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Biomedical subjects

M Usui

Publications and source records attributed to M Usui.

At least 271 records · Page 15Linked to original sources
PubMed1989

Inactivation of erythrocyte Cu-Zn-superoxide dismutase through nonenzymatic glycosylation.

Human erythrocyte Cu-Zn-superoxide dismutase undergoes glycation reaction in vitro and in vivo (Arai et al., 1987a; Arai et al., 1987b). In addition, an increase in the glycation of the superoxide dismutase was observed in aged erythrocytes, indicating that the glycation reaction is an age-related change under physiological conditions. In the cases of crude extracts as well as pure enzyme preparations obtained from erythrocytes of patients with Werner's syndrome, the specific activity of the glycated form expressed as units per mg Cu-Zn-superoxide dismutase protein as determined by both enzymatic assay and immunoenzymatic assay was significantly lower and the enzyme was unstable as compared to the normal form.

Adult↗
PubMed1989

[Intraocular fluid antibody quotients following inoculation with two different antigens in experimental herpes simplex virus retinochoroiditis].

Viral retinochoroiditis was induced experimentally by inoculation of herpes simplex virus into the vitreous body in rabbits. The animals were sensitized systemically using 2 pathogens as antigens (herpes simplex virus and toxoplasma gondii) 3 weeks prior to intraocular inoculation. Serum and intraocular fluid were collected 2 weeks after inoculation. The intraocular fluid antibody titers and quotients for these 2 pathogens were then measured to determine the effects of serum antibodies, which are thought to enter the eyes as a result of destruction of the blood-ocular barrier. Experimental criteria for antibody quotients were also determined. Antibody quotients for the etiological virus (herpes simplex virus) ranged from 2 to 20, with an average of 9.7. Those for toxoplasma gondii, the antibody of which is thought to enter the eye from the blood, were all less than 5 with average of 1.9. From these results, it would seem that when the antibody quotient of a pathogen in more than 6 in the intraocular fluid, it is likely to be an etiological organism, while the possibility of infection is very low when the quotient is under 2. More precise studies are required to identify an etiological pathogen when the quotient is 2-6.

Animals↗
PubMed1989

[A dissecting aortic aneurysm involving a right-sided aortic arch].

A 51-year-old woman suddenly developed severe pain in the chest and back, also dyspnea. On admission, she was in a state of preshock. Plain X-ray indicated the lack of the left aortic arch and poor pneumatization in the whole right lung. The thoracic fluid was transparent with yellowish tinge and was contaminated with neither any bacterium nor tubercle bacillus. The response to the Rivalta's reaction was negative. The possibility of pleurisy was, therefore, denied. The ECG and blood biochemical data on the second day suggested the possibility of myocardial ischemia. Plain chest X-ray on the fourth day revealed an increased right pulmonary pneumatization and an enlarged mediastinal shadow toward the aortic arch. Upper pulmonary CT showed a mass on the right side. Enhanced CT disclosed a dissepiment in the center, which was high medially and somewhat low laterally. It was diagnosed as a false lumen due to the lateral displacement of the right aortic arch. Hepatic CT disclosed the tapering of the abdominal aorta from right to left in the prevertebral region. These findings indicated that the aorta descended from the right aortic arch along the right side of the spine and crossed the spine dextrosinistrally at the hepatic level. In addition, dissociant aneurysm was observed in the right aortic arch. Echocardiography showed no evidence of dissociant aneurysm at the aortic base. Chest X-ray, CT and echocardiography showed the dissociation of the aorta from the aortic arch to the abdominal aorta. Thus the diagnosis of De Bakey type III was established. Clinically, DIC and multiorgan disorders were manifested but after medical treatments, the clinical course was uneventful.(ABSTRACT TRUNCATED AT 250 WORDS)

Aortic Dissection↗
PubMed1988

N-terminal amino acid sequence of a major allergen of Japanese cedar pollen (Cry j I).

A purified preparation of a major allergen of Japanese cedar pollen, sugi basic protein (SBP, Cry j I), was separated into 5 subfractions of 50-45 kDa. All of the SBP subfractions were confirmed to be reactive to IgE antibodies from patients with Japanese cedar pollinosis, and also to mouse anti-SBP monoclonal antibodies. The sequences of 20 N-terminal amino acids of these 5 subfractions were found to be identical. Peptide mapping analyses of the SBP subfractions showed similar patterns, with some differences which might in part be due to the existence of an N-linked carbohydrate chain. The N-terminal amino acid sequence of SBP was identical to the reported sequence of an allergen of mountain cedar which vegetated in North America.

