[Secondary prevention in patients with superficial urothelial carcinoma]. / Sekundäre Prävention bei Patienten mit oberflächlichem Urothelkarzinom.

BACKGROUND: Urothelial cancer is the 4th most common cancer in men and the 7th most common malignancy in women in Germany. 95 % of all tumors of the urinary bladder are urothelial carcinomas. At the time of diagnosis approximately 80 % of these carcinomas are not invasive. The affection is often multicentric. Approximately 10-15 % of the tumors develop into muscle-invasive growth. In this prospective study, we analyzed measures patients independently took to reduce their risk of bladder cancer recurrence. MATERIALS AND METHODS: During the period January 2012 to December 2013, we surveyed a total of 97 patients with superficial transitional cell carcinoma (pTa). The question was how far the diagnosis of urothelial cancer has changed their lives, eating and drinking habits or whether follow-up consultations had been carried out regularly. Furthermore, we recorded whether they accepted psychological care or had autonomously adopted prophylactic measures, as well as changed their smoking habits, if they had smoked. RESULTS: Of the 97 patients questioned, there were 79 men and 18 women (56 smokers and 41 nonsmokers). The median age was 71 years (range 36-96 years). For 22 patients (22.7 %), the diagnosis resulted in no changes. In 33 patients the changes were small (44 %), moderate in 20 (26.7 %), in 14 (18.6 %) strong and very strong in 8 (10.7 %). A total of 25 patients (25.8 %) changed their eating habits. In all, 49 patients changed their drinking habits; 48 patients claimed to drink more (> 2.0 L/day). One patient reduced his drinking amount. Regarding smoking, 40 patients (71.4 %) had stopped and 7 (12.5 %) reduced consumption, while 6 patients (10.7 %) had not changed their smoking habits. Overall, 44 patients (45.4 %) changed their physical activity: 11 (25 %) exercised more, 8 (18.1 %) less. Only 3 patients (3.1 %) used psycho-oncological care and 39 (40.2 %) patients used supportive/complementary medicine measures of favorablly influence their disease (mistletoe therapy, vitamin supplements). In addition, 22 patients (22.7 %) sought advice from their physician. However, 45.4 % of all patients did not believe in the success of their measures taken. CONCLUSION: Of all patients diagnosed with urothelial carcinoma, 77.3 % reported a change in their living habits and they were willing to take specific steps, such as giving up smoking, being more physically active, changing drinking and eating habits in order to positively influence their disease. However, almost half of the patients (45.4 %) did not believe in a resounding success of their measures taken.

Adiponectin and beta cell dysfunction in gestational diabetes: pathophysiological implications.

AIMS/HYPOTHESIS: Gestational diabetes mellitus (GDM) identifies a population of young women at high risk of developing type 2 diabetes and thus provides an excellent model for studying early events in the natural history of this disease. Adiponectin, a novel adipocyte-derived protein with insulin-sensitising properties, has been proposed as a factor linking insulin resistance and beta cell dysfunction in the pathogenesis of type 2 diabetes. We conducted the current investigation to determine whether adiponectin is associated with beta cell dysfunction in GDM. METHODS: We studied 180 women undergoing OGTT in late pregnancy. Based on the OGTT results, participants were stratified into three groups: (1) NGT (n=93); (2) IGT (n=39); and (3) GDM (n=48). First-phase insulin secretion was determined using a validated index previously proposed by Stumvoll. Insulin sensitivity was assessed using the validated OGTT insulin sensitivity index of Matsuda and DeFronzo (IS(OGTT)). RESULTS: To evaluate beta cell function in relation to ambient insulin sensitivity, an insulin secretion-sensitivity index (ISSI) was derived from the product of the Stumvoll index and the IS(OGTT), based on the existence of the predicted hyperbolic relationship between these two measures. Mean ISSI was highest in the NGT group (6,731), followed by that in the IGT group (4,976) and then that in the GDM group (3,300) (overall p<0.0001), compatible with the notion of declining beta cell function across these glucose tolerance groups. Importantly, adiponectin was significantly correlated with ISSI (r=0.34, p<0.0001), with a stepwise increase in mean ISSI observed per tertile of adiponectin concentration (trend p<0.0001). In multivariate linear regression analysis, ISSI was positively correlated with adiponectin and negatively correlated with GDM, IGT and C-reactive protein (r(2)=0.54). CONCLUSIONS/INTERPRETATION: Adiponectin concentration is an independent correlate of beta cell function in late pregnancy. As such, adiponectin may play a key role in mediating insulin resistance and beta cell dysfunction in the pathogenesis of diabetes.

