Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 61
Filtrar
1.
Gut Microbes ; 16(1): 2323231, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38436673

RESUMO

Rapid and accurate clinical staging of pediatric patients with inflammatory bowel disease (IBD) is crucial to determine the appropriate therapeutic approach. This study aimed to identify effective, convenient biomarkers for staging IBD in pediatric patients. We recruited cohorts of pediatric patients with varying severities of IBD to compare the features of the intestinal microbiota and metabolites between the active and remitting disease stages. Metabolites with potential for staging were targeted for further assessment in both patients and colitis model mice. The performance of these markers was determined using machine learning and was validated in a separate patient cohort. Pediatric patients with IBD exhibited distinct gut microbiota structures at different stages of disease activity. The enterotypes of patients with remitting and active disease were Bacteroides-dominant and Escherichia-Shigella-dominant, respectively. The bile secretion pathway showed the most significant differences between the two stages. Fecal and serum bile acid (BA) levels were strongly related to disease activity in both children and mice. The ratio of primary BAs to secondary BAs in serum was developed as a novel comprehensive index, showing excellent diagnostic performance in stratifying IBD activity (0.84 area under the receiver operating characteristic curve in the primary cohort; 77% accuracy in the validation cohort). In conclusion, we report profound insights into the interactions between the gut microbiota and metabolites in pediatric IBD. Serum BAs have potential as biomarkers for classifying disease activity, and may facilitate the personalization of treatment for IBD.


Assuntos
Colite , Microbioma Gastrointestinal , Doenças Inflamatórias Intestinais , Humanos , Animais , Criança , Camundongos , Ácidos e Sais Biliares , Biomarcadores
2.
Microb Pathog ; 187: 106507, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38145792

RESUMO

Candida albicans is an opportunistic human fungal pathogen that causes superficial and systemic infections, particularly in immunocompromised individuals. In response to C. albicans infection, innate immune cells of the host produce and accumulate reactive oxygen species (ROS), which can lead to irreversible damage and apoptosis of fungal cells. Several transcription factors involved in this oxidative stress response have been identified; however, a systematic study to identify the transcription factors that mediate the oxidative stress response has not yet been conducted. Here, we screened a comprehensive transcription factor mutant library consisting of 211 transcription factor deletion mutant strains in the presence and absence of hydrogen peroxide (H2O2), a potent ROS inducer, and identified five transcription factors (Skn7, Dpb4, Cap1, Dal81, and Stp2) that are sensitive to H2O2. Genome-wide transcriptional profiling revealed that H2O2 induces a discrete set of differentially regulated genes among the five identified transcription factor mutant strains. Functional enrichment analysis identified KEGG pathways pertaining to glycolysis/gluconeogenesis, amino sugar and nucleotide sugar metabolism, and ribosome synthesis as the most enriched pathways. GO term analysis of the top common differentially expressed genes among the transcription factor mutant strains identified hexose catabolism and iron transport as the most enriched GO terms upon exposure to H2O2. This study is the first to systematically identify and characterise the transcription factors involved in the response to H2O2. Based on our transcriptional profiling results, we found that exposure to H2O2 modulates several downstream genes involved in fungal virulence. Overall, this study sheds new light on the metabolism, physiological functions, and cellular processes involved in the H2O2-induced oxidative stress response in C. albicans.


Assuntos
Candida albicans , Fatores de Transcrição , Humanos , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Peróxido de Hidrogênio/farmacologia , Peróxido de Hidrogênio/metabolismo , Estresse Oxidativo , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Regulação Fúngica da Expressão Gênica
3.
Nat Commun ; 14(1): 8465, 2023 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-38123560

RESUMO

Inflammasome activity is important for the immune response and is instrumental in numerous clinical conditions. Here we identify a mechanism that modulates the central Caspase-1 and NLR (Nod-like receptor) adaptor protein ASC (apoptosis-associated speck-like protein containing a CARD). We show that the function of ASC in assembling the inflammasome is controlled by its modification with SUMO (small ubiquitin-like modifier) and identify that the nuclear ZBTB16 (zinc-finger and BTB domain-containing protein 16) promotes this SUMOylation. The physiological significance of this activity is demonstrated through the reduction of acute inflammatory pathogenesis caused by a constitutive hyperactive inflammasome by ablating ZBTB16 in a mouse model of Muckle-Wells syndrome. Together our findings identify an further mechanism by which ZBTB16-dependent control of ASC SUMOylation assembles the inflammasome to promote this pro-inflammatory response.


