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Biomedical subjects

R Gupta

Publications and source records attributed to R Gupta.

At least 73 records · Page 4Linked to original sources
PubMed2001

Microwave induced synthesis and antibacterial activity of cephalosporin derivatives using solid support.

Reaction of 7-amino-3-[5'-methyl-1',3',4'-thiadiazol-2'-ylthiomethyl]cephalo-sporanic acid with heterocyclic amines using basic alumina under microwave irradiation (MWI) afforded new cephalosporin analogs in shorter reaction time with improved yield as compared to conventional heating. All the synthesised compounds were tested for their in vitro antibacterial activity, using cefotaxime and cephalothin as reference drugs. All compounds showed significant in vitro antibacterial activity against E. herbicola, P. vulgaries, and Z. mobilis.

Anti-Bacterial Agents↗
PubMed2001

Cisplatin induces modifications in the development of cell surface patterns of ciliates.

Cisplatin [cis-dichlorodiammineplatinum (II)] brings about significant quantitative modifications in the development of cell surface patterns in two unrelated ciliates: Stylonychia and Tetrahymena. Cells cultured in the presence of cisplatin exhibit the formation of supernumerary surface structures in the form of extra cilia/cirri (fused cilia) and other organized ciliary organelles. The metal-induced formation of extra primordia and their differentiation into supernumerary ciliary structures is governed by the normal rules of development. Additional structures are accommodated within the framework of a defined pattern, suggesting the existence of an overall global control of pattern formation. The modified pattern is rectified to its normal state during post-treatment fission cycles, suggesting the role of the cell membrane in correcting developmental errors.

Animals↗
PubMed2001

Reduced uptake as a mechanism of zinc tolerance in Oscillatoria anguistissima.

Oscillatoria anguistissima could tolerate 50 ppm ZnSO4 x 7H2O, and a zinc-tolerant strain with maximum tolerance concentration (MTC) of 100 ppm ZnSO4 x 7H2O was obtained by stepwise transfer to higher concentrations. The adaptation was irreversible even after three generations in metal-free medium. In the presence of metal, the tolerant strain grew with a shorter lag period of 4 days as against 6 days in the case of the wild strain. The tolerant strain had higher MTC than that of the wild strain for other metals also, viz., Ni2+, Co2+, Cu2+ and Cd2+. The zinc resistance in the tolerant strain was a result of reduced uptake, since around 42% of the total metal was present on the surface as against only 30% in the wild strain. The calcium-stimulated uptake, as observed in the wild strain, was absent in the tolerant strain. Ultrastructural comparisons revealed no structural change in the tolerant strain on exposure to zinc, whereas in the wild strain a thick extracellular matrix was observed.

Adaptation, Physiological↗
PubMed2001

Dose reduction in evacuation proctography.

The goal of this study was to reduce the patient radiation dose from evacuation proctography. Ninety-eight consecutive adult patients referred for proctography to investigate difficult rectal evacuation were studied using a digital imaging system with either a standard digital program for barium examinations, a reduced dose digital program (both with and without additional copper filtration), or Video fluoroscopy. Dose-area products were recorded for each examination and the groups were compared. All four protocols produced technically acceptable examinations. The low-dose program with copper filtration (median dose 382 cGy cm2) and Video fluoroscopy (median dose 705 cGy cm2) were associated with significantly less dose than other groups (p < 0.0001). Patient dose during evacuation proctography can be reduced significantly without compromising the diagnostic quality of the examination. A digital program with added copper filtration conveyed the lowest dose.

Adult↗
PubMed2001

Comparison of the clinical profile and outcome for squamous cell carcinoma and adenocarcinoma of the distal esophagus and cardia in India.

This retrospective review aimed to assess the clinical profile and outcome of squamous cell carcinoma as compared with adenocarcinoma of the lower third of esophagus and cardia following a transhiatal esophagectomy. A total of 169 patients were analyzed retrospectively in this series from 1989 to 1994. There were 100 patients with squamous cell carcinoma (SCC) and 69 patients with adenocarcinoma (ADC). All tumors were assessed by an esophagogram, upper gastrointestinal endoscopy, and abdominal ultrasonography. The surgical procedure performed in all cases was a transhiatal esophagectomy (THE). The mean age of the patients with SCC and ADC was comparable (48 +/- 14 vs 54 +/- 12 years). Male/female ratio was 1.0:1.4 in the SCC group while in the ADC group it was 8.8:1.0. The main symptom in both the groups was grade II dysphagia (62% in SCC and 60% in ADC). The mean length of the tumor was 6.6 +/- 4.5 cm in the SCC group and 4.2 +/- 3.3 cm in the ADC group. The resectability rate of the SCC group was significantly higher (76%) than in the ADC group (55%). The 6-month and 1-year survival for the SCC patients was not significantly different from the ADC patients (83.7% and 49.3% vs 85.0% and 54.0%). The 5-year survival achieved in SCC was higher than in the ADC group (11.6% vs 7.2%) but the difference was not statistically significant. Adenocarcinoma arising from the distal esophagus and cardia was more common in males, and also occurred in a higher age group and had a lower resectability rate than squamous cell carcinoma. No case of Barrett's esophagus was encountered. The short- and long-term survival in both tumors were similar.

