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Biomedical subjects

U Sengupta

Publications and source records attributed to U Sengupta.

At least 19 recordsLinked to original sources
PubMed2006

Seroprevalence of HIV infection among paediatric tuberculosis patients in Agra, India: a hospital-based study.

In this study which was carried over a period of 2 years, from 2003 to 2004, 270 paediatric patients with active Tuberculosis (TB) disease attending the OPD of S.N. Medical College, Agra were screened for Human Immunodeficiency Virus (HIV)-1/2 antibodies. Of these, 23 were found to be HIV-positive. Seroprevalence of HIV infection among paediatric TB patients in Agra is 8.51% (23/270). The HIV infection was found to be significantly higher, i.e. 82.61% in male children than in female children, i.e. 17.39%. Among the age groups, which were divided into < or =1, 2-5, 6-10 and 11-15 years, maximum cases of HIV-positivity, i.e. 65.22% was observed in the age group, 2-5 years of age. Among the HIV-positive children with TB, 86.75% were of pulmonary and 13.04% were of extra-pulmonary type. Among the vaccinated children, 65.22% were found to be HIV-positive, while 34.78% of the HIV-positive children were not BCG vaccinated. HIV-positive children are more likely to suffer from prolonged fever, weight loss, failure to thrive, developmental delay, stunted growth, cough, anorexia, lethargy, lower respiratory tract infections (LRTI) and hepatosplenomegaly while HIV negative are more likely to suffer from fever, diarrhoea, lymphadenitis, pallor and LRTI. 82.60% (19/23) of these TB patients had a history of positive contact with HIV, i.e. one of the parents was HIV-infected. The mode of transmission of HIV infection among paediatric TB patients was perinatal as revealed during the counselling sessions (pre-test and post-test) of both the parents.

Adolescent↗
PubMed2005

Seroprevalence of HIV infection among tuberculosis patients in Agra, India--a hospital-based study.

In this study which was carried over a period of 4 years, from 2001 to 2004, 600 adult patients with active TB disease attending the OPD of TBDTC, Agra, were screened for HIV-1/2 antibodies. Of these, 26 were found to be HIV-positive. Seroprevalence of HIV infection among adult TB patients in Agra is 4.3% (26/600). The HIV infection was found to be more in females, i.e. 7.95% (7/88) than in males, 3.71% (19/512). HIV-positivity of 5% was observed in the age groups, 15-24 and 25-34 years, i.e. 3/60 and 13/260, respectively. Among HIV-positive TB patients, 4.2% (22/524) were of pulmonary and 5.3% (4/76) were of extra-pulmonary type. A total of 3.04% (6/197) of HIV-positive TB patients were PPD positive and 4.96% (20/403) were PPD negative and bacillary positivity was 4.4% (15/340) and bacillary negativity was 4.2% (11/260). A total of 3.5% (18/515) of TB patients had a history of positive contact, i.e. spouse or one of the family members was HIV-infected. The difference in signs and symptoms among the HIV positive and HIV negative TB patients was found to be statistically significant.

Adolescent↗
PubMed2005

Seroprevalence of HIV infection among the foreign students at Agra during a fifteen year period (1988-2002).

The present study reports a retrospective analysis of data of HIV testing of foreign students from Sub-Saharan Africa, South-East Asia and Europe, studying as well as staying at Agra, over a period of 15 yr (1988 to 2002). Of the 2653 [2092 (78.85%) were from the Sub-Saharan African countries, 377 (14.21%) from the South-East Asian countries, and 184 (6.93%) from the European countries], foreign students tested for HIV, only 26 were found to be positive for HIV-1/2 antibodies by the ELISA, rapid and Western Blot assays. Out of 26 HIV-positive, 17 males and 7 females were from Sub-Saharan Africa and 2 males were from the European countries. The range of HIV-positivity over a period of 15 yr varied greatly. When the five-year (1988-1992, 1993-1997 and 1998-2002) results were compared, the HIV-seropositivity showed a decline from 1.85, 0.50 to 0.36 per cent in the first, second and third 5 yr slots, respectively. While the data were not representative of all foreign students in India, this reflected the population tested in this centre was not a growing focus of HIV infection in this part of the country.

Adolescent↗
PubMed2005

Seroprevalence of HIV infection among leprosy patients in Agra, India: trends and perspective.

