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J Urata

Publications and source records attributed to J Urata.

At least 19 recordsLinked to original sources
PubMed2001

Clinical evaluation of aortic diseases using nonenhanced MRA with ECG-triggered 3D half-Fourier FSE.

The efficacy of the nonenhanced magnetic resonance angiography (MRA) technique known as fresh-blood imaging (FBI), using electrocardiograph (ECG)-triggered 3D half-Fourier fast spin-echo (FSE), was evaluated for the detection and characterization of aortic diseases. Seventy-five consecutive patients with aortic disease underwent the FBI examination on a 1.5-T clinical imager. The results showed that the FBI technique permits clear visualization of aortic diseases, and the vessel branches and their relationship, which provides valuable information. Therefore, the nonenhanced FBI technique is appropriate to use for screening purposes.

Aged↗
PubMed2001

Familial multiple trichoepithelioma associated with subclavian-pulmonary collateral vessels and cerebral aneurysm--case report.

A 63-year-old woman presented with cerebellar infarction caused by occlusion of the right posterior inferior cerebellar artery. She had papules on her face that were identified histologically as multiple trichoepithelioma. Angiography revealed right subclavian-pulmonary collateral vessels and a cerebral aneurysm arising from the bifurcation of the right middle cerebral artery. Her grandmother, mother, and uncle had had similar papules, and the deaths of her mother and uncle were due to subarachnoid hemorrhage.

Aged↗
PubMed2001

[Evaluation of time dependency of the acetazolamide effect on cerebral hemodynamics as measured by 99mTc-ECD single-photon emission computed tomography].

PURPOSE: Kuwabara et al. have examined the cerebral artery dilation with acetazolamide (ACZ) challenge test using PET. And, they reported that ACZ reaction came out time dependently. We have developed a unique SPECT's method using Technetium-99m ethyl cysteinate dimer (99mTc-ECD) to verify the results obtained by Kuwabara et al. METHOD: 1000 MBq of 99mTc-ECD was exactly divided into three syringes. Each of which was intravenous infused (i.v.) at rest, 7.5, and 20 minutes after ACZ administration. Data collection was started using dynamic SPECT immediately after 99mTc-ECD i.v. at rest. Using necessary data only, SPECT images representing each of the three 99mTc-ECD i.v. was reconstructed. SPECT counts were obtained by the ROI method from each images to calculate relative CBF from rest to 7.5 and 20 minutes after ACZ administration. RESULT: The 18 hemispheres of nine patients in the negative control group in whom ACZ was not loaded. CBF was stable during the three evaluation. The measurement error our method was estimated as small. The 18 hemispheres of nine patients in the positive control group who has normal vasodilatory reserve, CBF was increased by 26.2 +/- 8.1% at 7.5 minutes and 29.3 +/- 13.1% at 20 minutes after ACZ administration. Seven patients with and chronic stage unilateral internal carotid artery severe stenosis and/or occlusion were evaluated as the test group. Case of unaffected side, CBF was increased by 17.6 +/- 6.9% at 7.5 minutes and 24.8 +/- 11.3% 20 minutes after ACZ administration. And, increase rate of CBF in the affected side was 2.8 +/- 1.6% at 7.5 minutes and 17.3 +/- 5.0% at 20 minutes after ACZ administration. In the affected side, timing of the maximum CBF increase caused by ACZ was remarkably delayed. CONCLUSION: Our method based on 99mTc-ECD SPECT also revealed delayed cerebral artery dilation in the affected side. It was suggested that ACZ reaction came out time dependently, as reported by Kuwabara et al.

Acetazolamide↗
PubMed2000

Altered phase relation between sleep timing and core body temperature rhythm in delayed sleep phase syndrome and non-24-hour sleep-wake syndrome in humans.

Changes in the phase relation between sleep timing and the circadian pacemaker are suspected to have an etiological significance in circadian rhythm sleep disorders. Simultaneous recordings of rest-activity and rectal temperature in seven sighted delayed sleep phase syndrome (DSPS) patients, seven sighted non-24-h sleep-wake syndrome (non-24) patients, and 14 healthy controls were made for 10-14 days continuously in the subjects' homes. We found that sleep length and the interval from the body temperature (BT) trough to sleep offset were significantly longer in both non-24 and DSPS patients than in the controls, and that the interval between sleep onset and the BT trough was significantly less in the non-24 patients than in the DSPS patients and the controls. We postulate these alterations in phase relation to be associated with phase changes of the circadian pacemaker via different illumination timings.

