Decontamination of outdoor school swimming pools in Fukushima after the nuclear accident in March 2011.

Because of radioactive fallout resulting from the Fukushima Daiichi Nuclear Power Plant (NPP) accident, water discharge from many outdoor swimming pools in Fukushima was suspended out of concern that radiocesium in the pool water would flow into farmlands. The Japan Atomic Energy Agency has reviewed the existing flocculation method for decontaminating pool water and established a practical decontamination method by demonstrating the process at eight pools in Fukushima. In this method, zeolite powder and a flocculant are used for capturing radiocesium present in pool water. The supernatant is discharged if the radiocesium concentration is less than the targeted level. The radioactive residue is collected and stored in a temporary storage space. Radioactivity concentration in water is measured with a NaI(Tl) or Ge detector installed near the pool. The demonstration results showed that the pool water in which the radiocesium concentration was more than a few hundred Bq L was readily purified by the method, and the radiocesium concentration was reduced to less than 100 Bq L. The ambient dose rates around the temporary storage space were slightly elevated; however, the total increase was up to 30% of the background dose rates when the residue was shielded with sandbags.

Simultaneous multi-section perfusion CT and CT angiography for the assessment of acute ischemic stroke.

BACKGROUND: Introduction of helical computed tomography (CT) scanning has enabled rapid imaging of the vascular status by means of CT angiography and perfusion CT. By virtue of recent multi-detector technology, helical CT has the ability to perform both CT angiography and multi-section perfusion CT simultaneously. This study investigated the clinical feasibility of simultaneous assessment of perfusion CT and CT angiography in patients with acute ischemic stroke. METHOD: Perfusion CT and CT angiography were performed simultaneously in a series of consecutive 31 acute ischemic stroke patients. The time required for the entire processing was about 15 minutes. Contrast agent was used in a total dose of 100 ml (35 ml for perfusion CT and 65 ml for CT angiography). FINDINGS: Simultaneous perfusion CT scans and CT angiographies were of diagnostic quality for 29 patients (94%). In large territorial infarct patients, perfusion CT could predict all perfusion deficits of the final lesions (10 out of 10 lesions) and CT angiography could detect 9 of 10 occlusions of major cerebral arteries (90%). In patients with small lacunar or subcortical infarcts, perfusion CT could predict 9 out of 19 lesions (47.4%), and false-negative were encountered in small lesions (three patients) or in inadequate coverage of data acquisition (seven patients). Acute stage thrombolytic intervention could be carried out based on the findings, and the success of thrombolytic therapy could be demonstrated by follow-up study. CONCLUSIONS: Simultaneous perfusion CT and CT angiography is the very useful tool for the rapid and adequate diagnosis of almost all of the large territorial infarcts and some of non-territorial lacunar infarcts. It is an easy-to-perform and safe imaging technique to assess acute ischemic stroke.

[Development of comprehensive assessment system for elderly patients in a geriatric hospital].

Studies in the United States and Europe revealed that a comprehensive geriatric assessment is useful in the management and treatment of elderly disabled patients. In Japan, there are few reports of the development of such assessment. We examined the reliability of a scale designed to assess the performance of activities of daily living (ADL), a revised version of Hasegawa's Dementia Scale) HDSR, and a depression scale (GDS-15), using results from 140 patients over 65 years old who were admitted to our hospital from the end of January to early February 1994. The reliabilities of the ADL and HDSR scales were acceptable, but the kappa value of the GDS-15 was very low. The ADL score was low in patients with cerebrovascular diseases, dementia, and bone and joint problems, but the HDSR score was not low in the latter group. These results suggest that each disease has a characteristic pattern of impairments and disabilities. Although psychological assessment is essential and requires validation, a prospective study of outcomes in the evaluated elderly patients might also be fruitful.

Sympathetic hyperactivity in patients with vasospastic angina--assessment by spectral analysis of heart rate and arterial pressure variabilities.

The autonomic nervous system may play an important role in regulating coronary arterial tone. To evaluate the role of autonomic nervous activity in patients with vasospastic angina (VSA), we studied 10 VSA patients with patent coronary artery (mean; 56 yr, range; 44-66 yr) and 8 normal subjects (mean; 58 yr, range; 35-71 yr). ECG and arterial pressure were continuously recorded for 4 min in a supine position at 7:30 am, 10:30 am, and 4:30 pm. Low-frequency (LF; 0.04-0.15 Hz) and high-frequency (HF; 0.20 Hz) components of the beat-to-beat variabilities of the R-R interval (RRI) and systolic arterial pressure (SAP) were then estimated by autoregressive power spectral analysis. The LF-Normalized Power (LF-NP; [LF Power]/[Total Power]-[Direct Current Power]) of both the RRI and SAP variabilities were greater in VSA patients than in normal subjects (RRI: 0.51 +/- 0.07, 0.51 +/- 0.07, 0.53 +/- 0.06, vs 0.25 +/- 0.04, 0.31 +/- 0.05, 0.31 +/- 0.06, at 7:30 am, 10:30 am, and 4:30 pm respectively: p = 0.010, 0.044, 0.018. SAP: 0.62 +/- 0.06, 0.53 +/- 0.06, 0.57 +/- 0.06 vs 0.37 +/- 0.04, 0.30 +/- 0.06, 0.26 +/- 0.07, respectively: p = 0.006, 0.017, 0.003.). The LF-power of SAP variability also tended to be greater in VSA patients. There was no difference in the HF-component coefficient of variance (CCV (%) = 100 x (component power) (1/2)/ mean RR intervals) of the RRI variabilities between the 2 groups. These results indicate that increased sympathetic vasomotor tone and cardiac sympathetic predominance may play an important role in patients with VSA.

