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Background Chronic ischemia because of internal carotid artery (ICA) occlusive disease may result in dementia. The goal of this study was to assess cognitive impairment in symptomatic patients with hemodynamic cerebral ischemia and determine the efficacy of extracranial-intracranial (EC-IC) bypass in restoring neuropsychologic integrity. Methods Twenty-five patients were defined by clinical and neuroradiological criteria as suffering from hemodynamic cerebral ischemia because of unilateral ICA or middle cerebral artery occlusion. Subjects underwent assessment of cerebral blood flow and metabolism using positron emission tomography (PET) before and after bypass surgery. To provide data regarding cognition, changes in the Japanese Wechsler Adult Intelligence Scale Revised (WAIS-R) were recorded. Results Preoperative study of patients revealed significant impairment in cerebral blood flow and metabolism as well as reduced WAIS-R score. Among the factors considered, only elevated regional oxygen extraction fraction and reduced regional cerebral metabolic rates of oxygen were significantly associated with preoperative cognitive impairment (p = 0.0032 and p = 0.0255, respectively; logistic regression analysis). After bypass surgery, cerebral blood flow and metabolism improved significantly, and the WAIS-R score increased. Conclusion Symptomatic patients with hemodynamic cerebral ischemia displayed impaired cognition that was partially alleviated with EC-IC bypass surgery.

OBJECTIVE AND IMPORTANCE We describe a case of brainstem cavernous angioma in which the neural tracts were evaluated before surgery by three-dimensional anisotropy contrast (3-DAC) magnetic resonance imaging. CLINICAL PRESENTATION A 64-year-old man presented with a cavernous angioma located intrinsically in the brainstem and manifesting as gait ataxia. 3-DAC imaging demonstrated that the lesion was located outside the left inferior cerebellar peduncle and inside the middle cerebellar peduncle. INTERVENTION The intact brain surface was incised, and the lesion was removed successfully on the basis of the preoperative 3-DAC images. The patient exhibited temporary exacerbation of his gait ataxia, but the symptom improved 3 months after surgery. Postoperative 3-DAC imaging demonstrated resection of the lesion and preservation of the left inferior and middle cerebellar peduncles. CONCLUSION 3-DAC imaging may provide essential information about the neural tracts for the planning of brainstem surgery.

For the treatment of 11 patients with hyperacute embolic occlusion of major cerebral arteries (ten with occlusion of middle cerebral artery and one with occlusion of basilar artery), TCD-enhanced thrombolysis (TCDET) was performed in combination with ultrasound irradiation, using diagnostic transcranial Doppler (TCD) (TC2-64B: 2MHz, 100mW/cm2, pulsed wave) (TCDET group), and the effectiveness of this procedure was compared with that of local intra-arterial fibrinolysis (LIF) in 45 patients with embolic occlusion of the middle cerebral artery (LIF group). Regarding dose of TPA, the LIF group used 1046.7 ± 607.8 units and the TCDET group 700.0 ± 431.3 units (p < 0.05). Regarding time technically required to attain recanalization, the LIF group required 68.2 minutes, and the TCDET group 28.6 minutes. A good outcome was noted in 60.8% of the LIF group and 64% of the TCDET group. Haemorrhagic transformation was observed in 7.8% of the LIF group and in 0% of the TCDET group. No complications due to TCD irradiation were observed in the TCDET group. These findings suggest that TCDET can be an effective method of achieving recanalization.

During influenza epidemics in Japan, the number of children with acute encephalopathies and encephalitis has recently increased. Although the pathophysiologies remain unclear, there is usually brain edema with evidence of damage to the blood-brain-barrier (BBB). We investigated the glial reaction and apoptosis in brains of eight such cases comprising two of acute necrotizing encephalopathy and six of influenza encephalopathy, and compared the results with those in five control brains. Apoptosis, evidenced by chromatin condensation and fragmentation in hematoxylin sections, in situ end labeling of fragmented DNA (TUNEL) and DNA laddering, was observed in neurons and glial cells in four brains with influenza encephalopathy. In the TUNEL-positive brains, the increase in microglia was greater than in the TUNEL-negative brains. Immunoreactivity for active-caspase 3, demonstrated by immunohistochemistry, and the overexpression of a caspase-cleaved fragment of poly(ADP-ribose) polymerase, demonstrated by Western blotting, indicated that activation of caspase 3 is involved in the apoptotic pathway in the brains of influenza encephalopathy cases. Apoptosis or specific pathological processes that cause apoptosis may give rise to aggravated encephalopathy.

