镉对大头金蝇幼虫体长变化的影响

目的：探讨镉对大头金蝇幼虫生长发育的影响及其在法医学死亡时间推断中的意义。方法：取初产卵接入不同剂量（0、100、200、500、1 000 mg/kg）镉中毒小鼠尸体上,于（25.0±0.5）℃光照培养箱内饲养,对其幼虫体长变化进行测量分析。结果：大头金蝇幼虫体长在取食期极显著线性增长后,在离食期显著降低。就取食期幼虫而言,镉在≤200 mg/kg下可略微促进幼虫体长的增长,但在≥500 mg/kg下可极显著地抑制体长的增长并延长其幼虫的发育历期。结论：镉对大头金蝇幼虫体长有显著影响。     

大头金蝇成虫蝶啶荧光分析的方法学研究

目的：建立大头金蝇（Chrysomyia megacephala，C．megacephala）成虫头壳蝶啶含量的分析方法。方法：取C．megacephala头壳于3mL Tris-HCl缓冲液（pH8．0）中匀浆，离心。应用荧光分光光度计分析上清液的荧光强度。结果：当蝶啶溶液浓度低于0．8个头壳，3mL时。其荧光强度随溶液浓度的增长呈线性增加（r^2=0．9907。P〈0．01）。浓度较高时，蝶啶溶液对其荧光有着显著的浓度淬灭效应。其荧光强度随溶液浓度增加逐渐降低（P〈0．01）。光照条件下。蝶啶溶液的荧光强度随放置时间的延长而显著增加（r^2=0．9676，P〈0．01）；黑暗条件下．虽然蝶啶溶液的荧光强度也随时间的延长而显著增加（P〈0．0S），但其增长速率比光照条件下小得多。结论：在进行蝶啶荧光分析时。必须控制蝶啶溶液的终浓度，注意避光，并缩短从匀浆到荧光分析的时间间隔。以减少分析误差。     

自然条件下大头金蝇的发育速度和有效积温及其法医学应用

目的研究大头金蝇在自然条件下的发育规律,探讨其在法医学中的应用。方法对大头金蝇在自然条件下的发育速度及有效积温进行观察、记录和统计学处理。结果确立了Y1=0.430 8+0.237 1X,Y2=75.684 6-1.444 7X 2个有效积温与蛆长和蛹体质量的线性回归方程。结论在自然条件下用积温法建立起的大头金蝇发育数学模型可应用在法医学死亡时间推断中。     

昆虫病原线虫对大头金蝇Chrysomyia megacephale Fab.幼虫致死试验初报

大头金蝇是我国重要的肠道疾病的传播昆虫,本试验表明其幼虫期对昆虫病原线虫Steinernema carpocapsae Agriotos品系很敏感,在实验室条件下处理两天后有80％幼虫被线虫致死,处理四天后致死率达91.7％.     

铜绿蝇幼虫在不同脏器组织源食物上生长发育变化

目的：研究铜绿蝇幼虫在不同组织源的食物上生长发育变化。方法：在26 ℃恒温、相对湿度70%条件下,用猪的肌肉组织、肝脏组织、脑组织、肌肉与脂肪的混合物（6︰4）分别饲养铜绿蝇幼虫。每隔12 h测体长和体质量,化蛹后测蛹的体长和体质量。统计幼虫及蛹的死亡率。推算各组幼虫发育总历期和成虫的性别比。结果：40%脂肪混合组与其他3组相比生长缓慢,达到最大个体的时间延迟24 h以上。肝脏组幼虫体长（15.02±1.39） mm和40%脂肪混合组体长（14.85±1.43） mm明显小于脑组织组（17.53±2.08） mm、肌肉组（16.82±2.15） mm（F=5.440,P=0.003）;肝脏组幼虫体质量（72.8±14.2） mg和40%脂肪混合组体质量（70.4±15.4） mg均明显小于脑组织组（89.6±19.2） mg和肌肉组（85.9 ±16.7） mg（F=3.320,P=0.030）。40%脂肪混合组蛹体长及体重均明显小于脑组织组和肌肉组（F=7.890,P=0.001;F=9.280,P=0.001）。40%脂肪混合组幼虫和蛹的死亡率均明显高于脑组织组、肌肉组、肝脏组（F=3.470,P=0.040;F=4.720,P=0.035）。结论：铜绿蝇幼虫在40%脂肪混合食物上生长发育历期较长,肝脏组和40%脂肪混合组幼虫及蛹的体长和体质量较小。     

郑州市郊区秋季尸食性麻蝇生长发育规律

利用苍蝇的生长演化规律推断人体死亡时间,尤其是推断中晚期死亡时间,是法医工作中经常使用且行之有效的方法之一[1-4].苍蝇的生长发育规律受地区、季节、气候的影响较大.作者选择郑州市郊区作为实验地点,观察该地区秋季自然条件下麻蝇的生长发育规律,以便为该地区秋季人体死亡时间的推断提供较为准确的法医昆虫学依据.     

