Biomedical subjects

Bing Yan

Publications and source records attributed to Bing Yan.

At least 19 recordsLinked to original sources

PubMed2026

Improved donor-site biomechanics and functional recovery with xenogeneic acellular dermal matrix after ALT flap harvest: A prospective randomized controlled study.

BACKGROUND: Donor-site management after anterolateral thigh (ALT) flap harvest is a significant yet underaddressed concern in reconstructive surgery for oral cancer. While xenogeneic acellular dermal matrix (Xeno-ADM) is common in soft-tissue repair, its efficacy for fascia lata reconstruction at the ALT donor site remains insufficiently characterized. This study aimed to assess the efficacy of xeno-ADM in fascia lata repair, focusing on compartment pressure, inflammatory and muscle injury biomarkers, and functional recovery. METHODS: In this prospective, randomized, single-blind trial, 200 patients undergoing ALT flap reconstruction were allocated to Xeno-ADM repair (n = 100) or primary closure (n = 100). Primary endpoints included compartment pressure, inflammatory markers in drainage fluid, serum muscle injury biomarkers, and functional outcomes. RESULTS: The xeno-ADM group showed significantly lower compartment pressures throughout postoperative days (POD) 1-5. Inflammatory markers in drainage fluid (CRP on POD 3 and 5) and serum muscle injury biomarkers (creatine kinase on POD 1 and 5) were significantly lower in xeno-ADM group. Functional outcomes were superior in the Xeno-ADM group, with faster gait recovery, lower pain scores at POD 7, and better lower-limb function at the 1- and 6-month follow-ups. Drainage duration did not differ between groups. Stratified analyses revealed that the benefits of xeno-ADM were more pronounced in patients with defect width >3 cm or a body mass index ≥24 kg/m2. CONCLUSION: Xeno-ADM provides a safe and effective approach for fascia lata repair, reducing biomechanical and inflammatory burdens while enhancing functional recovery. These findings support a transition from simple structural closure toward functional donor-site reconstruction.

Humans↗

PubMed2025

CCDC137 knockdown suppresses bladder cancer progression by downregulating SCD.

BACKGROUND: The Coiled-coil domain-containing (CCDC) family, due to its unique protein structural domain and broad involvement in diverse biological processes, has emerged as a focus in oncology research. Nevertheless, its clinical significance and function in bladder cancer (BLCA) remain poorly defined. METHODS: Machine learning algorithms were employed to identify pivotal CCDC genes in the cancer genome atlas (TCGA), and a prognostic model was subsequently constructed. Multi-omics data encompassing pan-cancer cohorts, single-cell sequencing, and spatial transcriptomics were integrated to characterize the expression patterns and prognostic significance of Coiled-coil domain-containing 137 (CCDC137), a previously uncharacterized CCDC family member in BLCA. Tissue microarray confirmed CCDC137 abnormal expression in bladder carcinoma specimens. The effect of CCDC137 knockdown on BLCA progression was evaluated through CCK8 assay, clonogenic formation, wound healing, Transwell, and subcutaneous xenograft models. RNA sequencing, quantitative RT-PCR, and western blot were utilized to delineate its regulatory network. RESULTS: A prognostic model incorporating 10 CCDC genes was successfully established in the TCGA-BLCA cohort. Then, we found that CCDC137 exhibited pan-cancer overexpression and usually correlation with poor clinical outcomes. Immunohistochemistry further substantiated its dysregulation in bladder carcinoma. Integrated multi-omics analyses suggested associations between CCDC137 expression and a tumor immunosuppressive microenvironment. CCDC137 knockdown significantly suppressed bladder cancer cell proliferation and migratory capacity in vitro. Correspondingly, subcutaneous xenograft tumor growth was inhibited in vivo. Moreover, decreased expression of stearoyl-CoA desaturase (SCD), a key lipid metabolic enzyme, accompanied CCDC137 depletion. These findings collectively suggest a cancer-promoting role for CCDC137 in bladder carcinoma. CONCLUSIONS: This systematic investigation combining multi-omics bioinformatics analyses and experimental validation demonstrates the role of CCDC137 in bladder carcinoma progression, providing novel mechanistic insights into the pathogenesis of BLCA and offering a theoretical foundation for therapeutic targeting of CCDC137 in urothelial malignancies.

Urinary Bladder Neoplasms↗

PubMed2007

Structure-dependent response of a chemiluminescence nitrogen detector for organic compounds with adjacent nitrogen atoms connected by a single bond.

