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Biomedical subjects

Q Zhang

Publications and source records attributed to Q Zhang.

At least 469 records · Page 26Linked to original sources
PubMed1999

[Studies on pharmacognostic identification and quality control standards for hongqu].

OBJECTIVE: To develop effective methods for quality control of the traditional Chinese drug Hongqu. METHOD: TLC and microscopic identification were performed. HPLC was used to determine the content of lovastatin. RESULT: A lot of hyphae and spores in Hongqu were observed under microscope. The spot of lovastatin was found on the TLC chromatogram. The standard curve of lovastatin by HPLC was linera in the range of 5 micrograms/ml-100 micrograms/ml. The average recovery of lovastatin was 96.4%, RSD 3.68%, n = 5. CONCLUSION: The methods are simple, sensitive and accurate. These studies provide the scientific basis for quality evaluation and quality control of Hongqu.

Chromatography, High Pressure Liquid↗
PubMed1999

[Research on petroleum ether extract of rhizoma Drynariae].

OBJECTIVE: To study the petroleum ether extract of Rhizoma Drynariae. METHOD: Solvent extraction silica gel column isolation, and structure elucidation by physico-chemical evidence and spectral analysis. RESULT: Three compounds were isolated and elucidated as fern-9(11)-ene, hop-22(29)-ene and cyclolaudenol. CONCLUSION: All the three compounds are triterpenoids.

Drugs, Chinese Herbal↗
PubMed1999

[Observation of distortion product otoacoustic emissions in recovery course of sudden deafness].

OBJECTIVE: To realize the DPOAE resulting in sudden deafness and to investigate the changes of OAE in the recovery course of sudden deafness. METHOD: The basic characters of distortion product OAE (DPOAE) were studied in 60 ears of 30 cases with sudden deafness. The treatment and following-up were carried on too. RESULT: The incidence and amplitude of OAEs in the affected ears were lower than that of normal ears and normal group, and the threshold of DPOAE was higher too. In the recovery course the amplitude and threshold of DPOAE were improved with the restoration of auditory threshold, but the restoring rate (RR) of auditory threshold was higher. CONCLUSION: The DPOAE in sudden deafness implies a serious sensorineural hearing loss. In the recovery course, the amplitude and threshold of DPOAE is later than that of the pure-tone behavioral threshold, which implies that DPOAE is a sensitive and direct way in reflecting the function of cochlea.

Adult↗
PubMed1999

[Retention behavior of solutes on liquid chromatographic column packed with dynamically modified zirconia].

Zirconia was dynamically modified with stearic acid, beta-cyclodextrin and sodium dodecylsulfonate, separately, to form liquid chromatographic packings. The chromatographic behaviors of aromatic hydrocarbons, acidic compounds (phenol, nitrophenols and benzoic acids) and basic compounds (aniline, nitroanilines and toluidines) were investigated on these modified zirconia packings with a mixture of methanol/water as the mobile phase. On stearic acid modified zirconia, aromatic hydrocarbons and the basic compounds exhibit symmetrical peaks. The retention time of these solutes decreases with increasing the concentration of methanol in the mobile phase. When the mobile phases with stearic acid were used, the retention time of these solutes has a maximum with variation of stearic acid concentration (0-1.0 mmol/L) in the mobile phase. However, the acidic compounds such as nitrophenols and benzoic acids are strongly adsorbed and can not be eluted from the column with the mobile phases. No leaking of stearic acid on the modified zirconia was found after 3000 column volumes of the methanol/water mobile phase were used. The results showed that the stearic acid modified zirconia can be used as a stationary phase for reversed-phase liquid chromatography. On beta-cyclodextrin modified zirconia, aromatic hydrocarbons and basic compounds exhibit shorter retention time than those on the stearic acid modified zirconia under the same mobile phase composition, however, nitrophenols can be eluted but give unsymmetrical peaks. On sodium dodecylsulfonate modified zirconia packings, the basic compounds can not be retarded; Aromatic hydrocarbons and acidic compounds exhibit short retention time. The results can be ascribed to the weak adsorption of sodium dodecylsulfonate on the zirconia.

Adsorption↗
PubMed1999

[Study on high performance liquid chromatography/indirect photometric detection of fosfomycin with acridine as detection reagent].

