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Biomedical subjects

Y L Ma

Publications and source records attributed to Y L Ma.

At least 55 records · Page 3Linked to original sources
PubMed1993

[Influence of processing conditions on quality of calcined concha Osterae].

Concha Osterae (the shell of Ostera gigas) ignited under different conditions was compared and discussed in terms of appearance features, yielding ratio of ignited product, Ca content of the ignited product, decocting rate of total component, Ca2+ content of decoction and trace element content. Furthermore, calcined Concha Osterae products obtained commercially from 6 cities of China were also compared in regard to the quality.

Animals↗
PubMed1993

[B-mode ultrasonography in the diagnosis of appendicitis].

This article reports the ultrasonographic data in the diagnosis of 142 cases of appendicitis. 30 out of 40 cases originally misdiagnosed by the surgeon were proved to be other disease entity by this method preoperatively. Of 102 cases of appendicitis, 95 were accurately diagnosed by ultrasound including 14 cases with entirely atypical history and 7 cases with unusual position. The accuracy of diagnosis made by B-mode ultrasonography was 93.1%. By B-mode ultrasonography, the data of appendiceal diameter, inner diameter and the peri-appendiceal exudate were used to diagnose and classify appendicitis preoperatively, thus the misdiagnose rate went down from 10.6% to 1.8%.

Aged↗
PubMed1992

A study of calcium ion-selective PVC membrane electrode based on neutral carrier N,n,n',n'-tetracyclo-3-oxapentanediamide (correction of oxapetanediamide).

A calcium ion-selective PVC membrane electrode based on neutral carrier n,n,n',n'-tetracyclohexyl-3-oxapetanediamide, using di-(2-ethylhexyl)phthalate as the plasticizer and potassium tetrakis (4-chlorophenyl) borate as the additive is reported in this paper. The ion selective membrane consists of 1 wt% of the Ca2+ selective ligand, 65 wt% of the plasticizer, 1 wt% of the additive and 33 wt% of poly (vinyl chloride) powder. The electrode has the linear response range of 2.0 x 10(-7)-10(-1) mol/L with the Nernstian slope of 28 mV/decade at 25 degrees C and the detection limit of 2.0 x 10(-8) mol/L. The response time of the calcium ion-selective electrode is as the concentration of calcium ion is rapidly shifted from 10(-5) to 10(-4) mol/L. The potential stability and reproducibility are good. The free calcium in blood serum was determined by the calcium ion-selective electrode with satisfactory results.

Calcium↗
PubMed1992

A study of the effect of magnetized water on enzyme activities by potentiometric enzyme electrode method.

A very promising glutamate decarboxylase electrode, which has linear response range of 5.6 x 10(-5)-1.2 x 10(-2) mol/L. Nernstian slope of 50 mV/decade, detection limit of 3.2 x 10(-5) mol/L and response time less than 3 min, has been designed to observe and evaluate quantitatively the effect of magnetized water on enzyme activities by potentiometric enzyme electrode method. It was found that the activity of glutamate decarboxylase can increase by 30% in magnetized water. The mechanism of increased enzyme activity was discussed in the present paper. Such a new finding will probably lead to some new explanations for the physiological and biological mechanism of the effect of magnetized water on living organisms, thus providing a new approach to the study of the effect of magnetized water.

Electrodes↗
PubMed1990

Localization of endogenous galactoside-binding lectin during morphogenesis of Xenopus laevis.

A monoclonal antibody has been produced against Xenopus laevis galactoside-binding neural-crest-stage lectin. This antibody inhibits lectin-mediated hemagglutination. Using this antibody in conjunction with immunohistochemical techniques, lectin deposition has been studied in embryos and tadpoles at different stages of morphogenesis, from initial neural crest migration, up to the formation of a swimming tadpole. Lectin levels change during development in different regions of the embryo and tadpole, decreasing in migratory cells, and increasing in sites where cells become more adhesive to one another. The results suggest that galactoside-binding lectins may be an important class of cellular adhesion molecules during these stages of development.

Animals↗
PubMed1990

A carbon dioxide air-gap microelectrode based on a neutral hydrogen ion exchanger pH microelectrode.

