Expert consensus on difficulty assessment of endodontic therapy.

Endodontic diseases are a kind of chronic infectious oral disease. Common endodontic treatment concepts are based on the removal of inflamed or necrotic pulp tissue and the replacement by gutta-percha. However, it is very essential for endodontic treatment to debride the root canal system and prevent the root canal system from bacterial reinfection after root canal therapy (RCT). Recent research, encompassing bacterial etiology and advanced imaging techniques, contributes to our understanding of the root canal system's anatomy intricacies and the technique sensitivity of RCT. Success in RCT hinges on factors like patients, infection severity, root canal anatomy, and treatment techniques. Therefore, improving disease management is a key issue to combat endodontic diseases and cure periapical lesions. The clinical difficulty assessment system of RCT is established based on patient conditions, tooth conditions, root canal configuration, and root canal needing retreatment, and emphasizes pre-treatment risk assessment for optimal outcomes. The findings suggest that the presence of risk factors may correlate with the challenge of achieving the high standard required for RCT. These insights contribute not only to improve education but also aid practitioners in treatment planning and referral decision-making within the field of endodontics.

Short-Term Effects of Combining Moxibustion Therapy and Gua sha on Post-Multiple Cerebral Infarction Rehabilitation.

Objective: This study aimed to assess the impact of combined moxibustion therapy and Gua sha on enhancing functional independence, reducing fall risk, and alleviating pain in patients undergoing post-rehabilitation for multiple cerebral infarctions. Methods: In a prospective clinical trial, 67 patients diagnosed with multiple cerebral infarctions (age range: 40 to 93 years) were enrolled. Baseline health characteristics included a median hospital stay of 10 days, prevalent medical conditions such as hypertension (64.18%), and various comorbidities like spondylosis (17.91%) and heart disease (14.93%). Patients received moxibustion treatment daily for 20-30 minutes on specific acupoints of the upper and lower extremities. Additionally, Gua sha therapy targeting the the head, back, chest, abdomen, and selected acupoints was administered twice a week with an interval of 3 to 4 days. Assessments included Barthel Index (BI) for functional independence, Morse Fall Scale (MFS) for fall risk, and Visual Analogue Scale (VAS) for pain intensity before and after the intervention. Results: After one week of rehabilitation, significant improvements were observed in the patient's functional independence, as indicated by a median BI score of 100 (IQR: 95-100), compared to the pre-rehabilitation median score of 95 (IQR: 90-100). The MFS score also showed a significant decrease after rehabilitation, with a median score of 35 (IQR: 35-45) compared to the pre-rehabilitation median score of 45 (IQR: 35-45). Additionally, pain intensity significantly decreased, with a median VAS score of 0 (range: 0-2) after rehabilitation, compared to the pre-rehabilitation median score of 0 (range: 0-3). Conclusion: Combined moxibustion therapy and Gua sha demonstrated positive effects on functional independence, fall risk reduction, and pain alleviation in post-rehabilitation for multiple cerebral infarctions. These findings suggest the potential of moxibustion and Gua sha as complementary interventions in stroke rehabilitation. The observed improvements in functional independence, fall risk, and pain underscore the potential benefits of these therapies for patients with multiple cerebral infarctions. Further exploration could delve into long-term effects, larger-scale trials, and mechanistic studies to elucidate the underlying pathways of efficacy.

Study on 3D printed MXene-berberine-integrated scaffold for photo-activated antibacterial activity and bone regeneration.

The repair of mandibular defects is a challenging clinical problem, and associated infections often hinder the treatment, leading to failure in bone regeneration. Herein, a multifunctional platform is designed against the shortages of existing therapies for infected bone deficiency. 2D Ti3C2 MXene and berberine (BBR) are effectively loaded into 3D printing biphasic calcium phosphate (BCP) scaffolds. The prepared composite scaffolds take the feature of the excellent photothermal capacity of Ti3C2 as an antibacterial, mediating NIR-responsive BBR release under laser stimuli. Meanwhile, the sustained release of BBR enhances its antibacterial effect and further accelerates the bone healing process. Importantly, the integration of Ti3C2 improves the mechanical properties of the 3D scaffolds, which are beneficial for new bone formation. Their remarkable biomedical performances in vitro and in vivo present the outstanding antibacterial and osteogenic properties of the Ti3C2-BBR functionalized BCP scaffolds. The synergistic therapy makes it highly promising for repairing infected bone defects and provides insights into a wide range of applications of 2D nanosheets in biomedicine.

