Kaushal Kishor Prasad

Role of serotonin in gastrointestinal motility and irritable bowel syndrome.

Serotonin (5-HT) is an important signaling molecule in the gut targeting enterocytes, smooth muscles and enteric neurons. Most of the body serotonin is present in enterochromaffin cells. Serotonin activates both intrinsic and extrinsic primary afferent neurons to, respectively initiate peristaltic and secretory reflexes and to transmit information to the central nervous system. Serotonin is inactivated by the serotonin reuptake transporter (SERT) in the enterocytes or neurons. Exogenous serotonin application evokes so many responses that it is difficult to determine which is physiologically relevant. This effect is largely due to the presence of multiple receptor subtypes, which appear to be present on several classes of myenteric neurons, on smooth muscle cells, and on epithelial cells. Irritable bowel syndrome (IBS) is a complex disorder that is associated with altered gastrointestinal motility, secretion and sensation. Altered serotonin signaling may lead to both intestinal and extra intestinal systems in IBS. In this review, the literature related to role of serotonin signaling in pathophysiology of IBS has been searched and summarized. Therapeutic agents targeting altered serotonin signaling may provide new effective treatment for patients with IBS. Tegaserod, 5-HT(4) partial agonist is used in constipation predominant IBS while alosetron, a 5-HT(3) antagonist used in IBS with diarrhea. Other compounds such as tricyclic antidepressants and serotonin selective reuptake inhibitors have been used in some patients with IBS.

Abdominal tuberculosis of the gastrointestinal tract: Revisited

Abdominal tuberculosis is an increasingly common disease that poses diagnostic challenge, as the nonspecific features of the disease which may lead to diagnostic delays and development of complications. This condition is regarded as a great mimicker of other abdominal pathology. A high index of suspicion is an important factor in early diagnosis. Abdominal involvement may occur in the gastrointestinal tract, peritoneum, lymphnodes or solid viscera. Various investigative methods have been used to aid in the diagnosis of abdominal tuberculosis. Early diagnosis and initiation of antituberculous therapy and surgical treatment are essential to prevent morbidity and mortality. Most of the patients respond very well to standard antitubercular therapy and surgery is required only in a minority of cases. Imaging plays an important role in diagnosis of abdominal tuberculosis because early recognition of this condition is important. We reviewed our experience with the findings on various imaging modalities for diagnosis of this potentially treatable disease.

Pancreatic trauma: A concise review

Traumatic injury to the pancreas is rare and difficult to diagnose. In contrast, traumatic injuries to the liver, spleen and kidney are common and are usually identified with ease by imaging modalities. Pancreatic injuries are usually subtle to identify by different diagnostic imaging modalities, and these injuries are often overlooked in cases with extensive multiorgan trauma. The most evident findings of pancreatic injury are post-traumatic pancreatitis with blood, edema, and soft tissue infiltration of the anterior pararenal space. The alterations of post-traumatic pancreatitis may not be visualized within several hours following trauma as they are time dependent. Delayed diagnoses of traumatic pancreatic injuries are associated with high morbidity and mortality. Imaging plays an important role in diagnosis of pancreatic injuries because early recognition of the disruption of the main pancreatic duct is important. We reviewed our experience with the use of various imaging modalities for diagnosis of blunt pancreatic trauma.

Fecal lactoferrin, myeloperoxidase and serum C-reactive are effective biomarkers in the assessment of disease activity and severity in patients with idiopathic ulcerative colitis.

Background and Aim:  Disease activity and severity of ulcerative colitis (UC) is assessed using colonoscopy, which is invasive, costly and has poor patient acceptability. The role of non‐invasive biomarkers of intestinal inflammation in the evaluation of patients with UC is not known. The aim of the study was to examine the role of serum C‐reactive protein (SCRP), fecal myeloperoxidase (FMPO) and fecal lactoferrin (FLF) in assessing disease severity, activity and response to therapy.

Serotonin transporter promoter variant: Analysis in Indian IBS patients and control population.

Background Studies of serotonin reuptake transporter (SERT-P) polymorphism and irritable bowel syndrome (IBS) have shown diverse results among different populations, which might be due to racial and ethnic difference. Aim This study was to investigate the potential association between the SERT-P polymorphism and clinical subtypes of IBS patients in the Indian population. Method This prospective case-control study included 151 IBS patients. Ninety-two patients were diarrhea-predominant IBS, 44 were constipation-predominant IBS (C-IBS), 15 were alternating diarrhea and constipation IBS, and 100 were healthy controls. SERT gene polymorphism was studied by polymerase chain reaction. Result A genotypic association was observed between SS genotype of SERT-P polymorphism and C-IBS (P<0.05). When the L/S and L/L genotypes were combined into one group, the frequency of the S/S genotype was significantly higher than that of the non-S/S genotype between C-IBS and the control group (P<0.05). There was no significant difference in the SERT-P genotype and allele frequency between c-ibs, alternating diarrhea and constipation IBS, all types of IBS cases, and controls. Conclusions A significant association was observed between the SS genotype of SERT-P polymorphism and C-IBS in the Indian population.

