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Biomedical subjects

S K Dutta

Publications and source records attributed to S K Dutta.

At least 55 records · Page 3Linked to original sources
PubMed1997

Study of prevalence, severity, and etiological factors associated with acute pancreatitis in patients infected with human immunodeficiency virus.

OBJECTIVES: Patients with the human immunodeficiency virus (HIV) disease can develop pancreatic gland inflammation from HIV infection and related causes, or from factors totally independent of it. The incidence and severity acute pancreatitis in patients with HIV diseases and the frequency of associated etiological factors have not been examined in any detail. The purpose of this study was to (a) determine the prevalence of acute pancreatitis, (b) evaluate severity of pancreatic gland inflammation, (c) identify commonly associated etiological factors with acute pancreatitis, and (d) examine the relationship between CD4 lymphocyte counts and serum pancreatic enzyme levels (amylase and lipase) in patients with HIV disease. METHODS: We examined the medical records of 321 patients with HIV disease seen at Sinai Hospital of Baltimore between July of 1993 to June of 1994. Data collected from these records included clinical, laboratory, and radiologic features of pancreatitis, staging of HIV disease, risk factors, CD4 lymphocyte counts, medications associated with the presence of opportunistic infections, Kaposi's sarcoma, and lymphoma. RESULTS: From 321 patients with HIV disease, 45 patients developed at least one episode of acute pancreatitis as defined by clinical and laboratory criteria during the 1-yr period. A statistically significant negative correlation was found between serum pancreatic enzyme level and the number of CD4 lymphocytes (r = -0.15, p < 0.05 for serum amylase; r = -0.2, p < 0.05 for serum lipase). Furthermore, patients with asymptomatic HIV infection or CD4 lymphocyte count >500 mm3 did not develop asymptomatic hyperamylasemia or acute pancreatitis. Furthermore, the presence of gallstones, active injection drug use, pentamidine therapy, Pneumocystis carinii, Mycobacterium avium intracellulare correlated significantly (p < 0.001) with the diagnosis of acute pancreatitis. CONCLUSIONS: A detailed review of medical records of patients with HIV disease seen in a community hospital in 1 yr (1993-1994) suggests a high incidence (14%) of mild to moderately severe acute pancreatitis. In this group of patients, pancreatic gland inflammation is commonly associated with gallstones, intravenous drug abuse, pentamidine intake, and Pneumocystis carinii and Mycobacterium avium intracellulare infections. In addition, marked reduction in CD4 lymphocyte count is associated with increase in serum pancreatic enzyme levels (amylase, lipase activity) suggesting pancreatic gland inflammation or altered pancreatic enzyme turnover.

AIDS-Related Opportunistic Infections↗
PubMed1996

Structure of a Kunitz-type chymotrypsin from winged bean seeds at 2.95 A resolution.

Thc crystal structure of an alpha-chymotrypsin inhibitor (P6(1)22; a = 61.4, c = 210.9 A) isolated from winged bean (Psophocarpus. tetragonolobus) seeds has been determined at 2.95 A resolution by the molecular-replacement method using the 2.6 A coordinates of Erythrina trypsin inhibitor (ETI) as the starting model (57% sequence homology). This protease inhibitor, WCI, belongs to the Kunitz (STI) family and is a single polypeptide chain with 183 amino-acid residues having a molecular weight of 20 244 Da. Structure refinement with RESTRAIN and X-PLOR has led to a crystallographic R factor of 19.1% for 3469 observed reflections (I > 2sigma) in the resolution range 8-2.95 A. A total of 56 water molecules have been incorporated in the refined model containing 181 amino-acid residues. In the refined structure the deviations of bond lengths and bond angles from ideal values are 0.015 A and 2.2 degrees, respectively. The inhibitor molecule is spherical and consists of 12 antiparallel beta-strands with connecting loops arranged in a characteristic folding (a six-stranded beta-barrel and a six-stranded lid on one hollow end of the barrel) common to other homologous serine protease inhibitors in the Kunitz (STI) family as well as to some non-homologous proteins like interleukin-lalpha and interleukin-lbeta. In the structure the conformation of the protruding reactive-site loop is stabilized through hydrogen bonds mainly formed by the side chain of Asnl4, which intrudes inside the cavity of the reactive-site loop, with the side-chain and main-chain atoms of some residues in the loop region. A pseudo threefold axis exists parallel to the barrel axis of the structure. Each of the three subdomains comprises of four beta-strands with connecting loops.

