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Biomedical subjects

T Mizuta

Publications and source records attributed to T Mizuta.

At least 91 records · Page 5Linked to original sources
PubMed1989

The beneficial effect of superoxide dismutase on the rat liver graft.

We performed orthotopic liver transplantation in male Wistar rats and investigated the effect of superoxide dismutase (SOD) on the liver graft. Animals were divided into the four following experimental groups. Group I was an untreated control group, group II received oxygen, group III received SOD and group IV received both oxygen and SOD. The dose of SOD was 3 mg/kg which was injected intravenously into both donors and recipients during the operation. Oxygen was given through an oxygen inhaler to both donors and recipients during the operation. The preservation time of the liver graft ranged from 4 hours and 41 minutes to 5 hours and 40 minutes. The survival after liver transplantation was compared among groups I, II, III and IV. Group IV showed a significantly higher survival rate than groups I and II by two weeks after liver grafting, but there was no statistical difference in the survival rates between groups III and IV. These results indicate the beneficial effect of SOD on the rat liver graft and may implicate oxygen free radicals in the pathogenesis of ischemia/reperfusion injury in liver grafts.

Animals↗
PubMed1989

Chronic effects of imipramine and lithium on 5-HT receptor subtypes in rat frontal cortex, hippocampus and choroid plexus: quantitative receptor autoradiographic analysis.

The effects of chronic treatment with imipramine or lithium on serotonin (5-HT) receptor subtypes were analyzed in the frontal cortex, hippocampus and choroid plexus of rat brain by quantitative receptor autoradiographic procedures, using radioligands [3H]-5-HT, [3H]-8-hydroxy-2-(di-n-propylamino)tetralin ([3H]-8-OH-DPAT), [125I]-iodocyanopindolol ([125I]-CYP), [3H]-mesulergine and [125I]-7-amino-8-iodo-ketanserin ([125I]-ketanserin) or [3H]-spiperone. Chronic i.p. administration of imipramine (20 mg/kg/day for 21 days) decreased the densities of 5-HT1, 5-HT1A, 5-HT1C and 5-HT2 sites in the frontal cortex, hippocampus and choroid plexus. Lithium (2 mEq/kg/day for 21 days) also decreased the densities of 5-HT1, 5-HT1C and 5-HT2 sites in the frontal cortex, and the densities of those including 5-HT1A sites in the hippocampus and choroid plexus. Imipramine and lithium very markedly decreased the density of 5-HT1C sites in the choroid plexus. We propose that methods employing quantitative receptor autoradiographic analysis can be used to characterize and understand the local effects of these drugs on 5-HT receptor subtypes.

Animals↗
PubMed1989

[Serum and tissue concentration of tegafur and 5-FU after administration of tegafur suppository in patients with lung cancer--correcting the influence of residual blood in the tissue].

Tissue concentration of tegafur and 5-FU was studied in 25 patients with of primary lung cancer, given 2 x 750 mg of tegafur suppository daily preoperatively (total doses 3.75-9.75 g, mean 5.16 g). Furthermore, the influence of blood remaining in the tissue was corrected in the determination of tegafur and 5-FU concentration. The tegafur level in tumor tissue (9.614 +/- 5.739 micrograms/g) was significantly (p less than 0.01) low compared with those in serum and normal lung tissue (13.185 +/- 8.198 micrograms/ml, 12.954 +/- 10.048 micrograms/g). On the other hand, the 5-FU level in tumor tissue (0.124 +/- 0.208) was significantly (p less than 0.01, p less than 0.05) high compared with those in serum and normal lung tissue (0.019 +/- 0.013 micrograms/ml, 0.035 +/- 0.031 micrograms/g) and showed approximately 2.5 times more minimum effective concentration against tumor cells (0.05 micrograms/g). The results show that preoperative administration of 2 x 750 mg of tegafur suppository daily is effective for the transfer of tegafur and 5-FU to lung cancer tissue.

