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Biomedical subjects

H Sako

Publications and source records attributed to H Sako.

At least 55 records · Page 3Linked to original sources
PubMed1995

[Surgical treatment of traumatic rupture of the aortic valve with dove-coo murmur--case report].

Aortic regurgitation due to traumatic rupture of the aortic valve with dove-coo murmur is rare. A 71-year-old man was admitted for cardiac failure due to aortic regurgitation with dove-coo murmur, 4 years after the traffic accident. The aortic valve replacement was performed and his postoperative course was good. The aortic valve was tricuspid valve with the tear in the left side of right coronary cusp, and the size of the tear was 7 mm. The aortic valve was not recognized the findings of inflammatory or rheumatic change in the pathological study.

Aged↗
PubMed1995

[Surgical treatment of right atrial papillary fibroelastoma, originated from the eustachian valve--a case report].

Papillary fibroelastoma is one of the most common benign primary cardiac tumor after myxoma. However, it is rare to originate from Eustachian valve. A 44-year-old woman was pointed out the right atrial tumor during admission for vasospastic angina. On two-dimensional echocardiogram, the tumor was found in the right atrium, and easily moved to the right ventricle. At operation, the tumor originated from Eustachian valve, and was resected together with the valve by means of extracorporeal circulation. The size of tumor was 57 mm in length, and the histological diagnosis was papillary fibroleastoma. The post-operative course was uneventful.

Adult↗
PubMed1994

Ipsilateral connections of the anterior cingulate cortex with the frontal and medial temporal cortices in the macaque monkey.

The present study was attempted to study ipsilateral corticocortical connections of the anterior part (area 24) of the cingulate cortex of the macaque monkey by means of wheat germ agglutinin-conjugated peroxidase (WGA-HRP) method. In 2 out of 4 Japanese monkeys (Macaca fuscata) that were injected with WGA-HRP into the anterior part of the cingulate cortex, the sites of injection were successfully localized within the cortical regions corresponding to areas 24a and 24b. The results obtained from these monkeys indicate that areas 24a and 24b in the anterior part of the cingulate cortex are reciprocally connected with the prefrontal, premotor, and motor cortical regions, and also with the medial temporal cortical regions. Areas 24a and 24b were strongly connected with the lateral and medial prefrontal cortices and area 6a beta of the premotor cortex, moderately with the remaining premotor cortex, and weakly with the motor cortex. In the medial temporal cortex, areas 24a and 24b were strongly connected with the prosubiculum, entorhinal cortex (area 28), and perirhinal cortex (areas 35 and 36), and weakly with areas TF and TH of the parahippocampal gyrus, throughout their rostrocaudal extent. In addition, areas 24a and 24b projected to the molecular layer of the CAI subfield of Ammon's horn and the external pyramidal layer of the presubiculum. Our findings suggest that areas 24a and 24b of the anterior cingulate cortex may constitute relays in the reciprocal pathways between the prefrontal cortex and the hippocampal, entorhinal and/or perirhinal cortical regions.

Animals↗
PubMed1994

A simple method for predicting the cyclosporin A erythrocyte-to-plasma distribution ratio in blood, and its clinical assessment.

To adapt the monitoring of cyclosporin A (CyA) to clinical practice, we have developed a model to predict the CyA erythrocyte-to-plasma distribution ratio (CyA-EP), and evaluated its utility in clinical practice. We monitored CyA trough concentrations in whole blood and performed a series of biochemical tests during disease states in patients undergoing immunosuppressive therapy with CyA after transplantation. An estimate of CyA-EP (EPpr) was thus given by the following equation: EPpr = 6.0831 - 0.2944 x (TG+CHO) - 0.0037 x (CyAblood) - 0.0553 x (HCT) + 0.0463 x (BW) + 0.4447 x (CRE) - 0.0366 x (AGE). In this predictive model, EPpr is given as a function of the plasma lipid levels (TG+CHO, mM), the CyA concentration in whole blood (CyAblood, ng/ml), and the hematocrit (HCT, %), as well as the patient's body weight (BW, kg), serum creatinine (CRE, mg/dl) and age (AGE, years). The parameters TG+CHO, CyAblood, HCT, and AGE were negatively correlated with the CyA-EP, whereas BW and CRE exhibited a positive correlation. The predictive performance of this model was satisfactory for clinical use and changes in CyA-EP in transplant patients were obtained from monitoring CyA in whole blood and routine biochemical tests, without directly measuring CyA-EP. Since CyA-EP is an useful indicator for predicting a shift of CyA into tissues and its systemic clearance in plasma, our model to predict the CyA-EP will help the physician select a CyA regimen during immunosuppressive therapy in a variety of disease states after transplantation.

