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Patients suffering from chronic fatigue syndrome (CFS) or post-COVID syndrome (PCS) exhibit a reduced physiological performance capability. Impaired mitochondrial function and morphology may play a pivotal role. Thus, we aimed to measure the muscle mitochondrial oxidative phosphorylation (OXPHOS) capacity and assess mitochondrial morphology in CFS and PCS patients in comparison to healthy controls (HCs). Mitochondrial OXPHOS capacity was measured in permeabilized muscle fibers using high-resolution respirometry. Mitochondrial morphology (subsarcolemmal/intermyofibrillar mitochondrial form/cristae/diameter/circumference/area) and content (number and proportion/cell) were assessed via electron microscopy. Analyses included differences in OXPHOS between HC, CFS, and PCS, whereas comparisons in morphology/content were made for CFS vs. PCS. OXPHOS capacity of complex I, which was reduced in PCS compared to HC. While the subsarcolemmal area, volume/cell, diameter, and perimeter were higher in PCS vs. CFS, no difference was observed for these variables in intermyofibrillar mitochondria. Both the intermyofibrillar and subsarcolemmal cristae integrity was higher in PCS compared to CFS. Both CFS and PCS exhibit increased fatigue and impaired mitochondrial function, but the progressed pathological morphological changes in CFS suggest structural changes due to prolonged inactivity or unknown molecular causes. Instead, the significantly lower complex I activity in PCS suggests probably direct virus-induced alterations.
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COVID-19 , Síndrome de Fadiga Crônica , Humanos , Síndrome de Fadiga Crônica/metabolismo , COVID-19/complicações , COVID-19/metabolismo , Mitocôndrias Musculares/metabolismo , Mitocôndrias , Fibras Musculares Esqueléticas/metabolismoRESUMO
The Mediator kinase module regulates eukaryotic transcription by phosphorylating transcription-related targets and by modulating the association of Mediator and RNA polymerase II. The activity of its catalytic core, cyclin-dependent kinase 8 (CDK8), is controlled by Cyclin C and regulatory subunit MED12, with its deregulation contributing to numerous malignancies. Here, we combine in vitro biochemistry, cross-linking coupled to mass spectrometry, and in vivo studies to describe the binding location of the N-terminal segment of MED12 on the CDK8/Cyclin C complex and to gain mechanistic insights into the activation of CDK8 by MED12. Our data demonstrate that the N-terminal portion of MED12 wraps around CDK8, whereby it positions an "activation helix" close to the T-loop of CDK8 for its activation. Intriguingly, mutations in the activation helix that are frequently found in cancers do not diminish the affinity of MED12 for CDK8, yet likely alter the exact positioning of the activation helix. Furthermore, we find the transcriptome-wide gene-expression changes in human cells that result from a mutation in the MED12 activation helix to correlate with deregulated genes in breast and colon cancer. Finally, functional assays in the presence of kinase inhibitors reveal that binding of MED12 remodels the active site of CDK8 and thereby precludes the inhibition of ternary CDK8 complexes by type II kinase inhibitors. Taken together, our results not only allow us to propose a revised model of how CDK8 activity is regulated by MED12, but also offer a path forward in developing small molecules that target CDK8 in its MED12-bound form.
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Quinase 8 Dependente de Ciclina/metabolismo , Complexo Mediador/metabolismo , Domínio Catalítico , Ciclina C/genética , Ciclina C/metabolismo , Quinase 8 Dependente de Ciclina/química , Quinase 8 Dependente de Ciclina/genética , Ativação Enzimática , Humanos , Complexo Mediador/genética , Ligação Proteica , Conformação Proteica em alfa-Hélice , Domínios ProteicosRESUMO
Malignant gliomas are still extremely difficult to treat because complete surgical resection is biologically not feasible due to the invasive nature of these diseases and the proximity of tumors to functionally sensitive areas. Moreover, adjuvant therapies are facing a strong therapeutic resistance since the central nervous system is a highly protected environment and the tumor cells display a vast intra-tumoral genetic and epigenetic variation. As a consequence, new therapeutics are urgently needed but the process of developing novel compounds that finally reach clinical application is highly time-consuming and expensive. Drug repurposing is an approach to facilitate and accelerate the discovery of new cancer treatments. In malignant glioma, like in other cancers, pre-existing physiological pathways that regulate cell growth, cell death or cell migration are dysregulated causing malignant transformation. A wide variety of drugs are clinically used to treat non-cancerous diseases interfering with these malignancy-associated pathways. Repurposed drugs have key advantages: They already have approval for clinical use by national regulatory authorities. Moreover, they are for the most part inexpensive and their side effect and safety profiles are well characterized. In this work, we provide an overview on current repurposing strategies for the treatment of malignant glioma.
