Coronavirus Disease 2019 (COVID-19) Coronary Vascular Thrombosis: Correlation with Neutrophil but Not Endothelial Activation.

Severe coronavirus disease 2019 (COVID-19) increases the risk of myocardial injury that contributes to mortality. This study used multiparameter immunofluorescence to extensively examine heart autopsy tissue of 7 patients who died of COVID-19 compared to 12 control specimens, with or without cardiovascular disease. Consistent with prior reports, no evidence of viral infection or lymphocytic infiltration indicative of myocarditis was found. However, frequent and extensive thrombosis was observed in large and small vessels in the hearts of the COVID-19 cohort, findings that were infrequent in controls. The endothelial lining of thrombosed vessels typically lacked evidence of cytokine-mediated endothelial activation, assessed as nuclear expression of transcription factors p65 (RelA), pSTAT1, or pSTAT3, or evidence of inflammatory activation assessed by expression of intracellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), tissue factor, or von Willebrand factor (VWF). Intimal EC lining was also generally preserved with little evidence of cell death or desquamation. In contrast, there were frequent markers of neutrophil activation within myocardial thrombi in patients with COVID-19, including neutrophil-platelet aggregates, neutrophil-rich clusters within macrothrombi, and evidence of neutrophil extracellular trap (NET) formation. These findings point to alterations in circulating neutrophils rather than in the endothelium as contributors to the increased thrombotic diathesis in the hearts of COVID-19 patients.

Blinded review of hippocampal neuropathology in sudden unexplained death in childhood reveals inconsistent observations and similarities to explained paediatric deaths.

AIMS: Hippocampal findings are implicated in the pathogenesis of sudden unexplained death in childhood (SUDC), although some studies have identified similar findings in sudden explained death in childhood (SEDC) cases. We blindly reviewed hippocampal histology in SUDC and SEDC controls. METHODS: Hippocampal haematoxylin and eosin (H&E) slides (n = 67; 36 SUDC, 31 controls) from clinical and forensic collaborators were evaluated by nine blinded reviewers: three board-certified forensic pathologists, three neuropathologists and three dual-certified neuropathologists/forensic pathologists. RESULTS: Among nine reviewers, about 50% of hippocampal sections were rated as abnormal (52.5% SUDC, 53.0% controls), with no difference by cause of death (COD) (p = 0.16) or febrile seizure history (p = 0.90). There was little agreement among nine reviewers on whether a slide was within normal range (Fleiss' κ = 0.014, p = 0.47). Within reviewer groups, there were no findings more frequent in SUDC compared with controls, with variability in pyramidal neuron and dentate gyrus findings. Across reviewer groups, there was concordance for bilamination and granule cell loss. Neither SUDC (51.2%) nor control (55.9%) slides were considered contributory to determining COD (p = 0.41). CONCLUSIONS: The lack of an association of hippocampal findings in SUDC and controls, as well as inconsistency of observations by multiple blinded reviewers, indicates discrepancy with previous studies and an inability to reliably identify hippocampal maldevelopment associated with sudden death (HMASD). These findings underscore a need for larger studies to standardise evaluation of hippocampal findings, identifying the range of normal variation and changes unrelated to SUDC or febrile seizures. Molecular studies may help identify novel immunohistological markers that inform on COD.

Proteomic differences in hippocampus and cortex of sudden unexplained death in childhood.

