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Ping Yu

Publications and source records attributed to Ping Yu.

79 records · Page 5Linked to original sources
PubMed2002

The complementation of lymphotoxin deficiency with LIGHT, a newly discovered TNF family member, for the restoration of secondary lymphoid structure and function.

Highly organized lymphoid structures provide the intricate microenvironment essential for the mediation of the effective immune responses. Compared with lymphotoxin beta knockout mice (LTbeta-/-), LTbeta receptor knockout (LTbetaR-/-) mice present with more severely disorganized splenic structures, suggesting the potential involvement of another ligand. LIGHT, a newly identified TNF family member, is a costimulatory molecule for T cells and binds to LTbetaR and herpes virus entry mediator (HVEM) in vitro. Here, we show that the complementation of LTalpha-/- mice with a LIGHT transgene (LIGHT Tg/LTalpha-/-) leads to the restoration of secondary lymphoid tissue chemokine and T/B cell zone segregation. LIGHT Tg/LTalpha-/- mice also preserve dendritic cells, follicular dendritic cell networks, and germinal centers, though not the marginal zone. Consequently, IgG responses to soluble, but not particulate, antigens are restored, confirming the role of primary follicle and marginal zone in the responses to soluble and particulate antigens. The failure of the LIGHT transgene to rescue the defective splenic structures in LTbetaR-/- mice demonstrates that LIGHT can interact with LTbetaR in vivo. More severely disorganized splenic structures developed after blockade of endogenous LIGHT in LTbeta-/- mice. These findings uncover the potential interaction between LIGHT and one of its receptors, LTbetaR, in supporting even in the absence of LT the development and maintenance of lymphoid microenvironment.

Animals↗
PubMed2002

PJA1, encoding a RING-H2 finger ubiquitin ligase, is a novel human X chromosome gene abundantly expressed in brain.

RING-finger proteins contain cysteine-rich, zinc-binding domains and are involved in the formation of macromolecular scaffolds important for transcriptional repression and ubiquitination. In this study, we have identified a RING-H2 finger gene, PJA1 (for praja-1), from a human brain cDNA library and mapped it to human chromosome Xq12 between markers DXS983 and DXS1216, a region implicated in X-linked mental retardation (MRX). Northern blot analysis indicated a 2.7-kb transcript that was abundantly expressed in the brain, including regions of the cerebellum, cerebral cortex, medulla, occipital pole, frontal lobe, temporal lobe, and putamen. Amino acid sequence analysis of the 71-kDa protein PJA1 showed 52.3% identity to human PJA2 (for praja-2, also known as NEURODAP1/KIAA0438) and also a significant identity to its homologs in rat, mouse, and zebrafish. In vitro binding and immunoprecipitation assays demonstrated that both PJA1 and PJA2 are able to bind the ubiquitin-conjugating enzyme UbcH5B. Moreover, the ubiquitination assay indicated that PJA1 and PJA2 have an E2-dependent E3 ubiquitin ligase activity. Thus our findings demonstrate that PJA1 can be involved in protein ubiquitination in the brain and is a suitable candidate gene for MRX.

Amino Acid Sequence↗
PubMed2002

Increasing tumor antigen expression overcomes "ignorance" to solid tumors via crosspresentation by bone marrow-derived stromal cells.

To explain why solid cancers grow or are rejected, we examined how the tumor stroma affected the level of antigen expression necessary to induce an immune response. We applied a tamoxifen-regulated Cre-loxP system to induce a model SIYRYYGL antigen recognized by the 2C T cell receptor. Solid tumors expressing the antigen at lower levels grew, whereas solid tumors expressing antigen induced to 26-fold higher levels were rejected. In contrast, mice rejected cell suspensions expressing higher or lower levels of the antigen. The antigen was likely crosspresented because draining lymph node responses required bone marrow-derived cells in the tumor stroma. Thus, tumor antigens expressed at levels sufficient for crosspresentation by bone marrow-derived stromal cells may overcome immunological "ignorance" to solid tumors.

Animals↗
PubMedDate not supplied

Correlation of instrumental voice evaluation with perceptual voice analysis using a modified visual analog scale.

