Search PubMed⌕ Search

Biomedical subjects

Y Yang

Publications and source records attributed to Y Yang.

At least 685 records · Page 38Linked to original sources
PubMed1999

[Assay of sensitivity of Plasmodium falciparum to chloroquine, amodiaquine, piperaquine, mefloquine and quinine in Yunnan province].

AIM: To determine the sensitivity of P. falciparum to chloroquine, amodiaquine, piperaquine, mefloquine and quinine in Yunnan Province of China in 1992-1995. METHODS: Rieckmann's in vitro microtechnigue was used. The sensitivity of P. falciparum was tested to the above-mentioned antimalarials. RESULTS: The resistance rates of isolates of P. falciparum from the south, southeast and the west part of Yunnan to chloroquine and amodiaquine were 96.7% (29/30), 78.9% (30/38), 95.7% (22/23) and 100% (30/30), 85.3% (29/34), 8/9, respectively, with their corresponding ID50 of 125 nmol/L, 136 nmol/L and 176 nmol/L, and 52 nmol/L, 64 nmol/L and 72 nmol/L, respectively. All the isolates were sensitive to quinine and their ID50 were 480 nmol/L, 352 nmol/L, 608 nmol/L, respectively. The resistance rates of P. falciparum from the south part and southeast part of Yunnan to piperaquine were 96.4% (27/29), 72.9 (27/37), respectively, their ID50 were 320 nmol/L and 228 nmol/L; all the cases were sensitive to mefloqine, their ID50 were 68 nmol/L and 88 nmol/L. CONCLUSION: P. falciparum generally produces resistance to chloroquine, amodiaquine and piperaquine in Yunnan Province; the degree of resistance to chloroquine of P. falciparum from the west part of Yunnan were higher than the P. falciparum from the southeast part of Yunnan; all the isolates were sensitive to mefloquine and quinine in this region.

Amodiaquine↗
PubMed1999

[Protection of PNH red blood cells from lysis by transferring GPI-anchored protein vesicles of normal human RBCs in vitro].

OBJECTIVE: To observe the transfer of GPI-anchored protein CD59 from vesicles of normal RBCs to paroxysmal nocturnal hemoglobinuria(PNH) RBCs can correct the susceptibility to complement attack in vitro. METHODS: Vesicles released from normal RBCs under ATP depletion or storage, are rich in CD59. PNH CD59- RBCs were separated by elution from immunoaffinity column bound with monoclonal antibody CD59, and then incubated with normal RBCs vesicles. The content of CD59 in vesicles and RBCs was detected by Western blot and flowcytometric analysis respectively and hemolysis of PNH CD59- RBCs was detected by cobra venom factor hemolysis test. RESULTS: The fluorescence intensity of PNH CD59- RBCs were increased from (1.68 +/- 0.57)% to (58.42 +/- 8.25)% and the hemolysis was significantly decreased from (27.13 +/- 9.69)% to (19.49 +/- 7.61)% after incubation with vesicles prepared from normal donors (P < 0.05), while normal RBCs had no obvious change before and after the same treatment. (P > 0.05). CONCLUSIONS: It seems that CD59 protein molecules could be transfered from normal RBCs vesicles to PNH CD59- RBCs and retaining the complement regulatory function. CD59- RBCs could be rendered less liable to hemolyze during complement attack.

CD59 Antigens↗
PubMed1999

[Identification of Panax quinquefolius, P. ginseng and P. notoginseng by protein fingerprints].

Establish the way of protein fingerprints to identify P. quinquefolius, P. ginseng and P. notoginseng of genus Panax by SDS-PAGE, Tris-tricine and Western blot. The fingerprints of Panax species from 28 KD to 58 KD and 55 KD are in common. Very different fingerprints of P. quinquefolius are found below 28 KD. The fingerprints above 58 KD seemed to be peculiar for P. ginseng. Hence the approach may be used as a means to authenticate the concerned Panax species, especially for identification of P. quinquefolius.

Blotting, Western↗
PubMed1999

[The antitumour activity of total saponin of Clematis chinensis].

