Induction of immunoglobulin-producing human peripheral blood lymphocytes in serum-free medium

Induction of immunoglobulin-secreting cells from human peripheral blood lymphocytes in a serum-free culture medium was studied. Albumin, transferrin, insulin and fibronectin can replace serum entirely for support of pokeweed mitogen (PWM)-stimulated B lymphocytes, measured by a reverse hemolytic plaque assay using protein A-coated red cells. In this serum-free system, growth and maturation to IgM and IgG secretion occur at the same or higher efficiency as in conventional serum-containing medium, with maximum numbers of plaque-forming cells on day 6 at optimal dose of PWM, 0.5 ～ 5 μg/ml. This system can be used to avoid the interference from undefined serum components.     

A monoclonal antibody (RH1-38) which inhibits multiple systems of cell-mediated cytotoxicity--I. Identification of a novel epitope on a killer cell surface bimolecular complex important in the cytotoxic response

This paper presents the initial characterization of a mouse monoclonal antibody (RH1-38) which blocks, in the absence of complement, three different systems of cell-mediated cytotoxicity. This monoclonal antibody markedly inhibits cytotoxicity mediated by human natural killer cells, a monocyte-like cell [phorbol myristate acetate (PMA) stimulated HL-60], and cytotoxic T-lymphocytes generated in a mixed leukocyte reaction. RH1-38 is not nonspecifically toxic to cells since antibody-dependent cellular cytotoxicity was not inhibited and viability as assessed by trypan blue exclusion was not affected. Inhibition is specific since control hybridoma culture supernatants, parent (NS-1) ascites supernatant, monoclonal anti-HLA and normal mouse IgG were not significantly inhibitory. In the NK system, the inhibitory effect appears to be due to binding of monoclonal antibody to effector cell surface since exposure of targets to antibody followed by washing yielded no inhibition of killing. Inhibition requires the antigen-binding portion of the antibody molecule and thus appears to be related to steric hindrance of an effector cell surface molecule which is important in the expression of cell-mediated cytotoxicity. Immunoprecipitation of surface-radioiodinated membranes from PMA-stimulated HL-60 cells and analysis on sodium dodecyl sulfate-polyacrylamide gels revealed a bimolecular complex (195,000 and 125,000 daltons) without significant change under reducing conditions. Control immunoprecipitates yielded no peaks of activity. This monoclonal antibody should serve as a useful probe of the function and biochemistry of a killer cell surface antigen important in the expression of cell-mediated cytotoxicity. Since RH1-38 inhibits cytotoxicity mediated by at least three apparently unrelated effector cells, the relevant antigen may be part of a common mechanistic step. As the companion paper demonstrates, this monoclonal antibody does not affect the conjugation step, but appears to block a late step in the NK cytolytic mechanism. Thus, RH1-38 recognizes either an epitope district from previously-described anti-LFA-1 antibodies or alternatively recognizes a distinct functional killer cell surface molecule.     

The Follow-Up Study of Skin Reactivity to Recall Antigens and E- and EAC-RFC Profiles in Blood in Asbestos Workers

We have determined cutaneous DTH reactions to SK-SD and PPD and peripheral blood lymphocyte profiles in a group of asbestos workers in two consecutive surveys. It was found that asbestosis and, to a lesser extent, the presence of ANA are significantly correlated with the lack of response to the above antigens. 83% of asbestos workers when tested at a 4 year interval fell into the same two categories of responsiveness (lack of response or response at least to one antigen).The asbestosis cases had lower total lymphocyte count as well as proportions and absolute number of E-RFC as compared to asbestos workers without asbestosis and/or ANA. Furthermore, the latter group showed the lower percentages and absolute number of E-RFC than the matched controls. The presence of ANA is also correlated with lower proportions of E-RFC. However, this is related at least in part to asbestosis.     

