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Biomedical subjects

U Datta

Publications and source records attributed to U Datta.

At least 37 records · Page 2Linked to original sources

Detection of leishmania antigen in kala azar patients using monoclonal antibodies.

Twenty-one monoclonal antibodies were produced against promastigote antigens of Leishmania donovani. Five monoclonal antibodies (Hyb.17, 6, 5, 4 and 2) identifying molecules associated with various L. donovani antigenic determinants ranging from 42-116 kDa were selected as 'capture antibodies' and compared with specific anti-leishmania antisera for detection of circulating leishmania antigens in kala azar patients' sera in a competitive-enzyme-linked immunosorbent assay system (ELISA). The anti-leishmania antisera could detect circulating antigen in 30% of kala azar cases while out of the five monoclonals, Hyb.17 could effectively detect circulating leishmania antigen in 85.4%. The efficacy of Hyb.6 was however low (31.7%). The antigens recognized by these monoclonal antibodies in the western blot assay could possibly represent the ones circulating in sera of patients suffering from kala azar. A cocktail of these monoclonal antibodies may be more useful than the conventional polyclonal antisera in detection of circulating antigen for clinical diagnosis of kala azar.

Animals↗

A search for immunocontraceptive agent from marine sources--role of antispermatheca globulin of Telescopium telescopium on fertility regulation in male rat.

Polyclonal antisera were developed in rabbits against 'spermatheca', the reproductive gland of T. telescopium, a marine mollusc. The gland contains spermatozoa. Antisera and its IgG fraction (ASTG) indicated common antigenic determinants by immunodiffusion and had titer values 81920 and 1280 against crude antigen extract. Cycling female rats when exposed to passively immunized male rats with different doses of ASTG, had reduction in implantation sites and litter size. Females had pseudopregnancy when exposed to higher doses of immunized males and had normal cycle after 20 days in average. ASTG in male rats caused decrease in weight of the reproductive glands, alteration in sperm concentration, motility and morphology, formation of multinucleated giant cells and vacuoles leading to arrest of spermatogenesis and reduction in seminiferous tubular diameter. The effects were dose dependent with reversible infertility. The results indicate presence of a common antigenic determinants which cross-react with vertebrates and existence of common relation through phylogenetic evolution and their immune responses.

Animals↗

Secondary immune defects in non-Hodgkin's lymphoma.

Changes in the humoral, cellular and phagocytic components of the immune system were investigated in 44 biopsy proven, untreated patients of non-Hodgkin's lymphoma (NHL). There was significant decrease in the total lymphocyte number, their subsets (T and B) and the T helper (T mu) population. Impaired leukocyte migration inhibition response and DNA synthesis following stimulation by phytohaemagglutinin were noted. Significant reduction of serum IgA was found in patients of both diffuse and nodular NHL. Phagocytic activity and nitroblue tetrazolium (NBT) reduction were unaltered, but chemotaxis was significantly reduced and bactericidal activity showed variable results.

Antibody Formation↗

Immune status in ataxia telangiectasia.

Immune status of 22 patients of ataxia telangiectasia was studied over a period of 8 yr (mean age of patients: 9.5 +/- 3 yr; 9 of 22 were siblings). Low T-cell number was observed in 14 of 19 patients but the response to PHA challenge done in 10 patients was normal and migration inhibition to BCG antigen was positive in 6 of 6 patients. IgM defect was seen in 2 out of 18 patients and serum IgA was deficient in 10 out of 18 patients. Salivary IgA was also absent in these children. Four children had high spontaneous NBT reduction. None of the patients had lymphoma, leukemia or any other malignancy at the time of presentation. Candida killing was normal in all patients. The presenting feature related to the CNS in almost all children and gross infections were not seen.

Adolescent↗

Cell mediated immunity in herpes simplex keratitis in man.