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Antineoplásicos/uso terapêutico , Neoplasias Encefálicas/tratamento farmacológico , Descoberta de Drogas , Reposicionamento de Medicamentos/métodos , Glioma/tratamento farmacológico , Animais , HumanosRESUMO
Super-enhancers (SEs), which are composed of large clusters of enhancers densely loaded with the Mediator complex, transcription factors and chromatin regulators, drive high expression of genes implicated in cell identity and disease, such as lineage-controlling transcription factors and oncogenes. BRD4 and CDK7 are positive regulators of SE-mediated transcription. By contrast, negative regulators of SE-associated genes have not been well described. Here we show that the Mediator-associated kinases cyclin-dependent kinase 8 (CDK8) and CDK19 restrain increased activation of key SE-associated genes in acute myeloid leukaemia (AML) cells. We report that the natural product cortistatin A (CA) selectively inhibits Mediator kinases, has anti-leukaemic activity in vitro and in vivo, and disproportionately induces upregulation of SE-associated genes in CA-sensitive AML cell lines but not in CA-insensitive cell lines. In AML cells, CA upregulated SE-associated genes with tumour suppressor and lineage-controlling functions, including the transcription factors CEBPA, IRF8, IRF1 and ETV6 (refs 6-8). The BRD4 inhibitor I-BET151 downregulated these SE-associated genes, yet also has anti-leukaemic activity. Individually increasing or decreasing the expression of these transcription factors suppressed AML cell growth, providing evidence that leukaemia cells are sensitive to the dosage of SE-associated genes. Our results demonstrate that Mediator kinases can negatively regulate SE-associated gene expression in specific cell types, and can be pharmacologically targeted as a therapeutic approach to AML.
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Quinase 8 Dependente de Ciclina/antagonistas & inibidores , Quinases Ciclina-Dependentes/antagonistas & inibidores , Elementos Facilitadores Genéticos/genética , Regulação Neoplásica da Expressão Gênica/genética , Genes Neoplásicos/genética , Leucemia Mieloide Aguda/enzimologia , Leucemia Mieloide Aguda/genética , Animais , Proteínas de Ciclo Celular , Divisão Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Linhagem da Célula/efeitos dos fármacos , Linhagem da Célula/genética , Quinase 8 Dependente de Ciclina/metabolismo , Quinases Ciclina-Dependentes/metabolismo , Progressão da Doença , Regulação para Baixo/efeitos dos fármacos , Regulação para Baixo/genética , Feminino , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Genes Supressores de Tumor/efeitos dos fármacos , Compostos Heterocíclicos de 4 ou mais Anéis/farmacologia , Humanos , Leucemia Mieloide Aguda/tratamento farmacológico , Leucemia Mieloide Aguda/patologia , Masculino , Camundongos , Camundongos Endogâmicos , Camundongos SCID , Proteínas Nucleares/antagonistas & inibidores , Compostos Policíclicos/farmacologia , Fatores de Transcrição/antagonistas & inibidores , Fatores de Transcrição/biossíntese , Fatores de Transcrição/genética , Regulação para Cima/efeitos dos fármacos , Regulação para Cima/genéticaRESUMO
The sulfone dapsone is an old antibiotic used for the treatment of mycobacterial and protozoal infections. We postulated before that dapsone might possess biological activity exceeding its anti-infectious properties and that it could potentially be repurposed for the treatment of glioma. To test this hypothesis, we treated established and primary cultured glioma cells with dapsone or several dapsone analogues which we previously synthesized (D2-D5) and determined effects on proliferation, anchorage-independent growth and migration. While dapsone and its synthetic analogues D2-D5 displayed only modest anti-proliferative activity, important neoplastic features such as anchorage-independent growth, clonogenic survival and directed migration were significantly inhibited by dapsone treatment. Moreover, dapsone analogues D3, D4 and D5 yielded even enhanced anti-glioma activity against different pro-neoplastic features. Overall these data suggest that dapsone provides activity against glioma which can be further enhanced by molecular modifications. These compounds could potentially serve as a therapeutic adjunct to the treatment of gliomas in a repurposing approach.