Introduction of clinical high-field MRI has raised interest in the use of clinical imaging--the efficacy of which has not yet been fully established--in daily practice. A high signal-to-noise ratio and profound susceptibility effects can improve the spatial resolution and image contrast of clinical imaging, whereas the heating effects of the radio frequency tend to prolong acquisition time. As well, inhomogeneities in the static or local magnetic fields can have a negative effect on image quality. The T(1) prolongation may affect T(1) contrast yet improve the enhancement effect of gadolinium chelate and the inflow effect of MR angiography. High-contrast imaging, such as the short inversion-time inversion recovery technique, can provide excellent intra- and extracerebral contrast comparable to microscopic or macroscopic specimens. High-field systems can also be applied to microscopic imaging. High-field MRI is expected to have an increased clinical impact in the near future. Technological advances tailored to high-field systems, as well as the accumulation of scientific evidence, will be necessary to establish its predominance over conventional MRI.

In vivo, water diffusion displays directionality due to presence of complex microstructural barriers in tissue. The extent of directionality of water diffusion can be expressed as a fractional anisotropy (FA) value, using diffusion tensor MR imaging (DTI). The aim of this study was to determine whether FA values indicate microstructures in astrocytic tumors. We performed DTI in 31 patients with astrocytic tumor, and measured the FA values of tumor and normal brain regions prior to CT-guided stereotactic biopsy. After biopsy, FA values were compared to assess the cellularity and vascularity of tumor tissue. Although mean FA values trended to differ among histological types, all mean tumor FA values were lower than those of normal brain regions. Positive correlation was observed between FA values and both cellularity (r = 0.65, p < 0.05) and vascularity (r = 0.45, p < 0.05). We had hypothesized that the FA value of an astrocytic tumor would be determined by a balance between factors increasing the directionality of water diffusion, such as high cellularity and/or vascularity, and factors decreasing the directionality of water diffusion, such as fiber destruction. However, our results suggest that the FA values of glioblastoma, anaplastic astrocytoma, diffuse astrocytoma and pilocytic astrocytoma are largely affected by cellularity and/or vascularity, whereas that of gliomatosis cerebri are largely affected by the preservation of nerve fibers. Measurement of FA value using DTI will allow prediction of histological characteristics such as cellularity, vascularity and/or fiber structure in astrocytic tumors.

1996年1月から2002年4月までの期間に,初回CTにて急性硬膜下血腫およびそれに伴う脳腫張が主病変であり,GCSが10以下もしくはmidline shiftが10mm以上であった重症例52例に対し,救急外来での穿頭による血腫除去術を行った。52例中42例は搬入時既に瞳孔異常を伴う脳ヘルニア状態を呈していた。穿頭術のみによる血腫除去率は平均で69%であり,なかでもCT所見にて低吸収像の混在するmixed densityを呈する症例ほど除去率が高かった。穿頭術後に瞳孔所見や意識の改善が36例(69.2%)に認められた。穿頭術のみで脳圧管理が可能であった症例は13例であった。全症例の転帰は,GOS評価でGR 6例,MD 6例,SD 4例,PVS 4例,D 32例であった。さらに術式別にみると,穿頭術のみではGR 6例,MD 4例,SD 1例,D 22例であり,開頭術を追加されたものはMD 2例,SD 3例,PVS 4例,D 10例であった。穿頭血腫除去術は,急性硬膜下血腫に対しては効果的でかつ迅速に行える方法で,重症頭部外傷例においても施行可能な手技である。ゆえに救急外来での穿頭血腫除去術は,重症急性硬膜下血腫例に対して試みるべき方法であると思われた。

Hypoxic cells play a key role in the radioresistance of malignant glioma. Interferon-beta, ACNU as nimustine hydrochloride and radiotherapy (IAR) is a common therapy for malignant glioma in Japan. Since hyperbaric oxygenation (HBO) increases oxygen pressure in glioma tissue, we applied a modified IAR therapy, radiotherapy after HBO combined with interferon-beta and ACNU (HBO/IAR therapy), for supratentorial malignant gliomas. Daily radiation therapy was completed within 15min after HBO. We assessed HBO/IAR with respect to toxicity, response rates and the time of tumor progression (TTP). We also examined the incidence of responses by some prognostic factors before HBO/IAR, namely, age, Karnofsky performance scale (KPS), histological type, tumor size, tumor site and operation type. Of 39 patients who participated in this study, 35 underwent a complete schedule of HBO/IAR therapy in which toxicity was permissible. Thirty patients (76.9%) either maintained or increased KPS during HBO/IAR with a mean duration of 68±14 days. The response rates (CR+PR%) for glioblastoma, anaplastic astrocytoma and overall were 50%, 30% and 43%, respectively. The incidence of therapeutic responses among all prognostic factors before HBO/IAR did not significantly differ. Median TTP for patients with glioblastoma, patients with anaplastic astrocytoma, and overall were 38, 56 and 43 weeks, respectively. The present study suggested that HBO/IAR therapy could be applied to especially patients with poor prognostic factors, because of its short treatment period, its permissible toxicity and identical response to patients with good prognostic factors.

