The Optimal Combination of Cartilage Source and Apparatus for Long‐Term In Vitro Chondrocyte Viability Analysis

Abstract: Most studies of long‐term chondrocytes survival were for tissue banks. They showed a gradual reduction in the viable chondrocytes percentage as a function of time and ambient temperature, but the samples were harvested under optimal conditions. The aim of our study was to determine the most reliable combination of cartilage source and assay for the in vitro postmortem chondrocyte viability analysis in the conditions that imitate a dead body. Osteochondral cylinders were procured from femoral condyles and talar trochleas of three male donors and stored in the cell culture media at 4 ± 2°C and 23 ± 2°C. The samples were analyzed by a cell viability analyzer and a confocal laser scanning microscope (CLSM) initially 24–36 h after death and then in 4‐week intervals. The results reconfirmed the significant influence of time (p = 0.0002), but not of the temperature (p = 0.237). The largest reproducibility was presented for the knee joint and the CLSM.     

脑温死亡时间测定仪的研制

目的研制脑温死亡时间测定仪。方法根据动物和尸体实验了解脑温下降的规律,并选择针状温度传感器,确定测温入径途径。结果针状传感器的优点是:快速敏感、准确性高、对组织破坏少、插入方便。尽管这种方法仍有误差,但它与现在法医学上常用的方法相比误差已减少了许多。结论所研制的死亡时间测定仪具有体积小,便于携带、探头灵敏,可以迅速方便地探测死者的脑温,并能直接推断死亡时间,避免了某些人为的因素造成的误差。     

A New Method for Determination of Postmortem Interval: Citrate Content of Bone*

Abstract: Few accurate methods exist currently to determine the time since death (postmortem interval, PMI) of skeletonized human remains found at crime scenes. Citrate is present as a constituent of living human and animal cortical bone at very uniform initial concentration (2.0 ± 0.1 wt %). In skeletal remains found in open landscape settings (whether buried or not), the concentration of citrate remains constant for a period of about 4 weeks, after which it decreases linearly as a function of log(time). The upper limit of the dating range is about 100 years. The precision of determination decreases slightly with age. The rate of decrease appears to be independent of temperature or rainfall but drops to zero for storage temperature <0°C.     

中国与澳大利亚关系回暖后的“冷”思考

近年来,中国和澳大利亚两国关系经历了由热趋冷和由冷转暖的变化过程。在双方共同努力下,两国关系得到修复和改善,基本回归正常发展轨道并开始逐步回暖。本文在剖析两国关系冷暖变化原因的基础上找寻影响两国关系发展的主要因素,并对两国关系未来发展进行展望。     

芪归糖痛宁颗粒调节炎性因子预防糖尿病周围神经病变的机制研究

目的 通过观察芪归糖痛宁颗粒预防性给药对相关炎性因子的影响,探究其改善糖尿病周围神经病变(diabetic peripheral neuropathy,DPN)的机制。方法 将120只SD大鼠分为正常组,模型组,芪归糖痛宁颗粒高、中、低剂量组和甲钴胺组,采用链脲佐菌素腹腔注射联合高脂饲料喂养法复制糖尿病大鼠模型,预防性给予相应药物8周,以运动神经传导速度（motor nerve conduction velocity,MNCV）和摆尾温度阈值评价DPN的改善情况,采用酶联免疫吸附法测定大鼠血清基质金属蛋白酶-1 (matrix metalloproteinase 1,MMP-1)、肿瘤坏死因子-α(tumor necrosis factor-α,TNF-α)、白细胞介素-1（interleukin 1,IL-1）、单核细胞趋化蛋白-1（monocyte chemotactic protein 1,MCP-1)含量。结果 与正常组比较,模型组大鼠摆尾温度阈值显著升高（P<0.05）,MNCV显著下降（P<0.05）,血清MMP-1、TNF-α、IL-1和MCP-1均显著升高（P<0.05）。芪归糖痛宁颗粒对DPN大鼠的MNCV、摆尾温度阈值及血清MMP-1、TNF-α、IL-1和MCP-1的效应具有明显的剂量依赖性（P<0.05）,不同剂量对不同指标的效应呈现不同的量效关系;不同剂量芪归糖痛宁颗粒与甲钴胺对DPN大鼠的MNCV、摆尾温度阈值及血清MMP-1、TNF-α和IL-1的效应相比较,差异均具有统计学意义（P<0.05）。结论 芪归糖痛宁颗粒能预防DPN,其机制与调控复杂的炎性因子网络有关,其效应具有明显的剂量依赖性。     

A Study on the Estimation of Postmortem Interval Based on Environmental Temperature and Concentrations of Substance in Vitreous Humor

A method to determine postmortem interval (PMI) based on environmental temperature and the concentrations of vitreous humor (VH) molecules were explored. Rabbit carcasses were placed in a chamber at 5, 15, 25, or 35°C, and 80–100 μL of VH was collected with the double‐eye alternating micro‐sampling method every 12 h. A Roche DPPI biochemical analyzer was used to measure the concentrations of six substances in VH samples. The interpolation function model and mixed‐effect model were employed for data fitting to establish equations for PMI estimation. The concentrations of K⁺, P, Mg²⁺, creatinine (CRE), and urea nitrogen (UN) exhibited an upward trend with increasing PMI in all temperature groups, while the concentration of Ca²⁺ showed a downward trend. Validation results using K⁺ and Mg²⁺ ions revealed that the mixed‐effect model provided a better estimation than the interpolation function model using the data from our experiment. However, both models were able to estimate PMI using temperature and VH molecule concentrations.     