石墨炉原子吸收光谱法测定镉中毒小鼠尸体中大头金蝇体内的镉和金属硫蛋白

目的:研究尸食性蝇类大头金蝇体内的镉(cd)浓度能否反映所寄生尸体生前的Cd投毒量.方法:大头金蝇初产卵接入Cd中毒小鼠尸体,分别于产卵后3 d(幼虫)、7d(幼虫)、9d(蛹)收集幼虫(蛹)样本,用微酸量消化处理测Cd,用Cd-血红蛋白饱和法处理测金属硫蛋白(MT).塞曼效应校正背景,石墨炉原子吸收法进行测定.结果:方法检出限分别为:cd0.024μg/L和MT 0.027 μg/L.回收率实验分别为Cd 94.3％～105.0％,MT90.2％～108.0％.大头金蝇幼虫随着生长时间增加Cd蓄积也增加,但蛹期Cd浓度减少,MT表达也表现类似规律,各个生长期的Cd浓度与投毒量呈线性相关.结论:检测昆虫体内的Cd,可用于判断尸体生前摄入的Cd是否达到致死量.     

不同温度条件下盐酸吗啡对肥须亚麻蝇幼虫的影响及法医学意义

目的 研究不同浓度盐酸吗啡和不同温度对石家庄地区优势蝇种肥须亚麻蝇(Parasarcophaga crassi palpis)幼虫头咽骨的影响,积累石家庄地区尸源性蝇类的法医昆虫毒理学资料,从而为死后间隔时间( postmortem interval,PMI)的推断提供科学依据.方法 诱捕肥须亚麻蝇,并在培养箱中连续培养.选用家兔4只,其中1只经耳缘静脉注射生理盐水(对照),另3只分别给予0.5、1、2倍致死剂量盐酸吗啡经耳缘静脉注射.分别在24℃、28℃、32℃恒温条件下用新鲜猪肝诱导成蝇产幼虫并移至家兔肌肉组织上饲养.每隔12h留取幼虫标本一次直至达到离食期.将幼虫烫死并保存.体视显微镜下分离出幼虫的头节,然后将头咽骨进行对称分离,光学显微镜下观察、拍照.利用计算机图像分析系统对头咽骨的口钩及咽骨面积、骨化面积和平均光密度等指标进行测定.结果 (1)随着盐酸吗啡浓度和温度的增高,肥须亚麻蝇幼虫的生长速度均在一定程度上加快.(2)随着时间的延长,幼虫头咽骨的颜色从浅棕黄色逐渐加深直至变为黑褐色,同时,骨化程度逐渐加强,骨化面积不断加大,并在三龄期出现点状的附口骨.(3)幼虫口钩和咽骨面积均随时间的延长不断增加,在叠龄期时变化较剧烈,直至进入三龄期后很快达到最大值,并进入平台期,维持基本恒定.(4)幼虫口钩的骨化面积和平均光密度及咽骨的骨化面积和平均光密度在3个龄期中均随时间的延长而逐渐增高,直至三龄期结束.口钩和咽骨的骨化面积和平均光密度达到最大值的时间明显滞后于二者面积达到最大值的时间.结论 肥须亚麻蝇幼虫的口钩骨化面积和平均光密度及咽骨的骨化面积和平均光密度均随时间的延长呈现持续性增加的趋势,并一直维持到三龄期后,此4项指标是推测PMI的理想指标.     

应用PCR-SSCP分析我国不同地区常见嗜尸蝇类的研究

目的 探讨应用PCR-SSCP分析我国不同地区常见嗜尸蝇类,揭示其亲源关系及基因差异.方法 采集了中国部分城市,即广州、深圳、阳江、南京、长春、宜昌、北京、武汉、成都等地的常见嗜尸蝇类:家蝇(Muscdomestica),丝光绿蝇(Lucilia sericata),大头金蝇(Chrysomya megacephcda),黑尾麻蝇(Helicophagella melanura),棕尾麻蝇(Boettcherisca peregrina)等.用PCR.SSCP分析我国不同嗜尸蝇类的rDNA-ITS2基因片段.结果 PCR-SSCP分析结果显示,Chrysomya megacephata,Aldrichina grahami(巨尾阿丽蝇),Helicophagella melanura,Muscdomestica,Boettcherisca peregrina rDNA-ITS2基因的单链DNA(ssDNA)迁移率均有明显差异,我国不同地区常见嗜尸蝇种类rDNA-ITS2基因单链DNA迁移图型呈现多态性.结论 我国不同地区常见嗜尸蝇种类的rDNA-ITS2基因存在种内、种间及地理的基因多态性.     