This study compares the results of HIV seroprevalence, which was carried out in two phases, i.e., 1989 to 1993 and 1999 to 2004. Although the number of leprosy patients screened for HIV infection in the second phase is less (2125) as compared to those screened during the first phase (4025), a rise in HIV infection from 0.12% to 0.37% is certainly disturbing since this area appears to be endemic for both the infections. During the study period, the Out Patient department attendance of a few types of leprosy patients like borderline and borderline lepromatous have risen, whereas others like borderline tuberculoid and polar tuberculoid have declined in the second phase as compared to that of the first phase. The trend over a decade suggests that HIV infection is low among the leprosy patients when compared with other risk groups. Follow-up of these patients at an interval of six months, revealed that none of them downgraded into a severe form of leprosy nor developed ARC or AIDS. In this study, it appears that neither infection precipitated the other. The occurrence of downgradation as well as reversal reactions and neuritis (both chronic and acute) was not observed among the leprosy patients. None of them developed erythema nodosum leprosum reactions. Similarly, the HIV-positive leprosy cases did not develop either AIDS related complex (ARC) or full blown case of AIDS.

HIV Infections↗
PubMed2004

Utility of serodiagnostic tests for leprosy: a study in an endemic population in South India.

In order to evaluate the usefulness of natural disaccharide (PGL1) and 35 kDa antigens based serology in diagnosis of leprosy and in detecting high risk groups for leprosy, this study was conducted in an endemic population in South India. Out of 3346 cases and their households and neighbouring household contacts, serum samples from 2994 and 2875 individuals were screened for antibodies against PGL1 and 35kDa antigens respectively. While the overall positivity for contacts and leprosy cases was 3.3% for PGL1 antibody, the positivity for 35 kDa antibody was 6.3%. The positivity for contact population was 2.7% and 5.4% for PGL1 and 35 kDa antibodies, respectively. Lepromatous and borderline lepromatous patients showed positivity of 35.1% for PGL1 antibody and 45.7% for 35 kDa antibody. Follow-up of contacts showed that the majority (>90%) remained seronegative for both the antibodies and most of the new cases emerged from the seronegative group. The study clearly indicates that specific serological assays are not sensitive enough for application, both for diagnosis and for identifying any individual at risk for leprosy in the south Indian endemic population.

Adult↗
PubMed2003

Ultrastructural study of Schwann cells and endothelial cells in the pathogenesis of leprous neuropathy.

Peripheral nerve biopsies from 4 borderline tuberculoid (BT) and 4 lepromatous (LL) patients who were on multidrug therapy were investigated by light and electron microscopic studies. The variation of diameters and distribution of myelinated and unmyelinated fibers between BT and LL patients were not significant. This study has shown significant changes in peripheral nerves and endoneural blood vessels. It was revealed that besides Schwann cells (SC), the endothelial cells (EC) of endoneural blood vessels frequently harbor M. leprae. In BT, peripheral nerves in addition to the degenerative changes of SC and presence of perineural and perivascular cuffing by mononuclear cells, the endoneurial blood vessels showed thickening of basement membrane with hypertrophy of EC leading to narrowing or complete occlusion of lumen. On the other hand, peripheral nerves of LL patients were infiltrated with large number of M. leprae shown to be present in the electron transparent zone (ETZ) of the SC. The EC of endoneurial blood vessels were found to be loaded with M. leprae, and this bacillary loaded EC was found to release M. leprae into the lumen through its ruptured membrane.

Adult↗
PubMed2001

A major susceptibility locus for leprosy in India maps to chromosome 10p13.

Leprosy, a chronic infectious disease caused by Mycobacterium leprae, is prevalent in India, where about half of the world's estimated 800,000 cases occur. A role for the genetics of the host in variable susceptibility to leprosy has been indicated by familial clustering, twin studies, complex segregation analyses and human leukocyte antigen (HLA) association studies. We report here a genetic linkage scan of the genomes of 224 families from South India, containing 245 independent affected sibpairs with leprosy, mainly of the paucibacillary type. In a two-stage genome screen using 396 microsatellite markers, we found significant linkage (maximum lod score (MLS) = 4.09, P < 2x10-5) on chromosome 10p13 for a series of neighboring microsatellite markers, providing evidence for a major locus for this prevalent infectious disease. Thus, despite the polygenic nature of infectious disease susceptibility, some major, non-HLA-linked loci exist that may be mapped through obtainable numbers of affected sibling pairs.

Chromosome Mapping↗
PubMed2001

Immunological profile of treated lepromatous leprosy patients.

