Search PubMed⌕ Search

Biomedical subjects

Y Chen

Publications and source records attributed to Y Chen.

At least 1,261 records · Page 70Linked to original sources
PubMed1999

[Apoptosis of HL60 cells induced by inhibition of bcl-2 with antisense phosphorothioate oligodeoxynucleotides].

OBJECTIVE: To observe the effects of different bcl-2 antisense phosphorothioate oligodeoxynucleotide (ASPO) concentrations in inducing apoptosis of HL60 cells. METHODS: Signs of apoptotic cells were detected by acridine orange staining, transmission electron microscope, flow cytometry and DNA fragment electrophoresis. RESULTS: In presence of ASPO, the apoptosis of HL60 cells could be induced after 24 hours of incubation. The apoptosis rate at ASPO 5, 10 and 20 micromol/L were (9.67 +/- 2.16)%, (18.25 +/- 3.01)% and (23.42 +/- 2.75)% respectively. There was a statistically significant increase in apoptosis as the dose of ASPO increased. After incubation for 72 hours, the apoptotic rates of the 3 different ASPO concentration groups were (9.58 +/- 2.96)%, (29.58 +/- 4.04)% and (36.33 +/- 3.66)% respectively, of which the apoptic rate of HL60 cells incubated with ASPO 5 micromol/L was highest at 48 hours. CONCLUSION: Bcl-2 ASPO can specifically induce apoptosis of HL60 cells. Its effect depends upon the concentration of ASPO.

Apoptosis↗
PubMed1999

[Improved method of obtaining medial plantar cutaneous graft and its clinical application].

OBJECTIVE: To introduce a skin flap containing the middle cutaneous branch of the medial plantar artery. METHODS: Microanatomic study was performed on 8 fresh cadaveric feet, the arteries were dissected and infused with methylene blue to observe their vascular distribution and the skin area supplied by the middle cutaneous branch. Furthermore, the clinical application was reported. A local pedicled flap containing the middle cutaneous branch was used to repair the soft tissue defects of the foot in 7 patients, and free cutaneous graft was used to repair the skin defects of the fingers in 6 patients. RESULTS: The results showed that the medical plantar artery gave off 3 cutaneous branches to supply the medial aspect of the foot, among which the middle branch was the largest one and anastomosed with the other two branches. The skin flaps used clinically were all survived completely. CONCLUSION: Medial plantar cutaneous graft had a reliable blood supply, and it's one of the best choice in repairing small to middle sized skin defects of the foot and the fingers.

Adolescent↗
PubMed1999

[Chemical constituents of Saururus chinensis (Lour.) Bail].

OBJECTIVE: To search for the active chemical constituents of Saururus chinensis. METHOD: 95% ethanol extracts from the aerial part of Saururus chinensis was mixed with silica gel, and then eluted with petroleum ether, ethyl acetate and methanol. On the basis of physicochemical properties and spectroscopic analysis, structures of the compounds obtained were identified. RESULTS: Eight compounds were isolated from the ethyl acetate and methanol parts, and identified as aristolactam A II(I), daucosterol(II), hyperoside(III), isoquercitrin(IV), quercitrin(V), quercitin-3-O-beta-D-glucopyranosyl(1-->4)-alpha-L-rhamnopyranoside(VI), ellagic acid(VII) and corilagin(VIII) respectively. CONCLUSION: Compounds I, II, VI, VII and VIII were found from this plant for the first time.

Ellagic Acid↗
PubMed1999

[Effects of Chinese patent medicine tongfugushen on adenine-induced chronic renal failure in rats].

OBJECTIVE: To observe the effects of Tongfugushen(TFGS) on adenine-induced chronic renal failure in rats. METHODS: The model of chronic renal failure was made by feeding rats with food containing 0.5% adenine. Two weeks later, along with the above food, the treated group was administered the Chinese patent medicine TFGS, and the control group was given NS. Blood tests including urea nitrogen(BUN), serum creatinine(Scr), red blood cell(RBC), hemoglobin (Hb), hematocrit(HCT) and renal pathological tests were performed at the end of the fourth week. RESULT: In the TFGS treated group, the mean levels of BUN and Scr were lower and the mean values of RBC, Hb and HCT were higher than those in the control group, and the deposited crystals of adenine metabolite and the proliferation of fibroid tissue in kidney were decreased. CONCLUSION: TFGS is helpful in improving the symptoms of chronic renal failure in rats.

Adenine↗
PubMed1999

[Studies on Chinese drugs zhiqiao and zhishi origin investigation and merchandise identification].

OBJECTIVE: To sort out the main original plants of Chinese drugs Zhiqiao and Zhishi. METHOD: Investigating the medicinal plant resources in the growing area and conducting morphological identification of more than 40 pieces of these two commercial drugs. RESULT: A taxonomic table, a distribution table and a commercial drug identification table are given. CONVLUSION: The Chinese medicinal plants Zhiqiao and Zhishi originated from Citrus aurantium and its varieties C. aurantium "Xiucheng", C. aurantium "Xiangcheng" and Poncirus trifoliata x C. aurantium, some other plants from Citrus genus and Poncirus trifoliata are taken as the origin of Zhiqiao and Zhishi only in a few areas.

