Search PubMed⌕ Search

Biomedical subjects

S D Gupta

Publications and source records attributed to S D Gupta.

At least 37 records · Page 2Linked to original sources
PubMed1998

Mediastinal lymphangiomyoma in a child: report of a case.

Lymphangiomas and lymphangiomyomas are benign abnormal collections of lymphatic vessels which form a cystic mass. The mediastinum is an uncommon location for these hamartomas in children, but may be life-threatening. We report herein the case of a 23-month-old boy who presented with stridor and a history of recurrent respiratory tract infections. Soon after his admission he suddenly developed respiratory failure and was found to have a multiloculated, cystic mediastinal mass which was initially thought to be a lymphangioma. The mass was extensively infiltrative, and histological examination showed prominent smooth muscle proliferation in the walls of the cysts, confirming a diagnosis of lymphangiomyoma. The terminology and relevant literature on the topic are reviewed following the presentation of this case.

Humans↗
PubMed1998

Effectiveness of prenatal tetanus toxoid immunization against neonatal tetanus in a rural area in India.

BACKGROUND: Neonatal tetanus is the cause of 23 to 73% of neonatal deaths in developing countries and continues to be an important killer in many parts of India. METHODS: In this nonrandomized cohort study in a rural area in India, tetanus toxoid immunization status was recorded for 1688 pregnant women. Liveborn children were followed up for 30 days for the occurrence of neonatal tetanus. Nonimmunized and partially immunized women were asked their reasons for not receiving tetanus toxoid vaccine. RESULTS: Complete prenatal immunization with tetanus toxoid during pregnancy (two doses 1 month apart) was associated with an 88% reduction in the risk of neonatal tetanus among the newborn children [95% confidence interval (CI) 59 to 98%]. In multivariable analysis only complete immunization and the use of clean instruments for cutting the umbilical cord were independently associated with a reduction in risk of neonatal tetanus. Registration by the health care provider before 29 weeks of gestation, being 5 km or less from the vaccination facility, having two or more contacts with the health provider and having some school education were independently associated with complete immunization. CONCLUSIONS: Immunization of pregnant women with tetanus toxoid was the single most effective intervention against neonatal tetanus independent of other interventions.

Adult↗
PubMed1998

Histologic chorioamnionitis & its association with prematurity in a hospital-based study.

This prospective study was undertaken to study the occurrence of histologic chorioamnionitis and determine its association with prematurity; and to assess whether colonization of the genital tract of pregnant women by genital mycoplasmas or Chlamydia trachomatis is a risk factor for histologic chorioamnionitis. A total of 268 women with singleton pregnancies of over 26 weeks gestation were subjected to high vaginal cultures of genital mycoplasmas and endocervical specimens for chlamydia antigen. Placental histopathology was performed on multiple sections. Histologic chorioamnionitis was documented in 22.4 per cent (60/208) placentae. Genital tract colonization with Ureaplasma urealyticum or C. trachomatis was not a risk factor for histologic chorioamnionitis. Neonates born in association with histologic chorioamnionitis had a mean birth weight 111 g lower than those born without this lesion (2626.9 +/- 702 g vs 2737.8 +/- 500 g, NS). The relative risk (95% confidence interval) of prematurity in the presence of histologic chorioamnionitis was 1.49 (0.87-2.53). Analysis of linear trend in proportions for prevalence of histologic chorioamnionitis with decreasing gestation showed a significant association (P = 0.047, 1-tail). These results taken together suggest that histologic chorioamnionitis may be a risk factor of prematurity, but of only a modest magnitude.

Chorioamnionitis↗
PubMed1997

Mesenteric neurofibroma in von Recklinghausen's disease.

