The decomposition of a body, and the associated gaseous and liquid discharges emanating from it, attract gravid female blow flies which lay their eggs in or on the body. After the eggs have hatched, the emerging larvae start feeding on the body. As decomposition progresses, the blow fly larvae often migrate away, typically in a random manner in search of favourable conditions for pupation. In this paper, we report on a rarely described phenomenon of unidirectional mass migration of blow fly larvae and postulate on the factors which may drive this process. A decomposition trial utilising a 60-kg pig carcass, deployed in the summer months in Table Mountain National Park, Cape Town, South Africa, was conducted in 2022. On the fifth day of the trial, simultaneous unidirectional mass dispersal of blow fly larvae was observed. The larvae moved downhill in a southeasterly direction, following the flow of decomposition fluids oozing out from the pig carcass. The 'larval migration stream' had a length of approximately 1.5 m with a width of 40 cm, tapering to 17 cm at the terminal point. The larval migration stream consisted of the larvae of Chrysomya albiceps and Chrysomya chloropyga. This study demonstrates the importance of understanding the timing and pattern of dispersal of post-feeding blow fly larvae in each geographical region. This is crucial as the minimum post-mortem interval can be miscalculated if older immature insects dispersing from the corpse are not considered and collected during crime scene investigations. SIGNIFICANCE: • Understanding the timing and pattern of dispersal of blow fly larvae from decomposing vertebrate remains in each geographical region is important in time-since-death estimations when using entomological evidence. • In the summer season of the Western Cape Province, Chrysomya albiceps and Chrysomya chloropyga are among the blow fly species of forensic importance as they deposit their eggs on vertebrate remains. • When a decomposing body is found within the Table Mountain region, we suggest that crime scene investigators should examine the downhill area of the scene for larval/pupal entomological evidence that can assist in time and season of death estimations.

Resumen La entomotoxicología forense, que analiza insectos necrófagos para detectar sustancias tóxicas, es crucial en la determinación de causas de muerte y la estimación del intervalo post-mortem. Este estudio se centró en Peckia intermutans (Walker) (Diptera: Sarcophagidae) como marcador para la detección de metanol, un alcohol potencialmente letal presente como adulterante en bebidas alcohólicas debido a su bajo costo y parecido con el etanol. Se desarrolló un método de cromatografía de gases-espectrometría de masas (HS-GC-MS) para detectar metanol y se estudió su efecto sobre el tiempo de desarrollo, supervivencia y morfología de las moscas de la carne. Las larvas se criaron en sustratos de hígado enriquecidos con metanol (300, 500 y 1000 mg/kg). Los resultados mostraron: el método desarrollado detectó metanol en todos los estadios; el metanol afectó el tiempo de desarrollo de las moscas; la supervivencia aumentó con una mayor concentración de metanol; y los cambios morfológicos fueron evidentes en el peso. Este estudio ofrece valiosa información sobre la investigación entomotoxicológica del Ecuador, por lo que se debe considerar los cambios morfológicos de P. intermutans para evitar estimaciones inexactas de los intervalos post-mortem.

Abstract Forensic entomotoxicology, which analyzes necrophagous insects to detect toxic substances, is crucial in determining causes of death and estimating the post-mortem interval. This study focused on Peckia intermutans (Walker) (Diptera: Sarcophagidae) as a marker for detecting methanol, a potentially lethal alcohol often added as an adulterant in alcoholic beverages due to its low cost and similarity to ethanol. A gas chromatography-mass spectrometry (HS-GC-MS) method was developed to detect methanol, and its effects on the development time, survival, and morphology of flesh flies were investigated. Larvae were reared on liver substrates enriched with methanol (300, 500, and 1000 mg/kg). Results showed: the developed method detected methanol in all instars; methanol affected the developmental time of the flies; survival increased with higher methanol concentration; and morphological changes were evident in weight. This study provides valuable information on entomotoxicological research in Ecuador, emphasizing the need to consider morphological changes in P. intermutans to avoid inaccurate estimations of post-mortem intervals.