UPLC-quadrupole time-of-flight-tandem mass spectrometry combined with chemometrics and network pharmacology to differentiate Coreopsis tinctoria Nutt.

Coreopsis tinctoria Nutt. (C. tinctoria) is a traditional medicinal plant, primarily found in plateau areas with altitudes exceeding 3000 m. The efficacy of C. tinctoria appears to be intricately tied to its quality. However, there is a scarcity of studies focused on evaluating the quality of C. tinctoria from diverse geographical locations. In this study, we used ultra-performance liquid chromatography-quadrupole time-of-flight-tandem mass spectrometry to analyze and identify the prevalent chemical components in 12 batches of C. tinctoria sourced from Xinjiang, Qinghai, Tibet, and Yunnan provinces in China. By using cluster analysis and discriminant analysis of partial least squares, we assessed the similarity and identified varying components in the 12 batches of C. tinctoria. Subsequently, their quality was further evaluated. Utilizing network pharmacology, we identified potential active components for the treatment of diabetes mellitus. The findings revealed the presence of 16 flavonoids, 3 phenylpropanes, 2 sugars, 2 amino acids, and 7 hydrocarbons in the analyzed samples. Through variable importance screening, 17 constituents were identified as quality difference markers. Marein and flavanomarein emerged as pivotal markers, crucial for distinguishing variations in C. tinctoria. In addition, network pharmacology predicted 187 targets for 9 common active components, including marein and flavanomarein. Simultaneously, 1747 targets related to diabetes mellitus were identified. The drug-component-disease target network comprised 91 nodes and 179 edges, encompassing 1 drug node, 9 component nodes, and 81 target nodes. In summary, marein and flavanomarein stand out as key biomarkers for assessing the quality of C. tinctoria, offering a scientific foundation for the quality evaluation of C. tinctoria Nutt.

Air pollution exposure and plasma fatty acid profile in pregnant women: a cohort study.

Air pollution exposure was known to result in body impairments by inducing inflammation and oxidation. But little is known about the associations of air pollutants with plasma fatty acid profile which may play important roles in the impairment of air pollutants based on the related mechanism, especially in pregnant women. This study aimed to explore the relationships of air pollution exposure with plasma fatty acid profile and the potential effect modification by pre-pregnancy body mass index (BMI). Based on a cohort in Wuhan, China, we measured concentrations of plasma fatty acids of 519 pregnant women enrolled from 2013 to 2016 by gas chromatography-mass spectrometry (GC-MS). Levels of exposure to air pollutants (fine particulate matter (PM2.5), inhalable particles (PM10), nitrogen dioxide (NO2), sulfur dioxide (SO2), and carbon monoxide (CO)) were estimated by using spatial-temporal land use regression models and calculated in three periods (average concentrations during 1 day, 1 week, and 1 month before the phlebotomizing day in the first trimester). Per interquartile range increment of the levels of air pollution exposure 1 day before phlebotomizing was related to 1.21-2.01% increment of omega-6 polyunsaturated fatty acids (n-6PUFA) and 0.63-1.74% decrement of omega-3 polyunsaturated fatty acids (n-3PUFA). Besides, relationships above were kept robust in the analysis during 1 week and 1 month before phlebotomizing. In women with normal BMI, plasma fatty acid profile was observed to be more sensitive to air pollutants. Our study demonstrated that increment of exposure to air pollutants was associated with higher plasma n-6PUFA known to be pro-inflammatory and lower plasma n-3PUFA known to be anti-inflammatory, which was more sensitive in pregnant women with normal BMI. Our findings suggested that changes in plasma fatty acid profile should cause concerns and may serve as biomarkers in the further studies. Future studies are needed to validate our findings and elucidate the underlying mechanisms.

