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BACKGROUND: Ticks are medically important vectors capable of transmitting a variety of pathogens to and between host species. Although the spectrum of tick-borne RNA viruses has been frequently investigated, the diversity of tick-borne DNA viruses remains largely unknown. METHODS: A total of 1571 ticks were collected from forests and infested animals, and the diversity of the viruses they harbored was profiled using a DNA-specific virome method. The viromic data were phylogenetically analyzed and validated by PCR assays. RESULTS: Although diverse and abundant prokaryotic viruses were identified in the collected ticks, only eukaryotic DNA viruses with single-stranded circular genomes covering the anelloviruses and circular replication-associated (Rep) protein-encoding single-stranded (CRESS) DNA viruses were recovered from ticks. Anelloviruses were detected only in two tick pools, but CRESS DNA viruses were prevalent across these ticks except in one pool of Dermacentor spp. ticks. Phylogenetic analyses revealed that these tick-borne CRESS DNA viruses were related to viruses recovered from animal feces, tissues and even environmental samples, suggesting that their presence may be largely explained by environmental factors rather than by tick species and host blood meals. CONCLUSIONS: Based on the results, tick-borne eukaryotic DNA viruses appear to be much less common than eukaryotic RNA viruses. Investigations involving a wider collection area and more diverse tick species are required to further support this speculation.
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Doenças Transmitidas por Carrapatos , Carrapatos , Vírus , Animais , Carrapatos/genética , Filogenia , Viroma , Vírus/genética , Vírus de DNA/genética , DNA , DNA CircularRESUMO
During the Rituximab era, high dose intravenous methotrexate (HD) and intrathecal methotrexate (IT) are recommended prophylaxis in preventing central nervous system (CNS) relapse of diffuse large B-cell lymphoma (DLBCL) patients. However, the optimal CNS prophylaxis strategies remained uncertain. This meta-analysis research explored the findings of previous studies and highlighted the efficacy of HD and/or IT on CNS prophylaxis of DLBCL patients at intermediate to high risk. Specifically, it aims to answer the following research questions: (1) Is there a difference on CNS relapse rate between HD and IT cohorts? (2) Is there a correlation between CNS prophylaxis and survival? This meta-analysis research performed an in-depth examination of pertinent studies available in PubMed, Embase, and Cochrane databases. The primary endpoints included: CNS relapse rate and 2-year or 3-year survival rate. The findings of the qualified studies were reviewed and analyzed using 5.3 version of the Review Manager software. After thorough analysis of 12 studies involving 5950 DLBCL patients, it was revealed that in comparison with IT alone, HD with or without additional IT (HD ± IT) significantly reduced the risk of CNS relapse (Risk Ratio (RR)= 0.41, 95 % CI (0.24-0.68), P = 0.0007). Besides, the efficacy of HD alone was comparable to HD + IT (RR = 1.08, 95 % CI (0.19-6.32), P = 0.93), which was also considered to be more optimal than IT alone on CNS prophylaxis (RR = 0.39, 95 % CI (0.15-1.06), P = 0.06).Based on these results, IT alone or no-prophylaxis were viewed as a group of inadequate prophylaxis. Comparing to HD ± IT, the 3-year survival rate of inadequate prophylaxis group was lower (RR = 1.17, 95 % CI (1.03-1.32), P = 0.01). The results of this study reveals that in the Rituximab Era, prophylaxis strategies containing HD is better than IT alone or no-prophylaxis on preventing CNS relapse of DLBCL patients with intermediate to high risk.
