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Biomedical subjects

G Wang

Publications and source records attributed to G Wang.

At least 415 records · Page 23Linked to original sources
PubMed1999

[Application of X-ray diffraction to the analysis of traditional Chinese medicine].

OBJECTIVE: To approach the application of powder Xray diffraction in analysis of traditional Chinese medicine(TCM). METHOD: Studying the references published in recent years and making a summary on the subject of application of Xray in the pharmaceutical analysis of TCM. RESULT: This method is effective in identifying and analyzing TCM. CONCLUSION: This technique may have broad prospects for pharmaceutical analysis.

Drug Contamination↗
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

[Studies on introducing and cultivating ginseng in Emei Mountain area].

OBJECTIVE: To introduce and cultivate Panax ginseng in Emei Mountainarea of low latitudes. METHODS: Introduce and cultivate ginseng in some fields of different elevations, and determine the contents of ginsenosides in ginseng samples obtained from the different elevations and different growth periods. RESULTS: Ginseng was successfully introduced to Emei Mountain area. Its quality basically approaches the quality of ginseng growing in northeast China. CONCLUSION: It is feasible to introduce and cultivate ginseng in Emei Mountain area with elevations from 1200 m to 1600 m.

Altitude↗
PubMed1999

[The value of diagnosis with technetium-99m sequential scintigraphy of parotid gland in Sjögren's syndrome].

OBJECTIVE: To explore the value of diagnosis with 99mTcO4- sequential scintigraphy of parotid gland in Sjögren's syndrome. METHODS: Technetium-99m(99mTcO4-) sequential scintigraphy was used in 52 cases of Sjögren's syndrome. RESULTS: The results were analysed quantitatively with activity curve by using ROI computer program. 46 cases (88.46%) were parotid swelling. The contour was clear in 28 cases (53.85%) and blurred in 18 cases (34.62%). The function of parotid was normal in 7 cases (13.46%), parotids with light damage in 15 cases (28.84%), parotids with middle damage in 17 cases (32.69%), and parotids with serious damage in 13 cases (25%). Most cases of damaged secretary function was present in the early phase, and a few cases of damaged absorption function was found in the following process. CONCLUSION: 99mTcO4- sequential scintigraphy of parotid gland is greatly valuable to diagnosis of Sjögren's syndrome.

Adult↗
PubMed1999

[Application of supercritical fluid extraction (SFE) on environmental analysis].

In this paper, publications from 1993 are classified according to the type of matrix from which the environmental analytes are extracted. Although the most applications of SFE are used for the solid, some analysts have concerned with aqueous and gaseous media. Various aspects of investigation of environmental potential carcinogen, such as, polycyclic aromatic hydrocarbons, polychlorinated biphenyls, dioxins, pesticides, phenols and other hazardous and toxic pollutants in environmental samples have been reviewed with 55 references. The coupled techniques of SFE have also been introduced in this paper.

Air Pollutants↗
PubMed1999

Expression of Plasmodium falciparum-infected erythrocyte membrane protein from cerebral malaria patients.

AIM: To provide theoretical evidence for studying the molecular pathogenesis of human cerebral malaria. METHODS: The expressions of Plasmodium falciparum erythrocyte membrane protein 1(PfEMP1) on the surface of parasitized erythrocyte (PE) specimens from 19 cases of cerebral malaria patients in Yunnan Province were quantitatively analyzed by preparative sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) technique. 43 patients of falciparum malaria, 9 patients of vivax malaria and 6 healthy controls were also investigated. RESULTS: The expressions of higher molecular mass (Mr) 260-320 kDa forms of PfEMP1 were found on PE from cerebral malaria patients. By contrast, the expression of PfEMP1 and P. vivax erythrocyte membrane protein (PvEMP1) on PE from falciparum malaria patients and vivax malaria patients had a PfEMP1 with Mr 240 kDa and a PvEMP1 with Mr 180 kDa band, respectively. Healthy controls expressed an EMP of Mr 140 kDa. CONCLUSION: The binding of 260-320 kDa PfEMP1 proteins expressed on PE from cerebral malaria patients to diverse receptor molecules on the endothelial cell(EC) of the cerebral microvessels such as CD36, thrombospondin (TSP), intercellular adhesion molecule 1(ICAM-1), vascular cell adhesion molecule 1(VCAM-1), endothelial leukocyte adhesion molecule 1(ELAM-1) and chondroitin sulfate A (CSA) might be the molecular basis for the pathogenesis of cerebral malaria.

Adolescent↗
PubMed1999

[Modification of N-terminal cDNA of hGM-CSF and high-expression in E. coli].

