Design and implementation of electron diverters for lobster eye space-based X-ray optics.

Micropore optics have recently been implemented in a lobster eye geometry as a compact X-ray telescope. Fields generated by rare-earth magnets are used to reduce the flux of energetic electrons incident upon the focal plane detector in such a setup. We present the design and implementation of the electron diverters for X-ray telescopes of two upcoming missions: the microchannel X-ray telescope onboard the space-based multiband astronomical variable objects monitor and the soft X-ray instrument onboard the solar wind magnetosphere ionosphere link explorer. Electron diverters must be configured to conform to stringent limits on their total magnetic dipole moment and be compensated for any net moment arising from manufacturing errors. The two missions have differing designs, which are presented and evaluated in terms of the fractions of electrons reaching the detector, as determined by relativistic calculations of electron trajectories. The differential flux of electrons to the detector is calculated, and the integrated electron background is determined for both designs.

Infrared cameras are potential traceable "fixed points" for future thermometry studies.

The National physical laboratory (NPL) requires "fixed points" whose temperatures have been established by the International Temperature Scale of 1990 (ITS 90) be used for device calibration. In practice, "near" blackbody radiators together with the standard platinum resistance thermometer is accepted as a standard. The aim of this study was to report the correlation and limits of agreement (LOA) of the thermal infrared camera and non-contact infrared temporal thermometer against each other and the "near" blackbody radiator. Temperature readings from an infrared thermography camera (FLIR T650sc) and a non-contact infrared temporal thermometer (Hubdic FS-700) were compared to a near blackbody (Hyperion R blackbody model 982) at 0.5 °C increments between 20-40 °C. At each increment, blackbody cavity temperature was confirmed with the platinum resistance thermometer. Measurements were taken initially with the thermal infrared camera followed by the infrared thermometer, with each device mounted in turn on a stand at a fixed distance of 20 cm and 5 cm from the blackbody aperture, respectively. The platinum thermometer under-estimated the blackbody temperature by 0.015 °C (95% LOA: -0.08 °C to 0.05 °C), in contrast to the thermal infrared camera and infrared thermometer which over-estimated the blackbody temperature by 0.16 °C (95% LOA: 0.03 °C to 0.28 °C) and 0.75 °C (95% LOA: -0.30 °C to 1.79 °C), respectively. Infrared thermometer over-estimates thermal infrared camera measurements by 0.6 °C (95% LOA: -0.46 °C to 1.65 °C). In conclusion, the thermal infrared camera is a potential temperature reference "fixed point" that could substitute mercury thermometers. However, further repeatability and reproducibility studies will be required with different models of thermal infrared cameras.

Prognostic value of interim and restaging PET/CT in Hodgkin lymphoma. Results of the CHEAP (Chemotherapy Effectiveness Assessment by PET/CT) study - long term observation.

Very few studies have determined the prognostic value of interim and restaging PET/CT in patients with Hodgkin lymphoma using current standard of care therapy outside clinical trials. We analyzed the effect of the results of interim and restaging PET/CT on the survival (overall- and relapse-free) in patients who received standard first-line treatment based on the stage of disease and risk factors. We investigated the differences between the relapse and non-relapse groups based on the clinical pathological characteristics of patients who had positive interim PET/CT results.Between January 1, 2007 and December 31, 2011, the staging, interim and restaging PET/CT scans of patients with Hodgkin lymphoma were analyzed. The Deauville criteria were used for the evaluation of interim PET/CT scans. One hundred and thirteen Hodgkin lymphoma patients underwent staging, interim and restaging PET/CT scans. None of the therapy was modified based on the interim PET/CT results. The median follow-up time was 43.5 months. A total of 62 early stage patients and 51 advanced stage patients were identified. The five-year overall survival rates were 93.4% in the interim PET negative group and 58% in the interim PET positive group (p<0.001). The five-year relapse-free survival rates for the negative and positive groups were 92.7% and 40.8%, respectively (p<0.001). The negative predictive value was 100% in the early stage group and 82.35% in the advanced stage group. By comparison, the positive predictive values were 53.8% and 58.8%, respectively, in these two groups. In the interim PET positive group, patients over 40 years of age had a significantly higher probability of relapse (p=0.057).The routine clinical use of interim PET/CT is highly recommended based on our investigation. However, patients with positive interim PET/CT results required frequent additional evaluations.

Prognostic value of FDG-PET in Hodgkin lymphoma for posttreatment evaluation. Long term follow-up results.

Determining the viability of residual tumor masses is a great challenge after primary treatment of Hodgkin lymphoma. FDG-PET may play a crucial role in this procedure. In this study, files of 128 Hodgkin lymphoma patients were reviewed, who were treated in three Hungarian hematology centers between January 1995 and February 2005. CT scan showed residual tumor mass by all of them. Their median follow-up was 75.5 months from PET examination. The number of true-positive, true-negative, false-positive, false-negative subjects were 29, 83, 10, 6, respectively. Sensitivity of post-treatment FDG-PET was 83 %, specificity 93 %, positive predictive value 74 %, negative predictive value 93 %, and accuracy 88 %. The difference between the event free survival of PET positive and negative cases is highly significant (p=0.0000), according to the Mantel-Cox test. Our results in the largest cohort of patients, in accordance with literature, clearly indicates that patients with negative FDG-PET results are unlikely to progress or relapse during the longest follow-up.

Relationship between autonomic neuropathy and hypertension--are we underestimating the problem?