Assuntos
Inflamassomos , Proteína 3 que Contém Domínio de Pirina da Família NLR , Animais , Camundongos , Proteínas Adaptadoras de Sinalização CARD/genética , Proteínas Adaptadoras de Sinalização CARD/metabolismo , Caspase 1/metabolismo , Inflamassomos/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/genética , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Ligação Proteica , Sumoilação
4.
BMC Microbiol ; 23(1): 317, 2023 10 28.
Artigo em Inglês | MEDLINE | ID: mdl-37891489

RESUMO

BACKGROUND: Candida glabrata which belongs to normal microbiota, has caused significant concern worldwide due to its high prevalence and drug resistance in recent years. C. glabrata has developed many strategies to evade the clearance of the host immune system, thereby causing persistent infection. Although coping with the induced DNA damage is widely acknowledged to be important, the underlying mechanisms remain unclear. RESULTS: The present study provides hitherto undocumented evidence of the importance of the regulatory subunits of CgCK2 (CgCkb1 and CgCkb2) in response to DNA damage. Deletion of CgCKB1 or CgCKB2 enhanced cellular apoptosis and DNA breaks and led to cell cycle delay. In addition, deficiencies in survival upon phagocytosis were observed in Δckb1 and Δckb2 strains. Consistently, disruption of CgCKB1 and CgCKB2 attenuated the virulence of C. glabrata in mouse models of invasive candidiasis. Furthermore, global transcriptional profiling analysis revealed that CgCkb1 and CgCkb2 participate in cell cycle resumption and genomic stability. CONCLUSIONS: Overall, our findings suggest that the response to DNA damage stress is crucial for C. glabrata to survive in macrophages, leading to full virulence in vivo. The significance of this work lies in providing a better understanding of pathogenicity in C. glabrata-related candidiasis and expanding ideas for clinical therapies.


Assuntos
Candida glabrata , Candidíase , Animais , Camundongos , Candida glabrata/genética , Candida glabrata/metabolismo , Virulência/genética , Fagocitose , Macrófagos
5.
Front Immunol ; 14: 1114770, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37215108

RESUMO

Background: The overall 5-year survival rate of hepatocellular carcinoma (HCC), a major form of liver cancer, is merely 20%, underscoring the need for more effective therapies. We recently identified T cell receptors (TCR) specific for the HLA-A2/alpha fetoprotein amino acids 158-166 (AFP158) and showed that these TCR engineered T cells could control HCC xenografts in NSG mice. However, their efficacy was limited by poor expansion, loss of function, and short persistence of the TCR T cells. Here, we studied whether overexpression of c-Jun, a transcription factor required for T cell activation, in the TCR T cells could enhance their expansion, function, and persistence in HCC tumor models. Methods: Recombinant lentiviral vectors (lv), expressing either the HLA-A2/AFP158-specific TCR or both the TCR and c-Jun (TCR-JUN), were constructed and used to transduce primary human T cells to generate the TCR or TCR-JUN T cells, respectively. We compared the expansion, effector function, and exhaustion status of the TCR and TCR-JUN T cells in vitro after HCC tumor stimulation. Additionally, we studied the persistence and antitumor effects of the TCR and TCR-JUN T cells using the HCC xenografts in NSG mice. Results: We could effectively transduce primary human T cells to express both TCR and c-Jun. Compared to the HLA-A2/AFP158 TCR T cells, the TCR-JUN T cells have better expansion potential in culture, with enhanced functional capacity against HCC tumor cells. In addition, the TCR-JUN T cells were less apoptotic and more resistant to exhaustion after HepG2 tumor stimulation. In the HCC xenograft tumor model, c-Jun overexpression enhanced the TCR T cell expansion and increased the overall survival rate of the treated mice. Importantly, the TCR-JUN T cells were less exhausted in the tumor lesions and demonstrated enhanced tumor infiltration, functionality, and persistence. Conclusion: c-Jun overexpression can enhance the expansion, function, and persistence of the A2/AFP158 TCR engineered T cells. The c-Jun gene co-delivery has the potential to enhance the antitumor efficacy of AFP specific TCR T cells when treating patients with HCC.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Humanos , Camundongos , Animais , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/terapia , Carcinoma Hepatocelular/metabolismo , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/terapia , Neoplasias Hepáticas/metabolismo , alfa-Fetoproteínas/genética , Antígeno HLA-A2/genética , Antígeno HLA-A2/metabolismo , Genes jun , Receptores de Antígenos de Linfócitos T/genética , Linfócitos T
6.
Gut Microbes ; 15(1): 2192478, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36951545

