Gastromalacia (Postmortem Gastric Perforation): Two Cases Reports / 대한법의학회지

Gastromalacia refers to the postmortem acute autolytic erosion of the gastric wall. It should be distinguished from gastric perforations caused by antemortem injuries or other pathologic processes, such as ulcer perforations. It appears as a slimy brownish-black perforation of the gastric wall. The diagnosis is based on the presence of a typical macroscopic perforation in the fundic portion of the stomach, lack of vital reactions in the adjacent organs, and lack of clinical or autopsy evidence of trauma. Here, we report two cases of gastromalacia: one in a 53-year-old woman who died from severe head injury and another in a 2-year-old child who died from neglect by his father. Gastromalacia is a welldefined phenomenon, but due to its rarity in the practical work, it could be misdiagnosed as other causes of gastric perforation.

Usefulness of Near-infrared Spectroscopy for Diagnosis of Traumatic Intracranial Hemorrhage in Postmortem Inspection / 대한법의학회지

Near-infrared spectroscopy is a device used to determine whether traumatic intracranial hemorrhage has occurred and is primarily used for screening in emergency situations. In this study we examined the applicability of this equipment in postmortem inspection. This study included 124 autopsy cases and 59 postmortem inspection cases performed in the National Forensic Service from July 2017 to October 2018. We carried out the test using Infrascanner Model 2000 (Infrascan Inc.). Autopsy cases were divided into four groups (epidural hemorrhage or subdural hemorrhage group, traumatic subarachnoid hemorrhage or cerebral contusion group, nontraumatic intracerebral hemorrhage group, and control group) and analyzed. There was no difference in the test results according to the presence and type of intracranial hemorrhage. The possibility that variables related to postmortem change affected the test results was considered. In conclusion, this study confirmed that near-infrared spectroscopy is not suitable for the detection of traumatic intracranial hemorrhage in postmortem inspection.

Research Progress on Postmortem Changes of Computed Tomography Imaging Characteristics on Corpses / 法医学杂志

Postmortem changes on corpses appear immediately after death, and can transform the original structure characteristics of the corpse to different degrees as well as show specific changes on computed tomography （CT） images, sometimes with false positives and false negatives, influencing the identification of injuries or diseases. This paper systematically summarizes the postmortem changes of computed tomography imaging characteristics on corpses, to further expand the application of virtopsy in the practices of forensic pathology identification, and provide reference for the identification of injuries, diseases and changes after normal death.

Evaluation of the Usefulness of Cardiac Enzyme Analysis for the Diagnosis of Acute Myocardial Infarction in Postmortem Inspection / 대한법의학회지

Acute myocardial infarction is one of the most common causes of unexpected deaths, but there are limitations to its diagnosis in postmortem inspection. In this study, we aimed to investigate the usefulness of cardiac marker analysis for the diagnosis of acute myocardial infarction in postmortem inspection. This study was conducted on 30 postmortem inspection cases conducted by the National Forensic Service from 2016 to 2018. Tests for three myocardial enzymes (myoglobin, creatinine kinase-MB, and cardiac troponin I) were performed in each case, and the relationships between enzyme levels, cause of death, and factors affecting the postmortem tests were analyzed. Cardiac enzyme concentrations were not significantly different between the heart disease group and other disease groups, and the false-positive rate was increased due to postmortem changes. Therefore, we can conclude that it is not appropriate to use cardiac enzyme analysis for the diagnosis of acute myocardial infarction in postmortem inspection.

