Increased circulating stem cells and better cognitive performance in traumatic brain injury subjects following hyperbaric oxygen therapy.

Traumatic brain injury (TBI) may cause persistent cognitive dysfunction. A pilot clinical study was performed to determine if hyperbaric oxygen (HBO2) treatment improves cognitive performance. It was hypothesized that stem cells, mobilized by HBO2 treatment, are recruited to repair damaged neuronal tissue. This hypothesis was tested by measuring the relative abundance of stem cells in peripheral blood and cognitive performance during this clinical trial. The subject population consisted of 28 subjects with persistent cognitive impairment caused by mild to moderate TBI suffered during military deployment to Iraq or Afghanistan. Fluorescence-activated cell sorting (FACS) analysis was performed for stem cell markers in peripheral blood and correlated with variables resulting from standard tests of cognitive performance and post-traumatic stress disorder: ImPACT, BrainCheckers and PCL-M test results. HBO2 treatment correlated with stem cell mobilization as well as increased cognitive performance. Together these results support the hypothesis that stem cell mobilization may be required for cognitive improvement in this population.

Cognitive function in a traumatic brain injury hyperbaric oxygen randomized trial.

OBJECTIVE: Determine changes in cognition and post-traumatic stress disorder (PTSD) symptoms in subjects with traumatic brain injury (TBI) exposed to 2.4 atmospheres absolute (atm abs) breathing 100% oxygen vs. sham (1.3 atm-abs air). METHODS: Fifty randomized subjects completed a total of 30 exposures. A concussion history was taken, then baseline, post-series, and six-week follow-up immediate post-concussion assessment and cognitive testing, Brain-checkers and PTSD Checklist for Military (PCL-M) tests were administered. RESULTS: No statistically significant differences between groups were noted, but both groups improved. Subgroups analyses, based on concussion history and individual test components, showed improvement in the treatment group vs. the sham. These subgroups included the number of concussive events, time from event to consent, loss of consciousness, visual memory, processing, go--no go, and simple reaction time. CONCLUSION: There was no statistically significant difference between a sham and 2.4 atm abs hyperbaric oxygen (HBO2) in cognitive scores from ImPACT and Brain-checkers or composite scores in the PCL-M; however both groups showed improvement. Subgroups with favorable response to treatment are identified. Future studies evaluating HBO2 should consider concussion histories or focus on validating subgroup response to determine HBO2 as a potential adjunctive treatment for persistent symptoms following TBI.

Overlapping effector interfaces define the multiple functions of the HIV-1 Nef polyproline helix.

BACKGROUND: HIV-1 Nef is a multifunctional protein required for full pathogenicity of the virus. As Nef has no known enzymatic activity, it necessarily functions through protein-protein interaction interfaces. A critical Nef protein interaction interface is centered on its polyproline segment (P69VRPQVPLRP78) which contains the helical SH3 domain binding protein motif, PXXPXR. We hypothesized that any Nef-SH3 domain interactions would be lost upon mutation of the prolines or arginine of PXXPXR. Further, mutation of the non-motif "X" residues, (Q73, V74, and L75) would give altered patterns of inhibition for different Nef/SH3 domain protein interactions. RESULTS: We found that mutations of either of the prolines or the arginine of PXXPXR are defective for Nef-Hck binding, Nef/activated PAK2 complex formation and enhancement of virion infectivity (EVI). Mutation of the non-motif "X" residues (Q, V and L) gave similar patterns of inhibition for Nef/activated PAK2 complex formation and EVI which were distinct from the pattern for Hck binding. These results implicate an SH3 domain containing protein other than Hck for Nef/activated PAK2 complex formation and EVI. We have also mutated Nef residues at the N-and C-terminal ends of the polyproline segment to explore interactions outside of PXXPXR. We discovered a new locus GFP/F (G67, F68, P69 and F90) that is required for Nef/activated PAK2 complex formation and EVI.MHC Class I (MHCI) downregulation was only partially inhibited by mutating the PXXPXR motif residues, but was fully inhibited by mutating the C-terminal P78. Further, we observed that MHCI downregulation strictly requires G67 and F68. Our mutational analysis confirms the recently reported structure of the complex between Nef, AP-1 µ1 and the cytoplasmic tail of MHCI, but does not support involvement of an SH3 domain protein in MHCI downregulation. CONCLUSION: Nef has evolved to be dependent on interactions with multiple SH3 domain proteins. To the N- and C- terminal sides of the polyproline helix are multifunctional protein interaction sites. The polyproline segment is also adapted to downregulate MHCI with a non-canonical binding surface. Our results demonstrate that Nef polyproline helix is highly adapted to directly interact with multiple host cell proteins.

