Biomedical subjects

Tingting Wang

Publications and source records attributed to Tingting Wang.

16 recordsLinked to original sources

PubMed2026

Effect of renin-angiotensin system inhibitors on survival in glioma patients: A systematic review and meta-analysis.

PURPOSE: To evaluate the effect of renin-angiotensin system inhibitors (RASIs) on the survival outcomes of glioma patients, determine whether using RASIs correlates with survival benefit, and provide evidence-based guidance for the clinical treatment. METHODS: Studies assessing the effects of using RASIs versus non-use in glioma patients were retrieved from the PubMed, Cochrane Library, Web of Science, and Embase databases from inception to April 17, 2024. The included studies reported hazard ratios (HRs) with 95% confidence intervals (CIs) for overall survival (OS) and/or progression-free survival (PFS), as well as the effect on brain edema and steroid dosing in patients. RESULTS: Seven articles involving 2660 patients were included in this study. Pooled results indicated there was no significant difference in OS (HR = 0.89, 95% CI 0.75-1.06, P = 0.204) or PFS (HR = 0.98, 95% CI 0.82-1.18, P = 0.847) between RASIs-treated patients and non-RASIs-treated patients. Sensitivity analysis identified the ACEIs-focused trial reported by Happold et al. as a major contributor to inter-study heterogeneity. Subgroup analyses revealed that in recurrent glioblastoma, pooled OS was significantly longer in RASIs-treated patients than non-RASIs-treated patients (HR = 0.70, 95% CI 0.54-0.92, P = 0.01). Similarly, compared with bevacizumab monotherapy, bevacizumab combined with RASIs significantly extended OS in glioblastoma patients (HR = 0.73, 95% CI 0.63-0.86, P < 0.001). CONCLUSION: The results revealed that treatment with RASIs may show a trend toward prolonged overall survival (OS) in patients with glioma. For patients with glioblastoma, RASI therapy could prolong OS in those with recurrent disease. Furthermore, compared with bevacizumab monotherapy, the combination of RASIs and bevacizumab was associated with improved OS in glioblastoma patients.

Humans↗

PubMed2026

From Static to Dynamic: Fluorescence Imaging Technology Advances Precise Embryo Evaluation.

Live-cell imaging technology has revolutionized our understanding of preimplantation embryonic development, shifting the field from static morphological descriptions to dynamic functional analyses. This has tremendously advanced the fields of in vitro fertilization (IVF) and embryonic development. At the heart of this transition lies the strategic application of fluorescent probes, which provide the requisite sensitivity and specificity to resolve complex biological events. This review provides a comprehensive overview of fluorescent probe-based strategies designed to address four cardinal questions in peri-implantation embryology: genomic stability, cell fate determination, tissue morphogenesis, and embryo-maternal interactions. We systematically evaluate the chemical design principles and imaging modalities of various probes, which range from small-molecule organic fluorophores to genetically encoded reporters and nanoparticle-based sensors. Furthermore, we discuss how these tools facilitate the real-time visualization of chromosomal aberrations, lineage segregation, biomechanical forces, and enzymatic activities within the delicate embryonic microenvironment. This review summarizes methodological strategies for selecting and developing optimal probes across diverse application contexts. By identifying current technical bottlenecks and proposing future directions, such as NIR-II imaging and noninvasive labeling, it aims to drive the translation of basic embryonic research into advanced reproductive medicine.

Humans↗

PubMed2026

Decoding microbial metabolic complementarity from individual traits to community structuring.

