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Biomedical subjects

S Patra

Publications and source records attributed to S Patra.

16 recordsLinked to original sources
PubMed2006

Analysis of jumping/falling distance from a height.

The kinematic motion analysis of 50 jumps from a height of 5m demonstrated distinguishable maxima of jumping distances between passive and active jumps (1.0-3.4 and 3.7-7.1 m, respectively). The variation of several parameters concerning the 'take-off' mechanism showed less influence regarding the jumping distances. The congruence of the trajectory of the 'free-flight' domains of the jumps and the simple model for the parabola of an inclined throw has been proven. Thus, a prediction of the distance range for heights up to 20 m was extrapolated.

Accidental Falls↗
PubMed2005

Assessment of Godavari estuarine mangrove ecosystem through trace metal studies.

Trace metals (Fe, Mn, Cu, Co, Ni. Pb, Cd and Cr) analyses in particulate matter and sediments were carried out at 16 different stations in the Godavari mangrove ecosystem covering the three regions viz., Kakinada (KKD) bay, Goutami-Godavari estuary (GGE) and Coringa and Gaderu mangrove environments (CGME). Higher concentrations of trace metals in particulate matter and in sediments were noticed in the mangrove environment compared to the KKD bay and GGE region. The significant correlations observed between several couples of metals in different regions as well as between numbers of heavy metals (Fe, Mn, Zn) with Total Suspended Matter (TSM) in particulate organic matter could be an indication of the role of the complexation with organic matter in the distribution pattern of these metals. Further significant correlations between organic carbon (OC) and Cr, Co, Pb, Cu and Mn in sediments of all the three regions indicate that organic matter acts as a metal carrier. The values of Pollution Load Index (PLI) were low and varied between 0.34 and 0.68 in KKD bay, 0.47 and 0.49 in GGE and, from 0.62 to 1.03 in CGME area, which indicate that the estuarine ecosystem is not of pollution concern under the present scenario.

Avicennia↗
PubMed2003

Naringin and naringenin inhibit nitrite-induced methemoglobin formation.

Naringin and naringenin protect hemoglobin from nitrite-induced oxidation to methemoglobin. The protection is not observed when naringin and naringenin are added after the autocatalytic stage of the oxidation of hemoglobin by nitrite. The ability of naringin and naringenin to scavenge oxygen free radicals may be responsible for the action because superoxide, hydroxyl and other free radicals are implicated in promoting the autocatalytic stage of oxidation of hemoglobin by nitrite. Both compounds showed less ability to protect intact erythrocytes suggesting that they may not cross the erythrocyte membrane in sufficient amounts. Naringenin was more effective than naringin, probably because of the extra phenolic group in the aglycone.

Antioxidants↗
PubMed2002

Antimicrobial activity of Eupatorium ayapana.

Petroleum ether and methanolic extracts of leaves of Eupatorium ayapana were tested for their antimicrobial activity. The petroleum ether extract showed higher antibacterial and antifungal activity than the methanolic extract.

Anti-Bacterial Agents↗
PubMed2001

Nitric oxide protects the intestine from the damage induced by laparotomy and gut manipulation.

BACKGROUND: The intestine is highly susceptible to free radical-induced damage, and our earlier work has shown that surgical stress induces the generation of oxygen free radicals in enterocytes, resulting in intestinal damage along with ultrastructural changes. Since nitric oxide (NO) is an important mediator of gastrointestinal function, this study looked at the effect of NO on surgical stress-induced intestinal alterations. MATERIALS AND METHODS: Control rats and rats pretreated with the NO donor l-arginine were subjected to surgical stress by opening the abdominal wall and handling the intestine as done during laparotomy. Enterocytes were isolated and homogenate prepared, and the protection offered by l-arginine against damage due to surgical stress was determined and compared with normal controls. Protection to structural as well as functional aspects of the intestine was also examined. RESULTS: Intestinal manipulation affected intestinal structure as assessed by electron microscopy. Functional impairment of the enterocyte was also evident, with increased xanthine oxidase activity resulting in production of superoxide anion. This impairment is more dramatic in the crypt cells. Increased protease activity was also seen following laparotomy and handling. Pretreatment with the NO synthase substrate l-arginine prevented these damaging effects. Arginine protection was abolished in the presence of the NO synthase inhibitor NG-nitro-l-arginine methyl ester, indicating the role of NO. CONCLUSION: Stress in the small intestine due to any surgery can affect enterocyte structure and function. These damaging effects can be prevented by NO, an important modulator of cellular function.

Animals↗
PubMed2001

Intestinal mitochondrial dysfunction in surgical stress.

