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Biomedical subjects

T Morimoto

Publications and source records attributed to T Morimoto.

At least 433 records · Page 24Linked to original sources

Transplantation of the canine cadaver heart using a core-cooling technique.

We studied whether a cardiopulmonary bypass (CPB) and a core-cooling technique could resuscitate an arrested heart, and whether this procedure benefited canine cadaveric heart transplantation. Donor dogs were subjected to brain death by an intracranial balloon technique, and then, to cardiac arrest conducted by cutting off ventilatory support. In the control group (Group 1; n = 8), arrested hearts were flushed with cardioplegic solution and harvested thereafter without any resuscitation technique. In the experimental group (Group 2; n = 8), arrested hearts were once resuscitated using CPB, and then harvested using a core-cooling technique and cardioplegia. These hearts were transplanted orthotopically. Seven of eight recipients in Group 1 were weaned from CPB, and five of them finally became independent of dopamine administration. All recipients in Group 2 were successfully weaned from CPB, and also became dopamine free eventually. In Group 2, all post-transplantation hemodynamic values such as cardiac output during the period of dopamine administration were equivalent to those of post-brain death period. Chemical analysis of the serum and myocardial muscle demonstrated no difference between groups. We conclude that CPB combined with a core-cooling technique makes it possible to utilize an arrested heart as a donor organ for transplantation.

Animals↗

A closed chamber for intravital microscopy of the rat mesentery under controlled oxygen tension and temperature.

An airtight and watertight closed chamber for intravital microscopy of the rat mesentery was developed. It incorporates an oxygen microelectrode and a thermistor for monitoring the local environment around the mesentery, as well as a heater for controlling the chamber temperature. This chamber provides an alternative to the superfusion method for intravital microscopy of the mesenteric microcirculation under circumstances where well-defined experimental conditions are required.

Animals↗

Incidence of ultrasonographically-detected thyroid nodules in healthy adults.

We studied the incidence of thyroid nodules in healthy adults, who had no history of thyroid disease, in Tokushima, Japan, where goiter is not considered endemic. Examination was performed by palpation and using a 10-MHz real-time sonographic scanner. Palpable thyroid nodules were present in two (0.9%) of 227 men and in four (1.8%) of 224 women. On the other hand, nodules were detected by ultrasonography in 42 men (18.5%) and 47 women (21.0%). There was no significant difference in the incidence detected by ultrasonography between men and women in any of the age groups, except in men above 60 years old. It is concluded that thyroid nodules are not an uncommon disorder even in men. Since, clinically, the incidence of nodularity appears to be higher in women than in men, there may be difference between men and women in the development of nodules until they become clinically detectable.

Adult↗

Clinicopathological study on craniopharyngioma with sebaceous differentiation.

We presented 2 cases of craniopharyngioma, which showed sebaceous differentiation. Both cases shared the following features: 1) neuroradiological detection of a cystic tumor accompanied by calcification, 2) clear yellowish fluid detected in the cyst during surgery, 3) histological rating as an adamantinomatous type, 4) the presence of a nest-like distribution of multivacuolated cells in the innermost layer of the cyst.

Child↗

[Successful treatment by using a pedicled omental flap for sternal osteomyelitis and mediastinal infection caused by MRSA].

A 56-year-old male case, who was complicated with sternal osteomyelitis and mediastinitis after aortic valve replacement, was reported. Its infection was caused by MRSA (methicillin resistant Staphylococcus aureus). He was treated with sterilization of wound using povidone iodine, Minomycin solution and its injection for 10 days. And thereafter we decided to apply the plastic surgical technique to this case. After debridement of the infected granulation and sternum thoroughly, a pedicled omental flap was transposed successfully.

Humans↗

Hepatic vein reconstruction of the graft in partial liver transplantation from living donor: surgical procedures relating to their anatomic variations.

BACKGROUND: The surgical procedures to reconstruct the hepatic veins differ according to their anatomic variations to obtain the optimal graft volume for the recipient. This is an overview of the procedures used in our 25 living related liver transplantations. METHODS: The donor/recipient body weight ratio ranged widely from 1.2:1 to 9.6:1 (5.3 +/- 0.5:1, mean +/- SEM). RESULTS: The graft weight/recipient body weight was 2.40% +/- 0.21%. Graft components, which were determined by the optimal graft volume, and their drainage veins were the following: (1) segments 2 and 3 (S2+3) were used in 13 cases, 11 with the left hepatic vein (LHV) and two with the LHV and a partial drainage vein of S3; (2) S2+3 and a part of S4 in eight cases, seven with LHV and one with LHV and a partial drainage vein of S4; (3) S2+3+4 in three cases, with the common trunk of LHV and middle hepatic vein in all cases; and (4) S5+6+7+8 in one case with right hepatic vein. In two of three cases in which the graft had two drainage veins, the two vessels were reformed to have a common anastomotic orifice by the back-table plastic surgery procedure. In the other case in which the procedure could not be performed, two separate anastomoses of the individual vessels were performed successfully. Although stenosis of the reconstructed hepatic veins occurred four times in two cases at 3 months or more after transplantation, all incidences could be completely repaired by balloon dilation. CONCLUSIONS: These results show that, with careful consideration of the hepatic vein reconstruction, pediatric patients can receive optimal volume grafts from living donors.