Recent advances in 2D material-based phototherapy.

Phototherapy, which generally refers to photothermal therapy (PTT) and photodynamic therapy (PDT), has received significant attention over the past few years since it is non-invasive, has effective selectivity, and has few side effects. As a result, it has become a promising alternative to traditional clinical treatments. At present, two-dimensional materials (2D materials) have proven to be at the forefront of the development of advanced nanomaterials due to their ultrathin structures and fascinating optical properties. As a result, much work has been put into developing phototherapy platforms based on 2D materials. This review summarizes the current developments in 2D materials beyond graphene for phototherapy, focusing on the novel approaches of PTT and PDT. New methods are being developed to go above and beyond conventional treatment to fully use the potential of 2D materials. Additionally, the efficacy of cutting-edge phototherapy is assessed, and the existing difficulties and future prospects of 2D materials for phototherapy are covered.

Piperlongumine overcomes imatinib resistance by inducing proteasome inhibition in chronic myelogenous leukemia cells.

ETHNOPHARMACOLOGICAL RELEVANCE: Piper longum L., an herbal medicine used in India and other Asian countries, is prescribed routinely for a range of diseases, including tumor. Piperlongumine, a natural product isolated from Piper longum L., has received widespread attention due to its various pharmacological activities, such as anti-inflammatory, antimicrobial, and antitumor effects. AIM OF THE STUDY: Chronic myelogenous leukemia (CML) is a hematopoietic disease caused by Bcr-Abl fusion gene, with an incidence of 15% in adult leukemias. Targeting Bcr-Abl by imatinib provides a successful treatment approach for CML. However, imatinib resistance is an inevitable issue for CML treatment. In particular, T315I mutant is the most stubborn of the Bcr-Abl point mutants associated with imatinib resistance. Therefore, it is urgent to find an alternative approach to conquer imatinib resistance. This study investigated the role of a natural product piperlongumine in overcoming imatinib resistance in CML. MATERIALS AND METHODS: Cell viability and apoptosis were evaluated by MTS assay and Annexin V/propidium iodide counterstaining assay, respectively. Levels of intracellular signaling proteins were assessed by Western blots. Mitochondrial membrane potential was reflected by the fluorescence intensity of rhodamine-123. The function of proteasome was detected using 20S proteasomal activity assay, proteasomal deubiquitinase activity assay, and deubiquitinase active-site-directed labeling. The antitumor effects of piperlongumine were assessed with mice xenografts. RESULTS: We demonstrate that (i) Piperlongumine inhibits proteasome function by targeting 20S proteasomal peptidases and 19S proteasomal deubiquitinases (USP14 and UCHL5) in Bcr-Abl-WT and Bcr-Abl-T315I CML cells; (ii) Piperlongumine inhibits the cell viability of CML cell lines and primary CML cells; (iii) Proteasome inhibition by piperlongumine leads to cell apoptosis and downregulation of Bcr-Abl; (iv) Piperlongumine suppresses the tumor growth of CML xenografts. CONCLUSIONS: These results support that blockade of proteasome activity by piperlongumine provides a new therapeutic strategy for treating imatinib-resistant CML.

Nanotechnology-Based Drug Delivery System for Anticancer Active Ingredients from Traditional Chinese Medicines: A Review.

The variable dosage forms of most traditional Chinese medicines (TCMs) could be disadvantaged by low selectivity, poor biological distribution, limited bioavailability with low efficacy, and some adverse effects. These issues limit the control of clinical pharmacodynamics of the antitumor active components. With the progress of science and technology, many new polymer materials and new technologies have emerged, such as nanotechnology, cyclodextrin inclusion, solid dispersion, microcapsule and microsphere technologies. These new technologies provide a good basis for exploring novel TCM dosage forms for overcoming the shortcomings. The increased numbers of new technologies have been used to study TCM dosage forms with remarkable achievements. In this review paper, we will provide a systematic overview of the new dosage forms of nano-formulations and co-medications in relation to nano-delivery systems in an attempt to provide useful references for practical application of active antitumor ingredients from the TCMs.