Bacteria as Normal Flora in Postmortem Body Fluid Samples / 대한법의학회지

Bacterial culture and identification are both useful in the clinical and forensic fields, although the postmortem changes in human microbiology are poorly understood. This study aimed to identify bacteria that were considered normal flora in postmortem body fluid samples. Bacterial culture and identification testing were performed for 336 body fluid samples (e.g., cardiac blood, peripheral blood, pericardial fluid, pleural fluid, peritoneal fluid, cerebrospinal fluid, and urine) from 129 forensic autopsy cases. Bacteria were identified using both genetic and biochemical methods, and testing for C-reactive protein (CRP) was used to identify the presence of antemortem inflammation. Among the 129 autopsy cases, 79 cases (69.3%) were negative for CRP, and bacterial culture and identification testing were performed for 185 samples from those 79 cases. Bacteria that were considered both normal flora and pathogens were identified in the CRP-negative cases. Therefore, the results from postmortem bacterial culture and identification testing should be interpreted in the context of other postmortem examination, including CRP testing. Furthermore, case selection, postmortem testing, and interpretations of the results should be performed by both clinical bacteriologists and forensic pathologists. To best of our knowledge, this is the first study to examine normal flora in various postmortem body fluid samples form Korean autopsy cases.

El humor vítreo como fluido biológico de importancia clínica en ciencias forenses / Vitreous humour as a biofluid of clinical importance in forensic sciences / Humor vítreo como fluido biológico de importância clínica nas ciências forenses

El humor, cuerpo o fluido vítreo (HV) es un gel claro que ocupa la cavidad vítrea o cavidad posterior del globo ocular y cuyas funciones son las de dar volumen al ojo, sostener la retina y mantener su transparencia de manera que los haces de luz puedan atravesarla. En este estudio se aborda la importancia del humor vítreo como muestra en el área de la bioquímica clínica, y se destaca su valor en el ámbito de las ciencias forenses. El humor vítreo es una muestra indispensable en la investigación de casos de muertes sospechosas, inexplicables o violentas, puesto que su ubicación proporciona un medio estéril para determinaciones como la confirmación post mortem de la ingestión de etanol. Tiene un rol en la determinación de drogas, intervalo post mortem, diabetes, deshidratación, desnutrición e insuficiencia renal. La interpretación de los datos puede ser problemática donde factores como la difusión post mortem de las drogas desde el cerebro hacia la cavidad vítrea, el método analítico, la recolección de la muestra, la calibración y el tratamiento estadístico de los datos aportan dificultad en la interpretación y añaden más variables a la hipótesis de investigación. La investigación del humor vítreo como matriz de análisis tiene una importancia considerable y debería ser difundida en países como Brasil y otros de América Latina donde, a pesar de existir personal capacitado para trabajar con esta muestra, este tipo de análisis no se pone en práctica con la debida frecuencia.

The vitreous humor, body or fluid is the clear gel that fills the vitreous chamber or posterior chamber of the eyeball, whose functions are to give volume to the eye, serve as retina support and maintain its transparency to allow light beams to reach the retina. This study addresses the vitreous humor as an important sample for clinical biochemistry, pointing out its value for forensic sciences. The vitreous humor is a mandatory sample in cases of suspected, unexplained or violent deaths and its location gives a sterile medium for the postmortem confirmation of alcohol intake. It plays a role in the measurement of drugs, estimation of postmortem interval, and definition of diabetes, dehydration and renal failure. Factors such as drug postmortem diffusion in the vitreous humour coming from the brain, along with factors of the analytical method such asthe collection process, calibration and statistical processing of data, make it difficult to interpret and add more variables to the cases investigated. HV use should be promoted in countries like Brazil and in Latin America, which possess trained professionals to address and use this biological sample, but who do not work with it frequently.

O humor, corpo ou fluido vítreo (HV) é um gel claro que enche a cavidade vítrea ou cavidade posterior do globo ocular, cujas funções são dar volume ao olho, apoiar a retina e manter a sua transparência para permitir que os feixes de luz possam atravessá-la. Este trabalho aborda a importância do humor vítreo como amostra na área da bioquímica clínica, destacando seu valor no âmbito das ciências forenses. O humor vítreo é amostra obrigatória na investigação de casos de mortes suspeitas, inexplicáveis ou violentas, visto que sua localização provê um meio estéril para, por exemplo, determinações como a confirmação post mortem da ingestão de etanol. Tem um papel na mensuração de drogas, estimação do intervalo post mortem, diabetes, desidratação, desnutrição e insuficiência renal. Fatores como a difusão post mortem das drogas desde o cérebro para a cavidade vítrea, juntamente com o método analítico, o processo de coleta da amostra, calibração e tratamento estatístico dos dados, trazem dificuldades na interpretação e adicionam mais variáveis às hipóteses de investigação. A investigação do humor vítreo como matriz de análise tem importância considerável e deveria ser divulgada em países como o Brasil e outros da América Latina onde, apesar de contar com profissionais capacitados para trabalhar com esta amostra, ainda não colocam em prática esta análise com a merecida frequência.

