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Biomedical subjects

Q Zhang

Publications and source records attributed to Q Zhang.

At least 253 records · Page 14Linked to original sources
PubMed2001

[Determination of impurities in a technical chlorpyrifos by gas chromatography with atomic emission detection].

Mass fraction of impurities in a technical chlorpyrifos sample may be obtained by selective determination on carbon (496 nm and 193 nm), chlorine(479 nm), and sulfur (181 nm) channels using gas chromatography with atomic emission detection(GC/AED). According to the formulas from GC/MS and analytical results from GC/AED, mass fraction of compounds may be calculated by internal standard of elements. The results for the same compound obtained from different elemental channels were consistent. This shows the responses of carbon, chlorine and sulfur on AED are independent on molecular structures. Moreover, the reliability of the qualitative results of impurities from GC/MS was proved. If the formulas from GC/MS were wrong, the results from different elemental channels on GC/AED would be different. The relative deviations were in the range of -3.4% to 5.8%. When standards are not available, the results from GC/AED are more reliable than those from GC/FID which usually depend on the area normalization without corrections. Pesticides and other complex organic mixtures may be analyzed reliably and expediently by this method.

Chlorpyrifos↗
PubMed2001

[Study of unified analytical method of compatibleness for traditional Chinese medicines. II. The quantitation of curve fitting].

To introduce method of compatibleness analysis for traditional Chinese medicines, we select a part of the results from the study of astragalus root(A.), Chinese angelica root(Ca.) and their complex prescription (Danggui Buxue Tang, DBT) with an analytical mode of reversed-phase HPLC-photodiode array detector as an example of the quantitation of curve fitting. A new quantitative method, the concentration variation of components as the changing of single prescription dosage in complex prescriptions is discussed. This is the second part of the method of compatibleness analysis for traditional Chinese medicines.

Angelica sinensis↗
PubMed2001

[Experimental study of actin and myosin in the scar tissue].

OBJECTIVE: To investigate the different expression of actin, myosin II in hypertrophic scars, keloids and normal skins, and to understand the relationship of actin, myosin II and the scar contracture. METHODS: Fifteen cases with hypertrophic scars, 10 cases with keloids and 15 cases with normal skins were chosen randomly. The expression of actin and myosin II were detected by immunohistochemical method in the hypertrophic scars, keloids and normal skins. The fibroblasts isolated from three types of tissue were cultured in vitro, then actin and myosin II in three different fibroblasts were measured using flow cytometry. RESULTS: The immunohistochemical staining of myosin II in hypertrophic scars was positive, while the staining in keloids and normal skins were negative. The positive rate of myosin II expression in hypertrophic scars, keloids and normal skins were (95.11 +/- 2.78)%, (16.86 +/- 7.11)%, and (5.31 +/- 1.79)% respectively. There were significant difference between keloids and the two others(P < 0.01). The actin expression in three difference tissues were positive, there were no significant difference in hypertrophic scars, keloids and normal skins(P > 0.05). The positive rate of actin expression in hypertrophic scars, keoids and normal skins were(77.77 +/- 15.43)%, (88.89 +/- 10.29)%, and (82.92 +/- 13.48)% respectively, and there were no significant difference(P > 0.05). CONCLUSION: Myosin II may play an important role in the scar contracture. Actin is the contractile protein of cell, it plays important role in cellular movement. Actin is necessary protein in the cell.

Actins↗
PubMed2001

Clinical analysis of Leber's hereditary optic neuropathy harboring mtDNA mutation at nt11778.

PURPOSE: To improve our diagnostic technique through the analysis of clinical features of Leber's hereditary optic neuropathy (LHON) harboring mtDNA point mutation at nt11778. METHODS: Detection of nt11778 mutation was performed on 38 patients clinically diagnosed as LHON in our ophthalmic center from year 1998 to 2000. Circumstances of onset and family history were obtained and ophthalmoscopy, fundus fluorescein angiography, visual field and visual evoked potential were performed on all 38 patients. RESULT: 30 In 38 patients (78.95%) harbor nt11778 mutation, including 28 male (93.33%) and 2 female (6.67%). The ratio of affected male to female is 14:1. Patients harboring nt11778 mutation display typical clinical manifestations. CONCLUSION: Identification of one of the three LHON specifically associated mtDNA mutations is essential to confirm the diagnosis.