Evaluation for ulnar neuropathy at the elbow in Ironman triathletes: physical examination and electrodiagnostic evidence.

OBJECTIVE: Evaluation of the elbow in Ironman triathletes for ulnar compression neuropathy caused by aerobar use. DESIGN: Descriptive laboratory study. SETTING: Ironman California 70.3, Ironman Arizona, Ironman New Orleans 70.3, San Antonio, Texas. PARTICIPANTS: Study 1: (n = 712) Ironman California 70.3/Ironman Arizona participants. Study 2: (n = 54) Ironman New Orleans 70.3 finishers. Study 3: (n = 11) participants training for an Ironman triathlon. INTERVENTIONS: Pilot questionnaire (study 1). Pilot questionnaire and prerace and postrace physical examination (study 2). Pilot questionnaire and preride and postride (and postseason) physical examination, and electrodiagnostic testing (study 3). MAIN OUTCOME MEASURES: Participants with symptoms, physical examination findings, and electrodiagnostic findings (amplitude or conduction velocity decrease) (P < 0.05). RESULTS: In study 1, 20.8% reported a history of ulnar symptoms. In study 2, 35.2% reported a history of ulnar symptoms. Preevent physical examination testing of the elbow showed 39.5% with positive Tinel sign and 41.5% with positive flexion/compression test. Postevent testing showed 70.4% with positive Tinel sign and 75.9% with positive flexion/compression test. In study 3, 46% reported ulnar symptoms. Preride physical examination testing showed 4.5% with positive Tinel sign and 9% with positive flexion/compression test. Postride testing showed 95.5% with positive Tinel sign and 91% with positive flexion/compression test. Postseason testing showed 64% with positive Tinel sign and 82% with positive flexion/compression test. Electrodiagnostic testing comparing preride and postride showed that ulnar nerve latency increased in 82%, amplitude decreased in 50%, and conduction velocity slowed in 64%. Electrodiagnostic testing comparing preseason and postseason showed that ulnar nerve latency increased in 73%, amplitude decreased in 64%, and conduction velocity slowed in 82%. CONCLUSIONS: The findings support the hypothesis of an ulnar compression neuropathy at the elbow occurring at high rates in aerobar using Ironman triathletes.

Traumatic brain injury: next steps, research needed, and priority focus areas.

Traumatic brain injury (TBI) has been not only a major focus of concern during the recent conflicts in Afghanistan and Iraq, but also among our garrison service members. The prevalence of these injuries has compelled the nation and Congress to invest in the development of policies and programs that support evidence-based care for the full continuum of TBI, from mild (otherwise known as concussion) to severe and penetrating brain injuries. Although, the Department of Defense has made great strides in the areas of TBI clinical care, education, and research, there remains a great need to leverage scientific, policy, and clinical advancement to maximize care of the service member. The purpose of this article is to outline the 7 major areas of work currently being undertaken to help advance the field of TBI. The 7 areas include: (1) eliminating undetected mild traumatic brain injury through prompt early diagnosis, (2) ensuring force readiness and addressing cultural barriers, (3) improving collaborations with the Department of Veterans Affairs, other federal agencies, and academic and civilian organizations, (4) improving deployment-related assessments, (5) deploying effective treatments, (6) conducting military-relevant and targeted research, and (7) enhancing information technology systems.