Accuracy in external dosimetry of ionizing radiation.

A new approach to defining and calculating accuracy and uncertainty in external dosimetry is described. It is more comprehensive and mathematically rigorous than other approaches currently in use, while at the same time being practical to implement. The type testing required to demonstrate the performance of a dosimeter is described, and an example of the calculation of accuracy and uncertainty is given. The paper concludes with some recommendations concerning performance testing and independent testing.

Type testing of the Siemens Plessey electronic personal dosemeter.

This paper presents the results of a laboratory assessment of the performance of a new type of personal dosimeter, the Electronic Personal Dosemeter made by Siemens Plessey Controls Limited. Twenty pre-production dosimeters and a reader were purchased by Ontario Hydro for the assessment. Tests were performed on radiological performance, including reproducibility, accuracy, linearity, detection threshold, energy response, angular response, neutron response, and response time. There were also tests on the effects of a variety of environmental factors, such as temperature, humidity, pulsed magnetic and electric fields, low- and high-frequency electromagnetic fields, light exposure, drop impact, vibration, and splashing. Other characteristics that were tested were alarm volume, clip force, and battery life. The test results were compared with the relevant requirements of three standards: an Ontario Hydro standard for personal alarming dosimeters, an International Electrotechnical Commission draft standard for direct reading personal dose monitors, and an International Electrotechnical Commission standard for thermoluminescence dosimetry systems for personal monitoring. In general, the performance of the Electronic Personal Dosemeter was found to be quite acceptable: it met most of the relevant requirements of the three standards. However, the following deficiencies were found: slow response time; sensitivity to high-frequency electromagnetic fields; poor resistance to dropping; and an alarm that was not loud enough. In addition, the response of the electronic personal dosimeter to low-energy beta rays may be too low for some applications. Problems were experienced with the reliability of operation of the pre-production dosimeters used in these tests.

Monte Carlo calculations of monoenergetic electron depth dose distributions in LiF chips: skin dose correction factors for beta rays.

Monte Carlo calculations have been carried out for monoenergetic electrons from 0.1 to 4 MeV irradiating LiF chips in both perpendicular and isotropic geometry. This enabled the calculation of skin dose correction factors (beta factors) for typical beta energy spectra as measured with a beta-ray spectrometer at CANDU nuclear generating stations. The correction factors were estimated by averaging the depth dose distributions for the monoenergetic electrons over the experimentally measured beta-ray spectra. The calculations illustrate the large uncertainty in beta factors arising from the unknown angular distribution of the beta-ray radiation field and uncertainties in the shape of the beta-ray spectra below 500 keV.

A thermoluminescent dosimetry intercomparison in operational power station fields.

A dosimetry intercomparison was held among the five agencies in Canada that are recognized by the Atomic Energy Control Board as competent to perform external dosimetry. Exposures of thermoluminescent dosimeter badges were made under operational conditions to radiation fields in Candu nuclear generating stations. Details of the method are described including the large, block-type phantoms (with a rotating front face so that all badges were equally exposed) and a small device to measure the depth-dose distribution. Thirty-six exposures (or "runs") were made, exposing 522 badges for periods of 1 h-2 d. Normalization between the runs was based on the absorbed dose at 1,000 mg cm-2 for each run, as measured by the depth-dose device. Using this method, the average relative readings for the five participants ranged from 1.01-1.40 (dimensionless).

Detection and determination limits for thermoluminescence dosimetry.

The statistical theory of detection and determination limits is applied to thermoluminescence dosimetry (TLD), and equations are derived for calculating the limits. Three different levels of testing a TLD system are described, and a test procedure is given for each level. An example from a working system is presented, and the dependence of detection and determination limits on background radiation exposure is shown. The results show the importance of clearly defining the terms used to describe the low-dose performance of a TLD system.