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Neoplasias do Sistema Nervoso Central , Linfoma Difuso de Grandes Células B , Humanos , Rituximab/uso terapêutico , Metotrexato/uso terapêutico , Neoplasias do Sistema Nervoso Central/tratamento farmacológico , Neoplasias do Sistema Nervoso Central/prevenção & controle , Vincristina/uso terapêutico , Prednisona/uso terapêutico , Ciclofosfamida/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Recidiva Local de Neoplasia/prevenção & controle , Recidiva Local de Neoplasia/tratamento farmacológico , Doxorrubicina , Linfoma Difuso de Grandes Células B/tratamento farmacológico , Linfoma Difuso de Grandes Células B/patologia , Sistema Nervoso CentralRESUMO
In this work, the precipitates in Ti-Mo-V steel were systematically characterized by high-resolution transmission electron microscopy (HRTEM). The thermodynamics and kinetics of precipitates in Ti-Mo and Ti-Mo-V steels were theoretically analyzed, and the effect of vanadium on the precipitation behavior was clarified. The results showed that the precipitation volume fraction of the Ti-Mo-V steel was significantly higher than that of Ti-Mo steel. The randomly dispersed precipitation and interphase precipitation (Ti, Mo, V)C particles coexisted in the Ti-Mo-V steel. When the temperature was higher than 872 °C, the addition of vanadium could increase the driving force for (Ti, Mo, V)C precipitation in austenite, resulting in an increased nucleation rate and shortened incubation period, promoting the (Ti, Mo, V)C precipitation. When the temperature was lower than 872 °C, the driving force for (Ti, Mo, V)C precipitation in austenite was lower than that for (Ti, Mo)C precipitation, and the incubation period of (Ti, Mo, V)C precipitation was increased. Moreover, it was also found that the precipitated-time-temperature curve of (Ti, Mo, V)C precipitated in the ferrite region was "C" shaped, but that of (Ti, Mo)C was "ε" shaped, and the incubation period of (Ti, Mo, V)C was significantly shorter than that of (Ti, Mo)C.
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BACKGROUND: Enhanced recovery after surgery advocates that consuming carbohydrates two hours before anesthesia is beneficial to the patient's recovery. Patients with diabetes are prone to delayed gastric emptying. Different guidelines for preoperative carbohydrate consumption in patients with diabetes remain controversial due to concerns about the risk of regurgitation, aspiration and hyperglycemia. Ultrasonic gastric volume (GV) assessment and blood glucose monitoring can comprehensively evaluate the safety and feasibility of preoperative carbohydrate intake in type 2 diabetes (T2D) patients. AIM: To evaluate the impact of preoperative carbohydrate loading on GV before anesthesia induction in T2D patients. METHODS: Patients with T2D receiving surgery under general anesthesia from December 2019 to December 2020 were included. A total of 78 patients were randomly allocated to 4 groups receiving 0, 100, 200, or 300 mL of carbohydrate loading 2 h before anesthesia induction. Gastric volume per unit weight (GV/W), Perlas grade, changes in blood glucose level, and risk of reflux and aspiration were evaluated before anesthesia induction. RESULTS: No significant difference was found in GV/W among the groups before anesthesia induction (P > 0.05). The number of patients with Perlas grade II and GV/W > 1.5 mL/kg did not differ among the groups (P > 0.05). Blood glucose level increased by > 2 mmol/L in patients receiving 300 mL carbohydrate drink, which was significantly higher than that in groups 1 and 2 (P < 0.05). CONCLUSION: Preoperative carbohydrate loading < 300 mL 2 h before induction of anesthesia in patients with T2D did not affect GV or increase the risk of reflux and aspiration. Blood glucose levels did not change significantly with preoperative carbohydrate loading of < 200 mL. However, 300 mL carbohydrate loading may increase blood glucose levels in patients with T2D before induction of anesthesia.
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Multidrug-resistant pulmonary tuberculosis (MDR-TB) is a major health problem worldwide. The treatment for MDR-TB requires medications for a long duration (up to 20-24 months) with second-line drugs resulting in unfavorable outcomes. Nitroimidazoles are promising antimycobacterial agents known to inhibit both aerobic and anaerobic mycobacterial activity. Delamanid and pretomanid are two nitroimidazoles approved by the regulatory agencies for MDR-TB treatment. However, both agents possess unsatisfactory absorption and QTc prolongation. In our search for a safer nitroimidazole, we discovered JBD0131 (2). It exhibited excellent anti-mycobacterial activity against M. tuberculosis H37Rv in vitro and in vivo, improved PK and absorption, reduced QT prolongation potential of delamanid. JBD0131 is currently in clinical development in China for pulmonary tuberculosis (CTR20202308).