Sudden unexplained death in childhood (SUDC) is death of a child over 1 year of age that is unexplained after review of clinical history, circumstances of death, and complete autopsy with ancillary testing. Multiple etiologies may cause SUDC. SUDC and sudden unexpected death in epilepsy (SUDEP) share clinical and pathological features, suggesting some similarities in mechanism of death and possible abnormalities in hippocampus and cortex. To identify molecular signaling pathways, we performed label-free quantitative mass spectrometry on microdissected frontal cortex, hippocampal dentate gyrus (DG), and cornu ammonis (CA1-3) in SUDC (n = 19) and pediatric control cases (n = 19) with an explained cause of death. At a 5% false discovery rate (FDR), we found differential expression of 660 proteins in frontal cortex, 170 in DG, and 57 in CA1-3. Pathway analysis of altered proteins identified top signaling pathways associated with activated oxidative phosphorylation (p = 6.3 × 10-15, z = 4.08) and inhibited EIF2 signaling (p = 2.0 × 10-21, z = - 2.56) in frontal cortex, and activated acute phase response in DG (p = 8.5 × 10-6, z = 2.65) and CA1-3 (p = 4.7 × 10-6, z = 2.00). Weighted gene correlation network analysis (WGCNA) of clinical history indicated that SUDC-positive post-mortem virology (n = 4/17) had the most significant module in each brain region, with the top most significant associated with decreased mRNA metabolic processes (p = 2.8 × 10-5) in frontal cortex. Additional modules were associated with clinical history, including fever within 24 h of death (top: increased mitochondrial fission in DG, p = 1.8 × 10-3) and febrile seizure history (top: decreased small molecule metabolic processes in frontal cortex, p = 8.8 × 10-5) in all brain regions, neuropathological hippocampal findings in the DG (top: decreased focal adhesion, p = 1.9 × 10-3). Overall, cortical and hippocampal protein changes were present in SUDC cases and some correlated with clinical features. Our studies support that proteomic studies of SUDC cohorts can advance our understanding of the pathogenesis of these tragedies and may inform the development of preventive strategies.

A perfect storm: The distribution of tissue damage depends on seizure duration, hemorrhage, and developmental stage in a gyrencephalic, multi-factorial, severe traumatic brain injury model.

The pathophysiology of extensive cortical tissue destruction observed in hemispheric hypodensity, a severe type of brain injury observed in young children, is unknown. Here, we utilize our unique, large animal model of hemispheric hypodensity with multifactorial injuries and insults to understand the pathophysiology of this severe type of traumatic brain injury, testing the effect of different stages of development. Piglets developmentally similar to human infants (1 week old, "infants") and toddlers (1 month old, "toddlers") underwent injuries and insults scaled to brain volume: cortical impact, creation of mass effect, placement of a subdural hematoma, seizure induction, apnea, and hypoventilation or a sham injury while anesthetized with a seizure-permissive regimen. Piglets receiving model injuries required overnight intensive care. Hemispheres were evaluated for damage via histopathology. The pattern of damage was related to seizure duration and hemorrhage pattern in "toddlers" resulting in a unilateral hemispheric pattern of damage ipsilateral to the injuries with sparing of the deep brain regions and the contralateral hemisphere. While "infants" had the equivalent duration of seizures as "toddlers", damage was less than "toddlers", not correlated to seizure duration, and was bilateral and patchy as is often observed in human infants. Subdural hemorrhagewas associate with adjacent focal subarachnoid hemorrhage. The percentage of the hemisphere covered with subarachnoid hemorrhage was positively correlated with damage in both developmental stages. In "infants", hemorrhage over the cortex was associated with damage to the cortex with sparing of the deep gray matter regions; without hemorrhage, damage was directed to the hippocampus and the cortex was spared. "Infants" had lower neurologic scores than "toddlers". This multifactorial model of severe brain injury caused unilateral, wide-spread destruction of the cortex in piglets developmentally similar to toddlers where both seizure duration and hemorrhage covering the brain were positively correlated to tissue destruction. Inherent developmental differences may affect how the brain responds to seizure, and thus, affects the extent and pattern of damage. Study into specifically how the "infant" brain is resistant to the effects of seizure is currently underway and may identify potential therapeutic targets that may reduce evolution of tissue damage after severe traumatic brain injury.

Seizure-related deaths in children: The expanding spectrum.

