PubMed Health⌕ Search

Biomedical subjects

Y Y Qian

Publications and source records attributed to Y Y Qian.

5 recordsLinked to original sources
PubMed2006

Does endothelial chimerism correlate with renal allograft rejection?

BACKGROUND: The blood vessels of a transplanted organ are an interface between the donor and the recipient. The endothelium is believed to be a major target for graft rejection. After transplantation endothelial cells of a transplanted organ may be of recipient origin. OBJECTIVES: In this study we sought to determine whether endothelial chimerism correlates with graft rejection. METHODS: Biopsy samples from 34 renal transplants of female recipients who received kidneys from male donors were studied for the presence of endothelial cells of recipient origin. Formalin-fixed, paraffin-embedded tissue sections of renal biopsy samples were examined by fluorescence in situ hybridization (FISH) for the presence of endothelial cells containing two X chromosomes, using a biotinylated Y-chromosome probe and digoxigenin-labeled X-chromosome probe. RESULTS: The FISH methods identified endothelial cells of recipient origin. Endothelial chimerism was common, irrespective of rejection. Its presence was focal with these elements, coexisting in the biopsy. CONCLUSIONS: We observed no correlation between the percentage of recipient endothelial cells among vascular elements and the type of graft rejection (P > .05).

Biopsy↗
PubMed1996

Thermomechanical analysis of shape memory devices.

Shape memory alloys (SMA) are being increasingly used in various industrial applications as actuators, connectors, or damping materials. In the medical field, superelastic devices such as eyeglass frames, stents or guide catheters have come to market in the recent years. The design of SMA devices has usually been based on trial and error, since until recently no general simulation model was available to assist application engineers. The purpose of this article is to describe the computational methodology developed, validated and used for several industrial projects at Ecole Polytechnique of Montréal to simulate the thermomechanical behavior of shape memory materials. This new approach includes three main stages: experimental characterization, construction of a nonlinear material law based on dual kriging interpolation and finally, calculation of the thermomechanical response of SMA devices. For complex geometry, finite element analysis is used, but for simple devices such as springs or electrically activated SMA wires, simplified calculation methods are satisfactory. Validation results recently obtained will also be presented, and examples of industrial applications briefly reviewed.

Algorithms↗
PubMed1990

[Distribution and depth of internal mammary lymph nodes in breast cancer].

Lymphoscintigraphy was performed in 50 cases of breast cancer using 99mTc-colloid as a tracer. The results indicated that 277 lymph nodes, 128 on the right side and 149 on the left, were imaged. Most of the lymph nodes were located in the second and third intercostal spaces. The mean distance between these lymph nodes and mid line was 1.93 +/- 1.05 cm-2.70 +/- 0.93 cm. The mean depth was 2.42 +/- 0.52 cm-3.07 +/- 0.72 cm. It was over 4.0 cm in isolated cases. The lymph nodes which were not showed after repeated examination could have been involved by the cancer. Radionuclide lymphoscintigraphy, being safe, easily repeated and having low radiation dose and good image, is very useful for radiotherapy.

Adult↗
PubMed1989

Cyclosporin A is an adjuvant in murine IgE antibody responses.

Cyclosporin A (CsA) is an undecapeptide fungal metabolite and is generally regarded as a new generation of immunosuppressive drugs. We uncovered a novel immunomodulatory property of CsA as a potent immunologic stimulator in the murine IgE antibody system. The enhancement of IgE responses was observed in mice receiving as few as three daily i.m. injections before Ag priming. Our studies demonstrate the three points listed below. First, CsA potentiates murine IgE responses regardless of Ag specificities in inbred mice. A hierarchy of immunopotentiation by CsA follows the order of low, intermediate, and high IgE responder mice. Second, CsA, when administered along with Ag, exerts a thorough and long lasting impact on the Ag-specific IgE antibody response, and leads to an Ag-specific breakthrough of IgE antibody synthesis in mice rendered tolerant in the IgE antibody system by soluble Ag pretreatment or neonatal IgE treatment. Third, IgE enhancer cells become sensitive to a low dose of irradiation. Two enhancer cellular components are identified, those of the Th cells and B cells, which appear to favor the induction of IgE responses. Understanding the cellular basis of the immunopotentiating effect of CsA will provide further insight into the murine IgE antibody system.

Adjuvants, Immunologic↗