Adult↗
PubMed1989

[Phrenic nerve conduction disorder after open heart surgery--electrophysiological study].

In 32 consecutive adult patients undergoing heart surgery, the induced diaphragmatic muscle action potential was measured. Phrenic nerve conduction disorder was defined as disappearance of muscle action potential (Edi) and conduction time (CT). Phrenic nerve conduction disorder was observed in 10 patients (31%); 8 patients on the left side and 2 patients on both sides. In non-conduction disorder group (22 patients), Edi and CT were measured. Edi of the right side decreased significantly from preoperative value of 705 +/- 318 microV to 445 +/- 285 microV at 1-3 days after operation (stage I) and to 559 +/- 314 microV at 7-10 days after operation (stage II) (p less than 0.05). CT of the right side prolonged significantly from 7.1 +/- 0.7 msec before operation to 7.44 +/- 0.97 msec at postoperative stage I and to 7.40 +/- 0.21 msec at postoperative stage II (p less than 0.05). For the left phrenic nerve, Edi showed significant (p less than 0.05) decrease from 803 +/- 338 microV before operation to 429 +/- 251 microV at the postoperative stage I and 620 +/- 350 microV at the postoperative stage II. In the conduction disorder group, incidence of atelectasis, diaphragm elevation and pleural effusion as documented by chest roentgenographic findings were higher than those of non-conduction disorder group (p less than 0.01). Moreover, the lowest temperature of the myocardium during operation was significantly (p less than 0.05) lower for conduction disorder group as compared to non-conduction disorder group. We believed that it is necessary to develop a innovative method for preventing the phrenic nerve from cold injury.

Adult↗
PubMed1989

[Complication related to operative procedure in lung cancer and mediastinal malignancy--report of 6 cases].

Of the patients who underwent surgical treatment for the respiratory system at our hospital over the past 9 years, 6 were postoperatively complicated with chylothorax, 1 with liquorrhea and the other one with paraplegia. Chylothorax occurred after mediastinal lymph node dissection which was carried out for the treatment of malignant tumors. In five cases, it occurred on the left side, and in the sixth case, it occurred on the right side. In 2 patients who received conservative treatment, there was no reduction in chyle outflow, and they died of cerebral infarction and sepsis. The other 4 cases were surgically treated. In 3 of them, the impaired site of the thoracic duct was confirmed by administration of Sudan III before surgery. We confirmed that early reoperation for the chylothorax after lung resection should be performed. Liquorrhea occurred from the 5th costvertebral joint which had been directly infiltrated by lung carcinoma. Fortunately, the postoperative course was uneventful, though the patient complained of dizziness and headache until 14 postoperative days. The case of paraplegia was caused by oxydized cellulose cotton that entered the epidural space via the intervertebral foramen. It was used for hemostasis in the 5th costvertebral joint. This case indicates that oxydized cellulose cotton, which swells when it absorbs water, should be carefully used for hemostasis around the nerves.

Adolescent↗
PubMed1989

Simplified rat lung transplantation using a cuff technique.

A cuff technique is introduced to anastomose pulmonary vein and pulmonary artery in rat lung transplantation. In 11 consecutive cases, the average graft ischemic time was 13.5 +/- 2.0 minutes and operating time 100.7 +/- 4.8 minutes: The time for ischemia was less than one third of previous reports and the time for operation one half of previous reports. Excluding two operative deaths, the survival rate was 88.8% (8/9) on postoperative day 11, when contralateral pneumonectomy revealed excellent graft function supporting the oxygenation of the animals.

Anastomosis, Surgical↗
PubMed1989

[The result of extended thymectomy in patients with myasthenia gravis of pure ocular type].

