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Context.--Spontaneous (nontraumatic) subdural hematomas have been reported yet have not been well studied. Objective.--To identify the neuropathologic features of acute spontaneous SDHs (ASSDHs) and their associated medical conditions. Design.--A retrospective study of 235 autopsy cases of SDH was conducted. Review of demographics, underlying medical conditions, and coagulation profile as well as gross and histopathologic examination of the brain and other organs were performed. Results.--Among the 32 cases of ASSDH, 5 cases (15.6%) had severe hemorrhage and 4 (12.5%) demonstrated brain herniation. Twenty-two cases (68.8%) had concurrent but nonconnecting subarachnoid hemorrhage or intraparenchymal hemorrhage. The most common underlying medical condition was thrombocytopenia (n = 21; 65.6%), followed by immunosuppression (n = 15; 46.9), bloodstream infections or sepsis (n = 12; 37.5%), hypertension (n = 13; 40.6%), and coronary artery disease (n = 12; 37.5%). Many patients with thrombocytopenia or immunosuppression had underlying malignancies, with leukemia being the most common type (n = 11; 34.4%). The use of circulatory devices or hemodialysis was noted in a significant portion of ASSDH cases. In terms of coagulation factors, most of our ASSDH patients had normal prothrombin time and activated partial thromboplastin time, but abnormal platelet count and D-dimer levels. Conclusions.--ASSDHs can be severe and are often associated with subarachnoid hemorrhage and/or intra-parenchymal hemorrhage. The causes of ASSDH are limited to certain underlying medical conditions that ultimately lead to bleeding tendency. Autopsies are helpful in determining the etiology. Given their association with abnormal platelet count, correcting platelet deficiencies is a potential preventive measure for ASSDHs. doi: 10.5858/arpa.2024-0003OA, Subdural hematomas (SDHs) are collections of blood between the dura mater and leptomeninges, typically due to shearing of bridging veins as a result of trauma. (1) SDHs can occur in [...]

Latent HIV infection of long-lived cells is a barrier to viral clearance. Hematopoietic stem and progenitor cells are a heterogeneous population of cells, some of which are long-lived. CXCR4-tropic HIVs infect a broad range of HSPC subtypes, including hematopoietic stem cells, which are multi-potent and long-lived. However, CCR5-tropic HIV infection is limited to more differentiated progenitor cells with life spans that are less well understood. Consistent with emerging data that restricted progenitor cells can be long-lived, we detected persistent HIV in restricted HSPC populations from optimally treated people. Further, genotypic and phenotypic analysis of amplified env alleles from donor samples indicated that both CXCR4- and CCR5-tropic viruses persisted in HSPCs. RNA profiling confirmed expression of HIV receptor RNA in a pattern that was consistent with in vitro and in vivo results. In addition, we characterized a CD4high HSPC sub-population that was preferentially targeted by a variety of CXCR4- and CCR5-tropic HIVs in vitro. Finally, we present strong evidence that HIV proviral genomes of both tropisms can be transmitted to CD4-negative daughter cells of multiple lineages in vivo. In some cases, the transmitted proviral genomes contained signature deletions that inactivated the virus, eliminating the possibility that coincidental infection explains the results. These data support a model in which both stem and non-stem cell progenitors serve as persistent reservoirs for CXCR4- and CCR5-tropic HIV proviral genomes that can be passed to daughter cells.

Nonreceptor tyrosine phosphatases (NTPs) play an important role in regulating protein phosphorylation and have been proposed as attractive therapeutic targets for cancer and metabolic diseases. We have previously identified that 3-Hydroxy-1,2,3-benzotriazin-4(3H)-one (HODHBt) enhanced STAT activation upon cytokine stimulation, leading to increased reactivation of latent HIV and effector functions of NK and CD8 T cells. Here, we demonstrate that HODHBt interacted with and inhibited the NTPs PTPN1 and PTPN2 through a mixed inhibition mechanism. We also confirm that PTPN1 and PTPN2 specifically controlled the phosphorylation of different STATs. The small molecule ABBV-CLS-484 (AC-484) is an active site inhibitor of PTPN1 and PTPN2 currently in clinical trials for advanced solid tumors. We compared AC-484 and HODHBt and found similar effects on STAT5 and immune activation, albeit with different mechanisms of action leading to varying effects on latency reversal. Our studies provide the first specific evidence to our knowledge that enhancing STAT phosphorylation via inhibition of PTPN1 and PTPN2 is an effective tool against HIV.