Complete Autopsy Research Articles

Spontaneous hepatocellular and gastric tumours in African clawed frogs (Xenopus laevis).

Three seven-year-old African clawed frogs (Xenopus laevis) from an animal research facility showed weight loss, coelomic distention and an abnormal swimming gait were euthanised on welfare grounds. A complete necropsy of each animal showed a focal, firm, dark brown to green mass with multifocal haemorrhages in the left liver lobe in two animals and a transmural, firm, beige, multilobulated gastric mass in another animal. Additionally, one of the frogs with the hepatic mass had haemocoeloma. Histologically, the hepatic masses were diagnosed as hepatocellular adenomas and the gastric mass as a gastric carcinoma with trans-coelomic metastases. The three tumours were immunophenotyped using the following antibodies: cytokeratin AE1/AE3, vimentin, E-cadherin, P53 and Ki67 and, additionally, for the hepatic tumours only, synaptophysin, Prox-1, S100 and Sox-9. Masson's trichrome, Periodic acid Schiff and Gram stains was also performed in selected cases. One of the hepatocellular adenomas was weakly positively labelled with E-cadherin whereas the other showed variable positivity for Sox-9 only. Vimentin labelled the stroma and sinusoidal endothelia. Interestingly in the liver, the cytokeratin AE1/AE3 labelling was restricted to the biliary epithelium and sinusoidal endothelia. The gastric carcinoma labelled positively with cytokeratin AE1/AE3 only. This report aims to guide laboratory animal veterinarians to accurately diagnose multi-organ masses in amphibians. To the authors' knowledge, this is the first comprehensive morphological study on a case series of hepatocellular and gastric neoplasia in X. laevis.

Alveolar Capillary Dysplasia with Misaligned Pulmonary Veins diagnosed at autopsy in association with novel FOXF1 variant

Abstract Introduction/Objective Alveolar Capillary Dysplasia with Misalignment of Pulmonary Veins (ACD/MPV) is a rare disorder characterized by abnormal development of the pulmonary vasculature resulting in intractable pulmonary hypertension in neonates. Affected newborns present with progressive hypoxemia that is nearly always fatal. ACD/MPV is typically seen in the setting of other congenital anomalies, including gastrointestinal, genitourinary, and cardiac systems. Although the pathogenesis of ACD/MPV is poorly understood, inactivating mutations in the FOXF1 gene have been implicated. We present a case of ACD/MPV with associated gastrointestinal/cardiac anomalies and a novel heterozygous mutation of FOXF1. Methods/Case Report A complete autopsy was perfomed. Rapid whole exome sequencing of whole blood was done via reference laboratory. Results (if a Case Study enter NA) A 36-week gestational age male was born via cesarean delivery following a pregnancy course complicated by polyhydramnios. The neonate developed respiratory failure requiring intubation and Extracorporeal Membranous Oxygenation (ECMO). Further clinical evaluation revealed a patent foremen ovale and ductus arteriosus with right to left shunting. After 18 days on ECMO, he was transferred to comfort care where he later died. The body was that of a small for gestational age, phenotypic male neonate without gross dysmorphia noted on external examination. Internal examination revealed duodenal atresia, a patent ductus arteriosus and foramen ovale, and heavy, edematous lungs. Histologic examination of the lungs demonstrated prominent congested veins abutting small arteries with medial hypertrophy within shared adventitial sheaths. The interlobar septa contained dilated lymphatic spaces. Airspaces showed a dense neutrophilic exudate. Rapid whole exome sequencing revealed heterozygous mutations in FOXF1 (c.182T>C, p.Ile61Thr), NOTCH1 (c.7495A>C, p.Ser2499Arg) and a hemizygous mutation in SSR4 (c.20G>T, p.Gly7Val). The FOXF1 mutation was predicted to be damaging and has not yet been reported in the literature; however, its clinical significance was interpreted as uncertain. The significance of the NOTCH1 and SSR4 mutations were considered unknown. Given these findings, a diagnosis of ACD/MPV was given as the cause of death. Conclusion This case illustrates the classic clinical, gross and histologic findings described in ACD/MPV. Additionally, a novel heterozygous mutation of FOXF1 was identified and predicted to be damaging, supporting the role of FOXF1 mutations in the pathogenesis of ACD/MPV.