Journal Article↗
PubMed1996

Zinc and iron as bioindicators of precancerous nature of oral submucous fibrosis.

Oral Submucous Fibrosis (OSF) is a precancerous condition of oral cavity and oropharynx. Its etiopathogenesis is still obscure. Epithelial dysplasia is considered an important indicator of it. In the present study, the authors try to ascertain bioinorganic parameters as alternate indicators of malignant potential of OSF along with other clinicopathological attributes. They also try to identify causative factors. Thirty-six OSF patients, showing different degrees of epithelial dysplasia, and 12 normal individuals are studied with special reference to trace metal contents (Zn and Fe) in oral tissues. Statistical analyses of data indicate that trace metal contents can be regarded as an alternate indicator of the precancerous nature of OSF. Some clinicopathological attributes that are easier and cheaper to measure may also indicate OSF.

Adult↗
PubMed1996

Comparative merits of different tissue biopsies in the diagnosis of sarcoidosis: Indian perspective.

In sarcoidosis, diagnosis rests on positive tissue biopsy in association with suggestive clinical features. In absence of guidelines in India, multiple biopsies (494 in total) were undertaken from 170 suspected and later proven cases of sarcoidosis. Involved tissues, Kveim test site, right scalene node, palpable peripheral lymph nodes and open pulmonary biopsy gave 80-100% positive result. (Perbronchial lung biopsy proved positive in India by other workers.) Mantoux test site, a rather unusual tissue, even if negative at 72 hours, may show positive granuloma in 64.5% cases with active sarcoidosis. Positive liver biopsy has only corroborative importance.

Biopsy↗
PubMed1995

Pathogenic, immunologic, and molecular differences between two Ehrlichia risticii strains.

Ehrlichia risticii is the causative agent of Potomac horse fever (PHF), an acute infectious disease of horses. In the last few years, there have been several reports of PHF cases occurring even in vaccinated horses. We isolated a new strain of E. risticii (90-12 strain) from a vaccinated horse suffering from clinical PHF. The major pathogenic, immunologic, and molecular differences between the 90-12 strain and the 25-D stain, which was originally isolated during the outbreaks in 1984, were studied. The 90-12 strain was more pathogenic for mice and horses compared with the 25-D strain. In enzyme-linked immunosorbent assay and immunofluorescence assay with mouse and horse antisera of both the strains, two- to fourfold differences were observed between (immunoblot) with mouse and horse antisera and also with the recombinant clone-specific antibodies. Though several antigens were similar in both the strains, there were significant differences between them in the 110-, 85-, 70-, 51-, and 33-kDa antigens. The 85-kDa antigen was present only in the 90-12 strain but cross-reacted with a 50-kDa antigen of the 25-D strain. The 51-kDa antigens of both strains had different migration patterns, Southern blot hybridization of the genome from both the strains with DNA probes made from the 51-, 55-, and clones for both the strains, whereas the probe of the 85-kDa clone showed a completely different pattern. The 16S rRNA gene sequences from the two strains were identical. Neither strain replicated in gamma interferon-treated mouse peritoneal macrophages. In in vitro neutralization assay, sera from the 25-D strain-infected horse neutralized the homologous strain but did not neutralize the 90-12 strain, whereas sera from the 90-12 strain-infected horse neutralized both the strains. In mouse protection experiments, there was complete homologous protection. But in cross-protection, mice immunized with the 25-D strain were only partially protected against challenge with the 90-12 strain, whereas mice immunized with the 90-12 strain were completely protected against the 25-D strain challenge. These results clearly indicate that there are major differences between the 90-12 and 25-D strains which may have implications regarding the vaccine failure for PHF and the development of an efficient vaccine.