This paper has shown the cytocidal effects of total saponin of Clermatis chisensis Osbeck (CCS) on experimental tumours EAC cells, S180A cells and HepA cells in vitro, using microculture method 72 hours. The IC50 were 242 micrograms/ml, 193 micrograms/ml and 130 micrograms/ml respectively. In vivo the growth of transplanted mouse tumour(S180) was inhibited by the CCS with inhibitory rates 40.3% (0.25 g/kg), 55.1% (0.5 g/kg), 53.0% (1 g/kg), but CCS(0.2 g/kg, 0.4g/kg, 0.5 g/kg) hasn't effect on survival time of tumour mice(S180A).

Animals↗
PubMed1999

[Design of blood cell analyzers by using stationary suspending laser light scattering method].

The paper analyses the technology development of automatic blood cell analyzers, put forward the new method of blood cell counting and classification by stationary suspending laser light scattering. The new automatic blood cell analyser is designed by using this method. The design idea of the light route and data acquisition system is stressly provided in the paper. The calibration is performed by using the standard blood cell particulate.

Adult↗
PubMed1999

[A new digital filter method for eliminating 50Hz interference from the ECG].

The article discusses advantages and disadvantages of several conventional digital filter methods. Then, based on Levkov method, the author proposed a new filter method. We use these methods to remove 50 Hz interference from more than 50 persons' ECG signals. The results show that this new method is the best, and it can satisfy the real time requirement of digital ECG machine.

Algorithms↗
PubMed1999

[Detection of hepatitis C core antigen C33].

OBJECTIVE: To investigate the distribution of C33 antigen of HCV in serum and liver tissues from normal subjects and patients with different diseases. METHODS: Balb/C mice were immunized by HCV core antigen peptide C33(33 amino acids) which was conjugated with mice serum albzmin by a heterotypic difunctionalconnector(SPDP). Two strains of monoclonal antibody to C33 were produced. By using one of them as coated and the other as HRP(horseradish peroxidase)-labelled antibodies, an ELISA was developed to detect C33 antigen of HCV in 1236 serum samples from patients. RESULTS: The detectable rate of peptide C33 was 14.0%(6/43) in acute hepatitis C group, 8.8%(35/396) in anti-HCV-IgG positive group, 6.5%(4/62) in chronic hepatitis C group, 4.3%(1/23) in leukemia group, 3.3%(19/576) in hemodialysis group, 1.5%(2/136) in other diseases group, and 1. 4%(6/438) in blood donors. Results of immunohistochemistry and immunofluorescence for liver tissues obtained from biopsy showed that C33 peptide was found in nucli, cytoplasm and membranes of hepatic cells, scattered or laterally concentrated in the cytoplasm. CONCLUSION: The detection of C33 antigen of HCV may consider as one of the markers of HCV infection.

Animals↗
PubMed1999

HBV X protein (HBX) interacts with general transcription factor TFIIB both in vitro and in vivo.

OBJECTIVE: In order to demonstrate the binding of HBV X protein (HBX) with the general transcription factor TFIIB. METHODS: In vitro glutathion S-transferase (GST) resin Pull-Down assay and Far-Western Blotting assay, in vivo Co-immunoprecipition assay were used. RESULTS: The X199 (51-99) domain of HBX is reponsible for HBX binding to TFIIB. While the d10 domain (125-295) of TFIIB is required for TFIIB binding to HBX. When the two basic amino acids (K) at position 178 and 189 of TFIIB were substituted by neutral amino acids (L), the binding of TFIIB K178L and K189L to HBX was siginificantly reduced. When the the basic amino acids were substituted by the acidic amino acids (E), the binding of TFIIB K178E and K189E to HBX were almost lost. In vitro results of HBX binding to TFIIB were further confirmed by in vivo co-immunoprecipitation assay. Our results also indicated that the Woodchuck hepatitis virus X protein (WHX) interacts with TFIIB. CONCLUSION: These results suggested that the communication between HBX and general transcription factor TFIIB is one of the mechanisms which account for its transcriptional transactivation.

Binding Sites↗
PubMed1999

[Study on the mutual interference of rare earth elements by ICP-AES].

In this paper, the mutual interference of rare earth elements have been studied by ICP-AES. Thirty seven analyte lines of sixteen rare earth elemnts have been investigated. It is found useful to correctly select analyte lines of rare earth elements and overcome their mutual interference.