A Forensic Entomology Case Estimating the Minimum Postmortem Interval Using the Distribution of Fly Pupae in Fallow Ground and Maggots with Freezing Injury / 대한법의학회지

Forensic entomology investigates postmortem interval (PMI) estimation using insect evidence. We estimated the minimum PMI of a putrefied male cadaver using pupae in the soil and maggots found in the body. Most of the maggots, collected during the autopsy, were postfeeding third instar larvae with empty crop contents, which developed freezing injuries when the cadaver was placed in the freezer. Pupae in the soil were collected 45 days after the discovery of the body. DNA barcoding revealed that most pupae and maggots were Chrysomya pinguis, with a few exceptions. The minimum PMI was estimated at 10 days before the discovery time based on the scene investigation, maggot developmental stage, distribution of pupae moving away from the body toward pupariation sites, DNA barcoding results, and weather information. To reduce the gap between the minimum and maximum PMI values, complete entomological evidence collection should be conducted at the time of discovery.

Evaluation of Protein Expression in Housekeeping Genes across Multiple Tissues in Rats

BACKGROUND: Housekeeping genes, which show constant protein expression patterns between different tissue types, are very important in molecular biological studies as an internal control for protein research. METHODS: The protein expression profiles of seven housekeeping genes (HPRT1, PPIA, GYS1, TBP, YWHAZ, GAPDH and ACTB) in various rat tissues (cerebrum, cerebellum, cardiac ventricle and atrium, psoas muscle, femoral muscle, liver, spleen, kidney, and aorta) were analyzed by Western blot and compared by coefficient of variation (CV). RESULTS: HPRT1 was stably expressed (CV< or =10%) in six tissues (cerebrum, cerebellum, ventricle, femoral muscle, spleen, and kidney), PPIA was stably expressed in five tissues (cerebrum, cerebellum, ventricle, spleen and kidney), YWHAZ was stably expressed in three tissues (cerebrum, cerebellum, and kidney), and GAPDH was stably expressed in four tissues (cerebrum, ventricle, psoas muscle, and kidney). In comparison, GYS1, TBP, and ACTB were found to have CV values over 10% in all tissues. Of the seven genes examined, four (HPRT1, PPIA, YWHAZ, and GAPDH) were found to be stably expressed across multiple organs, with low CV values (< or =10%). CONCLUSIONS: These results will provide fundamental information regarding internal controls for protein expression studies and can be used for analysis of postmortem protein degradation patterns in forensic medicine.

Efecto de la degradación post mórtem sobre la detección inmunohistoquímica de antígenos en el cerebro de ratón / Effect of postmortem degradation on the immunohistochemical detection of antigens in the mouse brain

Introducción. Si bien lo ideal es llevar a cabo la preservación de los tejidos en el menor tiempo posible luego de la muerte de un animal objeto de un estudio neurohistoquímico, con frecuencia es inevitable trabajar con tejido nervioso obtenido varias horas post mórtem. Objetivo, Estudiar el efecto de la degradación post mórtem sobre la inmunorreacción de di-ferentes antígenos en el cerebro de ratón. Métodos. Se inocularon ratones con virus de la rabia y se extrajeron los cerebros luego de fijar los animales con paraformaldehído me-diante perfusión. En otro grupo de animales la extracción de los encéfalos se hizo para fi-jarlos por inmersión con el mismo fijador y en diferentes horas post mórtem. En un vibráto-mo se obtuvieron cortes coronales de los ce-rebros, y estos se procesaron para inmunode-tección de rabia y de otros cuatro antígenos. Resultados. Cuatro de los antígenos evalua-dos, calbindina, parvoalbúmina, glutamato y ácido gamma-aminobutírico (GABA), presen-taron pérdida de inmunorreacción cuando el tejido cerebral se había tratado previamente mediante fijación por inmersión. Este efecto fue más acentuado cuando aumentó el tiempo post mórtem antes de la fijación. Por el con-trario, la inmunorreacción al virus de la rabia se incrementó cuando transcurrieron más de seis horas post mórtem antes de la fijación. Conclusiones. La fijación por perfusión es ideal para estudios de inmunohistoquími-ca de diferentes antígenos. La degradación tisular post mórtem generalmente provoca disminución de la inmunorreacción. No obs-tante, los antígenos del virus de la rabia in-crementan su inmunorreacción a medida que transcurre el tiempo post mórtem antes de la fijación.

