脑干听觉诱发电位与后循环TIA及脑干梗死的相关性研究

目的:研究脑干听觉诱发电位(BAEP)与后循环短暂性脑缺血发作(TIA)及脑干梗死的相关性。方法:选取我院收治的后循环TIA患者46例作为TIA组,选取同期收治的脑干梗死患者44例作为脑干梗死组,选取同期健康体检者49例作为健康组,TIA组和脑干梗死组均在发病后1周内进行BAEP检查,健康体检者在体检时进行BAEP检查,比较3组的Ⅰ、Ⅲ、Ⅴ波的潜伏期(PL)及Ⅰ-Ⅲ、Ⅲ-Ⅴ、Ⅰ-Ⅴ波峰间的潜伏期(IPL)。结果:TIA组BAEP异常率71.74%,脑干梗死组BAEP异常率56.82%,健康组BAEP异常率24.49%,TIA组患者BAEP异常率高于健康组,差异有统计学意义(P0.05)。脑干梗死组BAEP异常率高于健康组,差异有统计学意义(P0.05)。TIA组患者PL的Ⅰ、Ⅲ、Ⅴ水平均高于健康组,差异有统计学意义(P0.05)。TIA组患者IPL的Ⅰ-Ⅲ、Ⅲ-Ⅴ、Ⅰ-Ⅴ水平均高于健康组,差异有统计学意义(P0.05)。脑干梗死组患者PL的Ⅰ、Ⅲ、Ⅴ水平均高于健康组,差异有统计学意义(P0.05)。脑干梗死组患者IPL的Ⅰ-Ⅲ、Ⅲ-Ⅴ、Ⅰ-Ⅴ水平均高于健康组,差异有统计学意义(P0.05)。脑干梗死组患者IPL与PL均明显高于TIA组(P0.05)。结论:BAEP与后循环TIA及脑干梗死存在相关性,并且较为敏感,是优秀的诊断方法之一。     

体温过高对大鼠脑干听觉诱发电位和中潜伏期反应的影响

目的 :探讨体温过高对大鼠脑干听觉诱发电位 (BAEP)和听觉中潜伏期反应 (MLR )的影响。方法 :诱发电位仪颅表记录大鼠BAEP和MLR ;体表物理升温法逐步升高麻醉大鼠体温 ,传感探头式数字体温计监测大鼠直肠体温 ;主要观察BAEP和MLR的波峰潜伏期 (PL)、波峰间潜伏期 (IPL)和波幅随体温升高而发生的变化及它们消失的临界体温。结果 :BAEP各波PL及Ⅰ Ⅱ、Ⅰ Ⅲ、Ⅰ ⅣIPL随体温升高 ( 3 7～ 41.5℃ )而逐步缩短 ,但当体温升高至 42℃和超过 42℃时各波PL及Ⅰ Ⅱ、Ⅰ ⅣIPL不再继续缩短 ,并略有反向延长 ;MLR各波PL和P1 P3、P2 P3IPL也随体温升高 ( 3 7～ 43℃ )而缩短。随体温升高 ,BAEP和MLR波幅的主要表现为降低 ,特别是在体温升高至42℃以后。BAEP和MLR在体温 ( 4 3 .1± 0 .5)℃时出现不可逆性消失 ,且两者同步消失。结论 :体温过高对大鼠BAEP和MLR有相似的显著影响 ,体温过高至一临界值时会造成BAEP和MLR的不可逆性损害。     

兔脑温升高时听觉诱发电位的变化

兔单侧颈总动脉血体外加温灌流可选择性地升高脑温。在脑温升高3℃过程中,听觉脑干诱发电位成分Ⅰ的峰潜伏期无明显改变,成分Ⅱ～Ⅵ及听觉中潜伏期诱发电位成分Pa的峰潜伏期则逐渐缩短,其中Pa变化最早和最显著;Ⅰ～Ⅲ,Ⅲ～Ⅵ和Ⅵ～Pa峰间期的缩短,以Ⅵ～Pa变化最早、最显著。经脑复温而仍存活的兔,缩短的峰潜伏期可逐渐恢复,当脑复温至加温前水平时,Ⅱ、Ⅴ和Ⅵ峰潜伏期及Ⅲ～Ⅵ峰间期较加温前延长。结果表明,兔脑温升高可使听觉中枢传导径路上各级神经元的传导功能增强,而脑复温时,增强的传导功能逐渐降低,随后,部分神经元的传导功能低于加温前水平。     