Neuropathologic Findings and Electrolyte Abnormalities in a Case of Lennox-Gastaut Syndrome (SCN2a- related) Encountered at Autopsy

Abstract Introduction/Objective Lennox-Gastaut syndrome is a severe form of childhood epilepsy which may be due to several conditions, including sodium channelopathies which alter neuronal firing patterns. We present a case of a 6-year-old female with Lennox-Gastaut syndrome (SCN2A-related) complicated by developmental delay, spastic quadriplegia, and gastrojejunostomy tube dependence who was referred for medicolegal autopsy due to death subsequent to becoming unresponsive during a supervised bath. Methods/Case Report A complete autopsy was performed, including gross and microscopic examination of all primary organ systems, formal neuropathologic examination, and postmortem microbiology, toxicology, and vitreous electrolyte studies. The decedent showed evidence of developmental delay and flexion contractures of the extremities. No significant traumatic injuries were identified. A postmortem nasopharyngeal swab was positive for Rhinovirus/Enterovirus and Influenza A H3. A postmortem vitreous electrolyte panel demonstrated a dehydration pattern, including markedly elevated sodium and chloride and elevated urea nitrogen. Gross examination of the brain showed a thin corpus callosum, small hippocampi, as well as abnormal cerebellar dentate and inferior olivary nuclei. Microscopic examination of the brain tissue supported the gross findings, including dentato-olivary dysplasia. The cause of death was certified as dehydration complicating Lennox-Gastaut syndrome (SCN2a-related). Rhinovirus/Enterovirus and Influenza A H3 infections were considered contributory to death. The manner of death remained undetermined, since it was unknown if the decedent’s natural diseases, issues following a scheduled gastrojejunostomy feeding regimen, neglect, or some combination thereof caused the dehydration. Results (if a Case Study enter NA) NA Conclusion This case highlights unique and rarely documented neuropathologic findings and electrolyte abnormalities that may be seen in Lennox-Gastaut syndrome associated with an SCN2A mutation in addition to demonstrating the challenges of cause and manner death certification in cases of severe developmental disorders of childhood related to sodium channelopathies.

Case of Bone Morphogenetic Protein Receptor Type 2 (BMPR2) Mutation Complicated by Pulmonary Hypertension Encountered at Autopsy

Abstract Introduction/Objective Bone morphogenetic protein receptor type 2 is a protein encoded by the BMPR2 gene which regulates cell division and apoptosis. BMPR2 mutations result in monoclonal plexiform lesions of proliferating endothelial cells in pulmonary arterioles, which leads to elevated pulmonary artery pressures, right ventricular failure, and death. Here, we present the case of a 12-year-old male with a known history of pulmonary hypertension secondary to BMPR2 mutation referred for medical autopsy after suffering cardiac arrest and passing away. Methods/Case Report This 12-year-old male was diagnosed with pulmonary hypertension in December 2022 after suffering a syncopal episode while running at recess. Genetic testing was obtained, and he was found to have a BMPR2 mutation. His father was tested and also harbored this mutation, but did not clinically have pulmonary hypertension. The decedent was initiated on ambrisentan, tadalafil, and spironolactone, but continued to present to the Emergency Department periodically for syncopal episodes. In April 2024, he presented to the Medical University of South Carolina in cardiac arrest which began while playing outside. A complete autopsy was performed, including gross and microscopic examination of tissues and postmortem vitreous electrolyte analysis. Gross examination revealed the decedent’s heart was enlarged to 350 grams (normal mean for age = 181 grams). Both cardiac ventricles were dilated and the right ventricle was markedly hypertrophic with a thickness of 1.2 cm. Microscopic sections are pending but will presumptively show significant cardiac myocyte hypertrophy and pulmonary arteriole thickening. Cause of death is pending certification but is presumed to be sudden cardiac death resulting from BMPR2 mutation- related pulmonary hypertension. Results (if a Case Study enter NA) NA Conclusion This case highlights a common genetic presentation of pulmonary arterial hypertension, with approximately 80% of familial cases of pulmonary arterial hypertension harboring BMPR2 mutations. Further research should be done to investigate treatment options and management of this genetic presentation.

Iatrogenic needle penetrating injury of cervical spinal cord: a case of fatal therapeutic complication.