Fibrin-Associated, EBV-Negative Diffuse Large B-Cell Lymphoma Arising in Atrial Myxoma: Expanding the Spectrum of the Entity.

Fibrin-associated diffuse large B-cell lymphoma (FA-DLBCL) is a provisional entity in the 2017 Revision of the World Health Organization Classification. This indolent entity, which is frequently discovered incidentally, is currently classified under the category of diffuse large B-cell lymphoma associated with chronic inflammation (DLBCL-CI), an aggressive lymphoma with poor survival. Several authors have proposed that it be classified separately since, in contrast to DLBCL-CI, transformation to aggressive lymphoma has rarely been reported and this entity has distinct clinical and histological features. We describe a rare case of a 62-year-old male with FA-DLBCL associated with atrial myxoma, which was incidentally discovered. In contrast to typically described immunophenotypic features of this entity, that is, activated B-cell phenotype (ABC) and Epstein-Barr virus (EBV) positivity, our case showed germinal center B-cell (GCB) phenotype and was EBV negative. Clinical staging revealed no evidence of lymphoma elsewhere in the body, and the patient did not receive adjuvant chemotherapy after surgical excision and remains in remission. This case illustrates that occasionally FA-DLBCL can show GCB phenotype, as opposed to the typical ABC phenotype. Moreover, we propose that the definition of the entity be expanded to include EBV-negative cases.

Identification and characterization of mitochondrial targeting sequence of human apurinic/apyrimidinic endonuclease 1.

Dually targeted mitochondrial proteins usually possess an unconventional mitochondrial targeting sequence (MTS), which makes them difficult to predict by current bioinformatics approaches. Human apurinic/apyrimidinic endonuclease (APE1) plays a central role in the cellular response to oxidative stress. It is a dually targeted protein preferentially residing in the nucleus with conditional distribution in the mitochondria. However, the mitochondrial translocation mechanism of APE1 is not well characterized because it harbors an unconventional MTS that is difficult to predict by bioinformatics analysis. Two experimental approaches were combined in this study to identify the MTS of APE1. First, the interactions between the peptides from APE1 and the three purified translocase receptors of the outer mitochondrial membrane (Tom) were evaluated using a peptide array screen. Consequently, the intracellular distribution of green fluorescent protein-tagged, truncated, or mutated APE1 proteins was traced by tag detection. The results demonstrated that the only MTS of APE1 is harbored within residues 289-318 in the C terminus, which is normally masked by the intact N-terminal structure. As a dually targeted mitochondrial protein, APE1 possesses a special distribution pattern of different subcellular targeting signals, the identification of which sheds light on future prediction of MTSs.

Thrombotic thrombocytopenic purpura with Graves' disease during pregnancy.

Thrombotic thrombocytopenic purpura may be seen with several autoimmune disorders such as immune thrombocytopenia purpura, immune hemolytic anemia, and systemic lupus erythematosus, but it is rarely associated with Graves' disease. We report a patient with thrombotic thrombocytopenic purpura associated with Graves' disease.

Extramedullary hematopoiesis masquerading as a cranial (clivus) tumor.

Extramedullary hematopoiesis (EMH) is a well-known phenomenon occurring during fetal development. In the postfetal condition, EMH is commonly associated with hematologic conditions including chronic myeloproliferative or lymphoproliferative disorders, leukemias, and chronic and inherited anemias. We report an unusual location for EMH that masqueraded as a cranial tumor.

Functional characterization of the human immunodeficiency virus type 1 Nef acidic domain.

