Biomedical subjects

Y Zhao

Publications and source records attributed to Y Zhao.

At least 631 records · Page 35Linked to original sources

PubMed1998

[Effect of different nitrogen concentrations on the growth and contents of berberine in rhizome of Coptis chinensis Franch].

OBJECTIVE: Selecting the best N concentrations for the growth of the Chinese goldthread(Coptis chinensis). METHOD: Employing sand culture procedures. RESULT: The symptoms of shortage of nitrogen were reduced in low N(1/5 N) solution, but the new roots and aerial parts were adversely affected in over nitrogen solution(2 N); the activity of NR in leaves and the content of berberine in rhizome were also low in 2 N solution; the range of optimum N concentrations for growth and high contents of effective components is 1/2 N to 1 N. CONCLUSION: The consumption of nitrogen by Coptis chinensis is lower in the period of maximum contents of effective components in rhizome than in the period of luxuriant growing of the plant.

Berberine↗

PubMed1998

[In vivo color measurement of 410 healthy maxillary anterior teeth].

OBJECTIVE: In order to measure and analyse the color characteristics of intra-oral vital teeth objectively and accurately. METHODS: The fiber-optic spectrophotometer (FMC-9204, Kunmin, China) was used for measurements of 410 healthy maxillary anterior teeth of 70 people aged from 18 to 70 years old who lived in Kunmin, China. RESULTS: The results were expressed by CIEL*A*B* systems. Statistical analysis showed that: L* of natural teeth is related to age positively, and the regressive equation is L* = 42.74 + 0.14 x age. Value of A* is related to age negatively, the regressive equation is A* = 1.73 - 0.03 x age. The color of the maxillary anterior teeth was also related to tooth position. The central incisor has the highest value of L*, but the canine is the darkest. Besides, the canine is redder, yellower, and more saturated. CONCLUSION: These results may help to make the optic character of oral prosthetic material well matched with the natural teeth.

Adolescent↗

PubMed1998

[Experimental study of cattle bone grafting in combination with implant insertion].

OBJECTIVE: To study the effect of cattle bone grafting in combination with implant insertion. METHODS: Twenty cattle bone blocks were onlayed on the rabbit tibial metaphysis, which were fixed by dental implants. Triple fluorochromes were sequentially given to animals following the operation. New bone formation was histologically and histomorphometrically evaluated. RESULTS: The fluorochrome-labelled new bone gradually replaced almost all the spongy bone and the partial cortical bone of the graft at the end of the experiment. There was a significant higher percentage of bone area at the first four thread levels at 84 days than at 21 days. The average mineral apposition rates ranged from 1.90 microns/d to 2.75 microns/d. CONCLUSION: The onlay cattle bone grafting in conjunction with screw-type dental implants can be used to increase the volume of the recipient bone.

Animals↗

PubMed1998

[Expression of nm23 in gastrointestinal smooth muscle tumors and its relation to cell proliferative activity].

OBJECTIVE: To determine the relationship between nm23 expression and benign or malignant degree, metastasis, prognosis and cell proliferative activity of gastrointestinal smooth muscle tumors (GISMT). METHOD: 86 cases of GISMT were studied, and nm23 was detected by the immunohistochemical staining S-P method. The cell proliferative activity was evaluated by the silver colloid method for argyrophilic nucleolar organizer regions proteins (AgNORs) and by the immunohistochemical staining S-P method for proliferating cell nuclear antigen (PCNA). RESULT: The expression of nm23 declined significantly according to the following order: leiomyomas, low malignant leiomyosarcomas, high malignant leiomyosarcomas (P < 0.01). The expression of nm23 was associated with the tumors with or without contiguous organ invasion or distant metastasis, the size of tumors, the tumors with or without center necrosis (P < 0.01 or P < 0.05). The five-year survival rate was significantly higher in patients with nm23 positive expression than that with nm23 negative expression (P < 0.05). The expression of AgNORs and PCNA with nm23 negative cases was obviously higher than that with nm23 positive cases (P < 0.01). CONCLUSION: nm23 is a valuable indicator for the biological characteristics of GISMT. nm23 expression and cell proliferative activity can supply a deficiency each other in distinguishing malignant from benign tumors, judging the malignant degree, and predicting the prognosis of the patients with GISMT.