Determinants of exercise capacity in the hypertensive elderly--a study based on the assessment of cardiac reserve by dipyridamole radionuclide angiography.

To evaluate the determinants of exercise capacity in the hypertensive elderly with an assessment of cardiac reserve by dipyridamole radionuclide angiography, 31 elderly subjects (aged 62 to 78 years, 15 hypertensive and 16 normotensive) underwent symptom-limited maximum treadmill exercise with measurement of maximal oxygen consumption along with radionuclide angiography in list mode at rest and after dipyridamole infusion. In the normotensive elderly, maximal oxygen consumption correlated with relative filling volume during the rapid filling period at rest (r = 0.58; p < 0.05), and correlated inversely with the percent change in the peak ejection rate with dipyridamole (r = -0.63; p < 0.01). In contrast, maximal oxygen consumption correlated with atrial contribution at rest (r = 0.69; p < 0.005), and correlated inversely with the percent change in atrial contribution with dipyridamole (r = -0.87; p < 0.0001) in the hypertensive elderly. These results indicate that the mechanisms for maintaining exercise capacity are different in elderly subjects with or without hypertension.

[Evaluation of subjective happiness in the elderly using a visual analogue scale of happiness to analyze the effect of life style and neurobehavioral function on subjective happiness].

The effects of activity of daily living (ADL), physical conditions, social environmental factors and neurobehavioral functions on subjective happiness were investigated in 313 elderly subjects. The degree of subjective happiness was measured using visual analogue scale of happiness (VAS-H). There was significant relationship between VAS-H and ADL. The VAS-H score had weak but significant correlation with physical conditions and neurobehavioral functions. The social environmental factors, especially economical conditions, family relationships and group behavior had a significant correlation with VAS-H. In conclusion, in apparent healthy elderly people, the subjective degree of happiness was not related to ADLs, but to social environment and information physical conditions.

[Assessment of prognosis of old myocardial infarction].

In an attempt to predict high risk myocardial infarction, we studied 201 patients with Q wave infarction with dipyridamole-loading thallium-201 myocardial perfusion scintigraphy (D-MPS), left ventriculography, coronary angiography and treadmill exercise testing. The results of these tests were related to the use of initial PTCA or CABG, and the occurrence of cardiac deaths and nonfatal cardiac events during a mean follow-up period of 39 months. Three high risk parameters were identified by D-MPS; partial redistribution, diffuse slow washout, and extensive fixed defects. The patients were categorized into 3 groups according to the numbers of high risk parameters: group A (n = 50), patients with 2 or more high risk parameters; group B (n = 95), patients with one high risk parameter; group C (n = 56), patients without a high risk parameter. The prevalence of 3-, 2-, and one- or insignificant vessel disease was 72, 20 and 8% in group A, 15, 16, and 69% in group B, and 5, 13 and 82% in group C, respectively. Initial PTCA or CABG was performed in 42% of the patients in group A, 5% of the patients in group B, and 2% of the patients in group C. Among medically-treated patients, cardiac deaths occurred in 31% in group A, 4% in group B, and in none in group C. Nonfatal cardiac events occurred in 24, 12, and 4%, respectively. Coronary angiography revealed 3-vessel disease in 53 patients, 2-vessel disease in 32, and one-vessel disease or insignificant lesions in 116 patients. Initial PTCA or CABG was performed in 45% of the patients with 3-vessel disease, 6% of those with 2-vessel disease and 1% of those with one-vessel disease. Among medically-treated patients, cardiac deaths occurred in 31% with 3-vessel disease, 7% with 2-vessel disease, and in 2% with one-vessel disease. Nonfatal cardiac events occurred in 17, 10, and 3%, respectively.

[Prognostic significance of perfusion defect and its extension in dilated cardiomyopathy: assessment with thallium-201 myocardial scintigraphy].

To determine whether a change in the size of a scintigraphic perfusion defect is of prognostic significance in dilated cardiomyopathy (DCM), we performed thallium-201 myocardial scintigraphy twice for each of 13 patients with mean intervals of 45 +/- 18 months. Seven patients showed clinical deterioration (Group D) during the follow-up period of 58 +/- 22 months; whereas, 6 patients improved clinically as well as echocardiographically (LVDd < or = 5.5 cm and %FS > or = 20%) (Group I). 1. The initial scintigraphy showed that 3 patients had large defects (LD), 2 had multiple small defects (MSD) and 2 had no defects (NL) in Group D. Among 6 patients in Group I, one had LD, 3 had MSD and 2 had NL. 2. The second scintigraphy showed that in 5 patients in Group D, the defects were progressively enlarged and in the remaining 2 who had no defects at the initial scintigraphy, new defects developed (MSD). Among 6 patients in Group I, no patient had enlargement of defects. In 4 patients with defects (1LD, 3MSD), the sizes in their defects reduced. 3. At the initial study, all 7 patients in Group D fitted NYHA functional class III-IV; while, in Group I, 4 of the 6 patients fitted class III-IV and 2 patients class II. In the second study, all 7 patients in Group D remained in class III-IV; whereas, all 6 patients in Group I fitted class I-II. Five of the 7 patients in Group D died of heart failure after the second study.(ABSTRACT TRUNCATED AT 250 WORDS)