The human immunodeficiency virus type 1 (HIV-1) accessory protein Nef downregulates major histocompatibility complex class I (MHC-I) from the cell surface. It has been proposed that the direct interaction of the acidic cluster (AC) of Nef, (62)EEEE(65), with the furin binding region (fbr) of PACS-1 is crucial for this Nef function. Contrary to this proposal, evidence is presented here that the four glutamates in Nef do not functionally engage the PACS-1 fbr. (i) The binding of Nef to the PACS-1 fbr in vitro is much weaker than the binding of the canonical furin AC to the PACS-1 fbr. (ii) The mutation of two of the four glutamates in Nef's AC to alanines does not alter Nef's ability to downregulate MHC-I, and triply mutated Nefs exhibit 50% activity. (iii) The introduction of lysine into the AC has little effect on Nef function. (iv) The mutation of all four glutamates to alanine does debilitate Nef MHC-I downregulation, but this quadruple mutation also impairs the ability of Nef to regulate p21-activated protein kinase and enhance viral particle infectivity. (v) The replacement of the Nef AC with the bona fide AC from furin results in the loss of the expected regulatory properties of the furin AC. (vi) The insertion of the conformation-disrupting amino acid proline into the Nef AC does not disrupt MHC-I downregulation. Our results are consistent with an alternative model in which (62)EEEE(65) plays a stabilizing role in the formation of a ternary complex between Nef, the MHC-I cytoplasmic domain, and AP-1.

Pulmonary lymphangioleiomyomatosis associated with aggressive renal angiomyolipoma.

Lymphangioleiomyomatosis (LAM) is a rare cystic pulmonary disease that may occur in association with mutations in the tuberous sclerosis genes or arise sporadically. The histologic hallmark of the disease is the "LAM" cell, a spindled to epithelioid smooth muscle-like cell that bears morphologic and immunohistochemical resemblance to the perivascular epithelioid cell tumors (PEComas). The origin of the "LAM" cell is unknown; emerging theories suggest that a member of the PEComa family, the renal angiomyolipoma, may be the primary source and that both LAM and angiomyolipomas are associated with the genetic syndrome tuberous sclerosis. We present a young woman with LAM with an aggressive renal angiomyolipoma confirmed at autopsy.

MRI in Management of Mild TBI/Concussion in the Deployed Setting.

Magnetic resonance imaging (MRI) has specific limitations in theater and has unique requirements for its safe use with patients which require additional technician training and strict adherence to MRI-specific safety protocols. Neuroimaging is recommended for the evaluation of service members with clinical red flags new onset or persistent or worsening symptoms, and individuals whose recovery is not progressing as anticipated. This article is a brief discussion of when MRI is appropriate.

The regulatory role of APE1 in epithelial-to-mesenchymal transition and in determining EGFR-TKI responsiveness in non-small-cell lung cancer.

BACKGROUND: Epithelial-to-mesenchymal transition (EMT) plays a pivotal role in resistance to EGFR tyrosine kinase inhibitors (TKIs) in non-small-cell lung cancer (NSCLC). Our previous study revealed that in osteosarcoma, human apurinic/apyrimidinic endonuclease 1 (APE1) regulates transforming growth factor-ß (TGF-ß), an important player in EMT. We therefore hypothesized a link between APE1 and EGFR-TKI responsiveness in NSCLC. METHODS: The protein levels of APE1 were analyzed in tumors of NSCLC patients receiving EGFR-TKI treatment. The correlation between APE1 expression and progression-free survival (PFS), overall survival (OS), or response rate were analyzed. The impact of APE1 on the response to EGFR-TKIs was measured by exogenous manipulation of APE1 in EGFR-TKI-sensitive and EGFR-TKI-resistant cells. RESULTS: We indicate that low expression of APE1 in tumors is associated with a significantly longer PFS (20.8 months vs 8.4 months, P = 0.008) and a preferential OS (39.0 months vs 17.0 months, P = 0.001), with no difference in initial response rate to EGFR-TKIs. We observed that APE1 protein level was significantly increased in EGFR-TKI-resistant cells and was associated with downregulated E-cadherin and upregulated vimentin. The EMT phenotype, as well as the levels of TGF-ß, was suppressed in APE1 knockdown HCC827/IR and PC-9/ER cells, while the EMT phenotype was promoted in APE1-overexpressed HCC827 and PC-9 cells. Furthermore, a specific APE1 redox inhibitor (ie, E3330) effectively reversed the EMT phenotype and further sensitized the cells to EGFR-TKIs. CONCLUSION: This study revealed a significant role of APE1 in EGFR-TKI resistance via novel regulatory effects on the EMT phenotype in NSCLC.

