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Biomedical subjects

U K Baveja

Publications and source records attributed to U K Baveja.

At least 19 recordsLinked to original sources

Evaluation of epidemiological and serological predictors of human immunodeficiency virus type-1 (HIV-1) infection among high risk professional blood donors with western blot indeterminate results.

BACKGROUND: Indeterminate pattern of results in Western blot (WBI) for human immunodeficiency virus type-1 (HIV-1) infection may represent early HIV-1 infection or may be non-specific in origin. This issue can be resolved by follow up testing upto at least 6 months resulting in psychological distress as well as in high drop out rates among those undergoing investigation pointing out the need for additional parameters that could help in determining the status of HIV-1 infection at the time of initial testing itself in individuals with WBI pattern. OBJECTIVE: The objectives of the present study were: (i) to determine the frequency of HIV-1 infected individuals in a group of professional donors showing WBI patterns in initial testing on the basis of follow up serological studies; (ii) to find out if any HIV related epidemiological or serological characteristics recorded at the time of initial testing could be considered as predictor for HIV-1 infection in WBI specimens; and (iii) to evaluate two alternative serodiagnostic strategies for HIV-1 infection viz. multiple EIAs based on different antigen preparations/principles and a line immunoassay (LIA) employing recombinant antigens in resolving status of HIV-1 infection in specimens showing WBI results at initial testing. STUDY DESIGN: Professional donors with WBI patterns belonging to EIA reactive and EIA nonreactive groups were subjected to study of epidemiological profile, prevalence of sexually transmitted diseases (STD) markers and follow up serological testing for HIV-1 at 6, 12, 24 and 48 weeks intervals to record any seroconversion. The initial and follow up specimens from the donors with initial WBI results were subjected to two EIAs (one based on dot immunoassay using synthetic HIV-1 antigens and other based on microwell EIA using recombinant HIV-1 proteins) as well as to LIA. RESULTS: Professional donors with initial WBI results, from the EIA reactive group had higher proportion of unmarried individuals (90.3%), with history of heterosexual promiscuity (75%) and visit to STD clinics (36.1%) compared with the WBI donors from the EIA nonreactive group (72.7, 42.4 and 12.1%, respectively, P values < 0.001). Prevalence of antitreponemal antibodies was higher in the former group (16.7%) compared with the later group (1.5%, P value < 0.002). Seroconversion was recorded in 4 (7.3%) out of 55 EIA reactive WBI donors from the EIA reactive group that were characterised by high optical density (OD) values in EIA, 'p24 only' pattern of band in WB and positivity by LIA at the time of initial testing. LIA was found to be more reliable test compared with combination of EIAs to determine status of HIV-1 infection in WBI specimens at the time of initial testing. CONCLUSION: The present study points out that parameters like history of heterosexual promiscuity, prevalence of STD markers, high OD values in screening EIA, 'p24' only pattern of bands in WB and positivity by LIA could have individual predictive values for HIV-1 infection in specimens showing WBI pattern of results at initial testing.

AIDS Serodiagnosis

Giardia lamblia: in-vitro sensitivity to some chemotherapeutic agents.

The susceptibility of Giardia lamblia to eight chemotherapeutic agents was studied in vitro. The criteria of viability of the parasite was the ability of the parasite to attach to the coverslip surface in situ, and to multiply in drug free media on subcultures. The giardicidal and 50% inhibitory concentrations of each drug were measured. The activity of metronidazole in vitro was found to be similar to that of mepacrine, whilst that of chloroquine was inferior. The sensitivity of G. lamblia to mepacrine and chloroquine is markedly greater than that reported for Entamoeba histolytica.

Animals

Immunodiagnosis of human hydatid disease.

A study was undertaken to evaluate the efficacy of Enzyme Linked Immunosorbent Assay using locally prepared antigens for immunodiagnosis of human hydatid disease. A total of 90 cases clinically suspected to be suffering from hydatid disease and 100 controls matched for age and sex were included in the study. Two types of ELISA were performed on detected specific antihydatid antibodies belonging to IgG/IgM/IgA classes and other type detected IgE class of antibodies. Antigen prepared from the human hydatid fluid was found to be unsuitable for diagnosis as it contained host proteins i.e. IgG. Sheep hydatid fluid obtained from the fertile hydatid cyst was used to prepare and standardize the antigen. ELISA test to detect anti hydatid antibodies belonging to either IgG, IgM and or IgA was found to be highly specific (98 per cent) in surgically confirmed hydatid disease and was negative in all the controls. The results of the study indicate that ELISA along with casoni test may provide the best results in diagnosis of hydatid disease.

Adolescent

Laboratory techniques for diagnosis of chlamydial infections of the eye.

