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1.
J Tradit Chin Med ; 41(5): 762-770, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34708635

RESUMO

OBJECTIVE: To investigate the effect of Roucongrong (Herba Cistanches Deserticolae) decoction on the substantia nigra in rats with Parkinson's disease (PD) induced by 6-hydroxydopamine hydrochloride (6-OHDA). To further determine whether the Wnt/ß-catenin signaling pathway is involved in the action. METHODS: A rat model of PD was established by intracranial injection of 6-OHDA. Subsequently, three concentrations of Roucongrong (Herba Cistanches Deserticolae) decoction were prepared and administered to rats by gavage therapy for 14 d. Behavioral changes were measured in PD rats. In vivo tyrosine hydroxylase (TH) levels in the substantia nigra were examined by immunohistochemistry. Additionally, gene and protein expression levels of members of the Wnt/ß-catenin signaling pathway were examined by Western blotting and polymerase chain reaction. Lastly, a Wnt/ß-catenin inhibitor was used to investigate the mechanism of action in 1-methyl-4-phenylpyridinium (MPP + )- treated MES23.5 cells in vitro. RESULTS: Roucongrong (Herba Cistanches Deserticolae) decoction improved performance in the stride and gait adjustment tests in PD rats. It also increased TH in the substantia nigra and altered the expression of genes and proteins in the Wnt/ß-catenin signaling pathway. Wnt/ß-catenin inhibitor reduced the effect of Roucongrong (Herba Cistanches Deserticolae) decoction in MPP +-treated MES23.5 cells. CONCLUSION: Roucongrong (Herba Cistanches Deserticolae) decoction may promote neuronal survival in PD in vivo and in vitro by increasing TH content in the substantia nigra and by activating the Wnt/ß-catenin signaling pathway.

2.
Artigo em Inglês | MEDLINE | ID: mdl-34709801

RESUMO

Most chronic wounds suffer from infections, and their treatment is challenging. The usage of antibiotics may lead to bacterial resistance and adverse side effects. Positively charged substances have shown promise, but their applications are usually limited by certain cytotoxicity or complex synthesis. Doped polyaniline that carries a high density of positive charges would be a promising candidate due to its good biocompatibility and easy availability, but its interaction with bacteria has not been elucidated. Herein, the distinct bactericidal effect of polyaniline against Gram-positive bacteria has been verified. The antibacterial activity may result from the specific interaction with lipoteichoic acid to destroy the Gram-positive bacterial cell wall. Polyaniline and a macromolecular dopant (sulfonated hyaluronic acid) are used to construct a flexible hydrogel with skin-mimic electrical conductivity. The in vivo results demonstrate that electrical stimulation (ES) through this hydrogel is superior to ES via separated electrodes (the ES strategy used clinically) for promoting infected chronic wound healing.

3.
Chemosphere ; : 132697, 2021 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-34715098

RESUMO

The widespread use of halogenated flame retardants in recent years has led to the accumulation of TBBPA in water, which may cause potential harm to living organisms. The phototransformation of the flame retardant TBBPA in alkaline saline water under simulated sunlight irradiation was investigated. The effects of abiotic factors such as the initial concentration of TBBPA, chloride ion concentration, solution pH, inorganic anions and cations, dissolved organic matter (DOM) were studied. The results showed that the phototransformation rate of TBBPA accelerated with the decrease of the initial concentration of TBBPA, the increase of chloride ion concentration and solution pH. The scavenging experiments showed that •OH, 1O2, O2•- and 3TBBPA* all participated in the phototransformation of TBBPA. The presence of NO3-, CO32-, SO42-, Mg2+, Ca2+, Fe3+ and fulvic acid (FA) all inhibited the phototransformation of TBBPA in the present study. The phototransformation products of TBBPA were detected by liquid chromatography-mass spectrometry (LC-MS), and the phototransformation pathways were proposed. This is the first report on the photo-induced generation of halogen exchange products from TBBPA in saline solutions, which will contribute to a better understanding of the environmental behavior and risks of BFRs in water.