Abstract Chrysomya albiceps (Calliphoridae) is among the earliest successional fauna on human and animal cadavers. Some immature Calliphoridae can be useful for determination of post-mortem interval. Toxins, particularly pesticides, can affect the rate of insect growth. Aluminum phosphide (AlP) is an affordable insecticide that has not been adequately entomotoxicologically evaluated. So, the impact of AlP on the developmental rate of different stages of C. albiceps was investigated. Larvae of C. albiceps were reared on the rabbit carcasses containing AlP as a treated group, and distilled water as a control group. The substances were administered by a gastric tube. The duration needed for development of C. albiceps stages was documented. Body length, width and weight of larvae were measured after 24, 48, 72 and 96 h from egg hatching. The duration of development increased significantly in the treated group compared to the control group. Larvae body measurements were significantly smaller in the treated group than in the control group. Therefore, it was demonstrated that AlP significantly influences the size of C. albiceps larvae and extends their development. During forensic application, interpretation of C. albiceps data should be used with caution when aluminum phosphide may be the cause of death. (Calliphoridae cadavers postmortem post mortem interval Toxins pesticides growth (AlP evaluated So C investigated tube documented length 24 48 7 9 hatching Therefore application death 2 4

Resumo Chrysomya albiceps (Calliphoridae) está entre as primeiras espécies a colonizar cadáveres humanos e animais. Alguns Calliphoridae imaturos podem ser úteis para a determinação do intervalo “post-mortem”. Toxinas, particularmente pesticidas, podem afetar a taxa de crescimento de insetos. O fosfeto de alumínio (AlP) é um inseticida acessível que não foi adequadamente avaliado entomotoxicologicamente. Assim, o impacto do AlP na taxa de desenvolvimento de diferentes estágios de C. albiceps foi investigado. Larvas de C. albiceps foram criadas em carcaças de coelho, contendo AlP como grupo tratado e água destilada como grupo controle. As substâncias foram administradas por sonda gástrica. A duração necessária para o desenvolvimento dos estágios de C. albiceps foi documentada. O comprimento, largura e peso do corpo das larvas foram medidos após 24, 48, 72 e 96 horas da eclosão dos ovos. A duração do desenvolvimento foi significativamente aumentada no grupo tratado, em comparação com o grupo controle. As medidas corporais das larvas foram significativamente menores no grupo tratado do que no grupo controle. Portanto, foi demonstrado que o AlP influencia significativamente o tamanho das larvas de C. albiceps e prolonga seu desenvolvimento. Durante a aplicação forense, a interpretação dos dados de C. albiceps deve ser usada com cautela, quando o fosfeto de alumínio puder ser a causa da morte. (Calliphoridae animais postmortem. postmortem post mortem . “post-mortem” Toxinas pesticidas insetos (AlP entomotoxicologicamente Assim C investigado coelho controle gástrica documentada comprimento 24 48 7 9 ovos Portanto forense cautela morte “post-mortem 2 4

ABSTRACT Forensic entomology has been developing in Brazil in recent years. In cases where traditional forensic methods cannot accurately determine the postmortem interval (PMI), entomological evidence can be crucial. In this novel study, we present the first results of the Forensic Entomology Division at Santa Catarina Scientific Police, southern Brazil, formally established in January 2022. From Jan 2022 to July 2023, minimum PMI was calculated based on entomological evidence in 34 cases. A total of 21 species of insects (16 species of Diptera belonging to 6 families and 5 species of Coleoptera belonging to 4 families) were collected from human bodies at different decomposition stages and in different types of environments. The most abundant and relevant species to estimate PMI were: Chrysomya albiceps (in 38% of the cases), followed by Hermetia illucens (18%), Oxelytrum discicolle (14%), Chrysomya megacephala (12%) and Peckia (Pantonella) intermutans (12%). Some species were reported for the first time colonizing human corpses in Santa Catarina and used for the first time to estimate minimum PMI in Brazil. Understanding the entomofauna present on a human corpse becomes an important tool in death investigations and is essential for forensic entomology applications. Our findings provide better understanding of entomological evidence from Santa Catarina State and have important implications for the advancement of forensic entomology in Brazil. years PMI, , (PMI) crucial study Police 202 2023 3 2 16 (1 environments 38 cases, cases) 18%, 18 18% (18%) 14%, 14 14% (14%) 12% 12 (12% Pantonella (Pantonella 12%. . applications (PMI 20 1 ( (18% (14% (12 (18 (14

