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Biomedical subjects

Y Takeuchi

Publications and source records attributed to Y Takeuchi.

At least 703 records · Page 39Linked to original sources
PubMed1991

[Transcranial color Doppler guided Matas' test].

Carotid artery involvement in head and neck tumor is a great concern to surgeons because of the unpredictable effects of its resection. For the investigation of brain collateral circulation, color Doppler guided Matas' test has been performed to examine blood flow in the middle cerebral artery (MCA) and internal carotid artery (ICA). SSA-270A convex (3.75MHz) and linear (3.75MHz, 2.5MHz) array probes (Toshiba Co., Ltd.) were used for this investigation. A temporary occlusion test (60 sec) was performed on the common carotid artery (CCA) in thirty patients who were scheduled to undergo radical neck dissection. The blood flow velocity of MCA during Matas' test was recorded. Then relative flow (percent blood flow before the test) of MCA during the 60 sec Matas' test was measured. The relative mean flow was 72% with a standard deviation of 15%. The results of thirty patients were classified into four groups according to the relative flow of MCA after 60 sec occlusion of the common carotid artery: Group A, over 87% (three cases); Group B, 86-72% (twelve cases); Group C, 71-57% (twelve cases); Group D, under 56% (three cases). Brain collateral circulation (BCC) of the Group A patients was considered to be excellent, and therefore reconstructive vascular surgery (RVS) was not necessarily indicated. In Group B patients (fair) and Group C patients (slightly poor) further investigation of BCC, i.e., Balloon Matas' test (occlusion of CCA and ICA), SPECT and brain angiography, was considered to be necessary. In Group D patients (poor) RVS was inevitable if either CCA or ICA had to be resected. Important information is provided by this noninvasive examination to predict the risk of carotid resection. This test seems to be useful to determine whether or not RVS is indicated.

Adult↗
PubMed1991

[Application of color Doppler to the head and neck region].

In the diagnosis of the head and neck region it is important to investigate the relationship between the lesions and surrounding vessels, including their hemodynamics, pre- and/or postoperatively. For this purpose color Doppler has been used in recent years. However, there is little information on the use of color Doppler in this region. This report describes an attempt to apply this examination to the region of the head and neck. Standard methods of detection of the main arteries and internal jugular vein have been devised, and the blood velocity and flow of those arteries were measured using SSA-270A convex (3.75 MHz) and linear (3.75 MHz, 2.5 MHz) array probes (Toshiba Co., Ltd.). This technique was also applied to several clinical cases. The results of these investigation were as follows. 1) The middle cerebral, vertebral and basilar, and carotid arteries and their branches could be studied. 2) Blood velocity and flow of the main arteries were reasonable when compared with the results of scintigraphy and electromagnetic studies. 3) The vessels surrounding the tumors were easy to detect. The location or hemodynamics of metastatic tumors, pseudoaneurysm, and tongue hemangioma could also be displayed. The technique was also useful for the blood flow estimation in the portion of vascular anastomosis.

Adult↗
PubMed1991

[A case of anomalous origin of circumflex artery from right sinus of valsalva recognized by transesophageal echocardiography].

A 56-year-old man visited our hospital for further examination of resting electrocardiographic abnormality. Positive exercise stress resulted in mild chest discomfort and 1.5 mm ST depression in II.III.aVF leads. Myocardial imaging perfusion with thallium-201 was normal and an anomalous origin of the left circumflex coronary artery from the right aortic sinus was observed by coronary angiography. MRI showed that the vessel running behind the aorta was connected to the right Valsalva's sinus. Furthermore, transesophageal echocardiography revealed that the vessel connected to the lateral wall of the left ventricle was running from the right Valsalva's sinus between the aorta and left atrium. The above results indicated that this vessel was the left circumflex artery. Although myocardial infarction or sudden death in patients with coronary anomaly has been discussed, the mechanism is still unknown. The present case is a rare one in which the anatomical relation between the anomalous coronary and the great vessels was directly detectable by transesophageal echocardiography. Transesophageal echocardiography is useful for the assessment of this type of coronary anomaly.