Adenocarcinoma↗
PubMed2001

Minimizing cervical esophageal anastomotic complications by a modified technique.

BACKGROUND: The anastomotic leak and stricture formation after esophagectomy and cervical esophagogastric anastomosis deny patients with esophageal carcinoma the benefits of surgery. The present study was designed to ascertain whether a wide cross-sectional area at the site of anastomosis leads to lesser anastomotic complications. METHODS: One hundred patients with resectable carcinoma of the esophagus were randomly distributed into two groups of 50 each. All patients underwent one-stage transhiatal esophagectomy. In group A, 3 x 2 cm gastric crescent was excised from the anterior wall of the gastric tube before constructing the cervical esophagogastric anastomosis. No such intervention was done in group B, which acted as control. All patients were followed up for at least 3 months for detection of anastomotic complications. RESULTS: The incidence of anastomotic leak in the study group was significantly less in comparison with the control group (4.3% versus 20.8%; P = 0.03). Similarly, anastomotic stricture formation was significantly lower in the study group (8.5% versus 29.2%; P = 0.02). CONCLUSIONS: A wide cross-sectional area achieved at the anastomotic site by removal of gastric crescent resulted in significantly lower anastomotic complications.

Adolescent↗
PubMed2001

Popliteal artery trauma. A critical appraisal of an uncommon injury.

Although popliteal artery injuries are uncommon, the consequent lack of management protocols may contribute to an already high level of outcome morbidity. We critically reviewed all nine cases of popliteal artery trauma treated at our institution in the last 5 years. The main findings were that blunt trauma was predominant and most patients presented with severe signs of ischaemia. Long delays occurred between injury and treatment, mostly due to the tyranny of distance. Nevertheless, most patients were subjected to further delay whilst undergoing unnecessary formal angiography. Interposition vein graft using contralateral long saphenous vein was the predominant procedure for arterial injury. Most patients did not receive systemic anticoagulation or fasciotomy, and none received intra-operative thrombolysis. Our limb salvage rate was 7/9, although two of these had persistent neurological disability. We criticise our shortcomings in the light of the current literature.

Adolescent↗
PubMed2001

Minor [correction of Mi1nor] burns and pneumatocoeles: a case report.

Minor burns in children need to be cautiously managed as they may manifest with life threatening complications especially in the presence of staphylococcal infection. A one and a half year old child with minor burns (12% TBSA), who developed large pneumatocoeles and peumomediastinum following Staphylococcus aureus pneumonia causing severe respiratory distress and needing ventilatory support is presented. Most of the pneumatocoeles were spontaneously absorbed over a period of 10 days while surgical interference was being contemplated. A conservative approach to pneumatocoeles as in non-burn patients may help prevent unnecessary surgery. An extensive English literature search (since 1966) did not reveal any report of pneumatocoeles in association with burns and therefore we believe this to be the first report of its kind.

Burns↗
PubMed2001

A novel plastid-targeted J-domain protein in Arabidopsis thaliana.

Arabidopsis cDNAs encoding ATJ11, the smallest known J-domain protein, have been isolated and characterized. The precursor protein of 161 amino acid residues was synthesized in vitro and imported by isolated pea chloroplasts where it was localized to the stroma and cleaved to a mature protein of 125 amino acid residues. The mature protein consists of an 80 amino acid J-domain, and N- and C-terminal extensions of 24 and 21 amino acid residues, respectively, which show no similarity to regions in other DnaJ-related proteins. ATJ11 produced in Escherichia coli stimulated the weak ATPase activity of E. coli DnaK, but was unable to stimulate refolding of firefly luciferase by DnaK, and inhibited refolding by DnaK, DnaJ and GrpE. ATJ11 is encoded by a single-copy gene on chromosome 4, and is expressed in all plant organs examined. A paralogue of ATJ11, showing 72% identity, is encoded in a 4.5 Mb duplication of chromosome 4 on chromosome 2. These proteins represent a novel class of J-domain proteins.