The immune responses of 19 treated lepromatous patients who had remained smear negative for a long period were assessed for specific cell-mediated immunity (CMI), anti-Mycobacterium leprae antibodies and cytokine release in response to challenge with M. leprae soluble antigen (MLSA). All of these patients remained anergic to Mitsuda lepromin. Lymphoproliferation in response to M. leprae antigen was noted in only two patients. Significant reduction in the phenolic glycolipid I (PGL-I) antibody response in treated patients with no difference in the M. leprae 35-kDa antibody response was observed when these responses were compared with those of active lepromatous patients. More treated patients produced interleukin-2 (IL-2) and interferon gamma (IFN-gamma) than did active patients. On the other hand, fewer treated patients produced IL-10 than did active patients. These limited findings suggest that the host immune response makes an attempt toward upregulation of CMI in some treated LL/BL patients.

Adult↗
PubMed2000

Experience and lessons from the use of lepromin and Mycobacterium leprae-specific serology.

Skin testing with lepromin, which produces a delayed-type hypersensitivity reaction, has been used in the classification of leprosy, and a good correlation has been found between immunological status and the reaction to lepromin. In addition, the prognostic value of the lepromin test has been demonstrated. More recently, skin testing with two soluble antigens of Mycobacterium leprae showed no difference of the mean size of the reaction between household contacts and non-contacts, indicating that these antigens are not useful for the diagnosis of leprosy. This and other evidence points to the need for a better skin test antigen capable of detecting infection of individuals by M. leprae. Whereas serological assays for antibodies against both PGL-1 and the 35 kDa antigen of M. leprae have been found to yield positive results in 90-100% of patients with lepromatous (BL/LL) leprosy, these assays fail to identify 40-60% of patients with tuberculoid (BT/TT) leprosy, because of the presence of only an insignificant level of antibody against components of M. leprae in these patients' serum, although, in many BT patients, antibody signal could be detected in the local lesions. These data indicate that there remains a need for a specific diagnostic test for leprosy.

Humans↗
PubMed1999

Immune responses to recombinant proteins of Mycobacterium leprae.

Identification of antigenic determinants of the polar immune response in leprosy may illuminate both protection and pathogenesis. Thirty subjects were studied (22 with polar disease and 8 healthy controls who were heavily exposed but disease-free) by assaying the proliferative, interferon (IFN)-gamma, and antibody responses to recombinant antigens of Mycobacterium leprae (10, 28, 36, and 65 kDa). The 10-kDa antigen elicited IFN-gamma production from all tuberculoid (TT) and borderline tuberculoid (BT) patients but little from controls, lepromatous (LL), or borderline lepromatous (BL) patients (P<.05). Production of 65-kDa-specific IFN-gamma was higher in TT/BT than in controls or LL/BL patients (P<.006). All subjects produced 65-kDa-specific antibody, but it was higher in LL/BL patients than in healthy controls, whose responses were higher than in TT/BT subjects (P=.035). The 36-kDa antibody responses were selectively increased in LL/BL subjects (P<.02). The intermediate phenotype of the controls suggests that M. leprae-specific production of IFN-gamma may contribute to pathology and to protection in leprosy.

Adult↗
PubMed1999

Specificity and function of immunogenic peptides from the 35-kilodalton protein of Mycobacterium leprae.

We identified a T-cell determinant of the 35-kDa antigen of Mycobacterium leprae which is discriminatory against cross-sensitization by its closely related homologue in Mycobacterium avium. From synthetic peptides covering the entire sequence, those with the highest affinity and permissive binding to purified HLA-DR molecules were evaluated for the stimulation of proliferation of peripheral blood mononuclear cells (PBMCs) from leprosy patients and healthy sensitized controls. Responses to the peptide pair 206-224, differing by four residues between M. leprae and M. avium, involved both species-specific and cross-reactive T cells. Lymph node cell proliferation in HLA-DRB1*01 transgenic mice was reciprocally species specific, but only the response to the M. leprae peptide in the context of DR1 was immunodominant. Of the cytokines in human PBMC cultures, gamma interferon production was negligible, while interleukin 10 (IL-10) responses in both patients and controls were more pronounced. IL-10 was most frequently induced by the shared 241-255 peptide, indicating that environmental cross-sensitization may skew the response toward a potentially pathogenic cytokine phenotype.

Animals↗
PubMed1999

Determination of circulating IgG subclasses against lipoarabinomannan in the leprosy spectrum and reactions.

