The Role of Bloodstain Pattern Analysis (BPA) in Reconstructing the Dynamics of Forensic Cases.

Background: Bloodstain Pattern Analysis (BPA) is a forensic scientific discipline used to resolve criminal events. By studying the size, shape, and distribution of the bloodstains that constitute one or more bloodstain patterns, it is possible to determine the physical events responsible for their creation, as well as the positions and movements of the victim and, in cases of homicide, the perpetrator during the act. Materials and Methods: BPA analysis was applied as a support in the reconstruction of the event dynamics in four forensic cases, in addition to the data collected during on-site inspections and instrumental investigations including PMCT, autopsies, histological, and toxicological analyses. Particularly laborious was its application in a case involving a decomposed body. In all cases, a thorough photographic analysis of the bloodstains found on the clothing worn as well as in the areas surrounding the location of the corpse was conducted. Conclusions: The combination of investigations, together with the data derived from the application of BPA, allowed events to be attributed to: homicide by blunt force trauma; homicide-suicide using a bladed weapon; homicide using firearms; unplanned complex suicide. The analysis of the cases presented highlights the importance of a multidisciplinary approach through the use of additional instrumental and specialist investigations such as the study of bloodstains present at the crime scene for the reconstruction of criminal events.

Homicide by drowning: a literature review and analysis of three cases.

Background: Homicide by drowning in adults is rare. Usually, marks of violence are found on both the victim and the perpetrator, unless the victim was under the influence of alcohol, drugs, or was unexpectedly forced or dragged into the water. Indeed, many cases of drowning in adults are believed to be accidental, but they may be the result of drunken fights or attempts to make the death appear ac-cidental. In order to define the manner of death, cooperation between the forensic pathologist and the investigators is mandatory. Indeed, the autopsy is important to distinguish homicide by drowning from other kinds of drowning. The purpose of this study is to highlight the features of homicide by drowning. Materials and Methods: Literature search was conducted using PubMed databases, using the following keywords: "(homicide) and (drowning)". 3 articles were included in the systematic review, in addition to 3 cases observed in our institute. Conclusions: Both external examination and autopsy findings and the results of the investigation are essential to differentiate a homicide by drowning from accidental ones. The low specificity and variability of external and internal findings, the possibility of atypical asphyctic and nonasphyctic pathophysiological mechanisms, whose nature is not detectable at postmortem examinations, makes the diagnosis of cause of death difficult and often based on exclusion criteria only. In complex cases only using a strict forensic method allows to use the essential tools to identify the real manner of death.

Asphyxia with a blunt instrument: which forensic evidence to use in complex cases of murder.

Background: The blunt injuries may be heterogeneous. Due to the diversity, it is often difficult to establish the type of weapon used. Particular attention must be paid to the circumstantial data and previous diseases because the injuries often could not correspond to the presumed instruments used. Case Report: A man was found dead in his bedroom wearing pajamas. On the bed there was a blanket with visible traces of blood, which had dried. There were around 10 dogs in the house, poor hygienic and sanitary conditions, widespread excrements and unbreathable air. Testimonies from general practitioner, neighbors and the partner were collected. An autopsy, histological and toxicological examination was performed. On external examination the face showed blood smearing down the nose, subconjunctival hemorrhages, and labial cyanosis. Mo-reover, a hypochromic skin area was present on the right lateral region of the neck. The inguinal region showed large de-epithelized areas with multiple purplish red ecchymoses which were histologically analyzed. These areas showed hemorrhagic infiltration in the superficial and deep dermis up to the adipose tissue due to traumatic action. Conclusion: The reconstruction of the case allowed us to state a strangulation probably attributable to a belt. The discovery of intradermal hemorrhagic infiltrations, supported by histopathological investigations, confirmed the diagnosis of blunt force injuries, excluding other type of non-violent causes of lesions. Therefore, we recommended the use of experimental methods and procedures to evaluate the harmful suitability on biological matrices.

The role of necroscopy and autopsy investigations in the diagno-sis and risk management of infections related to public health care: forensic and medico legal implications.