Giemsa and fluorescence antibody (FA) staining were used to diagnose patients clinically suspected to be suffering from trachoma. A total of 52 controls i.e. individuals with refractive errors and no clinical trachoma and 173 cases suffering from different stages of trachoma were studied. FA was found to be 2.52 times more sensitive in confirming the presence of Chlamydia trachomatis compared to Giemsa staining. 28/52 (53.8%) and 4/52 (7.,69%) controls were also positive by FA and Giemsa staining, respectively, indicating sub-clinical infection without symptoms. Post treatment staining with both methods revealed that clinical cure of trachoma did not necessarily mean the absence of Chlamydia trachomatis in the conjunctival smears. As a corollary it can be deduced that mere presence of Chlamydia trachomatis in conjunctival epithelial cells may not cause clinical trachoma, certain host factors (local immunity etc.) may play an important role in clinical disease.

Adolescent

A study of immune profile in human hydatid diseases.

A clinico haematological and immunological study was undertaken in 90 patients clinically suspected to be suffering from hydatid disease over a period of 1 year. The parameters studied included age of presentation, site of cyst localisation, haematological profile, total immunoglobins of different classes (IgG, IgM, IgA & IgE) and complement component C3, rosette forming lymphocytes, blast cell formation in response to phytohaemagglutinin (PHA-P) and concanavalin A (Con-A) and casoni test using standard methods. Twenty two out of 90 (22.44%) clinically suspected patients were surgically confirmed as hydatid disease cases. Hydatid disease occured in all age groups. Youngest case was 8 years and oldest 70 years. In 17/22 cases the cyst localised in the liver followed by lungs (3) neck (1) and kidney (1). Majority of patients (63.65%) belonged to blood group B. The mean total leucocyte and eosinophill counts were raised significantly (p < 0.001 and p < 0.05, respectively) in confirmed patients. The mean ESR value was raised in hydatid patients though, not significantly (P > 0.08). All the four classes of immunoglobulins viz. IgG, IgA, IgM, IgE and complement C3 were significantly raised in patients of hydatid disease compared to controls (P < 0.001, P < 0.002, p < 0.01 and p < 0.01, P < 0.02 respectively). The percentage of lymphocytes in peripheral blood in hydatid patients was reduced though, not significantly (P > 0.2). The absolute lymphocyte count was raised and mean percentage of T cells was reduced in patients with hydatid disease (P < 0.001 and P < 0.001, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent

Assessment of the immune and nutritional status of the host in childhood diarrhoea due to cryptosporidium.

Cryptosporidium oocysts were detected microscopically in the concentrated faecal smears (stained by modified kinyoun's acid fast stain) in 13 out of 100 (13 per cent) cases of acute diarrhoea (AD < 2 weeks duration), 7 out of 50 (14 per cent) cases of chronic diarrhoea (CD > 2 weeks duration) and none in 50 age matched controls. The grades of malnutrition of the cases and controls were calculated by the weight for age criteria and the immune status assessed by the levels of serum immunoglobulins and SIgA in duodenal fluids. Malnutrition was observed in 6 out of 13 cases (46.1 per cent) in acute and 6 out of 7 cases (85.71 per cent) in chronic cryptosporidial diarrhoeas. There was no significant statistical difference (P > 0.05) in serum immunoglobulins and SIgA levels in chronic cryptosporidiosis. SIgA was significantly reduced (P > 0.05) in cases of acute cryptosporidiosis. Cryptosporidium is an important cause of symptomatic infection in apparently immunocompetent children not having been detected in a single non-diarrhoeal control. Further a low SIgA could contribute to acute symptomatic cryptosporidiosis by favouring colonization with the parasite.

Acute Disease

Entamoeba histolytica cyst passers. Clinical profile and spontaneous eradication of infection.

The present study was carried out to examine whether Entamoeba histolytica cyst passers suffer from any parasite-related bowel symptoms and to assess the frequency of spontaneous eradication of this infection. The study was carried out in two parts. In part I, stool samples were collected at random from 3536 individuals living in rural communities around Delhi. E. histolytica was isolated by the culture technique in 345 (9.7%) subjects. There was no increase in the prevalence rate of bowel symptoms in the culture-positive compared to the culture-negative subjects. One hundred twenty-four (36%) of the culture-positive subjects agreed to take part in a longitudinal study; the subjects were left untreated and clinical assessment and stool examinations were carried out at three-month intervals. One hundred eighteen (95.2%) subjects had eradicated their parasite spontaneously at the end of one year; none developed any features of invasive amebiasis. Part II of the study was carried out on 625 patients attending our Gastroenterology Clinic. Positive cultures of E. histolytica were obtained from 99 (15.2%) patients. Again, there was no increase in the prevalence rate of bowel complaints in the culture-positive compared to the culture-negative subjects. Moreover, histological appearances of the rectal biopsy specimens were not significantly different between the two groups. Twenty-eight (28.2%) patients agreed to the longitudinal study and all eradicated the parasite spontaneously within five months; none developed any evidence of invasive amebiasis.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals

Human giardiasis: correlation of specific secretory IgA levels in duodenal fluid to the severity of disease and infestation by Giardia lamblia.

