冠心病、高脂血症和低高密度脂蛋白血症患者载脂蛋白Al基因的多态性

本实验用分析基因限制性内切酶片段长度多态性(Restriction fragment length olymorphisms,RFLPs)技术,检测到中国人载脂蛋白AI(Apolipoprotein AI。Apo AI)基因3′端存一PstI多态位点,并发现该多态位点与低高密度脂蛋白(HDL)血症及冠心病有较密切的关系。     

A dose–response study of total sleep time and the ability to maintain wakefulness

The apparent connection between sleep debt, performance decrements and workplace accidents has generated a need for feasible vigilance tests that focus on the quantification of daytime sleepiness in occupational settings. The objective of this study was to evaluate the sensitivity of the Maintenance of Wakefulness Test (MWT) to acute sleep deprivation of various doses. Eight healthy female volunteers, mean age 28.9 years (range 23–36), participated in this laboratory study. After an adaptation night, the subjects were assigned to four counterbalanced, randomly ordered night sleep conditions. These four conditions allowed for a time in bed (TIB) of 0, 2, 4 or 8 h, producing a total sleep time of 0, 113, 218 and 427 min, respectively. The ability to sustain wakefulness was measured after the TIB period at 11.00 and 17.00 hours by the MWT. Analysis of variance with repeated measures was used to study the dependence of MWT sleep latencies on the immediately prior TIB period. Both the latency of stage 1 sleep onset and the appearance of slow eye movements reduced significantly with increased sleep loss. The quantitative relationship between the previous total sleep time and the subsequent MWT sleep latencies followed an exponentially decaying function showing a high sensitivity to acute, severe night sleep loss but low sensitivity to less severe sleep restrictions. It is concluded that the MWT seems to be a sensitive method for the estimation of acute sleep deprivation. The test results appear, however, non-linearly related to the earlier sleep debt.     

Using the polymerase chain reaction to maintain DNA probe inventories in clinical and diagnostic laboratories

Clinical and diagnostic DNA laboratories must maintain a large inventory of DNA probes for use in hybridization studies. The preparation of plasmid DNA and isolation of DNA fragments for use as probes in both expensive and time consuming. We present here a rapid and relatively inexpensive method of producing large amounts of DNA fragments from stocks, using the polymerase chain reaction (PCR). Our experience over the past year using this technique has been very positive and we believe many laboratories could benefit by employing such a labor-saving approach to maintaining DNA probes. The technique uses the bacteriophage M13 DNA sequencing primers to amplify cloned inserts contained in commonly used plasmid vectors. As examples, we illustrate the use of DNA produced in this manner as probes for linkage analysis of the fragile X syndrome and for detection of deletions in the Duchenne muscular dystrophy gene. We have also found that at least two probes can be amplified in the same PCR reaction, allowing the detection of two different restriction fragment length polymorphisms (RFLP) simultaneously. It should be possible for laboratories to devise strategies particular to their individual needs using more than one DNA probe produced in the same PCR reaction to detect RFLP's. Such strategies would need only to consider that the predicted alleles of the multiple polymorphisms do not migrate to the same position during electrophoresis. Stocks of single or multiple probes produced by the PCR could then be maintained for more rapid Southern analyses.     

Hemophilia A: genetic prediction and linkage studies in all available families in Finland

RFLP studies were done in 82 (75%) of all known hemophilia A families in the Finnish population (approximately 5 million). Two intragenic RFLPs (Bc1I/F8A, XbaI/p482.6) and two extragenic markers (TaqI/St14, Bg1II/DX13) were used. Among 263 females at risk, carriership could be evaluated with an intragenic marker in 47% and with an extragenic marker in 26%. In 27% of the females, carriership could be neither excluded nor confirmed; 68% of these females were relatives of an isolated patient. Eight recombinations between the factor VIII gene (F8C) and DXS52 (lod 25.02 at theta max 0.06), eight recombinations between F8C and DXS15 (lod 21.91 at theta max 0.05), and two recombinations between DXS52 and DXS15 (lod 33.56 at theta max 0.01) were found. Using multipoint linkage analysis, the most likely order of loci supported by the data was: F8C-DXS15-DXS52-DXS134. RFLP segregation analysis provides a highly useful method of carrier detection and prenatal diagnosis of hemophilia A, but its limitations must be carefully taken into account.     