兔急性肺损伤死后肝内血管内皮生长因子时序性变化的研究

目的研究大潮气量机械通气致兔急性肺损伤（ALI）12h后处死，死后肝微血管内血管内皮生长因子（VEGF）的动态变化。方法机械通气（VT60mL／kg，R50次／min）致急性肺损伤后12h处死兔，应用免疫组织化学染色（SABC法）和图像分析系统，观测死后不同时间点肝内微血管内皮细胞内vEGF的动态变化。结果对照组死后即刻肝内微血管内皮细胞胞浆vEGF呈弱阳性染色，死后2h阳性染色程度有轻度增加，但以后随PMI的延长VEGF逐渐减弱，死后18h呈阴性；试验组死后肝内微血管的内皮细胞胞浆VEGF呈强阳性表达，但随着PMI延长逐渐减弱，在死亡后0-24h减弱幅度较小，但21-36h阳性染色程度下降较快，直至死后42h随肝内微血管结构崩解而完全消失。结论大潮气量机械通气致急性肺损伤12h处死后，肝微血管内VEGF的变化在一定的时间段内与死亡时间呈现相关关系。     

氯胺酮静脉麻醉时的儿童眼心反射观察

目的观察氯胺酮麻醉时的儿童眼心反射，以寻求较理想的麻醉方法。方法记录３４例儿童的睡眠脉率和氯胺酮静脉麻醉下斜视术中的脉率，并进行比较。结果９例患儿的脉率在牵拉眼外肌时减慢２０％以上，但仍高于他们的睡眠脉率。结论氯胺酮静脉麻醉时行儿童斜视矫正术较安全     

Correlative Analysis on the Relationship between PMI and DNA Degradation of Cell Nucleus in Human Different Tissues

Summary： To determining the postmortem interval （PMI） through quantitative analysis of the DNA degradation of cell nucleus in human brain and spleen by using image analysis technique （IAT）. The brain and spleen tissues from 32 cadavers with known PMI were collected, subjected to cell smear every 1 h within the first 5-36 h after death, stained by Feulgen-Van＇s staining, Three indices reflecting DNA in brain cells （astrocytes） and splenic lymphocytes, including integral optical density （IOD）, average optical density （AOD）, average gray （AG） were measured by employing the mage analysis instrument. The results showed that IOD and AOD declined and AG increased with the prolongation of dead time within 5 36 h. A correlation between the PMI and gray parameters （IOD,AOD and AG） was identified and the corresponding regression equation was obtained. The parameters （IOD, AOD and AG） were proved to be effective quantitative indicators for accurate estimation of PMI within 5-36 h after death.     

河北省丽蝇科种属及其分布(双翅目:环裂亚目)

目的:调查研究河北省丽蝇科昆虫的种类及其分布。方法:采用昆虫分类学原理和方法。结果:在河北省发现丽蝇科昆虫58种,隶属于4亚科4族21属。结论:河北省丽蝇科种数约占该科全国已知种数的23.20%。约占世界丽蝇科种数的5.27%。     

氯胺酮对小儿术后静脉镇痛中芬太尼作用的影响

目的研究氯胺酮在小儿术后静脉自控镇痛中对芬太尼作用的影响。方法全麻下择期腹部手术病儿38例,病人随机分为两组,每组19例。F组芬太尼0.3μg／（kg·h）,FK组0.2μg／（kg·h）＋氯胺酮70μg／（kg·h）静脉术后镇痛治疗。分别于手术结束后6、24、36、48h记录疼痛、镇静评分、发生的不良反应（瘙痒、恶心呕吐、精神症状）、血氧饱和度。结果FK组的疼痛评分在各时间点均明显低于F组在相同时间点的疼痛评分（P〈0.05）。两组之间的镇静评分无统计学差异（P〉0.05）。两组中F组恶心、呕吐（16.0％）、静脉炎的发生率较KF组高（P〈0.05）。两组中均未出现具有精神症状的病例。两组的血氧饱和度值在各时间点均不低于96％,而且两组之间无统计学差异（P〉0.05）。结论70μg／（kg·h）氯胺酮在静脉术后镇痛中能够增强芬太尼的镇痛作用,减少芬太尼的用量,从而减少副作用。     

Determination of the Early Time of Death by Computerized Image Analysis of DNA Degradation： Which Is the Best Quantitative Indicator of DNA Degradation？

This study evaluated the correlation between DNA degradation of the splenic lympho-cytes and the early time of death,examined the early time of death by computerized image analysis technique(CIAT) and identified the best parameter that quantitatively reflects the DNA degradation.The spleen tissues from 34 SD rats were collected,subjected to cell smearing every 2 h within the first 36 h after death,stained by Feulgen-Van's staining,three indices reflecting DNA content in splenic lymphocytes,including integral optical density(IOD),average optical density(AOD),aver-age gray scale(AG) were measured by the image analysis.Our results showed that IOD and AOD decreased and AG increased over time within the first 36 h.A stepwise linear regression analysis showed that only AG was fitted.A correlation between the postmortem interval(PMI) and AG was identified and the corresponding regression equation was obtained.Our study suggests that CIAT is a useful and promising tool for the estimation of early PMI with good objectivity and reproducibility,and AG is a more effective and better quantitative indicator for the estimation of PMI within the first 36 h after death in rats.     

