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Biomedical subjects

T Sakamoto

Publications and source records attributed to T Sakamoto.

At least 811 records · Page 45Linked to original sources
PubMed1992

[Prosthetic valve function evaluated by ultrafast computed tomography (Imatron C-100)].

Ultrafast computed tomography (UFCT) is a new diagnostic modality that includes not only imaging of cardiac structures, but also movement of cardiac muscles and valves. It can be useful in the evaluation of prosthetic valves, because the scan time is extremely short and whole cardiac structures are imaged with a slice thickness of 8 mm and within 7 cardiac cycles. We review our experience using UFCT to observe prosthetic valve function in 22 cases with various valvular diseases.

Adult↗
PubMed1992

[A family of Marchesani syndrome with mitral valve prolapse and anuloaortic ectasia].

Marchesani syndrome consists of short statue, small spherical lens, glaucoma and brachydactyly, which are manifestations of hyperplastic connective tissue disease in systemic organs of mesodermal origin (Marchesani 1939). Among nearly 200 cases of Marchesani syndrome reported in the ophthalmology field, none has shown cardiac manifestations which typically characterize Marfan syndrome caused by hypoplastic connective tissue disorders. We experienced 2 cases which met the diagnosis of Marchesani syndrome and yet showed annuloaortic ectasia and mitral valve prolapse. A 30-year-old man and a 26-year-old woman who are siblings suffered from manifested brachydactyly, spherophakia, glaucoma and cardiac involvements. Their parents are in consanguinity. These unprecedented cases with mixed manifestations provide the evidence of possible gene-crossing between these 2 dystrophic mesodermal disorders.

Adult↗
PubMed1992

[Study of postgastrectomy fatty liver].

Fatty liver was often found concomitantly by the ultrasound during the follow up study of the gastric cancer operation. By ultrasound, development of postgastrectomy fatty liver was seen in 29 out of 176 patients (16.5%) with several gastrectomies. The number of the patients with postgastrectomy fatty liver was 12 out of 104 patients (11.5%) with distal partial gastrectomy with B-I reconstruction, while that was 17 of 72 patients (23.6%) with total gastrectomy with several reconstructions. The incidence of postoperative fatty liver change was significantly higher in the patients under 59 years old compared to the elders. Seventy-five g oral glucose test induced oxyhyperglycemia and hyperinsulinemia in patients with gastrectomy, especially with total gastrectomy. Integrated plasma insulin and triglyceride responses during first one hour in postgastrectomy patients were significantly higher than preoperative values. Moreover, plasma insulin and blood sugar in response to oral glucose test were significantly higher in patients with postgastrectomy fatty liver, compared to those in patients without fatty liver. These results suggested that the postgastrectomy fatty liver was resulted from the abnormality of the glucose metabolism.

Age Factors↗
PubMed1992

[Surgical treatment of infected left atrial myxoma--a case report].

A 22-year-old man had undergone dental therapy following an intermittent fever, and the bacteriological examination by blood culture identified Streptococcus viridans. A left atrial myxoma was echocardiographically found out and the tumor was surgically resected with uneventful postoperative course. Multiple foci and Gram-positive cocci within the typical myxoma were revealed histopathologically. Reviewing previous reports on infected cardiac myxoma, the coexistence of cardiac myxoma and a confirmed positive blood culture has been considered diagnostic criteria for "infected cardiac myxoma". But, from the surgical viewpoint, the demonstration of infecting organisms within the tumor is essential for accurate diagnosis. Infected atrial myxoma has an extremely high incidence of systemic embolization, and its bacterial foci could be the source of persistent bacteremia. Therefore, in clinical situations suggesting infected cardiac myxoma, we recommend performing open heart surgery to prevent both the embolization and the infective progression into other cardiac valves, as soon as possible.

Adult↗
PubMed1992

[Clinical experience of continuous retrograde cerebral perfusion for assisted circulation during the surgical treatment of acute dissection of aorta: Stanford A type].

