Retrospective study of non-natural manners of death in Ontario: Effects of the COVID-19 pandemic and related public health measures.

BACKGROUND: The effects of the COVID-19 pandemic on non-natural manners of death in Ontario is not known. Understanding the indirect consequences of the pandemic and related public health measures (i.e. lockdown) fills a vital need to inform best practice in public health and guide policy decisions. METHODS: The Office of the Chief Coroner and the Ontario Forensic Pathology Service (OCC-OFPS) investigate sudden and unexpected deaths in the province of Ontario. The number of homicides, suicides, and accidental deaths (non-natural deaths=77,655) were extracted from the centralized Coroner's Information System database (total deaths=197,966), across four provincially defined stages of lockdown related to the COVID-19 pandemic (March 17 to December 31, 2020), and crude rates (per 100,000 people) were compared to the previous eleven years. FINDINGS: There was no major change to the rate of homicides during 2020 compared to 2009-2019 (RR 1⋅1, 95% CI 0⋅95-1⋅2; p=0⋅19; estimated annual effect=21 more deaths in 2020). The rate of suicides also did not show an overall major change in 2020 (RR 1⋅02, 95% CI 0⋅96-1⋅1; p=0⋅50; estimated annual effect=27 more deaths in 2020). However, during the first stage of lockdown (Stage 0), there was a decrease in the rate of suicides compared to all combinations of recent years from 2013 onwards (RRs 0⋅82-0⋅86, combined 95% CI 0⋅69-0⋅99; max p=0⋅039; estimated effect of 30 less deaths in Stage 0). There was an excess of over 1,500 accidental drug-related deaths that occurred during 2020 (RR 2⋅5, 95% CI 2⋅4-2⋅7; p<0⋅001). This finding held up to 'interrupted time series' robustness testing, indicating that 2020 had substantially more drug-related deaths, even when accounting for the linear increasing trend over time. Although motor vehicle collision associated fatalities appeared to decrease slightly in 2020 (RR 0⋅89, 95% CI 0⋅81-0⋅96; p=0⋅0039; estimated annual effect of 78 less deaths), we could not conclude any lockdown-associated effect, particularly when compared to 2019 (RR 0⋅26, 95% CI 0⋅75-1⋅1; p=0⋅26). INTERPRETATION: In Ontario, the short-term effects of the COVID-19 pandemic did not greatly increase homicide or suicide rates, nor decrease motor vehicle collision fatality rates; however, the longer-term impact of the pandemic remains to be elucidated and ongoing vigilance is warranted in the event that other trends emerge. Accidental drug-related fatalities substantially increased during all stages of the lockdown, marking an urgent need for consideration in policy. These results highlight the vital role of death investigation systems in providing high quality and timely data to inform public health recommendations.

Postmortem radiologic and pathologic findings in COVID-19: The Toronto experience with pre-hospitalization deaths in the community.

Over a year after the initial emergence of the disease, the COVID-19 pandemic continues to strain healthcare systems worldwide. The value of feedback and connection between clinical care, public health, and death investigation systems has never been more clear. To this end, knowledge of the radiologic and histopathologic features of fatal COVID-19 is critical for those working with the living and the dead. Most of the medical descriptions of COVID-19 are either focused on clinical in vivo medical imaging or autopsies performed following an intensive course of treatment over days to weeks prior to death, rather than deaths in the community prior to hospitalization. Here we report the postmortem computed tomography (PMCT) and lung histopathology in five fatal cases of COVID-19 that were subject to medicolegal death investigation. All individuals died in the community without medical treatment, or after a brief terminal admission to hospital. In these cases, the main PMCT findings included: diffuse lung changes including ground glass-type opacifications, a "crazy paving" appearance, variable areas of more dense consolidation, and relatively few areas of spared/less involved lung parenchyma. The unifying histopathology was diffuse alveolar damage in various stages of cellular evolution. In all cases, the pattern of PMCT and the lung histopathology corroborated the diagnosis of COVID-19. We propose the routine use of PMCT as a potential screening tool for the identification of COVID-19 related fatalities in the medicolegal setting where a paucity of historical information may not otherwise permit the identification of this disease prior to autopsy.

