Background: This pilot study was carried out to determine whether Helicobacter pylori can be detected in normal colon or in association with colorectal neoplasia.
The postmortem findings are reported from 9 cases of the Guillain-Barré syndrome with survival between 10 days and 1 yr. In 8 cases there was multifocal loss of myelin throughout the peripheral nervous system with relative preservation of axons. In 1 case there was predominant loss of axons. Inflammatory mononuclear cell infiltration was present in the peripheral nervous system of all cases except 1 case surviving a year. The extent and severity of cell infiltration was variable, usually being less prominent than in previous reports, and sometimes sparing nerves in which myelin destruction was severe. Vesicular dissolution of myelin noted by electron microscopy was considered to be a postmortem artefact. In cases examined within 30 days after the onset, immunohistochemical studies with monoclonal antibodies identified more leucocytes (PD7/2B11+) and T cells (UCHL1+) in the endoneurium than in cases examined later or control cases. These findings and recent single case reports indicate that the pathology of the Guillian-Barré syndrome is variable. This variability may reflect differences in pathogenesis, with greater cell-mediated immunity in some cases and greater antibody targeted macrophage-mediated demyelination in others.
The replacement of serum in hybridoma cultures is considered. The focus is on the effects of serum-free media on hybridoma growth and monoclonal antibody secretion. Comparative literature data with serum supplemented cultures are discussed with an analysis of serum-free formulations and selection rules for the serum-free ingredients. In general, serum-free media which are "lipid rich" can sustain cell growth rates approaching that of serum supplemented cultures. Specific antibody secretion rate, however, is usually higher in serum-free media, irrespective of the lipid content.
It has been cited in the literature on hollow fiber systems that pressure gradients persist, and the transmembrane flux of the hollow fiber system is dependent on the pattern of the pressure gradients. The pattern can be used to its advantage in immobilized enzyme systems. However, with immobilized living cell systems, the pressure gradients lead to a nonuniform environment within the hollow fiber cartridge and not necessarily favorable results. This article provides pertinent pressure-drop data on hollow fiber cartridges which are in flow configurations typical of immobilized cell culture work. The results illuminate operational problems that may arise in the culture of either anchorage dependent or independent cells. Possible solutions with crossflow systems are suggested.
The reported incidence of spontaneous bacterial peritonitis (SBP) is 7-30% per annum in cirrhotic patients. Timely diagnosis and treatment is crucial to reduce mortality owing to this infection. Recently, leucocyte esterase reagent strips have been tested in the diagnosis of infection in the ascitic fluid. The objective was to evaluate the diagnostic value of leucocyte esterase reagent strips in SBP in cirrhotic patients with ascites, by systematically reviewing the evidence from prospective clinical studies. We performed a comprehensive literature search in Medline up to July 2007 for adult human prospective clinical studies. Two reviewers independently checked all identified studies for fulfillment of predefined inclusion criteria, extracted data and assessed methodological quality of included studies. We had decided a priori to pool the studies via meta-analysis, only if statistical heterogeneity was found to be nonsignificant (P>0.10). Seventeen studies were included. Statistical heterogeneity among studies was found to be highly significant (P<0.001) in all analyses, precluding pooling of data for meta-analysis. Compared with the manual polymorphonuclear count ('gold standard'), leucocyte esterase reagent strips were found to have sensitivity ranging from 45 to 100%, specificity ranging from 81 to 100%, positive predictive value ranging from 42 to 100% and negative predictive value ranging from 87 to 100%. Despite the wide variation in sensitivity and positive predictive value between studies, the consistently high negative predictive value of leucocyte esterase reagent strips in SBP diagnosis should gain it a place in the ascitic tap diagnostic algorithm.
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