The authors report the case of a 6-year-old boy admitted for surgical removal of a 5- x 4-cm neurofibroma over the left wrist. On routine clinical examination a mobile firm, nodular, central abdominal mass was discovered. At laparotomy a tumor (measuring 7 x 5 x 3 cm) arising from the ileal mesentery was found. Complete excision of the mass together with a segment of ileum, followed by end-to-end bowel anastomosis was performed. Histological examination showed that the main elements of the mass consisted of wavy, long-spindled cells that crossed irregularly (pallisading negative). Special stains and immunocytochemistry for S-100 protein confirmed the mass to be a neurofibroma of the mesentery. The patient had an uneventful postoperative course and no signs of recurrence or fresh tumor have been recognized in the 4 years since his operation.

Anastomosis, Surgical↗
PubMed1997

Unusual computed tomography appearance of Castleman disease.

A case is presented here of Castleman disease in an uncommon location. Ultrasonography demonstrated a large hypoechoic mass with multiple vascular channels. On computed tomography, the lesions with a nodular contour were located lateral to the carotid sheath on the right side, and demonstrated a variegated enhancement pattern.

Adult↗
PubMed1997

A Salmonella typhimurium genetic locus which confers copper tolerance on copper-sensitive mutants of Escherichia coli.

Three distinct clones from a Salmonella typhimurium genomic library were identified which suppressed the copper-sensitive (Cu(s)) phenotype of cutF mutants of Escherichia coli. One of these clones, pCUTFS2, also increased the copper tolerance of cutA, -C, and -E mutants, as well as that of a lipoprotein diacylglyceryl transferase (lgt) mutant of E. coli. Characterization of pCUTFS2 revealed that the genes responsible for suppression of copper sensitivity (scs) reside on a 4.36-kb DNA fragment located near 25.4 min on the S. typhimurium genome. Sequence analysis of this fragment revealed four open reading frames (ORF120, ORF627, ORF207, and ORF168) that were organized into two operons. One operon consisted of a single gene, scsA (ORF120), whereas the other operon contained the genes scsB (ORF627), scsC (ORF207), and scsD (ORF168). Comparison of the deduced amino acid sequences of the predicted gene products showed that ScsB, ScsC, and ScsD have significant homology to thiol-disulfide interchange proteins (CutA2, DipZ, CycZ, and DsbD) from E. coli and Haemophilus influenzae, to an outer membrane protein (Com1) from Coxiella burnetii, and to thioredoxin and thioredoxin-like proteins, respectively. The two operons were subcloned on compatible plasmids, and complementation analyses indicated that all four proteins are required for the increased copper tolerance of E. coli mutants. In addition, the scs locus also restored lipoprotein modification in lgt mutants of E. coli. Sequence analyses of the S. typhimurium scs genes and adjacent DNAs revealed that the scs locus is flanked by genes with high homology to the cbpA (predicted curved DNA-binding protein) and agp (acid glucose phosphatase) genes of E. coli located at 22.90 min (1,062.07 kb) and 22.95 min (1,064.8 kb) of the E. coli chromosome, respectively. However, examination of the E. coli chromosome revealed that these genes are absent at this locus and no evidence has thus been obtained for the occurrence of the scs locus elsewhere on the genome.

Amino Acid Sequence↗
PubMed1997

Primary epithelioid haemangioendothelioma of the liver: case report and review of the literature.

A 31 year old female patient presented with a one and a half year history of pain in the upper abdomen. The pain was mild, constant, dull aching, and increased with change in posture or sudden movements. There was no definite relation to meals. She also had a lump in the right upper quadrant, which had been gradually increasing in size over three months. She had mild anorexia and reported a 5 kg weight loss over one year. She had no history of intake of oral contraceptive drugs, exposure to vinyl chloride, thorotrast or any other industrial toxin. Ultrasonography of the abdomen revealed multiple space occupying lesions of altered echotexture in both lobes of the liver. The portal venous system and hepatic vascular system were normal. Computed tomography of the abdomen confirmed the ultrasound findings. Histopathology was diagnostic for primary epithelioid haemangioendothelioma; the first such case reported from India. The patient has been put on a waiting list for a liver transplant.

Adult↗
PubMed1996

Acute viral hepatitis types E, A, and B singly and in combination in acute liver failure in children in north India.