Background: Healthcare-associated infections (HAIs) represent the most frequent adverse event in healthcare systems around the world. From a forensic point of view, HAIs show various legal implications. Therefore, it is essential in cases of death or injury from a suspected nosocomial infection that the infection itself, the source and the method of contamination are correctly diagnosed in order to evaluate any profiles of professional liability. Methods: This study combined a minireview of the scientific literature using the Pubmed search engine, the website of the Higher Institute of Health and the member states information sessions on infection prevention and control (IPC). Discussion: Despite the significant impact that HAIs have on healthcare systems, their severity is often not fully understood by healthcare professionals, leading to insufficient responses. In the autopsy setting, the diagnosis of these infections is not always simple due to the risk of post-mortem contamination determined by the endogenous bacterial flora. In the forensic field, the medical examiner during the autopsy can use various diagnostic techniques and investigative tools to identify the infection. Some usefulpp approaches include: 1) Macroscopic examination of the organs; 2) Histopathological investiga-tions; 3) Microbiological analyzes with the performance of swabs; 4) Immunofluorescence tests for the detection of antigens or antibodies on biological liquids; 5) Molecular tests. The choice of methods will depend on the nature of the suspected infection and the availability of diagnostic resources.

The experimental reconstruction of a complicated case of work accident due to a scraper.

Background: Workplace safety is a global public health issue. Re-constructing an accident can prove extremely complicated, especially when the event occurs without direct witnesses or when the scene is altered. In these cases, it is essential to adopt proper investigation pro-tocols in order to ensure the correct reconstruction of the dynamics. Case report: A man was found unconscious on the ground, having fallen from a height of approximately 2 meters, where there was a cabin in which a conveyor belt of raw materials for the production of cement ran. At the end of the path of this belt a scraper was found. An autopsy was carried out and the scraper present at the scene was examined and compared with the injuries on the victim. After the autopsy, the investigators returned to the scene and collected the traces found in the cabin. At the end of collecting the traces, the investigators simulated the dynamics of the event by turning on the conveyor belt and placing a scraper of the same dimensions and characteristics as the one found at the scene inside the cabin. Conclusion: The autopsy showed a maxillofacial trauma with multiple bruises on the face and a serious fracture of the epistropheus tooth. This trauma was therefore incompatible with a simple fall from 2 meters. The investigators created an experimental model that demonstrated a very high energy rebound of the tape when placed in contact with the scraper. This reconstruction made it possible to carry out a single report with the data collected by the medical examiner and the investigators, which was effective and exhaustive, allowing the Authority to be provided with the evidence to continue the investigations about the responsibilities of the worker and the employer.

Forensic aspects analyzed in a case series of femicides.

Background: Gender-based violence against women and its lethal outcome, femicide, represent important issues around the world. Although governments have passed specific laws, official data on gender-related violence and femicide are often absent and/or incomplete, difficult to access, rarely updated, contested and underestimated due to stigma, victim blaming or issues of legal interpretation. Femicide is an intentional killing in which a woman is murdered by an individual for misogyny and gender-related reasons. The most common type is in fact intimate femicide, which occurs when the murdered woman and the aggressor have an intimate, family, cohabitation or similar relationship. Case series: We analyzed 15 cases of femicide for which crime scene investigation and autopsy were carried out. For each case, a psychological autopsy was carried out and the means used to determine the individual's death were analysed. The circumstances in which the murder occurred were also examined. Discussion: Overkilling was evidenced in all cases analyzed. Over-killing in forensic medicine is known as a specific type of homicide in which the number of injuries inflicted far exceeds the number of injuries required to kill the victim. Therefore, the medico-legal management of the cases examined is complicated due to the multiple lesions present on the corpse on the victims which make difficult: 1) the reconstruction of the dynamics of the crime 2) the number of blows inflicted 3) the analysis of the fatal blow 4) the imputability of the offender.

Connected to the cloud at time of death: a case report.