High-throughput screening (HTS) of chemical libraries is indispensable for drug discovery research. However, the HTS data quality for lead discovery, lead optimization, and quantitative structure activity relationship studies has been severely compromised due to the uncertain compound concentrations in screening plates. In order to address this issue, we compared various high-throughput technologies for quantification of compounds in microtiter plate format without the need for authentic compounds as standards and identified the chemiluminescence nitrogen detector (CLND) as the method of choice at the present time. However, the structure dependence of this detector has not been well studied. A proposed rule suggested that the only exception to equimolar response is for compounds that contain adjacent nitrogen atoms. The response should be zero when the adjacent nitrogen atoms are connected by a double bond and 0.5 when they are connected by a single bond. In this investigation, we studied a broad range of compounds with isolated and adjacent nitrogen atoms. We confirmed that compounds with isolated nitrogen atoms produce an equimolar response with a 15-20% variation depending on structures and compounds with adjacent nitrogen atoms connected by a double bond giving nearly zero response. We discovered that the CLND response for compounds containing adjacent nitrogen atoms that are connected with a single bond is highly structure dependent. Substitutions on the nitrogen atoms or nearby in the molecule can increase the CLND response to approach a value higher than the predicted value 0.5 (maximal value 0.82/nitrogen atom). Without substitution, much lower values than predicted (minimal value 0.0-0.08/nitrogen atom) are obtained. Therefore, the prediction of response of 0.5/nitrogen atom for compounds with adjacent nitrogen atoms connected by a single bond should be abandoned. Compounds with similar structures should be used to generate calibration curves for quantification of this class of compounds.

Luminescence↗

PubMed2007

The proteasome as a potential target for novel anticancer drugs and chemosensitizers.

A major challenge in cancer therapy is tumor drug resistance. To overcome it, it is essential to understand the mechanisms and identify the molecules involved, so that they can be specifically targeted in combination therapies. The proteasome is such a validated target: it plays a key role in cancer cell proliferation, inhibition of chemotherapy-induced apoptosis and drug resistance development. Bortezomib (Velcade, PS-341) was the first proteasome inhibitor to receive regulatory approval from the US Food and Drug Administration for the treatment of multiple myeloma. Clinical combination trials have demonstrated a chemo-sensitizing effect of bortezomib on conventional agents in hematological malignancies and some solid tumors such as androgen-independent prostate and ovarian cancer. Although generally well-tolerated, bortezomib still generates toxicity which underscores the need for less toxic proteasome inhibitors. Several naturally occurring products, such as green tea polyphenols and the antibiotic lactacystin, have been shown to be potent proteasome inhibitors. Significantly, green tea polyphenols, as well as several flavonoids such as genistein, curcumin and resveratrol, have also been shown to have chemo-sensitizing properties in prostate, breast, hepatic, and lung tumors. Further studies on natural proteasome inhibitors as chemo-sensitizers could lead to identification of more potent and less toxic compounds that could be used in combination therapies for drug-resistant tumors.

Antineoplastic Agents↗

PubMed2007

Copper-binding compounds as proteasome inhibitors and apoptosis inducers in human cancer.

The trace element copper is vital to the healthy functioning of organisms. Copper is used in a multitude of cellular activities including respiration, angiogenesis, and immune responses. Recently, copper has become a focus in medical research ranging from Alzheimer's disease to cancer. Copper modulation has been suggested to be a potential modality for therapy in these diseases. Several copper-binding compounds have been found to spontaneously complex with copper and form active proteasome inhibitors and apoptosis inducers. This review examines compounds in the quinoline and dithiocarbamate families and from the National Cancer Institute (NCI) Diversity Set that bind with copper and act as anticancer agents. In each case, it is shown that these compounds can bind with copper, inhibit the proteasome activity, and induce apoptosis in cancer cells. These activities are absent when copper is not present. Compounds alone, clioquinol and pyrrolidinedithiocarbamate as examples, are shown to have no effects in normal breast cells. Current research suggests that a possible therapeutic modality for cancer may be developed using the difference of high copper load in tumors versus low copper load in normal cells. This strategy would convert tumor cellular copper into a potent, specific proteasome inhibitor and apoptosis inducer. Thus, this approach could pave the way for the development of nontoxic anticancer therapy.

Antineoplastic Agents↗

PubMed2006

Luminescent behavior of two novel thermo-sensitive poly(N-isopropylacrylamide) hydrogels incorporated with rare earth complexes.