✓ Although various biomaterials such as ceramics or titanium alloy are widely used in neurosurgery, the susceptibility artifacts that appear around these materials cause problems when a magnetic resonance (MR) imager is used to assess lesions after surgery. The purpose of the present study was to quantify the susceptibility artifacts produced by various biomaterials used for neurosurgical implants. Using a 3-tesla MR imaging unit, we obtained MR images of various biomaterials, including six types of ceramics, a cobalt-based alloy (Elgiloy), pure titanium, a titanium alloy, and stainless steel. All implants shared a uniform size and shape. In each image, a linear region of interest was defined across the center of the biomaterial in the transverse direction, and the diameter of the susceptibility artifact was calculated. The ceramics produced a considerably smaller artifact diameter than those produced by other biomaterials. Among the types of ceramics, zirconia was found to produce the smallest artifact diameter. Among the remaining biomaterials, the diameters of the artifacts decreased in order from that associated with stainless steel to those associated with cobalt-based alloys, pure titanium, and titanium alloy. Little difference was observed between the artifact diameters associated with pure titanium and titanium alloy. Ceramics are the most suitable biomaterials for minimizing artifacts in high-field MR imaging.

OBJECTIVE Multislice computed tomographic angiography (CTA) can provide clearer vascular images, even of the peripheral arteries, than conventional CTA. Multislice CTA was compared with digital subtraction angiography (DSA) for the detection of cerebral vasospasm in patients with acute aneurysmal subarachnoid hemorrhage (SAH) to analyze whether multislice CTA can replace DSA in the detection of vasospasm after SAH. METHODS Within 72 hours after the onset of symptoms, multislice CTA and DSA were performed in 20 patients with SAH. Multislice CTA and DSA were repeated on Day 7 to assess cerebral vasospasm. Regions of interest were established in the proximal and distal segments of the anterior and middle cerebral arteries on both multislice CTA and DSA images, and the agreement between the severity of vasospasm on multislice CTA and DSA images was statistically compared. The multislice Aquilon computed tomography system (Toshiba, Inc., Tokyo, Japan) used the following parameters: 1 mm collimation and 3.5 mm per rotation table increment (pitch, 3.5). RESULTS The degree of vasospasm as revealed by multislice CTA correlated significantly with the degree of vasospasm revealed by DSA (P < 0.0001). The agreement between the severity of vasospasm on multislice images obtained via CTA and DSA in the overall, proximal, and distal segments of the cerebral arteries was 91.6, 90.8, and 92.3%, respectively. CONCLUSION Multislice CTA can detect angiographic vasospasm after SAH with accuracy equal to that of DSA.

Connective tissue growth factor (CTGF) was recently described as a cysteine-rich mitogenic peptide that is the prototypic member of the CCN family of protein including CTGF/fisp12, cef/10/cyr61 and nov. Recently CTGF was reported to have a function of mediating endothelial cell adhesion and migration through integrin alpha(v)beta3, promoting endothelial cell survival, and inducing angiogenesis in vivo. To clarify involvement of CTGF in tumor angiogenesis, using brain tissues with glioblastoma, we examined CTGF expression and localization by immunohistochemical staining and reverse transcription-polymerase chain reaction. The result showed that both glioblastoma tumor cells and proliferating endothelial cells are positive for CTGF by immunohistochemical staining, and CTGF mRNA expression was evaluated by RT-PCR in the brain tissues of glioblastoma. These findings suggest that CTGF may have the potential to stimulate angiogenesis in glioblastoma and function as an angiogenic factor in the process of tumor growth.

The aim of this prospective study was to investigate whether decreased cerebrovascular reactivity to acetazolamide, as determined by single-photon emission computed tomography (SPECT), is an independent predictor of the 5-year risk of subsequent stroke in patients with symptomatic major cerebral artery occlusion. Cerebrovascular reactivity to acetazolamide in the middle cerebral artery (MCA) territory ipsilateral to the occluded artery was determined on the basis of two different methodologies: cerebral blood flow (CBF) percent change obtained quantitatively from xenon-133 (133Xe) SPECT, and asymmetry index (AI) percent change obtained qualitatively from N-isopropyl- p-[123I]-iodoamphetamine (IMP) SPECT. Seventy patients with unilateral internal carotid artery or MCA occlusion were divided into two groups within each SPECT methodology (normal or decreased CBF percent change and AI percent change) and followed up for 5 years. Cumulative recurrence-free survival rates for patients with decreased CBF percent change were significantly lower than for those with normal CBF percent change ( P = 0.0205). There was no significant difference in cumulative recurrence-free survival rates between patients with decreased AI percent change and those with normal AI percent change. Only decreased CBF percent change was a significant independent predictor of stroke recurrence ( P = 0.0051). The present study demonstrated that decreased cerebrovascular reactivity to acetazolamide determined quantitatively by Xe SPECT is an independent predictor of the 5-year risk of subsequent stroke in patients with symptomatic major cerebral artery occlusion, and that the qualitative method using I-IMP SPECT is a poor predictor of the risk of subsequent stroke in this type of patient.

