Biomedical subjects

Rakesh Tandon

Publications and source records attributed to Rakesh Tandon.

5 recordsLinked to original sources

PubMed2006

Chronic pancreatitis: evolving paradigms.

Chronic pancreatitis (CP) is characterized by progressive fibrosis, pain and/or loss of exocrine and endocrine functions. With the identification and characterization of pancreatic stellate cells (PSCs), the pathogenesis of CP and pancreatic fibrosis is now better understood. Molecular mediators shown to regulate the pathogenesis include transforming growth factor-beta, platelet-derived growth factor, and proinflammatory cytokines such as interleukin (IL)-1, IL-6 and tumor necrosis factor-alpha. Besides these, the roles of cyclooxygenase (COX)-2 and apoptosis-related proteins have also been implicated in the pathogenesis. Furthermore, molecular pathways involving mitogen-activated protein kinases, phosphatidylinositol 3-kinase, Ras superfamily G proteins, serine threonine protein kinase Raf-1 and peroxisome proliferator-activated receptor-gamma (PPAR-gamma) have been elucidated. Newer pathobiologic concepts concerning pain generation have also been put forward. Understanding the pathogenesis has led to the identification of novel molecular targets and the development of newer potential therapeutic agents. Those found to retard the progression of experimental CP and fibrosis in animal models include antioxidants, a Japanese herbal medicine called Saiko-keisi-to (TJ 10), the PPAR-gamma ligand troglitazone, the protease inhibitor Camostat mesilate, and Lovastatin.

Humans↗

PubMed2006

Colorectal neoplasia in Asia: a multicenter colonoscopy survey in symptomatic patients.

BACKGROUND: The incidence of colorectal cancer is rising rapidly in some Asian countries. OBJECTIVE: To determine the prevalence and the distribution of colorectal neoplasm in Asian populations. DESIGN: A multicenter colonoscopy survey. PATIENTS: Between July 2004 and April 2005, consecutive symptomatic patients undergoing colonoscopic examinations in 10 different Asian countries. SETTING: The location and the histologic features of all colonic neoplasms were recorded. Advanced neoplasm was defined as adenoma larger than 10 mm in size, with >25% villous features or with high-grade dysplasia or invasive carcinoma. MAIN OUTCOME MEASUREMENTS: The prevalence and the distribution of colorectal neoplasm and advanced neoplasm. RESULTS: A total of 5464 eligible patients underwent colonoscopy. Advanced neoplasm was found in 512 patients (9.4%). Factors associated with the presence of advanced neoplasm in this symptomatic Asian population included male sex (relative risk [RR] 1.52, 95% confidence interval [CI] 1.26-1.84), older age (RR 1.05, 95% CI 1.04-1.06), and ethnicity (P = .001). Advanced proximal neoplasm was detected in 136 patients (2.5%); 83 (61.0%) of the patients had normal distal colon. The RR of proximal advanced neoplasm was 2.5, 95% CI 1.7-3.7 in those with any adenoma in the distal colon compared with those with normal distal colon. LIMITATIONS: Possible underrepresentation of some ethnic groups because of uneven ethnic group distribution and the lack of population-based registry. CONCLUSIONS: This was the first multicenter colonoscopy survey that examined the characteristics of colorectal neoplasm in Asia. The results will have important implications on the planning for future colorectal cancer screening in this region.

Adenoma↗

PubMed2006

Management consensus of inflammatory bowel disease for the Asia-Pacific region.

