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Q S Zheng

Publications and source records attributed to Q S Zheng.

11 recordsLinked to original sources
PubMed2002

Effects of ascorbic acid and sodium selenite on growth and redifferentiation in human hepatoma cells and its mechanisms.

After being treated with ascorbic acid (AA) 3 mM + sodium selenite (SS) 1.5 microM, the growth rate and mitotic index of human hepatoma cells BEL-7402 decreased remarkably. The indexes related to cell malignancy were improved, such as cell surface charge obviously decreased, the electrophoresis rate fell from 1.76 microns.s-1.V-1.cm-1 to 0.93, the average of alpha-fetoprotein (alpha-FP) content decreased from 341 micrograms.g-1 protein to 92, and gamma-glutamyl-transpeptidase (gamma-GT) activity from 0.76 U.g-1 protein to 0.19. The indexes related to cell differentiation were affected favourably, such as the level of tyrosine-alpha-ketoglutarate transaminase (TAT) activity increased from 14.2 mumol.g-1 protein to 49.0, and the colonogenic potential decreased 95.3%. These results indicated that hepatoma cells had been successfully induced to redifferentiation by AA + SS. The activities of superoxide dismutase (SOD) and glutathione peroxidase (GPX) were significantly higher, while the activity of catalase (CAT) was slower in the treated group than in the control group. The malondialdehyde (MDA) content decreased slightly, reduced glutathione (GSH) decreased sharply, and H2O2 content increased dramatically. In conclusion, these results indicate that the combination of ascorbic acid and sodium selenite may induce the redifferentiation of hepatoma cells and inhibit cell growth by virtue of enhancing the activities of antioxidative enzymes and reducing the formation of H2O2, and altering the cell redox status. The combination of ascorbic acid and sodium selenite may be a potent anticancer treatment option for human hepatoma cells.

Antioxidants↗
PubMed2002

Ascorbic acid induces redifferentiation and growth inhibition in human hepatoma cells by increasing endogenous hydrogen peroxide.

The mechanisms of redifferentiation and growth inhibition induced in human hepatoma cells by ascorbic acid (AA) were studied. After treatment with AA, the content of hydrogen peroxide (H2O2) and the activity of superoxide dismutase (SOD) increased in a concentration- and time-dependent manner, while the activity of catalase (CAT) decreased in a concentration- and time-dependent manner. Using 6 mM AA as a positive control, after treatment by 50 microM hydrogen peroxide, the malignant characteristics of human hepatoma cells were alleviated; for example as cell surface charge markedly decreased, the electrophoresis rate dropped from 1.68 microns.s-1.V-1.cm-1 to 0.97, the average of alpha-fetoprotein content decreased from 327 micrograms.g-1 protein to 193, and gamma-glutamyl-transpeptidase activity fell from 0.84 U.g-1 protein to 0.30. The indexes related to cell differentiation were promoted, such as tyrosine-alpha-ketoglutarate transaminase activity increased from 17.1 mumol.g-1 protein to 33.1, and the colonogenic potential decreased by 79.3%. SOD and 3-amino-1,2,4-triazole (AT) exhibited some effects, but there were statistically significant differences between the SOD, AT and H2O2 or AA groups. AA induced growth inhibition and redifferentiation of human hepatoma cells through the production of hydrogen peroxide, since addition of SOD (200 units/ml), an enzyme that dismutates superoxide and generates hydrogen peroxide, and AT (1.5 mM), a CAT inhibitor that inhibits the activity of CAT and leads to an increase in H2O2 content, showed some inducing changes emphasizing the involvement of reactive oxygen species (ROS) in redifferentiation of hepatoma cells. AA can cause the content of H2O2 to increase, and the factor H2O2 showed a similar effect to AA on growth and redifferentiation suggests that H2O2 is involved in hepatoma cell redifferentiation. In conclusion, these results suggest that AA inhibits tumor growth and induces tumor redifferentiation by virtue of producing H2O2.

Amitrole↗
PubMed2001

Quantitative design of optimal analgesic combination of acetaminophen, caffeine, and butalbital.

