Vascular endothelial growth factor stimulates endothelial colony forming cells proliferation and tubulogenesis by inducing oscillations in intracellular Ca2+ concentration

Endothelial progenitor cells (EPCs) home from the bone marrow to the site of tissue regeneration and sustain neovascularization after acute vascular injury and upon the angiogenic switch in solid tumors. Therefore, they represent a suitable tool for cell-based therapy (CBT) in regenerative medicine and provide a novel promising target in the fight against cancer. Intracellular Ca(2+) signals regulate numerous endothelial functions, such as proliferation and tubulogenesis. The growth of endothelial colony forming cells (ECFCs), which are EPCs capable of acquiring a mature endothelial phenotype, is governed by store-dependent Ca(2+) entry (SOCE). This study aimed at investigating the nature and the role of VEGF-elicited Ca(2+) signals in ECFCs. VEGF induced asynchronous Ca(2+) oscillations, whose latency, amplitude, and frequency were correlated to the growth factor dose. Removal of external Ca(2+) (0Ca(2+)) and SOCE inhibition with N-(4-[3,5-bis(trifluoromethyl)-1H-pyrazol-1-yl]phenyl)-4-methyl-1,2,3-thiadiazole-5-carboxamide (BTP-2) reduced the duration of the oscillatory signal. Blockade of phospholipase C-γ with U73122, emptying the inositol-1,4,5-trisphosphate (InsP(3))-sensitive Ca(2+) pools with cyclopiazonic acid (CPA), and inhibition of InsP(3) receptors with 2-APB prevented the Ca(2+) response to VEGF. VEGF-induced ECFC proliferation and tubulogenesis were inhibited by the Ca(2+)-chelant, BAPTA, and BTP-2. NF-κB activation by VEGF was impaired by BAPTA, BTP-2, and its selective blocker, thymoquinone. Thymoquinone, in turn, suppressed VEGF-dependent ECFC proliferation and tubulogenesis. These data indicate that VEGF-induced Ca(2+) oscillations require the interplay between InsP(3)-dependent Ca(2+) release and SOCE, and promote ECFC growth and tubulogenesis by engaging NF-κB. This novel signaling pathway might be exploited to enhance the outcome of CBT and chemotherapy.     

Heart transplantation with donor-specific antibodies directed toward denatured HLA-A*02:01: a case report

The development of solid-phase assays for antibody detection has aided in the frequent detection of human leukocyte antigen (HLA) antibodies in nonalloimmunized males. Some scientists have reported that these HLA antibodies are produced to pathogens or allergens and the reactivity with HLA coated beads is the result of cross-reactive epitopes. These antibodies may also be directed toward cryptic epitopes exposed on the denatured beads. In this report, we describe the case of a heart transplanted patient who exhibited anti-HLA-A*02:01 donor-specific antibodies detected with a bead-based assay (Luminex) and undetected with the complement-dependent cytotoxicity (CDC) test. Posttransplant monitoring, carried out with CDC and with Luminex on sera from this patient collected at the 2nd, 4th, 8th, and 12th posttransplant weeks and at 1 year confirmed the presence of anti-HLA-A*02:01 in all serum samples. Additional tests carried out with denatured and intact HLA molecules using single antigen beads demonstrated that the antibody was directed toward a cryptic epitope. One year after transplantation the patient is doing well. No sign of antibody-mediated rejection was observed throughout the follow-up. A comprehensive evaluation of the anamnesis and of antibodies is critical to avoid needless exclusion of organ donors.     

Evidence of Renal Infection in Fatal Cases of 2009 Pandemic Influenza A (H1N1)

The 2009 pandemic influenza A (H1N1) caused significant morbidity and mortality. Acute lung injury is the hallmark of the disease, but multiple organ system dysfunction can develop and lead to death. Therefore, we sought to investigate whether there was postmortem evidence of H1N1 presence and virus-induced organ injury in autopsy specimens. Five cases in which patients died of influenza A (H1N1) virus infection were studied. The lungs of all patients showed macroscopic and microscopic findings already described for H1N1 (consolidation, edema, hemorrhage, alveolar damage, hyaline membrane, and inflammation), and H1N1 viruses were present in alveolar cells in immunochemical studies. Acute tubular necrosis was present in all cases, but there was no evidence of direct virus-induced kidney injury. Nevertheless, H1N1 viruses were found in the cytoplasm of glomerular macrophages in the kidneys of 4 patients. Therefore, our data provide strong evidence that H1N1 presence is not restricted to the lungs.     

