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Yang Jiao

Publications and source records attributed to Yang Jiao.

9 recordsLinked to original sources
PubMed2007

LC/ESI-MS method for the determination of trimetazidine in human plasma: application to a bioequivalence study on Chinese volunteers.

A rapid liquid chromatography electrospray ionization mass spectrometry (LC/ESI-MS) method with good sensitivity and specificity has been developed and validated for the identification and quantification of trimetazidine in human plasma. Trimetazidine and lidocaine (internal standard) were isolated from plasma samples by protein precipitation with methanol. The chromatographic separation was accomplished on a Xterra MS C18 Column (150 mm x 4.6 mm, 5 microm particle size) with the mobile phase consisting of methanol and water (40:60, v/v) (pH 2.0, adjusted with trifluoroacetic acid), and the flow rate was set at 0.6 mL/min. Detection was performed on a single quadruple mass spectrometer by selected ion monitoring (SIM) mode (m/z 267.0 for trimetazidine and m/z 235.0 for lidocaine) with the retention time at about 3.47 and 5.05 min, respectively. The calibration curve for trimetazidine was satisfactory with regression coefficient 0.9995 over the range of 2.5-100 ng/mL in the plasma. The LOQ (S/N=10) was accordingly 2.5 ng/mL. The intra-day and inter-day precision expressed as relative standard deviation was 2.83-6.10% and 4.83-5.82%. The method was successfully applied to investigate the bioequivalence between two kinds of tablets (test versus reference product) in 19 healthy male Chinese volunteers. After a single 20 mg dose for the test and reference product, the resulting mean of major pharmacokinetic parameters such as AUC(0-24), AUC(0-infinity), Cmax, Tmax and t(1/2) of trimetazidine were (673.1+/-117.6 ng h mL(-1) versus 652.3+/-121.9 ng h mL(-1)), (717.1+/-120.9 ng h mL(-1) versus 692+/-128.6 ng h mL(-1)), (74.85+/-12.13 ng mL(-1) versus 71.93+/-14.32 ng mL(-1)), (2.312+/-0.663 h versus 2.211+/-0.608 h) and (4.785+/-0.919 h versus 4.740+/-0.823 h), respectively, indicating that these two kinds of tablets were bioequivalent in the Chinese population.

Adult↗
PubMed2006

Association between Nef-specific CD8 T-cell responses and disease progression in HIV-1 subtype B infection.

BACKGROUND: The correlation between HIV-1 Nef-specific CD8 T-cell responses and markers of HIV-1 disease progression still remains unclear. This study analysed and compared the role of HIV-1 Nef-specific CD8 T-cell responses in patients with different disease status. METHODS: Two groups of patients with HIV-1 subtype B infection were selected according to CD4 count and clinical manifestations: long-term nonprogressors (LTNPs, n = 20) and advanced progressors (APs, CD4 count < 500 cells/microl, n = 34). Nef-specific CD8 T-cell responses were studied by interferon-gamma ELISpot assay against 3 pools of HIV-Nef peptides. RESULTS: Nef-specific CD8 T-cell responses did not correlate with viral load or CD4 count in all patients and no significant differences were found in the magnitude of Nef-specific CD8 T-cell responses between groups LTNPs and APs (670 SFC/10(6) peripheral blood mononuclear cells vs 1107 SFC/10(6) peripheral blood mononuclear cells, P = 0.255). Further comparisons showed that there were also no significant correlations observed in group LTNPs, but Nef-specific CD8 T cells correlated negatively with viral load (r = -0.397, P = 0.020) and positively with CD4 count (r = 0.364, P = 0.034) in group APs. CONCLUSION: These data suggest that different correlation patterns between Nef-specific CD8 T-cell responses and disease progression exist in LTNPs and APs. Although a negative association was observed with concurrent plasma HIV RNA in APs, Nef-specific CD8 T-cell responses might fail to play a protective role in different stages of HIV-1 infection.

Acquired Immunodeficiency Syndrome↗
PubMed2006

Accelerating effect of human leukocyte antigen-Bw6 homozygosity on disease progression in Chinese HIV-1-infected patients.

Most HIV-1-infected individuals progress to AIDS within 8 to 10 years after seroconversion. Less than 5% of them, however, remain asymptomatic, although their CD4 T-cell counts stay normal. In this study, our polymerase chain reaction sequence-specified primer (PCR-SSP) based human leukocyte antigen (HLA)-B genotyping of 28 typical progressors (TPs) and 15 long-term nonprogressors (LTNPs) revealed some evidence that an HLA-B locus polymorphism can influence the rate of disease progression in Chinese HIV-1-infected individuals: 12 of 28 TPs (43%) were HLA-Bw6 homozygotes. Only 1 of 15 LTNPs (6.7%) was homozygous for the polymorphism (P = 0.013), suggesting that HLA-Bw6 homozygosity is associated with accelerated disease progression. In contrast, 3 of 15 LTNPs (20%) were HLA-Bw4 homozygotes, whereas none of the 28 TPs were homozygotes (P = 0.037), supporting the conclusion that HLA-Bw4 homozygosity may have a protective role. Interestingly, the frequency of the HLA-B*15 allele was extremely high in the TP group (23.2%), which may be associated with faster disease progression in Chinese patients.