AIM: To quantitatively seek an optimal analgesic combination of acetaminophen (Ace), butalbital (Bul), and caffeine (Caf), and to characterize the pharmacodynamics of interaction among the three drugs. METHODS: The models of acute inflammatory pain in carrageenin-injected rats were applied to measure the vocalization threshold to paw pressure. Six groups with different ratios and doses were set to seek an optimal combination of Ace, Caf, and Bul, analyzed by the weighted modification method. Based on the ratio and doses in the optimal combination, four continuous doses were set to analyze the interactions of therapeutic effects by the reflection method. The interaction of the acute toxicity was evaluated by the parameter method. RESULTS: According to the degree of importance to the combined analgesic effect, Ace > Caf > Bul; Ace showed a significant dose-response relationship, whereas in Caf and Bul, this relationship was not apparent. A new combination was obtained by the theoretical analysis and confirmed further by experimentation. Namely, at a ratio of 8.6:1:1.5 Ace + Caf + Bul (240 + 28 + 42 mg/kg, ig) was an optimal combination. Both Caf and Bul had a synergism to Ace, but Caf was a stronger synergist in contrast to Bul. Such synergism increased the therapeutic effects in the range of Ace 153.6 - 300 mg/kg combined with Caf 17.9 - 35 mg/kg and Bul 26.8 -5 2.5 mg/kg (8.6:1:1.5). However, the dose of Ace + Caf + Bul at 300 + 35 + 52.5 mg/kg resulted in sedation in rats. The peak latency was approximately 1 h for all four continuous doses, but the peak amplitude was dose-related, and the duration of the therapeutic effect was less than 2 h. The acute toxicity of the three drugs in combination remained the same. CONCLUSION: Ace + Caf + Bul at a dose of (240 + 28 + 42) mg/kg (ig) results in an optimal combination. The therapeutic window of the combination is located in the range of Ace (153.6 - 240 mg/kg)+Caf (17.9 - 28 mg/kg)+Bul (26.8 - 42 mg/kg) (8.6:1:1.5). Caf has a stronger synergism with Ace than Bul.

Acetaminophen↗
PubMed2000

Analysis of drug interactions in combined drug therapy by reflection method.

AIM: To set up a new method to analyze multidrug interaction in combined drug therapy. METHODS: Based on a dose-effect curve of the combined drugs and the equieffective test, a new mathematical model was set as Q = (Eo - Et)/L (-1 < Q < 1 addition, Q < or = 1 antagonism, Q > or = 1 synergism) where Eo = an observed value (or its fitted value) of combined effect, Et = an expected value of combined effect, and L = an equieffective cutoff between Eo and Et, decided by the equieffective criterion of a special field, the number of data points, and the experimental error. The different types of experimental data were analyzed by the new model. RESULTS: This reflection method could deal with data in combined drug therapy, unnecessary to distinguish between independent and similar action, or exclusive and non-exclusive case among drugs. The number of drugs for combination did not need to be limited. But the experimental data should be enough to fit a dose-effect curve of drugs in combination. If every dose-effect curve of drugs for combination was made, a series of Q values was obtained from all levels of dose-effect for a systematic analysis. To large animal or human experiment, the points of dose-effect of each drug used alone could be reduced to even 1 point. The results of analysis took the criterion of a special field and laboratory error into account in this method. CONCLUSION: The reflection method is an effective method for analysis of multidrug interaction in combined drug therapy.

Animals↗
PubMed1999

The unvalidity of Kohlrausch' regulating function for Svensson's isoelectric focusing and stationary electrolysis at steady state.

Kohlrausch' regulating function is of important significance in the field of electrophoresis. In this paper, the relative regulating function is defined from Kohlrausch' regulating function. The relative values, including the limited values, of the regulating function for the stationary electrolysis of salt, on which the classic isoelectric focusing (IEF) is based, are computed and compared with the computer program of the QBASIC written by us. The results directly demonstrate that, (1) in a few cases the regulating function is valid for the stationary electrolysis and IEF, whereas (2) the function is, in most of cases, not valid for the stationary electrolysis and IEF at steady-state. Those findings may be useful for the studies on the relationships between Kohlrausch' regulating function and IEF and for the classification of numerous electrophoretic techniques.

