强心甙中毒的心肌超微结构变化和甘露醇的保护作用

ⅳ羟自由基清除剂甘露醇,1.1mol/L 2g/kg和3 g/kg可分别使哇巴因致豚鼠LD_(100)由298.54±33.30 μg/kg增高至367.44±44.58μg/kg(P<0.05)和398.49±35.39 μg/kg(P<0.01)。甘露醇略可提高哇巴因致心律失常发生的阈值,但无统计学意义。取哇巴因致心脏出现室性早搏、室性心动过速、室性纤维性颤动和心跳停止时的左室游离壁心肌,用透射电子显微镜观察心肌超微结构的改变,结果表明心肌细胞膜结构发生明显的破坏,并随中毒的加重,心肌结构的破坏亦更严重。     

食管癌细胞膜提取物体外诱导胚胎胸腺细胞抗癌效应的研究

本文探讨增强胚胎胸腺细胞抗肿瘤效应的方法。采用食管癌细胞膜抗原体外诱导培养的胚胎胸腺细胞 ;用3 H TdR掺入法检测其对食管癌细胞的细胞毒效应 ;用SP 免疫组化法检测其经诱导后细胞表面抗原的变化。结果经食管癌细胞膜抗原诱导 3～ 9d的胚胎胸腺细胞对食管癌细胞的杀伤率明显大于未经诱导的胚胎胸腺细胞 ;胚胎胸腺细胞经诱导后CD4 + /CD8+ 细胞无明显变化 ,但诱导后出现少量CD5 6细胞。食管癌细胞膜抗原体外诱导胚胎胸腺细胞可增强其对食管癌细胞的细胞毒作用     

Interleukin-15 is not required for the induction or maintenance of orally induced peripheral tolerance

Orally induced tolerance is a physiologically relevant form of peripheral tolerance, which is believed to be important for the prevention of pathological immune responses in the gut. Of several mechanisms proposed to mediate oral tolerance, one that has received much attention recently is the concept of regulatory CD4+ T cells. As recent studies have suggested that interleukin (IL)-15 may be important for the differentiation and maintenance of regulatory CD4+ T cells, we have examined the role of IL-15 in oral tolerance, using a soluble form of the IL-15 receptor (sIL-15R) which blocks the biological effects of IL-15 in vivo. Oral tolerance induced by feeding mice ovalbumin (OVA) in a low-dose regimen believed to induce regulatory T cell activity was not affected by the administration of sIL-15R during either the induction or maintenance phase of tolerance. Thus, oral tolerance does not involve an IL-15-dependent mechanism.     

Polymorphisms of four microsatellite DNA markers from telomeric HLA I region (D6S1624, D6S258, M6S211 and D6S510) and their linkage disequilibrium with HLA-A in a southern Chinese Han population]

OBJECTIVE: To explore the genetic polymorphisms of four microsatellite DNA markers from telomeric HLA I region (D6S1624, D6S258, M6S211 and D6S510) and their linkage disequilibrium with HLA-A in a southern Chinese Han population residing in Hunan province. METHODS: Fluorescent PCR/Size-sequencing was carried out to analyze the polymorphisms of D6S1624, D6S258, M6S211 and D6S510 loci, and polymerase chain reaction-sequence specific priming (PCR-SSP) technique was used for HLA-A typing. RESULTS: The genotypic distributions at the 5 loci were consistent with Hardy-Weinberg equilibrium (P> 0.05). The number of allelic variants for D6S1624, D6S258, M6S211 and D6S510 loci were 10, 10, 12 and 9, respectively. Each locus had several main alleles and the dominant alleles were D6S1624-*199, D6S258-*195, M6S211-*261 and D6S510-*186. All of the 4 microsatellite markers exhibited high heterozygosity values (0.7142-0.8316) and polymorphism information content values (0.6686-0.811). No global linkage disequilibrium (LD) was detected between D6S1624 and HLA-A (P= 0.2646), or between D6S258 and HLA-A (P= 0.3481). In contrast, very significant global LD was found between M6S211 and HLA-A (P< 0.0001), and between D6S510 and HLA-A(P< 0.0001). Subsequent analysis for haplotypes with an observed frequency of > or = 3% revealed that only 2 of the 10 D6S1624-HLA-A haplotypes and 3 of the 9 D6S258-HLA-A haplotypes displayed weak or moderate LD, while 7 out of the 8 M6S211-HLA-A haplotypes, 6 among the 7 D6S510-HLA-A haplotypes were in tight LD. CONCLUSION: Authors have characterized four microsatellite DNA markers, D6S1624, D6S258, M6S211 and D6S510 in a southern Chinese Han population. Findings shown here can be helpful for those studies mainly addressing the association between HLA I sub-region and diseases. The data also provide basis for future study in forensics, HLA matching in clinical transplantation and anthropology.     

