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Biomedical subjects

P Ravichandran

Publications and source records attributed to P Ravichandran.

16 recordsLinked to original sources
PubMed2006

Transabdominal modified devascularization procedure with or without esophageal stapler transection--an operation adequate for effective control of a variceal bleed. Is esophageal stapler transection necessary?

BACKGROUND: In Japan, the original Sugiura procedure reported favorable results in non-cirrhotic patients but in the West, the modified Sugiura procedure is not widely accepted because of high rebleeding, morbidity, and mortality in cirrhotics. We retrospectively analyzed the efficacy of our modified Sugiura procedure i.e., devascularization with/without esophageal transection combined with salvage endotherapy and pharmacotherapy for control of a variceal bleed. MATERIALS AND METHODS: Between January 1999 and December 2004, 912 patients with variceal bleeding were treated. Of these, 66 (7.2%) patients were subjected to surgery after failed endotherapy/propranolol. Among these 66 patients, 52 had transabdominal devascularization (16 emergency, 36 elective); 14 patients underwent devascularization with esophageal stapler transection (group I), and 38 patients had devascularization without esophageal stapler transection (group II). Another 14 patients underwent elective end-to-side proximal splenorenal shunt surgery. RESULTS: Postoperative mortality was 7.1% in group I, 10.5% in group II (P>0.05). Mortality for emergency surgery was 31.2% (5/16) but there were no deaths in the elective surgery group. Overall morbidity was 57.1% in group I and 21.0% in group II (P<0.05). The rates of variceal rebleeding were 7.1% and 7.8%; residual varices were 30.7% and 32.3%; recurrent varices were 7.6% and 5.8% following the group I and group II procedures, respectively, over a mean follow-up period of 39.9 (7-2) months. Esophageal transection-related morbidity (leak, stricture, and bleeding) was 21.4% (3/14) in group I. CONCLUSIONS: Devascularization without esophageal stapler transection is a safe and effective procedure for adequate (urgent and long-term) control of variceal bleeding with similar results and less morbidity when compared to devascularization with esophageal transection in cirrhotic patients, as well as non-cirrhotic patients.

Adult↗
PubMed2005

Nodavirus infection causes mortalities in hatchery produced larvae of Lates calcarifer: first report from India.

Larvae (15 to 21 d post hatch, dph) of the Asian sea bass Lates calcarifer (Bloch) suffered heavy mortalities (60 to 90%) during the hatchery-rearing phase. Darkened and moribund larvae showed no evidence of bacterial or parasitic infections. Tissue sections of brain and spinal cord showed clear necrotic vacuolation. Electron microscopy revealed membrane-bound viral particles in the cytoplasm of the nerve cells. The viral particles measured 28 to 30 nm in diameter. Primer sets, designed for the amplification of the RNA2 segment of the piscine nodavirus coat protein gene, were used in the RT-PCR analysis of moribund larvae of 20 and 21 dph which produced the amplified product of 430 bp. The clinical manifestations, pathology and electron microscopy observations supported by the RT-PCR analysis suggest that the nerve necrosis was due to nodavirus infection in the larvae. This is the first report of piscine nodavirus infection from the Indian sub-continent.

Animals↗
PubMed2005

Splenic radiation and double-filtration plasmapheresis in crossmatch-positive live renal transplantation.

