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Biomedical subjects

T Matsuo

Publications and source records attributed to T Matsuo.

At least 235 records · Page 13Linked to original sources

[Ewing's tests validation for autonomic dysfunction assessment].

The medical literature on the evaluation of autonomic dysfunction accumulated discordant results in the past decades, accentuating the need of validating the proposed tests. The Ewing's tests for studying autonomic abnormalities received increasing acceptance, as they recognize not only cardiovascular reflexes damage but lesions in any other segments of the autonomic nervous system. We proposed to validate them in our population by analysing their results on 30 normal individuals and 23 long-standing diabetics. Our results show that the five tests are highly sensitive and specific, reproducible, use simple and available office material, and fulfil their purpose.

Adolescent↗

[Trypanosoma cruzi infection in blood donor candidates].

INTRODUCTION: Transmission of American trypanossomiasis by transfusion has been reduced by expansion of control measures of blood quality in Brazil. A research project was, therefore, undertaken to evaluate soropositivity for Trypanosoma cruzi infection on blood donors and to compare this rate with those found in 1958 and 1975 in blood banks. METHOD: A transversal study was carried out on blood donors in Londrina, Paraná, Brazil. ELISA and Immunofluorescence were the serological test techniques used in the diagnosis of Trypanosoma cruzi infection. RESULTS AND CONCLUSION: A serumprevalence rate of 1.3% was found with a tendency for positive serum findings for Trypanosoma cruzi infection on blood donors to decrease over Aime (1958, 1975, and 1995).

Adolescent↗

Expression of amiloride-sensitive sodium channel in rat eye.

To study the expression of the amiloride-sensitive sodium channel, a putative mechano-receptor in the rat eye, reverse transcriptase-polymerase chain reaction and in situ hybridization were done. The gene for the alpha subunit of the amiloride-sensitive sodium channel was shown by polymerase chain reaction to be expressed in mRNA isolated from the whole eye tissue. In situ hybridization demonstrated that the gene was expressed in basal layers of the corneal and conjunctival epithelium, ciliary epithelial cells, lens epithelial cells at the equator, retinal and iris pigment epithelial cells, ganglion cells and cells in the inner and outer nuclear layers of the retina. The results suggest that the amiloride-sensitive sodium channel plays a role in maintaining sodium balance as well as in possible mechanosensation in these ocular tissues.

Animals↗

Transdifferentiation of chick embryonic retinal pigment epithelial cells to lentoid structure in suspension culture.

To test transdifferentiation of retinal pigment epithelial (RPE) cells in suspension culture, chick embryonic RPE sheets and dissociated RPE cells were cultured for two months in a non-adherent dish for suspension culture. RPE cells, isolated as a sheet, aggregated immediately and remained the same size with their differentiated characteristics for two months. The presence of basic fibroblast growth factor (bFGF) at concentrations of 10 ng/ml or higher induced the formation of a spherical lentoid structure which was positive for crystallin and bFGF receptor. In contrast, dissociated RPE cells did reaggregate but did not develop the lentoid structure even in the presence of bFGF. The transdifferentiation of RPE cells to the lentoid structure in this study was in contrast to their transdifferentiation to the retina, as reported in a previous study.

Animals↗

Earthquake-induced cardiovascular disease and related risk factors in focusing on the Great Hanshin-Awaji Earthquake.

The major earthquake increases cardiovascular disease during the period from night-time to morning, especially in the elderly patients living around the epicenter. Earthquake-induced stress increased BP and blood viscosity determinants, and enhanced fibrin turnover with endothelial cell stimulation in a group of hypertensive elderly subjects. Earthquake might trigger the cardiovascular events through the potentiation of these acute risk factors. Reduction of stress and related acute risk factors in this period may suppress cardiovascular deaths following a major earthquake. Further investigation of the mechanisms triggering cardiovascular events after the a major event such as a major earthquake is a necessary part of the strategy for the prevention of cardiovascular disease.

Aged↗

Tuberculosis associated with pulmonary sequestration.