Adult↗
PubMed2006

Correlation between gag-specific CD8 T-cell responses, viral load, and CD4 count in HIV-1 infection is dependent on disease status.

BACKGROUND: It still remains controversial which kind of relationships exist between HIV-1-specific CD8 T-cell responses and HIV RNA load or CD4 count over the course of the infection. This study was designed to investigate the role of HIV-specific CD8 responses in patients with different disease status. METHODS: Three cohorts of patients were selected according to CD4 count levels: long-term nonprogressors (LTNPs, n = 19), asymptomatic progressors (CD4 counts between 500 and 350 cells/mm(3), n = 14), and progressors (CD4 counts <350 cells/mm(3), n = 23). Six of the LTNPs experiencing a quick loss of CD4 T-cells and another 6 LTNPs with stable CD4 counts were followed up. T-cell responses were studied using interferon (IFN) gamma-ELISpot assay against HIV p24 and 11 pools of HIV-Gag peptides. RESULTS: No significant differences were found in Gag-specific CD8 responses among the 3 cohorts. However, inverse correlations were identified between CD8 responses and CD4 counts in asymptomatic progressors and between CD4 responses and viral loads in progressors. In addition, the sequential dynamics of CD8 responses in 6 LTNPs showed that with a quick loss of CD4 T-cells around the range of 500 to 300 cells/mm(3), more vigorous CD8 responses were induced simultaneously, and plasma viremia was still kept relatively stable. CONCLUSIONS: These data suggest that the relationship between CD8 response and viral load or CD4 count is not universally consistent throughout the entire course of HIV-1 infection. Gag-specific CD8 responses may play differential roles in different stages of HIV-1 infection, and the maintenance of a threshold level of CD4 T-cells may contribute to mediate effective HIV-specific responses in natural control of HIV-1 infection.

Adult↗
PubMed2005

Activation of mitogen-activated protein kinases during human lung transplantation.

BACKGROUND: Ischemia-reperfusion is one of the unavoidable steps in lung transplantation; it is associated with acute inflammatory responses and cell death. The intracellular signal transduction mechanisms of these events are largely unknown. We hypothesize that activation of mitogen-activated protein kinases (MAPKs) is one of the important signaling events during human lung transplantation. METHODS: Lung tissue biopsies were performed on 15 patients undergoing transplantation: after cold ischemic preservation; after warm ischemia (implantation); and after 1- or 2-hour reperfusion. The phosphorylation status of MAPK isoforms (ERK, p38-MAPK and JNK) was examined by Western blotting. RESULTS: Phosphorylation of ERK was dramatically increased during the first 2 hours of reperfusion. Phosphorylation of JNK also significantly increased at lower levels. In contrast, phosphorylation of p38 showed no significant changes. CONCLUSIONS: We speculate that the rapid and sustained activation of ERK and JNK during the early reperfusion period may contribute to acute inflammatory responses and cell death of lung grafts.

Adolescent↗
PubMed2005

Photonic crystal device sensitivity analysis with Wannier basis gradients.

We present a powerful sensitivity analysis method for devices in a photonic crystal. The method is based on a Wannier basis field expansion and efficient matrix analysis techniques for finding eigenvalue and transmission gradients with respect to the perturbation. The method permits fast analysis of a large number of dielectric perturbation situations for multiple devices in a photonic crystal. We verify the method with finite-difference time-domain and plane-wave expansion calculations.

Journal Article↗
PubMed2005

Demonstration of systematic photonic crystal device design and optimization by low-rank adjustments: an extremely compact mode separator.

We present a powerful design and optimization method for devices in a photonic crystal. The method is based on a Wannier basis field expansion and efficient matrix analysis techniques for searching through a vast number of designs. The method permits the design of many compact optical devices with complex and novel functions. We present a design example of a very compact mode separator that is 8.2 microm x 13.3 microm in size that demultiplexes the three modes of an input photonic crystal multimode waveguide into three single-mode output waveguides. We verify the method with finite-difference time-domain calculations.

Journal Article↗
PubMed2004

Designing for beam propagation in periodic and nonperiodic photonic nanostructures: extended Hamiltonian method.

We use Hamiltonian optics to design and analyze beam propagation in two-dimensional (2D) periodic structures with slowly varying nonuniformities. We extend a conventional Hamiltonian method, adding equations for calculating the width of a beam propagating in such structures, and quantify the range of validity of the extended Hamiltonian equations. For calculating the beam width, the equations are more than 10(3) times faster than finite difference time domain (FDTD) simulations. We perform FDTD simulations of beam propagation in large 2D periodic structures with slowly varying nonuniformities to validate our method. Beam path and beam width calculated using the extended Hamiltonian method show good agreement with FDTD simulations. By contrasting the method with ray tracing of the bundle of rays, we highlight and explain the limitations of the extended Hamiltonian method. Finally, we use a frequency demultiplexing device optimization example to demonstrate the potential applications of the method.

Journal Article↗