Although seizures are common in children, they are often overlooked as a potential cause of death. Febrile and nonfebrile seizures can be fatal in children with or without an epilepsy diagnosis and may go unrecognized by parents or physicians. Sudden unexpected infant deaths, sudden unexplained death in childhood, and sudden unexpected death in epilepsy share clinical, neuropathological, and genetic features, including male predominance, unwitnessed deaths, death during sleep, discovery in the prone position, hippocampal abnormalities, and variants in genes regulating cardiac and neuronal excitability. Additionally, epidemiological studies reveal that miscarriages are more common among individuals with a personal or family history of epilepsy, suggesting that some fetal losses may result from epileptic factors. The spectrum of seizure-related deaths in pediatrics is wide and underappreciated; accurately estimating this mortality and understanding its mechanism in children is critical to developing effective education and interventions to prevent these tragedies.

Type of bony involvement predicts genomic subgroup in sphenoid wing meningiomas.

PURPOSE: As sphenoid wing meningiomas (SWMs) are associated with varying degrees of bony involvement, we sought to understand potential relationships between genomic subgroup and this feature. METHODS: Patients treated at Yale-New Haven Hospital for SWM were reviewed. Genomic subgroup was determined via whole exome sequencing, while the extent of bony involvement was radiographically classified as no bone invasion (Type I), hyperostosis only (Type II), tumor invasion only (Type III), or both hyperostosis and tumor invasion (Type IV). Among additional clinical variables collected, a subset of tumors was identified as spheno-orbital meningiomas (SOMs). Machine-learning approaches were used to predict genomic subgroups based on pre-operative clinical features. RESULTS: Among 64 SWMs, 53% had Type-II, 9% had Type-III, and 14% had Type-IV bone involvement; nine SOMs were identified. Tumors with invasion (i.e., Type III or IV) were more likely to be WHO grade II (p: 0.028). Additionally, tumors with invasion were nearly 30 times more likely to harbor NF2 mutations (OR 27.6; p: 0.004), while hyperostosis only were over 4 times more likely to have a TRAF7 mutation (OR 4.5; p: 0.023). SOMs were a significant predictor of underlying TRAF7 mutation (OR 10.21; p: 0.004). CONCLUSIONS: SWMs with invasion into bone tend to be higher grade and are more likely to be NF2 mutated, while SOMs and those with hyperostosis are associated with TRAF7 variants. Pre-operative prediction of molecular subtypes based on radiographic bony characteristics may have significant biological and clinical implications based on known recurrence patterns associated with genomic drivers and grade.

Surgical strategies for older patients with glioblastoma.

OBJECTIVE: While adjuvant treatment regimens have been modified for older patients with glioblastoma (GBM), surgical strategies have not been tailored. METHODS: Clinical data of 48 consecutive patients aged 70 years or older, who underwent surgical resection for GBM with intraoperative ultrasonography (IoUS) alone or combination with intraoperative MRI (IoMRI) at Yale New Haven Hospital were retrospectively reviewed. Variables were analyzed, and comparative analyses were performed. RESULTS: The addition of IoMRI was not superior to IoUS alone in terms of overall survival (OS) (P = 0.306), Karnofsky Performance Score (KPS) at postoperative 6 weeks (P = 0.704) or extent of resection (P = 0.263). Length of surgery (LOSx), however, was significantly longer (P = 0.0002) in the IoMRI group. LOSx (P = 0.015) and hospital stay (P = 0.025) were predictors of postoperative complications. Increased EOR (GTR or NTR) (P = 0.030), postoperative adjuvant treatment (P < 0.0001) and postoperative complications (P = 0.006) were predictive for OS. Patients with relatively lower preoperative KPS scores (<70) showed significant improvement at postoperative 6 weeks (P<0.0001). Patients with complications (P = 0.038) were more likely to have lower KPS at postoperative 6 weeks. CONCLUSIONS: Aggressive management with surgical resection should be considered in older patients with GBM, even those with relatively poor KPS. The use of ioMRI in this population does not appear to confer any measurable benefit over ioUS in experienced hands, but prolongs the length of surgery significantly, which is a preventable prognostic factor for impeding care.