Adolescent↗

[A case complicated with a large perforation at the great curvature of the stomach after 6 days of omentopexy for tuberculous empyema].

A 72-year-old male with tuberculous empyema underwent omentopexy following thoracic window. However, acute abdomen developed 6 days after the latter surgery. During emergency laparotomy; a large perforation (8.5 x 3cm) was found at the great curvature of the stomach. Histology of the resected specimen showed this was ischemic ulcer, which was thought to have been caused by circulatory failure at the areas supplied by the right gastroepiploic arteries after pedicled omental flap. This case suggested that much attention should be paid not only to the blood circulation of the graft but also to that of the stomach.

Aged↗

[Comparison between antegrade and retrograde cardioplegia with warm blood].

Recently continuous warm blood cardioplegia (BCP) has been reported as a superior method of myocardial protection, but it is unknown which is more effective antegrade or retrograde cardioplegia. This study was performed to investigate the efficacy of antegrade infusion via aortic root and retrograde infusion via coronary sinus with continuous warm BCP in regard to metabolism, oxygen extraction ratio, serum enzyme release, cardiac function, and myocardial edema. Fourteen adult mongrel dogs were subjected to total cardiopulmonary bypass and cross-clamp of the aorta for 120 minutes, and followed by 60 minutes reperfusion. The dogs were divided into two groups according to the infusion type of continuous warm blood cardioplegia: Group A, antegrade warm BCP, and Group R, retrograde warm BCP. Changes in excess lactate (delta XL), redox potential (delta Eh), and myocardial lactate extraction ratio showed that aerobic metabolism could be maintained in group A and could not in group R. Myocardial oxygen extraction ratio during aortic cross-clamp was same in group A and in group R, but at 5 minutes after reperfusion it was significantly higher in group A than in group R (41 +/- 8% V.S. 22 +/- 9%). The incidence of ventricular fibrillation (V.F.) after reperfusion was significantly lower in group A than in group R (1/7 V.S. 7/7). CPK-MB and HBDH releases during aortic cross-clamp and 60 minutes reperfusion were lower in group A than in group R, but not significant. Generations of lipid peroxides (A-Cs difference) were lower in group R than in group A, but not significant.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

[Experimental study of acute spinal cord injury: a histopathological study].

The microscopic appearance of a rat spinal cord which was acutely compressed by aneurysmal clip for one minute, was investigated 15 minutes, 30 minutes, 1 hour, 3 hours and 6 hours after the injury. Although the resulting small hemorrhagic lesion involved primarily only the central gray matter of the injured portion 15 minutes after compression injury, hemorrhage, necrosis and edema in the central gray matter enlarged progressively until 3 hours after injury. Petechial hemorrhage, necrosis and edema were observed in the surrounding area one hour after spinal compression. Then these pathological changes extended rostrally and caudally, but their extension was more significantly remarkable in the rostral side than in the caudal side 3 hours after compression. It was observed that leukocytes begin to infiltrate into the injured capillary walls and plug up the capillary lumen 30 minutes after the injury. Three hours following the injury, leukocytes (lymphocyte, macrophage) extravasated into the surrounding spinal tissue. From these histopathological observations, we reached the following conclusions. A. Secondary injuries play an important role in grave impairment of neurological function of the spinal cord following acute trauma. B. Pathological findings (hemorrhage necrosis and edema) extend more prominently to the rostral side, because the direction of spinal blood flow may be rostral in the thoracic spinal cord. C. Severe disturbance of intraspinal capillary blood flow leading to grave spinal damage may be evoked, because leukocytes infiltrate into the capillary around the injured area and plug up the their lumen about 30 minutes after the injury.

Acute Disease↗

[Experimental study of acute spinal cord injury: a study of spinal blood flow].

It is well known that the worsening of neurological findings after spinal cord injury is due to the secondary progression of pathological changes which may be caused by spinal cord blood flow disturbance. We measured spinal blood flow of 5mm rostrally and caudally distant portions from the injured point, using the laser Doppler flowmeter experimentally. Forty rats were used. Ten of these were used as a control group. And thirty animals were injured at the level of the tenth thoracic cord with a 50g epidural one minute compression method and measured continuously from 30 minutes before the injury to 6 hours after the injury. Twenty two surviving animals were evaluated. In the control group, spinal blood flow was stable. But in the injured group, spinal blood flow dropped by 30.6 + 9.8% on the rostral side and 37.3 + 17.6% on the caudal side in comparison with the resting value soon after the injury. Although the flow improved to 89.3 + 11.1 and 71.3 + 17.8% respectively 15 minutes later, it dropped again gradually and reached 42.8 + 14.1 and 66.2 + 16.4% respectively 6 hours after the injury had been inflicted. Lastly, in the animals, carbon perfusion was performed through the left ventricle. The normal figured vasculature in the preparation of the injured and measured portion was calculated with a microcomputer imaging analyzer and compared with control groups. The number of the normal vessels was significantly more abundant on the caudal side than on the rostral side (p < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Relative effect of steroid hormone receptors on the prognosis of patients with operable breast cancer. A univariate and multivariate analysis of 3089 Japanese patients with breast cancer from the Study Group for the Japanese Breast Cancer Society on Hormone Receptors and Prognosis in Breast Cancer.

