Accumulation and effects of octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) exposure in the green anole (Anolis carolinensis)

Environmental contamination by energetic compounds is an increasing international concern, although little is known of their accumulation in and affect on wildlife. Reptiles are often good models for contaminants studies due to natural history traits that increase their potential for exposure. We report a study to assess accumulation and effects of octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX, High Melting Explosive) in green anoles (Anolis carolinensis). Acute oral toxicity (LD(50)) was estimated to exceed 2000 mg/kg body weight in adult male and female anoles using a standard up-and-down method. Accumulation of HMX was assessed in adult females via dietary exposure and into eggs by two routes (directly from the soil and via maternal transfer). HMX readily accumulated into adult females in a dose-dependent manner and into eggs following both exposure pathways. However, total HMX in soil-exposed eggs was up to 40-times greater than those exposed via maternal transfer. Although there was a suggestion of an HMX-induced reduction in body weight in adult females, overall there were no effects observed over the 12 week exposure period. The only significant effect on eggs was a 50% reduction in hatching success for eggs exposed to 2000 mg/kg HMX in the soil during incubation. Growth and survival of hatchlings was not affected by HMX exposure. Our results demonstrate that HMX accumulates through the food chain and into eggs from the soil, but likely poses minimal threat to lizards except to hatching success in eggs incubated in soils with HMX levels near maximum environmental concentrations.

Application of Baranyi function to model the antibacterial properties of solvent extract from Irish York cabbage against food spoilage and pathogenic bacteria

Cabbage is a rich source of a number of bioactive compounds such as flavonoids, glucosinolates and their breakdown products which may have antibacterial, antioxidant and anticancer properties. Outer green leaves of York cabbage were extracted with 60% methanol, ethanol or acetone. Antibacterial activities of vacuum dried crude extracts were estimated against a number of Gram-positive and Gram-negative food spoilage and food pathogenic bacteria. The crude extracts showed a broad spectrum of antibacterial activities but 60% methanol extract exhibited the highest antibacterial effect. Complete growth inhibition for Listeria monocytogenes was achieved with an extract concentration of 1.4%, whereas a two-fold concentration was required to achieve a reduction of 75% and 64% for Salmonella abony and Pseudomonas aeruginosa, respectively. For Enterococcus faecalis methanolic extract showed a weak inhibition only (31%). The lower concentrations of methanolic extract from York cabbage prolonged the lag phase and reduced both the exponential growth rate and final population densities of the culture. Survival of the micro-organisms in presence of methanolic extract was mathematically modeled using Baranyi model equations.

Foot-and-mouth disease marker vaccine: cattle protection with a partial VP1 G-H loop deleted virus antigen

Contrary to the dogma that the VP1 G-H loop is essential for FMD vaccine efficacy, it has been previously shown that foot-and-mouth disease 146s antigen containing heterologous VP1 G-H loops confers complete protection in pigs and cattle. Moreover, serological evaluation of cattle vaccinated with an antigen lacking a large proportion of the VP1 G-H loop indicated that these animals should be protected against infection with FMD. Absence of this loop provides opportunity for the development of an FMD negative marker vaccine, allowing infection to be detected by antibodies against this missing region. Cattle vaccinated with this negative marker vaccine were fully protected following virus challenge 28 days post vaccination as determined by the absence of generalised lesions on their feet. Furthermore, use of our improved differentiation ELISA identified animals exposed to infection as early as 7 days post-challenge. We thus demonstrate, for the first time, the ability of this FMD negative marker vaccine to fully protect cattle from experimental challenge and rapidly distinguish animals that are subsequently exposed to infection.