We studied postoperative status of 14 patients with myasthenia gravis of ocular type who underwent extended thymectomy. Nine patients were in remission, three improved, and two unchanged. No patient became worse and died. The remission rates at one, three, five, and ten years after operation were 50.0%, 58.3%, 60.0%, and 80.0%. The palliation rates at one, three, five, and ten years after operation were 64.3%, 75.0%, 80.0%, and 100%. The remission rate at one year after operation in patients of ocular type was significantly (p less than 0.05) higher than that in generalized type (191 patients). The mean preoperative duration of symptoms in patients who obtained remission after surgery was 7.2 +/- 6.5 months, while mean duration was 85.6 +/- 45.8 months in those patients who could not obtain remission, indicating a significant difference (p less than 0.05) of duration of symptoms between two groups. Among 89 patients with generalized as well as ocular symptoms before extended thymectomy, 62 patients (69.7%) still complained of ocular symptoms and 48 patients (53.9%) had generalized symptoms with or without ocular symptoms in 1 to 12 years after operation. This result shows that ocular symptoms do not disappear more easily than generalized ones. We conclude that extended thymectomy should be performed even in patients with myasthenia gravis of pure ocular type.

Adult↗
PubMed1989

[Surgical treatment of pulmonary metastases from osteogenic sarcoma-significance of aggressive resection of bilateral multiple metastases and tumors invading adjacent organs].

The results of surgical treatment of pulmonary metastases from osteogenic sarcoma were analyzed. Total cases were 23 with mean age of 17.0 +/- 9.1. The number of operations were 46, and operative procedures consisted of pneumonectomy in 1, lobectomy in 3, partial resection in 37 and resection of adjacent organs in 5. The overall five-year survival rate from the first thoracotomy was 21%. This was significantly higher than prognosis of the previous cases with pulmonary metastases which were not resected (p less than 0.001). Three-year survival rate for the group with 5 or less metastases was 57%, whereas that for the group with 6 or more metastases was 0% (p less than 0.02). To assess both the number and the diameter of metastases, an index called number-size score (NS score) was introduced, which was the sum of the diameters of each metastatic lesion. The three-year survival rate for the group with NS score 6 or less was 73%, whereas that for the group with NS score 7 or more was 9% (p less than 0.001). Disease free interval, the time of operation and histological effect of chemotherapy were not significantly related with prognosis. There was no long-term survivor among the patients with resection of adjacent organs. In conclusion, an aggressive resection of pulmonary metastases from osteogenic sarcoma should be performed with intensive chemotherapy, but significance of the resection of multiple metastases more than 20 or tumors invading adjacent organs is doubtful.

Adolescent↗
PubMed1989

[Study on indication of unilateral pulmonary artery occlusion test in patients undergoing pneumonectomy].

We tried to establish an indication of unilateral pulmonary artery occlusion test (UPAO), by analyzing the preoperative data of UPAO, overall and regional pulmonary function tests, and arterial blood gas in 55 patients who were intended for pneumonectomy. Our limits of functional indication for pneumonectomy were PPA less than or equal to 25 mmHg or TPVRI less than or equal to 700 dyne.cm-5.m2. PPA correlated with the inverse of contralateral FEV1.0/BSA (FEV section 1.0) and DLCO/BSA (section DLCO), which were calculated by multiplying preoperative values by contralateral ventilation fraction. TPVRI correlated with age, the inverse of PaO2, the inverse of FEV section 1.0, and the inverse of section DLCO. Multiple regression analysis yielded the equation, TPVRI approximately p = 1120/section DLCO + 24800/PaO2 + 6.40 X Age -506. In order to make false negative zero, the values of each parameter were as follows: age greater than or equal to 55, PaO2 less than or equal to 85 mmHg, FEV section 1.0 less than or equal to 0.8 L/m2, section DLCO less than or equal to 6.0 ml/min/mmHg/m2 and TPVRI approximately p greater than or equal to 450 dyne.sec.cm-5.m2. The specificities of each parameter were 18.6%, 20.9%, 39.2%, 40.4% and 59.0%. Therefore, in order to make false positive patients least, the criteria of TPVRI approximately p greater than or equal to 450 dyne.sec.cm-5.m2 should be used.

