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Biomedical subjects

K Tamura

Publications and source records attributed to K Tamura.

At least 883 records · Page 49Linked to original sources
PubMed1992

Toxic effects of oxygen-derived free radicals on rat pancreatic acini; an in vitro study.

Isolated pancreatic acini were incubated with either a combination of xanthine and xanthine oxidase which generates superoxide (O2), or hydrogen peroxide (H2O2), and the direct cytotoxic effect of active oxygen species on the pancreatic acini was examined in vitro in the isolated pancreatic acini system of the rat. Both amylase secretion and lactic dehydrogenase discharge were increased dose-dependently by the addition of xanthine and xanthine oxidase, and suppressed by the addition of a superoxide scavenger, superoxide dismutase. In addition, amylase and lectate dehydrogenase discharge was increased dose-dependently by hydrogen peroxide and decreased by catalase. These results suggest that superoxide and hydrogen peroxide directly injure pancreatic acinar cells and that active oxygen species are involved in the pathogenesis of acute pancreatitis.

Amylases↗
PubMed1992

Effect of synthetic protease inhibitors on superoxide (O2-), hydrogen peroxide (H2O2) and hydroxyl radical production by human polymorphonuclear leukocytes.

The effects of clinically used protease inhibitors (aprotinin, nafamostat mesilate, gabexate mesilate) on the production of oxygen-derived free radicals (O2-, H2O2, .OH) by human polymorphonuclear leukocytes were examined. Nafamostat mesilate and gabexate mesilate markedly and dose-dependently inhibited zymosan-stimulated O2- production by human polymorphonuclear leukocytes. However, aprotinin had a slight scavenging effect on O2- produced by the xanthine-xanthine oxidase system. All the protease inhibitors inhibited H2O2 production, but had no significant scavenging effect on H2O2. Nafamostat mesilate and gabexate mesilate slightly inhibited .OH production. These results indicate that the synthetic protease inhibitors nafamostat mesilate and gabexate mesilate inhibit the production of various activated oxygen radicals by human polymorphonuclear leukocytes, and the differences in their inhibitory effects suggest that each synthetic protease inhibitor is specific for a particular oxygen-derived free radical.

Adult↗
PubMed1992

Efficacy of manidipine on circadian blood pressure in essential hypertension.

The 24-h blood pressure (BP) response to once-daily manidipine monotherapy was examined in an open, nonrandomized study of 17 patients with untreated essential hypertension. Manidipine (10-30 mg) was administered once daily for a minimum of 2 weeks. BP and heart rate (HR) were monitored every 30 min for 48 h by an ambulatory BP monitoring device (ABPM-630, Nippon Colin) before and after therapy. Manidipine significantly (p < 0.005) decreased mean systolic and diastolic BP during the entire 24 h, day-active and night-resting periods. The reduction in both systolic and diastolic BP was consistent throughout the whole day. Manidipine also significantly reduced the fractionated pressure-time indices of both systolic and diastolic BP consistently throughout the 24-h period. The circadian amplitude of BP in hypertensive patients, which was higher than that in normal reference subjects, was reduced by manidipine into the reference range. The acrophase of BP in hypertensive patients, which was similar to the reference value, was not altered by manidipine treatment. Manidipine did not change the mean HR during 24-h, day-active or night-resting periods. Therefore, once-daily manidipine monotherapy showed a consistent antihypertensive effect over 24 h and optimized the circadian amplitude of BP without an increase in HR.

Adult↗
PubMed1992

[A surgical case of thoracic aortic aneurysm due to Takayasu's aortitis associated with ulcerative colitis].

We experienced a case of thoracic aortic aneurysm due to Takayasu's aortitis associated with ulcerative colitis. Steroid was medicated to control inflammation and operation was performed. The ascending aorta, aortic arch, brachiocephalic artery, and left carotid artery were replaced by artificial graft. We made elephant trunk type anastomosis at the distal side of the graft to provide for growth of the aneurysm after operation. This was a rare case considered autoimmune overlapping syndrome, and its background was complicated by HLA-Bw52 and parasitic Metagonimus Yokogawai. Relationship between steroid medication and progression of the disease is not certain yet. Postoperative course is uneventful, no recurrence of inflammation is seen and the aneurysm is not enlarged until now.

