Non-thermal atmospheric pressure plasma induces apoptosis in oral cavity squamous cell carcinoma: Involvement of DNA-damage-triggering sub-G(1) arrest via the ATM/p53 pathway.

Recent advances in physics have made possible the use of non-thermal atmospheric pressure plasma (NTP) in cancer research. Although increasing evidence suggests that NTP induces death of various cancer cell types, thus offering a promising alternative treatment, the mechanism of its therapeutic effect is little understood. In this study, we report for the first time that NTP led to apoptotic cell death in oral cavity squamous cell carcinoma (OSCC). Interestingly, NTP induced a sub-G(1) arrest in p53 wild-type OSCCs, but not in p53-mutated OSCCs. In addition, NTP increased the expression levels of ATM, p53 (Ser 15, 20 and 46), p21, and cyclin D1. A comet assay, Western blotting and immunocytochemistry of γH2AX suggested that NTP-induced apoptosis and sub-G(1) arrest were associated with DNA damage and the ATM/p53 signaling pathway in SCC25 cells. Moreover, ATM knockdown using siRNA attenuated the effect of NTP on cell death, sub-G(1) arrest and related signals. Taken together, these results indicate that NTP induced apoptotic cell death in p53 wild-type OSCCs through a novel mechanism involving DNA damage and triggering of sub-G(1) arrest via the ATM/p53 pathway. These findings show the therapeutic potential of NTP in OSCC.

Fibers of reduced graphene oxide nanoribbons.

Reduced graphene oxide nanoribbon fibers were fabricated by using an electrophoretic self-assembly method without the use of any polymer or surfactant. We report electrical and field emission properties of the fibers as a function of reduction degree. In particular, the thermally annealed fiber showed superior field emission performance with a low potential for field emission (0.7 V µm(-1)) and a giant field emission current density (400 A cm(-2)). Moreover, the fiber maintains a high current level of 300 A cm(-2) corresponding to 1 mA during long-term operation.

Macroscopic single-walled-carbon-nanotube fiber self-assembled by dip-coating method.

Pure macroscopic single-walled-carbon-nanotube (SWNT) fibers are fabricated by using a dip-coating method without any additive or additional electrical equipment or complex apparatus. The present method only utilizes microfluidics, which includes capillary condensation, capillary flow, and surface tension, and results in the self-assembly and self-alignment of SWNT colloids.

The dependence of the Schottky barrier height on carbon nanotube diameter for Pd-carbon nanotube contacts.

Direct measurements are presented of the Schottky barrier (SB) heights of carbon nanotube devices contacted with Pd electrodes. The SB barrier heights were determined from the activation energy of the temperature-dependent thermionic emission current in the off-state of the devices. The barrier heights generally decrease with increasing diameter of the nanotubes and they are in agreement with the values expected when assuming little or no influence of Fermi level pinning.

Outcome of endoscopic management of extensive laryngotracheal stenosis.

OBJECTIVES: When performing endotracheal intubation or tracheotomy in unconscious patients in emergent situations, one should consider the possibility of the later complication of laryngotracheal stenosis, which can result in difficulties with decannulation. We analyzed the clinical features of laryngotracheal stenosis to search for its possible etiologic factors and its proper preventive methods. METHODS: The medical records of 249 cases of laryngotracheal stenosis out of 2,208 patients who underwent tracheotomy in our hospital during the past 12 years were retrospectively reviewed regarding several parameters, such as the duration of endotracheal intubation, site of tracheostoma, site of stenosis, treatment method, and so forth. RESULTS: Non-otolaryngologists had a tendency to place the tracheostoma at a higher level of the trachea. We identified technical precautions that should be taken into consideration in performing an emergency tracheotomy. Bronchoscopic evaluation and tracheal stent insertion was the most commonly used treatment method. Successful decannulation was achieved in about 70%, and was especially frequent in patients whose endotracheal intubation was less than 20 days. CONCLUSIONS: It is desirable that the duration of endotracheal intubation be limited to less than 20 days. A database of patients who undergo tracheotomy should be submitted to careful follow-up to diagnose early development of laryngotracheal stenosis and to prevent long-term complications.

Mucosal melanoma arising in the eustachian tube.

Mucosal melanoma is a very rare disease. Most cases have their origins in the head and neck region. To date,only three cases of melanoma originating from the eustachian tube have been reported. We present a case of mucosal melanoma of eustachian tube origin in which a complete excision was performed. In this case, the patient underwent adjuvant radiotherapy and the mass size greatly decreased, which aided subsequent surgical excision. Systemic chemotherapy was not utilized in this case; however, it is often used for palliative purposes. A literature review is also presented.

A novel synthetic compound 3-amino-3-(4-fluoro-phenyl)-1H-quinoline-2,4-dione (KR22332) exerts a radioprotective effect via the inhibition of mitochondrial dysfunction and generation of reactive oxygen species.

