Immune-mediated hemolysis associated with the administration of a radiographic contrast medium

A female patient developed serious hemolysis in association with the injection of a radiographic contrast medium (RCM). Serologic investigation of her serum suggested complement-mediated hemolysis, induced by an RCM-dependent IgM antibody in her serum. The antibody was of high titer and low avidity. The antibody showed cross-reactions with related radiographic contrast media and reacted only with group I adult RBCs.     

Maternal immunization to Gov system alloantigens on human platelets

BACKGROUND: Immunization to platelet alloantigens can occur during pregnancy or after the transfusion of blood components. Platelet alloantibodies can cause neonatal alloimmune thrombocytopenia and posttransfusion purpura. Transfusion-induced alloimmunization to a novel platelet alloantigen system, Gov, expressed on the 175-kDa glycosyl phosphatidylinositol-anchored platelet glycoprotein, CD109, was previously described. This report describes three unrelated patients who were alloimmunized to Gov(a) or Gov(b) during pregnancy. STUDY DESIGN AND METHODS: Platelets were typed by using radioimmunoprecipitation for HPA-1a, -3a, -5a, -5b, Gov(a), and Gov(b) and by polymerase chain reaction-restriction fragment length polymorphism for HPA-1a, -1b, -3a, and -3b. Maternal sera were screened for platelet antibodies by using radioimmunoprecipitation and the antigen capture assay. RESULTS: Patients 1 and 2 were investigated after the diagnosis of neonatal alloimmune thrombocytopenia in their children, and alloantibodies specific for Gov(b) and Gov(a), respectively, were detected in maternal serum. Serum from patient 3, who had mild idiopathic thrombocytopenia purpura with no detectable autoantibody, was found to contain alloantibodies to Gov(b) and to HPA- 5b, presumably as a result of immunization during pregnancy. Platelet typings confirmed that the patients were at risk for alloimmunization to the respective antigen. CONCLUSION: This report of three cases of maternal alloimmunization to antigens in the Gov system indicates that immunization can occur via placental transfer of antigen and that Gov system alloantibodies may be associated with neonatal alloimmune thrombocytopenia.     

Double-blind randomized placebo-controlled study of homoeopathic prophylaxis of migraine

Homoeopathic remedies for migrane are widely available over the counter, statutorily offered by the national health service in the UK, and apparently popular with patients. Do they work? Sixty-three outpatients with migraine with or without aura b IHS criteria entered a 4-month randomized placebo-controlled, double-blind, parallel-groups trial of individualized homoeopathic prophylaxis, the first month being baseline with all patients on placebo. Three patients (4.8%) dropped out, leaving 30 in each treatment group. There were chance differences in attack frequency and severity between the groups at baseline (attacks were more frequent but less severe in the placebo group). Both groups improved on therapy but neither to a great extent on the primary outcome measure of attack frequency (verum: −19%; placebo: −16%). Reduction was mostly in mild attacks on placebo, more in moderate and severe attacks on homoeopathy. Few adverse events were reported. Overall, there was no significant benefit over placebo of homoeopathic treatment. The course of change differed between groups, and suggested that improvement reversed in the last month of treatment on placebo. On this evidence we cannot recommend homoeopathy for migraine prophylaxis, but cannot conclude that it is without effect.     

Studies with nonradioisotopic sodium chromate. I. Development of a technique for measuring red cell volume

A nonradioisotopic method for measuring red cell volume that involves the use of 52Cr-sodium chromate as the red cell label and of graphite furnace atomic absorption analysis of chromium is described. The technique allows the labelling of 20 mL of packed red cells with 40 to 50 micrograms of sodium chromate (Na2CrO4) in 30 minutes at 22 degrees C with 94 +/- 6 percent uptake. Approximately 40 micrograms of Na2CrO4 was injected for in vivo studies. This results in posttransfusion in vivo red cell chromium levels after sample processing in the range of 1 to 7 micrograms per L, which could be quantitated accurately (coefficient of variation = 4.7%) by Zeeman electrothermal atomic absorption spectrophotometry. The labeling concentration of chromium did not cause increased hemolysis, and the labeled cells exhibited an osmotic fragility curve similar to that of unlabeled, fresh ACD red cells. Red cell glutathione peroxidase was unaffected by labeling, although glutathione reductase was reduced by approximately 13 percent (p less than 0.05). The 52Cr red cell volume-measuring method was evaluated by concurrent in vivo studies with the standard 51Cr and 125I-albumin methods for that procedure. Simultaneous measurement of red cell volumes in seven volunteers by the 51Cr, 52Cr, and 125I-albumin techniques correlated highly with each other (r greater than 0.76), with mean values of 2294 +/- 199, 2191 +/- 180, and 2243 +/- 291 mL, respectively. The standard deviations of the differences were small: 134 mL for 52Cr versus 51Cr and 183 mL for 52Cr versus 125I.(ABSTRACT TRUNCATED AT 250 WORDS)     

Hyperkalemia enhances the effect of adenosine on IK,ADO in rabbit isolated AV nodal myocytes and on AV nodal conduction in guinea pig isolated heart