Adult↗
PubMed1992

Effect of intraarterial active oxygen species on the rat pancreas.

To explore the role of active oxygen species in the development and progression of acute pancreatitis, we studied the direct toxic effect on the rat pancreas of active oxygen species: superoxide anions generated by xanthine/xanthine oxidase (X/XO), and hydrogen peroxide (H2O2). After a continuous injection of X (10(-3)M, 0.9 ml/hour)/XO (1 U/ml, 0.3 ml/hour) into the celiac artery supplying the pancreas, hemorrhages and extensive edema developed in the pancreas. The amylase and lipase concentrations in the peritoneal fluid rose to 10.3 and 13.8 times the control values, respectively. The subsequent infusion of superoxide dismutase (SOD, 3600 U/hour) into the external jugular vein completely suppressed hemorrhages, and reduced edema and the amylase and lipase concentrations in the peritoneal fluid. After continuous injection of H2O2 (100 microM, 1.2 ml/hour), via the celiac artery, marked hemorrhages and edema appeared in the pancreas, and the amylase and lipase concentrations in the peritoneal fluid were 11.1 and 17.3 times higher than the control values, respectively. These abnormalities were significantly suppressed by the intravenous infusion of catalase (10 mg/kg/hour) or gabexate mesilate (10 mg/kg/hour). These results indicate that active oxygen species have a direct toxic effect on the pancreas and that free radicals may play an important role in the development of acute pancreatitis.

Amylases↗
PubMed1992

[Clinical analysis of 10 patients with chronic lymphoid leukemia].

Ten patients with chronic lymphoid leukemia were analyzed for clinical characteristics, morphology and phenotype of leukemic cells. There were 3 patients with T-chronic lymphocytic leukemia (CLL), 2 with T-prolymphocytic leukemia (PLL), 2 with B-CLL, 1 with B-PLL, 1 with non-T-non-B-CLL and 1 with Waldenström's macroglobulinemia. Although chronic lymphoid leukemia is usually characterized by proliferation of B-lymphocytes, our study revealed that 5 of 10 patients had T-cell phenotype. A peripheral blood specimen of T-CLL showed small lymphocytes with a mature appearance and an irregular nuclear margin. Most of the cells lacked large azurophilic granules in the cytoplasm and nucleoli were also inconspicuous in the nucleus by light and electron microscopic examinations. In PLL, a majority of the cells were large lymphocytes with a prominent nucleolus and abundant basophilic cytoplasm which were more clearly observed by transmitted electron microscopic examination. The patients were treated with cyclophosphamide and prednisolone, but response to treatment was transient. The median survival time was 7 months for all patients, while that of T-cell lineage cases was only 1 month. Therefore, new modalities of treatment must be investigated in the future.

Aged↗
PubMed1992

[Long-term follow-up of clinical features and ECG changes in 50 patients with HCM].

We studied the relation of ECG changes during the clinical course in patients with hypertrophic cardiomyopathy (HCM). Fifty patients with HCM were categorized in two groups; 20 patients with, and 30 patients without signs of deterioration of clinical state. The changes between the first and the final ECG were compared in these two groups. The average follow-up period was 7.6 years. Twenty patients with clinical deterioration presented increase in QRS intervals (0.06----0.071 sec, p less than 0.025), decrease in voltage of RV5 (2.81----2.38 sec, p less than 0.025), increase in newly developed abnormal Q waves, and P wave changes. In contrast to these cases, 30 patients without clinical deterioration presented no significant ECG changes. Amplitudes of the negative T wave were unchanged in both groups. We conclude that electrocardiographic observations proved to be useful for predicting clinical features in patients with HCM.