Background and Purpose — The present study prospectively evaluated relationships among baseline characteristics, cerebral hemodynamics, and outcome of patients with symptomatic major cerebral artery occlusion, by quantitative measurement of cerebral blood flow using xenon-133 ( 133 Xe) inhalation and single-photon emission computed tomography (SPECT). Methods — Regional cerebrovascular reactivity (rCVR) to acetazolamide was calculated at entry to the study using 133 Xe SPECT. Seventy consecutive patients aged less than 70 years with unilateral internal carotid artery (ICA) or middle cerebral artery (MCA) occlusion were divided into 2 groups: normal or reduced rCVR, and prospectively followed up for a period of 24 months. Results — During the follow-up period, recurrent strokes occurred in 8 of the 23 patients with reduced rCVR at entry and in 3 of 47 patients with normal rCVR. Cumulative recurrence-free survival rates in all patients, and in each subgroup of patients with ICA or MCA occlusion and reduced rCVR on entry, were significantly lower than in those with normal rCVR ( P =0.0030, P =0.0404, and P =0.0310, respectively; Kaplan-Meier analysis). Among the factors considered, only lower rCVR and resting regional cerebral blood flow values were significantly associated with the risk of stroke recurrence ( P =0.0019 and P =0.0080, respectively; Cox regression multivariate analysis). Conclusions — The present study demonstrated that reduced rCVR to acetazolamide as determined by 133 Xe SPECT is significantly associated with an increased risk of stroke recurrence in patients with symptomatic MCA or ICA occlusion.

Lesions in acute herpes simplex encephalitis (HSE) have been reported to show decreased uptake of Tc-99m ethyl cysteinate dimer (ECD). A patient with acute HSE displaying a lesion in the left temporal lobe was evaluated by means of Tc-99m ECD single-photon emission computed tomography (SPECT). Dynamic SPECT images indicated regionally increased uptake of tracer in the ipsilateral temporal lobe in early phases, followed by slight washout of Tc-99m ECD from the lesion. Static SPECT images revealed increased tracer uptake in the same region. MRI later demonstrated that the HSE lesion involved the whole cortex of the temporal lobe on the affected side. These findings suggest that acute HSE lesions do not always exhibit hypoactivity on static Tc-99m ECD SPECT, and that dynamic Tc-99m ECD SPECT may help physicians diagnose acute HSE.

OBJECTIVE AND IMPORTANCE Treatment of one side in cases of dissecting aneurysms of the bilateral vertebral arteries (VAs) with subarachnoid hemorrhage may result in dissection or rupture on the contralateral side. CLINICAL PRESENTATION Three patients presented with dissecting aneurysms of the bilateral VAs with subarachnoid hemorrhage. INTERVENTION Two patients underwent trapping of the ruptured VA, with side-to-side anastomosis between the bilateral posteroinferior cerebellar arteries. One patient underwent resection of the ruptured VA, with interposition of a saphenous vein graft. Two patients died as a result of rupture of the contralateral VA dissecting aneurysm after surgery. One patient demonstrated development of an unruptured dissecting aneurysm in the contralateral VA 1 month after surgery. CONCLUSION Surgical intervention to treat dissecting aneurysms of the bilateral VAs on one side carries the risk of rupture of the contralateral lesion. Increased hemodynamic stress may be important in the development and rupture of dissections in the contralateral VA.

Adaptive arrays are recognized as a solution to multipath fading environments that can be a serious problem in high-speed mobile communication systems. However, huge computational loads are required due to its spatio-temporal signal processing. Subband signal processing has been known as a parallel signal processing scheme on the frequency domain. It allows us to allocate heavy computational loads to several processors when it is implemented in digital signal processors (DSPs) or field programmable gate arrays (FPGAs) and so on. Basically, the performance of adaptive arrays based on subband signal processing is identical to that based on time domain signal processing. However, several types of configurations are possible. As a result, there is a configuration that is very advantageous in terms of the computational reduction even though its performance is slightly degraded compared to one configured in the time domain. In this paper, an adaptive array based on subband signal processing that can intensively reduce computational loads is implemented by using DSPs and its performance is verified through experiments in an anechoic chamber. Finally, the computational loads of adaptive arrays are examined and the implemented adaptive array is shown to realize very efficient signal processing.