A 52-year-old woman with of neck pain underwent percutaneous neck injection of local anesthetic and a corticosteroid without image guidance. She collapsed asystolic during the procedure was resuscitated and then died after 2 weeks in the intensive care unit with hypoxic encephalopathy. Complete postmortem examination included additional posterior neck dissection and cervical spinal cord removal with intact dura mater. The entire cervical spinal cord with the dura and leptomeninges was embedded in an oriented sequence of several paraffin blocks. Serial sections of each selected blocks were then studied to locate a putative puncture site. Serial sections from the third and fourth cervical levels (C3-C4) were stained with luxol fast blue-hematoxylin-eosin, iron stain, trichrome stain, and immunostained for b-amyloid precursor protein, and CD68. Histological examination revealed a linear needle track with a subacute healing reaction. The path included the dorsal spinal dura, arachnoid, and the left dorsal column. Clinicopathological correlation and the cause of death are discussed. Careful planning, dissection, sampling, and oriented serial sectioning with immunostaining were key points to document the injuries and understand this case.

56Fe-ion Exposure Increases the Incidence of Lung and Brain Tumors at a Similar Rate in Male and Female Mice.

The main deterrent to long-term space travel is the risk of Radiation Exposure Induced Death (REID). The National Aeronautics and Space Administration (NASA) has adopted Permissible Exposure Levels (PELs) to limit the probability of REID to 3% for the risk of death due to radiation-induced carcinogenesis. The most significant contributor to current REID estimates for astronauts is the risk of lung cancer. Recently updated lung cancer estimates from Japan's atomic bomb survivors showed that the excess relative risk of lung cancer by age 70 is roughly fourfold higher in females compared to males. However, whether sex differences may impact the risk of lung cancer due to exposure to high charge and energy (HZE) radiation is not well studied. Thus, to evaluate the impact of sex differences on the risk of solid cancer development after HZE radiation exposure, we irradiated Rbfl/fl, Trp53fl/+ male and female mice infected with Adeno-Cre with various doses of 320 kVp X rays or 600 MeV/n 56Fe ions and monitored them for any radiation-induced malignancies. We conducted complete necropsy and histopathology of major organs on 183 male and 157 female mice after following them for 350 days postirradiation. We observed that lung adenomas/carcinomas and esthesioneuroblastomas (ENBs) were the most common primary malignancies in mice exposed to X rays and 56Fe ions, respectively. In addition, 1 Gy 56Fe-ion exposure compared to X-ray exposure led to a significantly early incidence of lung adenomas/carcinomas (P = 0.02) and ENBs (P < 0.0001) in mice. However, we did not find a significantly higher incidence of any solid malignancies in female mice as compared to male mice, regardless of radiation quality. Furthermore, gene expression analysis of ENBs suggested a distinct gene expression pattern with similar hallmark pathways altered, such as MYC targets and MTORC1 signaling, in ENBs induced by X rays and 56Fe ions. Thus, our data revealed that 56Fe-ion exposure significantly accelerated the development of lung adenomas/carcinomas and ENBs compared to X rays, but the rate of solid malignancies was similar between male and female mice, regardless of radiation quality.

Targeting T cells with tetravalent bispecific antibodies for the treatment of graft-versus-host disease

AbstractAllogeneic hematopoietic stem cell transplantation is an established treatment for hematological malignancies and some genetic diseases. Acute graft-versus-host disease (GVHD) is the most common and debilitating side effect with poor survival rates of 5% to 30% for severe cases. In this manuscript, we describe a tetravalent T-cell–engaging bispecific antibody (BsAb) based on the immunoglobulin G-[L]-single-chain variable fragment (IgG-[L]-scFv) platform, with all 4 binding domains specific for CD3. In vitro, picomolar concentrations of the CD3×CD3 BsAb induced potent lysis of activated CD4 and CD8 T cells. In immunodeficient mice, in which human T cells induced xenogeneic GVHD, administration of 0.1 μg BsAb per dose depleted the majority of T cells from the peripheral blood, and 10 μg per dose completely reversed established GVHD and achieved a 100% survival rate. In mice bearing NALM6-luc xenografts, treatment with CD3×CD19 BsAb and activated human T cells induced complete remission of the leukemia, and all treated mice developed GVHD by 50 days after treatment. CD3×CD3 BsAb (3-30 μg doses) reversed clinical signs of GVHD, allowing long term follow-up beyond 250 days. T cells were undetectable by polymerase chain reaction in 4 of 5 mice in the 30 μg CD3×CD3 BsAb group 180 days after leukemia injection, and complete necropsies on day 259 revealed no evidence of human T cells or leukemia cells. Curing GVHD allows for long-term follow-up of tumor response heretofore impossible in humanized mouse models. Further studies are warranted to determine whether the CD3×CD3 BsAb has potential for treating clinical GVHD and other autoimmune diseases in humans.