Adolescent↗
PubMed1992

[Ischemic complications following parent artery occlusion with detachable balloons in the treatment of large carotid aneurysms: effectiveness of 99mTc-HMPAO SPECT and importance of postoperative management].

Three patients with large carotid aneurysms were treated by parent artery occlusion with detachable balloons. Of these, 2 had intracavernous carotid artery aneurysms and one had a carotid-ophthalmic aneurysm. All patients underwent a formal balloon occlusion test and tolerated it well. One patient with a carotid-ophthalmic aneurysm, however, developed postoperative ischemic effects. This case was that of a 55 year-old female with right visual disturbance. Her middle cerebral artery flow had been compromised during test occlusion under induced hypotension. Although initially intact after balloon occlusion, she was found to be hemiplegic 24 hours later. She subsequently developed multiple small infarcts which were shown on MRI and which corresponded exactly to the previously demonstrated region of decreased flow during testing. This ischemic complication is possibly due to hypoperfusion, but embolism from the thrombosed aneurysm can not be denied. To prevent these complications, an extracranial-intracranial artery anastomosis prior to parent artery occlusion should be considered if the preoperative 99mTc-HMPAO SPECT shows a compromised cerebral blood flow. In addition to this, postoperative anticoagulant therapy should be given even if test occlusion was well tolerated clinically.

Brain Ischemia↗
PubMed1992

[Presence of a PCR-inhibitor in hairs].

A polymerase chain reaction (PCR) system was used to amplify the noncoding 333-bp region of mitochondrial DNA (mt333DNA) contained in DNA extracts from single human hairs, and the following results were obtained: 1) Using natural black hairs, mt333 DNA was always amplified from a 5-cm length of hair shaft sampled within a region 11 cm from the hair root, but it was not always amplified from a 5-cm region adjacent to this 11-cm region, and was not amplified in almost all cases when a 5-cm length of hair shaft was sampled from a region more than 16 cm distant from the hair root. DNA preparations not responding to PCR were colored dark brown. 2) Using natural white hairs, mt333DNA was amplified from almost all specimens even up to a length of 31 cm. 3) When natural black hairs were stained with an oxidation-type hair-staining agent (Bigen-5Ge), mt333DNA was never amplified even from the hair root portion, whereas the same staining treatment of white hairs did not influence the amplification of mt333DNA. In the cases showing no response on PCR, DNA preparations were also colored dark brown. 4) These dark brown DNA preparations inhibited completely the amplification of mt333DNA even after addition of purified DNAs. These results suggest that the dark brown substance in the DNA preparations inhibits the amplification of mt333DNA by the PCR method. We therefore investigated the mechanism responsible for the development of this inhibitor. It was found that hydrogen peroxide (a component of hair-staining agent) induced formation of water-soluble melanins from insoluble melanins.(ABSTRACT TRUNCATED AT 250 WORDS)

DNA, Mitochondrial↗
PubMed1992

[Autonomic function and severity of hypertrophic cardiomyopathy by power spectrum analysis on heart rate variability].

To examine the relation of autonomic function and severity of hypertrophic cardiomyopathy (HCM) with and without ventricular tachycardia (VT) and poor blood pressure response on Treadmill exercise, 30 patients with HCM and 10 healthy controls were selected. Autonomic function was assessed by heart rate variability (HRV) on 24hr-Holter monitoring. The power spectrum analysis was classified into LF component, HF component and ratio of LF/HF. (1) Night time HF and LF decreased, and LF/HF increased in HCM compared with healthy controls. (2) HF decreased more in HCM with VT. (3) LF/HF also decreased in HCM with poor blood pressure response on exercise. These results suggest that autonomic function may be altered in HCM, and severity of HCM proved to be able to be assessed by power spectrum analysis of HRV.

Autonomic Nervous System↗
PubMed1992

[A case of thyroid medullary carcinoma-like tumor of the lung with amyloid stroma].

