三价砷和五价砷对鱼类乙酰胆碱脂酶的体外抑制比较

为开展水产品中三价砷的酶法快速检测工作,文中研究了三价砷(As3 + )、五价砷(As5+ )对8种鱼脑中乙酰胆碱酯酶(AChE)的抑制率。结果发现,在10 -7～10 -4mol/L范围内,草鱼和鲫鱼脑中AChE的抑制率与三价砷的浓度负对数值有较好的线性关系,相关系数都在0 .97以上;在10 -6～10 -4mol/L范围内,黑、马鲛、鲈鱼脑中AChE的抑制率与三价砷的浓度负对数值的线性相关系数大于0 .99。对于三价砷,由IC50 得到AChE的敏感性为:美国红鱼>草鱼,鲫,鲈鱼>黑,马鲛>鲤,白鲢。鱼种不同,AChE受到的三价砷、五价砷的抑制作用也不同。在浓度为10 -6～10 -4mol/L范围内,三价砷、五价砷对8种鱼脑中AChE的抑制作用存在极显著差异(p <0 .0 1) ,三价砷对AChE的抑制作用远大于五价砷的抑制作用。     

DL脑电地形图仪系统研制

阐述了脑电生理信号检测中,注重低噪声电路设计的同时,特别注重放大器的工艺设计,及应用微机对脑电信号功率谱分析、插值、脑电地形图绘制等系统研制的技术路线和方法。     

Changes of melatonin and its receptors in synchronizing turbot (Scophthalmus maximus) seasonal reproduction and maturation rhythm

In most fish, reproduction is seasonal or periodic under the suitable conditions. In turbot(Scophthalmus maximus) farms, one of the most economically important marine flatfish species, changes in daylength could cause changes in the spawning time. In this study, to characterize the regulation of reproductive physiology following light signals, three melatonin receptors(Mtnr) investigated in turbot were named sm Mtnr1, sm Mtnr2,and sm Mtnr1 c. Distinct expression profiles demonstrated that Mtnr m...     

头颅CT造影增强扫描技术临床应用价值

目的 探讨头颅CT增强造影扫描技术在临床应用价值。材料与方法 着重分析48例病例在CT造影增强扫描后的影像表现。结果 病灶均匀一致性强化8袋子例，环状强化9例，点状强化7例，结节状强化12例，不规则强化7例，强化不明显5例，脑膜或小脑幕强化结构清晰38例。结论 头颅CT增强造影扫描能够提高病变的密度分辨力，有利于明确病变的定位和定性，为临床提供更多的重要信息。     

Morphological and histological changes in the brains of turbot (Scophthalmus maximus) with gonadal development

The brain plays a critical role in controlling reproduction through the hypothalamus-pituitary-gonadal (HPG) axis in vertebrates. Turbot (Scophthalmus maximus) has become an economically important marine fish in Europe and North China. Previous research investigating turbot reproduction has focused on the role of the HPG axis in regulating egg and sperm production. However, the morphology and histology of the organs in the HPG axis have not been studied. In this study, we investigated the morphology and histology of brains in female and male turbot at different stages of gonadal development. The results showed that the brains of both female and male turbot were composed of seven parts that are typical of advanced teleosts: the telencephalon, diencephalon, cerebellum, hypothalamus, pituitary gland, myelencephalon, and olfactory bulbs. The telencephalon was well-developed and contained five distinct lobes, with the contiguous diencephalon at the caudal portion. The torus longitudinales and rostral torus semicircularis of the mesencephalon flattened along the dorsal surface, and the rostral corpus cerebellum was located in the dorsal portion. The actual total brain volume in mature males was significantly greater (p<0.05) than that of females with gonadal development. Notably, the pituitary volume in male turbot significantly increased (p<0.05) from immature to mature stage, but this difference did not occur in females. The data together illustrate a distinct sex difference in the turbot brain during gonadal development, providing insight into their HPG axes.     

