Multi-virulence-locus sequence typing clarifies epidemiology of recent listeriosis outbreaks in the United States

Multi-virulence-locus sequence typing (MVLST) was used to analyze isolates from two major listeriosis outbreaks in the United States in 1998 and 2002 that were due to consumption of contaminated hot dogs and turkey deli meat, respectively. MVLST demonstrated high epidemiological relevance and indicated that the two outbreaks were the result of one epidemic.     

急性髓系白血病血管内皮生长因子表达与预后的研究

目的 :观察人白血病细胞系血管内皮生长因子 (VEGF)表达水平 ,研究急性髓系白血病 (AML)患者血清VEGF表达水平与预后的关系。方法 :采用酶联免疫吸附法 (ELISA)对 4 9例初治、10例复发AML患者血清及人白血病细胞系U937、K5 6 2、HL - 6 0、TF - 1和NB4培养上清液 (4 8小时 )VEGF表达水平进行检测。结果 :五种人白血病细胞系培养上清液中均测到VEGF高表达。 4 9例初治、10例复发AML患者的血清VEGF表达水平分别为 2 0 1 17± 110 93pg ml和 2 32 5 9± 118 6 2pg ml,均明显高于正常对照组 (12 5 6 2± 4 5 4 3pg ml;p <0 0 5 )。初治AML患者中VEGF高表达组 (>2 0 1 17pg ml)完全缓解 (CR)率为 4 8% ,低表达组 (<2 0 1 17pg ml)CR率为 77% ,两者比较差异显著 (p<0 0 5 )。结论 :血管内皮生长因子在刺激白血病细胞增殖、迁移中发挥重要作用。AML患者血清VEGF水平与预后具相关性     

氧化苦参碱对LAK细胞活性的影响

ＬＡＫ细胞具有很强的广谱杀瘤作用，而氧化苦参碱具有较强的免疫抑制作用。本文研究了氧化苦参碱对ＬＡＫ细胞活力的影响，结果表明：氧化苦参碱可抑制ＩＬ－２对小鼠脾细胞的促增殖作用，并且对ＩＬ－２活化ＬＡＫ细胞杀伤Ｐ８１５的能力也有抑制作用。当ＩＬ－２（５００ｕ／ｍｌ）与２００μｇ／ｍｌ的氧化苦参碱共同孵育４ｄ后，可使ＬＡＫ细胞杀瘤能力（在效靶比为１００：１时）的８２．５％被抑制。同时氧化苦参碱本身对Ｐ８     

Monoclonal antibodies define genus-specific, species-specific, and cross-reactive epitopes of the chlamydial 60-kilodalton heat shock protein (hsp60): specific immunodetection and purification of chlamydial hsp60.

Ocular and urogenital tract infections with Chlamydia trachomatis can progress to chronic inflammatory diseases that produce blindness and tubal infertility. The pathophysiology of these chronic disease conditions is thought to be immunologically mediated, and the chlamydial 60-kDa heat shock protein (hsp60) has been implicated as a major target antigen that stimulates the immunopathological response. The lack of chlamydial hsp60 antibodies and purified hsp60 has severely restricted studies to define more thoroughly the role of this protein in the immunopathogenesis of chlamydial disease. We produced a panel of antichlamydial hsp60 monoclonal antibodies (MAbs) and defined their specificities by immunoblotting against lysates of C. trachomatis, C. psittaci, and six other genera of bacteria. Three patterns of anti-hsp60 immunoreactivity were observed: chlamydial species specific, chlamydial genus specific, and cross-reactive. The epitopes recognized by these MAbs were localized within the primary amino acid sequence of hsp60 by immunoblotting against recombinant amino-terminal truncated hsp60 fusion polypeptides and then precisely mapped by use of overlapping synthetic peptides. The majority of the MAbs mapped to either the amino or the carboxyl termini of hsp60. Epitopes defining all three MAb reactivities mapped within amino-terminal residues 6 to 16. Genus-specific hsp60 MAbs mapped to epitopes located within this region and to residues 17 to 28 and 177 to 189. Antichlamydial hsp60 MAbs stained inclusions as effectively as MAbs specific for the major outer membrane protein. Homogeneous preparations of full-length recombinant chlamydial hsp60 and amino-terminal truncated recombinant hsp60 polypeptides were obtained by immunoabsorption chromatography with an hsp60 MAb reactive to the carboxyl terminus of the protein. Thus, the antichlamydial MAbs described here should be extremely useful for the specific immunodetection of hsp60 in tissues from individuals having different disease manifestations and for the purification of hsp60 or truncated hsp60 polypeptides for use in serologic and lymphocyte proliferation assays. The availability of these MAbs will facilitate studies to define more precisely the role of hsp60 in the immunopathogenesis of chlamydial disease.     

丹参提取物F对大鼠乙酸性十二指肠溃疡愈合的影响及其机制的研究

本文观察了丹参提取物Ｆ对大鼠乙酸性十二指肠溃疡指数、十二指肠壁结合粘液量、粘膜上皮细胞标记指数及十二指肠组织ＰＧＥ＿２含量的影响，探讨了丹参提取物Ｆ抗大鼠乙酸性十二指肠溃疡的作用和机制。结果表明：丹参提取物Ｆ连续灌胃５ｄ后，溃疡指数显著低于对照组（Ｐ＜０．０１）；十二指肠壁结合粘液量及粘膜上皮细胞标记指数显著高于对照组（Ｐ＜０．０１），十二指肠组织ＰＧＥ＿２含量也高于对照组（Ｐ＜００５）。提示：促进十二指肠壁结合粘液分泌及上皮细胞再生，增加十二指肠组织ＰＧＥ＿２含量可能是丹参提取物Ｆ促进十二指肠溃疡愈合的主要机制。     

Oral immunization with an attenuated vaccine strain of Salmonella typhimurium expressing the serine-rich Entamoeba histolytica protein induces an antiamebic immune response and protects gerbils from amebic liver abscess.

