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Biomedical subjects

Y Okazaki

Publications and source records attributed to Y Okazaki.

At least 19 recordsLinked to original sources
PubMed1992

The effect of prostaglandin E1 on heart preservation.

The purpose of this study was to investigate the effect of prostaglandin E1 on rabbit heart preservation. The hearts were arrested with cardioplegia (CP) solution, followed by intracoronary infusion of Euro-Collins (E-C) solution. They were immersed in E-C solution at 4 degrees C for 9 hr, flushed with terminal warm CP solution, and reperfused with oxygenated Tyrodes' solution at 80 mmHg for 90 min. Eighteen rabbits (Kabushikigaishya BioTec Japanese white) were divided into 3 groups. Group I served as the control. In groups II and III, 200 ng/kg/min of PGE1 was given for 30 min before the heart was removed and 5 micrograms was added to the initial CP solution. In group III, 5 micrograms was also added to both E-C solutions and to the terminal CP solution. The values of CPK and LDH in the terminal CP solution and in the coronary effluent in groups II and III were lower, and coronary flow after reperfusion in group III was significantly greater at 5 min and from 60 min until the end of the experiment. Left ventricular maximum dP/dt at each end-diastolic pressure was significantly higher than control in groups II and III. The values of the wet/dry ratio of reperfused hearts in groups II and III were significantly lower than in the control. In conclusion, treatment with PGE1 before heart extraction and the addition of PGE1 to both E-C solutions and to the terminal CP solution contributed to superior left ventricular function after reperfusion, by improving preservation and reducing interstitial edema.

Alprostadil↗
PubMed1992

The effects of adenine and dimethyl sulfoxide on the mouse pancreas.

The authors have studied the effects of dimethyl sulfoxide (DMSO) on the plasma alpha-amylase activity in mice that sustained a pancreatic injury induced by an oral administration of adenine. In mice given a 5% solution of DMSO as drinking water for 3 d prior to the administration of adenine (175 mg/kg), and also drank this DMSO solution until the end of the experiment, hyperemia of the pancreas was observed and the level of plasma alpha-amylase activity became significantly higher than the level seen in the control mice. A pathological examination also revealed vacuolation and zymogenic degranulation. Further, the plasma alpha-amylase activity level increased only in mice given this 5% DMSO solution, and no increase was noted in mice given a 3% or a 1% DMSO solution for drinking water. Further, the pancreatic lipid peroxide level of mice given this 5% DMSO solution was significantly higher than the level seen in the control group. Based on the above results and associated data, it is thought that an oral administration of adenine can induce a pancreatic injury in the mouse, and that this injury is sustained with the assistance of DMSO.

Adenine↗
PubMed1992

[Studies on early stage changes of peroxide lipid in isoproterenol-induced myocardial injury].

The amount of peroxide lipid in vivo in the early stage of the experimental model of myocardial infarction in a rat induced by the administration of isoproterenol (Isp) was measured as the value of malonic dialdehyde (MDA). The model of myocardial infarction was made by giving 75 mg/kg of Isp to the rat weighing 270 +/- 10 g. After the administration of Isp, the amounts of lipid in the serum and in the myocardial tissue were measured, and a blood chemistry test (glutamic oxaloacetic dehydrogenase, glutamic pyruvic transaminase, lactate dehydrogenase, free fatty acid, creatine kinase) was simultaneously carried out on the serum. The value of the amount of peroxide lipid in the serum began to elevate 3 h after the administration of Isp and reached a maximum value at 6 h. The value of the amount of peroxide lipid in the tissue began to elevate 30 min after the administration and reached a maximum at 3 h. Each blood chemistry disclosed the elevation 30 min after the administration. As mentioned above, the production of peroxide lipid in vivo on the myocardial disorder in the early stage after the administration of Isp and the biochemical changes showed a significant correlation. From these results it is suggested that the myocardial disorder induced by the administration of Isp has already developed at 30 min after the administration.

Animals↗
PubMed1992

[An ultrasonic study of the relationship between extracranial carotid atherosclerosis and ischemic cerebrovascular disease in Japanese].

