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Biomedical subjects

M Iio

Publications and source records attributed to M Iio.

At least 19 recordsLinked to original sources
PubMed1992

Death of serum-free mouse embryo cells caused by transforming growth factor beta 1 and effects of nutritional factors.

Transforming growth factor beta 1 (1 ng/ml) caused death of serum-free mouse embryo cells cultured in a medium consisting of a 1:1 mixture of Dulbecco's Modified Eagle's medium and Ham's F12 medium supplemented with fibronectin, insulin, transferrin, epidermal growth factor, and high density lipoprotein. Cell death occurred in the presence of polyunsaturated fatty acids including linoleic acid in the absence of selenium. The death could be reversed by adding alpha-tocopherol to the culture indicating a mechanism involving fatty acid peroxidation. Butylated hydroxytoluene was a poor suppressor of cell death in contrast to alpha-tocopherol. High density lipoprotein and fatty acid-free albumin also suppressed cell death at the level of 20 micrograms/ml and 1 mg/ml, respectively. Transforming growth factor beta 1 also caused a low rate of cell growth after heat treatment of the cells at 45 degrees C.

Albumins↗
PubMed1992

[Regional pulmonary function in intra-emphysematous bulla and peri-emphysematous bulla].

We have measured regional alveolar volume and regional ventilation of emphysematous lesions and periemphysematous lesions with positron emission tomography and N-13 gas in 10 patients. The purpose of the study was to investigate how emphysematous lesion develops. The subjects were all male (except one) who put on a mask in supine position, and were connected with a spirometer. We gave N-13 gas in this closed circuit and had the gas rebreathed by the subjects. After activity reached equilibrium in closed circuit, an equilibrium scan was made. We took "activity gas" from the closed circuit and measured activity by well counter during equilibrium to get quantitative alveolar volume. The activity in closed circuit during equilibrium showed activity in the thoracic unit. After equilibrium, we used air to wash out radioactive gas from the circuit. During washout we took 3 sequential images. The decreased rate of activity in the region of interest from these 3 sequential washout images was expressed in a monoexponential curve. The index of monoexponential denotes V/V. Alveolar volume in emphysematous lesions was 34.8 +/- 19.5 ml/100ml thoracic volume, and V/V in these lesions was 0.27 +/- 0.21/min. On the other hand alveolar volume in periemphysematous lesions was 76.5 +/- 13.1 ml/100ml thoracic volume, and V/V was 0.38 +/- 0.22/min. Thus alveolar volume in periemphysematous lesions was relatively high. These results indicate that the effect of emphysematous lesions as compared with periemphysematous lesions was not direct compression of alveolar space. The direct effect was compression to the bronchiole of peripheral lesions, and check valve mechanism occurred in the bronchiole causing peripheral lesions resulting in the destruction of the alveolar wall.

Adult↗
PubMed1992

Cerebral blood flow and oxygen metabolism in the Rett syndrome.

Positron emission tomography (PET) was performed on six patients with the Rett syndrome and the results were compared with the concurrent clinical status of the patients. The cerebral metabolic rate of oxygen (CMRO2) was low in five patients, and oxygen extraction fraction (OEF) was low in four patients; both had a tendency to decline with advancing age. Although the cause is unknown, it is suggested that impaired oxidative metabolism exists in the Rett syndrome. An analysis of the distribution among brain regions showed that the ratios of values for the frontal cortex to those for the temporal cortex for both the cerebral blood flow (CBF) and CMRO2 were lower than those for the controls, which may indicate the loss of hyperfrontality in the Rett syndrome. Distribution of brain metabolism may be immature in the Rett syndrome.

Adolescent↗
PubMed1991

Pulmonary artery morphology and hemodynamics in pulmonic valve atresia with ventricular septal defect before and after repair.

