Cardiac output measurement by the thermodilution method: An in vitro test of accuracy of three commercially available automatic cardiac output computers

Objective To describe the accuracy and the reproducibility of the thermodilution flow measurements obtained using 3 commercially available cardiac output computers commonly used in intensive care units.Design An experimental in vitro study. Twelve different values of control flow (Qctr) were measured (Qmsr) using 3 different cardiac output computers (Abbott Critical Care System, Oximetrix 3 SvO₂/CO Computer, Baxter Oximeter/Cardiac Output Computer SAT-1^TM; American Edwards Laboratories, 9520 A Cardiac Output Computer). Standard equipment and techniques were employed, taking account of the specific weight and heat of warm water relative to blood. In addition, separate sets of measurements were performed in order to investigate the effect on Qmsr of some variables which may influence the indicator loss (time for injection, depth of immersion of the catheter, temperature of the injected fluid).Setting Our laboratory, inside the intensive care unit.Measurements and results The analysis of the linear regression of Qmsr versus Qctr (r values between 0.992 and 0.984; residual standard deviation values comprised between 0.24 and 0.49 l/min; intercepts and slopes not significantly different from identity line), the values of the percentage errors (PE=[Qctr–Qmsr]·100/Qctr; PE mean values 7.9, 5.0 and 13.1), and those of the coefficients of variability (CV=standard deviation mean value, %; CV mean values 5.4, 5.8 and 4.6), show a good level of accuracy and reproducibility of the measurements. Our data confirm previously reported results. Furthermore, the cumulative effect of variables capable of influencing the indicator loss, even if corrected according to the calculation constant the manufacturers provide, was found to result in statistically significant changes of Qmsr.Conclusion The accuracy and reproducibility of the automatic cardiac computers tested is sufficient for practical clinical purpose. It may also depend on the modality of injection of the cooling bolus, which may significantly influence the effective indicator losses.     

山慈菇抑制镉诱发遗传损伤研究

采用活体小鼠骨髓嗜多染红细胞（ＰＣＥ）微核试验（ＭＮＴ）,观察中草药山慈菇（ＢｕｌｂｕｓＩｐｈｉｇｅｎｉａｅ）水溶性提取物的诱变作用及对镉（Ｃｄ）、环磷酰胺（ｃｐ）的抗诱变作用。结果表明：山慈菇可以诱发微核（ＭＮ）产生,但其诱变作用不强;山慈菇对Ｃｄ及ｃｐ的诱变作用具有明显的抑制效果,并对Ｃｄ的抑制作用明显强于对ｃｐ的抑制作用。     

福建地区河弧菌噬菌体分型研究

采用７ 株噬菌体按 Ｇｅｒｓｈｍａｎ 的分型法,对从福建地区的人和外环境标本检出的２７１ 株河弧菌作了分型试验。结果有２２３ 株菌能被分型,分型率为８２２９ ％ ,共检出３８ 个不同噬菌体型,其中以６００ 、４００ 、７４０ 、５００ 、６４０ 、７６０ 、０２０ 和６２０ 等８个型较常见,占总分型 菌的４９０８ ％ ;发现人源菌的常见型别与海产品源菌、水源菌和食品源菌的型别关系密切。     

Cumulative biochemical effects of repeated subclinical hydrogen sulfide intoxication in mouse brain

Summary Adult female NMRI mice exposed four times to 100 ppm hydrogen sulfide vapour for 2 h at 4-day intervals showed increasing inhibition of the cerebral cytochrome oxidase activity. Cerebral RNA decreased significantly after the fourth exposure. This change was accompanied by the reduced orotic acid uptake in the RNA fraction. At the same time, 2,3-cyclic nucleotide 3-phosphohydrolase activity used as a marker for glia increased. Acetylcholine esterase activity remained unchanged. The initial exposures also caused an increase in the superoxide dismutase activity and an increase in the glutathione concentration. The latter effects were abolished in the third and fourth exposures. The present data seem to indicate that the biochemical effects of repeated subclinical hydrogen sulfide intoxications are cumulative.     

Biological monitoring of isocyanates and related amines

Summary Five men were exposed to toluene diisocyanate (TDI) atmospheres for 7.5 h. The TDI atmospheres were generated by a gas-phase permeation method, and the exposures were performed in an 8-m3 stainless-steel test chamber. The mean air concentration of TDI was ca. 40 g/m³, which corresponds to the threshold limit value (TLV) of Sweden. The inhaled doses of 2,4- and 2,6-TDI were ca. 120 g. TDI in the test chamber air was determined by an HPLC method using the 9-(N-methyl-aminomethyl)-anthracene reagent and by a continuous-monitoring filter-tape instrument. After hydrolysis of plasma and urine, the related amines, 2,4- and 2,6-toluenediamine 2,4-, and 2,6-TDA), were determined as pentafluoropropionic anhydride (PFPA) derivatives by capillary gas-chromatography using selected ion monitoring (SIM) in the electron-impact mode. The urinary elimination of the TDAs showed a possible biphasic pattern, with rapid first phases for 2,4-TDA (mean t _1/2 for the concentration in urine, 1.9 h) and for 2,6-TDA (mean t _1/2 for the concentration in urine, 1.6 h). The cumulative amount of 2,4-TDA excreted in urine within 28 h ranged from 8% to 14% of the estimated dose of 2,4-TDI, and the cumulative amount of 2,6-TDA in urine ranged from 14% to 18% of the 2,6-TDI dose. The average urinary level of 2,4-TDA was 5 g/l in the 6 to 8-h sample (range 2.8–9.6 g/l), and the corresponding value for 2,6-TDA was 8.6 g/l (range, 5.6–16.6 g/l). Biological monitoring of exposure to 2,4- and 2,6-TDI by analysis of 2,4- and 2,6-TDA in urine is feasible.     