PURPOSE: Acute side effects of radiation such as oral mucositis are observed in most patients. Although several potential radioprotective agents have been proposed, no effective agent has yet been identified. In this study, we investigated the effectiveness of synthetic compound 3-amino-3-(4-fluoro-phenyl)-1H-quinoline-2,4-dione (KR22332) as a radioprotective agent. MATERIALS AND METHODS: Cell viability, apoptosis, the generation of reactive oxygen species (ROS), mitochondrial membrane potential changes, and changes in apoptosis-related signaling were examined in human keratinocyte (HaCaT). RESULTS: KR22332 inhibited irradiation-induced apoptosis and intracellular ROS generation, and it markedly attenuated the changes in mitochondrial membrane potential in primary human keratinocytes. Moreover, KR22332 significantly reduced the protein expression levels of ataxia telangiectasia mutated protein, p53, and tumor necrosis factor (TNF)-α compared to significant increases observed after radiation treatment. CONCLUSION: KR22332 significantly inhibited radiation-induced apoptosis in human keratinocytes in vitro, indicating that it might be a safe and effective treatment for the prevention of radiation-induced mucositis.

How to optimize laryngeal and hypopharyngeal exposure in transoral robotic surgery.

OBJECTIVE: The aim of this study was to present the various strategies adopted in our center to improve and overcome problems with exposure of the operative field in 48 patients who underwent TORS for the treatment of laryngeal and hypopharyngeal cancer. METHODS: We present our operative and preoperative treatment protocols for patients undergoing TORS for laryngeal and hypopharyngeal cancer. In particular, we emphasize the role of preoperative exposure assessment and the usefulness of simple measures to overcome problems with exposure of the operative field. RESULTS: In 12 patients (25%), we experienced difficult laryngeal-hypopharyngeal exposure. However the correct positioning of the robotic arms, the proper use of the laryngeal and tongue blade and some simple maneuvers, such as the anterior traction of the tongue and the partial epiglottectomy, ensured the feasibility of TORS with negative margins in all patients. CONCLUSION: In TORS, the exposure of larynx and hypopharynx can be difficult, but the adoption of certain methods may make it possible in most patients. An accurate preoperative evaluation under general anesthesia is the primary strategy for reducing the number of cases terminated intraoperatively. Currently, TORS is not feasible in all patients, but in our opinion, reductions in the size of robotic equipment and development of new devices will extend the application of TORS to a larger number of patients.

Microporous carbon nanoplates from regenerated silk proteins for supercapacitors.

Novel carbon-based microporous nanoplates containing numerous heteroatoms (H-CMNs) are fabricated from regenerated silk fibroin by the carbonization and activation of KOH. The H-CMNs exhibit superior electrochemical performance, displaying a specific capacitance of 264 F/g in aqueous electrolytes, a specific energy of 133 Wh/kg, a specific power of 217 kW/kg, and a stable cycle life over 10000 cycles.

An ectopic hamartomatous thymoma.

An ectopic hamartomatous thymoma is an extremely rare benign tumor of the lower neck that is the most common in middle-aged males. Pathologically, the tumor is characterized by a mixture of spindle cells, epithelial cells, mature adipose tissue, and lymphocytes. The histogenesis of this tumor is controversial. Recently, an origin from a remnant of the cervical sinus of His was proposed. Malignant lesions such as synovial sarcomas or malignant peripheral nerve sheath tumors can have similar clinical features and radiologic images. Thus, recognition of this tumor is important because it follows a benign clinical course and conservative surgical excision is the treatment of choice. Here, we report the case of a 34-year-old man with an ectopic hamartomatous thymoma in the left supraclavicular region and a review of the literature on this tumor.

N-type graphene induced by dissociative H2 adsorption at room temperature.

Studies of the interaction between hydrogen and graphene have been increasingly required due to the indispensable modulation of the electronic structure of graphene for device applications and the possibility of using graphene as a hydrogen storage material. Here, we report on the behaviour of molecular hydrogen on graphene using the gate voltage-dependent resistance of single-, bi-, and multi-layer graphene sheets as a function of H2 gas pressure up to 24 bar from 300 K to 345 K. Upon H2 exposure, the charge neutrality point shifts toward the negative gate voltage region, indicating n-type doping, and distinct Raman signature changes, increases in the interlayer distance of multi-layer graphene, and a decrease in the d-spacing occur, as determined by TEM. These results demonstrate the occurrence of dissociative H2 adsorption due to the existence of vacancy defects on graphene.

c-Met expression as an indicator of survival outcome in patients with oral tongue carcinoma.

BACKGROUND: Hepatocyte growth factor (HGF) can promote proliferation, invasion, and angiogenesis in various tumor cells. However, the prognosis according to expression of HGF/c-Met has not been reported in patients with squamous cell carcinoma of the oral tongue (SCCOT). METHODS: Tumors from 61 patients with SCCOT were evaluated for the expression of HGF and c-Met by immunohistochemistry. For Western blot, we used fresh normal and cancer tissues from 3 patients with SCCOT. RESULTS: The positive rates of HGF and c-Met immunostaining in SCCOT were 57.3% and 54.1%, respectively. The c-Met staining was significantly correlated with lymph node metastasis (p = .005), tumor classification (p = .004), and recurrence (p = .018). Survival was significantly affected in patients with positive c-Met expression (p = .003). HGF and c-Met were strongly expressed in cancer tissues on Western blot. CONCLUSION: The c-Met expression may play an important role in the progression and the survival outcome of patients with SCCOT.