Heterogeneity of cerebral vasoreactivity in preterm infants supported by mechanical ventilation

The reaction of cerebral blood flow to acute changes in arterial carbon dioxide pressure (PaCO2) and mean arterial blood pressure was determined in 57 preterm infants supported by mechanical ventilation (mean gestational age 30.1 weeks) during the first 48 hours of life. All infants had normal brain sonograms at the time of the investigation. In each infant, global cerebral blood flow was determined by xenon-133 clearance two to five times within a few hours at different levels of PaCO2. Changes in PaCO2 followed adjustments of the ventilator settings. Arterial oxygen pressure was intended to be kept constant, and mean arterial blood pressure fluctuated spontaneously between measurements. The data were analyzed by stepwise multiple regression, with changes in global cerebral blood flow, PaCO2, mean arterial blood pressure, and postnatal age or intracranial hemorrhage used as variables. In infants with persistently normal brain sonograms, the global cerebral blood flow-carbon dioxide reactivity was markedly lower during the first day of life (mean 11.2% to 11.8%/kPa PaCO2) compared with the second day of life (mean 32.6/kPa PaCO2), and pressure-flow autoregulation was preserved. Similarly, global cerebral blood flow-carbon dioxide reactivity and pressure-flow autoregulation were present in infants in whom mild intracranial hemorrhage developed after the study. In contrast, global cerebral blood flow reactivity to changes in PaCO2 and mean arterial blood pressure was absent in infants in whom ultrasonographic signs of severe intracranial hemorrhage subsequently developed. These infants also had about 20% lower global cerebral blood flow before hemorrhage, in comparison with infants whose sonograms were normal, a finding that suggests functional disturbances of cerebral blood flow regulation. Several perinatal factors were tested, but only birth after abruptio placentae was related to subsequent periventricular hemorrhage (p = 0.037).     

小儿癫痫持续状态心肌损伤的初步研究

目的　探讨小儿癫痫持续状态是否存在心肌损伤。方法　测定 2 4例全身性惊厥性癫痫持续状态患儿 (试验组 )血清心肌酶谱 (包括AST、CK MB、CK、LDH1、LDH)、心肌肌钙蛋白T(cTnT)、心电图 (ECG) ,并与 2 7例非惊厥持续状态的惊厥儿 (对照组 )进行比较。结果　试验组各心肌酶值 (u/L)为AST 2 77.9± 766.8,CK 1615 .8± 70 2 .3 ,CK MB 70 .3±70 .2 ,LDH1180 .0± 162 .0 ,LDH 619.8± 3 91.9;对照组为AST 83 .6± 163 .7,CK 13 4.6± 12 6.8,CK MB 2 5 .4± 13 .4,LDH171.9± 3 8.8,LDH 3 3 9.2± 2 14 .3 ,两组均值进行比较 ,CK ,CK MB ,LDH ,LDH1差异有统计学意义 ,AST差异无统计学意义 ;cTnT试验组测 13例 ,阳性 6例 ,对照组测 8例均阴性 ,两组比较差异有统计学意义 ;ECG试验组查 2 3例异常 15例 ,对照组查 2 4例异常 4例 ,两组比较差异有统计学意义。结论　小儿全身性惊厥性癫痫持续状态可引起心肌损伤     

COMPARATIVE STUDY OF AMINO ACID CONTENTS AND LDH ISOZYME BY ELECTROPHORESIS AND SLAB-PAGE IN ADULT WORMS OF ASCARIS LUMBRICOIDES, ASCARIS SUUM AND TOXOCARA CANIS^

Comparative studies are made on the relative percentages of amino acid content and LDH isozyme by electrophoresis and Slab-PAGE in adult worms of Ascaris lumbricoides, Ascaris suum and Toxocara canis. The results show that there are remarkable differences of Arg and His of 17 amino acids bet. ween Toxocara canis and human intestinal ascaris, human biliary ascaris and pig ascaris; there are also obvious differences of band positions of LDH isozyme electrophoretic patterns and band position and amount of slab-PAGE patterns among them, whereas no marked differences are found in these three indices in human intestinal ascaris, human biliary ascaris and pig ascaris.     

Microsomal glutathione transferase 1 is not S-nitrosylated in rat liver microsomes or in endotoxin challenged rats.

In vitro activation of purified rat microsomal glutathione transferase 1 (MGST1) by S-nitrosylation has been recently reported. This study was designated to explore its in vivo relevance. Unexpectedly, we failed to detect S-nitrosylated MGST1 in rat liver microsomes treated with S-nitrosoglutathione (GSNO); neither did we observe MGST1 S-nitrosylation in endotoxin challenged rats. However, by using matrix-assisted laser dissociation/ionization time-of-flight mass spectrometry (MALDI-TOF MS), we identified several other proteins which are susceptible to S-nitrosylation in liver microsomes, including retinol dehydrogenase type I (RODH I), aldolase B, cytochrome P4502C11, and peroxiredoxin 1. Our results suggest that MGST1 S-nitrosylation is unlikely to be involved in the protection mechanism against nitrosative stress caused by endotoxin challenge. Further studies on the novel S-nitrosylable microsomal proteins are also warranted.     

多分类有序反应变量logistic回归应用条件的检验

目的 对多分类有序反应变量logistic回归的应用条件寻求科学合理的检验方法。方法 使用卡方分布的理论，SAS软件及抽样调查方法。结果 设计出多分类有序反应变量logistic回归应用条件的卡方检验方法，推导出反应变量取各水平的概率计算公式及卡方检验中理论值、自由度的计算公式，并在作者主持的国家医师资格临床实践技能考试研究中取得了成功效果。结论 多分类有序反应变量logistic回归得到完善和补充，具有较大的理论和实际意义。