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Biomedical subjects

M Iio

Publications and source records attributed to M Iio.

At least 127 records · Page 7Linked to original sources
PubMed1987

Hepatic haemangioma: dynamic MRI using gadolinium-DTPA.

Six patients with hepatic haemangioma were examined with a 1.5 tesla magnetic resonance scanner before and immediately after bolus injection of 0.05 mmol/kg gadolinium-DTPA. Eight to ten spin-echo images (TR: 100 msec, TE: 20 msec, scanning time: 26 sec) were obtained through the region of the haemangioma. In all cases, dense contrast enhancement of the lesion was demonstrated. The enhancement spread in all directions from the lesion on subsequent delayed scans (high signal fill-in); a signal higher than that from surrounding hepatic parenchyma was present two minutes after contrast injection. Dynamic MRI is a promising method for the evaluation of hepatic haemangioma and it is more easily tolerated by patients than dynamic CT using iodinated contrast medium.

Adult↗
PubMed1986

New polyvinyl alcohol gel material for MRI phantoms.

Nambu PVA gel which is produced by repeated freezing and thawing of PVA solution has overcome almost all of the problems which present substances have: It is close to human soft tissue in MRI parameters. MRI parameters (1H density, T1, T2) are adjustable to some extent. It has appropriate physical characteristics. The important problem with PVA gel is long-term stability. It is assumed that this problem can be solved by its periodic calibration and replacement.

Cold Temperature↗
PubMed1986

Preferential accumulation of 11C in human brain tumors after intravenous injection of 11C-1-pyruvate.

Regional cerebral turnover of 11C following intravenous injection of 11C-1-pyruvate was investigated in 12 patients with brain tumors. The positron emission tomography (PET) image taken at 10-15 min after the injection always demonstrated a high concentration of 11C in tumor, and thus visualized precise tumor contours. This phenomenon was not influenced qualitatively by the variation of blood flow in the tumor. Brain edema associated with the tumor was not visualized. We conclude that the localization of brain tumors would be well determined by the PET scan, using 11C-1-pyruvate.

Adult↗
PubMed1986

Brain ischemia and infarction positively visualized by pyruvate-1-11C using positron-emission tomography.

We describe positron-emission tomography (PET) scintigraphic findings obtained using pyruvate-1-11C in eight patients with cerebral ischemic hypoxia or infarction. The extraction of 11C by brain tissue from blood after an i.v. injection of 11C-pyruvate was very rapid, being almost complete after a single circulatory passage. Most ischemic lesions were found to be more or less deficient with regard to 11C-extraction capacity. With time, however, the ratio of 11C in ischemic tissue to that in normal tissue was inverted, and the ischemic lesion appeared as a 'hot' area in the scintigram. Very old infarcts did not exhibit this phenomenon. These observations indicate the usefulness of an 11C-pyruvate PET scan for the diagnosis of therapeutically restorable brain damage.

Adult↗
PubMed1986

Tailored angiographic approach to small hypovascular renal tumors.

The value of an appropriate oblique view renal arteriography which we call "tailored oblique," was illustrated in 2 cases. In the first case, a renal mass on the left side with anterior exophytic growth was found by computerized tomography (CT). In the second case, a tumor on the right side with posterior exophytic growth was detected by CT. Preoperative angiographies were performed. In both cases, the anteroposterior projections were not diagnostic. But in the "tailored oblique" projections both showed definite tumor vessels. Both tumors were resected and proved to be renal cell carcinomas. We believe "tailored oblique" projection provides additional confirmative information on the nature of the tumor.

Adult↗
PubMed1986

Response of regional cerebral blood flow and oxygen metabolism to thalamic stimulation in humans as revealed by positron emission tomography.

To clarify functional neural pathways originating from the thalamic nucleus ventralis posterolateralis (VPL) in humans, the responses of regional CBF (rCBF) and regional CMRO2 (rCMRO2) to VPL stimulation were investigated by positron emission tomography in five patients who had undergone chronic implantation of electrodes into the VPL for therapeutic purposes. Measurement of rCBF and rCMRO2 under continuous inhalation of C15O2 and 15O2 by steady-state methods revealed significant increases of rCBF and rCMRO2 in the frontal, postcentral, and thalamic regions. The increases in rCBF and rCMRO2 of the postcentral regions were clearly predominant in the stimulated hemisphere insofar as the stimulation produced moderate paresthesia in restricted areas of the body. These results indicate that the VPL relays peripheral somatosensory information, which has previously been demonstrated to be transmitted to the frontal as well as postcentral regions.

Cerebrovascular Circulation↗
PubMed1986

Scintigraphic manifestation of fibrous dysplasia.

Scintigraphic manifestations of fibrous dysplasia were analyzed in 59 lesions of 26 patients (12 monostotic, 14 polystotic). Bone imaging with Tc-99m MDP revealed a high percentage of increased uptake of radioisotope in the lesions of fibrous dysplasia. Four (14%) of 29 cystic lesions and two (7%) of 30 lesions with the appearance of ground glass showed no increase in radioisotope uptake, although roentgenograms showed marked changes. Therefore, care must be taken in the diagnosis of fibrous dysplasia with bone imaging alone. Nuclear methods, however, are indispensable in evaluating the dynamic aspects of bone mineral behavior and in demonstrating disease where none was suspected, or in visualizing polyostotic involvement in those cases where only monostotic disease was suspected clinically. It is concluded that both scintigrams and roentgenograms are complementary procedures in the diagnosis of fibrous dysplasia.

Adolescent↗
PubMed1986

Effects of flavonoids on xanthine oxidation as well as on cytochrome c reduction by milk xanthine oxidase.

That flavonoids inhibit xanthine oxidase from cow milk was confirmed by measuring oxygen consumption with an oxygen electrode. In contrast, flavonoids did not inhibit glucose oxidase, another oxygen consuming enzyme. Among the flavonoids tested, quercetin, kaempferol, myricetin, chrysin, quercitrin, and morin were potent inhibitors of xanthine oxidase; their inhibition rates (%) were 80, 70, 69, 62, 59, and 51 at 100 microM (except chrysin at 50 microM), respectively. The xanthine oxidase-inhibiting activities of the flavonoids were not always well correlated with the suppressive activities of the flavonoids on cytochrome c reduction by a xanthine-xanthine oxidase system. The inhibition of xanthine oxidase by quercetin was not affected by cupric ion. The partition rates of the flavonoids between n-butanol and a buffer solution seemed to account for some of the inhibition.

Animals↗