Nonmagnetic band gap at the Dirac point of the magnetic topological insulator (Bi(1-x)Mn(x))2Se3.

Magnetic doping is expected to open a band gap at the Dirac point of topological insulators by breaking time-reversal symmetry and to enable novel topological phases. Epitaxial (Bi(1-x)Mn(x))2Se3 is a prototypical magnetic topological insulator with a pronounced surface band gap of ∼100 meV. We show that this gap is neither due to ferromagnetic order in the bulk or at the surface nor to the local magnetic moment of the Mn, making the system unsuitable for realizing the novel phases. We further show that Mn doping does not affect the inverted bulk band gap and the system remains topologically nontrivial. We suggest that strong resonant scattering processes cause the gap at the Dirac point and support this by the observation of in-gap states using resonant photoemission. Our findings establish a mechanism for gap opening in topological surface states which challenges the currently known conditions for topological protection.

Activation of executioner caspases is a predictor of progression-free survival in glioblastoma patients: a systems medicine approach.

Glioblastoma (GBM) is the most common and aggressive primary brain tumor in adults. GBM cells are highly resistant to apoptosis induced by antitumor drugs and radiotherapy resulting in cancer progression. We assessed whether a systems medicine approach, analysing the ability of tumor cells to execute apoptosis could be utilized to predict the response of GBM patients to treatment. Concentrations of the key proapoptotic proteins procaspase-3, procaspase-9, Smac and Apaf-1 and the antiapopotic protein XIAP were determined in a panel of GBM cell lines and GBM patient tumor resections. These values were used as input for APOPTO-CELL, a systems biological based mathematical model built to predict cellular susceptibility to undergo caspase activation. The modeling was capable of accurately distinguishing between GBM cells that die or survive in response to treatment with temozolomide in 10 of the 11 lines analysed. Importantly the results obtained using GBM patient samples show that APOPTO-CELL was capable of stratifying patients according to their progression-free survival times and predicted the ability of tumor cells to support caspase activation in 16 of the 21 GBM patients analysed. Calculating the susceptibility to apoptosis execution may be a potent tool in predicting GBM patient therapy responsiveness and may allow for the use of APOPTO-CELL in a clinical setting.

Continuous extrapleural intercostal nerve block with continuous infusion of lidocaine after thoracotomy. A descriptive pilot study.

Continuous extrapleural intercostal block (EPIB) with bupivacaine has been reported to be an effective analgesic technique in patients after thoracotomy. We report a retrospective study of EPIB using a continuous infusion of 1% lidocaine hydrochloride at a dose of 1 mg/kg/h. A posterior parietal pleural pocket was created and cannulated with a 16-g polyethylene catheter. Lidocaine was perfused over a 3-day period following surgery. Patients also had access to morphine sulfate via patient-controlled analgesia. Eighteen consecutive posterolateral thoracotomies (in 17 patients) performed during a 6-month period were reviewed. Serum lidocaine exceeded the toxic level of 5 microgram/mL in only one patient, a 104.5-kg man who had a level of 5.9 micrograms/mL on postoperative day 2 but experienced no clinical toxicity. Pain was evaluated by verbal analog scores (0 = no pain and 10 = worst pain), which averaged 3.02, 3.14, and 2.8 in the 3 days following surgery. Mean total daily MS doses were 24.3, 37.75, and 34.32 mg (range, 0 to 94 mg). Sedation was scored on a 1 to 5 scale. Mean scores were 2.78, 2.56, and 2.6. No patient died or had a major respiratory complication. Continuous EPIB with lidocaine appears to be a promising adjuvant technique in the management of postthoracotomy pain. Effectiveness needs to be confirmed in a prospective randomized study.

Radical forequarter amputation with hemithoracectomy and free extended forearm flap: technical and physiologic considerations.

BACKGROUND: A radical forequarter amputation with partial chest wall resection (one to four ribs) has been reported for benign and malignant lesions involving the shoulder and chest wall region. Concerns about reconstruction and postoperative pulmonary function have previously limited more extensive chest wall resections. The current report describes the first case in which a complete unilateral anterior and posterior chest wall resection and pneumonectomy (hemithoracectomy) accompany a forequarter amputation. A novel reconstructive technique used the full circumference of the forearm tissue with an intact ulna as a free osseomyocutaneous flap. METHODS: In this case, a 21-year-old patient presented with an extensive recurrent desmoid tumor that involved the shoulder, brachial plexus, subclavian vein, and chest wall from the lateral sternal border to the midportion of the scapula and down to the eighth rib. The operative technique involved removal of the entire right hemithorax from the midline sternum to the transverse process posteriorly, down to the ninth rib inferiorly. Due to the absence of a rigid hemithorax, the uninvolved ipsilateral lung was also removed. The forearm flap was prepared before final separation of the specimen and division of the subclavian vessels. RESULTS: Postoperatively, the patient maintained excellent oxygenation without atelectasis or fever and was extubated on the 15th postoperative day. As expected after pneumonectomy, significant decreases from preoperative to immediate postoperative values were noted for the vital capacity (VC) (from 4.87 L to 1.29 L), forced 1-s expiratory volume (FEV1) (from 3.77 L to 1.02 L), and inspiratory capacity (IC) (3.33 l to 0.99 l). Rehabilitation included a specially designed external prosthesis to provide cosmesis and prevent scoliosis. By the 15th postoperative week the patient had returned to normal social and physical activities, with a gradual improvement in all respiratory parameters: VC 1.52 L, FEV1 1.29 L, IC 1.04 L. There has been no evidence of tumor recurrence at 1 year. CONCLUSIONS: This report provides evidence that a complete hemithoracectomy, pneumonectomy, and forequarter amputation can be safely performed for selective tumors involving the shoulder region with extensive chest wall invasion. Reconstruction may be achieved with an extended forearm osseomyocutaneous free flap with an excellent functional outcome.