Cardiac catheterization and angiography were performed in 22 patients with pulmonic valve atresia and ventricular septal defect to evaluate pulmonary morphology and hemodynamics before and after repair. In 12 of the 22, pulmonic valve atresia and ventricular septal defect were associated with major aortopulmonary collateral arteries, which were ligated in most. Mean postoperative pulmonary artery pressure (PAP) ranged from 9 to 92 mm Hg (mean 28 +/- 19) and pulmonary vascular resistance ranged from 1.1 to 35.2 U.m2 (mean 6.4 +/- 8.0). These data correlated (r = 0.89, p less than 0.001). The number of pulmonary artery subsegments connected to the central pulmonary arteries was 22 to 42 (mean 38 +/- 6). Univariate analysis revealed that the mean postoperative PAP correlated with the number of pulmonary artery subsegments connected to the central pulmonary arteries (r = -0.81, p less than 0.001), with mean postoperative PAP (r = 0.79, p less than 0.001), with the postoperative pulmonary artery area index of the right and left pulmonary arteries at prebranching (r = -0.76, p less than 0.001), and with the sum of the pulmonary artery areas after branching (r = -0.69, p less than 0.005). Pulmonary vascular resistance correlated with the number of pulmonary artery subsegments connected to the central pulmonary arteries (r = -0.85, p less than 0.001), with the mean preoperative PAP (r = 0.79, p less than 0.001), with the sum of the pulmonary artery areas after branching (r = -0.73, p less than 0.001), and with the postoperative pulmonary artery area index (r = -0.70, p less than 0.001). The incidence of pulmonary vascular resistance being less than 3 U.m2 was significantly higher in patients with greater than 36 pulmonary artery subsegments connected to the central pulmonary arteries and with a preoperative pulmonary artery area index greater than 0.5 (88%) (p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1991

CT and MR appearance of focal nodular hyperplasia of the liver in children with biliary atresia.

Two children with biliary atresia are described in whom focal nodular hyperplasia of the liver occurred following portoenterostomy. The lesions were low-or iso-dense on unenhanced CT and became hypodense post-contrast enhancement. There was normal 99mTc phytate on hepatic colloid scintigraphy. On T2-weighted spin echo MR images, there was increased signal intensity within the masses, and the surrounding liver parenchyma was divided by linear septa in one of the two cases.

Biliary Atresia↗
PubMed1991

Malignancy associated with chronic empyema: radiologic assessment.

Radiologic findings of six cases of malignancy associated with chronic empyema 5-39 years in duration were reviewed. Pathologic examination confirmed three B-cell non-Hodgkin lymphomas, one round-cell sarcoma, one mesothelioma, and one adenocarcinoma. Retrospective findings on plain chest radiographs suggested the occurrence of malignancy: increased radiopacity in the thoracic cavity, soft-tissue bulgings and/or unsharpness of fat planes in the chest walls, destruction of bone near the empyema, and extensive medial deviation of the calcified pleurae. Computed tomography delineated masses with soft-tissue attenuation more clearly than radiography in all cases. Magnetic resonance images of three cases were informative because empyema cavities were surrounded by low-intensity rims, and two of them showed a signal intensity different from that of necrotic tumors. Scintigraphy revealed increased uptake of gallium in all cases. Ultrasonography was useful for biopsy guidance. Every radiologist should know this entity in observation of chest radiographs obtained in patients with chronic empyema, and further radiologic assessment and aggressive biopsy are recommended if malignancy is suspected.

Adenocarcinoma↗
PubMed1991

[Late postoperative pulmonary vascular resistance in patients with tetralogy of Fallot and pulmonary atresia].

Twenty-two patients with tetralogy of Fallot and pulmonary atresia underwent cardiac catheterization and angiocardiography late after repair. In ten patients, the disease was not associated with the major aortopulmonary collateral artery (MAPCA), but in 12 patients, the disease was associated with it. Three patients died after restudy, two because of pulmonary hypertension and one because of pneumonia. Pulmonary artery mean pressure was 15-92 (28 +/- 21) mmHg, being higher in 75% of the patients with MAPCA than the normal range. The number of pulmonary artery subsegments connected to the central pulmonary arteries was determined from pulmonary arteriography, being 22-42 (38 +/- 6). Pulmonary artery mean pressure and pulmonary vasculature resistance (PVR), 0.8-35.2 (10 +/- 9), inversely correlated with the number of the centrally connected pulmonary artery subsegments (r = -0.81, p less than 0.001 vs PAP, r = -0.85, p less than 0.001 vs PVR). PVR per subsegment also inversely correlated with them (r = -0.81, p less than 0.001). These findings suggest that pulmonary vasculature resistance is abnormally high in this disease, and increase as the number of the centrally connected pulmonary artery subsegments decrease.

Adolescent↗
PubMed1991

[Clinical application of 99mTc-SQ30,217 myocardial imaging--a study of pharmacokinetics and imaging time].