ABSTRACT Sarcophagidae flies have great forensic importance, since different instars of their larval development are used in the determination of the postmortem interval (PMI) of corpses. However, for many species, intrapuparial developmental data are scarce. Here we analyzed the intrapuparial development of the sarcophagid Peckia pexata and describe the chronological and morphological changes that occur during metamorphosis. We reared approximately 330 specimens originating from the Colombian Amazon in the laboratory. Prepupae were identified by size reduction and coloration change. During the first five days of the study, four individuals were sampled every three hours, then every six hours until adult emergence. Specimens were fixed in 96% alcohol, then immersed in Carnoy solution for 24 hours and in formic acid (5%) for 48 hours for dissection and analysis of morphological changes. Four morphological phases of intrapuparial development of P. pexata were observed: 1) larva pupa apolysis, which lasted, in average, 9 h; 2) cryptocephalic pupa, 6 h; 3) phanerocephalic pupa, 6.5 h; and 4) pharate adult (transparent eyes, 48 h; yellow eyes, 216 h; pink eyes, 35 h; and red eyes, 52 h). The pharate adult was fully formed at 340 h and adult emergence occurred at 372.5 h or 15.5 days. We also described the formation of the prepupa, the pupariation and the final metamorphosis for the imago and compared it with the known events for Peckia intermutans, Peckia lambens (Sarcophagidae) and Lucilia eximia (Calliphoridae). importance PMI (PMI corpses However species scarce 33 laboratory change study 96 alcohol 2 5% 5 (5% 4 P observed 1 apolysis lasted average 3 65 6. transparent eyes 21 h. . h) 34 3725 372 372. 155 15 15. prepupa intermutans (Sarcophagidae Calliphoridae. Calliphoridae (Calliphoridae) (5 37 (Calliphoridae (

RESUMEN Las moscas Sarcophagidae tienen gran importancia forense, ya que diferentes etapas de su desarrollo larvario son utilizadas en la determinación del intervalo post mortem (IPM) de cadáveres. Sin embargo, para muchas especies los datos sobre el desarrollo intrapupal son escasos. Aquí analizamos el desarrollo intrapupal del sarcofagido Peckia pexata y describimos los cambios cronológicos y morfológicos que ocurren durante la metamorfosis. Criamos aproximadamente 330 especímenes originarios de la Amazonía colombiana en laboratorio. Prepupas se identificaron por la reducción de tamaño y cambio de color. Durante los primeros cinco días se tomaron muestras de cuatro individuos cada tres horas, y posteriormente cada seis horas hasta la emergencia de los adultos. Los especímenes se fijaron en alcohol al 96%, posteriormente se sumergieron en solución Carnoy durante 24 horas y en ácido fórmico (5%) durante 48 horas, para disección y el análisis de los cambios morfológicos. Observamos cuatro etapas del desarrollo intrapupal de P. pexata: 1) larva pupa apolisis, que duró, en promedio, 9 h; 2) pupa criptocefálica, 6 h; 3) pupa fanerocefálica, 6.5 h; y 4) adulto farado (ojos transparentes, 48 h; ojos amarillos, 216 h; ojos rosados, 35 h; y ojos rojos, 52 h). El adulto farado se formó completamente a las 340 h y la emergencia del adulto se produjo a las 372.5 h o 15,5 días. También describimos la formación de la prepupa, la pupariación y la metamorfosis final para el imago y lo comparamos con los eventos conocidos para Peckia intermutans, Peckia lambens (Sarcophagidae) y Lucilia eximia (Calliphoridae). forense IPM (IPM cadáveres embargo escasos 33 laboratorio color adultos 96 96% 2 5% 5 (5% 4 P 1 apolisis duró promedio criptocefálica 3 fanerocefálica 65 6. transparentes amarillos 21 rosados rojos h. . h) 34 3725 372 372. 155 15 15, prepupa intermutans (Sarcophagidae Calliphoridae. Calliphoridae (Calliphoridae) (5 37 (Calliphoridae (