Two novel luminescent temperature-sensitive poly(N-isopropylacrylamide) hydrogels fabricated with rare earth (Eu, Tb) picolinic acid complexes were in-situ synthesized within the interpenetration networks. Fluorescence spectra indicate the two functional gels exhibit red for Eu3+ species and green emissions for Tb3+ ones, respectively, whose luminescence intensities are changed due to temperature increasing from 5 to 30 degrees C until totally quenched at lower critical solution temperature (33 degrees C). In addition, the decreasing luminescence behavior obeys the simple linear equations. The releasing experiment substantiates that there may be complexation between O=C-NH- moieties of P-NIPAA and Eu3+ ions for the prolonged released time.

Journal Article↗

PubMed2006

Transactivation of epidermal growth factor receptor by insulin-like growth factor 1 requires basal hydrogen peroxide.

Insulin-like growth factor (IGF-1) plays an important role in prostate cancer development. Recent studies suggest that IGF-1 has mitogenic action through epidermal growth factor receptor (EGFR). However, the mechanism remains largely unknown. Here, we demonstrated in prostate cancer DU145 cells that IGF-1 induced EGFR transactivation, leading to ERK activation. Matrix metalloproteinase-mediated shedding of heparin-binding EGF is involved in this process. Antioxidants and catalase inhibited IGF-1-stimulated EGFR phosphorylation, indicating that H(2)O(2) is required for EGFR activation. However, exogenous H(2)O(2) did not activate EGFR or IGF-1R in DU145 cells. IGF-1 did not induced production of H(2)O(2) in DU145 cells. Our results suggest that transactivation of EGFR by IGF-1 requires basal intracellular H(2)O(2) in DU145 cells.

Cell Line, Tumor↗

PubMed2006

Photophysical properties of novel lanthanide (Tb3+, Dy3+, Eu3+) complexes with long chain para-carboxyphenol ester p-L-benzoate (L=dodecanoyloxy, myristoyloxy, palmitoyloxy and stearoyloxy).

In this paper, a series of 12 binary luminescent lanthanide coordination compounds with long chain p-carboxyphenol ester were assembled. Both elemental analysis and infrared spectroscopy allowed to determine the complexes formula: LnL3, where Ln=Tb, Dy, Eu; L=p-dodecanoyloxybenzoate (12-OBA), p-myristoyloxybenzoate (14-OBA), p-palmitoyloxybenzoate (16-OBA) and p-stearoyloxybenzoate (18-OBA), respectively. The photophysical properties of these complexes were studied in detail with various of spectroscopies such as ultraviolet-visible absorption spectra, low temperature phosphorescence spectra and fluorescent spectra. The ultraviolet-visible absorption spectra showed that some bands shift with the different chain length of p-carboxyphenol ester. From the low temperature phosphorescent emission, the triplet state energies for these four ligands were determined to be around 24,242 cm-1 (12-OBA), 24,612 cm-1 (14-OBA), 24,084 cm-1 (16-OBA) and 24,125 cm-1 (18-OBA), respectively, suggesting they are suitable for the sensitization of the above lanthanide ions, especially for Tb3+ and Dy3+. The fluorescence excitation and emission spectra for these lanthanide complexes of the four ligands take agreement with the above predict from energy match.

Benzoates↗

PubMed2006

Double fluorescence conversion in ultraviolet and visible region for some praseodymium complexes of aromatic carboxylates.

Four praseodymium complexes of aromatic carboxylates (benzoate, 4-tert-butylbenzoate, 2-benzoylbe-noate, and benzimidazole-5-carboxylate) have been synthesized and characterized, whose photophysical properties have been studied with ultraviolet spectra, phosphorescence spectra, and fluorescence spectra. The fluorescent emission spectra of all praseodymium complexes show two emission peaks under the excitation band of 245 nm at about 395 and 595 nm respectively, while one peak under 415 nm at about 595 nm, which attributed to be 1S0 --> 1I6 (395 nm) transition and the characteristic emission 1D2 --> 3H4 (595 nm) transition of Pr3+ ion. The 1S0 --> 1I6 transition can be ascribed as the transition of charge transfer state, and the 1D2 --> 3H4 can be further proved that there exists an antenna effect in the fluorescence of praseodymium with aromatic carboxylic acids. In conclusion, the praseodymium complexes systems can realize the double fluorescent conversion in both ultraviolet and visible region and can be further studied the application of this conversion.

Acids, Carbocyclic↗

PubMed2006

Photophysical properties of praseodymium complexes with aromatic carboxylic acids: double light conversion both in ultraviolet and visible region.

