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Biomedical subjects

S Zhao

Publications and source records attributed to S Zhao.

At least 253 records · Page 14Linked to original sources
PubMed1999

Studies on renin-2 gene in transgenic rats.

OBJECTIVE: To determine the function of, in vivo, renin and its role in the pathogenesis of hypertension. METHODS: A renin-2 gene restriction map was constructed by endonuclease digestion and Southern blotting hybridization. Transgenic rats were produced via microinjection method. RESULTS: The 24 kb fragments containing mouse full-length ren-2 and its flanking sequence were cleaved by single enzymes (EcoR I, Kpn I and BamH I) and combined enzymes (EcoR I/Kpn I, Kpn I/BamH I and BamH I/EcoR I), respectively. The digests were electrophoresed in 0.8% agarose plates and transferred onto NC membranes. Radioactive 735 bp and 1400 bp probes obtained from half and full-length renin-1 cDNA were used in southern blotting hybridization. According to the electrophoresis and hybridization patterns, a ren-2 restriction map was constructed. 1603 fertilized rat ova after injection with purified 24 kb renin-2 gene were implanted into the oviducts of 81 pseudopregnant recipients in about 20 ova per female rat. 306 progenies were obtained from 50 foster mothers (average of pregnancies was 56.6%). 248 survived pups were identified by PCR analysis and Southern hybridization, and eight positive rats were found to be the transgenic rats (founder, F). All of them carried long fragments (24 kb) of renin-2 gene with normal blood pressure. Preliminary breeding and screening were carried out in the founder. Total survival pups (17.8%) and overall efficiencies (1%) were harvested as the same as those reported in the literatures. A systemic observation and the problems occurred during production of transgenic rats were also described besides the technique procedure used in this study. CONCLUSIONS: Mapping of full-length murine ren-2 can be used in investigation of the structure and function of the gene. The results denoted that the ren-2 transgenic rats were successfully established in this study and the technique used in the production of transgenic rats was proved to be valid in leading to wide-spread application of transgenic technique to many other related researches.

Animals↗
PubMed1999

A diagnostic kit to screen individuals with glucose-6-phosphate dehydrogenase defect and its application on anti-malaria spot in the countryside.

OBJECTIVE: To prepare a kit for screening individuals with glucose-6-phosphate dehydrogenase (G6PD) defect. The kit is easy to use and to get the fast as well as reliable results. Especially it is suitable for the anti-malaria spots usually located in the remote countryside where no electricity is available. METHODS: The double filter paper method and other 2 techniques, the quantitative method and the single filter paper method, were used to determine G6PD activity in 70 samples of human erythrocytes. It was found that the results of the double filter paper method and those of the single filter paper method in the first 8 hours after the drying of the blood-soaked filter paper were consistent with those of the quantitative method. When a piece of blood-soaked paper is left under room temperature more than 24 hours, G6PD in the erythrocytes deteriorated spontaneously and consequently the number of positive cases increased along with the elapse of time. RESULTS: Satisfactory results were achieved when the kit was used to screen cases of G6PD defect from 151 farmers who were receiving anti-malaria therapy. The kit was made according to a technique named "double filter paper" method. CONCLUSIONS: These findings suggest that the double filter paper method can reveal the level of G6PD activity and the results are rapidly obtained when the method is used on the anti-malaria spot.

Anemia, Hemolytic↗
PubMed1999

[A study on the relationship between lymphocyte micronucleus rates and blood plasma benzo(a)pyrene levels in coking workers].

OBJECTIVE: To study the relationship between lymphocyte micronucleus rates and blood plasma levels of benzo(a)pyrene [B(a)P] in coking workers. METHODS: One hundred coking workers and 100 unexposed workers were selected, and their lymphocyte micronucleus rates and plasma levels, as well as workplace air concentrations, of B(a)P were determined. RESULTS: It showed that there was significant difference in plasma B(a)P level between coking workers and unexposed workers, and it correlated with air concentration of B(a)P in the workplace. Positive rates of micronucleus and rates of micronucleus lymphocyte were 60% and 1.79per thousand in coking workers and 29% and 1.10per thousand in controls, respectively, with very significantly statistical difference. It also showed that positive micronucleus rate correlated with plasma level of B(a)P in dose-effect pattern. Multivariate analysis showed that factors contributing to positive micronucleus rate ranked in such an order: plasma level of B(a)P, economic status, regularity of their lifestyle and smoking status of the coking workers. CONCLUSION: Accumulation of B(a)P in blood plasma played a major role in the formation of lymphocyte micronucleus. Results of micronucleus test in coking workers could reflect preliminary damage to their health caused by it.

