Biology subjects

Patel, N. S.

Publications and source records attributed to Patel, N. S..

3 recordsLinked to original sources

bioRxiv2021

Porcine pancreatic ductal epithelial cells transformed with KRASG12D and SV40T are tumorigenic

We describe our initial studies in the development of an orthotopic, genetically-defined, large animal model of pancreatic cancer. Primary pancreatic epithelial cells were isolated from pancreatic duct of domestic pigs. A transformed cell line was generated from these primary cells with oncogenic KRAS and SV40T. The transformed cell lines outperformed the primary and SV40T immortalized cells in terms of proliferation, population doubling time, soft agar growth, transwell migration and invasion. The transformed cell line grew tumors when injected subcutaneously in nude mice, forming glandular structures and staining for epithelial markers. Future work will include implantation studies of these tumorigenic porcine pancreatic cell lines into the pancreas of allogeneic and autologous pigs. The resultant large animal model of pancreatic cancer could be utilized for preclinical research on diagnostic, interventional, and therapeutic technologies.

cancer biology↗

bioRxiv2020

The effect of pre-resection obesity on post-resection body composition after 75% small bowel resection in rats

BackgroundIn patients with short bowel syndrome, an elevated pre-resection Body Mass Index may be protective of post-resection body composition. We hypothesized that rats with diet-induced obesity would lose less lean body mass after undergoing massive small bowel resection compared to non-obese rats. MethodsRats (CD(R)IGS; age = 2 mo; N = 80) were randomly assigned to either a high-fat (obese rats) or a low-fat diet (non-obese rats), and fed ad lib for six months. Each diet group then was randomized to either underwent a 75% distal small bowel resection (massive resection) or small bowel transection with re-anastomosis (sham resection). All rats then were fed ad lib with an intermediate-fat diet (25% of total calories) for two months. Body weight and quantitative magnetic resonance-determined body composition were monitored. ResultsPreoperative body weight was 884 {+/-} 95 vs. 741 {+/-} 75 g, and preoperative percent body fat was 35.8 {+/-} 3.9 vs. 24.9 {+/-} 4.6%; high-fat vs. low fat diet, respectively (p < 0.0001); preoperative diet type had no effect on lean mass. Regarding total body weight, massive resection produced an 18% vs. 5% decrease in high-fat vs. low-fat rats respectively, while sham resection produced a 2% decrease vs. a 7% increase, respectively (p < 0.0001, preoperative vs. necropsy data). Sham resection had no effect on lean mass; after massive resection, both high-fat and low-fat rats lost lean mass, but these changes were not different between the latter two rat groups. ConclusionThe high-fat diet and low-fat diet induced obesity and marginal obesity, respectively. The massive resection produced greater weight loss in high-fat rats compared to low-fat rats. The type of dietary preconditioning had no effect on lean mass loss after massive resection. A protective effect of pre-existing obesity on lean mass after massive intestinal resection was not demonstrated.

physiology↗

bioRxiv2018

Collateral development and arteriogenesis in hindlimbs of domestic swine after ligation of arterial inflow

IntroductionThe development of collateral vasculature is a key mechanism compensating for arterial occlusions in patients with peripheral artery disease (PAD). We aimed to examine the development of collateral pathways after ligation of native vessels in a porcine model of PAD. MethodsRight hindlimb Ischemia was induced in domestic swine (N=11, male, kg) using two different versions of arterial ligation. Version 1 (N=6) consisted of ligation/division of the right external iliac, profunda femoral (RPFA) and superficial femoral arteries (RSFA). Version 2 (N=5) consisted of the ligation of Version 1 with additional ligation/division of the right internal iliac artery (RIIA). Development of collateral pathways was evaluated with standard angiography at baseline (prior to arterial ligation) and at termination (4-8 weeks later). Relative luminal diameter of the arteries supplying the ischemic right hindlimb were determined by 2D angiography, as percent of the size of the distal aortic diameter. ResultsThe dominant collateral pathway that developed after version 1 ligation connected the RIIA to the RPFA and RSFA/popliteal artery. Mean luminal diameter ({+/-} standard error) of the RIIA at termination increased by 38% (P<0.05) compared to baseline. Two co-dominant collateral pathways developed in version: (i) from the common internal iliac trunk and left internal iliac artery to the reconstituted RIIA, which then supplied the RPFA and RSFA/popliteal arteries; and (ii) from left profunda artery to the reconstituted RPFA. Mean diameter of the common internal iliac trunk and left profunda artery both increased at termination in the range of 20% (p < 0.05). ConclusionTwo versions of hindlimb ischemia induction (right ilio-femoral artery ligation with and without right internal iliac artery ligation in swine produced differing collateral pathways, along with changes to the diameter of the inflow vessels (i.e., arteriogenesis). Radiographic and anatomical data of the collateral formation in this porcine model should have value in investigation of the pathophysiology of hindlimb ischemia, and assessment of angiogenic therapies as potential treatments for PAD.

physiology↗