A series of luminescent praseodymium complexes with different aromatic carboxylic acids have been synthesized and characterized. The photophysical properties of these complexes have been studied with ultraviolet spectra, phosphorescence spectra and fluorescence spectra. Ultraviolet absorption spectra show that the praseodymium complexes systems with aromatic carboxylate form the more extensive conjugated systems to be suitable for the distribution of electron in the whole coordination environment, resulting in the energy decrease and red-shifts of ultraviolet spectral bands. Phosphorescence spectra suggest that excited triplet state of aromatic carboxylic acids, which can indicate the energy match and intermolecular energy transfer process between the excited triplet state of ligands and the resonant emissive energy level of Pr ions. The emission spectra of all praseodymium complexes show two emission peaks under the excitation band of 245 nm at about 395 and 595 nm, respectively, while one peak at about 595 nm under 415 nm excitation, which attributed to be 1S0-->1I6 (395 nm) transition and the characteristic emission 1D2-->3H4 (595 nm) transition of Pr3+ ion. The 1S0-->1I6 transition can be speculated to belong to the transition of charge transfer state, and the 1D2-->3H4 can be further proved that there exists an antenna effect in the luminescence of praseodymium with aromatic carboxylic acids. In conclusion, the praseodymium complexes systems can realize the double proton light conversion both in the ultraviolet and visible region, which can be further studied to have potential application.

Acids, Carbocyclic↗

PubMed2006

[Taxol-producing fungi: a new approach to industrial production of taxol].

Produced by and purified from Taxus brevifolia, Taxol (paclitaxel) has become a widely used cancer drug in clinic. Due to the rapid growing market, current industrial production of taxol by semi-synthesis that consumes large amount of Taxus trees cannot meet the requirement of the market. The discovery of taxol-producing fungus Taxomyces andeanae, an endophyte of T. brevifolia, by Stierle et al (1993), paves a new way to the production of the drug, i.e. employing large-scale fungal fermentation to make Taxol at lower cost and yet higher yield. This review discusses the present problems in taxol production in pharmaceutical industry, the finding and research progress on taxol-producing fungi, and the potential application of fungal fermentation to manufacture this important drug.

Antineoplastic Agents, Phytogenic↗

PubMed2006

Vip3A is responsible for the potency of Bacillus thuringiensis 9816C culture supernatant against Helicoverpa armigera and Spodoptera exigua.

Culture supernatant of Bacillus thuringiensis 9816C had high toxicity against Helicoverpa armigera and Spodoptera exigua. However, it lost insecticidal activities after being bathed in boiling water for 5 min. Acrystalliferous mutants of Bt9816C (Bt9816C-NP1 and Bt9816C-NP2) cured of its endogenous plasmids no longer possessed vip3A gene and toxicity. The 89 kD protein which existed in Bt9816C supernatant disappeared in the two mutants' supernatant; nevertheless, the two mutants still exhibited hemolytic and phospholipase C activity as Bt9816C did. The vip3A gene of Bt9816C, vip3Aa18, was cloned and expressed in Escherichia coli BL21. Bioassay demonstrated that the recombinant E. coli had high toxicity against S. exigua. Taken together, it suggested that Vip3A protein was responsible for the toxicity of Bt9816C culture supernatants.

Animals↗

PubMed2006

[Expression, purification and activity analysis of anti-human transferrin receptor scFv].

Human transferrin receptor (TfR) was isolated from homogenates of placental tissues by affinity chromatography on transferrin-Sepharose, and then used to screen human scFv against it from a fully-synthesized phage scFv library. After verifying the specificity, gene fragment of one of the selected scFv was inserted into the plasmid pET22b(+) and transformed into E. coli BL21(DE3) . Expression of scFv in transformant was induced with 0.5mmol/L IPTG. ELISA assay on HeLa cells showed that scFv protein could recognize and bind to TfR on the surface of HeLa cells. The scFv was purified by one-step affinity chromatography with Ni+ -NTA agarose, and injected into Kunming mouse via tail veins. This scFv was detected in brain tissues 1h later by capillary depletion method, which indicates that scFv protein can permeate through the blood brain barrier by mediation of the TfR receptor. Our works lay the foundation for the treatment of tumors and central nervous system diseases.

Animals↗

PubMed2006

[Screening and identification of antibodies against transferrin receptor].

AIM: To screen the antibodies against transferrin receptor(TfR) from a full humanized phage antibody library. METHODS: Total RNA was extracted from HeLa cells and then the extracellular domain of TfR gene was amplified by RT-PCR in two parts. A full-length gene of extracellular domain was obtained by two rounds of PCR. The gene was inserted into the plasmid pPROEX(TM) HTa and transformed into E.coli BL21(DE3). Transformant was expressed under 1 mmol/L IPTG induction. The target protein was purified and refolded by one-step affinity chromatography with Ni(+)-NTA agarose. The antibodies against TfR were screened by proteins coupled to immunotubes from a whole-hog humanized phage single chain antibody library with sink size of 10(13) cfu/L. RESULTS: The extracellular domain of TfR gene with about 1.9 kb was obtained. DNA sequencing of TfR gene proved to be identical to the published sequence. Eight single chain antibodies specifically binding to human TfR have been screened. CONCLUSION: Antibodies specifically binding to natural TfR can be obtained by screening the library with refolded protein, which lays the foundation for treatment of tumor and central nervous system diseases.