99mTc-SQ30217 555 MBq (15 mCi) was intravenously injected to 6 healthy subjects to study its safety, pharmacokinetics and the imaging time. Neither side effects nor abnormalities in physical findings, hemato-biochemical tests, urinary test, etc. caused by this agent were observed in any case and its safety was suggested. Radiation dose estimates over the entire body was 4.88 mGy/1,110 MBq (0.488 rad) and that over the major organs was less than 10 mGy and they were within the allowable ranges. 99mTc-SQ30217 showed biphasic disappearance curve in blood with the half-life of alpha-phase 0.02 hour and that of beta-phase 10.14 hours. 99mTc-SQ30217 was considered to show characteristic pharmacokinetics in that the myocardial accumulation was high in an early stage of the administration, but it rapidly decreased. Both heart to liver ratio and heart to lung ratio were high within 10 minutes, but they decreased after 15 minutes. As a result of SPECT imaging of 4 patients with ischemic cardiac disease, the images obtained with 99mTc-SQ30217 at an early period after the administration was as good as those with 201Tl and the appearance of defects in the images with both agents was similar. 99mTc-SQ30217 was considered to be sufficiently useful as a 99mTc-labelled agent for myocardial blood flow.

Adult↗
PubMed1991

[Prediction of coronary artery bypass graft flow--analysis of time density curve obtained from digital subtraction angiography].

UNLABELLED: To predict the coronary artery bypass graft(CABG) flow based on the time density curve(TDC) obtained from the digital subtraction aortograms(DSA), we developed a pulsatile CABG model (perfusion pressure 60, 130 mmHg, pulse rate 53, 126/min, cardiac output 3-7 l/min, diameter of the graft 2.1-6.0 mm). After positioning the regions of interest (ROI), we injected contrast medium (5-40 ml/sec, 5-40 ml) into the outlet conduit. Concerning the TDCs, we calculated appearance time(Ta), peak densities(Dp), peak time(Tp), disappearance time(Td), integral of TDC, delta Tp (difference of Tp between two ROI) and delta Ta (difference of Ta between two ROI). RESULTS: Perfusion pressure, graft flow and output curve were similar to those of patients with CABG. Ta, Tp, Td and delta Tp were affected by both the injection rate and the volume of the contrast medium; while Dp and the TDC integral were only affected by the latter parameter. Under the same conditions of contrast medium injection, the TDC depended strongly on graft flow, diameter of the graft, output and pulse rate. 21.6 + 0.92 pi.d2/4.delta 1/delta Tp.60 provided the most accurate estimation of CABG flow (r = 0.865, p less than 0.01). We conclude that densitometric analysis of DSA may be useful in the prediction of CABG flow.

Absorptiometry, Photon↗
PubMed1991

[Surgical treatment of tetralogy of Fallot with pulmonary atresia: early and late results].

From 1968 to 1987, 45 consecutive patients with tetralogy of Fallot and pulmonary atresia underwent corrective surgery. In the former 10 years, there were 8 operative deaths (40%) in the 20 patients and no late death. In the recent 10 years, there were 4 operative deaths and 4 late deaths in the 25 patients. In the 17 patients associated with large aorto pulmonary collateral artery (LAPCA) which was ligated in the most patients, there were 5 operative deaths (29%) and 3 late deaths. Nine patients (53%) survived long-term. There were 7 operative deaths (25%), one late death and 20 patients (71%) being long-term survivors in the 28 patients without LAPCA. Pulmonary hemodynamics were investigated in 10 patients without LAPCA and 11 with LAPCA after corrective surgery. Pulmonary arterial mean pressure (PAm) ranged from 9-24 (17 +/- 6) mmHg in patients without LAPCA and 15-92 (37 +/- 23) mmHg in those with LAPCA. Pulmonary arteriography showed arborization abnormality in 7 of the 11 patients with LAPCA. PAm inversely correlated well with number of pulmonary artery segments connected to the central pulmonary arteries. Postoperative pulmonary hypertension was found in patients with less than 16 bronchopulmonary segments connected to the central pulmonary arteries, and two of them died of pulmonary hypertension late after surgery. These results suggested that unifocalization to connect the central pulmonary artery more than 15 bronchopulmonary segments may be an important strategy for correction of this anomaly with LAPCA.

Child↗
PubMed1991

[Clinico-radiological correlation of Wilson's disease by magnetic resonance imaging, computed and positron emission tomography].