A fundamental challenge in microbiome research lies in elucidating the functional capacity of microbial communities through community membership and genomic data. As community structuring and emergent functional traits are determined by bacterial community metabolic networks, it is important to gain insights into the principles that govern bacteria-bacteria interactions. Here, we applied an integrative framework linking individual strain-level traits to community structuring in a simplified synthetic bacterial community (SSC8) that promotes the growth of ungrafted watermelon. By combining mono- and coculture assays with genome-scale metabolic modeling and metabolomic profiling of spent media, we characterized directional interactions and resource dependencies among community members. Our findings show that positive interactions dominated the community network, accounting for 55% of all pairwise combinations, indicating a high prevalence of growth-promoting effects among strains. Genome-scale metabolic modeling showed that functional divergence among strains enhanced the potential for metabolic complementarity as phylogenetic distance increased. Integrating metabolic modeling with metabolomics further suggested that Pseudomonas azotifigens Q6 not only benefited from all other community members, but also exhibited mutualistic interactions with the other three strains, with metabolite exchange involving compounds such as L-lysine and L-cysteine. Pseudomonas azotifigens Q6 acted as an important driver of community composition by affecting the abundance of several other consortium members in vitro. These findings highlight the role of metabolic complementarity in driving community structuring by promoting selective persistence of specific strains. Our work provides mechanistic insights into microbial interaction networks in vitro and offers a conceptual foundation for the rational design of functionally robust and plant-beneficial microbiomes.

Bacteria↗

PubMed2023

H4S47 O-GlcNAcylation regulates the activation of mammalian replication origins.

The transmission and maintenance of genetic information in eukaryotic cells relies on the faithful duplication of the entire genome. In each round of division, excessive replication origins are licensed, with only a fraction activated to give rise to bi-directional replication forks in the context of chromatin. However, it remains elusive how eukaryotic replication origins are selectively activated. Here we demonstrate that O-GlcNAc transferase (OGT) enhances replication initiation by catalyzing H4S47 O-GlcNAcylation. Mutation of H4S47 impairs DBF4-dependent protein kinase (DDK) recruitment on chromatin, causing reduced phosphorylation of the replicative helicase mini-chromosome maintenance (MCM) complex and compromised DNA unwinding. Our short nascent-strand sequencing results further confirm the importance of H4S47 O-GlcNAcylation in origin activation. We propose that H4S47 O-GlcNAcylation directs origin activation through facilitating MCM phosphorylation, and this may shed light on the control of replication efficiency by chromatin environment.

Animals↗

PubMed2006

Leptin enhances in vitro secretion of IgG antiplatelet antibodies by splenocytes and peripheral blood mononuclear cells from patients with chronic idiopathic thrombocytopenic purpura.

Chronic idiopathic thrombocytopenic purpura (ITP) is an organ-specific autoimmune disease characterized by the production of antibodies against antigens on the membranes of platelets, resulting in enhanced destruction of the platelets by macrophages. Leptin, a cytokine-like hormone, plays a role in the pathogenesis of several autoimmune diseases. In this study, we observed significantly increased plasma leptin levels combined with decreased soluble leptin receptor (sOB-R) levels in 18 chronic ITP patients compared with 14 controls. We also demonstrated significantly elevated mRNA expression of long form leptin receptor (Ob-Rb) on peripheral blood mononuclear cells (PBMCs) from chronic ITP patients. Treatment with recombinant leptin or serum with high leptin levels enhanced in vitro secretion of IgG antiplatelet antibodies by splenocytes and PBMCs from patients with chronic ITP. After depletion of CD4(+) T cells from splenocytes, leptin lost this function. Further studies showed that leptin could increase platelet reactive T cells. These findings suggest that leptin may be involved in the pathogenesis of chronic ITP and might offer a potential target for the treatment of this disease.

Adult↗

PubMed2006

Peroxisome proliferator-activated receptor gamma in malignant diseases.