Blastic plasmacytoid dendritic cell neoplasm following acquired erythropoietic protoporphyria.

A 56-year-old Texas rancher with a prior diagnosis of acquired erythropoietic protoporphyria secondary to an underlying myelodysplastic disorder developed an uncommon tumor, blastic plasmacytoid dendritic cell neoplasm (BPDCN). During his initial disease, analysis revealed a TET2 mutation, which is the most common mutation associated with BPDCN. This article discusses this unusual hematopoietic neoplasm, the possible evolution from erythropoietic protoporphyria, and the underlying myelodysplastic process.

Serum APE1 as a predictive marker for platinum-based chemotherapy of non-small cell lung cancer patients.

PURPOSE: To define the role of the DNA repair protein apurinic/apyrimidinic endonuclease 1 (APE1) in predicting the prognosis and chemotherapeutic response of non-small cell lung cancer patients receiving platinum-containing chemotherapy. RESULTS: Our investigations found that serum APE1 level was significantly elevated in 229 of 412 NSCLC patients and correlated with its level in tissue (r2 = 0.639, p < 0.001). The elevated APE1 level in both tissue and serum of patients prior to chemotherapy was associated with worse progression-free survival (HR: 2.165, p < 0.001, HR: 1.421, p = 0.012), but not with overall survival. After 6 cycles of chemotherapy, a low APE1 serum level was associated with better overall survival (HR: 0.497, p = 0.010). EXPERIMENTAL DESIGN: We measured APE1 protein levels in biopsy tissue from 172 NSCLC patients and sera of 412 NSCLC patients receiving platinum-based chemotherapy by immunohistochemistry and a newly established sensitive and specific enzyme-linked immunosorbent assay, respectively. APE1 levels in sera of 523 healthy donors were also determined as control. CONCLUSIONS: Our studies indicate that APE1 is a biomarker for predicting prognosis and therapeutic efficacy in NSCLC. The chemotherapy-naïve serum APE1 level, which correlated with its tissue level inversely associated with progression-free survival of platinum-containing doublet chemotherapy, whereas post-treatment serum APE1 level was inversely associated with overall survival.

The effect of hyperbaric oxygen on symptoms after mild traumatic brain injury.

In this single-center, double-blind, randomized, sham-controlled, prospective trial at the U.S. Air Force School of Aerospace Medicine, the effects of 2.4 atmospheres absolute (ATA) hyperbaric oxygen (HBO2) on post-concussion symptoms in 50 military service members with at least one combat-related, mild traumatic brain injury were examined. Each subject received 30 sessions of either a sham compression (room air at 1.3 ATA) or HBO2 treatments at 2.4 ATA over an 8-week period. Individual and total symptoms scores on Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT®) and composite scores on Post-traumatic Disorder Check List-Military Version (PCL-M) were measured just prior to intervention and 6 weeks after completion of intervention. Difference testing of post-intervention means between the sham-control and HBO2 group revealed no significant differences on the PCL-M composite score (t=-0.205, p=0.84) or on the ImPACT total score (t=-0.943, p=0.35), demonstrating no significant effect for HBO2 at 2.4 ATA. PCL-M composite scores and ImPACT total scores for sham-control and HBO(2) groups revealed significant improvement over the course of the study for both the sham-control group (t=3.76, p=0.001) and the HBO2 group (t=3.90, p=0.001), demonstrating no significant HBO2 effect. Paired t-test results revealed 10 ImPACT scale scores in the sham-control group improved from pre- to post-testing, whereas two scale scores significantly improved in the HBO2 group. One PCL-M measure improved from pre- to post-testing in both groups. This study showed that HBO2 at 2.4 ATA pressure had no effect on post-concussive symptoms after mild TBI.

