Vemurafenib partially ameliorates muscle histopathology but does not improve muscle function in a mouse model of LAMA2-CMD

Laminin-α2-related Congenital Muscular Dystrophy (LAMA2-CMD) is a neuromuscular disease affecting around 1-9/1,000,000 children. LAMA2-CMD is caused by mutations in the LAMA2 gene resulting in the loss of laminin-211/221 heterotrimers in skeletal muscle. LAMA2-CMD patients exhibit severe hypotonia and progressive muscle weakness. Currently, there is no effective treatment for LAMA2-CMD and patients die prematurely. The loss of laminin-α2 results in muscle degeneration, defective muscle repair, and dysregulation of multiple signaling pathways. Signaling pathways that regulate muscle metabolism, survival, and fibrosis have been shown to be dysregulated in LAMA2-CMD. Since vemurafenib is an FDA-approved serine/threonine kinase inhibitor, we investigated whether vemurafenib could restore some of the serine/threonine kinase-related signaling pathways and prevent disease progression in the dyW-/- mouse model of LAMA2-CMD. Our results show vemurafenib reduced muscle fibrosis, increased myofiber size, and reduced the percentage of fibers with centrally located nuclei in dyW-/- mice hindlimbs. These studies show treatment with vemurafenib restored the TGF-β/SMAD3 and mTORC1/p70S6K signaling pathways in skeletal muscle. Together our results indicate vemurafenib partially improves histopathology but does not improve muscle function in a mouse model of LAMA2-CMD.

Illuminating subduction zone rheological properties in the wake of a giant earthquake

Deformation associated with plate convergence at subduction zones is accommodated by a complex system involving fault slip and viscoelastic flow. These processes have proven difficult to disentangle. The 2010 M _w 8.8 Maule earthquake occurred close to the Chilean coast within a dense network of continuously recording Global Positioning System stations, which provide a comprehensive history of surface strain. We use these data to assemble a detailed picture of a structurally controlled megathrust fault frictional patchwork and the three-dimensional rheological and time-dependent viscosity structure of the lower crust and upper mantle, all of which control the relative importance of afterslip and viscoelastic relaxation during postseismic deformation. These results enhance our understanding of subduction dynamics including the interplay of localized and distributed deformation during the subduction zone earthquake cycle.

Observed rapid bedrock uplift in Amundsen Sea Embayment promotes ice-sheet stability

The marine portion of the West Antarctic Ice Sheet (WAIS) in the Amundsen Sea Embayment (ASE) accounts for one-fourth of the cryospheric contribution to global sea-level rise and is vulnerable to catastrophic collapse. The bedrock response to ice mass loss, glacial isostatic adjustment (GIA), was thought to occur on a time scale of 10,000 years. We used new GPS measurements, which show a rapid (41 millimeters per year) uplift of the ASE, to estimate the viscosity of the mantle underneath. We found a much lower viscosity (4 × 10¹⁸ pascal-second) than global average, and this shortens the GIA response time scale from tens to hundreds of years. Our finding requires an upward revision of ice mass loss from gravity data of 10% and increases the potential stability of the WAIS against catastrophic collapse.

Does It Cost More to Train Residents or to Replace Them?: A Look at the Costs and Benefits of Operating Graduate Medical Education Programs

The policy issue underlying this study is whether Medicare support for graduate medical education (GME) should be restructured to differentiate between programs that are less costly or are self-sustaining and those that are more costly to the sponsoring institution and its educational partners. The authors used available literature, interviews with individuals involved in operating GME programs, and analysis of administrative data to explore how the financial impact of operating residency training programs might differ by specialty. The study does not quantify the variation in financial impact, but it provides a framework for examining both the costs and benefits of operating GME programs to the sponsoring institution and its educational partners. It also identifies the major factors that are likely to affect financial performance and influence program offerings and size. Marginal financial impacts are more likely to influence sponsor decisions on changes in GME program size and offerings and help explain why GME program expansions are occurring without additional Medicare funding. If the hospital has service needs, there is a marginal benefit to adding a resident, particularly in the more-lucrative specialty and subspecialty programs, before considering the additional benefits of any Medicare GME-related revenues.