The aetiological agents responsible for, and the outcome of, acute liver failure were investigated prospectively in 44 children (29 males, 15 females) attending a tertiary health care facility in India. The children were between the ages of 2 months and 13 years. Studies for viral infections and other etiologies could be carried out in 40 patients. Specific aetiological labels were possible in 35 (87.5%) patients. Thirty (75%) had evidence of acute viral hepatitis. Acute hepatitis E virus (HEV) infection was found in a total of 18 children, with hepatitis A (HAV) in 16, hepatitis B in 5, and C in 1. Seven had isolated infection with hepatitis E, five with A, and four with B. Nine had both E and A infection. Superinfection of HEV was observed in a child with Indian childhood cirrhosis (ICC). Acute HEV infection was confirmed by immunoblot assay in all the patients and in eight of these, HEV-RNA was also detected in the serum. HAV was involved in 37.5% of cases with isolated infection in 10% (4 of 40). The aetiological factors associated with acute liver failure, apart from HAV and HEV, were other hepatotropic viruses (22.5%), Wilson's disease (5%), ICC (5%), and hepatotoxic drugs (7.5%). In five patients, no serological evidence of acute viral hepatitis could be found, neither did the metabolic screen yield any result. It was observed that enterically transmitted hepatitis viruses (HAV and HEV) were associated with 60% of acute hepatic failure in children. Mixed infection of HAV and HEV formed the single largest aetiological subgroup. In developing countries, where hepatitis A and E infections are endemic, severe complications can arise in the case of mixed infection. This may contribute to most of the mortality from acute liver failure during childhood.

Acute Disease↗
PubMed1996

Human liver cancer cells and endothelial cells incorporate iodised oil.

Iodised oil (lipiodol) administered via the hepatic artery localises selectively in primary liver cell cancers (hepatocellular carcinomas or HCCs) for prolonged periods and has been used as a vehicle for cytotoxic agents. Despite clinical use, the mechanism of lipiodol retention by tumours has remained unclear, embolisation of oil droplets in the tumour vasculature being the prevailing hypothesis. We have investigated the role of tumour and endothelial cells in lipiodol retention. Human liver tumour (Hep G2) cells and human umbilical vein endothelial cells in culture were exposed to lipiodol. Light microscopy using selective silver impregnation stains and transmission electron microscopy revealed lipiodol incorporation by both cell types, probably by pinocytosis. This was not associated with cellular injury in terms of cell lysis, cell replication or radio-labelled leucine uptake. Histological analysis of 24 HCCs either surgically resected or discovered incidentally at liver transplantation (with prior arterial injection of lipiodol) revealed vesicles of lipiodol in the cytoplasm of tumour cells and endothelial cells lining tumour vessels. Thus, lipiodol is likely to deliver cytotoxic agents directly into tumour cells and endothelial cells, both in vitro and in vivo. This may also apply to other lipids and to other human tumours. These findings have significant therapeutic implications.

Carcinoma, Hepatocellular↗
PubMed1995

Morphometric image analysis and eosinophil counts in human liver allografts.

Histology of liver allografts is the gold standard for diagnosis of acute cellular rejection. However, scoring the severity of rejection and distinguishing it from other infiltrations is not easy. Only one group has evaluated biopsies morphometrically and also suggested that eosinophils are a specific diagnostic feature. We quantitated eosinophil count in 92 biopsies in a group of 25 patients and, in another group of 30 patients, used morphometric image analysis to measure the cross-sectional area and cell density in each portal tract in day 5 protocol liver biopsies. Rejection was diagnosed by pathological evaluation confirmed with clinical and biochemical graft dysfunction graded histologically into mild or moderate-to-severe. The control groups were five patients with no rejection, nine patients with CMV infection, and eight biopsies in eight patients for whom the cause of the liver dysfunction was obscure. The cross-sectional area, the inflammatory cell count of each portal tract and the mean portal tract inflammatory cell density (cells/mm2) increased with the severity of rejection. In each case the regression coefficient was statistically significant. Correlating the mean of the total inflammatory cell count with the mean of the portal inflammatory cell density (cell/mm2) gave far better separation of the mild rejection and moderate-to-severe rejection groups. Eosinophils were specific for the presence of acute cellular rejection and increased with the severity of rejection. They were absent in the no rejection group, in the CMV group and in those with obscure liver dysfunction. The eosinophil count fell markedly following treatment of rejection.(ABSTRACT TRUNCATED AT 250 WORDS)

Eosinophils↗
PubMed1995

Primitive neuroectodermal kidney tumor: 2 case reports and review of the literature.

