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1.
Apoptosis ; 28(5-6): 796-809, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-36881290

RESUMO

OBJECTIVE: Mandibular growth that is induced by functional appliances is closely associated with skeletal and neuromuscular adaptation. Accumulating evidence has proved that apoptosis and autophagy have a vital role in adaptation process. However, little is known about the underlying mechanisms. This study sought to determine whether ATF-6 is involved in stretch-induced apoptosis and autophagy in myoblast. The study also sought to uncover the potential molecular mechanism. MATERIALS AND METHODS: Apoptosis was assessed by TUNEL and Annexin V and PI staining. Autophagy was detected by transmission electron microscopy (TEM) analysis and immunofluorescent staining for autophagy-related protein light chain 3 (LC3). Real time-PCR and western blot were performed to evaluate the expression level of mRNA and proteins that were associated with endoplasmic reticulum stress (ERS), autophagy and apoptosis. RESULTS: Cyclic stretch significantly decreased the cell viability and induced apoptosis and autophagy of myoblasts time-dependently. Stretching stimuli activated ATF-6 pathway and induced ERS-mediated apoptosis. Moreover, using 4-PBA significantly inhibited ERS-related apoptosis, as well as partially decreasing autophagy. In addition, inhibition of autophagy by 3-MA enhanced apoptosis by affecting the expression of CHOP and Bcl-2. However, it had no obvious effects on ERS-related proteins of GRP78 and ATF-6. More importantly, knockdown ATF-6 effectively weakened apoptosis and autophagy. It did so by regulating the expression of Bcl-2, Beclin1 and CHOP, but not cleaved Caspase-12, LC3II and p62 in stretched myoblast. CONCLUSION: ATF-6 pathway was activated in myoblast by mechanical stretch. ATF-6 may regulate the process of stretch-induced myoblast apoptosis and autophagy via CHOP, Bcl-2 and Beclin1 signaling.


Assuntos
Apoptose , Autofagia , Proteína Beclina-1/genética , Proteína Beclina-1/metabolismo , Apoptose/fisiologia , Autofagia/genética , Estresse do Retículo Endoplasmático/fisiologia , Mioblastos/metabolismo
2.
Phytother Res ; 37(10): 4722-4739, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37443453

RESUMO

Epithelial ovarian cancer (EOC) is the most common and fatal subtype of ovarian malignancies, with no effective therapeutics available. Our previous studies have demonstrated extraordinary suppressive efficacy of enterolactone (ENL) on EOC. A chemotherapeutic agent, trabectedin (Trabe), is shown to be effective on ovarian cancer, especially when combined with other therapeutics, such as pegylated liposomal doxorubicin or oxaliplatin. Thrombospondin 1 (THBS1), a kind of matrix glycoprotein, plays important roles against cancer development through inhibiting angiogenesis but whether it is involved in the suppression of EOC by ENL or Trabe remains unknown. To test combined suppressive effects of ENL and Trabe on EOC and possible involvement of THBS1 in the anticancer activities of ENL and Trabe. The EOC cell line ES-2 was transfected with overexpressed THBS1 by lentivirus vector. We employed tube formation assay to evaluate the anti-angiogenesis activity of ENL and of its combined use with Trabe after THBS1 overexpression and established drug intervention and xenograft nude mouse cancer models to assess the in vivo effects of the hypothesized synergistic suppression between the agents and the involvement of THBS1. Mouse fecal samples were collected for 16S rDNA sequencing and microbiota analysis. We detected strong inhibitory activities of ENL and Trabe against the proliferation and migration of cancer cells and observed synergistic effects between ENL and Trabe in suppressing EOC. ENL and Trabe, given either separately or in combination, could suppress the tube formation capability of human microvascular endothelial cells, and this inhibitory effect became even stronger with THBS1 overexpression. In the ENL plus Trabe combination group, the expression of tissue inhibitor of metalloproteinases 3 and cluster of differentiation 36 was both upregulated, whereas matrix metalloproteinase 9, vascular endothelial growth factor, and cluster of differentiation 47 were all decreased. With the overexpression of THBS1, the results became even more pronounced. In animal experiments, combined use of ENL and Trabe showed superior inhibitory effects to either single agent and significantly suppressed tumor growth, and the overexpression of THBS1 further enhanced the anti-cancer activities of the drug combination group. ENL and Trabe synergistically suppress EOC and THBS1 could remarkably facilitate the synergistic anticancer effects of ENL and Trabe.


