an embryological remnant of the Mullerian duct system. It is often revealed incidentally on voiding cystourethrography in young males undergoing evaluation for possible vesicoureteral reflux. We present the case of a very large prostatic utricle found incidentally on ultrasound evaluation in a 4-year-old boy with a history of recurrent urinary tract infections.     

The clinical significance of lung hypoexpansion in acute childhood asthma

Background Many children experiencing acute asthmatic episodes have chest radiographs, which may show lung hyperinflation, hypoinflation, or normal inflation. Lung hypoinflation may be a sign of respiratory fatigue and poor prognosis.Objective To compare the clinical course in children with asthma according to the degree of lung inflation on chest radiographs.Patients and methods We conducted a retrospective study during a 24-month period (from July 1999 to July 2001) of children aged 0–17 years, who presented to a pediatric emergency department or outpatient clinic with an asthma exacerbation. Chest radiographs obtained at presentation were reviewed independently by three pediatric radiologists who were blinded to the admission status of the patient. The correlation between hypoinflation and hospital admission was assessed in three age groups: 0–2 years, 3–5 years, and 6–17 years.Results Hypoinflation on chest radiographs was significantly correlated with hospital admission for children aged 6–17 years (odds ratio 16.00, 95% confidence interval 1.89–135.43). The inter-reader agreement for interpretation of these radiographs was strong, with a kappa score of 0.76. Hypoinflation was not correlated with admission in younger children.Conclusion Lung hypoinflation is associated with a greater likelihood of hospital admission in children aged 6 years or older. Therefore, hypoinflation was a poor prognostic sign and may warrant more aggressive therapy.     

Effect of factor VIII on tissue factor-initiated spatial clot growth

Using time-lapse videomicroscopy, we studied the role of coagulation factor VIII (fVIII) in tissue factor-initiated spatial clot growth on fibroblast monolayers in a thin layer of non-stirred recalcified plasma from healthy donors or patients with severe Haemophilia A. Analysis of temporal evolution of light-scattering profiles from a growing clot revealed existence of two phases in the clot growth-initiation phase in a narrow (0.2 mm) zone adjacent to activator surface and elongation phase in plasma volume. While the initiation phase did not differ in normal and haemophilic plasmas, the rate of clot growth in the elongation phase in haemophilic plasma constituted only 30% of that in normal plasma. Supplementation of haemophilic plasma with 0.05 U/ml fVIII restored the normal clot growth rate (44.9 +/- 2.5 microm/min) at high but not at low fibroblast density. Our results indicate that the functioning of the intrinsic tenase complex is critical for normal spatial clot growth.