Antibodies↗

PubMed2006

Archaeal communities in mangrove soil characterized by 16S rRNA gene clones.

An archaeal 16S rRNA gene library was constructed from mangrove soil. Phylogenetic analysis revealed archaea in mangrove soil including the Crenarchaeota (80.4%) and Euryarchaeota (19.6%) phyla. The archaeal community in mangrove soil appears to be a mixture of organisms found in a variety of environments with the majority being of marine origin.

Archaea↗

PubMed2005

Photophysics of the lanthanide complexes with conjugated carboxylic acids by low temperature fluorescent spectroscopy.

In the context, some lanthanide (Eu(3+), Tb(3+) and Sm(3+)) complexes with conjugated carboxylic acids (pyridine-carboxylic acids derivatives) have been synthesized and characterized. The low temperature fluorescent spectra for these complexes have been measured at nitrogen atmosphere (77 K), indicating that the central Ln(3+) ions locate in an equivalent coordination environment with low symmetry for most of these lanthanide complexes belonging to dimeric or polymeric structure. Therefore, the electronic dipole transition (supersensitive transition) ((5)D(0) --> (7)F(2) for Eu(3+), (5)D(4) --> (7)F(6) for Tb(3+), (4)G(5/2) --> (6)H(9/2) for Sm(3+)) and magnetic dipole transition ((5)D(0) --> (7)F(1) for Eu(3+), (5)D(4) --> (7)F(5) for Tb(3+), (4)G(5/2) --> (6)H(5/2) for Sm(3+)) show the regular change in the corresponding split number of fluorescent spectra, which can be realized to predict the fine structure of lanthanide complexes.

Journal Article↗

PubMed2005

Spectroscopic study on the photophysical properties of lanthanide complexes with long chain mono-docosyl phthalate.

Ortho phthalic anhydride was modified with long chain alcohol (1-docosanol) to its corresponding monodocosyl phthalate (22-Phth). Subsequently, three novel lanthanide (Eu(3+), Tb(3+), and Dy(3+)) complexes with the long chain monodocosyl phthalate were synthesized and characterized by elemental analysis and Infrared spectra. The photophysical properties of these complexes were studied in detail with ultraviolet-visible absorption spectra, low temperature phosphorescence spectra and fluorescent spectra. The triplet state energy of 22-Phth was determined to be around 25,000 cm(-1) from the maximum phosphorescent peak at 400 nm, suggesting 22-Phth is suitable for the sensitization of the luminescence of Eu(3+), Tb(3+), and Dy(3+). The fluorescence excitation and emission spectra for these lanthanide complexes of the three ligands take agreement with the above predict from energy match principle.

Journal Article↗

PubMed2005

Spectroscopic study on the photophysical properties of novel lanthanide complexes with long chain mono-L phthalate (L=hexadecyl, octadecyl and eicosyl).

Ortho-phthalic anhydride was modified with long chain alcohol (1-hexadecanol, 1-octadecanol and 1-eicosanol) to their corresponding mono-L phthalate (L=hexadecyl, octadecyl and eicosyl), i.e. monohexadecyl phthalate (16-Phth), monooctadecyl phthalate (18-Phth), and monoeicosyl phthalate (20-Phth), respectively. Nine novel lanthanide (Eu(3+), Tb(3+) and Dy(3+)) complexes with these three mono-L phthalate ligands were synthesized and characterized by elemental analysis and IR spectra. The photophysical properties of these complexes were studied in detail with various spectroscopes such as ultraviolet-visible absorption spectra, low temperature phosphorescence spectra and fluorescent spectra. The ultraviolet-visible absorption spectra show some band shifts with the different chain-length of phthalate monoester and homologous lanthanide complexes. From the low temperature phosphorescent emission, the triplet state energies for these three ligands were determined to be around 22,650 cm(-1) (16-Phth), 23,095 cm(-1) (18-Phth) and 22,400 cm(-1) (20-Phth), respectively, suggesting they are suitable for the sensitization of the luminescence of Eu(3+), Tb(3+) and Dy(3+). The fluorescence excitation and emission spectra for these lanthanides complexes of the three ligands take agreement with the above predict from energy match.

Kinetics↗