4.
J Genet Genomics ; 2021 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-34500094

RESUMO

The developing human and mouse teeth constitute an ideal model system to study the regulatory mechanism underlying organ growth control since their teeth share highly conserved and well-characterized developmental processes and their developmental tempo varies notably. In the current study, we manipulated heterogenous recombination between human and mouse dental tissues and demonstrate that the dental mesenchyme dominates the tooth developmental tempo and FGF8 could be a critical player during this developmental process. Forced activation of FGF8 signaling in the dental mesenchyme of mice promoted cell proliferation, prevented cell apoptosis via p38 and perhaps PI3K-Akt intracellular signaling, and impelled the transition of the cell cycle from G1- to S-phase in the tooth germ, resulting in the slowdown of the tooth developmental pace. Our results provide compelling evidence that extrinsic signals can profoundly affect tooth developmental tempo and the dental mesenchymal FGF8 could be a pivotal factor in controlling the developmental pace in a non-cell-autonomous manner during mammalian odontogenesis.

5.
JAMA Netw Open ; 4(9): e2124721, 2021 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-34554238

RESUMO

Importance: Nonanatomic prognostic factors complement the traditional anatomic staging system and could be incorporated into the tumor-node-metastasis (TNM) framework. Several diseases have incorporated nonanatomic prognostic factors into the determination of TNM staging groups. Objective: To refine TNM staging groups for Epstein-Barr virus (EBV)-related nonmetastatic nasopharyngeal carcinoma (NPC) by incorporating EBV DNA status. Design, Setting, and Participants: This multicenter prognostic study included patients with NPC treated with radiotherapy at 2 hospitals in China from January 2008 to December 2016. Progression-free survival and overall survival according to EBV DNA status and the TNM staging system were compared. Recursive partitioning analysis (RPA) combined with supervised clustering was applied to derive prognostic groupings, and then a refined RPA staging schema was developed, validated, and compared with existing staging schemes. Statistical analyses were conducted from October 1, 2020, to June 15, 2021. Exposures: Curative intensity-modulated radiotherapy with or without platinum-based chemotherapy. Main Outcomes and Measures: The primary end point was progression-free survival. The performance of the staging system was assessed using the time-dependent area under the receiver operating characteristic curves and the TNM stage system's evaluation methodology. Results: A total of 2354 patients (1709 men [72.6%]; median [interquartile range] age, 45 [38-53] years) were split into training (1372 [58.3%]), internal validation (672 [28.5%]), and external validation (310 [13.2%]) cohorts. Pretreatment EBV DNA was detected in 1338 (56.8%) patients. EBV DNA status was an independent prognostic factor: lower survival probability by higher TNM stage was evident in EBV DNA-positive patients but not in those with EBV DNA-negative disease. After integrating EBV DNA status and TNM stage, nonmetastatic NPC cases were categorized into RPA-I (T1-3N0 or EBV DNA-negative T1-3N1 cancers), RPA-II (EBV DNA-positive T1-3N1-2 or EBV DNA-negative T1-3N2-3/T4N0-3 cancers), and RPA-III (EBV DNA-positive T4N0-3/T1-3N3 cancers) groups, each with distinctly different prognosis. This system of RPA staging outperformed the current TNM stage system and 2 reported RPA staging schemes. These results were internally and externally validated. Conclusions and Relevance: An RPA-based staging system for EBV-related NPC cases was associated with improved outcomes. This staging system may facilitate prognostic stratification and clinical trial designs.

