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Biomedical subjects

Y Osada

Publications and source records attributed to Y Osada.

At least 199 records · Page 11Linked to original sources
PubMed1981

A possible role of R plasmids in bacterial permeability for beta-lactam antibiotics.

Four strains of clinical isolates of Serratia marcescens (13039, 13090, 13093, 14093) harboring R plasmids were highly resistant to ampicillin (ABPC) and cephaloridine (CER). With elimination of R plasmids from these strains by acriflavine treatment, ABPC-resistance levels of these strains were markedly reduced. Reduction of CER-resistance levels was also demonstrated in strains 13039 and 13093, but not in strains 13090 and 14093. The permeability of the former strains for CER was also decreased, but not in the latter strains. At the same time, beta-lactamase activity of these strains also almost completely disappeared when the R plasmids were eliminated. By broth matings with these strains. The recipient strains of S. marcescens 13031 (rif), Escherichia coli K-12 (rif), and E coli 15046 (rif) all acquired a high permeability barrier against CER with inheritance of the R plasmids from strains 13039 and 13093, but not from strains 13090 and 14093. The transconjugant of strain 13031 that inherited R plasmid 13093 was resistant not only to CER but also to cefazolin, cephalothin, and cephalexin. Its permeability to these antibiotics was significantly lower than that of the original strain. This fact suggest the possibility that the R plasmid from strain 13093 may be involved not only in production of beta-lactamases, but also in regulation of bacterial permeability for cephalosporins.

Ampicillin↗
PubMed1981

[Pharmacological study on hydrocortisone 17-butyrate 21-propionate (author's transl)].

The topical and systemic anti-inflammatory activities of hydrocortisone 17-butyrate 21-propionate (HBP) were studied. The systemic anti-inflammatory activities of HBP and reference steroids were examined for their effects on dinitrochlorobenzene dermatitis, carrageenin edema, cotton pellet granuloma and adjuvant arthritis in rats and by the delayed allergic edema test in mice. The topical anti-inflammatory activities of these steroids were examined for their effects on croton oil dermatitis, croton oil ear edema, carrageenin edema and cotton pellet granuloma in rats. Furthermore, effects of these steroids on liver glycogen deposition in mice, thymolysis, and decrease of serum corticosterone level in rats were examined. Systemically administered HBP was less potent than betamethasone 17-valerate (BV), but was almost equal to hydrocortisone 17-butyrate (HB) in anti-inflammatory activity, and its effects on liver glycogen deposition, thymolysis, and the decrease of serum corticosterone level. However, the topical anti-inflammatory activity of HBP was more potent than that of BV and HB, although in the same experiment, thymolytic activity of HBP was less potent than that of BV, but was almost equal to HB. The inhibitory effect of HBP on hypotonic induced hemolysis was weaker than that of BV, but was stronger than that of HB in vitro. The affinity of HBP was higher than that of BV and HB to polymorphonuclear leucocytes used as the inflammatory cells in vitro. On the other hand no marked difference was observed in the affinity to erythrocytes used as the non-inflammatory cells in vitro. These results suggest that HBP is a useful drug which has superior topical anti-inflammatory activity, but has a weak systemic effect.

Animals↗
PubMed1981

Cefoxitin: synergism with aminoglycosides in vitro.

In vitro synergistic effect of cefoxitin with aminoglycosides such as gentamicin, tobramycin, amikacin and dibekacin against 15 Escherichia coli, 15 Staphylococcus aureus and 105 Pseudomonas aeruginosa strains of fresh clinical isolates was examined. The combination of cefoxitin with the aminoglycosides showed distinct synergy against many strains of P. aeruginosa which were highly resistant to cefoxitin alone, while it failed in synergism against E. coli and S. aureus. A possible mechanism of in vitro synergy between cefoxitin and aminoglycosides against P. aeruginosa was discussed.

Amikacin↗
PubMed1981

[Effects of anti-inflammatory drugs on the arachidonic acid induced erythema in guinea pigs (author's transl)].

The inhibitory effects of anti-inflammatory drugs on th erythema induced by arachidonic acid in guinea pigs were studied. Values of ED50 (mg/kg, p.o.) were; diclofenac sodium (19.9), indomethacin (28.1), naproxen (52.4), phenylbutazone (67.1), ibuprofen (81.3), aspirin (92.6). These drugs, however, were ineffective on the erythema induced by prostaglandin E2. Basic nonsteroidal and steroidal anti-inflammatory drugs and anti-oxidants were negative in the inhibition of arachidonic acid-induced erythema. Cyproheptadine as an anti-histamine and -serotonin agent and morphine as a CNS acting agent were also negative. Erythema did not occur following treatment with linoleic acid, linolenic acid and gamma-linolenic acid. Bishomo-gamma-linolenic acid-induced erythema was inhibited by diclofenac sodium. The inhibition of acidic nonsteroidal anti-inflammatory drugs in this system seemed to be the result of a block of the enzymatic conversion of arachidonic acid to prostaglandins. The arachidonic acid-induced erythema in guinea pigs can serve as a new animal model for evaluating prostaglandins biosynthesis inhibitors such as anti-inflammatory drugs.

Animals↗
PubMed1978

Surgical treatment of renovascular hypertension associated with bilateral renal artery stenosis.

We report on 15 patients operated upon for renovascular hypertension associated with bilateral renal artery stenosis. Followup has been for 1 to 12 years. Four of 5 patients with positive split renal function studies and 3 of 5 patients with positive renal vein renin assays underwent unilateral operations on the positive side. All of these patients were cured or improved. The guide for unilateral operations in hypertensive patients with bilateral renal artery stenosis by angiography was the physiological information obtained from the preoperative screening tests, especially the plasma renin activity ratios of the 3 different veins and the split renal function studies.

Clinical Enzyme Tests↗
PubMed1978

Experimental studies on the sexual and seasonal differences of the optimal thermal conditions.

Four male and four female students stayed for 90 min in a climate chamber with relative humidity of 60% and air velocity of less than 20 cm/sec at 16-24 degrees C effective temperature (E.T.) in summer and in winter. Measurements during the last period of exposure were used for the analysis. The neutral thermal sensation and the most comfortable sensation in sitting posture were obtained for both of males and females at 24 degrees C E.T. nude and 22 degrees C E.T. clothed both in summer and in winter. Light sedentary work, an addition test using a calculator, did not influence the relation between room temperature and the metabolic rate or the weighted averaged skin temperature, but the neutral point of thermal sensation and the most comfortable sensation were found at 20 degrees C E.T., 1--2 degrees C lower than at rest. Neither sexual nor seasonal differences was detected for the light work conditions. When the subjects performed light muscular work of 10 min of stepping up on and down from a 6 cm-high platform twice during the 90 min period, the relationship between room temperature and the metabolic rate or the weighted averaged skin temperature did not change by the work and the neutral thermal sensation and the most comfortable sensation were given at 18 degrees C E.T., 4 degrees C lower than at rest. Sexual and seasonal differences were not observed.

Environment, Controlled↗