DNA Mutational Analysis↗
PubMed2001

[Study on the dynamic changes of retinoblastoma gene of SO-Rb50 cell line].

PURPOSE: To study the dynamic changes of Retinoblastoma Gene of SO-Rb50 cell line. METHODS: 1) Southern blot hybridization was used to analyse the tumor cell DNA of 327th passage of SO-Rb50 cell line. 2) A promoter and 27 exons of Rb gene were screened exon-by-exon by using PCR-SSCP at 415th and 713th passages of SO-Rb50 cell line. 3) Three cell cloning strains named as MC2, MC3 and MC4 were isolated by single cell cloning technique from the SO-Rb50-775, and mutation of Rb gene were also screened exon-by-exon by using PCR-SSCP-HA in MC2-11, MC3-11, MC4-11 and MC3-138. RESULTS: The 3.5 Kb, 2.9 Kb and 1.0 Kb bands were deleted in the DNA of SO-Rb50-327 tumor cells, showing the deletion of Rb gene in SO-Rb50 cell line. Exon23 of 451th passage cells decreased one band; but exon 25 of 713th passage cells decreased two bands, indicating that exon 25 had new mutation. PCR-SSCP-HA analysis of exon24 showed that MC4-11 and MC3-138 had abnormal bands, but MC2-11 and MC3-11 weren't found mutation of Rb gene. This result suggested that new mutation occurred to exon24 of MC3 during a long-term culture in vitro. CONCLUSION: Retinoblastoma gene mutation of SO-Rb50 cell line had dynamic changes during a long-term culture.

Exons↗
PubMed2001

[Effects of combined transdermal acupoint electric stimulation and isoflurane anesthesia on isoflurane-induced hypotension and tissue oxygen metabolism in patients undergoing craniotomy].

OBJECTIVE: To observe the effects of combined transdermal acupoint electric stimulation and isoflurane anesthesia on isoflurane-induced hypotension and tissue oxygen metabolism in patients undergoing craniotomy. METHODS: Forty-two patients with brain tumor of ASA physical status I or II and scheduled for elective surgery were randomly divided into two groups. The craniotomy was undergoing in Group A with isoflurane anesthesia, while in Group B, with combined transdermal acupoint electric stimulation (TAES) and isoflurane anesthesia. Isoflurane induced hypotension was performed in both groups by augmenting the concentration of isoflurane to lower the mean arterial pressure than before anesthesia for 30%-40% and maintain for 30-45 mins. The tissue oxygen metabolism, blood gas and arterial lactic acid level before, during and after hypotension were monitored by Swan-Ganz floating catheterization. RESULTS: As compared with before hypotension, the pulmonary arterial and mixed with venous blood oxygen saturation lowered and oxygen supply lowered, and oxygen uptake increased significantly in both groups (P < 0.05), but the extent of changes in oxygen metabolic criteria in Group B were all lesser than those in Group A (P < 0.05). CONCLUSION: Combined acupoint electric stimulation and general anesthesia could maintain the tissue oxygen supply and demand balance better in the isofluraneinduced hypotension process.

Acupuncture Points↗
PubMed2001

[Clinical study on treatment of gastric ulcer with qingwei zhitong pill].

OBJECTIVE: To observe the therapeutical effect of Qingwei Zhitong pill (QWZTP) in treating gastric ulcer and clearance of the Helicobacter Pylori (HP). METHODS: Patients in the treated group (n = 60) and the control group (n = 60) were treated with QWZTP and Sifangwei tablet separately to observe the therapeutic effect of treatment on ulcer niche, TCM Syndromes and HP. RESULTS: The effective rate on ulcer niche evaluated by gastroscope was 86.67% in the treated group and 71.67% in the control group, the comparison between the two groups showed a significant difference, P < 0.05. The effective rate on improving TCM Syndrome in the two groups was 91.67% and 88.33% respectively, the difference between two groups was insignificant (P > 0.05). The HP clearance rate in the treated group was 47%. CONCLUSION: QWZTP has good effect in treating gastric ulcer and clearance of HP.