6.
J Mater Chem B ; 9(38): 8138-8146, 2021 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-34495024

RESUMO

Electrical stimulation (ES) via rigid electrodes near the wound is one of the promising approaches for chronic wound treatment, but it is unable to stimulate the whole wound area and treat infected wounds. In this study, a tough conductive hydrogel was prepared by the copolymerization of N-acryloyl glycinamide (NAGA) with quaternized chitosan-g-polyaniline (QCSP). The hydrogel showed a similar conductivity to the human skin and robust mechanical properties due to the dual hydrogen bonding motifs. The grafted polyaniline segments and functionalized quaternary ammonium groups showed intense antimicrobial activity against Pseudomonas aeruginosa and Staphylococcus aureus biofilms. The in vivo assay in diabetic rats proves that the ES via the conductive hydrogel was more effective in promoting the healing of infected wounds than the conventional ES via rigid electrodes. Due to the excellent flexibility and antibacterial properties, this conductive hydrogel shows great promise for infected chronic wound treatment.

7.
J Control Release ; 338: 610-622, 2021 10 10.
Artigo em Inglês | MEDLINE | ID: mdl-34481025

RESUMO

Ischemic stroke is still the major cause of disability worldwide. Although vascular endothelial growth factor (VEGF) is able to promote both angiogenesis and functional recovery, its use is limited by needle-induced injury, nonhomogenous VEGF distribution, and limited VEGF retention in the brain after intracranial or intravenous injection. Here, we first present a gelatin methacryloyl (GelMA) microneedle (MN)-based platform for the sustained and controlled local delivery of an adeno-associated virus (AAV) expressing human VEGF (AAV-VEGF) that achieves homogenous distribution and high transfection efficiency in ischemic brains. An ischemic stroke model was established in adult rats, and MNs loaded with AAV-VEGF were epicortically inserted into both the ischemic core and penumbra of these rats one day after the onset of ischemia. One week later, the inflammatory response and microneedle biocompatibility were assessed by enzyme-linked immunosorbent assay (ELISA) and immunofluorescence. Eight weeks later, angiogenesis and neural stem cell proliferation and migration were assessed. GelMA MN implantation did not elicit an obvious inflammatory response and had good biocompatibility in the brain. AAV-green fluorescent protein (GFP)-loaded MNs could achieve successful transfection and homogeneous distribution in the brain cortex three weeks postoperatively. MNs loaded with AAV-VEGF increased VEGF expression and enhanced functional angiogenesis and neurogenesis. In summary, MNs might emerge as a promising platform for delivering various therapeutics to treat ischemic stroke and repair other neurologically diseased tissues.


Assuntos
Isquemia Encefálica , Acidente Vascular Cerebral , Animais , Isquemia Encefálica/terapia , Dependovirus/genética , Neovascularização Fisiológica , Ratos , Recuperação de Função Fisiológica , Acidente Vascular Cerebral/terapia , Fator A de Crescimento do Endotélio Vascular , Fatores de Crescimento do Endotélio Vascular
8.
Mol Biotechnol ; 63(12): 1103-1124, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34309796

RESUMO

Antibiotics have been denoted as the orthodox therapeutic agents for fighting bacteria-related infections in clinical practices for decades. Nevertheless, overuse of antibiotics has led to the upsurge of species with antimicrobial resistance (AMR) or multi-drug resistance. Bacteria can also grow into the biofilm, which accounts for at least two-thirds of infections. Distinct gene expression and self-produced heterogeneous hydrated extracellular polymeric substance matrix architecture of biofilm contribute to their tolerance and externally manifest as antibiotic resistance. In this review, the difficulties in combating biofilm formation and AMR are introduced, and novel alternatives to antibiotics such as metal nanoparticles and quaternary ammonium compounds, chitosan and its derivatives, antimicrobial peptides, stimuli-responsive materials, phage therapy and other therapeutic strategies, from compounds to hydrogel, from inorganic to biological, are discussed. We expect to provide useful information for the readers who are seeking for solutions to the problem of AMR and biofilm-related infections.

