PubMed Health⌕ Search

Biomedical subjects

Y Mimura

Publications and source records attributed to Y Mimura.

At least 145 records · Page 8Linked to original sources

[The dynamics of leucocytes and complements in endotoxin induced uveitis].

The dynamics of leukocytes, complement and tumor necrosis factor (TNF) were studied in endotoxin induced uveitis (EIU) in rats. Endotoxin was administered to footpads and the time courses of the following were examined: 1) the number of leukocytes in peripheral blood 2) the number of leukocytes and protein concentration of aqueous humor 3) complement (CH50, C1, C3, C5) in serum and aqueous humor 4) TNF in serum 5) histological changes in the eyes, lungs, liver, and skin. The number of leukocytes in peripheral blood decreased to one third that of controls during three to six hours after endotoxin administration, but increased thereafter along with the number of leukocytes and protein concentration in aqueous humor. More leukocytes were observed than in controls in the small vessels of the iris, lung, liver and skin, some of which attached to the vascular endothelium. Serum C3 increased and serum C5 transiently decreased after endotoxin administration. Serum TNF reached a peak (3500 IU/ml) at 1.5 hours and rapidly decreased subsequently. It is suggested that the adhesion of leukocytes to vascular endothelium and the activation of complement system may play important roles in the development of EIU.

Animals↗

[Nutritional support in critically ill patients; with special reference to fat emulsion and carnitine].

Energy metabolism of fat emulsion was studied in rats with septic condition. The results indicate that fat emulsion was rapidly eliminated from the blood stream and metabolized readily even in such condition. Based on these findings, we have actively employed fat emulsion clinically as an energy source of septic patients. In septic rats, it was demonstrated that levels of carnitine decreased and that this decrease was based upon a decrease of synthesis. When carnitine was administered together with fat emulsion, the energy metabolism returned to approximately normal level. This reports also describes the absorption and utilization of orally administered fat in septic rats.

Animals↗

Insulin resistance of adjuvant-induced granuloma pouch formation in genetically diabetic KK-CAy mice.

The characteristics of adjuvant-induced pouch granuloma in genetically diabetic KK-CAy mice with hyperinsulinemia were investigated. Both the dose-response relationship and the time-course experiments showed that the wet weight of pouch granuloma in diabetic KK-CAy mice was lower than in ddY normal mice. Insulin treatment enhanced granuloma formation in KK-CAy mice, and it restored the suppressed DNA content in the granuloma tissue to the level in ddY mice. Although the DNA content was dose-dependently increased by insulin, the ratio of DNA content to granuloma weight was constant. In severely diabetic mice, the granuloma weight was not different from that in normoglycemic mice, despite significantly higher blood insulin levels and greater body weight. Insulin stimulated granuloma formation in severely diabetic KK-CAy mice only when higher doses (1 mg/kg) were given. This evidence suggests that suppression of granuloma formation in diabetic KK-CAy mice is due to insulin resistance and that restoration requires pharmacological doses of insulin.

Animals↗

Side effects in the treatment of herpetic keratitis.

Various side effects due to antiherpetic drugs observed in the last ten years in our department were studied. A total of 132 patients were treated with 5-iodo-2'-deoxyuridine (IDU), 69 with trifluorothymidine (F3T), 58 with acyclovir (ACV) and 33 with adenine arabinoside (ara-A). Patch tests were routinely done when patients exhibited contact dermatitis. Of the patients treated with IDU, 3 (2.3%) showed contact dermatitis, 2 (1.5%) follicular conjunctivitis and 1 (0.8%) punctate keratopathy. Of the patients treated with F3T, 7 (10.1%) exhibited contact dermatitis and 1 (1.4%) follicular conjunctivitis. In the group treated with ACV, 2 (3.4%) patients showed punctate keratopathy. The patients who received ara-A did not show any side effects. We found that F3T caused contact dermatitis more frequently in Japanese people than Europeans. These side effects were resolved by switching to another anti-herpetic drug without the occurrence of cross-allergy. Therefore, switching to another drug is strongly recommended when patients exhibit side effects in the treatment of herpetic keratitis. Other complications were allergy to atropine and to drug preservative.

Acyclovir↗

Anti-herpes simplex virus (HSV) effect of 9-(1,3-dihydroxy-2-propoxymethyl)guanine (DHPG) in rabbit cornea.

The anti-herpes simplex virus (HSV) effect and cytotoxicity of a new nucleoside analogue, 9-(1,3-dihydroxy-2-propoxymethyl)guanine (DHPG) in rabbit cornea were studied. In tests of the anti-HSV effect of DHPG, even 0.03% ointment, given 5 times per day for 2 days, prevented lesion formation. The preventive effect of DHPG was much stronger than that of acyclovir (ACV) or 5-iodo-2'-deoxyuridine (IDU). In tests on the therapeutic effect of DHPG against dendritic ulcers, 0.3% ointment, given 5 times per day for 4 days, had a dramatic therapeutic effect. The effect was stronger than that of 3% ACV or 0.5% IDU ointment. Application of 0.3%, 1% or 3% DHPG ointment to normal rabbit corneas, 5 times per day for 2 weeks resulted in no histopathological abnormalities. The above results show that DHPG is superior to ACV or IDU for treatment of HSV infections.

