红细胞膜Na+泵缺陷与原发性高血压:多元条件Logistic回归分析

1986年在某工厂对红细胞膜Na⁺泵缺陷与原发性高血压的关系进行了103对配比调查。资料分析采用了条件Logistic回归分析方法。本研究提示RBCNa⁺的增高,RBCK⁺及RBCNa⁺,K⁺ATP-ase活性的降低与高血压有显著的联系;血浆Na⁺与体重这两个高血压的重要危险因素均与RBCNa⁺,K⁺ATPase活性的降低有关,提出红细胞膜的Na⁺泵功能缺陷可能是这两个因素对高血压的共同作用环节。     

广西壮族自治区艾滋病抗病毒治疗患者CD4+T淋巴细胞动态趋势及影响因素分析

目的 了解广西壮族自治区(广西)抗病毒治疗患者CD₄⁺T淋巴细胞动态趋势及影响因素。方法 选择2013年1月1日后首次开始抗病毒治疗的成年艾滋病患者,对基线、治疗后6个月和12个月时间段的CD₄⁺T淋巴细胞计数结果进行回顾分析,采用一般线性模型重复测量方差分析描述和分析患者CD₄⁺T淋巴细胞动态趋势及影响因素。结果 4 082例患者基线、治疗后6个月和12个月的CD₄⁺T淋巴细胞计数均值分别为(195.3±155.7)cells/mm³、(331.9±202.6) cells/mm³ 和 (380.9±221.3) cells/mm³, 仅有时间效应时,总体差异有统计学意义(F=3 161.124,P=0.000)。治疗后CD₄⁺T淋巴细胞计数随时间推移而提升,主要影响因素为性别、年龄、基线CD₄⁺T淋巴细胞计数、治疗方案、漏服药物和停药。受性别、年龄、治疗方案、漏服药物、停药等因素影响,治疗后CD₄⁺T淋巴细胞计数随时间推移而呈线性提升趋势。受基线CD₄⁺T淋巴细胞计数、停药等因素影响,治疗后CD₄⁺T淋巴细胞计数提升趋势符合二次方曲线方程。结论 广西艾滋病患者抗病毒治疗后CD₄⁺T淋巴细胞计数提升速度受多种因素影响。针对不同患者适时进行抗病毒治疗可以获得良好预后结果。     

HBsAg阳性母亲HBeAg和新生儿调节性T淋巴细胞关系及对HBV宫内传播的影响

目的 探讨HBsAg阳性母亲的HBeAg与新生儿CD₄⁺CD₂₅⁺Foxp3⁺调节性T淋巴细胞（Treg）含量的关系以及对增加新生儿HBV宫内传播发生风险的影响。方法 选择太原市第三人民医院妇产科分娩的270对HBsAg阳性母亲及其新生儿,收集一般人口学特征及分娩情况等资料,采用荧光定量聚合酶链式反应（FQ-PCR）和化学发光免疫试验（CLIA）检测母婴外周血HBV DNA及HBV血清学标志物;流式细胞术（FCM）检测新生儿外周血Treg等免疫细胞含量。结果 母亲HBeAg阳性是HBV宫内传播的危险因素（OR=4.08,95% CI：1.89~8.82）;母亲HBeAg阳性者新生儿Treg含量高于阴性者（Z=2.29,P=0.022）;按母亲HBeAg滴度分为5组,各组间新生儿Treg、HBeAg及母亲HBV DNA随母亲HBeAg滴度增高呈上升趋势,差异均有统计学意义（χ²=18.73,P<0.001;χ²=181.60,P<0.001;χ²=183.09,P<0.001）。偏相关分析中控制母亲HBV DNA以及新生儿HBeAg后,母亲HBeAg与新生儿Treg呈正相关（r_s=0.19,P=0.039）。新生儿Treg与浆细胞样树突状细胞（pDC）、CD₄⁺T淋巴细胞含量为负相关（r_s=-0.21,P=0.017;r_s=-0.23,P=0.009）。结论 HBsAg阳性母亲的HBeAg可能通过上调新生儿Treg含量,影响树突状细胞和效应T淋巴细胞的功能及其对HBV的免疫应答,从而增加新生儿发生HBV宫内传播的风险。     

