PubMed Health⌕ Search

Biomedical subjects

Y P Ma

Publications and source records attributed to Y P Ma.

14 recordsLinked to original sources
PubMed2006

Characterization of bacterial susceptibility isolates in sixteen dairy farms in Taiwan.

Bacteria were isolated from dairy cows, dairy farm environments, and dairy workers in 2 geographically different areas of eastern and northern Taiwan. Isolates were evaluated for antimicrobial susceptibility and the phylogenetics of isolated Escherichia coli O157:H7 were characterized. A total of 1,346 bacteria were identified, including 226 E. coli, 30 Pseudomonas spp. (7 Pseudomonas aeruginosa), 259 other gram-negative bacteria, 271 Enterococcus spp., 314 Staphylococcus spp., 195 Streptococcus spp., and 51 other gram-positive bacteria. Among them, 88% (1,184/1,346) of the isolates were resistant to sulfadimethoxine. The percentages of gram-negative bacteria resistant to oxy-tetracycline and streptomycin were 48% (249/515) and 78% (404/515), respectively. Gram-positive bacteria isolated from eastern Taiwan, the least polluted region of Taiwan, were found to have greater antimicrobial resistance than those isolated from northern Taiwan. Two E. coli O157:H7 from 2 different geographical areas were isolated. Both were vt2-positive but vt1-negative and had phylogenetic similarities of 82 and 67%, respectively, compared with previous isolates. Information on antimicrobial susceptibility revealed from this dairy farm survey may serve as a baseline for future studies and may also highlight the need to formulate better regulation strategies for the safe use of antimicrobials on food-producing farms.

Adult↗
PubMed2001

[Bepridil inhibition on the delayed rectifier K+ currents in thyroxine induced hypertrophied guinea pig ventricular myocytes].

AIM: To study the effects of bepridil on the rapidly activating component (IKr), the slowly activating component (IKs) of the delayed rectifier potassium current and the inward rectifier potassium current (IK1) in hypertrophied guinea pig ventricular myocytes. METHODS: The whole cell patch clamp techniques were used. RESULTS: In hypertrophied guinea pig ventricular myocytes, bepridil 30 mumol.L-1 markedly inhibited IKr and IKs (by 20.9% and 27.2% at 0 mV and mV, respectively). The effect of bepridil on IKs was larger than on IKr. Bepridil 30 mumol.L-1 also significantly inhibited the inward component of IK1 (by 15.1% at +100 mV), but the reverse potential of IK1 was unaffected. Bepridil (1-100 mumol.L-1) was shown to inhibit IKr and IKs in a concentration-dependent manner. Their IC50 were 46.7 mumol.L-1 and 23.8 mumol.L-1, respectively. CONCLUSION: Bepridil inhibit IKr, IKs and IK1 in hypertrophied guinea pig ventricular myocytes, which may be important in understanding the antiarrhythmic effects of this drug.

Animals↗
PubMed1995

[Study on metabolite of 5-ethyl-5-(para-fluorobenzoylpropyl) barbituric acid in rabbits].

The metabolite of 5-ethyl-5-(p-fluorobenzoylpropyl) barbituric acid (coded as F-B-1) in rabbit has been separated with HPLC. UV-spectra of F-B-1 and its metabolite obtained with DAD, in combination with EI-MS and CI-MS of F-B-1, its metabolite and their derivatives were examined. Possible structure of the metabolite was obtained. Possible metabolic way of F-B-1 is the reduction of carbonyl on the benzene ring with formation of hydroxyl group. This was further confirmed by identity of HPLC and MS behavior of the metabolite and NaBH4 reductive product. In the structure of the latter, the carbonyl on the benzene ring was reduced, as proved by NMR (1H-NMR and 13C-NMR) spectra.

Animals↗
PubMed1991

Automatic end-expiratory air sampling device for breath hydrogen test in infants.