China↗
PubMed1999

[Studies on chemical constituents of Forsythia suspensa (Thunb) Vahl].

OBJECTIVE: To study the chemical constituents of Forsythia suspensa. METHOD: Basedon silicacolumn chromatography, of which six compounds were obtained from the alcohol extract of F. suspensa, three identified by physicochemical and spectroscopic analyses. RESULT: The three compounds were identified as stearic acid, palmitic acid and beta-sitosterol. CONCLUSION: The three compounds were separated from F. suspensa fruits for the first time.

Forsythia↗
PubMed1999

[Infrared spectral identification of rhizoma Corydalis and rhizoma Corydalis repentis].

OBJECTIVE: To study the IR spectra of Rhizoma Corydalis and Rhizoma Corydalis Repentis. METHOD: The petroleum ether, ethyl ether and water extracts obtained by the same isolating procedure from Rhizoma Corydalis and Rhizoma Corydalis Repentis were determined by IR spectrophotometry. RESULTS: The IR spectral evidences of the two samples showed distinct characteristics and good repeatability. CONCLUSION: The IR spectral evidences can be used to differentiate Rhizoma Corydalis and Rhizoma Corydalis Repentis.

Corydalis↗
PubMed1999

[The RYR1 genotype of the pigs from Neijiang of China].

The aim of this study was to test the RYR1 genotype of 25 Neijiang pigs ao as to provide data for the selective breeding of medical experimental pig strains. PCR-RFLP technique was used. The results showed that the RYR1 genotype of all the 25 porcine cases was HALNN and all of the 25 porcine cases were Halothane Negative. These suggested that Neijiang pig could be one of the porcine strains selectively bred for medical experiments and clinically for pig-to-human xenotransplantation. PCR-RFLP technique is a reliable and simple method for RYR1 gene testing.

Animals↗
PubMed1999

[Random amplified polymorphic DNA analysis on Curcuma wenuujin and C. sichuanensis].

OBJECTIVE: To discuss the problem of classifying Curcuma for Medical purposes. METHOD: RAPD was used to detect the DNA polymorphism within and among Curcuma wenyujin, C. sichuanensis and C. aromatica. RESULT: It is hard to differentiate between C. wenyujin and C. sichuanensis from the DNA level. The relationship between C. wenyujin and C. aromatica was also analyzed. CONCLUSION: Based on the morphological and chemical data, it is suggested that these two species should be combined into one and that classification based on peduncle central or peduncle lateral may not be right. This method will help to some degree to solve the problem of certifying the medicinal plant Curcuma.

Curcuma↗
PubMed1999

[Chemical composition of Fordia cauliflora Hemsl].

OBJECTIVE: To study chemical constituents of the root of Fordia cauliflora. METHOD: Three compounds were obtained from the ethanolic extract of the roots of F. cauliflora by silica column chromatography, and identified by physico-chemical and spectroscopic analysis. RESULT: The compounds were identified as stearic acid, palmitic acid and beta-sitosterol. CONCLUSION: These compounds were obtained from this plant for the first time.

Fabaceae↗
PubMed1999

[Study of relative factors which influenced the embolic level of microspheres in the hamster lingual carcinoma].

OBJECTIVE: To study the relative factors which influence the embolic level of microspheres in the hamster lingual carcinoma. METHODS: Micropicture analysis instrument was used to measure the embolic level of microspheres which were poured through ascending aorta. RESULTS: The optimum pressure of embolization was 30 kPa. The embolic level approached to remote site of the lingual artery as tongue cancer developed. In early invasive cancer period, the embolic level of microspheres was at arteriole level where microspheres block "the total values" which controlled the tumor microcirculation. The optimum embolic result and less offshoot microcirculation were obtained at this time. When in later period, microspheres mainly embolized the meta-arteriole. As the microvessels dilated, the dose of microspheres must be increased to get the best embolic result. CONCLUSION: The experimental data for clinical choice of optimum pouring pressure, optimum opportunity and optimum cases.

Albumins↗
PubMed1999

[The effects of fluoride on the bonding strength of brackets].

OBJECTIVE: To evaluate the effect of using fluoride during and after etching on the bonding strength of brackets. METHODS: 45 extracted human premolar were divided into three groups: Group 1, control, not applying fluoride. Group 2, applying fluoride during etching. Group 3, applying fluoride after etching. In each group, the teeth were treated with etching and fluoride respectively and stored in water for 24 hours. Then brackets bonding strength were measured. RESULTS: The results showed that there was not significant difference among the three groups. CONCLUSION: Fluoride can be used to prevent enamel white spot.

Acid Etching, Dental↗
PubMed1999

[Scanning electron microscopy study on different orthodontic methods of using fluoride in enamel white spot prevention].