Fosfomycin is a broad-spectrum antibacterial agent which has strong polarity and weak UV absorption. In this work, a method using standard ODS column and conventional UV detector set at 254 nm to analyse fosfomycin was investigated. Firstly, several UV detection reagents were tested and acridine(A) was found to give the highest indirect detection response and proper modification on retention of fosfomycin. With acridine as the UV detection reagent, the mobile phase parameters which affect retention and detection response of solute are discussed, e.g. pH, concentration of organic solvent and concentration of acridine. The mechanism is interpreted for each case. After optimization, we adopted mobile phase as V(CH3OH):V(H2O) = 50:50, pH 3.18, [HAc] = 2 mmol/L, [A] = 1 x 10(-5) mol/L. A new chromatographic system monitored by indirect photometry for detection of fosfomycin was established. This method was used for quantitative analysis, the minimum detectable level was 10 mumol/L, the relative deviation was 4.51%.

Acridines↗
PubMed1999

[Preparation of zirconia for high performance liquid chromatography using sol-gel technology].

Zirconia sol was prepared by dissolving zirconyl chloride in water, and the sol formed gel in water/cyclohexane W/O style emulsion to obtain monodispersed particles of ZrO2(2-10 microns). After being washed and classified, the zirconia particles (3-5 microns) were collected and calcined at 800 degrees C to remove the organic residues on the surface of the particles. The mean pore diameter, specific surface area and specific pore volume of the zirconia particles were found to be 14.2 nm, 11.2 m2/g, and 0.04 cm3/g, respectively, by means of the BET method. The adsorption behavior of various organic compounds on the ZrO2 shows it will be useful as a column packing material for high performance liquid chromatography.

Adsorption↗
PubMed1999

[Histopathologically observational study of cartilage-mucosa on the eustachian tube isthmus of temporal bone with otitis media].

OBJECTIVE: To explore the influence of inflammatory pathology change of otitis media upon cartilage-mucosa at the eustachian tube isthmus (ETI). METHOD: The cartilage-mucosa at ETI and bone-mucosa on the tympanic promontory of 32 temporal bones with otitis media were observated histopathologiclly in comparison with 50 normal temporal bones under light microscopy. RESULT: The eustachian tube isthmus in all the 32 temporal bone with otitis media and in 50 normal temporal bone were unblocked. The thick-measures and pathology observations of the cartilage-mucosa on ETI in the temporal bones with otitis media revealed there was no obviously inflammatory change and no significantly difference in comparison with the normal control group. But there was obviously inflammatory pathologic change on the bone-mucosa of tympanic promomtory of temporal bone with otitis media. The demarcation line of completely different inflammatory reaction in middle ear cleft was exactly at the connective line between cartilage and bone of eustachian tube. CONCLUSION: With the specifically histologic structure, the cartilage-mucosa on eustachian tube is possessed of very strong function of natural defence for inflammatory desease, and it almost is impossible to lead to obstruction of eustachian tube by inflammatory influence upon the cartilage-mucosa.

Cartilage↗
PubMed1999

[Transformation of effusion and formation of granulation tissue in the pathologic process of otitis media with effusion].

OBJECTIVE: To explore the transformation of stagnant effusion (SE) and the pathologic behavior leading to granulation tissue (GT) formation in the pathologic process of otitis media with effusion (OME). METHOD: The temporoal bone slides from 306 ears with OME at the Otopathology Laboratory of the University of Minnesota USA were studied histopathologically under light microscopy. RESULT: The observations revealed a pathologic process in which the type and the condition of stagnant effusion in the middle ear cleft was variable in the dynamics of OME progression from an early pathologic stage to an advanced pathologic stage. The granulation tissue was primarily formed by two types of fibroblast proliferation in subepithelial space. The absorption and the orgnization of SE and the formation of granulation tissue maybe occur simultaneously in same areas and a same pathologic process. CONCLUSION: The granulation tissue can only form in the areas where effusion has stagnated and has been absorpted. It is very important that effusion of the otitis media should be removed completly before the formation of granulation tissue.

Granulation Tissue↗
PubMed1999

[IFN alpha- and IFN gamma-induced differentially expressed genes].