Various rating scales have been used for perceptual voice analysis including ordinal (ORD) scales and visual analog (VA) scales. The purpose of this study was to determine the most suitable scale for studies using perceptual voice analysis as a gold standard for validation of objective analysis protocols. The study was carried out on 74 female voice samples from 68 dysphonic patients and 6 controls. A panel of 4 raters with experience in perceptual analysis was asked to score voices according to the G component (overall quality) of the GRBAS system. Two rating scales were used. The first was a conventional 4-point ORD scale. The second was a modified VA (mVA) scale obtained by transforming the VA scale into an ORD scale using a weighted conversion scheme. Objective voice evaluation was performed using the EVA workstation. Objective measurements included acoustic, aerodynamic, and physiologic parameters as well as parameters based on nonlinear mathematics (e.g., Lyapunov coefficient). Instrumental measurements were compared with results of perceptual analysis using either the conventional ORD scale or mVA scale. Results demonstrate that correlation between perceptual and objective voice judgments is better using a mVA scale than a conventional ORD scale (concordance, 88 vs. 64%). Data also indicate that the mVA scale described herein improves the correlation between objective and perceptual voice analysis.

Adult↗
PubMedDate not supplied

Acoustic and aerodynamic measurements of voice production after near-total laryngectomy with epiglottoplasty.

Objective voice analysis based on simultaneous aerodynamic and acoustic measurements is not common and there have been no reports dealing specifically with aerodynamic features of laryngeal performance after partial laryngectomy. The present study describes objective voice analysis after near-total laryngectomy using the Tucker technique (NTLT). We performed and compared acoustic and aerodynamic measurements in patients who underwent NTLT (n = 21) and normal controls (n = 10). Acoustic indexes of instability of frequency and intensity (jitter and shimmer) were always higher in patients. Oral airflow and estimated subglottic pressure (ESPG) were significantly greater in patients than in controls (400 vs. 169 cm(3)/s and 23 vs. 6.2 hPa, respectively). Poor closure of the glottis after surgery leads to a significant increase in glottal leakage in comparison with controls. Higher ESGP values observed in patients are probably related to two factors. The first involves compensation for glottal leakage in order to achieve sufficient air pressure to initiate vibration of the mucosa. The second factor is the poor vibratory quality of the residual mucosa, which may require higher pressure levels than the more compliant normal cord to initiate vibration. Our findings confirm the adverse effects of NTLT on the aerodynamic efficiency of the larynx due to glottal leakage and poor compliance of postoperative mucosa. Aerodynamic measurements could provide the basis for standardized objective evaluation of postoperative voice quality.

Adult↗
PubMedDate not supplied

Reproducibility of a semi-quantitative food frequency questionnaire in Chaoshan area, China.

OBJECTIVE: To examine reproducibility of assessed intake of foods and nutrients according to a semi-quantitative food frequency questionnaire (SQFFQ) in adult doctors and nurses residing in Chaoshan area of China. SUBJECTS: The SQFFQ was administered first in October to December of 2004 to 120 adult doctors and nurses living in Chaoshan area of China and was then re-administered to 102 three months later between January and March of 2005 (SQFFQ 1 and SQFFQ 2). METHODS: Reproducibility was evaluated in terms of consumption of 10 food groups and energy and 34 macro- and micro-nutrients based on the SQFFQ from the 102 doctors and nurses. RESULTS: For intake of foods, Pearsom's correlation coefficients (CCs) with log-transformation and energy adjustment (minimum - median - maximum) range from 0.43 (eggs) - 0.84 - 0.90 (teas). Spearman's rank CCs with energy adjustment ranged from 0.77 (cereals) - 0.84 - 0.94 (milks). Kappa statistics with energy adjustment ranged from 0.53 (vegetables) - 0.63 - 0.82 (teas). For consumption of nutrients, Pearson's correlation coefficients (CCs) with log-transformation and energy adjustment (minimum - median - maximum) range from 0.83 (docosahexaenoic acid and oryzanin) - 0.88 - 0.90 (linolenic acid, vitamin A, folic acid, vitamin E, calcium, sodium, selenium and magnesium). Spearman's rank CCs with energy adjustment ranged from 0.81 (oryzanin and vitamin C) - 0.86 - 0.90 (sodium). Kappa statistics with energy adjustment ranged from 0.49 (protein) - 0.60 - 0.77 (sodium). CONCLUSION: Substantially high reproducibility was observed; it is possible to use the tailored, relatively simple, but comprehensive, self-administered SQFFQ to facilitate assessment of the association between lifestyle and health/disease in large-scale epidemiological studies.

Adult↗