9.
Front Cell Dev Biol ; 9: 647165, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34178981

RESUMO

Palate-derived growth factor receptor α (Pdgfrα) signaling has been reported to play important roles in the cardiac development. A previous study utilizing Pdgfrα conventional knockout mice reported hypoplasia of the sinus venous myocardium including the sinoatrial node (SAN) accompanied by increased expression of Nkx2.5. This mouse line embryos die by E11.5 due to embryonic lethality, rendering them difficult to investigate the details. To elucidate the underlying mechanism, in this study, we revisited this observation by generation of specific ablation of Pdgfrα in the SAN by Shox2-Cre at E9.5, using a Shox2-Cre;Pdgfrα flox/flox conditional mouse line. Surprisingly, we found that resultant homozygous mutant mice did not exhibit any malformation in SAN morphology as compared to their wild-type littermates. Further analysis revealed the normal cardiac function in adult mutant mice assessed by the record of heart rate and electrocardiogram and unaltered expression of Nkx2.5 in the E13.5 SAN of Pdgfrα conditional knockout mice. Our results unambiguously demonstrate that Pdgfrα is dispensable for SAN development after its fate commitment in mice.

10.
Can J Public Health ; 112(Suppl 1): 168-182, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-34181231

RESUMO

OBJECTIVE: We previously examined the associations between dietary dichlorodiphenyldichloroethylene (DDE) and polychlorinated biphenyls (PCBs) intake from fish consumption and type 2 diabetes (T2D) prevalence in Ontario and Manitoba. This study aims to further explore the relationship in a regionally representative sample of First Nations adults living on-reserve across Canada. METHODS: Dietary, health and lifestyle data collected by the cross-sectional First Nations Food, Nutrition and Environment Study (2008-2018) were analyzed. This participatory study included 6091 First Nations adult participants who answered questions on T2D. The consumption of locally caught fish was estimated with a food frequency questionnaire. A total of 551 samples from 96 fish species were collected and analyzed for the presence of DDE and PCBs. The associations between fish and dietary DDE/PCBs intake with self-reported T2D were investigated using multiple logistic regression models adjusted for confounders. RESULTS: Dietary exposure to DDE (>2.11 ng/kg/bw) and PCBs (>1.47 ng/kg/bw) vs no exposure was positively associated with T2D with ORs of 2.33 (95% CI: 1.24-4.35) for DDE and 1.43 (95% CI: 1.01-3.59) for PCBs. The associations were stronger among females (DDE OR = 3.11 (1.41-6.88); PCBs OR = 1.76 (1.10-3.65)) and older individuals (DDE OR = 2.64 (1.12-6.20); PCBs OR = 1.44 (1.01-3.91)) as compared with males and younger participants. Also, significant dose-response relationships were found for fish consumption in females only. CONCLUSION: This study confirms our previous findings that dietary DDE/PCBs exposure may increase the risk of T2D. The effect of DDE/PCBs from fish consumption is driven by geographical differences in DDE/PCBs concentrations in fish and by the amount of fish consumed, and is more prominent in females than in males.


Assuntos
Diabetes Mellitus Tipo 2 , Exposição Dietética , Canadenses Indígenas , Adulto , Animais , Canadá/epidemiologia , Estudos Transversais , Diabetes Mellitus Tipo 2/epidemiologia , Exposição Dietética/efeitos adversos , Exposição Dietética/estatística & dados numéricos , Feminino , Peixes , Contaminação de Alimentos/análise , Humanos , Canadenses Indígenas/estatística & dados numéricos , Masculino , Pessoa de Meia-Idade , Poluentes Orgânicos Persistentes/toxicidade , Medição de Risco
11.
Cell Death Dis ; 12(6): 596, 2021 06 09.
Artigo em Inglês | MEDLINE | ID: mdl-34108448

RESUMO

Mesenchymal stem cell transplantation (MSCT) has been recognized as a potent and promising approach to achieve immunomodulation and tissue regeneration, but the mechanisms of how MSCs exert therapeutic effects remain to be elucidated. Increasing evidence suggests that transplanted MSCs only briefly remain viable in recipients, after which they undergo apoptosis in the host circulation or in engrafted tissues. Intriguingly, apoptosis of infused MSCs has been revealed to be indispensable for their therapeutic efficacy, while recipient cells can also develop apoptosis as a beneficial response in restoring systemic and local tissue homeostasis. It is notable that apoptotic cells produce apoptotic extracellular vesicles (apoEVs), traditionally known as apoptotic bodies (apoBDs), which possess characterized miRnomes and proteomes that contribute to their specialized function and to intercellular communication. Importantly, it has been demonstrated that the impact of apoEVs is long-lasting in health and disease contexts, and they critically mediate the efficacy of MSCT. In this review, we summarize the emerging understanding of apoptosis in mediating MSCT, highlighting the potential of apoEVs as cell-free therapeutics.