Double-filtration plasmapheresis (DFPP) and splenectomy prior to transplant is used in a few centers for high-risk transplantations. We undertook a prospective study to examine the outcome of 16 kidney transplantations in crossmatch-positive patients using splenic radiation and DFPP as pretransplant immunomodification procedures. All patients received a single dose of Zenapax (50 mg intravenously [IV] 8 hours before transplant), before treatment with cyclosporine, mycophenolate mofetil, and steroids immediately posttransplant. Follow-up ranged from 3 months to 1 year. Hyperacute rejection requiring graft nephrectomy was necessary in one patient; acute rejection, which was seen in three patients, was reversed with five doses of Iort3 at 1-month posttransplant the mean creatinine was 1.3 +/- 0.6 mg/dL in patients who did not have rejection and 1.9 +/- 0.3 mg/dL in the three patients who had acute rejection. Six patients were switched from cyclosporine to sirolimus. At the end of 3 months the mean creatinine levels was 1.4 +/- 0.3 mg%. The infections included oral candida (n = 2), urinary tract infection (UTI) (n = 1), bacterial pneumonia (n = 1), and herpes zoster (n = 1). With the advent of modern immunosuppressants, pretransplant immunomodification with DFPP and splenic radiation is safe and effective. Splenic radiation is devoid of surgical risk and more acceptable to patients.

Drug Therapy, Combination↗
PubMed2005

Endobronchial pseudo-tumour caused by herpes simplex.

Herpes simplex virus (HSV) causes tracheobronchitis and pneumonitis; however, to date, there has only been one report of an endobronchial mass caused by HSV type II. This case study describes a 68-yr-old female with severe kyphoscoliosis who was intubated for acute on chronic hypercapnic respiratory failure and developed blood-tinged endotracheal secretions. Fibreoptic bronchoscopy demonstrated an endobronchial mass in the right middle lobe. Cultures grew HSV type I and biopsy specimens demonstrated cytopathological changes consistent with HSV infection. This is the first reported case of HSV type I presenting as an endobronchial tumour.

Acyclovir↗
PubMed2003

Trichosporon loubieri infection in a patient with adult polycystic kidney disease.

A 45-year-old man from Nepal with a 13-year history of polycystic kidney disease was diagnosed as suffering from chronic renal failure with end-stage renal disease. After receiving empirical antituberculosis treatment, he was treated with broad-spectrum antibiotics. A left nephrectomy was performed, and after 4 months, he received a kidney transplant. The left kidney was grossly enlarged, with multiple cystic spaces filled with blackish material. Histologic examination of the excised left kidney tissue stained with hematoxylin and eosin and Gomori's methenamine silver stains showed numerous hyaline, septate, fungal hyphae of various lengths, many broken into rectangular arthroconidia in the cystic spaces. Culture of the kidney tissue yielded white, glabrous, yeast-like colonies. Based on its micromorphology, growth at 42 degrees C, and ribosomal DNA (rDNA) sequence analysis, and also sequence analysis of the internal-transcribed-spacer and D1/D2 rDNA regions, the yeast was identified as Trichosporon loubieri. Postsurgically, the patient was treated with amphotericin B and oral itraconazole, followed by maintenance therapy with fluconazole. He remained afebrile and asymptomatic. At the final follow-up, all parameters were found normal and the patient was doing well, with normal renal function reports. This paper presents the first known case of human infection caused by T. loubieri.

Adult↗
PubMed2001

Collagen-chitosan polymeric scaffolds for the in vitro culture of human epidermoid carcinoma cells.

A biodegradable polymer scaffold was developed using collagen and chitosan, in the form of interpenetrating polymeric network (IPN), for in vitro culture of human epidermoid carcinoma cells (HEp-2, Cincinnati). Glutaraldehyde was used as cross-linking agent for the development of scaffold. Various types of scaffolds were prepared using different proportionate mixtures of collagen and chitosan solutions in the ratio of 3:7, 4:6, 5:5, 6:4 and 7:3 (collagen:chitosan). These scaffolds were fully characterized by Fourier transform infrared spectroscopy (FT-IR), differential scanning calorimetry (DSC) and Thermogravimetric analysis (TGA). Equilibrium swelling studies were carried out in phosphate buffer of physiological pH (7.4) to study its swelling characteristics at slightly alkaline pH. The scaffold that showed optimum swelling property was selected as the best scaffold for performing in vitro culture studies. In vitro culture studies were carried out using HEp-2 cells, over the selected scaffold and its growth morphology was determined through optical photographs taken at different magnifications at various days of culture. The results of the above studies suggest that the scaffolds prepared from collagen and chitosan can be utilized as a substrate to culture HEp-2 cells and can also be used as an in vitro model to test anticancerous drugs.

