Characterization of monoclonal IgG cryoglobulins: fine-structural and morphological analysis

The morphology of the amorphous, gelatinous, and crystalline varieties of monoclonal IgG cryoglobulins was analyzed by light and transmission and scanning electron microscopy. Each cryoglobulin had a characteristic fine structure that correlated with its gross morphology. Transmission electron microscopy showed that the amorphous precipitates were random and disorganized molecular clumps. In contrast, cryogels were thin-walled, well-organized, and hydrated strawlike clusters, whereas cryocrystals formed tightly compacted, highly structured molecular clusters. Crystals that formed in blood produced rouleaux, and analysis by scanning electron microscopy indicated that the crystals could form thick-walled, branching, macromolecular nets that could physically trap cells. The morphological properties provided visual impressions by which cryoglobulins could cause clinical disease secondary to vascular occlusion produced by self- associated IgG cryoglobulin molecules.     

磷霉素在除尿路及胃肠道以外的感染中的应用

细菌耐药性问题越来越严重,医学界开始重新审视老的抗菌药,以期作为耐药菌感染的备选治疗手段。磷霉素是1969年从链霉菌中分离的一种磷酸衍生物,磷霉素氨丁三醇口服制剂主要用于治疗大肠埃希菌和粪肠球菌引起的单纯性尿路感染,磷霉素钠盐静脉制剂用于临床各类感染的治疗。该文综述了1971年至2007年国际上发表的有关磷霉素治疗革兰阳性菌和阴性菌感染（尿路和胃肠道感染除外）的疗效与安全性研究。     

Etheno adducts in spleen DNA of SJL mice stimulated to overproduce nitric oxide

In order to investigate specific DNA damage caused by nitric oxide (NO) induced lipid peroxidation, levels of promutagenic etheno adducts 1,N6- ethenodeoxyadenosine (epsilondA) and 3,N4-ethenodeoxycytidine (epsilondC) were measured in spleen DNA of SJL mice induced to produce high levels of NO by injection of RcsX (pre-B-cell lymphoma) cells. epsilondA and epsilondC levels were quantified by an ultrasensitive immunoaffinity-32P-post-labeling method. Spleen DNA of control mice (n = 5) had background levels of 9.2+/-5.4 epsilondA adducts per 10(9) dA and 13.1+/-5.7 epsilondC adducts per 10(9) dC. In RcsX cell-injected mice (n = 7), levels of these adducts were elevated approximately 6- fold, i.e. 53.9+/-39.4 epsilondA per 10(9) dA and 83.5+/-57.8 epsilondC per 10(9) dC (P < 0.05). Mice injected with RcsX cells and also treated with NG-methyl-L-arginine (NMA), an inhibitor of inducible nitric oxide synthase (n = 6), had significantly reduced levels (P < 0.05) of both epsilondA and epsilondC (13.5+/-5.7 epsilondA per 10(9) dA and 28.2+/- 15.7 epsilondC per 10(9) dC). These findings constitute the first available evidence of formation of etheno adducts associated with NO overproduction in vivo. The adducts were presumably formed from lipid peroxidation products such as trans-4-hydroxy-2-nonenal (HNE), generated via oxidation of lipids by peroxynitrite. The results suggest that etheno-DNA adducts, among other types of damage, may contribute to the etiology of cancers associated with chronic infection/inflammation in which NO is overproduced.      

Antibodies to hepatitis E virus among several populations in Greece: increased prevalence in an hemodialysis unit

BACKGROUND: Hepatitis E virus (HEV) has been found to be the causative agent of enterically transmitted non-A, non-B hepatitis in tropical and subtropical countries. Several investigators, however, have indicated that HEV could be endemic in Europe, albeit at a low prevalence. STUDY DESIGN AND METHODS: The purpose of this study was to estimate the prevalence of anti-HEV in various populations in northwestern Greece (Epirus region). Healthy blood donors (2636), refugees from southern Albania (350), children (165), injecting drug users (IDUs) (65), multiply transfused patients (62), patients with chronic viral hepatitis (75), and chronic hemodialysis patients (149) were investigated for anti-HEV by enzyme immunoassay and confirmatory Western blot assay. In addition, 380 consecutive healthy blood donors and 62 hemodialysis patients from a neighboring area (Agrinion, Greece) were investigated. RESULTS: A very low presence of anti-HEV antibody was found among healthy blood donors from Epirus (0.23%) and Agrinion (0.53%). Anti-HEV was not detected in children, IDUs, or multiply transfused patients. In contrast, a low but significant prevalence of anti-HEV was found among refugees (4.85%), patients with chronic viral hepatitis (5.3%), and hemodialysis patients from Epirus (1.34%), as compared with healthy blood donors from Epirus: p < 0.0001, p < 0.00001, and p < 0.10, respectively. A high prevalence (9.7%) of anti- HEV was revealed in patients at the hemodialysis unit of the General Hospital of Agrinion (p < 0.00005, compared to healthy blood donors from Agrinion). No significant association was found between anti-HEV positivity and the age or sex of donors, the duration of hemodialysis, positivity for hepatitis B or C virus infection markers, history of hepatitis, increased alanine aminotransferase, renal transplantation, a history of transfusion, or the number of units transfused. CONCLUSION: This study demonstrated a high prevalence of anti-HEV in a separate hemodialysis unit, without an association with the known routes of transmission of blood-borne viruses. This observation suggests that a still-undefined intra-unit factor or other factors are associated with HEV transmission.     

