Centre of Medical Imaging, Faculty of Health Sciences, Universiti Teknologi MARA Selangor, Puncak Alam Campus, 42300 Bandar Puncak Alam, Selangor, Malaysia.
Department of Microbiology and Parasitology, Faculty of Medicine, Universiti Teknologi MARA Selangor, Sungai Buloh Campus, 47000 Sungai Buloh, Selangor, Malaysia.
Trop Biomed. 2019 Sep 1;36(3):640-653.
Accurate estimation of the minimum post-mortem interval (minPMI) is important in the investigation of forensic cases. Various thanatological methods are being used to estimate this interval. However, entomology approach is the most reliable method for this minPMI estimation especially when death has occurred over 72 hours and involved insects or other arthropods evidence at the death scene. The current methods of age estimation are daunting and destructive especially when dealing with pupal stage. The aims of this study were to characterize the morphological changes during intra-puparial period of Chrysomya megacephala (Fabricius) (Diptera: Calliphoridae) and their relation with minPMI estimation by using a high resolution micro-Computed Tomography (micro-CT). Gravid C. megacephala were collected from a rural area in Sungai Buloh, Selangor and cultured in the laboratory at 23.83±0.25°C with light: dark hour of 12:12 to initiate oviposition. The resulting larvae were reared until pupal stage. A pupa was collected at first (24 hours), second (48 hours), third (72 hours), and fourth quarter (96 hours) of the intra-puparial period. The pupal samples were placed directly into 70% ethanol for preservation. Micro-CT scanning was employed to acquire microstructural information following pupal sample staining for contrast enhancement. Eight age-informative internal morphological landmarks were mapped from the micro-CT scanning. The present study enhanced the potential value of micro-CT for the estimation of minPMI based on the internal morphological changes of C. megacephala pupae. This novel method is a promising tool for improving medico-legal investigations in forensic entomology.
准确估计最小死后间隔时间（minPMI）在法医学案件调查中非常重要。各种尸僵学方法都被用于估计这个间隔时间。然而，昆虫学方法是估计这种最小 PMI 的最可靠方法，尤其是当死亡发生在 72 小时以上且在死亡现场涉及昆虫或其他节肢动物证据时。目前的年龄估计方法既令人生畏又具破坏性，尤其是在处理蛹期时。本研究的目的是通过使用高分辨率微计算机断层扫描（micro-CT）来描述丽蝇科巨蝇 Chrysomya megacephala（Fabricius）（双翅目：丽蝇科）的蛹内期间的形态变化及其与 minPMI 估计的关系。从雪兰莪州双溪毛糯的一个农村地区收集了丽蝇科巨蝇的怀孕个体，并在实验室中以 23.83±0.25°C 的温度和 12:12 的光照：黑暗小时来开始产卵。所得的幼虫被饲养至蛹期。在蛹内期的第一（24 小时）、第二（48 小时）、第三（72 小时）和第四（96 小时） quarters 收集一个蛹。将蛹样本直接放入 70%乙醇中保存。为了增强对比度，采用微计算机断层扫描对蛹样本进行染色以获取微观结构信息。从微计算机断层扫描中映射了 8 个与年龄相关的内部形态学标志。本研究增强了 micro-CT 基于丽蝇科巨蝇蛹内部形态变化来估计 minPMI 的潜在价值。这种新方法是法医昆虫学中改进医学法律调查的有前途的工具。