RESUMO

Clostridioides difficile is a pathogen contributing to increased morbidity and mortality of patients with inflammatory bowel disease (IBD). To determine how C. difficile affects the severity of colitis, we constructed a dextran sulfate solution-induced colitis model challenged with C. difficile. Without antibiotic administration, C. difficile led to transient colonization in mice with colitis, but still significantly enhanced disease severity as assessed by weight loss, histopathological damages, and inflammatory cytokine concentrations. Because this effect is independent of toxin production as shown by infection with a non-toxigenic strain, we focused on changes in the gut microbiota. The microbiota altered by C.difficile, featured with reduced proportions of g_Prevotellaceae_UCG-001 and g_Muribaculaceae, were confirmed to contribute to disease severity in colitis mice via fecal microbiota transplantations. The inflamed colon showed neutrophil accumulation by flow cytometric analysis and myeloperoxidase immunochemical staining. There was enrichment of upregulated genes in leukocyte chemotaxis or migration as shown by RNA sequencing analysis. The isolated neutrophils from C. difficile-infected mice with colitis showed a robust migratory ability and had enhanced expression of cytokines and chemokines. We observed a detrimental role of neutrophils in the progress of disease by hindering neutrophil recruitment with the CXCR2 inhibitor SB225002. Furthermore, neutrophil recruitment appeared to be regulated by interleukin (IL)-1ß, as inhibition of IL-1ß production by MCC950 markedly ameliorated inflammation with decreased neutrophil accumulation and neutrophil-derived chemokine expression. In conclusion, our study provides information on the complicated interaction between microbiota and immune responses in C. difficile-induced inflammation in mice with colitis. Our findings could help determine potential therapeutic targets for patients with IBD concurrent with C. difficile infection.


Assuntos
Clostridioides difficile , Colite , Microbioma Gastrointestinal , Doenças Inflamatórias Intestinais , Camundongos , Animais , Clostridioides difficile/metabolismo , Sulfato de Dextrana/toxicidade , Clostridioides/metabolismo , Infiltração de Neutrófilos , Colo/metabolismo , Inflamação/patologia , Citocinas/metabolismo , Doenças Inflamatórias Intestinais/patologia , Modelos Animais de Doenças , Camundongos Endogâmicos C57BL
7.
Crit Care ; 27(1): 127, 2023 03 28.
Artigo em Inglês | MEDLINE | ID: mdl-36978107

RESUMO

BACKGROUND: The gut microbiome plays a pivotal role in the progression of sepsis. However, the specific mechanism of gut microbiota and its metabolites involved in the process of sepsis remains elusive, which limits its translational application. METHOD: In this study, we used a combination of the microbiome and untargeted metabolomics to analyze stool samples from patients with sepsis enrolled at admission, then microbiota, metabolites, and potential signaling pathways that might play important roles in disease outcome were screened out. Finally, the above results were validated by the microbiome and transcriptomics analysis in an animal model of sepsis. RESULTS: Patients with sepsis showed destruction of symbiotic flora and elevated abundance of Enterococcus, which were validated in animal experiments. Additionally, patients with a high burden of Bacteroides, especially B. vulgatus, had higher Acute Physiology and Chronic Health Evaluation II scores and longer stays in the intensive care unit. The intestinal transcriptome in CLP rats illustrated that Enterococcus and Bacteroides had divergent profiles of correlation with differentially expressed genes, indicating distinctly different roles for these bacteria in sepsis. Furthermore, patients with sepsis exhibited disturbances in gut amino acid metabolism compared with healthy controls; namely, tryptophan metabolism was tightly related to an altered microbiota and the severity of sepsis. CONCLUSION: Alterations in microbial and metabolic features in the gut corresponded with the progression of sepsis. Our findings may help to predict the clinical outcome of patients in the early stage of sepsis and provide a translational basis for exploring new therapies.