At the present there are no large-scale epidemiologic data on inflammatory bowel disease (IBD) in the Asia-Pacific region, but several studies have shown an increased incidence and prevalence of IBD in this region. Compared to the West, there appears to exist a time lag phenomenon. With regard to the two main forms of IBD, ulcerative colitis (UC) is more prevalent than Crohn's disease (CD). In addition to geographic differences, ethnic differences have been observed in the multiracial Asian countries. Moreover, the genetic backgrounds are different in the Asian compared to Western patients. For instance, NOD2/CARD15 variants have not been found in Asian CD patients. In general, the clinical course of IBD seems to be less severe in the Asia-Pacific region than in Western countries. Diagnosis of IBD in this region poses special problems. The lack of a gold standard for the diagnosis of IBD, and the existence of a variety of infectious enterocolitis with similar manifestations to those of IBD make the differential diagnosis particularly difficult. So far, Western diagnostic criteria have been introduced for the diagnosis of IBD. A stepwise approach to exclude non-IBD enterocolitis also must be introduced, and a definite diagnosis must include typical histological features. In some patients, follow up and therapeutic trials might be necessary to obtain a definitive diagnosis. A better understanding of the pathogenesis of IBD will allow the development of better diagnostic markers. The management of IBD also poses some special problems in the Asia-Pacific Region. There is often a delay in using proper medications for IBD, and alternative local remedies are still widely used. With a combination of Western guidelines and regional experiences, similar principles can be used for induction and maintenance of remission. A stepwise selection of medications is advocated depending on the extent, activity and severity of the disease. Comprehensive and individualized approaches are suggested for different IBD patients. Deeper understanding of disease pathogenesis and the unique characteristics of IBD in the Asia-Pacific region, combined with reasonable and practical guidelines for drug management and the future use of biological agents would improve the therapeutic outlook of IBD in this region.

Anti-Inflammatory Agents↗

PubMed2005

The emergence of inflammatory bowel disease in the Asian Pacific region.

PURPOSE OF REVIEW: Inflammatory bowel disease has been traditionally considered rare in the Asian Pacific region, but recent evidence indicates that both Crohn disease and ulcerative colitis are becoming increasingly common among local populations. This review will validate this significant epidemiological and clinical observation using data published in the current Asian literature and information presented at the 2004 Asian Pacific Digestive Week in Beijing, China. RECENT FINDINGS: A progressive rise in the incidence and prevalence of inflammatory bowel disease is discernible is most Asian Pacific countries, more so for ulcerative colitis than Crohn disease. Some ethnic differences are notably evident, as Indians suffer more inflammatory bowel disease than Chinese or Malays. Age of onset and gender are similar to those of Western patients, as are the distribution and extent of disease which, however, tends to be clinically less severe than in European and North American patients. A family history is occasionally elicited, whereas smoking and appendectomy appear to have the same impact on inflammatory bowel disease as seen in the West. A remarkable difference is the absence of any association of Asian Crohn disease with NOD2/CARD15 mutations, as repeatedly observed in white and Jewish populations. Intestinal tuberculosis is still common in the Asian Pacific region, and poses major diagnostic and therapeutic hurdles, often delaying the diagnosis of true Crohn disease. SUMMARY: Investigation of inflammatory bowel disease in the Asian Pacific region offers the unprecedented opportunity to study the 'early stages' of the disease, and may provide new clues to its pathophysiology by identifying key environmental factors and distinct genetic make-ups.

Asia↗

PubMedDate not supplied

Stress ulcer prophylaxis in patients on ventilator.

The objective of the study was to assess the efficacy of the H2-receptor antagonists and sucralfate for the prophylaxis of stress ulcer in patients on a ventilator in an intensive care unit in the general intensive care unit of our institute. A randomized, clinical controlled trial was conducted. Fifty-two critically ill patients, who required mechanical ventilation for more than 24 hours, were randomly divided into 3 groups. Group I received ranitidine 50 mg (intravenous) 8 hourly, group II received tablet sucralfate 1 g 8 hourly through a Ryle's tube, whereas group III was not given any drug. The incidence of upper gastrointestinal bleed, change in gastric pH and growth of gram-negative organisms in the gastric juice and bronchoalveolar lavage (BAL) culture were noted and analysed. The treatment groups were similar with respect to the baseline characteristics. The incidence of upper gastrointestinal bleeding was similar in the ranitidine (12.5%) and sucralfate groups (14.35%) but was high in the control group (57.14%). The mean gastric pH was significantly low in the control group (mean pH 2.07) compared to the ranitidine (mean pH 5.25) and sucralfate groups(mean pH 3.54)(p < 0.05). The incidence of positive culture for gram-negative organisms was significantly high in the ranitidine group (75%) in comparison with the sucralfate group (33.33%) (p < 0.002). However, the incidence of positive growth in the BAL culture was similar in all three groups. We conclude that both ranitidine and sucralfate are equally effective in decreasing the incidence of upper gastrointestinal haemorrhage and other stress- related lesions. Though ranitidine was more effective in increasing the gastric pH, the incidence of gastric colonization was higher in the ranitidine group compared to the sucralfate group.

Adult↗