NCIC-CTG phase II study of gemcitabine in patients with malignant glioma (IND.94).

Purpose:We conducted a phase II multicentre study of gemcitabinein patients with anaplastic astrocytoma and glioblastoma multiforme at firstrelapse. Patients and methods:Patients with anaplastic astrocytoma orglioblastoma multiforme receiving a stable dose of steroids and ECOGperformance status 3 were eligible for this study at the time of firstrelapse. One adjuvant chemotherapy regimen was permissible. Patients receivedgemcitabine 1000 mg/m² i.v. weekly × 3, repeated on afour-weekly cycle. Results:Of 20 patients enrolled, 15 were evaluable for response,19 for non-hematological toxicity and 18 for hematological toxicity. Sevenpatients had anaplastic astrocytoma (AA) and twelve glioblastoma multiforme(GBM). Age ranged from 28–71 years (median 50). Fifteen patientsdiscontinued therapy due to disease progression. The median number of cyclesadministered was 1 (range 1–11); only two patients received more thanthree cycles. Hematologic toxicity was acceptable and no grade 4 toxicity wasseen. One patient developed Pneumocystispneumonia and eventualpulmonary embolism; one died of gastric hemorrhage related to steroid therapy.No objective responses were seen. Nine patients had stable disease (medianduration 2.7 months, range 0.9–11.2). Conclusions:Gemcitabine given in this dose and schedule seemswell tolerated but is not active in patients with recurrent high-gradegliomas.     

Hyperglycemia and reactive oxygen species mediate apoptosis in aortic endothelial cells through Janus kinase 2

The generation of reactive oxygen species (ROS) has been implicated in the perturbation of endothelial function and cell death. However, the specific signaling pathways which mediate and modifying this response have not been fully elucidated. Therefore, in this study we tested the hypothesis that activation of JAK2 is involved in the aortic endothelial cell (EC) response to ROS. When ECs were exposed to HG (25 mM) for 6 h or ROS (i.e., H(2)O(2) (100 microM)) for 1 h and returned to normal medium we found a decrease in cell density and morphologic signs of apoptosis. Furthermore, incubation of ECs with HG and H(2)O(2) also resulted in the tyrosine phosphorylation of JAK2. In addition, pretreatment of ECs with AG-490, an inhibitor of JAK2, prevented nuclear fragmentation, whereas inhibitors of Jun kinase (SP 600125), MAP kinase (PD 98059), Src kinase (PP2) or PI-3 kinase (wortmannin) were without effect. Finally, immunoblot analysis of caspase-3 and PARP cleavage confirmed a role for activation of JAK2 in both HG- or ROS-induced apoptosis, based on inhibition by either AG-490 or adenoviral transfection with a dominant-negative JAK2 mutant. In conclusion the activation of JAK2 plays a pivotal role in oxidant stress-induced commitment of ECs to apoptosis, based on studies with HG and H(2)O(2).     

Interferon production by bovine tracheal organ cultures infected with bovid herpesvirus 1 strains

Studies have been made of antiviral inhibitors produced by bovine tracheal organ cultures inoculated with strains of bovid herpesvirus 1. The inhibitors, which had properties of interferon, were assayed by a plaque-reduction method in bovine turbinate cell cultures with vesicular stomatitis virus as challenge virus. Each of the four strains of bovid herpesvirus 1 studied induced interferon in bovine tracheal organ cultures.