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Biomedical subjects

H Sako

Publications and source records attributed to H Sako.

At least 19 recordsLinked to original sources

Repair of a ruptured aortic arch aneurysm complicated by postoperative paraplegia: report of a case.

We report herein the rare case of a 79-year-old man who suffered permanent paraplegia after undergoing an otherwise successful total arch replacement for a ruptured aortic arch aneurysm. During cardiopulmonary bypass, perfusion to the distal aorta was maintained from the femoral artery, and postoperative aortography showed intact tributaries from the aorta including the intercostal arteries. Postoperative paraplegia is an extremely rare complication of operations on the aortic arch; however, we speculate that the paraplegia in this patient could be attributed either to a steal phenomenon involving the radicular artery, or to the anatomical particularity of the spinal cord artery described by Cole and Gutelius as the "segmental system".

Aged

A research to develop a predicting system of mammalian subacute toxicity. II. Single dose detailed toxicity studies.

"Single dose detailed toxicity study" in rats was conducted with 6 chemical substances to establish a predicting system of subacute toxicity of non-congeneric industrial chemicals. In the detailed examinations, new and previously reported biological parameters were developed and utilized for the establishment and confirmation of the correlations for both qualitative and quantitative prediction of target organs and effects in repeated dose toxicity studies of non-congeners; the new parameters were concerned with liver, kidneys and blood and the established relating equations for prediction had a correlation coefficient of 0.83 (liver), 0.49 (kidneys) and 0.94 (blood), while the old parameters effectively confirmed the previous correlations. The serial changes in the study gave a biological explanation to the established relationships between acute and subacute toxicities in terms of extrapolation.

Animals

[A clinical study of recurrent breast cancer].

In a recent 14-year period from December 1978 to December 1993, 180 patients with breast cancer were treated at the hospital, and out of these 180 patients, 38 patients (21.1%) who had a recurrent breast cancer were clinically evaluated. The first recurrence occurred in the local skin in 13 patients, regional lymph node in 1, bone in 13, lung in 4, liver in 4 and in other areas in 3. Histologically, the incidence of scirrhous carcinoma recurrence was higher than that of papillotubular carcinomas. There was no recurrence in mucinous carcinomas. The frequency of recurrence became higher in accordance with TNM classification, namely, 6.7% in Stage I, 23.7% in Stage II, 37.5% in Stage IIIa, and 47.1% in Stage IIIb cancers. An increasing tendency in the recurrence rate was also noted with an increase of tumor diameter or lymph node metastasis. Otherwise, there was no difference in cumulative survival after recurrence between TNM classification. There were no correlations between the estrogen receptor and incidence of recurrence or 5-year survival rate. The disease free interval (DFI) was less than 2 years in about 60% of the recurrent cases. DFI of bone metastasis was longer than for the other sites of recurrence. The survival rate increased according to prolongation of DFI. After through evaluation of these results, one should pay close attention to follow-up after mastectomy.

Adult

[A case of aortic dissection associated with congenital bicuspid aortic valve].

It is known that bicuspid aortic valve with dilatation of the ascending aorta is one of risk factors of the aortic dissection. A case of acute aortic dissection (DeBakey type-II) associated with bicuspid aortic valve who underwent successfully operation 8 hours after onset is reported. This patient went into cardiogenic shock because of cardiac tamponade and aortic valve regurgitation immediately after onset. Aortic valve and the ascending aorta were replaced using composite graft (#23 SJM prosthetic aortic valve and 26 mm woven Dacron vascular graft) combined with coronary artery reconstruction by Cabrol's technique. Aortic valve showed bicuspid and histological examination revealed cystic medionecrosis and loss of elastic fiber. Postoperative course was uneventful and this patients is doing well 3 years after the operation.

Acute Disease

The effect of body position on a free-floating ball thrombus as observed by transesophageal echocardiography.

Two cases of free-floating left atrial ball thrombi (FLABT) in association with mitral stenosis were observed by transesophageal echocardiography (TEE). Our report describes the relation between body position and thrombi kinetics. Both cases demonstrated similar kinetics. In the supine and right lateral decubitus positions, the thrombi recoiled from and sometimes became entrapped within the mitral valve. In the sitting and left lateral decubitus positions, the thrombi appeared to be nearly fixed and did not contact with the mitral valve. Our results indicate that the latter two positions prevent thrombi disintegration and incarceration into the mitral valve. Finally, TEE is an extremely useful tool for assessing the safest position for individuals with FLABT.