Cardiac Catheterization↗
PubMed1991

[Asbestos concentration and fiber size in lungs of the urban residents].

Asbestos fiber concentrations and fiber size distribution in lung tissues of 53 urban residents (males: 34, female: 19) were analyzed by low temperature ashing-analytical transmission electronmicroscopy. The following findings were obtained. 1. Pulmonary asbestos fibers were found in 51 out of 53 patients. The types of asbestos fibers were chrysotile, amosite, crocidolite, actinolite and tremolite. 2. Thirty-six of 53 patients had no history of occupational asbestos exposure, and their geometric mean concentration of asbestos fibers was 1.67 x 10(6) fibers/g dry lung. Most of these asbestos fibers are probably attributable to general environmental contamination. Thirteen patients who had a history of occupational asbestos exposure showed a geometric mean of their pulmonary asbestos concentrations (5.82 x 10(6) fibers/g dry lung) which was significantly higher than that of patients without occupational asbestos exposure (p less than 0.01). 3. The geometric mean concentration of asbestos fiber in males (2.70 x 10(6)) was higher than in females (1.59 x 10(6)), probably due to a difference in the occupational asbestos exposure between males and females. 4. Regardless of the patient's sex, the geometric mean concentration of asbestos fibers in patients without a history of smoking (male: 4.91 x 10(6), female: 1.78 x 10(6)) was higher than that in patients with a smoking history (male: 2.76 x 10(6), female: 1.37 x 10(6)). The difference, however, was not statistically significant, and no correlation was seen between the concentration of asbestos fibers and smoking history. 5. Although most asbestos fiber utilized in Japan is chrysotile, the geometric mean concentration of chrysotile (0.87 x 10(6)) was almost identical to that of amphibole asbestos fiber (0.90 x 10(6)). 6. Of the asbestos fibers observed, 95% of chrysotile and 85% of amphibole asbestos were less than 5 microns in length and 93% of the total asbestos fibers were too small to be visible by light microscopy.

Adult↗
PubMed1991

Simple and efficient method for clinical isolation of Bordetella pertussis.

Commercially available Amies transport medium with charcoal and three isolation media were tested to assess their efficiency in the clinical isolation of B. pertussis. First, the isolation rates of B. pertussis were compared between direct inoculation of nasopharyngeal specimens and inoculation after being stored in Amies transport medium for eight hours or less. The organism was detected in 43 specimens from 29 patients with at least one of the two inoculation methods. The comparative isolation rates were 81% (35 of 43) for both direct inoculation and transport medium. Second, nasopharyngeal specimens were incubated for five days at 35 degrees C on the three media; Bordet Gengou Medium (BG) with 5 micrograms of CEX per ml, Cyclodextrin Solid Medium (CSM) with 5 micrograms of CEX per ml, and Charcoal Agar with 40 micrograms of CEX per ml. The organism was detected from 44 nasopharyngeal specimens of 20 patients on at least one of the three tested media. The comparative isolation rates were 91% (40 of 44) on BG with 5 micrograms of CEX per ml, 93% (41 of 44) on CSM with 5 micrograms of CEX per ml, and 91% (40 of 44) on CA with 40 micrograms of CEX per ml. Although no differences in the isolation rates were observed among the three media, the appearance of the colonies was earlier by one day on BG than the other two media. The detection of B. pertussis was occasionally easier on CA than on the other two because of its higher suppression of nasopharyngeal flora.(ABSTRACT TRUNCATED AT 250 WORDS)

Bacteriological Techniques↗
PubMed1991

[Effects of verapamil on the left ventricular diastolic function and diastolic asynchrony in patients with hypertrophic cardiomyopathy].

