富氧水对高原移居青年PWC170的影响

目的探讨在高原服用富氧水对移居青年体力作业效率的影响。方法对进驻海拔3700m1年的10名青年在服用富氧水前和服用富氧水（每次500ml，每日2次）15d后分别用EGM-Ⅱ型踏车功量计做坐位踏车运动，初始负荷功率为50W，每3min递增50W，以60r／min连续踏车至200W3min后终止。用直线回归法计算每位受试者的PWC170。结果服用富氧水前PWC170为（223．75±15．41）W，服用富氧水后PWC170为（246．23±14．96）w，服用富氧水后较服用富氧水前PWC170明显增高，差异有非常显著性意义（P〈0．01）。结论服用富氧水能明显提高高原移居青年的心功能及做功效率。     

肾小管酸化功能的临床研究

单以尿 pH 作为尿酸化的指标,引起很大争论。本文用尿 pH、HCO_3~-、可滴定酸(TA)、铵(NH_4~ )和同步血气分析为指标,观察正常人氯化铵试验前后、肾脏病人肾功能不全不同时期和肾小管酸中毒病人尿酸化功能的改变。认为尿 NH_4~ 是比尿 pH 更为可靠的指标;在临床应将两者结合起来判断肾小管酸化功能。     

Comparison of patch test results among white Europeans and patients from the Indian subcontinent living within the same community

Background There are few studies comparing the incidence of allergic contact dermatitis among different racial groups living within the same community. Objectives The objectives of this study were to compare white European patients with Fitzpatrick's skin phototypes (FSP) I to IV and patients from Indian, Pakistan and Bangladesh with FSP V living within the same community. Referral rates for patch testing, incidence of contact allergies and differences in contact allergens found were assessed. Method All patients referred to the Contact Dermatitis Unit at Dewsbury and District Hospital between 2004 and 2006, inclusive, were included in the study. All patients were patch tested to the British Contact Dermatitis Society standard series, plus other series according to their clinical history, occupational history and clinical findings. Results Four hundred and thirty‐five consecutive patients from the patch testing clinic were included in the study. Fewer patients from the Indian subcontinent underwent patch testing (11.5%) than would have been expected for the size of the local population (18%). Fewer patients from the Indian subcontinent (44%) had one or more positive reactions compared with the white European patients (56%). No significant differences in the contact allergens responsible were detected between the two racial groups. Conclusion There is a lower incidence of positive patch test results among patients with racial origins from the Indian subcontinent compared with white Europeans. This modest difference could be explained by a lower average age within the study population, and increased or differing exposure to contact allergens rather than demonstration of variability in the susceptibility to develop contact sensitivities following equal exposure.     

Otoneurological abnormalities in asymptomatic HIV-seropositive patients

Twenty-four male patients, all homosexual except one, with asymptomatic HIV-infection were studied. The patients had no signs of opportunistic CNS-infections but 6 had been treated for syphilis. The patients were tested with auditory brainstem response (ABR) audiometry and with oculomotor tests (saccades and smooth pursuit eye movements). The ABR-recordings were pathological in 38% of the cases and the oculomotor tests in 50% of the cases. Abnormality of either one or of both methods were seen in 67% of the patients tested. The duration of the HIV-infection had no influence on the test results. The abnormal otoneurological tests indicate that occult CNS-dysfunction is a frequent finding in asymptomatic HIV-positive patients.     

Critical values for linearity tests in time‐varying smooth transition autoregressive models when data are highly persistent

Summary In this paper, we derive asymptotic distributions for linearity tests in time‐varying smooth transition autoregressive models in the presence of a unit root. The limiting distributions are non‐standard because of the unit root assumption, and it is shown that the linearity hypothesis is rejected far too often (up to 30.9% of the times at a 5% significance level) when using critical values from a chi‐square distribution.     

Behavioral changes during exposure to 1,1,1-trichloroethane: time-course and relationship to blood solvent levels

We report the results of an exposure chamber study in which volunteers were exposed to 0, 950 mg.m-3 (175 ppm) and 1,990 mg.m-3 (350 ppm) of 1,1,1-trichloroethane for 3.5 hours. The time-course of the behavioral changes and the relationship to blood concentrations of 1,1,1-trichloroethane were investigated. A pattern of performance deficits consistent with earlier work was found for some of the tests of psychomotor performance. The time-course of these appeared to be rapid, occurring in some cases within 20 minutes of exposure. For those tasks shown to be sensitive to 1,1,1-trichloroethane exposure, the development of performance changes followed the time-course of blood solvent levels. Two behavioral tests not previously used in this type of work were also employed. One was concerned with the distractability of attention and concentration (the Stroop test), and the other was concerned with analysing grammatical statements (the syntactic reasoning test). Different effects were found. In the Stroop test, enhanced performance was observed following exposure; however, the syntactic reasoning test was found to be resistant to solvent effects. Measures of short-term subjective well-being were not affected by exposure. It is suggested that the observations of time-course effects in performance and their relationship to change in blood solvent levels have implications for psychological test selection and for study designs for examining field exposure.     