Adolescent↗

PubMed1998

[Surgical treatment of the hypopharyngeal and cervical esophageal carcinoma].

OBJECTIVE: To review the experience of surgical treatment of hypopharyngeal and cervical esophageal carcinoma. METHOD: Seventy-six patients with squamous-cell carcinoma of the hypopharynx and cervical esophagus underwent surgery in our department from 1980 to June 1997. The site of the tumour was in hypopharynx in 31 patients and in cervical esophagus in 45. RESULT: The resectability rate of hypopharyngeal carcinoma (HPC) was 98.6% (30/31). The types of the esophageal reconstruction included pharyngo-esophageal anastomosis (3 patients) platysmamyocutaneous flaps reconstruction (PMFR) (12) free jejunal interposition (3) and gastric tube transposition following total pharyngolaryngo esophagectomy (12). The resectability rate of cervical esophageal carcinoma (CEC) was 91% (41/45). The esophageal construction applied gastric tube after esophagectomy without thoracotomy except one. The postoperative morbidity was 36.5% for gastric tube reconstruction (including one died of heart failure), 33.3% (1/3) for free jejunal interposition and zero for PMFR. The overall follow-up was from 2 to 108 months (median: 56.5 months) and the 1-, 3-, 5-year survival rates were 79.3%, 60% and 31.6% respectively for HPC and 68.3%, 9.5%, 0% respectively for CEC. CONCLUSION: Our data demonstrated that the resectability rate of the HPC and CEC was quite high but the long-term result of HPC was better than that of CEC. The PMFR after pharyngolaryngo-cervicalesophagectomy was a safe, effective operation with low morbidity and excellent long-term results.

Adult↗

PubMed1998

[Surgical treatment of cervical 1, 2 neurinomas].

OBJECTIVE: To analyse retrospectively 15 cases of C(1) and C(2) neurinomas treated between 1986 - 1997. METHOD: All patients were examined by clinical neurology, neuroradiology (CT/MRI/DSA) and identified operatively and pathologically. All samples were studied histopathologically. RESULT: Except 1 patient died from menotic nerve sheath tumor involving medulla oblongata and pia mater, 14 patients were cured. CONCLUSION: Lateral approach may be idoal in total tumor resection and improvement of neurological symptoms.

Adolescent↗

PubMed1998

[A study of lipid peroxide-induced damage and of ultrastructure of lens epithelial cells in lens organ culture in vitro].

OBJECTIVE: To understand the mechanism of the rabbit lens damage from lipid peroxidation (LPO) involved in cataract development. METHODS: Ultraviolet (UV) radiation was used to induce the damage of peroxidation on cultured rabbit lens. Cultured rabbit lenses were exposed to UV radiation in MEM cultural medium without or with superoxide dismutase (SOD) added at 10 U/ml. The thiobarbituric acid (TBA) colorimetric method was used to detect the lens malondialdehyde (MDA) content produced by LPO, and electron microscopy was used to observe the ultrastructure of rabbit lens epithelium. RESULTS: In the lens with UV radiation, MDA was increased as compared with that in non-irradiated one (P < 0.01) and in UV + SOD group (P < 0.01). The membranes of lens epithelial cells were damaged and mitochondria, etc. membranous structures disappeared with clumping pattern of chromatin, while the cells in UV + SOD and control groups appeared normal in structure. CONCLUSION: UV radiation can induce lipid peroxide damage in lens culture of rabbit.

Animals↗

PubMed1998

[Quantitative determination of fenfluramine hydrochloride and its tablets by high performance liquid chromatography].

