Protection Against Chemically-Induced Oxidative Gastrointestinal Tissue Injury in Rats by Bismuth Salts

Oxygen free radicals (OFR) are implicated in thepathogenesis of stress, chemically induced gastriclesions, and gastrointestinal injury. Theconcentration-dependent scavenging abilities of bismuthsubsalicylate (SBS), colloidal bismuth subcitrate (CBS), andselected OFR scavengers, including superoxide dismutase(SOD), catalase, mannitol, and allopurinol were examinedagainst biochemically or chemically generated superoxide anion, hydroxyl radical, andhypochlorite radical plus hypochlorous acid based on achemiluminescence assay. Furthermore, both gastric (GM)and intestinal mucosa (IM) were individually exposed in vitro to these free radical generatingsystems, and the concentration-dependent protectiveabilities of SBS and CBS against lipid peroxidation (LP)were compared with selected OFR scavengers. In addition, 24-hr fasted rats were orally treated with thenecrotizing agents 0.6 M HCl, 0.2 M NaOH, 80% ethanol,and aspirin (200 mg/kg). The extent of tissue injury inthe GM and IM was determined by assessing LP, DNA fragmentation, and membrane microviscosity.Dose- and time-dependent in vivo protective abilities ofCBS (100 mg/kg) and SBS (15 mg/kg) were also assessed.Following incubations with superoxide anion and hydroxyl radical generating systems in thepresence of 125 mg SBS/liter, approximately 47% and 61%inhibitions were observed in the chemiluminescenceresponse, respectively, while 48% and 46% inhibitions were observed with 125 mg CBS/liter. SBS andCBS exerted similar abilities towards hypochloriteradical plus hypochlorous acid. Approx. 3.1- and3.7-fold increases in LP were observed in the GM and IMof rats following oral administration of 0.6 MHCl. Pretreatment of the rats with SBS and CBS decreased0.6 M HCl-induced LP in the GM by approx. 39% and 27%,respectively, with similar decreases in LP in the IM. SBS exhibited better protectiveabilities towards 0.6 M HCl and 0.2 m NaOH-induced GMand IM injury as compared to CBS. SBS and CBS providedsimilar protection towards 80% ethanol-induced gastric injury, while CBS exerted a superior protectiveability towards aspirin-induced gastric injury. Theresults demonstrate that both SBS and CBS can scavengereactive oxygen species and prevent tissue damage produced by OFR.     

Immune complex glomerulonephritis in mice infected with Escherichia coli.

C57Bl/6 mice were injected intraperitoneally with 10(8) to 2 x 10(8) living K 38 Escherichia coli (E. coli) and serological changes and kidney involvement were studied. E. coli were found in the blood 45 min to 24 hr after injection. In serum, large amounts of deoxyribonucleic acid (DNA) were present 24 hr after E. coli injection, and thereafter disappeared. Seven days after infection, antibodies directed against E. coli, anti-DNA antibodies and C1q-binding substances were found in serum and the kinetics of the variations of these parameters were studied until day 35. Kidney lesions were evaluated immunochemically and by optical and electron microscopy. In the glomeruli, heavy granular deposits of IgG and IgM were constantly found in mesangium and along capillary walls. In most kidneys slight granular deposits of IgG and IgM were also found in the tubules. Histological studies revealed in the glomeruli mild endocapillary cell proliferation, focal thickening of glomerular basement membrane and dense deposits in mesangial and subendothelial areas and inside the glomerular basement membrane; in the tubules dense deposits were focally observed inside the tubular basement membrane.     

Epidemic typhoid in vietnam: molecular typing of multiple-antibiotic-resistant Salmonella enterica serotype typhi from four outbreaks

Multidrug-resistant Salmonella enterica serotype Typhi isolates from four outbreaks of typhoid fever in southern Vietnam between 1993 and 1997 were compared. Pulsed-field gel electrophoresis, bacteriophage and plasmid typing, and antibiotic susceptibilities showed that independent outbreaks of multidrug-resistant typhoid fever in southern Vietnam are caused by single bacterial strains. However, different outbreaks do not derive from the clonal expansion of a single multidrug-resistant serotype Typhi strain.     

Nucleation of calcium phosphate by surface-bound extracellular matrix

The native extracellular matrix (ECM) laid down on silicon and titanium surfaces by osteoblast-like SAOS-2 cells was exposed by selective removal of cells. This type of material surface ECM-Si, ECM-Ti was shown to promote the nucleation of calcium phosphate from a simulated body fluid (SBF). Microscopic and spectroscopic results revealed the effect was associated with a collagen fiber-free extracellular matrix.     

