Increased Levels of Inflammatory Mediators in Children and Adults Infected with Vibrio cholerae O1 and O139

Investigations were carried out to study the production of factors associated with the innate immune response in the systemic and mucosal compartments in adults and children infected with Vibrio cholerae O1 and V. cholerae O139. The levels of nonspecific mediators of the innate defense system, i.e., prostaglandin E₂ (PGE₂), leukotriene B₄ (LTB₄), and lactoferrin (Lf), as well as myeloperoxidase (MPO), were elevated at the acute stage of the disease in stools obtained from both O1- and O139-infected adults and children. In the systemic compartment, the levels of Lf were increased after onset of disease, which in children remained elevated up to convalescence compared to the healthy controls. Increased concentrations of C-reactive protein were seen in the sera of adult cholera patients at the acute stage of infection. Elevated levels of the nitric oxide (NO^·) metabolites (nitrite and nitrate [NO₂⁻ and NO₃⁻]) were detected in plasma but not in urine. The activity of the scavenger of reactive oxygen species, superoxide dismutase, was higher in the plasma of adults immediately after the onset of disease, suggesting that an active scavenging of reactive oxygen species was taking place. The concentration of 8-iso-prostaglandin F_2α remained unchanged in the systemic and mucosal compartments in the study subjects. After the recovery of patients from cholera, the concentration of the majority of the metabolites decreased to baseline levels by day 30 after the onset of infection. Immunohistochemical staining showed increased tissue expression of MPO, Lf, and inducible nitric oxide synthase at the acute stage in the duodenal biopsies of adults and rectal biopsies obtained from children with cholera. Very little difference was seen in the levels of the different inflammatory mediators in patients infected with V. cholerae O1 or the encapsulated V. cholerae O139. In summary, these results suggest that elevated concentrations of Lf, MPO, PGE₂, LTB₄, and NO^·, as well as other metabolites, during the acute stage of the disease indicate that the innate defense system, as well as the inflammatory process, is activated in both adults and pediatric patients infected with V. cholerae O1 and O139.     

Fine-needle aspiration cytology diagnosis of tuberculosis

Fine-needle aspiration cytology of lymph nodes and extranodal swellings in 160 cases showed granulomatous reaction with or without caseation necrosis in 83%. The material was acellular or predominantly composed of necrotic material, polymorphs, and lymphocytes in 17%. The age of the patient ranged from 1.5 to 72 yr. The male to female ratio was 1:1.3. Acid-fast bacilli (AFB) could be demonstrated in 40.6% of cases. In cases associated with cellular reaction and necrosis. AFB positivity was 50.0%, while it was 66.7% in cases with acellular necrotic material.     

Characterization and physical map of choleraphage φ149 DNA

Choleraphage φ149 DNA is a linear double-stranded molecule 69 × 10⁶ Da or 104 kilobase pairs (kbp). From restriction enzyme analysis, it has been concluded that the DNA is circularly permuted. There are at least three S1 nuclease-sensitive sites along the length of the molecule. These sites represent single-strand interruptions repairable by T4 DNA ligase. A physical map of the DNA has been constructed using the restriction endonucleases BamH1 and BglII.     

Infection with an extended-spectrum beta-lactamase-producing strain of Serratia marcescens following tongue reconstruction

We report a case of postsurgical wound infection of polymicrobial etiology caused by Serratia marcescens and Pseudomonas aeruginosa following the use of a radial forearm free flap for oncological tongue reconstruction. S. marcescens was a producer of SHV-12 extended-spectrum beta-lactamase (ESBL). This is the first report from India of this ESBL. S. marcescens and P. aeruginosa were resistant to the empirical perioperative antibiotics administered. Delay in the recognition of the type of infection and in the institution of appropriate therapy resulted in total loss of the free flap.     

The rising trend of invasive zygomycosis in patients with uncontrolled diabetes mellitus.

Zygomycosis is an emerging infection worldwide. A study was conducted to understand its spectrum in the Indian scenario. All patients diagnosed for invasive zygomycosis at a tertiary care center in north India from 2000-2004, were retrospectively analyzed. A total of 178 cases (mean average of 35.6 cases/year) of zygomycosis were diagnosed. Rhino-orbito-cerebral type (54.5%) was the commonest presentation followed by cutaneous (14.6%), disseminated (9.0%), and gastrointestinal (8.4%) zygomycosis. Renal and pulmonary zygomycosis were seen in 6.7% patients each. Uncontrolled diabetes mellitus (in 73.6% of cases) was the significant risk factor in all types (Odds Ratio 1.5-8.0) except renal zygomycosis. Breach of skin was the risk factor in 46.2% patients with cutaneous zygomycosis. However, no risk factor could be detected in 11.8% patients. Antemortem diagnosis was possible in 83.7% cases. The commonest (61.5%) isolate was Rhizopus oryzae followed by Apophysomyces elegans in 27% patients. Combination of debridement surgery and amphotericin B therapy was significantly better in survival of the patients (P<0.005) than amphotericin B alone (79.6% vs. 51.7% survival). Thus, a rising trend of invasive zygomycosis was observed in patients with uncontrolled diabetes mellitus in India. Consistent diagnosis of renal zygomycosis in apparently healthy hosts and the emergence of A. elegans in India demand further study.     