早产儿听神经通路的发育神经生物学特性

系统地观察了不同周龄正常早产儿脑干听觉诱发反应的特性,结果表明①刺激强度80、60dBnHL时Ⅰ波35周前,Ⅲ、Ⅴ波36周前明显长于足月新生儿(P<0.05,P<0.01),刺激强度30dBnHL时Ⅰ波35周前,Ⅲ、Ⅴ波至37周仍明显长于足月新生儿(P<0.05,P<0.01);②≤32周Ⅰ—Ⅲ、Ⅰ—ⅤIPL与足月新生儿比较分别延长0.40和0.55ms,33—35周平均延长0.31和0.29ms,36周接近足月新生儿;③Ⅰ、Ⅲ、Ⅴ波潜伏期—成熟函数曲线的斜率≤32—33周时分别为0.62、0.66和0.80ms/week,33—35周时分别为0.09、0.03和0.06ms/week,35—36周时分别为0.00、0.33和0.38ms/week。     

鸟类脑干听觉诱发电位的观察

采用短声刺激鸟类听觉感受器的方法,对15只健康成年虎皮鹦鹉的脑干听觉诱发电位进行了实验观察。结果发现,鸟类头顶均能记录到与听觉有关的脑干听觉诱发电位Ⅰ波、Ⅱ波、Ⅲ波、Ⅳ波和Ⅴ波。为鸟类语言发声研究的听力学评价提供一个简便可行的方法。     

高胆红素血症新生大鼠脑干听觉诱发电位快慢成分的变化

目的：探讨高胆红素血症新生大鼠脑干听觉诱发电位快成分（FC-BAEP）和慢成分（SC-BAEP）及脑干神经元线粒体超微结构的异常变化。方法：生后7天SD大鼠随机分为对照组（C组,17只）和两个实验组（T1和T2组,各17只）。T1和T2组大鼠生后7天和10天腹腔注射2g/L胆红素溶液,第二次腹腔注射6h后随机抽出7只断头取血用微量胆红素仪检测血清胆红素,其余大鼠生后17天和20天用诱发电位仪检测FC-BAEP和SC-BAEP,生后20天灌注固定、取耳蜗核进行透射电镜观察。结果：T1和T2组大鼠于生后10天腹腔注射6h后,血清胆红素浓度明显升高;T1和T2组大鼠生后17天三种刺激重复率（10/s,40/s,80/s）引导的FC-BAEP,除Ⅱ-Ⅳ波峰间潜伏期（IPL）外,各波波峰潜伏期（PL）和IPL显著延长,且T2组大鼠各波PL较T1组显著延长;T1和T2组大鼠生后20天三种刺激重复率引导的FC-BAEP,除刺激重复率10/s和40/s引导的Ⅱ-ⅣIPL外,各波PL和IPL显著延长;T1和T2组大鼠生后17天与20天刺激重复率10/s引导的SC-BAEP的PL显著延长,且T2组大鼠生后17天SC-BAEP的PL较T1组显著延长;T1和T2组大鼠耳蜗核电镜观察可见神经元线粒体肿胀变形、膜模糊不清和嵴断裂等。结论：高胆红素血症新生大鼠FC-BAEP和SC-BAEP及脑干神经元线粒体超微结构有显著异常变化,FC-BAEP与SC-BAEP的PL和IPL是早期监测胆红素诱发的听觉和脑损伤的客观灵敏指标。     

大鼠脑干听觉诱发电位和中潜伏期反应的生后发育

目的：探讨大鼠脑干听觉诱发电位（BAEP）和听觉中潜伏期反应(MLR)生后发育模式的异同。方法：在同一批新生SD纯种大鼠连续10周同时观察BAEP和MLR生后发育的变化。结果：BAEP和MLR分别在生后14d和17d出现;BAEP各波峰潜伏期（PL）随鼠龄增长而递减,生后3－4周是PL缩短的主要时期,I波PL在生后29d达成年值,其余各波PL在生后70d全部达成年值;首次出现的MLR,其Po和Na两波PL已达成年值,而Pa、Nb和Pb和PL也随鼠龄增长而缩短,但生后20－23d很快就达成年值;BAEP的Ⅰ、Ⅲ、Ⅳ波和MLR的Nb、Pb波波幅在生后3－4周期间迅速递增,且峰值明显大于成年值,然后逐渐回降。结论：大鼠MLR和BAEP生后发育的模式基本相同,但MLR各波PL较早达成年值。     