Assuntos
Microbioma Gastrointestinal , Microbiota , Sepse , Animais , Ratos , Microbioma Gastrointestinal/fisiologia , Metaboloma , Metabolômica , Sepse/microbiologia , RNA Ribossômico 16S/genética
8.
Infect Drug Resist ; 15: 7077-7093, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36483147

RESUMO

Purpose: To explore the diagnostic efficacy and optimal diagnosis threshold of T-SPOT.TB for active tuberculosis in adults and to evaluate the influential factors for T-SPOT.TB results. Patients and Methods: A retrospective study of 1193 adult inpatients from April 2015 to March 2018 in Ruijin Hospital was conducted. All included patients underwent T-SPOT.TB assay, and were divided into two groups, active tuberculosis (ATB) and non-active tuberculosis (non-ATB) groups. Their demographic data, underlying diseases, personal history and laboratory findings were collected to calculate the diagnostic efficacy at different diagnosis thresholds and analyze the impact factors. Symptoms and imaging features of ATB patients were recorded and analyzed. Results: A total of 114 ATB patients and 1079 non-ATB patients were included in the study, and ATB patients had a higher level of T-SPOT.TB than the non-ATB group. Sensitivity and specificity of T-SPOT.TB for diagnosing ATB are 78.95% and 68.58% as the threshold at 6sfu. In the diagnosis accordance curves, ESAT-6, CFP-10, and max (ESAT-6 or CFP-10) reached the plateau at 40sfu, while sum (ESAT-6 and CFP-10) reached the plateau at 70sfu. Multivariate logistic regression analysis showed that obsolescent tuberculosis (p=0.001), smoking history(p=0.005), diabetes(p=0.035) and advanced age (≥65 years old) (p=0.031) were risk factors for false-positive result of T-SPOT.TB. In terms of imaging features, logistic regression analysis suggested that the thin-wall cavitary lesion was the only feature associated with the result of T-SPOT.TB. Conclusion: As for using T-SPOT.TB test to diagnose active tuberculosis, increased threshold could significantly elevate the diagnosis accordance. And we suggest that the threshold of T-SPOT.TB could be increased to 40sfu for diagnosing ATB. Attention should be paid when diagnose ATB in population with obsolescent tuberculosis, smoking history, diabetes and advanced age, for the risk of false-positive.

9.
Transl Res ; 247: 39-57, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35452875

RESUMO

Fungal infection threatens human health worldwide due to the limited arsenal of antifungals and the rapid emergence of resistance. Epidermal growth factor receptor (EGFR) is demonstrated to mediate epithelial cell endocytosis of the leading human fungal pathogen, Candida albicans. However, whether EGFR inhibitors act on fungal cells remains unknown. Here, we discovered that the specific EGFR inhibitor osimertinib mesylate (OSI) potentiates azole efficacy against diverse fungal pathogens and overcomes azole resistance. Mechanistic investigation revealed a conserved activity of OSI by promoting intracellular fluconazole accumulation via inhibiting Pdr5 and disrupting V-ATPase function via targeting Vma1 at serine 274, eventually leading to inactivation of the global regulator TOR. Evaluation of the in vivo efficacy and toxicity of OSI demonstrated its potential clinical application in impeding fluconazole resistance. Thus, the identification of OSI as a dual action antifungal with co-targeting activity proposes a potentially effective therapeutic strategy to treat life-threatening fungal infection and overcome antifungal resistance.