Not everything acid fast is Mycobacterium tuberculosis--a case report.

The Ziehl-Neelsen (ZN) stain is important in identifying organisms that are acid fast, principally Mycobacterium tuberculosis. However, decolorisation with a weaker acid concentration (for example 1% hydrochloric acid), often used in ZN staining in histology, can result in a wider variety of organisms appearing acid fast and can be a cause of misidentification. To illustrate this point, a patient is described with pulmonary nocardiosis who was misdiagnosed as having tuberculous empyema on pleural biopsy.     

Competitive binding to a charged leucine motif represses transformation by a papillomavirus E6 oncoprotein

E6 oncoproteins from HPV-16 and bovine papillomavirus type 1 (BPV-1) bind to similar leucine-rich peptides termed charged leucine motifs found on the cellular focal adhesion protein paxillin and the E3 ubiquitin ligase E6AP. BPV-1 E6 (BE6) mutants that do not bind to paxillin are defective at inducing cellular transformation. It is possible, however, that BE6 mutants that do not bind paxillin are defective for transformation for an unrelated reason than the ability to bind to charged leucine motifs. To address the role of BE6 interaction with charged leucine motifs, we fused a BE6-binding charged leucine motif to the amino terminus of BE6, thereby creating an autoinhibitory binding domain. We found that the fusion protein failed to bind to paxillin or transform murine C127 cells. Mutation of the amino terminal binding motif in the fusion protein restored both interaction with paxillin and transformation. This demonstrates that BE6 transformation requires binding to charged leucine motifs on particular cellular proteins and that transformation by papillomavirus oncoproteins can be repressed by competitive interactions with charged leucine motifs.     

Heterogeneity of monoclonal antibody-reactive epitopes on mycobacterial 30-kilodalton-region proteins and the secreted antigen 85 complex and demonstration of antigen 85B on the Mycobacterium leprae cell wall surface.

Proteins of the antigen 85 complex in the 30-kDa region secreted by live mycobacteria are important in the immune response against mycobacterial infections and may play an important biological role in the host-parasite interaction. In the present study, we have characterized epitopes of the 30-kDa-region proteins and the antigen 85 complex by using a panel of 13 monoclonal antibodies (MAbs) reacting with these antigens, 6 of which have not been described before. By using five previously characterized related secreted proteins of Mycobacterium tuberculosis, MPT44 (85A), MPT59 (85B), MPT45 (85C), MPT51 (27 kDa), and MPT64 (26 kDa), we have identified at least 10 different MAb-reactive epitopes on the proteins of the antigen 85 complex. A heterogeneous distribution of epitopes was observed within the components of the antigen 85 complex. Two distinct epitopes specific for antigen 85B and two other epitopes restricted to the 85A and 85B components were recognized. Two of them were shared with a previously unidentified 27-kDa protein present in M. tuberculosis culture fluid from which all MPT proteins were derived. The rest of the MAb-reactive epitopes were found to be present mostly in antigens 85A and 85B and to a lesser extent in antigen 85C. None of these MAbs recognized component 85C alone nor did they bind to the related MPT51 and MPT64 proteins. Interestingly, most of the MAbs reacted with purified native proteins of the antigen 85 complex but not to them in their denatured forms. In contrast, reactivity of the MAbs with the cytosol fraction of M. tuberculosis in immunoblotting revealed that they bound to a closely related cytosolic 30-kDa protein(s) even when they were denatured. Heterogeneity of these MAb-reactive epitopes of the antigen 85 complex was further evident as they were found to be distributed in various patterns among 19 different mycobacterial species. By using fusion proteins of the Mycobacterium leprae 30/31-kDa antigen 85 complex, we have localized at least six different epitopes within amino acid residues 55 to 266 of the M. leprae antigen 85 complex. Finally, by immunohistochemical analysis, we have demonstrated the in situ expression of one of the novel MAb-reactive epitopes specific for antigen 85B on the cell wall surface of M. leprae within macrophages in lepromatous leprosy lesions and thus provide direct evidence for the presence of the B component of the antigen 85 complex on the surface of intact M. leprae.     

Mammalian sex chromosomes III. Activity of pseudoautosomal steroid sulfatase enzyme during spermatogenesis inMus musculus

Parallel to the inactivation of the X chromosome in somatic cells of female, the male X in mammals is rendered inactive during spermatogenesis. Pseudoautosomal genes, those present on the X-Y meiotically pairable region of male, escape inactivation in female soma. It is suggested, but not demonstrated, that they may also be refractory to the inactivation signal in male germ cells. We have assayed activity of the enzyme steroid sulfatase, product of a pseudoautosomal gene, in testicular cells of the mouse and shown its presence in premeiotic, meiotic (pachytene), and postmeiotic (spermatid) cell types. It appears that, as in females, pseudoautosomal genes may escape inactivation in male germ cells also.