Assuntos
Neoplasias Ovarianas , Trombospondina 1 , Animais , Camundongos , Humanos , Feminino , Carcinoma Epitelial do Ovário , Trabectedina/uso terapêutico , Trombospondina 1/uso terapêutico , Fator A de Crescimento do Endotélio Vascular , Células Endoteliais/metabolismo , Neoplasias Ovarianas/tratamento farmacológico , Neoplasias Ovarianas/patologia , Linhagem Celular Tumoral , Proliferação de Células/genética
3.
BMC Cancer ; 22(1): 918, 2022 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-36008793

RESUMO

BACKGROUND: Selective activation of Delta-like 1 (DLL1)-Notch signaling is a new approach to activate CD8+ T cell and suppress tumor growth, while the efficacy remains modest. Lentinan (LNT) is a clinically used immunomodulation agent. Thus, we hypothesized that LNT could improve the efficacy of DLL1. METHODS: The effects of LNT combined with DLL1 on tumor growth were evaluated by growth curve and tumor weight in EO771 breast and LAP0297 lung tumor models. The impacts on immune cells and gene expression in tumor tissues were determined by flow cytometry, qPCR. Neutrophil depletion was used to investigate the mechanism of the combination therapy on tumor growth. The data sets were compared using unpaired student's t-test or ordinary one-way ANOVA. RESULTS:  LNT treatments additively improved the antitumor effects of DLL1 in EO771 breast tumor growth. Remarkably, LNT treatments synergistically enhanced the suppression of DLL1 on LAP0297 lung tumor growth, resulting in tumor regression. Mechanically, the combination of LNT and DLL1 interventions not only promoted the accumulation and activation of CD8+ T cells, but also increased intratumoral CD45+CD11b+Ly6G+ neutrophils. Reduced neutrophils by anti-Gr1 antibody administrations reversed the improved antitumor effects by LNT treatments in LAP0297 lung tumor. These results suggest that LNT treatments improve the inhibition of DLL1 on tumor growth via neutrophils. CONCLUSIONS: Our findings indicates that LNT and DLL1 may induce synergistical antitumor immunity via simultaneous modulating lymphoid and myeloid cell populations regardless of the type of tumor, providing a potential new strategy to potentiate cancer immunotherapy.


Assuntos
Neoplasias da Mama , Neoplasias Pulmonares , Neoplasias da Mama/tratamento farmacológico , Linfócitos T CD8-Positivos , Feminino , Humanos , Lentinano/farmacologia , Lentinano/uso terapêutico , Neoplasias Pulmonares/tratamento farmacológico , Neutrófilos
4.
Crit Rev Food Sci Nutr ; : 1-27, 2022 Nov 12.
Artigo em Inglês | MEDLINE | ID: mdl-36369942

RESUMO

Food allergies (FA), a major public health problem recognized by the World Health Organization, affect an estimated 3%-10% of adults and 8% of children worldwide. However, effective treatments for FA are still lacking. Recent advances in glycoimmunology have demonstrated the great potential of sialic acids (SAs) in the treatment of FA. SAs are a group of nine-carbon α-ketoacids usually linked to glycoproteins and glycolipids as terminal glycans. They play an essential role in modulating immune responses and may be an effective target for FA intervention. As exogenous food components, sialylated polysaccharides have anti-FA effects. In contrast, as endogenous components, SAs on immunoglobulin E and immune cell surfaces contribute to the pathogenesis of FA. Given the lack of comprehensive information on the effects of SAs on FA, we reviewed the roles of endogenous and exogenous SAs in the pathogenesis and treatment of FA. In addition, we considered the structure-function relationship of SAs to provide a theoretical basis for the development of SA-based FA treatments.

