Cryo-EM structure of human HCN3 channel and its regulation by cAMP.

HCN channels are important for regulating heart rhythm and nerve activity and have been studied as potential drug targets for treating depression, arrhythmia, nerve pain, and epilepsy. Despite possessing unique pharmacological properties, HCN channels share common characteristics in that they are activated by hyperpolarization and modulated by cAMP and other membrane lipids. However, the mechanisms of how these ligands bind and modulate HCN channels are unclear. In this study, we solved structures of full-length human HCN3 using cryo-EM and captured two different states, including a state without any ligand bound and a state with cAMP bound. Our structures reveal the novel binding sites for cholesteryl hemisuccinate in apo state and show how cholesteryl hemisuccinate and cAMP binding cause conformational changes in different states. These findings explain how these small modulators are sensed in mammals at the molecular level. The results of our study could help to design more potent and specific compounds to influence HCN channel activity and offer new therapeutic possibilities for diseases that lack effective treatment.

Defects detection of GMAW process based on convolutional neural network algorithm.

It is significant to predict welding quality during gas metal arc welding process. The welding defect detection algorithm has been developed based on convolutional neural network (CNN). The sensing system and image processing algorithm for molten pools has been developed. It overcomes the interference caused by the arc light to obtain clear images of the molten pool's boundaries. The molten pools images are used to build up training set and test set for training and testing the CNN model. The model is designed to extract the visual features of molten pool images to predict the penetration state, the welding crater, and slags. Through optimizing the network parameters such as kernel-size, batch-size and learning rate, the prediction accuracy is higher than 95%. Moreover, the model enhances additional focus on the welding crater based on the welder experience. The mechanisms between molten pool characteristics and welding defects were analyzed based on the welder experience and the visual features of the model. It is found that the model judges the occurrence of burn-through with the black hole in the middle zone of the molten pool. When the surface pores are generated, the model exhibits a strong response to circular voids in the semi-solid region at the trailing end of the molten pool. The size and shape of fusion holes exhibit a strong correlation with the molten state. When the shape of the crater does not appear concave, it often signifies excessive penetration. It contributes to enhancing the algorithm's robustness during various welding scenarios.

Challenges and engineering application of landfill leachate concentrate treatment.

Landfill leachate concentrate (LLC) is a concentrated waste stream from landfill leachate treatment systems and has been recognized as a key challenge due to its high concentration of salts, heavy metals, organic matters, etc. Improper management of LLC (e.g. reinjection) would exacerbate the performance of upstream treatment processes and pose risks to the surrounding environments near landfill sites. Addressing the challenge and recovering resources from LLC have thus been attracting considerable attention. Although many LLC treatment technologies have been developed, a comprehensive discussion about the challenges still lacks. This review critically evaluates mainstream LLC treatment technologies, namely incineration, coagulation, advanced oxidation, evaporation and solidification/stabilization. We then introduce a geopolymer-based solidification (GS) process as a promising technology owning to its simple casting process and reusable final product and summarize engineering applications in China. Finally, we suggest investigating hybrid systems to minimize LLC production and achieve the on-site reuse of LLC. Collectively, this review provides useful information to guide the selection of LLC treatment technologies and suggests a sustainable alternative for large-scale application, while also highlighting the need of joint efforts in the industry to achieve efficient, ecofriendly and economical on-site management of landfill waste streams.

Flame atomic absorption spectrometry combined with surface-modified magnetic mesoporous silica microspheres by polyethyleneimine for enrichment, isolation and determination of Cu2+ in preserved eggs after high-temperature digestion.