Voluntary consumption of NaCl,KCl, CaCl2, and NH4Cl solutions by 28 mouse strains

Male mice from 28 inbred strains (129P3/J, A/J, AKR/J, BALB/cByJ, BUB/BnJ, C3H/HeJ, C57BL/6J, C57L/J, CAST/Ei, CBA/J, CE/J, DBA/2J, FVB/NJ, I/LnJ, KK/H1J, LP/J, NOD/LtJ, NZB/B1NJ, P/J, PL/J, RBF/DnJ, RF/J, RIIIS/J, SEA/GnJ, SJL/J, SM/J, SPRET/Ei, and SWR/J) were tested with NaCl (75–450 mM), KCl (30–300 mM), CaCl₂ (3–100 mM), and NH4Cl (10–300 mM) solutions using two-bottle preference tests with water as the second choice. For each mineral, there was a wide range of strain variation in solution intakes and preferences. This variation had a substantial genetic component as assessed using heritability estimates. In most cases, the strain means were continuously distributed; however, strains with deviating high or low intakes or preferences were also observed. The associations among the responses to different minerals were only modest, suggesting distinct genetic controls of sodium, potassium, calcium, and ammonium consumption. These results provide a valuable resource for investigators who wish to identify genes involved in the regulation of mineral consumption and balance.     

Chemical Characterization of Macrophage Cytotoxicity Factor,Macrophage Migration Inhibitory Factor,T-Helper Cell-Replacing Factor and Colony-Stimulating Factor from Culture Supernatants of Concanavalin A-Stimulated Murine Spleen Cells

Supernatants from Concanavalin A-stimulated murine spleen cells were subjected to hydrophobic interaction chromatography on phenyl-Sepharose. Macrophage cytotoxicity factor (MCF), macrophage migration inhibitory factor (MIF), T-helper cell-replacing factor (TRF) and colony-stimulating factor (CSF) were bound at high ionic strength and were released stepwise at low ionic strength. CSF thus could be separated from MCF, MIF and TRF and the bulk of other proteins. Chromatography of pools containing MCF, MIF and TRF on Sephadex did not lead to a separation of the three activities which were all found in a molecular weight range of 25.000-55.000. Isoelectric focusing of these pools in pH range from 4 to 9 gave two peaks for MCF at pH 8.2 and 7.2, whereas MIF activity focused from pH 4.5 to 5.5. TRF activity was found in a single sharp peak at pH 5.3. The results demonstrate that the four biological activities can be distinguished on a chemical basis and are accessible for purification and chemical characterization.     

Differential activation of hepatitis B DNA polymerase by detergent and salt

Three patterns of activity were evident when the differential activation of the DNA polymerase associated with serum Dane particles by nonionic detergent and salt was investigated. The patterns were obtained by plotting the increase in enzyme activity mediated by the detergent Nonidet P-40 (NP-40) in increasing concentrations of KCl compared to the activity observed in the absence of detergent. The pattern of differential activity of hepatitis B (HB) DNA polymerase in detergent and salt was altered by subjecting the HBAg preparations to shearing forces. Hepatitis B DNA polymerase activity was stable even in NP-40 concentrations as high as 10%. In addition to hepatitis B DNA polymerase, DNA polymerase activated by calf thymus DNA was found in pellets containing Dane particles. The latter DNA polymerase activity was also activated by NP-40 and was not decreased by DNAse; this DNA polymerase coprecipitated with hepatitis B antigen (HBAg) upon addition of anti-HBs. However, the DNA polymerase activated by calf thymus DNA was inhibited by 0.4 M KCl. Electron microscopic observations of serum Dane particles in 0.4 M KCl showed no alterations of morphology of these particles when compared to particles in low-salt buffer. The data indicated that KCl activated HB DNA polymerase by a different mechanism from that of shear or NP-40, which removed the surface antigen coat from the Dane particles.     