吴忠市城区高血压211例配对研究

211例原发性高血压配对研究提示:吴忠市城区回、汉族高血压高危年龄均在45~54岁年龄组。高血压的发生与遗传(χ²=36.13,P<0.001,RR=6.2)、体型肥胖(χ²=26.41,P<0.001,RR=4.38)、睡眠不足(χ²=15.76,P<0.001,RR=2.71)有密切的联系,与性格急躁(χ²=4.44,P<0.05,RR=1.54)、饮酒(χ²=5.04,P<0.05,RR=3)也有一定的联系;而吸烟和饮食口味偏咸两个因素与高血压的联系无显著的统计学意义。回、汉族资料表明:遗传作用在回族高血压发病中较汉族更为明显;性格急躁一因素在回、汉族中所分别显示出的患本病危险性也存在有差异,而以回族者为高。     

71例男性乳腺癌患者临床与预后分析

目的探讨男性乳腺癌(MBC)患者临床病理特征及其预后。方法回顾性分析天津医科大学附属肿瘤医院2002年3月至2012年3月71例MBC患者的临床病理及生存资料。结果MBC患者年龄43~84(M=62)岁，中位年龄大于同期女性乳腺癌(FBC)患者(t=6．355，P=0．000)，与同期FBC例数之比为o．42%(71：16 796)；MBC病理类型以浸润性导管癌(x²=29．875，P=0．000)、临床分期以>ⅢA(x²=13．377，P=0．037)多见。MBC患者雌激素受体阳性率明显高于FBC患者，而人类表皮生长因子受体-2(HER-2)阳性率明显低于FBC患者x²=3．741，P=0．048；x²=12．845，P-0．002)。单因素和多因素分析发现MBC患者预后比FBC患者差(P-0.004，P=0.046)。MBC患者的HER-2表达水平是影响其预后的重要因素(x²=4．219，P=0．040)。结论MBC与FBC的临床特征及预后均存在显著差异。HER一2阳性可能对MBC的预后及治疗有重要意义。     

母亲孕前BMI和孕期增重与子代孤独症之间关系的研究

目的 探讨母亲孕前BMI和孕期增重与子代孤独症之间的关系。方法 选取2013－2014年经医疗机构确诊的181例1～5岁孤独症儿童为病例组,采用1 ∶ 1病例对照研究方法选择同地区、同性别、同年龄发育正常的儿童作为对照组。按母亲孕前BMI值分为低、正常和高3组,孕期增重根据美国医学研究所标准分为低、正常和高3组,采用SPSS 18.0软件进行χ²检验和logistic回归分析。结果 两组儿童年龄和性别分布均衡(χ²=0.434,P >0.05)。病例组母亲孕前BMI平均值为(21.28±3.80)kg/m²,高于对照组的(19.87±2.83)kg/m²,差异有统计学意义(χ²=9.580,P< 0.05);病例组母亲高BMI人数(10.5%)多于对照组(2.8%);随着孕前BMI增加,子代孤独症患病风险逐渐增大,高BMI组子代孤独症发病风险是正常BMI组的3.7倍(OR=3.71,95%CI:1.34～10.24);病例组正常BMI母亲孕期增重过度(44.1%)高于对照组(33.9%);病例组高BMI母亲孕期增重过度(52.6%)明显高于对照组(20.0%),正常BMI(χ²=8.690,P< 0.05)和高BMI(χ²=4.775,P< 0.05)母亲孕期增重过度与孤独症发病有关。logistic回归分析显示,母亲孕前高BMI(调整前OR=1.89,95%CI:1.26～2.85;调整后OR=1.52,95%CI:1.19～2.27)和孕期增重过度(调整前OR=1.63,95%CI:1.08～1.25;调整后OR=1.64,95%CI:1.21～2.21)是子代孤独症发生的危险因素。结论 母亲孕前超重/肥胖和孕期增重过度与子代孤独症发生有一定的关系,可能是孤独症的危险因素。     

