Biomedical subjects

Juan Zhang

Publications and source records attributed to Juan Zhang.

At least 19 recordsLinked to original sources

PubMed2026

Clinical and genetic analysis of a family with 16p11.2 microduplication syndrome and variable multisystem manifestations.

16p11.2 microduplication syndrome (OMIM #614671) is a pathogenic recurrent copy-number gain at the 16p11.2 locus and is associated with variable expressivity across neurodevelopmental, growth, and medical phenotypes. Gastrointestinal symptoms have been reported in carrier cohorts, but detailed documentation of gastrointestinal motility and neuromuscular findings remains limited. We performed clinical and genetic analyses in a multigenerational family in which the proband (III1) presented with limb muscle pain, exercise intolerance, and chronic gastrointestinal symptoms. Next-generation sequencing (NGS), low-pass whole-genome sequencing (lpWGS)-based CNV analysis, Sanger sequencing, and qPCR validation identified a 0.8 Mb microduplication at 16p11.2 (BP4-BP5), involving 44 genes including TBX6, inherited from the mother (II2). The proband's clinical manifestations included developmental delay, pointed chin, low body mass index, gastrointestinal dysfunction (chronic abdominal pain, diarrhea, esophageal motility disorder, and rectal prolapse), forward-leaning gait, mild scoliosis, and limb muscle atrophy with inflammatory muscle involvement. Four family members (II2, III1, III2, and III4) carried the microduplication, but their available clinical features varied in severity and system involvement. The proband's twin brother (III2) had left ear deafness and epilepsy, individual II2 had blindness from cone-rod dystrophy, and III4 showed more pronounced scoliosis. This family provides a detailed clinical and genetic description of 16p11.2 microduplication carriers with prominent gastrointestinal motility and neuromuscular manifestations, thereby enriching the clinical characterization of this recurrent CNV and supporting substantial intrafamilial phenotypic heterogeneity.

16p11.2 microduplication syndrome↗

PubMed2026

USP10-SIRT6-PARP1 axis drives keratinocyte senescence and skin photoaging under chronic UVA exposure.

Chronic exposure to ultraviolet A (UVA) radiation is the principal environmental driver of skin photoaging, yet the upstream molecular events that commit irradiated keratinocytes to senescence remain poorly understood. Here we show that SIRT6, an NAD+-dependent protein deacetylase with established roles in genome maintenance and organismal longevity, functions as a central gatekeeper of keratinocyte homeostasis under photic stress. Using a chronic UVA irradiation model in mice together with cultured human keratinocytes, we demonstrate that UVA inflicts extensive DNA damage and G2/M cell-cycle arrest, accompanied by selective depletion of SIRT6 among all sirtuin family members. Mechanistically, UVA suppresses the deubiquitinase USP10 at both transcriptional and post-transcriptional levels, thereby licensing ubiquitin-dependent proteasomal degradation of SIRT6. The resulting SIRT6 deficiency unleashes hyperactivation of the DNA-damage sensor PARP1, amplifying genomic injury signaling and driving keratinocytes into irreversible senescence with concomitant elaboration of a broad pro-inflammatory secretory programme encompassing chemokines and cytokines. Pharmacological reactivation of SIRT6 with the selective agonist UBCS039 reverses epidermal hyperplasia, attenuates DNA damage and senescence marker accumulation, and suppresses inflammatory mediator induction both in vivo and in vitro, establishing SIRT6 loss as a causal rather than correlative event. Furthermore, molecular docking and functional validation identify osthole, a plant-derived coumarin from the medicinal herb Cnidium monnieri, as a candidate SIRT6-engaging compound that counteracts UVA-induced senescence and inflammation in keratinocytes. Collectively, these findings define a USP10-SIRT6-PARP1 signaling axis whose disruption underlies cutaneous photoaging and suggest that SIRT6-directed strategies may offer therapeutic benefit against UV-driven tissue degeneration.

