Cortical thickness as predictor of response to exercise in people with Parkinson's disease

We previously showed that dual‐task cost (DTC) on gait speed in people with Parkinson''s disease (PD) improved after 6 weeks of the Agility Boot Camp with Cognitive Challenge (ABC‐C) exercise program. Since deficits in dual‐task gait speed are associated with freezing of gait and gray matter atrophy, here we performed preplanned secondary analyses to answer two questions: (a) Do people with PD who are freezers present similar improvements compared to nonfreezers in DTC on gait speed with ABC‐C? (b) Can cortical thickness at baseline predict responsiveness to the ABC‐C? The DTC from 39 freezers and 43 nonfreezers who completed 6 weeks of ABC‐C were analyzed. A subset of 51 participants (21 freezers and 30 nonfreezers) with high quality imaging data were used to characterize relationships between baseline cortical thickness and delta (Δ) DTC on gait speed following ABC‐C. Freezers showed larger ΔDTC on gait speed than nonfreezers with ABC‐C program (p < .05). Cortical thickness in visual and fronto‐parietal areas predicted ΔDTC on gait speed in freezers, whereas sensorimotor‐lateral thickness predicted ΔDTC on gait speed in nonfreezers (p < .05). When matched for motor severity, visual cortical thickness was a common predictor of response to exercise in all individuals, presenting the largest effect size. In conclusion, freezers improved gait automaticity even more than nonfreezers from cognitively challenging exercise. DTC on gait speed improvement was associated with larger baseline cortical thickness from different brain areas, depending on freezing status, but visual cortex thickness showed the most robust relationship with exercise‐induced improvements in DTC.     

Effect of X-ray beam energy and image reconstruction technique on computed tomography numbers of various tissue equivalent materials

IntroductionComputed tomography (CT) numbers are used in radiological diagnosis, attenuation correction and radiotherapy treatment planning. Modern CT scanners use iterative reconstruction methods instead of the traditional filtered back projection (FBP). Hence, the investigation of CT number accuracy with image reconstruction techniques and X-ray tube potential (kVp) used in CT is warranted. The aim of this study is to evaluate the effect of Sinogram Affirmed Iterative Reconstruction (SAFIRE) Technique and image acquisition at different tube potentials on CT numbers of different tissue equivalent materials.MethodsImages of the Computerised Imaging Reference System Model 062M Electron Density Phantom were acquired at different tube potentials and reconstructed using FBP and different strengths of SAFIRE. Average CT numbers, in circular regions of interest, and their standard deviations were used to investigate any dependence of CT numbers on tube potentials and/or image reconstruction technique using non-parametric statistical tests with p-values set at 0.05.ResultsStatistically significant differences in CT numbers were not observed (p > 0.091) between the different image reconstruction techniques. CT number of bone equivalent materials increased significantly (p < 0.015), by up to 400 Hounsfield Units, when tube potential was decreased. Such extent of CT number change over the tube potentials range used in this study may influence diagnostic outcomes in lung nodule, contrast enhanced and calcium score studies. For all other tissue equivalent materials, the CT number did not change significantly for different tube potentials. Linear relationship was observed between CT numbers and electron densities.ConclusionThe study concludes that the CT numbers of all tissues did not change significantly with image reconstruction methods. However, the CT numbers of bone equivalent materials increased with decreasing tube potentials, which may result in misrepresentation of clinical information obtained.Implications for practiceWhen CT images are used to extract quantitative parameters such as calcium score, to characterise lung nodules and contrast enhanced structures, the kVp used for image acquisition should be carefully selected to avoid any misrepresentation of clinical information.     

Drug-resistant microorganisms with a higher fitness – can medicines boost pathogens?

Drug-resistant microorganisms (DRMs) are generally thought to suffer from a fitness cost associated with their drug-resistant trait, inflicting them a disadvantage when the drug pressure reduces. However, Leishmania resistant to pentavalent antimonies shows traits of a higher fitness compared to its sensitive counterparts. This is likely due the combination of an intracellular pathogen and a drug that targets the parasite’s general defense mechanisms while at the same time stimulating the host’s immune system, resulting in a DRM that is better adapted to withstand the host’s immune response. This review aims to highlight how this fitter DRM has emerged and how it might affect the control of leishmaniasis. However, this unprecedented example of fitter antimony-resistant Leishmania donovani is also of significance for the control of other microorganisms, warranting more caution when applying or designing drugs that attack their general defense mechanisms or interact with the host’s immune system.     

Total costs and clinical outcome of hematopoietic stem cell transplantation in adults with leukemia: comparison between reduced‐intensity and myeloablative conditioning

The total cost of hematopoietic stem cell transplantation (HSCT) as well as the financial impact of HSCT on the house holds of patients have been elusive. Between 2005 and 2012, we analyzed 191 HSCT in adult patients with leukemia with reduced‐intensity conditioning (RIC) regimen (n = 79) and with myeloablative conditioning (MAC) regimen (n = 112). The direct medical costs were calculated from healthcare claims obtained from the Seoul National University Hospital, and the direct non‐medical and the indirect costs were calculated from national statistics. The mean direct medical cost was $55 039, direct non‐medical cost was $6394, and indirect cost was $7503 from transplantation to one yr after transplantation in the RIC group and $72 916, $6993, and $9057 in the MAC group, respectively, based on the exchange rate of Korean won 1060 = US$1. The total costs for one yr were $68 938 and $88 967, constituting for 273% and 357% of the per capita income, respectively. The total costs, direct medical costs, and indirect costs showed statistically significant differences (p = 0.006, p = 0.007, and p = 0.017). No significant differences were found for leukemia‐free survival and overall survival. RIC‐HSCT provides lower costs within the first year of transplantation with comparable long‐term clinical outcomes.     

The economic efficiency of amlodipine in the treatment of coronary atherosclerosis--an analysis based on the PREVENT study

Background: High health service expenditure on the one hand, and the politically declared objective of stability of statutory contributions and restriction of public funds on the other hand, have been central points of the political and social discussion for several years. The over-proportional increase in health service expenditure is obvious, compared to the increase in the costs of living. Patients and Methods: Cost-effectiveness of amlodipine in the treatment of coronary atherosclerosis was analysed by applying the results of the PREVENT study to the Swiss health system. Results: Calculation of effectiveness shows an additional life expectancy of 0.083 years in the amlodipine cohort compared to the placebo cohort, over an observation period of 3 years. The cost-effectiveness of amlodipine treatment is approximately CHF 14,650 per life-year gained. Conclusion: The administration of the calcium antagonist amlodipine in CHD patients is cost-effective.