BACKGROUND: The atrioventricular (AV) node is insensitive to changes in extracellular potassium concentration, [K+]o, because of the absence of the inward rectifier potassium current (IK1). However, we propose that in the presence of adenosine, elevated [K+]o should increase the adenosine-activated inward rectifier potassium current (IK,ADO) in AV nodal myocytes and hence augment the negative dromotropic effect of the nucleoside. METHODS AND RESULTS: The effects of normal (4.8 mmol/L) and high (8.0 mmol/L) [K+]o on adenosine-induced changes in resting membrane potential (Vm), IK,ADO, and membrane resistance (Rm) in rabbit isolated AV nodal myocytes and in AV nodal conduction delay (atrium-to-His bundle, AH, interval) in guinea pig isolated hearts were determined with the use of whole-cell patch-clamp and His bundle electrogram techniques, respectively. High [K+]o alone did not significantly affect membrane current, Rm, or Vm in AV nodal myocytes. However, high [K+]o in the presence of adenosine (3 micromol/L) markedly increased Im (-0. 249+/-0.038 to -0.571+/-0.111 nA, P<0.05) at -100 mV and reduced Rm (151+/-21 to 77+/-8 MOmega, P<0.02). Adenosine still hyperpolarized Vm from -48+/-2 to -65+/-1 mV (P<0.001). High [K+]o alone did not significantly affect the AH interval in isolated hearts. However, high [K+]o markedly lengthened the AH interval prolongation caused by adenosine (4 micromol/L, 7.9+/-0.8 vs 22.1+/-3.0 ms, P<0.001). The potentiating effect of high [K+]o on adenosine-induced delay in AV nodal conduction was abolished by BaCl2 (100 micromol/L). CONCLUSIONS: By increasing IK,ADO and decreasing Rm of AV nodal myocytes, elevated [K+]o, augments the depressant effect of adenosine on AV nodal conduction.     

促红细胞生成素辅助治疗糖尿病心肌病的疗效观察

目的 探讨促红细胞生成素辅助治疗糖尿痛心肌痛心力衰竭的疗效.方法 将40例糖尿病心肌痛心力衰竭病人随机分为促红细胞生成素组(22例)和对照组(18例).对照组采用ACEI和β受体阻滞剂治疗.促红细胞生成素组采用促红细胞生成素(EP0 3000 IU IH每周2次)联合ACEI和β受体阻滞剂治疗,两组疗程均为5个月.结果 促红细胞生成素组治疗前后相比心功能测定LVEF、6 min步行距离均有显著改善(p＜0.05).组间比较促红细胞生成素组较对照组显著改善(p＜0.05).结论 促红细胞生成素能改善糖尿病心肌病心力衰竭的心功能状态.     

Influence of acetylsalicylic acid on development of radiation-induced nephropathy

Purpose : Previous studies have demonstrated that long-term treatment with acetylsalicylic acid (ASA) can significantly reduce the renal functional impairment that develops after high doses of irradiation. The effect is hypothesized to be mediated by selective inhibition of thromboxane A 2 synthesis and inhibition of platelet aggregation. The present study was undertaken to investigate this phenomenon further using more clinically relevant fractionated and re-irradiation schedules. Methods and materials : Groups of mice were given bilateral renal irradiation with a series of four or 20 daily fractions of X-rays, or 10 daily fractions with a single dose of re-irradiation (0-10Gy) after 27 weeks. Half the mice received ASA in drinking water (2.4 g.l -1) from 1 week before the start of irradiation and continuously throughout the follow-up period. Renal function was assessed by clearance of [ 51 Cr]EDTA, about every 4 weeks for up to 80 weeks after the start of treatment. Histological damage in representative groups of mice was also assessed. Results : Oral administration of ASA caused inhibition of thromboxane A2 synthesis (to < 36% of controls) and a strong inhibition of platelet aggregation in whole mouse blood (ex vivo) . Prolonged treatment with ASA also resulted in a small, non-significant reduction of radiation-induced renal functional damage. No reduction in histological damage was seen in the ASA treated mice. Conclusion : Long-term oral administration of ASA gave only a modest, non-significant reduction of renal radiation injury after clinically relevant fractionated irradiation schedules.     

Food Insecurity and Age at Menarche in Tampa Bay,Florida

ABSTRACT

The aim of this study was to assess whether household food insecurity is associated with delayed or early menarche among girls in the United States. Thirty-six dyadic household interviews were conducted with mothers and adolescent girls. The interviews included a socio-demographic survey, the USDA Six-Item Short Form Household Food Security Survey Module, anthropometric measurements, and the self-administered Youth-Adolescent Food Frequency Questionnaire. Using non-parametric quantitative analyses, we examined the associations among food insecurity, anthropometrics, diet, and age at menarche. Cox Proportional Hazards Models were used to evaluate the odds of menarche based on household food insecurity. Food insecurity significantly predicted earlier time to menarche. Food insecure girls were 4.38 times more likely to experience menarche at earlier ages when compared to food secure girls (HR = 4.38, p = .04). Furthermore, the hazard of menarche increased by 25% for each unit increase in food insecurity (OR = 1.253, p = .027). The findings suggest that household food insecurity is associated with earlier ages of menarche among girls in this sample. Early menarche has been associated with adult chronic disease risk. Thus, these findings propose that food security initiatives may be used to reduce the prevalence and health consequences of early-onset puberty.