杭州市社区医务人员慢性病防治技能干预效果评价

目的 评价牛津健康联盟-社区健康干预(Community Interventions for Health, CIH)项目是否有利于提高杭州市社区医务人员对慢性病防治相关技能的掌握及操作情况。方法 选取杭州市下城、拱墅和西湖区3个城区,采用平行对照、非随机分组的类实验设计设置干预区与对照区。在干预区开展为期2年的有关慢性病干预及管理技能的综合性干预,并对干预效果进行评价。基线调查获得有效问卷985份,随访调查获得有效问卷870份。结果 经过2年干预后,干预区医务人员对接诊或服务患者进行血胆固醇、血压、空腹血糖检测的比例高于干预前,差异有统计学意义(χ²=7.97,P=0.05; χ²=27.21,P=0.00; χ²=21.32,P=0.00),对照区的血糖测量比例(31.19%)高于基线调查时比例(25.37%),差异有统计学意义(χ²=15.29,P=0.00)。在干预区,平衡膳食、合理营养重要性的医患交流高于干预前,差异有统计学意义(χ²=8.64,P=0.03),如何增加体力活动、如何戒烟的交流无论干预区还是对照区干预前后均无统计学变化。多因素logistic回归分析显示,筛查常见慢性病的技能培训、管理慢性病患者的技能培训均与血胆固醇、血压和空腹血糖的检测相关联。慢性病咨询、建议的培训也在一定程度上影响着医患慢性病危险因素的交流。结论 对社区医务人员实施一系列慢性病防治知识、技能的培训,能够在一定程度上推动医务人员慢性病相关检测的开展,并促进慢性病防治知识、技能的医患交流。     

中国8省(自治区)高血压和2型糖尿病患者健康管理服务实施现状

目的了解基本公共卫生服务高血压和2型糖尿病患者健康管理项目的开展现状。方法在全国选取8省(自治区),采用分层多阶段随机抽样方法,共调查≥35岁管理满1年的高血压患者5 116名和2型糖尿病患者3 586名。通过面对面问卷调查和现场体检,调查患者接受健康管理情况、血压和血糖水平、随访满意度等。结果高血压和糖尿病患者管理率分别为23.6％(城市：17.1％,农村：28.1％,χ²=27 195,33,P<0.001)和19.1％(城市：14.1％,农村：23.8％,χ²=7423.67,P<0.001),规范管理率分别为61.1％(城市：63.3％,农村：58.6％,χ²=11.82,P<0.001)和59.0％(城市：61.5％,农村：55.6％,χ²=12.66,P<0.001),患者血压和血糖控制率分别为50.3％(城市：62.0％,农村：36.6％,x 2=329.31,P<0.001)和53.9％(城市：60.8％,农村：44.7％,f=90.53,P<0.001),高血压和糖尿病患者随访满意率分别为83.0％(城市：84.7％,农村：80.7％,f=13.42,P<0.001)和84.5％(城市：88.0％,农村：79.5％,χ²=43.90,P<0.001)。结论基本公共卫生服务高血压和糖尿病患者健康管理项目取得一定成效。     

华容县农村肝癌病例对照研究

为探讨肝癌病因,我们于1985年6月在华容县农村完成了99对随机样本的肝癌病例对照调查。病例对照同居一个大队,在性别、死亡年龄和死亡时间上配比。调查的因素有疟疾史、血吸虫史、肝炎史、家族史、饮酒史、接触农药史、饮食史和水源类型,运用OR、χ²和χ²MH进行统计处理.结果配比调查发现疟疾(OR=2.08,χ²=4.90)、遗传(OR=18.0,χ²=16.06)、饮酒(OR=1.88,χ²=4.59)与肝癌有关,其它因素无关联;进一步分析还证实,疟疾发作次数与肝癌之间,饮酒度与肝癌之间存在剂量反应关系。     

妊娠期妇女甲状腺功能减退对妊娠结局和胎儿影响的分析

目的 分析妊娠期妇女甲状腺功能减退(甲减)对妊娠结局和胎儿的影响。方法 选择2013年1月至2015年10月在上海市第八人民医院行产前检查并分娩的4286例孕妇为研究对象,入组患者均在孕10周时行甲状腺功能检查,分为甲减、亚临床甲状腺功能减退(亚甲减)和健康3组,分析甲减发生状况及其对妊娠结局和胎儿的影响。结果 共检出甲减209例,发生率为4.9%(209/4286),其中临床甲减85例,亚甲减124例。健康组早产发生率(1.0%)明显低于甲减组(10.6%)和亚甲减组(6.5%),差异有统计学意义(χ²=38.884,P<0.001;χ²=17.722,P<0.001);健康组贫血发生率(3.8%)明显低于甲减组(18.8%)和亚甲减组(9.7%),差异有统计学意义(χ²=30.949,P<0.001;χ²=23.275,P<0.001);健康组低体重发生率(1.1%)明显低于甲减组(14.1%)和亚甲减组(4.8%),差异有统计学意义(χ²=50.593,P<0.001;χ²=15.637,P<0.001);健康组胎儿窘迫发生率(1.9%)明显低于甲减组(10.6%)和亚甲减组(5.6%),差异有统计学意义(χ²=19.257,P<0.001;χ²=12.357,P<0.001);健康组胎儿Apgar评分(9.69±0.32)明显高于甲减组(9.25±0.45)和亚甲减组(9.28±0.44),差异有统计学意义(t=8.823,P<0.001;t=15.175,P<0.001)。结论 妊娠期妇女甲减可对妊娠结局和胎儿构成不利影响,临床应加强妊娠期妇女相关检查,早发现早治疗。     