Peroxisome proliferator-activated receptor gamma (PPAR-gamma) belongs to the family of nuclear hormone receptors (NHRs) and is a ligand-activated transcription factor. There are four mRNAs, PPAR-gamma1, PPAR-gamma2, PPAR-gamma3 and PPAR-gamma4, which encode two proteins, PPAR-gamma1and PPAR-gamma2. PPAR-gamma consists of five or six structural regions (A-F) in four functional domains. The NH2-terminal A/B domain harbors a ligand-independent transcriptional activation function (AF-1), the C domain is a DNA binding domain (DBD), the D hinge region is important for co-factor docking and the complex multifunctional COOH-terminal portion (E/F) encompasses the ligand binding domain (LBD), a dimerization interface and the ligand-dependent activation domain AF-2. Some long-chain polyunsaturated fatty acids, arachidonic acid metabolites and fatty acid derived components are natural ligands of PPAR-gamma. The anti-diabetic thiazolidinedione class of drugs, certain non-steroidal anti-inflammatory drugs (NSAIDs) and some non-thiazolidinedione tyrosine are the synthetic ligands of PPAR-gamma. After activation, it forms heterodimer with the retinoid X receptor (RXR) and then binds to specific recognition sites in the target gene, the peroxisome proliferator response elements (PPREs), and regulates transcription of specific genes. PPAR-gamma has potential anti-neoplastic effects both in solid cancer and in leukemia through inhibition of cell proliferation, induction of apoptosis and terminal differentiation, as well as inhibition of angiogenesis. The ligands of PPAR-gamma may represent a promising, novel therapeutic approach for certain human malignancies.

Animals↗

PubMed2006

Immobilization and characterization of gamma-aminobutyric acid on gold surface.

gamma-Aminobutyric acid (GABA) is one of two main inhibitory neurotransmitters in the central nervous system that plays an important role in neuronal function and dysfunction. Immobilization of GABA molecules on a rigid surface in an ordered fashion will provide an opportunity to understand some of the fundamental properties related to its structure and function. In this study, we report a novel strategy for immobilization of bioactive GABA on gold substrate. GABA was immobilized in three consecutive steps, namely gold substrate amination, dextran covalent attachment, and GABA immobilization. Surface chemistry was verified at each step using XPS and FTIR. Bioactivity of GABA immobilized on the gold surface was studied using atomic force microscopy to reveal antigen-antibody binding. Nonspecific protein adsorption on the bioactive surface was analyzed quantitatively using anti-GABA antibody and an enzyme linked nonspecific anti-immunoglobulin-G antibody in an ELISA assay. GABA functionalized surface has high affinity for anti-GABA, while showing significantly low affinity for nonspecific anti-IgG antibody. All these data support the presence of a bio-functional immobilized GABA on the gold surface. In conclusion, we report a novel technique for immobilizing bioactive GABA molecules in an orderly fashion on gold substrates.

Coated Materials, Biocompatible↗

PubMed2006

Splenectomy for chronic idiopathic thrombocytopenic purpura in children: a single center study in China.

The management of chronic and refractory idiopathic thrombocytopenic purpura (ITP) in children is controversial. We conducted a retrospective review of our single center experience in China between 1990 and 2003 with splenectomy for chronic ITP in children in order to determine the initial and long-term hematological response, morbidity, mortality, predictors of response to splenectomy and the therapy in children who failed splenectomy. Of 65 children analyzed, the overall immediate clinical response to splenectomy was 89.2%. The median postsplenectomy follow-up time was 52 months (8-124). During follow-up, 9 children (13.8%) relapsed within a median time of 6 months (2-58). The overall morbidity was 1.5% and perioperative mortality was zero. During follow-up, 1 child died of intracranial hemorrhage (ICH) and 1 died of overwhelming postsplenectomy infection (OPSI). The platelet count at day 7 after splenectomy was a predictor of a sustained response to splenectomy but no preoperative parameters were predictors of the response to splenectomy. Of the 15 children who failed splenectomy, excluding the one who died of ICH, only 2 children intermittently required corticosteroids and IVIG. Splenectomy is a potential therapy to provide long-term control of disease in children with chronic ITP and is associated with low morbidity and mortality. The risk of fulminant sepsis remains an omnipresent concern. Antipneumococcal vaccination and antibiotic prophylaxis should be recommended and children should receive timely and adequate antibiotics for bacteria infection to lessen the problem of OPSI.