Application of Next Generation Quality/Statistical Process Control and Expert-Led Case Review to Increase the Consistency of Diagnostic Rates in Precancerous Colorectal Polyps.

BACKGROUND: Prior work suggests high interrater variability in the pathologist diagnostic rate (PDR) of the precancerous polyp sessile serrated adenoma (SSA). OBJECTIVES: To improve the diagnostic consistency in the pathological evaluation of colorectal polyp specimens with diagnostic rate awareness, using funnel plots (FPs)/control charts (CCs), and a focused group case review. METHODS: All colorectal polyp specimen (CRPS) reports September 2015 to August 2017 were analyzed at one institution. PDRs were extracted using a hierarchical free-text string matching algorithm and visualized using FPs, showing pathologist specimen volume versus PDR, and CCs, showing pathologist versus normed PDR. The FPs/CCs were centered on the group median diagnostic rate (GMDR). Pathologists were shown their baseline SSA diagnostic rate in relation to the practice, and in January 2017, there was a focused group case review/open discussion of approximately 40 sequential cases signed as SSA with a gastrointestinal pathology expert. RESULTS: Nine pathologists interpreted more than 250 CRPSs per year. FPs/CCs for the first and second years showed 6/4 and 3/1 P < .05/P < .001 pathologist outliers, respectively, in relation to the GMDR for SSA and 0/0 and 0/0 P < .05/P < .001 pathologist outliers, respectively, in relation to the GMDR for tubular adenoma (TA). An in silico kappa (ISK) for SSA improved from 0.52 to 0.62. CONCLUSION: Diagnostic rate awareness facilitated by FPs/CCs coupled with focused expert-led reviews may help calibrate PDR. Variation in SSA PDRs still remains high in relation to TA. ISK represents an intuitive, useful metric and Next Generation Quality/Statistical Process Control a promising approach for objectively increasing diagnostic consistency.

Soluble CD200 in secretory phase endometriosis endometrial venules may explain endometriosis pathophysiology and provide a novel treatment target.

Retrograde menstruation is common and in about 10% of women, endometrial tissues implant at ectopic sites and grow as endometriosis (EM) deposits. To date, there has been no marker to identify which patients have an endometrium that will generate deposits. Both endometrial regulatory T cells (Tregs) and increased stromal cell indoleamine 2,3-dioxygenase (IDO) have been implicated, and may suppress rejection by peritoneal NK cells, neutrophils, and cytotoxic macrophages. CD200 is a tolerance signaling molecule which promotes Tregs, IDO-producing macrophages, and can directly inhibit cytolytic natural killer (NK) cells and neutrophils. To determine if CD200 might be overexpressed in the endometrium of women with endometriosis, a pilot study using quantitative immunohistochemistry was done using uterine sections and EM deposits from hysterectomy patients. Both CD200 and CD200R proteins were detectable in endometriosis (EM) deposits and in endometrial epithelium and stroma. CD200 increased slightly in secretory phase whole endometrium of EM patients, but strikingly increased soluble CD200 (sCD200) absent sCD200R within venules typified both endometriosis deposits and secretory phase endometrial stromal venules and lymphatics in EM endometria compared to secretory phase NE endometria (P = 0.000006). In our opinion, accumulation of sCD200 in secretory phase endometrial blood vessels may explain development of ectopic deposits and quantifying sCD200 in menstrual blood may cases and identify predisposition to EM. Animal model studies are required to determine if antagonizing CD200 could be therapeutic.

Changes in expression of the CD200 tolerance-signaling molecule and its receptor (CD200R) by villus trophoblasts during first trimester missed abortion and in chronic histiocytic intervillositis.

