Ultra-low-dose intraoperative X-ray imager for minimally invasive surgery: a pilot imaging study.

Background: With advances in surgical technology, thoracic surgeons have widely adopted minimally invasive limited-resection techniques to preserve normal tissues. However, it remains difficult to achieve in situ localization of invisible pulmonary nodules during surgery. Therefore, we proposed an in situ ultra-low-dose X-ray imaging device for intraoperative pulmonary nodule localization during minimally invasive surgeries. Methods: The proposed device features a hand-held type and consists of a carbon nanotube-based X-ray source and an intraoral dental sensor. In a preclinical study, we created pseudo pulmonary nodules using ex vivo pig lungs. Subsequently, its clinical feasibility was evaluated using ex vivo lung cancer specimens from patients with cancer who had undergone minimally invasive surgery. Results: Using the proposed device, we successfully differentiated normal and abnormal tissues from X-ray images of resected lung specimens. In addition, our proposed device only yielded an average radiation dose of 90.9 nGy for a single acquisition of X-ray images and demonstrated excellent temperature stability under consecutive X-ray irradiations. The radiation exposure of our proposed device (0.1±0.0006 µSv/h) was significantly lower than that of conventional C-arm fluoroscopy (41.5±51.8 µSv/h). In both preclinical and clinical studies, the margin of nodule shadows was clearly visualized using the proposed device. Conclusions: The proposed device substantially reduced radiation exposure to staff and patients and may allow in situ localization of pulmonary nodules. Our proposed device clearly revealed the margins of lung nodules with radiocontrast injection and showed the potential to identify solid nodules without the use of radiocontrast agents.

Body image following radical cystectomy and ileal neobladder or conduit in korean patients.

PURPOSE: The aim of this study was to compare the body images of patients who underwent radical cystectomy with an orthotopic ileal neobladder or an ileal conduit. MATERIALS AND METHODS: A total of 114 adult patients who underwent radical cystectomy between March 2006 and December 2012 at a single institution, Ewha Womans University Mokdong Hospital in Korea, were evaluated in this retrospective chart-review study. Forty-two patients (29 orthotopic ileal neobladder and 13 ileal conduit) who completed questionnaires were included in the final analysis; the remaining patients were excluded. The patients were assessed with two questionnaires: the Korean version of the Body Image Scale (K-BIS) and the self-designed questionnaire. RESULTS: The results did not differ significantly by age at surgery, time from surgery to survey, pathologic stage, grade, histologic subtype, education, residency, or Eastern Cooperative Oncology Group performance status, but did differ significantly by age at survey and sex. The mean summary score for K-BIS showed significant differences between the two groups (p=0.001). We found that patients who underwent an orthotopic ileal neobladder had a significantly better body image. The self-designed questionnaire score was not significantly different between the two groups (p=0.572). CONCLUSIONS: In our retrospective analysis, patients who underwent orthotopic ileal neobladder had a superior body image compared with those who underwent an ileal conduit.

Effect of stress on the expression of rho-kinase and collagen in rat bladder tissue.

PURPOSE: We examined the effect of stress on the pathophysiology of bladder stability in terms of enzyme levels, Rho-kinase, and bladder relaxation. MATERIALS AND METHODS: A total of 48 female Sprague-Dawley rats were studied in scheduled stress environments for 7, 14, and 28 days; 24 rats were in the control group and 24 rats were in the test (stressed) group. RESULTS: Estrogen decreased significantly whereas testosterone and dopamine increased significantly in the stress group (p<0.05). Rho-kinase was significantly increased in the rats exposed to stress stimuli for 14 days (p<0.05). Collagen types I and III in the bladder tissue were significantly higher in rats exposed to stress for 14 days and 28 days (collagen type I in the 14-day group, p<0.01; collagen type I in the 28-day group, p<0.05; collagen type III in the 14-day and 28-day groups, p<0.05). Voiding frequency increased significantly as the duration of stress exposure was prolonged, in addition to a significant decrease in volume per voiding (p<0.05). CONCLUSIONS: The changes observed in micturition pattern, factors that contribute to smooth muscle contraction, and relaxation in the female rat bladder support the hypothesis that stress affects bladder stability.

[Relationship between job stress contents, psychosocial factors and mental health status among university hospital nurses in Korea].

OBJECTIVES: The present study was intended to assess the mental health of nurses working for university hospitals and to establish which factors determine their mental health. METHODS: Self-administered questionnaires were given to 1,486 nurses employed in six participating hospitals located in Daejeon City and Chungnam Province between July 1st and August 31st, 2006. The questionnaire items included sociodemographic, job-related, and psychosocial factors, with job stress factors (JCQ) as independent variables and indices of mental health status (PWI, SDS and MFS) as dependent variables. For statistical analysis, the Chi-square test was used for categorical variables, with hierarchical multiple regression used for determining the factors effecting mental health. The influence of psychosocial and job-related factors on mental health status was assessed by covariance structure analysis. The statistical significance was set at p<0.05. RESULTS: The factors influencing mental health status among subject nurses included sociodemographic characteristics such as age, number of hours of sleep, number of hours of leisure, and subjective health status; job-related characteristics such as status, job satisfaction, job suitability, stresses such as demands of the job, autonomy, and coworker support; and psychosocial factors such as self-esteem, locus of control and type A behavior patterns. Psychosocial factors had the greatest impact on mental health. Covariance structure analysis determined that psychosocial factors affected job stress levels and mental health status, and that the lower job stress levels were associated with better mental health. CONCLUSIONS: Based on the study results, improvement of mental health status among nurses requires the development and application of programs to manage job stress factors and/or psychosocial factors as well as sociodemographic and job-related characteristics.

Oyster shell as substitute for aggregate in mortar.

Enormous amounts of oyster shell waste have been illegally disposed of at oyster farm sites along the southern coast of Korea. In this study to evaluate the possibility of recycling this waste for use as a construction material, the mechanical characteristics of pulverized oyster shell were investigated in terms of its potential utilization as a substitute for the aggregates used in mortar. The unconfined compressive strengths of various soil mortar specimens, with varying blending ratios of cement, water and oyster shell, were evaluated by performing unconfined compression tests, and the results were compared with the strengths of normal cement mortar made with sand. In addition, the effect of organic chemicals on the hardening of concrete was evaluated by preparing ethyl-benzene-mixed mortar specimens. The long-term strength improvement resulting from the addition of fly ash was also examined by performing unconfined compression tests on specimens with fly-ash content. There was no significant reduction in the compressive strength of the mortars containing small oyster shell particles instead of sand. From these test data, the possible application of oyster shells in construction materials could be verified, and the change in the strength parameters according to the presence of organic compounds was also evaluated.