Adult↗
PubMed2001

[Characterization and recognition key components in Astragalus membranaceus].

AIM: To separate, identify and quantify multi-components in complex traditional Chinese medicine (TCM) Astragalus membranaceus by unified analysis for systematic study of its relative contents. METHODS: The analytical method was reverse-phase HPLC/photodiode array detector. Based on the comparison of UV spectra, software of UV database to assist recognition has been established. Key components have been found and recognized in two reference Astragalus membranaceus and three samples from different sources. With the unified analytical project, relative peak heights of key components were recognized and contrasted. RESULTS: The water-soluble components can be separated by solvent system A, a gradient program with mobile phase of methanol-water. The liposoluble components can be separated with the solvent system B, a gradient program of mobile phase of 2-propanol-acetonitrile-water. UV detection wavelength was set at 202 nm and the flow rate was 1 mL.min-1 on a Hypersil ODS column. Twenty-nine components in the four Astragalus membranaceus were recognized using characteristic parameters of chromatography and UV spectroscopy. All of the 29 key components in two reference samples and three samples from different sources were shown in their chromatograms to be the same. The concentrations of some the key components in different samples were similar while those of the others were different. The chromatographic peaks of the reference Astragalus membranaceus and two samples were matched with each other. Many different fingerprints were found and differences were shown on their chromatograms. Not only there were differences among three samples from different source, but also there were differences in the two reference samples. CONCLUSION: To find out the key components and recognize them are the basis of quantitative recognition and are very useful when standards are not available. The method of multi-component quantitative recognition in Astragalus membranaceus was developed. The method is convenient and reproducible. It can be widely used for the quality control of the Astragalus membranaceus.

Astragalus propinquus↗
PubMed2001

[Structure characteristics of insulin liposomes].

AIM: To study the molecular location and state of insulin within insulin-lipids. METHODS: Particle size and distribution of insulin-lipids was determined by using laser light scattering instrument, and transmission electron microscopy (TEM) was used to examine the morphology of insulin-lipids. HPLC, fluorescence scanning, digestion with trypsin and polyacrylamide gel electrophoresis was used to determine the molecular localization and state of insulin in the lipids. RESULTS: The mean particle size, polydispersity and sample quality were 218.3 nm, 0.073 and 7.2 respectively. The results of HPLC determination showed insulin exist in the insulin-lipids. There was no insulin emission spectrum in the insulin-lipids fluorescence spectrum; nearly no insulin digested in the test of insulin digestion by trypsin, and no insulin band in the insulin-lipids in figure of polyacrylamide gel electrophoresis. CONCLUSION: Insulin was encapsulated within lipids.

Chromatography, High Pressure Liquid↗
PubMed2001

[The cluster analysis of trace elements in fructus cnidii from different region].

The contents of trace elements in Fructus Cnidii from different region were assayed by atom absorption spectrum and analyzed by cluster analysis methods. The results showed the contents of trace elements from different regions were different, which had some relativity with habitats, but should be further studied.

Cluster Analysis↗
PubMed2001

[Investigation of the effects of various factors affecting apoptosis of chronic lymphocytic leukemic cells mediated by P2Z receptors].