Contribution of genetic and environmental influences to ankle-brachial blood pressure index in the NHLBI Twin Study. National Heart, Lung, and Blood Institute

The ankle-brachial index (ABI) is widely used in the clinical diagnosis of peripheral arterial disease. The contributions of genetic and environmental influences to normal and abnormal ABI values are unknown. In this study, the authors used available data on 94 monozygotic pairs and 90 dizygotic pairs of elderly, White, male twins examined in 1995-1997 to investigate the contributions of genetic and environmental influences to normative ABI values. Within-twin-pair correlations for normative ABI values were statistically significant, and the correlation in monozygotic twin pairs was significantly greater than that in dizygotic pairs. Structural equation modeling of the variance-covariance matrices of monozygotic and dizygotic twins indicated that 48% of the observed variability in ABI values could be attributed to additive genetic effects. In contrast, concordance rates for low ABI values (ABI< or =0.9) for both monozygotic and dizygotic twins were significantly greater than would be expected by chance alone, but within-pair monozygotic similarity was not significantly greater than dizygotic similarity. A matched-cotwin analysis in 21 pairs that were discordant for low ABI values found that twins with low ABI values were physically less active and more likely to be persistent smokers than their normal-control brothers. These findings reinforce the role of individual health practices (e.g., physical activity, smoking) in the manifestation of peripheral arterial disease among subjects matched for age, genetics, and early shared environment.     

The role of genetic and environmental factors in the association between birthweight and blood pressure: evidence from meta-analysis of twin studies

BACKGROUND: An inverse association between birthweight and later blood pressure has been found in many studies in singletons. Twin studies have been used to examine whether genetic factors or family environment could account for this association. METHODS: A systematic review identified 10 studies covering 3901 twin pairs. Meta-analysis of regression coefficients for the association between birthweight and systolic blood pressure was carried out for unpaired versus paired associations and for paired associations in dizygotic versus monozygotic pairs. RESULTS: After adjustment for current weight or body mass index (BMI), the difference in systolic blood pressure per kg birthweight was -2.0 (95% CI: -3.2, -0.8) mmHg in the unpaired analysis and -0.4 (95% CI: -1.5, 0.7) mmHg in the paired analysis in the same subjects. In the paired analysis by zygosity, in all twins the coefficients were -0.7 (95% CI: -2.3, 0.8) mmHg in dizygotic pairs and -0.8 (95% CI: -2.1, 0.4) mmHg in monozygotic pairs, but in studies which included zygosity tests the coefficients were -1.0 (95% CI: -3.3, 1.6) mmHg in dizygotic pairs and -0.4 (95% CI: -1.9, 1.3) mmHg in monozygotic pairs. CONCLUSIONS: The attenuation of the regression coefficient in the paired analysis provides support for the possibility that factors shared by twins contribute to the association between birthweight and blood pressure in singletons. Comparison of paired analysis in monozygotic and dizygotic pairs could not provide conclusive evidence for a role for genetic as opposed to shared environmental factors.     

Lifestyle factors in monozygotic and dizygotic twins

In examining genetic influences on biological variables using twins, it may be important to examine the distribution between and within twin pairs of demographic and lifestyle factors that may themselves affect the biological variable being studied. We explored the distribution of demographic and lifestyle factors that may affect blood lipid levels or ischaemic heart disease (IHD) risk among a sample of 106 monozygotic (MZ) and 94 like-sex dizygotic (DZ) twin pairs. In our sample, MZ twins were statistically significantly different from DZ twins only in marital status, cigarette smoking habits, and the ratio of polyunsaturated to saturated fat (P:S ratio) in their dietary intake. The latter variable was among many dietary variables examined (using 4-day weighed food diaries), and the size of the difference in intake was small. When comparisons were made of the similarities within twin pairs, we found members of MZ twin pairs to be statistically significantly closer than DZ twins in educational achievement, occupation, cigarette smoking, and exercise habits, and the number of days a week on which alcohol was consumed. These last three variables were consistently closer among twins with closer contact than among those with a smaller degree of current shared environment. For 12 of the 13 nutrients examined, the within-pair correlations were higher for MZ than for DZ twins, although our test for significant genetic variance showed statistical significance only for intake of complex carbohydrates. We conclude that MZ twins share demographic and lifestyle factors that might influence the risk of IHD and blood lipid levels to a greater degree than do DZ twins, although it is difficult to say if these similarities in lifestyle result from genetic influences or not. Nevertheless, ascribing differences between correlations in MZ and DZ twin pairs for lipid levels as being purely "genetic"--as implicit in conventional measures of heritability--is likely to overestimate the influence of genetic factors.     