Application of MLST and pilus gene sequence comparisons to investigate the population structures of Actinomyces naeslundii and Actinomyces oris

Actinomyces naeslundii and Actinomyces oris are members of the oral biofilm. Their identification using 16S rRNA sequencing is problematic and better achieved by comparison of metG partial sequences. A. oris is more abundant and more frequently isolated than A. naeslundii. We used a multi-locus sequence typing approach to investigate the genotypic diversity of these species and assigned A. naeslundii (n = 37) and A. oris (n = 68) isolates to 32 and 68 sequence types (ST), respectively. Neighbor-joining and ClonalFrame dendrograms derived from the concatenated partial sequences of 7 house-keeping genes identified at least 4 significant subclusters within A. oris and 3 within A. naeslundii. The strain collection we had investigated was an under-representation of the total population since at least 3 STs composed of single strains may represent discrete clusters of strains not well represented in the collection. The integrity of these sub-clusters was supported by the sequence analysis of fimP and fimA, genes coding for the type 1 and 2 fimbriae, respectively. An A. naeslundii subcluster was identified with both fimA and fimP genes and these strains were able to bind to MUC7 and statherin while all other A. naeslundii strains possessed only fimA and did not bind to statherin. An A. oris subcluster harboured a fimA gene similar to that of Actinomyces odontolyticus but no detectable fimP failed to bind significantly to either MUC7 or statherin. These data are evidence of extensive genotypic and phenotypic diversity within the species A. oris and A. naeslundii but the status of the subclusters identified here will require genome comparisons before their phylogenic position can be unequivocally established.

Antiviral activity of apricitabine in treatment-experienced HIV-1-infected patients with M184V who are failing combination therapy

OBJECTIVES

Apricitabine (ATC) is a novel deoxycytidine analogue nucleoside reverse transcriptase inhibitor (NRTI) with significant antiviral activity in vitro, including activity against HIV-1 with reverse transcriptase mutations that confer resistance to other NRTIs. ATC has shown promising antiviral activity and good tolerability when given as monotherapy for 10 days in treatment-naïve HIV-1-infected patients.

METHODS

In this Phase II randomized, double-blind study, 51 treatment-experienced HIV-1-infected patients with the reverse transcriptase mutation M184V who were failing therapy which included lamivudine (3TC) were randomized to receive twice-daily 600 mg ATC, 800 mg ATC or 150 mg 3TC for 21 days. Patients remained on their existing background regimen until day 21, when background therapy could be optimized according to genotype at screening.

RESULTS

At day 21, the mean change in viral load was -0.71 and -0.90 log(10) HIV-1 RNA copies/mL in the 600 and 800 mg ATC groups, respectively, compared with a -0.03 log(10) change in the 3TC group. In patients with at least three thymidine analogue mutations (TAMs) at baseline, greater reductions in viral load were observed in the 800 mg ATC group at day 21 than in the 600 mg ATC group. Few genotypic changes were detected at day 21 [two patients (600 mg ATC) lost and three patients (800 mg ATC) gained a TAM] and all patients with detectable virus retained the M184V mutation. The safety profiles of the two ATC doses were similar to that of 3TC.

CONCLUSIONS

Over the 21-day treatment period, ATC showed promising antiviral activity and was well tolerated in treatment-experienced patients with M184V, with or without additional TAMs.

Feasibility of a 6-Month Diet, Exercise, and Behavior Modification Intervention for Post-Menopausal Breast Cancer Survivors

