Brain Fluid Content Related to Body Position and Postmortem Interval – An Animal Model

Adult male Sprague Dawley rats were euthanized and placed in a horizontal or vertical (head‐down) position at room temperature, after which brain fluid content was measured by a moisture analysis technique at variable time points. No significant difference in brain fluid content was observed between horizontal and vertical postmortem positions. A significant increase in brain fluid content was demonstrated 3, 6, and 24 h after death, with maximal fluid content observed at 24 h. Specifically, the brain fluid content of control animals was 77.79 ± 0.36%, increasing to 80.05 ± 0.22% at 24 h (p < 0.0001). This study has demonstrated no significant differences in brain fluid content related to postmortem position, suggesting that a head‐down position is not associated with increased brain fluid content or swelling. However, significant temporal increases in brain fluid content after death, most likely related to cerebral liquefaction, occur.     

根据股骨组织形态学变化进行骨骼种属鉴别

目的通过对成年人、成体黄牛、马、家猪、山羊、绵羊、狗、猫、长毛兔、鹅、鸭、鸡共12个种属动物股骨组织形态学结构特征的研究,建立一个有效的各类动物间种属鉴别的方法。方法在征得家属同意后,在尸检中取成人(20岁以上)右股骨中段约4cm,同时,收集黄牛、马、家猪、山羊、绵羊、狗、猫、长毛兔、鹅、鸭、鸡共11种常见动物右腿股骨,取中段约4cm,脱钙后制作成骨组织切片,在光学显微镜下观察,将显微镜下的图像录入电脑,选取24个指标进行分析。结果人与其他动物、以及各被检动物之间在骨单位数量等13个指标上具有显著差异,用这些指标建立种属判别数学模型,结果这些动物之间的判别率也可达89.4%。结论股骨中段骨密质的组织学结构具有明显的种属特征,且骨单位形态和数量呈现明显的生物进化趋势。根据这些特征可以有效地进行种属鉴别。     

81例外伤性鼻部骨折的特点及其法医学鉴定分析

研究鼻部损伤后骨折的特点、确诊的方法及法医学鉴定的相关问题。 81例以鼻部外伤为主诉 ,经鼻骨拍摄X线侧位片 ( 62例加做鼻部CT扫描 )检见有鼻骨骨折的患者 ,进行法医临床学鉴定分析。单纯性线性骨折 19例 ,骨折移位者 11例 ,粉碎性、多发性骨折 4 0例 ,鼻骨骨折伴上颌骨额突骨折或 (及 )伴眶骨骨折 11例 ;轻伤 58例 ( 72 % ) ,未构成轻伤 2 3例 ( 2 8% )。多数鼻骨骨折为粉碎性、多发性 ,且可伴有其它部位骨折。鼻骨X线侧位片只能明确部分粉碎性骨折及部分移位明显的骨折 ,CT扫描能确定鼻部骨折形态。     

Sudden Unexpected Death Due to Left Subclavian Artery‐esophageal Fistula Caused by Fish Bone

A 53‐year‐old woman was admitted to the hospital due to unexpected dizziness and died the following morning. To investigate the cause of death, a forensic autopsy along with histological examination was performed 3 days after her death. The major findings of the autopsy were that a fish bone had pierced the left subclavian artery after perforating the esophagus with 680 mL of blood in the stomach and bloody and tarry contents were present in the intestines, and the cause of death was confirmed to be subsequent hemorrhagic shock. Unfortunately, none of her family realized that she had eaten a fish 4 days before the tragedy until the fish bone was found. The present case is rare and instructive. The histopathological findings of left subclavian artery‐esophageal fistula induced by a fish bone can be used as a reference in forensic practice.     

Bone Area Histomorphometry

Quantifying the amount of cortical bone loss is one variable used in histological methods of adult age estimation. Measurements of cortical area tend to be subjective and additional information regarding bone loss is not captured considering cancellous bone is disregarded. We describe whether measuring bone area (cancellous + cortical area) rather than cortical area may improve histological age estimation for the sixth rib. Mid‐shaft rib cross‐sections (n = 114) with a skewed sex distribution were analyzed. Ages range from 16 to 87 years. Variables included: total cross‐sectional area, cortical area, bone area, relative bone area, relative cortical area, and endosteal area. Males have larger mean total cross‐sectional area, bone area, and cortical area than females. Females display a larger mean endosteal area and greater mean relative measure values. Relative bone area significantly correlates with age. The relative bone area variable will provide researchers with a less subjective and more accurate measure than cortical area.     