PROBLEM: Expression of CD200 at the feto-maternal interface is associated with successful murine and human pregnancy. CD200 binding to CD200 receptors on lymphomyeloid cells suppresses inflammation and induces Tregs. CD200 receptors are also expressed on mouse and human placental trophoblast cells. What is the expression of CD200 and CD200R in human missed abortions which have preserved Treg levels and in chronic histiocytic intervillositis (CHI) where maternal inflammatory cells cause IUGR? METHODS: Immunohistiochemistry for CD200, CD200R, and Ki67 using human placental sections from missed abortions, term placenta, and CHI. PCR testing was done for trisomy in missed abortion. RESULTS: CD200 and CD200R were expressed by human villus trophoblasts from 2 weeks post-implantation to term. Cytotrophoblast proliferation (Ki-67+ count) decreased at term. In first trimester missed abortion cases, CD200>CD200R villus trophoblasts accompanied missed abortion of non-trisomic male fetuses. CD200 and Ki67+ trophoblast proliferation was preserved in CHI with maternal inflammatory cell infiltration but CD200R was greatly decreased. CONCLUSION: Residual CD200 activity may prevent completion of abortions via induction of Treg cells. In CHI, infiltrating maternal effector T cells may block Treg induction. An autocrine role for CD200-CD200R interaction versus inhibition of soluble CD200 by soluble CD200R is discussed.

Father of neurosurgery: Harvey Cushing's early experience with a pediatric brainstem glioma at the Johns Hopkins Hospital.

OBJECT: The early 20th century posed several challenges in the diagnosis and surgical treatment of intracranial tumors. However, this was a time in which more information was becoming more readily available based on pathological examination and surgical case reports. Such early work was crucial in shaping the current understanding of the nervous system and in developing modern treatment strategies. An early historical overview of the diagnosis and surgical interventions in pediatric patients with brainstem gliomas has not been described. Furthermore, Dr. Harvey Cushing's contributions to this field have not been reported. METHODS: Following institutional review board approval, and through the courtesy of the Alan Mason Chesney Archives, the authors reviewed the Johns Hopkins Hospital surgical files dating from 1896 to 1912. RESULTS: The authors describe Cushing's early experience with a pediatric brainstem glioma during his time as a young attending physician at the Johns Hopkins Hospital. The case, presented in 1909, described the clinical events in a 15-year-old schoolgirl who presented with signs of a cerebellopontine lesion. A suboccipital exploration was performed by Cushing; his findings and surgical approach are described. CONCLUSIONS: Harvey Cushing's early contributions to the field of pediatric neurosurgery, and to the operative treatment of pediatric brainstem gliomas have remained largely unknown. The case presented here represents the early work of the American "Father of Neurosurgery."

The understanding and operative treatment of cerebral palsy at the turn of the twentieth century: Harvey Cushing's early forays into pediatric neurosurgery.

INTRODUCTION: At the turn of the twentieth century, cerebral palsy and its treatment were not well understood, and a variety of treatment modalities were tested with only limited success. MATERIAL AND METHODS: Following IRB approval and through the courtesy of the Alan Mason Chesney Archives, we reviewed the Johns Hopkins Hospital surgical files from 1896-1912. Eight patients who received a diagnosis consistent with cerebral palsy and were treated surgically by Dr. Cushing were selected for further analysis and are described here. RESULTS: A total of eight patients underwent operative intervention for treatment of symptoms consistent with cerebral palsy. Of these, seven were male; the mean age was 4.9 years (range, 1.5 to 12). Five patients underwent decompressive craniotomies, one underwent tenotomies, one underwent transection of the spinal nerve roots, and one underwent primary transection of the spinal nerve roots with secondary tenotomies. Four representative cases are reported here. CONCLUSIONS: Cushing's contributions to pediatric neuro-oncology have been previously described, but his endeavors in non-oncologic realms remain largely unknown. Although Cushing employed previously described operative approaches for the treatment of cerebral palsy, parents brought their children to him from across the nation, in an era when long distance travel was tedious, and a financial burden. These cases serve to emphasize Cushing's interest in improving patient quality of life, and his broad contributions to pediatric neurosurgery.

A novel, nongenomic mechanism underlies retinoic acid-induced growth cone turning.

The vitamin A metabolite, retinoic acid (RA), is well known for its roles in neural development and regeneration. We have previously shown that RA can induce positive growth cone turning in regenerating neurons in vitro. In this study, we address the subcellular mechanisms underlying this chemo-attractive response, using identified central neurons from the adult mollusc, Lymnaea stagnalis. We show that the RA-induced positive growth cone turning was maintained in the presence of the transcriptional inhibitor, actinomycin D. We also physically transected the neurites from the cell body and showed that isolated growth cones retain the capacity to turn toward a gradient of RA. Moreover, this attractive turning is dependent on de novo local protein synthesis and Ca(2+) influx. Most of RA's actions during neurite outgrowth and regeneration require gene transcription, although these data show for the first time in any species, that the chemotropic action of RA in guiding neurite outgrowth, involves a novel, nongenomic mechanism.