IgG subclasses against lipoarabinomannan of mycobacteria were analyzed in the sera of leprosy patients. Patients with active leprosy [tuberculoid and lepromatous, patients undergoing erythema nodosum leprosum (ENL) and reversal reactions] and inactive cases (tuberculoid and lepromatous who were cured after chemotherapy) were included in this study. Active lepromatous patients had higher levels of IgG subclasses, except IgG4, compared to active tuberculoid patients. Some of the inactive cases (lepromatous patients cured after chemotherapy) were positive for the IgG1, IgG2 and IgG3 subclasses. However, their levels are lower than active lepromatous cases. On the other hand, no difference in the subclass levels between the active and inactive tuberculoid groups could be observed. While a significant fall in the level of IgG3 in ENL was observed as compared to lepromatous leprosy without ENL, higher levels of IgG1 and IgG2 were found in patients with reversal reactions compared to their active counterparts without reactions.

Antibodies, Bacterial↗
PubMed1998

Levels of IgG subclasses in active and inactive cases in the disease spectrum of leprosy.

The present study was carried out to establish the role of IgG subclasses in leprosy. IgG subclasses to Mycobacterium leprae sonicated antigens (MLSA) and phenolic glycolipid-I (PGL-I) were determined in 124 patients with active leprosy across the disease spectrum and in 76 cases with inactive disease after completion of chemotherapy. IgG2 antibodies were found to be the predominant subclass across the disease spectrum. Lepromatous patients showed elevated levels of IgGI. IgG3 antibody levels were higher in lepromatous than that in tuberculoid patients. Patients with erythema nodosum leprosum showed a significant fall in IgG3 antibody to MLSA. While chemotherapy induced a reduction in IgG1, IgG2 and IgG3 to PGL-I in almost all types of leprous patients, for MLSA the reduction was noticed for these subclasses only in lepromatous patients. IgG4 responses to these antigens were low through out the disease spectrum and did not alter with chemotherapy.

Antibodies, Bacterial↗
PubMed1995

Detection of antibodies against phenolic glycolipid-1 (PGL-1), 35-kDa and 30-40-kDa components of Mycobacterium leprae in the cerebrospinal fluid of of leprosy patients.

The involvement of the central nervous system (CNS) in lepromatous leprosy (LL) patients was investigated; 33 patients were examined clinically in detail and upper motor neuron involvement was observed in eight and lower motor neuron in three of these patients. Anti-Mycobacterium leprae antibodies could be detected in the CSF by PGL-1 enzyme-linked immunosorbent assay (ELISA) and monoclonal antibody (MAb) based competitive assays against defined epitopes on the 35-kDa protein and 30-40-kDa polysaccharide (lipoarabinomannan) antigens with MAbs MLO4 and ML34, respectively. Antibodies against PGL-1 and 35-kDa protein were observed in more subjects than antibodies against the 30-40-kDa antigen. Some correlation was observed between the upper motor neuron signs and antibody positivity for 35-kDa and PGL-1 antigens in the CSF of these patients.

Adult↗
PubMed1995

A study on performance of two serological assays for diagnosis of leprosy patients.

We compared 2 serological tests for the diagnosis of leprosy to test their performances. The tests include the serum antibody competition test (SACT) for the detection of antibodies to Mycobacterium leprae-specific epitope on 35 KDa protein molecule, and M. leprae gelatin particle agglutination assay (MLPA), for the detection of antiphenolic glycolipid-1 (PGL-1) antibodies. In both the assays a higher serological positivity was seen amongst multibacillary (MB) patients than those in paucibacillary (PB) patients. Taking all leprosy patients together, the sensitivity of SACT (59.7%) was observed to be statistically comparable to that of MLPA (66.9%). However, SACT proved to be more specific (97.7%) than MLPA (75.0%). The agreement between these 2 assays was observed to be moderate.

Antibodies, Bacterial↗
PubMed1995

Membrane attack complex in thickened cutaneous sensory nerves of leprosy patients.

Membrane attack complex (MAC) is a terminal end product produced as a result of complement activation. The deposition of MAC, in tissues, is known to have a local tissue damaging effect in several clinical conditions. Therefore, an attempt was made to demonstrate MAC in peripheral nerve biopsies, collected from leprosy patients. Interestingly, we could demonstrate deposition of MAC in involved cutaneous sensory nerves from most of the lepromatous leprosy patients. Contrary to this, majority of nerve biopsies from tuberculoid leprosy patients did not stain for MAC. Though MAC positive sections showed reactivity for S-protein, our observations support the possibility that MAC, either acting directly or indirectly, may be implicated in nerve damage, at least, in lepromatous leprosy patients.

Antigens, Bacterial↗