BACKGROUND: Our case report provides the first clinical evaluation of autopsy practices for a patient death that occurs on the cloud. We question how autopsy practices may require adaptation for a death that presents via the 'Internet of Things', examining how existing guidelines capture data related to death which is no longer confined to the patient's body. CASE PRESENTATION: The patient was a British man in his 50s, who came to the attention of the medical team via an alert on the cloud-based platform that monitored his implanted cardioverter defibrillator (ICD). The patient had a background of congenital heart disease, with previous ventricular fibrillation cardiac arrest, for which the ICD had been implanted two years earlier. Retrospective analysis of the cloud data demonstrated a gradually decreasing nocturnal heart rate over the previous three months, falling to a final transmission of 24 beats per minute (bpm). In the patient post-mortem the ICD was treated as medical waste, structural tissue changes precluded the effective evaluation of device hardware, potential issues related to device software were not investigated and the cause of death was assigned to underlying heart failure. The documentation from the attending law enforcement officials did not consider possible digital causes of harm and relevant technology was not collected from the scene of death. CONCLUSION: Through this patient case we explore novel challenges associated with digital deaths including; (1) device hardware issues (difficult extraction processes, impact of pathological tissue changes), (2) software and data limitations (impact of negative body temperatures and mortuary radio-imaging on devices, lack of retrospective cloud data analysis), (3) guideline limitations (missing digital components in autopsy instruction and death certification), and (4) changes to clinical management (emotional impact of communicating deaths occurring over the internet to members of family). We consider the implications of our findings for public health services, the security and intelligence community, and patients and their families. In sharing this report we seek to raise awareness of digital medical cases, to draw attention to how the nature of dying is changing through technology, and to motivate the development of digitally appropriate clinical practice.

Neonatal autopsy-is it relevant in today's era?

Autopsy of infants can provide vital information about the cause of death and contributes to the detection of diagnostic errors, especially in a low- or middle-income country. To observe the clinicopathological agreement in neonatal deaths in neonatal intensive care units (NICU) and comment on the additional information retrieved by autopsy. A retrospective observational study was conducted in the NICU from January 2020 to December 2022. Neonatal deaths were analyzed, and clinical details and autopsy findings were collected. Both clinical and pathological diagnoses were classified according to the Goldman classification. Twenty-two newborn infants were enrolled. The mean gestational age was 33.5 (±4.38) weeks, and the median birth weight was 1510 (1005-2100) g. There was complete concordance between clinical and pathological diagnosis in 11 (50%) cases. Major diagnostic errors occurred in 41% of cases. Respiratory system disorders (lung infections, airway anomalies) accounted for six (54%) cases of missed diagnosis. Our study showed that the diagnosis was revised after autopsy in about one-third of cases, and newer findings were identified in one-fifth of cases.

Recognition of Field Signs, Necropsy Procedures, and Evaluation of Macroscopic Lesions of Cervids Infected with Epizootic Hemorrhagic Disease Virus.

Epizootic hemorrhagic disease virus (EHDV) is an arthropod-borne RNA virus in the genus Orbivirus, family Sedoreoviridae. Globally, seven known EHDV serotypes circulate among ruminant hosts and Culicoides species vectors. A variety of domestic and wild ruminant species are susceptible to EHDV infection, but infection outcome is highly variable between species, as well as between individuals of the same species. Thus, this disease system inherently operates at the wildlife-livestock interface. Domestic cattle are important hosts for EHDV, and while inapparent infection is the most common outcome, reports of clinical disease have increased in some parts of the world. However, fatal infection of cattle is rare. Among wildlife, white-tailed deer (Odocoileus virginianus) are highly susceptible to severe and often fatal disease. Considering the paucity of data and poorly characterized pathology of EHD in cattle, white-tailed deer represent a case study for describing the field signs and necropsy lesions associated with EHD. Here we describe the field signs that commonly define EHD outbreaks in North America, a basic approach to a gross necropsy examination of white-tailed deer, description of the gross lesions that may be present, and diagnostic sample collection. Field investigations of large-scale EHD outbreaks are common in North America. The necropsy examination is an essential tool in the study of disease and when coupled with other disciplines (e.g., virology, immunology, epidemiology) has been fundamentally important to understanding EHD in North America.

Glaucoma, More than Meets the Eye: Patterns of Demyelination Revealed in Human Postmortem Glaucomatous Optic Nerve.