A new efficient magnetic solid-phase extractant based on a surface-modified magnetic mesoporous silica microsphere referred as MMSM-PEI was synthesised and used for the enrichment and isolation of copper ions (Cu2+) in preserved eggs. The physicochemical properties and morphology of MMSM-PEI were characterized by X-ray diffraction (XRD) spectroscopy, Fourier transform infrared spectroscopy (FT-IR), vibration sample magnetometry (VSM), scanning electron microscopy (SEM) and thermos-gravimetric analyses (TGA). The concentrations of trace Cu2+ in the preserved egg were determined by flame atomic absorption spectroscopy (FAAS). The effects of important parameters were examined. The most suitable pH values and temperature for adsorbing Cu2+ were 6.5 and 25 °C, respectively. According to the determination of Cu2+ in egg white, egg yolk and the outer coating mixture (TOCM) of preserved eggs, the spiked recovery and RSD were 94.1-103.8% and 0.96-4.35%, respectively. The limit of detection (LOD) and the limit of quantitation (LOQ) were 0.14 mg/kg and 0.46 mg/kg, respectively. The developed method improved the sensitivity and accuracy of FAAS for the determination of Cu2+ and it could be applied to the determination of trace Cu2+ in real samples.

Cellularity and its relation with capsular characteristics as an influencing factor for operative strategies of pleomorphic adenoma.

INTRODUCTION: This study investigates the relationship between cellularity and capsular characteristics of pleomorphic adenoma and its influence on operative strategies. MATERIAL AND METHODS: The capsular characteristics and clinical data of patients with pleomorphic adenomas were reviewed according to Seifert's definition: (1) classic type with balanced amount of cells and stroma, (2) myxoid type with abundant ground substance, interspersed spindle cells, and (3) cellular type with predominance of ductal trabecular structures and little stroma. The immunoreactivity of cellular proliferation (Ki-67) was semi-quantitatively measured using immunohistochemistry. Variables were analyzed using Fisher's test and one-way ANOVA, with (p < 0.05) considered statistically significant. RESULTS: The duration of presence was associated with cellularity (p = 0.01). In terms of capsular characteristics, satellite nodules and positive resection margins were not related to cellularity, except for incomplete capsules (p = 0.03). There was no difference in the staining scores of Ki-67 (p = 0.12). CONCLUSION: Lower cellularity reflects higher probability of an incomplete capsule, requiring more consideration for operative strategies to prevent recurrence.

INTRODUCCIÓN: Este estudio investiga la relación entre la celularidad y las características capsulares del adenoma pleomórfico y su influencia en las estrategias operativas. MATERIAL Y MÉTODOS: Se revisaron las características capsulares y los datos clínicos de los pacientes con adenomas pleomórficos según la definición de Seifert: 1) tipo clásico con cantidad equilibrada de células y estroma, 2) tipo mixoide con abundante sustancia fundamental, células fusiformes intercaladas y 3) tipo celular con predominio de estructuras trabeculares ductales y poco estroma. La inmunorreactividad de la proliferación celular (Ki-67) se midió semicuantitativamente usando inmunohistoquímica. Las variables se analizaron mediante la prueba de Fisher y ANOVA de una vía, considerándose significativo un valor de p inferior a 0.05. RESULTADOS: La duración de la presencia se asoció con la celularidad (p = 0.01). En cuanto a las características capsulares, los nódulos satélites y los márgenes de resección positivos no se relacionaron con la celularidad, a excepción de las cápsulas incompletas (p = 0.03). No hubo diferencia en las puntuaciones de tinción de Ki-67 (p = 0.12). CONCLUSIONES: La celularidad más baja refleja una mayor probabilidad de una cápsula incompleta, lo que requiere una mayor consideración de las estrategias quirúrgicas para prevenir la recurrencia.

Protective Effect of Flavonoids from a Deep-Sea-Derived Arthrinium sp. against ox-LDL-Induced Oxidative Injury through Activating the AKT/Nrf2/HO-1 Pathway in Vascular Endothelial Cells.