Inhibition of proteasomal deubiquitinases USP14 and UCHL5 overcomes tyrosine kinase inhibitor resistance in chronic myeloid leukaemia.

BACKGROUND: Chronic myeloid leukaemia (CML) is a haematological cancer featured by the presence of BCR-ABL fusion protein with abnormal tyrosine kinase activation. Classical tyrosine kinase inhibitor (TKI)-based therapies are available to patients with CML. However, acquired resistance to TKI has been a challenging obstacle, especially stubborn T315I mutation is the most common cause. Therefore, it is especially urgent to find more effective targets to overcome TKI resistance induced by BCR-ABLT315I . Proteasomal deubiquitinases (USP14 and UCHL5) have fundamental roles in the ubiquitin-proteasome system and possess multiple functions during cancer progression. METHODS: The human peripheral blood mononuclear cells were collected to measure the mRNA expression of USP14 and UCHL5, as well as to detect the toxicity effect of b-AP15. We explored the effect of b-AP15 on the activity of proteasomal deubiquitinases. We detected the effects of b-AP15 on BCR-ABLWT and BCR-ABLT315I CML cells in vitro and in the subcutaneous tumour model. We knocked down USP14 and/or UCHL5 by shRNA to explore whether these proteasomal deubiquitinases are required for cell proliferation of CML. RESULTS: In this study, we found that increased expression of the proteasomal deubiquitinase USP14 and UCHL5 in primary cancer cells from CML patients compared to healthy donors. b-AP15, an inhibitor of USP14 and UCHL5, exhibited potent tumour-killing activity in BCR-ABLWT and BCR-ABLT315I CML cell lines, as well as in CML xenografts and primary CML cells. Mechanically, pharmacological or genetic inhibition of USP14 and UCHL5 induced cell apoptosis and decreased the protein level of BCR-ABL in CML cells expressing BCR-ABLWT and BCR-ABLT315I . Moreover, b-AP15 synergistically enhanced the cytotoxic effect caused by TKI imatinib in BCR-ABLWT and BCR-ABLT315I CML cells. CONCLUSION: Collectively, our results demonstrate targeting USP14 and UCHL5 as a potential strategy for combating TKI resistance in CML.

Cyclin-dependent kinase 7/9 inhibitor SNS-032 induces apoptosis in diffuse large B-cell lymphoma cells.

Approximately 40% of patients with diffuse large B-cell lymphoma (DLBCL) are refractory or relapse to standard chemotherapy, and most of them are activated B cell-like DLBCLs (ABC-DLBCL) and germinal center B cell-like DLBCLs (GCB-DLBCL). SNS-032, a novel and selective CDK7/9 inhibitor, that the first phase clinical trials approved by US FDA for cancer treatment have been completed. In this study, we investigated the anti-tumor effect of SNS-032 in ABC- and GCB-DLBCL subtypes. We report that SNS-032 induced growth inhibition and cell apoptosis in both DLBCL cells in vitro, and inhibited the growth of both DLBCL xenografts in nude mice. Mechanistically, SNS-032 inhibited RNA polymerase II, which led to transcriptional-dependent suppression of NF-κB signaling pathway and its downstream targets involved in cell survival; SNS-032 also downregulates BCL-2 and c-MYC in both mRNA and protein levels. Significantly, these findings provide pre-clinical evidence for application of targeting the CDK7/9 in DLBCL.

Preparation and characterization of paclitaxel palmitate albumin nanoparticles with high loading efficacy: an in vitro and in vivo anti-tumor study in mouse models.