Animals↗

PubMed2026

Insights into the fate and dynamics of antibiotic resistance in multidrug-resistant Bacillus cereus during in vitro simulated gastrointestinal digestion.

Bacillus cereus, an important pathogen responsible for causing foodborne diseases worldwide, releases pore-forming enterotoxins, which target host epithelial cells, leading to osmotic lysis and ultimately manifesting as diarrheal syndrome. Moreover, some B. cereus strains carry antimicrobial resistance genes that confer multidrug resistance against a spectrum of antibiotics. Characterizing the survival traits of multidrug-resistant (MDR) B. cereus strains in the intestinal microenvironment is essential for developing targeted strategies to effectively manage diarrheal foodborne diseases caused by this pathogen. This study used whole-genome sequencing (WGS) to evaluate the pre- and post-digestion toxigenic potential, antimicrobial resistance profiles, and genetic diversity of MDR B. cereus strains isolated from food samples in Guangdong Province, China. The four B. cereus isolates investigated in this study exhibited a genetic diversity, as determined by multilocus sequence typing analysis of WGS data. All four isolates produced the diarrheal toxins Hbl, Nhe, and CytK to varying levels, indicative of their potential to cause outbreaks of foodborne diseases. Each of the four isolates exhibited resistance to more than three classes of antibiotics, fulfilling the criterion for multidrug resistance. At an initial concentration of 9 log colony-forming units (CFU)/mL, the intestinal concentration of these four isolates crossed the threshold required to induce widespread diarrhea in the general population. Under rice slurry protection, all tested isolates maintained intestinal concentration beyond the threshold when the initial concentration was increased to ≥8 log CFU/mL. Moreover, the upregulations of genes associated with acid tolerance, bile tolerance and stress response were observed in the surviving MDR B. cereus isolates. Digestion markedly altered the antibiotic resistance profiles of the MDR B. cereus isolates. In the absence of a food matrix, the MDR isolates lost their resistance to imipenem, meropenem, amoxicillin-clavulanic acid, and trimethoprim-sulfamethoxazole post-digestion and was influenced by the initial concentration of the strains. In the presence of food matrix rice slurry, the effects of digestion on the antibiotic resistance of MDR B. cereus isolates can be mitigated, enabling them to maintain their antibiotic resistance to the greatest extent. Most remarkably, after digestion, the isolates Bce055 and Bce166 exhibited newly emergent resistance to cefotetan and trimethoprim-sulfamethoxazole, respectively. Our findings clarify the fate of MDR B. cereus isolates in the gastrointestinal tract and inform the development of prevention and control strategies for foodborne diseases caused by this pathogen.

Drug Resistance, Multiple, Bacterial↗

PubMed2026

Effect of intraoperative 40-hz gamma-frequency auditory stimulation on postoperative delirium in older adults undergoing major surgery: a randomized clinical trial protocol.

INTRODUCTION: Postoperative delirium (POD) is a common and clinically significant complication among older adults undergoing major surgery under general anesthesia. Gamma-frequency (40-Hz) auditory stimulation has demonstrated potential neuroprotective and cognition-enhancing effects, suggesting a plausible role in perioperative delirium prevention. However, direct clinical evidence supporting intraoperative 40-Hz auditory stimulation in reducing POD remains limited, warranting rigorous evaluation in a randomized trial. PATIENTS AND METHODS: This prospective, parallel-group, randomized controlled trial will enroll 550 older adults scheduled for major noncardiac, nonneurosurgical surgery under general anesthesia. Participants will be randomized in a 1:1 ratio to either the active stimulation group, receiving intraoperative 40-Hz gamma-frequency auditory stimulation delivered via headphones for 2 h following successful anesthesia induction, or the sham stimulation group, wearing headphones without active auditory output. The primary outcome is the incidence of POD on postoperative day 1 though 3, assessed using the Confusion Assessment Method (CAM) or the CAM for the ICU (CAM-ICU). Secondary outcomes include POD severity, sleep quality, pain scores, analgesic consumption, the incidence of postoperative nausea and vomiting (PONV), rescue antiemetic use, duration of post-anesthesia care unit (PACU) stay, length of hospital stay, quality of postoperative recovery, incidence of perioperative adverse events; postoperative morbidity, health-related quality of life, and all-cause 30-day mortality. DISCUSSION: This trial will determine whether intraoperative 40-Hz gamma-frequency auditory stimulation reduces the incidence of POD among older adults undergoing major surgery under general anesthesia. If efficacious, this noninvasive intervention could constitute a feasible perioperative strategy to mitigate delirium risk and enhance postoperative recovery. CLINICAL TRIAL REGISTRATION: Chinese Clinical Trial Registry (ChiCTR2500115156).