BACKGROUND: Cardiac autonomic neuropathy (CAN) is associated with significant morbidity and mortality in diabetes and the risk is even greater in those with hypertension. AIMS: The aim of our study was to investigate the relationship between CAN and 24-h blood pressure profile in normoalbuminuric patients with Type 2 diabetes mellitus. METHODS: Seventy patients with Type 2 diabetes (31 without CAN, 39 with CAN), who had no history of hypertension, and 29 healthy volunteers underwent five standard cardiovascular reflex tests to assess autonomic function and 24-h ambulatory blood pressure monitoring. RESULTS: Twenty-four-hour mean systolic blood pressure, blood pressure load and hyperbaric impact values were significantly higher in diabetic patients with CAN compared with control subjects and diabetic patients without CAN (P < 0.05). In spite of normal clinic blood pressures, 54% of diabetic subjects with CAN and 29% without CAN were hypertensive (systolic blood pressure load > 20%, P < 0.05). In the diabetes group as a whole, Valsalva ratio, postural systolic blood pressure changes and diastolic blood pressure responses during sustained handgrip correlated significantly and negatively with 24-h mean systolic blood pressure (P < 0.01, P < 0.001, P < 0.05) and blood pressure load (P < 0.05, P < 0.001, P < 0.05). CONCLUSIONS: Cardiovascular autonomic neuropathy is independently associated with hypertension in normoalbuminuric Type 2 diabetic patients with no history of hypertension. Relying on clinic blood pressures in subjects with CAN could lead to a failure to diagnose hypertension in over half of cases. All normotensive patients with CAN should be screened for hypertension using ambulatory blood pressure monitoring in order to institute early aggressive interventions to improve their long-term outlook.

Neuropathy as an extrahepatic manifestation of chronic liver diseases.

Gastrointestinal motor disturbances and various cardiovascular symptoms are the characteristic features of autonomic neuropathy. Autonomic and sensory neuropathy has been described in chronic alcoholic liver diseases. Cardiovascular autonomic reflex tests as the gold standard for autonomic neuropathy and measuring of thresholds for constant current electric sine wave stimulation by neurometer were used for measuring sensory neuropathy in patients with chronic liver diseases of different etiology. Autonomic and sensory neuropathy was also observed in non-alcoholic liver diseases. We proved that there is a correlation between autonomic neuropathy and prolongation of corrected QT interval in chronic liver diseases. We claim that autonomic neuropathy may have a role to play in the development of hyperdynamic circulation and portal hypertension in chronic liver diseases.

Peripheral sensory nerve dysfunction in children and adolescents with type 1 diabetes mellitus.

The aim of the present study was to investigate peripheral sensory nerve function in diabetic children and adolescents without neurological symptoms. Ninety-two children and adolescents with Type 1 (insulin-dependent) diabetes mellitus (mean +/- SD age: 14.2 +/- 2.1 years, diabetes duration: 5.8 +/- 3.0 years) and 80 healthy control subjects (age: 13.8 +/- 2.2 years) matched for age, sex, body mass index, and height standard deviation score were involved in the study. Using a sine-wave transcutaneous stimulator, current perception threshold (CPT) testing at 2000, 250 and 5 Hz was performed on the left median and peroneal nerves. Diabetic children had increased CPT at 2000 Hz on both nerves as compared to the control group (median (interquartile range), median nerve: 2.43 (2.20-3.43) vs 1.80 (1.51-2.60) mA, p = 0.02; peroneal nerve: 3.51 (2.81-4.82) vs 2.70 (2.04-3.70) mA, p = 0.01). Twenty-one (23%) of patients had CPT values higher than that of any healthy individual. Of these, elevated CPT was observed in 9 (9.8%) patients on the median nerve, in 8 (8.7%) patients on the peroneal nerve, and in 4 (4.3%) patients on both median and peroneal nerves. Using multiple logistic regression analysis, worse long-term metabolic control and advanced puberty were independently predictive of peripheral sensory nerve dysfunction as the dependent variable (adjusted OR (95% CI): 3.4 (1.2-6.2), p = 0.01, and 2.8 (1.1-5.6), p = 0.03, respectively). In conclusion, evidence of peripheral sensory nerve dysfunction is not rare in children and adolescents with diabetes and can be demonstrated by CPT testing in asymptomatic patients. Poor metabolic control is a risk factor for such subclinical neuropathy, and pubertal development may be involved in the pathogenesis of diabetic peripheral neuropathy.

Prolongation of the QTc-interval reflects the severity of autonomic neuropathy in primary biliary cirrhosis and in other non-alcoholic liver diseases.

It was the aim of our study to prove a potential correlation (a) between laboratory findings of cholestasis and autonomic neuropathy (AN) and (b) between the severity of AN and the prolongation of the corrected QT-time (QTc). The five standard tests of autonomic cardiac neuropathy were investigated. QTc was calculated according to Bazett's formula. 12 out of 14 patients with primary biliary cirrhosis, 18 out of 21 patients with HBsAg positive liver diseases and 11 out of 14 patients with cirrhosis of other origin had AN. No significant correlation between the laboratory parameters of cholestasis and AN was found. Abnormal QTc values (> 440 m/sec) were observed significantly more often (p < 0.002) in patients with AN than in patients without AN. Significant linear regression (p < 0.01) could be confirmed between the prolongation of the QTc-time and the severity of AN. Besides the non-invasive investigation of the cardiovascular reflexes the evaluation of the QT-time might be an additional diagnostic means to identify patients with an increased cardiovascular risk in chronic non-alcoholic liver diseases.