Cardiovascular autonomic testing in the work-up of cerebellar ataxia: insight from an observational single center study

Journal of Neurology - Cerebellar ataxias are a heterogeneous group of disorders of both genetic and non-genetic origin. In sporadic cases, two entities are recognized: multiple system atrophy of...     

Cardiac sympathetic innervation in Parkinson’s disease versus multiple system atrophy

Purpose

The aims of this study were to evaluate the diagnostic accuracy of the dual imaging method combining cardiac iodine-¹²³-metaiodobenzylguanidine single-photon emission computed tomography combined with low-dose chest computed tomography compared to routine cardiac scintigraphy, and assess regional differences in tracer distribution and the relationships between imaging and autonomic function in Parkinson’s disease and multiple system atrophy.

Methods

A prospective study including 19 Parkinson’s disease and 12 multiple system atrophy patients was performed. Patients underwent clinical evaluation, iodine-¹²³-metaiodobenzylguanidine single-photon emission computed tomography combined with chest computed tomography, planar scintigraphy, and cardiovascular autonomic function tests.

Results

Co-registration of single-photon emission computed tomography and chest computed tomography resulted in three groups with distinct patterns of tracer uptake: homogeneous, non-homogeneously reduced and absent. There was a significant difference in group allocation among patients with multiple system atrophy and Parkinson’s disease (p?=?0.001). Most multiple system atrophy patients showed homogeneous uptake, and the majority of Parkinson’s disease patients showed absent cardiac tracer uptake. We identified a pattern of heterogeneous cardiac tracer uptake in both diseases with reductions in the apex and the lateral myocardial wall. Sympathetic dysfunction reflected by a missing blood pressure overshoot during Valsalva manoeuvre correlated with cardiac tracer distribution in Parkinson’s disease patients (p?<?0.001).

Conclusions

The diagnostic accuracy of the dual imaging method and routine cardiac scintigraphy were similar. Anatomical tracer allocation provided by the dual imaging method of cardiac iodine-¹²³-metaiodobenzylguanidine single-photon emission computed tomography and chest computed tomography identified a heterogeneous subgroup of Parkinson’s disease and multiple system atrophy patients with reduced cardiac tracer uptake in the apex and the lateral wall. Sympathetic dysfunction correlated with cardiac imaging in Parkinson’s disease patients.

     

我国乡村治理体系的形成及其对乡村规划的启示

文章梳理了我国乡村治理体系的发展历程,认为现行"乡政村治"模式面临着基层政权治理能力弱化、其他新型农村治理主体涌现的新形势,并从推进实用型乡村规划出发,开展乡村治理体系与公共物品供给和乡村规划改革研究。文章将乡村治理领域划分为公、共、私三大范畴,重点讨论如何借助新兴"乡村组织"实现基于"共"的公共物品供给,以及据此改变乡村规划中公共服务中心配置的具体策略和途径。     

血栓弹力图应用价值的再探讨──在纤溶功能测定中的意义

本文采用在血样中加入一定量尿激酶，然后测定血栓弹力图（ＴＥＧ），并与常规方法进行了比较。本组共测定正常人３４例。各种临床疾病计５０例。结果表明本文介绍方法较常现方法更能敏感反应血块纤溶状况。同时还提出血块开始溶解时间（Ｔ０），最大溶解幅度（Ｐｍａｘ）和溶解速度（Ｖ）三种新的测定参数。并对其意义进行了分析。     

Neurofibromin-deficient Schwann cells secrete a potent migratory stimulus for Nf1+/- mast cells

The NF1 tumor suppressor gene encodes a GTPase-activating protein called neurofibromin that negatively regulates Ras signaling. Mutations in NF1 cause neurofibromatosis type 1 (NF1). The development of neurofibromas, which are complex tumors composed of multiple cell types, is a hallmark of NF1. Somatic inactivation of murine Nf1 in Schwann cells is necessary, but not sufficient, to initiate neurofibroma formation. Neurofibromas occur with high penetrance in mice in which Nf1 is ablated in Schwann cells in the context of a heterozygous mutant (Nf1+/-) microenvironment. Mast cells infiltrate neurofibromas, where they secrete proteins that can remodel the ECM and initiate angiogenesis. Thus, identification of mechanisms responsible for mast cell migration to tumor microenvironments is important for understanding tumorigenesis and for designing potential therapies. Here, we show that homozygous Nf1 mutant (Nf1-/-) Schwann cells secrete Kit ligand (KitL), which stimulates mast cell migration, and that Nf1+/- mast cells are hypermotile in response to KitL. Furthermore, we link hyperactivation of the Ras-class IA-PI3K-Rac2 pathway to increased Nf1+/- mast cell migration. Thus, these studies identify a novel interaction between Nf1-/- Schwann cells and Nf1+/- mast cells that is likely to be important in neurofibroma formation.     

Pharmacokinetics, pharmacodynamics, and safety of a prostaglandin D2 receptor antagonist

Laropiprant is a selective antagonist of the prostaglandin D(2) (PGD(2)) receptor subtype 1 (DP1). Three double-blind, randomized, placebo-controlled studies evaluated the safety, tolerability, pharmacokinetics, and pharmacodynamics of single and multiple oral doses of laropiprant in healthy male volunteers. Single doses up to 900 mg and multiple doses up to 450 mg were generally well tolerated. Laropiprant exhibited dose-proportional pharmacokinetics. Oral absorption is rapid (T(max)=0.8-2.0 h) and the terminal half-life is approximately 12-18 h. The pharmacokinetics of laropiprant was not affected by food. Single doses of 6 mg and higher were effective in suppressing PGD(2)-induced cyclic AMP accumulation in platelets, demonstrating laropiprant target engagement with DP1. Laropiprant has detectable off-target antagonist effects at the thromboxane A(2) receptor but no clinically significant effect on collagen-induced platelet aggregation or bleeding times with multiple doses up to 200 mg.     

A robust decision fusion strategy for SAR target recognition

This letter proposes a robust decision fusion strategy for synthetic aperture radar (SAR) automatic target recognition (ATR). The reliabilities of individual decisions and the consistency between different decisions are quantitatively evaluated. Then, only those decisions discriminative enough for target recognition are selected for the final decision fusion. Both the efficiency and robustness of the decision fusion methods can be enhanced using the proposed strategy. Moreover, as a general strategy, the proposed strategy can be applied to different types of decision fusions, e.g., the multi-feature decision fusion, multi-classifier decision fusion and multi-view decision fusion. Experiments are conducted on the moving and stationary target acquisition recognition (MSTAR) dataset under the standard operating condition and several typical extended operating conditions (EOCs) to validate the effectiveness and robustness of the proposed strategy.