Assuntos
Azóis , Micoses , Antifúngicos/farmacologia , Azóis/farmacologia , Azóis/uso terapêutico , Receptores ErbB , Fluconazol/farmacologia , Humanos , Testes de Sensibilidade Microbiana , Micoses/tratamento farmacológico , Micoses/microbiologia
11.
Hepatology ; 76(2): 330-344, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-34897774

RESUMO

BACKGROUND AND AIMS: Chimeric antigen receptor engineered T cells (CARTs) for HCC and other solid tumors are not as effective as they are for blood cancers. CARTs may lose function inside tumors due to persistent antigen engagement. The aims of this study are to develop low-affinity monoclonal antibodies (mAbs) and low-avidity CARTs for HCC and to test the hypothesis that low-avidity CARTs can resist exhaustion and maintain functions in solid tumors, generating durable antitumor effects. METHODS AND RESULTS: New human glypican-3 (hGPC3) mAbs were developed from immunized mice. We obtained three hGPC3-specific mAbs that stained HCC tumors, but not the adjacent normal liver tissues. One of them, 8F8, bound an epitope close to that of GC33, the frequently used high-affinity mAb, but with approximately 17-fold lower affinity. We then compared the 8F8 CARTs to GC33 CARTs for their in vitro function and in vivo antitumor effects. In vitro, low-avidity 8F8 CARTs killed both hGPC3high and hGPC3low HCC tumor cells to the same extent as high-avidity GC33 CARTs. 8F8 CARTs expanded and persisted to a greater extent than GC33 CARTs, resulting in durable responses against HCC xenografts. Importantly, compared with GC33 CARTs, there were 5-fold more of 8F8-BBz CARTs in the tumor mass for a longer period of time. Remarkably, the tumor-infiltrating 8F8 CARTs were less exhausted and apoptotic, and more functional than GC33 CARTs. CONCLUSION: The low-avidity 8F8-BBz CART resists exhaustion and apoptosis inside tumor lesions, demonstrating a greater therapeutic potential than high-avidity CARTs.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Animais , Anticorpos Monoclonais/farmacologia , Anticorpos Monoclonais/uso terapêutico , Carcinoma Hepatocelular/tratamento farmacológico , Glipicanas , Humanos , Neoplasias Hepáticas/patologia , Camundongos , Ensaios Antitumorais Modelo de Xenoenxerto
12.
Microb Biotechnol ; 15(2): 482-498, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-33955652

RESUMO

Fungal infections have emerged as a major global threat to human health because of the increasing incidence and mortality rates every year. The emergence of drug resistance and limited arsenal of antifungal agents further aggravates the current situation resulting in a growing challenge in medical mycology. Here, we identified that ponatinib, an FDA-approved antitumour drug, significantly enhanced the activity of the azole fluconazole, the most widely used antifungal drug. Further detailed investigation of ponatinib revealed that its combination with fluconazole displayed broad-spectrum synergistic interactions against a variety of human fungal pathogens such as Candida albicans, Saccharomyces cerevisiae and Cryptococcus neoformans. Mechanistic insights into the mode of action unravelled that ponatinib reduced the efflux of fluconazole via Pdr5 and suppressed the expression of the proton pump, Pma1. Taken together, our study identifies ponatinib as a novel antifungal that enhances drug activity of fluconazole against diverse fungal pathogens.


Assuntos
Antineoplásicos , Proteínas de Saccharomyces cerevisiae , Antifúngicos/farmacologia , Antineoplásicos/farmacologia , Candida , Reposicionamento de Medicamentos , Fluconazol/farmacologia , Humanos , Imidazóis , Testes de Sensibilidade Microbiana , Filogenia , ATPases Translocadoras de Prótons , Piridazinas , Saccharomyces cerevisiae/genética
13.
Front Cell Infect Microbiol ; 11: 627917, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33968796

RESUMO

Candida albicans (C. albicans) is an opportunistic human fungal pathogen that can cause severe infection in clinic. Its incidence and mortality rate has been increasing rapidly. Amphotericin B (AMB), the clinical golden standard antifungal agent, has severe side effects that limit its clinical application. Thus, lowering the concentration and increasing the efficacy of AMB in a combinatorial antifungal therapy have been pursued by both industry and academia. Here we identify that fingolimod (FTY720), an immunomodulatory drug used for oral treatment of relapsing-remitting multiple sclerosis, can potentiate the efficacy of AMB against C. albicans growth synergistically. Furthermore, we observe an antifungal efficacy of FTY720 in combination with AMB against diverse fungal pathogens. Intriguingly, cells treated with both drugs are hypersensitive to endothelial endocytosis and macrophage killing. This is later found to be due to the hyperaccumulation of reactive oxygen species and the corresponding increase in activities of superoxide dismutase and catalase in the cells that received combinatorial treatment. Therefore, the combination of AMB and FTY720 provides a promising antifungal strategy.