Adult↗
PubMed1994

Biocompatibility of a heparin-bonded membrane oxygenator (Carmeda MAXIMA) during the first 90 minutes of cardiopulmonary bypass: clinical comparison with the conventional system.

We clinically compared a heparin-bonded Carmeda MAXIMA membrane oxygenator to a nonheparin-bonded MAXIMA in 20 patients undergoing coronary artery bypass grafting or valve replacement. Reductions of fibrinogen, factor XII, and high molecular weight kininogen were greater in the MAXIMA group. Serum C3a and free hemoglobin were lower in the Carmeda group. The level of C4a, though remarkably lower than that of C3a, was higher in the Carmeda group then in the MAXIMA group. Both oxygenators performed well in terms of blood gas exchange. We conclude that the heparin-bonded Carmeda oxygenator offers superior biocompatibility during cardiopulmonary bypass.

Biocompatible Materials↗
PubMed1994

[A case of rupture of the ascending aorta owing to prosthetic graft dilation following replacement of the descending aorta].

A 55-year-old male was diagnosed as acute type A aortic dissection caused by retrograde propagation from a tear in the descending aorta. A replacement of the descending aorta was performed with a prosthetic graft (VASCUTEK). Sixteen days after the operation, the patient required an emergency operation due to a rupture in the ascending aorta. Transesophageal echo and contrast enhanced CT indicated the point of entry to be at the proximal anastomotic portion of the prosthetic graft and the prosthetic graft (30 mm in diameter) to be dilated to 45 mm. Intimal tear at anastomotic portion owing to graft dilation was suspected as the main factor causing rupture of the ascending aorta.

Aortic Dissection↗
PubMed1994

[Two cases of aortoesophageal fistula due to ruptured thoracic aortic aneurysm].

Aortoesophageal fistula due to ruptured thoracic aortic aneurysm is uncommon, and exhibits extremely high mortality. We experienced two cases of such lesion. The first case showed aneurysm in the aortic arch closed with Dacron patch but leaving the esophageal defect. The patient died of an infection of the patch graft after oral feeding. The second case was demonstrated infected aneurysm of the descending aorta. The patient was rescued by primary operation, replacement of the aorta by an artificial graft and resection of the esophagus, and the secondary operation, reconstruction of the esophagus. We recommend resection of aneurysm and the esophagus as well in the aspect of lower post-operative infection in the graft and of the better prognosis of the lesion.

Aged↗
PubMed1993

Effects of the direction and distance of horizontal arm movements on local muscular strain--a fundamental study on the teller workplace in bank.

This study was conducted to examine the relative differences in the muscular strain of the hand-arm-shoulder system in the repetitive arm movements which would directly depend on the layout of devices at teller counter. The subjects were five young male adults. The manual handling task was standardized and the repetition frequency was in self-pace. The arm movements were characterized by the different direction measured from the frontal plane of the subject between 0 degrees to 150 degrees combined with the distance measured from the acromion to the fixed points of 300, 500 and 700mm. The movements to all of the fourteen points tested were evaluated on both sides of the arms and shoulders by the integration of the EMG signals (IEMG) as to m. deltoid pars media and clavicularis, m. trapezius pars descendens, m. pectoralis major pars clavicularis and m. extensor carpi radialis brevis. It was found that IEMG of the deltoid muscles were sensitive to the direction and distance of the arm movements while the trapezius muscle showed the relative lower dependence on the direction. There were significant combined effects of the direction and distance in all muscles; i.e. effect of reach distance was greater with decreasing the arm angle, which was obvious at distance longer than 500mm in the arm abduction. When IEMG was divided by the task time in self-pace which increased in the arm abduction, the peak value was observed at the angle of 30 degrees. It was suggested that if the repetitive movement was required at the same frequency as at the angle of 30 degrees the position near the arm abduction (the angle of 0 degrees) would become the most expensive working direction.

Adult↗
PubMed1993

Intracellular Na+ activity of "diseased" human atrial muscles and its modifications by dihydro-ouabain.

