Mechanism for cotolerance in nonlethally conditioned mixed chimeras: negative selection of the Vbeta T-cell receptor repertoire by both host and donor bone marrow-derived cells

Bone marrow (BM) chimeras prepared by complete recipient ablation (A-- >B) exhibit donor-specific tolerance, yet survival is often limited by graft-versus-host disease (GVHD). Negative selection of potentially donor-reactive T cells, as assessed by relative T-cell receptor (TCR)- Vbeta expression, is dependent on donor BM-derived deleting ligands. Mixed chimerism and tolerance for both donor and host antigens can be achieved using partial recipient myeloablation with 500 cGy total-body irradiation (TBI) before transplantation followed by cyclophosphamide (CyP) on day +2. To examine the influence of residual host elements on negative selection, the peripheral TCR-Vbeta repertoire was analyzed in partially ablated C57BL/10SnJ (B10) recipients reconstituted with BM from major histocompatibility complex (MHC)-disparate B10.BR/SgSnJ or MHC, Hh-1 and Mls-disparate BALB/cByJ donors, which delete Vbeta5+ and 11+ or Vbeta3+, 5+, and 11+ TCR subsets, respectively. As in myeloblated recipients, donor-reactive subfamilies were deleted in B10.BR-->B10 and BALB/c-->B10 chimeras, suggesting that donor I-E and minor lymphocyte-stimulating (Mls) antigens contribute to the deleting ligands in the nonmyeloablated host. In striking contrast to completely ablated B10-->B10.BR chimeras, partially ablated recipients showed intramedullary I-E expression in the thymus and deleted host-reactive Vbeta5+ and Vbeta11+ subfamilies. These data demonstrate that efficient clonal deletion occurs after partial myeloablation and that both donor and host ligands contribute to TCR repertoire selection.     

Protective effect of YHI and HHII against experimental acute pancreatitis in rabbits

AIM: To observe the protective effect of combined i.v. administraction of Yuanhu injection (YHI) and Huoxuehuayu injection-I (HHI-I) against acute pancreatitis (AP) in rabbits.METHODS: Sever acute pancreatitis (SAP) was induced by retrograde infusion of artificial bile juice into biliary-pancreatic duct, and treated with YHI and HHI-I intravenously. The protective effect was judged by the survival time and rate, serum amylase, serum interleukin-6, pancreatic microcirculation and pathological alteration.RESULTS: Combined use of YHI and HHI-I could markedly increase the rabbits’ 5-d survival rate after AP (83.3% in the treatment group and 33.3% in control). The serum amylase value (x^- ± s) decreased to 1596.6 U/L ± 760.50 U/L in the 5th day from the high level (6320.83 U/L ± 2614.12 U/L) in the 1st day after AP in the treatment group, while in the control group the amylase activity in the 5th day was 2095.0 U/L ± 1081.87 U/L, being significantly different from that before AP (837.17 U/L ± 189.12 U/L). YHI and HHI-I also obviously improved the pancreatic microcirculation and lowered the serum interleukin-6 level, one of the indices of severe pancreatitis. Pathological examination indicated all the changes typical for AP in YHI and HHI-I treatment group were milder than those in the control.CONCLUSION: YHI and HHI-I used in combination might have protective effect against acute pancreatitis in rabbits.     

Heterogeneity of neutrophil antibodies in patients with primary Sjogren's syndrome

Our aims were to determine the prevalence of neutrophil antibodies in patients with primary Sjogren's syndrome (pSS), identify their target antigen(s), and evaluate their functional significance. Neutrophil antibodies were detected using an indirect immunofluorescence (IIIF) test and an enzyme-linked immunosorbent assay (ELISA), using recombinant human Fc-gamma receptor (Fc gamma RIIIb) as a capture agent. Luminol-dependent chemiluminescence was then measured by an established technique. Antibodies to neutrophils were detected in 30 of 66 patients (45%) and categorized on the basis of positivity for the two assays: IIF+/ELISA+ (group A: five patients), IIF+/ELISA- (group B: five patients), and IFF-/ELISA+ (group C: 20 patients). All positive sera contained antibodies directed to the neutrophil specific Fc gamma RIIIb, and none of them bound to NAnull neutrophils. The titer of neutrophil-reactive antibodies (groups A and B) showed no correlation with the neutrophil count, but these autoantibodies did reduce the cell ability to generate a respiratory burst. Thus, neutrophil antibodies are common in patients with pSS. Their main target appears to be Fc gamma RIII, and this may partly account for the dysfunction in Fc gamma R-mediated clearance by the reticuloendothelial system reported in these patients.     

