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1.
Virol Sin ; 2021 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-33835391

RESUMO

The ongoing coronavirus disease 2019 (COVID-19) pandemic caused more than 96 million infections and over 2 million deaths worldwide so far. However, there is no approved vaccine available for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the disease causative agent. Vaccine is the most effective approach to eradicate a pathogen. The tests of safety and efficacy in animals are pivotal for developing a vaccine and before the vaccine is applied to human populations. Here we evaluated the safety, immunogenicity, and efficacy of an inactivated vaccine based on the whole viral particles in human ACE2 transgenic mouse and in non-human primates. Our data showed that the inactivated vaccine successfully induced SARS-CoV-2-specific neutralizing antibodies in mice and non-human primates, and subsequently provided partial (in low dose) or full (in high dose) protection of challenge in the tested animals. In addition, passive serum transferred from vaccine-immunized mice could also provide full protection from SARS-CoV-2 infection in mice. These results warranted positive outcomes in future clinical trials in humans.

2.
Emerg Microbes Infect ; : 1-34, 2021 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-33739899

RESUMO

Coxsackievirus A6 (CV-A6) has been emerging as a major pathogen of hand, foot and mouth disease (HFMD). Study on the pathogenesis of CV-A6 infection and development of vaccines is hindered by a lack of appropriate animal models. Here, we report an actively immunized-challenged mouse model to evaluate the efficacy of a Vero-cell-based, inactivated CV-A6 vaccine candidate. The neonatal Kunming mice were inoculated with a purified, formaldehyde-inactivated CV-A6 vaccine on days 3 and 9, followed by challenging on day 14 with a naturally selected virulent strain at a lethal dose. Within 14 days postchallenge, all mice in the immunized groups survived, while 100% of the Alum-only inoculated mice died. Neutralizing antibodies (NtAbs) were detected in the serum of immunized suckling mice, and the NtAb levels correlated with the survival rate of the challenged mice. The virus loads in organs were reduced, and pathological changes and viral protein expression were weak in the immunized mice compared with those in Alum-only inoculated control mice. Elevated levels of interleukin-4, 6, interferon γ and tumor necrosis factor α were also observed in Alum-only control mice compared with immunized mice. Importantly, the virulent CV-A6 challenge strain was selected quickly and conveniently from a RD cell virus stock characterized with the natural multi-genotypes. The virulent determinants were mapped to V124M and I242V at VP1. Together, our results indicated that this actively immunized mouse model is invaluable for future studies to develop multivalent vaccines containing the major component of CV-A6 against HFMD.

3.
Bioengineered ; 12(1): 516-526, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33550896

RESUMO

In order to isolated and identified the bacterial strains from wheat rhizosphere and evaluated the effect of different concentration of bacterial fermentation broth on the wild oats weed growth. This experiment carried out the separation and purification of dominant bacterial strains from the wheat rhizosphere soil, and performed the fermentation broth biological activity assessment by measured the seed germination and plant growth from 20 wheat varieties. The results had shown that the bacterial fermentation broth inhibits the growth of wild oat seedlings and plants to varying degrees, bacterial strains of X3, X4, X8, X12, X16 and X20 has certain level of inhibition activity and X20 has the highest herbicidal effectiveness. According to molecular biology identification, obtained superior bacterial strains X20 was Bacillus as potentially inhibitor for developing of bacterial-based bioherbicides for wild oats weed control management in the wheat field.