Varied manifestations of herpes simplex keratitis are postulated to be related to alterations or paucity of protective immune response to the virus. In this study lymphocyte subpopulations and macrophage inhibition factor (MIF) assay are investigated in herpes simplex keratitis. Active T-lymphocytes are detected to be significantly low in active keratitis as compared to the healed stage (P less than 0.001) and normal control subjects (P less than 0.01). Active T-cells are also lower in bilateral keratitis than in unilateral keratitis (P less than 0.01), and in stromal keratitis than in epithelial keratitis (P less than 0.05). Total E-rosette-forming cells and leucocyte migration inhibition factor (MIF) assay demonstrates significantly lower values in bilateral keratitis than in unilateral keratitis, and in stromal keratitis than in epithelial keratitis. On healing, total E-RFC, active T-cells and MIF values improved and are comparable to those found in normal subjects. Enumeration of absolute lymphocyte counts and EAC rosette-forming cells (B-lymphocyte cells) did not yield any differences. Our observations demonstrate paucity of cell-mediated immune response in stromal keratitis. More marked deficiency is demonstrable in bilateral keratitis. Manifestations of herpes simplex keratitis and their healing is observed to be relatable to the level of cell mediated immune response.

Cell Movement↗

Non-organ specific & organ specific antibodies in rheumatoid arthritis.

Fifty patients of rheumatoid arthritis clinically diagnosed (by ARA criteria) were studied for both non-organ specific [rheumatoid factor (RF), anti-nuclear antibodies (ANA), extractable nuclear antibody (ENA), granulocyte specific anti-nuclear antibody (GS-ANA), anti-smooth muscle antibody (SMA) and anti-mitochondrial antibody (AMA)] and organ specific, [anti-adrenal (AAA), anti-islet cell (ICA), antithyroid antibody (ATA) and anti-parietal cell (PCA)] auto antibodies. RF was positive in 80 per cent of patients. ANA was positive in 44 per cent of patients, ENA in 62 per cent, SMA in 20 per cent, AMA in 18 per cent and GS-ANA in 68 per cent. Of the organ specific antibodies, PCA was demonstrable in 28 per cent of the patients and none of the other antibodies were present. Circumstantial evidence indicates that ANA and GS-ANA are not synonymous but independent, cross-reacting entities and the presence of both increase the sensitivity (94%) of diagnosis of RA.

Adolescent↗

Organization and size class homogeneity of ribosomal RNA genes of catfish Heteropneustes fossilis.

The ribosomal RNA genes of catfish Heteropneustes fossilis Bloch were examined by Southern blot analysis of genomic DNA digested with restriction enzymes and probed with labelled catfish ribosomal RNA. The major repeat length is 12 kb and about 300 copies per haploid genome are tandemly arranged. The repeat lengths are homogeneous in size in different tissues and individuals. A restriction site polymorphism exists in some of the repeats.

Animals↗

A study of nine anthroposcopic traits among the three tribes of the Bastar District in Madhya Pradesh, India.

Nine anthroposcopic traits, namely palmar and plantar digital formulae, hand-clasping, armfolding, handedness, tongue rolling and folding, ear lobe attachment and legfolding have been studied in the three tribal populations--Murias, Bisonhorn Marias and Halbas--from the Bastar District in Madhya Pradesh (Central India). An attempt has been made to compare the results of the present study with other population groups of Central India.

Adolescent↗

Cloning and characterization of a highly repetitive fish nucleotide sequence.

We have cloned and sequenced a highly repetitive HindIII fragment of DNA from the common carp Cyprinus carpio. It represents a tandemly repeated sequence with a monomeric unit of 245 bp and comprises 8% of the fish genome. Higher units of this monomer appear as a ladder in Southern blots. The monomeric unit has been sequenced; it is A + T-rich with some direct and some inverse-repeat nucleotide clusters.

Animals↗

Malignant lymphoma of convoluted lymphocytes: diagnosis by fine-needle aspiration cytology and cytochemistry.

The technique of fine-needle aspiration cytology (FNAC) was utilized in the diagnosis of 31 cases of malignant lymphoma of convoluted lymphocytes. The age of the patients ranged from 5 to 70 yr (median, 24 yr). Clinical history was available in 29 cases. All patients had peripheral lymphadenopathy. There was radiological evidence of mediastinal adenopathy in 62% of the cases, and 41% had pleural effusion; 52% of the patients presented with mediastinal compression syndrome. The diagnostically crucial convoluted cells comprised 47.3 +/- 23.73% of all lymphoid cells. Nuclear convolutions were appreciated in a significant number of cells in paraffin sections of 17 of 21 cases (85.7%) having subsequent histopathology. Cytochemical and E-rosette tests performed in 17 cases confirmed the T cell nature of the neoplasms. On an average, 72.3% of cells showed focal positive reaction for acid phosphatase, and 73.8% of cells formed E-rosettes.

Adolescent↗