Adult↗
PubMed1999

[Relationship of age, sex, body weight, smoking, blood lipids and fibrinolytic activities in healthy subjects].

Relationship of plasma activities of tissue-type plasminogen activator (tPA) and plasminogen activator inhibitor-1(PAI-1) with age, sex, body weight, smoking, blood lipids were studied in 131 healthy subjects. The results demonstrated that plasma PAI-1 activity increased with age and body weight. PAI-1/t-PA ratio was higher in smoking than in non-smoking subjects. With multivariate analyses, plasma PAI-1 activity was positively correlated with age, body weight index(BMI) in males, and positively correlated with low-density-lipoprotein-cholesterol(LDL) in females, and negatively correlated with plasma tPA activity. Plasma triglyceride, high-density-lipoprotein-cholesterol did not show a correlation to PAI-1 or tPA activity. It is indicated that age, BMI, blood lipids may contribute to moderate fibrinolytic activities and that smoking may affect fibrinolytic function.

Adult↗
PubMed1999

[Serum lipids, lipoprotein and stroke].

The serum levels of lipids and lipoproteins were measured in 180 consecutive patients with acute stroke(90 hemorrhagic stroke, 90 ischemic stroke) and 107 age- and sex-matched controls. As compared with the control group, hemorrhagic group had lower levels of total cholesterol(TC) (P < 0.05), low density lipoprotein-cholesterol(LDL-C) (P < 0.01) and Lp(a) (P < 0.05) while the ischemic group had higher serum TC(P < 0.05), LDL-C(P < 0.01), Lp(a) (P < 0.01) and lower high density lipoprotein-cholesterol(HDL-C) (P < 0.05) and ApoAI(P < 0.01). Multiple factor logistic regression showed that cigarette smoking, hypertension and family history of stroke were the common risk factors for both hemorrhagic and ischemic stroke, and that lowered TC and elevated LP(a) levels were independent risk factors for hemorrhagic stroke and ischemic stroke respectively.

Adult↗
PubMed1999

[Apolipoprotein E polymorphism and plasma lipid, lipoprotein, apolipoprotein levels in 291 children of Changsha].

In order to investigate the distribution of apolipoprotein (Apo) E polymorphism and effect of ApoE genotypes on plasma lipid, lipoprotein, apolipoprotein levels in children of Changsha, we determined ApoE genotypes in 291 children by means of PCR-RFLP. ApoE allele frequencies in the population were epsilon 2 = 0.081, epsilon 3 = 0.857, epsilon 4 = 0.062. There were no difference in the ApoE genotypes distribution between sexes. The children with Apo epsilon 2 allele had higher levels of ApoE, ApoA1 and high density lipoprotein-cholesterol together with lower levels of total cholesterol, ApoB100 and low density lipoprotein-cholesterol than those with other ApoE alleles. These changes were opposite in children with Apo epsilon 4 allele. The levels of plasma triglyceride, lipoprotein(a) were not affected significantly by ApoE alleles. Moreover, the effect of ApoE genotypes on levels of plasma lipids was different between sexes. These results suggest that ApoE polymorphisms could affect plasma lipids metabolism in children.

Adolescent↗
PubMed1999

[Chemical constituents of fruits of Gardenia sootepensis Hutch].

OBJECTIVE: To demonstrate the chemical constituents of the fruits of Gardenia sootepensis. METHOD: Column chromatographic technology was employed to separate the water soluble part, and the compounds obtained were elucidated by spectral and chemical analysis. RESULT: Ten compounds have been isolated, seven of which elucidated respectively as D-mannitol, beta-sitosterol, deacetylasperulosidic acid methyl ester, geniposidic acid, geniposide, scandoside methyl ester and dimeric molecule of quinide. CONCLUSION: All the compounds were obtained from this plant for the first time.

Drugs, Chinese Herbal↗
PubMed1999

[Plasma Lp (a) levels and correlation of Lp (a) with fibrinolysis activation in chronic renal failure].