OBJECTIVE: To determine which method of topical fluoride application could make the enamel uptake more fluoride. METHODS: 12 extracted human premolars were divided into three groups of 4 teeth each: Group 1, control and not applying fluoride; Group 2, applying fluoride during etching; Group 3, applying fluoride after etching. In each group, the teeth were treated with etching and fluoride respectively. The specimens were then examined with scanning electron microscopy. RESULTS: The results showed that there were more reaction products on the enamel surface of Group 3. CONCLUSION: There was more fluoride uptake into the enamel treated with fluoride after etching.

Acid Etching, Dental↗
PubMed1999

[Studies on standard growth curve chart on body weight of adolescent Chinese for orthodontic diagnosis].

OBJECTIVE: To establish the first new annual increase and growth curve charts on the body weight of Chinese children. METHODS: Data were surveyed in 1995, which were obtained from subjects consisting of 32524 students aged from 7 to 19 years in Sichuan province. RESULTS: Mean values of the annual increment of body weight, sex and area difference were analyzed. CONCLUSION: The new standard growth curve chart on the body weight is very useful for orthodontic diagnosis, treatment and prognosis.

Adolescent↗
PubMed1999

[Studies on standard growth curve chart on body height of Chinese adolescent for orthodontic diagnosis].

OBJECTIVE: To make a standard growth curve chart on the body height of Chinese adolescent. METHODS: Statistical data were surveyed in 1995, which were obtained from subjects consisting of 32,524 students aged from seven to nineteen years in the province of Sichuan. RESULTS: Mean values of the annual increment of body height and the ages of the pubertal growth periods were analyzed. CONCLUSION: The new standard growth curve chart on the body height of adolescent chinese were applied for better understanding the growth pattern of chinese orthodontic patients.

Adolescent↗
PubMed1999

[Key factors in the control of electroosmosis with external radial electric field in CE].

Direct control of electroosmosis flow (EOF) by external radial electric field was performed at room temperature using a home-made field-modulated capillary electrophoresis (CE) system. The EOF was monitored at 206 nm by using DMSO as a probe. To apply a radial electric field across the CE capillary wall, the capillary was cased with a wide column. Both of the concentric space and the capillary bore were then filled with an identical running buffer and applied with an axial electric field of 150 V/cm but starting from different levels. All of the tubes used were made of fused silica with polyimide over-coating (from the Yongnian Optical Fiber Work, Hebei, P. R. China). The size of the CE capillaries adopted was 25-100 microns i.d. (375 microns o.d.) x 28.5/45 cm (effective/total length), and that of the casing column 400 microns i.d. x 32 cm. To investigate the fundamentals of the external EOF control when using the flexible fused silica capillaries, various parameters have been inspected such as pH, buffer composition, additives and capillary wall feature etc.. As expected, to well control both of the magnitude and direction of the electroosmosis, the buffer pH should be kept below 4 and the buffer concentration below 50 mmol/L. However, buffers below 1 mmol/L should be avoided because such a diluted running buffer may result in poor CE separation. Weak electrolytes like citric acid, tartaric acid and acetic acid were found to be capable of generating better EOF control than the strong electrolytes such as phosphate and chlorides. This is possibly due to the formation of looser electric double layer with the weak rather than the strong electrolytes. Some wall coatings like calix arene and its derivatives can evidently improve the EOF control even at pH 5. This reveals an exciting way to expend the controllable pH range. In addition, narrow-bore capillaries were demonstrated to be better than wide-bore tubes. Other conditions such as buffer additives and capillary rinse procedure were shown to have only negligible influence on the control.

Electric Conductivity↗
PubMed1999

[Determination of baicalin and chlorogenic acid in yinhuang granule by capillary electrophoresis].

Yinhuang Granule is a kind of complex formulae made up of extract of Flos lonicerae and that of Radix scutellariae, of the fuctions of dispelling wind-heat to reduce fever, detoxicating, relieving inflammation, promoting urination and tranquilizimg the mind and can be applied to upper respiratory tract infection and tonsillitis. Baicalin and chlorogenic acid are referred to main effective components of it. In this paper, the separation and determination of baicalin and chlorogenic acid in Yinhuang Granule by capillary electrophoresis is described. The experimental conditions are stated as follow: separation column: bare fused-sillica capillary (50 microns i.d., 370 microns o.d., total length 47 cm, 40 cm from the inlet to UV detector); electrolyte: 25 mmol/L borax, pH 8.5; detection wavelength: 310 nm; sampling: 17 kPa.s; running voltage: 25 kV, polarity from anode (inlet) to cathode (outlelt); temperature: 25 degrees C; internal standard: p-nitrobenzoic acid. The linear ranges of determination for baicalin and chlorogenic acid were 160-960 mg/L(r = 0.9993, RSD = 1.76%-2.33%) and 80-960 mg/L(r = 0.9989, RSD = 1.07%-2.51%), respectively. The recoveries of baicalin and chlorogenic acid were (102.09 + 1.74)% (RSD = 1.71%, n = 6) and (99.81 + 3.11)% (RSD = 3.12%, n = 6). The method is simple, fast and accurate. It can be used for the quality control of Yinhuang Granule and its related Chinese medicines.

Anti-Infective Agents↗