Early loss of mitochondrial complex I and rewiring of glutathione metabolism in renal oncocytoma.

Renal oncocytomas are benign tumors characterized by a marked accumulation of mitochondria. We report a combined exome, transcriptome, and metabolome analysis of these tumors. Joint analysis of the nuclear and mitochondrial (mtDNA) genomes reveals loss-of-function mtDNA mutations occurring at high variant allele fractions, consistent with positive selection, in genes encoding complex I as the most frequent genetic events. A subset of these tumors also exhibits chromosome 1 loss and/or cyclin D1 overexpression, suggesting they follow complex I loss. Transcriptome data revealed that many pathways previously reported to be altered in renal oncocytoma were simply differentially expressed in the tumor's cell of origin, the distal nephron, compared with other nephron segments. Using a heuristic approach to account for cell-of-origin bias we uncovered strong expression alterations in the gamma-glutamyl cycle, including glutathione synthesis (increased GCLC) and glutathione degradation. Moreover, the most striking changes in metabolite profiling were elevations in oxidized and reduced glutathione as well as γ-glutamyl-cysteine and cysteinyl-glycine, dipeptide intermediates in glutathione biosynthesis, and recycling, respectively. Biosynthesis of glutathione appears adaptive as blockade of GCLC impairs viability in cells cultured with a complex I inhibitor. Our data suggest that loss-of-function mutations in complex I are a candidate driver event in renal oncocytoma that is followed by frequent loss of chromosome 1, cyclin D1 overexpression, and adaptive up-regulation of glutathione biosynthesis.

Autopsy Services and Emergency Preparedness of a Tertiary Academic Hospital Mortuary for the COVID-19 Public Health Emergency: The Yale Plan.

Pathology Autopsy and Mortuary Services have been front and center in the severe acute respiratory syndrome coronavirus 2 (SARS-Co-V-2) pandemic. The sheer number of fatalities from the pandemic have been unlike any other in recent memory and needed the rapid creation of new protocols and paradigms to manage the situation. This required rapidly escalating mortuary capacity to manage the increased fatalities from the pandemic with the establishment of lines of communication and networking with governmental entities, institution of new policies for patient flow, and implementation of worker infection control and well-being plans. Autopsies also assumed a crucial role, both to provide insight into the pathomechanisms of a novel disease and to allow tissue retrieval necessary to power research directed towards finding a vaccine. We here outline the plan adopted by the Yale Autopsy and Mortuary Services, in alignment with the institutional mission of high-quality patient care, education, research and health care worker safety and well-being, as the Corona Virus Disease of 2019 (COVID-19) pandemic surged in Connecticut. In the early response phase, ensuring sufficient mortuary capacity necessarily took center stage. As we enter the recovery and plateau phase of the pandemic, setting up a process for a rapid and safe autopsy, that will meet educational and research needs while ensuring the safety of our workforce is being implemented.

Failure to detect human papillomavirus in focal cortical dysplasia type IIb.

OBJECTIVE: Recent studies have reported evidence of human papillomavirus 16 (HPV-16) in a very high proportion of pathological specimens of focal cortical dysplasia type IIb, but not in control specimens, motivating the proposal that viral infection during fetal development may play a causal role in the pathogenesis of focal cortical dysplasias. However, the significance of the association between HPV infection and focal cortical dysplasia type IIb, and its reproducibility across surgical centers, remain unclear. Here we sought evidence for HPV-16 in an independent cohort of surgical specimens. METHODS: We identified 14 specimens of focal cortical dysplasia type IIb from a single surgical center between 1995 and 2013. Multiple methods were used to establish presence or absence of HPV, including DNA polymerase chain reaction, conventional in situ hybridization, chromogenic in situ hybridization, and immunohistochemistry for p16. RESULTS: We found no conclusive evidence of HPV in any of the specimens. All but 1 of the cases were negative by >1 method. INTERPRETATION: These results raise questions about the prevalence of HPV infection in focal cortical dysplasias and about its potential importance as a causative agent.