室外温度与室内恒温下EC随死后经历时间的变化

目的在室外环境和室内恒温条件下测定昼夜不同时间猪后腿肌肉电导率(electrical conductivity,EC)值,分析并比较两种环境条件下,EC值随死后经历时间(time since death, TSD)变化的规律。方法取5块即刻屠宰的猪后腿肌肉,均分为两份,随机分成两组,分别置于秋季室外环境和室内18℃恒温环境中。在死后10d内分别于早晚8时(每隔12h)取样,测定其浸渍液EC值。结果两种环境条件下,EC随TSD变化的趋势在整体上是一致的,二者相关性均较好(R2室外=0.971,P室外=0.004,R2室内=0.98,P室内=0.002)。室外环境温度下,肌肉的EC值在白天增长明显,夜间增长不明显,尤其环境温度低于13℃时,出现明显的平台现象,与室内恒温条件下肌肉EC值持续上升的变化趋势有显著的差异。结论无论室外环境温度还是室内恒温下,肌肉EC与TSD的相关性均较好,但在具体分析时,应考虑到夜间低温平台期造成的时间延搁。     

The theoretical aspects of the time dependent Z equation as a means of postmortem interval estimation using body temperature data only

It has been clearly demonstrated that the rectal cooling curve does not obey Newton's Law, which is exponential. The first success in modelling rectal cooling mathematically was achieved by Marshall and Hoare [1]. An amendment was made to the simple exponential curve which led to a good mathematical model, exhibiting the three main sections of rectal cooling, i.e. lag, linear and quasi-exponential. The resultant method of postmortem interval estimation required a knowledge of the body mass and height. The present study has led to a totally different amendment to Newton's Law, which provides a means of postmortem interval estimation from body temperature data only. The derivation of the method, with a background on Newton's Law follows.     

“尸热”现象初探

目的探讨在特定条件下尸体腐败过程中温度变化的规律,为解决死亡时间的推断提供科学依据,同时观察蝇蛆在尸体上所经历的温度变化,探寻其变化特点和规律为法医昆虫学检验提供依据。方法在深圳不同季节放置猪尸于室外的草地上,温度计探头分别置于舌下及插入直肠约5cm深处。分别观察记录口腔和直肠的温度,死亡第1d每小时测定尸体温度1次,从第2d开始每天定时测定3次。尸体上蝇类昆虫(成虫和幼虫)的发生情况逐日进行观察记录。在实验室观察恒温下不同蝇蛆滋生密度对猪肝块温度的影响。将初孵幼虫按不同密度分别接于新鲜的50g猪肝上,插入温度计,使温度计探头与猪肝块充分接触,再置于24℃的生化培养箱内饲养。在同样条件下,设立未接入初孵幼虫的猪肝块作为对照组。每天分别测定记录5次,然后对测得的结果进行统计。结果蝇蛆滋生可显著引起尸体温度上升,春季最高约上升8℃,夏季最高可上升22℃;升温主要集中在蝇蛆聚集的部位;蝇蛆滋生引起猪肝块温度上升的幅度较小,一般仅为数度;随着滋生密度的增加,升温幅度增加。结论蝇蛆活动可引起尸体温度上升,从而影响昆虫发育历期。凡有蝇蛆滋生的尸体均不能忽视"尸热现象"。     

不同温度下大鼠皮肤5种RNA指标与PMI的相关性

目的探讨大鼠皮肤内β-肌动蛋白(β-actin)、甘油醛-3-磷酸脱氢酶(glyceraldehyde-3-phosphate dehydrogenase,GAPDH)、18S核糖体RNA(18S ribosomal RNA,18S rRNA)、5S核糖体RNA(5S ribosomal RNA,5S rRNA)以及微小RNA-203(microRNA-203,miR-203)这5种RNA指标在不同温度下的表达水平与死亡时间(PMI)的相关性。方法将18只SD大鼠随机分为3组,处死后分别置于4℃、15℃和35℃的环境中,于死后0~120h内11个时间点取大鼠腹部皮肤。抽提皮肤总RNA,利用实时荧光定量PCR技术检测5种RNA表达水平。运用geNorm软件选取合适内参后,利用GraphPad软件对内参标准化的RNA指标进行回归分析。结果 5S rRNA和miR-203作为内参最合适。在4℃和15℃温度组中,β-actin和GAPDH的表达量变化与PMI线性关系良好。在35℃下,β-actin和GAPDH与PMI呈现S形曲线关系。而18S rRNA只在15℃和35℃温度组呈现一定的线性关系。结论皮肤组织比较适合作为提取RNA的检材,其中β-actin和GAPDH表达水平与PMI相关性良好,有望成为推测PMI的辅助指标。