Coronary computed tomography angiography in a single cardiac cycle with a mean radiation dose of approximately 1 mSv: initial experience

INTRODUCTION

The aim of this study was to evaluate the radiation dose, image quality and acquisition time of coronary computed tomography angiography (CCTA) using a 128-slice dual source scanner with prospective ECG-triggered high-pitch spiral acquisition (Flash Spiral).

METHODS

A series of 20 consecutive patients in sinus rhythm, with no contraindications to administration of iodinated contrast media and beta-blockers and no history of coronary revascularization, underwent CCTA either to rule out coronary artery disease (CAD) or to evaluate known or suspected CAD. Image quality was evaluated using a four-point scale (1 excellent, 4 poor). Data on acquisition time and radiation dose were recorded.

RESULTS

Mean acquisition time was 292 +/- 21 milliseconds. The mean effective radiation dose was 0.99 mSv +/- 0.34 mSv. All of the 266 coronary artery segments analyzed were of diagnostic image quality.

CONCLUSION

CCTA using a 128-slice dual source scanner with prospective ECG-triggered high-pitch spiral acquisition provides single cardiac cycle acquisition with high image quality at mean effective radiation doses of approximately 1 mSv.

Optically tunable spontaneous Raman fluorescence from a single self-assembled InGaAs quantum dot

We report the observation of all-optically tunable Raman fluorescence from a single quantum dot. The Raman photons are produced in an optically driven Lambda system defined by subjecting the single electron charged quantum dot to a magnetic field in Voigt geometry. Detuning the driving laser from resonance, we tune the frequency of the Raman photons by about 2.5 GHz. The number of scattered photons and the linewidth of the Raman photons are investigated as a function of detuning. The study presented here could form the basis of a new technique for investigating spin-bath interactions in the solid state.

Pilot- and bench-scale testing of faecal indicator bacteria survival in marine beach sand near point sources

AIM

Factors affecting faecal indicator bacteria (FIB) and pathogen survival/persistence in sand remain largely unstudied. This work elucidates how biological and physical factors affect die-off in beach sand following sewage spills.

METHODS AND RESULTS

Solar disinfection with mechanical mixing was pilot-tested as a disinfection procedure after a large sewage spill in Los Angeles. Effects of solar exposure, mechanical mixing, predation and/or competition, season, and moisture were tested at bench scale. First-order decay constants for Escherichia coli ranged between -0.23 and -1.02 per day, and for enterococci between -0.5 and -1.0 per day. Desiccation was a dominant factor for E. coli but not enterococci inactivation. Effects of season were investigated through a comparison of experimental results from winter, spring, and fall.

CONCLUSIONS

Moisture was the dominant factor controlling E. coli inactivation kinetics. Initial microbial community and sand temperature were also important factors. Mechanical mixing, common in beach grooming, did not consistently reduce bacterial levels.

SIGNIFICANCE AND IMPACT OF THE STUDY

Inactivation rates are mainly dependent on moisture and high sand temperature. Chlorination was an effective disinfection treatment in sand microcosms inoculated with raw influent.

Organochlorine compounds and stable isotopes indicate bottlenose dolphin subpopulation structure around the Iberian Peninsula

Isotopic signatures and organochlorine pollutant loads of organisms reflect the characteristics of the waters in which they live and feed. To investigate population structure of bottlenose dolphins around the Iberian Peninsula we determined delta(13)C and delta(15)N in the skin and organochlorine (OC) levels in the blubber of stranded bottlenose dolphins inhabiting the Mediterranean (Catalonia, Valencia and Balearic Islands) and adjacent Atlantic waters (Huelva and Portugal). OC levels were high in all regions, reflecting the predatory habits of the species, its coastal distribution and the existence of intense agricultural and industrial activity throughout the region. PCB congeners showed a gradient from the relatively more chlorinated forms to those that are less so, and followed a northeast to northwest direction across the Iberian Peninsula. This suggests that PCB inputs are more recent in the temperate latitudes of the eastern Atlantic Ocean than in the western Mediterranean Sea. Comparatively, OC ratios and isotopic signatures proved to be more efficient ways of discriminating groups than did raw OC concentrations. Significant differences in delta(13)C and in PCB congener profiles indicate that dolphins from the Atlantic and the Mediterranean do not intermingle. In addition, the two Atlantic groups differed in delta(15)N signature, tDDT concentration, DDT/PCB ratio and the PCB congener profile, which also suggests some degree of isolation between them. In the Mediterranean, dolphins from Catalonia and Valencia were indistinguishable, suggesting a common distribution area. However, dolphins from the Balearic Islands differed from those of the Peninsula in their DDT/PCB ratio and from all the other sample groups in their PCB congener profiles, which supports the hypothesis that the deep waters between the Islands and the Peninsula represent an effective barrier for the species.