Adult↗
PubMed2000

Creutzfeldt-Jakob disease associated with cadaveric dura mater grafts in Japan.

A nationwide survey and recent information documented 57 patients with Creutzfeldt-Jakob disease (CJD) who had received dura mater grafts during the period between January 1979 and September 1999. At least 54 of these 57 patients received the same brand of dura mater graft from the same processor. Mean age at disease onset in the 57 patients with dural grafts was younger (51.9 years) than that in patients with sporadic CJD (63 years) (p < 0. 0001). Initial symptoms were cerebellar ataxia, disorientation, and visual or oculomotor disturbance.

Cadaver↗
PubMed2000

Effects of small dose of brotizolam on P300.

Nine healthy men (mean age, 22.2 years) participated in two experimental sessions cross-overed randomly in a double blind manner; one with a placebo and the other with 0.125 mg of brotizolam (BTZ) administered in the morning. Resting electroencephalogram and event-related potential under oddball paradigm was recorded before and 1, 2, 4, 6 and 8 h after the administration. Mean 30-msec bin amplitude from 240 msec to 450 msec after the stimulus was compared between placebo and drug sessions in order to observe P300. Brotizolam reduced the amplitude of P300 at 6 h after administration. It was noted that the effects of BTZ were most marked at Fz.

Adult↗
PubMed2000

Melatonin treatment for circadian rhythm sleep disorders.

This study investigated the effects of melatonin administration on circadian rhythm sleep disorders, and aimed to clarify clinical characteristics of melatonin responders. The subjects were 46 patients with circadian rhythm sleep disorders: 30 Delayed Sleep Phase Syndrome (DSPS) and 16 non-24 h sleep-wake syndrome (non-24). Patients took 0.3-1.0 mg of melatonin 5, 3 and 1 h before habitual bedtime. Seventeen patients responded to melatonin (12 DSPS, five non-24). Comparison of clinical background between responders and non-responders revealed that the responders were characterized by short total sleep time and later onset age of clinical symptoms.

Administration, Oral↗
PubMed1999

Poor recovery sleep after sleep deprivation in delayed sleep phase syndrome.

To clarify disturbances in sleep regulation in patients with delayed sleep phase syndrome (DSPS), we studied three patients with DSPS and seven healthy controls. Sleep propensity and melatonin rhythms after 24-h sleep deprivation were investigated under dim light condition by using the ultra-short sleep-wake schedule. The sleep propensity curves displayed clear differences between DSPS patients and the controls. During the subjective day when melatonin was not produced, recovery sleep after the sleep deprivation did not occur in DSPS patients, while recovery sleep occurred during the subjective day in controls. This suggests that DSPS may involve problems related to the homeostatic regulation of sleep after sleep deprivation.

Adult↗
PubMed1999

Effects of a small dose of triazolam on P300.

Ten healthy men (mean age, 33.9 years) participated in two experimental sessions cross-overed randomly in a double-blind manner: one with the placebo and another with 0.125 mg of triazolam (TRZ). Resting electroencephalography and event-related potential under oddball paradigm were recorded before the drug administration, and 1, 2, 4, 6 and 8 h after that. P300 waveforms were analyzed by peak amplitudes and 30-ms bin data. Triazolam may cause cognitive dysfunction without general sedation or apparent sleepiness, and this effect appeared 2 h, 4 h and 6 h, most prominently 6 h, after TRZ administration.

Adult↗
PubMed1999

Incidence rate of Creutzfeldt-Jakob disease in Japan.

BACKGROUND: The objective of this study is to clarify the incidence rate of Creutzfeldt-Jakob disease (CJD) during the last decade in Japan. METHODS: A nationwide mail survey was conducted in all hospitals with a minimum bed capacity of 100 and having at least one of three departments: neurology, psychiatry, and neuropathology. The survey required the patient's sex, date of birth, date of diagnosis, diagnostic criteria, medical history and CJD incidence in the family. RESULTS: From 493 hospitals throughout the country, 821 patients with CJD were reported from January 1985 through March 1996. The annual incidence rate was 0.49 per million population for males and 0.68 for females. The age-specific incidence rate was highest among those 70-79 years of age, followed by the 60-69, and 50-59 age groups. The incidence and mortality increased during the observed period; however, the incidence rate among younger generations did not rise. CONCLUSION: A nationwide incidence survey of CJD in Japan revealed the incidence and distribution of the disease over the recent decade. It was found that the incidence and mortality rates had increased during the observed period.