Fenfluramine hydrochloride and its tablets were determined with high performance liquid chromatography by using an analytical column (25 cm x 0.46 cm i.d.) packed with Hypersil BDS C18 (5 microns), a UV detector at 264 nm and V(acetonitrile): V(0.4 mol/L ammonium acetate): V(triethylamine) = 30:70:2 as eluent. The quantitative determination was performed with caffeine as the internal standard. The internal standard method showed good linearity in the mass concentration range of 0.1-0.5 g/L with r = 0.9999. The average recovery of fenfluramine tablets was 99.98%. This method is simple, rapid, sensitive and reproducible.

Appetite Depressants↗

PubMed1998

[A new saikosaponin from Bupleurum Chinese DC].

Bupleurum chinese DC. is a well-known and very important traditional Chinese drug. It is often used to treat common cold with fever, alternating chill and fever, the feeling of fullness and oppression in the chest. A new saikosaponin was isolated from Bupleurum chinese DC. and its structure was identified as 3 beta, 16 beta, 28-trihydroxy-11-alpha-methoxy-olean-12-ene-3-O-beta-D-glucosyl-(1-->3)-beta D-fucoside on the basis of chemical and spectral evidence. In addition, six known saikosaponins were isolated and characterized as saikosaponin a, saikosaponin d, saikosaponin c, saikosaponin f, saikosaponin b3 and saikosaponin b2. All these compounds were isolated from Bupleurum chinese DC. for the first time.

Bupleurum↗

PubMed1998

[A new saikosaponin from Bupleurum chinense DC].

Bupleurum chinense DC. is a well-known and very important traditional Chinese drug. It is often used to treat common cold with fever, alternating chill and fever, feeling of fullness and oppression in the chest. A new saikosaponin was isolated from Bupleurum chinense DC. and its structure was identified as 3-O-[beta-D-glucopyranosyl (1-->3)-beta-D-fucopyranosyl]-3 beta, 16 alpha, 23, 28-tetrahydroxy-olean-11, 13 (18)-dien-30-oic acid 30-O-[xylityl(1-->1)]-beta-D-glucopyranosyl-6-ester on the basis of chemical and spectral evidence. In addition, three known saikosaponins were isolated and characterized as saikosaponin 1, 2"-O-acetyl-saikosaponin b2 and 2"-O-acetyl-saikosaponin a. All the compounds were isolated from Bupleurum chinense DC. for the first time.

Bupleurum↗

PubMed1998

[The study of precedent subgingival flora colonization on four kinds of crown and bridge restorative materials].

The purpose of this in vitro study was to investigate the effects of microbial colonization on different crown or fixed bridge-used restorative materials and discuss the standards for evaluating those materials microscopically. Four kinds of restorative materials such as SDA-II type medium alloy, ceramic-fused-to-metal material, heat cure composite resin for crown restoration, Plat castable ceramics and four species of precedent subgingival flora (A. viscosus, F. nucleterm, C. ochracea, S. sanguis) were used. The material specimen had been continuously anaerobic cultured with the experimental bacterial fluid for 3, 7 and 14 days respectively, then the OD values of the specimenwashing fluid which could stand for the biomass of colonized bacteria on the surfaces of materials were measured. The results indicated that the quantity of precedent subgingival flora colonization on the surfaces of different restorative materials varied among different species of bacteria, which might concern with the surface structure, composition, property of anticorrosion and antisoluability of those materials.

Actinomyces viscosus↗

PubMed1998

[A study on microbiological characteristics of upflow anaerobic filter].

This experiment was conducted to study the relationship between performance and bacterial population in upflow anaerobic filter by improved Hungate technique. The results obtained showed as follows: (1) There existed correlation closely between the bacterial population, COD and volatile fatty acids removal; (2) The bacterial population was affected to a small extent by the change of organic loading rate in short time and suspending performance; (3) Successful performance of the reactor depended on the microbes' composition and their coordinated metabolism.

Bacteria, Anaerobic↗

PubMed1998

[The composition and distribution of some kinds of anaerobic microorganisms in Yinqion basin].

