Nuclear receptors in vascular biology

Nuclear receptors sense a wide range of steroids and hormones (estrogens, progesterone, androgens, glucocorticoid, and mineralocorticoid), vitamins (A and D), lipid metabolites, carbohydrates, and xenobiotics. In response to these diverse but critically important mediators, nuclear receptors regulate the homeostatic control of lipids, carbohydrate, cholesterol, and xenobiotic drug metabolism, inflammation, cell differentiation and development, including vascular development. The nuclear receptor family is one of the most important groups of signaling molecules in the body and as such represent some of the most important established and emerging clinical and therapeutic targets. This review will highlight some of the recent trends in nuclear receptor biology related to vascular biology

Role of Rote Learning as an ESL Learning Strategy

Abstract Hundreds of thousands of graduates of both professional and non-professional courses are churned out every year by the universities and colleges in India. Unfortunately, a majority of them often find themselves in the status of perennial jobseekers running from one establishment to another. Ultimately, most of them reconcile themselves to the fate of being rejected by the job market as "unemployable", in spite of their score cards bearing the stamp of a 'first-class' or 'super-first class' . What causes this anomaly? This article attempts to probe some of the reasons behind the malady, from the perspective of ESL (English as Second Language) proficiency. The investigation is done with the help of a random survey carried out among a group of ESL learners at the point of their entry into various undergraduate courses in South India. Nevertheless, the findings of this study would be representative of the status of the ESL proficiency of a vast majority of the Indian student community

Optimization of stress response through the nuclear receptor-mediated cortisol signalling network

It is an accepted paradigm that extended stress predisposes an individual to pathophysiology. However, the biological adaptations to minimize this risk are poorly understood. Using a computational model based upon realistic kinetic parameters we are able to reproduce the interaction of the stress hormone cortisol with its two nuclear receptors, the high-affinity glucocorticoid receptor and the low-affinity pregnane X-receptor. We demonstrate that regulatory signals between these two nuclear receptors are necessary to optimize the body’s response to stress episodes, attenuating both the magnitude and duration of the biological response. In addition, we predict that the activation of pregnane X-receptor by multiple, low-affinity endobiotic ligands is necessary for the significant pregnane X-receptor-mediated transcriptional response observed following stress episodes. This integration allows responses mediated through both the high and low-affinity nuclear receptors, which we predict is an important strategy to minimize the risk of disease from chronic stress

Clear cell carcinoid tumor of the distal common bile duct

BACKGROUND: Carcinoid tumors rarely arise in the extrahepatic bile duct and can be difficult to distinguish from carcinoma. There are no reports of clear cell carcinoid (CCC) tumors in the distal bile duct (DBD) to the best of our knowledge. Herein, we report a CCC tumor in the DBD and review the literature concerning extrahepatic bile duct carcinoid tumors. CASE PRESENTATION: A 73-old man presented with fever and occult obstructive jaundice. Ultrasonography, computed tomography (CT) and magnetic resonance cholangiopancreaticography (MRCP) demonstrated a nodular tumor projection in the DBD without regional lymph node swelling. Under suspicion of carcinoma, we resected the head of the pancreas along with 2(nd )portion duodenectomy and a lymph node dissection. The surgical specimen showed a golden yellow polypoid tumor in the DBD (0.8 × 0.6 × 0.5 cm in size). The lesion was composed of clear polygonal cells arranged in nests and a trabecular pattern. The tumor invaded through the wall into the fibromuscular layer. Immunohistochemical stains showed that neoplastic cells were positive for neuron-specific enolase (NSE), chromogranin A, synaptophysin, and pancreatic polypeptide and negative for inhibin, keratin, CD56, serotonin, gastrin and somatostatin. The postoperative course was uneventful and he is living well without relapse 12 months after surgery. CONCLUSION: Given the preoperative difficulty in differentiating carcinoid from carcinoma, the pancreaticoduodenectomy is an appropriate treatment choice for carcinoid tumors located within the intra-pancreatic bile duct

Dysregulation of Gene Expression in the Artificial Human Trisomy Cells of Chromosome 8 Associated with Transformed Cell Phenotypes

