Biomedical subjects

Chuan Qin

Publications and source records attributed to Chuan Qin.

27 records · Page 2Linked to original sources

PubMed2004

[Expression of macrophage colony stimulating factor in brains of PDAPPV717I transgenic mice].

OBJECTIVE: To identify the expression and distribution of macrophage colony stimulating factor (M-CSF) in brains of PDAPPV717I transgenic mice. METHODS: We detected the expression and distribution of M-CSF mRNA in brains of PDAPPV717I transgenic mice by using hybridization in situ and immunohistochemical staining. RESULTS: Expression of M-CSF mRNA was significantly higher in brains of PDAPPV717I transgenic mice than that in non-transgenic mice, and M-CSF mRNA in brain was mainly produced by reactive astrocytes. CONCLUSION: The results indicate that astrocytes play an important role in the onset/development of neuropathology of Alzheimer's disease.

Alzheimer Disease↗

PubMed2004

[Using AR model to analyze injured nerve with needle EMG signal].

The two main factors to affect the style of the recruitment are temporal recruitment and spatial recruitment. This study sought a new way to analyze the recruitment with the modern spectrum method. The abnormal spatial recruitment and temporal recruitment of varied injury degrees of intramuscular neuron were compared through the AR model. At last, AR coefficients were extracted and passed through BP artificial neuron network to classify different NEMG signals and good result was gained.

Action Potentials↗

PubMed2004

[Potent neutralization antibody elicited in mice by SARS-associated coronavirus spike protein S1 domain].

OBJECTIVE: To study the antigenicity of SARS associated coronavirus (CoV) spike S1 (12-672Aa) domain. METHODS: BALB/c mice were immunized with a plasmid bearing codon-optimized SARS-CoV (Tor2 strain) S1 domain and then boosted with purified S1 protein; the SARS-CoV specific IgG antibody was tested by ELISA and neutralization antibody was determined by in vitro microneutralization assay. RESULTS: S1 domain of SARS-CoV spike, which has been demonstrated harboring the receptor binding domain, successfully elicited SARS-CoV specific IgG antibody in mouse after combined immunization with DNA and purified S1 protein; the antibody elicited solely by S1 could potently neutralize SARS-CoV (HKU-39849) in vitro, 50% of 1 000 TCID50 SARS-CoV challenged cells were protected from viral infection by a 1:1499.68 dilution of mice sera immunized with S1 protein, but negative control sera showed no protection. CONCLUSION: S1 domain of SARS-CoV spike protein, which is responsible for receptor binding, can efficiently and sufficiently induce highly potent neutralizing antibody in mice. This result suggested that S1 domain could be an effective subunit vaccines against SARS-CoV.

Animals↗

PubMed2003

Tempol-H inhibits opacification of lenses in organ culture.

Cataract is the world's leading cause of blindness and a disease for which no efficacious medical therapy is available. To screen potential anti-cataract agents, a lens organ culture model system was used. Opacification of lenses maintained in culture was induced by specific insults including H(2)O(2) or the cataractogenic sugar xylose. Potential anti-cataract agents were added to the culture medium and their ability to inhibit opacification and certain biochemical changes associated with the opacification were assessed. Among the compounds tested, Tempol-H, the hydroxylamine of the nitroxide Tempol, gave the most promising results. It significantly inhibited opacification of rat lenses in an H(2)O(2)-induced cataract system as well as opacification of rhesus monkey lenses induced by xylose. Tempol-H inhibited the loss of glutathione, the leakage of protein, and decreases in the ability of cultured lenses to accumulate (3)H-choline from the medium, all of which were associated with the development of lens opacification. The antioxidative activity of Tempol-H and its ability to re-dox cycle make it an attractive candidate as a therapeutic agent for the prevention of aging-related cataract.

Animals↗

PubMed2003

A novel recombinant adeno-associated virus vaccine reduces behavioral impairment and beta-amyloid plaques in a mouse model of Alzheimer's disease.

Memory impairment progressing to dementia is the main clinical symptom of Alzheimer's disease (AD). Deposition of the amyloid-beta peptide (Abeta) in brain, particularly its 42-amino acid isoform (Abeta42), has been shown to play a primary and crucial role in the pathogenesis of AD. In this study we have developed a recombinant adeno-associated virus (AAV) vaccine against AD. This vaccine could express CB-Abeta42 (cholera toxin B subunit and Abeta42 fusion protein) in vivo. A single administration of the AAV-CB-Abeta42 vaccine induced a prolonged, strong production of Abeta-specific serum IgG in transgenic mice that overexpressed the London mutant of amyloid precursor protein (APP/V717I), and resulted in improved ability of memory and cognition, decreased Abeta deposition in the brain, and a resultant decrease in plaque-associated astrocytosis. Our results extended the immunological approaches for the treatment and prevention of AD to an oral, intranasal, or intramuscular route that might be better tolerated in human patients than repetitive parental immunizations in the presence of adjuvant. AAV has attracted tremendous interest as a promising vector for gene delivery. Our results raised the possibility that AAV-CB-Abeta42 vector immunization may provide the basis of a novel and promising Alzheimer's disease vaccination program.