Glaucoma is a neurodegenerative disease affecting millions worldwide, characterised by retinal ganglion cell (RGC) degeneration which leads to blindness in more advanced cases. Although the pathogenesis and underlying mechanisms of glaucoma are not fully understood, there are theories that hint at demyelination playing a role in the disease process. Demyelination, or the degeneration of the myelin sheath surrounding axons, has been found in previous studies using animal models of glaucoma and clinical assessments of glaucoma patients. However, this has not been fully realised or quantified in glaucoma patients. Utilising postmortem optic nerve samples from glaucoma and healthy subjects, various immunohistochemical and morphological assessments were performed to determine the extent, if any, of demyelination in glaucomatous optic nerves. Our findings revealed that alongside nerve shrinkage and degeneration of nerve tissue fascicles, there were significantly less myelin proteins, specifically myelin basic protein (MBP), in glaucoma optic nerves. Additionally, the loss of MBP was correlated with decreased oligodendrocyte (OLG) precursors and increasing glial activity. This further supports previous evidence that demyelination may be a secondary degenerative process associated with glaucoma disease progression. Not only do these results provide evidence for potential disease mechanisms, but this is also the first study to quantify optic nerve demyelination in glaucoma postmortem tissue.

Stealthy Invader: Clinically Inapparent But Rapidly Progressive Multifocal Metastatic Melanoma Unveiled as Root Cause of Liver Failure.

BACKGROUND: Acute liver failure (ALF) secondary to metastatic melanoma presents a rare and diagnostically challenging clinical scenario. CASE REPORT: We report the case of a 57-year-old male who succumbed to fulminant liver failure attributed to hepatic infiltration by malignant melanoma. Despite extensive diagnostic evaluation, the underlying cause of ALF remained elusive until postmortem examination revealed multifocal metastatic melanoma. Notably, the autopsy disclosed a remarkable finding: a 10 cm lymph node in the right axilla, conspicuously harboring metastatic melanoma cells. Surprisingly, this progressive lymph node was not detected on admission or during comprehensive imaging studies conducted 24 h prior to death. Rigorous cross-referencing of radiological and autopsy findings highlighted the accuracy of prior interventions visible on imaging, further accentuating the dynamic nature of metastatic melanoma progression. CONCLUSION: This case underscores the importance of vigilance in detecting metastatic melanoma, even in atypical sites, and emphasizes the need for multidisciplinary collaboration in complex clinical scenarios.

Epigenetic and genetic risk of Alzheimer disease from autopsied brains in two ethnic groups.

Genetic variants and epigenetic features both contribute to the risk of Alzheimer's disease (AD). We studied the AD association of CpG-related single nucleotide polymorphisms (CGS), which act as a hub of both the genetic and epigenetic effects, in Caribbean Hispanics (CH) and generalized the findings to Non-Hispanic Whites (NHW). First, we conducted a genome-wide, sliding-window-based association with AD, in 7,155 CH and 1,283 NHW participants. Next, using data from the dorsolateral prefrontal cortex in 179 CH brains, we tested the cis- and trans-effects of AD-associated CGS on brain DNA methylation to mRNA expression. For the genes with significant cis- and trans-effects, we investigated their enriched pathways. We identified six genetic loci in CH with CGS dosage associated with AD at genome-wide significance levels: ADAM20 (Score = 55.19, P = 4.06 × 10-8), the intergenic region between VRTN and SYNDIG1L (Score = - 37.67, P = 2.25 × 10-9), SPG7 (16q24.3) (Score = 40.51, P = 2.23 × 10-8), PVRL2 (Score = 125.86, P = 1.64 × 10-9), TOMM40 (Score = - 18.58, P = 4.61 × 10-8), and APOE (Score = 75.12, P = 7.26 × 10-26). CGSes in PVRL2 and APOE were also significant in NHW. Except for ADAM20, CGSes in the other five loci were associated with CH brain methylation levels (mQTLs) and CGSes in SPG7, PVRL2, and APOE were also mQTLs in NHW. Except for SYNDIG1L (P = 0.08), brain methylation levels in the other five loci affected downstream mRNA expression in CH (P < 0.05), and methylation at VRTN and TOMM40 were also associated with mRNA expression in NHW. Gene expression in these six loci were also regulated by CpG sites in genes that were enriched in the neuron projection and glutamatergic synapse pathways (FDR < 0.05). DNA methylation at all six loci and mRNA expression of SYNDIG1 and TOMM40 were significantly associated with Braak Stage in CH. In summary, we identified six CpG-related genetic loci associated with AD in CH, harboring both genetic and epigenetic risks. However, their downstream effects on mRNA expression maybe ethnic specific and different from NHW.