A relatively simple potentiometric pCO2 gas-sensing microelectrode is described. It is based on an ion-exchanger pH electrode, has a 2- to 5-microns tip, and has an air gap which is formed by means of hydrophobic treatments. The microelectrode exhibits a linear response in the range 10(-4)-10(-2) M with a Nernstian slope of 59 to 62 mV/decade at 25 degrees C. Ninety-five percent of the steady-state response time is about 20-30 s at the flow system when the concentration of sodium bicarbonate in buffer solution (pH 4.5) suddenly shifts from 0.2 to 2 mM and the lifetime is longer than 1 week.

Animals↗
PubMed1989

Involvement of endogenous galactoside-binding lectin of Xenopus laevis in pattern formation of Xenopus neurites in vitro.

Galactoside-binding lectin has been purified from Xenopus laevis embryos at the stage of neural crest migration. Addition of this lectin to neurite cultures correlates with the appearance of fascicles of greater diameter and shorter length compared with controls. Lectin-treated neurites are also more spread out on the substratum than their controls. The potent hapten inhibitor of the endogenous lectin, thiodigalactoside (TDG), was also added to these cultures. TDG-treated neurites are less well spread out than the controls; fascicle diameters and lengths are not altered. These results suggest that galactoside-bearing receptors and endogenous galactoside-binding lectin are present in these neurites and can participate in controlling neuronal morphogenesis in vitro, although to differing extents.

Animals↗
PubMed1988

An ammonia-sensing air gap microelectrode.

An ammonia-sensing air gap microelectrode has been designed on the basis of a neutral carrier pH-sensing inner electrode. This electrode has a tip diameter of 2 to 5 microns, has a simple design, is easy to fabricate, and has a long shelf life. Its response to ammonium is linear in the range 3 x 10(-5) to 10(-2) M and its response time (95%) is 10 to 15 s. The electrode was converted to a microsensor for urea by immobilization of urease within its tip. The linear response to urea ranged from 3 x 10(-4) to 10(-2) M and the response time was 15 to 20 s.

Ammonia↗
PubMed1987

Studies on cellular adhesion of Xenopus laevis melanophores: modulation of cell-cell and cell-substratum adhesion in vitro by endogenous Xenopus galactoside-binding lectin.

We have investigated cell-cell and cell-substratum adhesion of Xenopus laevis neural crest cells at various stages of melanophore differentiation. Single-cell suspensions were obtained by trypsinization and aggregated in a cell-cell adhesion assay. Unpigmented cells did not adhere while the rate of adhesion of melanophores correlated with the degree of melanization. Melanophore cell-cell adhesion decreased significantly in the presence of beta-galactosidase, which suggests that cell-surface galactose is involved. Beta-galactoside-binding lectin has been isolated and purified from embryos at the stage of neural crest migration. When added to aggregating cells smaller, looser clusters formed compared to controls. When lectin was added to cells in stationary culture to test cell-substratum adhesion, melanophores spread more smoothly and formed more regular spacing patterns. These results suggest that this lectin can modulate receptors used in cell-cell and cell-substratum adhesion of melanophores.

Animals↗
PubMed1987

[Reactivity of monoclonal antibodies ALT-01 and ALT-04 and identification of lung cancer-associated antigens].

Two IgG1 type monoclonal antibodies ALT-01 and ALT-04 were prepared by two different immunization schedules. ALT-01 was generated by fusing murine myeloma NS-1 cells with splenocytes from a BALB/c mouse immunized by human lung squamous carcinoma cells, which were coated by antisera to mixed human lymphocytes. For preparation of ALT-04, human lung squamous carcinoma xenograft-bearing nude mice were injected I. P. with the spleen cells of normal BALB/c mice in order to acquire immunofunction. The spleen cells from these tumor-bearing nude mice were fused with NS-1 cells. Then, these hybridomas were screened and cloned for 3 times. Two antibodies were shown to recognize the surface antigen on human lung carcinoma cells and several kinds of tumor cell lines but not those on normal cell lines. ALT-01 reacted to neither human lung carcinoma tissue nor its xenograft. ALT-04 reacted to human lung carcinoma tissue, of which, reaction to adenocarcinoma was the strongest but not to various normal tissues. Immunoprecipitation followed by SDS-polyacrylamide gel electrophoresis and autoradiography was used to detect the associated antigen in 35S-labeled human lung carcinoma cells. Antigens, reacting to ALT-01, show one band of Mr 38,000 but those to ALT-04 reveal two bands of Mr 48,000 and 36,000.

Animals↗