Adolescent↗

PubMed2005

Photoinduced charge separation and charge recombination in [60]fullerene-ethylcarbazole and [60]fullerene-triphenylamines in polar solvents.

Molecules of C60 covalently connected with N-ethylcarbazole (EtCz) and triphenylamine (TPA) have been synthesized. Photoinduced electron transfer in C60-EtCz and C60-TPA has been studied in polar and nonpolar solvents using time-resolved transient absorption and fluorescence measurements. From the fluorescence lifetimes, the excited singlet state of the C60 moiety (1C60) of C60-TPA generates predominantly C60*--TPA*+, which decays quickly to the ground state within 6 ns even in polar solvents. In the case of C60-EtCz, on the other hand, about half of the 1C60 moiety generates short-lived C60*--EtCz*+, while the other half of the 1C60 moiety is transferred to the 3C60 moiety via intersystem crossing in dimethylformamide, in which the energy level of C60*--EtCz*+ is lower than that of 3C60. Thus, the charge separation takes place via 3C60 generating C60*--EtCz*+, having a lifetime as long as 300 ns, probably because of the triplet spin character of C60*--EtCz*+. A special property of the EtCz moiety to stabilize the hole in the charge-separated state was revealed.

Journal Article↗

PubMed2005

Splenectomy for adult chronic idiopathic thrombocytopenic purpura: experience from a single center in China.

OBJECTIVES: The aim of this study was to explore the results of Chinese chronic idiopathic thrombocytopenic purpura (ITP) patients who underwent splenectomy (SE). SUBJECTS AND METHODS: Data of 149 chronic ITP patients were retrospectively analyzed. Relapse-free survival was estimated by Kaplan-Meier analysis. Differences between responders and non-responders were evaluated using the chi-square. RESULTS: The immediate response rate was 82.6% and the sustained response rate was 63.1%. Twenty-nine patients (19.5%) relapsed during follow-up. The 5-year actuarial relapse-free survival was about 75%. The overall morbidity was 26.1% and mortality was 2.7%. Patients with higher postsplenectomy peak platelet count, shorter time from diagnosis to SE and previous response to IVIG therapy were more likely to have sustained response to SE. CONCLUSION: SE is potentially a useful therapy to provide long-term control of disease in adults with chronic ITP and is associated with low morbidity and mortality. Postsplenectomy peak platelet count, time from diagnosis to SE and previous response to intravenous immune globulin therapy appear predictive for response to SE.

Adolescent↗

PubMed2005

Retrospective analysis of 472 Chinese children with chronic idiopathic thrombocytopenic purpura: a single center experience.

We retrospectively analyzed the clinical characteristics and management of 472 Chinese children (age 1~14 years) with chronic idiopathic thrombocytopenic purpura (ITP). The distribution of cases by age showed a maximum at 4 years and more patients below 7 years old than between 7 and 14 years old had ITP (337, 71.4% vs. 135, 28.6%). Variable bleeding signs occurred in this series of patients. Steroids therapy was effective for Chinese children with chronic ITP whether as first- or second-line therapy. Traditional Chinese medicine was less effective than steroids.

Adolescent↗

PubMed2005

Type 1 and type 2 T-cell profiles in idiopathic thrombocytopenic purpura.