Under the strictly anaerobic conditions, the population of Sulfate-reducing bacteria, fermentative bacteria and methanogenic bacteria of serial samples got from erect sections of different Sedimentary of Yingqiong basin (a typical marine sedimentary environment) were measured by MPN method. The morphology of different kinds of bacteria and the metabolic types of methanogen and methanogenic activity were observed. The relation between population of bacteria and some indexes were compared. The results show that SRB present in all of the samples. The distribution of SRB and fermentative bacteria have no interrelation with the depth of samples but SRB has interrelation with the SO(4)2- concentration, and fermentative bacteria has negative interrelation with the contents of organic matter. Two kinds of methanogen present in all of the samples. They belong to Methanobacterium and Methanococcus, respectively. Their types of nutriment are H2/CO2.

Bacteria, Anaerobic↗

PubMed1998

[Clustering analysis of phonocardiagrams].

Through the development of the ART-2 neural network, we had constructed the 2-dimensional ART neural network appropriate for clustering the time-varying spectrums. After that, according to the character of phonocardiagram(PCG), we chose the scalogram of PCG to be the input feature of the network. By adjusting parameters the network was enabled to cluster the input PCGs to two clusters. The result demonstrates that the system we designed can pick out, from among 32 continuous PCGs, two PCGs which have the tendency toward abnormality. This result may be applicable to basic physiological studies and clinical diagnosis.

Cluster Analysis↗

PubMed1998

[Pulsatile microdialysis method with glucose sensor system].

To develop a miniature subcutaneous glucose sensor system, to simplify calibration procedure before or after glucose monitor, and to improve its temperature characteristics, a pulsatile micropump and the microdialysis technique were used. The experiments of glucose recovery in 5.5 mM and 10 mM G.S. and the temperature experiment from 20 degrees C to 40 degrees C were conducted. The results showed that glucose recovery was (97 +/- 2)%, the current values of glucose sensor varied with temperature, but the temperature parameter was only 3.4%. These indicate that the glucose sensor system is miniature and the calibration procedure is simple. Because of its modified temperature characterisic, it is useful to monitor the blood glucose of feverish diabetics.

Biosensing Techniques↗

PubMed1998

[Dental welding titanium and its clinical usage].

Due to its excellent biocompatibility, desirable chemical and mechanical properties, Titanium has been used for implant denture, RPD and FPD, where welding techniques were indispensable. This paper introduces 5 useful modern ways to weld Titanium and their clinical usage. They are: laser, plasma welding, TIG, infraned brazing and Hruska electrowelding.

Dental Soldering↗

PubMed1998

[The further studies on the pharmacological actions of Bupleurum smithii var. parvifolium].

Bupleurum smithii var. parvifolium grown widely in Ningxia, had a long history as a common medicinal herb. Its crude saponin had significant protective effect in hepatic damage caused by CCl4 in mice, its ether extract had significant analgesic effect. The ether extract also had significant immunological facilitation effect in mice, it could increase the thymus gland weight and the serum IgG content. These results were similar to or better than that of B. chinense and indicated that B. smithii var. parvifolium could be used as B. chinense.

Analgesics↗

PubMed1998

[Math-model of efficient cultivation of Angelica sinensis].

Using two-time general rotation-constitution design, the math-mdele has been founded about Angelica sinensis prodution efficiency and quantity of nitrogen, phosphorus and potassium to use by doing experiments in many different spots and production demonstration for testing and verifying. Accordin to the modle, computer is used to simulate the better, through which people can get fresh Chinese angelica over 500 Kg per mu and also net income over 500 yuan per mu. It shows that this is the best combination. 95% density riliability for this plan is 6860-7600 plants, pure nitrogen 18.75-22.2 Kg, P2O5 9.1-11.1 Kg and K2O 4.46-5.37 Kg One mu. Proportion for nitrogen, phosphorus, potassium is 1:0.49:0.24.

Angelica↗