4.
J Virol ; 95(6)2021 Feb 24.
Artigo em Inglês | MEDLINE | ID: mdl-33408178

RESUMO

Coxsackievirus A5 (CV-A5) has recently emerged as a main hand, foot, and mouth disease (HFMD) pathogen. Following a large-scale vaccination campaign against enterovirus 71 (EV-71) in China, the number of HFMD-associated cases with EV-71 was reduced, especially severe and fatal cases. However, the total number of HFMD cases remains high, as HFMD is also caused by other enterovirus serotypes. A multivalent HFMD vaccine containing 4 or 6 antigens of enterovirus serotypes is urgently needed. A formaldehyde-inactivated CV-A5 vaccine derived from Vero cells was used to inoculate newborn Kunming mice on days 3 and 10. The mice were challenged on day 14 with a mouse-adapted CV-A5 strain at a dose that was lethal for 14-day-old suckling mice. Within 14 days postchallenge, groups of mice immunized with three formulations, empty particles (EPs), full particles (FPs), and a mixture of the EP and FP vaccine candidates, all survived, while 100% of the mock-immunized mice died. Neutralizing antibodies (NtAbs) were detected in the sera of immunized mice, and the NtAb levels were correlated with the survival rate of the challenged mice. The virus loads in organs were reduced, and pathological changes and viral protein expression were weak or not observed in the immunized mice compared with those in alum-inoculated control mice. Another interesting finding was the identification of CV-A5 dense particles (DPs), facilitating morphogenesis study. These results demonstrated that the Vero cell-adapted CV-A5 strain is a promising vaccine candidate and could be used as a multivalent HFMD vaccine component in the future.IMPORTANCE The vaccine candidate strain CV-A5 was produced with a high infectivity titer and a high viral particle yield. Three particle forms, empty particles (EPs), full particles (FPs), and dense particles (DPs), were obtained and characterized after purification. The immunogenicities of EP, FP, and the EP and FP mixture were evaluated in mice. Mouse-adapted CV-A5 was generated as a challenge strain to infect 14-day-old mice. An active immunization challenge mouse model was established to evaluate the efficacy of the inactivated vaccine candidate. This animal model mimics vaccination, similar to immune responses of the vaccinated. The animal model also tests protective efficacy in response to the vaccine against the disease. This work is important for the preparation of multivalent vaccines against HFMD caused by different emerging strains.

5.
J Mol Graph Model ; 103: 107819, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33373855

RESUMO

Under the guidance of the targeted molecules, brain-targeted liposomes can carry drugs quickly through the blood-brain barrier to achieve the target enrichment of drugs in the brain, so the design of the target molecules is the key to the preparation of high-efficiency brain targeted liposomes. In this study, SYBYL-X2.1.1 software was used to study the number and connection mode of each segment structure (glucose segment, fatty-chain and cholesterol segment) in the design of targeted molecular structure. GROMACS is used for calculation of molecular dynamics simulation, and G_MMPBSA is used for calculation of binding free energy. The results showed that glucose molecules interacted with 4PYP through hydrogen bond and Van der Waals forces. The amount of glucose in the glucoside molecule and the length of the fatty-chain had a significant effect on the interaction between the molecule and 4PYP. On this basis, through a series of optimizations in this study, a glucoside targeted molecule, which had high affinity with 4PYP and stable binding with liposome, was constructed. In summary, the use of computer-assisted screening technology could significantly accelerate the research and development efficiency of new brain-targeted molecules and provide new technical means for the design of new brain-targeted materials.

6.
J Hazard Mater ; 405: 124669, 2020 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-33301969

RESUMO

Chromium sludge is a hazardous solid waste which cannot be effectively treated but only piled up and abandoned, causing serious environment pollution and resource wasting. This work proposes an effective novel process to separately recover all resources in chromium sludge via a sustainable way. The obtained acid solving liquid from chromium sludge is desiliconized by cationic flocculant (PCAM) to induce coprecipitation of polysilicate gel and PCAM, which mixture is calcinated to generate the product of white carbon black in purity of 94.35% with a recovery of 92.58%. After desiliconization, V in the solving liquid is selectively extracted by microemulsion (ME), which is recovered as V2O5 in purity of 99.34% with a recovery of 95.53% by the subsequent procedure of stripping-precipitation-calcination. The Fe3+ in raffinate is reduced to Fe2+ cations by Na2SO3, and is then recovered by H2C2O4 precipitation to generate the FeC2O4 product in purity of 99.12% with a recovery of 98.25%. Cr3+ cations in residual solution are recovered by alkaline precipitation and calcination to generate the Cr2O3 product in purity of 98.25% with a recovery of 92.68%. This work provides fresh penetrations into the synchronous detoxification, resource recovery and value-added utilization of hazardous industrial solid wastes.