Adult↗
PubMed1988

Expression of Ley antigen in human immunodeficiency virus-infected human T cell lines and in peripheral lymphocytes of patients with acquired immune deficiency syndrome (AIDS) and AIDS-related complex (ARC).

Ley determinant (Fuc alpha 1----2Gal beta 1----4[Fuc alpha 1----3]GlcNAc beta 1----R) defined by mAb BM-1 is highly expressed in human immunodeficiency virus (HIV)-infected T cell lines and in CD3+ peripheral mature T cells of patients with acquired immune deficiency syndrome (AIDS) or with AIDS-related complex (ARC). Ley expression increased greatly in the CD3+ population in the advanced stage of AIDS when the CD4+ population decreased greatly. Six other carbohydrate antigens tested by their respective mAbs were not detected in these same cells. None of the carbohydrate antigens tested by the seven mAbs used in this study were found in noninfected T cell lines and in normal peripheral blood lymphocytes.

AIDS-Related Complex↗
PubMed1988

An interposed superficial temporal artery graft bypass for anterior cerebral artery ischemia.

A new microsurgical revascularization technique for anterior cerebral artery ischemia is reported. An arterial graft bypass interposed between the superficial temporal artery and the distal anterior cerebral artery was successfully completed in a 43-year-old male with transient ischemic attacks in the anterior cerebral artery territory. The contralateral superficial temporal artery was harvested and used as an arterial graft. Both procedures were carried out with one single transcoronal scalp incision. The patient's postoperative cerebral angiogram revealed good filling of the area distal to the stenotic lesion of the anterior cerebral artery through the bypass graft. The patient was discharged with no neurological deficit and has been free of ischemic events for more than 2 years since the surgery. If the bilateral superficial temporal arteries are fairly well developed, the ipsilateral superficial temporal artery can be used as an arterial graft for revascularization of the anterior cerebral artery territory.

Adult↗
PubMed1988

Tissue-type plasminogen activator inhibits aggregation of platelets in vitro.

The effects of tissue-type plasminogen activator (t-PA) on the platelet aggregation were studied using citrated whole blood and platelet-rich plasma (PRP) obtained from human donors. t-PA suppressed adenosine 5'-diphosphate (ADP)- or collagen-induced platelet aggregation in a dose-dependent manner. The 50% inhibitory concentration (IC50) for t-PA was lower by one order of magnitude than that for urokinase (UK) in whole blood and PRP. The suppression of platelet aggregation was not completely inhibited by alpha-2-antiplasmin. t-PA did not cause the degradation of fibrinogen or fibrin in PRP, whereas UK caused the reduction of fibrinogen and fibrin, and the increase of fibrinogen- and fibrin-degradation products (FDP). These results suggest that the mode of action of t-PA in inhibiting platelet aggregation may be different from that of UK.

Adenosine Diphosphate↗
PubMed1988

Prediction of postoperative respiratory failure in patients undergoing lung resection for lung cancer.

To evaluate the correlation between predicted postoperative lung function and postoperative respiratory morbidity, 156 patients with lung cancer who underwent resection were classified into four groups based on the degree of postoperative problems: Group 1--no problems (116 patients); Group 2--retention of sputum or atelectasis requiring bronchofiberscopy two or more times (17 patients); Group 3--tracheostomy or mechanical ventilation for more than 2 days or both (14 patients); and Group 4--postoperative death (9 patients). The mean ages of Groups 2, 3, and 4 were significantly (p less than 0.05) higher than the mean age of Group 1. The predicted postoperative lung function (F) was assessed by the formula F = [1-(b-n)/(42-n)] x f, where f is the preoperative vital capacity or forced expiratory volume in one second, b is the number of subsegments of the resected lung lobe, and n is the number of subsegments obstructed by the tumor, which was assessed by the findings on the chest tomogram, on the bronchogram, at bronchofiberscopy, or a combination of these. The total number of subsegments was assumed to be 42. The predicted postoperative % FEV1 was 65.1 +/- 19.3% in Group 1,55.3 +/- 10.6% in Group 2,37.6 +/- 12.1% in Group 3, and 42.3 +/- 18.4% in Group 4. It was significantly (p less than 0.05) different between all the groups except between Groups 3 and 4. All 10 patients with a predicted postoperative % FEV1 of less than 30% were in Groups 3 and 4. We conclude that special attention to postoperative management is needed for patients whose predicted postoperative %FEV1 is lower than 30%.