Longitudinal prescribing patterns for psychoactive medications in community-based individuals with developmental disabilities: utilization of pharmacy records

BACKGROUND

Little is known about longitudinal prescribing practices for psychoactive medications for individuals with intellectual disabilities and developmental disabilities (IDDD) who are living in community settings.

METHODS

Computerized pharmacy records were accessed for 2344 community-based individuals with IDDD for whom a total of 3421 prescriptions were written during a 17-month period of study. Forty-two psychoactive medications were rank ordered in terms of prescription frequency.

RESULTS

Fifty-two per cent (52%) of all prescriptions written during the study period were for psychoactive medications. Anticonvulsant, antipsychotic and antidepressant medications were the most commonly filled prescriptions among psychoactive medications. Sixty per cent (62%) of the study population was given prescriptions for more than one psychoactive medication and 36% received three or more psychoactive medications. During the study period there was a statistically significant increase in prescriptions filled for olanzapine, risperidone, valproic acid, and clonazepam whereas prescriptions filled for thioridazine, haloperidol, and benzotropine showed a significant decline (P < 0.05-0.001). Distribution of psychoactive drug class by age showed that the majority of prescriptions were filled for individuals between 20 and 50 years with the exception of prescriptions for psychostimulants which peaked for individuals prior to 20 years.

CONCLUSIONS

(1) Analysis of pharmacy billing records provides a method for assessing prescribing patterns of psychoactive medications in community-based individuals with IDDD. (2) Polypharmacy for psychoactive medications is prevalent in this setting. (3) The second-generation antipsychotic medications are prominently represented by an increasing number of filled prescriptions during the study period.

Efficacy of a commercial mycotoxin binder in alleviating effects of ochratoxin A, fumonisin B1, moniliformin and zearalenone in adult mink

The addition of nutritionally inert adsorbents to mycotoxin-contaminated animal feed has been a popular approach to decreasing toxicity in animals and carryover of mycotoxins from contaminated feed to animal by-products. Some studies suggest that esterified glucomannan derived from the cell wall of Saccharomyces cerevisiae is effective in reducing the bioavailability of at least some of the mycotoxins occurring in contaminated feed. Because cereal grains are important components of ranch mink diets, mycotoxicoses in mink is a potential problem faced by mink ranchers. We conducted a series of studies to determine if inclusion of a commercially available esterified glucomannan in ranch mink feed was effective in alleviating clinical signs indicative of exposure to ochratoxin A, fumonisin B1, moniliformin or zearalenone in adult mink. In 4 separate trials, mink were fed diets that contained 2.5, 5 or 10 mg ochratoxin A/kg feed, 200 mg fumonisin B1/kg feed, 20 mg moniliformin/kg feed, or 30 mg zearalenone/kg feed with or without 2 g esterified glucomannan/kg feed. Male mink fed diets containing ochratoxin A had significantly decreased feed intake as well as renal lesions characteristic of exposure to that mycotoxin. Inclusion of the esterified glucomannan did not ameliorate these effects. Male mink exposed to fumonisin B1 had increased urinary sphinganine concentration, which was not significantly reduced by the mycotoxin adsorbent. Male mink that consumed monilformin-contaminated diets had characteristic ultrastructural changes in the heart that were not reduced in severity by the esterified glucomannan. Female mink exposed to zearalenone had increased uterine weight, which was not reversed by inclusion of commercial mycotoxin binder in the contaminated feed. The results of this study suggest that a commercial esterified glucomannan was generally ineffective in alleviating effects indicative of exposure to ochratoxin A, fumonisin B1, monilformin and zearalenone in mink.