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Wei Liang

Publications and source records attributed to Wei Liang.

8 recordsLinked to original sources
PubMed2026

Exposure to size-specific particulate matter accelerates DNA methylation aging in people with HIV.

BACKGROUND: People with HIV (PWH) face accelerated aging and increased health risks, with DNA methylation age (DNAmAge) as a critical senescence biomarker. Particulate matter is linked to DNAmAge acceleration (DNAmAA) in general population, but its impact in PWH remains unstudied. METHODS: Thirty-two PWH from Wuhan, China, were enrolled in a prospective panel study with follow-up, and each participant underwent at least two repeated measurements during the study period. Portable air quality monitor measured PM 1 , PM 2.5 , and PM 10 exposures 72 h preblood sampling. We analyzed genome-wide DNA methylation in peripheral blood and calculated six AA metrics. Linear mixed-effects and weighted quantile sum regression models evaluated associations between particulate matter exposure and DNAmAA. RESULTS: Significant associations between particulate matter exposure and DNAmAA were observed at various lag windows. For every 10 μg/m 3 increase in 24-h average PM 2.5 , Hannum DNAmAA, Pheno DNAmAA, Grim DNAmAA, SkinBlood DNAmAA, and Elastic DNAmAA increased by 0.266 years [95% confidence interval (CI): 0.035-0.480], 0.421 years (95% CI: 0.032-0.701), 0.336 years (95% CI: 0.073-0.546), 0.295 years (95% CI: 0.021-0.495), and 0.254 years (95% CI: 0.034-0.445), respectively. PM 10 contributed most substantially to the cumulative PM effect on epigenetic AA in the lag0-24 h window. CONCLUSION: Short-term particulate matter exposure, particularly PM 10 , significantly accelerates epigenetic aging in PWH, highlighting the need to integrate air quality management into healthy aging strategies for this vulnerable population.

China↗
PubMed2003

Resistance of the human beta 1-adrenergic receptor to agonist-mediated down-regulation. Role of the C terminus in determining beta-subtype degradation.

Prolonged agonist stimulation results in down-regulation of most G protein-coupled receptors. When we exposed baby hamster kidney cells stably expressing the human beta1-adrenergic receptor (beta 1AR) to agonist over a 24-h period, we instead observed an increase of approximately 30% in both beta 1AR binding activity and immune-detected receptors. In contrast, beta 2AR expressed in these cells exhibited a decrease of > or =50%. We determined that the basal turnover rates of the two subtypes were similar (t(1/2) approximately 7 h) and that agonist stimulation increased beta 2AR but not beta 1AR turnover. Blocking receptor trafficking to lysosomes with bafilomycin A1 had no effect on basal turnover of either subtype but blocked agonist-stimulated beta 2AR turnover. As beta 1AR mRNA levels increased in agonist-stimulated cells, beta 1AR up-regulation appeared to result from increased synthesis with no change in degradation. To explore the basis for the subtype differences, we expressed chimeras in which the C termini had been exchanged. Each chimera responded to persistent agonist stimulation based on the source of its C-tail; beta 1AR with a beta 2AR C-tail underwent down-regulation, and beta 2AR with a beta 1AR C-tail underwent up-regulation. The C-tails had a corresponding effect on agonist-stimulated receptor phosphorylation and internalization with the order being beta 2AR > beta 1AR with beta 2AR C-tail > beta 2AR with a beta 1AR C-tail > beta 1AR. As internalization may be a prerequisite for down-regulation, we addressed this possibility by co-expressing each subtype with arrestin-2. Although beta 1AR internalization was increased to that of beta 2AR, down-regulation still did not occur. Instead, beta 1AR accumulated inside the cells. We conclude that in unstimulated cells, both subtypes appear to be turned over by the same mechanism. Upon agonist stimulation, both subtypes are internalized, and beta 2AR but not beta 1AR undergoes lysosomal degradation, the fate of each subtype being regulated by determinants in its C-tail.

Adrenergic beta-Agonists↗
PubMed2003

Data communication between brain implants and computer.

Recent advances in neuroscience, microelectronics, and information technology have allowed construction of miniature, but highly intelligent, devices to be implanted within the brain to perform in vitro diagnostic and therapeutic functions. However, there exists a significant problem in establishing an effective wireless data communication link between brain implants and external computer. This communication investigates this link and presents a new design using the mechanism of volume conduction of biological tissues. A theoretical model of volume conduction of the head is utilized to compute signal strength in data communication and the result is evaluated by a physical model. The two-way data communication sensitivity of the volume conduction channel is found to be symmetric, as suggested by the reciprocity theorem. A high-performance, x-shaped volume conduction antenna has been designed. Experiments are performed on animals which demonstrate the effectiveness of this volume conduction approach.

Animals↗
PubMed2003

Application of autologous tumor cell vaccine and NDV vaccine in treatment of tumors of digestive tract.