5.
J Math Biol ; 84(6): 50, 2022 05 05.
Artigo em Inglês | MEDLINE | ID: mdl-35513730

RESUMO

We derive a stochastic SIS pairwise model by considering the change of the variables of this system caused by an event. Based on approximations, we construct a low-dimensional deterministic system that can be used to describe the epidemic spread on a regular network. The mathematical treatment of the model yields explicit expressions for the variances of each variable at equilibrium. Then a comparison between the stochastic pairwise model and the stochastic mean-field SIS model is performed to indicate the effect of network structure. We find that the variances of the prevalence of infection for these two models are almost equal when the number of neighbors of every individual is large. Furthermore, approximations for the quasi-stationary distribution of the number of infected individuals and the expected time to extinction starting in quasi-stationary are derived. We analyze the approximations for the critical number of neighbors and the persistence threshold based on the stochastic model. The approximate performance is then examined by numerical and stochastic simulations. Moreover, during the early development phase, the temporal variance of the infection is also obtained. The simulations show that our analytical results are asymptotically accurate and reasonable.


Assuntos
Epidemias , Modelos Biológicos , Simulação por Computador , Modelos Epidemiológicos , Humanos , Processos Estocásticos
6.
Clin Lab ; 67(4)2021 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-33865257

RESUMO

BACKGROUND: Since December 2019, an outbreak of coronavirus disease 2019 (COVID-19) began in Wuhan and rapidly spread globally. The speed and scope of the spread of COVID-19 makes it urgent to define clinical characteristics, serological and radiological changes of the affected patients. METHODS: Seven patients with laboratory-confirmed COVID-19 who were admitted to the Third Affiliated Hospital of Sun Yat-Sen University Yuedong Hospital from January 2020 to March 2020 were retrospectively enrolled and their clinical features, serological and radiological longitudinal changes were analyzed. RESULTS: Among the 7 patients, all (100%) had a clear epidemiological history. The most common symptoms were respiratory symptoms 6 (85.7%), and only 2 (28.6%) of the patients had fever at their first visit. The cohort included 4 (57.1%) common types and 3 (42.9%) severe types. Two (28.6%) common type patients developed to severe type in a short time. All of the 7 patients (100%) had abnormal liver function, normal renal function, and normal procalcitonin. The detection time of specific antibody in 7 patients was 5 - 13 days after symptoms. Before the specific antibody could be detected, the absolute value of lymphocytes decreased in 2 (28.6%) common type cases transferred to severe type cases accompanied with obvious progress in pulmonary imaging. The phenomenon of decreased albumin and elevated globulin occurred in 6 patients (85.7%). The predominant pattern of lung lesions observed was bilateral (71.4%) and mainly near the pleura at the first diagnosis. Bilateral pulmonary involvement occurred in 6 cases (85.7%) during the course of disease. In 4 cases (57.1%) with obvious pulmonary lesions, the absolute value of lymphocytes decreased, albumin decreased, and globulin increased during the course of the disease. CONCLUSIONS: Serum specific antibodies can be detected within 2 weeks of onset. Close observation of the dynamic changes of absolute value of blood lymphocytes, serum albumin, and globulin which were related to pulmonary imaging changes in patients will contribute to assessment of COVID-19.


Assuntos
COVID-19/sangue , COVID-19/diagnóstico por imagem , Anticorpos Antivirais/sangue , China , Febre , Humanos , Pulmão/diagnóstico por imagem , Pulmão/patologia , Contagem de Linfócitos , Estudos Retrospectivos , Albumina Sérica Humana/análise , Soroglobulinas/análise
7.
Invest New Drugs ; 38(5): 1373-1382, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32734371

RESUMO

Cancer is one of the leading causes of death worldwide, but effective therapies remain the topic of many research activities. Many recent studies have thus focused on particular gut microbiota due to their important roles in treating cancers, but very few microbes of therapeutic value have been reported. In this study, we isolated four bacterial strains, BY38, BY40, BY43 and BY45, from the fecal specimens of healthy individuals and cancer patients. The treatment of cancer cells with the products of these cultured bacteria induced significant inhibitory effects on the proliferation of ovarian cancer cells and colorectal cancer cells in a dose-dependent manner. A phylogenetic analysis showed that the four anticancer strains belong to the genus Bacillus, and flow cytometry assays indicated that the inhibitory effects might be achieved through the induction of cell apoptosis. These results suggest that these bacteria could be novel and promising anticancer agents against cancers.