Assuntos
Anfotericina B , Antifúngicos , Candida albicans , Cloridrato de Fingolimode , Humanos , Testes de Sensibilidade Microbiana
14.
Front Pharmacol ; 12: 638556, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33967773

RESUMO

Background: Coronavirus disease 2019 (COVID-19) pandemic is continuing to impact multiple countries worldwide and effective treatment options are still being developed. In this study, we investigate the potential of high-dose intravenous vitamin C (HDIVC) in the prevention of moderate COVID-19 disease aggravation. Methods: In this retrospective before-after case-matched clinical study, we compare the outcome and clinical courses of patients with moderate COVID-19 patients who were treated with an HDIVC protocol (intravenous injection of vitamin C, 100 mg/kg/day, 1 g/h, for 7 days from admission) during a one-month period (between March 18 and april 18, 2020, HDIVC group) with a control group treated without the HDIVC protocol during the preceding two months (January 18 to March 18, 2020). Patients in the two groups were matched in a 1:1 ratio according to age and gender. Results: The HDIVC and control groups each comprised 55 patients. For the primary outcomes, there was a significant difference in the number of patients that evolved from moderate to severe type between the two groups (HDIVC: 4/55 vs. control: 12/55, relative risk [RR] = 0.28 [0.08, 0.93], P = 0.03). Compared to the control group, there was a shorter duration of systemic inflammatory response syndrome (SIRS) (P = 0.0004) during the first week and lower SIRS occurrence (2/21 vs 10/22, P = 0.0086) on Day 7 (6-7 days after admission). In addition, HDIVC group had lower C-reactive protein levels (P = 0.005) and higher number of CD4+ T cells from Day 0 (on admission) to Day 7 (P = 0.04)." The levels of coagulation indicators, including activated partial thromboplastin time and D-dimer were also improved in the HDIVC compared to the control group on Day 7. Conclusion: HDIVC may be beneficial in limiting disease aggravation in the early stage of COVID-19 pneumonia, which may be related to its improvements on the inflammatory response, immune function and coagulation function. Further randomized controlled trials are required to augment these findings.

15.
Entropy (Basel) ; 23(3)2021 Feb 24.
Artigo em Inglês | MEDLINE | ID: mdl-33668144

RESUMO

In this paper, a fractional-order active disturbance rejection controller (FOADRC), combining a fractional-order proportional derivative (FOPD) controller and an extended state observer (ESO), is proposed for a permanent magnet synchronous motor (PMSM) speed servo system. The global stable region in the parameter (Kp, Kd, µ)-space corresponding to the observer bandwidth ωo can be obtained by D-decomposition method. To achieve a satisfied tracking and anti-load disturbance performance, an optimal ADRC tuning strategy is proposed. This tuning strategy is applicable to both FOADRC and integer-order active disturbance rejection controller (IOADRC). The tuning method not only meets user-specified frequency-domain indicators but also achieves a time-domain performance index. Simulation and experimental results demonstrate that the proposed FOADRC achieves better speed tracking, and more robustness to external disturbance performances than traditional IOADRC and typical Proportional-Integral- Derivative (PID) controller. For example, the JITAE for speed tracking of the designed FOADRC are less than 52.59% and 55.36% of the JITAE of IOADRC and PID controller, respectively. Besides, the JITAE for anti-load disturbance of the designed FOADRC are less than 17.11% and 52.50% of the JITAE of IOADRC and PID controller, respectively.

