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Biomedical subjects

Z Tan

Publications and source records attributed to Z Tan.

At least 73 records · Page 4Linked to original sources
PubMed1995

[The damped torsion swing test in guinea pigs].

The damped torsion swing test (DTST) was carried out for assessing the vestibular function in guinea pigs. Twenty guinea pigs which had normal pinna reflexes and normal tympanic membranes were used. In the formula, L represented the number of the left nystagmus, and R the right nystagmus during DTST. The symmetric rate [formula: see text] between left and right nystagmus was calculated. Then the animals were randomly divided into two groups: (1) Gentamicin group (n = 10): DTST was reexamined, Animals were injected with gentamicin (250 mg/kg) for three days. (2) Endolymphatic hydrops group (n = 10): Surgical obliteration of the right endolymphatic sac and duct was done, 30 days later DTST was carried out again. The results showed: (1) The normal value [formula: see text] of DTST in the 20 healthy guinea pigs is less than 8.25%. (2) Both of left and right nystagmus were reduced (P < 0.01) in gentamicin group. (3) The number of the right nystagmus was reduced in endolymphatic hydrops group (P < 0.01) and the symmetric rate of 6 animals was more than 8.25%. It is concluded that DTST is an important method of evaluating vestibular function in guinea pigs.

Animals↗
PubMed1994

DNA damage and the proliferation and aging of cells in culture: a mathematical model with time lag.

This paper is an extension of an earlier one by the same author in which a mathematical model was presented to describe the proliferation and aging of cells in culture. The model consists of a group of ordinary differential equations with a time lag. In the previous paper, the time lag was omitted for simplicity and the resulting differential equations were resolved analytically. It was shown that the model explains the behavior of a cell culture reasonably well. In this paper, the analytical solution of the original differential equations is presented without omitting the time lag. An analytical description of the variations in doubling capability between sister cells that was only simulated numerically in the earlier paper is given.

Animals↗
PubMed1994

[Quality control of xiaoqinglong mixture].

TLC was used to detect ephedrine, paeoniflorin, glycyrrhizic acid, cinnamic aldehyde and xixin volatile oils in Xiaoqinglong mixture. Paeoniflorin was determined by HPLC. The average recovery is 99.42%, and RSD 0.23%.

Acrolein↗
PubMed1993

[Effects of air pollution on health of residents in vicinity of an electrometallurgical factory in Chengdu].

Air pollution in an electrometallurgical plant in Chengdu was monitored in 1988. Results showed that atmospheric TSP and Ni concentrations in the vicinity of the plant were higher than those in control area; and TSP content higher than its health standard level. A population of 262 children was physically examined in the same pollution and control areas in May, 1988. Physical examinations were as follows:otorhinolaryngological examination, skin patch test of Ni and Co, immune function test (including PHA skin test, salivary LZM content), Ni levels in human hair and urine etc. We found that body burdens of Ni in population of pollution area increased because of the pollution of Ni compounds in the atmosphere. Hair Ni content in pollution area was significantly higher than that in control area, and the positive rate of Ni skin patch test was also markedly higher than that in control area. Case history indicated that there was a significant difference in Ni content as detected by otorhinolaryngological examinations between the pollution and control areas. Some measures were suggested to improve the air quality based on the study.

Adolescent↗
PubMed1992

Association of Phosphatidylinositol Kinase, Phosphatidylinositol Monophosphate Kinase, and Diacylglycerol Kinase with the Cytoskeleton and F-Actin Fractions of Carrot (Daucus carota L.) Cells Grown in Suspension Culture : Response to Cell Wall-Degrading Enzymes.

Phosphatidylinositol kinase (PI), phosphatidylinositol monophosphate (PIP) kinase, and diacylglycerol (DAG) kinase activities were detected in the cytoskeletal fraction isolated from microsomes and plasma membranes of carrot (Daucus carota L.) cells grown in suspension culture. The lipid kinase activities were associated with the actin filament fraction (F-actin fraction) isolated from the cytoskeleton. The PI and PIP kinase activity in the F-actin fraction significantly increased after cells were treated with Driselase, a mixture of cell wall-degrading enzymes; however, the DAG kinase activity in the F-actin fraction was unaffected by the Driselase treatment. These data indicate that at least one form of PI, PIP, and DAG kinase preferentially associates with actin filaments and/or actin binding proteins and that cytoskeletal-associated PI and PIP kinase activities can change in response to external stimulation.

Journal Article↗
PubMed1992

Oxygen-dependent reperfusion injury in the isolated rat lung.

To further define the relationship between oxygen dependence of lung injury during ischemia and ischemia-reperfusion, we used the isolated, perfused, and ventilated rat lung model, so that oxygenation and perfusion could be separated. During ischemia, lungs were ventilated with various oxygen concentrations and then ventilated with 95% oxygen during the 60-min reperfusion period. Other lungs were ventilated with 0% oxygen (nitrogen) during ischemia, and the reperfusion phase oxygen concentration was varied. Tissue and perfusate lipid peroxidation products (thiobarbituric acid-reactive substances and conjugated dienes), dry-to-wet weight ratio, and lactate dehydrogenase were measured as indexes of lung damage. In addition, electron microscopy of some lungs was performed. Results demonstrate an oxygen dependence of lipid peroxidation in both the ischemic and reperfusion phases, but lipid peroxidation is severalfold greater in the reperfusion than in the ischemic phase. Products of lipid peroxidation closely correlate with indexes of lung injury (dry-to-wet weight ratio, lactate dehydrogenase, and electron microscopy).

Animals↗
PubMed1991

Electrolyte induced vesiculation of MA782 mice mammary adenocarcinoma ascites cells.

MA782 ascites cells were found to vesiculate when incubated in electrolyte solutions and release giant plasma membrane vesicles with diameters ranging from 5 microns to 15 microns. The vesicles, generated from the plasma membrane and free of cellular organelles, as visualized by microscopy and marker-enzyme analysis, could be proposed as a useful model membrane system.

Adenocarcinoma↗