The Stability of 4-Chloromethcathinone in Blood and Vitreous Humor

We present results of our study on the stability of 4-chloromethcathinone (4-CMC) in authentic postmortem peripheral blood and vitreous humor samples. The stability of 4-CMC was determined in postmortem blood samples (for a period of 90 days) and vitreous humor (30 days) at three different temperatures: −15°C, +4°C, and + 23°C. The analyses were carried out using ultra-high-performance liquid chromatography coupled with triple-quadrupole tandem mass spectrometry (UHPLC-QqQ-MS/MS). In both materials, the lowest 4-CMC stability was demonstrated at room temperature. The blood samples stored in a freezer (−15°C) showed stability for the entire study period (90 days), while in the case of the vitreous humor sample stored at the same temperature the concentration of the substance decreased by 53% after 30 days. The study carried out in authentic postmortem blood and vitreous humor samples confirms the previous reports of 4-CMC instability in biological material. Authors suggest that the biological material should be stored frozen until analyses are carried out as soon as possible after collection of the material.     

气相色谱仪双毛细管柱双检测器技术在毒物检测中的应用

目的利用双毛细管柱双检测器技术建立常见毒物的检验方法,并对其进行定性分析。方法样品进样后通过VSOS装置进入两根不同极性的毛细管柱,经分离后到达两个不同选择性的检测器。结果利用VSOS装置可对毒物进行较好的分离、定性。结论该方法可对常见毒物进行准确定性。     

家兔急性胰腺炎死后不同时间眼玻璃体液淀粉酶变化

目的探讨急性胰腺炎死后不同时间眼玻璃体液淀粉酶变化。方法用1%牛胆酸钠诱导家兔急性胰腺炎动物模型建立,于死后不同时间和正常对照组,观察其淀粉酶变化。结果家兔急性胰腺炎死后72h眼玻璃体液淀粉酶含量(x)与死亡时间(y)存在相关关系,并导出其二项式回归方程为y=8.7420 0.7699x-0.0083x2(R2=92.62792,F=14.89734,P=0.001)。可作为推定早期损伤时间的参考指标。结论家兔急性胰腺炎死后不同时间眼玻璃体液淀粉酶改变为法医早期死亡时间推断提供了灵敏客观的实验依据。     

家兔死后眼玻璃体液锌、镍含量与 PMI关系的研究

目的寻找一种精确推定PMI的方法。方法应用电感耦合等离子体质谱（ICP－MS）,检测了家兔死后96小时内眼玻璃体液锌、镍元素含量,探讨其与PMI的相关性。结果家兔死后24h内眼玻璃体液锌、镍元素含量与PMI显著相关,可作为推定早期PMI的参考指标,其二项式回归方程分别为y=0.1404x2－1.3351x＋3.8298（R2=0.9202）、y=0.0043x2－0.0596x＋0.2665（R2=0.9103）。结论家兔眼玻璃体液中Zn、Ni元素含量变化是推定早期PMI的参考指标之一。     

家兔死后玻璃体液离子浓度检测的微量重复取样法

目的探讨微量重复取样法对兔玻璃体液样本离子浓度或元素含量检测的可行性。方法28只家兔分为3组:Ⅰ组:死后12h一次取出所有玻璃体液;Ⅱ组:死后12h微量取样50μl,连续取15次;Ⅲ组:死后120h微量取样50μl,连续取15次。分别检测样本中Ca2+、C l-、K+、Na+和磷元素的含量,并对所得数据进行统计分析。结果Ⅰ、Ⅱ、Ⅲ组左、右眼的Ca2+均数分别为1.956和2.068,1.942和1.948,2.071和2.045;C l-为111.520和121.240,116.744和117.022,106.322和106.767;K+为13.016和13.900,11.230和11.144,35.411和34.828;Na+为127.200和141.880,133.872和134.566,111.511和110.647;磷元素为0.556和0.744,0.284和0.280,5.585和5.597。3组双眼上述5种成分含量经配对t检验,其P值范围分别为0.2753~1.2365,0.1627~1.6596,0.1520~1.3446,0.2386~1.0892和0.0575~0.8195;Ⅱ、Ⅲ组的重复取样检测经方差分析,其P值为0.9433和0.8638,两组总体重复取样检测的方差分析,P值为0.8772。结论微量重复取样法对兔玻璃体液样本离子或元素含量的检测无实际影响。     

The Application of Flow Cytometry as a Rapid and Sensitive Screening Method to Detect Contamination of Vitreous Humor Samples and Avoid Miscalculation of the Postmortem Interval

Research into maximizing the speed, precision, and reliability of estimating the postmortem interval (PMI) has been a recurring object of investigation and methodologies based on the vitreous humor (VH) have provided good results. However, contamination from causes not readily apparent, such as blood, can occur, and thus lead not only to an erroneous estimation of PMI, but also interfere with the correct identification of other substances in the VH. We have developed a flow cytometry method which quantifies blood contamination and is able to detect erythrocytes in 1:750,000 dilution of contaminated VH which affects the results of hypoxanthine. It is an improvement on the previous more complex mass spectrometry method, being faster, more sensitive, and readily available. As such, it could be proposed for the rapid screening of appropriate samples by detecting and eliminating blood contaminated samples from PMI estimation.     