A Computational Framework for Age‐at‐Death Estimation from the Skeleton: Surface and Outline Analysis of 3D Laser Scans of the Adult Pubic Symphysis

In forensic anthropology, age‐at‐death estimation typically requires the macroscopic assessment of the skeletal indicator and its association with a phase or score. High subjectivity and error are the recognized disadvantages of this approach, creating a need for alternative tools that enable the objective and mathematically robust assessment of true chronological age. We describe, here, three fully computational, quantitative shape analysis methods and a combinatory approach that make use of three‐dimensional laser scans of the pubic symphysis. We report a novel age‐related shape measure, focusing on the changes observed in the ventral margin curvature, and refine two former methods, whose measures capture the flatness of the symphyseal surface. We show how we can decrease age‐estimation error and improve prior results by combining these outline and surface measures in two multivariate regression models. The presented models produce objective age‐estimates that are comparable to current practices with root‐mean‐square‐errors between 13.7 and 16.5 years.     

黄牛脑水通道蛋白4的表达及其对高原脑水肿的易感性

为了探讨黄牛对高原脑水肿的易感性,并为青藏高原养牛业提供参考,运用免疫组织化学SABC染色法并采用Image-Pro Plus 6.0软件,对成年黄牛大脑不同功能区水通道蛋白4(AQP4)的表达及分布特征进行了研究。结果显示,黄牛不同功能区脑组织中AQP4表达面积(S)和积分光密度(IOD)值的大小顺序为S扣带回>S中央前回>S丘脑>S尾状核,IOD扣带回>IOD中央前回>IOD丘脑>IOD尾状核,且扣带回和中央前回的S和IOD值均显著高于丘脑和尾状核(P<0.01)。结果证实,成年黄牛脑不同功能区、同功能区不同层及同功能区同层不同类型细胞对水的通透性及代谢功能存在较大差异,对脑水肿的易感性是不同的。     

Full STR profile of a 67-year-old bone found in a fresh water lake

DNA extraction from and DNA typing of fresh water-exposed aged bone specimens poses a challenging task and is not very well examined. This study presents a new method to extract typable DNA from such problematic bone specimens. The procedure comprises low-heat drilling and cryogrinding, mild lysis conditions, and silica-column-based DNA cleaning. DNA quantity is assessed by quantitative PCR prior to short tandem repeat (STR) amplification. The procedure was employed with a 67-year-old tibia bone fragment recovered from a fresh water lake and succeeded to produce a full STR profile using the MPX-SP1 and MPX-SP2 mini-STR kits and a partial profile with 12 successfully amplified STRs using the Identifiler STR kit. The new method for the extraction of DNA from aged fresh water-exposed bone specimens presented herein was successfully applied to prepare DNA of sufficient quality and quantity to generate a full STR profile.     

Quantitative assessment of the percent fat in domestic animal bone marrow

Measurement of the amount of fat in femoral bone marrow can provide a quantitative assessment of the nutritional status of an individual animal. An analytical method is presented for quantitating the percent fat in bone marrow from three domestic species: bovine, canine, and equine. In this procedure, fat is extracted from bone marrow using pentane, and the percent fat recovered is determined gravimetrically. Based on analyses from adult animals (normal body condition scores), the average percentage of fat in the bone marrow was >80%. In cases in which animals have been diagnosed as emaciated or exhibit serous atrophy of fat (body scores of 1 or 2), the femoral bone marrow fat was less than 20%. In domestic animals, bone marrow fat analysis can be a useful, quantitative measure that, when used in conjunction with all other data available, can support a diagnosis of starvation or malnutrition.     

Evaluation of a Freezer Mill for Bone Pulverization prior to DNA Extraction: An Improved Workflow for STR Analysis

Traditional methods for bone pulverization typically generate heat, risking stability of DNA sample. SPEX? has developed cryogenic grinders which introduce liquid nitrogen to cool the sample and aid in the grinding process. In this study, the Freezer Mill 6970 EFM was used with two DNA extraction methods and routine downstream STR analysis procedures. DNA from as little as 0.1 g of bone powder was used to develop full STR profiles after freezer mill pulverization, and the method was reproducible. Further, no contamination was detected upon cleaning/reuse of the sample vials. There were no significant differences in DNA yield, STR alleles detected, or peak heights using the freezer mill as compared to traditional grinding, and successful DNA profiles were achieved from as low as 0.1 g of bone powder with this method. Overall, this work indicates that this cryogenic mill method may be used as a viable alternative to traditional tissue grinders.