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Longitudinal changes of cortical microstructure in Parkinson's disease assessed with T1 relaxometry
(2016)
Background: Histological evidence suggests that pathology in Parkinson's disease (PD) goes beyond nigrostriatal degeneration and also affects the cerebral cortex. Quantitative MRI (qMRI) techniques allow the assessment of changes in brain tissue composition. However, the development and pattern of disease-related cortical changes have not yet been demonstrated in PD with qMRI methods. The aim of this study was to investigate longitudinal cortical microstructural changes in PD with quantitative T1 relaxometry.
Methods: 13 patients with mild to moderate PD and 20 matched healthy subjects underwent high resolution T1 mapping at two time points with an interval of 6.4 years (healthy subjects: 6.5 years). Data from two healthy subjects had to be excluded due to MRI artifacts. Surface-based analysis of cortical T1 values was performed with the FreeSurfer toolbox.
Results: In PD patients, a widespread decrease of cortical T1 was detected during follow-up which affected large parts of the temporo-parietal and occipital cortices and also frontal areas. In contrast, age-related T1 decrease in the healthy control group was much less pronounced and only found in lateral frontal, parietal and temporal areas. Average cortical T1 values did not differ between the groups at baseline (p = 0.17), but were reduced in patients at follow-up (p = 0.0004). Annualized relative changes of cortical T1 were higher in patients vs. healthy subjects (patients: − 0.72 ± 0.64%/year; healthy subjects: − 0.17 ± 0.41%/year, p = 0.007).
Conclusions: In patients with PD, the development of widespread changes in cortical microstructure was observed as reflected by a reduction of cortical T1. The pattern of T1 decrease in PD patients exceeded the normal T1 decrease as found in physiological aging and showed considerable overlap with the pattern of cortical thinning demonstrated in previous PD studies. Therefore, cortical T1 might be a promising additional imaging marker for future longitudinal PD studies. The biological mechanisms underlying cortical T1 reductions remain to be further elucidated.
First results on the longitudinal asymmetry and its effect on the pseudorapidity distributions in Pb–Pb collisions at √sNN = 2.76 TeV at the Large Hadron Collider are obtained with the ALICE detector. The longitudinal asymmetry arises because of an unequal number of participating nucleons from the two colliding nuclei, and is estimated for each event by measuring the energy in the forward neutron-ZeroDegree-Calorimeters (ZNs). The effect of the longitudinal asymmetry is measured on the pseudorapidity distributions of charged particles in the regions |η| < 0.9, 2.8 < η < 5.1 and −3.7 < η < −1.7 by taking the ratio of the pseudorapidity distributions from events corresponding to different regions of asymmetry. The coefficients of a polynomial fit to the ratio characterise the effect of the asymmetry. A Monte Carlo simulation using a Glauber model for the colliding nuclei is tuned to reproduce the spectrum in the ZNs and provides a relation between the measurable longitudinal asymmetry and the shift in the rapidity (y0) of the participant zone formed by the unequal number of participating nucleons. The dependence of the coefficient of the linear term in the polynomial expansion, c1, on the mean value of y0 is investigated.
This paper presents the first measurements of the charge independent (CI) and charge dependent (CD) two-particle transverse momentum correlators GCI 2 and GCD 2 in Pb–Pb collisions at √sNN = 2.76 TeV by the ALICE collaboration. The two-particle transverse momentum correlator G2 was introduced as a measure of the momentum current transfer between neighboring system cells. The correlators are measured as a function of pair separation in pseudorapidity (Δη) and azimuth (Δφ) and as a function of collision centrality. From peripheral to central collisions, the correlator GCI 2 exhibits a longitudinal broadening while undergoing a monotonic azimuthal narrowing. By contrast, GCD 2 exhibits a narrowing along both dimensions. These features are not reproduced by models such as HIJING and AMPT. However, the observed narrowing of the correlators from peripheral to central collisions is expected to result from the stronger transverse flow profiles produced in more central collisions and the longitudinal broadening is predicted to be sensitive to momentum currents and the shear viscosity per unit of entropy density η/s of the matter produced in the collisions. The observed broadening is found to be consistent with the hypothesized lower bound of η/s and is in qualitative agreement with values obtained from anisotropic flow measurements.
An ongoing study of the longhorned beetle fauna in the cloud forests of Cusuco National Park revealed multiple additions to the Honduran fauna. Four new species are described: Heterachthes caceresae sp. nov. (Cerambycinae, Neoibidionini), Oreodera kawasae sp. nov. (Lamiinae, Acrocinini), Phrynidius guifarroi sp. nov. (Lamiinae, Apomecynini), and Strangalia lunai sp. nov. (Lepturinae, Lepturini). Additionally, Lagocheirus parvulus Casey, 1913 (Lamiinae, Acanthocinini) is revalidated as Lagocheirus araneiformis parvulus Casey, 1913 (Lagochirus [sic]). We recorded Arixiuna varians (Bates, 1881) (Lamiinae, Hemilophini) for the first time for Honduras. These findings confirm how poorly the invertebrate biodiversity of cloud forests is documented and hints at the large number of species we are losing with the ongoing deforestation.