足月新生儿听觉脑干电反应的特性

本文工作根据北京市儿童医院临床的需要,在临床实验条件下对足月新生儿的ABR进行了测量,以期分析足月新生儿ABR的电反应特征。 新生儿听觉脑干反应(ABR)的波形是Ⅰ、Ⅲ、Ⅴ波为主的连续波复合体;新生儿在声强80dB(HL)刺激频率20次/秒的短声刺激条件下,I、Ⅲ、Ⅴ波潜伏期大体为2.50,5.00和7.00ms;新生儿ABR潜伏期—刺激强度函数的斜率是30—60μsec/dB(声刺激强度从80到50dB(HL),声刺激频率20次/秒);新生儿ABR Ⅴ波对Ⅰ波的比率大于1.0(短声强度80dB(HL),刺激频率20次/秒);在80dB(HL)短声条件下,改变声刺激频率(从20次/秒增止100次/秒),Ⅴ波潜伏期约延长0.6—1.0ms;新生儿ABR阈值在30—60dB(HL)的范围。综上所述新生儿ABR电反应特性,可以为其听力和脑干功能的临床诊断提供可靠的指标和依据。     

听性脑干反应在脑外伤后听力患者的早期诊断及预后中的意义

目的:探讨脑外伤后伴发听力损伤的患者听性脑干反应的特点及其和预后的相关性。方法:纳入颅脑外伤伴发听力障碍的患者50例,其中男34例,女16例,为观察组,选健康正常成年人50例为对照组,其中男30例,女20例。对观察组受伤后2周内及6个月后进行听性脑干反应检查,对比分析两组患者听性脑干反应波特点及其和预后的相关性。结果:正常人听觉阈值的95%置信区间是[10.24-19.33]d BHL。观察组和对照组的听觉阈值分别为52.24±21.75(d Bn HL)、11.36±3.02(d Bn HL),差异有统计学意义(p0.05)。对照组主波Ⅰ、Ⅲ、Ⅴ出现率为100%,观察组的出现率分别为78.00%、66.00%、88.00%,差异有统计学意义(P0.05)。病例组和对照组相比,Ⅰ、Ⅱ、Ⅲ、Ⅳ、Ⅴ潜伏期均延长,差异存在统计学意义(P0.05)。预后良好组患者受伤2周内和6个月后Ⅰ、Ⅲ、Ⅴ出现率明显增加,潜伏期缩小,差异有统计学意义(P0.05)。而无改善组患者Ⅰ、Ⅲ、Ⅴ出现率略有增加,潜伏期缩小不明显,差异无统计学意义(P0.05)。结论:脑外伤患者听性脑干反应主波Ⅰ、Ⅲ、Ⅴ缺失,潜伏期缩小,若此种变化持续不改善,预示着听力损伤预后较差。     

促红细胞生成素对脑损伤早产儿NBNA评分、肝肾功能以及脑干听觉诱发电位的影响

目的:探讨促红细胞生成素(EPO)对脑损伤早产儿新生儿神经行为测定(NBNA)评分、肝肾功能以及脑干听觉诱发电位的影响。方法:选取2015年2月~2018年7月期间我院收治的脑损伤早产儿117例,将上述研究对象根据随机数字表法将其分为对照组(n=58)和观察组(n=59),对照组患儿给予常规对症治疗,观察组在对照组的基础上联合EPO治疗,比较两组NBNA评分、肝肾功能以及脑干听觉诱发电位,记录两组患儿治疗期间并发症发生情况。结果:观察组纠正胎龄40周时NBNA评分高于对照组(P<0.05)。两组患儿治疗后峰间期(Ⅰ~Ⅲ波、Ⅲ~Ⅳ波、Ⅰ~Ⅳ波)、潜伏期(Ⅰ波、Ⅲ波、Ⅳ波)均较治疗前降低,且观察组低于对照组(P<0.05)。两组患儿治疗前、后尿素氮(BUN)、肌酐(Cr)、血清谷丙转氨酶(SGPT)、总胆红素(TBIL)比较差异均无统计学意义(P>0.05)。两组患儿动脉导管未闭、新生儿败血症发生率比较差异无统计学意义(P>0.05),而观察组支气管肺发育不良、颅内出血、脑干听觉诱发电位异常等发生率低于对照组(P<0.05)。结论:EPO对脑损伤早产儿具有一定的神经保护作用,能够有效保护受损神经细胞与听觉神经通路,降低脑损伤并发症的发生率,且不影响患儿的肝肾功能。     

