Citations

While much work has previously been done in the modeling of skeletal muscle, no model has, to date, been developed that describes the mechanical behavior with an explicit strain-energy function associated with the active response of skeletal muscle tissue. A model is presented herein that has been developed to accommodate this design consideration using a robust dynamical approach. The model shows excellent agreement with a previously published model of both the active and passive length-tension properties of skeletal muscle.

Abstract Epidermal growth factor receptor variant III (EGFRvIII) is a constitutively active mutant form of EGFR that is expressed in 40% to 50% of gliomas and several other malignancies. Here, we describe the therapeutic effects of silencing EGFRvIII on glioma cell lines in vitro and in vivo. A small interfering RNA molecule against EGFRvIII was introduced into EGFRvIII-expressing glioma cells (U87Δ) by electroporation resulting in complete inhibition of expression of EGFRvIII as early as 48 h post-treatment. During EGFRvIII silencing, a decrease in the proliferation and invasiveness of U87Δ cells was accompanied by an increase in apoptosis (P < 0.05). Notably, EGFRvIII silencing inhibited the signal transduction machinery downstream of EGFRvIII as evidenced by decreases in the activated levels of Ras and extracellular signal-regulated kinase. A lentivirus capable of expressing anti-EGFRvIII short hairpin RNA was also able to achieve progressive silencing of EGFRvIII in U87Δ cells in addition to inhibiting cell proliferation, invasiveness, and colony formation in a significant manner (P < 0.05). Silencing EGFRvIII in U87Δ cultures with this virus reduced the expression of factors involved in epithelial-mesenchymal transition including N-cadherin, β-catenin, Snail, Slug, and paxillin but not E-cadherin. The anti-EGFRvIII lentivirus also affected the cell cycle progression of U87Δ cells with a decrease in G1 and increase in S and G2 fractions. In an in vivo model, tumor growth was completely inhibited in severe combined immunodeficient mice (n = 10) injected s.c. with U87Δ cells treated with the anti-EGFRvIII lentivirus (P = 0.005). We conclude that gene specific silencing of EGFRvIII is a promising strategy for treating cancers that contain this mutated receptor. [Mol Cancer Ther 2008;7(11):3586–97]

Purpose In this report, we update survival (OS) and time-to-progression (TTP) data for the Intergroup trial N9741 after a median 5 years of follow-up by using risk-stratified and prognostic factor analyses to determine if treatment outcomes differ in specific patient subgroups. Patients and Methods A total of 1,691 patients were randomly assigned to one of seven fluorouracil-, oxaliplatin-, and irinotecan-containing regimens. OS and TTP were calculated by treatment arm and baseline risk group (on the basis of WBC, performance status, number of sites of disease, and alkaline phosphatase). Multivariate prognostic factor analysis was used to assess clinical factors for their relationships to OS, TTP, response, and toxicity by using Cox and logistic regression models. Results The observed 5-year survival with infusional fluorouracil, leucovorin, and oxaliplatin (FOLFOX) of 9.8% was better than with irinotecan plus bolus fluorouracil and leucovorin (IFL; 3.7%; P = .04) or with bolus irinotecan/oxaliplatin (IROX; 5.1%; P = .128). OS and TTP were significantly longer for FOLFOX (20.2 months and 8.9 months, respectively) than for IFL (14.6 months and 6.1 months, respectively; P < .001 for both) or for IROX (17.3 months and 6.7 months, respectively; P < .001 for both). OS differed by risk group: 20.7 months for low risk, 17.4 months for intermediate risk, and 9.4 months for high risk (P < .001). FOLFOX treatment was superior in all risk groups and was the most powerful prognostic factor for OS, TTP, response rate, and toxicity. Conclusion The 9.8% 5-year OS in patients with metastatic colorectal cancer who were treated with first-line FOLFOX sets a new benchmark. Neither baseline risk group nor any prognostic factor examined was predictive of treatment-specific outcome. However, treatment efficacy and patient longevity varied as a function of risk group.