OBJECTIVE: N-terminal cDNA of human granulococyte-macrophage colony stimulating factor(GM-CSF) was designed to be modified and highly-expressed in E. coli. METHODS: A pair of oligo-nucleotide primers were used to modify the mature N-terminal cDNA sequence of hGM-CSF with the method of PCR. the modified cDNA of hGM-CSF was cloned into E. coli. expressive vector PBV220 and expressed in E. coli DH5 alpha strain, the biological activities of the recombinant protein was identified by means of cell colony formation and TF-1 cell growth assay in vitro. RESULTS: The expression level of modified hGM-CSF cDNA was higher than that of unmodified native type. SDS-PAGE revealed that expressed protein of hGM-CSF accounted for about 25% of total bacterial cell protein. The biological activity of recombinant protein was about 1.5 x 10(7) U/mg protein. The sequence of 1-16 amino acid of N-terminal of the recombinant protein was same with native hGM-CSF. CONCLUSIONS: Modification of the N-terminal cDNA of hGM-CSF could dramatically enhance the expression level in E. coli system.

Amino Acid Sequence↗
PubMed1999

[Study on the inclusion of oridonin-beta-cyclodextrin].

The inclusion compound of Oridonin-beta-cyclodextrin was prepared by the liquid-phase method in aqueous solution. And it was confirmed by thin layer chromatography, differential thermal analysis and specific rotation. The change (A) of ultraviolet spectrum was determined. The composition ratio of inclusion compound between Oridonin and beta-CD was obtained by the continuous variation method.

Calorimetry, Differential Scanning↗
PubMed1999

[A study on the treatment of congenital velopharyngeal insufficiency].

OBJECTIVE: To evaluate the effectiveness of speech therapy after pharyngoplasty in patients with congenital velopharyngeal insufficiency (CVPI). METHODS: Seven patients with CVPI had received pharyngoplasty and speech therapy. The blowing test and the Chinese articulation clear degree test were measured before and after speech therapy. RESULTS: The treatment results of seven patients appeared to be reasonably satisfactory after speech therapy. Both the index of blowing test and the Chinese articulation clear degree test increased significantly after speech therapy. CONCLUSION: Pharyngoplasty combined with speech therapy is effective in the treatment of patients with CVPI.

Child↗
PubMed1999

[Ultra trace determination of platinum, palladium, gold and rhodium in minerals].

Our work studied the minerals dissolved in aqua regia. The trace Pt(II), Pd(II) Au (III) and Rh(I) complexes were loaded by the mixed carbon powder which carried diphenyl thiourea when aqua regia or hydrochloric acid media as well as stannous chloride were present. We added some carbon powder in ashen loader and determined the elements with atomic emission spectrometry. The determination sensitivity counted with 10 grams of samples is 1 x 10(-9). The RSD for 0.05 x 10(-6) standard Pt, Pd, Au and Rh solutions are 6.0%, 5.1%, 8.5% and 11.4%, respectively. The method is simple and operation is easy. The results satisfy our requirement.

English Abstract↗
PubMed1999

[Determination of potassium, calcium, manganese, chromium and cadmium in 10 kinds of (tobacco) cigarettes by flame atomic absorption spectrophotometer].

We used the flame atomic absorption spectrophometer to determine the contents of potassium,calcium,manganese, chromium and cadmium in 10 kinds of (tobacco) cigarettes. The results showed that there were different contents of five kinds of metals in different cigarettes, providing useful data for plant and dryness of tobacco as well as the reduction of harm of smoking to human body.

Cadmium↗
PubMed1998

[Effects of cooking methods on iodine content in iodized salt].

Effects of cooking methods and variety of foods on the retention of iodine content in food with iodized salt were studied. Vegetables from market and usual cooking methods were selected, including procedures of various cooking methods. The samples were fixed by potassium carbonate, ashed with zinc sulfate at 550 degrees C, then determined by colorimetric method with Ce-As-I catalytical reaction. The different cooking methods had different effects on the retention of iodine, in general, the retention of iodine by stewing of steaming was higher than by stir-frying. The effect of various vegetables on the retention of iodine was also different. The retention of iodine after stir-frying was 84.2%, 56.9%, 44.5%, 36.6% for fruit-bearing vegetables, leafy vegetables, roots and beans. The retention of iodine after stewing was 66.1%, 53.4%, 47.0%, and 43.2% for fruit-bearing vegetables, roots, beans and meat. The stability of organic iodine in food is higher than that of inorganic iodine.

Cooking↗
PubMed1998

Selective peptide antagonist of the class E calcium channel from the venom of the tarantula Hysterocrates gigas.