Animals↗
PubMed1994

Frequency-dependent alterations in enolase activity in Escherichia coli caused by exposure to electric and magnetic fields.

Some neurochemical effects of low-intensity electric and magnetic fields have been shown to be nonlinear functions of exposure parameters. These effects occurred within narrow ranges of frequency and intensity. Previous studies on membrane-associated endpoints in cell culture preparations demonstrated changes in calcium efflux and in acetylcholinesterase activity following exposure to radiofrequency radiation, amplitude modulated (AM) at 16 and at 60 Hz, at a specific absorption rate of 0.05 W/kg. In this study, these modulation frequencies were tested for their influence on the activity of a cytoplasmic enzyme, enolase, which is being tested clinically for detection of neoplasia. Escherichia coli cultures containing a plasmid with a mammalian gene for enolase were exposed for 30 min, and cell extracts were assayed for enolase activity by measuring absorbance at 240 nm. The enolase activity in exposed cultures was compared to the activity in paired control cultures. Exposure to 147 MHz carrier waves at 0.05 W/kg, AM at 16 Hz showed enolase activity enhanced by 62%, and AM at 60 Hz showed enolase activity reduced by 28%. Similarly, exposure to 16 Hz fields alone, at 21.2 V/mrms (electric) and 97 nTrms (magnetic), showed enhancement in enolase activity by 59%, whereas exposure to 60 Hz fields alone, at 14.1 V/mrms (electric) and 65 nTrms (magnetic), showed reduction in activity by 24%. Sham exposures as well as exposure to continuous-wave 147 MHz radiation at 0.05 W/kg showed no change in enolase activity.(ABSTRACT TRUNCATED AT 250 WORDS)

Acetylcholinesterase↗
PubMed1994

DNA sequences encoding enolase are remarkably conserved from yeast to mammals.

Enolase (2-phospho-D-glycerate hydrolase, EC 4.2.1.11), particularly isoform neuron-specific enolase (NSE), is primarily localized in neurons and neuroendocrine cells and is a cancer diagnostic marker for brain tumors. Homology of enolase-coding DNA sequences from human, dog, cow, rat, mouse, rabbit, chicken, and yeast cells was investigated using hybridization techniques, percent sequence divergence, and amino acid analysis. Because enolase is a significant enzyme of the glycolytic pathway, enolase-coding DNA sequences have been found in all organisms tested so far. The human enzyme was found to be more like those of monkey and dog in structure than to those of chicken and yeast. The implications of the existence of the genetic conservation of enolase-coding DNA sequences in understanding concerted evolution as well as post-transcriptional regulation during differentiation are discussed. This is the first report is which sequence divergence in the coding region for enolase has been determined in a variety of organisms.

Amino Acid Sequence↗
PubMed1994

Detection of Ehrlichia risticii from feces of infected horses by immunomagnetic separation and PCR.

Potomac horse fever, caused by Ehrlichia risticii, is an important disease of equines. The major features of the disease are fever, leukopenia, and diarrhea. The organism has been detected from the blood mononuclear cells of infected horses, but its presence in the feces has not been known. A method for immunomagnetic separation of E. risticii from the feces of infected horses was developed, and the separated organisms were detected by PCR. Coating immunomagnetic beads (Dynabeads) with a 1:5 dilution of rabbit anti-E. risticii serum and incubating the Dynabeads with fecal samples for 25 min at room temperature gave optimum results. E. risticii was detected from the feces during the course of diarrhea from two experimentally infected horses. In horse 1, watery diarrhea occurred from days 11 to 16 postinfection (p.i.), after which the feces became soft on day 17 p.i. and then returned to normal. The organisms were first detected from the feces on day 11 p.i., peaked on day 13 p.i., and then gradually decreased until day 16 p.i., after which they became undetectable. In horse 2, first, on day 12 p.i., there was soft feces which continued and progressed to diarrhea on day 17 p.i. The feces became normal after day 18 p.i. The organisms in the feces of this horse were first detected on day 12 p.i. and peaked on day 14 p.i., after which they declined until day 16 p.i. and then became undetectable. In both horses, the number of organisms in the mononuclear cells peaked on days 10 and 11 p.i., respectively, 3 days prior to the respective peaks in the feces. E. risticii was not detected from the plasma samples obtained from these horses. There was a drastic reduction in PCR amplification of E. risticii DNA for fecal samples stored frozen at -20 degrees C in comparison with those stored at 4 degrees C. The presence of the organism in the feces only during the soft- or diarrheal-feces phase supports the previous hypothesis that the diarrhea is caused by the organisms replicating in cells lining the intestines. This rapid simple method of detection of the organisms from the feces will be helpful in diagnostic and epidemiologic studies of Potomac horse fever.