Assuntos
Antibacterianos/uso terapêutico , Dapsona/química , Dapsona/farmacologia , Glioma/tratamento farmacológico , Humanos , Interleucina-8/metabolismo , Leucotrieno B4/antagonistas & inibidores , Receptores de Formil Peptídeo/efeitos dos fármacosRESUMO
In contrast with the very well explored concept of structure-activity relationship, similar studies are missing for the dependency between binding kinetics and compound structure of a protein ligand complex, the structure-kinetic relationship. Here, we present a structure-kinetic relationship study of the cyclin-dependent kinase 8 (CDK8)/cyclin C (CycC) complex. The scaffold moiety of the compounds is anchored in the kinase deep pocket and extended with diverse functional groups toward the hinge region and the front pocket. These variations can cause the compounds to change from fast to slow binding kinetics, resulting in an improved residence time. The flip of the DFG motif ("DMG" in CDK8) to the inactive DFG-out conformation appears to have relatively little influence on the velocity of binding. Hydrogen bonding with the kinase hinge region contributes to the residence time but has less impact than hydrophobic complementarities within the kinase front pocket.
Assuntos
Ciclina C/química , Quinase 8 Dependente de Ciclina/química , Motivos de Aminoácidos , Domínio Catalítico , Cristalografia por Raios X , Desenho de Fármacos , Humanos , Ligação de Hidrogênio , Cinética , Ligantes , Modelos Moleculares , Ligação Proteica , Conformação Proteica , Sais/química , Temperatura , Fatores de TempoRESUMO
RAF protein kinases are essential effectors in the MAPK pathway and are important cancer drug targets. Structural understanding of RAF activation is so far based on cryo-electron microscopy (cryo-EM) and X-ray structures of BRAF in different conformational states as inactive or active complexes with KRAS, 14-3-3 and MEK1. In this study, we have solved the first cryo-EM structures of CRAF2/14-3-32 at 3.4 Å resolution and CRAF2/14-3-32/MEK12 at 4.2 Å resolution using CRAF kinase domain expressed as constitutively active Y340D/Y341D mutant in insect cells. The overall architecture of our CRAF2/14-3-32 and CRAF2/14-3-32/MEK12 cryo-EM structures is highly similar to corresponding BRAF structures in complex with 14-3-3 or 14-3-3/MEK1 and represent the activated dimeric RAF conformation. Our CRAF cryo-EM structures provide additional insights into structural understanding of the activated CRAF2/14-3-32/MEK12 complex.
Assuntos
Proteínas 14-3-3 , MAP Quinase Quinase 1 , Proteínas Proto-Oncogênicas c-raf , Antineoplásicos/química , Microscopia Crioeletrônica , Proteínas 14-3-3/química , MAP Quinase Quinase 1/química , Proteínas Proto-Oncogênicas c-raf/química , Conformação ProteicaRESUMO
This paper describes a dataset of residential electricity household and heat pump load profiles, measured in 38 single-family houses in Northern Germany. We provide data per household of apparent, active and reactive power (W), voltage (V), current (A) and the power factor (no unit) in 10 seconds to 60 minutes temporal resolution from May 2018 to the end of 2020. We validated the dataset both in itself, comparing different measurements that should produce the same results, and externally to standard load profiles and found no major inconsistencies. We identified an average consumption per single-family house with 2.38 inhabitants of 2829 kWh for the household and an additional 4993 kWh for the heat pump. The dataset can support the understanding of patterns in electrical load curves and can help to estimate the additional load on distribution networks induced by heat pumps.