Anthropozoonotic parasitoses of dogs and cats in the urban ecosystem of Vladivostok, Russia

To investigate the role of domestic dogs and cats in the spread of parasitoses in the Vladivostok urban ecosystem. Biological materials from 782 dogs and 189 cats were used in the research, which were examined by methods of complete parasitological autopsy, microscopy and flotation of faecal samples using saturated solutions of zinc sulfate and sodium nitrate.Fourteen parasite taxa have been identified: nematodes (Nematoda) Ancylostoma caninum, Dirofilaria immitis, Toxascaris leonina, Toxocara canis, T. mystax, Uncinaria stenocephala, Taenia sp., T. hydatigena; tapeworms (Cestoda) Diphyllobothrium latum, Dipylidium caninum, Hydatigera taeniaeformis; flukes (Trematoda) Metagonimus sp.; and parasitic alveolates (Conoidasida) Cystoisospora sp., C. felis. The paper presents the values of the prevalence of infection and statistical reliability of their differences for different groups of animals, depending on gender and age. Nematodes were the core taxa of the parasitofauna identified. Explanations for the results obtained are offered and possible sources of human infection are described. Despite the fact that parasitic‐faunal complexes in the ecosystem of a modern city are much less branched and represented by fewer species than in the wild, there remains a high risk of human infection with zoonotic parasites in urban biocenoses due to the high level of intensive population interactions. Therefore, there is a requirement of high alertness of supervisory authorities in relation to anthropozoonotic parasitoses in an urban environment.

Bioecological Characterization of Nematode Distribution Among Livestock in the North-Eastern Territories of the Lesser Caucasus of Azerbaijan Republic

Helminthological studies of sheep and goats were conducted in the northeastern territories of the Lesser Caucasus of the Republic of Azerbaijan in 2013-2022. The northeastern areas of the Lesser Caucasus include Ganja and Goygeli, Dashkesan, Geranboy, Naftalan, Samukh, Shamkir, Tovuz, Agstafa, Gazakh and Kadabek districts, as well as the areas around the Kura and Jeyranchel rivers, which are wintering places of livestock farms. This process plays a special role in the formation of helminth fauna of animals, as small horned livestock farms in these areas lead a nomadic and sedentary lifestyle. As a result of helminthological research 52 species of helminths, including 43 species of nematodes were identified. Of these, 7 species are indicated for the study region for the first time. All detected nematode species were registered in sheep, while only 26 species were found in goats, which are common to the sheep helminth fauna. These helminth species can be considered as permanent elements of the helminthofaunistic complex of livestock production in the studied region. It was found that young sheep and goats are relatively heavily infested with helminths. Infestation is higher in late spring — early summer and early fall. For this purpose, 957 sheep and 619 goats were examined for nematode pathogens in different landscape-ecological zones of the region by the method of complete helminthological autopsy according to K. I. Skryabin. Some species of helminths are absent in the studied animals before driving them to summer pastures but are observed in them after their return to wintering. Animals become infected by ingesting larvae or mature helminth eggs on summer pastures. -

ЭКОЛОГО-ЭПИЗООТОЛОГИЧЕСКАЯ ХАРАКТЕРИСТИКА АНОПЛОЦЕФАЛИДОЗОВ МЕЛКОГО РОГАТОГО СКОТА В ФЕРМЕРСКИХ ХОЗЯЙСТВАХ АЛТАЙСКОГО КРАЯ