A study of visual and auditory verbal working memory in schizophrenic patients compared to healthy subjects

Impaired working memory (WM) performance is considered as a central feature of schizophrenia. Divided into two components, verbal and spatial, WM has been shown to involve frontal and parietal regions. Verbal WM can be tested either visually or aurally. The present study aimed to test schizophrenic patients in both visual and auditory verbal WM in order to assess a possible distinct pattern of alteration of these two modalities. Twenty-four schizophrenic patients and 24 healthy controls were compared with 2-back continuous visual and auditory verbal WM testing. Both groups were also tested on a neuropsychological battery including Wisconsin Card Sorting Test (WCST). Schizophrenic patients were less efficient in both verbal WM tests. When taking age and educational level as covariates and both WM modalities as dependent variables, there was no differential effect of modalities across groups. In further exploratory analyses, partial correlations brought association between verbal WM and psychosocial adaptation, WCST and length of illness. These results suggest a similar pattern of alteration of both modalities of verbal WM in schizophrenic patients. The implications of this finding are discussed. Received: 16 February 1999 / Accepted: 20 December 1999     

不同浓度乙醇对内皮细胞分泌作用的影响

目的 研究不同浓度乙醇对内皮细胞的保护作用。方法 应用过氧化氢损伤培养的人脐静脉内皮细胞,并与不同浓度乙醇进行孵育,检测内皮细胞产生的内皮素及一氧化氮。结果低、中浓度乙醇明显减少损伤的内皮细胞产生的内皮素。同时实验还提示长时间高浓度乙醇对内皮细胞有明显损伤作用;不同浓度的乙醇均抑制内皮细胞产生一氧化氮。结论低、中浓度乙醇使内皮细胞在受损时生成的内皮素明显减少。     

灌肠合剂的药效学试验

目的:研究灌肠合剂抗炎、解热及促进大肠运动和直肠蠕动等作用。方法:灌肠合剂生药剂量为9.36g/kg(大剂量)和3.12g/kg(小剂量),相当于临床用药的6.9倍和2.3倍。阳性对照药为导便栓,阴性对照品为蒸馏水,其中抗炎试验未设阳性对照。结果:直肠给药,灌肠合剂对鸡蛋清致大鼠足跖肿胀有抑制作用,大剂量组与蒸馏水组比较有显著性差异(P<0.01);能抑制大肠杆菌内毒素致家兔体温升高,受试组与蒸馏水对照组比较有显著差异(P<0.05和P<0.01);能增强大鼠和家兔的大肠运动,给药后粪便排泄量增加,墨汁推进距离延长,受试组与蒸馏水对照组比较有显著差异(P<0.05和P<0.01)。结论:经直肠给药灌肠合剂有抗炎、解热、增强大肠运动和直肠蠕动作用。     

2264例海洛因依赖者HIV抗体检测结果分析

目的：了解海洛因依赖者HIV抗体阳性率并对阳性人群的相关情况进行分析。方法：对所有检测病例抽静脉血3ml，先用HIV(1 2)抗体酶联免疫吸附法进行初筛试验，阳性者送浙江省疾病控制中心用蛋白印迹法进行确诊试验，仍为阳性者确诊为HIV抗体阳性。结果：2264例海洛因依赖者中HIV抗体阳性21例，阳性率为0．93％，全部为男性，且全部为有互用针头及注射器行为的静脉注射者，年龄24～39岁，平均29．3岁，多见于原籍新疆、广西等边远贫困地区的无业人员，文化程度多在初中以下。结论：海洛因依赖者，特别是互用针头及注射的静脉注射者是HIV感染高危人群，新疆、广西等边远贫困地区，男性、无业、初中以下文化水平的青壮年感染率高。     

过氧化氢对豚鼠耳蜗功能及形态的影响

目的 在体观察过氧化氢(H2O2)对豚鼠耳蜗功能及形态的影响。方法 实验动物分为4组，分别灌流人工外淋巴液(artificial perilymph,APL)，50μMH2O2，100μMH2O2和200μMH2O2(H2O2均溶于APL中)，并用Pl和H033342双染色方法观察H2O2引起的内耳细胞损伤情况。结果 所有H2O2灌流组复合动作电位((CAP)阈移和耳蜗微音电位(CM)幅度变化与人工外淋巴液组比较差异有显著性，且各H2O2组的变化呈现出浓度依赖性；Pl和H033342双染色方法发现外毛细胞是H2O2攻击的主要靶细胞，而Hensen细胞未见任何损伤痕迹。结论 H2O2可导致耳蜗功能下降及耳蜗毛细胞损伤：Hensen细胞较毛细胞可能具有更强的抗氧化能力。