Acyclovir↗

Superoxide in ocular inflammation: human and experimental uveitis.

A possible involvement of superoxide in the pathogenesis of uveal inflammation in man and experimental animals was investigated. Superoxide production by the leukocytes of Behcet patients was significantly higher in the attack phase than in the remission phase. Leukocyte superoxide generation was also enhanced in guinea pigs with S-antigen-induced experimental autoimmune uveoretinitis (EAU). If the animals were treated with superoxide dismutase (SOD) at the onset of EAU, aqueous humor cell count was significantly lower than that of control (i.e., without SOD treatment). Infiltration of the inflammatory cells in the anterior retina was markedly reduced in SOD-treated animals. A similar protective effect of SOD against tissue damage was also observed in a bovine serum albumin-induced passive Arthus type uveitis in rabbits. These results suggest that superoxide may play a role in causing tissue damage in animal models of ocular inflammation and possibly in Behcet disease.

Animals↗

Potentiation by retinoic acid of ornithine decarboxylase induction by phytohemagglutinin or phorbol 12-myristate 13-acetate in guinea pig lymphocytes.

Retinoic acid potentiated the increases in ornithine decarboxylase (L-ornithine carboxy-lyase [EC 4.1.1.17]) activity, [3H]difluoromethylornithine binding to ornithine decarboxylase, intracellular levels of polyamines and DNA synthesis in guinea pig lymphocytes stimulated with phytohemagglutinin. The stimulatory effect on the ornithine decarboxylase induction was dependent on the dose of retinoic acid and on the time of addition of the drug. Retinoic acid has to be added not later than 2 h after phytohemagglutinin to elicit the potentiation. Retinyl acetate also potentiated ornithine decarboxylase induction caused by phytohemagglutinin. Both of these retinoids augmented ornithine decarboxylase induction caused by phorbol 12-myristate 13-acetate. The half-life of ornithine decarboxylase activity estimated after addition of actinomycin D was longer in cells treated with phytohemagglutinin or phorbol 12-myristate 13-acetate together with retinoic acid than in cells treated with the mitogen alone. The half-life after addition of cycloheximide was not affected by retinoic acid. These results suggest that the retinoids are stimulators rather than inhibitors of ornithine decarboxylase induction caused by phytohemagglutinin or phorbol 12-myristate 13-acetate in guinea pig lymphocytes and that retinoic acid potentiates the enzyme activity at the transcriptional or posttranscriptional, but not at the post-translational stage.

Animals↗

Purification to apparent homogeneity of inactive kallikrein from rat urine.

Inactive kallikrein was purified from rat urine by a procedure including ammonium sulfate fractionation, DEAE cellulose chromatography, phenyl-Sepharose CL-4B chromatography, and gel filtration on Sephadex G-100 and Sephadex G-75 columns. The resulting preparation was essentially homogeneous, as assessed by polyacrylamide gel electrophoresis. This preparation migrated as a single protein band on a SDS-polyacrylamide gel and the molecular weight was 41000. The purified material underwent marked activation by trypsin, but not by deoxycholate, Triton X-100, SDS or acidification. These results indicate that the purified inactive kallikrein is the precursor rather than a complex with a substance binding to the active form of kallikrein.

Animals↗

Neutrophil collagenolytic activity in patients with Behçet disease.

Studies were made on neutrophil dysfunction in Behçet disease by examining collagenolytic activity in neutrophils. The collagenolytic activity of neutrophil was found to be significantly higher in patients during the attack phase of this disease than in patients during the remission phase, in patients with other forms of uveitis and in normal controls. Collagenase was present in the collagenolytic enzyme, which showed high activity in the attack phase. The molecular weight of this enzyme was similar to that of mammalian neutrophil collagenase.

Adult↗

Studies on vitamin K-dependent factor deficiency during early childhood with special reference to prothrombin activity and antigen level.

8 young infants aged 14 days to 5 months with vitamin K-dependent factor deficiency were studied with special reference to prothrombin activity and antigen level. Among them, 3 infants had congenital bile duct atresia and 5 were breast-fed babies with severe hemorrhagic tendency of unknown cause. In the patients with both congenital bile duct atresia and breast feeding the ratio of prothrombin activity to prothrombin antigen was lower than 0.1. Furthermore, the arc of prothrombin antigen in these patients demonstrated a faster anodal shift than did normal prothrombin antigen on crossed immunoelectrophoresis. This abnormal prothrombin antigen was not consumed after recalcification of patient plasma, and absorbed poorly on BaSO4. In addition, the abnormal prothrombin antigen disappeared from the patient plasma within a few days after parenteral administration of vitamin K. These results suggest that this abnormal prothrombin is PIVKA-II.

Bile Ducts↗