Attenuated salmonellae represent attractive candidates for the delivery of foreign antigens by oral vaccination. In this report, we describe the high-level expression of a recombinant fusion protein containing the serine-rich Entamoeba histolytica protein (SREHP), a protective antigen derived from virulent amebae, and a bacterially derived maltose-binding protein (MBP) in an attenuated strain of Salmonella typhimurium. Mice and gerbils immunized with S. typhimurium expressing SREHP-MBP produced mucosal immunoglobulin A antiamebic antibodies and serum immunoglobulin G antiamebic antibodies. Gerbils vaccinated with S typhimurium SREHP-MBP were protected against amebic liver abscess, the most common extraintestinal complication of amebiasis. Our findings indicate that the induction of mucosal and immune responses to the amebic SREHP antigen is dependent on the level of SREHP-MBP expression in S. typhimurium and establish that oral vaccination with SREHP can produce protective immunity to invasive amebiasis.     

Multilocus short sequence repeat sequencing approach for differentiating among Mycobacterium avium subsp. paratuberculosis strains

We describe a multilocus short sequence repeat (MLSSR) sequencing approach for the genotyping of Mycobacterium avium subsp. paratuberculosis (M. paratuberculosis) strains. Preliminary analysis identified 185 mono-, di-, and trinucleotide repeat sequences dispersed throughout the M. paratuberculosis genome, of which 78 were perfect repeats. Comparative nucleotide sequencing of the 78 loci of six M. paratuberculosis isolates from different host species and geographic locations identified a subset of 11 polymorphic short sequence repeats (SSRs), with an average of 3.2 alleles per locus. Comparative sequencing of these 11 loci was used to genotype a collection of 33 M. paratuberculosis isolates representing different multiplex PCR for IS900 loci (MPIL) or amplified fragment length polymorphism (AFLP) types. The analysis differentiated the 33 M. paratuberculosis isolates into 20 distinct MLSSR types, consistent with geographic and epidemiologic correlates and with an index of discrimination of 0.96. MLSSR analysis was also clearly able to distinguish between sheep and cattle isolates of M. paratuberculosis and easily and reproducibly differentiated strains representing the predominant MPIL genotype (genotype A18) and AFLP genotypes (genotypes Z1 and Z2) of M. paratuberculosis described previously. Taken together, the results of our studies suggest that MLSSR sequencing enables facile and reproducible high-resolution subtyping of M. paratuberculosis isolates for molecular epidemiologic and population genetic analyses.     

Availability of complement bound to Staphylococcus aureus to interact with membrane complement receptors influences efficiency of phagocytosis

Complement-mediated opsonization of encapsulated Staphylococcus aureus (CP+) of the predominant capsule types, 5 and 8, remains poorly understood. Our previous work showed that complement is important for mouse survival of CP+ type 5 bacteremia and that the type 5 capsule inhibits the binding of opsonic C3 fragments to the organism. The importance of complement-mediated opsonization of CP+ was tested by neutrophil phagocytosis assays. Complement-mediated opsonization of CP+ increased phagocytosis by 57% compared to opsonization in complement-inhibited serum. Agar-grown CP+, enhancing capsule expression, was phagocytosed only one-tenth as well as the capsule-negative organisms (CP-), supporting the belief that staphylococcal polysaccharide capsules impair phagocytosis. Despite relatively poor phagocytosis of CP+ compared to CP-, complement activation increased the phagocytosis of CP+ by 103%. Thus, complement in normal human serum may have an important role in opsonizing CP+, even when capsule expression is strong. The ability of bound C3 fragments to interact with complement receptor 1 (CD35) on the membrane of human erythrocytes was tested in an immune adherence assay. S. aureus capsule was able to mask C3 fragments on the organism from binding to complement receptor 1. The inhibition of C3 binding to CP+ and the masking of deposited C3 fragments caused by the presence of capsule was associated with markedly decreased phagocytosis. The addition of anti-capsule antibodies to normal human serum was found to markedly improve the recognition of deposited C3 fragments by complement receptor 1 even when the absolute number of C3 molecules bound to S. aureus was not increased.     

肺淋巴管平滑肌瘤病临床病理学观察

目的 探讨肺淋巴管平滑肌瘤病临床、病理特征。方法 对5例肺淋巴管平滑肌瘤病临床资料进行收集分析,HE切片观察,采用免疫组织化学(SP法)检测平滑肌肌动蛋白(SMA)、HMB45、基质金属蛋白酶(MMP)2、孕激素受体(PR)、雌激素受体(ER),并进行文献复习。结果 肺淋巴管平滑肌瘤病是原因不明的肺部疾病,只发生在女性,特别是绝经前妇女。临床表现为呼吸困难,咯血,气胸和乳糜胸等。病理学检查显示不同成熟度平滑肌细胞在细支气管壁、肺泡壁、淋巴管壁和血管壁周围增生,肺实质呈囊性变。增生的平滑肌细胞免疫组织化学5例SMA、HMB45、MMP2均阳性;1例的ER和PR均阳性,1例仅ER阳性,1例仅PR阳性,1例的ER和PR均阴性。结论 育龄期妇女如反复出现自发性气胸、咯血、活动后呼吸困难应考虑肺淋巴管平滑肌瘤病的可能,病理检查可确定肺淋巴管平滑肌瘤病的诊断。