黄胸鼠年龄研究及其鼠疫动物流行病学意义

本文对200匹黄胸鼠臼齿的研究结果表明,一龄以上鼠占总体的68.5%(1～3龄占62%),10月龄以下鼠占31.5%;在344匹检测鼠疫菌阳性的黄胸鼠中,一龄以上鼠占85.76%,一龄以下鼠占14.24%。这一年龄分布特点,反映了黄胸鼠种群生态演替规律及其鼠疫动物流行病学意义。     

西林县鼠疫流行期间主要宿主动物和媒介蚤的调查

目的研究西林县鼠疫流行期间主要宿主动物和媒介蚤的特征，探讨鼠疫流行的危险因素。方法在2001年鼠疫流行期间对一、二和三类疫区采用笼捕法进行鼠密度调查，采用粘蚤纸法进行地面游离蚤调查，对捕获的鼠蚤进行分类鉴定。结果一类区黄胸鼠密度为5．73％，高于二、三类区的4．B7％和4．77％；二类区的黄胸鼠体印鼠客蚤指数为0．14，明显低于一、三类区的0．98和0．93；一类区的地面游离蚤指数为0．06，明显高于二、三类区的0．0054和0。结论家鼠鼠疫疫区黄胸鼠和印鼠客蚤占总数的70％以上，当室内黄胸鼠密度大于5％及黄胸鼠体印鼠客蚤指数大于1等三项指标同时成立是鼠疫流行前期的预兆。     

Translation of an integral membrane protein in distal dendrites of hippocampal neurons

Maintenance of synaptic plasticity requires protein translation. Because changes in synaptic strength are regulated at the level of individual synapses, a mechanism is required for newly translated proteins to specifically and persistently modify only a subset of synapses. Evidence suggests this may be accomplished through local translation of proteins at or near synapses in response to plasticity-inducing patterns of activity. A number of proteins important for synaptic function are integral membrane proteins, which require a specialized group of organelles, proteins and enzymatic activities for proper synthesis. Dendrites appear to contain machinery necessary for the proper production of these proteins, and mRNAs for integral membrane proteins have been found localized to dendrites. Experiments are described that investigate the local translation of membrane proteins in the dendrites of cultured rat hippocampal neurons, using fluorescence recovery after photobleaching. Neurons were transfected with cDNAs encoding a fluorescently labeled transmembrane protein, TGN-38. Under conditions where the transport of this reporter construct was inhibited, the appearance of newly synthesized protein was observed via fluorescent microscopy. The dendritic translation of this protein required activation of glutamate receptors. The results demonstrate a functional capacity for activity-dependent synthesis of integral membrane proteins for distal dendrites in hippocampal neurons.     

NMDA-evoked calcium transients and currents in the suprachiasmatic nucleus: gating by the circadian system

A variety of evidence suggests that the effects of light on the mammalian circadian system are mediated by glutamatergic mechanisms and that the N-methyl- D-aspartate (NMDA) receptor plays an important role in this regulation. One of the fundamental features of circadian oscillators is that their response to environmental stimulation varies depending on the phase of the daily cycle when the stimuli are applied. For example, the same light treatment, which can produce phase shifts of the oscillator when applied during subjective night, has no effect when applied during the subjective day in animals held in constant darkness (DD). We examined the hypothesis that the effects of NMDA on neurons in the suprachiasmatic nucleus (SCN) also vary from day to night. Optical techniques were utilized to estimate NMDA-induced calcium (Ca2+) changes in SCN cells. The resulting data indicate that there was a daily rhythm in the magnitude and duration of NMDA-induced Ca2+ transients. The phase of this rhythm was determined by the light-dark cycle to which the rats were exposed with the Ca2+ transients peaking during the night. This rhythm continued when animals were held in DD. gamma-Aminobutyric acid (GABA)ergic mechanisms modulated the NMDA response but were not responsible for the rhythm. Finally, there was a rhythm in NMDA-evoked currents in SCN neurons that also peaked during the night. This study provides the first evidence for a circadian oscillation in NMDA-evoked Ca2+ transients in SCN cells. This rhythm may play an important role in determining the periodic sensitivity of the circadian systems response to light.     