Aged

Relationship between apparent total body clearance of cyclosporin A and its erythrocyte-to-plasma distribution ratio in renal transplant patients.

To establish an optimal method for determining a cyclosporin A (CyA) regimen based on physiological changes that occur during immunosuppressive therapy, the relationship between apparent CyA body clearance (CL/f) and the CyA erythrocyte-to-plasma distribution ratio (CyA-EP) was examined using clinical time courses obtained during routine monitoring. The CyA-EP, which was calculated by a multiple regression formula using routine data, was increased during renal dysfunction involving the normal recovery phase after transplantation, during nephrotoxicity, during acute tubular necrosis, and during acute renal rejection. CyA total body clearance (CLt), calculated by multiplying CL/f and converted bioavailability, fc (which is equal to 0.009 x LD, where LD represents the CyA level in blood per dose ratio), showed hyperbolic decay with increasing CyA-EP (the mean CLt was defined as follows: CLt = 0.937/CyA-EP), whereas fc showed exponential decay with increasing CyA-EP (the mean fc was defined as follows: fc = 0.593 x exp(-0.155 x CyA-EP)). These findings suggest that total CyA body clearance and its bioavailability were suppressed during the renal dysfunction phase. Hence, the mean CL/f as a function of the CyA-EP was given by the following equation: CL/f = 1.390 x exp(0.204 x CyA-EP)/CyA-EP. Since the CyA-EP reflects a patient's disease state and alterations in the CyA pharmacokinetic profile, these model formulae should provide an adequate method for determining a CyA dosage regimen for several disease states after renal transplantation.

Adult

Hemodynamic profiles during concurrent intraaortic balloon pumping and venoarterial bypass--a canine study comparing subclavian and femoral artery perfusion sites.

Concomitant use of venoarterial bypass (VAB) with centrifugal pump and intraaortic balloon pumping (IABP) is a common technique for cardiopulmonary resuscitation. This experimental study examines whether coronary perfusion and hemodynamics are affected by the site of the blood supply, comparing the subclavian artery and the femoral artery. VAB and IABP were performed in 11 mongrel dogs with cardiopulmonary failure induced by acute myocardial infarction and hypoventilation. Aortic root pressure (AP), left atrial pressure, central venous pressure and coronary sinus blood flow (CSF) were measured, and blood gas analysis was performed. Subclavian artery perfusion (SAP) and femoral artery perfusion (FAP) were compared at bypass ratios of 25, 50, 75, 85, 100%. At bypass ratios of 75% and 85% the mean systolic AP was higher with SAP than with FAP. The mean diastolic AP was higher with SAP than with FAP at a bypass ratio of 50% or higher. CSF was higher with SAP than with FAP at a bypass ratio of 50% or higher. The coronary arteriovenous O2 content difference was lower with SAP than with FAP at a bypass ratio of 85% or higher. In conclusion, at a high bypass ratio, SAP was more effective than FAP in achieving diastolic augmentation, thus enhancing myocardial oxygen balance, even though SAP had less of a systolic unloading effect. These data support the use of SAP over FAP in patients with severe cardiopulmonary dysfunction requiring high-flow bypass, and especially in patients with myocardial ischemia.

Animals

[Factors affecting the occurrence of anastomotic leakage after graft replacement of type A aortic dissection].

Fifty-seven patients of type A aortic dissection were underwent operations from Jan. 1985 to Nov. 1994. The number of patients who underwent graft replacement of the aorta and received aortogram after the operation was twenty-nine. To investigate factors affecting the occurrence of anastomotic leakage after graft replacement of the aorta, the aortograms of the 29 patients were examined retrospectively. The aortograms revealed leakage at the distal anastomotic site on 11 of the 29 patients. Eight factors: the kind of graft, Marfan's syndrome, the use of felt at the anastomotic site, the clamping method, distal anastomotic site, acute or chronic, the state of the aortic wall at the anastomotic site and the blood pressure control after operation, were examined relating to the occurrence of anastomotic leakage. The results showed 3 factors; acute or chronic, the state of the aortic wall and the blood pressure control, affected the occurrence of anastomotic leakage. In short, the anastomotic leakage easily occurred in patients who underwent in the acute stage and whose blood pressure was uncontrolled after the operation. Therefore, strict control of the blood pressure after the operation is the most effective for preventing anastomotic leakage.

Anastomosis, Surgical

[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

[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

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

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

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

[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

[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