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Lifestyle interventions can have a positive impact on quality of life and psychological parameters in patients with metabolic syndrome (MetS). In this randomized controlled trial, 145 participants with MetS (62.8% women; 59.7 ± 9.3 years) were randomized to (1) 5-day fasting followed by 10 weeks of lifestyle modification (F + LM; modified DASH diet, exercise, mindfulness; n = 73) or (2) 10 weeks of lifestyle modification only (LM; n = 72). Outcomes were assessed at weeks 0, 1, 12, and 24, and included quality of life (Short-Form 36 Health Survey Questionnaire, SF-36), anxiety/depression (Hospital Anxiety and Depression Scale, HADS), stress (Cohen Perceived Stress Scale, CPSS), mood (Profile of Mood States, POMS), self-efficacy (General Self-Efficacy Scale, GSE), mindfulness (Mindfulness Attention Awareness Scale, MAAS), and self-compassion (Self-Compassion Scale, SCS). At week 1, POMS depression and fatigue scores were significantly lower in F + LM compared to LM. At week 12, most self-report outcomes improved in both groups-only POMS vigor was significantly higher in F + LM than in LM. Most of the beneficial effects within the groups persisted at week 24. Fasting can induce mood-modulating effects in the short term. LM induced several positive effects on quality of life and psychological parameters in patients with MetS.
Assuntos
Síndrome Metabólica , Qualidade de Vida , Depressão/psicologia , Depressão/terapia , Jejum , Feminino , Humanos , Estilo de Vida , Masculino , Síndrome Metabólica/terapia , Medidas de Resultados Relatados pelo Paciente , Qualidade de Vida/psicologiaRESUMO
BACKGROUND: Lifestyle interventions, such as fasting, diet, and exercise, are increasingly used as a treatment option for patients with metabolic syndrome (MS). This study assesses the efficacy and safety of fasting followed by lifestyle modification in patients with MS compared to lifestyle modification only. METHODS: Single-blind, multicenter, parallel, randomized controlled trial in two German tertiary referral hospitals in metropolitan areas. INTERVENTIONS: (a) 5-day fasting followed by 10 weeks of lifestyle modification (modified DASH diet, exercise, mindfulness; n = 73); (b) 10 weeks of lifestyle modification only (n = 72). MAIN OUTCOMES AND MEASURES: Co-primary outcomes were ambulatory systolic blood pressure and the homeostasis model assessment (HOMA) index at week 12. Further outcomes included anthropometric, laboratory parameters, and the PROCAM score at weeks 1, 12, and 24. RESULTS: A total of 145 patients with metabolic syndrome (62.8% women; 59.7 ± 9.3 years) were included. No significant group differences occurred for the co-primary outcomes at week 12. However, compared to lifestyle modification only, fasting significantly reduced HOMA index (Δ = -0.8; 95% confidence interval [CI] = -1.7, -0.1), diastolic blood pressure (Δ = -4.8; 95% CI = -5.5, -4.1), BMI (Δ = -1.7; 95% CI = -2.0, -1.4), weight (Δ = -1.7; 95% CI = -2.0, -1.4), waist circumference (Δ = -2.6; 95% CI = -5.0, -0.2), glucose (Δ = -10.3; 95% CI = -19.0, -1.6), insulin (Δ = -2.9; 95% CI = -5.3, -0.4), HbA1c (Δ = -0.2; 95% CI = -0.4, -0.05;), triglycerides (Δ = -48.9; 95% CI = -81.0, -16.9), IL-6 (Δ = -1.2; 95% CI = -2.5, -0.005), and the 10-year risk of acute coronary events (Δ = -4.9; 95% CI = -9.5, -0.4) after week 1. Fasting increased uric acid levels (Δ = 1.0; 95% CI = 0.1, 1.9) and slightly reduced eGRF (Δ = -11.9; 95% CI = -21.8, -2.0). Group differences at week 24 were found for weight (Δ = -2, 7; 95% CI = -4.8, -0.5), BMI (Δ = -1.0; 95% CI = -1.8, -0.3), glucose (Δ = -7.7; 95% CI = -13.5, -1.8), HDL (Δ = 5.1; 95% CI = 1.5, 8.8), and CRP (Δ = 0.2; 95% CI = 0.03, 0.4). No serious adverse events occurred. CONCLUSIONS: A beneficial effect at week 24 was found on weight; fasting also induced various positive short-term effects in patients with MS. Fasting can thus be considered a treatment for initializing lifestyle modification for this patient group; however, it remains to be investigated whether and how the multilayered effects of fasting can be maintained in the medium and longer term.