The effects of verapamil on the diastolic function and regional asynchrony of the left ventricle were echocardiographically investigated in 37 patients with hypertrophic non-obstructive cardiomyopathy (HCM). Before and 20 min after the intravenous administration of verapamil (0.1 mg/kg), blood pressure (BP), heart rate (HR), transmitral pulsed Doppler indices (R, A, A/R), M-mode echo indices (Dd, Ds, %FS) and the echo-phonocardiographic index (isovolumic relaxation time; IRT) were measured. We also measured the rapid extension times of the posterior walls at the chordae and papillary muscle level [Tc(pw), Tp(pw)] as the indices of regional diastolic function, and their difference [Tp-c(pw)] was used as the index of diastolic asynchrony. Before verapamil administration, the HCM patients had significantly larger A, A/R, IRT and Tp-c(pw) and smaller R than did 20 healthy controls, but showed no significant differences in HR, BP, Dd, Ds and %FS. After verapamil injection, R increased and A, A/R, IRT, Tp-c(pw) decreased significantly without any changes in BP and HR. The increment of R (delta R) correlated significantly with the decrement of Tp-c(pw) (r = -0.66, p less than 0.001). According to the value of delta R/R, 37 patients with HCM were categorized in 2 groups (19 responders with delta R/R greater than or equal to 10% and 18 non-responders with delta R/R less than 10%). The responders had smaller R and larger A/R, IRT and Tp-c(pw) before verapamil administration than did the non-responders. Verapamil increased R, Dd, Ds and decreased A, A/R and Tp-c(pw) in the responders, but not in the non-responders. These results suggested that verapamil might improve left ventricular diastolic function in HCM patients through the improvement of left ventricular diastolic asynchrony.

Adult↗
PubMed1991

Role of CD4 molecule in intrathymic T-cell development.

We have investigated the role of CD4 molecules in intrathymic T-cell repertoire selection. The administration of monoclonal antibody (mAb) to CD4 in organ culture of murine foetal thymus (FTOC) completely inhibited the development of CD4+8- cells, and additional treatment with anti-class II MHC (Ia) mAb caused no further effects on this inhibition. On the other hand, when the potentially autoreactive cells in Mls-1a mice were monitored by expression of the Mls-1a-reactive V beta 6 gene product of T-cell receptor alpha beta (TcR alpha beta), the treatment with anti-CD4 resulted in the appearance of V beta 6-bearing cells to some extent, but this effect was considerably reinforced by the combinatory use of anti-Ia mAb with anti-CD4. In a model system where the bacterial superantigen staphylococcal enterotoxin B serves as self-antigen to deplete V beta 8-bearing cells in FTOC, the depletion of V beta 8+ cells was restored partially by anti-CD4 alone but completely by the combination with anti-Ia. These results suggest that CD4 is indispensable for positive selection of all CD4+8- thymocytes, whereas participation of CD4 in negative selection is only partial. It was also observed that the development of TcR alpha beta-bearing cells in the CD4-8- population was inhibited by the treatment with anti-CD4 mAb. In Mls-1a mice, V beta 6-bearing cells were developed in CD4-8+, CD4+8+, and also in CD4-8- populations after anti-CD4 mAb treatment. It is suggested that TcR alpha beta-bearing CD4-8- cells are possibly originated from CD4+ cells and undergo CD4-mediated thymic selection.

Animals↗
PubMed1991

[Sequential MRI in two cases with periventricular leukomalacia].

We investigated two children with cystic periventricular leukomalacia, which we had detected by ultrasonography (US) during the neonatal period, with magnetic resonance imaging (MRI) of the brain at 4, 9, and 15 or 19 corrected months of age. Both inversion-recovery (IR) and T2-weighted spin-echo (SE) sequences were used for this study. We observed cysts involving the periventricular white matter at the region adjacent to bilateral frontal horns in case 1 and adjacent to the posterior horns of the lateral ventricles in case 2. MRI at 4 months showed the irregularity of the ventricular wall and delayed myelination, compared to that of an age-matched control. The T2-weighted SE and IR imaging at 9 months demonstrated abnormally increased signal in the white matter. These findings were more evident at the 3rd MRI examination. The location of end-stage periventricular leukomalacia lesions were consistent with the distribution of cystic lesions seen on US. MRI at sagittal sections was useful for the detection of main periventricular leukomalacia lesions. A possibility exists that MRI might be useful in detecting subtle lesions of periventricular leukomalacia in which we cannot find by US.