ABSTRACT This study investigated the effects of burning on the richness, abundance, and community structure of necrophagous flies in southern Brazil. Flies were collected over a period of seven days in the field, and were subsequently observed for 60 days in the laboratory. There were three bovine liver treatments: unburnt, burnt, and gasoline-treated (control). A total of 2,501 flies, representing 14 families and 41 species, were identified, including Chrysomya albiceps, Fannia subgroup pusio, Synthesiomyia nudiseta, and Fannia femoralis. While the abundance of flies was similar across the three treatments, exhibiting a quadratic distribution, species richness displayed a quadratic trend with a significant temporal shift; peak richness occurred 20 hours earlier in the unburnt liver than in the burnt or the control treatments. Both total abundance and patterns of community composition in our analysis indicated important factors to take into account. Total abundances were similar between the burnt and unburnt treatments, demonstrating a uniform ecological response to burning, irrespective of the condition of the liver. In contrast, the community composition of these treatments showed a significant divergence from the control treatment, which was distinctively dominated by Drosophilidae and Phoridae. These findings are crucial for accurate postmortem Interval (PMI) estimations in forensic entomology, particularly in cases involving burnt remains, and highlight the significant impact of fire on necrophagous fly communities. Brazil field 6 laboratory gasolinetreated gasoline treated control. . (control) 2501 2 501 2,50 1 4 identified albiceps pusio nudiseta femoralis distribution shift account contrast treatment Phoridae PMI (PMI entomology remains communities (control 250 50 2,5 25 5 2,

ABSTRACT Entomofauna associated with decaying cadavers may be useful in criminal investigation, either through the development of immature insects of interest or through entomological succession in corpses. These factors may vary if the insects are exposed to toxic substances that can modify the insect's developmental cycle, as well as its own occurrence, which would imply significant changes in the results of any investigation. However, there are few studies on how contamination by toxic compounds can affect the action of insects on carcasses and their consequence for forensic expertise. Therefore, this study aimed to test the hypothesis that the normal visitation of flies and beetles is altered in insecticide-contaminated carcasses. The experiment was carried out in a sugarcane plantation, using pig carcasses contaminated with insecticide and the same number of carcasses without any type of contamination as a control. In all experiments, the contaminated carcasses reached the final phase of decomposition in a longer time than the uncontaminated carcasses of the control group. A total of 2.767 specimens were collected and identified, 2.103 individuals from the order Diptera and 664 from the order Coleoptera. There was a significant geometric regression adjustment during the decomposition phases only for the control group, different from the contaminated carcasses in which this pattern did not occur. Results show that contamination by insecticide alters decomposition time and phase, altering the action of flies and beetles, affecting the abundance, composition of species as well as their activities, which can alter the data used by experts in criminal experts. investigation corpses insect s cycle occurrence However expertise Therefore insecticidecontaminated plantation experiments group 2767 2 767 2.76 identified 2103 103 2.10 66 Coleoptera occur abundance activities 276 76 2.7 210 10 2.1 6 27 7 2. 21 1

Abstract Objective: To study the impact of age and the interval between disease diagnosis and death on the organotropism of SARS-CoV-2. Method: Patients underwent post-mortem biopsies from lungs, Waldeyer ring, heart, liver, kidneys and bone marrow between 2020–2021. SARS-CoV-2 organotropism was mapped by using molecular RT-PCR analyses for SARS-CoV2 targeting the Envelope gene (E), the RNA Polymerase Gene (RdRp), and the Nucleocapsid gene (N). Statistical and linear regression analysis was performed to study the impact of age and illness duration in SARS-CoV-2 organotropism. Results: We performed 158 postmortem biopsies in 21 patients, with a mean age of 76 years old. The mean interval between the diagnosis of the infection to the death was 23 days. The RNA of the SARS-CoV-2 was detected in 100% of lung biopsies, 76%–82% of Waldeyer’s ring biopsies, 55% of heart biopsies, 40% of kidney biopsies, 33% of liver and 25% of bone marrow biopsies. Patients who died before the day 9, presented extensive visceral dissemination of SARS-CoV-2 RNA. Most of the patients older than 80 years (90%) presented visceral dissemination of SARS-CoV-2 RNA, while among younger patients, only 3/11 patients presented visceral dissemination of the virus. The relationship between “age” and “illness duration” and multitropism of the virus was statistically significant (p< 0.001). Conclusion: Disease interval and age were factors that were significantly associated with RT-PCR positive results in multiple organs. Critical COVID-19 patients have multiorganic viral dissemination in early stages. In the critical older patients, multiorganic viral dissemination is the rule. Level of evidence: 4. Case Series. Objective SARSCoV2. SARSCoV2 SARSCoV SARS CoV 2. 2 Method post mortem lungs 20202021 2020 2021 2020–2021 SARS-CoV- RTPCR RT PCR CoV2 SARS-CoV E, E , (E) RdRp, RdRp (RdRp) N. N . (N) Results 15 7 old days 100 7682 82 76%–82 Waldeyers s 55 40 33 25 9 8 90% 90 (90% 311 3 11 3/1 “age p< p (p 0.001. 0001 0.001 0 001 0.001) Conclusion organs COVID19 COVID 19 COVID-1 stages rule evidence 4 Series 2020202 202 2020–202 (E (RdRp (N 1 10 768 76%–8 5 (90 31 3/ 000 0.00 00 COVID1 COVID- 202020 20 2020–20 76%– (9 0.0 20202 2020–2 76% ( 0. 2020–