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Infiltration of immune cells into adipose tissue plays a central role in the pathophysiology of obesity-associated low-grade inflammation. The aim of this study was to analyze the role of adipocyte NF-κB signaling in the regulation of the chemokine/adipokine interferon-γ-induced protein 10 kDa (IP-10) and adipocyte-mediated T cell migration. Therefore, the regulation of IP-10 was investigated in adipose tissue of male C57BL/6J mice, primary human and 3T3-L1 preadipocytes/adipocytes. To specifically block the NF-κB pathway, 3T3-L1 cells stably overexpressing a transdominant mutant of IκBα were generated, and the chemical NF-κB inhibitor Bay117082 was used. Adipocyte-mediated T cell migration was assessed by a migration assay. It could be shown that IP-10 expression was higher in mature adipocytes compared with preadipocytes. Induced IP-10 expression and secretion were completely blocked by an NF-κB inhibitor in 3T3-L1 and primary human adipocytes. Stable overexpression of a transdominant mutant of IκBα in 3T3-L1 adipocytes led to an inhibition of basal and stimulated IP-10 expression and secretion. T cell migration was induced by 3T3-L1 adipocyte-conditioned medium, and both basal and induced T cell migration was strongly inhibited by stable overexpression of a transdominant IκBα mutant. In addition, with the use of an anti-IP-10 antibody, a significant decrease of adipocyte-induced T cell migration was shown. In conclusion, in this study, we could demonstrate that the NF-κB pathway is essential for the regulation of IP-10 in 3T3-L1 and primary human adipocytes. Adipocytes rather than preadipocytes contribute to NF-κB-dependent IP-10 expression and secretion. Furthermore, NF-κB-dependent factors and especially IP-10 represent novel signals from adipocytes to induce T cell migration.
Assuntos
Adipócitos/metabolismo , Movimento Celular/fisiologia , NF-kappa B/metabolismo , Receptores de Citocinas/biossíntese , Linfócitos T/metabolismo , Linfócitos T/fisiologia , Células 3T3-L1 , Tecido Adiposo/citologia , Tecido Adiposo/fisiologia , Animais , Western Blotting , Células Cultivadas , Ensaio de Desvio de Mobilidade Eletroforética , Ensaio de Imunoadsorção Enzimática , Vetores Genéticos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Receptores CXCR3/biossíntese , Retroviridae/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , TransfecçãoRESUMO
Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is the most common monogenic cause of stroke and vascular dementia. Disease-causing mutations invariably affect cysteine residues within epidermal growth factor-like repeat domains in the extracellular domain of the NOTCH3 receptor (N3(ECD)). The biochemical and histopathological hallmark of CADASIL is the accumulation of N3(ECD) at the cell surface of vascular smooth muscle cells which degenerate over the course of the disease. The molecular mechanisms leading to N3(ECD) accumulation remain unknown. Here we show that both wild-type and CADASIL-mutated N3(ECD) spontaneously form oligomers and higher order multimers in vitro and that multimerization is mediated by disulfide bonds. Using single-molecule analysis techniques ('scanning for intensely fluorescent targets'), we demonstrate that CADASIL-associated mutations significantly enhance multimerization compared with wild-type. Taken together, our results for the first time provide experimental evidence for N3 self-association and strongly argue for a neomorphic effect of CADASIL mutations in disease pathogenesis.