7.
Sci Rep ; 10(1): 20909, 2020 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-33262488

RESUMO

Coxsackievirus A6 (CV-A6) and Coxsackievirus A10 (CV-A10) have been emerging as the prevailing serotypes and overtaking Enterovirus A71 (EV-A71) and Coxsackievirus A16 (CV-A16) in most areas as main pathogens of hand, foot and mouth disease (HFMD) in China since 2013. To investigate whole etiological spectrum following EV-A71 vaccination of approximate 40,000 infants and young children in Xiangyang, enteroviruses were serotyped in 4415 HFMD cases from October 2016 to December 2017 using Real Time and conventional PCR and cell cultures. Of the typeable 3201 specimen, CV-A6 was the predominant serotype followed by CV-A16, CV-A10, CV-A5, CV-A2 and EV-A71 with proportions of 59.54%, 15.31%, 11.56%, 4.56%, 3.78% and 3.03%, respectively. Other 12 minor serotypes were also detected. The results demonstrated that six major serotypes of enteroviruses were co-circulating, including newly emerged CV-A2 and CV-A5. A dramatic decrease of EV-A71 cases was observed, whereas the total cases remained high. Multivalent vaccines against major serotypes are urgently needed for control of HFMD.

8.
Microb Pathog ; : 104603, 2020 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-33271234

RESUMO

Coxsackievirus A16 (CVA16) is one of the major etiological agents of hand, foot and mouth disease (HFMD), a common acute infectious disease affecting infants and young children. Severe symptoms of the central nervous system may develop and even lead to death. Here, a plaque-purified CVA16 strain, L731-P1 (P1), was serially passaged in Vero cells for six times and passage 6 (P6) stock became highly attenuated in newborn mice. Genomic sequencing of the P1 and P6 revealed seven nucleotide substitutions at positions 1434 (C to U), 2744 (A to G), 2747 (A to G), 3161 (G to A), 3182 (A to G), 4968 (C to U), and 6064 (C to U). Six of these substitutions resulted in amino acid changes at VP2-T161 M, VP1-N102D, VP1-T103A, VP1-E241K, VP1-T248A, and 2C-S297F, respectively. P1-based infectious cDNA was generated to further investigate these virulent determinants. Independent reverse transcription-polymerase chain reaction (RT-PCR) amplifications for mutant constructions and plaque-purification of the P6 for isolation of variants were performed to determine dominant mutations and strains more related to attenuation. The virulent P1, attenuated P6, as well as a plaque purified strain (PP) and other four recombinant mutants, were inoculated into one-day-old BALB/c mice and the 50% lethal dose of each strain was determined. Comparison of virulence among these strains indicated that amino acid changes of VP1-N102D, VP1-E241K and 2C-S297F might be associated more closely with a high level attenuation of CVA16-L731-P6 than other mutations. Identification of novel residues associated with virulence may contribute to understanding of molecular basis of virulence of CVA16 and other enteroviruses.

9.
Emerg Microbes Infect ; : 1-29, 2020 Nov 24.
Artigo em Inglês | MEDLINE | ID: mdl-33232205

RESUMO

In the face of COVID-19 pandemic caused by the newly emerged SARS-CoV-2, an inactivated, Vero cell-based, whole virion vaccine candidate has been developed and entered into phase III clinical trials within six months. Biochemical and immunogenic characterization of structural proteins and their post-translational modifications in virions, the end-products of the vaccine candidate, would be essential for the quality control and process development of vaccine products and for studying the immunogenicity and pathogenesis of SARS-CoV-2. By using a panel of rabbit antisera against virions and five structural proteins together with a convalescent serum, the spike (S) glycoprotein was shown to be N-linked glycosylated, PNGase F-sensitive, endoglycosidase H-resistant and cleaved by Furin-like proteases into S1 and S2 subunits. The full-length S and S1/S2 subunits could form homodimers/trimers. The membrane (M) protein was partially N-linked glycosylated; the accessory protein 3a existed in three different forms, indicative of cleavage and dimerization. Furthermore, analysis of the antigenicity of these proteins and their post-translationally modified forms demonstrated that S protein induced the strongest antibody response in both convalescent and immunized animal sera. Interestingly, immunization with the inactivated vaccine did not elicit antibody response against the S2 subunit, whereas strong antibody response against both S1 and S2 subunits was detected in the convalescent serum. Moreover, vaccination stimulated stronger antibody response against S multimers than did the natural infection. This study revealed that the native S glycoprotein stimulated neutralizing antibodies, while bacterially-expressed S fragments did not. The study on S modifications would facilitate design of S-based anti-SARS-CoV-2 vaccines.