Assuntos
Antineoplásicos/farmacologia , Bacillus/metabolismo , Produtos Biológicos/farmacologia , Microbioma Gastrointestinal , Neoplasias/tratamento farmacológico , Adulto , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Fezes/microbiologia , Genoma Bacteriano , Humanos , Pessoa de Meia-Idade , Filogenia , Sequenciamento Completo do Genoma
8.
Cell Mol Biol (Noisy-le-grand) ; 66(7): 186-189, 2020 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-33287940

RESUMO

To investigate the diagnostic value of cell-free DNA (cfDNA) and long fragment DNA in breast cancer patients.Female patients with breast cancer (n = 80) were recruited over one year for this study, and served as an observation group. The control group consisted of 50 normal, healthy females. Plasma levels of cfDNA and long fragment DNA were determined a day before treatment, 7 days after treatment, and on the 20th day of treatment. The levels of cfDNA and long fragment DNA in breast cancer patients before treatment were significantly higher than those of the control group (p<0.05). Patients cfDNA and long fragment DNA levels 7 days after treatment were not significantly different from the corresponding values at 1 day before treatment (p>0.05), but they decreased significantly on the 20th day of treatment, when compared with levels before treatment (p<0.05). Before treatment, the optimal cut-off point for cfDNA in patients' peripheral blood, sensitivity, specificity and accuracy were 12.25ng/mL, 79.12%, 86.15%, and 73.32%, respectively. The area under the ROC curve (AUC) was 0.865 (95% CI = 0.754-0.903). Close monitoring of cfDNA levels in peripheral blood of breast cancer patients in real-time can be used for early diagnosis of the disease.


Assuntos
Neoplasias da Mama/sangue , Neoplasias da Mama/diagnóstico , Ácidos Nucleicos Livres/sangue , DNA de Neoplasias/sangue , Estudos de Casos e Controles , Feminino , Humanos , Pessoa de Meia-Idade
9.
Clin Lab ; 66(12)2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-33337843

RESUMO

BACKGROUND: Coronavirus disease (COVID-19) has affected more than 100 countries worldwide and the discharge criteria of patients with COVID-19 vary across different countries. In China, patients with two negative respiratory viral RNA tests taken at least one day apart can be discharged with no further quarantine required. Currently, PCR testing of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in fecal sample is not routinely performed. METHODS: We present a patient with COVID-19, whose respiratory swabs became negative but fecal sample remained positive for SARS-CoV-2 RNA. RESULTS: Stool sample collected on 27th of February was still positive for SARS-CoV-2 RNA, 24 days after the first negative respiratory swab. CONCLUSIONS: Based on the experience from the 2003 SARS epidemic, we recommend that fecal RNA testing of SARS-CoV-2 should be incorporated into the discharge criteria to minimize the risk of transmission from the gastrointestinal tract.


Assuntos
Teste de Ácido Nucleico para COVID-19 , COVID-19/virologia , Convalescença , Fezes/virologia , Alta do Paciente/normas , RNA Viral/isolamento & purificação , Reação em Cadeia da Polimerase Via Transcriptase Reversa , SARS-CoV-2/isolamento & purificação , Adulto , Anticorpos Antivirais/sangue , Antivirais/uso terapêutico , Infecções Assintomáticas , COVID-19/diagnóstico , COVID-19/prevenção & controle , Teste Sorológico para COVID-19 , Quimioterapia Combinada , Reações Falso-Negativas , Feminino , Humanos , Nasofaringe/virologia , Faringe/virologia , Distanciamento Físico , SARS-CoV-2/imunologia , Timalfasina/uso terapêutico , Tratamento Farmacológico da COVID-19
10.
BMC Genomics ; 20(1): 930, 2019 Dec 04.
Artigo em Inglês | MEDLINE | ID: mdl-31801462