Major genetic susceptibility for venous thromboembolism in men: a study of Danish twins

BACKGROUND: Although several genetic determinants (mutations or polymorphisms) have been associated with increased risk of venous thromboembolism, the overall influence of genetic factors on this disease is unknown. METHODS: We linked the Danish Twin Registry, which includes twins born 1870-1953, with the Danish National Registry of Patients, comprising all hospitalizations in Denmark since 1977. We then determined the risk of venous thromboembolism as determined from discharge diagnosis. RESULTS: We identified 26,982 twins who were alive on 1 January 1977, and computed measures of familial and genetic association of venous thrombotic disorders. Individuals were classified according to zygosity and hospitalization with venous thromboembolism. Since 1977, 678 twins were hospitalized with an episode of venous thromboembolism. Of these, only 545 pairs (281 male pairs and 264 female pairs) were alive in 1977. For men, the concordance rates for mono- and dizygotic twin pairs, respectively, were 0.22 (95% confidence interval = 0.14 to 0.30) and 0.08 (0.04-0.12). The odds ratio (interpreted as the relative risk of venous thromboembolism for one twin, given venous thromboembolism in the partner twin) was 13.5 (7.3-24.8) among monozygotic twins and 3.8 (1.8-8.3) among dizygotic twins. The respective correlations for venous thromboembolism were 0.55 (0.38-0.70) and 0.26 (0.09-0.42). The proportion of the variance attributable to genetic effects on venous thromboembolism in males was 55% (39%-68%). The remaining variation could be attributed to men's nonfamilial environments. In contrast, for women there was no intra-twin pair similarity for venous thromboembolism. CONCLUSIONS: We found differences in genetic susceptibility to venous thromboembolism between the sexes, with genetic factors playing a substantially stronger role in males than in females.     

Genetic and environmental causes of variation in renal tubular handling of sodium and potassium: a twin study

We have conducted a study of renal sodium and potassium reabsorption in 205 pairs of twins on freely chosen diets; 89 of the subjects were studied on more than one occasion. Renal tubular sodium and potassium handling, as measured by the fractional excretions FENa and FEK, show repeatable differences between individuals. Siblings (in this case monozygotic and dizygotic pairs of twins) are more alike in this respect than unrelated individuals. Comparison of monozygotic and dizygotic twin pairs indicates that genetic, rather than shared environmental, factors are probably responsible for this similarity, with heritability estimates of 0.5 for sodium and 0.6 for potassium. There are indications of sex differences in the sizes of the genetic and environmental effects for both variables and indications that the genetic effects may be qualitatively different for FEK. Such findings need further investigation.     

Comparison of the Concordance of Cardiometabolic Diseases and Physical and Laboratory Examination Findings between Monozygotic and Dizygotic Korean Adult Twins: A Cross-Sectional Study Using KoGES HTS Data

This study investigated the contribution of genetic and environmental factors to cardiometabolic diseases (CMDs) by comparing disease concordance in monozygotic and dizygotic twins. This cross-sectional study analyzed 1294 (1040 monozygotic and 254 dizygotic) twin pairs (>20 years) based on the Korean Genome and Epidemiology Study data (2005–2014). The odds ratios of disease concordance were calculated using binomial and multinomial logistic regression models. The occurrence of CMDs (hypertension, hyperlipidemia, type 2 diabetes, cerebral stroke, transient ischemic attack, and ischemic heart disease) and related physical and laboratory levels did not differ between the monozygotic and dizygotic twin groups. The odds for concordance of the presence/absence of CMDs and the likelihood of incident CMD within monozygotic twins were comparable to that of dizygotic twins. The absolute differences in hemoglobin A1c, insulin, low- and high-density lipoprotein cholesterol, total cholesterol, triglycerides, and systolic blood pressure were lower in monozygotic twins than in dizygotic twins. Absolute differences in fasting glucose and diastolic blood pressure did not differ between groups. Although baseline levels of several laboratory parameters related to CMD showed a strong likelihood of heritability in monozygotic twins, CMD phenotype appears to be largely affected by environmental factors.     