The subventricular zone in the immature piglet brain: anatomy and exodus of neuroblasts into white matter after traumatic brain injury.

Stimulation of postnatal neurogenesis in the subventricular zone (SVZ) and robust migration of neuroblasts to the lesion site in response to traumatic brain injury (TBI) is well established in rodent species; however, it is not yet known whether postnatal neurogenesis plays a role in repair after TBI in gyrencephalic species. Here we describe the anatomy of the SVZ in the piglet for the first time and initiate an investigation into the effect of TBI on the SVZ architecture and the number of neuroblasts in the white matter. Among all ages of immaturity examined the SVZ contained a dense mesh network of neurogenic precursor cells (doublecortin+) positioned directly adjacent to the ependymal cells (ventricular SVZ, Vsvz) and neuroblasts organized into chains that were distinct from the Vsvz (abventricular SVZ, Asvz). Though the architecture of the SVZ was similar among ages, the areas of Vsvz and Asvz neuroblast chains declined with age. At postnatal day (PND) 14 the white matter tracts have a tremendous number of individual neuroblasts. In our scaled cortical impact model, lesion size increased with age. Similarly, the response of the SVZ to injury was also age dependent. The younger age groups that sustained the proportionately smallest lesions had the largest SVZ areas, which further increased in response to injury. In piglets that were injured at 4 months of age and had the largest lesions, the SVZ did not increase in response to injury. Similar to humans, swine have abundant gyri and gyral white matter, providing a unique platform to study neuroblasts potentially migrating from the SVZ to the lesioned cortex along these white matter tracts. In piglets injured at PND 7, TBI did not increase the total number of neuroblasts in the white matter compared to uninjured piglets, but redistribution occurred with a greater number of neuroblasts in the white matter of the hemisphere ipsilateral to the injury compared to the contralateral hemisphere. At 7 days after injury, less than 1% of neuroblasts in the white matter were born in the 2 days following injury. These data show that the SVZ in the piglet shares many anatomical similarities with the SVZ in the human infant, and that TBI had only modest effects on the SVZ and the number of neuroblasts in the white matter. Piglets at an equivalent developmental stage to human infants were equipped with the largest SVZ and a tremendous number of neuroblasts in the white matter, which may be sufficient in lesion repair without the dramatic stimulation of neurogenic machinery. It has yet to be determined whether neurogenesis and migrating neuroblasts play a role in repair after TBI and/or whether an alteration of normal migration during active postnatal population of brain regions is beneficial in species with gyrencephalic brains.

Characterization of cells from patient-derived fibrovascular membranes in proliferative diabetic retinopathy.

PURPOSE: Epiretinal fibrovascular membranes (FVMs) are a hallmark of proliferative diabetic retinopathy (PDR). Surgical removal of FVMs is often indicated to treat tractional retinal detachment. This potentially informative pathological tissue is usually disposed of after surgery without further examination. We developed a method for isolating and characterizing cells derived from FVMs and correlated their expression of specific markers in culture with that in tissue. METHODS: FVMs were obtained from 11 patients with PDR during diabetic vitrectomy surgery and were analyzed with electron microscopy (EM), comparative genomic hybridization (CGH), immunohistochemistry, and/or digested with collagenase II for cell isolation and culture. Antibody arrays and enzyme-linked immunosorbent assay (ELISA) were used to profile secreted angiogenesis-related proteins in cell culture supernatants. RESULTS: EM analysis of the FVMs showed abnormal vessels composed of endothelial cells with large nuclei and plasma membrane infoldings, loosely attached perivascular cells, and stromal cells. The cellular constituents of the FVMs lacked major chromosomal aberrations as shown with CGH. Cells derived from FVMs (C-FVMs) could be isolated and maintained in culture. The C-FVMs retained the expression of markers of cell identity in primary culture, which define specific cell populations including CD31-positive, alpha-smooth muscle actin-positive (SMA), and glial fibrillary acidic protein-positive (GFAP) cells. In primary culture, secretion of angiopoietin-1 and thrombospondin-1 was significantly decreased in culture conditions that resemble a diabetic environment in SMA-positive C-FVMs compared to human retinal pericytes derived from a non-diabetic donor. CONCLUSIONS: C-FVMs obtained from individuals with PDR can be isolated, cultured, and profiled in vitro and may constitute a unique resource for the discovery of cell signaling mechanisms underlying PDR that extends beyond current animal and cell culture models.