OBJECTIVES: It was previously found that IFN alpha could reduce, while IFN gamma could enhance metastatic potential of a mouse mammary adenocarcinoma cell line MA891. The aim of this study was to identify the sequence of cDNA fragments that were differentially expressed by the two types of IFN, respectively. METHODS: Total RNA was extracted from MA891 cells treated with IFN alpha or IFN gamma. Northern blotting was used to confirm the differentially expressed gene fragments. DNA sequencing was then carried out. RESULTS: The Northern blots indicated that among the 10 cDNA fragments obtained by mRNA differential display technique, 4(G15 gamma, C4 alpha, T2 gamma, and T11 gamma) were shown to be unequivocally differentially expressed. Among them, the nucleotide sequence of G15 gamma did not show homology with any of the existing genes, while that of C4 alpha, T2 gamma and T11 gamma was highly homolgous to mouse minor histocompatility complex gene, mouse beta-actin gene and hamster high blood pressure gene, respectively. CONCLUSIONS: Four differentially expressed cDNA fragments by IFN alpha- and IFN gamma-treated MA891 cells have been ascertained. Regardless of sequence homology, none of them is reportedly related to tumor cell metastasis. The results herein reported provide basis for the elucidation of new metastasis-associated gene(s).

Adenocarcinoma↗
PubMed1999

[Genotype-phenotype correlation in Chinese patients with retinitis pigmentosa due to rhodopsin mutation].

PURPOSE: To investigate the genotype-phenotype correlation in Chinese patients with retinitis pigmentosa caused by rhodopsin gene mutation. METHODS: On the basis of the onset of symptoms, degree of morphological changes and progression of visual disability in three (3/83) patients with identified mutations, the correlation of the phenotype with the corresponding mutations was assessed. RESULTS: There was a certain degree of allele-specificity. Severe form of retinitis pigmentosa was found in patients with mutation in the cytoplasmic domain and mild form of retinitis pigmentosa in patients with mutation in the intradiscal domain. CONCLUSION: Although there is a certain relation between the mutant rhodopsin and ocular manifestation, we need to accumulate more materials before relating a rhodopsin mutation to a specific phenotype.

Adult↗
PubMed1999

Differential gene expression in retina of myopic chicken eyes using mRNA differential display.

PURPOSE: To study differentially expressed genes in retina of experimental myopic chicken. METHODS: Experimental myopia in chicken was induced by form-deprivation. The mRNA in chicken retina was analyzed by using differential display. RESULTS: Experimental myopia was successfully induced in chicken through form-deprivation. Differentially expressed gene fragments were detected in retina of chicken with myopic development and recovery as compared with normal controls. CONCLUSION: The differential display of mRNA may be a useful way in cloning myopic-related genes.

Animals↗
PubMed1999

[Corneal limbal stem cell autograft and conjunctiva transplantation for treatment of pterygium].

PURPOSE: To observe the therapeutic effects of corneal limbal stem cell autograft and conjunctiva transplantation for the treatment of pterygium. METHODS: Corneal limbal stem cell autograft and conjunctiva transplantation were performed on 38 cases (43 eyes) with newly developed or recurrent pterygium. The post-operative follow-up period ranged from 3 to 30 months (mean, 10 months). RESULTS: Of 38 cases (43 eyes), there were 34 cases (38 eyes) with stable epithelial healing and recovery of corneal transparency with no abnormal proliferation of pterygium-like tissue. 4 cases (5 eyes) were lost during the follow-up. CONCLUSION: To provide new stem cell source for injured limbus with limbal epithelial autograft transplantation is a reasonable therapeutic method for treatment of pterygium.

Adult↗
PubMed1999

[Detection of ECG characteristic using wavelet transform].

This paper discusses the characteristic detection of modulus maxima of the loavelet transform, based on the properties of the singularity of the signal and noise. Theoretical analysis and experimental results show That the method is fitting for ECG signal detection and positioning.

Algorithms↗
PubMed1999

[Analysis of HLA-DRB1 allele polymorphism for patients with allergic rhinitis].

OBJECTIVE: To analyze the association between allergic rhinitis and HLA-DRB1 in northeast area of China. METHODS: Using polymerase chain reaction/sequence specific primers (PCR/SSP) technique, we studied distributive speciality of HLA-DRB1 alleles in 35 patients with (AR) and 94 healthy controls. RESULTS: The statistical results showed that the frequencies of DRB1 * 0101.2 and DRB1 * 0302 alleles were significantly higher in AR patients than in those of controls. The frequencies of DRB1 * 0101,2 and DRB1 * 0302 were 12.86% (relative risk = 15.92 Pc < 0.0004) and 5.71% (relative risk = 12.00, Pc < 0.05) respectively, the other gene frequencies bore no significant difference. CONCLUSION: AR was associated with HLA-DRB1 * 0101.2 and DRB1 * 0302 alleles.

Adult↗