Adolescent↗
PubMed1999

Power Doppler sonography assessment of tumor recurrence after chemoembolization therapy for hepatocellular carcinoma.

OBJECTIVE: This study was undertaken to determine the value of power Doppler sonography in the evaluation of recurrent hepatocellular carcinomas after transcatheter arterial chemoembolization therapy. SUBJECTS AND METHODS: Forty-five patients (age range, 45-81 years; mean age, 61 years) with hepatocellular carcinomas prospectively underwent power Doppler sonography, helical CT, and intraarterial digital subtraction angiography before and after transcatheter arterial chemoembolization therapy to evaluate for tumor recurrence. Three to 6 months after transcatheter arterial chemoembolization therapy, the Doppler signal, its location, and shape were evaluated. The results were compared with tumor vascularity as determined on helical CT and intraarterial digital subtraction angiography, which were used as the gold standards (n = 142). RESULTS: A sonographic signal was seen in 80 of 142 lesions with power Doppler sonography. Flow signal in lesions tended to be more difficult to detect in the left lobe (sensitivity, 74%) than in the right lobe (sensitivity, 93%). The location of the color signal was in the tumor's center, on its periphery, or both. No correlation between tumor recurrence and the location of a signal within a tumor was found. Power Doppler sonography had a sensitivity of 87%, a specificity of 85%, and an accuracy of 86% in revealing tumor recurrence after transcatheter arterial chemoembolization therapy. All lesions that showed linear signals in the center or at the periphery of the tumors proved to be recurring tumors (n = 20). In lesions with spotty signals, tumor recurrence was not revealed in nine of 60 lesions. CONCLUSION: Power Doppler sonography can be used for follow-up studies after transcatheter arterial chemoembolization therapy as a sensitive and cost-effective imaging technique. Although spotty signals were frequently seen, linear signals appeared to be specific for tumor recurrence.

Aged↗
PubMed1999

[Technical investigation of cerebral blood flow measurements using the Patlak Plot method--a contrivance for positioning of the gamma camera at data collection in radionuclide angiography].

The time-activity curve for the aortic arch obtained from radionuclide angiography (RNA) is handled as an input function parameter according to the method of Matsuda et al., which determines regional cerebral blood flow non-invasively. The data are collected from a frontal view of the thorax captured by RNA by their method, however we encountered a case in which it was difficult to identify aortic arch in the data collection from the frontal view. The precise identification of the aortic arch was implemented when the RNA data were collected from the left anterior oblique view of the thorax. No significant difference was noted in the measured values between the data collection from the frontal view and from the left anterior oblique view. Our method seems to be useful modification of the Patlak plot method.

Aged↗
PubMed1999

[Reduction of the influence of the liver uptake to the myocardial uptake on technetium-99m myocardial SPECT; usefulness and problems of a mask processing method].

The aim of this study is to evaluate the usefulness of a mask processing method for obtaining the true myocardial tracer distribution by eliminating the influence of the liver uptake to the myocardial uptake on myocardial SPECT images by using technetium-99m (99mTc) blood flow agents. A SPECT imaging was performed with a two-head SPECT system (GCA-7200A/DI) in both phantom and clinical studies. The mask processing method was applied to the reconstructed and projection images. The phantom consisted of heart, lung, liver and spine. A defect was located in the inferior wall of the left ventricle and other parts of the heart and liver were filled with 99mTc solution. For clinical study 10 patients with difficulty in the interpretation of the inferior wall were selected for the evaluation of usefulness of the mask method. In the phantom study, the mask processing method applied to the reconstructed images was able to remove the overlapped liver from the heart, but was not able to remove the influence of the liver uptake to the myocardial uptake. Nevertheless, the mask processing method applied to the projection images successfully eliminated not only the overlapped liver but also the influence of the liver uptake to the myocardial uptake. In the clinical study, the liver uptake could be removed from the uptake in the inferior wall in 8 of 10 patients with the mask processing methods. In 2 patients, the overlapped liver uptake could not be eliminated from the uptake in the inferior wall because the distance between the liver and heart was too short. The mask processing method applied to the projection images was thought to be superior to that applied to the reconstruction images in both phantom and clinical studies. The mask processing method, especially applied to the projection images, seems to be useful for the elimination of the liver uptake from the inferior wall of the myocardium on myocardial SPECT images using 99mTc blood flow agents.

