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The fate of developing T cells is determined by the strength of T cell receptor (TCR) signal they receive in the thymus. This process is finely regulated through the tuning of positive and negative regulators in thymocytes. The Family with sequence similarity 49 member B (Fam49b) protein is a newly discovered negative regulator of TCR signaling that has been shown to suppress Rac-1 activity in vitro in cultured T cell lines. However, the contribution of Fam49b to the thymic development of T cells is unknown. To investigate this important issue, we generated a novel mouse line deficient in Fam49b (Fam49b-KO). We observed that Fam49b-KO double positive (DP) thymocytes underwent excessive negative selection, whereas the positive selection stage was unaffected. Fam49b deficiency impaired the survival of single positive thymocytes and peripheral T cells. This altered development process resulted in significant reductions in CD4 and CD8 single-positive thymocytes as well as peripheral T cells. Interestingly, a large proportion of the TCRγδ+ and CD8αα+TCRαβ+ gut intraepithelial T lymphocytes were absent in Fam49b-KO mice. Our results demonstrate that Fam49b dampens thymocytes TCR signaling in order to escape negative selection during development, uncovering the function of Fam49b as a critical regulator of the selection process to ensure normal thymocyte development and peripheral T cells survival.

Introduction: Traumatic intracranial hemorrhages (TIH) have traditionally been managed in the intensive care unit (ICU) setting with neurosurgery consultation and repeat head CT (HCT) for each patient. Recent publications indicate patients with small TIH and normal neurological examinations who are not on anticoagulation do not require ICU-level care, repeat HCT, or neurosurgical consultation. It has been suggested that these patients can be safely discharged home after a short period of observation in emergency department observation units (EDOU) provided their symptoms do not progress. Methods: This study is a retrospective cross-sectional evaluation of an EDOU protocol for minor traumatic brain injury (mTBI). It was conducted at a Level I trauma center. The protocol was developed by emergency medicine, neurosurgery and trauma surgery and modeled after the Brain Injury Guidelines (BIG). All patients were managed by attendings in the ED with discretionary neurosurgery and trauma surgery consultations. Patients were eligible for the mTBI protocol if they met BIG 1 or BIG 2 criteria (no intoxication, no anticoagulation, normal neurological examination, no or non-displaced skull fracture, subdural or intraparenchymal hematoma up to 7 millimeters, trace to localized subarachnoid hemorrhage), and had no other injuries or medical co-morbidities requiring admission. Protocol in the EDOU included routine neurological checks, symptom management, and repeat HCT for progression of symptoms. The EDOU group was compared with historical controls admitted with primary diagnosis of TIH over the 12 months prior to the initiation of the mTBI protocols. Primary outcome was reduction in EDOU length of stay (LOS) as compared to inpatient LOS. Secondary outcomes included rates of neurosurgical consultation, repeat HCT, conversion to inpatient admission, and need for emergent neurosurgical intervention.  Results: There were 169 patients placed on the mTBI protocol between September 1, 2016 and August 31, 2019. The control group consisted of 53 inpatients. Median LOS (interquartile range [IQR]) for EDOU patients was 24.8 (IQR: 18.8 – 29.9) hours compared with a median LOS for the comparison group of 60.2 (IQR: 45.1 – 85.0) hours (P < .001). In the EDOU group 47 (27.8%) patients got a repeat HCT compared with 40 (75.5%) inpatients, and 106 (62.7%) had a neurosurgical consultation compared with 53 (100%) inpatients. Subdural hematoma was the most common type of hemorrhage. It was found in 60 (35.5%) patients, and subarachnoid hemorrhage was found in 56 cases (33.1%). Eleven patients had multicompartment hemorrhage of various classifications. Twelve (7.1%) patients required hospital admission from the EDOU. None of the EDOU patients required emergent neurosurgical intervention.  Conclusion: Patients with minor TIH can be managed in an EDOU using an mTBI protocol and discretionary neurosurgical consults and repeat HCT. This is associated with a significant reduction in length of stay.