Animals↗
PubMed2000

Collagenous gastritis: a case report, morphologic evaluation, and review.

Collagenous gastritis is rare; there are only four previous case reports. Histologic features seem to overlap with the other "collagenous enterocolitides"; however, pathologic criteria are not yet established for the diagnosis of collagenous gastritis. We describe an additional case of ostensible collagenous gastritis in a patient who initially presented with celiac sprue and subsequently developed colonic manifestations of mucosal ulcerative colitis. Endoscopic biopsies of the stomach revealed deposition of patchy, very thick bandlike subepithelial collagen in gastric antral mucosa, focal superficial epithelial degeneration, numerous intraepithelial lymphocytes, and a dense lamina propria lymphoplasmacytic infiltrate. Image analysis evaluation of gastric antral biopsies demonstrated a mean thickness of subepithelial collagen of 27.07 micron. Morphologic comparison was made with age-matched control groups of 10 patients who had normal gastric mucosal biopsies and 10 patients who had "chronic" gastritis, which revealed mean subepithelial collagen measures of 1.37 micron and 1.19 micron, respectively. We compared these morphologic findings with those of all previous case reports of collagenous gastritis and propose a pathologic definition based on the limited combined data. It seems that subepithelial collagen is dramatically thickened in reported cases of collagenous gastritis, with a cumulative mean measure of 36.9 micron. It is also apparent from this and previous reports that the thickened subepithelial collagen is accompanied by a chronic or chronic active gastritis and sometimes intraepithelial lymphocytes and surface epithelial damage. Recently described associations of lymphocytic gastritis, sprue, and lymphocytic colitis as well as collagenous and lymphocytic colitis suggest a common pathogenesis that empirically may include collagenous gastritis in the same disease spectrum. We propose that collagenous gastritis can be confidently identified by using analogous defined features of collagenous colitis: subepithelial collagen more than 10 micron in a patchy distribution, lamina propria lymphoplasmacytic infiltrates, intraepithelial lymphocytes, and surface epithelial damage. Collagenous gastritis also seems to have the same spectrum of associated clinical findings as collagenous colitis, including frequent coexistence of celiac sprue, watery diarrhea syndrome, and female predominance.

Adolescent↗
PubMed2000

In vitro adventitious shoot formation from leaf cultures of Clerodendrum inerme (L) Gaertn.

In vitro adventitious shoots (about 28) of Clerodendrum inerme were regenerated from leaf segments on MS medium containing BA (4 mg/L). These shoots developed directly from the leaf explants without callusing after 5 weeks. Leaf explant when cultured in MS medium containing BA (2 mg/L) and NAA (0.5 mg/L) developed compact callus that became nodular and regenerated shoots (about 50) after 5 weeks. The in vitro developed shoots were rooted in MS medium supplemented with IAA (2 mg/L). The hardened plantlets were successfully established in the field with 90% survival.

Lamiaceae↗
PubMed1999

Chemopreventive effect of Ocimum sanctum on DMBA-induced hamster buccal pouch carcinogenesis.

Ocimum sanctum L., a plant having multi-medicinal properties, has been investigated for its chemopreventive activity against 7,12-dimethylbenz (a) anthracene (DMBA)-induced hamster buccal pouch carcinogenesis. O. sanctum, in the form of fresh leaf paste, aqueous extract and ethanolic extract were topically applied and the extracts were orally administered to buccal pouch mucosa of animals exposed to 0.5% of DMBA. Incidence of papillomas and squamous cell carcinomas were significantly reduced, and increased the survival rate in the topically applied leaf paste and orally administered extracts to animals. Among them, the orally administered aqueous extract showed profound effect than the other two forms. Histopathological observations made on the mucosa confirmed these findings. Further fluorescent spectral studies at 405 nm excitation on the mucosa of control, DMBA and extracts orally administered experimental animals showed a prominent maxima at 430 nm for control, 628 nm for DMBA induced carcinomas while aqueous and ethanolic extracts administered animals showed at 486 nm and 488 nm, respectively. The fluorescent intensity at 630 nm (FI630 nm) was significantly reduced and the ratio of fluorescent intensities at 520 nm and 630 nm (FI520 nm/630 nm) were significantly increased in orally administered extracts compared to DMBA treated animals. These observations suggest that the orally administered extract of O. sanctum may have the ability to prevent the early events of carcinogenesis.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1998

