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Biomedical subjects

A Choudhury

Publications and source records attributed to A Choudhury.

At least 73 records · Page 4Linked to original sources
PubMed1994

Characterization and functional activity of dendritic cells from rat choroid.

Cell preparations from the posterior eye cup of the eye cultured for 2 days exhibited accessory activity for T-cell responses to a mitogenic treatment and stimulatory activity in a mixed leukocyte reaction (MLR), two functions characteristic of dendritic cells (DC). These activities both partitioned with cells having a low buoyant density, another characteristic of DC. Immunomagnetic separations with monoclonal antibodies against lymphoid dendritic cell surface antigens revealed that the accessory activity of the low-density cells was entirely associated with a small population of cells positively selected by these antibodies. Immunofluorescent staining with these same antibodies also revealed a small subpopulation of low-density cells having the morphology of DC. On cryostat sections of eye tissue the positively-stained cells were localized in the choroid and were not observed within the sclera or the retina. Based on these results we conclude that there are functional DC in the choroid, and we speculate that they may have a significant role in the inflammatory process during posterior uveitis.

Animals↗
PubMed1994

Epidemiological studies of blood groups in the district of Bankura with special reference to tribals.

Distribution of ABO blood groups was studied in 4301 subjects, both tribals and non-tribals of the district of Bankura in West Bengal. It was observed that group 'O' blood was found in most cases and group 'AB' was seen in least number of cases. It was also found that there was no significant difference in distribution of blood groups between the tribals and non-tribals.

ABO Blood-Group System↗
PubMed1993

Purification and partial characterization of a N-glycolylneuraminic acid specific lectin from the clam Anadara granosa (L).

The N-glycolylneuraminic acid-specific lectin (AFL) from the foot muscles of the marine clam Anadara granosa has been purified to homogeneity by affinity chromatography on bovine submaxillary mucin-Sepharose 4B. The Ca(2+)-dependent lectin agglutinates rabbit erythrocytes. The purified lectin is a tetrameric protein of native M(r) 254 kDa having a pI value of 6.65. The M(r) of two subunits is 65 kDa each and that of the remaining two is 62 kDa each. The dominant amino acids of the lectin are aspartic acid, glutamic acid, serine and glycine. The lectin activity is inhibited only by N-glycolylneuraminic acid specially when it is present in the macromolecular structure of mucin viz., porcine submaxillary mucin, which is the most potent inhibitor. The binding site does not recognize N-acetylneuraminic acid. Due to this strict specificity, the lectin appears to be unique.

Amino Acids↗
PubMed1992

A novel galactosyl-binding lectin from the plasma of the blood clam, Anadara granosa (L) and a study of its combining site.

The marine blood clam species Anadara granosa (L) belong to arcidae, a family with some extraordinary haematological features. The plasma of this species exhibited strong haemagglutinating activities, from which a galactosyl binding lectin, Anadarin P, was purified in a single step affinity chromatography using Sepharose 4B-asialofetuin as an affinity matrix. The purified lectin, eluted with lactose, was found to be homogeneous by alkaline polyacrylamide disc gels, gel-filtration and isoelectric focusing. Native M(r) of the lectin was 130,000 having a PI value of 6.82 and was composed of two subunits of M(r) 17,000 and M(r) 16,000 which were noncovalently bound. The lectin was remarkably thermostable; the agglutinating titre remained unchanged over a wide range of pH (from 5 to 10) but increased with neuraminidase treated rabbit erythrocytes. Anadarin P combining site has been proposed to be small pocket-like structure which recognised only C-3 and C-4 hydroxyl groups of D-galactose. Presence of bulky groups at C-2 and C-6 exert strong steric hindrance as L-arabinose, 2-deoxy-D-galactose and D-xylose are better inhibitors than D-galactose. The lectin fails to differentiate methyl substituted galactosides as both alpha- and beta- methyl galactosides are equally active; but in case of substituted phenyl glycosides, the lectin shows different affinity towards alpha and beta anomers. The avidity of the lectin to bind the aromatic aglycons of galactosides suggests the presence of a hydrophobic region in the combining site. Interactions with some disaccharides indicate the presence of an extended area near the monosaccharide binding site.

Animals↗
PubMed1992

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↗
PubMed1991

A phase II trial of interleukin-2 by continuous infusion and interferon by intramuscular injection in patients with renal cell carcinoma.

Fifteen patients with advanced, measurable renal cell carcinoma entered a Phase II clinical trial of interleukin-2 (IL-2) (Teceleukin, Hoffmann-La Roche Inc., Nutley, NJ) and interferon (IFN) (Roferon A, Hoffmann-La Roche Inc.). IL-2 was administered by continuous infusion daily for 4 days and IFN was administered by intramuscular injection daily for 4 days; therapy continued for 4 weeks. Eight men and seven women were treated in this trial (median age, 61 years). Toxicity was moderate to severe with fatigue, nausea, vomiting, hypotension, and elevated blood urea nitrogen bunion and creatinine levels seen in all patients. Two patients achieved a complete remission and two patients achieved a partial remission. The median duration of response was 18 months. IL-2 and IFN is an active combination in the treatment of renal cell carcinoma and warrants further investigation.

Adult↗
PubMed1991

Polypodium sp. (Coelenterata) from lake sturgeon (Acipenser fulvescens rafinesque) in the prairie region of Canada.