Purpose: This multicenter, randomized, double-blinded, active sham-controlled pivotal study was designed to assess the efficacy and safety of high-frequency nerve block treatment for chronic post-amputation and phantom limb pain. Patients and Methods: QUEST enrolled 180 unilateral lower-limb amputees with severe post-amputation pain, 170 of whom were implanted with the Altius device, were randomized 1:1 to active-sham or treatment groups and reached the primary endpoint. Responders were those subjects who received ≥ 50% pain relief 30 min after treatment in ≥ 50% of their self-initiated treatment sessions within the 3-month randomized period. Differences between the active treatment and sham control groups as well as numerous secondary outcomes were determined. Results: At 30-min, (primary outcome), 24.7% of the treatment group were responders compared to 7.1% of the control group (p=0.002). At 120-minutes following treatment, responder rates were 46.8% in the Treatment group and 22.2% in the Control group (p=0.001). Improvement in Brief Pain Inventory interference score of 2.3 ± 0.29 was significantly greater in treatment group than the 1.3 ± 0.26-point change in the Control group (p = 0.01). Opioid usage, although not significantly different, trended towards a greater reduction in the treatment group than in the control group. The incidence of adverse events did not differ significantly between the treatment and control groups. Conclusion: The primary outcomes of the study were met, and the majority of Treatment patients experienced a substantial improvement in PAP (regardless of meeting the study definition of a responder). The significant in PAP was associated with significantly improved QOL metrics, and a trend towards reduced opioid utilization compared to Control. These data indicate that Altius treatment represents a significant therapeutic advancement for lower-limb amputees suffering from chronic PAP. [ABSTRACT FROM AUTHOR]

In the last decade there has been incredible interest and advancement in the surgical care of adult patients with upper motor neuron (UMN) injuries. Spasticity represents a prevalent and debilitating feature of UMN syndrome, which can result from cerebral palsy, spinal cord injury, cerebrovascular accident and traumatic or anoxic brain injury. While several diagnostic tools and management strategies have been described for upper limb spasticity, evidence-based practice guidelines do not currently exist due to low patient volume and a paucity of surgeons routinely performing surgeries in UMN syndrome patients. As such, expert consensus may help provide guidance for patients, therapists and clinicians alike. In this article an expert panel was assembled, and the Delphi method was utilized to present diagnostic considerations, define operative indications, discuss surgical treatment modalities and encourage a standard set of outcome measures for patients with upper extremity spasticity. [ABSTRACT FROM AUTHOR]

Background: Patients with upper limb dysfunction from a brain injury often have different goals of treatment and expectations following a fracture of the upper extremity. This study retrospectively reviewed outcomes of nonoperative management of acute humerus fractures in patients with severe ipsilateral hemiparesis or hemiplegia. Methods: Patients who had sustained an acute humerus fracture managed nonoperatively, greater than 1 year following an upper motor neuron (UMN) injury resulting in ipsilateral severe hemiparesis or hemiplegia at a single tertiary care center from 1988 to 2019, were reviewed. Fractures were classified using the AO-Müller/Orthopaedic Trauma Association and/or Neer classifications. Primary outcome measures included House classification level of function, pain, achievement of and time to radiographic union, and the need for subsequent surgical procedures. Results: Ten distinct nonoperatively managed humerus fractures—3 proximal (11A23), 5 mid-shaft (12A2b = 1, 12A2c = 2, 12A3a = 1, 12A2b = 1), and 2 distal (13A2 = 1, 13 C1 = 1)—were identified in 8 patients (6 women and 2 men) with ipsilateral hemiparesis or hemiplegia. The median radiographic follow-up was 20 months (range: 78 days to 12 years). The median clinical follow-up was 33.5 months (range: 100 days to 12 years). All patients presented with severe pain that was absent at final follow-up. Radiographic union was achieved in all patients with a mean time to union of 90.9 ± 39.3 days (range: 35-185 days). No patients required operative management. Conclusions: Nonoperative management of humerus fractures in patients with an ipsilateral UMN injury might result in reliable pain relief and union without the need for further surgical intervention. Management of humerus fractures in this patient population should be individualized toward their goals of care. [ABSTRACT FROM AUTHOR]