Phylogenetic and epidemiologic evidence of multiyear incubation in human rabies.

Eight years after emigrating from Brazil, an otherwise healthy man developed rabies. An exposure prior to immigration was reported. Genetic analysis revealed a canine rabies virus variant found only in the patient's home country, and the patient had not traveled internationally since immigrating to the United States. We describe how epidemiological, phylogenetic, and viral sequencing data provided confirmation that rabies encephalomyelitis may present after a long, multiyear incubation period, a consideration that previously has been hypothesized without the ability to exclude a more recent exposure. Accordingly, rabies should be considered in the diagnosis of any acute encephalitis, myelitis, or encephalomyelitis.

Rocky Mountain Spotted Fever Encephalitis and "Starry Sky" Pattern on MRI: A Case Report.

INTRODUCTION: Rocky Mountain Spotted Fever (RMSF) is a tick-borne disease caused by Rickettsia rickettsii (R. rickettsii). RMSF presents after a tick bite with fever, rash, and headache but can also cause more serious neurological manifestations. We report a case of RMSF encephalitis presenting with altered sensorium and rapid progression to coma, fever, and petechial rash, and an magnetic resonance imaging (MRI) brain notable for a "starry sky" pattern. CASE REPORT: A 61-year-old woman presented with confusion and fever and was diagnosed with a urinary tract infection. Two days later, she became comatose. MRI brain revealed lacunar infarcts in the right centrum semiovale and splenium of the corpus callosum. Lumbar puncture was notable for neutrophilic pleocytosis and elevated protein with negative bacterial and viral cultures. Empiric meningitis therapy was initiated, and she was transferred to our institution. On transfer, she was febrile, comatose, and had a diffuse petechial rash. Repeat MRI brain demonstrated diffuse, innumerable punctate foci of diffusion restriction with susceptibility-weighted signal attenuation throughout cerebral hemispheres in a "starry sky" pattern. Skin biopsy revealed perivascular lymphocytic infiltrates. Serologic RSMF antibody titers were obtained, and doxycycline was initiated for presumed RMSF encephalitis. The family opted to pursue palliative measures, given no clinical improvement. RSMF titers and postmortem PCR from brain tissue were positive for R. rickettsii. CONCLUSIONS: This case report highlights the clinical presentation of RMSF encephalitis. RMSF encephalitis should be suspected in a patient presenting with encephalopathy, fever, petechial rash, and MRI brain findings of diffuse punctate foci of diffusion restriction and susceptibility-weighted signal attenuation in a "starry-sky" pattern.

Variations in the genomic profiles and clinical behavior of meningioma by racial and ethnic group.