Child, Preschool↗
PubMed1991

[Cerebral blood flow changes in a patient recovered from hypocarbia].

The changes of cerebral blood flow velocity (CBFV) and pulsatility index (PI) in anterior cerebral artery were examined by cranial color Doppler ultrasonography while a patient recovered from hypocarbia. As arterial PCO2 was elevated, PI was decreased and color imaging of CBF from basilar artery to anterior cerebral artery were improved in sagittal view. Hypocarbia is considered to induce the constriction of the cerebral vessels and the decrease of CBF in premature infants.

Blood Flow Velocity↗
PubMed1991

[A case of successful surgical repair for congenital corrected transposition of the great arteries associated with Ebstein's malformation and diverticulum of atrialized ventricle].

Congenital corrected transposition of the great arteries (C-TGA) is frequently associated with VSD and PS. Systemic atrioventricular valve regurgitation is also sometimes present in patients with C-TGA. It is though that left-sided A-V valve regurgitation is caused by the deformities of the tricuspid valve (TV) or intolerance of TV and the right ventricle (RV) against systemic pressure load. We had a patient with C-TGA associated with Ebstein's malformation. The patient suffered from congestive heart failure due to left-sided A-V valve regurgitation. In this case, the septal and posterior leaflets were displaced below the atrioventricular annulus. The edges of all valves were thickened and partially calcified. Focal agenesis was found in the septal leaflet. There was a distinct atrialized ventricle which had a thin wall and no trabeculae. It shaped like a diverticulum of 3 cm in depth toward the diaphragm. Preoperative cardiac catheterization showed that the functional RV had an adequate size (RVEDVI 162% of normal) and ejection fraction was 53%. Left-sided valve replacement was performed using SJM 31M with preservation of TV. Left-sided atrioventricular annulus was so deformed due to the diverticulum that the prosthetic valve was sutured at the ventricular wall below the atrioventricular annulus to which TV had attached. Good clinical result was obtained after surgical treatment.

Diverticulum↗
PubMed1991

[A case of graft-versus-host disease following irradiated fresh blood transfusion].

We reported a case of a fatal graft-versus-host disease (GVHD) which developed in a 65-year-old, male patient which was considered to have been induced by irradiated fresh blood donated by his son after a coronary bypass surgery. Fresh blood was obtained from his relatives, and a 15 Gy irradiation was performed before transfusion. The diagnosis of acute GVHD was made by clinical symptoms and histological examinations of the skin and the bone marrow. He died of sepsis on the 19th post-operative day. The HLA typing of the lymphocytes, revealed that the patient had A 2, A 24, Bw 52, Bw 62, Cw 4, DR 2, and his son had A 24, Bw 52, DR 2. A 24 and Bw 52 were homogeneous making his son histocompatible with one of the patient's haplotype. This might well be attributable to the occurrence of GVHD in this case, meaning that 15 Gy irradiation was not sufficient for the prevention of this disease.

Aged↗
PubMed1991

[Hypoxic-ischemic brain damage: detection of early stage].

The type of hypoxic-ischemic brain damage is determined by the distribution of lesions, which has different mechanism in each. Neuroimaging is important for detection of the lesions, but morphological changes appear 12 hours after hypoxic episodes even in neuropathology. Hemodynamic, biochemical and neurophysiological changes during the acute stage are also valuable for earlier diagnosis of the lesions. Doppler sonography and near-infrared spectroscopy, reflected intracranial hemodynamics and metabolism. In our clinicopathological studies, the infants with pontosubicular necrosis showed significantly high incidence in severe hypocarbia, which may be associated with hypoperfusion. Thus, the monitoring of brain hemodynamics and metabolism may be important for early treatment as well as prevention of the brain damage.

Animals↗