Aged↗
PubMed1988

Spontaneously occurring hypertrophic cardiomyopathy in the rat. II. Distribution of, and correlations between, various cardiac abnormalities in the WKY/NCrj and its related strains.

We performed gross-anatomic and histologic examinations quantitatively on 18 male and 30 female WKY/NCrj rats, and their 299 first generation off spring. The results were analyzed in comparison with those obtained from 3 other strains of rats. The offspring of the WKY rats showed various cardiac abnormalities quite similar to those in their parents. The cardiac abnormalities in the offspring of the WKY rats were: increased heart weight (in about 10%), left or right atrial hypertrophy (50%), disproportionate septal thickening (50%), small left ventricular cavity (40%), right ventricular hypertrophy (40%), abnormal fiber arrangement greater than 5% in either of the 3 ventricular walls (90%), myocardial fibrosis (70%), and abnormal location of arteries in the ventricular septum (30%). ECG findings of the WHY-F rats such as high QRS complexes and high T waves and axis deviation showed a high sensitivity and specificity in the diagnosis of marked cardiac hypertrophy. Another conspicuous histologic finding observed in the WKY hearts was that the continuity of the latitudinal fiber bundle of the ventricular septum with that of the left ventricular free wall, an important functioning unit for pressure generation in the left ventricle, was markedly disturbed in the area of junction between the 2 walls; the smaller the continuity, the greater the cardiac hypertrophy; the disadvantage of the discontinuity for the pressure generation may be related to the development of cardiac hypertrophy. Also examined were two strains of Wistar rats with the same origin as the WKY/NCrj. These rats also had gross-anatomic and histologic abnormalities of the heart quite similar to those in the 2 generations of WKY/NCrj rats, suggesting that a common factor related to the development of the abnormalities, probably a genetic predisposition, has been transmitted in these 3 strains.

Animals↗
PubMed1988

Chronic effects of imipramine and lithium on postsynaptic 5-HT1A and 5-HT1B sites and on presynaptic 5-HT3 sites in rat brain.

The effects of chronic treatment with imipramine, a tricyclic antidepressant, or lithium, an antimanic-depressive illness drug, on postsynaptic serotonin-1A (5-HT1A) and 5-HT1B sites and on presynaptic 5-HT3 sites in the frontal cortex and hippocampus from rat brains were studied. Chronic i.p. administration (21 days) of imipramine reduced the maximum number of binding sites (Bmax) for postsynaptic 5-HT1A as monitored by the radioligands 3H-5-HT or 3H-8-hydroxy-2-(di-n-propylamino)tetralin (3H-8-OH-DPAT), but did not change the Bmax for postsynaptic 5-HT1B and presynaptic 5-HT3 in either the frontal cortex or the hippocampus. Chronic i.p. administration (21 days) of lithium reduced the Bmax for postsynaptic 5-HT1A sites in the hippocampus, but not in the frontal cortex. There was a specific difference between imipramine and lithium regarding the inhibitory effect on postsynaptic 5-HT1A sites in the frontal cortex. In addition, lithium decreased the affinity of presynaptic 5-HT3 sites in the hippocampus. These findings may be also consistent with the inhibitory effect of lithium on presynaptic autoreceptors, which results in an increase of 5-HT release. It is concluded that enhanced 5-HT neurotransmission which develops during chronic treatment with imipramine or lithium seems tob e related to the down-regulation of postsynaptic 5-HT1A receptors in addition to postsynaptic 5-HT2 receptors, which may also have an important role in the antidepressant effects of these drugs.

Animals↗