Intraperitoneal Invasion of Retroperitoneal Sarcomas: A Risk Factor for Dismal Prognosis

Annals of Surgical Oncology - Retroperitoneal sarcomas (RPS) lie in the retroperitoneal space and are covered by a peritoneal layer. However, some RPS have an intraperitoneal component (IPC), which...     

Microcin E492, a channel-forming bacteriocin from Klebsiella pneumoniae, induces apoptosis in some human cell lines

The cytotoxic effect of microcin E492, a low-molecular-mass channel-forming bacteriocin (7,887 Da) produced by a strain of Klebsiella pneumoniae, was characterized in HeLa cells. At low (5 microg/ml) and intermediate (10 microg/ml) concentrations, microcin E492 induced biochemical and morphological changes typical of apoptosis, such as cell shrinkage, DNA fragmentation, extracellular exposure of phosphatidylserine, caspase activation, and loss of mitochondrial membrane potential. Treatment with zVAD-fmk, a general caspase inhibitor, completely blocked the cytotoxic effect of this bacteriocin. At higher microcin concentrations (>20 microg/ml) a necrotic phenotype was observed. Induction of apoptosis by microcin E492 was associated with the release of calcium from intracellular stores, probably after microcin-triggered ion channel formation. Microcin E492 also presented a cytotoxic effect on Jurkat and RJ2.25 cells, but had no effect on KG-1 cells nor on a primary culture of human tonsil endothelial cells, suggesting that there is a specific interaction of the bacteriocin with components of the target cell surface. This report describes a bacteriocin that has the capacity to induce apoptosis in human cell lines.     

Small-molecule synergist of the Wnt/beta-catenin signaling pathway

The Wnt/beta-catenin signaling pathway regulates cell fate and behavior during embryogenesis, adult tissue homeostasis, and regeneration. When inappropriately activated, the pathway has been linked to colorectal cancer and melanoma, and when attenuated it may contribute to Alzheimer's disease and osteoporosis. Small molecules that modulate Wnt signaling will likely provide new insights into the regulation of this key developmental pathway and ultimately provide pharmacological agents to control Wnt signaling in vivo. To this end, we screened a library of 100,000 small molecules for activity in a cell-based assay of Wnt/beta-catenin signaling and discovered a purine derivative, QS11, that synergizes with Wnt-3a ligand in the activation of Wnt/beta-catenin signal transduction. Through affinity chromatography and subsequent functional assays, we showed that QS11 binds and inhibits the GTPase activating protein of ADP-ribosylation factor 1 (ARFGAP1), suggesting that QS11 modulates Wnt/beta-catenin signaling through an effect on protein trafficking. Consistent with its function as an ARFGAP inhibitor, QS11 inhibits migration of ARFGAP overexpressing breast cancer cells.     

Methylenetetrahydrofolate reductase C677T polymorphism and liver fibrosis progression in patients with recurrent hepatitis C

Background/Aims: Methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism, being a putative steatogenic factor, may promote liver fibrosis progression in patients with chronic hepatitis C. This study aimed to verify the role of recipient MTHFR polymorphism in favouring graft fibrosis progression in patients with recurrent HCV after orthotopic liver transplantation (OLT). Methods: We studied 63 such patients, followed for >1 year. MTHFR allelic variants were determined by a polymerase chain reaction/restriction fragment length polymorphism method. Results: Recipients carrying the TT genotype had more frequently, 1‐year post‐OLT, homocysteine serum levels >23 μmol/L (P<0.05), serum triglycerides >180 mg/dL (P<0.02) and de novo diabetes mellitus (P<0.05) but not a higher frequency of graft steatosis. Time‐to‐event analysis in reaching an Ishak staging score >2 was performed by stratifying the recipients as follows: (a) patients with donor age ≤45 years, (b) patients with donor age >45 and C/^* genotype, and (c) patients with donor age >45 years and TT genotype. A significant linear trend was observed, with increasing frequencies as follows: (a) 8/37, (b) 10/19 and (c) 6/7 (P=0.0005). Conclusion: The MTHFR C677T polymorphism may play a role in influencing liver fibrosis progression in patients with recurrent hepatitis C, in conjunction with donor age, but not via steatosis promotion.     