武汉市褐家鼠和黄胸鼠对杀鼠灵的抗药性研究

目的调查武汉市褐家鼠和黄胸鼠对杀鼠灵的抗药性状况,为制定灭鼠措施提供依据。方法无选择摄食实验测试法。结果褐家鼠和黄胸鼠对杀鼠灵抗药性率分别为0和13.33%,致死剂量分别为25.45和156.16 mg/kg,平均致死天数为7.7和11.1 d。结论武汉市褐家鼠对杀鼠灵未监测到抗药性,少数黄胸鼠对杀鼠灵产生了抗药性,但未出现抗药性种群。     

常用鼠药对褐家鼠和黄胸鼠药效测试

目的测试几种常见武汉市售鼠药对褐家鼠和黄胸鼠药效。方法在实验室做无选择摄食实验,测试8种鼠药对褐家鼠及3种鼠药对黄胸鼠的药效。结果除1号鼠药毒杀率达80%外,其他7种鼠药对褐家鼠毒杀率均达100%。1号、3号鼠药对黄胸鼠毒杀率10%,经χ2检验它们与该鼠药对褐家鼠毒杀率相比有极显著差异(χ2=9.90和16.36>χ0.01=6.63)。6号鼠药毒杀率为70%与该鼠药对褐家鼠毒杀率相比无显著差异(χ2=3.53<χ0.05=3.84)。结论黄胸鼠比褐家鼠更能耐受某些鼠药,在以黄胸鼠为主的地点灭鼠可以选用6号灭鼠剂或增加鼠药在现场留存时间。     

福建省广州管圆线虫及中间宿主的调查

调查福建省广州管圆线虫的分布,发现除沿海地区外,福建的山区也有广州管圆线虫的感染,在全省范围内呈点状分布,感染率从5.95％到15.93％不等;广州管圆线虫的终宿主主要为褐家鼠,而中间宿主以福寿螺为主,对人们的健康构成威胁,应加强科学研究和宣传教育,预防广州管圆线虫病的发生。     

中药对膝骨关节炎黑鼠血清SOD,HA,NO水平的影响

为比较益肾、健脾和柔肝方药对膝骨关节炎血清ＳＯＤ、ＨＡ、ＮＯ水平的影响,以运动负荷方法造成Ｃ５７黑鼠早、中、晚三期膝骨关节炎模型,分别测定各期,各组黑鼠血清ＳＯＤ、ＨＡ和ＮＯ的含量,结果示骨关节炎早期和晚期,各指标组间相比均无显著性差异。中期、血清ＳＯＤ水平模型组怀空白组无差异;与模型组比较,益肾组、柔肝组水平升高,健脾组无差异。血清ＨＡ水平模型组、健脾组、芬必得组明显高于空白组;益肾组和柔肝组明     

Class I and class II regions of the major histocompatibility complex both contribute to individual odors in congenic inbred strains of rats

The major histocompatibility complex (MHC) of the rat has three regions—A (class I), B/D (class II), and C/E (class I)—and congenic strains are available which differ in each of these regions. We used the habituation-dishabituation procedure to examine the ability of PVG-RT1^u male rats to discriminate between the urinary odors of congenic rat strains which differ genetically only at certain individual regions of the MHC. The results of five experiments indicate that discrimination can be made between urine from rats which differ in all three regions of the MHC (PVG vs. PVG-RT1^av1 donors), only in the class I A region (PVG vs. PVG.R1 donors), only in the class I C/E region (PVG.R19 vs. PVG-RT1^av1 donors), only in the class II B/D region (PVG.R1 vs. PVG.R19 donors), and in all regions except the classical class IA locus (PVG-RT1^av1 vs. PVG.R1 donors). These results indicate that all of the MHC regions may contribute to the individual odors of rats.This research was supported by Natural Sciences and Engineering Research Council of Canada Grant A7441 (R.E.B.), the Medical Research Council of Great Britain (B.R.), and a NATO Collaborative Research Grant. P.B.S. is working under an AFRC New Initiatives Grant.     

Immobilization-produced gastric pathology in wild rats (Rattus norvegicus)

Seven groups of wild rats (Rattus norvegicus) were deprived of food and immobilized in wire mesh cocoons for varying periods of time. Following immobilization, they were examined for gastric ulcers. Minimum immobilization necessary to produce ulcers given that pre-immobilization food deprivation was sufficiently long appeared to be between 12 and 24 hr. Results are compared to those obtained by other investigators using laboratory rats.