Assuntos
Apoptose/fisiologia , Transplante de Células-Tronco Mesenquimais , Animais , Vesículas Extracelulares/patologia , Vesículas Extracelulares/fisiologia , Humanos , Imunomodulação/fisiologia , Células-Tronco Mesenquimais/fisiologia , Regeneração/fisiologia , Transdução de Sinais/fisiologia
12.
J Cell Mol Med ; 2021 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-33993634

RESUMO

5'-Nucleotidase Domain Containing 2 (NT5DC2) is a novel oncoprotein, the regulatory effects of which have not been well characterized. This study aimed to investigate the expression profile and functional regulation of NT5DC2 and its potential interplay with TEAD4 in leiomyosarcoma (LMS). Bioinformatic analysis was conducted using data from The Cancer Genome Atlas (TCGA) and Genotype-Tissue Expression (GTEx) program. LMS cell lines SK-LMS-1 and SK-UT-1 were used for both in vitro and in vivo analysis. Results showed that NT5DC2 is aberrantly upregulated in LMS. Its overexpression was associated with unfavourable survival. Deletion of NT5DC2 significantly reduced the expression of cyclin B1, cyclin A2, cyclin E1 and CDK1 and increased G1 phase arrest in LMS cell lines, and suppressed their proliferation both in vitro and in vivo. NT5DC2 interacted with unpalmitoylated TEAD4, and this association reduced TEAD4 degradation via the ubiquitin-proteasome pathway. TRIM27 is a novel E3 ubiquitin ligase that induces K27/48-linked ubiquitination of unpalmitoylated TEAD4 at Lys278. TEAD4 inhibition significantly suppressed LMS cell growth both in vitro and in vivo. Dual-luciferase assay demonstrated that TEAD4 could bind to the NT5DC2 promoter and activate its transcription. Based on these findings, we infer that the NT5DC2-TEAD4 positive feedback loop plays an important role in LMS development and might serve as a potential therapeutic target.

13.
Medicine (Baltimore) ; 100(1): e23034, 2021 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-33429727

RESUMO

BACKGROUND: Botulinum toxin A injection is an established method of treatment. Clinical practitioners use it widely in their practice to prevent the occurrence of facial scars. However, the effectiveness and safeness of has not been comprehensively established. The objective of the current systematic review is to evaluate the efficacy and safety of using botulinum toxin A injection to improve facial scars. METHODS AND ANALYSIS: This systematic review involves browsing a number of electronic databases to search for related articles. The search will include databases in both English (PubMed, EMBASE, Web of Science, Spocus, and Cochrane Central Register of Controlled Trials) and Chinese (WanFang database, China Nation Knowledge Infrastructure, and VIP database), the periods of searching will be from inception till the 15th of September 2020. Completing the search in databases allows to consider randomized controlled studies that compares botulinum toxin A interventions to any comparison interventions in those who have facial scars. The review will be inclusive of papers in both languages, English and Chinese. The independent screening of studies for eligibility is conducted by 2 independent authors. Discussion was used to resolve discrepancies between the authors. The Cochrane Risk of Bias Tool V.2.0 is adopted for evaluating the methodological quality of each study. Data extraction was performed by 2 independent authors. For dichotomous outcomes, the were expressed as relative risk (RR) with 95% confidence intervals (CI). For continuous outcomes the results were expressed as the mean difference (MD) or standardized mean difference (SMD) with 95% CI. The statistical analysis of the present study is carried out in RevMan 5.3 software. RESULTS: This study will output a comprehensive synthesis of existing evidence in relation to botulinum toxin A. Moreover, the results will also provide an interpretation of the effectiveness and safety of botulinum toxin A. CONCLUSION: The present review contributes to the existing body of knowledge by adding more evidence to evaluate if botulinum toxin A is effective and safe to be used as an intervention for improving facial scars. OSF REGISTRATION NUMBER: DOI 10.17605/OSF.IO/94TXP (https://osf.io/94TXP/).


