Application of voxelwise analysis in the detection of regions of reduced fractional anisotropy in multiple sclerosis patients

PURPOSE: To investigate the utility of voxelwise analysis in the detection of lesions in the normal appearing white matter (NAWM) of individual multiple sclerosis (MS) patients. MATERIALS AND METHODS: Diffusion tensor imaging (DTI) was performed on 10 normal controls and six patients with MS lesions. The fractional anisotropy (FA) maps derived from the diffusion-weighted images were then spatially normalized (via an affine transformation) into Montreal Neurological Institute (MNI) space, and the normalized FA map of each of the patients was compared voxelwise with the normalized FA maps of the group of normals in a one-sample t-test (P = 0.0001). Two independent board-certified neuroradiologists reviewed the data. RESULTS: In the patient data for all six cases, the two reviewers determined detection sensitivities of 72% and 96% for the voxelwise technique based on known fluid-attenuated inversion-recovery (FLAIR) lesions. In addition, between the two reviewers, nine NAWM regions exhibiting FA reductions were identified in the six patients. However, numerous regions of abnormal FA were detected that were attributed to poor intersubject image registration. CONCLUSION: Voxelwise analysis of spatially normalized FA maps has the potential to identify regions of FA reduction in lesions and in the NAWM of individual MS patients in a rapid and reproducible fashion. J. Magn. Reson. Imaging 2007;26:552-556. (c) 2007 Wiley-Liss, Inc.     

Evaluation of the effects and mechanisms of action of mercuric chloride on striatal dopamine release by using in vivo microdialysis in freely moving rats

The in vivo effects of inorganic mercury (Hg(2+)) on striatal dopamine (DA) release were studied in freely moving and conscious rats using brain microdialysis techniques. Intrastriatal administration of HgCl(2) (1mM) produced an increase in extracellular DA levels of 1717+/-375% with respect to basal levels. This effect was attenuated in a Ca(2+)-free medium (361+/-66%), after pre-treatment with reserpine (231+/-66%), and was prevented in the presence of tetrodotoxin (TTX). Thus, the HgCl(2) treatment increases striatal DA according to an external calcium and vesicular dependent mechanism, being affected by the blockade of voltage sensitive sodium channels. Moreover, HgCl(2) decreased KCl-evoked DA release. Conversely, the coinfusion of HgCl(2) with nomifensine produced increases in DA extracellular levels different to that produced by nomifensine alone, suggesting that these effects probably involve an independent DA transporter (DAT) mechanism.     

Pulmonary endothelium dependent vasodilation emerges after birth in mice

At birth, with the first breath, pulmonary vessels undergo profound adaptive processes. A failure in the ability of pulmonary vessels to adapt at birth results in persistent pulmonary hypertension of the new born. The mechanisms regulating pulmonary adaptation at birth are still unclear. Progress in this area is slow, not least because genetically modified mice have not yet been used to address questions in this area of research, principally because pulmonary vessels in new born mice are very small making the study of dilator response in vitro difficult. In the current study we have used precision cut lung slices to characterise the functional vasomotor changes in lung vessels of new born mice (1-4 days old), 8-15 day old mice or adult mice. The internal luminal area of pulmonary artery and airways was measured digitally. Vasoconstriction and vasodilatation were expressed as the percentage change in internal luminal area compared with the control area. The thromboxane A(2) mimetic U-46619 (3x10(-7) M) caused a significant vasoconstriction in vessels of all groups. However, acetylcholine (3x10(-5) M) induced arterial dilation only in the 8-15 days, and adult groups. By contrast, sodium nitroprusside, which acts independently of the endothelium, was an effective vasodilator in lung vessels from neonates. These data are the first to characterise the development of endothelium dependent vasodilatation in lung after birth in mice. This approach can be used with genetically modified mice, which is important to further our understanding of the physiology in this area.     

Bacterial vaginitis

Bacterial vaginitis is responsible for approximately 10 million office visits per year. This condition may disrupt marriages and cause psychologic stress that may be reflected in the individual's work and social life. Bacterial vaginitis also has been thought to lead to postpartum endometritis, pelvic cellulitis, pelvic inflammatory disease, and chorioamnionitis.     

醋酸棉酚对离体大鼠黄体和人蜕膜、滋养层细胞的影响

以细胞分泌功能和存活率为指标,观察了醋酸棉酚对无血清培养的大鼠黄体和人蜕膜、滋养层细胞的直接损伤作用和可能的作用途径。结果表明:醋酸棉酚对黄体细胞有直接杀伤作用,LD₅₀为:1.6(0.4～2.9)μg·mL^-1。在非致死剂量(0.5μg·mL^-1)下,醋酸棉酚显著抑制黄体细胞基础孕酮分泌,但不能显著抑制hCG,Forskolin的促孕酮作用和3β-HSD的活性。此外,醋酸棉酚对蜕膜细胞和滋养层细胞也有直接杀伤作用,其LD₅₀分别为:3.5(0.4～6.6)μg·mL^-1,4.1(0.6～7.6)μg·mL^-1。本文结果提示,直接杀伤黄体,蜕膜和滋养层细胞并影响孕酮合成是醋酸棉酚抗生育的重要作用环节。     

南蛇藤素抑制豚鼠体外精子的受精能力

南蛇藤素(Cel)对豚鼠精子前向运动(FM)、获能(Cap)、顶体反应(AR)和穿透去透明带仓鼠卵(SPA)均有明显的抑制作用,其作用强度随剂量而增加;对Cel的敏感性依次为精子Cap>FM>SPA>AR。Cel对豚鼠精子AR,FM和Cap的抑制作用比乙酸棉酚(GA)明显为强。     

Pica With Paradichlorobenzene Mothball Ingestion Associated With Toxic Leukoencephalopathy

This is a case report of central nervous system toxicity associated with paradichlorobenzene (PDCB) ingestion. The patient had ingested mothballs composed of 99.99% PDCB for a period of 7 months. She was admitted for depression and had no neurologic symptoms. Later she developed an acute cerebellar syndrome followed by stupor and coma. An extensive workup was negative except for decreasing levels of PDCB in her serum. Imaging revealed a diffuse leukoencephalopathy. Her clinical picture was attributed to PDCB toxicity.