Surgical treatment of the dissection involving the ascending aorta or aortic arch represents one of the most complicated technical challenges. Recently continuous retrograde cerebral perfusion (CRCP) is sometimes applied in order to avoid cerebral complications. We compared two surgical groups, one of which was performed graft-replacement of ascending aorta using CRCP and another was utilized normograde cerebral circulation, about the technique of operation, total extracorporeal circulation (ECC) time, aortic clamp time, separate ECC time, total bleeding volume, and urination during operation. In the group using CRCP, separate ECC time was 53 min (mean), and intraoperative bleeding volume was only 1,170 ml. Good urination was obtained during operation. Postoperative courses were uneventful, and consciousness was smoothly and soon recovered. The new method of separate ECC has some advantages over the previously described methods, particularly for avoidance of cerebral complications. As it is not necessary to require dissecting, taping, and clamping of cephalic branches, operative procedure will be very simplified, easier and safer, leading to intraoperative bleeding is a fewer. It is our belief that this method should be widely applied in the operation of graft-replacement of ascending aorta or aortic arch in the near future.

Aged↗
PubMed1992

[A case of incomplete endocardial cushion defect with mirror-image dextrocardia, IVC defect and azygos connection].

A case of incomplete endocardial cushion defect associated with mirror-image dextrocardia, IVC defect and azygos connection is reported. Intracardiac defect was corrected under moderate hypothermia with cardiopulmonary bypass. Three venous drainage cannulas were necessary to be indwelled into SVC, hepatic vein and right common iliac vein to maintain adequate venous drainage for extra-corporeal circulation. Thus, anomaly of venous system, which is commonly associated with mirror-image dextrocardia, must be recognized correctly and prepared before intracardiac correction.

Azygos Vein↗
PubMed1992

[Clinicopathological and immunohistochemical study of malignant lymphoma of the orbit].

The authors performed histopathological and immunohistochemical studies of 14 cases of orbital malignant lymphoma except for the conjunctival one. The patients were composed of 9 males and 5 females, and the average age of the cases was 61.5 +/- 12.3 years old. All cases were unilateral malignant lymphomas, 5 cases were right and 9 cases were left. Two patients had stage I disease, 10 patients had stage II disease, and 2 patients had stage III disease. The 5 year-survival rate was in 7/12 (58%). Histopathological examination revealed that 3 cases belonged to small lymphocytic, 4 cases diffuse small cleaved, 3 cases diffuse mixed and 4 cases diffuse large cell type by the working formulation. Immunohistochemical examination showed that all cases reacted positively against the B cell markers, while negatively against the T cell markers except for 1 case, indicating the cases were B cell lymphomas. Additionally, an immunoglobulin study contributed to elucidate the monoclonal proliferation of the tumor cells.

Adult↗
PubMed1992

[A case of metastatic breast carcinoma with cardiac tamponade and pleural effusion showing long survival by local treatment combined with systemic chemotherapy].

This report describes a case of metastatic breast carcinoma in a 62-year-old woman with cardiac tamponade and pleural effusion. Pericardiocentesis followed by ADM (10 mg) instillation successfully controlled cardiac tamponade. After local treatment CAF systemic chemotherapy was performed without serious complications. A long survival time of 50 months was observed. This result suggests that in this case pericardiocentesis with ADM instillation was life saving and that systemic chemotherapy prolonged life.

Breast Neoplasms↗
PubMed1992

[Regulation of the cultured mouse parenchymal liver cells (P-LC) by mast cells].

Mast cells suppressed the proliferation of parenchymal liver cells (P-LC) in a dose-dependent manner, when they were cocultured with P-LC. On the contrary, mast cells activated by IgE and anti-IgE enhanced DNA synthesis of P-LC dose-dependently. The activity enhancing the proliferation of P-LC was found in the supernatant of the activated mast cells, but not in that of untreated mast cells, suggesting the secretion of active factors by active mast cells. Histamine, which are released by the activated mast cells, suppressed the enhancement of P-LC proliferation by activated mast cells. Since histamine and heparin did not effect the proliferation of P-LC directly, histamine may bring the suppression through regulating the activated mast cell. On the basis of these findings, we discuss the role of mast cells in liver regeneration.

Animals↗
PubMed1991

[Renal sodium handling and renal dopaminergic activity in overweight normotensive subjects].