OBJECTIVE: To explore the effects of various factors affecting apoptosis of chronic lymphocytic leukemia (CLL) cells mediated by P2Z purinoceptor. METHODS: In vitro exposure of CLL cells with P2Z receptors to 1 mmol/L ATP or 0.1 mmol/L benzoylbenzoic ATP (BzATP) for 8 h in the presence of 1.0 mmol/L Mg2+ or other bivalent cations, 150 mmol/L choline in media, 1, 2, 4 mmol/L EDTA or EGTA, or under different temperature. ATP-induced apoptosis was detected by agarose gel electrophoresis, TdT assay and flow cytometric analysis (FCA). RESULTS: The results showed that 1. Extracellular Mg2+ or Ca2+ stimulated ATP-induced DNA fragmentation in a dose-dependent manner, and the compatible evidence was provided by the inhibition of ATP-induced DNA fragmentation in the presence of EGTA or EDTA; 2. ATP-induced DNA fragmentation was completely inhibited by 1.0 mmol/L Zn2+; 3. ATP-induced DNA breaks were not affected by Ba2+, Sr2+, Co2+ when they were substituted for extracellular Mg2+ or Ca2+; 4. Choline, an inhibitor of phospholipase D (PLD) stimulated by ATP through P2Z receptor in human lymphocytes, was also a partial inhibitor of ATP-induced DNA fragmentation, and the results were confirmed by flow cytometric analysis (FCA); 5. ATP-induced DNA fragmentation was completely obliterated when the temperature was lower than 10 degrees C. CONCLUSION: These results suggest that the endonuclease and PLD may be involved in ATP-induced apoptosis in human lymphocytes via P2Z receptor.

Adenosine Triphosphate↗
PubMed2001

[Surgery of substernal goiter].

OBJECTIVE: To study the surgical approaches and operative techniques for substernal goiter. METHOD: A retrospective study of 27 cases with substernal thyroid nodules was made in our hospital. RESULT: The operations on 27 patients with substernal nodules have been successfully carried out. Among them, 10 were goiters, 9 adenomas, 4 malignancy and 4 were thyroid cancer metastasizing to paratracheal or substernal nodes. Resection via cervical collar incision was adequate in 23 cases. Three thyroid cancers with paratracheal node metastasis were completely resected by sternotomy and only one thyroid cancer with paratracheal and substernal nodes metastasis was resected by combined thoracotomy and cervical collar incision. CONCLUSION: Resection via cervical collar incision for all retrosternal thyroid nodules were advised. The preliminary experience with this procedure suggests that it has some advantages in the management of substernal goiter, including: 1. ease of operation compared to both sternotomy and thoracotomy; 2. relatively low morbidity; 3. safe and reliable.

Adult↗
PubMed2001

[Influence of clinical staging of type III sinusitis on the operative effectiveness].

OBJECTIVE: To explore the influences of different degree of pathological changes in chronic polypous sinusitis patients on the effectiveness of endoscopic sinus surgery. METHOD: According to history, anatomic structures and severity of lesions, 104 cases (208 sides) of Type III sinusitis were divided into 3 stages. Rates of clinical effectiveness and complications were compared and analyzed. RESULTS: The total effective rates were 93.06%, 82.89% and 70.00% and the rates of complications were 5.56%, 14.47% and 25.00% in stages 1, 2, 3 respectively. CONCLUSION: The effective rates, difficulties and risks of operation depend upon the anatomic variations (integration of ostiomeatal complex) and the degree of lesions (augmentation of granulation and osseous hypertrophy of ethmoid bone). All these should be listed as objective bases in classifying stages of patients which will play a directional role in clinical work.

Adolescent↗
PubMed2001

[Value of surgical margin in directing the treatment of early laryngeal carcinoma after partial laryngectomy].

OBJECTIVE: To investigate the value of surgical margin in directing the treatment of early laryngeal carcinoma after partial laryngectomy. METHODS: We studied 87 cases of T1N0M0 and T2N0M0 laryngeal carcinoma in which the surgical margins were reserved during partial laryngectomy. The recurrence and survival rates between the positive and negative margin groups were compared; the survival between the positive margin groups with postoperative radiotherapy and negative groups; the survival between groups with and without postoperative radiotherapy in negative margins. RESULTS: Recurrent rate of the negative group was lower than that of the positive group (5.8% vs 33.3%, chi 2 = 10.64 P = 0.001). The estimated survival was higher in the negative group than in the positive group(P = 0.011), and also in tumor-free time(P = 0.007). The survival of those with positive surgical margin and received postoperative RT was lower than that with negative margins(P = 0.01). In the negative group, the difference in the survival between those with or without postoperative RT was not significant (P = 0.405). CONCLUSION: The prognosis of the positive margin group of the early laryngeal carcinoma was worse than that of the negative group, but postoperative RT can improve it; it is not necessary for the negative group to be treated by postoperative RT.