Assessment of the diagnostic value of duodenal bulb histology in patients with celiac disease, using multiple biopsy sites.

Background Multiple endoscopic biopsies from the descending duodenum are usually recognized as the standardized method for the evaluation of mucosal changes in celiac disease (CD). Generally, the duodenal bulb is not considered a useful site for biopsies, owing to some difficulties in histologic evaluation. Goal We wanted to verify if duodenal bulb histology establish a correct diagnosis of CD. Study Fifty-two consecutive children with suspicion of CD and positive antitissue transglutaminase antibodies were enrolled in a prospective fashion. During upper gastrointestinal endoscopy, 2 to 4 biopsies each were taken from descending duodenum distal to the papilla of Vater (D2) and duodenal bulb (B). The histologic lesions were classified according to the modified Oberhuber classification by single pathologist who was blinded to the site of biopsy. Results A total of 52 children had a final diagnosis of CD. The main presenting symptoms were diarrhea 43/52 (82.7%), anemia 40/52 (76.9%), and failure to thrive 32/52 (61.5%). All had type 3 lesion—(a) mild, (b) moderate, or (c) severe—in at least 1 site. There was 45/52 (86.5%) CD patients with lesions of identical type (type 2 or 3) in both biopsy sites. The number of intraepithelial lymphocytes was not significantly different in the descending part of the duodenum as compared with duodenal bulb. Conclusions The biopsies from the duodenal bulb and second part of the duodenum in CD can be equally representative of the underlying disease. The diagnosis of CD can reliably be made even if biopsies are taken from the duodenal bulb rather than distal duodenum or jejunum.

Functional and morphological alterations in small intestine mucosa of chronic alcoholics

Background and Aim:  Alcohol‐related diseases constitute the third largest health problem after heart disease and cancer in the world. The objective was to study the effects of chronic alcohol intake on small bowel cellular functions with focus on brush border enzymes, membrane enzymes, cellular enzymes and their relationship with structural changes in small bowel mucosa of chronic alcoholics.

Prevalence of coeliac disease in healthy blood donors: A study from north India

BACKGROUND Blood donor screening can help predict prevalence of coeliac disease in population. METHODS Between December 2010 and June 2011, healthy blood donors were screened using anti-tissue glutaminase antibodies. Those positive underwent duodenoscopy. Their age, gender, body mass index and haemoglobin and histological changes were recorded. RESULTS Of the 1610 blood donors screened, 1581 (98.2%) were males. The mean age of donors was 31.51 ± 9.66 years and the mean body mass index was 22.12 ± 4.24 kg/m(2). Nine (0.56%) men were seropositive. Endoscopic features included reduced fold height (9), scalloping (8), grooving (7) and mosaic mucosal pattern (3). Eight had Marsh IIIa changes whilst one had IIIb change. The prevalence of coeliac disease was 1:179 (0.56%, 95% confidence interval 1/366-1/91, 0.27-1.1%). None of the 9 patients had any symptoms. Their mean haemoglobin and body-mass index was similar to rest of the cohort. CONCLUSION The prevalence of coeliac disease amongst apparently healthy blood donors was 1:179 (0.56%).

Brush border enzyme activities in relation to histological lesion in pediatric celiac disease

Background and Aim:  In celiac disease (CD), abnormalities of brush border enzyme activities have been detected in the course of the disease activity. There are conflicting results on intestinal mucosal enzyme activities and its correlation to mucosal injury in CD. The aim of the present study was to evaluate the brush border enzyme activities (disaccharidases and alkaline phosphatase) in the duodenal mucosa of North Indian children with CD and to examine their correlation to duodenal mucosal morphological alterations.

Effect of biotherapeutics on cyclosporin-induced Clostridium difficile infection in mice

Background and Aim:  Immunosuppressive therapy may precipitate Clostridium difficile associated disease (CDAD). We evaluated the role of cyclosporin in the development of CDAD in the experimental mouse model and studied the effect of probiotic and epidermal growth factor (EGF) as biotherapeutics measures.