OBJECTIVE: The influence of socioeconomic factors on racial disparities among patients with sporadic meningiomas is well established, yet other potential causative factors warrant further exploration. The authors of this study aimed to determine whether there is significant variation in the genomic profile of meningiomas among patients of different races and ethnicities and its correlation with clinical outcomes. METHODS: The demographic, genomic, and clinical data of patients aged 18 years and older who had undergone surgery for sporadic meningioma between September 2008 and November 2021 were analyzed. Statistical analyses were performed to detect differences across all racial/ethnic groups, as were direct comparisons between Black and non-Black groups plus Hispanic and non-Hispanic groups. RESULTS: This study included 460 patients with intracranial meningioma. Hispanic patients were significantly younger at surgery (53.9 vs 60.2 years, p = 0.0006) and more likely to show symptoms. Black patients had a higher incidence of anterior skull base tumors (OR 3.2, 95% CI 1.7-6.3, p = 0.0008) and somatic hedgehog mutations (OR 5.3, 95% CI 1.6-16.6, p = 0.003). Hispanics were less likely to exhibit the aggressive genomic characteristic of chromosome 1p deletion (OR 0.28, 95% CI 0.07-1.2, p = 0.06) and displayed higher rates of TRAF7 somatic driver mutations (OR 2.96 95% CI 1.1-7.8, p = 0.036). Black patients had higher rates of recurrence (OR 2.6, 95% CI 1.3-5.2, p = 0.009) and shorter progression-free survival (PFS; HR 2.9, 95% CI 1.6-5.4, p = 0.002) despite extents of resection (EORs) similar to those of non-Black patients (p = 0.745). No significant differences in overall survival were observed among groups. CONCLUSIONS: Despite similar EORs, Black patients had worse clinical outcomes following meningioma resection, characterized by a higher prevalence of somatic hedgehog mutations, increased recurrence rates, and shorter PFS. Meanwhile, Hispanic patients had less aggressive meningiomas, a predisposition for TRAF7 mutations, and no difference in PFS. These findings could inform the care and treatment strategies for meningiomas, and they establish the foundation for future studies focusing on the genomic origins of these observed differences.

Backpack-mediated anti-inflammatory macrophage cell therapy for the treatment of traumatic brain injury.

Traumatic brain injury (TBI) is a debilitating disease with no current therapies outside of acute clinical management. While acute, controlled inflammation is important for debris clearance and regeneration after injury, chronic, rampant inflammation plays a significant adverse role in the pathophysiology of secondary brain injury. Immune cell therapies hold unique therapeutic potential for inflammation modulation, due to their active sensing and migration abilities. Macrophages are particularly suited for this task, given the role of macrophages and microglia in the dysregulated inflammatory response after TBI. However, maintaining adoptively transferred macrophages in an anti-inflammatory, wound-healing phenotype against the proinflammatory TBI milieu is essential. To achieve this, we developed discoidal microparticles, termed backpacks, encapsulating anti-inflammatory interleukin-4, and dexamethasone for ex vivo macrophage attachment. Backpacks durably adhered to the surface of macrophages without internalization and maintained an anti-inflammatory phenotype of the carrier macrophage through 7 days in vitro. Backpack-macrophage therapy was scaled up and safely infused into piglets in a cortical impact TBI model. Backpack-macrophages migrated to the brain lesion site and reduced proinflammatory activation of microglia in the lesion penumbra of the rostral gyrus of the cortex and decreased serum concentrations of proinflammatory biomarkers. These immunomodulatory effects elicited a 56% decrease in lesion volume. The results reported here demonstrate, to the best of our knowledge, a potential use of a cell therapy intervention for a large animal model of TBI and highlight the potential of macrophage-based therapy. Further investigation is required to elucidate the neuroprotection mechanisms associated with anti-inflammatory macrophage therapy.

A systematic review and individual participant data meta-analysis of gonadal steroid hormone receptors in meningioma.

