Automatic plaque characterization employing quantitative and multicontrast MRI.

Multicontrast magnetic resonance imaging (MRI) has shown promise in identifying and characterizing atherosclerotic plaques. One of the limitations of this technique is the lack of a practical automated plaque characterization scheme. In the current study, a prior-information-enhanced clustering (PIEC) technique that utilizes both multicontrast MR images and quantitative T(2) maps is proposed to characterize atherosclerotic plaque components automatically. The PIEC algorithm was assessed on computationally simulated images and multicontrast MRI data of coronary arteries. Multicontrast (T(1)-, T(2)-, partial T(2)-, and proton density-weighted) MR images were acquired from freshly excised human coronary arteries using a 4.7T small-animal scanner. The T(2) distribution for each plaque constituent was measured by exponentially fitting the signal from multiple MR images with different TEs and the same TR. The calculated T(2) distributions were used as the a priori information and combined with the Fuzzy C-Means (FCM)-based clustering algorithm to characterize plaque constituents. The proposed PIEC technique appears to be a promising algorithm for accurate automated plaque characterization.     

Relaxation-compensated fast multislice amide proton transfer (APT) imaging of acute ischemic stroke.

Amide proton transfer (APT) imaging is a variant form of chemical exchange saturation transfer (CEST) imaging that is based on the magnetization exchange between bulk water and labile endogenous amide protons. Given that chemical exchange is pH-dependent, APT imaging has been shown capable of imaging ischemic tissue acidosis, and as such, may serve as a surrogate metabolic imaging marker complementary to perfusion and diffusion MRI. In order for APT imaging to properly diagnose heterogeneous pathologies such as stroke and cancer, fast volumetric APT imaging has to be developed. In this study the evolution of CEST contrast after RF irradiation was solved showing that although the CEST steady state is reached by the apparent longitudinal relaxation rate, the decreases of CEST contrast after irradiation is governed by the intrinsic relaxation constant. A volumetric APT imaging sequence is proposed that acquires multislice images immediately after a single long continuous wave (CW) RF irradiation, wherein the relaxation-induced loss of CEST contrast is compensated for during postprocessing. The proposed technique was verified by numerical simulation, a tissue-like dual-pH phantom, and demonstrated on an embolic stroke animal model. In summary, our study has established a fast volumetric pH-weighted APT imaging technique, allowing further investigation to fully evaluate its diagnostic power.     

神经生长因子基因转染联合强化铁营养防治豚鼠爆震性聋的实验研究

Objective To study the protective effects of adenovirus-mediated human beta-nerve growth factor gene (hNGFβ) transfer combined with iron fortified nutrition on blast hearing damage in guinea pigs. Methods Deafness was induced by blast (172dB SPL) in 35 healthy guinea pigs. Seven days after noise exposure, 10 guinea pigs were inoculated with adenovirus-mediated hNGFβ (Ad-hNGFβ) into the perilymphatic space (the gene group), another 10 guinea pigs were given hNGFβ combined with iron fortified nutritional diet (the combination group), still another 10 guinea pigs were inoculated with artificial perilymphatic fluid (APF), and 5 guinea pigs served as control, given neither medicine nor noise exposure. Auditory brainstem response (ABR) threshold shifts were monitored in the guinea pigs before blast exposure and after gene transfer. Changes in cochlear morphology were examined with immunohistochemical and HE staining. Results One week after successful inoculation of hNGFβ, it was noted that Ad-hNGFβ protein was expressed in each turn of the cochlea, and its intensity was almost equal. After gene transfer in the combination group and the gene group, ABR threshold shifts at week 1 and 4 were significantly smaller than those of the APF group. HE staining showed that the number of the spiral ganglion cells in the combination group and the Ad-hNGFβ group was significantly higher than that of the control group after 4 weeks (P<0.01). Conclusions Ad-hNGFβ combined with iron fortified nutritional diet was effective in the prevention and treatment of blast hearing damage of cochlear hair cells.     