Detection of endogenous retinoids in the molluscan CNS and characterization of the trophic and tropic actions of 9-cis retinoic acid on isolated neurons.

Retinoic acid (RA) is an active metabolite of Vitamin A that plays an important role in the growth and differentiation of many cell types. All-trans RA (atRA) is the retinoic acid isomer that has been most widely studied in the nervous system, and can induce and direct neurite outgrowth from both vertebrate and invertebrate preparations. The presence and role of the 9-cis-RA isomer in the nervous system is far less well defined. Here, we used high-pressure liquid chromatography (HPLC) and mass spectrometry (MS) to show for the first time, the presence of both atRA and 9-cis-RA in the CNS of an invertebrate. We then demonstrated that 9-cis-RA was capable of exerting the same neurotrophic and chemotropic effects on cultured neurons as atRA. In this study, significantly more cells showed neurite outgrowth in 9-cis-RA versus the EtOH vehicle control, and 9-cis-RA significantly increased the number and length of neurites from identified neurons after 4 d in culture. 9-cis-RA also extended the duration of time that cells remained electrically excitable in culture. Furthermore, we showed for the first time in any species, that exogenous application of 9-cis-RA induced positive growth cone turning of cultured neurons. This study provides the first evidence for the presence of both atRA and 9-cis-RA in an invertebrate CNS and also provides the first direct evidence for a potential physiological role for 9-cis-RA in neuronal regeneration and axon pathfinding.

Retinoic acid induces neurite outgrowth and growth cone turning in invertebrate neurons.

Identification of molecules involved in neurite outgrowth during development and/or regeneration is a major goal in the field of neuroscience. Retinoic acid (RA) is a biologically important metabolite of vitamin A that acts as a trophic factor and has been implicated in neurite outgrowth and regeneration in many vertebrate species. Although abundant in the CNS of many vertebrates, the precise role of RA in neural regeneration has yet to be determined. Moreover, very little information is available regarding the role of RA in invertebrate nervous systems. Here, we demonstrate for the first time that RA induces neurite outgrowth from invertebrate neurons. Using individually identified neurons isolated from the CNS of Lymnaea stagnalis, we demonstrated that a significantly greater proportion of cells produced neurite outgrowth in RA. RA also extended the duration of time that cells remained electrically excitable in vitro, and we showed that exogenously applied RA acted as a chemoattractive factor and induced growth cone turning toward the source of RA. This is the first demonstration that RA can induce turning of an individual growth cone. These data strongly suggest that the actions of RA on neurite outgrowth and cell survival are highly conserved across species.

Retinoic acid-dependent attraction of adult spinal cord axons towards regenerating newt limb blastemas in vitro.

Adult urodele amphibians possess the unique ability to regenerate amputated limbs and to re-innervate these regenerating structures; however, the factors involved in mediating this re-innervation are largely unknown. Here, we investigated the role of retinoic acid (RA) and one of its receptors, RARbeta, in the reciprocal neurotropic interactions between regenerating limb blastemas and spinal cord explants from the adult newt Notophthalmus viridescens. First, we showed that retinoic acid induced directed axonal outgrowth from cultured spinal cord tissue. This RA-induced outgrowth was significantly reduced when spinal cord explants were pre-treated with either the synthetic RAR pan antagonist, LE540, or the specific RARbeta antagonist, LE135. The role of RARbeta was also investigated using co-cultured regenerating limb blastemas and spinal cord explants. Blastemas induced significantly more axonal outgrowth from the near side of co-cultured explants, than from the far side (when cultured less than 1 mm apart). This blastema-induced directed outgrowth from co-cultured spinal cord explants was also abolished in the presence of the RARbeta antagonist, LE135. These data strongly suggest that endogenous retinoic acid is one of the tropic factors produced by the blastema and that it may be capable of guiding re-innervating axons to their targets. Moreover, this interaction is likely mediated by the retinoic acid beta nuclear receptor.