B1b lymphocytes confer T cell-independent long-lasting immunity

Many microbial pathogens employ antigenic variation as a strategy to evade the immune system, posing a challenge in vaccine development. To understand the requirements for immunity against such pathogens, we studied Borrelia hermsii, a relapsing fever bacterium. We found that mice deficient in T, follicular B, marginal zone B, or B1a lymphocytes resolved B. hersmii bacteremia and became resistant to reinfection. The resolution of bacteremia coincided with an expansion and persistence of B1b lymphocytes, and purified B1b lymphocytes from convalescent wild-type or TCR-betaxdelta-/- mice conferred immunity to Rag1-/- mice. The B1b lymphocytes in the reconstituted Rag1-/- mice provided long-lasting immunity by rapidly generating B. hermsii-specific IgM but not IgG upon bacterial challenge. Unmutated IgM is sufficient to eliminate B. hermsii, because AID-/- mice deficient in somatic hypermutation and class switch recombination efficiently resolved all bacteremic episodes. These data demonstrate that B1b lymphocytes can provide long-lasting T cell-independent IgM memory.     

Cytological diagnosis of nonulcerative penile neoplasms: report of two cases

Nonulcerative penile mass lesions are rare. Pathological diagnosis of these lesions would traditionally be a biopsy. We report two such primary penile lesions which were diagnosed by fine-needle aspiration cytology (FNAC). Both lesions were present in the shaft and were diagnosed as squamous cell carcinoma (SCC). The first patient had a recurrence on the penile stump of partial amputation without any ulceration. The second had a primary urethral carcinoma on the terminal penile shaft infiltrating the corpora cavernosa dorsally. Open biopsies were avoided in both cases. FNAC was associated with very little and tolerable discomfort. There were no complications. The aspirate yield was sufficient for cytological diagnosis. FNAC of nonulcerated penile lesions is safe, well tolerated, and capable of providing a cytological diagnosis. Hence, it is a very useful outpatient procedure and could be the procedure of choice for diagnosis.     

The architecture of variant surface glycoprotein gene expression sites in Trypanosoma brucei

Trypanosoma brucei evades the immune system by switching between Variant Surface Glycoprotein (VSG) genes. The active VSG gene is transcribed in one of approximately 20 telomeric expression sites (ESs). It has been postulated that ES polymorphism plays a role in host adaptation. To gain more insight into ES architecture, we have determined the complete sequence of Bacterial Artificial Chromosomes (BACs) containing DNA from three ESs and their flanking regions. There was variation in the order and number of ES-associated genes (ESAGs). ESAGs 6 and 7, encoding transferrin receptor subunits, are the only ESAGs with functional copies in every ES that has been sequenced until now. A BAC clone containing the VO2 ES sequences comprised approximately half of a 330 kb 'intermediate' chromosome. The extensive similarity between this intermediate chromosome and the left telomere of T. brucei 927 chromosome I, suggests that this previously uncharacterised intermediate size class of chromosomes could have arisen from breakage of megabase chromosomes. Unexpected conservation of sequences, including pseudogenes, indicates that the multiple ESs could have arisen through a relatively recent amplification of a single ES.     

Association of DR4 with pemphigus

HLA typing for the A, B, C, and D locus antigens was performed on 65 patients with pemphigus vulgaris and on 558 controls living in the Los Angeles area. The patients were divided into several categories. These included Jewish and non-Jewish patients, patients with only mucous membrane involvement, only skin or both mucous membrane and skin involvement, and those with a single-episode or recurrent disease. Depending on the highest titer of anti-intercellular cement substance antibody titer, the patients were categorized into those whose titers were 0-80, 160-320, and 640 or greater. A statistically increased incidence of HLA-A25, HLA-B38, and HLA-DR4 antigens was observed in patients compared to controls. This incidence was significantly higher in Jewish compared to non-Jewish patients. The correlations were insignificant in the group with an antibody titer of 0-80, but significant in those with a titer of 160-320, and even more significant in those with titers greater than 640. No significant differences were present between patients who had a single-episode or recurrent disease or in those that had only mouth or only skin involvement. In all categories tested, the association was stronger with DR4 than with A26 or B38. DR4 was present equally in B38-positive and B38-negative patients. The primary association of pemphigus vulgaris may be with the DR4 antigen, and it may be a marker for the severity of the disease.     

Cervical squamous intra-epithelial changes and human papillomavirus infection in women infected with human immunodeficiency virus in Pune, India

In view of the dual burden of HIV infection and cervical cancers in India, this study was undertaken to estimate the prevalence of Pap smear abnormalities and human papillomavirus infection among HIV-infected women. Consecutive HIV-infected women attending voluntary counseling testing clinics were enrolled. Written informed consent, demographic information, Pap smears, cervical swabs for HPV typing and a blood sample for CD4+ cell count were collected. Treatment for opportunistic and sexually transmitted infections and reproductive tract infections was provided. Women with Pap smear abnormality were referred for further intervention. Between January 2003 and May 2004, 287 HIV-infected women were enrolled. Pap smear abnormalities were seen in 6.3% women and were more common among women aged 30 and above (P=0.042) and those who had suffered from opportunistic infections (P=0.004). In multivariate analysis, Pap smear abnormalities were associated independently with opportunistic infections (P=0.02, AOR 3.8, 95% CI 1.2--11.5). Of the 100 random cervical specimens screened for HPV 16 and 18 genotypes, 33% (95 CI 23.9--43.1) were positive for HPV 16/18. Of the 122 patients who returned for a follow-up visit, 5 patients (4.1%) who did not have Pap smear abnormality at baseline, had developed Pap smear abnormality. The incidence of Pap smear abnormalities was 5.5 per 100 person year of follow-up. In order to prevent thousands of deaths due to cervical cancer in India, there is a need for strengthening the Pap smear screening program and HPV vaccine development.     

Kinetic Evaluation for Removal of an Anionic Diazo Direct Red 28 by Using Phytoremediation Potential of Salvinia molesta Mitchell

Bulletin of Environmental Contamination and Toxicology - The dye removal using phytoremediation has demonstrated its potential to degrade many recalcitrant dyes. The kinetic investigations for...     

Height-weight relationship in young healthy Indian males

Height-weight relationship in young healthy Indian males (19-22 yrs.) has been established. It is concluded that the relationship of the form: log w = 1.18 + 0.35 h fits well to the data on height h (in metres) and weight w (in kilograms) for this group of subjects, the logarithm is taken to the base 10. The results of the present study show that Ehrenberg's equation of the form: log w = 0.8 h + 0.4 cannot be extended beyond the age of 18 years in young healthy Indian males.