We describe the first potent and selective blocker of the class E Ca2+channel. SNX-482, a novel 41 amino acid peptide present in the venom of the African tarantula, Hysterocrates gigas, was identified through its ability to inhibit human class E Ca2+ channels stably expressed in a mammalian cell line. An IC50 of 15-30 nM was obtained for block of the class E Ca2+ channel, using either patch clamp electrophysiology or K+-evoked Ca2+ flux. At low nanomolar concentrations, SNX-482 also blocked a native resistant or R-type Ca2+ current in rat neurohypophyseal nerve terminals, but concentrations of 200-500 nM had no effect on R-type Ca2+ currents in several types of rat central neurons. The peptide has the sequence GVDKAGCRYMFGGCSVNDDCCPRLGCHSLFSYCAWDLTFSD-OH and is homologous to the spider peptides grammatoxin S1A and hanatoxin, both peptides with very different ion channel blocking selectivities. No effect of SNX-482 was observed on the following ion channel activities: Na+ or K+ currents in several cultured cell types (up to 500 nM); K+ current through cloned potassium channels Kv1.1 and Kv1. 4 expressed in Xenopus oocytes (up to 140 nM); Ca2+ flux through L- and T-type Ca2+ channels in an anterior pituitary cell line (GH3, up to 500 nM); and Ba2+ current through class A Ca2+ channels expressed in Xenopus oocytes (up to 280 nM). A weak effect was noted on Ca2+ current through cloned and stably expressed class B Ca2+ channels (IC50 > 500 nM). The unique selectivity of SNX-482 suggests its usefulness in studying the diversity, function, and pharmacology of class E and/or R-type Ca2+ channels.

Amino Acid Sequence↗
PubMed1998

[Reference value of urinary arsenic for nonoccupational exposed subjects in Henan].

Urinary arsenic levels of 2065 nonoccupational exposed subjects in Henan were determined by spectrophotometric analysis. The results showed: (1) The difference was not significant among Zhengzhou, Luoyang, Anyang, Xinyang and Shangqiu (0.01 < P < 0.025). (2) The difference was not significant among different ages(0.01 < P < 0.025) and between sexes(P > 0.05). (3) The distribution was positive skewness. The median of urinary arsenic was 17.8 micrograms/L. The arithmetic mean was 20.7 micrograms/L. The standard deviation was 15.2 micrograms/L. The geometric mean was 17.3 micrograms/L. (4) It is suggested that the reference upper limit value of urinary arsenic for nonoccupational exposed subjects in Henan in 56 micrograms/L.

Adolescent↗
PubMed1998

[Comparison of plasma fibrinogen level in members of Uygur family of longevity and non-longevity in Xinjiang].

OBJECTIVE: The associations of plasma fibrinogen level with age in members from longevity families and non-longevity families were compared and the influences of relationship in family members to plasma fibrinogen level were analysed to study the relationship between plasma fibrinogen level and life-span run in family. MEANS: The authors measured fibrinogen in 156 Uygur subjects from 7 longevity families and 9 non-longevity families. RESULTS: Fibrinogen level was relatively stable among different age groups in longevity families. It was an association positively with age in non-longevity. Fibrinogen level of children was closely correlative with parent's. CONCLUSIONS: Genetic factor probably contributes to plasma fibrinogen level. Plasma fibrinogen level correlates with life-span run in family.

Adolescent↗
PubMed1998

The fission yeast chromo domain encoding gene chp1(+) is required for chromosome segregation and shows a genetic interaction with alpha-tubulin.

In eukaryotes, the segregation of chromosomes is co-ordinated by the centromere and must proceed accurately if aneuploidy and cell death are to be avoided. The fission yeast centromere is complex, containing highly repetitive regions of DNA showing the characteristics of heterochromatin. Two proteins, Swi6p and Clr4p, that are associated with the fission yeast centromere also contain a chromo (chromatin organisation modifier) domain and are required for centromere function. We have analysed a novel fission yeast gene encoding a putative chromo domain called chp 1(+) (chromo domain protein in Schizosaccharomyces p ombe ). In the absence of Chp1p protein, cells are viable but show chromosome segregation defects such as lagging chromosomes on the spindle during anaphase and high rates of minichromosome loss, phenotypes which are also displayed by swi 6 and clr 4. A fusion protein between green fluorescent protein (GFP) and Chp1p, like Swi6p, is localized to discrete sites within the nucleus. In contrast to Swi6p and Clr4p, Chp1p is not required to repress silent mating-type genes. We demonstrate a genetic interaction between chp 1(+) and alpha-tubulin ( nda 2(+)) and between swi 6(+) and beta-tubulin ( nda 3(+)). Chp1p and Swi6p proteins may be components of the kinetochore which captures and stabilizes the microtubules of the spindle.

Amino Acid Sequence↗
PubMed1998

A unifying Tm diagram for phosphatidylethanolamines with sn-1 C20 saturated and sn-2 C18 unsaturated acyl chains.

We have determined calorimetrically the phase transition temperature (Tm) values of five sn-1 saturated/sn-2 unsaturated phosphatidylethanolamines (PE) in which the sn-1 acyl chain has 20 carbons and the sn-2 acyl chain has 18 carbons with different number and position of the cis double bond. When these Tm values are combined with the five published Tm values of related unsaturated PE, a unifying Tm diagram is generated for the first time. Moreover, as the molecular mechanics simulated structures of these lipids are taken into consideration, this unifying Tm diagram provides insight into how variations in the number and position of the cis double bond in the lipid's sn-2 acyl chain can influence the phase transition behavior of the lipid bilayer.

Calorimetry, Differential Scanning↗