Prevalence of infections in renal transplant recipients of north India

Renal transplant is usually performed at the end stage of renal disease. Most of the transplant recipients become susceptible to infections due to chronic uremia, protein depletion, anemia and administration of immunosuppressive drugs. It is a retrospective study of 510 post renal transplant recipients. 378 (74%) renal transplant recipients suffered from the infections. Most common site of infection was urinary tract infection (53%). Out of 26% of wound infections, the deep wound infection (23%) was six times higher than superficial wound infection (3.5%). Chest infection and bacteraemia were noticed to be 18% and 8%, respectively. The common isolate was Escherichia coli (160) followed by Staphylococcus aureus (140), Enterococcus (86) and Pseudomonas (69).     

Natural human antibody responses to Plasmodium vivax apical membrane antigen 1 under low transmission and unstable malaria conditions in Sri Lanka

Plasmodium vivax apical membrane antigen 1, an important malaria vaccine candidate, was immunogenic during natural malaria infections in Sri Lanka, where low transmission and unstable malaria conditions prevail. Antibody prevalence increased with exposure in areas where malaria was or was not endemic. A marked isotype switch to cytophilic (immunoglobulin G1 [IgG1]/IgG3) antibodies was evident with increasing exposure exclusively in residents from areas of endemicity.     

Outer membranes are competitive inhibitors of Escherichia coli O157:H7 adherence to epithelial cells.

Escherichia coli of serotype O157:H7 are Vero cytotoxin-producing enteric pathogens that have been associated recently with sporadic cases and outbreaks of hemorrhagic colitis and with the hemolytic-uremic syndrome. Adherence of many enteropathogenic bacteria to mucosal surfaces is a critical step in the pathogenesis of diarrheal disease. We showed previously that adherence of E. coli O157:H7 strain CL-56 to epithelial cells in vitro is inhibited by outer membranes. In this study we examined whether outer membranes from a series of E. coli O157:H7 strains mediated competitive inhibition of bacterial binding to epithelial cells grown in tissue culture. We also determined which constituents of the outer membrane mediated inhibition of CL-56 adherence. Binding of six O157:H7 strains to HEp-2 cells was determined by quantitating the number of adherent bacteria in the presence and absence of outer membranes which were extracted from each strain with N-lauroyl sarcosinate (1.7%, wt/vol). After separation of outer membranes by gel electrophoresis, four bands (94, 40, 36, and 30 kDa) were collected by electroelution. Immune sera were raised in rabbits to each of the four eluted bands. Outer membrane extracts from each of the six O157:H7 strains inhibited binding of homologous organisms to the HEp-2 cells. At dilutions which did not cause bacterial agglutination, antiserum raised against the 94-kDa outer membrane protein showed maximal inhibition of bacterial adherence (17.0 +/- 7.3% adherence of control levels). Growth of bacteria in iron-depleted broth did not affect their binding to HEp-2 cells, suggesting that iron-regulated outer membranes were not involved. Fluid accumulation in ileal ligated loops of rabbits in response to E. coli O157:H7 challenge was diminished following both parenteral immunization with outer membranes extracted from the homologous strain and coincubation of organisms with immune serum which contained antibodies to outer membrane extracts. These data indicate that outer membranes are competitive inhibitors of E. coli O157:H7 adherence. Specific constituents of the outer membrane may function as bacterial attachment factors (i.e., adhesins) for E. coli O157:H7 adherence to epithelial cell surfaces.     

Epstein-Barr virus nuclear antigen 1 linear epitopes that are reactive with immunoglobulin A (IgA) or IgG in sera from nasopharyngeal carcinoma patients or from healthy donors.

The entire amino acid sequence of the unique region of the EBNA 1 protein was synthesized as a set of 41 20-residue peptides with an overlap of 10 amino acids. The peptides were tested in the enzyme-linked immunosorbent assay for reactivity with immunoglobulin A (IgA) and IgG in sera from 50 patients with nasopharyngeal carcinoma (NPC) as compared with 36 serum samples from healthy Epstein-Barr virus (EBV)-seropositive donors and 5 serum samples from EBV-negative donors. The most immunoreactive peptide for both IgA and IgG binding was localized to the glycine-alanine repeat domain of the antigen. In the unique regions, 16 immunoreactive peptides were found. Of these, four were reactive with IgG but not IgA and three peptides were reactive with IgA but not IgG in NPC sera. In addition, several IgA and IgG epitopes on the carboxy-terminal region were specifically reactive with NPC sera, but unreactive with sera from healthy EBV-positive donors. The results suggest that EBV serology specific for individual epitopes may provide additional useful information not available by conventional serology with whole antigens or the EBNA complex.     

Motor, but not sensory, cortical potentials are amplified by high-protein diet.

Animals fed a high-protein diet (50% casein) are hyperactive and more responsive to nociceptive stimuli than those fed either a normal- or low-protein diet. The mechanisms mediating dietary protein-induced behavior are unknown and may include both central and peripheral neural effects. Adult, Sprague-Dawley rats were fed 50% casein (treatment group) and 24% casein (control group) ad lib for 36-40 weeks. The animals were anesthetized with alpha-chloralose and urethane (50 mg/kg and 1.5 mg/kg, IP). EEG recordings were averaged while the anesthetized animal was conditioned using an alerting stimulus-imperative stimulus (AS-IS) paradigm. AS consisted of a 1.5 kHz, 90 dB tone cue. This was followed 2 seconds later by IS, an electrical tail stimulation (11 V, 1.4 s duration). Two negative deflections (N1 and N2) were generated by the frontal cortex during the AS-IS interstimulus interval. N1, an alerting response, was not different between the two groups. N2 amplitude and peak latency were significantly increased in the high-protein group (205% and 117% of control, respectively; p less than 0.05). N2 represents the activation of cells in the motor cortex. Brainstem auditory-evoked responses and somatosensory-evoked potentials also were recorded, but no differences were observed between the two diet groups. These data suggest that consumption of a high-protein diet results in an increase in central arousal mechanisms (measured by cortical negativity response), specifically involving increased excitability of the motor cortex, that is not associated with a disorder of information processing in the cerebral cortex (measured by brainstem auditory-evoked responses and somatosensory-evoked potentials).