10.
Emerg Microbes Infect ; 9(1): 2606-2618, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33241728

RESUMO

The ongoing COVID-19 pandemic is causing huge impact on health, life, and global economy, which is characterized by rapid spreading of SARS-CoV-2, high number of confirmed cases and a fatality/case rate worldwide reported by WHO. The most effective intervention measure will be to develop safe and effective vaccines to protect the population from the disease and limit the spread of the virus. An inactivated, whole virus vaccine candidate of SARS-CoV-2 has been developed by Wuhan Institute of Biological Products and Wuhan Institute of Virology. The low toxicity, immunogenicity, and immune persistence were investigated in preclinical studies using seven different species of animals. The results showed that the vaccine candidate was well tolerated and stimulated high levels of specific IgG and neutralizing antibodies. Low or no toxicity in three species of animals was also demonstrated in preclinical study of the vaccine candidate. Biochemical analysis of structural proteins and purity analysis were performed. The inactivated, whole virion vaccine was characterized with safe double-inactivation, no use of DNases and high purity. Dosages, boosting times, adjuvants, and immunization schedules were shown to be important for stimulating a strong humoral immune response in animals tested. Preliminary observation in ongoing phase I and II clinical trials of the vaccine candidate in Wuzhi County, Henan Province, showed that the vaccine is well tolerant. The results were characterized by very low proportion and low degree of side effects, high levels of neutralizing antibodies, and seroconversion. These results consistent with the results obtained from preclinical data on the safety.

11.
Front Genet ; 11: 587509, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33193724

RESUMO

Chinese sacbrood virus (CSBV) is a serious threat to eastern honeybees (Apis cerana), especially larvae. However, the pathological mechanism of this deadly disease remains unclear. Here, we employed mRNA and small RNA (sRNA) transcriptome approach to investigate the microRNAs (miRNAs) and small interfering RNAs (siRNAs) expression changes of A. cerana larvae infected with CSBV under natural condition. We found that serine proteases involved in immune response were down-regulated, while the expression of siRNAs targeted to serine proteases were up-regulated. In addition, CSBV infection also affected the expression of larvae cuticle proteins such as larval cuticle proteins A1A and A3A, resulting in increased susceptibility to CSBV infection. Together, our results provide insights into sRNAs that they are likely to be involved in regulating honeybee immune response.

12.
Nanoscale ; 12(42): 21901-21912, 2020 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-33108431

RESUMO

The antitumor activity of artemisinin derivatives has attracted much attention. However, lack of tumor targeting limits the anti-tumor activity of artemisinin derivatives. It is reported that tumor cells acquire energy through the glycolysis pathway. To meet their elevated glucose requirements, high expressions of glucose transporters (GLUTs) are observed in many malignant cells. On this basis, novel alkyl glycoside-modified dihydroartemisinin liposomes were successfully prepared with GLUT1 as the target and the glucose segment of an alkyl glycoside as the targeting head on the surface of liposomes. The particle size of the liposomes was 100.67 ± 1.25 nm, zeta potential was -22.93 ± 0.92 mV and encapsulation efficiency was 75.28 ± 0.73%, meanwhile the liposomes had good stability. In vitro targeting of liposomes was evaluated by fluorescence microscopy and flow cytometry. Compared with human L02 hepatocyte cells, the liposomes showed better targeting ability to human liver carcinoma cells HepG2 with the help of the glucose segment modified on the liposomes. In vivo targeting evaluation also showed that the tumor targeting of alkyl glycoside-modified liposomes was significantly improved, as well as the anti-tumor activity. These findings provide a research and theoretical basis for the development of artemisinin derivatives and other drug targeted antitumor nano-agents.