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CADASIL/genética , Mutação , Multimerização Proteica , Receptores Notch/química , Receptores Notch/genética , CADASIL/metabolismo , Linhagem Celular , Humanos , Ligação Proteica , Receptor Notch3 , Receptores Notch/metabolismoRESUMO
The aim of this study was to develop and evaluate an enzyme immunoassay (EIA) for the cephalosporin antibiotic in milk, in combination with a new microbiological test system (brilliant black reduction test, BRT-P). Polyclonal antibodies against cefquinome were produced in rabbits, using cefquinome-keyhole limpet hemocyanine as the immunogen. These antibodies and a cefquinome-glucose oxidase conjugate were used in a competitive indirect EIA. The detection limit for cefquinome in milk was 1.5 ng ml(-1), recoveries were 80-128% at 4-40 ng ml(-1). Cross-reactivities with other cephalosporins/penicillins were all <1%. The EIA was used to determine cefquinome in incurred raw milk, the BRT-P (detection limit ≈ 20 ng ml(-1)) and a receptor assay (ßeta-s.t.a.r., detection limit ≈ 15 ng ml(-1)) were used in parallel. Five lactating cows, suffering from clinical mastitis, were treated with cefquinome by simultaneous intramammary and intramuscular injection. Cefquinome residues (maximum 10-27 µg ml(-1)) were most exclusively found in the udder quarter which was treated intramammary, residue levels in the other three quarters were low (<20 ng ml(-1)). Even in milk from intramammary-dosed quarters, residue levels fell below European Union maximum residue level (MRL, 20 µg kg(-1)) 2 days before the end of the withdrawal period. EIA, BRT-P, and ßeta-s.t.a.r. results showed acceptable agreement for milk samples, but the newly developed EIA is superior in aspects of sensitivity. In conclusion, this is the first one description of immunoassay and microbiological tests capable to determine cefquinome in milk at the MRL in incurred sample material.
Assuntos
Antibacterianos/análise , Cefalosporinas/análise , Glucose Oxidase/metabolismo , Técnicas Imunoenzimáticas/métodos , Mastite Bovina/tratamento farmacológico , Leite/química , Animais , Bovinos , Feminino , Glucose Oxidase/química , Hemocianinas/química , Estrutura Molecular , EstereoisomerismoRESUMO
Bacteriological analysis of milk samples from quarters of a dairy cow suffering from subclinical mastitis yielded two isolates of Staphylococcus aureus which gave a negative reaction in the standard coagulase test. Both isolates were also clumping factor and thermonuclease negative, and gave a negative reaction in the Staphaurex® test. The isolates were identified by using commercial biochemical systems, and by PCR analysis of different staphylococcal cell surface protein and exoprotein genes. Further molecular identification of the isolates, which included sequencing of the 16S rRNA gene and RT-PCR of coagulase (coa), clumping-factor (clfA) and thermonuclease (nuc) genes, was consistent with the diagnosis phenotypically 'coagulase-negative variant of Staph. aureus'. The fact that coagulase-negative Staph. aureus variants can occur in the context of intramammary infections in cattle may result in the incorrect diagnosis 'coagulase-negative staphylococci (CNS)' in routine mastitis diagnostic, at least in rare cases. To fully ensure correct species diagnosis, sequencing of the 16S rRNA gene and amplification of specific genes such as coa is necessary in these cases.
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Coagulase/análise , Mastite Bovina/microbiologia , Leite/microbiologia , Staphylococcus aureus/classificação , Staphylococcus aureus/enzimologia , Animais , Bovinos , Coagulase/genética , DNA Bacteriano/análise , DNA Bacteriano/química , Feminino , Nuclease do Micrococo/análise , Nuclease do Micrococo/genética , RNA Ribossômico 16S/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Análise de Sequência de DNA , Infecções Estafilocócicas/diagnóstico , Infecções Estafilocócicas/microbiologia , Staphylococcus aureus/genéticaRESUMO
BACKGROUND: Epidemiology and risk factors for bacteremia in pediatric and adolescent patients have not been fully elucidated. OBJECTIVE: The purpose of this study was to identify primary causative agents of bacteremia in pediatric and adolescent patients and associated risk factors. We hypothesized that these would be different than those seen in adults. PATIENTS AND METHODS: This retrospective cohort, epidemiologic evaluation included patients admitted to a tertiary referral center from January 01, 2013, to December 31, 2015. Patients <18 years old with a confirmed positive blood culture were included; the first positive culture per organism per patient was analyzed. The primary outcome was to determine the most frequent causative organisms of bacteremia; the secondary outcome was an evaluation of risk factors for acquiring staphylococcal bacteremia. RESULTS: A total of 913 isolates were evaluated, including 92 unique organisms. The most frequently identified were Staphylococcus epidermidis (238/913, 26.1%), followed by Staphylococcus aureus (136/913, 14.9%). Methicillin resistance was observed in 60.3% of S aureus. Two hundred thirty-six patients were included in the risk factor analysis. Prematurity, previous antibiotics, and intubation/ventilation were more likely associated with S epidermidis (P < .001, P < .001, and P = .032, respectively). Patients with a recent or previous hospitalization and those with dermatitis/eczema were statistically more likely to grow S aureus (P < .001, P = .029, respectively). CONCLUSIONS: Although epidemiology of organisms associated with pediatric and adolescent bacteremia was similar to adults, risk factors were different than seen in that population. Further understanding of these risk factors may be helpful in developing preemptive infection control strategies in patients at risk.