BACKGROUND AND OBJECTIVES: Adult idiopathic thrombocytopenic purpura (ITP) is a chronic acquired organ-specific autoimmune hemorrhagic disease characterized by the production of antibodies against antigens on the membranes of platelet, resulting in enhanced Fc-mediated destruction of the platelets by macrophages in the reticuloendothelial system. Dysfunctional cellular immunity is considered important in the pathophysiology of ITP. The aim of this study was to explore the profile of type1 and type2 T cells in chronic ITP patients. DESIGN AND METHODS: The balance of Th1/Th2 and Tc1/Tc2 was studied by simultaneous analysis of intracellular cytokines of peripheral blood mononuclear cells and splenocytes in short-term cultures activated with PMA/ionomycin as well as mRNA expression of T-bet and GATA-3 in peripheral blood mononuclear cells and splenocytes using real-time polymerase chain reaction. RESULTS: Patients with active disease but not patients in remission had significant higher Th1/Th2 (p<0.01) and Tc1/Tc2 (p<0.01) ratios in peripheral blood (PB) and significant higher Th1/Th2 ratio in splenocytes (p<0.01) than those in the control group. The Tc1/Tc2 ratio in splenocytes in ITP patients was higher than that in control, but did not reach significant difference (p=0.082). GATA-3 mRNA expression in ITP patients was significantly lower both in PB (p<0.01) and in splenocytes (p<0.01) than in corresponding samples from controls while there was no difference in T-bet expression. INTERPRETATION AND CONCLUSIONS: Our data indicate that ITP is a T1 cell (Th1 and Tc1) predominant disease although the precise mechanisms await further functional assay. The T-bet/GATA-3 ratio may provide a surrogate marker of T1/T2 cytokine balance. Shifting the cytokine patterns from T1 to T2 might be a potential immunotherapy for ITP.

Adolescent↗

PubMed2005

[Effects of pesticides metolachlor and S-metolachlor on soil microorganisms in aquisols of Southern China. I. Catalase activity].

This paper studied the effects of different concentrations (0, 5, 20, and 100 mg.kg(-1)) metolachlor and its enantiomer S-metolachlor (Dual Gold) on soil catalase activity. The results showed that 20 mg.kg(-1) metolachlor had the most successive stimulating effect, 5 mg.kg(-1) metolachlor had an inhibitory effect in the early period, while 100 mg.kg(-1) metolachlor had a stimulating effect in the late period. Different concentrations Dual Gold displayed a tendency stimulation-inhibition-stimulation. 5 and 100 mg.kg(-1) metolachlor might have more damage on soil ecosystem than different concentrations Dual Gold.

Acetamides↗

PubMed2003

Molecular dynamics simulation of the unfolding of the human prion protein domain under low pH and high temperature conditions.

Four 10-ns molecular dynamics (MD) simulations of the human prion protein domain (HuPrP 125-228) in explicit water solution have been performed. Each of the simulations mimicked a different environment of the protein: the neutral pH environment was simulated with all histidine residues neutral and bearing a ND proton and with other titratable side chains charged, the weakly acidic environment was simulated with all titratable side chains charged, the strongly acidic environment was simulated with all titratable side chains protonated. The protein in neutral pH environment was simulated at both ambient (298 K) and higher (350 K) temperatures. The native fold is stable in the neutral pH/ambient temperature simulation. Through out all other simulations, a quite stable core consisted of 10-20 residues around the disulfide bond retain their initial conformations. However, the secondary structures of the protein show changes of various degrees compared to the native fold, parts of the helices unfolded and the beta-sheets extended. Our simulations indicated that the heat-induced unfolding and acid-induced unfolding of HuPrP might follow different pathways: the initial stage of the acid-induced unfolding may include not only changes in secondary structures, but also changes in the tertiary structures. Under the strongly acidic condition, obvious tertiary structure changes take place after 10-ns simulation, the secondary structure elements and the loops becoming more parallel to each other, resulting in a compact state, which was stabilized by a large number of new, non-native side chain-side chain contacts. Such tertiary structure changes were not observed in the higher temperature simulation, and intuitively, they may favor the further extension of the beta-sheets and eventually the agglomeration of multiple protein molecules. The driving forces for this tertiary structure changes are discussed. Two additional 10-ns MD simulations, one with Asp202 protonated and the other with Glu196 protonated compared to the neutral pH simulation, were carried out. The results showed that the stability of the native fold is very subtle and can be strongly disturbed by eliminating a single negative charge at one of such key sites. Correlations of our results with previous experimental and theoretical studies are discussed.