Giardia lamblia specific secretory immunoglobulin A (sIgA) levels in the duodenal fluid of adult giardiasis cases are reported for the first time. The sIgA levels in the study group were found to be significantly higher (p less than 0.01) than in the 20 age- and sex-matched controls comprising cases classified as non-ulcerative dyspepsia who did nor reveal any G. lamblia in their stools and the duodenal fluid. An inverse relationship between the clinical severity of giardiasis and the level of sIgA in the duodenal fluid was noted. Cases with a higher trophozoite load in duodenal aspirate tended to be associated with envanescent G. lamblia-specific antibodies.

Adult

Colonic immunity in patients and amoebic liver abscess.

Secretory immunoglobulin A (S-IgA), coproantibody titre (antiamoebic) and IgA, IgG, IgM immunocytes in rectal mucosa were studied in 13 patients with amoebic liver abscess (ALA) prior to and 4-6 weeks after completion of antiamoebic therapy. Ten asymptomatic Entamoeba histolytica cyst passers and 17 healthy age and sex matched volunteers served as controls. Fecal S-IgA levels and counts of IgA bearing immunocytes in mucosa were significantly higher in patients with ALA and cyst passers as compared to healthy controls and showed a significant fall after treatment. Fecal antiamoebic antibodies were high in cyst passers and in cases of ALA after treatment. Raised levels of S-IgA and IgA class immunocyte counts probably indicate a local mucosal immune response directed at containing the infection.

Antibodies, Protozoan

Kinetics of specific IgM in patients of hepatic amoebiasis.

Entamoeba histolytica (EH) specific IgM was measured in 54 patients with diagnosed amoebic liver abscess (ALA), 13 with non-suppurative hepatic amoebiasis (NSHA) and 50 controls. The mean levels of EH specific IgM, estimated by ELISA were significantly raised in patients of invasive amoebiasis (both ALA and NSHA) compared to controls (P less than 0.05). EH specific IgG was also raised in both groups of patients. Follow up of patients with ALA showed a significant decline (P less than 0.05) in the specific IgM levels three months after treatment while the specific IgG antibodies persisted in high titres (1:160). Only four patients of NSHA could be followed up and all showed a decline in specific IgM levels. Raised specific serum IgM seems to be an indicator of active (invasive) amoebiasis.

Adult

Dot immunobinding assay versus sandwich ELISA in diagnosis of invasive amoebiasis.

Sera from 34 patients of amoebic liver abscess (ALA) and 11 patients with amoebic dysentery (AD) were examined for the presence of specific Entamoeba histolytica (EH) antibodies and amoebic antigen by enzyme linked immunosorbent assay (ELISA) and dot immunobinding assay (DIB). Both techniques were found to be equally sensitive for detecting antiamoebic antibodies (89.5 and 91.9% respectively) and highly specific (100%) in patients of ALA. ELISA was found to be more sensitive (94.4%) in detecting circulating amoebic antigen compared to DIB (68%) in patients of ALA. Specific antibodies, in significant levels, were detected in 3 and 5 patients of AD by ELISA and DIB assay, respectively. As DIB assay is easier to perform and less expensive, is recommended for detection of antibodies in patients with invasive amoebiasis.

Animals

Enzyme linked immunosorbent assay for the diagnosis of human neurocysticercosis: a preliminary report.

The diagnostic efficacy of an indirect enzyme linked immunosorbent assay (ELISA) was evaluated in cases of neurocystecercosis. Subjects studied included 22 cases and 30 controls (comprising 12 cases of surgically confirmed hydatid disease, 5 cases each of tuberculoma and P.U.O. and 8 cases of pyogenic meningitis). A standard ELISA was performed using porcine cysticerci as antigen. Sensitivity and specificity of the test were calculated for serum and cerebrospinal fluid separately. The test was found to give a sensitivity of 68 and 33 per cent for serum and C.S.F. respectively. The specificity for confirmed case was found to be cent per cent for both with the criteria of reporting used. The sensitivity of the test may be increased by using purified specific antigen and/or sandwich ELISA instead of indirect ELISA technique.

Brain Diseases

Isoenzyme studies of Giardia lamblia isolated from symptomatic cases.

Strains of Giardia lamblia were isolated from symptomatic cases of giardiasis and axenized in the laboratory. Electrophoretic mobility patterns of four enzymes, viz., EC 5.3.1.9 glucose phosphate isomerase (GPI); EC 1.1.1,4.0.L-malate; NADP+ Oxidoreductase (Oxaloacetate decarboxylating) (ME); EC 2.7.5.1 phosphoglucomutase (PGM); and EC 2.7.1.1 hexokinase (HK) of the lysates prepared from these isolates were studied using starch-gel. Based on differences in mobility patterns of PGM and HK, the four strains studied could be grouped into three different isoenzyme types (Zymodemes). ME mobility was identical in all the four strains. Some relative difference was seen in the mobility of GPI, though the pattern of mobility was similar in all the strains.

Adolescent