It has been reported that Tc-99m ethyl cysteinate dimer (ECD) SPECT imaging may not show reperfusion hyperemia in patients with subacute stroke. The authors describe a patient with embolic middle cerebral artery occlusion who was examined using xenon-133 and dynamic and standard Tc-99m ECD SPECT immediately after early recanalization. Standard Tc-99m ECD SPECT images revealed hypoactivity in the ipsilateral middle cerebral artery territory. In contrast, the dynamic Tc-99m ECD SPECT images from the first scan (very early images acquired 36 seconds after injection) showed hyperactivity in the same region and provided imaging contrast comparable to what would be obtained with xenon-133 tomography. Hemorrhagic transformation later developed in this region. These results indicate that images from very early dynamic Tc-99m ECD SPECT of areas with irreversible changes produced by acute stroke can reveal reflow hyperemia that standard Tc-99m ECD SPECT images fail to show.

The temperature and pH of human lower leg muscles were estimated noninvasively using1H-NMR spectroscopy at 3.0 and 1.5 T on five normal volunteers (21M, 24M, 27M, 34M, 47M). The chemical shifts of water and imidazole protons relative to cholines (–N+CH3) or creatines (–CH3) could be used as the temperature and pH probes, respectively [1–4]. Using the chemical shift, estimated values of the temperature in gastrocnemius (GAS; shell region) and soleus muscles (SOL; core region) under ambient temperature (21–25°C) were 33.6±0.4 and 35.3±0.4°C (mean±SE), respectively (significantly different; P < 0.01). The values of pH in these muscles were estimated to be 6.97 ± 0.01 and 6.96 ± 0.02, respectively. Alternation of the surface temperature of the lower leg from 40 to 10°C significantly changed the temperature in GAS (P < 0.0001) from 35.8 ± 0.4 to 26.2 ± 1.2°C and the pH in GAS rose from 6.95 ± 0.01 to 7.01 ± 0.01 (P r= –0.59, P

Measurement of oxygen pressure (pO2) in tumor tissue is important, because pO2 is a major factor for radiosensitivity in malignant glioma treatment. We attempted to elucidate the changes in pO2 level in glioblastoma tissue of patients under various conditions. Eighteen patients with newly diagnosed glioblastoma were recruited to this study. Disposable Clark-type electrodes were inserted using CT guided stereotactic surgery under local anesthesia and left in the intra- and peritumoral regions. pO2 was measured in patients under conditions of being awake and asleep, inhaling 100% O2, being administered osmotic diuretics and following hyperbaric oxygen exposure (HBO). Peritumoral tissue had a significantly higher pO2 value in both awake and sleeping patients. O2 inhalation could not significantly increase the pO2 level, whereas administration of osmotic diuretics induced an increase in pO2 levels in peritumoral tissue alone. The pO2 levels were significantly increased in both regions after HBO, and a high pO2 level was maintained until 15 min after HBO in both regions. It is possible that the pO2 level in peritumoral tissue is affected by intracranial pressure, whereas that in the intratumoral tissue is usually low. HBO was the optimal procedure for oxygenation, but its benefit was reduced over time.

大学における情報処理教室の施設は、情報処理教育、専門性の強いシミュレーション、実験、製図ばかりでなく、施設のマルチメディア機能の活用を意図する多くの授業で使用されるようになってきた。授業で使用されないときは、自習等による自由使用のために開放されることが多い。このような利用形態においては、種々な原因により多様の障害が頻繁に発生するが、大学の保守体制の実情を鑑みると、最小の人数で効率よく「いつも正常に機能させる」ことがより強く求められる。本稿では、大学の情報処理教室で発生している障害の状況を紹介し、FDドライバ、MOドライバ、CR-ROMドライバ、一部の応用ソフトウェアの故障など、比較的軽微な障害については早期発見が困難で、対応が遅れがちになることを示す。次いで、情報処理教室の設備保守作業の効率化・省力化に役立つ手法の体系化を行い、前述の比較的軽微な障害を含み、効果的な手法が見出されていない領域の障害対策として作成された、情報処理教室の利用者ログより障害をもつコンピュータを見つけ出すソフトウェア「ログ追跡ビューア」について報告する。「ログ追跡ビューア」を使用した結果、重大な障害をもつ学生機ばかりでなく、比較的軽微な障害をもつ学生機も検出できる可能性が確かめられた。, The university's information processing practice rooms have been increasingly used by various classes for computer-aided and comprehension clarification purposes, as well as for information-processing education. Additionally, while not being used for classes the rooms are open for self- study and other purposes. Such use of the rooms may lead to problems. With the university's present maintenance resources, the classrooms are required to be maintained and fully functioning with a minimum number of staff. This paper describes the results of the development of the Log-Tracking Viewer software, which has been shown to be effective in detecting small problems such as the breakdown of FD, MO, CD-ROM drivers and the malfunction of sections of application software. We also show that it has previously been difficult to detect such small problems in a timely manner.