BACKGROUND: Surgical stress is associated with altered intestinal function. Our earlier study using a rat model indicated that oxidative stress plays an important role in this process. Since mitochondria are crucial to cellular function and survival and are both a target as well as a source of reactive oxygen species, the present study looks at the changes in enterocyte mitochondria during surgical stress. METHODS: Surgical stress was induced by opening the abdominal wall and handling the intestine as done during laparotomy. Mitochondria were prepared from the isolated enterocytes at different time periods after surgical stress. The effect of surgical stress on enterocyte mitochondrial ultrastructure, respiration, anti-oxidant enzyme activity, thiol redox status, calcium flux, permeability, and matrix enzymes was then studied. RESULTS: Surgical stress resulted in alterations in mitochondrial respiration and thiol redox status. It was also associated with altered mitochondrial matrix enzyme activity, decreased superoxide dismutase activity, induction of mitochondrial permeability transition, and swelling, as well as impairment of mitochondrial calcium flux. These alterations were seen at a maximum of 60 min following surgical stress and were reversed by 24 h. CONCLUSIONS: Laparotomy and mild intestinal handling itself results in enterocyte mitochondrial damage. Since mitochondria are important cellular organelles, this damage can probably lead to compromised intestinal function.

Animals↗
PubMed2000

Increased permeability in dextran sulphate colitis in rats: time course of development and effect of butyrate.

BACKGROUND: Increased mucosal permeability is an important factor in the genesis of mucosal inflammation in inflammatory bowel disease. This study examined the time course of increased permeability and the effect of butyrate on permeability in experimental colitis in rats. METHODS: Colitis was induced in albino rats by administration of 4% dextran sulphate sodium (DSS) orally for up to 7 days. Rats were killed sequentially after 1-7 days of DSS feeding and compared with control animals. Distal colon sheets, from normal and DSS rats, were mounted in Ussing chambers. Electric resistance and passive permeation of 14C-mannitol were measured over 90 min. In control and 5-day DSS rats additional permeability measurements were made in the presence of butyrate (25 mmol/l) in the bathing solutions. The permeability of the normal distal colon was measured after addition of DSS in vitro. Sections of colon were examined by light microscopy. The viability of colonocytes, from normal and DSS rat colon, was measured by release of lactate dehydrogenase immediately and during a 60-min incubation after isolation. RESULTS: Focal mild inflammation and shedding of epithelium were noted after 2 days of DSS administration; crypt loss with flattened epithelium in adjacent areas after 5 days; and fibrosis after 7 days. Decreased epithelial cell survival after 60 min of incubation was noted after 1 day of DSS administration, whereas decreased viability at the time of isolation was noted after 2 days of DSS administration (viability, 72.7% +/- 1.4%; mean +/- standard error) compared with control (89.3% +/- 0.8%) (P < 0.01). Increased permeability was noted after 1 day of DSS administration. Electric resistance (mu omega/cm2/h) was significantly reduced after 1 day of DSS administration to 85.9 +/- 4.6 (mean +/- standard error) compared with control animals (117.2 +/- 2.2; P < 0.001). Serosa-mucosa flux of mannitol (micromol/cm2/h) was also significantly increased after 1 day of DSS feeding (0.169 +/- 0.01) compared with control (0.061 +/- 0.08) (P < 0.01). Electric resistance and mannitol permeability were significantly returned towards normal by the presence of butyrate. DSS added directly to the bathing solution did not significantly alter the colon permeability in vitro. CONCLUSIONS: Increased mucosal permeability is a very early change in colitis induced by DSS, is accompanied by decreased cell survival, and precedes detectable changes in histology. Reversal of increased mucosal permeability by butyrate may explain its utility in the therapy of inflammatory disease of the colon.

Animals↗
PubMed1999

Cytomegalovirus infection of the human gastrointestinal tract.

BACKGROUND: Current interest in cytomegalovirus (CMV) is largely due to an increase in the number of cases of acquired immunodeficiency syndrome and organ transplantation in recent years. The proper recognition of CMV-infected cells in gastrointestinal mucosal biopsies is critical for effective treatment of this condition. METHODS: A total of 6580 endoscopic mucosal biopsies from 6323 patients in the 8-year period (1989-1996) were examined for CMV inclusion bodies. The endoscopic appearance and particularly the presence of ulcers were also analysed. RESULTS AND CONCLUSIONS: The prevalence of cytomegalovirus (CMV) inclusions was 9 per thousand in the gastrointestinal mucosal biopsies from an unselected group of patients. Of the 54 patients with CMV infection, 37 were immunocompromised and 17 apparently immunocompetent. Typical Cowdry inclusions and atypical inclusions were present, the latter more frequently in immunocompromised patients. The maximum prevalence of inclusions was in the oesophageal mucosa in immunocompromised individuals.

Adolescent↗
PubMed1999

Endoscopic mucosal biopsies are useful in distinguishing granulomatous colitis due to Crohn's disease from tuberculosis.

