Long-term exposure to high radon concentration exerts pathological effects and elicits changes in respiratory function, increasing an individual’s risk of developing lung cancer. In health risk assessment of indoor radon, consideration of long-term exposure thereto is necessary to identify a relationship between indoor radon exposure and lung cancer. However, measuring long-term indoor radon concentration can be difficult, and a statistical model for predicting mean annual indoor radon concentrations may be readily applicable. We investigated the predictability of mean annual radon concentrations using national data on indoor radon concentrations throughout the spring, summer, fall, and winter seasons in Korea. Indoor radon concentrations in Korea were highest in the winter and lowest in the summer. We derived seasonal correction and seasonal adjustment factors for each season based on the method proposed by previous study. However, these factors may not be readily applicable unless measured in a specific season. In this paper, we separate seasonal correction factors for each month of the year (new correction factors) based on correlations between indoor radon and meteorological factors according to housing type. To evaluate the correction factors, we assessed differences between estimated and measured mean annual radon concentrations. Roughly 97% of the estimated values were within ±40 Bq/m3 of actual measured values in detached houses, and roughly 85–87% of the estimated values were within ±40 Bq/m3 of the measured values in other residences. In most cases, the seasonal correction factors and the new correction factors had slightly better agreement than the seasonal adjustment factor. For predicting mean annual radon concentrations, the seasonal correction factors or seasonal adjustment factors can be of use when actual measurements of indoor radon concentrations for a specific season are available. Otherwise, the new correction factors may be more readily applicable.
We investigated levels of the β-amyloid 1–42 (Aβ42), total tau protein (T-tau) and tau phosphorylated at position threonine 181 (P-tau) in cerebrospinal fluid (CSF) of idiopathic normal pressure hydrocephalus (iNPH) patients and tried to find their clinical implications in the evaluation and treatment of iNPH. Twenty-five possible iNPH patients were prospectively enrolled and their CSF was collected to analyze levels of Aβ42, T-tau and P-tau using ELISA method. Gait disturbance, urinary incontinence, and cognitive impairment were semi-quantified and detailed neuropsychological (NP) test was performed. Eight iNPH patients were classified into the lower CSF Aβ42 group and 17 patients were classified into the higher CSF Aβ42 group. There was no difference in the iNPH grading score and its improvement after LP between the two groups. The lower CSF Aβ42 group showed more deficits in attention, visuospatial function and verbal memory in the baseline NP test and less improvement in phonemic categorical naming and frontal inhibitory function after LP. Our study suggested that concomitant AD in iNPH patients might contribute to lumbar puncture or shunt unresponsiveness, especially in the field of cognitive dysfunction.
1 January 2021 in Allergy, Asthma & Immunology Research
Objective:To assess the feasibility and accuracy of synthetic MRI compared to conventional T1 weighted and multi-echo spin-echo (MESE) sequences for obtaining T2 values in the knee joint at 3 Tesla.Methods:This retrospective study included 19 patients with normal findings in the knee joint who underwent both synthetic MRI and MESE pulse sequences for T2 quantification. T2 values of the two sequences at the articular cartilage, bone marrow and muscle were measured. Relative signal intensity (SI) of each structure and relative contrast among structures of the knee were measured quantitatively by T1 weighted sequences.Results:The mean T2 values for cartilage and muscle were not significantly different between MESE pulse sequences and synthetic MRI. For the bone marrow, the mean T2 value obtained by MESE sequences (124.3 ± 3.6 ms) was significantly higher than that obtained by synthetic acquisition (73.1 ± 5.3 ms). There were no significant differences in the relative SI of each structure between the methods....