BACKGROUND: Combination of the prodrug technique with an albumin nano drug-loaded system is a novel promising approach for cancer treatment. However, the long-lasting and far-reaching challenge for the treatment of cancers lies in how to construct the albumin nanometer drug delivery system with lead compounds and their derivatives. METHODS: In this study, we reported the preparation of injectable albumin nanoparticles (NPs) with a high and quantitative drug loading system based on the NabTM technology of paclitaxel palmitate (PTX-PA). RESULTS: Our experimental study on drug tissue distribution in vivo demonstrated that the paclitaxel palmitate albumin nanoparticles (Nab-PTX-PA) remained in the tumor for a longer time post-injection. Compared with saline and paclitaxel albumin nanoparticles (Abraxane®), intravenous injection of Nab-PTX-PA not only reduced the toxicity of the drug in normal organs, and increased the body weight of the animals but maintained sustained release of paclitaxel (PTX) in the tumor, thereby displaying an excellent antitumor activity. Blood routine analysis showed that Nab-PTX-PA had fewer adverse effects or less toxicity to the normal organs, and it inhibited tumor cell proliferation more effectively as compared with commercial paclitaxel albumin nanoparticles. CONCLUSIONS: This carrier strategy for small molecule drugs is based on naturally evolved interactions between long-chain fatty acids (LCFAs) and Human Serum Albumin (HSA), demonstrated here for PTX. Nab-PTX-PA shows higher antitumor efficacy in vivo in breast cancer models. On the whole, this novel injectable Nab-PTX-PA has great potential as an effective drug delivery system in the treatment of breast cancer.

The efficacy of positioning stents in preventing Oral complications after head and neck radiotherapy: a systematic literature review.

BACKGROUND: Positioning stent in head and neck radiotherapy seems to have benefit to prevent oral complications but it hasn't been summarized by an evidence-based method. OBJECTIVES: This review aims to evaluate the efficacy of positioning stents in preventing oral complications after radiotherapy. METHODS: We conducted an electronic search in MEDLINE, EMBASE, Cochrane CDSR, and Cochrane CENTRAL database for randomized-controlled clinical trials, controlled clinical trials and cohort studies that assessed oral complications after head and neck radiotherapy with positioning stents. Two reviewers extracted information on radiotherapy, follow-up period, oral complications and assessments independently. RESULTS: Three RCTs and two cohort studies were included in this review. Oral complications such as mucositis, xerostomia, taste alteration, trismus, salivary changes, dysphagia and pain on swallowing were assessed by different methods in these studies. CONCLUSIONS: Oral complications were common in patients after head and neck radiotherapy. There is insufficient evidence that positioning stents have a preventive effect against xerostomia, and it needs more high-quality and prospective trials with long-term follow-up to support it.

Study on the cellular internalization mechanisms and in vivo anti-bone metastasis prostate cancer efficiency of the peptide T7-modified polypeptide nanoparticles.

Bone-metastasis prostate cancer (BMPCa)-targeting gene therapy is gaining increasing concern in recent years. The peptide T7-modified polypeptide nanoparticles for delivery DNA (CRD-PEG-T7/pPMEPA1) was prepared as our previous study. However, the feasibility of CRD-PEG-T7/pPMEPA1 for BMPCa treatment, the mechanisms underlying cellular uptake, anti-BMPCa effect, and administration safety requires further research. LNCaP cells treated with endocytosis inhibitors and excessive T7 under different culture condition were carried out to investigate the mechanisms of cellular uptake of the CRD-PEG-T7-pPMEPA1. A transwell assay was applied to evaluate the cell migration ability. Besides, the tumor volume and survival rates of the PCa xenograft mice model were recorded to estimate the anti-tumor effect. In addition, the weight profiles of the PCa tumor-bearing mice, the blood chemistry, and the HE analysis of visceral organs and tumor was conducted to investigate the administration safety of CRD-PEG-T7/pPMEPA1. The results showed that PCa cellular uptake was decreased after treating with excessive free T7, endocytosis inhibitors and lower incubation temperature. Besides, CRD-PEG-T7/pPMEPA1 could inhibit the LNCaP cells chemotaxis and tumor growth. In addition, the survival duration of the PCa tumor-bearing mice treating with CRD-PEG-T7/pPMEPA1 was significantly prolonged with any systemic toxicity or damage to the organs. In conclusion, this research proposes a promising stratagem for treatment BMPCa by providing the biocompatible and effective carrier for delivery DNA therapeutic agents.

Nanoparticle Conjugation of Ginsenoside Rg3 Inhibits Hepatocellular Carcinoma Development and Metastasis.