An automatic electronically operated end-expiratory air sampler has been developed for use in small infants. Upon expiration, which is detected by a hot-wire sensor, a small portion of the end-expiratory air is automatically collected into a syringe mounted on a syringe driver. The sampler obtained 87% of the end-expiratory air sample. Additionally, highly reproducible and consistent results were obtained for the respiratory gases (O2, N2, CO2). The sampler has been applied for studying breath hydrogen excretion to detect lactose malabsorption. It may also be applicable to study other expiratory gases in infants.

Breath Tests↗
PubMed1991

Identification of a mouse brain beta-spectrin cDNA and distribution of its mRNA in adult tissues.

A mouse brain beta-spectrin of cDNA was identified within a lambda Gt11 expression library using an antibody which specifically binds with the 235 kDa spectrin beta-subunit. Restriction mapping and DNA sequencing analyses of the brain cDNA revealed that this clone contained 1185 bp of sequence, of which a 999 bp single open reading frame encoding 333 amino acids was determined. The deduced amino acid sequence exhibited homology with beta-spectrins, demonstrating the characteristic 106 amino acid repeating unit. The homology between our mouse brain sequence and human RBC beta-spectrin was approximately 56% beginning at the beta 15 repeat unit and extending to the C-terminus of sequence elucidated for human RBC sequence. An additional 62 amino acids were found at the C-terminus of the 235 kDa brain beta-spectrin subunit not seen in the human RBC sequence. The approximately 1.2 Kb brain spectrin cDNA insert hybridized with a single 9 Kb mRNA transcript in various adult mouse tissues, with the most abundant hybridization demonstrated in RNA isolated from brain tissue. This mRNA was found to be present at high levels in heart tissue and at lower levels in spleen and skeletal muscle tissue. The 9 Kb mRNA was different in content and in size to mRNAs which hybridized with a cDNA encoding the mouse erythroid beta-spectrin subunit, demonstrating that the brain spectrin cDNA is a distinct gene product and represents the first known sequence of a nonerythroid beta-spectrin subunit.

Animals↗
PubMed1989

[Interaction of component (E) with tumor cellular DNA].

Some antitumor activities of component (E), extracted from the root of Fagopynum Cymosum (TreV) meisn (FCTM), have recently been discovered in vitro and in vivo. The component (E)'s pattern of action with tumor cellular DNA at the molecular pharmacological level was investigated by macromolecular synthesis experiment (MSE) and human DNA interaction HDI system established in our laboratory. The experiments demonstrated that, in vitro, the agent could markedly inhibit incorporation of H3-TdR into the cellular DNA, and the IC50 in P388 and SGC-7901 was 17.86 micrograms/ml and 110.4 micrograms/ml, respectively. The agent, at level of mg/ml, could produce an intercalation reversion pattern with DNA within a short time (2 hours). But when the interval was prolonged for over 4 hours, the pattern of action changed to intercalation irreversible pattern. According to these observations, the authors infer that component (E) interacts with DNA in two ways-directly and indirectly. The indirect action, especially in low concentrations, probably plays the major role. The authors have also compared the interaction of component (E) with those of components (CD1) and (CB3) extracted from FCTM by the same method and found that component (E) is the most active agent against the DNA of cancer cells among the extracts from FCTM.

Adenocarcinoma↗
PubMed1983

Pseudo-on-line fast response microvessel dimensions video graphic recorder with electrical signal output.

The present article describes a new method of microvessel dimensions measurement in which a writing oscilloscope is used to continuously and graphically record the microvessel video signal from television microscopy at a fast rate of 50 records per second. Dimensions of interest, such as the microvessel red blood cell flux diameter, are then easily marked out manually from the graphic records and a dynamic electrical signal proportional to the dimensions is generated. The signal is then recorded on one channel of a multichannel voltage recorder and is synchronised with other experimental signals which have previously been recorded on-line during the experiment. The result is that the dimension signal appears to have been recorded on-line during the experiment as well. This is desirable for electronic signal correlation and processing. This method is useful when poor experimental conditions, commonly encountered, make automatic recording of microvessel dimension unsatisfactory and manual inspection and processing become necessary.

Animals↗