OBJECTIVE: The relationship between patient and meningioma characteristics and hormone receptors (HRs) of progesterone, estrogen, and androgen remains poorly defined despite literature suggesting that meningiomas are sensitive to gonadal steroid hormones. Therefore, the authors sought to collect and compare data on this topic by performing a systematic review and meta-analysis of reported studies of HR status in meningiomas. METHODS: A MEDLINE PubMed literature review conducted for articles published between January 1, 1951, and December 31, 2020, resulted in 634 unduplicated articles concerning meningiomas and HRs. There were 114 articles that met the criteria of detailed detection protocols for progesterone receptor (PR), estrogen receptor (ER), and/or androgen receptor (AR) using immunohistochemistry (IHC) or ligand-binding (LB) assays and simultaneous reporting of HR status with at least one variable among age, sex, histology, location, grade, or recurrence. Between-study heterogeneity and risk of bias were evaluated using graphical and statistical methods. The authors performed a multilevel meta-analysis using random-effects modeling on aggregated data (n = 4447) and individual participant data (n = 1363) with subgroup results summarized as pooled effects. A mixed-effects meta-regression using individual participant data was performed to analyze independently associated variables. RESULTS: The 114 selected articles included data for 5810 patients with 6092 tumors analyzed to determine the expression of three HRs in human meningiomas: PRs, ARs, and ERs. The proportions of HR+ meningiomas were estimated to be 0.76 (95% CI 0.72-0.80) for PR+ and 0.50 (95% CI 0.33-0.66) for AR+ meningiomas. ER+ meningioma detection varied depending on the measurement method used and was 0.06 (95% CI 0.03-0.10) with IHC and 0.11 (95% CI 0.06-0.20) with LB assays. There were associations between age and PR and ER expression that varied between male and female patients. PR+ and AR+ were more common in female patients (OR 1.84, 95% CI 1.47-2.29 for PR and OR 4.16, 95% CI 1.62-10.68 for AR). Additionally, PR+ meningiomas were enriched in skull base locations (OR 1.89, 95% CI 1.03-3.48) and meningothelial histology (OR 1.86, 95% CI 1.23-2.81). A meta-regression showed that PR+ was independently associated with age (OR 1.11 95% CI 1.09-1.13; p < 0.0001) and WHO grade I tumors (OR 8.09, 95% CI 3.55-18.44; p < 0.0001). ER+ was negatively associated with meningothelial histology (OR 0.94, 95% CI 0.86-0.98; p = 0.044) and positively associated with convexity location (OR 1.12, 95% CI 1.05-1.18; p = 0.0003). CONCLUSIONS: The association between HRs and meningioma features has been investigated but unexplained for decades. In this study the authors demonstrated that HR status has a strong association with known meningioma features, including WHO grade, age, female sex, histology, and anatomical location. Identifying these independent associations allows for a better understanding of meningioma heterogeneity and provides a foundation for revisiting targeted hormonal therapy in meningioma on the basis of proper patient stratification according to HR status.

The clinical and genomic features of seizures in meningiomas.

Meningiomas are the most common central nervous system tumors. Although these tumors are extra-axial, a relatively high proportion (10%-50%) of meningioma patients have seizures that can substantially impact the quality of life. Meningiomas are believed to cause seizures by inducing cortical hyperexcitability that results from mass effect and cortical irritation, brain invasion, or peritumoral brain edema. In general, meningiomas that are associated with seizures have aggressive features, with risk factors including atypical histology, brain invasion, and higher tumor grade. Somatic NF2 mutated meningiomas are associated with preoperative seizures, but the effect of the driver mutation is mediated through atypical features. While surgical resection is effective in controlling seizures in most patients with meningioma-related epilepsy, a history of seizures and uncontrolled seizures prior to surgery is the most significant predisposing factor for persistent postoperative seizures. Subtotal resection (STR) and relatively larger residual tumor volume are positive predictors of postoperative seizures. Other factors, including higher WHO grade, peritumoral brain edema, and brain invasion, are inconsistently associated with postoperative seizures, suggesting they might be crucial in the development of an epileptogenic focus, but do not appear to play a substantial role after seizure activity has been established. Herein, we review and summarize the current literature surrounding meningioma-related epilepsy and underscore the interaction of multiple factors that relate to seizures in patients with meningioma.