Hepatocellular carcinoma (HCC) is the third leading cause of cancer-related death worldwide. The prognosis of HCC remains very poor; thus, an effective treatment remains urgent. Herein, a type of nanomedicine is developed by conjugating Fe@Fe3 O4 nanoparticles with ginsenoside Rg3 (NpRg3), which achieves an excellent coupling effect. In the dimethylnitrosamine-induced HCC model, NpRg3 application significantly prolongs the survival of HCC mice. Further research indicates that NpRg3 application significantly inhibits HCC development and eliminates HCC metastasis to the lung. Notably, NpRg3 application delays HCC-induced ileocecal morphology and gut microbial alterations more than 12 weeks during HCC progression. NpRg3 administration elevates the abundance of Bacteroidetes and Verrucomicrobia, but decreases Firmicutes. Twenty-nine predicted microbial gene functions are enriched, while seven gene functions are reduced after NpRg3 administration. Moreover, the metabolomics profile presents a significant progression during HCC development, but NpRg3 administration corrects tumor-dominant metabolomics. NpRg3 administration decreases 3-indolepropionic acid and urea, but elevates free fatty acids. Importantly, NpRg3 application remodels the unbalanced correlation networks between gut microbiota and metabolism during HCC therapy. In conclusion, nanoparticle conjugation of ginsenoside Rg3 inhibits HCC development and metastasis via the remodeling of unbalanced gut microbiota and metabolism in vivo, providing an antitumor therapy strategy.

Proteasomal cysteine deubiquitinase inhibitor b-AP15 suppresses migration and induces apoptosis in diffuse large B cell lymphoma.

BACKGROUND: The first line therapy for patients with diffuse large B cell (DLBCL) is R-CHOP. About half of DLBCL patients are either refractory to, or will relapse, after the treatment. Therefore, identifying novel drug targets and effective therapeutic agents is urgently needed for improving DLBCL patient survival. b-AP15, a selective small molecule inhibitor of proteasomal USP14 and UCHL5 deubiquitinases (DUBs), has shown selectivity and efficacy in several other types of cancer cells. This is the first study to report the effect of b-AP15 in DLBCL. METHODS: Cell lines of two DLBCL subtypes, Germinal Center B Cell/ GCB (SU-DHL-4, OCI-LY-1, OCI-LY-19) and Activated B Cell/ABC (SU-DHL-2), were used in the current study. Cell viability was measured by MTS assay, proliferation by trypan blue exclusion staining assay, cellular apoptosis by Annexin V-FITC/PI staining and mitochondrial outer membrane permeability assays, the activities of 20S proteasome peptidases by cleavage of specific fluorogenic substrates, and cell migration was detected by transwell assay in these GCB- and ABC-DLBCL cell lines. Mouse xenograft models of SU-DHL-4 and SU-DHL-2 cells were used to determine in vivo effects of b-AP15 in DLBCL tumors. RESULTS: b-AP15 inhibited proteasome DUB activities and activated cell death pathway, as evident by caspase activation and mitochondria apoptosis in GCB- and ABC- DLBCL cell lines. b-AP15 treatment suppressed migration of GCB- and ABC-DLBCL cells via inhibiting Wnt/ß-catenin and TGFß/Smad pathways. Additionally, b-AP15 significantly inhibited the growth of GCB- and ABC DLBCL in xenograft models. CONCLUSIONS: These results indicate that b-AP15 inhibits cell migration and induces apoptosis in GCB- and ABC-DLBCL cells, and suggest that inhibition of 19S proteasomal DUB should be a novel strategy for DLBCL treatment.

Ginsenoside Rg3 Prolongs Survival of the Orthotopic Hepatocellular Carcinoma Model by Inducing Apoptosis and Inhibiting Angiogenesis.