Animals↗
PubMed1994

Characterization of insulin-like growth factor I receptors in human esophageal epithelial cells.

In the present study we used 125I-labeled insulin-like growth factor I (125I-IGF-I) to identify and characterize IGF-I receptors in the well-characterized and propagable human esophageal epithelial (HEE) cell line and to characterize their role in cell growth. Binding of 125I-IGF-I was saturable, time and temperature dependent, reversible, and specific for IGF-I and related peptides. Scatchard analysis of binding data demonstrated that HEE cells possess two classes of IGF-I receptors: high affinity [dissociation constant (Kd) = 0.058 nM] and low capacity (13,870 receptors/cell), and low affinity (Kd = 2.2 nM) and high capacity (39,000 receptors/cell). Binding of 125I-IGF-I was inhibited with the following relative potencies (half-maximal inhibition): IGF-I (3.0 pM) > IGF-II (1.2 mM) >> insulin (1.0 microM). Affinity cross-linking of cell membranes using disuccinimidyl suberate as a cross-linking agent under reducing conditions revealed a single polypeptide band (relative mol wt 133,000) representing the alpha-subunit of the IGF-I receptor. IGF-I stimulated [3H]thymidine incorporation and cell proliferation in a dose-dependent manner with detectable effect observed with 0.5 nM IGF-I and maximal effect at 50 nM IGF-I. IGF-I occupation of low-affinity IGF-I receptors appears to mediate cell growth. The present results demonstrate that HEE cells possess two classes of IGF-I receptors: one class has a high affinity and low capacity and the other has a low affinity and high capacity for IGF-I. Occupation of low-affinity IGF-I receptors by IGF-I appears to mediate cell growth.

Binding Sites↗
PubMed1994

Serum IgE levels and its clinical correlation with varying patterns of bronchial asthma and nasal allergy.

In a study of 847 cases of bronchial asthma and nasal allergy frequent association with raised serum IgE was noticed. Degree of atopy (as judged by skin allergy tests), age, sex and duration of disease tended to influence IgE levels in asthmatics. Both extrinsic and intrinsic varieties of asthma showed similar raised serum IgE levels. In subjects with nasal allergy alone, the values were considerably lower but still much higher than found in control patients.

Adult↗
PubMed1993

Prolonged regional nerve blockade by controlled release of local anesthetic from a biodegradable polymer matrix.

BACKGROUND: Prolonged nerve blockade is potentially useful in the management of many acute and chronic pain problems. Aside from infusions via an indwelling catheter, most currently available nondestructive techniques for prolonging local anesthetic action cannot provide more than 1-2 days of blockade. Bioerodible polymer matrixes have been used to deliver a variety of drugs in patients and animals for periods lasting weeks to years. Previously, dibucaine and bupivacaine were incorporated into copolymers of 1,3 bis(p-carboxyphenoxy) propane-sebacic acid anhydride (1:4), and demonstrated sustained release in vitro following incubation of the drug-polymer matrixes in phosphate-buffered solution (pH 7.4, 37 degrees C). METHODS: In the present study, cylindrical pellets made from polymer matrixes incorporated with bupivacaine-HCl were implanted surgically along the sciatic nerves of rats. Neural block was assessed by direct observation of motor skills and by leg-withdrawal latency to a hot surface. Biochemical and histologic examinations were performed 2 weeks after implantation. RESULTS: Sensory and motor blockade was produced for periods ranging from 2 to 6 days. Contralateral control legs receiving polymer implants without drug showed no block. Blockade was reversible, and animals appeared to recover sensory and motor function normally. Biochemical indexes of nerve and muscle function were indistinguishable from contralateral controls. CONCLUSIONS: This biodegradable polymer system provides a promising new alternative for the delivery of local anesthetics to peripheral nerves to produce prolonged blockade for the management of acute and chronic pain.