In quiescent human atrial muscles obtained from patients with various cardiac diseases, the intracellular Na+ activity (aNai) and the resting membrane potential (Vm) were recorded simultaneously, using double-barreled Na(+)-selective microelectrodes. The Vm averaged -44.1 +/- 5.0 mV and the aNai, 6.9 +/- 1.7 mM under normal Tyrode's solution containing 5.4 mM [K]oi,The aiNa value was within the range of aNai reported in various cardiac tissues from intact animals. Dihydro-ouabain (10(-5) M) significantly increased the aNai and depolarized the Vm. The results suggest that even in these depolarized atrial muscles the aNai remains within physiologic levels and that the Na-K pump may not be impaired. This is the first report to measure the aNai in human atrial muscles.

Adolescent↗
PubMed1993

[Surgical treatment of endocardial cushion defect in 3 elderly patients].

We performed surgical treatment for partial endocardial cushion defect in 3 patients over fifty year old. Case 1 was a 55-year-old-male with TR of grade II. Case 2 was a 59-year-old-female with TR and MR, and was repaired mitral cleft by a mattress suture. She needed infusion of dopamine (over 5 micrograms/kg/min) for 6 days and therapy of mediastinitis postoperatively. Case 3 was 56-year-old-male without atrioventricular valve regurgitation. Preoperative left ventricular volume was small in all patients, therefore perioperative circulatory control, mainly water balance, and respiratory control were importance. All patients survived, and both decreasing of CTR and improvement of NYHA classification were recognized in all three patients. In conclusion the operation for ECD in even elder patients was effective, but intensive care needed perioperatively.

Endocardial Cushion Defects↗
PubMed1993

[A case of aortic dissection (DeBakey-I) occurring 20 months after aortic valve replacement].

Simple aortic valve replacement was performed in a 59-year-old man whose ascending aorta was moderately dilated (45 mm) because he had no characteristics of Marfan's syndrome or other connective tissue diseases. However, about 20 months later, reoperation needed to be performed for aortic dissection of DeBakey type I. The pathological findings of the aortic wall obtained at the initial operation revealed cystic medial necrosis. The occurrence of aortic dissection after aortic valve replacement is uncommon but not rare, especially in patients with cystic medial necrosis and/or dilated aortic root. Therefore, in these patients, wrapping or replacement of the ascending aorta may be required at the same time of aortic valve replacement.

Aortic Dissection↗
PubMed1992

Development of serotoninergic system in the brain and spinal cord of the chick.

(1) Development of serotonin positive cells and fibers was immunohistochemically studied by the use of an antibody against serotonin. (2) Serotoninergic neurons were first observed in the immature rohmbencephalon raphe nuclei on embryonic day (E)4, where two clusters of serotonin positive neurons were located: one observed at the rostral part of the rohmbencephalon corresponding to the dorsal raphe nuclei had many serotonin positive cells: the other located at the caudal part of the rohmbencephalon corresponding to the medullary raphe nuclei of the adult animals had only a small number of serotoninergic cells. (3) By E8 the number of serotonin positive cells in the brain stem increased, and virtually all the raphe nuclei found in an adult animal were located. (4) Serotonin positive fibers in the marginal layer reached up to the diencephalon and telencephalon on E6 and E8, respectively. (5) Serotonin positive cells were found beside the midline regions in the ventral part of the spinal cord of the embryonic as well as posthatching chick. (6) Because almost all the serotoninergic fibers in the spinal cord originated from the brain stem raphe nuclei, propriospinal serotonin positive cells were considered as phylogenetic vestiges. (7) Serotoninergic fibers were first found in the marginal layer of the cervical and lumbar spinal cord on E6 and E8, respectively. (8) There was a waiting period of a few days before they penetrated into the mantle layer. (9) Terminal arbolization of the serotoninergic fibers started from late embryonic periods (E16 less than), and was maximized within one week of hatching. (10) Thereafter the density of serotonin positive fibers decreased in all the regions of the spinal cord. (11) Developmental changes of the density of serotonin determined with a high performance liquid chromatography were the same as those determined through immunohistochemistry. Namely the density of serotonin increased linearly from E6 to hatching period, and reached the maximum value one week posthatching. (12( The density of the serotonin in the adult spinal cord was about half of the maximum value. (13) It is to say that the densities of serotonin and serotoninergic fibers transiently increased around one week posthatching. (14) Following the transient increase serotoninergic fibers were eliminated from the neuropil, the fibers were localized in the specific regions of the motor nucleus: motor neuron pools of extensor muscles of the hip joint in the lumbosacral spinal cord.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1991

Gait patterns of young Japanese women.

Gait patterns of 440 young Japanese women walking along a sidewalk were observed in September. Walking speed, step length and cadence were significantly greater in single walking than in group walking. Time of day, walking direction and clothes did not influence the walking patterns. Step length in heeled shoes was shorter than that in sneakers and flat shoes.