Antimutagenicity mechanisms of the Rhoeo discolor ethanolic extract

Introduction

Rhoeo discolor, a medical plant from Mexico, is known to be an antioxidant and chemoprotective antimutagen. Rhoeo discolor ethanolic extract (EERD) is a complex mixture, so in this study its antimutagenic mechanisms were further evaluated.

Material and methods

Employing Ames test, with uvrB− and uvrB+ strains, its antimutagenic activity against frameshift mutagens 2-amino-anthracene (AA), and 2 amino-fluorene (AF), alkylating: methyl-N′-nitro-N-nitrosoguanidine (MNNG) and ethyl-N′-nitro-N-nitrosoguanidine (ENNG) and mitomycin C were evaluated. Induction of ogt, alkyl-DNA-glycosylases were studied with Salmonella typhimurium strains deficient in ada and ogt genes (YG7100 ada−/ogt+ YG7104 ada+/ogt−, G7108 ada−/ogt−).

Results

EERD, was not antimutagenic against AA or AF on S. typhimurium TA98 neither in UTH8413 uvrB+ strains. It significantly reduced mutations induced by Mitomycin C on strain TA102. EERD was antimutagenic to mutations induced by alkylating compounds on S. typhimurium TA100 or UTH8414 uvrB+. This antimutagenic effect was not observed on strains lacking ogt gene.

Conclusions

EERD, did not affect CYP450 in vitro microsomal activation of AF or AA, on the Ames test, neither improved DNA uvrB excision repair system. EERD reduced oxidative damages on strain TA102, caused by Mitomycin C. This plant extract might be used to avoid DNA damage by alkylation, corrected mainly alkylguanine transferase protein encoded by ogt gene.     

Evaluation of the immunomodulatory and antiviral effects of the cytokine combination IFN-α and IL-7 in the lymphocytic choriomeningitis virus and Friend retrovirus mouse infection models

Existing therapies for chronic viral infections are still suboptimal or have considerable side effects, so new therapeutic strategies need to be developed. One option is to boost the host's immune response with cytokines. We have recently shown in an acute ex vivo HIV infection model that co-administration of interferon (IFN)-α and interleukin (IL)-7 allows us to combine the potent anti-HIV activity of IFN-α with the beneficial effects of IL-7 on T-cell survival and function. Here we evaluated the effect of combining IFN-α and IL-7 on viral replication in vivo in the chronic lymphocytic choriomeningitis virus (LCMV) and acute Friend retrovirus (FV) infection models. In the chronic LCMV model, cytokine treatment was started during the early replication phase (i.e., on day 7 post-infection [pi]). Under the experimental conditions used, exogenous IFN-α inhibited FV replication, but had no effect on viral replication in the LCMV model. There was no therapeutic benefit of IL-7 either alone or in combination with IFN-α in either of the two infection models. In the LCMV model, dose-dependent effects of the cytokine combination on T-cell phenotype/function were observed. It is possible that these effects would translate into antiviral activity in re-challenged mice. It is also possible that another type of IFN-α/β or induction of endogenous IFN-α/β alone or in combination with IL-7 would have antiviral activity in the LCMV model. Furthermore, we cannot exclude that some effect on viral titers would have been seen at later time points not investigated here (i.e., beyond day 34 pi). Finally, IFN-α/IL-7 may inhibit the replication of other viruses. Thus it might be worth testing these cytokines in other in vivo models of chronic viral infections.     

Management of Peritoneal Dialysis within a Home Care Program for Hematological Malignancies: Concerns and Perspectives Illustrated by a Case Report

The case of an 86-year-old man suffering from acute myeloid leukemia and end-stage renal disease, managed at home, with continuous peritoneal dialysis regimen, is described.     

NEPHROBLASTOMA. DNA CHARACTERISTICS AND THEIR MODIFICATIONS INDUCED BY PRENEPHRECTOMY CHEMOTHERAPY: A CYTOFLUORIMETRIC STUDY