In a retrospective multicenter study to investigate the correlation between estrogen (ER) and/or progesterone receptors (PgR) in primary breast cancer with patient prognosis, 3118 patients with operable breast cancer (International Union Against Cancer Stages I, II, and III) were investigated from ten hospitals in Japan who underwent surgery from October 1972 to December 1982; 3089 were evaluable. The ER-positive and PgR-positive cancers were found in 56% and 34% of patients, respectively. The positivities decreased as the tumor size increased but were independent on lymph node metastasis. There were no significant differences in relapse-free survival (RFS) in relation to receptor status (median follow-up, 89 months [ER], 84 months [PgR]). However, in patients with four or more positive nodes, those with PgR-positive cancer had a longer RFS. The patients with ER-positive cancer survived significantly longer than ER-negative ones, with the greatest difference seen in those with four or more positive nodes. There was a significantly longer postrelapse survival (PRS) for patients with ER-positive cancer because of the different distribution of the major metastasis and better responses to first-line and subsequent treatments. Cox's multivariate analysis showed that overall survival but not PRS was affected by ER (and more weakly by PgR) because of the longer PRS in patients with ER-positive cancer.

Adult↗

Establishment of a sensitive radioimmunoassay for serum thymic factor with a special reference to extraction procedures.

A radioimmunoassay (RIA) for serum thymic factor (facteur thymique serique) was established. This assay could detect less than 0.5 pg of serum thymic factor without the interference by other thymic hormones, including thymopoietin II and thymosin alpha 1. Both zinc-free and zinc-bound serum thymic factor showed a similar standard curve, indicating that this RIA could detect both forms of serum thymic factor in the same way. We observed that two procedures were required prior to the measurement in order to measure serum thymic factor content in plasmas; the first, the extraction procedure to remove substances interfering with the assay nonspecifically; the second, the storage of the sample with ethylenediamine tetraacetic acid disodium salt to inhibit the proteases in the plasma to degrade serum thymic factor. By employing this assay system, we observed that cord blood plasmas contained significantly higher level of serum thymic factor than did adult blood plasmas.

Adult↗

Basic fibroblast growth factor, a protein devoid of secretory signal sequence, is released by cells via a pathway independent of the endoplasmic reticulum-Golgi complex.

Basic fibroblast growth factor (bFGF) modulates functions of a variety of cell types. Whereas bFGF is known to act extracellularly, the protein lacks a transient signal peptide. No defined mechanism for bFGF secretion has been characterized besides release from dead or injured cells. To study this problem we devised an experimental system to examine bFGF-mediated migration of isolated single cells. Under these conditions individual cells are not affected by bFGF derived from other cells. By this method we have previously shown that bFGF released by NIH 3T3 cells transfected with bFGF cDNA modulates migration in an autocrine manner. We have now examined the effects on cell motility of drugs or treatments known to affect various pathways of protein secretion. Drugs that block secretion via the endoplasmic reticulum (ER)-Golgi complex or via multidrug resistance proteins did not inhibit cell motility. Migration was enhanced by the calcium ionophore A23187, which stimulates exocytosis, and was inhibited by methylamine, serum-free, and low temperature (18 degrees C) conditions, which block endo- and exocytosis. The reversal of these effects by the concomitant addition of affinity-purified anti-bFGF IgG or recombinant bFGF showed that the alterations in cell migration were mediated by changes in bFGF externalization. Thus bFGF can be released via a mechanism of exocytosis independent of the ER-Golgi pathway.

Animals↗

Thyroid carcinoma in patients with secondary hyperparathyroidism.

There have been few reports of coexistence of secondary hyperparathyroidism (2 degrees HPT) and thyroid carcinoma. Eleven consecutive patients with 2 degrees HPT who underwent parathyroidectomy were analyzed. They consisted of six males and five females, whose age ranged from 34 to 55 years. None of the patients had a history of irradiation of the head or neck. Associated thyroid nodules were also present in seven patients (64%): four patients with benign nodules, and three patients with papillary carcinomas, and one with papillary carcinoma and two follicular adenomas. This incidence of thyroid carcinoma in the patient group with 2 degrees HPT (36%) was significantly higher than that of the autopsy group in the same geographical area (11%). The level of carboxyl-terminal parathyroid hormone in the patients with thyroid carcinoma was higher than that in the patients without thyroid carcinoma (P less than 0.05). The importance of searching for possible thyroid cancer in patients with 2 degrees HPT should be emphasized.

Adult↗