【背景】近年胃の発癌因子としてHelicobacter pylori (以下H. pylori) の感染が広く認知されてきたが, 感染者のうち胃癌に進展するのは僅かな例である.【目的, 方法】H.pylori感染胃癌例の個体差を明らかにするため年齢, 性別, 胃癌の分化度, ABO式血液型について検討を行った.【対象】1996～2000年に診断が確定している胃癌例113例, 胃・十二指腸良性疾患18例を対象とした.【結果】男性の H.pylori陽性は分化型が, 陰性例は低分化型が多く, 女性ではその逆の傾向がみられた.H. pylori陽性胃癌, 胃十二指腸良性疾患例では血液型比率は日本人における比率とほぼ同様であったが, H. pylori陰性胃癌ではA型が減少しAB, O型が増加する傾向がみられた.【考察】H. pylori感染と胃発癌における決定的な相関を有する因子は認められなかったが, 男女差, 血液型で一定の傾向が認められた.予防医学的見地からも胃発癌性の個体差の解明が必要と考えられた.

To examine the degree to which price fluctuations affect how individuals approach an intertemporal decision-making problem, we conduct a laboratory experiment in which subjects spend their savings on consumption over 20 periods. In the control treatment, the commodity price is constant across all periods. In the small (large) price-fluctuation treatment, the price rate of change is always 1% (20%), and the rate of change of savings is always the same as the commodity price. Therefore, the optimal amount of consumption is the same in all three treatments. Our main findings are threefold. First, the magnitude of misconsumption (i.e., the deviation from optimal consumption) is significantly high in order of the control, small price-fluctuation, and large price-fluctuation treatments. Second, in the control treatment, the magnitude of misconsumption shrinks over time, whereas it gradually increases in the small and large price-fluctuation treatments. Finally, regardless of the presence of price fluctuations, subjects exhibit under-consumption (over-saving) behavior, and the presence of price fluctuations strengthens such a tendency.

Here, we present a digital phantom for evaluating the kurtosis model in diffusion analysis of a human brain. The phantom images can be acquired by a simulation with setting the parameters in the cortex, white matter and some nuclei in the basal ganglia. The phantom may contribute to the estimation for the robustness to noise and it has the possibility to validate the reproducibility in the fitting for diffusion analysis in human study.

Mental health is one of the most important issues facing disaster survivors. The purpose of this study is to determine the prevalence and correlates of mental health problems in survivors of the Great East Japan Earthquake and Tsunami at 6-11 months after the disaster. The questionnaire and notification were sent to the survivors in three municipalities in the Tohoku area of the Northern part of Honshu, Japan's largest island, between September 2011 and February 2012. Questionnaires were sent to 12,772, 11,411, and 18,648 residents in the Yamada, Otsuchi, and Rikuzentakata municipalities, respectively. Residents were asked to bring the completed questionnaires to their health check-ups. A total of 11,124 or (26.0%) of them underwent health check-ups, and 10,198 were enrolled. We excluded 179 for whom a K6 score was missing and two who were both 17 years of age, which left 10,025 study participants (3,934 male and 6,091 female, mean age 61.0 years). K6 was used to measure mental health problems. The respondents were classified into moderate (5-12 of K6) and serious mental health problems (13+). A total of 42.6% of the respondents had moderate or serious mental health problems. Multivariate analysis showed that women were significantly associated with mental health problems. Other variables associated with mental health problems were: younger male, health complaints, severe economic status, relocations, and lack of a social network. An interaction effect of sex and economic status on severe mental health problems was statistically significant. Our findings suggest that mental health problems were prevalent in survivors of the Great East Japan Earthquake and Tsunami. For men and women, health complaints, severe economic status, relocations, and lack of social network may be important risk factors of poor mental health. For men, interventions focusing on economic support may be particularly useful in reducing mental health problems after the disaster.