13.
AMB Express ; 10(1): 152, 2020 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-32816147

RESUMO

To develop a new antiviral preparation from a microbial source, the halophilic bacterium Bacillus pumilus E303035 was isolated from a soil sample collected at Qarhan Salt Lake in Qinghai, China. The inhibitory activity of an ethyl acetate extract of its fermentation broth was higher than that of an n-butanol extract. After isolation and purification, 9 compounds were obtained: cyclo(L-Leu-L-Pro) (1), cyclo(L-Pro-L-Tyr) (2), Brevianamide F (3), 2-(3-Indolyl) ethanol (4), N-[2-(1H-indol-3-yl) ethyl] acetamide (5), 3, 3-di(1H-indol-3-yl)propane-1,2-diol (6), Lincomycin B (7), dibutylphthalate (8), and p-hydroxyphenethyl alcohol (9). Compounds 1, 5, and 9 showed inhibitory activities against potato virus Y (PVY). Compounds 1, 4, and 9 had significant inhibitory activity against genes HC-pro, P3, and Nib, compound 5 against gene P3, and compounds 1 and 4 against NIa. Compounds 1, 4, 5, and 9 had significant inhibitory activity against genes VPg and 6K1. Active compounds 1, 5, and 9 had various effects on the expression of viral genes related to pathogenesis. Expression of genes cullin and XTH was up-regulated and CP was down-regulated, compared to the positive control. In conclusion, compounds 1, 5, and 9 might be considered as potential antiviral agents for future development.

14.
JAMA ; 324(10): 951-960, 2020 09 08.
Artigo em Inglês | MEDLINE | ID: mdl-32789505

RESUMO

Importance: A vaccine against coronavirus disease 2019 (COVID-19) is urgently needed. Objective: To evaluate the safety and immunogenicity of an investigational inactivated whole-virus COVID-19 vaccine in China. Interventions: In the phase 1 trial, 96 participants were assigned to 1 of the 3 dose groups (2.5, 5, and 10 µg/dose) and an aluminum hydroxide (alum) adjuvant-only group (n = 24 in each group), and received 3 intramuscular injections at days 0, 28, and 56. In the phase 2 trial, 224 adults were randomized to 5 µg/dose in 2 schedule groups (injections on days 0 and 14 [n = 84] vs alum only [n = 28], and days 0 and 21 [n = 84] vs alum only [n = 28]). Design, Setting, and Participants: Interim analysis of ongoing randomized, double-blind, placebo-controlled, phase 1 and 2 clinical trials to assess an inactivated COVID-19 vaccine. The trials were conducted in Henan Province, China, among 96 (phase 1) and 224 (phase 2) healthy adults aged between 18 and 59 years. Study enrollment began on April 12, 2020. The interim analysis was conducted on June 16, 2020, and updated on July 27, 2020. Main Outcomes and Measures: The primary safety outcome was the combined adverse reactions 7 days after each injection, and the primary immunogenicity outcome was neutralizing antibody response 14 days after the whole-course vaccination, which was measured by a 50% plaque reduction neutralization test against live severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Results: Among 320 patients who were randomized (mean age, 42.8 years; 200 women [62.5%]), all completed the trial up to 28 days after the whole-course vaccination. The 7-day adverse reactions occurred in 3 (12.5%), 5 (20.8%), 4 (16.7%), and 6 (25.0%) patients in the alum only, low-dose, medium-dose, and high-dose groups, respectively, in the phase 1 trial; and in 5 (6.0%) and 4 (14.3%) patients who received injections on days 0 and 14 for vaccine and alum only, and 16 (19.0%) and 5 (17.9%) patients who received injections on days 0 and 21 for vaccine and alum only, respectively, in the phase 2 trial. The most common adverse reaction was injection site pain, followed by fever, which were mild and self-limiting; no serious adverse reactions were noted. The geometric mean titers of neutralizing antibodies in the low-, medium-, and high-dose groups at day 14 after 3 injections were 316 (95% CI, 218-457), 206 (95% CI, 123-343), and 297 (95% CI, 208-424), respectively, in the phase 1 trial, and were 121 (95% CI, 95-154) and 247 (95% CI, 176-345) at day 14 after 2 injections in participants receiving vaccine on days 0 and 14 and on days 0 and 21, respectively, in the phase 2 trial. There were no detectable antibody responses in all alum-only groups. Conclusions and Relevance: In this interim report of the phase 1 and phase 2 trials of an inactivated COVID-19 vaccine, patients had a low rate of adverse reactions and demonstrated immunogenicity; the study is ongoing. Efficacy and longer-term adverse event assessment will require phase 3 trials. Trial Registration: Chinese Clinical Trial Registry Identifier: ChiCTR2000031809.