Oxidized low-density lipoprotein (ox-LDL)-induced oxidative injury in vascular endothelial cells is crucial for the progression of cardiovascular diseases, including atherosclerosis. Several flavonoids have been shown cardiovascular protective effects. Recently, our research group confirmed that the novel flavonoids isolated from the deep-sea-derived fungus Arthrinium sp., 2,3,4,6,8-pentahydroxy-1-methylxanthone (compound 1) and arthone C (compound 2) effectively scavenged ROS in vitro. In this study, we further investigated whether these compounds could protect against ox-LDL-induced oxidative injury in endothelial cells and the underlying mechanisms. Our results showed that compounds 1 and 2 inhibited ox-LDL-induced apoptosis and adhesion factors expression in human umbilical vein vascular endothelial cells (HUVECs). Mechanistic studies showed that these compounds significantly inhibited the ROS level increase and the NF-κB nuclear translocation induced by ox-LDL. Moreover, compounds 1 and 2 activated the Nrf2 to transfer into nuclei and increased the expression of its downstream antioxidant gene HO-1 by inducing the phosphorylation of AKT in HUVECs. Importantly, the AKT inhibitor MK-2206 2HCl or knockdown of Nrf2 by RNA interference attenuated the inhibition effects of these compounds on ox-LDL-induced apoptosis in HUVECs. Meanwhile, knockdown of Nrf2 abolished the effects of the compounds on ox-LDL-induced ROS level increase and the translocation of NF-κB to nuclei. Collectively, the data showed that compounds 1 and 2 protected endothelial cells against ox-LDL-induced oxidative stress through activating the AKT/Nrf2/HO-1 pathway. Our study provides new strategies for the design of lead compounds for related cardiovascular diseases treatment.

Synthesis and biological evaluation of novel indole-pyrazoline hybrid derivatives as potential topoisomerase 1 inhibitors.

A series of novel indole-pyrazoline hybrid derivatives were designed, synthesized, and evaluated for topoisomerase 1 (Top1) inhibitory activity. Top1-mediated relaxation assays showed that our synthesized compounds had variable Top1 inhibitory activity. Among these compounds, 3-(5-(naphthalen-1-yl)-1-phenyl-4,5-dihydro-1H-pyrazol-3-yl)-1-(phenylsulfonyl)-1H-indole (6n) was found to be a strong Top1 inhibitor with better inhibitory activity than CPT and hit compounds. Our further experiments rationalized the mode of action for this new type of inhibitors, which showed no significant binding to supercoiled DNA.

Iridium-catalyzed B-H insertion of sulfoxonium ylides and borane adducts: a versatile platform to α-boryl carbonyls.

Iridium-catalyzed boron-hydrogen bond insertion reactions of trimethylamine-borane and sulfoxonium ylides have been demonstrated, furnishing α-boryl ketones in moderate to excellent yields in most cases (51 examples; up to 84%). This practical and scalable insertion reaction showed broad substrate scope, high functional-group compatibility and could be applied in late-stage modification of structurally complex drug compounds. Further synthetic applications were also demonstrated.

Electrochemical dual-aptamer-based biosensor for nonenzymatic detection of cardiac troponin I by nanohybrid electrocatalysts labeling combined with DNA nanotetrahedron structure.

The accurate detection of biomarkers for acute myocardial infarction (AMI) plays an important role in clinical diagnosis and management process. In this work, we developed an electrochemical biosensor by using magnetic metal organic framework (MMOF) nanocatalysts and DNA nanotetrahedron (NTH) based dual-aptamer probes for nonenzymatic detection of cardiac troponin I (cTnI), a gold standard biomarker for the early diagnosis of AMI. Firstly, the NTH-assisted dual-aptamer (Tro4 and Tro6) capture probes were immobilized on the screen-printed gold electrode (SPGE) for the highly enhanced capture the target cTnI with steady support and optimized interface density. Then, the MMOF Fe3O4@UiO-66 nanozymes were decorated by bimetallic Cu@Au nanoparticles and two kinds of aptamer. This fabricated nonenzymatic nanoprobe1 (NP1) can be applied for recognizing the cTnI specifically and amplifying the current signal by catalyzing the oxidation of hydroquinone (HQ) to benzoquinone (BQ) with H2O2. The target proteins were captured to fabricate a supersandwich-like structure on a SPGE interface. Furthermore, the nanoprobe2 (NP2) of Cu@Au nanozymes labeled with dual-complementary DNA (cDNA) to the dual-aptamer, were anchored on the NP1 through DNA hybridization, leading to the formation of cluster-based nanoprobes for further enhancing detection sensitivity. Finally, this enzyme-free electrochemical aptasensor exhibited great analytical performance with a dynamic range of 0.05-100 ng/mL, a low detection limit of 16 pg/mL, high selectivity and good repeatability. The fabricated aptasensor has great potential development in the field of clinic disease diagnostics for AMI.

