Adeno-associated virus vector-mediated systemic delivery of IFN-beta combined with low-dose cyclophosphamide affects tumor regression in murine neuroblastoma models.

PURPOSE: Type I IFNs (IFN-alpha/beta) have shown significant antitumor activity in preclinical models but limited efficacy and significant toxicity in clinical trials. We hypothesized that the antitumor activity of type I IFNs could be enhanced by chronic, low-dose systemic delivery and sought to test this in murine neuroblastoma models. EXPERIMENTAL DESIGN: Continuous liver-generated expression of human IFN-beta (hINF-beta) was achieved through a gene therapy-mediated approach using adeno-associated virus vectors encoding hIFN-beta (AAV hINF-beta). Orthotopic localized retroperitoneal and disseminated models of neuroblastoma were established using three different xenografts. Immunohistochemical analysis and ELISA were used to evaluate the antiangiogenic effect of therapy. RESULTS: The development of both localized orthotopic (retroperitoneal) and disseminated neuroblastoma was prevented in all mice expressing hINF-beta. Continued growth of established retroperitoneal tumors, treated with AAV hINF-beta as monotherapy, was significantly restricted, and survival for mice with established, disseminated disease was significantly prolonged following administration of AAV hINF-beta. Analysis of treated tumors revealed a significant antiangiogenic effect. Mean intratumoral vessel density was diminished and expression of the angiogenic factors vascular endothelial growth factor and basic fibroblast growth factor were both decreased. Finally, combination therapy in which AAV hIFN-beta was used together with low-dose cyclophosphamide resulted in regression of both established retroperitoneal and disseminated disease. CONCLUSIONS: AAV-mediated delivery of hIFN-beta when used as monotherapy was able to restrict neuroblastoma growth due in part to inhibition of angiogenesis. When used in combination with conventional chemotherapy, AAV hIFN-beta was able to effect complete tumor regression.     

Systemic endotoxin and gastric mucosal pH are the best parameters to predict lethal outcome in a porcine model of abdominal sepsis according to multivariate analysis.

This study was devised to identify sepsis-relevant parameters that early and reliably predict a lethal outcome in intra-abdominal sepsis. In 18 Duroc pigs, peritonitis was induced through standardized gastrotomy. Twelve hours later the defect was oversewn and the abdominal cavity lavaged thoroughly. Sepsis relevant parameters were measured before initiating therapy, and 30 min later animals were extubated and observed for a period of 6 days under adequate analgesia with free access to water and food. All parameters were correlated with survival postoperatively. In the treatment group, 7 out of 18 pigs (39%) died within the observation period. Endotoxin level at 30 min after initiation of therapy [17.9 EU/mL (+/- 12.1) vs. 110.9 EU/mL (+/- 21); p <.001] and Delta pHi [0.015 (+/- 0.011) vs. -0.039 (+/- 0.013); p =.016] were identified as the two parameters with highest predictive power regarding mortality in a multivariate analysis. In conclusion measurement of endotoxin and gastric tonometry should gain wider clinical application in septic patients.     

Urination Frequency and Cystic Pressure Resistance After Fractionated whole or Partial Irradiation of the Rabbit Urinary Bladder

Urination frequency and cystic pressure resistance have been used as end-points to assess x-ray-induced changes of bladder function. Whole or half bladders of adult male rabbits were irradiated, caudally or cranially. The absorbed dose was 33 Gy, 36 Gy or 39 Gy, given in 5 daily fractions. Animals which received a whole bladder dose of 39 Gy or 36 Gy showed increased urination frequency and enhanced bladder pressure resistance during the whole follow-up time of 100 weeks, compared with the sham-irradiated controls. At half bladder irradiation, only the highest doses (39 Gy to the cranial part of the bladder and 39 Gy or 36 Gy to the caudal part) gave rise to a slight increase in frequency at about 20 weeks after exposure.     

Association of human polyomavirus JC with peripheral blood of immunoimpaired and healthy individuals

JC virus (JCV) infection is regularly asymptomatic in healthy individuals. In contrast, in immunocompromised individuals, highly activated virus replication may lead to PML. Peripheral blood cells (PBCs) are found to habor JCV DNA in healthy and diseased individuals and it is discussed that they might be responsible for dissemination of the virus to the central nervous system (CNS) during persistence. To better understand the role of JCV DNA in PBCs for persistent infection and pathogenesis, the authors characterized the extent of JCV infection in Ficoll-gradient purified blood cells (peripheral blood mononuclear cells [PBMCs]) of healthy and human immunodeficiency virus type 1 (HIV-1)-infected individuals. Virus activation in PBMCs from healthy JCV-infected individuals was found at a rate of 0% to 38% at low polymerase chain reaction (PCR) sensitivity. In progressive multifocal leukoencephalopathy (PML) patients, a stronger signal was found, indicating increased virus activation. JCV DNA was regularly detected in T and B lymphocytes and in monocytes at low levels. However, granulocytes were shown to be the predominant reservoir of JCV DNA harboring high copy numbers. Although the overall distribution of viral genomes holds true for the population studied, in the individual, a markedly changed pattern of distribution can be found.