Space geodetic evidence for rapid strain rates in the New Madrid seismic zone of central USA

In the winter of 1811-1812, near the town of New Madrid in the central United States and more than 2,000 km from the nearest plate boundary, three earthquakes within three months shook the entire eastern half of the country and liquefied the ground over distances far greater than any historic earthquake in North America. The origin and modern significance of these earthquakes, however, is highly contentious. Geological evidence demonstrates that liquefaction due to strong ground shaking, similar in scale to that generated by the New Madrid earthquakes, has occurred at least three and possibly four times in the past 2,000 years (refs 4-6), consistent with recurrence statistics derived from regional seismicity. Here we show direct evidence for rapid strain rates in the area determined from a continuously operated global positioning system (GPS) network. Rates of strain are of the order of 10(-7) per year, comparable in magnitude to those across active plate boundaries, and are consistent with known active faults within the region. These results have significant implications for the definition of seismic hazard and for processes that drive intraplate seismicity.

Postsurgical adjuvant chemotherapy with or without radiotherapy in women with breast cancer and positive axillary nodes: a South-Eastern Cancer Study Group (SEG) Trial

In a prospective study of 622 women with breast cancer, those with one to three histologically positive axillary lymph nodes were randomised after mastectomy to receive cyclophosphamide 100 mg/m2 orally on days 1-14, methotrexate 40 mg/m2 intravenously on days 1 and 8, and fluorouracil 600 mg/m2 intravenously on days 1 and 8 every 28 days for six cycles (CMF x six), or for twelve cycles of the same chemotherapy (CMF x 12). Those with > or = four positive nodes were randomised to one of these two groups or to 5000 cGy of postmastectomy regional radiotherapy (RT) followed by six cycles of the same chemotherapy (RT + CMF x six). With about 10 years median follow-up, there was no significant difference in survival or disease-free survival among the three groups. There was evidence of decreased locoregional recurrence in patients with > or = four nodes who received RT + CMF x six (relative risk 0.53, P = 0.067). Multivariate analysis indicated that the presence of > or = four positive nodes (negatively) and the percentage of ideal (full) dose of CMF received (positively) were the strongest factors predictive of survival. This study shows no advantage for 12 over six cycles of CMF chemotherapy in women with breast cancer and positive axillary nodes. There was a suggestion of decreased locoregional recurrence but no improvement in survival with radiotherapy for women with > or = four positive nodes.

Selective interferon-induced enhancement of tumor-associated antigens on a spectrum of freshly isolated human adenocarcinoma cells

Freshly isolated cells from patients with pleural or peritoneal effusions cytologically diagnosed as adenocarcinoma (n = 43), malignant nonepithelial neoplasms (n = 10), and benign (n = 8) were analyzed for expression of constitutive levels of the tumor antigens TAG-72 [recognized by monoclonal antibody (MAb) B72.3] and carcinoembryonic antigen (CEA) (recognized by MAb COL-4) as well as the class I and class II major histocompatibility (MHC) antigens, and the ability of human interferons (Hu-IFNs) to enhance cell surface expression of those antigens as measured by MAb binding. Both type I and type II IFNs enhanced the expression of TAG-72 and CEA and altered the level of expression of the MHC antigens. Comparative studies of three different Hu-IFNs (IFN-alpha A, IFN-beta ser, and IFN-gamma) revealed that IFN-gamma was the most potent in augmenting either B72.3 or COL-4 binding. Unlike the IFN-gamma -mediated induction of the class II human leukocyte antigens, the change in tumor antigen expression consisted of enhanced constitutive antigen expression; de novo induction of either TAG-72 or CEA could not be achieved by either type I or type II IFN. Of 43 effusions isolated from different adenocarcinoma patients, 42 (97.7%) expressed either CEA or TAG-72, and treatment with Hu-IFN increased the level of expression of either antigen in 36 of 42 samples (85.7%). These studies demonstrate the augmentation of tumor-associated antigens on human carcinoma cells isolated from serous effusions by Hu-IFNs which may be used to enhance the targeting of conjugated MAbs to human carcinoma lesions.

