Adeno-associated virus transduction of islets with interleukin-4 results in impaired metabolic function in syngeneic marginal islet mass transplantation

Previous studies suggest that therapeutic expression of interleukin (IL)-4 by islet cells improves their efficacy in transplantation models directed at reversing type 1 diabetes. We investigated the effects of introducing IL-4 into islets with recombinant adeno-associated virus (rAAV) on the reversal of hyperglycemia in a syngeneic marginal islet mass transplantation model. C57BL/6 islets were mock-transduced or transduced with rAAV expressing murine IL-4 (rAAV-IL-4) or rAAV expressing green fluorescent protein (rAAV-GFP) before transplantation of a marginal mass into diabetic mice. Normoglycemia was achieved in only 1/7 mice receiving rAAV-IL-4 transduced islets in comparison to 6/6 mock-transduced and 4/6 rAAV-GFP transduced animals. The failure of IL-4 expressing islets was not associated with cellular toxicity of rAAV or impairment of glucose-stimulated insulin release in vitro. Islet expression of IL-4 led to impaired metabolic function in mice receiving a marginal mass of syngeneic islets.     

Electrocardiogram with prolonged QT interval in Gitelman disease

BACKGROUND: Potassium and magnesium deficiency prolong the QT interval on a standard electrocardiogram and predispose the patient to dangerous cardiac arrhythmias. No information is available on QT interval in patients diagnosed with Gitelman disease. METHODS: The QT interval was assessed on lead II in 27 patients with biochemically and genetically defined Gitelman disease, who had discontinued medical treatment for at least four weeks. They included 15 female and 12 male subjects, aged 6.7 to 40 years old, median 20 years old. The corrected QT interval was calculated from the measured QT interval and heart rate using the Bazett formula. RESULTS: The corrected QT interval was normal (between 391 and 433 msec) in 16 and prolonged in the remaining 11 patients (between 444 and 504 msec). Patients with prolonged and patients with normal QT interval did not significantly differ with respect to female to male ratio, plasma potassium, plasma total magnesium, and plasma ionized calcium. Plasma sodium and chloride values were slightly but significantly lower and bicarbonate levels higher in patients with a prolonged than in those with a normal QT interval. CONCLUSIONS: The corrected QT interval is often pathologically prolonged in patients with Gitelman disease, suggesting that there is an increased risk for development of dangerous arrhythmias. Further investigations are required in patients with a prolonged QT interval to assess the true hazard of dangerous arrhythmias.     

Impact of endoscopic surveillance of Barrett's esophagus on survival of patients with esophageal adenocarcinoma

In an attempt to reduce mortality from oesophageal adenocarcinoma, it has been recommended to enroll patients with Barrett's oesophagus in endoscopic surveillance programs in order to detect malignant degeneration at an early and possibly curable stage. The aim of this study was to assess the impact of endoscopic biopsy surveillance on the outcome of Barrett's adenocarcinoma. From November 1992 to December 2000, 328 patients with histologically proven oesophageal adenocarcinoma were referred to our department. One hundred of these patients had Barrett's adenocarcinoma. In 12 (12%) patients, cancer was discovered during endoscopic surveillance for Barrett's metaplasia. The prevalence of gastro-oesophatgeal reflux disease in the Barrett's group was 38.8% versus 8.1% (P < 0.01) of non-Barrett's patients. In the surveyed group, there were 9 (75%) early stage tumours (Tis-1N0), versus 10 (11.4%, P < 0.01) in the non-surveyed patients. Three out of five surveyed patients operated on for high grade dysplasia proved to have invasive carcinoma in the oesophagectomy specimen. All surveyed patients were alive after a median follow-up period of 50 months; the median survival in the non-surveyed group was 24 +/- 3 months (P < 0.01). Endoscopic surveillance of Barrett's oesophagus allows early detection of malignant degeneration and better long-term survival than in non-surveyed patients.     