Recently, we reported that the blunted natriuretic ability related to an attenuation of renal dopaminergic activity might play an important role in the hypertensive mechanisms of overweight patients with essential hypertension. On the other hand, the interrelationships between obesity, blood pressure and renal sodium handling in normotensives (NT) have not been clear. The purpose of the present study is to reveal the role of renal dopaminergic activity on renal sodium handling in overweight NT. The study consisted of 52 hospitalized NT receiving a regular diet containing 200mEq of sodium, 75mEq of potassium, 2400kcal/day, who were divided into two groups of 31 non-obese (NNT) and 21 obese (ONT) subjects. NNT was categorized as the body mass index (BMI) less than, and ONT as the BMI equal to or more than, 25kg/m2. In the early morning, after overnight fasting, all subjects remained in a supine state and were examined for renal clearance. During the clearance period, mean arterial pressure (MAP), heart rate (HR), endogenous creatinine clearance (Ccr), urinary excretion of sodium (UNaV), fractional excretion of sodium (FENa) and of inorganic phosphorus (FEP) and urinary excretion of free dopamine (uDA) were determined. There were no significant differences in age, HR, Ccr or UNaV between the two groups. Higher MAP and lower FENa) were observed in ONT than in NNT, but the differences in these parameters were not statistically significant. However, FENa in ONT was significantly lower than in MAP-and Ccr-matched NNT. In addition, FENa correlated negatively with BMI in ONT, unlike in NNT. MAP was correlated positively with FENa, and a similar tendency was found between MAP and FEP in NNT, but not in ONT. On the other hand, there was no significant correlation between BMI and uDA in either NNT or ONT. This result was different from our previous data in patients with essential hypertension (EHT) in which BMI correlated with uDA positively in non-obese EHT and negatively in obese EHT. These findings suggest that blunted natriuretic ability may exist in ONT, and the role of renal dopaminergic activity related to the attenuated natriuretic ability in ONT may be less important than in obese EHT.

Adult↗
PubMed1991

Ocular histopathologic findings in a 46-year-old man with primary hyperoxaluria.

A 46-year-old Japanese man with familial primary hyperoxaluria had been suffering from urolithiasis since the age of 6 years and had been treated by hemodialysis for 8 years before his death. The alpha-ketoglutarate glyoxylate carboligase and serine pyruvate transoxylase activities in the patient's liver had markedly decreased, indicating type I primary hyperoxaluria. Ocular tissues obtained at autopsy were studied immunohistochemically and histochemically. The ocular alterations were characterized by an unusual distribution of oxalate deposits, mainly located in the outer plexiform layer and the nuclear layer but not in the retinal pigment epithelium or in the vascularized layer of the sensory retina. These distributions of the oxalate deposits were determined to be unrelated to the blood vessels.

Blood Chemical Analysis↗
PubMed1991

Class II major histocompatibility complex on melanocytes of Vogt-Koyanagi-Harada disease.

The eyes obtained from two Japanese autopsy cases of patients with Vogt-Koyanagi-Harada disease were immunohistochemically examined. Both patients, a 63-year-old woman and a 68-year-old man, were clinically and histologically diagnosed as having Vogt-Koyanagi-Harada disease. Immunohistochemically, the choroidal infiltrate was composed predominantly of T lymphocytes with a larger proportion of helper/inducer T cells than suppressor/cytotoxic T cells and it also included activated lymphocytes expressing CD26 and CD25 antigens. Class II major histocompatibility complex was expressed in the choroidal melanocytes as well as in the endothelium of the choriocapillaris. Depositions of complement, however, were focally noticed in the choroid. Our results indicate that the cell-mediated immune process plays an important role in the development and progression of Vogt-Koyanagi-Harada disease, while choroidal melanocytes appear to play a pathogenic role in this disease.

Aged↗
PubMed1991

The liver and the hematolymphoid system: I. The regulation of nylon-passed spleen cell proliferation by active factors released from syngeneic nonparenchymal liver cells.

Nylon-passed spleen cells were found to proliferate when cultured with syngeneic nonparenchymal adherent liver cells and their culture supernatants. The supernatants contained IL-1, IL-6, GM-CSF, and IFN (alpha + beta) activities but not IL-2 and IL-3 activities. The IFN level was higher in early culture sup (2-24 hr) than in later culture sup (48-72 hr). Proliferation was greatly increased by anti-IFN (alpha + beta) serum in the spleen cells cultured in the earlier sup. This antiserum increased the spleen cell proliferation only slightly in the later culture sup. This suggests that nonparenchymal liver cells produce two factors, one having a suppressor, and the other an enhancer action, with IFN being one of the suppressor factors. With culture time, DNA synthesis of spleen cells increased and IL-2 and IL-3 activities were generated in the culture sup. Cells proliferated during culture were found to be morphologically lymphocytes, granulocytes, and macrophages. The mechanisms by which nonparenchymal liver cells regulate the hematolymphoid system are discussed based on our observations.