RESUMO

BACKGROUND: Salmonella bongori infect mainly cold-blooded hosts, but infections by S. bongori in warm-blooded hosts have been reported. We hypothesized that S. bongori might have diverged into distinct phylogenetic lineages, with some being able to infect warm-blooded hosts. RESULTS: To inspect the divergence status of S. bongori, we first completely sequenced the parakeet isolate RKS3044 and compared it with other sequenced S. bongori strains. We found that RKS3044 contained a novel T6SS encoded in a pathogenicity island-like structure, in addition to a T6SS encoded in SPI-22, which is common to all S. bongori strains so far reported. This novel T6SS resembled the SPI-19 T6SS of the warm-blooded host infecting Salmonella Subgroup I lineages. Genomic sequence comparisons revealed different genomic sequence amelioration events among the S. bongori strains, including a unique CTAG tetranucleotide degeneration pattern in RKS3044, suggesting non-overlapping gene pools between RKS3044 and other S. bongori lineages/strains leading to their independent accumulation of genomic variations. We further proved the existence of a clear-cut genetic boundary between RKS3044 and the other S. bongori lineages/strains analyzed in this study. CONCLUSIONS: The warm-blooded host-infecting S. bongori strain RKS3044 has diverged with distinct genomic features from other S. bongori strains, including a novel T6SS encoded in a previously not reported pathogenicity island-like structure and a unique genomic sequence degeneration pattern. These findings alert cautions about the emergence of new pathogens originating from non-pathogenic ancestors by acquiring specific pathogenic traits.


Assuntos
Ilhas Genômicas , Periquitos/microbiologia , Salmonella/classificação , Sequenciamento Completo do Genoma/métodos , Animais , Evolução Molecular , Especiação Genética , Tamanho do Genoma , Genoma Bacteriano , Humanos , Filogenia , Salmonella/genética , Salmonella/patogenicidade , Fatores de Virulência/genética
11.
Mol Genet Genomics ; 294(3): 597-605, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30710177

RESUMO

Antimicrobial resistance makes pathogenic bacteria hard to control, but little is known about the general processes of resistance gain or loss. Here, we compared distinct S. typhimurium DT104 strains resistant to zero, two, five, or more of the tested antimicrobials. We found that common resistance phenotypes could be encoded by distinct genes, on SGI-1 or plasmid. We also demonstrated close clonality among all the tested non-resistant and differently resistant DT104 strains, demonstrating dynamic acquisition or loss (by total deletion or gradual decaying of multi-drug resistance gene clusters) of the genetic traits. These findings reflect convergent processes to make the bacteria resistant to multiple antimicrobials by acquiring the needed traits from stochastically available origins. When the antimicrobial stress is absent, the resistance genes may be dropped off quickly, so the bacteria can save the cost for maintaining unneeded genes. Therefore, this work reiterates the importance of strictly controlled use of antimicrobials.


Assuntos
Adaptação Fisiológica/genética , Farmacorresistência Bacteriana Múltipla/genética , Evolução Molecular , Salmonella typhimurium/genética , Estresse Fisiológico , Adaptação Fisiológica/efeitos dos fármacos , Antibacterianos/farmacologia , Sequência de Bases , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Genes Bacterianos/genética , Genoma Bacteriano/genética , Filogenia , Plasmídeos/classificação , Plasmídeos/genética , Salmonella typhimurium/classificação , Salmonella typhimurium/efeitos dos fármacos , Homologia de Sequência do Ácido Nucleico
13.
J Theor Biol ; 444: 28-37, 2018 05 07.
Artigo em Inglês | MEDLINE | ID: mdl-29452174

RESUMO

We establish an SIS-UAU model to present the dynamics of epidemic and information spreading in overlay networks. The overlay network is represented by two layers: one where the dynamics of the epidemic evolves and another where the information spreads. We theoretically derive the explicit formulas for the basic reproduction number of awareness R0a by analyzing the self-consistent equation and the basic reproduction number of disease R0d by using the next generation matrix. The formula of R0d shows that the effect of awareness can reduce the basic reproduction number of disease. In particular, when awareness does not affect epidemic spreading, R0d is shown to match the existing theoretical results. Furthermore, we demonstrate that the disease-free equilibrium is globally asymptotically stable if R0d<1; and the endemic equilibrium is globally asymptotically stable if R0d>1. Finally, numerical simulations show that information plays a vital role in preventing and controlling disease and effectively reduces the final disease scale.