Treatment of inoperable non-small cell carcinoma of the lung with radiation therapy, with or without levamisole. A randomized trial of the Southeastern Cancer Study group

In a randomized trial, 251 patients with inoperable non-small cell lung cancer received radiation therapy (RT) with or without levamisole (2.5 mg/kg twice weekly for 1 year, or until progression). Radiation therapy was delivered to 6000-6500 rad for Stages I and II, and 4000-4500 rad by continuous or split course for Stage III disease. Responses were observed in 40% of patients receiving placebo, and in 29% of patients taking levamisole. Relapse occurred at local sites only in 53% of the placebo- and 75% of the levamisole-treated patients. The frequency of relapse in distant sites was lower (25%) in the levamisole group as compared with the placebo group (47%). No significant difference in survival was observed between the placebo and levamisole-treated groups (median survival, 48.2 and 45 weeks, respectively). Responders to radiotherapy survived significantly longer than nonresponders (median survival, 73 vs. 33.3 weeks, p = 0.001). Among responders, the median survival of patients treated with levamisole was shorter (63.9 weeks) than that of patients receiving placebo (92.7 weeks). Toxicity attributable to levamisole included severe granulocytopenia in five patients and severe nausea and vomiting in nine. It is concluded that levamisole is without significant benefit in this setting.

Postmastectomy adjuvant chemotherapy with or without radiation therapy in women with operable breast cancer and positive axillary lymph nodes: the Southeastern Cancer Study Group experience

Between September 1976 and June 1982, 308 patients with operable breast cancer with 1-3 involved axillary nodes were stratified according to institution, type of mastectomy, and time from surgery to protocol entry, and then randomized to receive either six or 12 months of adjuvant chemotherapy with cyclophosphamide, methotrexate, and 5-fluorouracil (CMF). With a median time of follow-up of 33 months, relapse rates among 181 reviewed and evaluable patients are 20/85 (23.5%) for pre- and 23/96 (24%) for postmenopausal patients. Results for premenopausal women, while better than historical controls at a similar time interval, appear inferior to other published adjuvant studies (e.g., NSABP and Milan). Although total relapse rates were 23/100 (23%) for six months and 20/81 (25%) for 12 months of therapy, suggestive differences were encountered by menopausal status with early trends favoring 12 months of treatment for premenopausal patients and six months of treatment for postmenopausal patients. During this same period, 283 patients with four or more involved axillary nodes were randomized to 1-3 treatment arms: six months of CMF, six months of CMF preceded by local-regional x-ray therapy (XRT), or 12 months of CMF. The latter arm was closed in February 1980 while the two six-month chemotherapy arms remain open as of January 1983. Relapse rates for 174 reviewed and evaluable patients on the three arms include: 27/76 (36%) for six months CMF, 15/54 (28%) for XRT and CMF, and 24/44 (45%) for 12 months CMF. Local-regional relapse rates were 12/120 (10%) for the combined two non-XRT arms and 3/54 (6%) for the XRT treatment arm (p = 0.34). Thus, at this early stage of follow-up there are still no statistically significant differences between six or 12 months of adjuvant CMF therapy and neither definite beneficial nor detrimental effects of prechemotherapy adjuvant radiation therapy. Longer follow-up will be needed to provide definitive conclusions.

An evaluation of hexamethylmelamine, cis-diamminedichloroplatinum, and mitomycin-C in advanced breast cancer. A pilot study of the Southeastern Cancer Study Group

Eleven patients with metastatic breast cancer refractory to conventional therapy were treated with a combination of hexamethylmelamine 250 mg/m2 p.o. days 1-14, repeated at 4-week intervals; cis-platinum 30 mg/m2 I.V. q 28 days; and mitomycin-C 7.5-10 mg/m2 I.V. q 56 days. There were no complete responders and three partial responders for a response rate of 27%. Two patients (18%) had stabilization of disease for brief periods. The gastrointestinal toxicity of hexamethylmelamine was unacceptable. Recent reports that cis-platinum and hexamethylmelamine lack activity in breast cancer suggest that the activity of the combination was due to mitomycin-C alone.