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Biomedical subjects

H Yama

Publications and source records attributed to H Yama.

8 recordsLinked to original sources
PubMed2001

Isolation and identification of antheridiogens in the ferns, Lygodium microphyllum and Lygodium reticulatum.

Antheridiogens in culture media of 6-week-old prothallia of two species of Schizaeaceous ferns, Lygodium microphyllum and Lygodium reticulatum, were analyzed by gas chromatography-mass spectrometry. In both species, the gibberellin A73 methyl ester (GA73-Me) was identified as the most abundant antheridiogen, and the methyl esters of GA9 and of several monohydroxy-GA73 derivatives were also detected. Since both species produced antheridiogens at a high level, they were classified into high-antheridiogen-producing ferns. The response to GA73-Me of gametophytes of both species is also discussed.

Ferns↗
PubMed1996

Evidence of a direct action of taurine and calcium on biological membranes. A combined study of 31P-nuclear magnetic resonance and electron spin resonance.

To determine the actions of taurine and calcium on biological membranes, the effects of these compounds on the mobility of phospholipids of resealed and sonicated ghosts of human erythrocytes were investigated, using 31P-NMR spectroscopy. In addition, the effects of taurine and calcium on lipid fluidity were investigated by ESR spectroscopy, using a spin-labeling method with 5-doxyl stearic acid. The mobility of the membranes decreased following treatment with 10 mM taurine, but coadministration of 2.5 mM calcium blocked this effect. The fluidity of the membranes was not changed following treatment with 10 mM taurine, but decreased following coadministration of 2.5 mM calcium. These actions of taurine and calcium on the dynamics of biological membranes might explain, in part, the observation that most of the pharmacological effects of taurine on mammalian organs occur in the presence of calcium ions.

Calcium↗
PubMed1991

[Antibiotic sensitivity of bacteria isolated from patients at 6 hospitals in Osaka].

We examined MICs of 6 oral new quinolones and 4 oral cephems against bacteria isolated from patients at 6 hospitals in Osaka during the period from January to June in 1990, and the following results were obtained. 1. All species excluding Streptococcus pyogenes were more sensitive with less frequencies of resistance to new quinolones than to cephems. In new quinolones, tosufloxacin (TFLX) was the most active against Gram-positive cocci and ciprofloxacin (CPFX) and TFLX had the highest activities against Gram-negative rods. 2. Resistant (MIC of CPFX greater than or equal to 3.13 micrograms/ml) strains to new quinolones were observed at higher frequencies than 10% among Staphylococcus spp., Enterococcus faecalis, Citrobacter freundii, Morganella morganii, Providencia rettgeri, Serratia spp., Pseudomonas aeruginosa, Pseudomonas cepacia and Xanthomonas maltophilia. 3. The frequency of Staphylococcus aureus resistant to new quinolones isolated from in-patients or urine was significantly higher than that from out-patients or other sources. On the other hand, there was no significant difference in resistance frequencies of P. aeruginosa due to types of patients or sources. But, there were significant differences in frequencies of resistant organisms of either species to new quinolones among hospitals. 4. Twenty-seven strains (19.7%) of 137 S. aureus strains examined were methicillin-resistant, and they were similarly resistant to new quinolones also. Methicillin susceptible S. aureus were also similarly sensitive to new quinolones.

Anti-Bacterial Agents↗
PubMed1979

[Clinico-antimicrobial evaluation of cefuroxime by observation of transitional change of micro-organisms in urine specimen (author's transl)].

Cefuroxime (CXM) was administered for 1 week to spinal cord injury patients with chronic complicated urinary tract infection and the transitional change of micro-organisms was observed. Bacterial counts and identification of isolated organisms were performed daily on the mid-stream urine for 1 week. MIC was also determined on the strains before and after CXM treatment. The results with 83 strains from 28 patients are as follows: 1. CXM's efficacy appears in line with MIC of strains. With the cases given 0.75 g twice daily intramuscularly, all the 14 strains with MIC lower than 50 micrograms/ml were eradicated, but 2 of the 14 strains were found re-growing, with only bacteriostatic action noted (in region of minimal inhibitory action). With the group of the cases given 1.5 g twice daily, all the 15 strains with MIC lower than 200 micrograms/ml were eradicated from urine 1 approximately 3 days after start of treatment (in region of bactericidal action). 2. At dose of bactericidal action CXM responded effectively with no relationship to organism species or bacterial count before CXM treatment. 3. Dose response was noted between the cases given 1.5 g daily and those given 3.0 g daily. 4. From the above result, we can presume appropriate doses in accordance with the disease conditions. From above observation, combined with correlation between organism species, bacterial count, MIC of strains, etc., CXM's efficacy was assessed quantitatively and objectively.

Bacteria↗
PubMed1976

[Experimental study on aldolase isozyme during the development of hepatoma in the rat (author's transl)].

Aldolase (ALD) consists of three different types of isozyme, i.e. muscle or A type, liver or B type and brain or C type, their relative proportions being fixed for each tissue. In this study, isozyme profiles in the serum and DAB induced hepatoma as it grows were examined in comparison with those in the fetal liver, in the hope to obtain information for early detection of the malady. In the very early phase of hepatoma growth with no elevated enzyme activity, ALD-A fraction after electrophoresis was found to increase. In the course of hepatoma growth, ALD-B decreased while ALD-A increased with appearance of hybrid of ALD-A and ALD-C. In the normal adult liver, no hybrid of ALD-A and ALD-C was encountered. Serum profile of the rat with DAB induced hepatoma was similar to that of the cancer tissue. On the other hand, the fetal liver shows a profile with high ALD-A fraction and even with hybrid of ALD-A and -C. These features disappeared gradually as maturation proceeded and became close to the adult pattern. Thus it is clear that DAB induced hepatoma exhibits retrogressive change in hepatic differentiation in its isozyme profile. The results also indicate usefulness of isozyme profile for early detection of the hepatoma.

Animals↗