Citations

Abstract Interactions between the malignant plasma cells of multiple myeloma and stromal cells within the bone marrow microenvironment are essential for myeloma cell survival, mirroring the same dependence of normal bone marrow-resident long-lived plasma cells on specific marrow niches. These interactions directly transduce prosurvival signals to the myeloma cells and also induce niche production of supportive soluble factors. However, despite their central importance, the specific molecular and cellular components involved remain poorly characterized. We now report that the prototypic T cell costimulatory receptor CD28 is overexpressed on myeloma cells during disease progression and in the poor-prognosis subgroups and plays a previously unrecognized role as a two-way molecular bridge to support myeloid stromal cells in the microenvironment. Engagement by CD28 to its ligand CD80/CD86 on stromal dendritic cell directly transduces a prosurvival signal to myeloma cell, protecting it against chemotherapy and growth factor withdrawal-induced death. Simultaneously, CD28-mediated ligation of CD80/CD86 induces the stromal dendritic cell to produce the prosurvival cytokine IL-6 (involving novel cross-talk with the Notch pathway) and the immunosuppressive enzyme IDO. These findings identify CD28 and CD80/CD86 as important molecular components of the interaction between myeloma cells and the bone marrow microenvironment, point to similar interaction for normal plasma cells, and suggest novel therapeutic strategies to target malignant and pathogenic (e.g., in allergy and autoimmunity) plasma cells.

Abstract Immune responses against cancer rely upon leukocyte trafficking patterns that are coordinated by chemokines. CCR5, the receptor for chemotactic chemokines MIP1alpha, MIP1beta, and RANTES (CCL3, CCL4, CCL5), exerts major regulatory effects on CD4+- and CD8+ T cell-mediated immunity. Although CCR5 and its ligands participate in the response to various pathogens, its relevance to tumoral immune control has been debated. Here, we report that CCR5 has a specific, ligand-dependent role in optimizing antitumor responses. In adoptive transfer studies, efficient tumor rejection required CCR5 expression by both CD4+ and CD8+ T cells. CCR5 activation in CD4+ cells resulted in CD40L upregulation, leading to full maturation of antigen-presenting cells and enhanced CD8+ T-cell crosspriming and tumor infiltration. CCR5 reduced chemical-induced fibrosarcoma incidence and growth, but did not affect the onset or progression of spontaneous breast cancers in tolerogenic Tg(MMTV-neu) mice. However, CCR5 was required for TLR9-mediated reactivation of antineu responses in these mice. Our results indicate that CCR5 boosts T-cell responses to tumors by modulating helper-dependent CD8+ T-cell activation. Cancer Res; 71(16); 5455–66. ©2011 AACR.

Barbed sutures and connecting devices have been historically described and used in flexor tendon tenorrhaphies. With the improvement in biomaterial, we have witnessed recently the resurgence of this concept. In this article, we review the historical use of barbed devices in repairing flexor tendons and explore the available barbed surgical devices that have been described in recent years.

AbstractBackgroundBloating, flatulence, early satiety, and dysphagia resolve in more than 90% of patients early after fundoplication. Gastric dysfunction can persist, however, and a small number of patients develop severe gastric dysfunction (gastroparesis). Management of gastroparesis after antireflux procedures is generally conservative, but gastroparesis can become refractory to medical therapy. The aim of this study was to assess the role of gastric resection in the management of the unusual patient with severe postfundoplication gastric dysfunction.MethodsFrom January 1990 to October 2010, a total of 5,129 gastric resections were performed at our institution. From this cohort, we identified nine patients with postfundoplication gastric dysfunction managed with gastric resection. Clinical records were reviewed retrospectively for preoperative evaluation, perioperative course, and long‐term outcomes.ResultsOver 20 years, nine patients were treated with gastric resection for debilitating gastric dysfunction after antireflux surgery. Seven of the nine patients were female; the median preoperative body mass index was 25 kg/m2 (18–31 kg/m2). Median follow‐up was 23 months (1–97 months). Preoperatively, five patients required enteral feeding. Postoperatively, although there were no deaths, one patient required operative drainage of a subphrenic abscess, one developed temporary respiratory failure, and one was readmitted for partial small bowel obstruction. Six of the nine patients maintain their nutrition orally, but three are maintained with enteral nutrition. Only two patients are subjectively asymptomatic.ConclusionsOutcomes after gastric resection for postfundoplication gastric dysfunction are poor, with three of the nine patients requiring supplemental nutrition and seven of the nine having persistent symptoms.