ABSTRACT Insects attracted to cadavers can be used to estimate postmortem interval (PMI). In this study, inmature stages and adults of Dermestes maculatus and Chrysomya albiceps were collected in association with a human cadaver in a closed aquatic environment in Caquetá, Colombia, and analyzed to determine the PMI. We also conducted an experiment with a pig carcass to estimate the emersion time, which began three days after carcass submersion. The minimum PMI was 481.5 hours. Time of death, time of emersion and period of insect activity matched the actions of the murder suspects, who confessed to murdering the victim 25 days prior to the discovery of the body.

RESUMEN Los insectos atraídos a cadáveres pueden ser usados para estimar el intervalo post mortem (IPM). En este estudio, una muestra de estados inmaduros y adultos de Dermestes maculatus y Chrysomya albiceps fueron recolectados en asociación con un cadáver humano en un ambiente cerrado y acuático en Caquetá, Colombia, y analizada para determinar el IPM. Además, se condujo un experimento con un cadáver porcino para estimar el tiempo de emersión, que comenzó tres días después de la sumersión del cadáver. El IPM mínimo fue 481.5 horas. El tiempo de muerte, tiempo de emersión y el periodo de actividad insectil coincidieron con las acciones de los sospechosos del crimen, quienes confesaron haber asesinado a la víctima 25 días antes del descubrimiento del cadáver.

SUMMARY: The postmortem interval (PMI) equals the time that has elapsed since a human being has died until his postmortem examination. After death, the body experiences modifications in its physical and chemical composition know as postmortem changes expressed by signs that can be analyzed for the calculation of the MPI. The aim of the study was to describe the histological changes present in rat lingual striated musculature in different PMIs. 10 two-month-old male Sprague dawley rats were used. The animals were euthanized and left at room temperature (4-14 ?C) to sample the tongue at different PMIs (0, 6, 12, 24, 48, 72, 96 and 120 hours postmortem). The study was carried out considering the recommendations of the Guide for the Care and Use of Laboratory Animals. The samples were fixed in 10% buffered formaldehyde and processed for inclusion in paraplast. 5 μm thick sections were made and stained with HE for análisis with light microscopy. Histological changes in the striated muscle cells of the tongue were associated with the different PMIs. At 6 hours postmortem, there were initial changes in nuclear morphology and its pigmentation. At 12 and 24 hours postmortem, changes in muscle striae and an increase in the number of cases with nuclear alterations were observed. At 48 and 72 hours postmortem, cytoplasmic vacuoles, changes in myofiber coloration, and increased nuclear alterations were evident. At 92 and 120 hours postmortem, a decrease in muscle striae and cell nuclei was observed. The nuclei were pyknotic and pinpoint; there was loss of cell morphology and presence of smooth muscle. In conclusion, changes in the histology of rat lingual skeletal muscle make it possible to estimate MPI. This model could be applicable to forensic medicine.