Cardioinhibitory syncope due to bloodphobia associated asystole.

Neurocardiogenic syncope is not an uncommon occurrence in the general population and affects people across a wide range of age groups. Several sub-specialties are involved in the management of this phenomenon and quite often a multidisciplinary approach is needed for arriving at the final diagnosis and deciding on the optimal treatment for this condition. Often, a thorough history and physical examination will aid in narrowing the differential of syncope and, in the right setting, both passive and provocative testing can be complementary. Neurocardiogenic syncope with a malignant course is a serious entity and usually needs prompt identification of its underlying etiology. It has been generally attributed to a severe cardioinhibitory or vasodepressor mechanism and most cases required tailored therapy. We describe a case which has many of the elements described above - a multidisciplinary approach, malignant neurocardiogenic syncope with profound asystole from a cardioinhibitory response, simplistic bed-side provocative testing, and tailored therapy.

Intra- and intersubtype alternative Pak2-activating structural motifs of human immunodeficiency virus type 1 Nef.

The design of antiviral strategies against human immunodeficiency virus type 1 (HIV-1) has been largely derived from studies of subtype B viruses, although they constitute only 12% of infections worldwide. At 50% of all HIV-1 infections worldwide, subtype C viruses are the most predominant. Here, we present evidence that subtype C Nefs display functional Pak2-activating motifs that differ from those found in subtype B and E Nefs. The identification of multiple Pak2-activating structural motifs that singly affect one Nef activity revealed a functional plasticity that has implications for future drug and vaccine design aimed at HIV-1 Nef and its effects on the deregulation of the immune system.

Reconstitution and molecular analysis of an active human immunodeficiency virus type 1 Nef/p21-activated kinase 2 complex.

Human immunodeficiency virus type 1 (HIV-1) Nef activation of p21-activated kinase 2 (PAK-2) was recapitulated in a cell-free system consisting of in vitro-transcribed RNA, rabbit reticulocyte lysate, and microsomal membranes on the basis of the following observations: (i) Nef associated with a kinase endogenous to the rabbit reticulocyte lysate that was identified as PAK-2, (ii) Nef-associated kinase activity was detected with Nefs from HIV-1(SF2), HIV-1(YU2), and SIV(mac239), (iii) kinase activation was not detected with a myristoylation-defective Nef (HIV-1(SF2)NefG2A) or with a Nef defective in PAK-2 activation but fully competent in other Nef functions (HIV-1(SF2)NefF195I), and (iv) Nef-associated kinase activation required activated endogenous p21 GTPases (Rac1 or Cdc42). The cell-free system was used to analyze the mechanism of Nef activation of PAK-2. First, studies suggest that the p21 GTPases may act transiently to enhance Nef activation of PAK-2 in vitro. Second, addition of wortmannin to the cell-free system demonstrated that Nef activation of PAK-2 does not require PI 3-kinase activity. Third, ultracentrifugation analysis revealed that whereas the majority of Nef and PAK-2 partitioned to the supernatant, Nef-associated PAK-2 activity partitioned to the membrane-containing pellet as a low-abundance complex. Lastly, Nef activation of PAK-2 in vitro requires addition of microsomal membranes either during or after translation of the Nef RNA. These results are consistent with a model in which activation of PAK-2 by Nef occurs by recruiting PAK-2 to membranes. As demonstrated herein, the cell-free system is a new and important tool in the investigation of the mechanism of PAK-2 activation by Nef.