Association between morphologic distortion of sickle cells and deoxygenation-induced cation permeability increase

We hypothesized that the deoxygenation-induced increase in cation permeability of sickle cells was related to mechanical distention of the membrane by growing HbS polymer within the cell. To test this hypothesis, we determined the effect of deoxygenation on cation fluxes in sickle cells under conditions that restricted or permitted extensive growth of polymer, producing different degrees of membrane distention. Manipulation of suspending medium osmolality for density-isolated high and low mean cell hemoglobin concentration (MCHC) cells was used to regulate the extensional growth of polymer bundles and hence membrane distortion. For initially low MCHC cells, the deoxygenation-induced increase in both Na and K fluxes was markedly suppressed when the MCHC was increased by increasing the osmolality. This suppression corresponded to the inhibition of extensive morphologic cellular distortion. For initially high MCHC, ISC-rich cells, deoxygenation had minimal effect on K permeability. However, reduction of MCHC by a decrease in osmolality produced a concomitant increase in cation permeability and cellular distortion. These observations support the idea that the sickling-associated increase in membrane permeability is related to mechanical stress imposed on the membrane by bundles of HbS polymer.     

Production and Evaluation of Toxoplasma gondii Recombinant Surface Antigen 1 (SAG1) for Serodiagnosis of Acute and Chronic Toxoplasma Infection in Human Sera

Background

The assays currently available for the detection of specific anti-Toxoplasma antibodies may vary in their abilities to detect serum immunoglobulins, due to the Lack of a purified standardized antigen. The aim of this study was evaluation the recombinant Toxoplasma gondii SAG1 antigen for the serodiagnosis of acute and chronic toxoplasmosis.

Methods

This study describes an ELISA using recombinant SAG1 for detection of IgM and IgG antibodies against Toxoplasma gondii in human sera. Genomic DNA of T. gondii (RH Strain) was isolated and PCR reaction was performed. Recovered DNA was cloned into PTZ57R cloning vector. The recombinant plasmid was detected by restriction analysis. The SAG1 gene was subcloned in the pET- 28a expression vector. Protein production was then induced with 1 mM isopropyl-D – thiogalactopyranoside (IPTG). A total of 204 sera were tested using a commercial IgG and IgM ELISA kit (Trinity, USA) as gold standard prior to testing them with the recombinant antigen.

Results

Tested sera were divided into the following groups:(a) The 74 T. gondii IgG positive (b) 70 T.gondii IgM positive (c) 60 sera who had no serological evidence of toxoplasmosis as negative sera.To determine the specificity of the test, we used other parasitic diseases including echinococusis (N=5), malaria (N=14), leishmaniasis (N=7),fasciolasis (N=4), sterengyloidiasis (N=1). Sensitivity and specificity of the generated recombinant IgG ELISA in comparison with commercial ELISA (Com ELISA) were 93% and 95%, and the sensitivity and specificity of the generated recombinant IgM ELISA were 87% and 95% respectively.

Conclusion

The results acquired here show that this antigen is useful for diagnostic purposes and could be replaced by lysed, whole cell antigens for diagnosis of chronic toxoplasmosis.     

A new radioimmunoassay for the detection of small amounts of white cells and platelets in red cell concentrates: implications for blood transfusion

In the procedure for quality control of red cell concentrates, made white cell (WBC)-poor by filtration, the particle-counting technique was found to be insufficiently sensitive in detecting the remaining WBCs and platelets. Therefore, direct radioimmunoassays were developed using murine monoclonal antibodies specific for platelets, granulocytes, and T lymphocytes. The sensitivity for platelets was 40 x 10(3) per mL, that for granulocytes was 10 x 10(3) per mL (starting from 0.2 mL of red cell filtrate), and that for T lymphocytes was 0.006 x 10(6) per mL (starting from 5 mL) and 0.0015 x 10(6) per mL (starting from 50 mL). These direct assays were used in experiments on filtration with three types of filters: the Cellselect B-1005, B-1014 and the B-1013 (bedside filter). After filtration of 1 unit of blood cell suspension through the B-1005, the number of remaining platelets was found to vary between less than or equal to 0.04 x 10(6) and greater than 15 x 10(6) per mL (n = 16); after filtration through the B-1013 filter, the remaining platelets were greater than 0.04 x 10(6) per mL. Upon filtration of a second unit of blood cell suspension through the B-1013 filter, the number of remaining platelets varied between less than or equal to 0.04 x 10(6) and 5 x 10(6). In both filter types, the number of remaining granulocytes was always less than 0.01 x 10(6) per mL. A study of T-lymphocyte contamination revealed that, upon filtration of 1 unit of blood through the B-1005, T-lymphocyte numbers were less than or equal to 0.0015 x 10(6) to 0.15 x 10(6) per mL (starting from 5 and 50 mL); upon filtration through the B-1013 filter, the number of remaining T lymphocytes varied between less than or equal to 0.006 x 10(6) and 0.2 x 10(6) per mL (starting from 5 mL). After filtration of a second unit of blood cell suspension through the B-1013 filter, the number of remaining T lymphocytes ranged from less than or equal to 0.006 x 10(6) to 0.1 to 0.5 x 10(6) per mL (starting from 5 mL). The direct radioimmunoassay is an improvement over the present electronic particle-counting techniques with regard to both sensitivity and specificity and may therefore be useful in quality control procedures in blood transfusion as well as in the development of new filters.     

