Design of the polarization multi-pass Thomson scattering system

A novel configuration of the multi-pass Thomson scattering (TS) system is proposed to improve the time resolution and accuracy of electron temperature measurements by use of a polarization control technique. This configuration can realize a perfect coaxial multi-passing at each pass, and the number of round trips is not limited by the optical configuration. To confirm the feasibility of the new method, we installed this system in the GAMMA 10 plasma system. As a result, the integrated scattering signal of the double-pass configuration is about two times larger than that of the single-pass configuration. These results are in good agreement with the design.

A new frequency-multiplied interferometer system in the GAMMA 10 tandem mirror

A new interferometer is installed on the west anchor cell of the GAMMA 10 tandem mirror. In GAMMA 10, we have used a heterodyne-type interferometer with a 70-GHz IMPATT oscillator and a 150-MHz oscillator for frequency modulation. The new interferometer consists of a 17.5-GHz phase locked dielectric resonator oscillator and a 37.5-MHz temperature-compensated crystal oscillator, as well as frequency multipliers. The main motivation for the new interferometer using frequency multipliers is to achieve a stable and cost effective interferometer. Direct anchor heating experiments with new anchor ion cyclotron range of frequency antennas in both the west and the east anchor cells are carried out. Density increases in both anchor cells are clearly observed using the new interferometer.

Development of polarization-controlled multi-pass Thomson scattering system in the GAMMA 10 tandem mirror

In the GAMMA 10 tandem mirror, the typical electron density is comparable to that of the peripheral plasma of torus-type fusion devices. Therefore, an effective method to increase Thomson scattering (TS) signals is required in order to improve signal quality. In GAMMA 10, the yttrium-aluminum-garnet (YAG)-TS system comprises a laser, incident optics, light collection optics, signal detection electronics, and a data recording system. We have been developing a multi-pass TS method for a polarization-based system based on the GAMMA 10 YAG TS. To evaluate the effectiveness of the polarization-based configuration, the multi-pass system was installed in the GAMMA 10 YAG-TS system, which is capable of double-pass scattering. We carried out a Rayleigh scattering experiment and applied this double-pass scattering system to the GAMMA 10 plasma. The integrated scattering signal was made about twice as large by the double-pass system.

Copy number amplification of the PIK3CA gene is associated with poor prognosis in non-lymph node metastatic head and neck squamous cell carcinoma

Background

Deregulation of the EGFR signaling pathway is one of the most frequently observed genetic abnormalities that drives cancer development. Although mutations in the downstream components of the EGFR signaling pathway, including KRAS, BRAF and PIK3CA, have been reported in numerous cancers, extensive mutation and copy number analysis of these genes in clinical samples has not been performed for head and neck squamous cell carcinoma (HNSCC).

Methods

We examined the mutations and copy number alterations of KRAS, BRAF and PIK3CA in 115 clinical specimens of HNSCC obtained from surgically treated patients.

We used DNA sequencing to detect mutations and the copy number changes were evaluated by qPCR and array comparative genomic hybridization (CGH) analysis.

Results

We examined the mutations and copy number alterations of KRAS, BRAF and PIK3CA in 115 clinical specimens of HNSCC obtained from surgically treated patients. We identified 3 mutations (2.6%) in K-RAS and 3 mutations (2.6%) in PIK3CA. Copy number amplification was found in 37 cases (32.2%) for PIK3CA, 10 cases (8.7%) for K-RAS and 2 cases (1.7%) for BRAF. Kaplan-Meier survival analysis revealed that copy-number amplification of PIK3CA was markedly associated with cancer relapse in patients without lymph node metastasis. (Log-rank test, p = 0.026)

Conclusions

Copy number amplification of the PIK3CA gene is associated with poor prognosis in HNSCC patients without lymph node metastasis. The PIK3CA copy number status will serve as a marker of poor prognosis in patients with HNSCC.