Virus overrides the propensity of human CD40L-activated plasmacytoid dendritic cells to produce Th2 mediators through synergistic induction of IFN-{gamma} and Th1 chemokine production

Depending on the activation status, plasmacytoid dendritic cells (PDC) and myeloid DC have the ability to induce CD4 T cell development toward T helper cell type 1 (Th1) or Th2 pathways. Thus, we tested whether different activation signals could also have an impact on the profile of chemokines produced by human PDC. Signals that induce human PDC to promote a type 1 response (i.e., viruses) and a type 2 response [i.e., CD40 ligand (CD40L)] also induced PDC isolated from tonsils to secrete chemokines preferentially attracting Th1 cells [such as interferon-gamma (IFN-gamma)-inducible protein (IP)-10/CXC chemokine ligand 10 (CXCL10) and macrophage inflammatory protein-1beta/CC chemokine ligand 4 (CCL4)] or Th2 cells (such as thymus and activation-regulated chemokine/CCL17 and monocyte-derived chemokine/CCL22), respectively. Activated natural killer cells were preferentially recruited by supernatants of virus-activated PDC, and supernatants of CD40L-activated PDC attracted memory CD4(+) T cells, particularly the CD4(+)CD45RO(+)CD25(+) T cells described for their regulatory activities. It is striking that CD40L and virus synergized to trigger the production of IFN-gamma by PDC, which induces another Th1-attracting chemokine monokine-induced by IFN-gamma/CXCL9 and cooperates with endogenous type I IFN for IP-10/CXCL10 production. In conclusion, our studies reveal that PDC participate in the selective recruitment of effector cells of innate and adaptive immune responses and that virus converts the CD40L-induced Th2 chemokine patterns of PDC into a potent Th1 mediator profile through an autocrine loop of IFN-gamma.     

Anti-tumor immunoglobulin M increases lung metastasis in an experimental model of malignant melanoma

Cancer metastasis involves distinct steps that depend on complicated tumor–host interactions. The hematogenous dissemination of tumor cells may be facilitated by factors that promote the arrest and adherence of cancer cells in capillaries. We examined whether anti-tumor monoclonal immunoglobulin M (IgM) antibodies promoted the hematogenous dissemination of B16 melanoma cells in syngeneic mice. IgM monoclonal antibodies were generated that selectively bind to B16 melanoma cells as compared to syngeneic fibroblasts, lymphocytes or Lewis lung carcinoma cells. Incubation of B16-BL6 or B16-F0 melanoma cells with these IgM anti-tumor antibodies significantly increased the number of lung colonies as compared with control antibodies. Moreover, intraperitoneal injection of specific antibody also significantly increased lung colonization. All anti-tumor antibodies promoted the aggregation of B16 melanoma cells. A chemically generated immunoglobulin G (IgG)-like fragment of an anti-tumor IgM antibody displayed greatly reduced tumor aggregation and, in contrast to intact IgM, did not significantly increase lung colonization of B16 melanoma cells. Neither intact IgM nor the IgG-like fragment enhanced the in vitro invasiveness of B16 melanoma cells across Matrigel-coated membranes. Our results, therefore, suggest that besides their beneficial anti-tumor effects, anti-tumor IgM antibodies may also promote the hematogenous dissemination of cancer cells. This revised version was published online in July 2006 with corrections to the Cover Date.     

北京女校大学生进食障碍与心境的问卷调查

目的:探讨北京女校大学生的进食障碍状况及其相关心境。方法:通过班级集体施测的方法,采用进食障碍问卷(EDI)和简式简明心境问卷(POMS-SF)对北京市女子大学352名年龄为17-25岁的大学生进行调查,同时搜集被试的体重、身高等人口学资料(身高=161±5厘米,体重=52.3±5.61千克)。结果:当前北京女校大学生进食障碍的相关行为普遍存在;与体形偏瘦和过瘦的学生相比,体形正常的大学生进食障碍相关的不良态度和行为表现较为严重;进食障碍相关的不良态度和行为存在年级差异(X~2=17.94,P<0.01),大一、大四较为严重;进食障碍症状与不良心境相关(r=0.42,P<0.01)。结论:北京女校大学生进食障碍相关态度和行为较严重,并与其心境和其它因素有一定关系。     

Simultaneous differentiation and typing of Entamoeba histolytica and Entamoeba dispar

Sequences corresponding to some of the polymorphic loci previously reported from Entamoeba histolytica have been detected in Entamoeba dispar. Comparison of nucleotide sequences of two loci between E. dispar strain SAW760 and E. histolytica strain HM-1:IMSS revealed significant differences in both repeat and flanking regions. The tandem repeat units varied not only in sequence but also in number and arrangement between the two species at both the loci. Using the sequences obtained, primer pairs aimed at amplifying species-specific products were designed and tested on a variety of E. histolytica and E. dispar samples. Amplification results were in complete agreement with the original species classification in all cases, and the PCR products displayed discernible size and pattern variations among the isolates.     

Persistent changes in the intrinsic excitability of rat deep cerebellar nuclear neurones induced by EPSP or IPSP bursts

The deep cerebellar nuclei (DCN) are the major output of the cerebellum, and have been proposed as a site of memory storage for certain forms of motor learning. Microelectrode and whole-cell patch recordings were performed on DCN neurones in acute slices of juvenile rat cerebellum. DCN neurones display tonic and bursting basal firing patterns. In tonically firing neurones, a stimulus consisting of EPSP bursts produced a brief increase in dendritic Ca²⁺ concentration and a persistent increase in the number of spikes elicited by a depolarizing test pulse, along with a decrease in spike threshold. In intrinsically bursting DCN neurones, EPSP bursts induced an increase in the number of depolarization-evoked spikes in some neurones, but in others produced a change to a more tonic firing pattern. Application of IPSP bursts evoked a large number of rebound spikes and an associated dendritic Ca²⁺ transient, which also produced a persistent increase in the number of spikes elicited by a test pulse. Intracellular perfusion of the Ca²⁺ chelator BAPTA prevented the increase in intrinsic excitability. Thus, rapid changes in intrinsic excitability in the DCN may be driven by bursts of both EPSPs and IPSPs, and may result in persistent changes to both firing frequency and pattern.