Architectural alterations in rat cerebral microvessels after hypobaric hypoxia

We performed 3-dimensional studies of vascular casts of the microvasculature of the cerebral cortex of rats that were exposed to three weeks of hypobaric hypoxia and of control rats. Scanning electron microscopy of the casts gave the qualitative impression of increased vascularity of the cerebral cortex, particularly the deeper layers, in hypoxic rats. Quantitative analysis of capillary segment lengths revealed a significant shift in the frequency distribution to longer lengths (from 77 ± 8 to 90 ± 14 μm) in the deep, but not in the superficial, layers of the cerebral cortex of hypoxic rats. These findings agree with previous results reporting increased capillary density in the brain after exposure to prolonged hypobaric hypoxia and suggest that capillary segment elongation plays a role in the increased capillary density in the deeper layers of the cerebral cortex.     

269例10万元以上住院费用及影响因素分析

目的分析高额住院费用的成因及影响因素,以控制医疗费用的过快增长.方法选择某综合医院2002年住院费用在10万元以上的病例共269例,分析其费用构成,并对其影响因素进行多元回归分析.结果269例病人的平均费用为159 765元,以治疗费最高,所占比例为51.32%,药费其次,所占比例为36.25%.住院费用的影响因素为:住院天数、院内感染和预后.结论降低过高的住院费用要缩短无效住院日、控制院内感染以及减少无效的治疗和用药.     

巩膜环扎加压术后眼轴与屈光状态的改变

目的：探讨视网膜脱离巩膜环扎加压术后眼部屈光状态的改变。方法：用眼科A超、检影验光等对86例原发性视网膜脱离患者的86只患眼手术前1d及术后1、4、12w时的眼轴长度、眼屈光度等进行测量并将结果进行比较。结果：眼轴长度在术后1、4、12w时均较术前增长(P＜0．01)。眼屈光度在术后1、4、12w时均较术前增加，且向负值偏移(术后1、4w，P＜0．015术后12w，P＜0．05)。结论：巩膜环扎加压术后眼轴长度和屈光状态的变化与眼内嵴有关，术后眼轴增长是眼屈光度负值增加的主要因素。     

红色素基因RFLP及其与情感性精神病关系的研究

以红色素基因全长ｃＤＮＡ作探针，２０例正常人，２６例双相型情感性精神病患者进行ＲＦＬＰ分析。ＳａｃＩ酶切显示：部分正常人和部分患者基因组ＤＮＡ产生的７．５ｋｂ，４．８ｋｂ，４．５ｋｂ呈多态性改变的片段。正常人具多态改变的占４５％，患者为４６．２％，按Ｘ染色体数计，正常人出现７．５ｋｂ限制性片段的频率为１４．３％，患者为３２．４％，但两者差异不显著。     

The relation between conduction velocity and axonal length

Motor evoked potentials (MEPs) obtained by electrical root stimulation and F waves were used to examine the proximal nerve conduction velocity (CV) to tibialis anterior (TA), extensor digitorum brevis (EDB), flexor carpi radialis (FCR), and abductor pollicis brevis (APB) muscles in 40 humans. By subtracting motor latencies obtained by stimulating the peripheral nerve at the same point from the F-wave and MEP latencies, we could measure the CV over identical proximal segments. It was found that proximal CV to TA and FCR was significantly higher than to EDB and APB, respectively. Combining the data of the proximal CV to all four muscles in relation with axonal length resulted in a highly significant inverse relationship (r² = 0.77). Thus the axonal length explained to a large extent the higher CV of the arm nerves and also the inverse relation between body height and CV. The distal CV was always lower than proximal CV; however, there was no support for an additional effect of this gradient in explaining the relationship between CV and height since it was constant for all body heights. © John Wiley & Sons, Inc.     

Work at sea: a study of sleep,and of circadian rhythms in physiological and psychological functions,in watchkeepers on merchant vessels

Summary Sleep length and sleep quality scores were collected on board ships over periods of up to two weeks from 38 watchkeepers working a 4-on/8-off routine and 29 dayworkers. All watchkeepers exhibited fragmented sleeping patterns, which indicated a lack of adaptation of the sleep/wakefulness cycle to the hours of work. There were only slight differences in total sleep length between watchkeepers and dayworkers, however, both groups did not obtain an adequate amount of sleep. Within the watchkeeping crews the 3rd Officers had by far the shortest sleep length. Concerning sleep quality, daytime sleep was generally given the lowest ratings, whereas sleep starting before midnight was on average evaluated as the best, both by watchkeepers and dayworkers. Watchkeeping personnel do not normally have any days off during a voyage so that missed sleep might even amount to a sleep deficit. A solution for this problem could perhaps be a new, stabilized system that allows a single uninterrupted sleep, which is required for full recuperation, to be taken each day.Dedicated to Professor J. Aschoff on the occasion of his 75th birthdayPartly supported by a grant from the Ministry for Technology and Research, Federal Republic of Germany, Project Schiff der Zukunft, Part ET83b