F-19 MR imaging of glucose metabolism in the rabbit

Noninvasive metabolic magnetic resonance (MR) imaging reflecting glucose metabolism in the aldose-reductase-sorbitol (ARS) pathway was performed in the rabbit head; after administration of the fluorinated glucose analogue 3-fluoro-3-deoxy-D-glucose (3FD-glucose), fluorine-19 images were generated. Images of 3FD-glucose showed significant 3FD-glucose uptake by adipose tissue, indicating its buffering effects in case of excess loads of glucose. Images of 3-fluoro-3-deoxy-D-sorbitol (3FD-sorbitol) demonstrated the spatial distribution of aldose reductase activities and significant sorbitol accumulation in the lens. Images of 3-fluoro-3-deoxy-D-fructose (3FD-fructose) showed preferential uptake of fructose by muscle tissue. The extremely low toxicity of 3FD-glucose indicates promise for its clinical application in metabolic imaging.     

Magnetic Properties and the Electronic Structure of the Gd0.4Tb0.6Co2 Compound

We report on the comprehensive experimental and theoretical studies of magnetic and electronic structural properties of the Gd_0.4Tb_0.6Co₂ compound crystallization in the cubic Laves phase (C15). We present new results and compare them to those reported earlier. The magnetic study was completed with electronic structure investigations. Based on magnetic isotherms, magnetic entropy change (ΔS_M) was determined for many values of the magnetic field change (Δμ₀H), which varied from 0.1 to 7 T. In each case, the ΔS_M had a maximum around room temperature. The analysis of Arrott plots supplemented by a study of temperature dependency of Landau coefficients revealed that the compound undergoes a magnetic phase transition of the second type. From the M(T) dependency, the exchange integrals between rare-earth R-R (J_RR), R-Co (J_RCo), and Co-Co (J_CoCo) atoms were evaluated within the mean-field theory approach. The electronic structure was determined using the X-ray photoelectron spectroscopy (XPS) method as well as by calculations using the density functional theory (DFT) based Full Potential Linearized Augmented Plane Waves (FP-LAPW) method. The comparison of results of ab initio calculations with the experimental data indicates that near T_C the XPS spectrum collects excitations of electrons from Co3d states with different values of exchange splitting. The values of the magnetic moment on Co atoms determined from magnetic measurements, estimated from the XPS spectra, and results from ab initio calculations are quantitatively consistent.     

Stroke management: updated recommendations for treatment along the care continuum

The Australian Clinical Guidelines for Stroke Management 2010 represents an update of the Clinical Guidelines for Stroke Rehabilitation and Recovery (2005) and the Clinical Guidelines for Acute Stroke Management (2007). For the first time, they cover the whole spectrum of stroke, from public awareness and prehospital response to stroke unit and stroke management strategies, acute treatment, secondary prevention, rehabilitation and community care. The guidelines also include recommendations on transient ischaemic attack. The most significant changes to previous guideline recommendations include the extension of the stroke thrombolysis window from 3 to 4.5 h and the change from positive to negative recommendations for the use of thigh-length antithrombotic stockings for deep venous thrombosis prevention and the routine use of prolonged positioning for contracture management.     

Use of medications for secondary prevention in stroke patients at hospital discharge in Australia

