新疆汉族和维吾尔族健康人群VKORC1启动子区基因多态性研究

目的了解VKORC1—1639A／G基因多态性在新疆汉族和维吾尔健康人群中的分布及其与国外其他不同民族之间的差异。方法采用PCR—RFLP技术对205名汉族和204名维吾尔族乌鲁木齐地区体检健康者VKORC1—1639A／G基因多态性进行检测，计算其基因型和等位基因频率，并与国外多个民族VKORC1—1639A／G基因多态性分布进行比较。结果新疆汉族和维吾尔族健康人群中共检测到2种等位基因：A和G。汉族A和G等位基因频率分别为87％和13％，维吾尔族A和G等位基冈频率分别为62％和38％。新疆汉族和维吾尔族健康人群VKORC1—1639A／G基因多态性共检测到3种基因型，新疆汉族健康人群以AA基因型常见，基因型频率74％。其次是AG基因型，基因型频率分别为26％。GG基因型的个体仅检测到1例，基因型频率小于1。新疆维吾尔族健康人群以AG基因型常见，基因型频率58％。其次是AA基因型，基因型频率分别为33％。GG基因型频率为9％。结论新疆汉族VKORC1—1639A／G基因多态性以AA基因型为主。维吾尔族VKORC1—1639A／G基因多态性以AG基因型为主，新疆汉族VKORC1—1639A／G基因多态性分布与维吾尔族人群和欧美人群存在较大差异。新疆维吾尔族人群VKORC1—1639A／G基因多态性分布与欧关人群接近。     

Increased central adiposity is associated with pro-inflammatory immunoglobulin G N-glycans

Background

Increased body fat may be associated with an increased risk of developing an underlying pro-inflammatory state, thus leading to greater risk of developing certain chronic conditions. Immunoglobulin G has the ability to exert both anti- and pro-inflammatory effects, and the N-glycosylation of the fragment crystallisable portion is involved in mediating this process. Body mass index, a rudimentary yet gold standard indication for body fat, has been shown to be associated with agalactosylated immunoglobulin G N-glycans.

Disruption of the putative splice acceptor site for SIV(mac239)Vif reveals tight control of SIV splicing and impaired replication in Vif non-permissive cells

Vif is dispensable for simian immunodeficiency virus (SIV) replication in some cells, termed permissive (i.e., CEM-SS), but not in others, termed non-permissive (i.e., H9, CEMx174, and peripheral blood lymphocytes). Non-permissive cells express the RNA editing enzyme, APOBEC3G. To determine whether vif mRNA could be alternatively spliced, a mutation altering the putative vif splice acceptor site (SA1) was introduced into SIV(mac239) (SIV(Deltavif-SA)). Despite three consensus splice acceptor sites nearby SA1, SIV(Deltavif-SA) did not efficiently generate alternatively spliced vif mRNA. SIV(Deltavif-SA) was growth attenuated in CEMx174 and H9 cells but not in CEM-SS cells. Following SIV(Deltavif-SA), but not SIV(mac239), infection in either H9 or CEMx174 cells viral cDNA contained numerous G to A mutations; no such differences were observed in CEM-SS cells. This pattern is consistent with mutations generated by APOBEC3G in the absence of Vif. Therefore, efficient splicing of SIV vif mRNA is tightly controlled and requires the SA1 site.     

In vivo and in vitro correlates of food allergy.

Sera of 86 patients clinically sensitive to foods were tested by passive sensitization of human and/or monkey lung (127 tests) and the radioallergosorbent test (RAST) (72 tests), using whole-food antigens; the results were compared with skin (prick) testing. Results of the prick test correlated with history in 76% of cases; lung sensitization correlated with history in 37% and with prick test in 57%; and RAST correlated with history in 54% and prick test in 72%. It is concluded that a very large percentage of adverse reactions to foods are IgE-mediated. The prick test is of use in diagnosis, particularly when combined with RAST; the lung sensitization test is technically impractical and not a reliable indicator. The best diagnostic method is careful history with food challenge and withdrawal and rechallenge; the latter is safe except in patients with a history of violent reaction.     

Evidence of allosteric conformational changes in the antibody constant region upon antigen binding

We have addressed the question of whether antigen binding induces a conformational change in the heavy chain constant (C(H)) domain of antibodies using staphylococcal protein A or streptococcal protein G as probes, since these proteins are known to bind to IgG domains such as C(H)1 and C(H)2-C(H)3 domains. Biosensor assays on interactions between these proteins and mouse IgG specific to (4-hydroxy-3-nitrophenyl)acetyl (NP) or their enzymatic fragments conducted in the presence or absence of the hapten, NP-epsilon-aminocaproic acid (NP-Cap), showed that the binding of IgG to these proteins was inhibited by the binding of NP-Cap. The results of isothermal titration calorimetry also revealed that the association constant for the interaction of protein A with IgG2b decreased by the addition of NP-Cap. These results suggested that antigen binding induced conformational changes in binding sites for protein G or protein A located at C(H)1 and C(H)2-C(H)3 domains, respectively.     

Morphological variability, lectin binding and Na+,K+-activated adenosine triphosphatase activity of isolated Müller (glial) cells from the rabbit retina

Rabbit retinal Müller cells were isolated by means of papaine and mechanical dissociation. These cells were shown to have a well preserved morphology and to preserve viability for many hours. Intense wheat germ agglutinin binding occurs on the photoreceptor side of Müller cells, especially in the microvillous region. Rabbit retinal Müller cells have a Na+,K+-activated adenosine triphosphatase activity in the same order of magnitude as brain astroglial cells.     

陕西、青海、新疆三省(区)部分人群庚型肝炎病毒血清学调查

目的：调查陕西、青海、新疆三省（区）部分人群庚型肝炎病毒（HGV／GBV）血清学特征。方法：采用ELISA方法，共调查三省（区）1469份血清中GBV－IgG抗体。结果：少数民族血清GBV－IgG抗体的阳性率（藏族4．11％，蒙古族5．36％，维吾尔族4．55％，回族4．00％）略高于汉族（1．36％－1．73％），但差异无显著性（P＞0．05）；吸毒人群GBV－IgG阳性率（11．30％，34／301）明显高于正常人群（2．44％，18／736），（P＜0．01）；献血员GBV－IgG阳性率为1．02％－7．68％。结论：三省区民族间GBV－IgG抗体阳性差异无显著性，血源性传播是其重要途径，应加强对献血员及吸毒人员的监管。