Mucosal metabolism in ulcerative colitis and Crohn's disease.

PURPOSE: Colonic mucosal metabolism of butyrate may be impaired in ulcerative colitis. In this study we sought to confirm this observation, to determine if a similar change occurs in Crohn's colitis, and to establish whether a panenteric disorder of butyrate metabolism exists in either condition. METHODS: With use of a microculture technique, mucosal metabolic fluxes of 14[C]-labeled butyrate and 14[C]-labeled glutamine were measured as 14[C] carbon dioxide production in mucosal biopsy specimens from the colon and ileum in patients with ulcerative colitis, Crohn's colitis, and healthy bowel. Results were expressed as pmol/microg biopsy DNA/hour. RESULTS: In the colon the mucosal metabolic fluxes of both butyrate and glutamine are reduced in both ulcerative colitis and Crohn's colitis compared with healthy controls. These changes were most marked in the presence of moderate to severe mucosal inflammation, there being no significant difference in mucosal metabolic flux between mildly inflamed mucosa and healthy controls. In the ileum the mucosal metabolic fluxes of butyrate and glutamine did not differ between healthy controls and those with either ulcerative colitis or Crohn's colitis. CONCLUSIONS: Changes in colonic mucosal metabolism of butyrate and glutamine in inflammatory bowel disease occur as a consequence of the inflammatory process and are not peculiar to ulcerative colitis. Ileal mucosal metabolism is unchanged in ulcerative colitis and Crohn's colitis, indicating the absence of a panenteric abnormality of mucosal metabolism in these two conditions.

Biopsy↗
PubMed1995

Azo polymeric hydrogels for colon targeted drug delivery.

Azo polymeric hydrogels were developed for colon specific targeting. Methacryloyloxy azobenzene was synthesized and hydrogels were prepared by copolymerizing with hydroxyethyl methacrylate. These hydrogels were characterized by various spectral techniques such as Fourier transform infrared spectroscopy, thermogravimetric analysis and scanning electron microscopy. Equilibrium swelling measurements of the hydrogels were carried out in distilled water and also in simulated gastric and intestinal fluids. The in vitro release studies of the incorporated 5-flurouracil were carried out in simulated gastric and intestinal fluids. The in vitro release profiles of the drug were also obtained in the presence of azoreductase in the culture of intestinal flora. The release was faster and almost followed a zero order pattern. This can be attributed to the cleavage of the azo crosslinks in the hydrogel by the azoreductase and the release of the entrapped drug at the site of targeting i.e., colon.

Azo Compounds↗
PubMed1992

Myxoid variant of primary cutaneous malignant melanoma.

We report a rare case of primary cutaneous myxoid melanoma. Histologically, the tumour was composed of spindle and stellate-shaped cells, embedded in a myxoid stroma. Positivity for S-100 protein and the presence of melanosomes were demonstrated in the tumour. Primary cutaneous myxoid melanoma is rare. This is the second report of such a case.

Aged↗
PubMedDate not supplied

Delinquency in children.

Delinquency among children is not a problem only in Western countries. Psychosocial analysis of inmates of an approved school revealed that broken home was the reason for the emotional stress which triggered antisocial behaviour. Children want to be with their parents inspite of the injustice done to them.

Adolescent↗