Plasma Lp (a) concentration and activation of tissue-type plasminogen activator (t-PA) and plasminogen activator inhibitor-1(PAI-1) were determined in 50 patients with chronic renal failure (CRF) and in 50 healthy subjects. The results demonstrated that plasma concentration of Lp(a) was significantly higher and plasma t-PA activation was significantly lower in CRF patients than in healthy subjects. With multivariate analyses, plasma Lp(a) concentration was positively correlated with the total amount of 24 h uric protein, plasma BUN and uric protein concentration. Moreover, a negative significant correlation between plasma Lp(a) levels and t-PA activation was observed. Plasma Lp(a) levels did not show a correlation to PAI-1 activation. It is indicated that renal function may contribute to moderate plasma Lp(a) concentration and elevated Lp(a) levels may be related with fibrinolytic impairment.

Adult↗
PubMed1999

[Ultrastructural changes after space flight in Platycodon grandiflorum (Jacq.) DC].

OBJECTIVE: To substantiate the effect of space conditions on medicinal plants. METHOD: The seeds of platycodon grandiflorumg were set up in retrievable satellites. After returning to earth, the ultrastructural changes of leaves were studied. RESULT: Under light microscope, the leaf tissue structure of the flight group and the earth controlled group were alike and under electron microscope, some differences could be found in the nucleus and choloroplasts between the two groups. CONCLUSION: Space environment has some effect on Platycodon grandiflorum, and the effect needs to be further explored.

Cell Nucleus↗
PubMed1999

[Studies on the effects of space flight on Carthamus tinctorius L].

OBJECTIVE: To substantiate the effects of space condition of medicinal plants. METHODS: The seeds of Carthamus tinctorius were sent to space in retrievable satellites. After returning to earth, the seeds were stored at 0-4 degrees C, and cultured in the test field in the spring of next year. The peroxidases, soluble proteins and ultrastructure of leaves were studied in flowering stage. RESULTS: The peroxidase activity of the flight group was lower than that of the earth controlled group, and the protein content of the flight group was higher than that of the earth controlled group. The main bands in electrophoresis patterns of peroxidases and proteins were alike, and some bands were different. Some changes could be observed in the ultrastructure of chloroplast between the flight group and the earth controlled group. CONCLUSION: Space environments have some effect on Carthamus tinctorius. The results of this experiment are consistent with those of the previous experiment.

Carthamus tinctorius↗
PubMed1999

[A study on chemical composition of Gardenia sootepensis Hutch--quantitative determination of iridoid compounds by RP-HPLC].

OBJECTIVE: To determine the iridoid contents in Gardenia sootepensis. METHODS: Using RP-HPLC with geniposidic acid, geniposide and scandoside methyl ether as standards. RESULT: According to the selected chromatographic conditions, the linear ranges of geniposidic acid, geniposide and scandoside methyl ether were 0.097-0.606 microgram, 0.0638-3.990 micrograms and 0.198-1.239 micrograms, respectively. The average recoveries of these three compounds were 100.0%, 99.9% and 100.1%, and RSD 1.23%, 1.38% and 1.53% (n = 5) respectively. CONCLUSION: The method is easy, rapid, and reproducible.

Chromatography, High Pressure Liquid↗
PubMed1999

[Research on anti-thrombosis effect of ethanol extract from beheaded leech (EEBL)].

OBJECTIVE: To study the anti-thrombosis effect of EEBL and its possible mechanism. METHOD: Using a thrombosis model induced by collagen-adrenaline in mice and an artery-vein bypass in rats. The effect of EEBL on erythrocyte membrane and thrombocyte membrane fluidity were measured by fluorescence polarization. RESULT: EEFL inhibited the thrombosis induced by collagen-adrenaline in mice and the thrombosis in artery-vein bypass in rats significantly. EEBL also enhanced in vitro erythrocyte membrane fluidity and thrombocyte membrane fluidity markedly. CONCLUSION: The anti-thrombosis effect of EEBL may possibly be associated with the enhancement of fluidity of erythrocyte membrane and thrombocyte membrane. There exist anti-thrombosis chemical constituents in the body of beheaded leech.

Animals↗
PubMed1999

[Effect of space flight on ultrastructure in medicinal plant Datura innoxia Mill].

OBJECTIVE: To substantiate the effect of space environment on medicinal plants. METHOD: The seeds of Datura innoxia were set up in retrievable satellites. After returning to earth, the ultrastructural changes were observed by means of electron microscope. RESULTS: In cells of weightless group and hit group, some changes were found in chloroplast grana, starch grains and vesicles in chloroplasts. No obvious changes were observed in nuclei. CONCLUSION: Space environment has some effect on the ultrastructure in D. innoxia, and chloroplast is more sensitive to space environment than other organs.

Chloroplasts↗
PubMed1999

[Cell proliferation and programmed cell death in tooth development].