The purpose of the study is to identify in the Altay Region the most pathogenic helminths among small livestock that threaten the health of farm animals, and their harmfulness and extent of spread. Using the coprooscopic method, fecal samples from sheep of 3 groups were examined: up to one year, from 1 to 2 years and over 2 years. Using the method of complete helminthological autopsies, 18 heads of sheep were opened on farms, of which 11 were aged from 1 to 2 years and 7 heads were older than 2 years. We studied the timing of infection in lambs by monthly examination of the same animals, starting from two months of age until they reach two years of age. All lambs were from the same farm; no anticestodal measures were carried out, so the natural course of the invasion was not disturbed. The survey began at the end of May 2020 with a group of lambs that reached two months of age in the amount of 26 heads. The number of oribatid mites was studied by collecting oribatid mites using a special technique. From the class of cestodes among sheep, 5 species are most often recorded with an average level of extensive infestation from 0.5 to 44.4 %. Anoplocephalid eggs were first discovered in lambs of the current year of birth in July. Moniesia were found throughout the year in young animals from one to two years of age. In March, April, and May they were recorded in single animals in this group of sheep. The seasonal dynamics of the number of oribatid ticks is directly dependent on natural and climatic conditions: significantly fewer ticks were recorded in the steppe zone than in the forest-steppe and floodplain zones. The results of the study show that monieziosis in young lambs kept on pasture is detected coprologically in the conditions of the Altai Region no earlier than July. Two peaks of activity of the intermediate hosts of moniesia, oribatid mites, have been recorded: spring and autumn.

Blunt Force Trauma in the Canarian Houbara Bustard (Chlamydotis undulata fuertaventurae) Produced by Collision with Overhead Lines.

The mortality of birds resulting from collisions and electrocutions with overhead lines, such as power lines and phone lines, among others, has been implicated in the decline of various avian species globally. Specifically, overhead line collisions pose a significant threat to the conservation of the Canarian houbara bustard (Chlamydotis undulata fuertaventurae), an endangered subspecies endemic to the Canary Islands. This study centers on the postmortem findings of Canarian houbara bustards that have collided with overhead lines, providing insights into the post-collision outcomes for these birds. A complete standardized necropsy of nine Canarian houbara bustards revealed that trauma was the cause of death in all cases. The most notable gross lesions associated with trauma included bone fractures, soft tissue lacerations, hemorrhages, luxations, and hemocoelom. The inguinal area, chest, and wings were the body regions more frequently affected. A histopathology, immunohistochemistry, and entomology analysis confirmed that numerous birds survived the initial trauma. We concluded that when a houbara bustard collides with an overhead line, it frequently survives the initial trauma, with a survival time ranging from minutes to hours. The histopathology, immunohistochemistry, or entomologic analysis may be helpful to approximate the timing interval between trauma and death.

Are invasive postmortem examinations still the &amp;lsquo;gold standard&amp;rsquo; in diagnosing the cause of death?

For many years, the foundations of both its art and science in medicine grew from the observations made at the autopsy table. The observations of the pathologists formed the pathologic basis and manifestations of disease, which further advanced the development of therapeutics. For most of the 18th and 19th centuries, morbid anatomy (autopsy pathology) was considered the science of medicine. Today, the autopsy and the knowledge that derives from it do not hold the position they once did in the profession’s history. There is a belief among the medical community a complete autopsy is necessary to find out the answers when someone dies. In some jurisdictions, the forensic pathology community is reluctant to follow the targeted or minimally invasive approach in postmortem examinations due to a lack of understanding of the process. With a complete external examination, trace evidence collection, total body computed tomography (CT) scan, and minimally invasive/targeted dissection with a collection of samples for further analysis, almost all answers can be provided in hospital and medicolegal autopsy settings. We must collaborate with sister disciplines, such as experts in radiology and the legal community, to educate them on the importance of this new approach using advanced technology.Continuously evolving modern radiological imaging has remarkably increased the accuracy of clinical diagnosis. Conventionally, when you hear the word postmortem examination, people think it includes an external examination and dissection of all body cavities. In the 21st century, most questions raised by the family, clinicians, the coroner (medical examiner), courts, and law enforcement agencies can be answered with a complete external examination of the body, total body CT scan +/- magnetic resonance imaging, and targeted dissection or minimally invasive approach incorporated with sample collection for further testing. This is cost-effective and can produce reviewable data.