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Mycobacterium tuberculosis , Nitroimidazóis , Tuberculose Resistente a Múltiplos Medicamentos , Tuberculose Pulmonar , Antituberculosos/farmacologia , Antituberculosos/uso terapêutico , Humanos , Nitroimidazóis/farmacologia , Nitroimidazóis/uso terapêutico , Oxazóis/farmacologia , Oxazóis/uso terapêutico , Tuberculose Resistente a Múltiplos Medicamentos/tratamento farmacológico , Tuberculose Pulmonar/tratamento farmacológico , Tuberculose Pulmonar/microbiologiaRESUMO
Background: Propofol (PPF) has been shown in studies to cause cognitive impairment and neuronal cell death in developing animals. PPF has been demonstrated to decrease the expression of microRNA-17-5p (miR-17-5p) in a recent study. Nonetheless, the function of miR-17-5p in PPF-induced neurotoxicity and related mechanisms is uncharacterized. Methods: After the induction of neurotoxicity by treating the SH-SY5Y cells with PPF, qRT-PCR was conducted to evaluate the level of miR-17-5p. Using MTT and flow cytometry, cell viability and apoptosis rate were assessed, respectively. Interaction between miR-17-5p and BCL2 like 11 was (BCL2L11) studied using a Luciferase reporter assay. With the help of western blot analysis, we determined the level of proteins of apoptosis-related genes and autophagy-related markers. Results: In SH-SY5Y cells, PPF treatment induced neurotoxicity and downregulated miR-17-5p expression. In SH-SY5Y cells post-PPF exposure, overexpression of miR-17-5p increased cell viability and decreased apoptosis. Consistently, miR-17-5p mimics mitigated PPF-generated autophagy via inhibition of Atg5, Beclin1, and LC3II/I level and elevation of p62 protein expression. In addition, BCL2L11, which was highly expressed in PPF-treated SH-SY5Y cells, was directly targeted by miR-17-5p. Further, in PPF-treated SH-SY5Y cells, overexpressed BCL2L11 counteracted the suppressing behavior of miR-17-5p elevation on PPF-induced apoptosis. Conclusion: Overexpressed miR-17-5p alleviates PPF exposure-induced neurotoxicity and autophagy in SH-SY5Y cells via binding to BCL2L11, suggesting the possibility that miR-17-5p can serve as a candidate in the treatment of neurotoxicity (caused by PPF).
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Anestesia , Proteína 11 Semelhante a Bcl-2 , MicroRNAs , Neuroblastoma , Propofol , Apoptose/genética , Autofagia/genética , Proteína 11 Semelhante a Bcl-2/genética , Linhagem Celular Tumoral , Humanos , MicroRNAs/genética , Propofol/farmacologiaRESUMO
In this study, we comparatively study the microstructures and mechanical properties of prequenching-quenching and partitioning (QQ&P) and traditional Q&P samples at different annealing temperatures (intercritical annealing temperatures). When the annealing temperature is 780 °C, the ferrite and retained austenite in QQ&P samples with lath and blocky morphologies. The lath retained austenite is mainly distributed along the lath ferrite. As the annealing temperature increases, the lath ferrite recrystallizes and gradually grows into the blocky (equiaxed) shape, leading to a decrease in the lath retained austenite content. When the annealing temperature increases to 870 °C, the ferrite content decreases significantly, and the retained austenite is mainly blocky and thin film, distributed at the boundaries of prior austenite grains and between martensite laths, respectively. Different from QQ&P samples, the ferrite and retained austenite in Q&P samples are mainly blocky when the annealing temperature is 780 °C or 810 °C. When the annealing temperature is increased to 870 °C, the microstructures of the Q&P sample are basically the same as that of the QQ&P sample. The 780 °C-QQ&P sample and the 810 °C-QQ&P sample have higher total elongation and product of strength and elongations (PSEs) than their counterpart Q&P samples due to the fact that lath ferrite and retained austenite are conducive to carbon diffusion and carbon homogenization in austenite grains, thereby improving the thermal stability and volume fraction of the retained austenite. In addition, the lath structures can release local stress concentration and delay the formation of voids and microcracks. The difference of mechanical properties between QQ&P samples and Q&P samples decreases with the increase in the annealing temperature. The results show that the low annealing temperature combined with prequenching-Q&P heat treatments can significantly improve the elongation and PSE of Q&P steel.
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Multidrug resistant tuberculosis (MDR-TB) remains a major human health challenge. Bedaquiline was approved in 2012 by the US FDA, and listed by WHO as a treatment for multidrug-resistant tuberculosis (MDR-TB) in 2018. However, the side effects of bedaquiline including the risk of unexplained mortality, QTc prolongation and hepatotoxicity limit its wide clinical use. Based on bedaquiline, we describe herein discovery and development of a novel diarylpyridine series, which led to identification of WX-081 (sudapyridine, 21l). It displayed excellent anti-mycobacterial activity against M. tuberculosis H37Rv in vitro and in vivo and low cytotoxicity; additionally WX-081 had excellent pharmacokinetic parameters in animals, better lung exposure and lower QTc prolongation potential compared to bedaquiline. WX-081 is currently under clinical phase II development (NCT04608955).
