Biomedical subjects

Xin Yu

Publications and source records attributed to Xin Yu.

76 records · Page 5Linked to original sources

PubMed2002

Immune complex stimulation of human neutrophils involves a novel Ca2+/H+ exchanger that participates in the regulation of cytoplasmic pH: flow cytometric analysis of Ca2+/pH responses by subpopulations.

The activation of human phagocytic leukocytes by immune complexes (IC) or opsonized microbes via their Fc and complement receptors has been well-described. The mechanisms involved in this process are complex and depend on the receptors involved. The biochemical events that lead to the destruction of invading organisms in turn display varying degrees of interdependence, but the controlling elements that lead to the ultimate killing of ingested organisms within phagosomes by lysosomal enzymes and reactive oxygen intermediates are still not completely understood. We have addressed these mechanisms by following and correlating the kinetics of responses by individual cells, using multiparameter flow cytometry. Using nonopsonized IC as stimuli, we document here the presence of a novel Ca(2)(+)/H(+) voltage-independent channel in human neutrophils, which helps to control their cytoplasmic pH.

Antigen-Antibody Complex↗

PubMed2002

[Determination of benzo[a]pyrene in mainstream smoke by solid-phase extraction and gas chromatography-mass spectrometry].

A novel method is suggested for the determination of benzo[a]pyrene in mainstream smoke. Extraction of Cambridge pads was cleaned up with methanol/n-heptane extraction system and silica solid-phase extraction (SPE). The eluted solution containing benzo[a]pyrene was evaporated gently to complete dryness with N2 flow, then reconstituted in 200 microL ethyl acetate for determination with gas chromatography-mass spectrometry selected ion monitoring (SIM). The proposed method had good results and precision for the separation of pyrene in complex matrices.

Benzo(a)pyrene↗

PubMed2001

The LIM domain protein LMO4 interacts with the cofactor CtIP and the tumor suppressor BRCA1 and inhibits BRCA1 activity.

LMO4 belongs to the LIM-only (LMO) group of transcriptional regulators that appear to function as molecular adaptors for protein-protein interactions. Expression of the LMO4 gene is developmentally regulated in the mammary gland and is up-regulated in primary breast cancers. Using LMO4 in a yeast two-hybrid screen, we have identified the cofactor CtIP as an LMO4-binding protein. Interaction with CtIP appeared to be specific for the LMO subclass of LIM domain proteins and could be mediated by a single LIM motif of LMO4. We further identified the breast tumor suppressor BRCA1 as an LMO4-associated protein. The C-terminal BRCT domains of BRCA1, previously shown to bind CtIP, also mediated interaction with LMO4. Tumor-associated mutations within the BRCT repeats that abolish interaction between BRCA1 and CtIP had no effect on the association of BRCA1 with LMO4. A stable complex comprising LMO4, BRCA1, and CtIP was demonstrated in vivo. The LIM domain binding-protein Ldb1 also participated in this multiprotein complex. In functional assays, LMO4 was shown to repress BRCA1-mediated transcriptional activation in both yeast and mammalian cells. These findings reveal a novel complex between BRCA1, LMO4, and CtIP and indicate a role for LMO4 as a repressor of BRCA1 activity in breast tissue.

Adaptor Proteins, Signal Transducing↗

PubMedDate not supplied

The cognitive subscale of Alzheimer's Disease Assessment Scale, Chinese version in staging of Alzheimer disease.

This study was designed to examine the utility of the ADAS-Cog, Chinese version (ADAS-Cog-C) for staging of dementia in Alzheimer disease (AD). A total of 305 patients with AD (199 mild AD and 106 moderate AD) meeting the NINCDS-ADRDA criteria of probable AD were recruited. The ADAS-Cog-C was administered to all AD subjects. The total score of ADAS-Cog-C and each item score differed significantly between mild and moderate AD groups, with moderate AD group scoring higher. Statistical analysis showed insignificant influence of age or educational level on the ADAS-Cog-C total score. The item score of orientation and constructional praxis and the ADAS-Cog total score could classify mild and moderate AD efficiently, with a sensitivity of 78% to 82% and a specificity of 70% to 73%. The results of this study indicate that the ADAS-Cog-C can discriminate mild AD from moderate AD efficiently and be useful for staging of AD. It is recommended that the ADAS-Cog-C be introduced for monitoring the cognitive efficacy in AD drug treatment among Chinese AD patients.

Aged↗