A 58-year-old man with history of productive cough and mild exertional dyspnea for several years was admitted to our hospital because of abnormal shadow on chest radiograph. Bronchofiberscopic examination revealed a polypoid tumor almost completely obstructing the right main bronchus. Bronchoscopic biopsy specimens showed amyloid-like deposits in the connective tissue surrounded by epithelium-like tumor cells with squamous metaplasia, but no diagnostic findings. Malignant tumor was suspected and right upper lobectomy was performed. The surgical specimen revealed nests of tumor cells surrounded by amorphous eosinophilic substance, which was confirmed to include amyloid fibrils by electron microscopy. A few tumor cells contained argyrophil granules by Grimelius staining, and some showed PAP staining for calcitonin. There was no evidence of involvement of other organs including the thyroid gland during the four year postoperative follow-up period. This case was diagnosed as thyroid medullary carcinoma-like tumor of the lung, which is a bronchopulmonary carcinoid-related tumor.

Carcinoma↗
PubMed1992

[A case of paraesophageal bronchogenic cyst with esophageal communication].

A case of mediastinal bronchogenic cyst communicating with the esophagus was reported. Previously, only 2 cases have been reported in the available literature. A 34-year-old man was admitted with a cystic mass communicating with the esophagus which was demonstrated on a barium study. Operation was performed with a suspect of esophageal diverticulum or congenital cyst with esophageal communication. At right thoracotomy, a mass measuring 6.0 x 5.0 cm with a well-defined patent communication to the esophagus was resected. It was a monolocular cyst containing a small amount of viscous mucus. Histologically, the cyst lined by a ciliated columnar epithelium, and it was diagnosed as a bronchogenic cyst because of the presence of the mucous glands, smooth muscle tissue and cartilage. This is the first case report of mediastinal bronchogenic cyst with esophageal communication appeared in the Japanese literature.

Adult↗
PubMed1992

[Intraperitoneal chemotherapy using CBDCA for malignant gynecological tumors].

At our clinic for peritoneal dissemination cases of gynecological malignant tumors, we have been using intraperitoneal administration (ip) of anticancer agents such as CDDP with favorable results. However, since CDDP cannot be used for patients with renal dysfunction, we have administered CBDCA ip, and along with determining drug concentration, we also studied therapeutic effects. At the time of laparotomy in 5 cases of malignant tumors (ovarian cancer 4 cases, oviduct cancer 1 case), we subcutaneously implanted a reservoir port for the peritoneum in the upper inguinal region. Through this completely open port we administered by natural dripping 200-450 mg/body of CBDCA dissolved abdominal fluid and peripheral venous blood, and we determined the concentrations of total and free platinum. The ip concentration of platinum reached a peak of 142-19.8 micrograms/ml immediately after administration, and then gradually declined; at 8 hours it became 20.1-2.23 micrograms/ml, and was still detectable at 48 hours. In the peripheral venous blood peaked at 2 hours at 4.78-1.2 micrograms/ml, and was still observed at 48 hours. One 84-year-old patient with stage III oviduct cancer and renal dysfunction showed a marked reduction in ascites and improvement in PS from 4 to 1, so she is being treated on an outpatient basis. The efficacy rate was 60.0% with 2 CR and 1PR. Repeated ip administration of CBDCA was possible even in cases with renal damage rather than CDDP, but the side effects on the blood were severe. CBDCA ip achieves an effective level of free platinum in both the peritoneum administration methods for treating peritoneal disseminated cases.

Administration, Oral↗
PubMed1992

[Effect of heart rate on cardiac hemodynamics in patients with aortic regurgitation].

We evaluated the effects of heart rate on cardiac hemodynamics in 10 patients with aortic regurgitation (AR, mean regurgitant fraction: 64.3%). Cardiac catheterization was performed in all patients, and the hemodynamic parameters were obtained by increasing heart rate (80.100.120.140) using right atrial pacing. Regurgitant fraction and total systemic resistance were improved up to 100/min, but aggravated on further increase in heart rate. Cardiac function curve was remarkably improved up to 100/min, but aggravated on further increase in heart rate. LV end-diastolic pressure-volume relation was moved toward the left lower direction up to 100/min, but toward the left upper direction on further increase in heart rate. Thus, it was concluded that in severe AR, cardiac function was improved up to 100/min, but aggravated on further increase in heart rate.