AIM: To treat patients with stage I-IV malignant tumors of digestive tract using autologous tumor cell vaccine and NDV (Newcastle disease virus) vaccine, and observe the survival period and curative effect. METHODS: 335 patients with malignant tumors of digestive tract were treated with autologous tumor cell vaccine and NDV vaccine. The autologous tumor cell vaccine received were assigned for long-term survival observation. While these failed to obtain the autologous tumor tissue were given with NDV vaccine for a received short-term observation on curative effect. RESULTS: The colorectal cancer patients treated with autologous tumor cell vaccine were divided into two groups: the controlled group (subjected to resection alone) (n=257), the vaccine group (subjected to both resection and immunotherapy) (n=310). 25 patients treated with NDV immunotherapy were all at stage IV without having resection. In postoperation adjuvant therapy patients, the 5, 6 and 7-year survival rates were 66.51 %, 60.52 %, 56.50 % respectively; whereas in patients with resection alone, only 45.57 %, 44.76 % and 43.42 % respectively. The average survival period was 5.13 years (resection alone group 4.15 years), the median survival period was over 7 years (resection alone group 4.46 years). There were significant differences between the two groups. The patients treated with resection plus vaccine were measured delayed-type hypersensitivity (DTH) reactions after vaccination, (indurative scope >5 mm). The magnitude of DTH was related to the prognosis. The 5-year survival rate was 80 % for those with indurations greater than 5 mm, compared with 30 % for those with indurations less than 5 mm. The 1-year survival rate was 96 % for 25 patients treated with NDV immunotherapy. The total effective rate (CR+PR) was 24.00 % in NDV immunotherapy; complete remission (CR) in 1 case (4.00 %), partial remission (PR) in 5 cases (20.00 %), stabilizedin in 16 cases (64.00 %), progression (PD) in 1 case (4.00 %). After NDV vaccine immunotherapy, the number of NK cell increased and immune function imporved obviously. CONCLUSION: The autologous tumor cell vaccine and NDV vaccine can prolong the patients' life. NDV vaccine is notably effective for short-term with promotion of quality of life and can be used whenever necessary with good prospects.

Cancer Vaccines↗
PubMed2003

[A study on the lingual shape and position of the teeth in Chinese with normal occlusion].

OBJECTIVE: To measure the lingual surfaces of the teeth in normal occlusion and obtain the data for lingual brackets' bonding and modifying for Chinese. METHODS: 50 casts of nonorthodontic subjects with ideal occlusion were examined using the YM-2115 3D measurement instrument. The data was calculated by the relevant software and analysed statistically. RESULTS: The reference values of the lingual surfaces of the teeth in normal occlusion were obtained. These include crown angulation(tip), crown inclination(torque), offset angles of molars and crown facial prominence. CONCLUSIONS: Compared with the data of foreigners, the characteristics of the lingual surface of the teeth in Chinese normal occlusion has many differences. The accurate placement of the lingual orthodontic brackets should be assisted by laboratory techniques because of the highly variable morphology of the lingual surfaces of the teeth.

Asian People↗
PubMed2002

Within the fold: assessing differential expression measures and reproducibility in microarray assays.

BACKGROUND: 'Fold-change' cutoffs have been widely used in microarray assays to identify genes that are differentially expressed between query and reference samples. More accurate measures of differential expression and effective data-normalization strategies are required to identify high-confidence sets of genes with biologically meaningful changes in transcription. Further, the analysis of a large number of expression profiles is facilitated by a common reference sample, the construction of which must be carefully addressed. RESULTS: We carried out a series of 'self-self' hybridizations in which aliquots of the same RNA sample were labeled separately with Cy3 and Cy5 fluorescent dyes and co-hybridized to the same microarray. From this, we can analyze the intensity-dependent behavior of microarray data, define a statistically significant measure of differential expression that exploits the structure of the fluorescent signals, and measure the inherent reproducibility of the technique. We also devised a simple procedure for identifying and eliminating low-quality data for replicates within and between slides. We examine the properties required of a universal reference RNA sample and show how pooling a small number of samples with a diverse representation of expressed genes can outperform more complex mixtures as a reference sample. CONCLUSION: Analysis of cell-line samples can identify systematic structure in measured gene-expression levels. A general procedure for analyzing cDNA microarray data is proposed and validated. We show that pooled reference samples should be based not only on the expression of individual genes in each cell line but also on the expression levels of genes within cell lines.

Brain Neoplasms↗
PubMed2002

Solubilization of drugs by physiological mixtures of bile salts.

PURPOSE: The solubilization of a number of steroids was determined in bile salt simple micelles and a bile salt/phospholipid micellar system to provide a better basis to predict the extent of drug solubilization in vivo. METHODS: Excess solid drug was dispersed in taurodeoxycholate or mixed micelle solutions prepared with fixed mole ratios of taurocholate, taurodeoxycholate, taurochenodeoxycholate, glycodeoxycholate, glycocholate, and glycochenodeoxycholate with egg phosphatidylcholine. Drug concentrations were determined from the absorbance following centrifugation. Using NMR spectroscopy, the diffusivities of the simple and mixed micelles were 2 x 10(-6) and 8 x 10(-7) cm2/s, respectively. RESULTS: From the change in the concentration of drug in solution with a change in the lipid concentration, the solubilization ratio (SR) was calculated. The SR and aqueous solubility were used to calculate the micelle/aqueous partition coefficients (Km/w). Km/w was correlated with octanol/water partition (Po/w) for the TDC and mixed micelle data sets with correlation lines of logKm/w = 0.74logPo/w + 1.55 (r2 = 0.91) and logKm/w = 0.61 logPo/w + 2.44 (r2 = 0.95), respectively. CONCLUSIONS: With such data, a refined, predictive relationship between the in vitro and the in vivo solubilization with additional information concerning the bile salt/lipid concentration in the human intestine appears possible.

Bile Acids and Salts↗