Allergens↗
PubMed1988

[A case of multiple aneurysms originated from the superior mesenteric artery branch, and a review of literature].

A case of multiple aneurysm of superior mesenteric artery (SMA) branch is presented. A 54-year-old man with sudden onset of back pain was admitted to our hospital. Severe abdominal pain was developed and he fell into shock. Selective angiography of the SMA demonstrated aneurysm of the accessory middle colic artery to splenic flexure. Laparotomy disclosed much intraperitoneal blood and a large clot under the pancreatic body with a gushing hemorrhage. The bleeding vessel was ligated and sutured. The postoperative course was uneventful, but the subsequent angiography revealed another aneurysm of SMA branch, which was not able to be seen in the previous angiography because of overlapping with main SMA trunk. Resection of the aneurysm was done. The etiology of the latter aneurysm was suggested to be medial degeneration histologically. Fourty-nine cases of SMA aneurysm from the Japanese literature were reviewed and discussed. Emphasis is placed on early diagnostic laparotomy for appropriate management and the role of angiography in confirmation of bleeding site in case of spontaneous intraabdominal hemorrhage.

Aneurysm↗
PubMed1988

[Efficacy and problems of radio- and chemo-combination therapy for malignant bone tumors].

In this study we reviewed cases of osteosarcoma, malignant lymphoma of bone and Ewing's sarcoma. Historically, osteosarcoma was unresponsive to chemotherapy. Most patients were treated by radiation or amputation alone and 80% of them died from pulmonary metastasis within 2 years. Five-year survival rate was 13%. Introduction of ADM, HD-MTX and CDDP improved dramatically the prognosis of these cases. Five-year survival rate was 60%. On the other hand, 11 cases of malignant lymphoma of bone and 4 cases of Ewing's sarcoma were treated by radiation with no local recurrence. VEPA or CHOP chemotherapy was used for the former with a five-year survival rate of 45%. For the latter, T-11 protocol (Rosen) was applied, and all patients survive with no metastasis. Other organ injuries circulatory disturbance, bone necrosis and growth-disturbance of bone in radiotherapy, myocardiopathy caused by ADM and renal toxicity of CDDP are all problematic.

Adolescent↗
PubMed1988

[Orthopedic local treatment of metastatic bone tumor].

Since 1971, we have treated 76 patients with metastatic bone tumor. Forty-eight of 76 cases were treated surgically. In 34 cases, removal of metastatic foci of the spine was attempted from the anterior and/or posterior approach. In the remaining 14 cases, resection of the tumor with or without prosthetic replacement, osteosynthesis, or amputation was performed according to the site of bone metastasis. In cases of spinal metastasis, if foci were located anteriorly, resection and replacement of vertebral body by ceramic spacer and/or bone cement was effective for both relief of pain and reduction of paralysis. If foci were located posteriorly, however, the results of simple laminectomy were poor, and those of spinal instrumentation in addition to laminectomy were satisfactory. In the treatment of metastatic foci of pelvis, scapula and long bone, the results of orthopedic surgery were satisfactory, because relief of pain and maintenance of function were achieved in almost all cases. From the standpoint of prolongation of life, 15 out of 76 cases (20%) were alive with or without disease; 13 of them were treated not only surgically but also by radiation and/or chemotherapy.

Adult↗
PubMed1988

[Operative treatment of bone and soft tissue tumors involving pelvic region, especially retroperitoneal area including lumbar region].

During the past 17 years, 35 of 60 patients with malignant bone and soft tissue tumors of the pelvic and surrounding tissues, were treated surgically. There were 13 bone tumors and 22 soft tissue tumors, There were 12 recurrent cases and 23 non-recurrent cases with cumulative 5-year survival rates of 20% and 70%, respectively. In the tumors involved even in the iliolumbar area, curative resection was difficult with poor prognosis. Serious complications also developed with high incidence immediately after operation, including ileus, severe infections and postoperative bleeding. When the affected limb was preserved, many difficulties were encountered in functional recovery. Therefore, we combine preoperative radiation and intra arterial infusion for the prevention of recurrence at the resection margin. However, we have not obtained completely satisfying results. Operations involving these tumors should be performed in cooperation with other fields.