Adult↗
PubMed2001

DNA typing system for HLA-A2 alleles by polymerase chain reaction with sequence-specific primers.

OBJECTIVE: To establish a PCR-SSP method for discriminating as many HLA-A*02 alleles, which could easily be introduced into a routine laboratory. METHODS: In this study we typed HLA-A*02 polymorphisms by a sequence-specific primer (SSP) method, which involved round 1 and round 2 PCR reactions to detect 17 HLA-A*02 alleles (they are HLA-A*0201-0217 alleles) covering exon 2 and exon 3. RESULTS: We have found that DNA sample concentration and purity were the most important variable in determining the quality of the result. For identifying correct band size, the size marker used was important. We noticed that different PCR machines performed differently. By this method, we detected 20 HLA-A*02 positive genomic DNA samples and found 4 kinds of HLA-A*02 alleles. They were HLA-A*0201, 0203, 0206 and 0210. CONCLUSION: The HLA-A*02 PCR-SSP method was proven to be a reliable and easily applicable typing method. Our results suggest that the SSP described here provides an optimal HLA-A*02 typing technique that may be useful in selecting donor-recipient pairs in bone marrow transplantation between unrelated individuals.

Alleles↗
PubMed2001

Experimental study of the morphology of cerebral bridging vein.

OBJECTIVE: To investigate the morphological properties of pig cerebral bridging vein. METHODS: The morphology and fibre arrangement of 15 cerebral bridging veins obtained from 7 Danish Yorkshire landrace pigs were observed. RESULTS: There was a narrow region at the junction of the cerebral bridging veins and superior sagittal sinus termed "outflow cuff segment". The diameter and length of outflow cuff segment were much smaller and the thickness was higher than those of the cerebral bridging veins ( P < 0.01), and circumferential collagen fibres were most dense in the outflow cuff segment. The opening angle of the outflow cuff segment and the cerebral bridging veins were 115 +/- 4 degrees and 120 +/- 4 degrees ( P > 0.05). CONCLUSIONS: There were differences in fibre arrangement and morphological properties between the outflow cuff segment and the cerebral bridging vein, just like a resistance valve, the outflow cuff segment may play an important role in stabilizing cerebral venous outflow and regulating intracranial pressure.

Animals↗
PubMed2001

[Synthesis, spectra and magnetic properties of ion-pair charge transfer complexes bis(1-(4-nitrobenzyl) pyridinium) bis(maleonitriledithiolato) cobaltate(II or III)].

Two new ion-pair charge transfer complexes, [NO2Py]x[Co(mnt)2](NO2Py = 1-(4-nitrobenzyl)pyridinium; mnt = male-onitriledithiolate; x = 1 or 2 for complex 2 or 1), were synthesized and characterized by element analysis(EA), electronic spray mass spactrum(ES-MS), infrared spectrum (IR) and reflection electrolic spectra. Variable temperature magnetic susceptibilities of the complexes in range of 77-300 K indicate that complex 2 exhibits diamagnetivity complex 2, and the magnetic behavior for complex 1 obeys modification Bleaney-Bowers equation, that is, chi m = [Ng2 mu B2/3k(T-theta)][1 + (1/3)exp(-2J/kT)]-1. The best fitting gives a good results: g = 2.392, 2J/k = 5.9 K, theta = -4.9 K and agreement factor R = 7.20 x 10(-9) (R = sigma (chi (i)obs-chi (i)calcd)2/sigma (chi (i)obs)2).

English Abstract↗