Animals↗
PubMed1991

Clinical experience of coenzyme Q10 to enhance intraoperative myocardial protection in coronary artery revascularization.

Seventy-eight patients undergoing coronary artery bypass grafting (CABG) were compared retrospectively to evaluate whether pretreatment with coenzyme Q10 (CoQ) is effective in preventing left ventricular depression in early reperfusion following CABG. CoQ (5 mg/kg, intravenously) was given to 60 patients, 2 hours prior to the onset of cardiopulmonary bypass (CPB). CABG was performed using saphenous vein under CPB associated with cold cardioplegia in the standard fashion. Heart rate, mean arterial pressure, and cardiac index showed no significant difference between the CoQ and control groups. However, left ventricular stroke work index was significantly elevated at 6 and 10 hours of reperfusion following CABG in the CoQ-treated group compared with the controls. Serum MB-CK was lower at 0 and 6 hours of reperfusion in the CoQ group compared with the controls. These results suggest that pretreatment with intravenous CoQ is effective in preventing left ventricular depression in early reperfusion and in minimizing myocardial cellular injury during CABG followed by reperfusion.

Coenzymes↗
PubMed1991

Monoclonal antibody to the corneal endothelium: partial characterization of the antigen and its expression in fetal and adult rabbits.

Monoclonal antibodies (mAbs) were developed against corneal endothelial cells (CECs) using cultured bovine CECs as immunogens by the mouse hybridoma technique. One of these mAbs, KP14D10 (IgM type), reacted specifically with CECs in human, bovine and rabbit ocular tissues as judged by immunohistochemical methods. This mAb also reacted with some epithelial cells of human esophageal and gastric glands but not with those of bovine and rabbit origin. The molecular weight of the antigen was determined to be 60,000 Da by the immunoblotting method. This antigenicity was apparently decreased by treatment with hyaluronidase, trypsin, and pronase. In the immunohistochemical study of rabbit fetal corneas, the immunofluorescence appeared specifically in the CECs after the 15th day of gestation and its intensity became stronger as gestation advanced. These results suggest that this antibody would be a valuable tool in the further analysis of corneal development and of divese pathological alterations of CECs.

Animals↗
PubMed1991

Effect of secretin on lower esophageal sphincter pressure in patients with esophageal achalasia.

The effect of a bolus intravenous administration of secretin (2.0 U/kg) on resting lower esophageal sphincter pressure (LESP) was investigated in seven patients with esophageal achalasia. Basal LESP before secretin injection in the patients was 60.1 +/- 3.4 mmHg (Mean +/- SEM), which was significantly higher than 26.9 +/- 2.5 mmHg in normal controls consisting of eight healthy volunteers. LESP significantly decreased within 1 min after the injection both in the patients and the controls. The maximum pressure change from each basal LESP was 31.2 +/- 5.2 mmHg in the patients, which was significantly greater than 12.1 +/- 1.8 mmHg in the controls. The effect of secretin disappeared within 5 min in the controls. The effect in the patients, however, lasted throughout the investigation time of 30 min. It is concluded that secretin has a long-acting effect on muscular relaxation of the lower esophageal sphincter in esophageal achalsia patients.

Adult↗
PubMed1991

Multifocal pancreatic serous cystadenoma with atypical cells and focal perineural invasion.

A case of multifocal pancreatic serous cystadenoma with atypical cells is reported. The patient was a 72-yr-old female who complained of jaundice. The distal common bile duct was obstructed, and the proximal bile duct was remarkably dilated on cholangiography. The main portal vein was obstructed and collateral vessels had developed on portal angiography. Total pancreatectomy was performed. The resected specimen contained one tumor in the head of the pancreas, five in the body, and one in the tail. The tumors of the head and body were morphologically the same. Microscopically, both contained spongelike multilocular cysts on their cut surfaces. These cysts were covered with low cuboid epithelium containing clear cytoplasm and abundant glycogen. Neural invasion was also found. The tumor cells exhibited an increased N/C ratio, variable nuclear size, irregular nuclear margins, and coarse nuclear chromatin. These tumors had aneuploid nuclear DNA with a DNA index of 1.9 and a proliferation index of 0.28. We feel that it is necessary to reconsider the biological concept of serous cystadenoma.

Aged↗