Humans↗

PubMed2025

A complete and near-perfect rhesus macaque reference genome: lessons from subtelomeric repeats and sequencing bias.

A truly complete, telomere-to-telomere (T2T), and error-free reference genome remains a foundational resource-and long-standing goal-for unbiased comparative and functional genomics. While recent T2T assemblies of humans and other primates have made substantial progress, most still contain thousands of base-level errors, particularly within highly repetitive regions. Here, we present T2T-MMU8v2.0, a near-perfect T2T assembly of the rhesus macaque (Macaca mulatta), representing the highest base-level accuracy reported in a primate genome to date. By employing an optimized ONT-only assembly strategy, we identify subtelomeric satellite-rich regions as the principal bottleneck to improving assembly quality, owing to technological biases in long-read platforms and limitations in current hybrid assembly frameworks. We discover 268 previously unannotated repeat families and resolve ~8 Mbp of SATR satellite arrays, with over 99-fold enrichment in historically misassembled subtelomeric regions. These satellites form four distinct genomic architectures, each with unique SATR satellite composition, segmental duplication organization, and epigenetic signatures, distinct from the subtelomeric architectures observed in hominid genomes. Notably, in contrast to the largely gene-poor subtelomeric regions in African hominids, the SATR architectures in macaques harbor 58 actively transcribed genes, supported by open chromatin and expression data, suggesting gene innovation within these repetitive regions. Functionally, T2T-MMU8v2.0 improves read mappability and accuracy across sequencing platforms, and results in a 19% improvement of transcription start site enrichment scores and 5,821 additional chromatin accessibility peaks on average, thereby enhancing variant detection, regulatory annotation, and transcriptomic resolution in population genetics or single-nucleus studies. Together, this work establishes a new benchmark for genomics, offers a roadmap for resolving complex repetitive regions, and reveals previously unrecognized features of subtelomeric genome structure and evolution.

Journal Article↗

PubMed2025

Kin17 promotes rDNA transcription, ribosomal biogenesis, and cortical lamination.

During brain development, neural progenitor cells (NPCs) undergo rapid division, necessitating efficient ribosomal biogenesis for proliferation. Yet, the regulatory mechanisms remain largely elusive. Here, we report that the DNA binding protein Kin17 exhibits development-dependent expression and plays a vital role in embryonic development. Complete loss of Kin17 in mice leads to embryonic lethality, while Kin17 depletion specifically in NPCs allows embryonic survival but results in reduced brain size and cortical lamination defects. Our findings demonstrate that these cortical malformation stems from impaired NPC proliferation and differentiation. Mechanistically, we show that Kin17 binds to the promoter region of rDNA, sequentially recruiting NCL and Polr1a, thereby promoting rDNA transcription. Consequently, Kin17 facilitates ribosome biogenesis and protein translation in NPCs. This study underscores a critical role of Kin17 in promoting rDNA transcription and ribosomal biogenesis in NPCs during brain development, which is essential for proper cortical lamination.

Animals↗

PubMed2025

Rice transcription factor bHLH25 confers resistance to multiple diseases by sensing H2O2.