Assuntos
Epidemias/estatística & dados numéricos , Disseminação de Informação , Modelos Estatísticos , Conscientização , Número Básico de Reprodução , Doenças Endêmicas , Humanos , Medicina Preventiva/métodos
14.
Apoptosis ; 21(4): 432-42, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26801321

RESUMO

It is well recognized that mandibular growth, which is caused by a variety of functional appliances, is considered to be the result of both neuromuscular and skeletal adaptations. Accumulating evidence has demonstrated that apoptosis plays an important role in the adaptation of skeletal muscle function. However, the underlying mechanism of apoptosis that is induced by stretch continues to be incompletely understood. Endoplasmic reticulum stress (ERS), a newly defined signaling pathway, initiates apoptosis. This study seeks to determine if caspase-12 is involved in stretch-induced apoptosis mediated endoplasmic reticulum stress in myoblast and its underlying mechanism. Apoptosis was assessed by Hochest staining, DAPI staining and annexin V binding and PI staining. ER chaperones, such as GRP78, CHOP and caspase-12, were determined by reverse transcription polymerase chain reaction (RT-PCR) and Western blot. Furthermore, caspase-12 inhibitor was used to value the mechanism of the caspase-12 pathway. Apoptosis of myoblast, which is subjected to cyclic stretch, was observed in a time-dependent manner. We found that GRP78 mRNA and protein were significantly increased and CHOP and caspase-12 were activated in myoblast that was exposed to cyclic stretch. Caspase-12 inhibition reduced stretch-induced apoptosis, and caspase-12 activated caspase-3 to induce apoptosis. We concluded that caspase-12 played an important role in stretch-induced apoptosis that is associated by endoplasmic reticulum stress by activating caspase-3.


Assuntos
Apoptose/fisiologia , Caspase 12/metabolismo , Caspase 3/metabolismo , Estresse do Retículo Endoplasmático/fisiologia , Proteínas de Choque Térmico/metabolismo , Mioblastos/metabolismo , Fator de Transcrição CHOP/metabolismo , Animais , Caspase 12/genética , Inibidores de Caspase/farmacologia , Linhagem Celular , Ativação Enzimática , Proteínas de Choque Térmico/genética , Ratos , Transdução de Sinais/fisiologia , Fator de Transcrição CHOP/genética
15.
J Environ Manage ; 181: 304-311, 2016 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-27376869

RESUMO

Modeled results are very important for environmental management. Unreasonable modeled result can lead to wrong strategy for air pollution management. In this work, an improved physically constrained source apportionment (PCSA) technology known as Multilinear Engine 2-species ratios (ME2-SR) was developed to the 11-h daytime and nighttime fine ambient particulate matter in urban area. Firstly, synthetic studies were carried out to explore the effectiveness of ME2-SR. The estimated source contributions were compared with the true values. The results suggest that, compared with the positive matrix factorization (PMF) model, the ME2-SR method could obtain more physically reliable outcomes, indicating that ME2-SR was effective, especially when apportioning the datasets with no unknown source. Additionally, 11-h daytime and nighttime PM2.5 samples were collected from Tianjin in China. The sources of the 11-h daytime and nighttime fine ambient particulate matter in China were identified using the new method and the PMF model. The calculated source contributions for ME2-SR for daytime PM2.5 samples are resuspended dust (38.91 µg m(-3), 26.60%), sulfate and nitrate (38.60 µg m(-3), 26.39%), vehicle exhaust and road dust (38.26 µg m(-3), 26.16%) and coal combustion (20.14 µg m(-3), 13.77%), and those for nighttime PM2.5 samples are resuspended dust (18.78 µg m(-3), 12.91%), sulfate and nitrate (41.57 µg m(-3), 28.58%), vehicle exhaust and road dust (38.39 µg m(-3), 26.39%), and coal combustion (36.76 µg m(-3), 25.27%). The comparisons of the constrained versus unconstrained outcomes clearly suggest that the physical meaning of the ME2-SR results is interpretable and reliable, not only for the specified species values but also for source contributions. The findings indicate that the ME2-SR method can be a useful tool in source apportionment studies, for air pollution management.