家兔玻璃体液间隔多次微量取样方法研究

目的探讨间隔多次微量取样玻璃体液是否可用于死亡时间推断。方法99只家兔分为2大组(I)大组45只,再分为A、B、C、D、E五个小组(每组9只),右眼(实验眼)于死后间隔12h多次取样直至24h(A组)、48h(B组)、72h(C组)、96h(D组)和120h(E组);各小组左眼(对照眼)仅分别于死后24h、48h、72h、96h和120h取样一次。检测Ca2+、Cl-、K+、Na+和P含量,同一取样时间的双眼做配对t检验。(II)大组54只,再分为2小组F组9只,每隔12h双眼交替多次取样直至120h;G组45只,每隔12h一次取样10眼(动物左右眼均编号后随机抽取每次10眼),直至120h;检测Ca2+、K+和Na+,两组差值做t检验及PMI回归方程比较。结果E组K+有差异(P<0.05),其余A~E组双眼物质含量配对t检验均无差异(P>0.05)。F与G组物质含量差值t检验无差异(P>0.05);K+、Na+的PMI线性回归方程的斜率、截距无差异(P>0.05),Ca2+与PMI无相关性。结论控制间隔时间和取样次数,多次微量取样对死后玻璃体液元素含量的规律性变化无显著影响,可以替代传统方法进行死亡时间研究。     

References for determining the time of death by potassium in vitreous humor

The different statements concerning the slope and intercept of the regression line and the 95% limits of confidence are the reason that potassium in vitreous humor is not used (at least in Germany) as an aid in estimating the time of death. The relationship between the concentration of potassium and the time of death is mainly influenced by antemortem electrolyte imbalances caused by disease and/or duration of terminal episode. The influence of terminal episode is best identified by its duration (Adelson et al., J. Forensic Sci., 8 (1963) 503–514). In order to have a method suitable for every case and to be as precise as possible we looked therefore for parameters in vitreous humor which were stable postmortem and indicating antemortem electrolyte imbalance. Urea is such a parameter, being stable postmortem (Coe, Am. J. Clin. Pathol., 51 (1969) 741–750) and useful as a marker of antemortem electrolyte imbalance. Our investigations on potassium in vitreous humor, including sudden and hospital deaths after chronic lingering disease, revealed 95% limits of confidence of ±34 h up to 120 h postmortem. Reviewing only cases with urea less than 100 mg/dl the 95% limits of confidence could be reduced to ±22 h. Considering the duration of terminal episode (<6 h) the precision was ±20 h. In this way our modified procedure is suitable for every case with the resulting precision of estimation being determined only by the duration of the terminal episode and urea concentration.     

Relationships between concentrations of cocaine and its hydrolysates in peripheral blood, heart blood, vitreous humor and urine

Cocaine is known to degrade in vivo and in vitro by several hydrolytic mechanisms. A previous study found that the initial amount of cocaine added to plasma could be accounted for by summing the molar concentrations of cocaine's hydrolysis products and the cocaine remaining after hydrolysis. The present study was undertaken to investigate whether or not relationships might exist between such molar concentration sums for different postmortem bodily fluids. Determinations of cocaine, benzoylecgonine, ecgonine methyl ester, and ecgonine were performed using liquid chromatography/mass spectrometry (LC/MS/MS) with heart blood, femoral blood, vitreous humor (VH), and urine (UR). The results demonstrate a strong correlation between blood and VH concentrations (correlation coefficients of 0.88-0.94), weak correlation between the UR and blood concentrations (correlation coefficients of 0.61-0.64), and weak correlation between UR and VH concentrations (correlation coefficient of 0.59). The results demonstrate that ecgonine is a significant hydrolysate with concentrations on the same order of magnitude as benzoylecgonine. The results are consistent with rapid distribution of the parent drug and its hydrolysates in the blood and VH. The strong correlation between the blood and VH demonstrates that VH is an important medium for toxicology testing when attempting to make a determination of cocaine intoxication.     

Debating rape jokes vs. rape culture: framing and counter-framing misogynistic comedy

ABSTRACT

Humor controversies can simultaneously reveal and obscure relations of power, as well as the rhetorical/political nature of jokes. US comedian Daniel Tosh ignited one such controversy in July 2012 when he directed a rape joke toward a female audience member during a live performance in Hollywood, CA. This paper consists of a two-part analysis of this humor controversy. First, we examine a televised debate following this incident, between a comedian and feminist, to map the dominant framing and counter-framing of rape jokes. We contend these positions are representative of two frames that repeatedly surface in response to controversial sexist humor: a dominant patriarchal frame and an oppositional feminist counter-frame. Second, we analyze the saliency of these two frames among college students to observe the way individual interpretations resonate with, challenge, and complicate those frames. In light of our findings, we argue the dominant framing/interpretation of rape jokes reinforce patriarchal and free-market ideologies, and deny real-world implications of misogynistic humor, particularly when comedians/audiences defend such jokes as harmless fun.