Treatment of embolic stroke in rats with bortezomib and recombinant human tissue plasminogen activator

Stroke elicits a progressive vascular dysfunction, which contributes to the evolution of brain injury. Thrombolysis with tissue plasminogen activator (tPA) promotes adverse vascular events that limit the therapeutic window of stroke to three hours. Proteasome inhibitors reduce vascular thrombotic and inflammatory events, and consequently protect vascular function. The present study evaluated the neuroprotective effect of bortezomib,a potent and selective inhibitor of the proteasome, alone and in combination with delayed thrombolytic therapy on a rat model of embolic focal cerebral ischemia. Treatment with bortezomib reduces adverse cerebrovascular events including secondary thrombosis,inflammatory responses,and blood brain barrier (BBB) disruption, and hence reduces infarct volume and neurological functional deficit when administrated within 4 h after stroke onset. Combination of bortezomib and tPA extends the thrombolytic window for stroke to6 h, which is associated with the improvement of vascular patency and integrity. Real time RT-PCR of endothelial cells isolated by laser-capture microdissection from brain tissue and Western blot analysis showed that bortezomib upregulates endothelial nitric oxide synthase (eNOS) expression and blocks NF-κB activation. These results demonstrate that bortezomib promotes eNOS dependent vascular protection, and reduces NF-κB dependent vascular disruption, all of which may contribute to neuroprotection after stroke.

A phase II evaluation of bortezomib in the treatment of recurrent platinum-sensitive ovarian or primary peritoneal cancer: a Gynecologic Oncology Group study

OBJECTIVE

To determine the activity and pharmacodynamics (PD) of bortezomib in platinum-sensitive epithelial ovarian or primary peritoneal cancer (EOC/PPC).

PATIENTS AND METHODS

Eligible women with recurrent EOC/PPC progressing between 6 and 12 months after initial chemotherapy were treated with bortezomib on days 1, 4, 8, and 11 [1.5 (cohort I) and 1.3 (cohort II) mg/m(2)/dose]. Patients must have had initial chemotherapy only. Response Evaluation Criteria in Solid Tumors (RECIST) was assessed by computed tomography (CT) scan every 2 cycles. 20S proteasome activity was quantified in three pre-treatment and a 1-hour post-treatment (cycle one, day 1) whole blood lysates.

RESULTS

Initially, 26 evaluable patients were treated at the 1.5 mg/m(2)/dose level. Objective response rate was 3.8% (1/26), a partial response. An additional 10 patients (38.5%) had stable disease. Given concerns that treatment discontinuations due to toxicity limited drug exposure/activity a second cohort of 29 evaluable patients was accrued at 1.3 mg/m(2)/dose. The 1.3 mg/m(2)/dose regimen is currently approved as an indication for multiple myeloma and mantle cell lymphoma. Treatment was more tolerable, although objective responses remained low at 6.9% (2/29, partial responses). Second stage accrual was not warranted at either dose. Bortezomib effectively inhibited 20S proteasome activity in whole blood lysates between 37 and 92% in 24/25 (96%) patients in cohort I, and 14-84% in 27/28 (96%) patients in cohort II who provided satisfactory pre- and post-treatment specimens for testing.

CONCLUSION

Bortezomib has minimal activity as a single-agent in the treatment of recurrent platinum-sensitive EOC/PPC. Treatment with bortezomib at 1.5 mg/m(2)/dose was not feasible in this patient population due to excess toxicity. Bortezomib was well tolerated at 1.3 mg/m(2)/dose.

A consensus rating method for small virus-retentive filters. I. Method development

Virus filters are membrane-based devices that remove large viruses (e.g., retroviruses) and/or small viruses (e.g., parvoviruses) from products by a size exclusion mechanism. In 2002, the Parenteral Drug Association (PDA) organized the PDA Virus Filter Task Force to develop a common nomenclature and a standardized test method for classifying and identifying viral-retentive filters. One goal of the task force was to develop a test method for small virus-retentive filters. Because small virus-retentive filters present unique technical challenges, the test method development process was guided by laboratory studies to determine critical variables such as choice of bacteriophage challenge, choice of model protein, filtration operating parameters, target log10 reduction value, and filtration endpoint definition. Based on filtration, DLS, electrospray differential mobility analysis, and polymerase chain reaction studies, a final rating based on retention of bacteriophage PP7 was chosen by the PDA Virus Filter Task Force. The detailed final consensus filter method was published in the 2008 update of PDA Technical Report 41. Virus Filtration.