Cytotoxic effector cells of the immune system

Summary The organism contains several types of cytotoxic cells which are able to lyse host and foreign cells. Cytotoxic T-lymphocytes (CTL) appear to play the most important role among the killer cells but other lymphatic cells, such as natural killer (NK) cells and lymphokine-activated killer (LAK) cells as well as macrophages are also highly effective in the lysis of appropriate targets. The various cytotoxic effector cells differ distinctly concerning origin, phenotype, morphology and target cell specificity, but they bear the common feature that they destroy the target cells in a contact-dependent non-phagocytotic process.CTL are characterized by typical lysosomal granules and by the expression of a characteristic pattern of surface molecules. They recognize specific antigens which are presented in context with molecules of class I major histocompatibility complex (MHC). NK cells, on the other hand, kill the appropriate targets without prior immunisation and without requiring recognition of MHC molecules at the target cells. They also bear a typical pattern of surface markers which differ in several aspects from that of CTL. Human NK cells are further characterized by peculiar cytoplasmic granules with parallel tubular arrays which are not present in other cytotoxic cells. LAK cells constitute an additional, only recently described, killer cell population which arise from lymphatic cells in the presence of interleukin-2. They appear to represent a functional unique cytotoxic effector cell system with an exceptionally wide target cell spectrum including normal and malignant cells of different origin. LAK cells, however, show a profound heterogeneity concerning the expression of phenotype surface markers and it is not yet clear whether they are a unique cell line. By electron microscopy they display peculiar intranuclear inclusion bodies which may be associated with prolonged stimulation by interleukin-2. CTL, NK and LAK cells appear to possess similar mechanisms for cytolysis including secretion of pore-forming proteins, serine proteases and other proteins. Furthermore, they are able to trigger the cleavage of DNA in the target cell nucleus by a hitherto unknown pathway.Macrophages differ substantially from other cytotoxic effector cells concerning morphology, phenotype, kinetic of activation and target cell spectrum. They perform a variety of functions whereby contact-dependent target cell lysis represents only one of their properties. After target cell binding they release over 20 different molecules such as interleukin-1 and tumor necrosis-factor-alpha as mediators for cytolysis. Thus, macrophages appear like other cytotoxic effector cells to destroy their appropriate targets by different factors.Taken together the data obtained hitherto suggest that cellular cytotoxicity is mediated by various effector cells which may make a major contribution in the defence against infections and malignancies.Abbreviations ADCC antibody dependent cellular cytotoxicity - CD clone of differentiation - CTL cytotoxic T-lymphocyte - HTL helper T-lymphocyte - IL-2 interleukin-2 - LAK lymphokine-activated killer cell - LGL large granular lymphocytes - MHC major histocompatibility complex - NK natural killer cell - P1 perforin 1 - PTA parallel tubular arrays - TCR T-cell receptor complex     

关于外加死腔和气流阻力复合负荷的心理生理效应研究

以20名健康男性青年为被试者,观察了外加死腔和呼吸阻力联合作用对呼吸功能和呼吸阻力感觉的影响。结果表明,在外加阻力条件下,外加死腔使反映通气功能和呼吸型式的参数值增加,且对反映呼吸功的参数具有相互增强的作用。当外加死腔增大时,呼吸阻力感觉阈限提高,相同的呼吸阻力值引起更强的呼吸感觉。上述结果讨设计制作呼吸防护装备具有参考价值。     

Natural killer and lymphokine-activated killer activities in stomach cancer patients with special emphasis on the effect of 5-fluorouracil, adriamycin and mitomycin-C chemotherapy

The cytotoxicities of peripheral blood lymphocytes (PBL) and lymphokine-activated killer (LAK) cells were studied to evaluate the effect of chemotherapy on cellular immunity, in 18 patients with unresectable stomach cancer before and after chemotherapy with 5-fluorouracil, adriamycin and mitomycin-C (FAM), and in 21 healthy volunteers. LAK cells were generated in vitro by culturing PBL with 100 U recombinant human interleukin-2 (rH-IL-2)/ml for 72 h. K562 (human myelogenous leukemia), MKN-45 (human stomach adenocarcinoma) and PC-14 (human pulmonary adenocarcinoma) were used as target cells. The cytotoxicity of PBL to K562 and MKN-45 was suppressed in patients with stomach cancer before chemotherapy, compared with that in healthy volunteers (P less than 0.05). The cytotoxicity of LAK cells was significantly higher to all three cell lines tested than that of PBL in both the healthy volunteers and stomach cancer patients (P less than 0.01); however, a lower level of LAK activity was generated in patients with cancer compared to that in the healthy volunteers. FAM therapy did not suppress the cytotoxicities of PBL and LAK cells. The surface markers of PBL and LAK cells were measured, demonstrating that there was no significant change in the percentage of lymphocytes with CD3+, CD4+, CD8+, CD16+ or CD19+ after chemotherapy. The ratios of CD4+ to CD8+ cells in PBL and LAK cells were also not significantly changed after chemotherapy. In the present study, we have demonstrated that the PBL of stomach cancer were defective in generating LAK activity compared to those of controls, but the LAK activity generated from PBL receiving chemotherapy was similar to that from PBL without chemotherapy in stomach cancer patients.