Femoral neck fractures in patients on Clopidogrel. The effect of delaying surgery and the introduction of the new SIGN guidelines.

INTRODUCTION: Femoral neck fractures are an increasingly common injury in the elderly. Frequently these patients present taking Clopidogrel, an irreversible inhibitor of platelet aggregation. Although this is associated with an increased risk of intra-operative bleeding and also an increased risk of spinal haematoma where regional anaesthesia is employed, the recent SIGN (Scottish Intercollegiate Guidance Network) guidelines recommend that surgery should not be delayed. METHODS: We conducted a retrospective review of consecutive patients admitted with femoral neck fractures between April 2008 and October 2009. Patients on Clopidogrel were identified and data including ASA grade, time to operation, medical co-morbidities, and post-admission complications were recorded. Comparative information from the National Hip Fracture Database was used. RESULTS: 405 patients were included. 27 patients were taking Clopidogrel on admission and they were all ASA 3 or 4. Mean time to theatre was 8 days. Post-admission medical complications occurred in 7 patients (25.9%). A further 4 patients (14.8%) died, 3 of them post-operatively. From the study population a control group of 72 ASA 3 and 4 patients was further studied. The mean time to operation was 2.3 days. Post-admission medical complications occurred in 13 patients (18%) and 8 patients (11%) died post-operatively. The difference in the mortality and morbidity of these two groups was found to be statistically not significant. In 2009 the national mean time to operation was 2.19 days with an associated mortality rate of 8.67%. DISCUSSION AND CONCLUSION: Patients receiving Clopidogrel have complex medical co-morbidities and a higher anaesthetic risk. Delaying operative management might be contributing to the increased rate of mortality and morbidity. In accordance with the SIGN guidelines we recommend early operative intervention in these high risk patients.

Entrectinib is a potent inhibitor of Trk-driven neuroblastomas in a xenograft mouse model.

Neuroblastoma (NB) is one of the most common and deadly childhood solid tumors. These tumors are characterized by clinical heterogeneity, from spontaneous regression to relentless progression, and the Trk family of neurotrophin receptors plays an important role in this heterogeneous behavior. We wanted to determine if entrectinib (RXDX-101, Ignyta, Inc.), an oral Pan-Trk, Alk and Ros1 inhibitor, was effective in our NB model. In vitro effects of entrectinib, either as a single agent or in combination with the chemotherapeutic agents Irinotecan (Irino) and Temozolomide (TMZ), were studied on an SH-SY5Y cell line stably transfected with TrkB. In vivo growth inhibition activity was studied in NB xenografts, again as a single agent or in combination with Irino-TMZ. Entrectinib significantly inhibited the growth of TrkB-expressing NB cells in vitro, and it significantly enhanced the growth inhibition of Irino-TMZ when used in combination. Single agent therapy resulted in significant tumor growth inhibition in animals treated with entrectinib compared to control animals [p < 0.0001 for event-free survival (EFS)]. Addition of entrectinib to Irino-TMZ also significantly improved the EFS of animals compared to vehicle or Irino-TMZ treated animals [p < 0.0001 for combination vs. control, p = 0.0012 for combination vs. Irino-TMZ]. We show that entrectinib inhibits growth of TrkB expressing NB cells in vitro and in vivo, and that it enhances the efficacy of conventional chemotherapy in in vivo models. Our data suggest that entrectinib is a potent Trk inhibitor and should be tested in clinical trials for NBs and other Trk-expressing tumors.

Acquired Resistance to the TRK Inhibitor Entrectinib in Colorectal Cancer.

UNLABELLED: Entrectinib is a first-in-class pan-TRK kinase inhibitor currently undergoing clinical testing in colorectal cancer and other tumor types. A patient with metastatic colorectal cancer harboring an LMNA-NTRK1 rearrangement displayed a remarkable response to treatment with entrectinib, which was followed by the emergence of resistance. To characterize the molecular bases of the patient's relapse, circulating tumor DNA (ctDNA) was collected longitudinally during treatment, and a tissue biopsy, obtained before entrectinib treatment, was transplanted in mice (xenopatient), which then received the same entrectinib regimen until resistance developed. Genetic profiling of ctDNA and xenopatient samples showed acquisition of two point mutations in the catalytic domain of NTRK1, p.G595R and p.G667C. Biochemical and pharmacologic analysis in multiple preclinical models confirmed that either mutation renders the TRKA kinase insensitive to entrectinib. These findings can be immediately exploited to design next-generation TRKA inhibitors. SIGNIFICANCE: We provide proof of principle that analyses of xenopatients (avatar) and liquid biopsies allow the identification of drug resistance mechanisms in parallel with clinical treatment of an individual patient. We describe for the first time that p.G595R and p.G667C TRKA mutations drive acquired resistance to entrectinib in colorectal cancers carrying NTRK1 rearrangements.