Adenosine Triphosphatases↗
PubMed2001

H9724, a monoclonal antibody to Borrelia burgdorferi's flagellin, binds to heat shock protein 60 (HSP60) within live neuroblastoma cells: a potential role for HSP60 in peptide hormone signaling and in an autoimmune pathogenesis of the neuropathy of Lyme disease.

Although Borrelia burgdorferi, the causative agent of Lyme disease, is found at the site of many disease manifestations, local infection may not explain all its features. B. burgdorferi's flagellin cross-reacts with a component of human peripheral nerve axon, previously identified as heat shock protein 60 (HSP60). The cross-reacting epitopes are bound by a monoclonal antibody to B. burgdorferi's flagellin, H9724. Addition of H9724 to neuroblastoma cell cultures blocks in vitro spontaneous and peptide growth-factor-stimulated neuritogenesis. Withdrawal of H9724 allows return to normal growth and differentiation. Using electron microscopy, immunoprecipitation and immunoblotting, and FACS analysis we sought to identify the site of binding of H9724, with the starting hypotheses that the binding was intracellular and not identical to the binding site of II-13, a monoclonal anti-HSP60 antibody. The current studies show that H9724 binds to an intracellular target in cultured cells with negligible, if any, surface binding. We previously showed that sera from patients with neurological manifestations of Lyme disease bound to human axons in a pattern identical to H9724's binding; these same sera also bind to an intracellular neuroblastoma cell target. II-13 binds to a different HSP60 epitope than H9724: II-13 does not modify cellular function in vitro. As predicted, II-13 bound to mitochondria, in a pattern of cellular binding very different from H9724, which bound in a scattered cytoplasmic, nonorganelle-related pattern. H9724's effect is the first evidence that HSP60 may play a role in peptide-hormone-receptor function and demonstrates the modulatory potential of a monoclonal antibody on living cells.

Antibodies, Monoclonal↗
PubMed2001

Urinary schistosomiasis: urographic features and significance of drooping kidney appearance.

The purpose of the study was to analyse the urographic features of schistosomiasis and to see the theurapeutic implications of "drooping kidney" appearance for the urologists. Over a period of one year, 1636 patients undergoing intravenous urography (IVU) were analysed to look for urographic features of schistosomiasis. A total of 136 patients revealed the classical urographic feature such as ureteric strictures, vesical and ureteric calcification and calculi etc. 131 of these patients were of Egyptian origin. In addition to above mentioned classical features, 8 patients (6%) with urinary schistosomiasis revealed "drooping kidney" appearance. In the remaining patients with no evidence of clinical or urographic features of urinary schistosomiasis, only one patient (0.07%) showed similar bilateral appearance. Renogram in 6 to 8 patients with "drooping kidney" revealed poorer renal function on the affected side. Ureteroscopy (URS) revealed more florid ureteritis cystica on the side with "drooping kidney" in 6 out of 8 patients compared with the normal side. URS also confirmed the presence of a kink and more difficulty with insertion of J stents. "Drooping kidney" a new urographic feature of urinary schistosomiasis may have theurapeutic implications for the urologists and should be looked for on the I.V.U. of patients with urinary schistosomiasis.

Humans↗
PubMed2001

Biocatalytic potential of Fusarium globulosum lipase in selective acetylation/deacetylation reactions and in ester synthesis.

AIMS: The present study was carried out to assess the potential of Fusarium globulosum lipase (FGL) for chemoselective and regioselective biotransformations for the synthesis of industrially important organic compounds. METHODS AND RESULTS: Different acetylation/deacetylation reactions and ester synthesis reactions were carried out in organic media. Fusarium globulosum lipase showed exclusive selectivity for the acetylation of the alcoholic hydroxyl group over the phenolic hydroxyl group of the hydroxymethylated phenols and aryl alkyl ketones. This also led to the enantiomeric resolution of the aryl alkyl ketone. In contrast, the lipase showed reversed selectivity in deacetylation where it preferred the phenolic acetoxy group over the alcoholic acetoxy moiety of the peracetates of hydroxymethylated compounds. The enzyme also exhibited strict regioselection for deacetylation at the para position of the peracetate of an aryl alkyl ketone. In addition, the lipase also synthesized a variety of industrially important fatty acid esters of sugars, sugar alcohols, alcohols and ascorbic acid with high preference for middle-chain fatty acids. CONCLUSION: Fusarium globulosum lipase shows versatile catalytic potential in terms of chemo-, enantio- and regioselectivity and fatty acid specificity in carrying out a variety of industrially important biotransformations. SIGNIFICANCE AND IMPACT OF THE STUDY: The biocatalytic potential of FGL can thus be utilized for the synthesis and modification of different types of polyphenolic compounds and esters. These compounds find widespread uses as surfactants, bioactive analogues, antioxidants and flavour components in the food, detergent, pharmaceutical and cosmetic industries.