The little known ladybird, Serangium parcesetosum SICARD (Col., Coccinellidae) seems to be an important predator of whiteflies. It has found attacking Bemisia tabaci (GENN.) (Hom., Aleyrodidae) (KAPADIA & PURI 1992), Aleurolobus barodensis MASK (PATEL et al. 1996), Aleurothrixus floccosus MASKELL (ABBOUD & AHMAD 1998), Bemisia argentifolii BELLOWS and PERRING (LEGASPI et al. 2001) as well as Dialeurodes citri (ASHMEAD) (YIGIT et al. 2003). However, in Germany the laboratory studies demonstrated that S. parcesetosum is a promising predator of B. tabaci (AL-ZYOUD & SENGONCA 2004; SENGONCA et al. 2004; AL-ZYOUD et al. 2005a, b; SENGONCA et al. 2005). One of the important features for a successful predator is to live for a long period on the prey species and also not feed on the plant in the prey absence. Long longevity accomplished by voraciously feeding of S. parcesetosum adults resulted in a successful control of B. argentifolii (ELLIS et al. 2001). To use this predator successfully in controlling the whiteflies, especially B. tabaci and Trialeurodes vaporariorum WESTWOOD (Hom., Aleyrodidae), it was important to investigate its natural and artificial nutritional sources. However, such knowledge of S. parcesetosum is still insufficient or completely lacking in the literature. Therefore, the present work was directed to study the longevity of S. parcesetosum on natural nutritional sources such as B. tabaci and T. vaporariorum as well as on certain artificial nutritional sources at two different temperatures in the laboratory.
Background: The aim of this study was to evaluate the longer-term results of bicuspid aortic valve (BAV) repair with or without aortic root replacement. Methods: From 1999 to 2017, 142 patients with or without aortic root dilatation who underwent repair of a regurgitant BAV were included in the study. Ninety-four patients underwent isolated BAV repair (Group 1; median age 43 years) and 48 patients underwent valve-sparing aortic root replacement plus BAV repair (aortic valve reimplantation—Group 2; median age 48 years). Median clinical follow-up time was 5.9 years (range 0.5–15) in Group 1 and 3 years (range 0.5–16) in Group 2, respectively. Results: In-hospital mortality was 1% in Group 1, and 2% in Group 2 (p = .6). The 5- and 10-year survival was 93 ± 2.9% and 81 ± 5.8% in Group 1 and 96 ± 3.1% and 96 ± 3.1% in Group 2, respectively (p = .31). Eleven patients of Group 1 (1.7%/patient-year) and five patients of Group 2 (2.2%/patient-year) underwent reoperation of the aortic valve (p = .5). The 5- and 10-year freedom from reoperation were 93.0 ± 2.1% and 77.1 ± 7.1% in Group 1 and 93.0 ± 5.0% and 76.7 ± 9.6% in Group 2 (p = .83), respectively. At the latest follow-up, only two patients of Group 1 and 1 patient of Group 2 had AV regurgitation = 2° (p = .7). The cumulative linearized incidence of all valve-related complications (bleeding, stroke, endocarditis, and reoperation) was 2.9%/patient-year in Group 1% and 4%/patient-year in Group 2, respectively (p = .6). Conclusions: Isolated BAV repair and combined aortic valve reimplantation plus BAV repair provide good clinical longer-term outcomes with relatively low reoperation rate and durable valve function.
Hyponatremia is the most common and by far underestimated electrolyte disorder in clinical practice. Especially in elderly patients, treatment of symptomatic hyponatremia is challenging. Herein we describe the case of an octogenarian with recurrent symptomatic hyponatremia due to idiopathic syndrome of inappropriate antidiuretic hormone release (SIADH). Fluid restriction was insufficient to prevent repeated episodes of hyponatremia complicated by falls and coma. After introduction of a low-dose therapy with tolvaptan, serum sodium levels as well as the clinical condition were stable under vaptan therapy, without any relapse for more than six years now. This case demonstrates that long-term tolvaptan treatment for hyponatremia caused by SIADH is safe and well tolerated, even in the elderly.