LANSOPRAZOLE PLUS CLARITHROMYCIN: EVALUATION OF A NEW DUAL THERAPY FOR Helicobacter pylori ERADICATION

SUMMARY The aim of this pilot study was to evaluate the efficacy and safety of lansoprazole plus clarithromycin for eradication of Helicobacter pylori. A total of 26 patients with H. pylori infection were randomised to receive clarithromycin, 500 mg t.i.d. for 14 days, plus either lansoprazole, 30 mg o.m., (group L30, n=13) or lansoprazole, 30 mg b.i.d., (group L60, n=13). H. pylori status was determined pre-treatment and four to six weeks after completion of the study medication by histology and ¹³C-urea breath test. Two patients were unable to complete the course of medication. Of the remaining 24 patients, 14 (58%) successfully eradicated H. pylori — 8/12 (67%) patients in group L30 and 6/12 (50%) in group L60. Side-effects were experienced by 17/26 (65%) of patients, most commonly a taste disturbance. The results from this pilot study suggest that dual therapy with lansoprazole plus clarithromycin is only a moderately effective regimen for eradicating H. pylori.     

腹部超低磁场磁共振胃肠道充液利弊的探讨

本文回顾性总结分析100例腹部ULF-MRI检查,阐述胃肠道人为充盈准备和不准备,与使用弹力腹带紧裹季肋部等措施．对图像分析的利弊关系。介绍了所用设备、方法、资料和结果,用不同内含的水模(白开水、铁剂、牛奶等)．寻得信号规律,与临床实践比较．讨论三种液体作为人为充盈液的优缺点．有利于正确判别组织．有利于临床诊断。     

Long-term follow-up of blood donors with indeterminate human immunodeficiency virus type 1 results on Western blot

BACKGROUND: At present, tens of thousands of United States blood donors who are at low risk for human immunodeficiency virus type 1 (HIV-1) infection are indefinitely deferred. These persons are repeatably reactive for HIV-1 antibody in enzyme immunoassay (EIA) and are indeterminate in Western blot. STUDY DESIGN AND METHODS: To determine the significance and persistence of anti-HIV-1 reactivity in plasma from volunteer blood donors with HIV-1-indeterminate Western blots, 66 donors were retested for HIV-1 antibody by the same manufacturers' EIA and Western blot 5 to 7 years after the initial Western blot. In addition, donors' peripheral blood mononuclear cells were tested by polymerase chain reaction (PCR) for HIV-1 DNA gag sequences. RESULTS: Thirty-five (53%) of 66 donors were still repeatedly reactive for HIV-1 on EIA and indeterminate on Western blot, 23 (35%) were negative on EIA and indeterminate on Western blot, 7 (11%) were negative in EIA and Western blot, and 1 (2%) was repeatedly reactive on EIA and negative on Western blot. Donors with persistently indeterminate Western blots had a band pattern nearly identical to that on the original Western blot. No donor was positive in Western blot, p24 antigen, or PCR testing. No donor had signs or symptoms of HIV-1 infection. CONCLUSION: Long-term follow-up of Western blot-indeterminate blood donors does not reveal evidence of HIV-infection. A mechanism to return these donors to the donor pool should be considered.     

Ontogeny of B-lymphocyte function. III. In vivo and in vitro studies on the ease of tolerance induction in B lymphocytes from fetal, neonatal, and adult mice

The ease of tolerance induction in B lymphocytes from fetal, neonatal, and adult mice was studied in vivo, in a cell transfer system, and in vitro. Three different tolerogens were used: ultracentrifuged BGG, DNP(6)-D-GL, and ultracentrifuged DNP(22)-BGG. Irradiated thymectomized mice were reconstituted with B cells from fetal or neonatal liver or adult spleen or bone marrow. The mice were injected with tolerogen 1 day later. They were given normal thymus cells and challenged with either BGG or DNP(44)-BGG between 4 and 14 days after tolerance induction. With BGG no difference in ease of B-cell tolerance induction was observed in mice reconstituted with B cells from 17-day fetal liver, neonatal liver, 8- day-old spleen, adult spleen, or adult bone marrow. B cells from 14-day fetal donors are relatively resistant to tolerance induction. In contrast, with DNP(6)-D-GL and DNP(22)-BGG B cells from neonatal donors were clearly more susceptible to tolerance induction than were B cells from adult donors. Comparable results were obtained in studies on tolerance induction in vitro. Neonatal B cells were more susceptible than adult B cells to tolerance induction upon culture with DNP(6)-D-GL or DNP(22)-BGG. However, neonatal and adult B cells were identical with respect to ease of tolerance induction in vitro with deaggregated BGG. The results suggest that there are multiple mechanisms for B-cell tolerance induction. Immature B cells appear to be more susceptible to tolerance induction by some mechanisms but not by others. It is suggested that immature B cells are more susceptible to tolerance induction with moderately polyvalent antigens such as hapten-carrier conjugates. With antigens like BGG which do not haverepeated epitopes no difference between mature and fetal B cells in regard to ease of tolerance induction is observed. These observations raise questions about the importance of relative ease of tolerance induction in immature B cells as a mechanism controlling the normal induction of self tolerance.     

颈椎保健理疗仪的研制

本文介绍了一种适合治疗各种类型颈椎病的颈椎保健理疗仪。它是由颈椎按摩装置、热疗装置和颈椎牵引装置构成。治疗颈椎病时,先利用颈椎按摩、热疗装置对颈部进行揉捏推拿、振动按摩、热疗;然后利用牵引装置对椎间小关节紊乱、椎间隙狭窄（椎间盘病变）等疾病进行牵引治疗。