Comparison of the Coincidence of Osteoporosis,Fracture, Arthritis Histories,and DEXA T-Score between Monozygotic and Dizygotic Twins: A Cross-Sectional Study Using KoGES HTS Data

We explored the genetic and environmental inter-relationships among osteoporosis, fracture, arthritis, and bone mineral density concordance in monozygotic twins compared to those in dizygotic twins. This cross-sectional research assessed data of 1032 monozygotic and 242 dizygotic twin pairs aged >20 years included in the Healthy Twin Study data of the Korean Genome and Epidemiology Study between 2005 and 2014. Outcomes of interest included illness concordance and absolute differences in dual-energy X-ray absorptiometry (DEXA) T-scores. We found comparable concordances of osteoporosis, fractures, osteoarthritis, and rheumatoid arthritis between monozygotic and dizygotic twins. Medical histories of osteoporosis, fractures caused by accident or falling, osteoarthritis, and rheumatoid arthritis were not distinct between monozygotic and dizygotic twins. Accidental fracture occurrence in both monozygotic twins showed significantly lower odds than that in dizygotic twins. Genetic influence on liability to fracture risk might thus be maintained. DEXA T-scores for bone mineral density indicated more comparable tendencies within monozygotic twin pairs than within dizygotic ones, suggesting the relative importance of genetic contribution to bone mineral density. The relative importance of genetic factors in bone mineral density is sustained between monozygotic twins; overt disease expression of osteoporosis, fractures, or arthritis may be affected by environmental factors.     

Effect of cadmium on transmembrane Na+ and K+ transport systems in human erythrocytes.

The effects of cadmium (Cd2+) on Na+,K(+)-ATPase in disrupted human erythrocyte membranes and on various transmembrane Na+ and K+ transport systems in intact erythrocyte suspensions were studied. Cadmium2+ inhibited the erythrocyte Na+,K(+)-ATPase enzyme with a 50% inhibition at a Cd2+ concentration of 6.25 microM. The Cd2+ inhibition in the human erythrocyte was non-competitive with respect to Na+,K+, and ATP. Cadmium2+ exerted no acute effect, however, on the Na+,K(+)-ATPase pump activity as measured by the ouabain sensitive 86Rb uptake or Na+ efflux in intact red blood cells. Cadmium2+ also inhibited the Ca2+ dependent K+ channels in human red blood cells, whereas it had no effect on Na+,K+ cotransport, Na+,Li+ countertransport, anion carrier, and the number of active Na+ pump units. The data indicate that in human erythrocytes under acute conditions Cd2+ exerts an inhibitory effect on Na+,K(+)-ATPase enzyme in disrupted erythrocytes and the Ca2+ stimulated K+ efflux in intact red blood cells without affecting the Na+ pump, Na+,K+ cotransport, and Na+,Li+ countertransport activity.     

Effect of cadmium on transmembrane Na+ and K+ transport systems in human erythrocytes.

The effects of cadmium (Cd2+) on Na+,K(+)-ATPase in disrupted human erythrocyte membranes and on various transmembrane Na+ and K+ transport systems in intact erythrocyte suspensions were studied. Cadmium2+ inhibited the erythrocyte Na+,K(+)-ATPase enzyme with a 50% inhibition at a Cd2+ concentration of 6.25 microM. The Cd2+ inhibition in the human erythrocyte was non-competitive with respect to Na+,K+, and ATP. Cadmium2+ exerted no acute effect, however, on the Na+,K(+)-ATPase pump activity as measured by the ouabain sensitive 86Rb uptake or Na+ efflux in intact red blood cells. Cadmium2+ also inhibited the Ca2+ dependent K+ channels in human red blood cells, whereas it had no effect on Na+,K+ cotransport, Na+,Li+ countertransport, anion carrier, and the number of active Na+ pump units. The data indicate that in human erythrocytes under acute conditions Cd2+ exerts an inhibitory effect on Na+,K(+)-ATPase enzyme in disrupted erythrocytes and the Ca2+ stimulated K+ efflux in intact red blood cells without affecting the Na+ pump, Na+,K+ cotransport, and Na+,Li+ countertransport activity.