Aortic Valve Insufficiency↗
PubMed1992

[Therapeutic occlusion of unilateral vertebral artery for unclippable aneurysms; special reference to postoperative brainstem ischemia].

Seven cases of unclippable vertebral artery aneurysms (3 dissecting, 1 fusiform, 2 saccular and 1 giant) are reported. Five of these had subarachnoid hemorrhage, one showed mass effect and the other was found incidentally. Trapping of the involved portion of the vertebral artery was performed in 4 cases, proximal clip occlusion in 2 and proximal balloon occlusion in 1. There were no operative deaths and no rebleeding, but brainstem ischemia developed in 4 cases, two being transient and two permanent. The ischemic complications were possibly due to; (a) hypoperfusion in the transient cases and (b) thromboenbolism, from the partially thrombosed giant aneurysm or thrombosis of the cul-de-sac vertebral artery, in the permanent ones. Preoperative temporary vertebral artery occlusion with an inflatable balloon or postoperative anticoagulant therapy should be considered in the management protocol.

Aortic Dissection↗
PubMed1992

Correlation of serum concentration of alpha 1-acid glycoprotein with lymphocyte blastogenesis and development of experimentally induced or naturally acquired hepatic abscesses in cattle.

Changes in serum alpha 1-acid glycoprotein (alpha 1AG) concentration in cattle with hepatic abscesses were observed, and function of alpha 1AG was evaluated, particularly its influence on cellular immune response. Test cattle (n = 4) were inoculated with Fusobacterium necrophorum, control cattle (n = 2) were inoculated with inactivated bacteria, and naturally affected cattle (n = 11) were found in a slaughterhouse. Determination of alpha 1AG was made by use of a single radial immunodiffusion method. The action on lymphocyte blastogenesis was determined by [3H]thymidine incorporation. Cultured lymphocytes from healthy cattle were treated with variable concentrations of alpha 1AG purified from serum obtained from cattle with hepatic abscesses and suppression of blastogenesis stimulated by each of 3 mitogens was measured. In cattle with experimentally induced abscesses, serum alpha 1AG concentration increased for 7 to 10 days after F necrophorum inoculation, its change being parallel to that of sialic acid. High concentration of alpha 1AG was found in naturally affected cattle and was highly correlated to sialic acid concentration. Suppression of lymphocyte blastogenesis in cattle with experimentally induced hepatic abscesses was highly correlated to serum alpha 1-AG concentration.

Animals↗
PubMed1992

[Complications of Nd-YAG laser treatment on tracheobronchial lesions].

Neodymium-yttrium-aluminum-garnet (Nd-YAG) laser was clinically introduced to the treatment of tracheobronchial lesions 10 years ago. Since then, the apparatus of the laser therapy and the flexible bronchoscopy have been improved, and the indication for its treatment has been established. Nd-YAG laser is useful at the field of the treatment of the tracheobronchial stenotic or obstructed lesions. But various complications occur, because of the lesions occupying in the narrow tracheo and bronchial lumen. In our institute, 83 cases have been treated in 196 sessions (from one to fifteen sessions per patient) for the past ten years. The stenotic or obstructed lesions were divided into three etiologies, 64 cases with malignant lesion, 8 cases with post operative granulation at the suture line and 11 cases with benign lesion. All procedures were performed under local anesthesia by using flexible bronchoscope. Among them, complications were noticed in eleven cases. They involved hemorrhage (6 cases) and respiratory disturbances (2 cases) during operative period, and massive hemorrhage (2 cases) and edema of the tumor (1 case) in the adjacent period of laser treatments.

Adult↗