小包装全氟丙烷气体动力学实验研究

为检验塑料小包装全氟丙烷气体（C3F8）在不同包装和储存方法时浓度变化，将装有5～7mlC3F8的聚氯乙烯小袋，根据不同储藏温度和外包装方法随机分成四组：（1）22℃聚乙烯外包装，（2）36℃聚乙烯外包装，（3）22℃铝箔真空外包装，（4）-29℃聚乙烯外包装；每一组C3F8小袋气体存放一定时间后，应用气相色谱分析方法进行浓度测量。结果：第3组C3F8浓度最高和稳定，第2组浓度随放置时间降低最明显，第4组是临床应用气体的储藏和包装方法，其30天样本浓度和第3组相等，但放置一年时浓度降低。结果显示：塑料小包装C3F8予以铝箔真空外包装是一种可行的方法，利于C3F8运输和普及；聚乙烯外包装的C3F8，应放在-29℃保存，时间不超过一年。     

A genetic and environmental time series analysis of blood pressure in male twins

Systolic and diastolic blood pressures were measured on 254 monozygotic (MZ) and 260 dizygotic (DZ) male twin pairs, during middle age (average age 48 years) and at two later age points. Genetic and environmental components of covariation were modeled by time series. For both measures, shared environmental influences were absent and specific environmental influences were largely time-specific. Although heritability was about 0.5 at each time point, genetic variation present at middle age contributed only about 60% to that present 9 years later, the remaining 40% being new. Fifteen years later, at the third time point, no new genetic variation was evident, variation in individual differences being entirely attributable to genetic differences laid down at the two earlier ages. © 1993 Wiley-Liss, Inc.     

维持肢体正常的运动感觉功能所需最少神经根数的实验研究

目的 研究臂丛神经根单发断，２根切断（不同方式联合）及３根切断后对肢体的影响，为治疗臂丛根性撕脱伤寻找更多的潜在移位神经，方法 ２５２只ＳＤ大鼠随机分为１３组：（１）第１－５组（单根神经根切断组）；每组１２只大鼠。分别切断Ｃ５－８Ｔ１各神经根；（２）第６－１２组（２根神经根切断组）；每组２４只大鼠。分别切断相邻及不相邻２根神经根，即Ｃ５，６，Ｃ６，７，Ｃ７，８，Ｃ８Ｔ１，Ｃ５，７，Ｃ６，８和Ｃ７Ｔ     

Reduction in sodium chloride intake: effects on urinary Na, K and aldosterone output in healthy free-living adults

Eleven healthy free-living adults (six women, five men) weighed and recorded all food and drink consumed and collected all urine for two non-consecutive 7-day periods whilst eating their usual diet (Period 1) and attempting to reduce salt intake (Period 2). Bread (including pitta bread) provided on average a quarter of total Na intake of subjects in Period 1 so that wholemeal bread made without added salt was made available in Period 2. All subjects achieved substantial reductions (mean 65%) in Na intake in Period 2 with no change in K intake so that the Na:K molar ratio fell from 1.3 to 0.5. Urinary Na output closely followed intakes and there was a large increase (mean 11.2 μg/d) in aldosterone excretion with a non-significant increase in K output. Simple linear relationships which allow prediction of Na and K intake from the more easily measured urinary output were derived.     

Surgical management for mentosternal contractures by flap procedures

Mentosternal contractures still represent a surgical challenge due to their prominent position. They require early operative treatment for both function and aesthetic reasons. Careful clinical examination of scar position and traction forces, both at rest and when functioning, in addition to proper evaluation of the surrounding soft tissue are mandatory for precise preoperative planning of the required reconstruction. In general, the technically most feasible operation is favored if the functional and aesthetic results are good and postoperative risk for recurrence is low. Between 1987 and 1994, 21 patients with cervical, mentosternal, and mentothoracic contractures were operated upon. Eight patients were reconstructed with local flaps and 13 with microvascular free flaps.     

Transhemation of bovine and human hemoglobin polymers in a simulated circulatory system

All-Union Hematology Research Center, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR A. I. Vorob'ev.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 112, No. 11, pp. 500–501, November, 1991.     

Mutagenicity of benzo(a)pyrenyl-1-sulfate in the Ames test.

Comparison of the mutagenicity of nine isomeric benzo(a)pyrenyl [B(a)P] phenols conjugated with either sulfate or glucuronide was carried out using strain Salmonella typhimurium TA98. Of the nine conjugates tested, only B(a)P-1-sulfate was mutagenic. Accordingly, the mutagenicity of B(a)P-1-sulfate was compared with that of B(a)P and 1-hydroxybenzo(a)pyrene [B(a)P-1-OH] in the presence and absence of rat lung S9 and Aroclor-induced liver S9 with and without an NADPH-generating system. B(a)P-1-sulfate was slightly mutagenic, whereas B(a)P and the 1-hydroxy derivative were nonmutagenic when S9 fractions and NADPH were omitted. Addition of induced liver S9 with NADPH caused mutagenicity with B(a) -1-OH greater than B(a)P greater than B(a)P-1-sulfate. B(a)P-1-sulfate was the only mutagenic species when lung S9 was added. This mutagenicity did not require NADPH. Sodium sulfite, an inhibitor of arylsulfatase, decreased the mutagenicity of B(a)P-1-sulfate. These data suggest that a unique mutagenic species is generated from B(a)P-1-sulfate via arylsulfatase in rat lung.     

Body composition in the elderly: Total body water and anthropometry

Body composition measured with isotopic dilution was compared with anthropometric measurements. The study was carried out in 47 subjects from both sexes, 65 to 92 years old. Total body water (TBW), anthropometric measurements, and dynamometry were assessed. TBW was significatively higher in men than women and decreased with age. Dynamometry and fatfree mass were well correlated (r=0.73 in males and r=0.58 in females) and significantly different between sexes. A negative correlation was found for dynamometry with age, being significant for women. Linear regression equations to predict TBW from anthropometric measurements in males and females were obtained: Males: TBW(I)=19.349+0.617 weight(kg) — 0.931 mid-arm circumference(cm)+0.122 dynamometry (kg) Females: TBW(l)=−5.531+0.343 weight(kg)-0.213 triceps skinfold (mm)+ 0.148 dynamometry(kg) + 3.424 wrist diameter (cm). This simple model is proposed for use in epidemiological and field studies where other more sophisticated methods can not be applied.