We describe a case of intralober pulmonary sequestration in association with tuberculosis. Sequestrations of the lung are classically divided into two types of extralober and intralober. Intralober pulmonary sequestration in association with tuberculosis is rare. We diagnosed the present case to be Pryce type 1 with tuberculosis infection.

Bronchopulmonary Sequestration↗

Flow visualization and 1- and 3-D laser-Doppler-anemometer measurements in models of human carotid arteries.

Pulsatile flow, wall distensibility, non-Newtonian flow characteristics of blood in flow separation regions, and high/low blood pressure were studied in elastic silicon rubber models having a compliance similar to human vessels and the same surface structure as the biological intima models of (1) a healthy carotid artery model, (2) a 90% stenosis in the ICA, and (3) 80% stenosis in both the internal and external carotid arteries. Flow was visualized for steady flow and pulsatile studies to localize flow separation regions and reattachment points. Local velocity was measured with a 1-, 2-, or 3-D laser-Doppler-anemometer (LDA). Flow in the unstenosed model was Re = 250. In the stenosed models, the Re number decreased to Re = 180 and 213 under the same experimental conditions. High velocity fluctuations with vortices were found in the stenosed models. The jet flow in the stenosis increased up to 4 m/s. With an increasing bifurcation angle, the separation regions in the ECA and ICA increased. Increased flow (Re = 350) led to an increase in flow separation and high velocity shear gradients. The highest shear stresses were nearly 20 times higher than normal. The 90% stenosis created high velocity shear gradients and velocity fluctuations. Downstream of the stenoses, eddies were found over the whole cross-section. In the healthy model a slight flow separation region was observed in the ICA at the branching cross-section whereas in the stenosed models, the flow separation regions extended far into the ICA. We conclude that a detailed understanding of flow is necessary before vascular surgery is performed especially before artificial grafts or patches are implanted.

Blood Flow Velocity↗

[Role of biochemical and fibrinolytic parameters on cardiac events associated with Hanshin-Awaji earthquake-induced stress].

Catastrophic stress induced by Hanshin-Awaji earthquake seems to promote rheological deterioration associated with high blood pressure, increased blood viscosity due to hemoconcentration and increased fibrinogen level. These changes lead to prolonged endothelial cell dysfunction demonstrating high levels of von Willebrand factor, tissue type plasminogen activator and plasmin.alpha 2 plasmin inhibitor complex, and accelerate fibrin turnover as the result of a high D-dimer level from the post earthquake period until 4-6 months later. There were remarkable changes in biochemical parameters except for uric acid, BUN, triglyceride level. An increase in these acute changes caused by mental and physical stress might trigger obstructive thrombus in coronary arteries in the elderly after an earthquake. In conclusion, earthquake induced stress could be considered a transient cardiovascular risk factor.

Blood Pressure↗

Endothelial cell damage and angiotensin-converting enzyme insertion/deletion genotype in elderly hypertensive patients.

OBJECTIVES: The purpose of this study was to investigate the angiotensin-converting enzyme (ACE) insertion/deletion (I/D) genotype and endothelial cell dysfunction or hypercoagulable state in elderly hypertensive patients. BACKGROUND: Angiotensin-converting enzyme (ACE) insertion/ deletion (I/D) polymorphism was recently reported to be associated with various cardiovascular diseases. However, the precise mechanism of this association remains unknown, and some confounding factors might also affect the association. Endothelial cell dysfunction and coagulation activation play important roles in both the atherosclerotic process and the onset of cardiovascular events. METHODS: We identified the ACE I/D genotype and measured the plasma levels of markers of endothelial cell damage (von Willebrand factor [vWF] and thrombomodulin) and of coagulation activation (prothrombin fragment F1 + 2 [F1 + 2]) in 318 asymptomatic elderly patients with hypertension, aged 59-93 years. RESULTS: The vWF level was significantly higher in those with the DD genotype (n = 54) than in those with the II genotype (n = 131, p < 0.0001) or with the ID genotype (n = 133, p < 0.0001). The TM levels were also higher in patients with the ID genotype (p < 0.005) and the DD genotype (p < 0.01) than in those with the II genotype. There were no differences in F1 + 2 level among the groups. Positive correlations of systolic blood pressure with levels of both vWF and thrombomodulin were found predominantly in patients with the II genotype (both p < 0.001), but no correlation was noted in those with the DD genotype. CONCLUSIONS: Considering the increased plasma levels of both endothelial cell-derived markers in the hypertensive patients with ACE DD genotype, we speculate that the ACE D allele is a risk factor for the development of hypertensive cardiovascular disease associated with endothelial cell damage.