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Síndrome do QT Longo , Mycobacterium tuberculosis , Tuberculose Resistente a Múltiplos Medicamentos , Animais , Antituberculosos/farmacologia , Antituberculosos/uso terapêutico , Síndrome do QT Longo/induzido quimicamente , Síndrome do QT Longo/tratamento farmacológico , Tuberculose Resistente a Múltiplos Medicamentos/tratamento farmacológicoRESUMO
The present study aimed to characterize the effect of microRNA (miR)-367-3p on sevoflurane anesthesia and elucidate the underlying mechanism. A total of 36 4-month-old adult Sprague-Dawley rats were divided into six groups. Sevoflurane was inhaled at concentrations of 0, 1, 2, 4, 8 and 16% for a total of 6 h; the hippocampus of the brain was subsequently minced and digested, and astrocytes were isolated. Various methods, including reverse transcription-quantitative (RT-q)PCR, western blotting and TUNEL staining, were used to determine the expression levels of Bax, BCL-2 and BCL-2-like protein 11 (BCL2L11), as well as the level of apoptosis. The rats were treated with 8% sevoflurane and the astrocytes from the rats were transfected with miR-367-3p or anti-miR-367-3p. The present study demonstrated that sevoflurane promoted astrocytes apoptosis. Western blotting revealed that with an increase of sevoflurane concentration, the expression levels of the apoptotic proteins Bax and BCL2L11 were significantly increased, whereas the protein expression levels of BCL-2 were significantly decreased. However, overexpression of miR-367-3p reversed these effects. TUNEL staining revealed that sevoflurane promoted the apoptosis of astrocytes, while apoptosis was reversed by miR-367-3p overexpression. RT-qPCR demonstrated that sevoflurane inhibited the expression of miR-367-3p. Notably, miR-367-3p reduced the expression of BCL2L11, thereby inhibiting the apoptosis of astrocytes originating from the hippocampal area of adult rats induced by sevoflurane. Therefore, miR-367-3p and BCL2L11 may act as effective targets for the study of anesthesia.
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Dexmedetomidine, a potent α2-adrenoceptor (α2-AR) agonist, is extensively used in the operating room (OR) and intensive care unit (ICU) and has been applied for the treatment of several diseases. Western blotting has been routinely used to investigate the protein levels of α-adrenergic receptor (α-AR), apoptosis related proteins (Bcl-2, Bax and Cleaved Caspase 3) and a range of proteins associated with the Nrf2/ARE pathway (Nrf2, HO-1, NQO-1, SOD) in neurons. The CCK-8 assay was used to determine cell survival rates while the Co-IP assay was used to investigate the binding ability between α2-AR and Nrf2. The TUNEL assay was used to detect cell apoptosis in neurons. OGD/R treatment reduced the level of α2-AR protein in neurons and reduced neuronal survival in a time-dependent manner. However, treatment with dexmedetomidine led to the increased protein expression of α2-AR in OGD/R-treated neurons and enhanced survival rate of OGD/R-treated neurons. From a mechanistic point-of-view, Nrf2 can effectively bind with α2-AR. Silencing Nrf2 reversed the effects of dexmedetomidine on cell viability, oxidative stress, and neuronal apoptosis in OGD/R-treated neurons. The activation of α2-AR by dexmedetomidine had a protective effect in neurons against OGD/R-triggered oxidative stress and neuronal apoptosis by modulating the Nrf2/ARE pathway.