Polypodium sp. is reported for the first time from Canadian waters. It occurred in lake sturgeon (Acipenser fulvescens) eggs, from the Nelson River, Manitoba, and from Cumberland House, Saskatchewan. The prevalence of this parasite was 100% in females with eggs of 3.0 mm diameter or more. One, 4, 25, and 179 infected eggs were collected in gonads with eggs of this size class, but infected eggs were not apparent in individuals with smaller eggs. This is the northernmost occurrence of this parasite reported in North America.

Animals↗
PubMed1991

Diphyllobothrium, Anisakis and other fish-borne parasitic zoonoses.

Fish-borne parasitic zoonoses such as anisakiasis and diphyllobothriasis occur infrequently in Canada and more work needs to be done on the interactions and transmission dynamics of marine and freshwater anisakids in North America. The diphyllobothriid tapeworms are primarily restricted to the northern Canada. Problems with the specific identification of these parasites from their fish hosts prompted the development of a series of nucleic acid probes. Use of the polymerase chain reaction proved to be quick, accurate and requires little skill, once developed.

Animals↗
PubMed1989

A new surgical localization technique for biopsy in patients with nipple discharge.

In a series of 12 patients with bloody nipple discharge, a new technique of mammary ductal localization was used to identify the duct responsible for the discharge and assure its complete removal for pathological diagnosis. This procedure utilizes a 30-gauge anterior chamber needle that is gently advanced into the offending duct, and methylene blue dye is injected to outline the involved duct for easy dissection though a circumareolar incision. This provides the pathologist with an intact specimen and avoids the problems associated with specimen roentgenography or loss of a ductal probe during the procedure. Because we feel that all patients with a bloody nipple discharge warrant a biopsy, this procedure provides a safe, rapid, effective method and allows the biopsy to be done on an outpatient basis.

Biopsy, Needle↗
PubMed1989

Blocking of Mycobacterium leprae adherence to dissociated Schwann cells by anti-mycobacterial antibodies.

The association of Mycobacterium leprae with Schwann cells may represent an early crucial step in M. leprae pathogenesis. Using a dissociated Schwann-cell system and anti-mycobacterial monoclonal and polyclonal antibodies directed against surface and cytoplasmic components, we investigated the nature of M. leprae epitopes that mediate cytadhesion. Antibodies to polysaccharide and lipid components of M. leprae cell wall inhibited cytadhesion, whereas those directed against both surface and cytoplasmic protein epitopes did not show any such effect. No synergistic or antagonistic activity in inhibiting cytadhesion was observed when antibodies were used in combination. Thus, the association of M. leprae with Schwann cells may be mediated collectively by more than one of its lipid/polysaccharide epitopes. Also, a role for humoral immunity in intervention in the initial steps of M. leprae pathogenesis needs to be considered.

Animals↗
PubMed1989

Effects of a derivative of serotonin (deoxyfructoserotonin) and other antileprosy drugs on attachment and uptake of Mycobacterium leprae by Schwann cells in vitro.

The association (attachment and/or uptake) of Mycobacterium leprae with cultured Schwann cells was studied at 8 and 72 h in the presence of a new antileprosy compound, deoxyfructoserotonin (DFS), as well as conventional antileprosy drugs such as rifampin (RFP) and 4,4'-diaminodiphenyl sulfone (DDS). DFS significantly inhibited bacterial association with Schwann cells at 8 h. RFP also affected the association of M. leprae but not to the same extent as DFS. A similar inhibition at 8 h was noted when M. leprae but not Schwann cells were pretreated with DFS or RFP for 5 days before infection of cultures, implying that modulation was achieved through some form of drug action on bacteria. DDS had no effect on M. leprae association; however, the combination of DFS and DDS was neither antagonistic nor additive. At 72 h postinfection, when attached but noninternalized bacteria were removed with trypsin-EDTA from Schwann cell cultures containing DFS or RFP, a 50% reduction in the number of bacteria in the drug-treated group was obtained as compared with the numbers in drug-free cultures. This indicated a slow entry of M. leprae into Schwann cells in the presence of these drugs. Collectively, these observations point to differing requirements for late and early association of M. leprae with Schwann cells, besides suggesting a role for DFS and RFP in the prevention and minimization of M. leprae-induced nerve damage in vivo.

Bacterial Adhesion↗
PubMed1989

Omnatax in acute urinary tract infection. A clinical study.

25 patients of acute urinary tract infection with E. coli received Omnatax, 1 gm. b.d. 80% patients had bacteriologic cure on second day and 96% on fourth day of treatment. When assessed in light of the disappearance or decrease in pyuria and bacteriuria, 72% patients showed excellent response and 28% moderate response at the end of treatment. Clinical cure was achieved in 84% of patients. Mean number of days required for the patients to become symptom-free was 3.5 and mean time to achieve complete bacterial elimination was 1.96 days.

Acute Disease↗
PubMed1980

Undifferentiated (embryonal) sarcoma of the liver with alpha-1-antitrypsin deposits: immunohistochemical and ultrastructural studies.

Periodic acid-Schiff-positive diastase-resistant globules are described in an undifferentiated (embryonal) sarcoma of the liver in a 14-year-old boy. These globules were shown to contain alpha-1-antitrypsin (A-1-AT) protein by immunofluorescence techniques. Further immunohistochemical studied revealed albumin and gamma globulins, but no alpha-feto protein (AFP). Electron microscopic studies showed large, electron-dense bodies consistent with phagolysosomal structures, and distinct from that described in alpha-1-antitrypsin deficiency (A-1-ATD). These findings suggested that the globules in this tumor may represent trapping of serum proteins by the malignant cell. These observations are discussed in connection with recent studies linking the deficiency disease and epithelial hepatic tumors.

Adolescent↗