Introduction: It is advisable to carry out the preservation of tissues in the shortest time after the death of an animal subject of neu-rochemical study but it is often unavoidable to work with nervous tissue obtained several hours postmortem. Objective: To study the effect of postmor-tem degradation on immunoreactivity of di-fferent antigens in the mouse brain. Methods: Mice were inoculated with rabies virus and the brains were removed after the animals were fixed by perfusion with parafor-maldehyde. In another group of animals the brain extraction was performed and they were fixed by immersion in the same fixative solu-tion at different hours postmortem. Coronal sections of the brains were obtained in a vibra-tome and they were processed for immunode-tection of rabies, and other four antigens. Results: Four of the antigens studied, cal-bindin, parvalbumin, glutamate and GABA, showed loss of immunoreactivity when brain tissue was pretreated by immersion fixa-tion. This effect was more noticeable when postmortem time increase before the fixing. Conversely immunoreactivity to rabies virus was increased over six hours postmortem before fixation. Conclusions: Fixation by perfusion is ideal for immunohistochemical studies of diffe-rent antigens. Postmortem tissue degrada-tion usually causes decreased immunoreac-tivity. However, rabies virus antigens show increased immunoreactivity when elapses more postmortem time before fixation.

Cambios postmortem y data de la muerte en ambientes tropicales / Post mortem changes and dates of death in tropical environments

La alta temperatura y humedad del trópico contribuyen al rápido deterioro de los cadáveres alterando su aspecto y la morfología de las lesiones. El clima tropical también aumenta la probabilidad de la aparición de artefactos ya sea por factores externos (especialmente la actividad animal) o internos (propios del cadáver). Ante el hallazgo de un cuerpo putrefacto, el intervalo post mortem se establece utilizando, entre otros, los criterios de referencia disponibles en la literatura médico legal. Sin embargo, son escasos los estudios específicos sobre cambios postmortem y data de la muerte en ambientes tropicales, como los de la mayor parte del territorio de la República de Panamá, casi todos los datos disponibles se refieren a las variaciones que ocurren en ambientes de clima templado con transiciones estacionales de medio ambiente. Se revisan los criterios de aparición y desarrollo de los fenómenos cadavéricos (especialmente la putrefacción) consignados por autores de diferentes países con distintos climas, con el propósito de documentar las disparidades de criterios existentes, señalar su limitada aplicación en la estimación de la data de la muerte en ambientes tropicales y proponer líneas de investigación sobre este tema.

High temperature and humidity contribute to the rapid deterioration of bodies altering their aspect and the morphology of the injuries. The tropical climate also increases the probability of the appearance of artifacts due to external factor (especially animal activity) or internal (body factors). When a decomposed body is found, the post mortem interval is established using, among others, the available criteria of reference in the medico legal literature. Nevertheless, specific studies on post mortem changes and time of death in tropical environments, as those found in the Republic of Panama, are scanty. Most of the available information refers to the variations in moderate climates with seasonal variations. A review of the criteria of beginning and development of the cadaveric phenomena (especially decomposition) recorded by authors of different countries in different climates, with the intention of documenting the disparities of existing criteria and limited application in the establishment of the post mortem interval in tropical environments, is done, proposing lines of research in this topic.