Hydrogen peroxide (H2O2) is a ubiquitous signal regulating many biological processes, including innate immunity, in all eukaryotes. However, it remains largely unknown that how transcription factors directly sense H2O2 in eukaryotes. Here, we report that rice basic/helix-loop-helix transcription factor bHLH25 directly senses H2O2 to confer resistance to multiple diseases caused by fungi or bacteria. Upon pathogen attack, rice plants increase the production of H2O2, which directly oxidizes bHLH25 at methionine 256 in the nucleus. Oxidized bHLH25 represses miR397b expression to activate lignin biosynthesis for plant cell wall reinforcement, preventing pathogens from penetrating plant cells. Lignin biosynthesis consumes H2O2 causing accumulation of non-oxidized bHLH25. Non-oxidized bHLH25 switches to promote the expression of Copalyl Diphosphate Synthase 2 (CPS2), which increases phytoalexin biosynthesis to inhibit expansion of pathogens that escape into plants. This oxidization/non-oxidation status change of bHLH25 allows plants to maintain H2O2, lignin and phytoalexin at optimized levels to effectively fight against pathogens and prevents these three molecules from over-accumulation that harms plants. Thus, our discovery reveals a novel mechanism by which a single protein promotes two independent defense pathways against pathogens. Importantly, the bHLH25 orthologues from available plant genomes all contain a conserved M256-like methionine suggesting the broad existence of this mechanism in the plant kingdom. Moreover, this Met-oxidation mechanism may also be employed by other eukaryotic transcription factors to sense H2O2 to change functions.

Hydrogen Peroxide↗

PubMed2007

Redundancy in B cell developmental pathways: c-Cbl inactivation rescues early B cell development through a B cell linker protein-independent pathway.

Deficiency in the adaptor protein B cell linker protein (BLNK) results in a substantial but incomplete block in B cell development, suggesting that alternative pathways exist for B lineage differentiation. Another adaptor protein, c-Cbl, plays a negative regulatory role in several BCR-signaling pathways. We therefore investigated the role of c-Cbl during B cell development and addressed the possibility that redundancies in pathways for B cell differentiation could be further revealed by eliminating negative effects mediated by c-Cbl. Strikingly, c-Cbl inactivation reversed a number of the critical defects in early B cell differentiation that are seen in BLNK-deficient mice. c-Cbl(-/-)BLNK(-/-) mice exhibited normalized down-regulation of pre-BCR and CD43, up-regulation of MHC class II, and augmented L chain rearrangement, resulting in a successful transition from pre-B cells to immature B cells. c-Cbl inactivation also reversed the potentially tumor-predisposing hyperproliferative response of BLNK(-/-) pre-B cells to IL-7. Pre-BCR cross-linking induced enhanced and prolonged tyrosine phosphorylation in c-Cbl(-/-)BLNK(-/-) pre-BCR(+) pre-B cells compared with c-Cbl(+/-)BLNK(-/-) cells, including elevated phosphorylation of Lyn, Syk, Btk, and phospholipase C-gamma2. Our studies suggest that some, but not all, pre-BCR-triggered developmental events can be mediated by BLNK-independent pathways that are negatively regulated by c-Cbl, and further suggest that different events during early B cell development require different strength or duration of pre-BCR signaling.

Adaptor Proteins, Signal Transducing↗

PubMed2006

Synthesis of poly(ethylene glycol)-metaxalone conjugates and study of its controlled release in vitro.

Metaxalone (Met), a drug for treatment of pain and stiffness due to muscular injuries, was covalently linked to poly(ethylene glycols) (PEG) via a chloroacetyl chloride spacer. The average weight molecular weights used for PEG are 4000, 6000 and 10,000, respectively, and the procedure of chemical modification for PEGs was conducted by a two-step protocol: (1) synthesis of N-chloroacetyl-metaxalone; (2) synthesis of PEG(4000)-Met, PEG(6000)-Met and PEG(10000)-Met. The controlled drug release studies were performed in buffer solutions with pH values equal to 1.1, 7.4 and 10.0. The results demonstrate that, in the same condition, the rate of hydrolysis for PEG(10000)-Met is the slowest among three prodrugs, and more amount of metaxalone can be detected releasing from prodrug matrices at the presence of alpha-chymotrypsin in a buffer solution with pH 8.0. It was also found that these novel prodrugs can effectively improve the metaxalone's pharmacokinetics, and furthermore can markedly increase its half-life period.