The prevalence of patients with asymptomatic unruptured intracranial aneurysms (UIAs) increases with the advancing age of the general population. The goal of the present study was to identify risk factors for the growth of UIAs detected with serial MR angiography (MRA) in patients 70 years of age or older.This prospective study enrolled 79 patients (age range 70-84 years) with 98 UIAs. Patients were followed up every 4 months, including an assessment of the aneurysm diameter and morphological changes on MRA, neurological status, and other medical conditions. Aneurysm growth was categorized into two different patterns on the basis of the MRA findings: 1) maximum increase in aneurysm diameter of 2 mm or more; and 2) obvious morphological change, such as the appearance of a bleb.The mean duration of follow-up was 38.5 months (250.2 patient-years). Aneurysm rupture did not occur, but aneurysm growth was observed in 8 aneurysms (8 patients) during the study period. Univariate analysis showed that female sex, patient age ≥ 75 years, and an aneurysm location in the internal carotid artery (ICA) or middle cerebral artery (MCA) were associated with aneurysm growth (p = 0.04, p = 0.04, and p0.001, respectively). Multivariate analysis demonstrated that female sex was the only independent predictor of aneurysm growth (p = 0.0313, OR 2.3, 95% CI 1.3-30.2).Female sex is an independent risk factor for the growth of UIAs in elderly patients. In addition, an age ≥ 75 years and aneurysm location in the ICA or MCA are characteristics that may warrant additional attention during follow-up imaging.

We investigate endogenous timing in a mixed duopoly in a differentiated product market. We find that private leadership is better than public leadership from a social welfare perspective if the private firm is domestic, regardless of the degree of product differentiation. Nevertheless, the public leadership equilibrium is risk-dominant, and it is thus robust if the degree of product differentiation is high. We also find that regardless of the degree of product differentiation, the public leadership equilibrium is risk-dominant if the private firm is foreign. These results may explain the recent revival of public financial institutions in Japan.

Although a higher heart rate is known to be a risk factor for cardiovascular disease (CVD) events, there have been no reports concerning bradycardia. Whether lower and higher resting pulse rates (RPRs) are associated with cardiovascular risk was investigated in subjects from a community-based, prospective cohort study.After subjects with atrial fibrillation, subjects with a history of CVD, and subjects receiving antihypertensive treatment were excluded, 17,766 subjects (5958 men), aged 40-79 (mean 61.5) years, were analyzed. The RPR at baseline was categorized into four groups (RPR60, 60-69.5, 70-79.5, ≥80 beats per minute (bpm)) using the average value of two consecutive measurements. The endpoint was set as the composite outcome of myocardial infarction, stroke, or sudden death.During a mean follow-up of 5.6 years, there were 213 events in men and 186 events in women. In Cox regression models, increased risks of CVD were found in the men group with RPR60 bpm, as well as the group with RPR≥80 bpm, compared with the reference group with RPR 60-69.5 bpm (hazard ratio [HR] = 1.73, p = 0.005 and HR = 2.01, p 0.001). These increased risks were found even when adjusted for age and other CVD risk factors (HR = 1.55, p = 0.026 with RPR60 bpm and HR = 1.72, p = 0.009 with RPR≥80 bpm). In women, there were no significant associations between RPR and CVD risk.Bradycardia, as well as a higher pulse rate, may be an independent risk factor for future cardiovascular events in apparently healthy men.

Background and Purpose— About one half of those who develop adult-onset moyamoya disease experience intracranial hemorrhage. Despite the extremely high frequency of rebleeding attacks and poor prognosis, measures to prevent rebleeding have not been established. The purpose of this study is to determine whether extracranial–intracranial bypass can reduce incidence of rebleeding and improve patient prognosis. Methods— This study was a multicentered, prospective, randomized, controlled trial conducted by 22 institutes in Japan. Adult patients with moyamoya disease who had experienced intracranial hemorrhage within the preceding year were given either conservative care or bilateral extracranial–intracranial direct bypass and were observed for 5 years. Primary and secondary end points were defined as all adverse events and rebleeding attacks, respectively. Results— Eighty patients were enrolled (surgical, 42; nonsurgical, 38). Adverse events causing significant morbidity were observed in 6 patients in the surgical group (14.3%) and 13 patients in the nonsurgical group (34.2%). Kaplan–Meier survival analysis revealed significant differences between the 2 groups (3.2%/y versus 8.2%/y; P =0.048). The hazard ratio of the surgical group calculated by Cox regression analysis was 0.391 (95% confidence interval, 0.148–1.029). Rebleeding attacks were observed in 5 patients in the surgical group (11.9%) and 12 in the nonsurgical group (31.6%), significantly different in the Kaplan–Meier survival analysis (2.7%/y versus 7.6%/y; P =0.042). The hazard ratio of the surgical group was 0.355 (95% confidence interval, 0.125–1.009). Conclusions— Although statistically marginal, Kaplan–Meier analysis revealed the significant difference between surgical and nonsurgical group, suggesting the preventive effect of direct bypass against rebleeding. Clinical Trial Registration— URL: http://www.umin.ac.jp/ctr/index.htm . Unique identifier: C000000166.