Aged↗

Evaluation of intraaneurysmal blood velocity by time-density curve analysis and digital subtraction angiography.

PURPOSE: Our purpose was to evaluate intraaneurysmal blood velocity by using time-density curve analysis and digital subtraction angiography. METHODS: In 31 aneurysms, aneurysmal blood velocity was examined with digital subtraction angiography to determine mean transit time (MTF), peak density time (time to peak opacification) (PDT), and time to half-peak opacification (T1/2). Thirty frames per second were acquired, and the time-density curve was calculated. Regions of interest were drawn on the proximal parent artery, on the distal parent artery, and on the aneurysm itself. RESULTS: There was no significant difference in MTT of blood velocity in the proximal site on the parent artery, in the distal site on the parent artery, and in the aneurysm. Similarly, there was no significant difference in PDT in the parent artery, in the distal site on the parent artery, and in the aneurysm; nor was there a significant difference in T1/2 in the parent artery, in the distal site on the parent artery, and in the aneurysm; that is, intraaneurysmal blood velocity was similar to that in the parent artery. PDT and T1/2 of small aneurysms were faster than that of large aneurysms; that is, blood velocity of small aneurysms was faster than that of large aneurysms. CONCLUSION: Intraaneurysmal blood velocity in small aneurysms is similar to that in the parent artery; consequently, the central stream probably reaches the aneurysmal wall. Intraaneurysmal blood velocity in large aneurysms appears to be somewhat slower than that in small aneurysms.

Acute Disease↗

Purification and characterization of 38-kDa protein in plasma of dietary magnesium-deficient rat.

We have found an increase of a 38-kDa plasma protein level from 10 to 30 days in rats on a magnesium-deficient diet (Mg; 0.001 per cent), using sodium dodecylsulfate-polyacrylamide gel electrophoresis (SDS-PAGE). This 38-kDa protein returned to the control level after feeding the rats a magnesium-sufficient diet (Mg; 0.07 per cent) for 1 week. Purification of the protein by reverse-phase HPLC separated it into two components (p38k-1 and p38k-2). Amino acid analysis showed that these components were both haptoglobin (Hp) beta-chain. Furthermore, hemoglobin-immobilized affinity chromatography analysis confirmed the increase of Hp in magnesium-deficient rat plasma. This is the first demonstration of an increase of Hp in plasma of dietary magnesium-deficient rats.

Amino Acid Sequence↗

[Genetic analysis including predictive DNA testing in a Japanese family with dentatorubral-pallidoluysian atrophy].

Dentatorubral-pallidoluysian atrophy (DRPLA) is a neurodegenerative disease showing autosomal dominant inheritance, which is associated with a specific trinucleotide repeat expansion in the DRPLA gene. We performed DNA analysis of two affected and one non-affected individuals of a Japanese family with DRPLA. The proband (case 1) developed seizures at age 17, and these gradually evolved to intractable myoclonic epilepsy. His father (case 2) had manifested gait disturbance since the age of 40, which was followed by progressive dementia. DNA analysis disclosed that these patients had an expanded CAG repeat in the DRPLA gene, which confirmed the diagnosis. The brother of case 1, who was asymptomatic, expressed a desire to undergo predictive DNA testing for DRPLA. We discussed the ethical and social issues of this predictive testing, and decided to carry out the testing after obtaining informed consent from him and his wife. The test revealed no expanded allele, thus proving that he would not develop DRPLA, and relieving him of his fears. Our results suggest that predictive testing improves the psychological well-being of non-affected individuals in DRPLA families.

Adult↗