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Estresse Oxidativo , Apoptose , Dexmedetomidina/farmacologia , Glucose , Fator 2 Relacionado a NF-E2/genética , Fator 2 Relacionado a NF-E2/metabolismo , Neurônios/metabolismo , Transdução de SinaisRESUMO
Staphylococcus aureus (S. aureus) infections are a leading cause of death by an infectious agent. Survival within host phagocytic cells is one mechanism by which S. aureus evades antibiotic treatment. A novel THIOMAB™ antibody-antibiotic conjugate (TAC) strategy was developed to kill S. aureus intracellularly and mitigate the spread of infection. In this report, we used a longitudinal whole-body bioluminescence imaging method to study the antibacterial dynamics of TAC alone or in combination with vancomycin in a mouse infection model. Injections of stably luminescent S. aureus bacteria into mice resulted in exponential increases in whole body bioluminescence with a reduction in body weight and survival rate. Vancomycin, a standard-of-care antibiotic, suppressed bacterial growth in mice. However, bacterial growth rebounded in these animals once treatment was discontinued. In contrast, single dose of TAC showed rapid reduction of bioluminescence intensity, which persisted for up to 19 days. The combination of TAC and vancomycin achieved a more sustained and significantly greater reduction of bioluminescence compared with vancomycin alone. In summary, the present study showed an imaging method to longitudinally assess antibacterial drug dynamics in mice and demonstrated that TAC monotherapy or in combination with vancomycin had superior and sustained activity compared to vancomycin alone.
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Antibacterianos/farmacologia , Anticorpos Antibacterianos/farmacologia , Anticorpos Monoclonais/farmacologia , Modelos Animais de Doenças , Imunoconjugados/farmacologia , Infecções Estafilocócicas/tratamento farmacológico , Staphylococcus aureus/efeitos dos fármacos , Animais , Antibacterianos/química , Anticorpos Antibacterianos/química , Anticorpos Monoclonais/química , Feminino , Camundongos , Camundongos SCID , Testes de Sensibilidade Microbiana , Infecções Estafilocócicas/microbiologia , Vancomicina/farmacologiaRESUMO
A novel peroxisome proliferator-activated receptor (PPAR) α/δ dual agonist 5c was developed with an EC50 of 8 nM for PPARα, 5 nM for PPARδ, and >300-fold selectivity against PPARγ (EC50 = 2939 nM), respectively. Further ADME and pharmacokinetic studies indicated 5c possessed distinguished in vitro and in vivo profiles. The excellent in vivo efficacy of compound 5c was demonstrated by the rat primary biliary cirrhosis (PBC) model.
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BACKGROUND: To assess the effect of dexmedetomidine added to ropivaccaine on the onset and duration of sensory block, as well as postoperative analgesia during caudal anesthesia in patients undergoing hemorrhoidectomy. METHODS: Fifty adult patients scheduled for hemorrhoidectomy were divided into 2 groups. The group R received caudal anesthesia using 18 mL 0.3% ropivacaine plus 2 mL normal saline. The group RD received 18 mL 0.3% ropivacaine plus 2 mL 1âµg/kg dexmedetomidine. Heart rate, mean blood pressure, onset time and duration of sensory block, and duration of analgesia were observed. RESULTS: The onset time of sensory block was shortened (9.2â±â1.3 vs 7.2â±â1.2), and the duration of sensory block (3.0â±â0.7 vs 3.8â±â0.8) and duration of analgesia (3.9â±â0.7 vs 5.3â±â0.8) were prolonged in group RD compared with group R (Pâ<â.05). The heart rate and the mean blood pressure were also lower in the group RD compared with group R at each observation time points, except the baseline (Pâ<â.05). No bradycardia or hypotension was reported. CONCLUSION: Dexmedetomidine as an adjuvant to ropivacaine prolonged the duration of caudal block and improved postoperative analgesia without significant side effects in adult patients undergoing hemorrhoidectomy.
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Amidas/administração & dosagem , Analgésicos não Narcóticos/administração & dosagem , Anestésicos Locais/administração & dosagem , Dexmedetomidina/administração & dosagem , Dor Pós-Operatória/prevenção & controle , Adulto , Anestesia Caudal , Quimioterapia Combinada , Feminino , Hemorroidectomia , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Ropivacaina , Resultado do TratamentoRESUMO
A series of caspase inhibitors containing γ-amino acid moiety have been synthesized. A systemic study on their structure-activity relationship of anti-apoptotic cellular activity is presented. These efforts led to the discovery of compound 20o as a potent caspase inhibitor, which demonstrated preclinical ameliorating total bilirubin efficacy with a significantly improved pharmacokinetic profile.
