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Biomedical subjects

Y R Li

Publications and source records attributed to Y R Li.

36 records · Page 2Linked to original sources
PubMed1989

[The influence of GABA injected into cerebral ventricle on electrical activities of pain-excitation neurons and pain-inhibition neurons in nucleus parafascicularis of the thalamus of rats].

The influence of intraventricular injection of GABA on electrical activities of PEN and PIN in nucleus parafascicularis of the thalamus of rats was studied. The results showed that GABA could significantly inhibit the electrical discharges of PEN and increase the electrical discharges of PIN. So it was believed that intraventricularly injected GABA could antagonize or partly antagonize the excitatory action of noxious stimuli and might thus produce analgesia.

Animals↗
PubMed1988

Health survey among farmers exposed to deltamethrin in the cotton fields.

A health survey was conducted among spraymen exposed to 2.5% deltamethrin EC in the cotton fields. The subjects were exposed to deltamethrin at concentrations of 0.022-24.070 micrograms/m3 in respiratory zone air and of 0.013-0.347 micrograms/cm2 of skin contact. Results showed that one-half of the 44 subjects examined complained of itching and burning sensations on their faces. A few miliary red papules also appeared on the face of one subject but not sign of acute deltamethrin poisoning was evident on physical examination. There were no significant differences between the subjects examined and the controls in sodium, potassium, and urea contents in the serum, sodium potassium ATPase and serotonin in whole blood, and 3-methyl-4-hydroxymandelic acid and 5-hydroxyindoleacetic acid in the urine. Deltamethrin in the urine of spraymen was below the detection limit (0.20 microgram/liter) of the method used.

Adolescent↗
PubMed1988

Studies on the effect of tetrandrine on microtubules. I. Biochemical observation and electron microscopy.

Microtubules were purified by using two cycles of assembly and disassembly processes on fresh brain homogenates from 30 guinea pigs. The yield was about 60 mg. The effect of tetrandrine on tubulin was determined by spectrophotometric analysis and electron microscopy. In addition, we used the indirect immunofluorescent method including tubulin antibody to locate the presence of microtubules in 3T3 cells by fluorescence microscopy. The effects of colchicine and P204 were studied for comparison at the same time. The results showed that colchicine can effectively depolymerize microtubules, while tetrandrine showed aggregation, and in a different manner. The shape and structure of microtubules were definitely destroyed by colchicine, but were not affected by P204 which protected against the destructive effect of tetrandrine. This result indicated the safety of using a combination of P204 and tetrandrine in the treatment of silicosis.

Alkaloids↗
PubMed1988

Studies on the effect of tetrandrine on microtubules. II. Observation with immunofluorescence techniques.

Microtubules were purified by using two cycles of assembly and disassembly processes on fresh brain homogenates from 30 guinea pigs. The yield was about 60 mg. The effect of tetrandrine on tubulin was determined by spectrophotometric analysis and electron microscopy. In addition, we used the indirect immunofluorescent method including tubulin antibody to locate the presence of microtubules in 3T3 cells by fluorescence microscopy. The effects of colchicine and P204 were studied for comparison at the same time. The results showed that colchicine can effectively depolymerize microtubules, while tetrandrine showed aggregation, and in a different manner. The shape and structure of microtubules were definitely destroyed by colchicine, but were not affected by P204 which protected against the destructive effect of tetrandrine. This result indicated the safety of using a combination of P204 and tetrandrine in the treatment of silicosis.

Alkaloids↗
PubMed1988

Studies on the inhibitory effect of tetrandrine on silica-induced fibrogenesis in vitro.

Two cell culture systems composed of rat peritoneal macrophages and 2BS fibroblasts were used to study the inhibitory action of tetrandrine on collagen and glycosaminoglycan synthesis. The activation of silica-treated macrophage supernatants stimulated collagen synthesis by 2BS fibroblast cells. Tetrandrine had an inhibitory effect on the biosynthesis of collagen and glycosaminoglycans. The increase in the content of hydroxyproline, representing collagen, was verified by comparing it with that of DNA.

Alkaloids↗
PubMed1984

The simultaneous discharges of two neurons in N. Pf and RF and the influences on them by stimulating central gray matter.

This paper employs the method of simultaneous recording of the electric discharges of two neurons with two microelectrodes to study the interrelationship of simultaneous electric activities of pain excitation neurons (PEN) and pain inhibition neurons (PIN) in N. parafascicularis (Pf) of thalamus and reticular formation (RF) of midbrain in 42 rats. The results prove: (i) There are both PEN and PIN in RF in midbrain and they act coordinately; (ii) noxious messages may simultaneously act on PEN and PIN in N. Pf and RF, and the reciprocal coordination of electric activities of these two kinds of neurons is very obvious; (iii) stimulating central gray matter or injecting morphine may weaken the activities of PEN simultaneously, with the opposite effects on PIN.

Action Potentials↗
PubMed1983

Studies on the contents of glycosaminoglycans from lungs of silicotic rats and tetrandrine-treated silicotic rats.

In this report the differences in the total content of glycosaminoglycans (GAG) and in the relative contents of individual GAG among normal rat lung, silicotic rat lung, and tetrandrine (TT)-treated silicotic rat lung were studied. The differences were also observed with the histochemical method. In normal rat lung the content of GAG was 6.35 mg/g dry tissue. The percentage of heparin sulfate (HeS) was higher than the others. The content of GAG in silicotic rat lung was raised much more than that of the normal rat. Percentages of hyaluronic acid (HyA) and dermatan sulfate (DeS) were higher. Percentage of HeS was lower than that of the normal rat. In silicotic lung GAG existed around the collagen fibers and were netlike in shape. After treatment with TT, most of the GAG were seen to be present within the cells. It was proved that TT could inhibit the increase in the content of GAG in silicotic rat lung and could also obstruct the change in the relative contents of individual GAG.

Alkaloids↗
PubMed1982

[Proteoglycan].

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Animals↗