Adenoviridae↗

PubMed2003

The mouse Chrna4 A529T polymorphism alters the ratio of high to low affinity alpha 4 beta 2 nAChRs.

Previously, a missense polymorphism was identified in the mouse nicotinic receptor alpha4 subunit gene, Chrna4. This polymorphism leads to an Ala/Thr variation at amino acid position 529 of the alpha4 subunit. Chrna4 A529T is associated with several measures of acute sensitivity to nicotine as well as with mouse strain differences in nicotine-stimulated (86)Rb(+) efflux from synaptosomes. Here, we report that the variant forms of the mouse alpha4 subunit confer functional differences when expressed with the beta2 subunit in a heterologous system. alpha4beta2 receptors containing the T529 variant of the alpha4 subunit exhibited a higher EC(50) value for the high affinity receptor population and an apparent reduced sensitivity to blockade by DHbetaE relative to alpha4beta2 receptors containing the A529 variant of the alpha4 subunit. Moreover, the proportion of the total agonist-elicited current contributed by the high affinity alpha4beta2 receptor population was greater for alpha4beta2 receptors containing the alpha4(T529) variant (64%) than the alpha4beta2 receptors containing the alpha4(A529) variant (41%). These data suggest that the polymorphism in the mouse alpha4 subunit is located in a previously unidentified functional domain of the receptor subunit that influences receptor function, including regulation of the affinity population ratio of alpha4beta2 receptors.

Alanine↗

PubMed2003

[Analysis on the SARS-CoV genome of PUMC01 isolate].

OBJECTIVE: To perform variation and phylogenetics analysis on the SARS-CoV genome sequence (PUMC01) isolated in the Peking Union Medical College Hospital. METHODS: The cDNA library of SARS-CoV (PUMC01 isolate) was constructed by means of random-priming strategy. Random selected plasmid was sequenced and the genome sequence of SARS-CoV-PUMC01 was assembled by conventional methods (The Genebank Accession No. of SARS-CoV-PUMC01 is AY350750). The variation and phylogenetics analysis were performed by comparing the PUMC01 sequence with other SARS-CoV isolates. RESULTS: Ten variation sites were found by comparing PUMC01 isolate with Tor2 and Urbani isolates. In phylogenetic analysis of 18 SARS-CoV isolates, two classes were observed and there is different differential time between these two classes and the different isolates in each class. CONCLUSIONS: The evidence of phylogenetic analysis of different SARS-CoV isolates from different region is instructive for understanding the clinical relations between the different isolates and the transmission chain of SARS-CoV.

Amino Acid Sequence↗

PubMed2003

[cDNAs cloning of SARS-CoV PUMC2 viral genome].

OBJECTIVE: To get the cDNA clones which cover the whole genome of SARS-CoV PUMC2 strain. METHODS: Using the SARS-CoV PUMC2 strain genomic RNA as the template, the cDNA fragments were amplified by RT-PCR, the PCR products were further purified and ligated into the pGEM-T vector, and all the clones obtained were sequenced. RESULTS: The cDNA clones which cover the whole genome of SARS-CoV PUMC2 strain were obtained. CONCLUSIONS: These cDNAs can be provided for the function study of SARS-CoV proteins and the construction of full-length infectious cDNA clone of SARS-CoV.

Amino Acid Sequence↗

PubMed2003

[Cloning, expression and purification of SARS coronavirus PUMC2 strain nucleocapsid protein].

OBJECTIVE: To clone, express and purify nucleocapsid protein from SARS coronavirus PUMC2 strain. METHODS: According to the published SARS coronavirus genome sequences, the full length cDNA of N protein from SARS coronavirus PUMC2 strain was cloned by RT-PCR and the cDNA was cloned into the pET32a expression vector. The recombinant N protein was expressed in E. coli BL21 (DE3), and purified by Ni(2+)-NTA. RESULTS: Prokaryoticly expressed and purified N protein of SARS coronavirus PUMC2 strain was obtained. CONCLUSIONS: The SARS coronavirus recombinant N protein obtained by genetic engineering methods can be used for further functional study of SARS coronavirus N protein.

Amino Acid Sequence↗