Background Stroke is one of the leading causes of death and disability. Significant proportions (33 %) of stroke presentations are by patients with a previous stroke or transient ischaemic attack. Consequently, the stroke management guidelines recommend that all ischaemic stroke patients should receive three key evidence-based preventive drug therapies: antihypertensive drug therapy, a statin and an antithrombotic drug therapy (anticoagulant and/or antiplatelet). Objective To determine the rates of utilization of the three key evidence-based drug therapies for the secondary prevention of stroke and to identify factors associated with use of treatment at discharge. Setting Five metropolitan hospitals in New South Wales, comprising two tertiary referral centres and three district hospitals. Method A retrospective clinical audit was conducted in the study hospitals. Patients discharged with a principal diagnosis of ischaemic stroke during a 12-month time period (July 2009–2010) were identified for review. Main outcome measure The rate of utilization of each of the three key evidence-based drug therapies and the factors associated with use of treatment at discharge. Results A total of 521 medical records were reviewed. Of these, 469 patients were discharged alive with a mean age of 73.6 ± 14.4 years. Overall, 75.4 % were prescribed an antihypertensive agent at discharge versus only 65.7 % on admission (P < 0.05). Three hundred-sixty patients (77.6 % of the eligible patients) were prescribed a statin at discharge (compared to only 43.9 % on admission, P < 0.05), of whom 74.0 % received monotherapy. Almost all (97.6 %) eligible patients were prescribed an antithrombotic drug therapy at discharge, of whom 68.5 % were prescribed monotherapy and 28.2 % were prescribed dual therapy. Only 60.0 % of eligible patients were discharged on all three key guideline recommended secondary preventive drug therapies. Multivariate logistic regression analyses showed that hypertension (OR 6.67; 95 % CI 4.35–11.11), hypercholesterolemia (OR 2.04; 95 % CI 1.32–3.23), and discharge destination (OR 0.22; 95 % CI 0.10–0.48) were associated with the utilization of all three guideline recommended therapies. Conclusion There is a scope for improvement in implementing the stroke management guidelines when it comes to prescribing secondary preventive drug therapies using antihypertensives, antithrombotics and statins. Appropriate risk/benefit assessment is indispensable for optimal prescribing and maximizing patient outcomes, particularly in older people.     

Factors linked to bacterial vaginosis in nonpregnant women

OBJECTIVES: The purposes of this study were to test the hypothesis that vaginal douching is linked to bacterial vaginosis in both symptomatic and asymptomatic women and to identify other demographic, reproductive, and lifestyle factors associated with bacterial vaginosis. METHODS: In this cross-sectional study involving 3 clinic sites, 496 nonpregnant women completed a self-administered questionnaire. Their vaginal smears were assessed and cross-validated for bacterial vaginosis. RESULTS: The prevalence of bacterial vaginosis across clinics ranged from 15% to 30%. In analyses restricted to site 1, adjusted odds ratios (ORs) for bacterial vaginosis remained significant for African American women with 13 or fewer years of education (OR = 5.5, 95% confidence interval [CI] = 2.1, 14.5), hormone use within the past 6 months (OR = 0.5, 95% CI = 0.2, 0.8), and vaginal douching within the past 2 months (OR = 2.9, 95% CI = 1.5, 5.6). CONCLUSIONS: Two lifestyle factors emerge as strongly associated with bacterial vaginosis: systemic contraceptives appear protective, whereas douching is linked to an increase in prevalence. The temporal relationship between douching and bacterial vaginosis needs further clarification.     

Digital beam attenuator technique for compensated chest radiography

The feasibility of producing patient-specific beam attenuators for chest radiography has been investigated using an anthropomorphic phantom and a human volunteer. A low-dose test exposure is digitized, processed, and used to print a small cerium filter, which is placed in the x-ray beam near the collimator. The final radiograph is recorded on film. The technique results in relatively uniform film exposure, so that structures in all regions of the chest are simultaneously displayed with optimal film contrast. The equalized exposure improves image quality in the normally underpenetrated regions and reduces the role of cross-scatter from the lungs. The image is analogous to optical or computer-processed unsharp masking techniques, but the processing is accomplished in the x-ray beam and results in an improved exposure distribution, giving advantages that cannot be achieved with image processing techniques alone.     

A prospective study of liver function in infants and children exposed to daily isoflurane for several weeks

Eleven infants and children presenting for daily radiotherapy for a period of at least 2 weeks were anaesthetised with isoflurane in 33% oxygen and nitrous oxide. They were unpremedicated and given no other agents to supplement anaesthesia. The average number of exposures was 24 (SD 11; range 10-39) and the total anaesthetic time per exposure varied between 15 and 30 minutes. Liver function was assessed by determining serum total bilirubin, aspartate amino transferase, gamma glutamyl transferase and alkaline phosphatase before the start of treatment and at 5-daily intervals thereafter. There was no measurable change in any of these determinants of liver function. All children accepted daily induction of anaesthesia with isoflurane. Induction, maintenance and recovery from anaesthesia were uncomplicated.