The impact of ischemic heart disease on main pulmonary artery blood flow patterns: a comparison between magnetic resonance phase velocity mapping and transesophageal color Doppler

OBJECTIVE: To give a detailed evaluation on main pulmonary artery blood velocity patterns, in patients with ischemic heart disease and to provide recommendations for pulsed Doppler sample volume placement, in order to optimize cardiac output estimation. METHODS: Using magnetic resonance phase and esophageal color Doppler velocity mapping in 12 patients with ischemic heart disease and undergoing coronary artery by-pass grafting, very similar data on pulmonary artery blood velocity patterns were provided for comparison with each other. RESULTS: Peak blood velocities were located in the inferior half of the main pulmonary artery cross-sectional area. Early after peak systole the highest velocities shifted towards the superior/left (major curvature) with a simultaneous decrease in velocities inferiorly. The velocity decrease further evolved into retrograde flow to the inferior/right (minor curvature). This feature was significantly enhanced compared to earlier findings in healthy volunteers. The mean temporal blood velocity profiles were asymmetrically skewed, thereby giving unreliable cardiac output estimates based on single point Doppler blood velocity recordings. The error incurred may amount to more than 100% in extreme cases. According to our data, optimal assessment of cardiac output should be based on multiple sample volumes placed along the inferior/right to superior/left diameter. CONCLUSIONS: MR-phase velocity mapping and multiplane transesophageal color Doppler recordings provided similar blood velocity patterns in patients with ischemic heart disease. The skewness of the mean temporal blood velocity profile is enhanced compared with healthy subjects, resulting in error in the assessment of CO by means of pulsed Doppler echocardiography. By using multiple Doppler sample volumes, the error can be minimized.     

School-screening for scoliosis. A prospective epidemiological study in northwestern and central Greece

A two-year prospective study was done to assess the prevalence and distribution of various parameters associated with scoliosis in schoolchildren in northwestern and central Greece. A total of 82,901 children (41,939 boys and 40,962 girls) who were nine to fourteen years old were screened for scoliosis. Five thousand eight hundred and three children had clinical signs of scoliosis and, of these, 4185 were referred for posteroanterior radiographs (to be made with the patient standing) because they had a positive result on the forward-bending test (a difference of more than five millimeters between the two sides of the torso as measured in the thoracic or thoracolumbar region with use of a ruler and a level plane) at the time of a second screening. The prevalence of scoliosis (defined as a curve of 10 degrees or more) was 1.7 per cent (1436 of 82,901 children), and most of the curves (1255; prevalence, 1.5 per cent) were small (10 to 19 degrees). The ratio of boys to girls was 1:2.1 over-all but varied according to the magnitude of the curve (1:1.5 for curves of less than 10 degrees, 1:2.7 for curves of 10 to 19 degrees, 1:7.5 for curves of 20 to 29 degrees, 1:5.5 for curves of 30 to 39 degrees, and 1:1.2 for curves of 40 degrees or more). Thoracolumbar curves were the most common type of curve identified, followed by lumbar curves; specifically, of the 1436 children who had a curve of at least 10 degrees, 493 (34.3 per cent) had a thoracolumbar curve, 475 (33.1 per cent) had a lumbar curve, 261 (18.2 per cent) had a thoracic curve, and 207 (14.4 per cent) had a double curve. Although most (753) of these curves were to the left, the left:right ratio varied according to the location of the apex of the curve (1:3.1 for thoracic curves, 2.0:1 for thoracolumbar curves, and 3.2:1 for lumbar curves). The cost of the screening process was negligible (estimated at thirty cents per child); however, the decreased number of operative procedures performed in children from the geographical area of our University Hospital, the identification of a large number of previously undiagnosed curves (eleven of which were treated operatively and 170 of which were treated with a brace), and the identification of children who were at high risk for progression were considered important benefits of the school-screening program.     

Microwave-assisted rapid discharge sintering of a bioactive glass�Cceramic

Bioactive glass-ceramics have been developed as successful bone graft materials. Although conventional sintering in an electrically-heated furnace is most commonly used, an alternative microwave plasma batch processing technique, known as rapid discharge sintering (RDS), is examined to crystallise the metastable base glass to form one or more ceramic phases. Apatite-mullite glass-ceramics (AMGC) were examined to elucidate the effects of RDS on the crystallization of a bioactive glass-ceramic. By increasing the fluorine content of the glass, the fluorapatite (FAp) and mullite crystallization onset temperatures can be reduced. Samples were sintered in a hydrogen and hydrogen/nitrogen discharge at temperatures of ≈800 and 1000 °C respectively with the higher sintering temperature required to form mullite. Results show that the material can be densified and crystallised using RDS in a considerably shorter time than conventional sintering due to heating and cooling rates of ≈400 °C/min.     