Mass rearing of Lucilia sericata Meigen (Diptera: Calliphoridae)

Objective

To carry out an experimental study with the main objective of mass rearing of sheep flies (Lucilia sericata).

Methods

Hand collection and beef- or cattle liver-baited net traps were used for field fly sampling from April, 2010 to November, 2010. The samples collected from different places were placed in properly labeled tubes and sent to the Entomology Laboratory. Since maggot identification is important in inducing mortality, they were kept under insectary condition to develop to adult stage and identified using systematic keys.

Results

A total of 218 flies were collected in three rounds of sampling from the field of Tehran and Karaj Counties. In the first generation, 433 flies including 135 (31.17%) male, and 298 (68.82%) female were yielded. The female/male of parent ratio was calculated as 1.72 in Tehran and in Karaj areas, whereas it was 2.20% and 1.81%, respectively in F1 and F2 generations, respectively.

Conclusions

During this study, the mass rearing of sheep blow fly has been established at the School of Public Health, Tehran University of Medical Sciences and can be used for producing flies for maggot therapy.     

Spectrophotometric Determination of Trimethylamine-nitrogen in Cadaver Tissues for the Estimation of Late Postmortem Interval：A Pilot Study

To study the relationship between the late postmortem interval (PMI) and trimethyl-amine-nitrogen (TMA-N) in postmortem tissues of cadaver, TMA-N in muscles, livers and kidneys of rats was measured at different postmortem intervals (PMI) by using a modified spectrophotometric method. The results indicated that the detection sensitivity of TMA-N was 1 mg/L, and there was a good linear correlation between the value of absorbance (A value) and TMA-N at the concentration of 1-10 mg/L (R2=0.9991). Although TMA variation in muscles was different from that in inner organs during the time since death, TMA-N changes in cadaver tissues was positively correlated with PMI. During 2 to 7d since death, the best correlation between PMI and TMA-N concentration was found in muscles. With PMI as an independent variable, the cubic polynomial regression equation was y=-0.457x3 6.519x2-24.574x 27.207 (R2=0.969). During 3 to 8 days since death, PMI was best correlated with TMA-N concentration in inner organs. With PMI as the independent variable, the cubic polynomial regression equation was y=0.509x3-9.153x2 55.727x-95.819 (R2=0.953). It was concluded that TMA-N in tissues could be used as a new estimator for late PMI. The method used in this study offered advantages such as accuracy, sensitivity, little samples required and wide PMI estimation.     

氯胺酮和咪哒唑仑联合使用对乳鼠神经细胞凋亡的影响

目的　探讨联合使用氯胺酮和咪达唑仑对乳鼠神经细胞凋亡的影响。方法　新生 7日龄SD大鼠 2 4只 ,随机分成 4组 (n =6 ) :对照组 (C组 ) :腹腔注射生理盐水 (10ml·kg-1) ;K组 :腹腔注射氯胺酮 (2 0mg·kg-1) ;M组 :腹腔注射咪哒唑仑 (10mg·kg-1) ;K M组 :腹腔注射氯胺酮 (2 0mg·kg-1)和咪哒唑仑 (10mg·kg-1)。用药后2 4h ,用原位缺口末端标记法 (TUNEL法 )检测神经细胞的凋亡情况 ,免疫组织化学SP法检测Caspase 3的表达水平。结果　①对照组仅有少量的凋亡神经细胞。②与对照组相比 ,K组和M组的凋亡细胞及Caspase 3阳性细胞数明显增多 ,其中K组的凋亡细胞以皮层区多见 (P <0 0 5 ) ;M组的凋亡细胞以海马区多见 (P <0 0 5 )。两组在丘脑部位均可见较多的凋亡细胞 (P <0 0 5 )。③K M组的凋亡细胞及Caspase 3阳性细胞数明显多于对照组 (P <0 0 1) ,与K组、M组比较 ,差异有极显著性意义 (P <0 0 1)。结论　氯胺酮和咪哒唑仑联合使用可引起未成熟鼠脑明显的神经细胞凋亡 ,其机制可能与Caspase 3激活有关。