To evaluate the performance and efficacy for intensity inhomogeneity correction of various sequences of the human brain in 7T MRI using the extended version of the unified segmentation algorithm.Ten healthy volunteers were scanned with four different sequences (2D spin echo [SE], 3D fast SE, 2D fast spoiled gradient echo, and 3D time-of-flight) by using a 7T MRI system. Intensity inhomogeneity correction was performed using the "New Segment" module in SPM8 with four different values (120, 90, 60, and 30 mm) of full width at half maximum (FWHM) in Gaussian smoothness. The uniformity in signals in the entire white matter was evaluated using the coefficient of variation (CV); mean signal intensities between the subcortical and deep white matter were compared, and contrast between subcortical white matter and gray matter was measured. The length of the lenticulostriate (LSA) was measured on maximum intensity projection (MIP) images in the original and corrected images.In all sequences, the CV decreased as the FWHM value decreased. The differences of mean signal intensities between subcortical and deep white matter also decreased with smaller FWHM values. The contrast between white and gray matter was maintained at all FWHM values. LSA length was significantly greater in corrected MIP than in the original MIP images.Intensity inhomogeneity in 7T MRI can be successfully corrected using SPM8 for various scan sequences.

BACKGROUND A patient with normal perfusion pressure breakthrough (NPPB) after surgical removal of an arteriovenous malformation (AVM) was evaluated using single photon emission computed tomography cerebral blood flow (CBF) imaging. CASE DESCRIPTION A 48-year-old man suffered consciousness disturbance because of an intraventricular hemorrhage and underwent ventricular drainage. Cerebral angiography showed a medium-sized AVM in the left parietal lobe. Three months after the ictus, a left parietal craniotomy was performed and total removal of the AVM was achieved. A brain region adjacent to the AVM with preoperative decreased vasoreactivity to acetazolamide showed marked hyperperfusion after AVM excision. Hemorrhage subsequently occurred in this area. CONCLUSION CBF mapping seems to offer a noninvasive method for the preoperative identification of AVM patients at risk for NPPB, and to allow for early postoperative diagnosis of NPPB.

To clarify how Alzheimer disease pathology develops in the brains of nondemented subjects, we examined the interrelations among the amounts and morphology of Abeta deposition, neurofibrillary pathology, and apolipoprotein E (ApoE) genotype in the frontal association cortex of 101 autopsy brains from patients aged between 40 to 83. Senile plaque density correlated well with the logarithmic data of insoluble Abeta measured by enzyme immunoassay (EIA). The amounts of Abeta42-ETA increased dramatically in the late preclinical stage, whereas the AP42+ plaque density increased in the early preclinical stage. Neurofibrillary pathology appeared only in the areas with severe Abeta deposition and in subjects aged over 70. The ApoE epsilon4 allele enhanced the Abeta3 deposition in presenile subjects. Plaque-associated glial Abeta was prominent in subjects with mild to moderate Abeta deposition. The morphology of cerebral Abeta deposition changed from diffuse plaques with small amounts of Abeta in each plaque in the early preclinical stage to primitive/neuritic plaques with larger amounts of Abeta in each plaque in the late preclinical stage. Our findings suggest that the prevention of Abeta deposition in the late preclinical stage can be a rational therapeutic target, especially in elderly people with ApoE epsilon4 allele.

From a practical point of view, it is important to be able to predict the collection efficiency of the axial flow hydro-cyclone. In order to perform such estimation, it is necessary to predict the cut-size for the various operating conditions. Up to this time, there were many papers that derived the cut-sizes theoretically based upon the effect of the centrifugal force on the suspended solid particles, and experimentally based upon the effect of the geometrical construction of the hydro-cyclone on particle size. However, there have been few, if any, papers that included the effects of gravitational settling on the suspended solid particles when estimating the cut-size for the hydro-cyclone. Therefore, this paper presents the theoretical equation of the cut-size, which includes the gravitational and centrifugal forces acting on the suspended solid particles in the axial flow hydro-cyclone. The equation is derived based on the mass balance. The characteristics of the predicted cut-size are divided into two ...

In this paper we will discuss the MAP receiver design for the reception of the image signal. It is impractical to use the MAP algorithm for the source detection because of its huge calculation costs. To solve this problem we propose a novel MAP receiver structure, where the receiver contains a predictor within it. With an aid of the predictor we can reduce the calculation. Furthermore we can approximate the a priori probability by the prediction error distribution.