Creatine supplements in patients with idiopathic inflammatory myopathies who are clinically weak after conventional pharmacologic treatment: Six-month, double-blind, randomized, placebo-controlled trial

OBJECTIVE: To test the hypothesis that oral creatine supplements with exercise are more effective than exercise alone in improving muscle function in patients with established dermatomyositis or polymyositis receiving chronic medical therapies who are clinically weak yet stable. METHODS: In a 6-month, 2-center, double-blind, randomized controlled trial, patients were randomized to receive oral creatine supplements (8 days, 20 gm/day then 3 gm/day) or placebo. All patients followed a home exercise program. The primary outcome was aggregate functional performance time (AFPT), reflecting the ability to undertake high-intensity exercise. Secondary outcomes included a functional index measuring endurance and muscle bioenergetics on (31)P magnetic resonance spectroscopy ((31)P MRS). Patients were receiving stable immunosuppressive treatment and/or corticosteroids. RESULTS: A total of 37 patients with polymyositis or dermatomyositis were randomized (19 to creatine, 18 to placebo); 29 completed 6 months. Intent-to-treat analyses demonstrated that AFPT improved significantly at 6 months with creatine (median decrease 13%, range -32-8%) compared with placebo (median decrease 3%, range -13-16%; P = 0.029 by Mann-Whitney U test). A completer analysis also showed significant benefits from creatine (P = 0.014). The functional index improved significantly with both creatine and placebo (P < 0.05 by paired Wilcoxon's rank sum test), with a significant benefit between groups in the completer analysis only. Phosphocreatine/beta-nucleoside triphosphate ratios using MRS increased significantly in the creatine group (P < 0.05) but not in the control group. No clinically relevant adverse events were associated with creatine. CONCLUSION: Oral creatine supplements combined with home exercises improve functional performance without significant adverse effects in patients with polymyositis or dermatomyositis. They appear safe, effective, and inexpensive.     

ErbB3 expression and dimerization with EGFR influence pancreatic cancer cell sensitivity to erlotinib

Abnormal expression and signaling of ErbB receptors has been implicated in multiple epithelial malignancies, including pancreatic cancer. Erlotinib, an epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI), has been recently approved for pancreatic cancer treatment, but there are no reliable predictors of patient response. Expression of additional ErbB receptors seems to influence tumor response to EGFR-targeted therapy. We analyzed the influence of ErbB3 expression on pancreatic cancer cell response to erlotinib treatment. Proliferation assays of five human pancreatic cancer cell lines were performed following treatment with erlotinib. Expression and phosphorylation profiles of ErbB receptors and downstream adaptor protein (Akt, ERK1/2, STAT3, mTOR) were evaluated following stimulation with EGF or neuregulin-beta. The formation of EGFR homodimers and EGFR-ErbB3 heterodimers, necessary to enable ErbB3 downstream signaling, was demonstrated by chemical cross-linking assays. The effects of RNA inhibition of ErbB3 on sensitivity to erlotinib treatment were evaluated in AsPC-1 pancreatic cancer cells. Erlotinib inhibited Akt phosphorylation and proliferation of all the ErbB3-expressing cell lines but did not affect mTOR activation. Cross-linking studies confirmed the presence of EGFR-ErbB3 heterodimers in pancreatic cancer cells. Only the ErbB3-deficient MIA PaCa-2 cells displayed persistent Akt activation and ongoing proliferation in spite of erlotinib treatment. siRNA-mediated inhibition of ErbB3 expression in AsPC-1 cells resulted in acquired resistance to erlotinib treatment. Pancreatic cancer cells which lack ErbB3 do not display activation of the ErbB3-PI3K-Akt cascade induced by EGFR/ErbB3 heterodimers and become less critically dependent on EGFR signaling and therefore resistant to erlotinib. Pancreatic cancer expression of ErbB3 may be useful for EGFR-targeted therapy patient selection.     

Disparities in Surgery: Access to Outcomes

Surgery is an important intervention to sustain human life through its ability to cure disease, heal fractures, avert maternal death, and provide comfort for those suffering. However, surgical care is unevenly delivered throughout the world. More surprisingly, we have little knowledge about the adequacy and quality of surgical resources globally. The Brigham and Women’s Hospital Center for Surgery and Public Health, a joint program of Harvard Medical School and the Harvard School of Public Health, seeks to remedy the knowledge deficit, to provide direction for stakeholders, and direct improvement in public health related to surgical care. To the end of raising awareness of the issue of disparities in surgical care in the United States and the world, an invitational conference on Disparities in Surgical Care: Access to Outcomes was conceived. The Symposium brought together experts from around the world to critically examine this challenging problem. Surgeons, other clinicians, administrators, and health services researchers came together to develop approaches to translate research into practice to address disparities in access and outcomes in surgical care. The synergy of population-based research and clinical practice may allow the surgical healthcare team of the near future to implement strategies to achieve health equity, an important dimension of quality, in surgery.     

Muckle–Wells Cryopyrinopathy: Complex Phenotyping and Response to Therapy in a New Multiplex Kindred

Muckle–Wells syndrome (MWS) is a member of the cryopyrin-associated periodic syndrome family of auto-inflammatory diseases, originally described as a triad of urticaria, sensorineural deafness and amyloidosis. IL-1 blockade is a proven therapy for MWS. The clinical, laboratory and genotypic characteristics of a novel kindred of five individuals with Muckle–Wells syndrome are described. Response to IL-1 blockade therapy in the proband was evaluated. All five affected family members experienced symptoms of multi-organ inflammation. Lead time between symptom onset and diagnosis was approximately 30 years in the proband. Fever was not a universal feature in all affected family members. Anti-IL-1 therapy in the proband resulted in improvements in patient-reported symptoms, inflammatory markers, auditory acuity and reversal of her infertility. Muckle–Wells syndrome is a rare, multisystem, auto-inflammatory syndrome. Delay in diagnosis prevents effective treatment. We propose reversal of infertility to be among the potential benefits of IL-1 inhibition in this disease.     

Photoaffinity Labeling of Nicotinic Receptors: Diversity of Drug Binding Sites!

For almost 30 years, photoaffinity labeling and protein microsequencing techniques have been providing novel insights about the structure of nicotinic acetylcholine receptors (nAChR) and the diversity of nAChR drug binding sites. Photoaffinity labeling allows direct identification of amino acid residues contributing to a drug binding site without prior knowledge of the location of the binding site within the nAChR or the orientation of the ligand within the binding site. It also distinguishes amino acids that contribute to allosteric binding sites from those involved in allosteric modulation of gating. While photoaffinity labeling was used initially to identify amino acids contributing to the agonist binding sites and the ion channel, it has been used recently to identify binding sites for allosteric modulators at subunit interfaces in the extracellular and the transmembrane domains, and within a subunit's transmembrane helix bundle. In this article, we review the different types of photoaffinity probes that have been used and the various binding sites that have been identified within the structure of nAChR, with emphasis on our recent studies of allosteric modulator binding sites.