鼻咽癌放疗后正常显示脑灰质的容积变化——基于体素的MR形态学研究

目的:探讨鼻咽癌患者放疗后全脑灰质体积的改变情况。方法:对20例接受过放射治疗的鼻咽癌患者及16例已确诊而未行放射治疗的鼻咽癌患者,进行全脑高分辨率T1WI扫描,采用基于体素形态测量学(VBM)方法,分析鼻咽癌治疗组与未治疗组脑灰质体积变化的差异。结果:与未治疗组比较,鼻咽癌治疗组双侧颞中回、左侧额上回、左侧枕下叶脑灰质体积显著减少。结论:鼻咽癌放疗后部分脑区脑灰质体积减少,VBM可早期发现常规MRI未显示的异常。     

天气、气候变化与心、脑血管疾病死亡

通过对卫生部统计信息中心1987～1996年北京地区各类疾病死亡资料的详尽分析,结合同期的天气、气候资料,研究发现：（1）心、脑血管疾病是北京地区死亡率最高的疾病之一,其死亡率随人口年龄段增长显著增加,且男性死亡率大于女性死亡率,70～74岁年龄段为死亡高峰;（2）中、老年人的心、脑血管疾病死亡率有明显年际变化,其年际变化与同期的年平均气温变化有显著的反相关关系;（3）心血管疾病的诱发与冷锋、寒潮前等低值天气系统的出现有密切的关系。     

我国心脑血管病的医学气象研究

回顾了20世纪80年代以来我国心脑血管病医学气象研究的主要成果，总结分析了这些研究的结论、进展和不足，提出加强和改进此类研究的建议和对策。     

牙鲆gnrh基因的表达分析

本文通过qPCR方法,研究了我国重要海水鱼类——牙鲆（Paralichthys olivaceus）雌、雄成体组织以及性腺分化期的脑、性腺中gnrh1、gnrh2和gnrh3的表达水平。结果显示,gnrh1分布于所有检测的组织：在脑、垂体、肾脏和肝脏中高表达,在性腺中表达相对较低;gnrh2则在雌、雄性的肝脏以及雄性的肠、肾脏、眼睛和头肾中;而gnrh3只在雄性的肾脏、眼睛和肌肉中检测到微弱表达。人工诱导的牙鲆雌核发育鱼苗分别用17β-雌二醇（E₂）和17α-甲基睾酮（MT）处理,使其分化为雌性或雄性个体表型。在性腺分化期的脑中,gnrh1的表达呈现上升趋势,在全长（total length,TL）4 cm鱼苗中,E₂组的表达显著高于MT组（P<0.05）;gnrh2在2 cm TL时E₂组显著高于MT组（P<0.05）,随后在E₂和对照组的表达水平均出现下降趋势;gnrh3在2 cm TL时E₂和对照组的表达均显著高于MT组（P<0.05）,自6 cm TL时MT和E₂组的表达开始下降。在性腺中,三种gnrh在性腺分化前2 cm TL表达量都相对较高,随后呈现下降趋势。综上,推测牙鲆gnrh1可能参与了性腺分化的启动、分化过程及性腺发育,gnrh2主要参与了性腺分化的启动,gnrh3主要参与了性腺分化的启动和分化过程。     

MSCTA在颅内动脉瘤诊断中的应用

目的: 探讨多层螺旋CT血管成像在颅内动脉瘤的诊断中的应用。方法: 收集经手术证实或DSA的颅内动脉瘤31例,所有的病例均行多层螺旋CT血管成像。CTA通过采取VR、MIP及CPR等后处理重建技术,实现脑内血管重现,展现颅内血管的真实情况。20例行手术治疗,11例行DSA检查。结果: 本组31例,共36个颅内动脉瘤。29例单发,2例多发(7个动脉瘤)。MSCTA发现颅内动脉瘤33个,1个动脉瘤误诊;MSCTA正确诊断动脉瘤32个,4个动脉瘤漏诊。MSCTA诊断颅内动脉瘤的准确率为97%(32/33),敏感度为89%(32/36),平均直径为8mm(范围在3~35mm之间)。MSCTA所显示的动脉瘤与手术及DSA所见显示动脉瘤位置、大小、形态基本一致。结论: MSCTA能清楚显示颅内动脉瘤的形态、位置及其与周围的解剖关系,其诊断结果与DSA或/手术诊断符合率相当高,在颅内动脉瘤的诊断中有重要的价值。