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Prasenjit Das,Ritika Rampal,Sonakshi Udinia,Tarun Kumar,Sucharita Pilli,Nahid Wari,Imtiaz Khan Ahmed,Saurabh Kedia,Siddhartha Datta Gupta,Dhiraj Kumar,Vineet Ahuja 대한장연구학회 2018 Intestinal Research Vol.16 No.3
Background/Aims: Classical M1 macrophage activation exhibits an inflammatory phenotype while alternative M2 macrophage activation exhibits an anti-inflammatory phenotype. We aimed to determine whether there are discriminant patterns of macrophage polarization in Crohn’s disease (CD) and intestinal tuberculosis (iTB). Methods: Colonic mucosal biopsies from 29 patients with iTB, 50 with CD, and 19 controls were examined. Dual colored immunohistochemistry was performed for iNOS/CD68 (an M1ϕ marker) and CD163/CD68 (an M2ϕ marker), and the ratio of M1ϕ to M2ϕ was assessed. To establish the innate nature of macrophage polarization, we analyzed the extent of mitochondrial depolarization, a key marker of inflammatory responses, in monocyte-derived macrophages obtained from CD and iTB patients, following interferon-γ treatment. Results: M1ϕ polarization was more prominent in CD biopsies (P=0.002) than in iTB (P=0.2) and control biopsies. In granuloma-positive biopsies, including those in CD, M1ϕ predominance was significant (P=0.001). In iTB, the densities of M1ϕ did not differ between granuloma-positive and granuloma-negative biopsies (P=0.1). Interestingly, higher M1ϕ polarization in CD biopsies correlated with high inflammatory response exhibited by peripheral blood-derived monocytes from these patients. Conclusions: Proinflammatory M1ϕ polarization was more common in colonic mucosa of CD patients, especially in the presence of mucosal granulomas. Further characterization of the innate immune system could help in clarifying the pathology of iTB and CD.
Prasenjit Das,Gaurav PS Gahlot,Alka Singh,Vandana Baloda,Ramakant Rawat,Anil K Verma,Gaurav Khanna,Maitrayee Roy,Archana George,Ashok Singh,Aasma Nalwa,Prashant Ramteke,Rajni Yadav,Vineet Ahuja,Vishnu 대한장연구학회 2019 Intestinal Research Vol.17 No.3
Background/Aims: The existing histological classifications for the interpretation of small intestinal biopsies are based on qualitative parameters with high intraobserver and interobserver variations. We have developed and propose a quantitative histological classification system for the assessment of intestinal mucosal biopsies. Methods: We performed a computer-assisted quantitative histological assessment of digital images of duodenal biopsies from 137 controls and 124 patients with celiac disease (CeD) (derivation cohort). From the receiver-operating curve analysis, followed by multivariate and logistic regression analyses, we identified parameters for differentiating control biopsies from those of the patients with CeD. We repeated the quantitative histological analysis in a validation cohort (105 controls and 120 patients with CeD). On the basis of the results, we propose a quantitative histological classification system. The new classification was compared with the existing histological classifications for interobserver and intraobserver agreements by a group of qualified pathologists. Results: Among the histological parameters, intraepithelial lymphocyte count of ≥25/100 epithelial cells, adjusted villous height fold change of ≤0.7, and crypt depth-to-villous height ratio of ≥0.5 showed good discriminative power between the mucosal biopsies from the patients with CeD and those from the controls, with 90.3% sensitivity, 93.5% specificity, and 96.2% area under the curve. Among the existing histological classifications, our quantitative histological classification showed the highest intraobserver (69.7%–85.03%) and interobserver (24.6%–71.5%) agreements. Conclusions: Quantitative assessment increases the reliability of the histological assessment of mucosal biopsies in patients with CeD. Such a classification system may be used for clinical trials in patients with CeD.
Prasenjit Dey,Ajoy K. Das 한국원자력학회 2016 Nuclear Engineering and Technology Vol.48 No.6
The present study aims to predict the heat transfer characteristics around a square cylinderwith different corner radii using multivariate adaptive regression splines (MARS). Further, the MARS-generated objective function is optimized by particle swarm optimization. The data for the prediction are taken from the recently published article by thepresent authors [P. Dey, A. Sarkar, A.K. Das, Development of GEP and ANN model to predictthe unsteady forced convection over a cylinder, Neural Comput. Appl. (2015) 1-13]. Further,the MARS model is compared with artificial neural network and gene expression programming. It has been found that the MARS model is very efficient in predicting the heattransfer characteristics. It has also been found that MARS is more efficient than artificialneural network and gene expression programming in predicting the forced convectiondata, and also particle swarm optimization can efficiently optimize the heat transfer rate.
Deepak Patel,Prasenjit Biswas,Anil Kumar,Hiren R. Kotadia,Archana Mallik,Sanjeev Das 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.7
The present investigation focuses on grain refinement in pure aluminum and its alloy under mechanical stirring with a verylow degree of forced convection of 800 rpm as compared to reported values of up to 8000 rpm during direct chill castingprocess (DC). Commercially pure aluminum (99.7%) and Al6082 alloy billets were fabricated in an in-house designed DCcasting simulator. Mechanical forced convection (MFC) was applied to the melt during casting by a common four-bladedimpeller. The microstructural properties of the as-cast billets have been analysed to study the effect of MFC during casting andsolidification. The structure of both Al and its alloy is found to be refined in presence of MFC as compared to conventionalDC. A combination of simulation, experimental and theoretical approaches has been used to determine the effect of MFCin melt-temperature distribution to propose the mechanism of grain refinement. It has been observed that MFC prominentlyreduces the temperature gradient and extends undercooling time, resulting in fine grain structure.