Computer Simulation↗

PubMed2003

Aspartate-induced aminoacylase folding and forming of molten globule.

Aspartate is an osmolyte found in some marine invertebrates and cyclostome fish. The aspartate-induced unfolding of N-acylamino acid amido hydrolase (aminoacylase) has been studied by measuring enzyme activity, fluorescence emission spectra, 8-anilino-1-naphthalenesulfonate (ANS) fluorescence spectra and far-UV circular dichroism (CD) spectra. The results showed that aspartate caused the inactivation and unfolding of aminoacylase. Surprisingly, increasing concentration of aspartate showed the "acid-induced folding", which used to be seen only in strong acids or salts at much lower pH. Although aspartate has the pI of 2.77 that is the lowest among all the free amino acids, it is actually a weak acid. It is thus of great interest why it causes this phenomenon to happen. The relative change of intrinsic fluorescence and ANS binding spectra have shown that there existed a stable molten globule state of aminoacylase with slightly disrupted tertiary structure and more hydrophobic surface. The molten globule state indicates that intermediates existed during aminoacylase refolding process. Unlike the other acids, such as trichloroacetic acid, there is no precipitation observed as the aspartate concentrations increased. It suggests the aspartate anions have an osmotic effect for the molten globule formed during unfolding process. Binding of aspartate anion to the protonated protein, which minimizes the intramolecular repulsion, might explain the osmotic effect of this amino acid in the nature. The results also showed the Apo-aminoacylase followed similar rules as Holo-enzyme, which suggested the zinc ion may play more important roles on activity other than structure.

Amidohydrolases↗

PubMed2002

Continuous positive airway pressure treatment improves pulmonary hemodynamics in patients with obstructive sleep apnea.

Daytime pulmonary hypertension (PH) is relatively common in obstructive sleep apnea (OSA) and is thought to be associated with pulmonary vascular remodeling (PRm). The extent to which PH is reversible with treatment is uncertain. To study this, we measured pulmonary hemodynamics (Doppler echocardiography) in 20 patients with OSA (apnea-hypopnea index [AHI] 48.6 +/- 5.2/h, mean +/- SEM) before and after 1 and 4 mo of CPAP treatment (compliance 4.7 +/- 0.5 h/night). Patients had normal lung function, and no cardiac disease or systemic hypertension. Doppler studies were performed at three levels of inspired oxygen concentration (11%, 21%, and 50%) and during incremental increases in pulmonary blood flow (10, 20, and 30 microg/kg/min dobutamine infusions). Treatment resulted in a decrease in pulmonary artery pressure (Ppa, 16.8 +/- 1.2 mm Hg before CPAP versus 13.9 +/- 0.6 mm Hg after 4 mo CPAP, p < 0.05) and total pulmonary vascular resistance (231.1 +/- 19.6 versus 186.4 +/- 12.3 dyn. s. cm(-)(5), p < 0.05). The greatest treatment effects occurred in the five patients who were pulmonary hypertensive at baseline. The pulmonary vascular response to hypoxia decreased after CPAP (DeltaPpa/DeltaSa(O(2)) 10.0 +/- 1.6 mm Hg before versus 6.3 +/- 0.8 mm Hg after 4 mo CPAP, p < 0.05). The curve of Ppa versus cardiac output (Q), derived from the incremental dobutamine infusion, shifted downward in a parallel fashion during treatment. Systemic diastolic blood pressure also fell significantly. Improvements in pulmonary hemodynamics were not attributable to changes in left ventricular diastolic function or Pa (O(2)). We conclude that CPAP treatment reduces Ppa and hypoxic pulmonary vascular reactivity in OSA and speculate that this may be due to improved pulmonary endothelial function.

Cardiac Output↗