Abstract Notch signaling plays a role in normal lymphocyte development and function. Activating Notch1-mutations, leading to aberrant downstream signaling, have been identified in human T-cell acute lymphoblastic leukemia (T-ALL). While this highlights the contribution of Notch signaling to T-ALL pathogenesis, the mechanisms by which Notch regulates proliferation and survival in normal and leukemic T cells are not fully understood. Our findings identify a role for Notch signaling in G1-S progression of cell cycle in T cells. Here we show that expression of the G1 proteins, cyclin D3, CDK4, and CDK6, is Notch-dependent both in vitro and in vivo, and we outline a possible mechanism for the regulated expression of cyclin D3 in activated T cells via CSL (CBF-1, mammals; suppressor of hairless, Drosophila melanogaster; Lag-1, Caenorhabditis elegans), as well as a noncanonical Notch signaling pathway. While cyclin D3 expression contributes to cell-cycle progression in Notch-dependent human T-ALL cell lines, ectopic expression of CDK4 or CDK6 together with cyclin D3 shows partial rescue from γ-secretase inhibitor (GSI)-induced G1 arrest in these cell lines. Importantly, cyclin D3 and CDK4 are highly overexpressed in Notch-dependent T-cell lymphomas, justifying the combined use of cell-cycle inhibitors and GSI in treating human T-cell malignancies.

Purpose The purpose of this study was to evaluate the results of arthroscopic capsulolabral repair for traumatic anterior shoulder instability and to compare the outcome in patients who have Bankart lesions versus those with anterior labroligamentous periosteal sleeve avulsion (ALPSA) lesions. Methods This study included 99 patients (93 shoulders), 72 male and 17 female, with a mean age of 32 years, who underwent arthroscopic Bankart repair for traumatic, recurrent anterior shoulder instability, by use of suture anchors. In 67 shoulders (72%) a discrete Bankart lesion was repaired, and in 26 shoulders (28%) an ALPSA lesion was repaired. The 2 groups were analyzed with regard to the number of preoperative dislocations and number of postoperative recurrences. Results At a mean follow‐up of 47 months (range, 24 to 98 months), recurrence of instability was documented in 10 shoulders (10.7%). Of the shoulders, 5 had Bankart lesions (7.4%) and 5 had ALPSA lesions (19.2%) ( P = .0501). The mean number of dislocations or subluxations before the index surgery was significantly higher in the ALPSA group (mean, 12.3 [range, 2 to 57]) than in the Bankart group (mean, 4.9 [range, 2 to 24]) ( P < .05). However, there were no significant differences in the number of anchors used, incidence of minor glenoid erosion, or incidence of bony Bankart lesions between the groups ( P > .05 for all). Conclusions Patients with ALPSA lesions present with a higher number of recurrent dislocations than those with discrete Bankart lesions. In addition, the failure rate after arthroscopic capsulolabral repair is higher in the ALPSA group than in the Bankart group. Level of Evidence Level IV, therapeutic case series.

Abstract Rash from epidermal growth factor receptor inhibitors is common and negatively impacts the quality of life of cancer patients. Published guidelines recommend holding cancer therapy if the rash is severe. Does this recommendation hinge solely on improving patients' quality of life, or does it also hinge on the prevention of a potentially fatal, cutaneous adverse event? In other words, do patients die from rashes from epidermal growth factor receptor inhibitors? To our knowledge, the latter question has never before been asked and answered in an evidence-based fashion. Therefore, we conducted a systematic review of the published, prospectively conducted clinical trial literature on epidermal growth factor receptor inhibitors. The primary aim was to determine whether rash-related death has ever been reported in such trials. Among 117 such trials, which included 8,998 cancer patients, the rate of rash development was &gt;50%, as expected. However, there were no reported deaths from a rash. Although we cannot conclude that a rash-related death from this class of agents can never occur, this systematic review provides evidence-based guidance on how best to counsel cancer patients who develop a rash from an epidermal growth factor receptor inhibitor. It suggests that quality of life issues should remain at the forefront as cancer patients and health care providers make decisions about holding cancer therapy.