The study is to evaluate the relationship between extracranial carotid atherosclerosis and ischemic cerebrovascular disease using noninvasive B-mode ultrasonography and X-ray computed tomography. The sensitivity of bruits for diagnosing severe carotid stenosis was also evaluated. A total of 229 consecutive Japanese patients were recruited for this study, of which 97 had chronic-stage ischemic cerebrovascular disease and remaining 132 patients had at least one risk factor for atherosclerosis. Carotid atherosclerosis was evaluated by B-mode ultrasonography. Ischemic cerebrovascular disease was assessed by history taking, neurological findings and X-ray CT examination. The severity of carotid atherosclerosis was assessed by using two indices; plaque score and maximum percentage diameter stenosis. We also evaluated whether it was ulcerated plaque or not. Plaque score was computed by summing up all carotid plaque thicknesses (mm) on both sides. According to the CT findings, cerebral infarction was divided into two types; deep subcortical infarction and cortical infarction. The incidence of cerebral infarction increased in relation to plaque score and maximum percentage stenosis. Although the incidence of cerebral infarction in patients without carotid atherosclerosis was only 33% (38/116), it in patients with moderate carotid atherosclerosis (plaque score > 5) was 59% (26/44) (p < 0.05, chi-square test). The incidence of ipsilateral infarction was revealed to be higher in patients with severe (50% or more) carotid stenosis (61%) than in cases of mild stenosis (28%) (p < 0.05). Thirteen patients had ulcerated plaques and they suffered more frequently cerebral infarction than patients without ulcerated lesions. Cortical infarction was more frequent in patients with severe carotid stenosis than in patients without carotid atherosclerosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1992

[A case of inflammatory breast cancer treated with medroxyprogesterone acetate (MPA) in combination with intra-arterial infusion chemotherapy].

A 55-year-old female with severe inflammatory breast cancer was treated with the combined use of MPA and the intraarterial infusion chemotherapy. One cycle consisted of 4'-epi-adriamycin; 210 mg (day 1, 4 and 8) and daily administration of MPA; 1,200 mg. A marked shrinkage of the tumor was obtained with this treatment. The regressive change was noted not only in the primary lesion but in lymph nodes of the axillary region. Therefore, the combined use of MPA with intra-arterial infusion chemotherapy may well contribute to the treatment of inflammatory breast cancer.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1991

Effects of various mucosal protective drugs on diethyldithiocarbamate-induced antral ulcer in rats.

This study was designed to determine the effects of exogenous Cu,Zn-superoxide dismutase (SOD) and various mucosal protective agents against antral ulcer induced by diethyldithiocarbamate (DDC), inhibitor of Cu,Zn-SOD. Exogenous Cu,Zn-SOD reduced ulcer formation and prevented a decrease in SOD activity in gastric mucosa. This result indicates that maintenance of mucosal SOD activity is essential to prevent the ulcerogenicity of DDC. Many mucosal protective drugs that increase blood flow, mucus secretion, and endogenous prostaglandin failed to prevent ulcer formation and decrease of mucosal SOD activity. Rebamipide, however, significantly reduced ulcerogenesis and maintained mucosal SOD activity. This suggests that rebamipide has new protective effects on gastric mucosa.

Alanine↗
PubMed1991

Marginal zinc deficiency and changes in behavioral salt taste threshold and salt preference in mice.

An animal model of marginal zinc deficiency was tested in mice, and salt taste threshold and salt preference were investigated in the state of marginal zinc deficiency. Two experiments were conducted. In Experiment 1, four-week-old male ICR mice were fed diets of three different levels of zinc content (3.17, 9.27, or 48.13 micrograms Zn/g) for 60 days. Food intake, growth, zinc levels in tissues, hepatic metallothionein (MT) content, and activities of selected enzymes (hepatic and RBC delta-amino-levulinic acid dehydratase (ALAD) and plasma alkaline phosphatase (ALP] did not differ among the groups throughout the experiment, and no overt signs of zinc deficiency were manifested in any group. In Experiment 2, four-week-old male ICR mice were fed a zinc-deficient diet (1.98 micrograms Zn/g) or a zinc-adequate diet (49.14 micrograms Zn/g) for 56 days. Food intake and growth did not differ between the two groups, and no overt signs of zinc deficiency were observed throughout the experiment. Zinc levels in the plasma and femur--but not those in the brain, kidneys, liver, and red blood cell (RBC)--and plasma ALP activities were significantly lower on Day 42 and Day 56 of the experiment in the mice fed the zinc-deficient diet (ZnD group) than in those fed the zinc-adequate diet (ZnA group). Hepatic MT contents were lower in the ZnD group than in the ZnA group on Day 56 only. Salt taste threshold was 0.05% in the ZnA group, while it was 0.1% in the ZnD group, between Day 30 and Day 38, and between Day 44 and Day 52 of the experiment. Preference for 0.9% NaCl solution was no different in the two groups when tested between Day 38 and Day 40 or between Day 52 and Day 54, but that for 1.6% NaCl solution was significantly higher in the ZnD group than in the ZnA group between Day 40 and Day 42, and between Day 54 and Day 56.