Two-year carcinogenicity study of a novel plasticizer, bis(2-ethylhexyl) cyclohexane-1,4-dicarboxylate (Eco-DEHCH), by oral diet in Han Wistar rats

Plasticizers are necessary for the usability of various products, including food contact materials. Exposure to plasticizers is most commonly made through the oral route. Several plasticizers have been reported to have adverse effects on humans and the environment. Thus, the present study aimed to determine the long-term toxicity and carcinogenicity of a novel plasticizer called bis(2-ethylhexyl) cyclohexane-1,4-dicarboxylate (Eco-DEHCH), which is an ecofriendly and biologically less harmful replacer. Groups of 50 male and 50 female Han Wistar rats were fed Eco-DEHCH at daily doses of 1,600, 5,000, or 16,000 ppm in their diet for at least 104 weeks. The rats were regularly monitored for mortality, clinical signs, body weight, food consumption, food efficiency, and perceivable mass. All animals were subjected to complete necropsy and histopathological examination. The results indicate that the rats well tolerated chronic exposure to Eco-DEHCH at highest daily doses of 16,000 ppm, with was equivalent to 805.1 mg/kg/day in males and 1060.6 mg/kg/day in females and did not show signs of toxicity or carcinogenicity. In conclusion, Eco-DEHCH could be a safe and promising alternative plasticizer.

Histopathological impact of SARS-CoV-2 on the liver: Cellular damage and long-term complications.

Coronavirus disease 2019 (COVID-19), caused by the highly pathogenic severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), primarily impacts the respiratory tract and can lead to severe outcomes such as acute respiratory distress syndrome, multiple organ failure, and death. Despite extensive studies on the pathogenicity of SARS-CoV-2, its impact on the hepatobiliary system remains unclear. While liver injury is commonly indicated by reduced albumin and elevated bilirubin and transaminase levels, the exact source of this damage is not fully understood. Proposed mechanisms for injury include direct cytotoxicity, collateral damage from inflammation, drug-induced liver injury, and ischemia/hypoxia. However, evidence often relies on blood tests with liver enzyme abnormalities. In this comprehensive review, we focused solely on the different histopathological manifestations of liver injury in COVID-19 patients, drawing from liver biopsies, complete autopsies, and in vitro liver analyses. We present evidence of the direct impact of SARS-CoV-2 on the liver, substantiated by in vitro observations of viral entry mechanisms and the actual presence of viral particles in liver samples resulting in a variety of cellular changes, including mitochondrial swelling, endoplasmic reticulum dilatation, and hepatocyte apoptosis. Additionally, we describe the diverse liver pathology observed during COVID-19 infection, encompassing necrosis, steatosis, cholestasis, and lobular inflammation. We also discuss the emergence of long-term complications, notably COVID-19-related secondary sclerosing cholangitis. Recognizing the histopathological liver changes occurring during COVID-19 infection is pivotal for improving patient recovery and guiding decision-making.

Intoxications involving methoxyacetylfentanyl and U-47700: a study of 3 polydrug fatalities

Novel synthetic opioids (NSOs) represent an emerging group of novel psychoactive substances, acting as agonists at the opioid receptors. NSOs include fentanyl-related compounds, e.g. methoxyacetylfentanyl (MeACF), and non-fentanyl analogs, e.g. “U compounds” including U-47700. Here we present three cases of death involving MeACF and U-47700, with particular reference to preliminary data on pharmacokinetics and tissue distribution.After a complete post-mortem examination, general unknown screenings and analysis of drugs of abuse were performed on postmortem samples by immunoassays, gas chromatography–mass spectrometry and liquid chromatography–mass spectrometry. To quantify the analytes of interest in post-mortem blood and tissues, the standard addition method was used. A toxicological significance score (TSS), weighing the role of the NSO in each death case, was assigned.Case 1 died at the hospital after consumption of U-47700, methadone (serum levels: 2,600 ng/ml and 37 ng/ml), tilidine and benzodiazepines. In case 2, U-47700 (204 ng/ml) together with methadone (290 ng/ml), flubromazepam (480 ng/ml) and diazepam (300 ng/ml) were detected in peripheral blood. In case 3, methoxyacetylfentanyl (266 ng/ml), furanylfentanyl (4.3 ng/ml) 4-ANPP (15 ng/ml) and alprazolam (69 ng/ml) were quantified in femoral blood. In all cases, the NSO likely contributed to the death (TSS = 3).NSOs appear to be often consumed in the setting of polydrug intoxications, especially in combination with other opioids and benzodiazepines, which often exert synergistic effects. The standard addition method remains the most reliable in post-mortem analysis and toxicological results should always be evaluated together with circumstantial and autopsy data.