AbstractPurpose: Conventional therapies to treat prostate cancer (CaP) of androgen-dependent phenotype (ADPC) and castration-resistant phenotype (CRPC) are deficient in outcome which has necessitated a need to identify those agents that could target AR for both disease types. We provide mechanism-based evidence that lupeol (Lup-20(29)-en-3b-ol) is a potent inhibitor of androgen receptor (AR) in vitro and in vivo.Experimental Design: Normal prostate epithelial cell (RWPE-1), LAPC4 (wild functional AR/ADPC), LNCaP (mutant functional/AR/ADPC), and C4-2b (mutant functional/AR/CRPC) cells were used to test the anti-AR activity of lupeol. Cells grown under androgen-rich environment and treated with lupeol were tested for proliferation, AR transcriptional activity, AR competitive ligand binding, AR–DNA binding, and AR–ARE/target gene binding. Furthermore, in silico molecular modeling for lupeol–AR binding was done. Athymic mice bearing C4-2b and LNCaP cell–originated tumors were treated intraperitoneally with lupeol (40 mg/kg; 3 times/wk) and tumor growth and surrogate biomarkers were evaluated. To assess bioavailability, lupeol serum levels were measured.Results: Lupeol significantly inhibited R1881 (androgen analogue) induced (i) transcriptional activity of AR and (ii) expression of PSA. Lupeol (i) competed antagonistically with androgen for AR, (ii) blocked the binding of AR to AR-responsive genes including PSA, TIPARP, SGK, and IL-6, and (iii) inhibited the recruitment of RNA Pol II to target genes. Lupeol sensitized CRPC cells to antihormone therapy. High-performance liquid chromatography analysis showed that lupeol is bioavailable to mice. Lupeol inhibited the tumorigenicity of both ADPC and CRPC cells in animals. Serum and tumor tissues exhibited reduced PSA levels.Conclusion: Lupeol, an effective AR inhibitor, could be developed as a potential agent to treat human CaP. Clin Cancer Res; 17(16); 5379–91. ©2011 AACR.

With improved treatments and increasingly life expectancy, the burden of metastatic disease in the spine is expected to rise. The role of conventional surgery for spinal metastases is well established but often involves procedures of large magnitude. We describe minimally invasive techniques for spinal stabilization and decompression in patients with symptomatic metastatic disease of the spine.

Background— Data on the association between myocardial infarction (MI) and fractures are scarce. Recent changes in the epidemiology of MI justify exploring this relationship. We evaluated whether MI constitutes a risk factor for osteoporotic fracture and examined secular trends in this association. Methods and Results— Consecutive Olmsted County, Minnesota, residents with incident MI diagnosed in 1979 to 2006 and community control subjects individually matched (1:1) to cases on age, sex, and year of onset (n=6642) were followed up through 2009. Outcome measures were time to osteoporotic fracture, overall and by anatomic site, and death. Fracture incidence rates were stable in controls but increased markedly over time among MI cases. Accordingly, although an overall excess of fracture risk after MI was observed (adjusted hazard ratio, 1.32; 95% confidence interval, 1.12 to 1.56), substantial temporal variations were noted (1979 to 1989: hazard ratio, 0.81; 95% confidence interval, 0.58 to 1.12; 1990 to 1999: hazard ratio, 1.47; 95% confidence interval, 1.10 to 1.96; 2000 to 2006: hazard ratio, 1.73; 95% confidence interval, 1.32 to 2.27; P for trend <0.001). Trends were similar regardless of age, sex or fracture site. Conversely, the overall hazard ratio for death in MI cases versus controls did not change materially despite a continuous decline in 30-day case fatality rate (12.5% in 1979 to 1989; 6.7% in 2000 to 2006). Observed changes in the baseline prevalence of cardiovascular risk factors, MI characteristics, and comorbidities did not fully account for the trends in fracture risk. Conclusions— Over the past decades, the association between MI and osteoporotic fractures increased steadily. The trend is consistent with the displacement of post-MI outcomes toward noncardiovascular events, highlighting the need for comprehensive prevention strategies to accommodate the changing epidemiology of MI.

The mechanisms underlying the regenerative capacity of endothelial progenitor cells (EPCs) are not fully understood. We hypothesized that biosynthesis of tetrahydrobiopterin is an important mechanism responsible for the stimulatory effects of peroxisome proliferator-activated receptor–δ (PPARδ) activation on regenerative function of human EPCs. Treatment of human EPCs with a selective PPARδ agonist GW501516 for 24 hours increased the levels of mRNA, protein, and enzymatic activity of GTP cyclohydrolase I (GTPCH I), as well as the production of tetrahydrobiopterin. The effects of GW501516 were mediated by suppression of PTEN expression, thereby increasing phosphorylation of AKT. The AKT signaling also mediated GW501516-induced phosphorylation of endothelial NO synthase. In addition, activation of PPARδ significantly enhanced proliferation of EPCs. This effect was abolished by the GTPCH I inhibitor, 2,4-diamino-6-hydroxypyrimidine, or genetic inactivation of GTPCH I with small interfering RNA but not by inhibition of endothelial NO synthase with N G -nitro- l -arginine methyl ester. Supplementation of NO did not reverse 2,4-diamino-6-hydroxypyrimidine-inhibited 5-bromodeoxyuridine incorporation. Furthermore, transplantation of human EPCs stimulated re-endothelialization in a mouse model of carotid artery injury. Pretreatment of EPCs with GW501516 significantly enhanced the ability of transplanted EPCs to repair denuded endothelium. GTPCH I-small interfering RNA transfection significantly inhibited in vivo regenerative capacity of EPCs stimulated with GW501516. Thus, in human EPCs, activation of PPARδ stimulates expression and activity of GTPCH I and biosynthesis of tetrahydrobiopterin via PTEN-AKT signaling pathway. This effect enhances the regenerative function of EPCs.