Alkaline Phosphatase↗
PubMed1991

Fiberoptic ductoscopy of the breast: a new diagnostic procedure for nipple discharge.

A fiberoptic ductoscopy system was successfully developed by means of which we were able to observe the duct cavity of the breast. Two kinds of silicafiberscopes with outer diameters 0.80 and 0.45 mm were used in the present study. Fiberoptic ductoscopy was applied to 52 ducts in 46 patients with nipple discharge for whom no tumor was palpable; the intraductal appearance could be observed in 47 ducts from 41 patients (90.3%). Fourteen ducts from 13 patients were operated upon and were histologically diagnosed as carcinoma (four cases), intraductal papilloma (nine ducts from eight patients) and mastitis (one case). The internal surface of a normal duct was lustrous and smooth. Cancer growing on the surface of a duct wall appeared white and was slightly elevated, forming a bridging structure. The intraductal papillomas formed intraductal solid nodules, being yellow in most cases and red at the site of hemorrhage. Fiberoptic ductoscopy can be used to recognize the growth of minute intraductal lesions in cases of nipple discharge. Clinical endoscopic diagnosis for minute intraductal lesions will make an important contribution to the early detection of cancer and the evaluation of nipple involvement in intraductal carcinoma.

Breast Neoplasms↗
PubMed1991

[Effect, recurrence and prognosis of intra-arterial infusion chemotherapy with anticancer agents for advanced breast cancer--especially, the significance of tumor blood vessels].

Between January 1977 and March 1991, 86 patients of Stage III and Stage IV breast cancer were treated by intra-arterial infusion chemotherapy (IAIC) in Sapporo Medical College. The 5- and 10-year overall survival rates of Stage III b were: infusion group 53.1% and 53.1%, non infusion group 50.1% and 16.7%, respectively. A significant difference was seen in the 10-year survival rate (p less than 0.05). The 5- and 10-year overall survival rate of Stage III b histologically effective group was 67.3% and non-effective group 31.8%. A significant difference was seen between these two groups (p = 0.0241). A significant difference was seen between n2 positive Stage III b infusion group and non-infusion group in 7-year survival rate (p less than 0.01). The ischemic effect on tumor cells by degeneration changes of the blood vessels was important for the histological effect. Pre-operative angiography helped in the choice of anticancer agents. The sufficient adjuvant chemo-endocrine therapy will assure a good prognosis for IAIC-treated Stage III b breast cancer patients.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1991

Transport of cyclosporin A in kidney epithelial cell line (LLC-PK1).

The characteristics of cyclosporin A transport have been studied in cultured kidney epithelial cell line LLC-PK1. The uptake of cyclosporin A by LLC-PK1 cells was time-dependent and reached a steady state at about 30 min. The initial uptake was saturable and was inhibited by cyclosporin A analogs, cyclosporin C and D and by verapamil, but not by metabolic inhibitors such as 2,4-dinitrophenol and rotenone. Cyclosporin A uptake as well as efflux was strongly dependent on temperature. The Arrhenius plot for cyclosporin A uptake was biphasic, whereas the Arrhenius plot for sulfanilamide uptake, which is transported by a simple diffusion, was linear. These results indicate that a specific mechanism is concerned in the transport of cyclosporin A in LLC-PK1, cells.