Acetates↗

PubMed2006

A novel mutation of PAX3 in a Chinese family with Waardenburg syndrome.

PURPOSE: The molecular characterization of 34 members of a Chinese family, with 22 members in four generations, affected with Waardenburg syndrome (WS1). METHODS: A detailed family history and clinical data were collected. A genome-wide scan by two-point linkage analysis using more than 400 microsatellite markers in combination with haplotype analysis was performed. Mutation screening was carried out in the candidate gene by sequencing of amplified products. RESULTS: A maximum two-point lod score of 6.53 at theta = 0.00 was obtained with marker D2S2248. Haplotype analysis placed the WS1 locus to a 45.74 cM region between D2S117 and D2S206, in close proximity to the PAX3 gene on chromosome 2q35. Mutation screening in PAX3 identified a 701T > C mutation which converted a highly conserved Leu to Pro. This nucleotide alteration was neither seen in unaffected members of the family nor found in 50 unrelated control subjects. CONCLUSIONS: The present study identified a novel 701T > C mutation in PAX3. The mutation observed in this family highlights the phenotypic heterogeneity of the disorder.

Amino Acid Substitution↗

PubMed2006

Staged pendulous-prostatic anastomotic urethroplasty followed by reconstruction of the anterior urethra: an effective treatment for long-segment bulbar and membranous urethral stricture.

OBJECTIVES: To describe a novel surgical technique for male long-segment urethral stricture after pelvic trauma using the intact and pedicled pendulous urethra to replace the bulbar and membranous urethra, followed by reconstruction of the anterior urethra. METHODS: Two patients with long-segment post-traumatic bulbar and membranous urethral strictures with short left pendulous urethras who had undergone several failed previous surgeries were treated with staged pendulous-prostatic anastomotic urethroplasty followed by reconstruction of the anterior urethra. This procedure was divided into three stages. First-stage surgery was mobilization of the anterior urethra down to the coronary sulcus and then rerouted to the prostatic urethra followed by pendulous-prostatic anastomotic urethroplasty with transposition of the penis to the perineum. Second-stage surgery was transecting the anterior urethra at the revascularised coronary sulcus 6 mo later, followed by straightening of the penis and urethroperineostomy. Third-stage surgery was reconstruction of the anterior urethra 6 mo later. RESULTS: Postoperatively, the two patients reported satisfactory voiding. For patient 1, retrograde urethrography showed that the urethra was patent, and that the mean maximal flow rate (MFR) was 18.4 ml/s with no postvoiding residual urine after the third-stage surgery and at 3-yr follow-up. For patient 2, a 22F urethral catheter could pass smoothly through the urethra, and the MFR was 19.5 ml/s with no postvoiding residual urine at 2-yr follow-up. CONCLUSIONS: This procedure was an effective surgical option for men with complex long-segment post-traumatic bulbar and membranous urethral strictures, especially for those who had undergone failed previous surgical treatments.

Adult↗

PubMed2006

Molecular and functional characterization of sulfiredoxin homologs from higher plants.