Post-liver transplantation medical complications

Liver transplantation (LT) is widely accepted as an effective therapeutic modality for a variety of irreversible acute and chronic liver disease. The success of liver transplantation has increased steadily over the last two decades and several advances have been made since the first human liver transplant. This procedure has become routine with an excellent outcome in terms of both quality and length of survival. The results of liver transplantation have improved due to advances in perioperative technique, a better understanding of the course and prognosis of several liver disease, improved immunosuppressive therapy and more effective postoperative care. Nevertheless, improved tools detecting under immunosuppression, new strategies against viral infections(i.e. cytomegalovirus), and new immunosuppressive drugs will probably even prevent further graft dysfunction in the future. However, complications are common in the early and long term period and contribute to significant morbidity and mortality. One of the major challenges facing the transplant community is the increasing metabolic complications that are now affecting quality of life and long-term survival. Thus, knowledge of complications that emerge during follow up period, early and accurate establishment of diagnosis, and prompt institution of appropriate interventions are essential for optimal patient and graft outcome. This review summarizes available data about medical complications of the early and long term follow up.     

Efficacy of two telemonitoring systems to improve glycaemic control during basal insulin initiation in patients with type 2 diabetes: The TeleDiab-2 randomized controlled trial

TeleDiab-2 was a 13-month randomized controlled trial evaluating the efficacy and safety of two telemonitoring systems to optimize basal insulin (BI) initiation in subjects with inadequately controlled type 2 diabetes (HbA1c, 7.5%-10%). A total of 191 participants (mean age 58.7 years, mean HbA1c 8.9%) were randomized into three groups: group 1(G1, standard care, n = 63), group 2 (G2, interactive voice response system, n = 64) and group 3 (G3, Diabeo-BI app software, n = 64). The two telemonitoring systems proposed daily adjustments of BI doses, in order to facilitate the achievement of fasting blood glucose (FBG) values targeted at ~100 mg/dL. At 4 months follow-up, HbA1c reduction was significantly higher in the telemonitoring groups (G2: −1.44% and G3: −1.48% vs. G1: −0.92%; P < 0.002). Moreover, target FBG was reached by twice as many patients in the telemonitoring groups as in the control group, and insulin doses were also titrated to higher levels. No severe hypoglycaemia was observed in the telemonitoring groups and mild hypoglycaemia frequency was similar in all groups. In conclusion, both telemonitoring systems improved glycaemic control to a similar extent, without increasing hypoglycaemic episodes.     

Prediction of incident hypertension and arterial stiffness using the non–insulin‐based metabolic score for insulin resistance (METS‐IR) index

Hypertension is associated with insulin resistance (IR), metabolic syndrome (MS), and arterial stiffness. Non–insulin‐based IR indexes were developed as tools for metabolic screening. Here, we aimed to evaluate the novel non–insulin‐based Metabolic Score for IR (METS‐IR) index for the prediction of incident hypertension and arterial stiffness evaluated using pulse wave velocity (PWV) analysis, compared with other non–insulin‐based IR indexes. We evaluated two populations, a cross‐sectional evaluation of high‐risk individuals (n = 305) with a wide range of metabolic comorbidities and dyslipidemia in whom PWV measurement was performed and a 3‐year prospective cohort of normotensive individuals (N = 6850). We observed a positive correlation between METS‐IR and PWV in the cross‐sectional cohort, which was higher compared with other non–insulin‐based fasting IR indexes; furthermore, PWV values >75th percentile were associated with the upper tercile of METS‐IR values. In the prospective cohort, we observed an increased risk for incident hypertension for the upper METS‐IR tercile (METS‐IR ≥ 46.42; HR: 1.81, 95% CI: 1.41‐2.34), adjusted for known cardiovascular risk factors, and observed that METS‐IR had greater increases in the predictive capacity for hypertension along with SBP and the Framingham Hypertension Risk Prediction Model compared with other non–insulin‐based IR indexes. Therefore, METS‐IR is a novel non–insulin‐based IR index which correlates with arterial stiffness and is a predictor of incident hypertension, complementary to previously validated risk prediction models.     