AIM: Microvessel density is a marker of tumor angiogenesis activity for development and metastasis. Our preliminary study showed that ginsenoside Rg3 (Rg3) induces apoptosis in hepatocellular carcinoma (HCC) in vitro. The aim of this study was to investigate the cross-link for apoptosis induction and antiangiogenesis effect of Rg3 on orthotopic HCC in vivo. METHODS: The murine HCC cells Hep1-6 were implanted in the liver of mouse. With oral feeding of Rg3 (10 mg/kg once a day for 30 days), the quantitative analysis of apoptosis was performed by using pathology and a transmission electron microscope and microvessel density was quantitatively measured by immunohistochemical staining of the CD105 antibody. The mice treated with Rg3 (n = 10) were compared with the control (n = 10) using Kaplan-Meier analysis. Animal weight and tumor weight were measured to determine the toxicity of Rg3 and antitumor effect on an orthotopic HCC tumor model. RESULTS: With oral feeding of Rg3 daily in the first 30 days on tumor implantation, Rg3 significantly decreased the orthotopic tumor growth and increased the survival of animals (P < 0.05). Rg3-treated mice showed a longer survival than the control (P < 0.05). Rg3 treatment induced apoptosis and inhibited angiogenesis. They contributed to the tumor shrinkage. Rg3 initialized the tumor apoptotic progress, which then weakened the tumor volume and its capability to produce the vascularized network for further growth of the tumor and remote metastasis. CONCLUSION: Rg3 inhibited the activation of microtumor vessel formation in vivo besides its apoptosis induction. Rg3 may be used as an adjuvant agent in the clinical HCC treatment regimen.

Effect of residential exposure to green space on maternal blood glucose levels, impaired glucose tolerance, and gestational diabetes mellitus.

BACKGROUND: Residential surrounding green spaces can affect human health. However, limited studies have examined their impacts on maternal blood glucose homeostasis outcomes. OBJECTIVE: We examined the associations of residential exposure to green space with maternal blood glucose levels, gestational impaired glucose tolerance (IGT), and gestational diabetes mellitus (GDM). METHODS: Pregnant women were recruited from a prospective birth cohort between October 2012 and September 2015. Exposure to green space was calculated as the mean value of the normalized difference vegetation index (NDVI) within a 300-m circular buffer area surrounding each residence. Maternal glucose was measured between 24 and 28 weeks of gestation, and gestational IGT and GDM were diagnosed using valid methods. We estimated the associations of residential NDVI with maternal glucose levels using multiple linear regression models with adjustment for age, education, BMI, passive smoking during pregnancy, parity, season of conception, income, and urbancity. We estimated the relative risks of residential NDVI with IGT and GDM using a generalized estimating equation model with modified Poisson regression. The mediation effects of residential exposure to air pollution and maternal physical activity were assessed using causal mediation analysis. RESULTS: Of 6807 pregnant women, 751 (11.3%) and 604 (8.8%) were diagnosed with IGT and GDM, respectively. One SD increment of residential NDVI was associated with a decrease of 0.06 mmol/L (95% CI: -0.07, -0.05), 0.09 mmol/L (95% CI: -0.13, -0.05), and 0.06 mmol/L (95% CI: -0.09, -0.03) in maternal fasting glucose levels, 1-h glucose levels, and 2-h glucose levels, respectively, as well as reduced risks of incident IGT (RR: 0.92, 95% CI: 0.86, 0.99) and GDM (RR: 0.85, 95% CI: 0.79, 0.92). The association between residential NDVI and maternal fasting glucose levels was partly mediated by maternal exposure to PM2.5. CONCLUSION: Living with higher levels of green space was significantly associated with decreased maternal glucose levels and attenuated risks of incident maternal IGT and GDM. Our findings provide evidence linking green space to better maternal glucose outcomes. More studies are needed to further explore the maternal and child health benefits related to our findings.

Sensitivity of docetaxel-resistant MCF-7 breast cancer cells to microtubule-destabilizing agents including vinca alkaloids and colchicine-site binding agents.