Activation of MAP kinase-activated protein kinase 2 in human neutrophils after phorbol ester or fMLP peptide stimulation

In response to extracellular stimulation, one of the earliest events in human neutrophils is protein phosphorylation, which mediates signal transduction and leads to the regulation of cellular functions. Mitogen- activated protein (MAP) kinases are rapidly activated by a variety of mitogens, cytokines, and stresses. The activated MAP kinases in turn regulate their substrate molecules by phosphorylation. MAP kinase- activated protein (MAPKAP) kinase 2, a Ser/Thr kinase, has been shown to be phosphorylated by p38 MAP kinase both in vivo and in vitro. Phosphorylation of the Thr-334 site of MAPKAP kinase 2 results in a conformational change with subsequent activation of the enzyme. To better define the role of MAPKAP kinase 2 in the activation of human neutrophils, its enzymatic activity was measured after stimulation by either a phorbol ester (phorbol myristate acetate [PMA]), a potent protein kinase C activator, or the tripeptide fMLP, which is a chemotactic factor. The in vitro kinase assays indicate that both PMA and fMLP stimulated a transient increase in the enzymatic activity of cellular MAPKAP kinase 2. The induced kinase activation was concentration-dependent and reached a maximum at 5 minutes for PMA and 1 minute for fMLP. To identify potential substrate molecules for MAPKAP kinase 2, a highly active kinase mutant was generated by mutating the MAP kinase phosphorylation site in the C-terminal region. The replacement of threonine 334 with alanine resulted in a marked augmentation of catalytic activity. Analysis of in vitro protein phosphorylation in the presence of the active kinase indicates that a 60-kD cytosolic protein (p60) was markedly phosphorylated and served as the major substrate for MAPKAP kinase 2 in human neutrophils. Based on the MAPKAP kinase 2 phosphorylation site of Hsp27, a competitive inhibitory peptide was synthesized. This competitive inhibitory peptide specifically inhibited MAPKAP kinase 2 enzymatic activity, as well as the in vitro and in vivo kinase-induced p60 phosphorylation. To assess the contribution of MAPKAP kinase 2 in neutrophil function, the oxidative burst response after manipulation of endogenous kinase activity was measured. Intracellular delivery of the competitive inhibitory peptide into human neutrophils reduced both PMA- and fMLP- stimulated superoxide anion production. Thus, the results strongly suggest that MAPKAP kinase 2 is involved in the activation of human neutrophils.     

傣药小灯台中的吲哚生物碱

从傣药小灯台(Winchia catophylla A. DC.)中分到4个吲哚生物碱,经理化常数测定,光谱分析和化学转化,分别鉴定为echitamine chloride(Ⅰ),echitamidine(Ⅱ),N_B-demethyl-echitamine(Ⅲ)和22-O-acetyl-N_b--demethyl-echitamine(Ⅳ),其中Ⅳ为新的吲哚生物碱。     

消旋15(R)-15-甲基PGE2甲酯的合成

d,l-15(R)-15-Methyl-PGF_2α methyl ester 11-trimethylsilyl ether(II)wasprepared from selective monosilylation of d,l-15(R)-15-methyl-PGF_2αmethyl ester(I) withtrimethylsilyldiethylamine in acetone. Oxidation of(II ) with Collin's reagent gave d,l-15(R)-15-methyl-PGE₂ methyl ester 11-trimethylsilyl ether(III)which,without purification,was converted to d,l-15(R)-15-methyl-PGE₂ methyl ester(IV)under mild acidic conditions.     

Arthroscopy in septic arthritis. Lidocaine- and iodine-containing contrast media are bacteriostatic

Puncture of septic foci is usually performed to determine the responsible bacteria. If contrast medium is used instead of saline to rinse the lesion and to withdraw an adequate bacteriologic specimen, the opacification provides valuable information about the extent of the changes. Since lidocaine is usually used as a local anesthetic when patients undergo this procedure, we tested the in vitro antibacterial effects of lidocaine 1%, as well as those of 2 contrast media--meglumine amidotrizoate and metrizamide--on several bacteria. In particular, we looked at the influence of the concentration of inoculum used and the duration of contact before culture. The contrast media did not significantly affect bacterial growth when contact before culture did not exceed 3 hours. In contrast, lidocaine had a significant antibacterial effect, indicating that it should not enter into contact with the bacteriologic specimen.     

琼脂扩散盒中人癌细胞集落形成试验及应用

应用改良式软琼脂扩散盒(ADC)进行人癌克隆形成试验,检测26例6种手术切除肿瘤标本,培养成功率为65.4%,铺板率在0.003～0.814%之间,接种细胞与克隆形成之间有明显的线性关系(P<0.05)。采用ADC技术筛选铂兰化合物,初步试验显示该药能抑制集落形成,结果与动物实验一致。