Assuntos
Poluentes Atmosféricos/análise , Poluição do Ar/análise , Modelos Teóricos , Material Particulado/análise , China , Cidades , Carvão Mineral , Bases de Dados Factuais , Poeira , Monitoramento Ambiental/métodos , Nitratos/análise , Sulfatos/análise , Emissões de Veículos/análise
16.
BMC Microbiol ; 14: 157, 2014 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-24928416

RESUMO

BACKGROUND: Acquisition of exogenous genetic material is a key event in bacterial speciation. It seems reasonable to assume that recombination of the incoming DNA into genome would be more efficient with higher levels of relatedness between the DNA donor and recipient. If so, bacterial speciation would be a smooth process, leading to a continuous spectrum of genomic divergence of bacteria, which, however, is not the case as shown by recent findings. The goal of this study was todetermine if DNA transfer efficiency is correlated with the levels of sequence identity. RESULTS: To compare the relative efficiency of exogenous DNA acquisition among closely related bacteria, we carried out phage-mediated transduction and plasmid-mediated transformation in representative Salmonella strains with different levels of relatedness. We found that the efficiency was remarkably variable even among genetically almost identical bacteria. Although there was a general tendency that more closely related DNA donor-recipient pairs had higher transduction efficiency, transformation efficiency exhibited over a thousand times difference among the closely related Salmonella strains. CONCLUSION: DNA acquisition efficiency is greatly variable among bacteria that have as high as over 99% identical genetic background, suggesting that bacterial speciation involves highly complex processes affected not only by whether beneficial exogenous DNA may exist in the environment but also the "readiness" of the bacteria to accept it.


Assuntos
DNA/genética , Recombinação Genética , Salmonella/genética , Transdução Genética , DNA/metabolismo , DNA Bacteriano/química , DNA Bacteriano/genética , Especiação Genética , Dados de Sequência Molecular , Salmonella/metabolismo , Análise de Sequência de DNA , Transformação Bacteriana
17.
Phys Chem Chem Phys ; 16(37): 19972-83, 2014 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-25159551

RESUMO

We report the hydrostatic compression studies of the ß-polymorph of a cyclotetramethylene tetranitramine (HMX) energetic molecular crystal using DFT-D2, a first-principles calculation based on density functional theory (DFT) with van der Waals (vdW) corrections. The molecular structure, mechanical properties, electronic properties, and equations of state of ß-HMX are investigated. For the first time, we predict the elastic constants of ß-HMX using DFT-D2 studies. The equations of state under hydrostatic compression are studied for pressures up to 100 GPa. We found that the N-N bonds along the minor axis are responsible for the sensitivity of ß-HMX. The analysis of the charge distribution shows that the electronic charge is transferred from hydrogen atoms to nitro groups with the amount of 0.131 and 0.064e for the nitro groups along the minor axis and major axis, respectively, when pressure changes from 0 GPa to 100 GPa. The electronic energy band gap changes from direct at a pressure of 0 GPa to indirect at a pressure of 50 GPa and higher. The band gap decreases with respect to an increase in pressure, implying that the impact sensitivity increases with compression. Our study suggests that the van der Waals interactions are critically important in modeling the mechanical properties of this molecular crystal.

18.
Genomics ; 102(4): 331-7, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23933189

RESUMO

The deadly human typhoid agent was initially classified as a species called Salmonella typhi but later reclassified as a serovar of Salmonella enterica together with other pathogenically diverse serovars. The dynamic changes of Salmonella taxonomy reflect the need to clarify the phylogenetic status of the Salmonella serovars: are they discrete lineages or variants of a genetic lineage? To answer this question, we compared S. typhi and other Salmonella serotypes. We found that the S. typhi and Salmonella typhimurium strains had over 90% and ca. 80%, respectively, of their genes identical; however, between S. typhi and S. typhimurium, this percentage dropped to 6%, suggesting the existence of genetic boundaries between them. We conclude that S. typhi and the other compared Salmonella serovars have developed into distinct lineages circumscribed by the genetic boundary. This concept and methods may be used to delineate other Salmonella serotypes, many of which are polyphyletic, needing differentiation.