原发性高血压1 490例服药依从性调查分析

目的探讨影响原发性高血压患者服药依从性的原因及提高服药依从性的方法。方法对我院1500例原发性高血压患者从一般情况、高血压知识得分和服药依从性进行问卷调查,分析影响服药依从性的相关因素。结果原发性高血压患者服药依从性与受教育程度和经济收入有关。结论医护人员应加强对高血压患者的健康指导,促进家庭和社会的支持,以提高患者的服药依从性。     

血浆灌流治疗腹部开放伤海水浸泡犬肝功能损伤的研究

目的 探讨血浆灌流对腹部开放伤后海水浸泡实验犬肝功能损伤的治疗作用.方法24只腹部开放伤实验犬分为对照组(海水浸泡1.5 h后打捞出水,单纯观察),普通治疗组(海水浸泡后打捞出水,给予一般的急救及补液处理)和血浆灌流组(经海水浸泡后打捞出水,给予一般的急救补液处理,30 h后给予血浆灌注治疗),每组8只.于致伤前及致伤后定时取血测定总胆红素(TB)、血清丙氨酸转氨酶(ALT)、天冬氨酸转氨酶(AST)、乳酸脱氢酶(LDH)、凝血酶原时间(PT)、内毒素、肿瘤坏死因子-α(TNF-α)、白介素-6(IL-6),同时对肝组织进行病理检查.结果 对照组和普通治疗组血清TB、ALT、AST和LDH明显升高,血浆灌流组灌流后ALT、AST、LDH、TB、内毒素、TNF-α比灌流前明显下降(P<0.05),血细胞、血小板数量与普通治疗组比较明显下降.结论 血浆灌流对外伤后海水浸泡导致的实验犬肝功能损伤的治疗效果良好,此法可应用于该类肝损害的治疗.     

男性激素避孕临床研究的某些进展

随着社会的发展 ,迫切需要研制可供男性选用、安全高效、可复性和可接受性均好的避孕药。男性激素类避孕是当今最有前途的方法之一 ,其基本原理是通过外源性激素来抑制垂体促性腺激素和睾丸内睾酮的合成与分泌 ,进而抑制精子发生 ;同时给予的外源雄激素维持男性性征和性功能。研究中的男性激素避孕方法 ,包括单用雄激素、雄激素与孕激素合用、GnRH类似物与雄激素合用、激素相关的免疫途径等 ,寻求更长效、使用更方便、副作用小的雄激素制剂也是当今研究的重点之一     

Analysis of differences of gene expressions in keloid and normal skin with the aid of cDNA microarray

Background: Microarray analysis is a popular tool to investigate the function of genes that are responsible for the phenotype of the disease. Keloid is a intricate lesion which is probably modulated by interplay of many genes. We ventured to study the differences of gene expressions between keloids and normal skins with the aid of cDNA microarray in order to explore the molecular mechanism underlying keloid formation. Methods: The PCR products of 8400 human genes were spotted on a chip in array. The DNAs were then fixed on the glass plate by a series of treatments. Total RNAs was isolated from freshly excised human keloids and normal skin, and then was purified to mRNA by Oligotex. Both the mRNA from keloids and normal skin was reversely transcribed to cDNAs with the incorporations of fluorescent dUTP, for preparing the hybridization probes. The mixed probes were then hybridized to the cDNA microarray. After highly stringent washing, the cDNA microarray was scanned for the fluorescent signals to display the differences between two kinds of tissues. Results: Among 8400 human genes, there were 402 genes (4.79%) with different expression levels between the keloids and normal skins in all cases, 250were up-regulated (2.98%) and 152 down-regulated (1.81%). Analyses of collagen, fibronectin, proteoglycan,growth factors and apoptosis related molecule gene expression confirmed that our molecular data obtained by cDNA microarray were consistent with published biochemical and clinical observations of keloids. Conclusions: DNA microarray technology is an effective technique in screening for differences in gene expression between keloid and normal skin. Many genes are involved in the formation of keloids. Further analysis of the obtained genes will help understand the molecular mechanism of keloid formation.     

泰魄颗粒剂治疗慢性功能性便秘35例

目的　 探讨泰魄颗粒剂对慢性功能性便秘的临床疗效。 方法　 对慢性功能性便秘患者采用不含蒽醌类泻下药的泰魄颗粒剂治疗 ,并以麻仁丸作对照 ,进行临床观察。 结果　 治疗组和对照组有效率分别为 5 1 4%和 2 6 7% ,治愈率分别为 2 2 8%和 10 0 %。两组间临床疗效差异有显著性意义。泰魄颗粒剂并能改善长期服用刺激性泻下药的便秘患者肠电图抑制现象 ,治疗后肠电图的波幅、频率与治疗前相比差异分别达显著 (P <0 0 5 )和极显著 (P <0 0 1)水平。 结论　 泰魄颗粒剂能改善肠道运动功能 ,对刺激性泻下药耐受者有较好疗效。