By reducing cysteine-sulfinic acid in oxidized peroxiredoxin, sulfiredoxin (Srx) plays an important role in oxidation stress resistance in yeast and human cells. Here, we report the first molecular and functional characterization of Srx homolog from higher plants. Bioinformatic analysis revealed the presence of potential Srx encoding sequences in both monocot and dicot plant species. Putative plant Srx proteins exhibited significant identities to their orthologs from yeast and human, and contained the conserved signature sequence and residues essential for catalysis. However, unlike yeast and human orthologs, plant Srxs were all predicted to possess chloroplast transit peptide in their primary structure. The Srx proteins from Arabidopsis and rice (designated as AtSrx and OsSrx, respectively) complemented functional deficiency of Srx in the SRX1 deletion yeast cells. A GFP fusion protein of AtSrx was targeted to chloroplast in Arabidopsis mesophyll protoplast. AtSrx transcription occurred in both vegetative and reproductive organs, and the highest transcript level was detected in leaves. Under oxidation stress, AtSrx transcript level was substantially increased, which paralleled with enhanced transcription of 2-Cys peroxiredoxins that have been found essential in maintaining chloroplast redox balance. In addition to oxidation stress, osmotic/water deficit or cold treatments also raised AtSrx transcript level. Consistent with above findings, the knock-out mutant of AtSrx was significantly more susceptible to oxidation stress than wild type Arabidopsis plant. Taken together, the results of this work indicate the existence of functional Srx homolog in higher plants that is essential for plants to cope with oxidation stress.

Amino Acid Sequence↗

PubMed2006

[Preparation and characterization of monoclonal antibody against Vibrio cholerae O139].

AIM: To prepare monoclonal antibody (mAb) against Vibrio cholerae O139, which would be used as the gold colloidal reagent strip for rapid detection of O139, and to determine its biological characterization. METHODS: BALB/c mice were immunized by inactivated Vibrio cholerae O139. Anti-O139 mAbs were prepared by using hybridoma technique. The specificity of mAb was determined by indirect ELISA and Western blot. The indirect ELISA was used to identify Ig subgroup, detect its titer in ascites and relative affinity, and analyze antigen-binding epitope of mAbs. RESULTS: Two hybridoma cells (O4D7 and O4D10), secreting anti-O139 mAbs were obtained. The Ig subgroups of O4D7 and O4D10 were IgG2b and IgG3, respectively. The mAb's titer in ascites was 1:10(7). The relative affinity of mAb O4D7 was more than 10(5) and that of O4D10 was more than 10(4). The result of additive ELISA showed that two mAbs could recognize different antigen epitopes. CONCLUSION: The successful preparation of two anti-O139 mAbs provides a powerful tool for the development of a rapid method of detecting Vibrio cholerae O139 infection.

Animals↗

PubMed2006

[An optimized method for construction of genomic library].

Construction of genomic libraries is basic and important. Because of the laboriousness and high background of traditional methods for constructing genomic libraries, we improved them by overcoming these disadvantages. Two Ear I sites were chosen as the cloning sites, which can produce variable 3-base cohesive ends. Therefore the two overhangs could be devised to prevent a match and to avoid self-ligation of vector. Genomic DNA is cleaved partially with Sau3A I and subsequently incubated with dGTP and Klenow fragment of DNA polymerase Iso the self-ligation of fragments and ligation between them are blocked. In this study, the ARS probe vector (pHBM803/Trp) based on the improved method was constructed and then we constructed the Oryza sativa genomic library separately with the traditional method and improved method and compared them. The result of experiment indicated that the improved method could optimize the quality of library.

Cloning, Molecular↗

PubMed2005

Construction and characterization of a bi-functional EGFP/sBAFF fusion protein.

A fusion between gene encoding fluoresce-enhanced green fluorescent protein variant (EGFP) and soluble domain of human B-cell-activating factor of the TNF family (sBAFF) was constructed and expressed in Escherichia coli. The EGFP/sBAFF had an apparent molecular weight of 45 kDa and was detected with anti-hsBAFF and anti-His(6) monoclonal antibodies. After being purified by immobilized metal affinity chromatography (IMAC), the fusion protein retained similar fluorescence spectra to those of EGFP. Biological activity assays showed the EGFP/sBAFF as well as sBAFF could co-stimulated human B lymphocyte proliferation in vitro. In addition, EGFP/sBAFF has shown specific binding to BAFF receptors positive-cells and the stained cells could be analyzed with flow cytometry. Thus, the fusion protein represents a readily obtainable source of biologically active sBAFF that may prove useful in further studies on BAFF and its receptors.