Assuntos
Betacoronavirus/imunologia , Infecções por Coronavirus/prevenção & controle , Imunogenicidade da Vacina , Pandemias/prevenção & controle , Pneumonia Viral/prevenção & controle , Vacinas Virais/imunologia , Adjuvantes Imunológicos/administração & dosagem , Adjuvantes Imunológicos/efeitos adversos , Adolescente , Adulto , Hidróxido de Alumínio/administração & dosagem , Hidróxido de Alumínio/efeitos adversos , Anticorpos Neutralizantes/sangue , Anticorpos Antivirais/sangue , Betacoronavirus/genética , Infecções por Coronavirus/imunologia , Relação Dose-Resposta Imunológica , Método Duplo-Cego , Feminino , Humanos , Injeções Intramusculares , Masculino , Pneumonia Viral/imunologia , Propiolactona , Vacinas de Produtos Inativados/imunologia , Vacinas Virais/administração & dosagem , Vacinas Virais/efeitos adversos , Adulto Jovem
16.
Drug Des Devel Ther ; 14: 2091-2100, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32546972

RESUMO

Background: Leukemia threatens so many lives around the world. Dihydroartemisinin (DHA), as a typical derivative of artemisinin (ART), can efficiently inhibit leukemia, but the controversial mechanisms are still controversial. Many reports showed that tumor cells acquire energy through the glycolysis pathway, pyruvate kinase M2 (PKM2) plays a crucial role in regulating glycolysis. However, it is unclear whether PKM2 or other key molecules are involved in DHA induced cytotoxicity in leukemia cells. Thus, this paper systematically investigated the anticancer effect and mechanism of DHA on human chronic myeloid leukemia K562 cells. Methods: In vitro, cytotoxicity was detected with CCK-8. Glucose uptake, lactate production and pyruvate kinase activity were investigated to evaluate the effect of DHA on K562 cells. To elucidate the cellular metabolism alterations induced by DHA, the extracellular acidification rate was assessed using Seahorse XF96 extracellular flux analyzer. Immunofluorescence, real-time PCR, and Western blotting were used to investigate the molecular mechanism. Results: We found that DHA prevented cell proliferation in K562 cells through inhibiting aerobic glycolysis. Lactate product and glucose uptake were inhibited after DHA treatment. Results showed that DHA modulates glucose uptake through downregulating glucose transporter 1 (GLUT1) in both gene and protein levels. The cytotoxicity of DHA on K562 cells was significantly reversed by PKM2 agonist DASA-58. Pyruvate kinase activity was significantly reduced after DHA treatment, decreased expression of PKM2 was confirmed in situ. Conclusion: The present study implicated that DHA inhibits leukemia cell proliferation by regulating glycolysis and metabolism, which mediated by downregulating PKM2 and GLUT1 expression. Our finding might enrich the artemisinins' antitumor mechanisms.

17.
Zhongguo Ying Yong Sheng Li Xue Za Zhi ; 36(1): 62-66, 2020 Jan 28.
Artigo em Chinês | MEDLINE | ID: mdl-32476374

RESUMO

OBJECTIVE: To investigate the effects of cerium oxide (CeO2) nanoparticles on the viabilities of nerve cells PC12 and SH-SY5Y. METHODS: CeO2 nanoparticles were synthesized, structures were characterized and properties were evaluated. PC12 cells and SH-SY5Y cells were treated with CeO2 nanoparticles at different concentrations (1, 2.5, 5, 10, 25, 50, 75, 100, 150 µg/ml) for 24 h and the cell viability was measured by MTT assay. Then PC12 cells and SH-SY5Y cells were co-treated with CeO2 and active oxygen scavenger NAC and the cells were stained with DCFH-DA probe for ROS. The number of cells and the fluorescence intensity were observed under a fluorescent inverted microscope. Differences were assessed by one-way ANOVA. RESULTS: After treatment with CeO2 nanoparticles, the viabilities of both PC12 cells (P<0.01) and SH-SY5Y cells (P<0.01) were decreased comparing with the control group. After staining with DCFH-DA probe, the fluorescence intensity of the nerve cells was enhanced depending on the concentration of CeO2 nanoparticles suggesting that CeO2 induced the generation of reactive oxygen species (ROS). The fluorescence intensity of PC12 cells was decreased after CeO2 nanoparticles (100 µg/ml) co-treatment with active oxygen scavenger NAC. Compared with CeO2 nanoparticles alone at 25 µg/ml (P<0.01), 50 µg/ml (P<0.01), 75 µg/ml (P<0.01), 100 µg/ml (P<0.01), the cell viability was significantly increased after co-treatment with NAC. CONCLUSION: CeO2 nanoparticles has a negative effect on the viabilities of nerve cells PC12 and SH-SY5Y, and the effect might be depend on ROS.


