MHV68 complement regulatory protein facilitates MHV68 replication in primary macrophages in a complement independent manner

Murine gammaherpesvirus-68 (MHV68) is genetically related to human Epstein-Barr virus and Kaposi's sarcoma-associated herpesvirus and provides a tractable model to study gammaherpesvirus-host interactions in vivo and in vitro. The MHV68-encoded v-RCA product inhibits murine complement activation and shares sequence homology with other virus and host regulators of complement activation. Here we show that v-RCA is required for efficient MHV68 replication in primary murine macrophages, but not in murine embryonic fibroblasts. v-RCA-deficient MHV68 mutant viruses display defects in viral DNA synthesis in infected macrophages. Importantly, attenuated growth of v-RCA mutant viruses is not rescued in macrophages lacking critical components of the complement system including C3, indicating that the macrophage-specific role of v-RCA in MHV68 replication is complement-independent. This contrasts with the situation in vivo in which attenuated neurovirulence of v-RCA mutant viruses is rescued in C3-deficient mice. This study shows a novel, complement independent cell-type-specific function of a gammaherpesvirus RCA protein.     

Risk Assessment of Toxaphene and its Breakdown Products: Time for a Change?

Technical toxaphene (TT) was last used in commerce in about 1982. Any environmental exposure to toxaphene in this century is to environmentally degraded forms of toxaphene, termed weathered toxaphene. Several hundred chlorinated bornane congeners have been identified in technical toxaphene. The degradation of technical toxaphene to weathered toxaphene can result in various congener mixtures, but the primary mode of degradation is dechlorination. The U.S. Environmental Protection Agency (EPA) presently estimates the risk of exposure to toxaphene by relying upon rat and mouse toxicology studies performed on technical toxaphene. No adjustment is made for the dechlorination of toxaphene in the environment. The European Union (EU), however, has modeled toxaphene risks from eating fish with chlorinated bornane residues through a series of studies on toxaphene degraded by either ultraviolet light, or biodegradation in fish. The EU risk assessment relies upon rat liver studies in vivo and mouse in vitro studies on the inhibition of gap junction intercellular communication (GJIC). This article reviews the current state of knowledge of technical and weathered toxaphene toxicology. We discuss the various current methods and opportunities to advance the risk assessment of weathered toxaphene beyond the existing U.S. EPA assessment of technical toxaphene.     

Public Policy and Headache: Observations of Health Care Policy in the US Congress From a Legislative Fellow's Perspective

Many neurologists and headache specialists are befuddled by inside the Beltway wheelings and dealings as they follow health care politics. A few of us join lobbying efforts, and even fewer become strangers in a strange land.     

A direct comparison of rejection by CD8 and CD4 T cells in a transgenic model of allotransplantation

INTRODUCTION: The relative contributions of CD4+ and CD8+ T cells to transplant rejection remain unknown. The authors integrated a previous model of CD4-mediated graft rejection with a complementary model of CD8-mediated rejection to directly compare the function of graft-reactive CD4+ and CD8+ lymphocytes in vivo in a model where rejection requires transgenic T cells. These studies allow direct comparison of CD4 and CD8 T cell responses to the same antigen without the confounding effects of T cell depletion or homeostatic proliferation. MATERIALS AND METHODS: Clone 4 and TS1 mice possess MHC class I- and II-restricted CD8+ and CD4+ T cells, respectively, which express transgenic T cell receptors that recognize the influenza hemagglutinin antigen (HA). We compared the in vivo response of CFSE-labeled, HA-specific transgenic CD8+ and CD4+ T cells after adoptive transfer into syngeneic BALB/c mice grafted with HA-expressing skin. RESULTS: As in the authors' CD4+ model, HA104 skin was consistently rejected by both Clone 4 mice (n=9, MST: 14.2) and by 5 x 10(5) Clone 4 lymphocytes transferred to naive BALB/c hosts that do not otherwise reject HA+ grafts. Rejection correlated with extensive proliferation of either graft-reactive T cell subset in the draining lymph nodes, and antigen-specific CD4+ and CD8+ cells acquired effector function and proliferated with similar kinetics. CONCLUSIONS: These data extend the authors' unique transgenic transplantation model to the investigation of CD8 T cell function. The initial results confirm fundamental functional similarity between the CD4 and CD8 T cell subsets and provide insight into the considerable redundancy underlying T cell mechanisms mediating allograft rejection.     

C‐terminal agrin fragment is inversely related to neuromuscular fatigue in older men

Introduction: The aim of this study was to examine the relationship between serum C‐terminal agrin fragment (CAF) concentrations and neuromuscular fatigue in older adults. Methods: Twenty‐two healthy older men and women volunteered for this study. Resting fasted blood samples were collected and prepared for measurement of serum CAF concentration by a commercially available ELISA kit. The onset of neuromuscular fatigue was measured by monitoring electromyographic fatigue curves from the vastus lateralis muscle using the physical working capacity at fatigue threshold (PWC_FT) test. Results: A significant inverse correlation for men was observed between CAF and PWC_FT (r = ?0.602; P = 0.05), but not for women (r = 0.208; P = 0.54). After controlling for age and body mass index, significant correlations (r = ?0.69; P = 0.042) remained for men, but not for women (r = 0.12; P = 0.76). Conclusions: These data suggest that serum CAF concentrations were significantly related to the onset of neuromuscular fatigue independent of age and BMI in men only. Muscle Nerve 51 : 132–133, 2015     

Phase II evaluation of dibromodulcitol and actinomycin D,hydroxyurea, and cyclophosphamide in previously untreated patients with malignant melanoma

In this Eastern Cooperative Oncology Group (ECOG) phase II study, dibromodulcitol (DBD) and a combination of actinomycin D, hydroxyurea, and cyclophosphamide (AHC) were compared with methyl-CCNU, the current ECOG standard, in patients who had received no prior chemotherapy for disseminated malignant melanoma. The response rates were 6% (3/50) for AHC, 9% (3/34) for DBD, and 14% (7/49) for methyl-CCNU. Median survival times were 4, 5, and 6 months, respectively. Neither regimen appears to offer any advantage over methyl-CCNU as front-line therapy for patients with disseminated melanoma.