RETROSPECTIVE STUDY OF MORBIDITY AND MORTALITY IN A CAPTIVE POPULATION OF CRYPTOSPORIDIUM-POSITIVE LOUISIANA PINE SNAKES (PITUOPHIS RUTHVENI).

The Louisiana pine snake (Pituophis ruthveni) is a diurnal colubrid species native to Louisiana and eastern Texas whose free-ranging populations have been declining over at least the past 30 yr. The creation and maintenance of sustainable captive breeding programs of P. ruthveni to restore native populations has also provided ample opportunity for research into this species and for P. ruthveni to serve as a research model for other colubrid snakes. However, no investigation into prevalent causes of morbidity and mortality in captive populations of this species has been described. A research population of P. ruthveni was maintained at Louisiana State University (LSU) for over 4 yr due to unsuitability for breeding after testing positive for Cryptosporidium serpentis. Since arrival at LSU, the snakes were under close veterinary surveillance. Complete postmortem examinations were performed on 12 snakes that died or were euthanized. The aim of this study was to further understanding of common factors influencing morbidity and mortality in captive P. ruthveni infected with C. serpentis, by retrospectively reviewing postmortem exam findings from the 12 deceased members of the population at LSU. A predominant finding across individuals included bacterial infections, which were responsible for major illness or death in 37.5% of the animals. Fifty percent of snakes tested positive for Cryptosporidium sp. based on PCR performed from postmortem samples; it was directly implicated as cause of death or morbidity in 83.3% of positive cases. Although infectious disease represented the most common pathologic postmortem finding, several noninfectious disease processes were identified, including gout, goiter, and neoplasia. These findings mirror those of other retrospective investigations of reptile collections at various institutions and highlight the need for appropriate emphasis on the identification, treatment, and prevention of infectious disease as part of routine veterinary care.

Positional Asphyxia: Remains Hard to Diagnose?

Positional asphyxia is a type of asphyxia where the position of an individual compromises the ability to breathe. It is commonly caused by accidents due to alcohol or drug intoxication, diseases, and/or being in a confined space. In this study, the authors reviewed autopsy cases at their institute over the past 5 years where positional asphyxia is suspected as a contributing factor or cause of death. The autopsy cases (n=24) were divided into three groups: positional asphyxia was the cause of death (n=15); unknown cause of death but positional asphyxia was considered (n=4); and positional asphyxia was suspected to be a contributing factor (n=5). All cases of group A included postures that could interfere with breathing, but the typical jackknife or head-down postures were seen in approximately half of the cases; “classic signs of asphyxia” were also observed in approximately half of the cases. They shared features such as high blood alcohol concentration, therapeutic levels of drugs, various disease, minor head trauma, and morbid obesity; however, no definite diagnostic criteria have been established for forensic practice. Positional asphyxia is a form of mechanical asphyxia which must be differentiated from traumatic asphyxia. In addition to a complete autopsy, thorough laboratory tests and understanding of the circumstances of the case and the situation at the death scene are required for diagnosis. Special attention is required for the diagnosis of special types of positional asphyxia such as death during institutional restraint or prone restraint.

Gastric ischemia as an under-reported cause of death in older people.

Acute gastric ischemia is a rare condition due to the rich vascular supply of the stomach. Here we present a case of fatal gastric ischemia associated with bowel ischemia, only diagnosed at autopsy, which was requested for the suspicion of medical liability. A complete post-mortem examination was conducted, along with a macroscopic analysis of the superior mesenteric artery and detailed histological analyses. Past clinical data was also reviewed. The macroscopic blackish discoloration of the stomach and the bowel, coupled with the presence of neutrophils in the mucosa and submucosal non-occlusive thrombi, were consistent with gastric and bowel ischemia, despite the presence of confounding putrefactive changes. The unique aspect of this case resides in the ante-mortem peculiar vascularization of the stomach, supplied by small collateral vessels. No mechanical occlusion was identified, and the cause of the ischemia was deemed as non-occlusive, likely due to systemic hypoperfusion. The analysis of clinical data and documentation of associated comorbidities are strongly recommended, especially when a rare cause of death is suspected. With the aging population, especially among women, and the prevalence of risk factors, the forensic pathologist could increasingly encounter rare cases of gastric ischemia.