Background: Obesity is prevalent in general population and among breast cancer (BrCa) survivors. Weight at diagnosis and weight gain after diagnosis are associated with increased risk of breast cancer recurrence and mortality. Regular exercise similarly reduces the risk of dying from breast cancer. This study was conducted to determine the feasibility of a structured diet/exercise/behavioral intervention program with a goal to achieve a weight loss of 5% or more, and to study the effect of participation in the program on serum biomarkers of breast cancer risk, measures of overall health, strength, and fitness level..Methods: Subjects in this prospective pilot study are female, overweight BrCa survivors with a BMI >25, and who were at least 3 months out of adjuvant chemotherapy. The 6-month combined modality diet/exercise/behavior modification intervention included: 225 minutes per week of cardiovascular exercise in addition to resistance training, a 1200-1500 calorie/day diet including participant purchased pre-packaged meals and low calorie shakes, and a weekly in-person group behavioral meeting. Women were recruited into groups of 10 to15 participants (total n=50), with a planned goal of 4 cohorts, and anticipated complete data collection by December 2009. Participants underwent pre and post intervention assessments including: anthropometric measures, serum biomarkers, fitness test, and questionnaires to assess food frequency, fatigue, and quality of life. Changes over time were assessed using Wilcoxon signed rank test. We present here the data on first 12 women who have completed the 6 month intervention, out of a planned accrual of 50.Results: Since November 2008, 55 women were screened and 38 women agreed to participate in the 6-month intervention (13 in cohort 1; 10 in cohort 2; 15 in cohort 3). Only 1 participant dropped out of cohort 1 due to a non-study related injury. Major reasons for not participating included: already started another weight loss program, timing, and lack of availability for the evening meeting. Mean age of the participants was 50.7 (range 40-57) and mean time from diagnosis to the time of enrollment was 45 months (range 20-132). Eight five percent of the participants received adjuvant or neo-adjuvant chemotherapy and 77% were either currently or had previously taken anti-hormonal therapy.Median weight was 230 lbs (range 165-268) at baseline .and 198 lbs (range 139.6-243.8) at 6 month (median weight loss: 32 lbs or 14%; p=0.00); median BMI was 36.4kg/m2 (range 30.3-45.4) at baseline and 31.54kg/m2 (range 26.4-40.7) at 6-months (p=0.00), median percent body fat by DEXA scan was 50.9 (range 45-58.4) at baseline and 46.3 (range 35.6-55.4) at 6-months (p=0.00). Participants increased their metabolic equivalent task hours per week (MET/HRS) of exercise from 6.6 (range 0-25) at baseline to 20.4 (range11.8-40.5) at 6-months (p=0.01).Conclusion: A 6-month diet/exercise/behavior modification intervention program is feasible and results in a significant decrease in overall weight and percent body fat among overweight breast cancer survivors.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 1058.

Unusual magneto-optical phenomenon reveals low energy spin dispersion in the spin-1 anisotropic Heisenberg antiferromagnetic chain system NiCl2-4SC(NH2)_{2}

Electron paramagnetic resonance measurements of NiCl2-4SC(NH2)_{2} reveal the low-energy spin dispersion, including a magnetic-field interval in which the two-magnon continuum is within k_{B}T of the ground state, allowing a continuum of excitations over a range of k states, rather than only the k=0 single-magnon excitations. This produces a novel Y shape in the frequency-field EPR spectrum measured at T > or = 1.5 K. Since the interchain coupling J_{ perpendicular}<<k_{B}T, this shape can be reproduced by a single S=1 antiferromagnetic Heisenberg chain with a strong easy-plane single-ion anisotropy. Importantly, the combination of experiment and modeling we report herein demonstrates a powerful approach to probing spin dispersion in a wide range of interacting magnetic systems without the stringent sample requirements and complications associated with inelastic scattering experiments.

Evaluation of a monoclonal antibody-based approach for the selection of foot-and-mouth disease (FMD) vaccine strains

Foot-and-mouth disease (FMD) virus exists as seven serotypes within which are numerous variants necessitating careful selection of vaccine strains. Currently, a serological assay system based on the use of polyclonal vaccine antisera is widely used for this selection. However, inherent variability in the matching antisera used makes the tests poorly reproducible and difficult to interpret. In this study, we have explored the possibility of replacing or supplementing the polyclonal antibody (PAb)-based method with one based on use of monoclonal antibodies (MAb). Panels of MAbs raised against two serotype O vaccine strains were examined for reactivity with 22 field viruses, isolated over a 10-year period between 1991 and 2001. Antigenic site 2 was found to comprise more than one epitope. The sequence variation in capsid protein VP2 harbouring antigenic site 2 was analysed and the amino acid residues at positions 79 and 134 appeared to greatly influence the binding of site 2 MAbs. Prediction of antigenic match based on MAb reactivity did not correlate closely with the results of a PAb-based "gold-standard" method and it was concluded that a wider panel of MAbs are needed that recognise all protective epitopes present on the surface of FMD virus together with a better understanding of those epitopes which are important in conferring protection.