A Cross-Sectional Study of Endogenous Antioxidants and Patterns of Dental Visits of Periodontitis Patients.

Periodontitis is an inflammatory disease, wherein endogenous antioxidants help to balance the inflammatory status. Oral health behaviors are related to the periodontal disease status. The aim of this study was to explore the associations between oral health behaviors and endogenous antioxidants in periodontitis patients. In total, 225 subjects diagnosed with periodontitis were enrolled in the study. Information obtained from the initial interview included socioeconomic and demographic characteristics, lifestyle factors, and oral health-related behaviors. The clinical periodontal parameters evaluated included bleeding on probing (BOP), the plaque index (PI), and probing depth (PD). Stimulated saliva was collected before periodontal therapy to determine five endogenous antioxidants (copper-zinc superoxide dismutase (Cu/Zn SOD), manganese SOD (MnSOD), thioredoxin 1 (Trx1), peroxiredoxin 2 (Prx2), and catalase (CAT)). When these five factors were adjusted for in patients whose last previous dental visit was >1 year, the patients' PI, BOP, and PD showed significant decreases because of an elevation in the Cu/Zn SOD level. Associations of endogenous antioxidants with levels of clinical periodontal parameters were much higher in subjects whose last previous dental visit was >1 year, compared to subjects whose last previous dental visit was <1 year. This study provides a better understanding of dental visit patterns and the salivary endogenous antioxidants that may underlie the symptomatic development of preclinical periodontitis.

The association between fecal hemoglobin concentration and oral potentially malignant disorders.

OBJECTIVES: The present study was to investigate the association between fecal hemoglobin (f-Hb) concentration and oral cancer and its precursor, oral potentially malignant disorders (OPMD). METHODS: We used a population-based longitudinal cohort study data based on both Taiwanese nationwide oral and colorectal cancer screening programs implemented between 2004 and 2009. The total of 235,234 smokers and/or betel-quid chewers aged 50 to 69 years free of oral cancer and OPMD at entry were followed up over time to quantify the association between baseline f-Hb concentration on newly diagnosed oral cancer and OPMD. RESULTS: The risk of OPMD increased with baseline f-Hb in a dose manner, yielding a statistically significant elevated risk of developing OPMD in parallel with the incremental concentration of f-Hb (adjusted hazard ratios = 0.99, 1,11, 1,07, 1,57, and 1,63 for f-Hb categories of 1-9, 10-19, 20-49, 50-89, and ≥90 µg Hb/g, respectively, as compared with the reference group (low and undetectable f-Hb concentrations)) However, there was lacking of a statistical significance for the corresponding association regarding the risk of oral cancer, which is possibly due to sparse cases given a shorter follow-up time. CONCLUSION: We discovered that f-Hb concentration was positively related to the risk of OPMD. f-Hb can be used as a biomarker for early detection of OPMD.

Cigarette Smoking Aggravates the Activity of Periodontal Disease by Disrupting Redox Homeostasis- An Observational Study.

The aim of this study was to evaluate the associations between cigarette use and five salivary oxidative stress biomarkers, copper-zinc superoxide dismutase (Cu/Zn SOD), manganese superoxide dismutase (MnSOD), catalase, thioredoxin-1 (TRX1), and peroxiredoxin-2 (PRX2), to assess the effectiveness of non-surgical periodontal therapy. MATERIALS AND METHODS: This is an observational study,167 patients diagnosed with periodontitis were recruited. Both saliva samples and clinical measurements (plaque index (PI), bleeding on probing (BOP), and pocket depth (PD)) were taken at baseline and after completing non-surgical periodontal therapy. The Levels of salivary biomarkers were determined using a MILLIPLEX® MAP Human Oxidative Stress Magnetic Bead Panel kit. The overall reductions in PI and BOP were 31.56% and 42.16%, respectively. BOP reduction after treatment in female or male non-smokers was significantly higher than in male former smokers (p < 0.05). After completing non-surgical periodontal therapy, Cu/ZnSOD, MnSOD, catalase, and Prx2 significantly decreased. There was a significant interaction between smoking status and ΔCu/ZnSOD on PI and a significant interaction between smoking status and ΔCatalase on BOP. CONCLUSIONS: Cigarette smoking interferes with redox homeostasis in the body, alters antioxidants levels, and influences the periodontal disease activity.