Detection of hepatitis B virus in plasma using flow cytometric analyses of polymerase chain reaction-amplified DNA incorporating digoxigenin-11- dUTP

Blood donations are routinely screened by multiple serologic assays for antigens/antibodies associated with infection by blood-borne viruses, including hepatitis B virus (HBV), hepatitis C virus (HCV), human immunodeficiency viruses (HIV-1 and HIV-2), and human T-cell lymphotropic virus (HTLV-I and HTLV-II). A direct detection of these viruses would be more effective for the prevention of transfusion- transmitted infections than the indirect measurement of the variable host immune response to these agents. Because the polymerase chain reaction (PCR) for viral gene amplification offers the most sensitive and direct means of detecting viruses in blood, we have developed a nonisotopic PCR procedure for the detection of HBV, chosen as a prototype. The problems, common to previously described PCR methods, of nucleic acid extraction and inhibition of the PCR by plasma proteins were overcome by isolation of HBV from plasma by means of 450-microns polystyrene beads covalently coated with monoclonal antibody to the Pre- S1 region of the viral envelope protein. Detergent lysis and proteinase K digestion of the immunocaptured virions isolated from plasma released the HBV DNA. A modified PCR-amplification protocol, incorporating digoxigenin-labeled dUTP in the amplified gene products followed by hybridization with a specific biotinylated oligonucleotide probe bound to streptavidin-coated 2.8-microns magnetic beads, allowed flow cytometric analyses of HBV-specific PCR products by means of antibodies to digoxigenin labeled with fluorescein isothiocyanate. The endpoint serial dilutions of pedigreed human plasma samples containing chimpanzee infectious dose (CID50) of 10(7) for adw and CID50 of 10(7.5) for the ayw subtypes were compared in repeated testing of PCR products by our immunoreactive bead (PCR-IRB) assay. HBV DNA was consistently detected in a 5 x 10(-10) dilution of each sample. In testing 20 coded specimens of blood donors, with or without serologic markers of HBV infection, the PCR-IRB was specific and more sensitive than the PCR analyses by slot blot hybridization with radioactive probe. The PCR-IRB assay can be adapted for simultaneous detection of multiple blood-borne viruses by an automated flow cytometric analysis system.     

Opportunistic microorganisms in individuals with lesions of denture stomatitis

The aim of this study was to isolate, quantify, identify, and compare opportunistic microorganisms (Candida and Staphylococcus genera and Enterobacteriaceae/Pseudomonadaceae families) from prosthesis-fitting surfaces, the hard palate, and mouth rinses of individuals wearing removable maxillary prosthesis with (50) and without (50) lesions of denture stomatitis (DS). The strains were collected and identified using phenotypic, biochemical and molecular tests. The counts of microorganisms were significantly higher in the group of individuals with DS (P < 0.05). C. albicans was the most frequently isolated yeast species in both groups, following by C. tropicalis and C. glabrata. Six isolates were identified as C. dubliniensis. S. aureus and S. epidermidis were the most frequent Staphylococcus species in both groups. Klebsiella pneumoniae was the predominant species in both groups. The association between Candida spp. and bacteria isolated in this study with DS suggests that these microorganisms may play important roles in the establishment and persistence of this disease.     

中老年人左心室舒张功能减退及其相关危险因素——广州生物库心血管疾病亚队列研究

目的探讨广州市相对健康的中老年人左心室舒张功能减退及其相关危险因素。方法采用单纯随机方法收集390名年龄≥50岁,无脑卒中、心肌梗死、肺心病及恶性肿瘤等重大慢性疾病史的中老年人进行横断面研究,收集其个人资料及病史、体格检查并测定血清空腹血糖、血脂水平;采用彩色多普勒超声诊断仪,进行左心舒张功能指标测定,包括二尖瓣舒张早期血流峰值(E)和舒张晚期血流峰值(A)及E/A,E峰减速时间(DT)和等容舒张时间(IVRT)。结果①A峰随着年龄的增长而增高,E/A随着年龄的增长而减低(均P<0.05)。②调整了年龄和性别之后,随着腰围的增大,A峰和IVRT随之升高,而E/A则随之降低;同时也发现A峰随三酰甘油和空腹血糖水平升高而升高(均P<0.05)。③用三分位数分组,对310名未服用抗高血压药物者的血压水平,调整了年龄和性别,结果显示A峰随收缩压和脉压差升高而增高(P<0.05),而E/A则随收缩压和舒张压的升高而降低(P<0.05)。④理想血压组、正常血压高值组和高血压组的A峰水平呈逐步升高(P<0.05),而E/A则呈逐步下降的趋势(P<0.05)。结论血压升高是左心室舒张功能损伤的独立危险因素,即使血压在正常水平...