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Subba Rao M.,Institute of Basic science and Translational Research | Sasikala M.,Institute of Basic science and Translational Research | Reddy D.N.,Asian Institute of Gastroenterology
World Journal of Gastroenterology | Year: 2013

The discovery of induced pluripotent stem cells (iPSCs) unraveled a mystery in stem cell research, after identification of four re-programming factors for generating pluripotent stem cells without the need of embryos. This breakthrough in generating iPSCs from somatic cells has overcome the ethical issues and immune rejection involved in the use of human embryonic stem cells. Hence, iPSCs form a great potential source for developing disease models, drug toxicity screening and cell-based therapies. These cells have the potential to differentiate into desired cell types, including hepatocytes, under in vitro as well as under in vivo conditions given the proper microenvironment. iPSC-derived hepatocytes could be useful as an unlimited source, which can be utilized in disease modeling, drug toxicity testing and producing autologous cell therapies that would avoid immune rejection and enable correction of gene defects prior to cell transplantation. In this review, we discuss the induction methods, role of reprogramming factors, and characterization of iPSCs, along with hepatocyte differentiation from iPSCs and potential applications Further, we discuss the location and detection of liver stem cells and their role in liver regeneration. Although tumor formation and genetic mutations are a cause of concern, iPSCs still form a promising source for clinical applications. © 2013 Baishideng. All rights reserved.

Rao P.N.,Asian Institute of Gastroenterology
Journal of Clinical and Experimental Hepatology | Year: 2014

Conventional ultrasonogram of the abdomen being noninvasive, inexpensive and ubiquitously available is the first imaging modality that raises suspicion of HCC in a patient with chronic liver disease with or without cirrhosis. The lesions in liver particularly nodule are being recognized with increased frequency with the wide spread use of ultrasonogram as the initial investigation and computerized tomography and magnetic resonance imaging subsequently. Any nodule in a cirrhotic liver should be considered as hepatocellular carcinoma until otherwise proved. This approach certainly is helpful in diagnosing HCC at its earliest possible stage to offer meaningful curative measures be it transplant, resection or ablative therapy. After a nodule is detected on ultrasonogram the next imaging modality can be a contrast enhanced study (dynamic CT scan or an MRI) to see if are present or not. Two vital clues for diagnosis of HCC by contrast enhanced imaging are presence of arterial hypervascularity and washout which are considered as "classical imaging features". This sequence of events of arterial uptake followed by washout is highly specific for diagnosis of HCC by imaging. If the features are typical showing classical imaging features (i.e hypervascular in the arterial phase with washout in portal venous or delayed phase) the lesion should be treated as HCC biopsy is not necessary. Nodular lesions showing an atypical imaging pattern, such as iso- or hypovascular in the arterial phase or arterial hypervascularity alone without portal venous washout, should undergo further examinations with another contrast enhanced imaging. Biopsy is advisable for those lesions which do not show classical features on the imaging. © 2014.

Ramchandani M.,Asian Institute of Gastroenterology | Reddy D.N.,Asian Institute of Gastroenterology
Gastrointestinal Endoscopy | Year: 2013

Background Zenker's diverticulum (ZD) is a rare disorder but is associated with significant morbidity. Cricopharyngeal (CP) myotomy is the mainstay of treatment, and various flexible endoscopic techniques have been used for division of the septum. However, there is a constant need for improvement in accessories. Objective To evaluate the safety and effectiveness of a new electrocautery endoscopic scissor for CP myotomy in patients with symptomatic ZD. Design Observational human study. Setting Tertiary-care hospital. Patients This study involved 3 patients with symptomatic ZD. Intervention Flexible endoscopic CP myotomy was performed by using a novel scissors-type grasping device. CP myotomy involved 4 steps: (1) opening of the forceps, (2) grasping the muscle fiber, (3) closure of the forceps with application of gentle traction, and (4) dissection of muscle fibers by using cutting current. Intraprocedural bleeding was controlled with the same instrument by grasping vessels and applying coagulation current. Main Outcome Measurements Overall feasibility and performance, procedure time to achieve complete CP myotomy. Results CP myotomy was successfully performed in all patients. Mean procedure time was 10.6 minutes. There were no major adverse events. Minor intraprocedure bleeding occurred in 1 patient. Limitations Single arm, limited number of patients. Conclusion The new instrument has potential advantages in comparison with standard instruments used for CP myotomy. The advantages of this new technique are better control of cutting and hemostatic abilities. Copyright © 2013 by the American Society for Gastrointestinal Endoscopy.

Talukdar R.,Asian Institute of Gastroenterology | Inoue H.,Showa University | Reddy D.N.,Asian Institute of Gastroenterology
Surgical Endoscopy and Other Interventional Techniques | Year: 2015

Background: Peroral endoscopic myotomy (POEM) is an evolving therapeutic modality for achalasia. We aim to determine efficacy of POEM for the treatment of achalasia and compare it with laparoscopic Heller’s myotomy (LHM). Materials and methods: Systematic review and meta-analyses was conducted on 19 studies using POEM for achalasia. Pubmed, Medline, Cochrane, and Ovid databases, were searched using the terms ‘achalasia’, ‘POEM’, ‘peroral endoscopic myotomy’, ‘per oral endoscopic myotomy’, and ‘per-oral endoscopic myotomy’. Reduction in Eckhart’s score and lower esophageal sphincter (LES) pressure were the main outcome measures. Results: A total of 1,045 patients underwent POEM in 29 studies. Ninety patients undergoing POEM was compared with 160 undergoing LHM in five studies. Nineteen and 14 studies, respectively, evaluated for Eckhart’s score and LES pressure. There was significant reduction in Eckhart’s score and LES pressure with effect sizes of −7.95 (p < 0.0001) and −7.28 (p < 0.0001), respectively. There was significant heterogeneity among the studies [(Q = 83.06; I2 = 78.33 %; p < 0.0001) for Eckhart’s score and (Q = 61.44; I2 = 75.68 %; p < 0.0001) for LES pressure]. There were no differences between POEM and LHM in reduction in Eckhart’s score, post-operative pain scores and analgesic requirements, length of hospital stay, adverse events, and symptomatic gastroesophageal reflux/reflux esophagitis. Operative time was significantly lower for POEM. Conclusions: POEM is effective for achalasia and has similar outcomes as LHM. Multicenter randomized trials need to be conducted to further compare the efficacy and safety of POEM between treatment naïve achalasia patients and those who failed treatment. © 2014, Springer Science+Business Media New York.

Gupta R.,Asian Institute of Gastroenterology | Reddy D.N.,Asian Institute of Gastroenterology
Journal of Hepato-Biliary-Pancreatic Sciences | Year: 2011

Endoscopic stenting is an effective treatment option in the management of both benign biliary strictures and pancreatic ductal strictures. Plastic stents and selfexpandable metal stents have been used with variable success for the management of both benign biliary strictures and pancreatic ductal strictures caused by chronic pancreatitis. Fully covered self-expandable metal stents of improved design represent a major technological advance which has added to the endoscopic armamentarium. Both multiple plastic stents and covered self-expandable metal stents have shown promising results. However, data to support the use of self-expandable metal stents over multiple plastic stents or vice versa are still lacking. © Japanese Society of Hepato-Biliary- Pancreatic Surgery and Springer 2011.

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