B-Cell Activating Factor↗

PubMed2005

Investigation of physicochemical properties of lactam-based Brønsted acidic ionic liquids.

Novel lactam-cation-based Brønsted acid ionic liquids (ILs) were prepared through a simple and atom-economic neutralization reaction between a lactam, such as caprolactam and butyrolactam, and a Brønsted acid, HX, where X is BF4-, CF3COO-, phCOO-, ClCH2COO-, NO3-, or H2PO4-. The density, viscosity, acidic scale, electrochemical window, temperature dependency of ionic conductivity, and thermal property of these ILs were measured and investigated in detail. The results show that protonated caprolactam tetrafluoroborate (CPBF) has a relatively strong acidity with -0.22 of Hammett acidic scale H0 and caprolactam trifluoroacetate (CPTFA) and pyrrolidonium trifluoroacetate (PYTFA) ILs possess very low viscosities, that is, 28 cP and 11 cP, respectively. An investigation of thermal property showed that a wide liquid range (up to -90 degrees C), moderate thermal stability (up to 249 degrees C for 10% of decomposition), and complex polymorphism were observed in these ILs. In comparison to imidazolium-cation-based ILs, the lactam-cation-based Brønsted acid ILs have a relatively lower cost, lower toxicity, and comparable ion conductivity and heat storage density (more than 200 MJ/m3). They have wide applicable perspectives for fuel cell devices, thermal transfer fluids, and acid-catalyzed reaction media and catalysts as replacements of conventional inorganic acids.

Journal Article↗

PubMed2005

Ionic liquid as an efficient promoting medium for fixation of carbon dioxide: a clean method for the synthesis of 5-methylene-1,3-oxazolidin-2-ones from propargylic alcohols, amines, and carbon dioxide catalyzed by Cu(I) under mild conditions.

[reaction: see text] The reactions of propargylic alcohols, aliphatic primary amines, and CO2 were conducted in CuCl/[BMIm]BF4 system to produce the corresponding 5-methylene-1,3-oxazolidin-2-ones under relatively mild conditions. The products could be conveniently isolated by means of liquid-liquid extraction. The solvent ionic liquid as well as CuCl catalyst can be recovered and reused three times without appreciable loss of activity. By this green approach, several new 5-methylene-1,3-oxazolidin-2-ones were prepared in excellent yields and purity and were well-characterized.

Journal Article↗

PubMed2005

Antitumor activity of a fusion of esophageal carcinoma cells with dendritic cells derived from cord blood.

The aim of this experiment was to develop a cytotoxic cancer vaccine (EC109-DC) prepared by fusions of esophageal carcinoma cells with dendritic cells derived from cord blood and to study the biological characteristics and resultant induction of antitumor immunity. CD34+ hematopoietic stem cells were isolated from cord blood using a CD34+ Progenitor Cell Isolation Kit by magnetic cell sorting system (MACS). CD34+ cells were incubated with rhGM-CSF, rhTNF-alpha and rhSCF for 2 weeks as DC (dendritic cells), and then by PEG-3600 to fuse with an esophageal carcinoma cell line. Selection with MACS marked with HLA-DR MicroBeads generated EC109-DC. Phenotypes and proliferation were analyzed by flow cytometry and cell culture in vitro. The lymphocyte proliferation reaction and CTL cytotoxicity were examined by MTT assay. The EC109-DC cells could proliferate slowly in vitro and highly expressed CD80, CD83 and CD86. The lymphocyte proliferation reaction and specific cytotoxicity against EC109 induced by EC109-DC cells were significantly higher than in control groups (p < 0.05). EC109-DC cells obtained by PEG fusion acquired the immuno-stimulating phenotype and could significantly stimulate the lymphocyte proliferation reaction and CTL activity. The results of this research provide the basis for materials to develop the DC-based vaccine against esophageal carcinoma.

Animals↗