BACKGROUND: Intestinal tuberculosis and Crohn's disease are chronic granulomatous disorders that are difficult to differentiate histologically. AIMS: To characterise distinctive diagnostic features of tuberculosis and Crohn's disease in mucosal biopsy specimens obtained at colonoscopy. METHODS: Selected histological parameters were evaluated retrospectively in a total of 61 biopsy sites from 20 patients with tuberculosis and 112 biopsy sites from 20 patients with Crohn's disease. The patients were chosen on the basis of clinical history, colonoscopic findings, diagnostic histology, and response to treatment. RESULTS: The histological parameters characteristic of tuberculosis were multiple (mean number of granulomas per section: 5.35), large (mean widest diameter: 193 microm), confluent granulomas often with caseating necrosis. Other features were ulcers lined by conglomerate epithelioid histiocytes and disproportionate submucosal inflammation. The features characteristic of Crohn's disease were infrequent (mean number of granulomas per section: 0.75), small (mean widest diameter: 95 microm) granulomas, microgranulomas (defined as poorly organised collections of epithelioid histiocytes), focally enhanced colitis, and a high prevalence of chronic inflammation, even in endoscopically normal appearing areas. CONCLUSIONS: The type and frequency of granulomas, presence or absence of ulcers lined by epithelioid histiocytes and microgranulomas, and the distribution of chronic inflammation have been identified as histological parameters that can be used to differentiate tuberculosis and Crohn's disease in mucosal biopsy specimens obtained at colonoscopy.

Adult↗
PubMed1999

Use of serology, the urease test & histology in diagnosis of Helicobacter pylori infection in symptomatic & asymptomatic Indians.

Age-specific prevalence of IgA and IgG antibodies in 714 subjects without gastrointestinal complaints aged 6 months to 90 yr was measured by an enzyme linked immunoassay using an acid-glycine extract of H. pylori as the antigen. The urease test and histology were used for the diagnosis of H. pylori infection in 83 subjects with a clinical diagnosis of dyspepsia, and these results were compared with measurement of IgG, IgA and IgM antibodies. The age specific prevalence of IgG and IgA antibodies respectively was 57 and 43 per cent for subjects aged 6 months to 4 yr and showed an increase with age to a maximum of 90 per cent for IgG in subjects > 60 yr of age and to 87 per cent for IgA in subjects between 51 and 60 yr. In symptomatic patients, there was a high degree of correlation between severity of H. pylori infection on histopathological examination and IgG (P < 0.02) levels. The use of IgG and IgA estimation could have identified H. pylori infection without endoscopy in 50 of the 83 patients. Serology for IgG and IgA antibodies against H. pylori may play a major role in decreasing the need for endoscopy, but cut-off values must be determined for each assay based on the prevalence of antibodies in the population.

Adolescent↗
PubMedDate not supplied

Toxic megacolon in a renal allograft recipient with cytomegalovirus colitis.

We report a 35-year-old man, a renal allograft recipient, who presented with toxic megacolon. Segmental biopsies from the colon were consistent with cytomegalovirus colitis. Serum polymerase chain reaction for cytomegalovirus DNA confirmed the diagnosis. He was treated with ganciclovir but, though his abdominal condition improved initially, he worsened later and succumbed to his illness.

Adult↗
PubMedDate not supplied

Crohn's disease in rheumatology clinic--an Indian experience.

BACKGROUND: Prevalence of Crohn's disease (CD) among patients with rheumatic illnesses in India is grossly under estimated, especially when it has overtaken that of Ulcerative Colitis in the West. AIM: To study the frequency of histologically unequivocal CD amongst clinically suspected patients with enteropathic arthropathy and to ascertain if the arthritics with CD have any independent clinical predictor. SETTINGS AND DESIGNS: Retrospective datasheet analysis from a Rheumatology clinic of a large tertiary care centre. MATERIALS AND METHODS: Patients of suspected enteropathic arthropathy were studied by ileocolonoscopy and segmental colonic biopsy for histological evidence of Crohn's disease and followed up. STATISTICAL ANALYSIS: Logistic regression analysis was done to find out any clinical predictor of histologically proven CD. RESULTS: Fourteen of the twenty-nine patients studied had histologically confirmed CD. Those with CD were younger than those without (34.7 yr vs 41.6 yrs, p=0.057). The CD group also had significantly higher number of people with loss of weight (12 vs 1), fever (11 vs 0), perianal fistula (4 vs 0), abdominal pain (8 vs 2), history of dysentery (4 vs 0) and uveitis (6 vs 1) (p=0.00002, 0.00001, 0.026, 0.013, 0.026 & 0.01 respectively). However logistic regression analysis of the most relevant ones among these, namely, loss of weight, fever, and perianal fistula showed loss of weight as only independent predictor of CD in this subset of patients (p=0.03 with odds ratio of 28). CONCLUSION: Presence of significant loss of weight in an Indian patient with clinically suspected enteropathic arthropathy is an independent predictor of CD.

Adult↗