Diversity of Helminths of Insectivorous Mammals (Mammalia: Eulipothyphla) from Large Forest Protected Areas of the Middle Volga Region (European Russia)

Insectivores (Eulypotiphla) are a substantial component of Russian forest ecosystems. The parasites of these animals also form an important part of natural biocenoses and act as one of the factors in the formation of biodiversity. The Mordovia Nature Reserve and National Park “Smolny” are large, forested areas located in the center of European Russia. We studied the helminth fauna of insectivores in these protected areas in 2018–2022. In total, using the method of complete helminthological necropsy, we examined 478 individuals of shrews, moles, and hedgehogs and recorded 34 species of parasitic worms, i.e., 8 trematode, 7 cestode, 1 acanthocephalan, and 18 nematode species. The most diverse helminth fauna was found in Sorex araneus (22 species). The composition of helminths in S. isodon (12), Neomys fodiens (9), Sorex minutus, and Erinaceus roumanicus (8 species each) turned out to be less diverse. The lowest species diversity of helminths was observed in Neomys milleri (3) and Talpae europaea (2 species). Taking into account the newly obtained data, we conducted a review of the helminth diversity in shrews, hedgehogs, and moles in the Middle Volga region. According to our literature data, the helminth fauna of insectivores in this region consists of 52 species, including 14 cestodes, 13 trematodes, 22 nematodes, and 3 acanthocephalans. Most of them belong to the Palearctic faunal complex (36 species). The helminth fauna of insectivores in the studied protected areas was compared with the helminth fauna of micromammals in other areas of the Middle Volga region. Our comparative analysis showed a high and average degree of similarity in the helminth fauna within individual species and genera of Eulipotyphla.

Unexplained infant death in Houston, TX: A 17-year retrospective

SIDS/SUID (henceforth referred to as SIDS) is a leading cause of neonate death, taking the lives of ~10 infants every day in the US alone. SIDS is defined as the death of an infant for which no cause of death can be determined after a complete autopsy, death scene investigation, and medical history review, all of which makes SIDS a very diffcult disease to study. Death scene investigations have identified several contributing environmental factors. However, etiological investigation has been complicated by inconsistencies in classification of death by medical examiners or coroners and unreliable resources for law enforcement to complete death scene investigations, which leads to epidemiological studies often lacking rigor or suffcient data. Using data from Child Fatality Review Team (CFRT) of Harris County, the Medical Examiner’s Offce, and the Texas Department of State Health Services, we performed a retrospective analysis of 17-years of SIDS cases in Harris County, Texas. We applied a novel birth rate correction for SIDS rates over the first year of life. Associations were tested using a Tukey HSD and linear regression models with co-linear factors considered. To focus on biologically unexplained SIDS cases, we subsetted our dataset to only include SIDS and Undetermined causes of death. Our preliminary data includes 1,094 cases comprised of ~43% black, ~32% Hispanic, ~20% white, ~3% Asian, and ~0.4% unknown and 57% male infants. Distribution of death across the first 12 months of life shows a peak of death around 2 months of age. We do not see an association with month or season in the raw SIDS data nor when using our novel correction for birth rates. When we apply the standard per 1,000 live births normalization, we see a significant increase in Spring and Winter. We also report race-dependent significant differences in yearly and monthly case numbers, male-to-female ratios, and age at death and additional significant race-dependent associations between SIDS cases and adults diagnosed with asthma, income level, and overcrowding based on Zip Code. This dataset represents one of the most racially and socio-economically diverse in the United States. Our data suggests that standard trends may be driven by majority white datasets and that response to socioeconomic stress varies by race/ ethnicity, which leads to differences in risk between classically described minority groups. NIH: 1F32HL160073-01A1, R01HL130249 44617-S4. BCM McNair Scholar Program, March of Dimes Basil O'Connor Research Award, Parker B. Francis Fellowship, CJ Foundation for SIDS. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.