Discovery of Novel Schizocommunin Derivatives as Telomeric G-Quadruplex Ligands That Trigger Telomere Dysfunction and the Deoxyribonucleic Acid (DNA) Damage Response.

Telomeric G-quadruplex targeting and telomere maintenance interference are emerging as attractive strategies for anticancer therapies. Here, a novel molecular scaffold is explored for telomeric G-quadruplex targeting. A series of novel schizocommunin derivatives was designed and synthesized as potential telomeric G-quadruplex ligands. The interaction of telomeric G-quadruplex DNA with the derivatives was explored by biophysical assay. The cytotoxicity of the derivatives toward cancer cell lines was evaluated by the methyl thiazolyl tetrazolium (MTT) assay. Among the derivatives, compound 16 showed great stabilization ability toward telomeric G-quadruplex DNA and good cytotoxicity toward cancer cell lines. Further cellular experiments indicated that 16 could induce the formation of telomeric G-quadruplex in cells, triggering a DNA damage response at the telomere and causing telomere dysfunction. These effects ultimately provoked p53-mediated cell cycle arrest and apoptosis, and suppressed tumor growth in a mouse xenograft model. Our work provides a novel scaffold for the development of telomeric G-quadruplex ligands.

Natural Alkaloids and Heterocycles as G-Quadruplex Ligands and Potential Anticancer Agents.

G-quadruplexes are four-stranded nucleic acid secondary structures that are formed in guanine-rich sequences. G-quadruplexes are widely distributed in functional regions of the human genome and transcriptome, such as human telomeres, oncogene promoter regions, replication initiation sites, and untranslated regions. Many G-quadruplex-forming sequences are found to be associated with cancer, and thus, these non-canonical nucleic acid structures are considered to be attractive molecular targets for cancer therapeutics with novel mechanisms of action. In this mini review, we summarize recent advances made by our lab in the study of G-quadruplex-targeted natural alkaloids and their derivatives toward the development of potential anticancer agents.

Bone regeneration using a porcine bone substitute collagen composite in vitro and in vivo.

The biocharacteristics of xenogeneic grafts make them a possible substitute for autogenous bone grafts in dental bone graft procedures. This study aimed to develop a novel porcine graft with collagen capable of generating new bone in bone defects via osteoconduction over 8 weeks of healing and to compare it with a porcine graft. The porcine collagen graft was made to undergo a cell viability test (MTT) and alkaline phosphatase assay (ALP). The surgical procedure was performed in 20 male adult New Zealand white rabbits. Four calvarial critical-size defects of 6 mm in diameter were prepared in each rabbit. The upper left defect was filled with a porcine graft of 500-1000 µm, the upper right with a porcine collagen graft, the lower left with hydroxyapatite/beta-tricalcium phosphate and the lower right served as the control without any filling material. The rabbits were divided and sacrificed at 2, 4, 6 and 8 weeks after surgery. Histological and micro-CT scan results showed that the performance of the porcine collagen graft is superior for regenerating new bone. Porcine collagen graft showed cell viability and osteoblast-like cell differentiation in vitro. The results indicate that porcine collagen graft is a potential bone substitute for clinical application.

Static magnetic fields enhance dental pulp stem cell proliferation by activating the p38 mitogen-activated protein kinase pathway as its putative mechanism.