Assuntos
Toxinas Botulínicas Tipo A/normas , Cicatriz/tratamento farmacológico , Protocolos Clínicos , Face/fisiopatologia , Toxinas Botulínicas Tipo A/efeitos adversos , Toxinas Botulínicas Tipo A/uso terapêutico , Cicatriz/fisiopatologia , Humanos , Injeções/efeitos adversos , Injeções/métodos , Metanálise como Assunto , Revisões Sistemáticas como Assunto
14.
Chemosphere ; 269: 128769, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33143892

RESUMO

This study reports the lead ions release and species transformation of minium pigment under UV-irradiation in aqueous phase. The effects of fulvic acid (FA) and pH on lead ions release were investigated. Lower pH and higher FA concentration facilitate the release of lead ions. During photoreaction, electron donors (FA) are provided to scavenge photogenerated holes and enhance the charge separation, leading to the increased lead ions release. When significant amounts of FA exist in the water, they will complex with the released lead ions preferentially. Then, lead ions react with CO2 and proton resulting in the formation of insoluble Pb3(CO3)2(OH)2 after FA consumed. Correspondingly, the dissolved lead ion concentration in water showed a trend of increasing first and then decreasing. Based upon characterization and experimental results, lead ions release and lead species transformation mechanisms of minium were eventually speculated. This research is helpful for better understanding the environmental behavior and risk of semiconductor pigments in natural water.


Assuntos
Chumbo , Poluentes Químicos da Água , Íons , Raios Ultravioleta , Água
15.
Environ Res ; 194: 110496, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33220245

RESUMO

Synergistic adsorption and oxidative degradation (via persulfate activation) on metal-free carbonaceous materials are expected to be environmentally friendly and highly efficient approach toward contaminants removal. Herein, nitrogen and sulfur codoped mesoporous carbon (NSDMC) were firstly synthesized via co-carbonization of calcium citrate and thiourea without any templates. NSDMC samples exhibit remarkably enhanced adsorption capacity and oxidative degradation (by activating PDS) for chlorophenols elimination. Increased SBET and introduced N-containing functional groups are beneficial for chlorophenols adsorption, PDS accessibility and successive activation. Doped sulfur species (especially for thiophenic S) can enhance the electron-transport performance of NSDMC, further promoting PDS activation and chlorophenols degradation. It can be ascribed to the synergistic effect of N and S codoping. NSDMC-30 (containing 5.83 at.% nitrogen and 2.15 at.% sulfur, and possessing SBET of 1935.9 m2 g-1) exhibits the optimal adsorption and catalytic oxidation capability for 4-CP removal. Degradation rate constant of NSDMC-30 is 0.125 min-1, which is 3.0 times and 7.8 times higher than nitrogen-doped MC and pristine MC, respectively. Radicals quenching experiments and EPR tests demonstrate that non-radical pathways play dominant role for PDS activation and chlorophenols degradation. Based on the influences of catalyst loading, initial 4-CP concentration, and PDS dosage on degradation kinetics of 4-CP, the pre-adsorption is unveiled to be the critical step determining oxidation rate of chlorophenols. More importantly, the results of in-situ Raman and electrochemical tests show that the surface-confined and activated PDS complex (carbon-PDS*) and continuous electron transfer from co-adsorbed 4-CP are mainly responsible for the oxidative degradation of chlorophenols. The intermediate products and TOC removal indicate that chlorophenols can be efficiently degraded and mineralized by as-synthesized NSDMC via activating PDS. Besides, the present NSDMC/PDS system is also applicable for purification of actual polluted water samples. This work provides in-depth knowledge of carbon-driven nonradical process for PDS activation and contaminants remediation.