Genetic and pathophysiological insights from autopsied patient with primary familial brain calcification: novel MYORG variants and astrocytic implications.

Primary familial brain calcification (PFBC) is a genetic neurological disorder characterized by symmetric brain calcifications that manifest with variable neurological symptoms. This study aimed to explore the genetic basis of PFBC and elucidate the underlying pathophysiological mechanisms. Six patients from four pedigrees with brain calcification were enrolled. Whole-exome sequencing identified two novel homozygous variants, c.488G > T (p.W163L) and c.2135G > A (p.W712*), within the myogenesis regulating glycosidase (MYORG) gene. Cerebellar ataxia (n = 5) and pyramidal signs (n = 4) were predominant symptoms, with significant clinical heterogeneity noted even within the same family. An autopsy of one patient revealed extensive brainstem calcifications, sparing the cerebral cortex, and marked by calcifications predominantly in capillaries and arterioles. The pathological study suggested morphological alterations characterized by shortened foot processes within astrocytes in regions with pronounced calcification and decreased immunoreactivity of AQP4. The morphology of astrocytes in regions without calcification remains preserved. Neuronal loss and gliosis were observed in the basal ganglia, thalamus, brainstem, cerebellum, and dentate nucleus. Notably, olivary hypertrophy, a previously undescribed feature in MYORG-PFBC, was discovered. Neuroimaging showed reduced blood flow in the cerebellum, highlighting the extent of cerebellar involvement. Among perivascular cells constituting the blood-brain barrier (BBB) and neurovascular unit, MYORG is most highly expressed in astrocytes. Astrocytes are integral components of the BBB, and their dysfunction can precipitate BBB disruption, potentially leading to brain calcification and subsequent neuronal loss. This study presents two novel homozygous variants in the MYORG gene and highlights the pivotal role of astrocytes in the development of brain calcifications, providing insights into the pathophysiological mechanisms underlying PFBC associated with MYORG variants.

Causes of sudden unexpected death in infants with and without pre-existing conditions: a retrospective autopsy study.

OBJECTIVE: We investigated sudden unexpected death in infancy (SUDI) autopsy data from 1996 to 2015 inclusive, comparing findings from infants with and without pre-existing medical conditions. DESIGN: Large, retrospective single-centre autopsy series. SETTING: Tertiary paediatric hospital, London, UK. METHODS: Non-identifiable autopsy findings were extracted from an existing research database for infants older than 7 days up to and including 365 days old who died suddenly and unexpectedly (SUDI; n=1739). Cases were classified into SUDI with pre-existing condition (SUDI-PEC) (n=233) versus SUDI without PEC (SUDI non-PEC) (n=929), where PEC indicates a potentially life-limiting pre-existing medical condition. Findings were compared between groups including evaluation of type of PEC and whether the deaths were medically explained (infectious or non-infectious) or apparently unexplained. RESULTS: Median age of death was greater in SUDI-PEC compared with SUDI non-PEC (129 days vs 67 days) with similar male to female ratio (1.4:1). A greater proportion of deaths were classified as medically explained in SUDI-PEC versus SUDI non-PEC (73% vs 30%). Of the explained SUDI, a greater proportion of deaths were non-infectious for SUDI-PEC than SUDI non-PEC (66% vs 32%). SUDI-PEC (infectious) infants were most likely to have respiratory infection (64%), with susceptible PEC, including neurological, prematurity with a PEC, and syndromes or other anomalies. CONCLUSION: SUDI-PEC deaths occur later in infancy and are likely to have their death attributed to their PEC, even in the absence of specific positive autopsy findings. Future research should aim to further define this cohort to help inform SUDI postmortem guidelines, paediatric clinical practice to reduce infant death, and to reduce the risk of overattribution of deaths in the context of a PEC.

Biomarker patterns and mechanistic insights into hypothermia from a postmortem metabolomics investigation.