Animals↗
PubMed1990

Role of active oxygen species in diethyldithiocarbamate-induced gastric ulcer in the rat.

Diethyldithiocarbamate, an inhibitor of Cu,Zn-superoxide dismutase, was recently found to be ulcerogenic in the rat stomach, and active oxygen species were found to be responsible for its ulcerogenicity. To clarify which active oxygen species play a role in ulcerogenesis, the effects of various scavengers and iron-chelators were studied. As superoxide dismutase and catalase reduced the ulcerogenesis induced by diethyldithiocarbamate, the superoxide radical and hydrogen peroxide were considered to play a pathogenic role in this ulcer model.

Animals↗
PubMed1990

High resolution ultrasound of the chest wall.

To study the detailed normal ultrasonic anatomy of the pleura and chest wall, high resolution (7.5 MHz) ultrasonograms were obtained from cadaver chest wall specimens and compared with thin section computed tomograms and anatomical specimens. Ultrasonograms show three layers of the intercostal muscles (internal, external and innermost), covered by the "echogenic pleural line." The "echogenic pleural line" is caused by composite echoes from the inner parietal pleura, and the outer endothoracic fascia, with the fatty tissue covering both sides of the fascia, which are located deep to the chest wall muscles. On ultrasonograms, the subpleural fat tissue, when abundant, appeared as an apron-like structure hanging down from the inner surface of the rib (subpleural fat pad), or diffuse fat accumulation mimicking the pleural thickening.

Humans↗
PubMed1990

An immunohistochemical study of copper, zinc-containing superoxide dismutase detected by a monoclonal antibody gastric mucosa and gastric cancer.

The immunohistochemical localization of copper, zinc-superoxide dismutase (Cu,Zn-SOD) in human gastric mucosa and gastric cancer was studied using a monoclonal antibody. In gastric mucosa, parietal cells, pyloric glandular cells and foci of intestinal metaplasia showed positive staining in the cytoplasm and/or nucleus. The wide distribution of Cu, Zn-SOD in the gastric mucosa suggests cell function may be vulnerable to active oxygen species. In gastric cancer, 34 of 70 cases showed a positive reaction for Cu, Zn-SOD. There was a relationship between the grade of Cu,Zn-SOD immunoreactivity and the histological type of gastric cancer, well-differentiated types of gastric cancer being more frequently positive. The positive cases of poorly-differentiated adenocarcinoma were characterized by a pattern of diffusely infiltrative invasion. These results suggest that some types of gastric cancer are resistant to active oxygen species.

Adenocarcinoma↗
PubMed1990

Mechanism of diethyldithiocarbamate-induced gastric ulcer formation in the rat.

Diethyldithiocarbamate (DDC) was injected subcutaneously in the rat and the mechanism of gastric ulcer formation was investigated. DDC induced gastric ulcers in a dose-dependent manner. DDC significantly suppressed gastric mucosal copper-zinc superoxide dismutase (Cu, Zn-SOD) activity at 2 hr. However, manganese-superoxide dismutase (Mn-SOD) activity was not changed. Gastric mucosal blood flow (GMBF) decreased to 52% of the control level at 2 hr after administration of DDC and gradually increased to reach the control level by 7 hr. A Shay rat preparation (4 hr) was used to study gastric secretion. DDC (200, 400 and 800 mg/kg) inhibited acid secretion to about 80% of the control level. Histopathological examination of the gastric mucosa after administration of DDC revealed mucosal congestive findings from 1 hr to 3 hr. These data suggested that the mechanism of DDC-induced gastric ulcer formation may be attributable to a decreased level of GMBF and O2- production owing to decreased SOD activity.

Animals↗
PubMed1990

Ruptured amebic liver abscess.

We treated two patients with a ruptured amebic liver abscess. The diagnosis was made at a relatively early stage and treatment was successful for one patient, but an accurate diagnosis of liver abscess was not made and invasive extraintestinal amebiasis led to multiple organ failure and to death for the other. Neither patient had been outside of Japan, and both were heterosexual. The origins of Entamoeba histolytica infection could not be determined. Though the mortality rate is high in cases of ruptured amebic liver abscess, appropriate management can lead to a good prognosis.

Adult↗