Follow-up magnetic resonance imaging (MRI) and computed tomography (CT) examinations were performed on five patients with Wilson's disease at intervals from 6 to 29 months. We studied the clinical correlation with MRI and CT, and whether the examination of MRI and CT could be useful for evaluation of the therapeutic effect. Positron emission tomography (PET) was also carried out on 4 cases except for an asymptomatic case (patient 2, sister of patient 1). Close relationship has been observed by MRI between dystonia and the lesion of the lenticular nuclei, abnormality of smooth pursuit eye movements and the brain stem lesion, and severe dysarthria/dysphagia and the lesion of the caudate and lenticular nuclei, respectively. In patient 4, repeated MRI of an interval of 18 months demonstrated decrease of the abnormal high signal in the lateral part of the putamen on T2-weighted image in accordance with marked improvement of clinical manifestations. In patient 3, who had severe dystonia of the extremities and trunk, T2-weighted image showed high signals in the lenticular nuclei. Marked decrease of the high signal in the lenticular nuclei was observed by MRI in this patient after 29 months, when her neurological manifestations were markedly improved. Patient 5 with severe cerebellar signs disclosed abnormal signals in the middle cerebellar peduncles, brain stem and dentate nuclei in addition to low signals in the caudate and lenticular nuclei, and high signals in the lateral part of the putamen on T2-sequence.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1991

[Quantitative regional alveolar volume and specific ventilation (V/VA) in healthy subjects measured with positron emission tomography].

We have measured quantitative regional alveolar volume and specific ventilation in healthy subjects by Nitrogen-13 gas and Positron Emission Tomography. Studies have proceeded in the supine position. Subjects have rebreathed N-13 gas in closed circuit. After radioactivity has reached equilibrium, Scan was carried out. During equilibrium, we have taken radioactive gas from the closed circuit to make quantitative alveolar volume and we have measured the radioactivity by well counter. This value means radioactivity in unit of thoracic volume. Well counts/PET counts denote alveolar volume/thoracic volume. After equilibrium, RI has been washed out by air, during the washout phase we have 3 sequential images. Using these sequential images, we have fitted RI activity in the washout phase monoexponential curve. Index of the monoexponential curve means -V/V, if we do not consider rebreathing from dead space. The data shows a large alveolar volume in the ventral region compared to that in the dorsal region, and also a high V/V in the dorsal region compared to that in the ventral region. It seems that the error of V/V in healthy subjects due to rebreathing from dead space is about 8%.

Animals↗
PubMed1990

[Development of all-silicone detachable balloons].

Treatment of cerebral vascular lesions such as carotid cavernous sinus fistulas and giant aneurysms is now being performed with intravascular detachable balloon embolization techniques. We have developed several types of all-silicone detachable balloons. Our balloons have self-sealing valves (with or without collars) and detach with simple traction. The self-sealing valve is smaller than 0.6 mm and the balloon can easily be placed through a 7-F catheter. We started clinical trials and a representative case was reported.

Embolization, Therapeutic↗
PubMed1990

[Avascular necrosis of the femoral head: chronological change of MR images].

Tl-weighted MR images of thirty-six hips in 25 patients with avascular necrosis of the femoral head were obtained two to five times during the course of 2 to 26 months. We investigated these MR images in the light of the chronological change and compared them with plain radiographs. MR images change in 16 femoral heads; in general, the abnormal low intensity area in the femoral head reduced in extent and the internal high intensity area became smaller of disappeared. Thirteen femoral heads among them became more flattened on plain radiographs in the same period. It is noted that four different zones are defined in the femoral head after bone necrosis takes place: the dead bone marrow, the dead marrow which still contains fat, the reactive interface and the hyperemic bone marrow. In Tl-weighted MR images, the dead bone marrow, the reactive interface and the hyperemic bone marrow are demonstrated as low intensity area, while the dead marrow containing fat may remain high in intensity. On the basis of this knowledge of histopathology and MR images of this disease, we suggest that reduction of the abnormal low intensity area and disappearance of the internal high intensity area on MR images can be regarded as diminution of hyperemia in the living bone marrow and loss of fat in the dead bone marrow, respectively.

Adult↗
PubMed1990

Quantitative measurement of regional myocardial blood flow in patients with coronary artery disease by intravenous injection of 13N-ammonia in positron emission tomography.

Measurement of myocardial blood flow with 13N-ammonia, a technique previously employed successfully in animal experiments, was introduced into clinical use to study patients with coronary artery disease. This advance has become possible by the development of a high resolution gated scan positron emission tomographic (PET) scanner equipped with a real time decay correction mechanism, HEADTOME-IV. The information obtainable includes myocardial size and wall motion as well as the absolute quantity of blood flow in various myocardial regions. The technique is simple but requires continuous arterial blood withdrawal for calculation of the arterial input function time integral. The alternative to this technique, i.e. the computation of intra left ventricular blood pool activity by PET is also discussed.

Adult↗