Assessing the Impact of Salt Reduction Initiatives on the Chronic Disease Burden of Singapore

Globally, many countries are facing an increasing burden of chronic disease due to ageing populations, of which cardiovascular disease forms a large proportion. Excess dietary sodium contributes to cardiovascular disease risk and requires intervention at a population level. This study aimed to quantify the impact of several salt reduction initiatives on population health over a 30-year horizon using GeoDEMOS, a population model from Singapore. Four interventions were modelled in four demographic groups in 2020 for a total of 16 intervention scenarios. The effect of 0.5, 2.0, and 4.0 g/day reductions in daily salt consumption, along with adherence to the World Health Organization guidelines of a maximum of 5.0 g of salt each day, was modelled in the entire population, including the overweight and obese, the elderly, and diabetics. In each scenario, the number of averted incident cases of acute myocardial infarction and stroke, along with the disability-adjusted life years up to 2050, was monitored. We found 4.0 g/day reductions in salt consumption were the most effective when implemented across the entire population, resulting in 24,000 averted incident cases of cardiovascular disease and 215,000 disability-adjusted life years over 30 years. This is a large figure when compared with the 29,200 projected annual incident cases of cardiovascular disease in 2050. When targeted at specific high-risk demographic groups, the largest effects were observed in the overweight and obese, with the same intervention yielding 10,500 averted incident cases of cardiovascular disease and 91,500 disability-adjusted life years. Quantifying the benefits of salt reduction initiatives revealed a significant impact when administered across the entire population or the overweight and obese. Health promotion efforts directed toward sustainably reducing salt consumption will help to lower the chronic disease burden on the healthcare system in years to come.     

湖南省2019年碘缺乏病监测结果分析

目的 分析2019年碘缺乏病监测结果,掌握干预措施实施效果,为适时采取针对性防治措施和科学调整干预策略提供依据。 方法 2019年4—5月全省122个县(市、区,简称县)按东、西、南、北、中划分5个抽样片区,在每个片区各随机抽取1个乡(镇、街道,简称乡);每个乡各抽取1所小学校,每所小学抽取8～10岁儿童40名,采集尿样和儿童家中食用盐样,检测尿碘和盐碘含量,采用B超法测量儿童甲状腺容积。每个县在所抽取的5个乡中各随机抽取20名孕妇,采集孕妇随机尿样和家中食用盐,检测尿碘含量和盐碘含量。 结果 共收集36 667份盐样进行定量检测,盐碘均数(26.32±5.69)mg/kg,变异系数21.61%,碘盐覆盖率为99.68%,合格碘盐食用率为95.24%。共检测儿童尿样24 450份,儿童尿碘中位数为231.1 μg/L,共检测孕妇尿样12 204份,孕妇尿碘中位数为186.5 μg/L,共检测8 224名8～10岁儿童甲状腺容积,甲状腺肿大率为0.79%。 结论 监测重点人群碘营养状况处于适宜水平,湖南省处于持续消除碘缺乏病状态。以食盐加碘防治碘缺乏病的干预措施成效显著,应继续针对重点人群加强健康宣教,号召因地制宜,科学补碘和按需补碘。     

老年人慢性肺源性心脏病并发低盐综合征临床分析

目的探讨发生慢性肺心病并发低盐综合征的诱因及其防治.方法采用临床回顾方法分析住院肺心病并发低盐综合征患者的临床特点、诊断和防治方法.结果和结论低盐综合征是老年人慢性肺心病常见并发症之一,正确的防治措施可改善本并发症的预后.     

Human Peripheral Eosinophils with Receptors for IgM: Demonstration and Ultrastructural Morphology

Receptors for IgM were detected on peripheral blood human eosinophils by a rosette technique with ox red blood cells coated with the IgM fraction of the specific immunserum. Between 14 % and 43 % (mean 27 %) FcµR positive cells were found after an overnight incubation period at 37°C by using this technique. The specificity of the receptors for IgM was assessed by studying the inhibitory capacity of purified human IgM in the rosette assay. From an ultrastructural point of view, the EA^M rosette-forming cells are mature eosinophlic granulocytes characterized by a nucleus with a variable number of lobes and a certain number of «first type» granules partially or totally devoid of their content.