16.
ISA Trans ; 114: 136-149, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33531140

RESUMO

In this paper, a practical and systematic tuning procedure combining both frequency-domain (FD) and time-domain (TD) specifications is proposed to obtain an optimal robust fractional order (FO) PIλD (FOPIλD) controller for the first order plus time delay (FOPTD) processes. The FD specifications (i.e. phase margin (PM), gain crossover frequency (ωgc) and flat phase constrain (FPC)) guarantee the systemic stability and robustness to plant gain variations. Meanwhile, the TD specification (i.e. the smallest JITAE) achieves optimal dynamic performance. Furthermore, the entire feasible regions of two frequency-domain specifications ωgc and PM have been obtained with a synthesis scheme and visualized in three-dimensional plots which can be used as prior knowledge before the controller design. The comparisons of feasible region with FOPI and integer order PID (IOPID) controllers clearly present the superiority of proposed FOPIλD controller. Simulation illustration for delay dominant systems, lag dominant systems and high order system with one zero, using the proposed optimal robust FOPIλD controller is presented to demonstrate the significant performance improvement over FOPI controller, three-parameter FOPID controller, Ziegler-Nichols FOPID controller, fractional filter-FOPID controller and SIMC-PI controller.

17.
Front Microbiol ; 12: 776892, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34992586

RESUMO

Toxin A-negative, toxin B-positive Clostridioides difficile strains, which primarily include the ST81 and ST37 genotypes, are predominant in C. difficile infections leading to antibiotic-associated diarrhea in China. Recently, ST81 has been reported as the most prevalent genotype rather than ST37, although the genetic and functional characteristics of the two genotypes remain ambiguous. In this study, we conducted comprehensive comparative analysis of these two genotypes through complete genome sequencing and phenotypic profiling. The whole genome sequencing revealed that the ST81 and ST37 isolates were closely related genetically with similar gene compositions, and high rate of the core genome shared. The integrative and conjugative elements identified in ST81 were similar to those in ST37, albeit with more diverse and insertion regions. By characterizing the phenotypes related to colonization or survival in the host, we found that the ST81 isolates exhibited robust colonization ability and survival both in vitro and in vivo, enhanced spore production, and slightly increased motility, which may be attributable to the discrepancy in non-synonymous single-nucleotide polymorphisms in the relevant functional genes. Furthermore, the ST81 isolates displayed a significantly higher rate of resistance to fluoroquinolones compared with the ST37 isolates (94.12% vs. 62.5%) and mostly carried the amino acid substitution Asp426Val in GyrB. In summary, the results of our study indicate that ST81 isolates exhibit enhanced ability to transmit between hosts and survive in harsh environments, providing key genetic insights for further epidemiological investigations and surveillance of C. difficile infection.

18.
Ann Palliat Med ; 10(2): 1599-1609, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33222462

RESUMO

BACKGROUND: Coronavirus disease 2019 (COVID-19) is a global public health event without specific therapeutic agents till now. We aim to determine if high dose intravenous vitamin C (HDIVC) was effective for COVID-19 patients in severe condition. METHODS: COVID-19 patients admitted in Shanghai Public Health Clinical Center from January 22, 2020 to April 11, 2020 were retrospectively scrolled. The enrolled patients were those with confirmed diagnosis of severe or critical COVID-19 pneumonia, who received HDIVC within 24 hours after disease aggravation. Main clinical outcomes obtained from 3-5 days (day 3) and 7-10 days (day 7) after HDIVC were compared to the ones just before (day 0) HDIVC. RESULTS: Totally, twelve patients were enrolled including six severe [age of mean, 56; interquartile range (IQR), 32-65 years, 3 men] and six critical (age of mean, 63; IQR, 60-82 years, 4 men) patients. The dosage of vitamin C [median (IQR), mg/kg (body weight)/day] were [162.7 (71.1-328.6)] for severe and [178.6 (133.3-350.6)] for critical patients. By Generalized estimating equation (GEE) model, C-reactive protein (CRP) was found to decrease significantly from day 0 to 3 and 7 (severe: 59.01±37.9, 12.36±22.12, 8.95±20.4; critical: 92.5±41.21, 33.9±30.2, 59.56±41.4 mg/L). Lymphocyte and CD4+ T cell counts in severe patients reached to normal level since day 3. Similar improving trends were observed for PaO2/FiO2 (severe: 209.3±111.7, 313.4±146, 423.3±140.8; critical: 119.9±52.7, 201.8±86.64, 190.5±51.99) and sequential organ failure assessment score (severe: 2.83±1.72, 1.33±1.63, 0.67±1.03; critical: 6.67±2.34, 4.17±2.32, 3.83±2.56). Better improving effect was observed in severe than critical patients after HDIVC. CONCLUSIONS: HDIVC might be beneficial in aspects of inflammatory response, immune and organ function for aggravation of COVID-19 patients. Further clinical trials are in warrant. TRIAL REGISTRATION: This trial has been retrospectively registered in Chinese Clinical Trail Registry (ChiCTR2000032716) on May 8, 2020. http://www.chictr.org.cn/showproj.aspx?proj=53389.