Treatment of embolic stroke in rats with bortezomib and recombinant human tissue plasminogen activator

Stroke elicits a progressive vascular dysfunction, which contributes to the evolution of brain injury. Thrombolysis with tissue plasminogen activator (tPA) promotes adverse vascular events that limit the therapeutic window of stroke to three hours. Proteasome inhibitors reduce vascular thrombotic and inflammatory events, and consequently protect vascular function. The present study evaluated the neuroprotective effect of bortezomib, a potent and selective inhibitor of the proteasome, alone and in combination with delayed thrombolytic therapy on a rat model of embolic focal cerebral ischemia. Treatment with bortezomib reduces adverse cerebrovascular events including secondary thrombosis, inflammatory responses, and blood brain barrier (BBB) disruption, and hence reduces infarct volume and neurological functional deficit when administrated within 4 h after stroke onset. Combination of bortezomib and tPA extends the thrombolytic window for stroke to 6 h, which is associated with the improvement of vascular patency and integrity. Real time RT-PCR of endothelial cells isolated by laser-capture microdissection from brain tissue and Western blot analysis showed that bortezomib upregulates endothelial nitric oxide synthase (eNOS) expression and blocks NF-kappaB activation. These results demonstrate that bortezomib promotes eNOS dependent vascular protection, and reduces NF-kappaB dependent vascular disruption, all of which may contribute to neuroprotection after stroke.

Inhibition of acute graft-versus-host disease with retention of graft-versus-tumor effects by the proteasome inhibitor bortezomib

Graft-versus-host disease (GVHD) represents a major hurdle impeding the efficacy of allogeneic bone marrow transplantation (BMT). Bortezomib is a proteasome inhibitor that was recently approved for treatment of myeloma. We found that bortezomib potently inhibited in vitro mixed lymphocyte responses and promoted the apoptosis of alloreactive T cells. Bortezomib given at the time of allogeneic BMT in mice resulted in significant protection from acute GVHD. Reductions in GVHD-associated parameters and biological evidence of proteasome inhibition were observed with this regimen but with no adverse effects on long-term donor reconstitution. Assessment of graft-versus-tumor responses in advanced leukemia-bearing mice demonstrated that only the combination of allogeneic BMT and T cells with bortezomib promoted significant increases in survival. Increased cytotoxic T cell killing of the tumor was also observed. Thus, the combination of proteasome inhibition with selective immune attack can markedly increase the efficacy of BMT in cancer.

The 24-hour posttransfusion survival, oxygen transport function, and residual hemolysis of human outdated-rejuvenated red cell concentrates after washing and storage at 4 degrees C for 24 to 72 hours

Red cell concentrates with hematocrit values of 80 +/- 5 percent were stored at 4 degrees C either in citrate-phosphate-dextrose for 22 to 28 days or in citrate-phosphate-dextrose-adenine-one for 35 to 39 days. After storage, the red cells had reduced 2,3-diphosphoglycerate and adenosine triphosphate levels, and biochemical treatment with a solution called PIPA was used to restore these levels. The red cells were not preserved further, but instead were washed after rejuvenation with an unbuffered sodium chloride-glucose solution, pH 5.0, for in vivo studies, and with a buffered sodium chloride-glucose-phosphate solution, pH 6.8, for comparative in vitro studies. The red cells were stored in the wash solution at 4 degrees C for 72 hours after washing. Red cell recovery after washing was about 95 percent. Twenty-four-hour posttransfusion survival value was about 80 percent, and the index of therapeutic effectiveness was greater than 75 percent. These biochemically modified washed red cells exhibited higher than normal P50 values, even after 3 days of postwash storage at 4 degrees C. The units that were washed with the sodium chloride-glucose solution with a pH of 5.0 exhibited a greater degree of hemolysis after 3 days of postwash storage at 4 degrees C than did the units that were washed with the sodium chloride-glucose-phosphate solution with a pH of 6.8.(ABSTRACT TRUNCATED AT 250 WORDS)

The lower esophagus and glucagon

A bolus impaction of the lower esophagus in a 54-year-old woman was rapidly and safely relieved by the administration of intravenous glucagon. This case report reviews a known but little appreciated use of this drug. The history, pharmacology, and uses of glucagon are discussed.