( Sawan Bopanna ),( Maitreyee Roy ),( Prasenjit Das ),( S Dattagupta ),( V Sreenivas ),( V Pratap Mouli ),( Saurabh Kedia ),( Rajan Dhingra ),( Rajesh Pradhan ),( N Suraj Kumar ),( Dawesh P Yadav ),( 대한장연구학회 2016 Intestinal Research Vol.14 No.3
Background/Aims: Recent data suggest that the incidence of ulcerative colitis (UC) related colorectal cancer (CRC) in India is similar to that of West. The optimum method for surveillance is still a debate. Surveillance with random biopsies has been the standard of care, but is a tedious process. We therefore undertook this study to assess the yield of random biopsy in dysplasia surveillance. Methods: Between March 2014 and July 2015, patients of UC attending the Inflammatory Bowel Disease clinic at the All India Institute of Medical Sciences with high risk factors for CRC like duration of disease >15 years and pancolitis, family history of CRC, primary sclerosing cholangitis underwent surveillance colonoscopy for dysplasia. Four quadrant random biopsies at 10 cm intervals were taken (33 biopsies). Two pathologists examined specimens for dysplasia, and the yield of dysplasia was calculated. Results: Twenty-eight patients were included. Twenty-six of these had pancolitis with a duration of disease greater than 15 years, and two patients had associated primary sclerosing cholangis. No patient had a family history of CRC. The mean age at onset of disease was 28.89±8.73 years and the duration of disease was 19.00±8.78 years. Eighteen patients (64.28%) were males. A total of 924 biopsies were taken. None of the biopsies revealed any evidence of dysplasia, and 7/924 (0.7%) were indefinite for dysplasia. Conclusions: Random biopsy for surveillance in longstanding extensive colitis has a low yield for dysplasia and does not suffice for screening. Newer techniques such as chromoendoscopy-guided biopsies need greater adoption.
Swati Chowdhury,Sudipta Roy,Anirban Mitra,Prasenjit Das 보안공학연구지원센터 2016 International Journal of Signal Processing, Image Vol.9 No.7
Image segmentation subdivided an image into its constituent regions or segments. This regions or segments of an image is known as ‘cluster’ and the method used for this is called ‘clustering method’. There are different methods or algorithms are out there to segment an image. There is a problem with those algorithms user has to supply the number of cluster in which it has to be segmented. Here we introduced a method using combination of both entropy of RGB color component and histogram to automatic determination of cluster present in a color image.
Peeyush Kumar,Sudheer K. Vuyyuru,Prasenjit Das,Bhaskar Kante,Mukesh Kumar Ranjan,David Mathew Thomas,Sandeep Mundhra,Pabitra Sahu,Pratap Mouli Venigalla,Saransh Jain,Sandeep Goyal,Rithvik Golla,Shubi 대한장연구학회 2023 Intestinal Research Vol.21 No.4
Background/Aims: Evidence on predictors of primary nonresponse (PNR), and secondary loss of response (SLR) to anti-tumor necrosis factor (anti-TNF) agents in inflammatory bowel disease is scarce from Asia. We evaluated clinical/biochemical/molecular markers of PNR/SLR in ulcerative colitis (UC) and Crohn’s disease (CD).Methods: Inflammatory bowel disease patients treated with anti-TNF agents (January 2005–October 2020) were ambispectively included. Data concerning clinical and biochemical predictors was retrieved from a prospectively maintained database. Immunohistochemistry for expression of oncostatin M (OSM), OSM receptor (OSM-R), and interleukin-7 receptor (IL-7R) were done on pre anti-TNF initiation mucosal biopsies.Results: One-hundred eighty-six patients (118 CD, 68 UC: mean age, 34.1±13.7 years; median disease duration at anti-TNF initiation, 60 months; interquartile range, 28–100.5 months) were included. PNR was seen in 17% and 26.5% and SLR in 47% and 28% CD and UC patients, respectively. In CD, predictors of PNR were low albumin (<i>P</i><0.001), postoperative recurrence (<i>P</i>=0.001) and high IL-7R expression (<i>P</i><0.027) on univariate; and low albumin alone (hazard ratio [HR], 0.09; 95% confidence interval [CI], 0.03–0.28; <i>P</i><0.001) on multivariate analysis respectively. Low albumin (HR, 0.31; 95% CI, 0.15–0.62; <i>P</i>=0.001) also predicted SLR. In UC, predictors of PNR were low albumin (<i>P</i><0.001), and high C-reactive protein (<i>P</i><0.001), OSM (<i>P</i><0.04) and OSM-R (P=0.07) stromal expression on univariate; and low albumin alone (HR, 0.11; 95% CI, 0.03–0.39; <i>P</i>=0.001) on multivariate analysis respectively. Conclusions: Low serum albumin at baseline significantly predicted PNR in UC and PNR/SLR in CD patients. Mucosal markers of PNR were high stromal OSM/OSM-R in UC and high IL-7R in CD patients.