Electrolysis↗
PubMed1999

Quantitative design of drug compatibility by weighted modification method.

AIM: To set up a new method for designing and quantitatively analyzing drug compatibility. METHODS: Drugs for compatibility were divided into 6 dose levels which were evenly distributed to 6 compound groups according to a fixed design. A new mathematical model was set up to fit the dose-effect data of 6 groups. The coefficients, obtained from the model, reflected the dose-effect relationship and the important degree of every drug in combination. According to the coefficients, the drugs in compatibility could be distinguished into principal drug, synergist, inferior, antagonist, and assistant. Because compatibility in the maximal effect group was nearly (or was) an optimal one in 6 groups, the doses in the group were taken as a base for further modification which considered interaction among drugs. The results of the modification were demonstrated by further experiment. This method was applied to design and to quantitatively analyze the compatibility of allantoin, metronidazole, and dexamethasone sodium phosphate by 2 effect indices in mice. RESULTS: This new method was able to effectively determine important degree of drugs in combination, and to optimize their doses for designing compatibility. CONCLUSION: This weighted modification method is a highly efficient, accurate, and practical means for designing and quantitatively analyzing drug compatibility.

Allantoin↗
PubMed1998

Analysis of multidrug effects by parameter method.

AIM: To set up a new analytic method for multidrug effects. METHODS: Based on the principles of the target site kinetics and the equieffective test, a new mathematical model was set as Q = (Eo-Ee)/magnitude of Ee x W-sx x T (-1 < Q < 1 addition, Q < or = -1 antagonism, Q > or = 1 synergism) where Eo = a fitted value of the observed effect of a combination, Ee = an expected value of combined effect, W = an equieffective criterion decided by a special field, sx = a common standard error of Eo and Ee, and T = a value of one-sided t0.05. All the calculations were completed with computer. Dose-effect data from different types of experiments were fitted by the new model and the results were compared with those of other methods. RESULTS: This parameter method dealt with different types of data well fitted with the Hill equation, and was not limited to analyze receptor interaction of drugs, or the number of combined drugs. A series of Q values was obtained from all levels of dose-effect for a systematic analysis. The analysis took the criterion of a special field and laboratory error into account. CONCLUSION: This parameter method can effectively analyze the multidrug effects.

Acetylcholine↗
PubMed1997

Analysis of social factors and human behavior attributed to family distribution of schistosomiasis japonica cases.

An investigation of family distribution patterns of schistosomiasis japonica was carried out in four pilot villages in Yunnan Province. Family clustering of the disease was present in Bihuayuan Village before and after economic reform (site A); however, such clustering did not occur in Tuanshan and Liantie Villages (sites B and C) in the same periods. Being contrary to the stage prior to economic reform family clustering existed in Zhonghe Village (site D) after the reform. The results obtained from single- and multifactor analysis showed that the main human behavior related to family distribution of schistosomiasis in mountainous regions of Yunnan Province included the frequency of laborer migration, contact with cercariae-infested water in public places or family microenvironments with a high transmission potential, promiscuous defecation and status of cattle grazing. The frequency of laborer migration and human contact with cercariae-infested water in public places in sites B and C without family clustering was higher than that in sites A and D with family clustering. Place for promiscuous defecation and cattle grazing in site A converged compared with that in sites B and C.

Animals↗
PubMed1997

Influence of livestock husbandry on schistosomiasis transmission in mountainous regions of Yunnan Province.

An investigation was conducted in the highly endemic areas of schistosomiasis japonica in Weishan and Eryuan counties, Yunnan Province. The results are summarized as follows: 1) the number of domestic animals was increasing annually; 2) the proportion of animal husbandry gains in the total agriculture income had a yearly escalating tendency; 3) the infection rate of inhabitants was upgrading as a result of the development of and the prevalence in domestic animals in the recent decades. Owing to frequent migration of domestic animals, serious spread of infection sources and high prevalence of schistosomiasis japonica occurred. It is suggested that more attention should be paid to the control of schistosomiasis japonica in mountainous endemic regions during the course of economic development, especially in the development of domestic animals.

Agricultural Workers' Diseases↗