Adult↗
PubMed1990

[A study on the hemodialysis period following cadaveric kidney transplantation--a comparison between two centers sharing cadaver donor kidney pairs].

To study the hemodialysis period following cadaveric renal transplantation, we reviewed 18 consecutive cadaver donor kidney pairs of which one kidney was transplanted at Shiga University of Medical Science (SUMS) while the contralateral kidney was transplanted at Kyoto Prefectural Medical University (KPMU) between January 1983 and September 1988. Of these 18 pairs, graft function was satisfactory and the recipient was free from hemodialysis in 13 pairs. However, the postoperative hemodialysis periods were different between the two centers. To clarify the factors causing this difference, recipient factors, such as age, HLA matching, total ischemic time of the graft (TIT), immunosuppression, onset of diuresis and postoperative complications were studied. There were no significant differences in age, HLA matching, or immunosuppression. TIT of cases at SUMS was significantly longer than that of cases at KPMU. The postoperative hemodialysis period at SUMS was 25.8 days and that at KPMU was 17.8 days, however, the difference was not statistically significant. The results of this study indicate that TIT seems to be a major factor relating to delayed graft function in cadaveric renal transplantation.

Adolescent↗
PubMed1989

Developmental changes in serotonin levels in the chick spinal cord and brain.

Developmental changes in 5-hydroxytryptamine (5-HT) and 5-hydroxyindoleacetic acid (5-HIAA) in the developing chick spinal cord and brain were examined using high-performance liquid chromatography with electrochemical detection and immunohistochemistry. On embryonic day (E)6 only small amounts of 5-HT (0.086 ng) and 5-HIAA (0.0144 ng) were found in the spinal cord. By contrast, large amounts of 5-HT (x30) and 5-HIAA (x60) were detected in non-neuronal tissue outside the spinal cord; a similar distribution of 5-HT was also detected by immunohistochemistry. Up to E10, the highest concentrations of 5-HT in the spinal cord were found in the cervical region, followed by the thoracic and lumbar regions. In embryos older than E16, as well as in posthatched chicks, however, the highest and lowest concentrations of 5-HT were found in the lumbar and thoracic spinal cord, respectively. The concentration of spinal cord 5-HT reached maximal values on posthatching day (P)7, after which there was a marked decrease. By P120, 5-HT levels in the spinal cord decreased to the same level as on E10-E16. Concentrations in the brain, however, gradually increased with development. The basic pattern of development of 5-HIAA was similar to that of 5-HT.

Aging↗
PubMed1989

Unaffected electrogenic Na-K pump activity in "diseased" human atrial fibers, as assessed by intracellular K+ activity.

To investigate the role of the electrogenic Na-K pump in the resting membrane of "diseased" or "depolarized" human atrial muscles, intracellular K+ activity (aiK) and resting membrane potential (Vm) were simultaneously measured using double-barreled K(+)-selective microelectrodes. Under perfusion with normal Tyrode's solution (37 degrees C) containing 5.4 mM [K]o, Vm averaged -43.9 +/- 1.4 mV, and aiK was 99.7 +/- 1.3 mM (mean +/- S.E., n = 33). The aiK was comparable to that of atrial muscles obtained from other intact mammalian species. In 5.4 mM [K]o, dihydro-ouabain (DHO) at concentrations of 10(-6) and 10(-5) M significantly decreased aiK and depolarized Vm. Similar decreases in aiK were observed when [K]o was decreased from 5.4 to 0.5 mM or when the temperature of the perfusing solution was decreased from 37 to 22 degrees C. Upon returning [K]o from 0.5 to 5.4 mM at 37 degrees C, aiK increased, Vm hyperpolarized markedly for about 3 min, and this was followed by less marked levels of hyperpolarization in the steady state. The high [K]o-induced increases in aiK were inhibited in the presence of DHO, and at low temperature (22 degrees C). Isoproterenol (10(-7) M) increased aiK and hyperpolarized Vm. Acetylcholine (10(-5) M) hyperpolarized Vm with no change in aiK. The rate of reduction of Na(+)-efflux during application of DHO (10(-5) M) was calculated based on the change in aiK and surface-to-volume ratio of the cell measured electronmicroscopically in the same tissue, and estimated to be 2.6 to 3.8 pmol/(cm2.s), close to the value reported for Purkinje fibers excised from intact animals. We conclude that the Na-K pump functions normally even in "diseased" human atrial muscles, thereby keeping aiK within a physiological range.

Adolescent↗