MIPAS-Envisat is a satellite-borne sensor which measured vertical profiles of a wide range of trace gases from 2002 to 2012 using IR emission spectroscopy. We present geophysical validation of the MIPAS-Envisat operational retrieval (version 6.0) of N2O, CH4, CFC-12, and CFC-11 by the European Space Agency (ESA). The geophysical validation data are derived from measurements of samples collected by a cryogenic whole air sampler flown to altitudes of up to 34 km by means of large scientific balloons. In order to increase the number of coincidences between the satellite and the balloon observations, we applied a trajectory matching technique. The results are presented for different time periods due to a change in the spectroscopic resolution of MIPAS in early 2005. Retrieval results for N2O, CH4, and CFC-12 show partly good agreement for some altitude regions, which differs for the periods with different spectroscopic resolution. The more recent low spectroscopic resolution data above 20 km altitude show agreement with the combined uncertainties, while there is a tendency of the earlier high spectral resolution data set to underestimate these species above 25 km. The earlier high spectral resolution data show a significant overestimation of the mixing ratios for N2O, CH4, and CFC-12 below 20 km. These differences need to be considered when using these data. The CFC-11 results from the operation retrieval version 6.0 cannot be recommended for scientific studies due to a systematic overestimation of the CFC-11 mixing ratios at all altitudes.
Background: In this study, we examined patients who had non-progressive disease for at least 2 years after diagnosis of inoperable locoregional recurrent or metastatic breast cancer under continuous trastuzumab treatment. Our primary goal was to assess the long-term outcome of patients with durable response to trastuzumab.
Methods: 268 patients with HER2-positive inoperable locally recurrent or metastatic breast cancer and non-progressive disease for at least 2 years under trastuzumab treatment were documented retrospectively or prospectively in the HER-OS registry, an online documentation tool, between December 2006 and September 2010 by 71 German oncology centers. The study end point was time to tumor progression.
Results: Overall, 47.1% of patients (95% confidence interval (CI): 39.9–54.1%) remained in remission for more than 5 years, while the median time to progression was 4.5 years (95% CI: 4.0–6.6 years). Lower age (<50 years) and good performance status (ECOG 0) at time of trastuzumab treatment initiation as well as complete remission after initial trastuzumab treatment were associated with longer time to progression. Interruption of trastuzumab therapy correlated with shorter time to progression.
Conclusions: HER2-positive patients, who initially respond to palliative treatment with trastuzumab, can achieve a long-term tumor remission of several years.
Background: Published estimates of mortality and progression to AIDS as children with HIV approach adulthood are limited. We describe rates and risk factors for death and AIDS-defining events in children and adolescents after initiation of combination antiretroviral therapy (cART) in 17 middle- and high-income countries, including some in Western and Central Europe (W&CE), Eastern Europe (Russia and Ukraine), and Thailand.
Methods and findings: Children with perinatal HIV aged <18 years initiating cART were followed until their 21st birthday, transfer to adult care, death, loss to follow-up, or last visit up until 31 December 2013. Rates of death and first AIDS-defining events were calculated. Baseline and time-updated risk factors for early/late (≤/>6 months of cART) death and progression to AIDS were assessed. Of 3,526 children included, 32% were from the United Kingdom or Ireland, 30% from elsewhere in W&CE, 18% from Russia or Ukraine, and 20% from Thailand. At cART initiation, median age was 5.2 (IQR 1.4–9.3) years; 35% of children aged <5 years had a CD4 lymphocyte percentage <15% in 1997–2003, which fell to 15% of children in 2011 onwards (p < 0.001). Similarly, 53% and 18% of children ≥5 years had a CD4 count <200 cells/mm3 in 1997–2003 and in 2011 onwards, respectively (p < 0.001). Median follow-up was 5.6 (2.9–8.7) years. Of 94 deaths and 237 first AIDS-defining events, 43 (46%) and 100 (42%) were within 6 months of initiating cART, respectively. Multivariable predictors of early death were: being in the first year of life; residence in Russia, Ukraine, or Thailand; AIDS at cART start; initiating cART on a nonnucleoside reverse transcriptase inhibitor (NNRTI)-based regimen; severe immune suppression; and low BMI-for-age z-score. Current severe immune suppression, low current BMI-for-age z-score, and current viral load >400 c/mL predicted late death. Predictors of early and late progression to AIDS were similar. Study limitations include incomplete recording of US Centers for Disease Control (CDC) disease stage B events and serious adverse events in some countries; events that were distributed over a long time period, and that we lacked power to analyse trends in patterns and causes of death over time.
Conclusions: In our study, 3,526 children and adolescents with perinatal HIV infection initiated antiretroviral therapy (ART) in countries in Europe and Thailand. We observed that over 40% of deaths occurred ≤6 months after cART initiation. Greater early mortality risk in infants, as compared to older children, and in Russia, Ukraine, or Thailand as compared to W&CE, raises concern. Current severe immune suppression, being underweight, and unsuppressed viral load were associated with a higher risk of death at >6 months after initiation of cART.