A change in chromosome number, known as aneuploidy, is a common characteristic of cancer. Aneuploidy disrupts gene expression in human cancer cells and immortalized human epithelial cells, but not in normal human cells. However, the relationship between aneuploidy and cancer remains unclear. To study the effects of aneuploidy in normal human cells, we generated artificial cells of human primary fibroblast having three chromosome 8 (trisomy 8 cells) by using microcell-mediated chromosome transfer technique. In addition to decreased proliferation, the trisomy 8 cells lost contact inhibition and reproliferated after exhibiting senescence-like characteristics that are typical of transformed cells. Furthermore, the trisomy 8 cells exhibited chromosome instability, and the overall gene expression profile based on microarray analyses was significantly different from that of diploid human primary fibroblasts. Our data suggest that aneuploidy, even a single chromosome gain, can be introduced into normal human cells and causes, in some cases, a partial cancer phenotype due to a disruption in overall gene expression

Antimicrobial activities of pomegranate rind extracts: enhancement by addition of metal salts and vitamin C

BACKGROUND: Punica granatum L. or pomegranates, have been reported to have antimicrobial activity against a range of Gram positive and negative bacteria. Pomegranate formulations containing ferrous salts have enhanced although short-term, antibacteriophage activities which are rapidly diminished owing to instability of the ferrous combination. The aim of this study was to determine the antimicrobial activities of combinations of pomegranate rind extracts (PRE) with a range of metals salts with the added stabiliser vitamin C. METHODS: PRE solutions, prepared by blending rind sections with distilled water prior to sterilisation by autoclaving or filtration, were screened with a disc diffusion assay using penicillin G as a control. Suspension assays were used to determine the antimicrobial activities of PRE alone and in combination with salts of the following metals; Fe (II), Cu (II), Mn (II) or Zn (II), and vitamin C, against a panel of microbes following exposure for 30 mins. The test organisms included Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Pseudomonas aeruginosa and Proteus mirabilis. RESULTS: The screening assay demonstrated that PRE exhibited activity against the Gram positive organisms at 24 h with no observable effect on any of the Gram negative bacteria. However, after 12 h, zones of inhibition were only observed for Ps. aeruginosa. In contrast, using the suspension assay, addition of Cu (II) salts to PRE solutions extended the activities resulting in no detectable growth being observed for the PRE/Cu (II) combination against E. coli, Ps. aeruginosa and P. mirabilis. Minimal antimicrobial activity was observed following incubation with Fe (II), Mn (II) or Zn (II) salts alone or in combination with PRE against any of the organisms in the test panel. The addition of vitamin C markedly enhanced the activities of both PRE/Fe (II) and PRE/Cu (II) combinations against S. aureus. CONCLUSION: This is the first report demonstrating the enhanced efficacy of PRE/metal salt combinations in the presence of the stabilising agent vitamin C, to which all isolates were sensitive with the exception of B. subtilis. This study has validated the exploration of PRE along with additives such as metal salts and vitamin C as novel antimicrobial combinations

Delayed construction of the bilio-digestive anastomosis in right living donor liver transplantation

We describe a two-step procedure in the transplantation of a right lobe liver graft obtained from a living donor, in which the biliary anastomosis is delayed until the day after the actual implantation of the graft. The purpose of the two-step procedure is to minimize the factors that might contribute to biliary complications in living donor liver transplantation (LDLT). Three patients who received a graft with two hepatic ducts underwent Roux-en-Y hepatico-jejunostomies during a separate procedure the day after the implantation of the graft. Length of intubation, recovery of enteral alimentation, and hospital stay were similar to the patients who underwent one-step transplant. No biliary or infectious complications occurred. Delaying the hepatico-jejunostomy when two ducts are present and a bilio-digestive anastomosis is planned has no negative impact on the postoperative course of the patients but can ameliorate the conditions under which the anastomoses must be performed

Delayed Construction of the Bilio-Digestive Anastomosis in Right Living Donor Liver Transplantation

We describe a two-step procedure in the transplantation of a right lobe liver graft obtained from a living donor, in which the biliary anastomosis is delayed until the day after the actual implantation of the graft. The purpose of the two-step procedure is to minimize the factors that might contribute to biliary complications in living donor liver transplantation (LDLT). Three patients who received a graft with two hepatic ducts underwent Roux-en-Y hepatico-jejunostomies during a separate procedure the day after the implantation of the graft. Length of intubation, recovery of enteral alimentation, and hospital stay were similar to the patients who underwent one-step transplant. No biliary or infectious complications occurred. Delaying the hepatico-jejunostomy when two ducts are present and a bilio-digestive anastomosis is planned has no negative impact on the postoperative course of the patients but can ameliorate the conditions under which the anastomoses must be performed