Assuntos
Genes Bacterianos , Salmonella enterica/classificação , Salmonella enterica/genética , Febre Tifoide/microbiologia , Evolução Molecular , Especiação Genética , Humanos , Dados de Sequência Molecular , Filogenia , Salmonella typhi/classificação , Salmonella typhi/genética , Salmonella typhimurium/classificação , Salmonella typhimurium/genética , Homologia de Sequência , Sorotipagem , Febre Tifoide/patologia
19.
PLoS One ; 19(4): e0299020, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38669232

RESUMO

OBJECTIVES: To report the first and largest systematic review and meta-analysis of randomized controlled trials (RCT) to evaluate the efficacy and safety of aripiprazole or bupropion augmentation and switching in patients with treatment-resistant depression (TRD) or major depressive disorder(MDD). METHODS: We conducted a systematic literature retrieval via PubMed, Embase, Web of Science, and Cochrane until April 2023 for RCT, which evaluated the efficacy and safety of aripiprazole or bupropion augmentation and switching for patients with TRD or MDD. Outcomes measured were changes in the Montgomery-Asberg Depression Rating Scale (MADRS), response and remission rate, and serious adverse events. RESULTS: Five RCTs, including 4480 patients, were included for meta-analysis. Among them, two RCTs were rated as "high risk" in three aspects (allocation concealment, blinding of participants and personnel and blinding of outcome assessment) because of the non-blind method, and the quality evaluation of the remaining works of literature was "low risk". Augmentation treatment with Aripiprazole (A-ARI) was associated with a significant higher response rate compared with augmentation treatment with bupropion (A-BUP) (RR: 1.15; 95% CI: 1.05, 1.25; P = 0.0007; I2 = 23%). Besides, A-ARI had a significant higher remission rate compared with switching to bupropion (S-BUP) (RR: 1.22; 95% CI: 1.00, 1.49; P = 0.05; I2 = 59%) and A-BUP had a significant higher remission rate compared with S-BUP (RR: 1.20; 95% CI: 1.06, 1.36; P = 0.0004; I2 = 0%). In addition, there was no significant difference in remission rate(RR: 1.05; 95% CI: 0.94, 1.17; P = 0.42; I2 = 33%), improvement of MADRS(WMD: -2.07; 95% CI: -5.84, 1.70; P = 0.28; I2 = 70%) between A-ARI and A-BUP. No significant difference was observed in adverse events and serious adverse events among the three treatment strategies. CONCLUSIONS: A-ARI may be a better comprehensive antidepressant treatment strategy than A-BUP or S-BUP for patients with TRD or MDD. More large-scale, multi-center, double-blind RCTs are needed to further evaluated the efficacy and safety of aripiprazole or bupropion augmentation and switching treatment strategies.


Assuntos
Aripiprazol , Bupropiona , Transtorno Depressivo Maior , Transtorno Depressivo Resistente a Tratamento , Ensaios Clínicos Controlados Aleatórios como Assunto , Aripiprazol/uso terapêutico , Aripiprazol/efeitos adversos , Bupropiona/uso terapêutico , Bupropiona/efeitos adversos , Bupropiona/administração & dosagem , Humanos , Transtorno Depressivo Maior/tratamento farmacológico , Transtorno Depressivo Resistente a Tratamento/tratamento farmacológico , Resultado do Tratamento , Quimioterapia Combinada
20.
Food Chem ; 443: 138614, 2024 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-38301561

RESUMO

Studies have shown that high hydrostatic pressure (HHP) processing and chlorogenic acid (CA) treatment can effectively reduce food allergenicity. We hypothesize that these novel processing techniques can help tackle crayfish allergy and examined the impact and mechanism of HHP (300 MPa, 15 min) and CA (CA:tropomyosin = 1:4000, 15 min) on the allergenicity of crayfish tropomyosin. Our results revealed that CA, rather than HHP, effectively reduced tropomyosin's allergenicity, as evident in the alleviation of allergic symptoms in a food allergy mouse model. Spectroscopy and molecular docking analyses demonstrated that CA could reduce the allergenicity of tropomyosin by covalent or non-covalent binding, altering its secondary structure (2.1 % decrease in α-helix; 1.9 % increase in ß-fold) and masking tropomyosin's linear epitopes. Moreover, CA-treated tropomyosin potentially induced milder allergic reactions by up-regulating TLR8. While our results supported the efficacy of CA in alleviating crayfish allergy, further exploration is needed to determine clinical effectiveness.


Assuntos
Hipersensibilidade Alimentar , Tropomiosina , Animais , Camundongos , Tropomiosina/metabolismo , Astacoidea/metabolismo , Ácido Clorogênico , Receptor 8 Toll-Like , Simulação de Acoplamento Molecular , Alérgenos/química
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