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Biomedical subjects

C Zhao

Publications and source records attributed to C Zhao.

251 records · Page 14Linked to original sources
PubMed1992

[Preparation of an anti-human immunotoxin against bladder carcinoma and its in vitro targeting cytotoxicity].

The intact ricin was linked to a monoclonal antibody BD I-1, which recognizes a determinant expressed on two human bladder carcinoma cell lines, BIU-87 and E-J, to form an immunotoxin BD I-1 Ricin. The results of indirect immunofluorescence test, FACS analysis and competition binding assay showed that the binding activity of antibody in this immunotoxin was retained by 80% of the original activity. The in vitro cytotoxicity assay indicated that the immunotoxin in the presence of 0.1 mol/L galactose is potent cytotoxic agent for BIU-87 and E-J cell lines. The immunotoxin BD 1-1-Ricin could kill the target cells BIU-87 and E-J cell lines by 50% at a concentration of 0.00008 mumoI/L and 0.00025 mumol/L respectively. At a concentration of 0.001 mumol/L no apparent cytotoxic activity to human colon carcinoma Lovo cell line was observed.

Antibodies, Monoclonal↗
PubMed1991

Potent HIV-1 protease inhibitors with antiviral activities in vitro.

A series of novel difluoroketones with low molecular weight (less than 600 m.u.) and which are potent inhibitors of the HIV-1 protease (IC50 = 1.0 to 21 nM) were synthesized. These compounds also exhibited antiviral activity by inhibition of the cytopathic effect of HIV-1(3)B in MT-4 cells in vitro.

Antiviral Agents↗
PubMed1990

[Determination of water soluble silicon from herbal drugs].

This article has set up a method for silicon determination by ammonium molybdate-ferrous sulfate-sodium carbonate spectrophotometry. The method is simple, convenient, quick, effective and free of the influence of phosphate ion and reducing agents such as vitamin C and so on. By this method water soluble silicon has been determined in 38 herbal drugs.

Drugs, Chinese Herbal↗
PubMed1990

[An APC composite analysis system for analyzing the cause of perinatal death].

As the cause of perinatal death is multi-factorial and complex, its analysis should be a composite one. The method stated here includes the following: The APC analysis system. A is autopsy, P is placental pathological examination and C is the clinical data. The analysis is based mainly on the diagnosis of autopsy, with the findings of placenta as a non-negligible component part of the autopsy. As for the clinical data, they are both as the start point of the autopsy and the final check for the conclusion drawn from the pathological examination. The analysis procedure of a complex case is given in detail for example. Strictly applying this system, the causes of perinatal death were clarified in 99.3% of 137 cases, and in 98.6% (66/67) of stillbirths. The underlying factors of primary perinatal death are usually neglected, which could be found out as well with this system. For example, the underlying factors inducing intrauterine anoxia of 92.3% of cases (36/39) were determined by using the APC system. The role played by the placental pathological examination in this analysis system is clearly shown and stressed, especially in the stillbirths. The quality of causal analysis of perinatal death is greatly improved by applying the APC analysis system.

Cause of Death↗
PubMed1990

Observations on the treatment of coronary heart disease by kuo guan qu yu ling.

Based on the therory of promoting flow of qi and dispersing blood stasis, the KUO GUAN QU YU LING coronary--dilating and stagnation--dispersing) powder in capsules were prepared for the treatment of 60 cases of coronary heart disease. After a 30 day course of treatment, cardiac ischemia was improved in 64.7% and the symptom of angina pectoris was relieved in 61.7% of the patients. This drug also acted to reduce blood lipids and to improve left cardiac function. Pharmacological study indicated that this preparation improved the tolerance of cardiac muscle against anoxia and prevented ventricular fibrillation and cardiac damage from ischemia.

Adult↗
PubMedDate not supplied

Effects of low-level lead on retinal ganglion sustained and transient cells in developing rats.

Neonatal rats were exposed to lead from parturition to weaning via the milk of dams drinking 0.2% lead acetate solutions. The alterations in the excitability and temporal response properties of retinal ganglion cells in adult rats (90 days) following developmental lead exposure were studied. The results of this investigation demonstrated that the lead exposure in neonatal rats caused an increase in excitability, and a decrease in optimal temporal frequency, bandwidth at half amplitude, temporal resolution, and response phase of the retinal ganglion cells in adult rats. Compared with the sustained cells, the transient cells had a much greater alteration in excitability and temporal response properties.

Action Potentials↗
PubMedDate not supplied

Estimation of the mutation rate during error-prone polymerase chain reaction.

Error-prone polymerase chain reaction (PCR) is widely used to introduce point mutations during in vitro evolution experiments. Accurate estimation of the mutation rate during error-prone PCR is important in studying the diversity of error-prone PCR product. Although many methods for estimating the mutation rate during PCR are available, all the existing methods depend on the assumption that the mutation rate is low and mutations occur at different places whenever they occur. The available methods may not be applicable to estimate the mutation rate during error-prone PCR. We develop a mathematical model for error-prone PCR and present methods to estimate the mutation rate during error-prone PCR without assuming low mutation rate. We also develop a computer program to simulate error-prone PCR. Using the program, we compare the newly developed methods with two other methods. We show that when the mutation rate is relatively low (< 10(-3) per base per PCR cycle), the newly developed methods give roughly the same results as previous methods. When the mutation rate is relatively high (> 5 x 10(-3) per base per PCR cycle, the mutation rate for most error-prone PCR experiments), the previous methods underestimate the mutation rate and the newly developed methods approximate the true mutation rate.

Biometry↗
PubMedDate not supplied

Cryopreservation of axillary buds of grape (Vitis vinifera) in vitro plantlets.

Axillary buds sampled from in vitro plants of four grape varieties could withstand cryopreservation using the encapsulation-dehydration technique. Regrowth percentages ranged between 15 and 40%. Buds were encapsulated in alginate beads containing 0.5M sucrose, precultured at 5 degrees C on media containing daily increasing sucrose concentrations from 0.1 to 1.0M, then desiccated to 21% moisture content (fresh weight basis) and frozen slowly (pre-freezing to -40 degrees C at 0.2 degrees C/min followed by immersion in liquid nitrogen). The physiological state of the in vitro mother-plants and the freezing procedure employed dramatically influenced the results. Regrowth after cryopreservation was achieved only when buds were sampled from mother-plants that had been kept without subculture for 3 to 4 months. An additional one-month period of cold-acclimation of mother-plants at 5 degrees C and a two-step freezing procedure improved growth recovery. The multiplication rate of shoots produced from cryopreserved buds was lower than that of controls during the first subcultures after thawing. However, the rooting ability of control and cryopreserved plantlets became similar from the fourth subculture onwards.

Cryopreservation↗