[Evaluation of clinical features of antrochoanal polyps]

Current knowledge on the prevalence and clinical features of antrochoanal polyps (ACPs), benign lesions arising in the maxillary sinus and extending into the choana, is very limited in Japan. We prospectively evaluated prevalence and clinical features in 15 subjects with ACPs from among 728 undergoing endoscopic endonasal sinus surgery between April 2007 and March 2008, and prospectively enrolled in this study. The 15 subjects, who accounted for 2.1% of the total, had nasal obstruction, rhinorrhea, and postnasal drip. Symptoms significantly reduced postoperatively. Maxillary-sinus-origin ACP distribution was 40% from the maxillary sinus floor to the posterior wall, 26.7% from maxillary sinus floor, and 20% from the maxillary sinus floor to the internal wall. Postoperative recurrence was 13.3%. Endoscopic endonasal sinus surgery for ACPs was most effective for polyp is originating in the maxillary sinus determined carefully and excised as completely as possible, followed by appropriate postoperative treatment.

[Endoscopic sinus surgery complications a prospective multicenter study]

OBJECTIVE

Our objective was to determine the rate of complications in endoscopic sinus surgery (ESS) and associated risk factors.

METHODS

We prospectively studied 1,382 subjects undergoing ESS for rhinosinusitis and cystic sinus disease at 16 hospitals during 2007 and 2008. Surgeons provided information on peri-and postoperative complication occurrence.

RESULT

Results of complications were seen in 80 subjects (5.8%), the most frequent was perioperative lamina papyracea injury. Analysis showed the complication rate to be linked to gender, and anesthesia type, but not the grade of surgeon.

CONCLUSIONS

While care should be taken to avoid them, complications should be identified and treated in a timely and accurate manner.

Identification of chronic rhinosinusitis phenotypes using cluster analysis

BACKGROUND

The pathophysiology of chronic rhinosinusitis (CRS) is not fully understood. In Europe and the United States, major subsets of CRS classification are based on the presence or absence of polyps. Although nasal polyps (NPs) are a critical factor, many other factors also contribute to the pathogenesis of CRS. The aim of this study was to investigate diverse CRS phenotypes using cluster analysis.

METHODS

This was a multicenter study examining clinical data from CRS patients treated at five hospitals. The study design was a retrospective analysis of prospectively collected data. Complete data were available for 425/496 patients. Data were subjected to k-means cluster analysis in an attempt to identify the different phenotypes involved in CRS.

RESULTS

CRS was divided into four clusters. Cluster 1 (n = 180) and cluster 2 (n = 129) comprised patients with low peripheral eosinophil and mucosal eosinophil counts. However, polyp scores in cluster 2 were higher than cluster 1. Cluster 3 (n = 50) comprised patients with very high mucosal eosinophil counts but low polyp and symptom scores. Finally, subjects in cluster 4 (n = 66) showed severe polyposis. Polyp score and mucosal eosinophil count were the strongest predictors of clustering by discriminant analysis.

CONCLUSION

The results of this study identified distinct clinical CRS phenotypes. CRS was classified into four phenotypes based on NPs and mucosal eosinophil counts. Cutoff points for these factors were identified by tree analysis. Additional studies are needed to establish clinical significance of the phenotypes.

Expression of nitric oxide synthases in leukocytes in nasal polyps

BACKGROUND

Nitric oxide (NO) has various roles in airway physiology and pathophysiology. Monitoring exhaled NO levels is increasingly common to measure airways inflammation and inhaled NO studied for its therapeutic value in premature infants and adult respiratory distress syndrome. NO is produced by 3 isoforms of NO synthase (NOS1, 2, 3), and each can play distinct and perhaps overlapping roles in the airways. However, the distribution, regulation, and functions of NOS in various cells in the upper airways, particularly in leukocytes, are incompletely understood.

OBJECTIVE

To characterize the expression of NOS isoforms in leukocytes in normal middle turbinate tissues (MT) and in inflammatory nasal tissue (nasal polyps, NP).

METHODS

Normal MT tissue was collected from surgical specimens that were to be discarded. The NP samples were from surgical tissue archives of 15 patients with chronic rhinosinusitis. Isoforms of NOS in cells were identified by double immunostaining using NOS isoform-specific and leukocyte-specific (mast cell, eosinophil, macrophage, neutrophil, or T cell) antibodies.

RESULTS

The proportion of total cells below the epithelium that were positive for each isoform of NOS was higher in NP than in MT. Each isoform of NOS was found in all leukocyte populations studied, and there were significant differences in the percentage of leukocytes expressing NOS isoforms between MT and NP.

CONCLUSION

All isoforms of NOS are expressed in leukocytes in MT and NP, and their expression varies among leukocyte types. Our data provide a basis to investigate the regulation, cell distribution, and distinct functions of NOS isoforms in normal and inflamed nasal tissues.