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Aminoácidos/química , Inibidores de Caspase/química , Animais , Bilirrubina/sangue , Sítios de Ligação , Caspase 1/química , Caspase 1/metabolismo , Inibidores de Caspase/farmacocinética , Inibidores de Caspase/uso terapêutico , Modelos Animais de Doenças , Meia-Vida , Humanos , Células Jurkat , Hepatopatias/tratamento farmacológico , Hepatopatias/patologia , Camundongos , Simulação de Acoplamento Molecular , Estrutura Terciária de Proteína , Relação Estrutura-Atividade , Receptor fas/antagonistas & inibidores , Receptor fas/metabolismoRESUMO
Farnesoid X receptor (FXR) has become a particularly attractive target for the discovery of drugs for the treatment of liver and metabolic diseases. Obeticholic acid (INT-747), a FXR agonist, has advanced into clinical phase III trials in patients with nonalcoholic steatohepatitis (NASH), but adverse effects (e.g., pruritus, LDL increase) were observed. Pruritus might be induced by Takeda G-protein-coupled receptor 5 (TGR5, GPBAR1), and there are chances to develop FXR agonists with higher selectivity over TGR5. In this letter, novel bile acids bearing different modifications on ring A and side chain of INT-747 are reported and discussed. Our results indicated that the side chain of INT-747 is amenable to a variety of chemical modifications with good FXR potency in vitro. Especially, compound 18 not only showed promising FXR potency and excellent pharmacokinetic properties, but also proved superior pharmacological efficacy in the HFD + CCl4 model.
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Enterovirus 71 (EV71) is a major causative agent of hand, foot, and mouth disease (HFMD), which can spread its infections to the central nervous and other systems with severe consequences. The viral caspid protein VP1 is a well-known target for antiviral efficacy because its occupancy by suitable compounds could stabilize the virus capsid, thus preventing uncoating of virus for RNA release. In this Letter, design, synthesis, and biological evaluation of novel anti-EV71 agents (aminopyridyl 1,2,5-thiadiazolidine 1,1-dioxides) are described. One of the most promising compounds (14) showed excellent antiviral activity against EV71 (EC50 = 4 nM) and exhibited excellent in vivo efficacy in the EV71 infected mouse model.
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In 2013, the Centers for Disease Control highlighted Clostridium difficile as an urgent threat for antibiotic-resistant infections, in part due to the emergence of highly virulent fluoroquinolone-resistant strains. Limited therapeutic options currently exist, many of which result in disease relapse. We sought to identify molecules specifically targeting C. difficile in high-throughput screens of our diversity-oriented synthesis compound collection. We identified two scaffolds with apparently novel mechanisms of action that selectively target C. difficile while having little to no activity against other intestinal anaerobes; preliminary evidence suggests that compounds from one of these scaffolds target the glutamate racemase. In vivo efficacy data suggest that both compound series may provide lead optimization candidates.
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Isomerases de Aminoácido/antagonistas & inibidores , Antibacterianos/farmacologia , Proteínas de Bactérias/antagonistas & inibidores , Clostridioides difficile/efeitos dos fármacos , Enterocolite Pseudomembranosa/tratamento farmacológico , Compostos Heterocíclicos com 2 Anéis/farmacologia , Compostos de Fenilureia/farmacologia , Pirróis/farmacologia , Quinolinas/farmacologia , Isomerases de Aminoácido/genética , Isomerases de Aminoácido/metabolismo , Animais , Antibacterianos/síntese química , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Clostridioides difficile/enzimologia , Clostridioides difficile/genética , Clostridioides difficile/crescimento & desenvolvimento , Desenho de Fármacos , Enterocolite Pseudomembranosa/microbiologia , Enterocolite Pseudomembranosa/mortalidade , Enterocolite Pseudomembranosa/patologia , Feminino , Expressão Gênica , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Negativas/crescimento & desenvolvimento , Bactérias Gram-Positivas/efeitos dos fármacos , Bactérias Gram-Positivas/crescimento & desenvolvimento , Compostos Heterocíclicos com 2 Anéis/síntese química , Camundongos , Camundongos Endogâmicos C57BL , Testes de Sensibilidade Microbiana , Compostos de Fenilureia/síntese química , Pirróis/síntese química , Quinolinas/síntese química , Especificidade da Espécie , Relação Estrutura-Atividade , Análise de SobrevidaRESUMO
The Candida albicans fitness test is a whole cell screening platform that utilizes a mixed-pool of C. albicans mutants, each of which carries a heterozygous deletion of a particular gene. In the presence of an antifungal inhibitor, a subset of these mutants exhibits a growth phenotype of hypersensitivity or hyposensitivity. Collectively these mutants reflect aspects of the mechanism of action of the compound in question. In the course of screening natural products a culture of Streptomyces sp. MS-1-4 was discovered to produce a compound, dretamycin, which yielded a fitness profile exhibiting significant hypersensitivity of the DRE2 heterozygote and hyposensitivity of the DIP5 heterozygote. Herein we report the production, isolation, and structure elucidation of dretamycin.