Acetylation↗
PubMed2001

An epidemiological view of vascular trauma in Western Australia: a 5-year study.

BACKGROUND: Although Australia encounters vascular injury less frequently than countries such as the USA, the predominance of blunt trauma with associated complex injuries continues to pose problems for clinicians. The present paper reviews Royal Perth Hospital's experience of vascular trauma epidemiology. METHODS: All individuals who presented to the Royal Perth Hospital (RPH) with a vascular injury between August 1994 and January 2000 were identified from a prospective trauma database. Injuries were classified using the Abbreviated Injury Score (AIS 90 code). The five major vascular injury groups as defined by AIS 90 (neck, thorax, abdomen, upper limb and lower limb) were analysed in turn to determine which injuries were most frequent, what the common causes were, effects of alcohol and drugs, common associated injuries, investigations performed, mortality, proportion of rural vascular trauma with transfer details and lengths of hospital stay. RESULTS: During the study period, 153 patients (1% of total trauma workload) sustained 175 vascular injuries. The commonest causes of injury for each group were stabbing (neck and lower limb), motor vehicle accident (thorax and abdomen) and work machinery (upper limb). Mortality was highest for thoracic injury (14/32; 44%) followed by abdominal injury (10/29; 34%). The ratio of blunt to penetrating vascular trauma is high and is increasing, as is the ratio of truncal to extremity vascular trauma. The most common artery-vein combination injury was to the femoral vessels. CONCLUSIONS: The injury patterns emerging from the present study will hopefully help all medical personnel to recognize the potential for vascular injury in a trauma setting.

Abdominal Injuries↗
PubMed2001

Sonographic diagnosis of diastematomyelia in utero: a case report and literature review.

Fetal diastematomyelia is a rare form of spinal dysraphism that is characterized by a complete or incomplete division of the spinal cord by an osseous or fibrocartilaginous septum. A case of diastematomyelia, which was detected on the routine third trimester detailed ultrasound scan, is presented. The diagnosis was based on the detection of an echogenic focus in the posterior aspect of the spine in association with widening of the interpedicular vertebral space. The case illustrates that diastematomyelia can occur in the absence of overt spina bifida and that prenatal detection will allow timely postnatal investigation and treatment. Prenatal literature is further reviewed to assess the clinical significance of this finding.

Adult↗
PubMed2001

Autoimmune hepatitis in the Indian subcontinent: 7 years experience.

BACKGROUND: Autoimmune hepatitis (AIH) is presumed to be rare in India. The present prospective study was carried out to determine the prevalence, clinical, biochemical and histological profile of patients with AIH in India. METHODS: Consecutive patients with chronic liver disease suspected to be AIH, were screened for antinuclear antibodies (ANA), antismooth muscle antibodies (ASMA), antimitochondrial antibody (AMA), and anti-liver kidney microsomal antibodies (anti-LKM-1). Serum protein electrophoresis and liver biopsy were done. Autoimmune hepatitis was diagnosed according to the International Autoimmune Hepatitis Group criteria. RESULTS: Fifty of 1358 (3.43%) patients with chronic liver disease were diagnosed as autoimmune liver disease; 39 with AIH, two with overlap syndrome, five with primary sclerosing cholangitis, and four with primary biliary cirrhosis. Twenty-nine patients were categorized as definite AIH and 10 as probable AIH. Autoimmune hepatitis was common in females (males : females 1:3), with a mean age of 31 +/- 17 years. Patients often presented with fatigue, jaundice and anorexia. Skin lesions (58%), joint symptoms (30%), and menstrual abnormalities (26%) were not uncommon. Mildly elevated alkaline phosphatase and hyper gamma globulinemia were seen in 78 and 91% patients, respectively. Eighty percent of patients were type I AIH, while 20% of cases remained unclassified. Histopathological changes included piecemeal necrosis (100%), plasma cell infiltration (91%), rosette formation (82%), and cirrhosis (76%). Overall mortality was 25% during a mean follow up of 15.7 +/- 17.0 months. CONCLUSIONS: Our results clearly demonstrate that: (i) AIH is not uncommon in India; and (ii) while the profile and spectrum of AIH resembles that seen in the West, Indian patients present late, often in a cirrhotic state.

Adolescent↗