Artifacts↗
PubMed1998

Hepatic parenchymal perfusion abnormalities after pancreaticobiliary surgery. Evaluation with dynamic helical CT.

PURPOSE: To evaluate perfusion abnormalities of the liver after pancreaticobiliary surgery. MATERIAL AND METHODS: We retrospectively evaluated 128 patients with pancreaticobiliary malignant tumors who had been examined both before and after surgery by means of helical CT of the liver. An infusion of 3 ml/s of 60% nonionic contrast material was followed by helical CT of the liver in a sequential arterial phase, portal venous phase, and equilibrium phase. RESULTS: Of 128 patients, we followed 97. In 21 patients (22%) we found 47 lesions with perfusion abnormalities that were detected 1-33 months (mean 6.6 months) after the operation. All patients were asymptomatic. The shape of each perfusion abnormality was characterized as geographic (n = 23, 47%), wedge-shaped (n = 21, 45%), or round (n = 3, 8%). The abnormalities were seen in the arterial phase in 46 lesions (98%), in the portal venous phase in 18 lesions (38%), and in the equilibrium phase in 1 lesion (0.2%). In all lesions, the size either decreased spontaneously, or it remained unchanged for more than one year. CONCLUSION: Perfusion abnormalities of the liver may occur in patients who undergo pancreaticobiliary surgery. This findings should not be confused with hypervascular metastases.

Aged↗
PubMed1998

The effects of transjugular intrahepatic portosystemic shunt on portal hypertensive gastropathy.

In addition to variceal bleeding, haematemesis may occur due to haemorrhagic gastritis in patients with portal hypertension. This has been known as portal hypertensive gastropathy (PHG). We have evaluated the effects of the transjugular intrahepatic portosystemic shunt (TIPS) on portal venous pressure (PVP) and endoscopic gastric mucosal changes observed in patients with portal hypertension. We performed TIPS in 12 patients with complications due to portal hypertension as follows: variceal bleeding in nine patients (bleeding from oesophageal varices in seven and gastric varices in two), refractory ascites in three and haemorrhage from severe PHG in one. Endoscopic examinations were performed before and after TIPS for all patients. Changes of PVP and gastric mucosal findings on endoscopy were analysed. Before TIPS, PHG was seen in 10 patients. Portal venous pressure decreased from an average of 25.1+/-8.8 to 17.1+/-6.2 mmHg after TIPS (P<0.005). On endoscopy, PHG improved in nine of 10 patients. Oesophagogastric varices improved in eight of 11 patients. In one patient with massive haematemesis, haemorrhage from severe PHG completely stopped after TIPS. Because TIPS effectively reduced PVP, this procedure appeared to be effective for the treatment of uncontrollable PHG.

Endoscopy, Gastrointestinal↗
PubMed1998

Clinical characteristics of circadian rhythm sleep disorders.

From our practice at the sleep disorders clinic in Kohnodai Hospital, National Center of Neurology and Psychiatry (NCNP), we report the clinical characteristics of circadian sleep-wake rhythm disorders. Nearly 90% of circadian rhythm sleep disorders were diagnosed as delayed sleep phase syndrome (DSPS) or as non-24 sleep-wake syndrome (non-24). While DSPS was equally common in males and females, non-24 was more frequently seen in men. It was of psychiatric interest that a considerable number of patients had depressive states in the course of their circadian rhythm sleep disorders. Difficulty in adapting to social life was more severe in patients with non-24 than in those with DSPS.

Adult↗
PubMed1998

Continuous measurement of temperature in non-24 hour sleep-wake syndrome.

The onset of the low temperature (LT) zone which was defined as a period when the rectal temperature was below its daily mean is a convenient circadian phase marker. In this study, we document three cases of non-24 h sleep-wake syndrome in which identification of the LT zone as an evening circadian phase marker contributed to clinical judgments. We found that the LT zone was correlated well with dim light melatonin onset. Moreover, calculating the LT zone was useful in determining phase position in irregular sleep pattern and in determining the timing of bright light therapy.

Adult↗