False Positives Observed on the Seratec® PSA SemiQuant Cassette Test with Condom Lubricants

Abstract: In the course of the validation of a new component of the prostate‐specific antigen (PSA) SemiQuant Cassette Test marketed by Seratec^®, a false‐positive reaction was observed when testing samples collected from the surface of unused, lubricated condoms. A variety of personal lubricants and condoms were tested to determine the frequency of the false positive, as well as its potential source. Samples were extracted in both water and the manufacturer‐provided buffer, and the test was performed according to the manufacturer’s suggested protocol. The false positive was observed intermittently, but occurred consistently with samples containing nonoxynol‐9, a strong detergent utilized as a spermicide. The reaction may be attributable to the combination of latex and nonoxynol‐9. Because of the unreliability of the test to confirm the presence of PSA in samples collected from condoms, the PSA cassette is an unsuitable method for confirming the presence of seminal fluid in condoms.     

液相电喷雾离子质谱技术在法医DNA中的应用

生物质谱技术是近年来发展较为迅速的生物分析技术之一,在对大分子生物质量测定中,其以快速、准确、灵敏等优点受到研究者的青睐。其中,液相电喷雾离子电离质谱(LC-ESI-MS)在法医DNA分析中对STR以及SNP遗传标记的检测具有独特的应用价值和广阔的应用前景。本文对ESI-MS的现状和在法医DNA分析中的应用等方面进行了综述,分析了LC-ESI-MS技术在法医学DNA分析中的优缺点,以促进其在国内法医DNA分析中的应用与发展。     

Validation study of KPICS SpermFinder™ by NicheVision Forensics, LLC for the identification of human spermatozoa

Abstract: Microscopic analysis for the identification of spermatozoa is commonly performed during the forensic examination of sexual assault evidence. Two widely utilized methods for the confirmation of the presence of spermatozoa are visualization of the cells via phase‐contrast microscopy with wet mounted samples and bright field microscopy with histologically stained samples. The KPICS SpermFinder? by NicheVision Forensics, LLC accelerates this time‐consuming process via an automated microscope with an algorithm designed to locate spermatozoa on a Christmas tree histologically stained microscope slide. Upon a qualified scientist’s review of the generated data, the KPICS SpermFinder? was able to locate spermatozoa, typically finding on average 106.28% ± 115.37% more spermatozoa than with manual examinations. The KPICS SpermFinder? provided the location of identified cells with reproducible results.     

Isolation and Individualization of Conceptus and Maternal Tissues from Abortions and Placentas for Parentage Testing in Cases of Rape and Abandoned Newborns*

Abstract: Abortion specimens are often submitted to forensic laboratories as the only piece of physical evidence in rape and incest cases. The recovery of conceptus tissues from this evidence permits the use of paternity testing to evaluate suspects. In cases of abandoned newborns, the recovery of maternal tissue from the placenta allows for the direct comparison of genetic profiles between the suspected mother and the biological mother. We report on the identification and isolation of conceptus tissues from embryonic‐ and fetal‐period abortions, and maternal tissues from delivered placentas, by gross and low‐magnification examination with manual dissection. Hundreds of single‐source samples have been successfully recovered by this method and short tandem repeat typed using standard forensic procedures. We additionally describe extraembryonic tissues that can be recovered and typed in the absence of the embryo proper. We conclude that an expertise and protocols can be developed by forensic laboratories for the routine analysis of this evidence.     

Bloodstains on Leather: Examination of False Negatives in Presumptive Test and Human Hemoglobin Test

Presumptive tests for blood are very simple and sensitive tests used in the search for evidence. They also provide initial information on the nature of stains. A second test can confirm their nature. However, these tests can present false–negative results for different reasons. Some of those reasons have been studied, while others, those caused by the substrate material that contains the stain, are less well known. This work studies the effect of one component of a leather substrate—quebracho extract—on presumptive and human hemoglobin blood tests. Assays were performed using samples of blood dilutions contaminated with quebracho extract and others formed on a substrate containing the contaminant. Results show an undoubted interference that causes false negatives and even visible to the naked eye stains and also indicate that some tests (phenolphthalein) are more affected than others. Examiners should be taken into account when working on this kind of substrates.     

从元整体观看医学分子生物学的发展

医学思维方式上的根本差异,使中医和西医形成两种不同的思路.当代西医在分子生物学方面,已经达到从基因水平进行科学研究,但在细胞间信号转导问题上尚未取得突破性进展.从中医的元整体观可以针对这些问题及下一步的研究方向提出较为中肯的观点.元整体观认为:整体分化出部分,整体决定部分,提示我们在研究中应有的放矢,有些是无法从微观研究中得到明确结果的.     

蚯蚓处理垃圾产业化问题的探讨

利用蚯蚓处理垃圾可以使垃圾真正地实现无害化、减量化、资源化。每亩土地每年可以处理 10 0t有机垃圾 ,生产 2～ 4t蚯蚓和 37t高级蚯蚓粪。蚓体可提取蚓激酶和蛋白饲料添加剂 ,蚓粪可做高效生物有机肥 ,是继填埋、焚烧和堆肥后的第 4种垃圾处理的可行性方式。     

Gastrointestinal Functionality of Aquatic Animal (Oreochromis niloticus) Carcass in Water Allows Estimating Time of Death

Postmortem changes have been previously studied in some terrestrial animal models, but no prior information is available on aquatic species. Gastrointestinal functionality was investigated in terms of indices, protein concentration, digestive enzyme activity, and scavenging activity, in an aquatic animal model, Nile tilapia, to assess the postmortem changes. Dead fish were floated indoors, and samples were collected within 48 h after death. Stomasomatic index decreased with postmortem time and correlated positively with protein, pepsin‐specific activity, and stomach scavenging activity. Also intestosomatic index decreased significantly and correlated positively with protein, specific activity of trypsin, chymotrypsin, amylase, lipase, and intestinal scavenging activity. In their postmortem changes, the digestive enzymes exhibited earlier lipid degradation than carbohydrate or protein. The intestine changed more rapidly than the stomach. The findings suggest that the postmortem changes of gastrointestinal functionality can serve as primary data for the estimation of time of death of an aquatic animal.     

早期死亡时间推断研究进展

死亡时间推断在判断案件的性质、划定侦查范围及锁定嫌疑人等方面至关重要,一直是法医病理学工作的重点和难点。早期死亡时间,即指死后24 h以内,由于距离案发时间更短,对其准确推断能促进案件的成功侦破,具有重要的法医学意义。近年来,国内外法医学者运用一系列新方法和新技术对早期死亡时间推断进行了大量研究。本文对体液生物化学、超生反应、代谢组学、影像学、遗传物质降解规律等方面的研究进展进行综述,以期为早期死亡时间推断的研究和应用提供新的思路。