Tumor angiogenesis in lymph node-negative rectal cancer: Correlation with clinicopathological parameters and prognosis

BACKGROUND: Intratumoral microvessel density (MVD) could be used as a prognostic factor in colorectal cancer. We retrospectively analyzed the value of microvessel count in predicting the clinical outcome of stage I and II (Dukes A and B) rectal cancer patients. METHODS: Eighty-four patients who had undergone curative resection of lymph node-negative rectal cancer were included. Tumor type and differentiation, the depth of local invasion, venous invasion, the character of the invasive margin, and the degree of lymphocytic infiltration were evaluated for each tumor specimen. Immunohistochemical staining for the CD31 endothelial antigen was performed to highlight the microvessels. RESULTS: The median value of MVD was 45 microvessels. Low MVD (microvessels < or = 45) was observed in 41 patients (48.8%), and high MVD (>45) was found in 43 (51.2%). The presence of conspicuous lymphocytic infiltration was significantly associated with increased vessel density. With uni- and multivariate survival analysis MVD did not show any prognostic significance. The character of the invasive margin was the only parameter with independent prognostic value. CONCLUSIONS: MVD does not seem to provide any additional prognostic information when compared with standard histopathological parameters in lymph node-negative rectal cancer. It is likely that the strong association between MVD and the presence of conspicuous lymphocytic infiltration may interfere with its predictive value.     

Down-regulation of insulin-like growth factor I receptor activity by NVP-AEW541 has an antitumor effect on neuroblastoma cells in vitro and in vivo.

PURPOSE: Signaling through insulin-like growth factor I receptor (IGF-IR) is important for growth and survival of many tumor types. Neuroblastoma is sensitive to IGF. EXPERIMENTAL DESIGN: We assessed the ability of NVP-AEW541, a recently developed small molecule that selectively inhibits IGF-IR activity, for neuroblastoma growth effects in vitro and in vivo. Our data showed that, in a panel of 10 neuroblastoma cell lines positive for IGF-IR expression, NVP-AEW541 inhibited in vitro proliferation in a submicromolar/micromolar (0.4-6.8) range of concentrations. RESULTS: As expected, NVP-AEW541 inhibited IGF-II-mediated stimulation of IGF-IR and Akt. In addition to growth inhibition, the drug also induced apoptosis in vitro. Oral administration of NVP-AEW541 (50 mg/kg twice daily) inhibited tumor growth of neuroblastoma xenografts in nude mice. Analysis of tumors from the drug-treated animals revealed a marked apoptotic pattern and a decrease in microvascularization compared with controls. Interestingly, quantitative real-time PCR detected both in vitro and in vivo a significant down-regulation of mRNA for vascular endothelial growth factor (VEGF) caused by NVP-AEW541. In addition, in Matrigel-coated chambers and in severe combined immunodeficient mice tail vein injected with neuroblastoma cells, tumor invasiveness was significantly reduced by this agent. Analysis of IGF-IR expression in a series of 43 neuroblastoma primary tumors revealed IGF-IR positivity in 86% of cases. CONCLUSIONS: Taken together, these data indicate that NVP-AEW541 can be considered as a novel promising candidate for treatment of neuroblastoma patients.     

Flow cytometric DNA analysis does not predict the radiochemoresponsiveness of esophageal cancer

The relationship between the DNA pattern and the responsiveness to chemotherapy or chemoradiotherapy has been evaluated in 30 patients with squamous cell carcinoma of the esophagus. In 24 patients polychemotherapy with cisplatin (100 mg/m² on day 1) and 5-fluorouracil (1,000 mg/m²/ 24 h, continuous infusion of 120 h) every 3 weeks, was performed. Six other patients received chemoradiotherapy with cisplatin 80 mg/m² on day 1 and 18.5 Gy (split course). Before treatment, at least three endoscopic biopsies were taken from each tumor and frozen at ?85°C. Five patients were excluded from the evaluation, three because of interrupted treatment and two due to unsuitable biopsy material obtained endoscopically. The response rate to the cytoreductive treatment was 40% (10/25). DNA content was analyzed with flow cytometry. Out of 25 evaluable patients, a diploid and aneuploid tumor was present in 8 (32.0%) and 17 (68.0%) patients, respectively. According to the DNA pattern, a major response was observed in 4 of 8 patients with a diploid tumor and in 6 of 17 patients with an aneuploid tumor (P = 0.5). No relationship between the percentage of cells in the S-phase and the response to the cytoreductive treatment was evident. Although a slightly higher percentage of major responses was found in euploid tumors, there is no evidence that flow-cytometric DNA analysis can be helpful in the selection of patients for chemotherapy or chemoradiotherapy.© 1993 Wiley-Liss, Inc.     