Recent advances in the study of Kaposi's sarcoma-associated herpesvirus replication and pathogenesis

It has now been over twenty years since a novel herpesviral genome was identified in Kaposi's sarcoma biopsies. Since then, the cumulative research effort by molecular biologists, virologists, clinicians, and epidemiologists alike has led to the extensive characterization of this tumor virus, Kaposi's sarcoma-associated herpesvirus(KSHV; also known as human herpesvirus 8(HHV-8)), and its associated diseases. Here we review the current knowledge of KSHV biology and pathogenesis, with a particular emphasis on new and exciting advances in the field of epigenetics. We also discuss the development and practicality of various cell culture and animal model systems to study KSHV replication and pathogenesis.     

The structure, reproduction and taxonomy of Vidalia and Osmundaria (Rhodophyta, Rhodomelaceae)

Comprises species occurring mostly in subtidal habitats in tropical, subtropical and warm-temperate areas of the world. An analysis of the type species, V. spiralis (Sonder) Lamouroux ex J. Agardh, a species from Australia, establishes basic characters for distinguishing species in the genus. These characters are (1) branching patterns of thalli, (2) flat blades that may be spiralled on their axis, (3) width of the blade, (4) primary or secondary derivation of sterile and fertile branchlets and (5) position of sterile and fertile branchlets on the thalli. Application of the latter two characters provides an important basic method for separation of species into three major groups. Osmundaria , a genus known only in southern Australia, was studied in relation to Vidalia , and its separation from the Vidalia assemblage is not accepted. Species of Vidalia therefore are transferred to the older genus name, Osmundaria. Two new species, Osmundaria papenfussii and Osmundaria oliveae are described from Natal. Confusion in the usage of the epithet, Vidalia fimbriala Brown ex Turner has been clarified, and Vidalia gregaria Falkenberg, described as an epiphyte on Osmundaria pro/ifera Lamouroux, is revealed to be young branches of the host, Osmundaria prolifera.     

New or rare chromosome counts in Artemisia L. (Asteraceae, Anthemideae) and related genera from Kazakhstan

Fifteen chromosome counts of six Artemisia taxa and one species of each of the genera Brachanthemum, Hippolytia, Kaschgaria, Lepidolopsis and Turaniphytum are reported from Kazakhstan. Three of them are new reports, two are not consistent with previous counts and the remainder are confirmations of very scarce (one to four) earlier records. All the populations studied have the same basic chromosome number, x = 9, with ploidy levels ranging from 2x to 6x. Some correlations between ploidy level, morphological characters and distribution are noted.     

肝癌中HBV和HCV基因和抗原的分布及意义

采用原位分子杂交方法检测HCV RNA及HBV X基因;采用免疫组织化学方法研究HCV核心抗原,非结构区C33c抗原及HBxAg在肝细胞肝癌中的定位及分布.结果表明(1)HCV RNA、HBV X基因在肝细胞肝癌组织检出率分别为40%(55/136)和82%(112/136).HCV RNA定位于癌细胞的胞浆内,阳性细胞呈散在、灶状及弥漫分布三种形式;HBV X基因在肝癌细胞中的分布呈胞浆型、核型及核浆型,阳性细胞也呈上述三种分布形式;(2)HCV C33c抗原、核心抗原在肝细胞肝癌中的阳性率为81%(133/164)及86%(141/164).C33c抗原定位于癌细胞及肝细胞的胞浆内;核心抗原既定位于癌细胞核中,又可定位于胞浆中.C33c抗原阳性细胞以灶状分布为主;而核心抗原阳性细     

Selection with two alleles and complete dominance

For a plant selection model with frequency-independent viabilities, fertilities and selfing rates, it is shown that apart from global fixation, for certain parameter combinations a protected polymorphism and facultative fixation (either allele may become fixed according to initial frequencies) may both occur. Facultative fixation requires different selling rates for the dominant and recessive type. Protection of the polymorphism requires resource allocation for male and female function. In this connection the problem of purely genetically caused population extinction is discussed.
For general frequency dependence and regular segregation, the chances for establishment of a completely recessive gene are compared to those of a completely dominant gene. It is proven that the process of establishment of the recessive gene, despite a fitness advantage, may be considerably endangered by drift effects if random mating prevails. The recessive gene may reach the same effectivity in establishment as a dominant gene, only if the recessive homozygote mates exclusively with its own type during the period of establishment.