The impact of a text messaging service on orthopaedic clinic Did Not Attend rates.

BACKGROUND: Missed clinic appointments cause delays in treatment of other patients, under utilization of clinical manpower or facilities and impact upon hospital finances. AIMS: The primary aim of this study is to evaluate whether a text messaging reminder service reduces the Did Not Attend rate. The secondary aim is to evaluate the cost-effectiveness of a mobile text message reminder service. METHODS: The study focused on the outpatient department of a district general hospital. In January 2011 a patient text messaging reminder service was implemented across the outpatient departments in the trust. Data were collected prospectively 24 months prior and 24 months following the implementation of this service. A reminder was sent to patients one week prior to the scheduled appointment as a text message. All patients attending the orthopaedic department were included in the study. Patients who had an appointment and cancelled/rescheduled it prior to their original consultation date were excluded. Children were also excluded from the study. RESULTS: The overall Did Not Attend rate was reduced by 12% following the intervention (p < 0.0001). The new appointment follow-up rate was reduced by 2% (p = 0.74) and the follow-up rate decreased by 13.7% (p < 0.0001). The economic analysis revealed a saving of £19,853 over a two-year period following the intervention. CONCLUSION: Thus mobile technology is a feasible tool in improving attendance rates at outpatient clinics and is economically viable.

Regulation of immune responsiveness in vivo by disrupting an early T-cell signaling event using a cell-permeable peptide.

The inducible T cell kinase (ITK) regulates type 2 (Th2) cytokines that provide defense against certain parasitic and bacterial infections and are involved in the pathogenesis of lung inflammation such as allergic asthma. Activation of ITK requires the interaction of its SH3 domain with the poly-proline region of its signaling partner, the SH2 domain containing leukocyte phosphoprotein of 76 kilodaltons (SLP-76). The specific disruption of the ITK-SH3/SLP-76 poly-proline interaction in vitro by a cell-permeable competitive inhibitor peptide (R9-QQP) interferes with the activation of ITK and the transduction of its cellular functions in T lymphocytes. In the present investigation, we assessed the effects of R9-QQP treatment on the induction of an in vivo immune response as represented by lung inflammation in a murine model of allergic asthma. We found that mice treated with R9-QQP and sensitized and challenged with the surrogate allergen ovalbumin (OVA) display significant inhibition of lung inflammation in a peptide-specific manner. Thus, parameters of the allergic response, such as airway hyper-responsiveness, suppression of inflammatory cell infiltration, reduction of bronchial mucus accumulation, and production of relevant cytokines from draining lymph nodes were significantly suppressed. These findings represent the first demonstration of the biological significance of the interaction between ITK and SLP-76 in the induction of an immune response in a whole animal model and specifically underscore the significance of the ITK-SH3 domain interaction with the poly-proline region of SLP-76 in the development of an inflammatory response. Furthermore, the experimental approach of intracellular peptide-mediated inhibition might be applicable to the study of other important intracellular interactions thus providing a paradigm for dissecting signal transduction pathways.

In vivo significance of ITK-SLP-76 interaction in cytokine production.

In vitro data have suggested that activation of the inducible T-cell kinase (ITK) requires an interaction with the adaptor protein SLP-76. One means for this interaction involves binding of the ITK SH3 domain to the polyproline-rich (PR) region of SLP-76. However, the biological significance of this association in live cells and the consequences of its disruption have not been demonstrated. Here, we utilized a polyarginine-rich, cell-permeable peptide that represents the portion of the SLP-76 PR region that interacts with the ITK SH3 domain as a competitive inhibitor to disrupt the association between ITK and SLP-76 in live cells. We demonstrate that treatment of cells with this peptide, by either in vitro incubation or intraperitoneal injection of the peptide in mice, inhibits the T-cell receptor (TCR)-induced association between ITK and SLP-76, recruitment and transphosphorylation of ITK, actin polarization at the T-cell contact site, and expression of Th2 cytokines. The inhibition is specific, as indicated by lack of effects by the polyarginine vehicle alone or a scrambled sequence of the cargo peptide. In view of the role of ITK as a regulator of Th2 cytokine expression, the data underscore the significance of ITK as a target for pharmacological intervention.