Biomedical subjects

Liu Ying

Publications and source records attributed to Liu Ying.

5 recordsLinked to original sources

PubMed2005

A powerful graphical pulse sequence programming tool for magnetic resonance imaging.

A powerful graphical pulse sequence programming tool has been designed for creating magnetic resonance imaging (MRI) applications. It allows rapid development of pulse sequences in graphical mode (allowing for the visualization of sequences), and consists of three modules which include a graphical sequence editor, a parameter management module and a sequence compiler. Its key features are ease to use, flexibility and hardware independence. When graphic elements are combined with a certain text expressions, the graphical pulse sequence programming is as flexible as text-based programming tool. In addition, a hardware-independent design is implemented by using the strategy of two step compilations. To demonstrate the flexibility and the capability of this graphical sequence programming tool, a multi-slice fast spin echo experiment is performed on our home-made 0.3 T permanent magnet MRI system.

Animals↗

PubMed2005

Environmental scanning electron microscopy observation of the ultrastructure of Demodex.

In this study, numbers of Demodex of hair follicles and sebaceous glands were prepared and the ultrastructure (especially the mouthparts) of Demodex was observed firstly with environmental scanning electron microscopy (ESEM). The most suitable treatment methods and optimal environmental condition for observing the genus samples were found. The samples were washed with detergent and rinsed with distilled water, and then were taken to the specimen stage, on which there was carbon adhesive tape, using special tools. When the temperature was at 5 degrees C and chamber pressure at 5 mbar respectively, the surface of the samples could be fully imaged without covering water or dehydration. The sample surfaces were plump and clear without postmortem changes and charging artifacts. Detailed information about each part of Demodex was observed by ESEM, and clear three-dimensional images were recorded. The mouthparts of D. folliculorum were composed of a complex set of structures, which included a round oral opening, a sharp oral needle, and a special hypostome that looked like a longitudinal spindle in the central position. On the end segment of palpus, there were seven strong palpal claws located on each side of the mouthparts. D. folliculorum had special piercing mouthparts, while the mouthparts of D. brevis were a simpler structure. We could not observe the oral needle of D. brevis, and there were only five pairs of palpal claws on the end segment of palpus. The offensive organs of Demodex resulted in its pathogenic effects. After studying hundreds of Demodex, we identified both female and male species of D. folliculorum, but only females of D. brevis in our sample.

Animals↗

PubMed2005

Induction of anti B-cell malignance CTL response by subfamily-shared peptides derived from variable domain of immunoglobulin heavy chain.

The variable domain of immunoglobulin heavy chain (Ig HV) is well-characterized tumor associated antigen expressed in B-cell malignancies, which may function as a T-cell target. However, T-cell epitopes derived from shared framework regions (FRs) of each IgHV subfamily capable of inducing cytotoxic T lymphocytes (CTLs) against the B-cell malignancy, have not been identified. Using the specific PCR primers of seven IgHV gene subfamilies, we amplified the IgHV gene rearrangement for 108 cases of B-cell acute lymphoblastic leukemia (B-ALL) patients. The IgHV gene rearrangement fragments of B-ALL patients were directly sequenced then classified into seven different subfamilies. The T-cell epitopes encoded by the IgHV gene in the B-ALL patients were predicted by SYFPEITHI and BIMAS programs and compared with those from 56 representative germline IgHV sequences in the genebank. For the HLA-A*0201 locus, we found 1 or 2 top score shared epitopes from each subfamily and got 12 epitopes altogether. Results showed that ten of them were in the FRs. Using an antigen-specific T-cell expansion system, we generated the peptide-special CTLs in vitro, which were capable of killing B lymphoma cell lines that belonged to the same IgHV subfamily in a peptide-specific and HLA-restricted manner. Furthermore, we proved that the cytotoxicity of CTLs was IgHV subfamily-specific. These data indicate possible immunotherapy approaches for B-cell malignances patients based on IgHV gene subfamilies.

Burkitt Lymphoma↗

PubMed2003

Use of multiplex PCR to identify Staphylococcus aureus adhesins involved in human hematogenous infections.

We have developed a multiplex PCR procedure to determine the distribution of nine adhesin genes in Staphylococcus aureus isolates. Only genes encoding bone sialoprotein binding protein and fibronectin binding protein B were significantly associated with hematogenous osteomyelitis/arthritis and native-valve endocarditis, respectively, suggesting their involvement in hematogenous tissue infections.

Adhesins, Bacterial↗

PubMed2002

Reaching and identifying the STD/HIV risk of sex workers in Beijing.

China's HIV cases are growing by more than 30% annually. Few researchers have been able to reach sex workers and examine their risk behavior patterns. Key informants in illegal prostitution connected with owners of establishments in Beijing to recruit the involvement of sex workers. A total of 69 were surveyed about their background and risk behaviors in spring, 2000 in four venues; hair salons, bathing centers, karaoke bars, and the street. The women were mostly young (in their 20s), of low socioeconomic status, and from small towns and villages. They worked about 3 to 4 days a week, averaged one to two clients per day, made the equivalent of about U.S. $135 a week, and averaged about 3 months at any one establishment. They lacked accurate knowledge of STDs/HIV, and although 61% reported consistent condom usage 93% associated usage with prevention of pregnancy and 72% perceived a low risk of HIV infection. Nearly all (98%) felt condoms were affordable, yet 37% reported they were not accessible; 74% had obtained a medical exam in the last year, but 29% were examined when sick; only 10% received prevention information during medical visits, and 55% did not know where to go for HIV testing. Based on venue, stratification among sex workers existed, impacting their risk. Sex workers are at high risk of HIV infection/transmission, especially as the virus becomes more established in Beijing. Although risk factors were consistent with those of sex workers in other countries, the variation by venue, the low perceived vulnerability to HIV, the highly illegal nature of prostitution, and high mobility of sex workers in Beijing calls for a tailored intervention approach. Prevention messages/strategies should be responsive to the differing background, knowledge,

AIDS Serodiagnosis↗