English Abstract↗
PubMed1999

[Synthesis and characterization of lanthanum(III) with O-chlorophenoxyacetic acid].

This work has synthesized a binary solid complex using rare earth ion La3+ with the ligand HL (HL = O-chlorophenoxyacetic acid). The chemical formula of the complex was determined to be LaL3 x H2O by elemental analysis. The composition, structure and properties of this type of complex were tentatiovely investigated by the analysis of molar conductivity, IR, UV, TG-DTA and 1H NMR. The center ion in the complex was considered to be chelated by a bidentate ligand HL.

English Abstract↗
PubMed1999

[The analysis of manganese through electrochemical stripping ellipsometry].

This paper introducing the cathodic stripping ellipsometry with a new function Vop for analyzing manganese quantitatively. The results indicated that the related average deviation of this method are more smaller than the stripping voltamimetry of electrochemistry and providing a lot of information about electrode processes.

English Abstract↗
PubMed1999

[X-ray photoelectron spectroscopy (XPS) of carbon nitride (CN) films].

The chemical structure of carbon nitride thin films, prepared by rf-dc plasma enhanced chemical vapor deposition (PECVD) was studied by XPS. Analyzing the C(1s) and N(1s) core level lines indicated two types of chemical structure N-sp3C and N-sp2C binding states existed in the CN films. There is also little N-spC binding state in the CN film with a nitrogen content of 22%. The ratio of N/C in N-sp3C binding state is 1.28 which is near 4 : 3, thus demonstrated the existence of C3N4-like phase. High nitrogen content in the CN films is useful to increase the content of beta-C3N4 phase. Light changes of the chemical structure of the CN films can be observed under ion irradiation. With the increase of ion dose, the ratio of N-sp3C/N-sp2C increase, while the N/C ratio in the films decrease.

English Abstract↗
PubMed1999

[Study on the interaction of human serum albumin and Mn (II), Co (II) by fluorescence method].

The interaction of Mn (II), Co(II) and HSA has been studied by fluorescence method at pH 7.4 and 5.3. Based on Forste non-radiative energy transfer theory, the distance between Trp-214 residue of HSA and the first strong binding site to Mn (II), Co (II) in HSA was determined, and it is much larger than that of reference. This notable different result has been discussed according to the binding site of Mn (II), Co (II ) and domain structure in HSA.

Binding Sites↗
PubMed1998

The use of neamine as a molecular template: identification of active site residues in the bacterial antibiotic resistance enzyme aminoglycoside 3'-phosphotransferase type IIa by mass spectroscopy.

Four novel aminoglycoside-based affinity inactivators were shown to covalently modify the active site of aminoglycoside 3'-phosphotransferase type IIa (APH(3')-IIa), an important resistance factor in bacteria for aminoglycoside antibiotics. Standard peptide mapping techniques failed with this enzyme. A novel mass spectroscopic analysis which combines protease digestion on the instrument probe, followed by matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) is described which permitted rapid identification of the sites of protein modification. By this new technique, Glu-3 and Asp-23 were identified as active-site residues, the side chains of which potentially may serve as counter ions for the ammonium functionalities at positions 6', and 1 and 3 of the antibiotic substrates, respectively. These findings contradict previous assertions that the C-terminal third of the enzyme should form the active site, by placing the active site clearly in the N-terminal portion of the enzyme.

Aspartic Acid↗
PubMed1998

[Distribution of three STR loci in Dai ethnic group in China].

OBJECTIVE: This study was conducted to investigate the distribution of three STR loci in Dai ethnic group. METHODS: Multiplex amplifications of CSF1PO, TPOX and TH01 were carried out. Using denaturing polyacrylamide gel electrophoresis and silver staining the authors investigated the distribution of allele frequencies of CSF1PO, TPOX and TH01 loci in Dai ethnic group living in Yunnan province. RESULTS: 7 alleles and 15 genotype of CSF1PO locus, 7 alleles and 18 genotypes of TPOX locus, 6 alleles and 17 genotypes of TH01 locus were observed. CONCLUSION: The allele distribution of the loci is in good agreement with the Hardy-Weinberg equilibrium.

China↗