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Bacteriemia , Staphylococcus aureus Resistente à Meticilina , Infecções Estafilocócicas , Adolescente , Adulto , Bacteriemia/diagnóstico , Bacteriemia/epidemiologia , Criança , Humanos , Resistência a Meticilina , Estudos Retrospectivos , Fatores de Risco , Infecções Estafilocócicas/diagnóstico , Infecções Estafilocócicas/epidemiologiaRESUMO
Although thousands of breast cancer cells disseminate and home to bone marrow until primary surgery, usually less than a handful will succeed in establishing manifest metastases months to years later. To identify signals that support survival or outgrowth in patients, we profile rare bone marrow-derived disseminated cancer cells (DCCs) long before manifestation of metastasis and identify IL6/PI3K-signaling as candidate pathway for DCC activation. Surprisingly, and similar to mammary epithelial cells, DCCs lack membranous IL6 receptor expression and mechanistic dissection reveals IL6 trans-signaling to regulate a stem-like state of mammary epithelial cells via gp130. Responsiveness to IL6 trans-signals is found to be niche-dependent as bone marrow stromal and endosteal cells down-regulate gp130 in premalignant mammary epithelial cells as opposed to vascular niche cells. PIK3CA activation renders cells independent from IL6 trans-signaling. Consistent with a bottleneck function of microenvironmental DCC control, we find PIK3CA mutations highly associated with late-stage metastatic cells while being extremely rare in early DCCs. Our data suggest that the initial steps of metastasis formation are often not cancer cell-autonomous, but also depend on microenvironmental signals.
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Interleucina-6/metabolismo , Células-Tronco Neoplásicas/metabolismo , Células-Tronco Neoplásicas/patologia , Transdução de Sinais , Medula Óssea/patologia , Mama/citologia , Neoplasias da Mama/patologia , Classe I de Fosfatidilinositol 3-Quinases/genética , Classe I de Fosfatidilinositol 3-Quinases/metabolismo , Receptor gp130 de Citocina/metabolismo , Células Epiteliais/metabolismo , Células Epiteliais/patologia , Feminino , Humanos , Interleucina-6/genética , Mutação , Metástase Neoplásica/genética , Receptores de Interleucina-6/deficiência , Receptores de Interleucina-6/metabolismo , Células Estromais/metabolismo , Microambiente TumoralRESUMO
Goats' milk cheeses (n=181) from the Hessian market (retail shops, weekly markets, farm markets) were quantitatively analysed for Staphylococcus (S.) aureus, and 14 were found positive. From these samples, 64 isolates of S. aureus were characterized biochemically and genetically, including their potential to produce staphylococcal enterotoxins (SE). SE genes sea to selo was studied by PCR and gene expression was evaluated by reverse transcriptase (RT)-PCR. SEA-SEE production in culture was determined by enzyme immunoassay (EIA). One isolate produced SEA, 18 isolates (from 4 samples) produced SEC, while SEB, SED, and SEE were not found. Toxin production was in agreement with PCR and RT-PCR results for the presence and expression, respectively, of the corresponding toxin genes. Trans-SE genes seg, sei, selm, seln, and selo were detected in 14 isolates from 4 cheese samples, exclusively as clusters. These samples were all from small-scale producers which directly or indirectly market their products regionally. No isolate was positive for seh or sej. RT-PCR detected the presence of the corresponding mRNA for all genes except selo, further indicating the possibility that respective proteins indeed have been produced in culture. These results suggest that S. aureus in goats' milk cheese potentially produces SE like proteins, besides SEA and SEC.