Bone Neoplasms↗
PubMed1988

Changes in serum myoglobin levels caused by tourniquet ischemia under normothermic and hypothermic conditions.

Serum myoglobin levels have been found to be elevated for a few hours after removal of a tourniquet. In the present study, levels of serum myoglobin were measured by radioimmunoassay from local blood samples in patients who were treated with surgery of the hand in a bloodless field. After removal of the tourniquet blood samples were obtained from the antecubital vein of each patient immediately after release, five minutes, one hour, and 24 hours later. In these samples the serum myoglobin levels were not influenced by the mode of anesthesia, tourniquet time, or specific type of surgery. When the upper extremity was cooled with ice water before application of the tourniquet, however, the increase of serum myoglobin was statistically significantly inhibited when compared with the normothermic condition. Muscle injury due to tourniquet ischemia may be decreased by cooling of the upper extremity prior to tourniquet application.

Adolescent↗
PubMed1987

Free vascularized fibular grafts in the treatment of congenital pseudarthrosis of the tibia.

Five patients with congenital pseudarthrosis of the tibia treated by a free vascularized fibular graft are described. Follow-up evaluation ranged from 15 to 81 months, with a mean of 40 months. Bony union was attained in three of five cases as determined roentgenographically. The remaining two cases failed to attain bony union. All cases except one, who was treated with a below-knee amputation, subsequently attained bony union. However, four cases had five fractures after bony union. We discussed unsolved problems regarding the free vascularized fibular graft and fracture after bony union.

Child↗
PubMed1987

A novel concept on the pathogenetic mechanism underlying ischaemic brain oedema: relevance of free radicals and eicosanoids.

A survey on literature reports and our own experimental studies on the pathogenetic mechanisms underlying ischaemic brain oedema is given and a new concept proposed. In regional incomplete ischaemia the lipoxygenase activity is enhanced, presumably caused by an increase of free radicals and hydroperoxides, leading to an enhancement of endothelial Na+, K+-AtPase and increased sodium and water transport from blood to brain. The aggravation of brain oedema and post-ischaemic hypoperfusion following recirculation appears to be mainly due to an activation of the cyclo-oxygenase pathway with release of oxidants from PGG2, which causes non-specific but detrimental damage to the endothelial and parenchymal cells. This new concept may open future perspectives in treatment which are briefly discussed.

Animals↗
PubMed1987

Splenic arteriovenous fistula formation due to angiodysplasia in a splenic aneurysm of a patient with liver cirrhosis--a report of a case.

A 53 year-old Japanese woman with liver cirrhosis manifested massive hematemesis due to ruptured esophageal varices. Celiac angiography demonstrated an aneurysm of the splenic hilus and arteriovenous fistula around the aneurysm. She underwent splenectomy, proximal gastrectomy, distal esophageal devascularization and pyloroplasty. Histological examination of the aneurysm revealed arterial dysplasia with a focal medial gap. Microscopic tissue clefts at the site of a medial gap were considered to be the source of the angiographic arteriovenous fistula.

Aneurysm↗
PubMed1987

IRBP from bovine retina is poorly uveitogenic in guinea pigs and is identical to A-antigen.

Retinal interphotoreceptor retinoid-binding protein (IRBP) is a potent uveitogen in Lewis rats, producing experimental autoimmune uveitis (EAU) reproducibly at doses lower than those of S-antigen (S-Ag). In contrast, IRBP was found to be poorly uveitogenic in three strains of guinea pigs, inducing only minor changes in a small proportion of these animals. On the other hand, S-Ag was found to induce EAU in the majority of immunized guinea pigs, with changes more severe than those induced by IRBP. Unlike the difference in their uveitogenicity, IRBP and S-Ag induced similar levels of specific immune responses in the immunized guinea pigs. The poor uveitogenicity of IRBP in guinea pigs resembles that of A-antigen (A-Ag). The two proteins are also similar in other features and were found in this study to be antigenically identical. It is proposed that IRBP and A-Ag are one and the same protein.

Animals↗