RESUMEN: El intervalo postmortem (IPM) equivale al tiempo que ha transcurrido desde que un ser humano ha muerto hasta su examinación postmortem. Después de la muerte, el cuerpo experimenta modificaciones en su composición física y química denominados cambios postmortem expresados por signos que pueden ser analizados para el cálculo del IPM. El objetivo del estudio fue describir los cambios histológicos presentes en la musculatura estriada lingual de rata en diferentes IPM. Se utilizaron 10 ratas machos Sprague dawley de dos meses de edad. Los animales fueron eutanasiados y dejados a temperatura ambiente (4 - 14 ?C) para tomar muestras de la lengua a distintos IPM (0, 6, 12, 24, 48, 72, 96 y 120 horas postmortem). El estudio se llevó a cabo considerando las recomendaciones de la Guía para el Cuidado y Uso de Animales de Laboratorio. Las muestras fueron fijadas en formaldehido tamponado a 10 % y procesadas para su inclusión en paraplast. Se realizaron cortes de 5 μm de grosor y fueron teñidas con HE para su análisis con microscopía óptica. Los cambios histológicos en las células musculares estriadas de la lengua estaban asociados a los distintos IPM. A las 6 horas postmortem, hubo cambios iniciales en la morfología nuclear y su pigmentación. A las 12 y 24 horas postmortem, se observaron cambios en las estrías musculares y aumento en el número de casos con alteraciones nucleares. A las 48 y 72 horas postmortem, eran evidentes las vacuolas citoplasmáticas, cambios en la coloración de las miofibras y aumento en las alteraciones nucleares. A las 92 y 120 horas postmortem, se observó disminución de las estrías musculares y núcleos celulares. Los núcleos eran picnóticos y puntiformes; hubo pérdida de la morfología celular y presencia de musculo liso. En conclusión, los cambios de la histología del músculo estriado lingual de rata permiten estimar el IPM. Este modelo podría ser aplicable a la medicina forense.

Abstract Dermester ater De Geer is recorded for the first time from the state of Yucatan, Mexico. Within the field of Forensic Entomology, it is a species of relevance for its usefulness in the estimation of the postmortem interval (PMI). Adult specimens of this species were collected from mummified and dried remains of pig heads (Sus scrofa domestica Linnaeus, 1758) used as necrotraps placed in a semi-urban area. Photographs of D. ater, an identification key and illustrations for the 4 species of Dermestes present in the state are included.

Resumen Se registra por primera vez a Dermestes ater De Geer en el estado de Yucatán, México. Dentro del campo de la Entomología Forense es una especie de relevancia por su utilidad en la estimación del intervalo postmortem (IPM). Ejemplares adultos de esta especie fueron recolectados en los estados de momificación y restos secos de cabezas de cerdo (Sus scrofa domestica Linnaeus, 1758) utilizadas como necrotrampas colocadas en una zona semiurbana. Se incluyen fotografías de D. ater, una clave de identificación e ilustraciones para las 4 especies de Dermestes presentes en el estado.

SUMMARY: The postmortem interval (PMI) is an important challenge to be solved in forensic pathology, and it consists of being able to determine the time elapsed from death to the moment of autopsy. Given the unreliability of some methods due to the great influence of external factors and those specific to the corpse, forensic biochemistry has received considerable attention for its levels of safety. The city of Quito is located in the Andes mountain range at 2850 meters above sea level, however, in the literature there are no reports of measurement of these parameters at a height like this. The objective was to establish a correlation between sodium (Na+), chlorine (Cl-) and potassium (K+) of the vitreous humor and the MPI at a height of 2,850 masl. For the study, 128 samples of vitreous humor were used from 16 autopsies performed in the Zone 9 Legal Medicine Unit, in IPM of 6, 12, 24, 48, 72, 96, 120 and 144 hours. To obtain the vitreous humor, the conventional method was followed, it was divided for the 8 aliquots and it was frozen at -20 ° C until the moment of its analysis. The quantification of the concentration of electrolytes Na+, Cl- and K+ was carried out using an ISE analyzer from Roche Cobas (Roche Diagnostics) C501, calibrated for urinalysis, and no dilution was necessary. During calibration and every third sample, an internal standard was measured to correct for the effects of systematic deviation on the calibration. The statistical approach was based on a linear correlation analysis, using the Spearman correlation coefficient. The correlation between the postmortem hours and the concentrations of the different electrolytes were statistically significant. A significant linear correlation between the PMI and the increase in K+ in vitreous humor could be corroborated.