Fatal avian influenza A (H5N1) in a child presenting with diarrhea followed by coma

In southern Vietnam, a four-year-old boy presented with severe diarrhea, followed by seizures, coma, and death. The cerebrospinal fluid contained 1 white cell per cubic millimeter, normal glucose levels, and increased levels of protein (0.81 g per liter). The diagnosis of avian influenza A (H5N1) was established by isolation of the virus from cerebrospinal fluid, fecal, throat, and serum specimens. The patient's nine-year-old sister had died from a similar syndrome two weeks earlier. In both siblings, the clinical diagnosis was acute encephalitis. Neither patient had respiratory symptoms at presentation. These cases suggest that the spectrum of influenza H5N1 is wider than previously thought.     

Origin and primary dispersal of the Mycobacterium tuberculosis Beijing genotype: clues from human phylogeography

We suggest that the evolution of the population structure of microbial pathogens is influenced by that of modern humans. Consequently, the timing of hallmark changes in bacterial genomes within the last 100,000 yr may be attempted by comparison with relevant human migrations. Here, we used a lineage within Mycobacterium tuberculosis, a Beijing genotype, as a model and compared its phylogeography with human demography and Y chromosome-based phylogeography. We hypothesize that two key events shaped the early history of the Beijing genotype: (1) its Upper Palaeolithic origin in the Homo sapiens sapiens K-M9 cluster in Central Asia, and (2) primary Neolithic dispersal of the secondary Beijing NTF::IS6110 lineage by Proto-Sino-Tibetan farmers within east Asia (human O-M214/M122 haplogroup). The independent introductions of the Beijing strains from east Asia to northern Eurasia and South Africa were likely historically recent, whereas their differential dissemination within these areas has been influenced by demographic and climatic factors.     

A new PCR-SSP typing method for six single-nucleotide polymorphisms impairing the blood-clotting cascade as well as T-cell stimulation

Single-nucleotide polymorphisms (SNPs) within the genes of factor V (FV) (G1691A; exon 10), prothrombin (FII) (G20210A; 3'untranslated - region) and methylenetetrahydrofolate reductase (MTHFR) (C677T; exon 4) are associated with hypercoagulability, and systematic screening of individuals being at higher risk of thrombosis has been suggested. SNPs in the 2q33 region within the genes of CD28 (+17T/C; intron 3) and CTLA4 (-318C/T; promoter and +49A/G; exon 1) are likely to affect T-cell proliferation and antigen presentation signaling, which may lead to altered sensitivity of allograft or self-tissue recognition and affect the incidence of autoimmune diseases. We developed primers that allow specific amplification of these six SNPs at test conditions identical with those used for HLA typing with the CTS PCR-SSP reagents. One hundred ninety-six healthy German Caucasian individuals were tested for the six SNPs. The genotype frequencies for all SNPs were in Hardy-Weinberg equilibrium. There was no significant difference in the distribution of genotypes when compared to other published studies in which these SNPs were tested. The described PCR-SSP method can be used to screen large numbers of patients for these SNPs.     

Social–Emotional Profiles of PTSD,Complex PTSD,and Borderline Personality Disorder Among Racially and Ethnically Diverse Young Adults: A Latent Class Analysis

The debate around the construct validity of complex posttraumatic stress disorder (CPTSD) has begun to examine whether CPTSD diverges from posttraumatic stress disorder (PTSD) when it co‐occurs with the diagnosis of borderline personality disorder (BPD). The present study (a) examined the construct validity of CPTSD through a latent class analysis of a non–treatment‐seeking sample of young trauma‐exposed adults and (b) characterized each class in terms of trauma characteristics, social emotions (e.g., shame, guilt, blame), and interpersonal functioning. A total of 23 dichotomized survey items were chosen to represent the symptoms of PTSD, CPTSD, and BPD and administered to 197 trauma‐exposed participants. Fit statistics compared models with 2–4 latent classes. The four‐class model showed the best fit statistics and clinical interpretability. Classes included a “high PTSD+CPTSD+BPD” class, characterized by high‐level endorsement of all symptoms for the three diagnoses; a “moderate PTSD+CPTSD+BPD” class, characterized by endorsement of some symptoms across all three diagnoses; a “PTSD” class, characterized by endorsement of the ICD‐11 PTSD criteria; and a “healthy” class, characterized by low symptom endorsement overall. Pairwise comparisons showed individuals in the high PTSD+CPTSD+BPD class to have the highest levels of psychological distress, traumatic event history, adverse childhood experiences, and PTSD symptoms. Shame was the only social emotion to significantly differ between the classes, p = .002, η² = .16. The findings diverge from the literature, indicating an overlap of PTSD, CPTSD, and BPD symptoms in a non–treatment‐seeking community sample. Further, shame may be a central emotion that differentiates between presentation severities following trauma exposure.