Dental pulp stem cells (DPSCs) can be a potential stem cell resource for clinical cell therapy and tissue engineering. However, obtaining a sufficient number of DPSCs for repairing defects is still an issue in clinical applications. Static magnetic fields (SMFs) enhance the proliferation of several cell types. Whether or not SMFs have a positive effect on DPSC proliferation is unknown. Therefore, the aim of this study was to investigate the effect of SMFs on DPSC proliferation and its possible intracellular mechanism of action. For methodology, isolated DPSCs were cultured with a 0.4-T SMF. Anisotropy of the lipid bilayer was examined using a fluorescence polarization-depolarization assay. The intracellular calcium ions of the SMF-treated cells were analysed using Fura-2 acetoxymethyl ester labelling. The cytoskeletons of exposed and unexposed control cells were labelled with actin fluorescence dyes. Cell viability was checked when the tested cells were cultured with inhibitors of ERK, JNK and p38 to discern the possible signalling cascade involved in the proliferative effect of the SMF on the DPSCs. Our results showed that SMF-treated cells demonstrated a higher proliferation rate and anisotropy value. The intracellular calcium ions were activated by SMFs. In addition, fluorescence microscopy images demonstrated that SMF-treated cells exhibit higher fluorescence intensity of the actin cytoskeletal structure. Cell viability and real-time polymerase chain reaction suggested that the p38 signalling cascade was activated when the DPSCs were exposed to a 0.4-T SMF. F-actin intensity tests showed that SB203580-treated cells decreased even with SMF exposure. Additionally, the F-/G-actin ratio increased due to slowing of the cytoskeleton reorganization by p38 mitogen-activated protein kinase inhibition. According to these results, we suggest that a 0.4-T SMF affected the cellular membranes of the DPSCs and activated intracellular calcium ions. This effect may activate p38 mitogen-activated protein kinase signalling, and thus reorganize the cytoskeleton, which contributes to the increased cell proliferation of the DPSCs. Copyright © 2016 John Wiley & Sons, Ltd.

Prophylactic supplement with melatonin successfully suppresses the pathogenesis of periodontitis through normalizing RANKL/OPG ratio and depressing the TLR4/MyD88 signaling pathway.

Periodontitis (PD) is an inflammatory disease characterized by gingival inflammation and resorption of alveolar bone. Impaired receptor activator of nuclear factor-kappa B ligand/osteoprotegerin (RANKL/OPG) signaling caused by enhanced production of pro-inflammatory cytokines plays an essential role in the pathogenesis of PD. Considering melatonin possesses significant anti-inflammatory property, this study aimed to determine whether prophylactic treatment with melatonin would effectively normalize RANKL/OPG signaling, depress toll-like receptor 4/myeloid differentiation factor 88 (TLR4/MyD88)-mediated pro-inflammatory cytokine activation, and successfully suppress the pathogenesis of PD. PD was induced in adult rats by placing the ligature at molar subgingival regions. Fourteen days before PD induction, 10, 50, or 100 mg/kg of melatonin was intraperitoneally injected for consecutive 28 days. Biochemical and enzyme-linked immunosorbent assay were used to detect TLR4/MyD88 activity, RANKL, OPG, interleukin 1ß, interleukin 6, and tumor necrosis factor-α levels, respectively. The extent of bone loss, bone mineral intensity, and calcium intensity was further evaluated by scanning electron microscopy, micro-computed tomography, and energy-dispersive X-ray spectroscopy. Results indicated that high RANKL/OPG ratio, TLR4/MyD88 activity, and pro-inflammatory cytokine levels were detected following PD. Impaired biochemical findings paralleled well with severe bone loss and reduced calcium intensity. However, in rats pretreated with melatonin, all above parameters were successfully returned to nearly normal levels with maximal change observed in rats receiving 100 mg/kg. As prophylactic treatment with melatonin effectively normalizes RANKL/OPG signaling by depressing TLR4/MyD88-mediated pro-inflammatory cytokine production, dietary supplement with melatonin may serve as an advanced strategy to strengthen oral health to counteract PD-induced destructive damage.

An evaluation of the biocompatibility and osseointegration of novel glass fiber reinforced composite implants: In vitro and in vivo studies.