Estimativa do intervalo pós-morte em cadáveres congelados através da entomologia

Objetivo: Estimar o intervalo pós-morte (IPM) de cadáveres putrefeitos congelados encontrados no IMLAPC da cidade do Recife- PE por meio de evidências entomológicas. Material e Método: três corpos em adiantado estado de putrefação, todos masculinos, que possuíam larvas de mosca, foram submetidos à remoção dessas larvas e postas para criação em laboratório até a emergência dos dípteros, sendo monitorada a umidade relativa do ar e a temperatura em todos os momentos da pesquisa. Também foram obtidas as temperaturas durante um período de dez dias que ocorreram na região da localização dos cadáveres. Após a identificação taxonômica dos indivíduos adultos, usaram-se cálculos estabelecidos na literatura para se chegar à estimativa do IPM. Resultados: Foram encontradas duas espécies de moscas: Chrysomya putoria e Chrysomya albiceps, todas da mesma família Calliphoridae. Os cálculos entomológicos foram conclusivos na afirmação de que as datas estipuladas pelos peritos do IMLAPC foram posteriores às encontradas pelo nosso estudo, sendo um caso com quarenta e oito horas de antecedência e os outros dois com um intervalo de aproximadamente vinte e quatro horas. Conclusão: Foi obtida a estimativa do IPM, baseando-se em cálculos do grau dia acumulado em cadáveres congelados, em que houve uma discordância da estimativa do IPM nos casos avaliados, por meio da entomologia, comparados ao registro na declaração de óbito.

Objective: To estimate the postmortem interval (PMI) of decomposing corpses found frozen in IMLAPC of Recife-PE through entomological evidence. Methods: Three bodies in an advanced state of putrefaction all male, who had fly larvae underwent removal of these larvae and put to laboratory rearing until the emergence of flies, and monitored the relative humidity and temperature at all times search. The temperatures were also obtained for a period of ten days occurring in the region of the location of cadavers. After the taxonomic identification of adults used to established literature calculations to arrive at the estimate of IPM. Results: We found two species of flies: Chrysomya putoria and Chrysomya albiceps, all from the same family Calliphoridae. The entomological calculations were conclusive statement on the dates stipulated by the experts of the IMLAPC were later found by our study, one case forty-eight hours in advance and the other two with an interval of approximately twenty-four hours. Conclusion: We achieved estimating the PMI based on calculations of the degree days accumulated in frozen corpses where there was a disagreement with the estimate of IPM in cases evaluated by comparing the record of entomology in the death certificate.

Postmortem acinar autolysis in rat sublingual gland: a morphometric study

ABSTRACT OBJECTIVE: To analyze and to quantify morphological acinar postmortem changes in rat sublingual glands (SLG). MATERIAL AND METHODSs: Fifty rats were divided into two groups of 25 animals each. Group I was used for morphological and morphometric evaluations and group II for the determination of gland density and processed gland volume. Acinar autolytic changes were studied at 0 (control group), 3, 6, 12 and 24 h postmortem periods. The morphometric analysis of the volume density (Vv) and total volume (Vt) of intact (ia) and autolyzed (aa) acini was performed under light microscopy using a Zeiss II integration grid with 100 symmetrically distributed points. RESULTS: Morphologically, temporal progressive nuclear alterations and gradual loss of the structural architecture of acinar cells were found. Regarding quantitative results, both the Vvaa and the Vvia showed statistically significant differences among all postmortem periods (p<0.05). Vvaa increased from 0.42 percent at 0 h to 75.84 percent at 24 h postmortem and Vvia decreased from 71.16 percent to 0 percent over the same period. For Vtaa and Vtia, no statistically significant differences occurred between 12-24 h and 0-3 h (p>0.05), respectively. Vtaa increased from 0.18 mm³ at 0 h to 38.17 mm³ at 12 h, while Vtia showed a decrease from 33.47 mm³ to 0 mm³ between 3-24 h postmortem. Data concerning Vtaa were adjusted by two-variable linear regression, obtaining the equation: y=-3.54 + 3.38x (r²=0.90). The Vtaa growth rate calculated by this equation was 3.38 mm³/h between 0-12 h. CONCLUSION: Acinar autolysis on rat SLG demonstrated the most significant signs during the first 6 h postmortem and was widely spread through the gland at 12 h.