RESUMEN: El intervalo Postmortem (IPM) es un importante desafío por resolver en la patología forense, y consiste en poder determinar el tiempo transcurrido desde la muerte hasta el momento de la autopsia. Dada la poca confiabilidad de algunos métodos por la gran influencia de factores externos y propios del cadáver, la bioquímica forense ha recibido considerable atención por sus niveles de seguridad. La ciudad de Quito se ubica en la cordillera de Los Andes a 2850 msnm, sin embargo, en la literatura no existen reportes de medición de estos parámetros a una altura como ésta. El objetivo fue establecer una correlación entre sodio (Na+), cloro (Cl-) y potasio (K+) del humor vítreo del cuerpo vítreo y el IPM a la altura de la ciudad de Quito. Para el estudio se utilizaron 128 muestras de cuerpo vítreo provenientes de 16 autopsias practicadas en la Unidad de Medicina Legal Zona 9, en IPM de 6, 12, 24, 48, 72, 96, 120 y 144 horas. Para la obtención del humor vítreo se siguió el método convencional, se dividió para las 8 alícuotas y se llevó a congelación -20 °C hasta el momento de su análisis. La cuantificación de la concentración de electrolitos Na+, Cl- y Potasio+ se realizó mediante analizador ISE de Roche Cobas (Roche Diagnostics) C501, calibrado para uroanálisis, y no fue necesaria la dilución. Durante la calibración y cada tres muestras, se midió un estándar interno para corregir los efectos de la desviación sistemática en la calibración. El enfoque estadístico se basó en un análisis de correlación lineal, utilizando el coeficiente de correlación de Spearman. La correlación entre las horas postmortem y las concentraciones de los diferentes electrolitos, fueron estadísticamente significativas. Se pudo corroborar una correlación lineal significativa entre el IPM y el aumento del K+ en el HV.

Abstract This study aimed to develop a visual scale for beef color evaluation. A total of 1,165 loins were analyzed 24 h postmortem in four slaughterhouses in Mexico. In each sample, it was determined color using a visual pattern and a spectrophotometer (CIELAB scale), taking a photograph of each loin. Seven categories were identified using the visual method (from very light red to very dark red), and the instrumental color variables (L*, a*, b*, C*, and h*) were used to create prediction models for the visual categories. The scale was constructed using L* as the sole predictor, as this model explained > 90 % of the observed variation. The pattern was illustrated with photos of the samples with an L* value within the 95 % confidence interval of the mean in each category, from very light red (48.1 <L*<48.8) to very dark red (32.7 <L*<33.4). The total color difference between the categories fluctuated between 2.8 and 5.5, which suggests that these are distinguishable with the naked eye. A trained sensory panel and a consumer panel, through tests, validated the scale. Trained panelists correctly rated the samples in 92.6 % of the evaluations. In meat with dark-cutting (DC) appearance, the trained panelists had 100 % hits, and the consumer panelists 85.3 %. The proposed visual pattern is supported by instrumental measurements and proved to be technically feasible for the evaluation of color in beef by trained personnel and consumers.

Resumen El objetivo fue desarrollar una escala visual para la evaluación del color en carne de bovino. Se analizaron 1,165 lomos, a las 24 h post mortem, en cuatro rastros de la República Mexicana. En cada muestra se evaluó el color con ayuda de un patrón visual y con un espectrofotómetro (escala CIELAB), tomándose una fotografía de cada lomo. Por el método visual se identificaron siete categorías, (de rojo muy pálido a rojo muy oscuro) y las variables instrumentales del color (L*, a*, b*, C* y h*) se usaron para generar modelos de predicción de las categorías visuales. La escala se construyó utilizando L* como único predictor, pues este modelo explicó >90 % de la variación observada. El patrón se ilustró con fotos de las muestras con valor de L* dentro del intervalo de confianza al 95% de la media en cada categoría, desde rojo muy pálido (48.1<L*<48.8) hasta rojo muy oscuro (32.7<L*<33.4). La diferencia total de color entre categorías fluctuó entre 2.8 y 5.5, lo que sugiere que éstas son diferenciables a simple vista. La escala se validó mediante pruebas con un panel sensorial entrenado y otro de consumidores. Los jueces entrenados calificaron correctamente las muestras en el 92.6 % de las evaluaciones. En carne con apariencia de corte oscuro (CO), el panel entrenado tuvo 100 % de aciertos y el de consumidores 85.3 %. El patrón visual propuesto se sustenta en mediciones instrumentales y mostró ser técnicamente viable para la evaluación del color en carne de bovino por personal entrenado y por consumidores.