OBJECTIVES: The aim of this study was to evaluate the in vitro biocompatibility and in vivo osseointegration of three novel bioactive glass fiber reinforced composite (GFRC) implants and to compare these with metal (Ti6Al4V) implants. METHODS: The surfaces of these experimental substrates were characterized by scanning electron microscopy (SEM), a 2D profilometer and by contact angle measurement. In vitro biological performance was assessed using MG-63 human osteoblast-like cell morphology, cell proliferation assays and the alkaline phosphatase (ALP) activity testing. Furthermore, in vivo osseointegration performance was examined by installing samples into rabbit femurs and evaluated the results using micro-CT, histology and histomorphometrical analysis; these assessments were carried out after 1, 2, 4 and 8 weeks of healing. RESULTS: The results showed that moderate surface roughness, moderate hydrophilic exposure and moderate homogenous exposure of bioactive glass fibers were present for all of the GFRC substrates. Furthermore, MG-63 cells, when cultured on all of the GFRC substrates, grew well and exhibited a more differentiated phenotype than cells grown on titanium alloy (Ti6Al4V) substrate. Histological evaluation revealed more newly-formed bone regeneration within the thread of the GFRC implants during the initial healing period. In addition, the novel GFRC implants with a bioactive Bio-fiber structure and glass particles within the epoxy resin matrix showed better bone volume/tissue volume (BV/TV) values at 4 weeks and this was accompanied by bone-implant contact (BIC) values at 8 weeks comparable to the Ti6Al4V group. SIGNIFICANCE: These findings demonstrated that novel GFRC implants seem to show improved osteogenesis and osseointegration functionality and have potential as a substitute for Ti6Al4V, or other metal-based materials, when used for clinically dental and orthopedic applications.

Design, Synthesis, and Evaluation of Isaindigotone Derivatives To Downregulate c-myc Transcription via Disrupting the Interaction of NM23-H2 with G-Quadruplex.

Transcriptional control of c-myc oncogene is an important strategy for antitumor drug design. G-quadruplexes in the promoter region have been proven to be the transcriptional down-regulator of this gene. The transcriptional factor NM23-H2 can reactivate c-myc transcription by unwinding the G-quadruplex structure. Thus, down-regulation of c-myc transcription via disrupting G-quadruplex-NM23-H2 interaction might be a potential approach for cancer therapy. Here, a series of new isaindigotone derivatives were designed and synthesized based on our previous study. The abilities of these derivatives on interacting with G-quadruplexes or NM23-H2, and disrupting G-quadruplex-NM23-H2 interaction were evaluated. Among these derivatives, 19d and 22d showed remarkable abilities on disrupting G-quadruplex-NM23-H2 interaction. They exhibited significant effects on c-myc-relating processes in SiHa cells, including inhibiting the transcription and translation, inhibiting cellular proliferation, inducing apoptosis, and regulating cell cycle. Our findings provided the basis for the anticancer strategy based on c-myc transcriptional regulation via small molecules disrupting G-quadruplex-protein interaction.

Fluconazole induces rapid high-frequency MTL homozygosis with microbiological polymorphism in Candida albicans.

BACKGROUND: Candida albicans, a common fungal pathogen that can cause opportunistic infections, is regarded as an apparently asexual, diploid fungus. A parasexual cycle was previously found between homozygotes with opposite mating type-like loci (MTLa/α). Fluconazole-resistant strains had a higher proportion of MTL homozygotes, whereas MTL homozygous C. albicans was found in only about 3.2% of clinical strains. MTL heterozygotes had a low frequency (1.4 × 10-4) of white-opaque switching to MTL homozygotes in nature. METHODS: Here, a reference C. albicans strain (SC5314) was used in a fluconazole-induced assay to obtain standard opaque MTL homozygous strains and first-generation daughter strains from the fluconazole inhibition zone. Further separation methods were employed to produce second- and third-generation daughter strains. Polymerase chain reaction analysis based on MTL genes was used to define MTL genotypes, and microscopic observations, a flow-cytometric assay, and an antifungal E-test were used to compare microbiological characteristics. RESULTS: MTL homozygotes were found at a high frequency (17 of 35; 48.6%) in fluconazole-induced first-generation daughter strains, as were morphological polymorphisms, decreased DNA content, and modified antifungal drug susceptibility. High-frequency MTL homozygosity was identified inside the fluconazole inhibition zone within 24 hours. The DNA content of fluconazole-induced daughter strains was reduced compared with their progenitor SC5314 and standard MTL homozygous strains. CONCLUSION: Treatment with fluconazole, commonly used to treat invasive candidiasis, inhibited the growth of C. albicans and altered its microbiological characteristics. Our results suggest that fluconazole treatment induces the high frequency of loss of heterozygosity and microbiological polymorphism in C. albicans.