Immunosuppression and procedure-related complications in 26 patients with type 1 diabetes mellitus receiving allogeneic islet cell transplantation

BACKGROUND: The success of sirolimus and low-dose tacrolimus in islet cell transplantation has influenced many transplant centers to utilize this novel regimen. The long-term safety and tolerability of this steroid-free immunosuppressive protocol for allogeneic islet transplantation has yet to be determined. METHODS: We transplanted 26 adult patients with long standing type 1 diabetes mellitus between April 2000 and June 2004. Immunosuppression consisted of induction with daclizumab and maintenance therapy with tacrolimus and sirolimus. Adverse events (AEs) in patients were followed and graded using the Common Terminology Criteria for Adverse Events, version 3.0 (National Cancer Institute). RESULTS: To date, the majority of patients were able to remain on the immunosuppression combination for up to 22+/-11 months. Four patients were successfully converted to Mycophenolate Mofetil due to tacrolimus-related toxicity. Withdrawal from immunosuppression was decided in four patients due to hypereosinophilic syndrome, parvovirus infection, aspiration pneumonia, and severe depression, respectively. Six patients required filgrastim therapy for neutropenia. Transient elevation of liver enzymes was observed in most patients early after islet infusion. Increased LDL in 20 patients required medical treatment. CONCLUSION: There was a varying range of AEs, most of them mild and self-limiting; however, some required urgent medical attention. The majority of patients were able to tolerate and remain on this effective regimen. To date, no deaths, cytomegalovirus disease, graft-versus-host disease, or posttransplant lymphoproliferative disease has been observed.     

Prolonged allogeneic islet graft survival by protoporphyrins

Transplantation of islets of Langerhans in patients with type 1 diabetes allows for improved metabolic control and insulin independence. The need for chronic immunosuppression limits this procedure to selected patients with brittle diabetes. Definition of therapeutic strategies allowing permanent engraftment without the need for chronic immunosuppression could overcome such limitations. We tested the effect of the use of protoporphyrins (CoPP and FePP), powerful inducers of the cytoprotective protein heme-oxygenase 1 (HO-1), on allogeneic islet graft survival. Chemically induced diabetic C57BL/6 mice received DBA/2 islets. Treatment consisted in peritransplant administration of CoPP or saline. Islets were either cultured in the presence of FePP or vehicle before implant. Short-course administration of CoPP led to long-term islet allograft survival in a sizable proportion of recipients. Long-term graft-bearing animals rejected third-party islets while accepting a second set donor-specific graft permanently, without additional treatment. Preconditioning of islets with FePP by itself led to improved graft survival in untreated recipients, and provided additional advantage in CoPP-treated recipients, resulting in an increased proportion of long-term surviving grafts. Preconditioning of the graft with protoporphyrins prior to implant resulted in reduction of class II expression. Administration of protoporphyrins to the recipients of allogeneic islets also resulted in transient powerful immunosuppression with reduced lymphocyte proliferative responses, increased proportion of regulatory cells (CD4+CD25+), decreased mononuclear cell infiltrating the graft, paralleled by a systemic upregulation of HO-1 expression. All these mechanisms may have contributed to the induction of donor-specific hyporesponsiveness in a proportion of the protoporphyrin-treated animals.     

Attentional load of the primary task influences the frontal but not the temporal generators of mismatch negativity

According to the model hypothesized by N??t?nen and Michie, the generation of the mismatch negativity (MMN) requires a mismatch detection, taking place in temporal areas, followed by the activation of frontal generators, underlying attention switching toward the deviant stimulus. We aimed at verifying whether the activation of temporal and frontal regions is dependent on the amount of attentional resources allocable toward the deviant stimulus. We recorded event-related potentials (ERPs) in nine healthy subjects while reading and during a demanding visual task (Multiple Features Target Cancellation, MFTC). Raw data were further evaluated by Brain Electrical Source Analysis (BESA). During the Reading condition, distraction toward the unattended auditory stimuli was reflected by the enhancement of the N1 response to frequent stimuli and by the elicitation of a P3a response to deviant ones. The MMN distribution was explained by bilateral temporal dipoles. During the MFTC condition, no P3a was detected, while source analysis showed the activation of a right frontal generator. Temporal dipoles showed no change between the two conditions: we thus conclude that the earlier mismatch detection is independent on the attentional load. By contrast, the activation of a right frontal subcomponent occurred only during the high-load task, independently on any actual attention shift reflected by the P3a component. We thus discuss the hypothesis whether the right frontal MMN generator, rather than subserving a simple attention switching toward the deviant stimulus, plays a role in modulating the auditory change detection system ("contrast enhancement" model).