Anesthetics, Local↗
PubMed1993

C-myc, c-fos, and c-ras coding sequences are conserved from yeast to mammals.

Oncogenes, along with the autocrine secretion growth factors, emerged as a unifying theme in the search for the molecular and cellular basis of malignant transformation. To investigate whether some of the oncogene coding sequences are phylogenetically conserved, we performed hybridization experiments using well characterized c-myc, c-fos and c-ras oncogene probes to establish the sequence divergence in the genomes of different organisms. Our results indicate the c-myc, c-fos, and c-ras coding sequences exist in human, cow, monkey, rabbit, chicken, and yeast genomes. To the best of our knowledge this is the first report wherein a correlation among species in the oncogenes coding region has been established. The evolutionary implication of the present studies is discussed.

Animals↗
PubMed1993

Immunomodulation and 'Ia' variability in dendritic lymph cells: a radiobinding immunoassay versus immune response study.

A radiobinding immunoassay technique has been employed to determine the 'Ia' antigens localised on the surface of the following immunocompetent cells: Dendritic lymph cells from peripheral intestinal lymph, peritoneal macrophages and thymocytes all gathered from sheep red blood cell treated animals, and the irradiated cell controls. A corresponding popliteal lymph node assay was performed following the administration of the same cells into the foot pad of allogeneic rats to determine the comparative immunogenic responsiveness. Dendritic lymph cells in free flowing lymph of sensitised, irradiated and control animals showed a significantly higher 'Ia' content and consequently greater immunogenicity as measured by the popliteal lymph node assay. Sheep red blood administration in animals may stimulate surface 'Ia' expression in lymph derived dendritic cells resulting in higher immune-responsiveness.

Animals↗
PubMed1993

Histopathological and immunological studies in a cohort of balanitis xerotica obliterans.

Balanitis xerotica obliterans consisting of 52 cases had been studied in the present series. This disease entity is an insidious sclerosing disease of unknown aetiology, affecting mainly the skin and mucous membrane of glans, prepuce and sometimes the fossa navicularis urethrae or even terminal urethra. Atrophic white patches on external genitalia and obstructive uropathy are two common presenting features. It has been classified as local form of lichen sclerosus et atrophicus. Poor local hygiene, circumcision and association of auto-immune diseases like vitiligo are responsible as suggested in this study. Routine tests detected associated cystitis in 8 cases, haematuria in 4 cases, non-reactive VDRL in all cases and impaired glucose tolerance in 5 cases. Immunoglobulin profile (39 cases) showed altered pattern, suggesting some chronic antigenic stimulation. Out of 33 cases where biopsy done, histologically proved typical balanitis xerotica obliterans was found in 19 cases. Malignant change was noted in one case only. Circumcision and dilatation offered temporary relief.

Adolescent↗
PubMed1993

Microwave induced alteration in the neuron specific enolase gene expression.

Exposure of pNGE7, a recombinant clone containing the coding and regulatory sequences for the expression of neuron specific enolase gene, cells to electromagnetic radiations (915 MHz, 16 Hz AM, SAR 0.05 mW/kg) resulted in the elevation of neuron specific enolase (NSE), a diagnostic marker for neuron and lung cancer. Using ion-exchange chromatography we separated the neuron specific enolase activity from the non-neuronal enolase (NNE) activity and observed an alteration in the expression of neuron specific enolase and non-neuronal enolase. The clinical applications of the present studies have been discussed.

Base Sequence↗