Treatment of nephroblastoma (Wilms' tumor) has presently achieved a 90% survival rate. Stage and grade are considered the most reliable prognostic parameters, but other biological factors are under study in order to improve patient stratification. Deoxyribonucleic acid (DNA) ploidy has been suggested to be useful in this setting. We retrospectively studied 79 patients with nephroblastoma (58 pretreated with chemotherapy and 21 not pretreated) by means of flow cytometry. DNA content and synthetic phase values were correlated with pathologic features and outcome. DNA modifications induced by chemotherapy were investigated. Sixty-nine tumors were diploid and 10 aneuploid. DNA content did not correlate with clinical course and was not modified by pretreatment. Aneuploid tumors were restricted to lower stages. Mean S-phase rate was lower and did not vary according to histology in pretreated tumors, while it was higher and increased with grade (p = 0.007) in previously untreated tumors. The fraction of cells in synthetic activity was related to outcome: Patients whose tumors displayed higher S-phase rates had a more favorable clinical course. Ploidy did not appear to be of prognostic significance. S-phase rate decreased after chemotherapy (p = 0.0002) and was related to survival. The worse outcome of pretreated patients might be attributed to a minor sensitivity to postoperative treatment: Preoperative chemotherapy would decrease the cell proliferation and might select resistant cellular clones of (possible) neoplastic residues.     

R0 resection in the treatment of gastric cancer: Room for improvement

Gastric carcinoma is one of the most frequent malignancies in the world and its clinical behavior especially depends on the metastatic potential of the tumor.In particular,lymphatic metastasis is one of the main predictors of tumor recurrence and survival,and current pathological staging systems reflect the concept that lymphatic spread is the most relevant prognostic factor in patients undergoing curative resection.This is compounded by the observation that two-thirds of gastric cancer in the Western world...     

Cardiac mass and function, carotid artery intima-media thickness and lipoprotein (a) levels in children and adolescents with type 1 diabetes mellitus of short duration

OBJECTIVE: To evaluate cardiac mass and function, carotid intima-media thickness, and serum lipid and lipoprotein (a) (Lpa) levels in children and adolescents with type 1 diabetes mellitus (DM) of short duration. BACKGROUND: Diabetes mellitus has been found to be an important risk factor for macrovascular disease in adults. Increased serum lipids and Lpa levels have been reported in adolescents with type 1 DM; atherosclerotic vascular lesions involving a combination of fatty degeneration and vessel stiffening of the arterial wall and myocardial involvement impairing diastolic function may be present in adolescents and young adults with type 1 DM. DESIGN/METHODS: Twenty children and adolescents (10 males, 10 females) diagnosed with type 1 DM before 3.4 +/- 3.3 years with a mean age of 11.9 +/- 3.6 years were studied; their HbA1c levels were 8.0 +/- 1.9%. Twenty healthy non-diabetic controls, 10 males and 10 females, aged 12.1 +/- 3.4 years, matched for height and weight, participated in the study. Fasting blood samples were obtained for lipid and Lpa analysis. Patients underwent transthoracic M-mode and two-dimensional echocardiographic evaluation for measurement of left atrial and ventricular dimensions and left ventricular (LV) wall thickness and mass. Stroke volume and cardiac output were measured using pulsed Doppler echocardiography; carotid intima-media thickness was measured using high-resolution mode B ultrasound. RESULTS: Interventricular septal thickness (7.1 +/- 1.8 vs 7.0 +/- 1.5 mm), LV posterior wall thickness (7.1 +/- 1.4 vs 7.5 +/- 2.0 mm) and LV mass after correction for body surface area (70.6 +/- 27.4 vs 70.7 +/- 18.0 g/m2) were similar in patients and controls. Similarly, the LV ejection fraction at rest was similar in patients and controls (69.9 +/- 2.3 vs 70.0 +/- 0.6%), as were pulmonary venous flow velocities (0.56 +/- 0.09 vs 0.55 +/- 0.10 m/s for diastolic peak velocity, 0.54 +/- 0.08 vs 0.50 +/- 0.09 m/s for systolic peak velocity and 0.17 +/- 0.07 vs 0.19 +/- 0.05 m/s for atrial reversal filling). Carotid intima-media thickness (0.60 +/- 0.02 and 0.59 +/- 0.02 mm for the right and left carotid artery) was similar to that of controls (0.60 +/- 0.03 and 0.61 +/- 0.02 mm for the right and left carotid artery). Low density lipoprotein cholesterol and Lpa levels were increased in patients compared to controls (113.2 +/- 26.0 mg/dl and 20.1 +/- 11.7 mg/dl in patients vs 90.4 +/- 14.3 mg/dl and 9.8 +/- 2.9 mg/dl in controls; p <0.01), while total cholesterol, HDL cholesterol and serum triglyceride concentrations were similar to those in controls. CONCLUSIONS: Although children and adolescents with type 1 DM seem not to show alterations in cardiac mass and function or early atherosclerotic changes in the first few years after diagnosis, their cardiovascular risk is increased as they present with dyslipidemia at an early stage of the disease.