Assuntos
Carbono , Clorofenóis , Elétrons , Nitrogênio , Oxirredução , Enxofre
16.
J Hazard Mater ; 408: 124445, 2021 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-33221076

RESUMO

Chlorinated organic compounds are ubiquitously detected in saline waters. The photochlorination of organic compounds is one possible source, and chlorine radicals originating from other photosensitive substances have been reported to be responsible for organic compounds chlorination in previous reports. In this study, benzo[a]pyrene (BaP) chlorination in 10% acetonitrile/NaCl aqueous solution was initiated by self-sensitization of BaP, while chlorine radicals were not involved in the reaction. After 45 min of photoreaction in four seawater samples, chlorinated product (6-ClBaP) accounted for 10-17% of the fraction of transformed BaP, which was higher than that previously reported. The influences of Cl-, pH, humic acid, electron donors, and particulate matter on the formation of chlorobenzo[a]pyrene were systematically investigated. A self-sensitized photochlorination reaction mechanism was proposed as follow: photoexited BaP was activated to singlet state and then transformed to triplet state through inter-system crossing. Then the excited triplet state and oxygen formed [3BaP*-3O2] or [BaP-1O2] complex, which further reacted with Cl- to produce 6-ClBaP.

17.
Plants (Basel) ; 9(11)2020 Nov 12.
Artigo em Inglês | MEDLINE | ID: mdl-33198278

RESUMO

In a natural environment, plants usually interact with their neighbors predominantly through resource competition, allelopathy, and facilitation. The occurrence of the positive effect of allelopathy between peat mosses (Sphagnum L.) is rare, but it has been observed in a field experiment. It is unclear whether the stability of the water table level in peat induces positive vs. negative effects of allelopathy and how that is related to phenolic allelochemical production in Sphagnum. Based on field experiment data, we established a laboratory experiment with three neighborhood treatments to measure inter-specific interactions between Sphagnum angustifolium (Russ.) C. Jens and Sphagnum magellanicum Brid. We found that the two species were strongly suppressed by the allelopathic effects of each other. S. magellanicum allelopathically facilitated S. angustifolium in the field but inhibited it in the laboratory, and relative allelopathy intensity appeared to be positively related to the content of released phenolics. We conclude that the interaction type and intensity between plants are dependent on environmental conditions. The concentration of phenolics alone may not explain the type and relative intensity of allelopathy. Carefully designed combined field and laboratory experiments are necessary to reveal the mechanism of species interactions in natural communities.

18.
Artigo em Inglês | MEDLINE | ID: mdl-33062012

RESUMO

The main pathological changes inherent in Parkinson's disease (PD) are degeneration and loss of dopamine neurons in the midbrain and formation of Lewy bodies. Many studies have shown that the pathogenesis of PD is closely related to endoplasmic reticulum (ER) oxidative stress. This study combined various traditional Chinese medicines to prepare Congrong Shujing granules (CSGs). The optimal dose combination of the ingredients was identified by experimental intervention in SH-SY5Y cells in vitro. A PD rat model was established by intraperitoneal injection of rotenone sunflower oil emulsion. The suspension tests were performed on the 14th day after modeling and also on the 14th day after CSG intervention (5.88 g/kg, 11.76 g/kg, and 23.52 g/kg). We evaluated the changes in motor function and the expression of neuronal cell functional marker proteins, ER stress (ERS) marker proteins, and apoptosis-related pathway proteins of neuronal cells. Changes in cellular ultrastructure were observed by electron microscopy. Our results showed that CSG treatment lengthened the duration of PD rats' gripping to the wire. 78 kDa glucose-regulated protein (GRP78) expression in the substantia nigra was significantly upregulated in the middle- and high-dose CSG groups after 14 days of treatment compared with the model group. The expression of the key dopaminergic neuron functional enzyme tyrosine hydroxylase (TH) and cerebral dopamine neurotrophic factor (CDNF) was elevated. The expression of c-Jun N-terminal kinase (JNK) and phosphorylated c-Jun decreased, and cell apoptosis was significantly reduced. Compared with the model group, the treatment groups had fewer ER fragmentation and degranulation (ribosome shedding) and abundant ER and mitochondria suggesting that CSG reduced ER stress and neuronal apoptosis in the midbrain of a PD rat model by inducing the expression of molecular chaperone GRP78.