Postmortem metabolomics holds promise for identifying crucial biological markers relevant to death investigations and clinical scenarios. We aimed to assess its applicability in diagnosing hypothermia, a condition lacking definitive biomarkers. Our retrospective analysis involved 1095 postmortem femoral blood samples, including 150 hypothermia cases, 278 matched controls, and 667 randomly selected test cases, analyzed using UHPLC-QTOF mass spectrometry. The model demonstrated robustness with an R2 and Q2 value of 0.73 and 0.68, achieving 94% classification accuracy, 92% sensitivity, and 96% specificity. Discriminative metabolite patterns, including acylcarnitines, stress hormones, and NAD metabolites, along with identified pathways, suggest that metabolomics analysis can be helpful to diagnose fatal hypothermia. Exposure to cold seems to trigger a stress response in the body, increasing cortisol production to maintain core temperature, possibly explaining the observed upregulation of cortisol levels and alterations in metabolic markers related to renal function. In addition, thermogenesis seems to increase metabolism in brown adipose tissue, contributing to changes in nicotinamide metabolism and elevated levels of ketone bodies and acylcarnitines, these findings highlight the effectiveness of UHPLC-QTOF mass spectrometry, multivariate analysis, and pathway identification of postmortem samples in identifying metabolite markers with forensic and clinical significance. The discovered patterns may offer valuable clinical insights and diagnostic markers, emphasizing the broader potential of postmortem metabolomics in understanding critical states or diseases.

A scoping review on virtual autopsy: Main concepts, qualified professionals and future prospects.

The beginning of post-mortem evaluation studies through minimally invasive procedures began between 1800 and 1930. It started with Dr. Howard Kelly and was later followed by Décio Parreiras and Werneck Genofre, due to the yellow fever outbreak in Brazil. However, despite its early beginnings, the intensification of the research on this field occurred around 2010, when the publications about this subject became three times more frequent than before. There are basically two classifications for this procedure. The first one is virtual non-invasive autopsy, which is based only on imaging exams; the second is the minimally invasive autopsy, in which imaging exams are associated with other techniques such as biopsy and angiography. The main objective of the present study is to evaluate the existent data published about virtual autopsy from 2010, and highlight the key concepts related to this theme. A search was conducted in PUBMED, MEDLINE, and LILACS databases using the descriptors "virtual autopsy" and "minimally invasive autopsy", the review protocol has been registered on Open Science Framework (OSF), the total number of studies included were 28, and the data was presented through the PRISMA-ScR flowchart. Although, it is well known that this theme is recent in research fields and, because of that, there is still a lot to explore.

The artificial intelligence in autopsy and crime scene analysis.

Background: In the evolving field of forensic medicine, artificial intelligence (AI) technologies may revolutionize traditional autopsy practices by enhancing the precision and efficiency of postmortem examinations. Methods: A review of the literature was carried out on the Pub-med and Scopus search engines by inserting the keywords "artificial intelligence" AND "forensic" AND ("autopsy" OR "crime scene management" OR "forensic odontology" OR "post mortem interval" OR "forensic anthropology" OR "forensic sciences"). The works that analyzed the applications of artificial intelligence in the forensic and autopsy field were analyzed. Conclusion: The results showed the application of different forms of artificial intelligence such as machine learning, deep learning, robotics, artificial neural networks. Various applications are therefore possible in the autopsy field including forensic identification, analysis of radiological data through Virtopsy, estimation of the weapon used through analysis of firearm damage with ballistics, estimation of the Post-Mortem Interval (PMI), forensic toxicology. AI's potential to aid in the precise identification of causes of death, estimation of postmortem intervals. With forensic pathologists facing the constant challenge of making accurate diagnoses under pressure, AI applications can offer much-needed support by reducing subjective judgment and the inherent human error due to fatigue. Therefore, the integration of AI into autopsies, while promising in terms of efficiency and accuracy, demands a careful balance between technological advancement and ethical responsibility to ensure trust and integrity in forensic practices.

Neuropathological hallmarks in the post-mortem retina of neurodegenerative diseases.