INTRODUCTION: One of the main reasons for disease recurrence in the curative breast cancer treatment setting is the development of drug resistance. Microtubule targeted agents (MTAs) are among the most commonly used drugs for the treatment of breaset cancer and therefore overcoming taxane resistance is of primary clinical importance. Our group has previously demonstrated that the microtubule dynamics of docetaxel-resistant MCF-7TXT cells are insensitivity to docetaxel due to the distinct expression profiles of ß-tubulin isotypes in addition to the high expression of p-glycoprotein (ABCB1). In the present investigation we examined whether taxane-resistant breast cancer cells are more sensitive to microtubule destabilizing agents including vinca alkaloids and colchicine-site binding agents (CSBAs) than the non-resistant cells. METHODS: Two isogenic MCF-7 breast cancer cell lines were selected for resistance to docetaxel (MCF-7TXT) and the wild type parental cell line (MCF-7CC) to examine if taxane-resistant breast cancer cells are sensitive to microtubule-destabilizing agents including vinca alkaloids and CSBAs. Cytotoxicity assays, immunoblotting, indirect immunofluorescence and live imaging were used to study drug resistance, apoptosis, mitotic arrest, microtubule formation, and microtubule dynamics. RESULTS: MCF-7TXT cells were demonstrated to be cross resistant to vinca alkaloids, but were more sensitive to treatment with colchicine compared to parental non-resistant MCF-7CC cells. Cytotoxicity assays indicated that the IC50 of MCF-7TXT cell to vinorelbine and vinblastine was more than 6 and 3 times higher, respectively, than that of MCF-7CC cells. By contrast, the IC50 of MCF-7TXT cell for colchincine was 4 times lower than that of MCF-7CC cells. Indirect immunofluorescence showed that all MTAs induced the disorganization of microtubules and the chromatin morphology and interestingly each with a unique pattern. In terms of microtubule and chromain morphology, MCF-7TXT cells were more resistant to vinorelbine and vinblastine, but more sensitive to colchicine compared to MCF-7CC cells. PARP cleavage assay further demonstrated that all of the MTAs induced apoptosis of the MCF-7 cells. However, again, MCF-7TXT cells were more resistant to vinorelbine and vinblastine, and more sensitive to colchicine compared to MCF-7CC cells. Live imaging demonstrated that the microtubule dynamics of MCF-7TXT cells were less sensitive to vinca alkaloids, and more sensitive to colchicine. MCF-7TXT cells were also noted to be more sensitive to other CSBAs including 2MeOE2, ABT-751 and phosphorylated combretastatin A-4 (CA-4P). CONCLUSION: Docetaxel-resistant MCF-7TXT cells have demonstrated cross-resistance to vinca alkaloids, but appear to be more sensitive to CSBAs (colchicine, 2MeOE2, ABT-751 and CA-4P) compared to non-resistant MCF-7CC cells. Taken together these results suggest that CSBAs should be evaluated further in the treatment of taxane resistant breast cancer.

Non-Ligand-Induced Dimerization is Sufficient to Initiate the Signalling and Endocytosis of EGF Receptor.

The binding of epidermal growth factor (EGF) to EGF receptor (EGFR) stimulates cell mitogenesis and survival through various signalling cascades. EGF also stimulates rapid EGFR endocytosis and its eventual degradation in lysosomes. The immediate events induced by ligand binding include receptor dimerization, activation of intrinsic tyrosine kinase and autophosphorylation. However, in spite of intensified efforts, the results regarding the roles of these events in EGFR signalling and internalization is still very controversial. In this study, we constructed a chimeric EGFR by replacing its extracellular domain with leucine zipper (LZ) and tagged a green fluorescent protein (GFP) at its C-terminus. We showed that the chimeric LZ-EGFR-GFP was constitutively dimerized. The LZ-EGFR-GFP dimer autophosphorylated each of its five well-defined C-terminal tyrosine residues as the ligand-induced EGFR dimer does. Phosphorylated LZ-EGFR-GFP was localized to both the plasma membrane and endosomes, suggesting it is capable of endocytosis. We also showed that LZ-EGFR-GFP activated major signalling proteins including Src homology collagen-like (Shc), extracellular signal-regulated kinase (ERK) and Akt. Moreover, LZ-EGFR-GFP was able to stimulate cell proliferation. These results indicate that non-ligand induced dimerization is sufficient to activate EGFR and initiate cell signalling and EGFR endocytosis. We conclude that receptor dimerization is a critical event in EGF-induced cell signalling and EGFR endocytosis.