Assuntos
Sobrevivência Celular , Cério/farmacologia , Nanopartículas , Neurônios/efeitos dos fármacos , Animais , Linhagem Celular Tumoral , Humanos , Células PC12 , Ratos , Espécies Reativas de Oxigênio/metabolismo
18.
Sci Total Environ ; 732: 139125, 2020 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-32438143

RESUMO

Aquatic contamination, oil spills in particular, could lead to the accumulation of antibiotic resistance by promoting selection for and/or transfer of resistance genes. However, there have been few studies on antibiotic resistance in marine mammals in relation to environmental disturbances, specifically oil contaminations. Here we initiated a study on antibiotic resistance bacteria in bottlenose dolphins Tursiops truncatus in relation to oil contamination following the 2010 BP Oil Spill in the northern Gulf of Mexico. Bacterial communities and antibiotic resistance prevalence one year after the 2010 BP Oil Spill were compared between Barataria Bay (BB) and Sarasota Bay (SB) by applying the rarefaction curve method, and (generalized) linear mixed models. The results showed that the most common bacteria included Vibrio, Shewanella, Bacillus and Pseudomonas. The prevalence of antibiotic resistance was high in the bacterial isolates at both bays. Though bacterial diversity did not differ significantly among water or dolphin samples, and antibiotic resistance did not differ significantly among water samples between the two bays, antibiotic resistance and multi-drug resistance in dolphin samples was significantly higher in the BB than in the SB, mainly attributed to the resistance to E, CF, FEP and SXT. We also found sulfamethoxazole-trimethoprim-resistant Stenotrophomonas maltophilia the first time in the natural aquatic environment. The higher antibiotic resistance in the dolphins in BB is likely attributed to 2010 BP Oil Spill as we expected SB, a more urbanized bay area, would have had higher antibiotic resistance based on the previous studies. The antibiotic resistance data gathered in this research will fill in the important data gaps and contributes to the broader spatial-scale emerging studies on antibiotic resistance in aquatic environments.


Assuntos
Golfinho Nariz-de-Garrafa , Animais , Bactérias , Farmacorresistência Bacteriana , Golfo do México , Poluição por Petróleo
19.
Br J Cancer ; 122(6): 857-867, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31969677

RESUMO

BACKGROUND: About 25-37% of resectable pancreatic ductal adenocarcinoma (PDAC) had a great chance of early recurrence after radical resection, which is mainly due to preoperative micrometastasis. We herein demonstrated the profiles of ctDNA in resectable PDAC and use of ctDNA to identify patients with potential micrometastasis. METHODS: A total of 113 and 44 resectable PDACs were enrolled in discovery and validation cohorts, separately. A panel containing 50 genes was used to screen ctDNA by an NGS-based assessment with high specificity. RESULTS: In the discovery cohort, the overall detection rate was 38.05% (43/113). Among positive ctDNA, KRAS mutation had the highest detection rate (23.01%, 26/113), while the others were <5%. Survival analysis showed that plasma KRAS mutations, especially KRAS G12D mutation, had significant association with OS and RFS of resectable PDAC. Plasma KRAS G12D mutation showed a strong correlation with early distant metastasis. In the validation cohort, survival analysis showed similar association between plasma KRAS G12D mutation and poor outcomes. CONCLUSIONS: This study demonstrated that plasma KRAS mutations, especially KRAS G12D mutation, served as a useful predictive biomarker for prognosis of resectable PDAC. More importantly, due to high correlation with micrometastasis, preoperative detection of plasma KRAS G12D mutation helps in optimising surgical selection of resectable PDAC.

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