Impact of diet on the induction of infection with Giardia lamblia cysts in Sprague-Dawley rats

OBJECTIVE: To assess the effect of malnutrition on the development of giardiasis in Sprague-Dawley rats, using different inoculum sizes of Giardia lamblia cysts. MATERIAL AND METHODS: An experimental study was conducted between 1995 and 1999 at Centro de Investigación, Alimentación y Desarrollo (Center for Research, Food, and Development), in Hermosillo, Sonora, Mexico. The study population consisted of two groups of six to eight experimental units that were fed two different diets and inoculated five different concentrations of Giardia lamblia cysts. Data were collected on excretion of cysts, weight gain, food intake, bowel contents, and macro and microscopic lesions in the intestinal mucosa. Statistical analysis consisted of analysis of variance and residuals. RESULTS: Animals fed with a diet meeting nutritional requirements required an infecting inoculum of 60 cysts, while malnourished rats required only six cysts to develop mucosal lesions. CONCLUSIONS: Weight gain monitored during ten days was not a good indicator of Giardia lamblia infection. Infection depended on cyst inoculum size as well as on the nutritional status of the tested animals. The English version of this paper is available at: http://www.insp.mx/salud/index.html.     

MTHFR C677T Polymorphism and Risk of HCC in Patients With Liver Cirrhosis: Role of Male Gender and Alcohol Consumption

Background:  A single nucleotide polymorphism (SNP) C677T in the methylenetetrahydrofolate reductase (MTHFR) gene has been identified. The TT or CT genotypes show a marked reduction of the enzyme activity; this causes higher homocysteine levels and alterations of folate metabolism. Folate metabolism is essential for DNA synthesis and methylation, crucial steps in carcinogenesis. In this paper, we investigated whether the MTHFR C677T SNP could influence the occurrence of hepatocellular carcinoma (HCC) in a cohort of patients transplanted for end stage liver disease of different etiologies.
Methods:  Two hundred and twelve consecutive patients who underwent liver transplantation for end stage liver disease due to hepatitis B or C, alcoholic liver disease, and other causes were studied. Two hundred and thirty-six blood donors served as controls. Focal hepatic lesions were searched in the sectioned explanted livers. The presence of the MTHFR C677T SNP was determined via polymerase chain reaction amplification.
Results:  Among the 65 patients with HCC, 22 had the CC genotype, 30 the CT, and 13 the TT genotype. Only in patients with alcoholic liver disease was a significant association detected between the TT genotype and the presence of liver cancer (6/17 vs. 5/46, p  < 0.05). At stepwise logistic regression analysis the independent selected predictors of HCC were found: age at transplantation >55 years ( p  < 0.001) and the association among male gender, alcoholic liver disease, and MTHFR TT genotype ( p  = 0.002).
Conclusions:  The present study suggests that male TT carriers with alcoholic cirrhosis bear an increased risk of developing HCC.     

A new member of the tumor necrosis factor/nerve growth factor receptor family inhibits T cell receptor-induced apoptosis

By comparing untreated and dexamethasone-treated murine T cell hybridoma (3DO) cells by the differential display technique, we have cloned a new gene, GITR (glucocorticoid-induced tumor necrosis factor receptor family-related gene) encoding a new member of the tumor necrosis factor/nerve growth factor receptor family. GITR is a 228-amino acids type I transmembrane protein characterized by three cysteine pseudorepeats in the extracellular domain and similar to CD27 and 4-1BB in the intracellular domain. GITR resulted to be expressed in normal T lymphocytes from thymus, spleen, and lymph nodes, although no expression was detected in other nonlymphoid tissues, including brain, kidney, and liver. Furthermore, GITR expression was induced in T lymphocytes upon activation by anti-CD3 mAb, Con A, or phorbol 12-myristate 13-acetate plus Ca-ionophore treatment. The constitutive expression of a transfected GITR gene induced resistance to anti-CD3 mAb-induced apoptosis, whereas antisense GITR mRNA expression lead to increased sensitivity. The protection toward T cell receptor-induced apoptosis was specific, because other apoptotic signals (Fas triggering, dexamethasone treatment, or UV irradiation) were not modulated by GITR transfection. Thus, GITR is a new member of tumor necrosis factor/nerve growth factor receptor family involved in the regulation of T cell receptor-mediated cell death.