OBJECTIVE: To evaluate the role of cell proliferation and programmed cell death (PCD) in the tooth development by detecting programmed cell death and expression of proliferating cell nuclear antigen (PCNA). METHODS: Expression of PCNA and PCD were detected by immunohistochemical staining and Tdt-mediated dUTP nick end labelling (TUNEL) in different stages of the tooth development of Sprague-Dawley rats. RESULTS: The positive cells of PCNA and PCD predominantly appeared at the proliferating growth center in the bud, the cap and the earlier bell stages of tooth development. PCNA and PCD were also observed in ameloblasts and odontoblasts, especially in the stellate reticulum cells of enamel organ and dental papilla during the period of dentin formation. CONCLUSION: Cell proliferation and programmed cell death are interrelated and interact on each other in the development of teeth, and they both involve in sculpturing the shape of teeth.

Animals↗
PubMed1999

[Observation on the immune function of circulating red cells of patients with periodontal diseases].

OBJECTIVE: To find out the relation between the causes of periodontal diseases and the immune function of red blood cells (RBC). METHODS: The functional state of SOD activity, red blood cell C3b receptor rosstte (C3bR), red cell immune complex rosstte (RBCICR), RBC immune adherence enhance factor (RFER) and RBC immune adherence inhibitor factor (RFIR) of red cells from the systemic circulation of patients with periodontal diseases were determined and compared with the normal control group. RESULTS: The SOD activity C3bR and RFER of red cells were lower, while RFIR and RBCICR were higher for patients with periodontal diseases comparing to the normal control. CONCLUSION: It indicates that the compromised function of red cells may contribute to the initiation and development of periodontal diseases.

Adult↗
PubMed1999

[Best minimization to locate the brain sources of magnetic waves].

Locating the sources of brain magnetic fields is a basic question in magnetoencephalography (MEG). This question belongs to the indeterminate problem, that is, infinite solutions can be obtained from the equations of the measured small magnetic fields on the detector. Therefore a model of mathematics is needed to give more information. The major models of mathematics are the search method with many dipoles and the Lp minimum norm method. For the first model, if a global search is used, too much calculation time will be spent; if the gradient search is used, the searches usually converge to a local minimun. So other methods are introduced to find out the initial values, and then the gradient search can be used. For the second model, the depth of the brain sources will dependend on the choice of the weight functions which have several different types, and we do not know in advance which type is correct, so that it is difficult to have a good estimation of the depth of the brain sources. To overcome the difficulties, we use the method with three object functions which are the minimum Lp norm, the deviation between the calculated magnetic fields and the measured magnetic fields, and the number of the sources. This method is similar to the minimum norm method, a weight function is also introduced. But this weight function contains many reference variables which have to be determined through the minimization with three object functions. By choosing suitable weight function and its reference variables, the correct estimation of the depth of the brain sources can be achieved.

Algorithms↗
PubMed1999

[A comparative study of finger plethysmography and aortic pressure for monitoring the effect of external counterpulsation].

Invasive pressure detecting and monitoring of aortic root was conducted in 20 volunteers so as to study the effect of Enhanced External Counterpulsation (EECP) on aortic pressure and finger plethysmography. The results demonstrated that the changes of aortic diastolic pressure linearly related to the counterpusation's bladder pressure, and the aortic augmentation increased to the top of 168.56 mmHg with a D/S ratio of 2.75(amplitude ratio of diastolic waveform and systolic waveform, D/S ratio) following the bladder pressure of 0.45 Kg/cm2. With the increase of bladder pressure, the dp/dt of aortic augmentation elevated gradually, but a down-regulating trend was seen in systolic waveform. During EECP, the starting time of plethysmographic augmentation had a mean delay of 108.20 +/- 25.70 ms comparing with that of aortic augmentation. The duration between the starting time of aortic systolic waveform and that of finger plethysmogram was arround 96.69 +/- 38.70 ms. When the bladder pressure changed, no significant difference was observed among them. The D/S ratio of finger plethysmographic waveform changed in concord with that of aortic pressure with the promotion of bladder pressure. Therefore, a relationship between aortic D/S ratio (Y) and plethysmographic D/S ratio (x) was constructed by the linear regression analysis: Y = 0.376 + 0.457X. It can be concluded that EECP has significant effects on aortic D/S ratio, aortic peak augmentation and its dp/dt value. Finger plethysmography, to date, still plays important roles in monitoring and controlling EECP work safely and effectively.

Adolescent↗