Radioactive contamination in feral dogs in the Chernobyl exclusion zone: Population body-burden survey and implications for human radiation exposure.

This report describes a two-year effort to survey the internal 137Cs and external ß-emitter contamination present in the feral dog population near the Chernobyl nuclear power plant (ChNPP) site, and to understand the potential for human radiation exposure from this contamination. This work was performed as an integral part of the radiation safety and control procedures of an animal welfare oriented trap-neuter-release (TNR) program. The measurement program focused on external contamination surveys using handheld ß-sensitive probes, and internal contamination studies using a simple whole-body counter. Internal 137Cs burden was measured non-invasively during post-surgical observation and recovery. External ß contamination surveys performed during intake showed that 21/288 animals had significant, removable external contamination, though not enough to pose a large hazard for incidental contact. Measurements with the whole-body counter indicated internal 137Cs body burdens ranging from undetectable (minimum detection level ∼100 Bq/kg in 2017, ∼30 Bq/kg in 2018) to approximately 30,000 Bq/kg. A total of 33 animals had 137Cs body-burdens above 1 kBq/kg, though none posed an external exposure hazard. The large variation in the 137Cs concentration in these animals is not well-understood, could be due to prey selection, access to human food scraps, or extended residence in highly contaminated areas. The small minority of animals with external contamination may pose a contamination risk allowing exposures in excess of regulatory standards.

Application of a drug-induced apoptosis assay to identify treatment strategies in recurrent or metastatic breast cancer.

BACKGROUND: A drug-induced apoptosis assay has been developed to determine which chemotherapy drugs or regimens can produce higher cell killing in vitro. This study was done to determine if this assay could be performed in patients with recurrent or metastatic breast cancer patients, to characterize the patterns of drug-induced apoptosis, and to evaluate the clinical utility of the assay. A secondary goal was to correlate assay use with clinical outcomes. METHODS: In a prospective, non-blinded, multi institutional controlled trial, 30 evaluable patients with recurrent or metastatic breast cancer who were treated with chemotherapy had tumor samples submitted for the MiCK drug-induced apoptosis assay. After receiving results within 72 hours after biopsy, physicians could use the test to determine therapy (users), or elect to not use the test (non-users). RESULTS: The assay was able to characterize drug-induced apoptosis in tumor specimens from breast cancer patients and identified which drugs or combinations gave highest levels of apoptosis. Patterns of drug activity were also analyzed in triple negative breast cancer. Different drugs from a single class of agents often produced significantly different amounts of apoptosis. Physician frequently (73%) used the assay to help select chemotherapy treatments in patients, Patients whose physicians were users had a higher response (CR+PR) rate compared to non-users (38.1% vs 0%, p = 0.04) and a higher disease control (CR+PR+Stable) rate (81% vs 25%, p<0.01). Time to relapse was longer in users 7.4 mo compared to non-users 2.2 mo (p<0.01). CONCLUSIONS: The MiCK assay can be performed in breast cancer specimens, and results are often used by physicians in breast cancer patients with recurrent or metastatic disease. These results from a good laboratory phase II study can be the basis for a future larger prospective multicenter study to more definitively establish the value of the assay. TRIAL REGISTRATION: Clinicaltrials.gov NCT00901264.

The microculture-kinetic (MiCK) assay: the role of a drug-induced apoptosis assay in drug development and clinical care.

A drug-induced apoptosis assay, termed the microculture-kinetic (MiCK) assay, has been developed. Blinded clinical trials have shown higher response rates and longer survival in groups of patients with acute myelocytic leukemia and epithelial ovarian cancer who have been treated with drugs that show high apoptosis in the MiCK assay. Unblinded clinical trials in multiple tumor types have shown that the assay will be used frequently by clinicians to determine treatment, and when used, results in higher response rates, longer times to relapse, and longer survivals. Model economic analyses suggest possible cost savings in clinical use based on increased generic drug use and single-agent substitution for combination therapies. Two initial studies with drugs in development are promising. The assay may help reduce costs and speed time to drug approval. Correlative studies with molecular biomarkers are planned. This assay may have a role both in personalized clinical therapy and in more efficient drug development.

A phase I/II study examining pentostatin, chlorambucil, and theophylline in patients with relapsed chronic lymphocytic leukemia and non-Hodgkin's lymphoma.

In an attempt to exploit bcl-2 overexpression and aberrant p53 function, two frequently encountered aberrations that predict marked treatment resistance and worse prognosis in patients with chronic lymphocytic leukemia (CLL) and non-Hodgkin's lymphoma (NHL), we combined theophylline, pentostatin, and chlorambucil at two dose levels (cohort I: 30 mg/m(2); cohort II: 20 mg/m(2)) on a 21-day cycle for up to six courses. We employed a phase I/II design to determine feasibility, define the maximum tolerated dose (MTD), and explore the impact of biologic modulation on response and time to progression (TTP) in 20 patients with relapsed or refractory CLL and NHL. Eight patients were enrolled in cohort I. They demonstrated a response rate (RR) of 28% and a 16.5-month TTP after receiving a median of two cycles. A 50% RR was observed in this cohort when patients with adverse histologies were excluded. Because of myelotoxicity, this dose level defined the MTD, and de-escalation occurred. All 12 patients in cohort II received 20 mg/m(2) chlorambucil. A 50% RR and an 18-month TTP were observed after a median of 5.5 cycles. An RR of 47% and a complete remission (CR) of 5% were observed for the entire group, although responses and TTP varied greatly by histology. Significant activity was observed in patients with B-cell CLL and follicular lymphoma (FL). RR and TTP for fludarabine-sensitive/naïve and fludarabine-refractory (FR) B-cell CLL patients were 66 vs 25% and 20 vs 8.5 months, respectively. Both FL patients responded (one with partial remission and one with CR), with a 22.5-monthly median TTP. For responding patients, median TTP and overall survival (OS) was 21 and 69 months, respectively, compared to a median TTP of 2 months and an OS of 13.5 months for nonresponders. The combination of pentostatin, chlorambucil, and theophylline is the active regimen in patients with FL and B-cell CLL.