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Antifúngicos/isolamento & purificação , Produtos Biológicos/isolamento & purificação , Proteínas Fúngicas/metabolismo , Proteínas Ferro-Enxofre/metabolismo , Pirróis/isolamento & purificação , Streptomyces/química , Antifúngicos/química , Antifúngicos/farmacologia , Produtos Biológicos/química , Produtos Biológicos/farmacologia , Candida albicans/efeitos dos fármacos , Proteínas Fúngicas/genética , Proteínas Ferro-Enxofre/genética , Testes de Sensibilidade Microbiana , Estrutura Molecular , Pirróis/química , Pirróis/farmacologiaRESUMO
BACKGROUND: Primary cardiac sarcomas are rare diseases with a poor prognosis. This study aims to provide a prognostic analysis after different levels of resections of cardiac sarcomas. METHODS: Twenty-nine patients undergoing resections of primary cardiac sarcomas at the Zhongshan Hospital from September 1995 to July 2012 were retrospectively reviewed. RESULTS: There were 15 women and 14 men. The mean age was 41.0 years. The most common histologic type was angiosarcoma (28%). The median survival for the entire cohort was 17 months (range, 5 to 216 months). Patients with microscopically negative margin (R0) resections had a better median survival than those with microscopically positive margin (R1) resections (58 months versus 11 months; p<0.001). The median survival after an R1 resection was not different from that after a partial resection (12 months; p=0.81). The median local recurrence-free survival after an R0 resection was longer than that after an R1 resection (36 months versus 6 months; p<0.001). Five patients who underwent R0 resections and repeated resections of local recurrences or metastases had the longest median survival of 72 months. None of the patients with R0 resections received adjuvant therapy. Multimodality treatment after R1 and partial resections slightly increased the survival. CONCLUSIONS: For nonmetastatic and localized primary cardiac sarcoma, an R0 surgical resection of cardiac sarcomas should be performed. Aggressive surgical treatment or radiation therapy for local recurrence or metastasis prolongs the survival. Multimodality treatment is recommended after incomplete resections of cardiac sarcomas. The role of adjuvant chemotherapy after R0 resections is unclear.
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Neoplasias Cardíacas/mortalidade , Neoplasias Cardíacas/terapia , Sarcoma/mortalidade , Sarcoma/terapia , Adulto , Feminino , Humanos , Masculino , Prognóstico , Estudos Retrospectivos , Taxa de SobrevidaRESUMO
Phaeofungin (1), a new cyclic depsipeptide isolated from Phaeosphaeria sp., was discovered by application of reverse genetics technology, using the Candida albicans fitness test (CaFT). Phaeofungin is comprised of seven amino acids and a ß,γ-dihydroxy-γ-methylhexadecanoic acid arranged in a 25-membered cyclic depsipeptide. Five of the amino acids were assigned with d-configurations. The structure was elucidated by 2D-NMR and HRMS-MS analysis of the natural product and its hydrolyzed linear peptide. The absolute configuration of the amino acids was determined by Marfey's method by complete and partial hydrolysis of 1. The CaFT profile of the phaeofungin-containing extract overlapped with that of phomafungin (3), another structurally different cyclic lipodepsipeptide isolated from a Phoma sp. using the same approach. Comparative biological characterization further demonstrated that these two fungal lipodepsipeptides are functionally distinct. While phomafungin was potentiated by cyclosporin A (an inhibitor of the calcineurin pathway), phaeofungin was synergized with aureobasidin A (2) (an inhibitor of the sphingolipid biosynthesis) and to some extent caspofungin (an inhibitor of glucan synthase). Furthermore, phaeofungin caused ATP release in wild-type C. albicans strains but phomafungin did not. It showed modest antifungal activity against C. albicans (MIC 16-32 µg/mL) and better activity against Aspergillus fumigatus (MIC 8-16 µg/mL) and Trichophyton mentagrophytes (MIC 4 µg/mL). The linear peptide was inactive, suggesting that the macrocyclic depsipeptide ring is essential for target engagement and antifungal activity.