SUMMARY: The postmortem interval (IPM) is an important challenge to be solved in forensic pathology, and it consists in determine the time elapsed since death until the autopsy. Given the low reliability of some methods due to the great influence of external factors, Histochemistry (HQ) and Immunohistochemistry (IHQ), among others, have received considerable attention for their levels of objectivity in forensic investigation. A scoping review of experimental studies that apply HQs and IHQs methods to estimate the MPI on human cadaveric material is presented. We identified 1053 articles, of which 12 met the criteria; we added 4 articles through a manual search (n = 16 articles). Germany was the most productive country, with 8 articles. HQ techniques of AgNORs, TRAP and PAS were used in 5 studies (on sweat glands, skin, liver, bone marrow and labial mucosa), while IHQs techniques were used with different antigenic groups in 12 studies (on pancreas, brain, lung, thyroid, liver, pituitary glands, sweat glands and gingival mucosa). IPM estimates were possible with margins between 2-3 hours up to 20 days depending on the technique. The analysis of oral tissues ensures a non-invasive route, easily accessible and under natural protection to the influence of environmental factors. Although there is no single method that reliably allows these estimates, the introduction of new techniques would prevent the production of errors.

RESUMEN: El intervalo postmortem (IPM) es un importante desafío a resolver en patología forense, y consiste en poder determinar el tiempo transcurrido desde la muerte hasta el momento de la autopsia. Dada la poca confiablidad de algunos métodos por la gran influencia de factores externos, la Histoquímica (HQ) y la Inmunohistoquímica (IHQ), entre otros, han recibido considerable atención por sus niveles de objetividad en la investigación forense. Se presenta una revisión con búsqueda sistemática de estudios experimentales que apliquen métodos HQs e IHQs para la estimación del IPM sobre material cadavérico humano. Se identificaron 1053 artículos de los cuales 12 cumplieron con los criterios, a los que se agregaron 4 mediante una búsqueda manual (n=16 artículos). Alemania fue el país con más publicaciones destacando con 8 artículos. Las técnicas HQs de AgNORs, TRAP y PAS fueron utilizadas en 5 estudios (glándulas sudoríparas, piel, hígado, médula ósea y mucosa labial), mientras que las IHQs fueron empleadas con diferentes grupos antigénicos en 12 estudios (páncreas, cerebro, pulmón, tiroides, hígado, glándulas pituitarias, glándulas sudoríparas y mucosa gingival). Las estimaciones del IPM fueron posibles con márgenes entre 2-3 h. hasta los 20 días dependiendo de la técnica. El análisis de tejidos provenientes de cavidad oral asegura una vía no invasiva, de fácil acceso y bajo resguardo natural a la influencia de factores ambientales. Si bien no existe un método único que permita de manera confiable estas estimaciones, la introducción de nuevas técnicas permitiría evitar la producción de errores.

BACKGROUND. Decedents who remain unidentified and/or unclaimed following postmortem investigations are an international occurrence. Salt River Mortuary (SRM), one of the largest and busiest mortuaries in Cape Town, South Africa, also experiences this burden; however, little is known about the nature of these cases.OBJECTIVES. To review all cases admitted to SRM between 1 January 2010 and 31 December 2017 (n=26 960), with the objectives of quantifying the number of decedents who remained unidentified, and to better understand circumstances surrounding death and the identification methods that were attempted.METHODS. Data pertaining to unidentified cases were collected from mortuary burial records and medicolegal case files. Data were analysed using Microsoft Excel 2013 (Microsoft, USA).RESULTS. Over the 8-year period, 2 476 cases (mean 9.2% of caseload per annum) admitted to SRM remained unidentified. Bodies underwent an autopsy after a median of 3 days after a death declaration. However, in cases of decomposition, skeletonisation or other physical inhibitors of visual identification (n=345; 14.1%), the time between death and autopsy was undetermined owing to the overall lack of entomology analyses. Approximately 56.9% (n=1408) of cases were between 20 and 50 years of age, and were predominantly males (78.7%). Unnatural injury-related deaths accounted for 32.4% of unidentified deaths, with firearms, assault and stabbings contributing approximately one-third each. With regard to identification attempts, forensic anthropology was requested in only 1.5% of these cases, and DNA analysis appeared to be used in only 23.6% of cases. Data pertaining to secondary identifiers, forensic odontology and fingerprint analyses were not formally recorded.CONCLUSIONS. The relatively short time interval between death declaration and postmortem examination suggests that DNA analysis should be more regularly utilised. Furthermore, it is urged that other ancillary investigations should be more regularly employed; that there is a greater collaboration between stakeholders and identification attempts; and that results are centrally recorded.