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Queijo/microbiologia , Enterotoxinas/genética , Contaminação de Alimentos/análise , Staphylococcus aureus/isolamento & purificação , Animais , Contagem de Colônia Microbiana , Qualidade de Produtos para o Consumidor , DNA Bacteriano/química , DNA Bacteriano/genética , Enterotoxinas/biossíntese , Microbiologia de Alimentos , Cabras , Humanos , Leite/microbiologia , Reação em Cadeia da Polimerase , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Staphylococcus aureus/genética , Staphylococcus aureus/metabolismoRESUMO
The gene encoding the 16S rRNA of Enterobacter (E.) sakazakii (ATCC 29544, plus four strains isolated from powdered infant formula) was studied, and the sequence compared with those of other Enterobacteriaceae in aspects of genetic variability. Sequence differences between E. sakazakii and other Enterobacteriaceae within the hypervariable regions V1, V2, and V3, respectively, were used to develop two PCR methods for E. sakazakii. PCR1 employed a primer pair located in V1/V2, while PCR2 utilized a primer pair located in V1/V3, respectively. The two PCR methods were tested against a set of 57 E. sakazakii and 148 non-E. sakazakii isolates. PCR1 gave an amplicon with a size of 406 bp and resulted in 100% positive results for E. sakazakii, but also detected Citrobacter koseri/amalonaticus and all nine tested Salmonella enterica serovars. In contrast, PCR2 (amplicon size of 952 bp) gave positive results only for E. sakazakii, thus allowing specific identification of this species.
Assuntos
Cronobacter sakazakii/genética , Cronobacter sakazakii/isolamento & purificação , Contaminação de Alimentos/análise , Variação Genética , Reação em Cadeia da Polimerase/métodos , Sequência de Bases , Qualidade de Produtos para o Consumidor , DNA Bacteriano/química , Humanos , Lactente , Fórmulas Infantis , Recém-Nascido , RNA Ribossômico 16S/genética , Homologia de Sequência do Ácido Nucleico , Especificidade da EspécieRESUMO
To determine the occurrence of Salmonella and Shigella in infant formula from Southeast Asia, 74 packages of dehydrated powdered infant follow-on formula (recommended age, > 4 months) from five different manufacturers, four from Indonesia and one from Malaysia, were analyzed. None of the 25-g test portions yielded Salmonella or Shigella. However, further identification of colonies growing on selective media used for Salmonella and Shigella detection revealed the frequent occurrence of several other Enterobacteriaceae species. A total of 35 samples (47%) were positive for Enterobacteriaceae. Ten samples (13.5%) from two Indonesian manufacturers yielded Enterobacter sakazakii. Other Enterobacteriaceae isolated included Pantoea spp. (n = 12), Escherichia hermanii (n = 10), Enterobacter cloacae (n = 8), Klebsiella pneumoniae subsp. pneumoniae (n = 3), Citrobacter spp. (n = 2), Serratia spp. (n = 2), and Escherichia coli (n = 2). To our knowledge, this is the first report to describe the contamination of dehydrated powdered infant formula from Indonesia with E. sakazakii and several other Enterobacteriaceae that could be opportunistic pathogens. Improper preparation and conservation of these products could result in a health risk for infants in Indonesia.
Assuntos
Qualidade de Produtos para o Consumidor , Enterobacteriaceae/isolamento & purificação , Contaminação de Alimentos/análise , Manipulação de Alimentos/métodos , Fórmulas Infantis , Contagem de Colônia Microbiana , Manipulação de Alimentos/normas , Microbiologia de Alimentos , Humanos , Indonésia , Lactente , Malásia , Salmonella/isolamento & purificação , Shigella/isolamento & purificaçãoRESUMO
Beginning with promiscuous COT inhibitors, which were found to inhibit CDK8, a series of 6-aza-benzothiophene containing compounds were developed into potent, selective CDK8 inhibitors. When cocrystallized with CDK8 and cyclin C, these compounds exhibit an unusual binding mode, making a single hydrogen bond to the hinge residue A100, a second to K252, and a key cation-π interaction with R356. Structure-based drug design resulted in tool compounds 13 and 32, which are highly potent, kinase selective, permeable compounds with a free fraction >2% and no measurable efflux. Despite these attractive properties, these compounds exhibit weak antiproliferative activity in the HCT-116 colon cancer cell line. Further examination of the activity of 32 in this cell line revealed that the compound reduced phosphorylation of the known CDK8 substrate STAT1 in a manner identical to a CDK8 knockout clone, illustrating the complex effects of inhibition of CDK8 kinase activity in proliferation in these cells.