The development and application of a proxy measure of alcohol-related traffic crashes for rural communities

Context

To date, no studies have adequately examined whether community-level, rather than individual-level, characteristics, are associated with high rates of alcohol-related traffic crashes (ARTC).

Objective

This study aims to identify a proxy measure of ARTC most appropriate to rural communities in New South Wales (NSW), Australia, and to identify community characteristics that predict higher rates of ARTC.

Methods

ARTC (2001–2007) incident data from 20 rural communities in NSW were obtained. Cost data were applied to take account of ARTCs of different severity.

Results

The method used to define a proxy measure of ARTCs for NSW generally was found to be inadequate when applied to local communities within NSW: specifically, two time periods were found to be alcohol-related for local communities only and seven time periods were found to be non-alcohol-related for local communities only. Applying a community-specific proxy measure of ARTCs to 20 communities identified substantial variation in ARTC cost-ratios, ranging from 1.20 to 0.15. Higher cost-ratios were statistically significantly predicted by the proportion of residents who were male and less than 25 years.

Conclusions

Proxy measures of ARTCs represent an ideal method of utilising routinely collected data to identify specific types of ARTCs that are most relevant to a defined community, identify community-specific factors associated with higher rates of ARTCs and measure the impact of interventions tailored to those risk factors. Such measures ought to be community-specific because these results suggest national or provincial-level definitions are not necessarily directly applicable to local communities. These results show substantial variability between communities in their rates of ARTC and identify communities with higher proportions of young males as being at increased risk.     

Onboard assessment of XRF spectra using genetic algorithms for decision making on an autonomous underwater vehicle

In order to optimise use of the limited resources (time, power) of an autonomous underwater vehicle (AUV) with a miniaturised X-ray fluorescence (XRF) spectrometer on board to carry out in situ autonomous chemical mapping of the surface of sediments with desired resolution, a genetic algorithm for rapid curve fitting is reported in this paper. This method quickly converges and provides an accurate in situ assessment of metals present, which helps the control system of the AUV to decide on future sampling locations. More thorough analysis of the available data could be performed once the AUV has returned to the base (laboratory).     

Discovery and evaluation of a series of 3-acylindole imidazopyridine platelet-activating factor antagonists

Studies conducted with the goal of discovering a second-generation platelet-activating factor (PAF) antagonist have identified a novel class of potent and orally active antagonists which have high aqueous solubility and long duration of action in animal models. The compounds arose from the combination of the lipophilic indole portion of Abbott's first-generation PAF antagonist ABT-299 (2) with the methylimidazopyridine heterocycle moiety of British Biotechnology's BB-882 (1) and possess the positive attributes of both of these clinical candidates. Structure-activity relationship (SAR) studies indicated that modification of the indole and benzoyl spacer of lead compound 7b gave analogues that were more potent, longer-lived, and bioavailable and resulted in the identification of 1-(N, N-dimethylcarbamoyl)-4-ethynyl-3-[3-fluoro-4-[(1H-2-methylimidazo[4,5-c] pyrid-1-yl)methyl]benzoyl]indole hydrochloride (ABT-491, 22 m.HCl) which has been evaluated extensively and is currently in clinical development.     

Flap prefabrication: effectiveness of different vascular carriers

A new experimental model of a vascular carrier to prefabricate a "secondary" island flap, the popliteal musculovascular pedicle, was developed in the rat. Using quantitative skin-surface fluorometry 30 minutes after sodium fluorescein injection and a flap survival area in the prefabricated 8 x 2.5-cm abdominal composite island flap, we compared the revascularization ability of our muscular carrier to nonrevascularized controls: the skeletonized arteriovenous pedicle and the fasciovascular pedicle. The free composite graft with no vascular carrier exhibited near-total necrosis. The skeletonized vascular pedicle demonstrated 15.2% +/- 7.8% perfusion of normal skin on dye fluorescence index measurements and 50% flap survival. The fasciovascular pedicle exhibited better revascularization, with a dye fluorescence index of 36.2 +/- 15.5 (p < 0.01) and 90% +/- 10% flap survival (p < 0.001). India ink injection study and histological examination of our model provided visual evidence of revascularization from the musculovascular pedicle, along with preservation of the carrier's muscular architecture. The musculovascular pedicle is a reliable carrier for making new, vascularized composite flaps.