19.
Cancer Manag Res ; 12: 7475-7485, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32904466

RESUMO

Purpose: Angiopoietin-2 (Ang-2) has been proven to be a potential agent for malignant cancer treatment. The aim of the current study was to investigate the inhibitory effects of chitosan magnetic nanoparticles (CMNPs) loaded with Ang-2 small interfering RNA (Ang2-siRNA) plasmids (Ang2-CMNPs) on malignant melanoma. Materials and Methods: Melanoma-bearing nude mice were treated with Ang2-CMNPs and control CMNPs. Tumor volumes in each group were recorded. Real-time fluorescence quantitative-PCR was used to measure the relative Ang-2gene expression. Angiogenesis and Ang-2 expression in tumors were measured by immunohistochemistry. Cell apoptosis in each group was measured by TUNEL staining, and the expression of Bax, Bcl-2 and cleaved caspase-3 was analyzed by immunohistochemistry. Results: The progression of melanoma was significantly inhibited by Ang2-CMNP treatment. Ang2-CMNP treatment efficiently inhibited tumor growth and in-situ Ang-2 expression compared with those of the control group. Furthermore, Ang2-CMNP treatment significantly inhibited tumor angiogenesis and promoted cell apoptosis by regulating the Bax/Bcl-2 ratio and increasing cleaved caspase-3 expression in vivo. Conclusion: In summary, Ang2-CMNP treatment increased the regression of normal-appearing vessels in the tumor microenvironment and induced the melanoma cells apoptosis through the mitochondrial apoptotic pathway, suggesting the potential clinical use of Ang2-CMNPs in malignant melanoma treatment.

20.
ACS Appl Mater Interfaces ; 12(37): 40990-40999, 2020 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-32808753

RESUMO

Flexible bioelectronics for biomedical applications requires a stretchable, conductive, self-healable, and biocompatible material that can be obtained by cost-effective chemicals and strategies. Herein, we synthesized polypyrrole or Zn-functionalized chitosan molecules, which are cross-linked with poly(vinyl alcohol) to form a hydrogel through dynamic di-diol complexations, hydrogen bonding, and zinc-based coordination bonds. These multiple dynamic interactions endow the material with excellent stretchability and autonomous self-healing ability. The choice of Food and Drug Administration (FDA)-approved materials (poly(vinyl alcohol) and chitosan) as the matrix materials ensures the good biocompatibility of the hydrogel. The conductivity contributed by the polypyrrole allowed the hydrogel to sense strain and temperature, and the coordinated Zn significantly enhanced the antibacterial activity of the hydrogel. Moreover, using a diabetic rat model, we have proved that this hydrogel is capable of promoting the healing of the infected chronic wounds with electrical stimulation.


Assuntos
Antibacterianos/farmacologia , Materiais Biocompatíveis/farmacologia , Hidrogéis/farmacologia , Pseudomonas aeruginosa/efeitos dos fármacos , Staphylococcus aureus/efeitos dos fármacos , Temperatura , Animais , Antibacterianos/síntese química , Antibacterianos/química , Materiais Biocompatíveis/síntese química , Materiais Biocompatíveis/química , Condutividade Elétrica , Estimulação Elétrica , Hidrogéis/síntese química , Hidrogéis/química , Masculino , Testes de Sensibilidade Microbiana , Tamanho da Partícula , Ratos , Ratos Sprague-Dawley , Propriedades de Superfície , Cicatrização/efeitos dos fármacos
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