Peripheral neuroectodermal tumors are uncommon cancers arising from outside the central nervous system. The urinary system is rarely involved. The differentiation of these tumors from other small cell cancer and neuroblastoma is based on immunohistochemical differences. We report 2 cases of such tumors arising from the renal parenchyma. Tumor behavior and treatment modalities are discussed.

Adult↗
PubMed1995

Identification of cutC and cutF (nlpE) genes involved in copper tolerance in Escherichia coli.

It has been suggested previously that copper transport in Escherichia coli is mediated by the products of at least six genes, cutA, cutB, cutC, cutD, cutE, and cutF. A mutation in one or more of these genes results in an increased copper sensitivity (D. Rouch, J. Camakaris, and B. T. O. Lee, p. 469-477, in D. H. Hamer and D. R. Winge, ed., Metal Ion Homeostasis: Molecular Biology and Chemistry, 1989). Copper-sensitive cutC and cutF mutants were transformed with a genomic library of E. coli, and copper-tolerant transformants were selected. Two distinct clones were identified, each of which partially restores copper tolerance in both the cutC and cutF mutants of E. coli. Subcloning, physical mapping, and sequence analysis have revealed that the cutC gene is located at 42.15 min on the E. coli genome and encodes a cytoplasmic protein of 146 amino acids and that the cutF gene is located at 4.77 min on the E. coli genome and is allelic to the nlpE gene independently identified by Silhavy and coworkers (W. B. Snyder, L. J. B. Davis, P. N. Danese, C. L. Cosma, and T. J. Silhavy, J. Bacteriol. 177:4216-4223, 1995). Results from the genetic mapping of the copper-sensitive mutations in the cutF mutant and sequencing of the cutC and cutF (nlpE) alleles from both cutC and cutF mutants indicate that both the cutC and cutF mutants are in fact double mutants altered in these two genes, and mutations in both the genes appear to be required for the copper-sensitive phenotype in each mutant.

Alleles↗
PubMed1993

Isolation and characterization of a temperature-sensitive mutant of Salmonella typhimurium defective in prolipoprotein modification.

A temperature-sensitive (ts) mutant of Salmonella typhimurium that accumulated unmodified murein prolipoprotein at 42 degrees C but not at 30 degrees C was identified. In vivo and in vitro studies of the biosynthesis of Braun's lipoprotein revealed that this mutant (SE5221) was defective in the glyceryl modification of prolipoprotein. The ts mutation was mapped to 60.6 min of the S. typhimurium chromosome and was linked to argA and cysH. A clone with a 1.4-kilobase S. typhimurium DNA insert that complemented the ts mutation and restored the prolipoprotein modification activity both in vivo and in vitro was isolated. DNA sequencing of the complementing region revealed an open reading frame encoding a protein with 291 amino acids lacking NH2-terminal signal sequence. This open reading frame is immediately 5' to the thyA gene and is allelic to umpA of Escherichia coli. Wild-type strains harboring the cloned gene exhibited elevated levels of prolipoprotein modification activity. At the non-permissive temperature, the mutation affected both growth and viability, and the mutant cells exhibited anomalous cell morphology. The ts phenotype was suppressed by the introduction of a lpp::Tn10 mutation. These results suggest that the cloned gene encodes prolipoprotein glyceryl transferase (lgt), and in the wild-type background, this prolipoprotein modification enzyme is essential for the growth and viability of S. typhimurium.

Alleles↗