Assuntos
Ácido Ascórbico/administração & dosagem , Tratamento Farmacológico da COVID-19 , Vitaminas/administração & dosagem , Administração Intravenosa , Adulto , Idoso , Idoso de 80 Anos ou mais , China , Estado Terminal , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos
19.
Cancers (Basel) ; 12(10)2020 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-33053752

RESUMO

Immunocompetent metastatic head and neck cancer (HNC) models, although scarce, can help understanding cancer progression and therapy responses in vivo. Their comprehensive genome characterizations are essential for translational research. We first exome-sequenced the two most widely used spontaneous metastatic immunocompetent models, namely AT-84 and SCC VII, followed by comprehensive genomic analyses with three prior-sequenced models (MOC2, MOC2-10, and 4MOSC2), together with patient tumors for utility assessment. AT-84 and SCC VII bear high HNC tumor resemblance regarding mutational signatures-Trp53, Fanconi anemia, and MAPK and PI3K pathway defects. Collectively, the five models harbor genetic aberrations across 10 cancer hallmarks and 14 signaling pathways and machineries (metabolic, epigenetic, immune evasion), to extents similar in patients. Immune defects in HLA-A (H2-Q10, H2-Q4, H2-Q7, and H2-K1), Pdcd1, Tgfb1, Il2ra, Il12a, Cd40, and Tnfrsf14 are identified. Invasion/metastatic genome analyses first highlight potential druggable ERBB4 and KRAS mutations, for advanced/metastatic oral cavity cancer, as well as known metastasis players (Muc5ac, Trem3, Trp53, and Ttn) frequently captured by all models. Notable immunotherapy and precision druggable targets (Pdcd1, Erbb4, Fgfr1, H/Kras, Jak1, and Map2k2) and three druggable hubs (RTK family, MAPK, and DNA repair pathways) are frequently represented by these models. Immunocompetent metastatic HNC models are worth developing to address therapy- and invasion/metastasis-related questions in host immunity contexts.

20.
Infect Drug Resist ; 13: 2733-2743, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32801807

RESUMO

PURPOSE: Candida tropicalis (C. tropicalis) has emerged as an important fungal pathogen due to its increasing resistance to conventional antifungal agents, especially fluconazole (FLC). Pseudolaric acid B (PAB), a herbal-originated diterpene acid from Pseudolarix kaempferi Gordon, has been reported to possess inhibitory activity against fungus. The present study aims to investigate the antifungal effect of PAB alone and in combination with FLC on planktonic and biofilm cells of C. tropicalis. METHODS: The antifungal activity of PAB against planktonic isolates was evaluated alone and in combination with FLC using the chequerboard microdilution method and growth curve assay. The anti-biofilm effects were quantified by tetrazolium (XTT) reduction assay, which were further confirmed by scanning electron microscopy (SEM) and fluorescent microscope to observe morphological changes of biofilm treated with PAB and FLC. RESULTS: It was revealed that PAB alone exhibited similar inhibitory activity against FLC-resistant and FLC-susceptible strains with median MIC ranging from 8 to 16 µg/mL. When administered in combination, synergism was observed in all (13/13) FLC-resistant and (2/9) FLC-susceptible strains with FICI ranging from 0.070 to 0.375. Moreover, the concomitant use of PAB and FLC exhibited a strong dose-dependent synergistic inhibitory effect on the early and mature biofilm, eliminating more than 80% biofilm formation. SEM found that PAB, different from azoles, could significantly inhibit spore germination and destroy the cell integrity causing cell deformation, swelling, collapse and outer membrane perforation. CONCLUSION: PAB was highly active against FLC-resistant isolates and biofilm of C. tropicalis, particularly when combined with FLC. These findings suggest that PAB may have potential as a novel antifungal agent with different targets from azole drugs.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...