The retina is increasingly recognised as a potential source of biomarkers for neurodegenerative diseases. Hallmark protein aggregates in the retinal neuronal tissue could be imaged through light non-invasively. Post-mortem studies have already shown the presence of specific hallmark proteins in Alzheimer's disease, primary tauopathies, synucleinopathies and frontotemporal lobar degeneration. This study aims to assess proteinopathy in a post-mortem cohort with different neurodegenerative diseases and assess the presence of the primary pathology in the retina. Post-mortem eyes were collected in collaboration with the Netherlands Brain Bank from donors with Alzheimer's disease (n = 17), primary tauopathies (n = 8), synucleinopathies (n = 27), frontotemporal lobar degeneration (n = 8), mixed pathology (n = 11), other neurodegenerative diseases (n = 6), and cognitively normal controls (n = 25). Multiple cross sections of the retina and optic nerve tissue were immunostained using antibodies against pTau Ser202/Thr205 (AT8), amyloid-beta (4G8), alpha-synuclein (LB509), pTDP-43 Ser409/410 and p62-lck ligand (p62) and were assessed for the presence of aggregates and inclusions. pTau pathology was observed as a diffuse signal in Alzheimer's disease, primary tauopathies and controls with Alzheimer's disease neuropathological changes. Amyloid-beta was observed in the vessel wall and as cytoplasmic granular deposits in all groups. Alpha-synuclein pathology was observed as Lewy neurites in the retina in synucleinopathies associated with Lewy pathology and as oligodendroglial cytoplasmic inclusions in the optic nerve in multiple system atrophy. Anti-pTDP-43 generally showed typical neuronal cytoplasmic inclusion bodies in cases with frontotemporal lobar degeneration with TDP-43 and also in cases with later stages of limbic-associated TDP-43 encephalopathy. P62 showed inclusion bodies similar to those seen with anti-pTDP-43. Furthermore, pTau and alpha-synuclein pathology were significantly associated with increasing Braak stages for neurofibrillary tangles and Lewy bodies, respectively. Mixed pathology cases in this cohort consisted of cases (n = 6) with high Braak LB stages (> 4) and low or moderate AD pathology, high AD pathology (n = 1, Braak NFT 6, Thal phase 5) with moderate LB pathology, or a combination of low/moderate scores for different pathology scores in the brain (n = 4). There were no cases with advanced co-pathologies. In seven cases with Braak LB ≥ 4, LB pathology was observed in the retina, while tau pathology in the retina in the mixed pathology group (n = 11) could not be observed. From this study, we conclude that the retina reflects the presence of the major hallmark proteins associated with neurodegenerative diseases. Although low or moderate levels of copathology were found in the brains of most cases, the retina primarily manifested protein aggregates associated with the main neurodegenerative disease. These findings indicate that with appropriate retinal imaging techniques, retinal biomarkers have the potential to become highly accurate indicators for diagnosing the major neurodegenerative diseases of the brain.

Differential Expression of PACAP/VIP Receptors in the Post-Mortem CNS White Matter of Multiple Sclerosis Donors.

Pituitary adenylate cyclase-activating polypeptide (PACAP) and vasoactive intestinal peptide (VIP) are two neuroprotective and anti-inflammatory molecules of the central nervous system (CNS). Both bind to three G protein-coupled receptors, namely PAC1, VPAC1 and VPAC2, to elicit their beneficial effects in various CNS diseases, including multiple sclerosis (MS). In this study, we assessed the expression and distribution of PACAP/VIP receptors in the normal-appearing white matter (NAWM) of MS donors with a clinical history of either relapsing-remitting MS (RRMS), primary MS (PPMS), secondary progressive MS (SPMS) or in aged-matched non-MS controls. Gene expression studies revealed MS-subtype specific changes in PACAP and VIP and in the receptors' levels in the NAWM, which were partly corroborated by immunohistochemical analyses. Most PAC1 immunoreactivity was restricted to myelin-producing cells, whereas VPAC1 reactivity was diffused within the neuropil and in axonal bundles, and VPAC2 in small vessel walls. Within and around lesioned areas, glial cells were the predominant populations showing reactivity for the different PACAP/VIP receptors, with distinctive patterns across MS subtypes. Together, these data identify the differential expression patterns of PACAP/VIP receptors among the different MS clinical entities. These results may offer opportunities for the development of personalized therapeutic approaches to treating MS and/or other demyelinating disorders.