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DNA polymerases are important drug targets, and many structural studies have captured them in distinct conformations. However, a detailed understanding of the impact of polymerase conformational dynamics on drug resistance is lacking. We determined cryoelectron microscopy (cryo-EM) structures of DNA-bound herpes simplex virus polymerase holoenzyme in multiple conformations and interacting with antivirals in clinical use. These structures reveal how the catalytic subunit Pol and the processivity factor UL42 bind DNA to promote processive DNA synthesis. Unexpectedly, in the absence of an incoming nucleotide, we observed Pol in multiple conformations with the closed state sampled by the fingers domain. Drug-bound structures reveal how antivirals may selectively bind enzymes that more readily adopt the closed conformation. Molecular dynamics simulations and the cryo-EM structure of a drug-resistant mutant indicate that some resistance mutations modulate conformational dynamics rather than directly impacting drug binding, thus clarifying mechanisms that drive drug selectivity.
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Many individuals mount nearly identical antibody responses to SARS-CoV-2. To gain insight into how the viral spike (S) protein receptor-binding domain (RBD) might evolve in response to common antibody responses, we studied mutations occurring during virus evolution in a persistently infected immunocompromised individual. We use antibody Fab/RBD structures to predict, and pseudotypes to confirm, that mutations found in late-stage evolved S variants confer resistance to a common class of SARS-CoV-2 neutralizing antibodies we isolated from a healthy COVID-19 convalescent donor. Resistance extends to the polyclonal serum immunoglobulins of four out of four healthy convalescent donors we tested and to monoclonal antibodies in clinical use. We further show that affinity maturation is unimportant for wild-type virus neutralization but is critical to neutralization breadth. Because the mutations we studied foreshadowed emerging variants that are now circulating across the globe, our results have implications to the long-term efficacy of S-directed countermeasures.
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Anticorpos Antivirais/imunologia , COVID-19 , Evolução Molecular , Evasão da Resposta Imune/imunologia , Hospedeiro Imunocomprometido , Fragmentos Fab das Imunoglobulinas/imunologia , SARS-CoV-2 , Glicoproteína da Espícula de Coronavírus , Anticorpos Neutralizantes , COVID-19/genética , COVID-19/imunologia , Feminino , Células HEK293 , Humanos , Masculino , Domínios Proteicos , SARS-CoV-2/genética , SARS-CoV-2/imunologia , Glicoproteína da Espícula de Coronavírus/genética , Glicoproteína da Espícula de Coronavírus/imunologiaRESUMO
Respiratory syncytial virus (RSV) and human metapneumovirus (HMPV) cause severe respiratory diseases in infants and elderly adults1. No vaccine or effective antiviral therapy currently exists to control RSV or HMPV infections. During viral genome replication and transcription, the tetrameric phosphoprotein P serves as a crucial adaptor between the ribonucleoprotein template and the L protein, which has RNA-dependent RNA polymerase (RdRp), GDP polyribonucleotidyltransferase and cap-specific methyltransferase activities2,3. How P interacts with L and mediates the association with the free form of N and with the ribonucleoprotein is not clear for HMPV or other major human pathogens, including the viruses that cause measles, Ebola and rabies. Here we report a cryo-electron microscopy reconstruction that shows the ring-shaped structure of the polymerase and capping domains of HMPV-L bound to a tetramer of P. The connector and methyltransferase domains of L are mobile with respect to the core. The putative priming loop that is important for the initiation of RNA synthesis is fully retracted, which leaves space in the active-site cavity for RNA elongation. P interacts extensively with the N-terminal region of L, burying more than 4,016 Å2 of the molecular surface area in the interface. Two of the four helices that form the coiled-coil tetramerization domain of P, and long C-terminal extensions projecting from these two helices, wrap around the L protein in a manner similar to tentacles. The structural versatility of the four P protomers-which are largely disordered in their free state-demonstrates an example of a 'folding-upon-partner-binding' mechanism for carrying out P adaptor functions. The structure shows that P has the potential to modulate multiple functions of L and these results should accelerate the design of specific antiviral drugs.
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Metapneumovirus/enzimologia , Fosfoproteínas/química , RNA Polimerase Dependente de RNA/química , Sequência de Aminoácidos , Animais , Linhagem Celular , Microscopia Crioeletrônica , Metapneumovirus/genética , Modelos Moleculares , Fosfoproteínas/metabolismo , Ligação Proteica , Estrutura Quaternária de Proteína , RNA Polimerase Dependente de RNA/genética , RNA Polimerase Dependente de RNA/metabolismoRESUMO
OBJECTIVES: Potential reverse causality and unmeasured confounding factors are common biases in most neuroimaging studies on tinnitus and central correlates. The causal association of tinnitus with neuroimaging features also remains unclear. This study aimed to investigate the causal relationship of tinnitus with neuroplastic alterations using Mendelian randomization. DESIGN: Summary-level data from a genome-wide association study of tinnitus were derived from UK Biobank (n = 117,882). The genome-wide association study summary statistics for 4 global-brain tissue and 14 sub-brain gray matter volumetric traits were also obtained (n = up to 33,224). A bidirectional Mendelian randomization analysis was conducted to explore the causal relationship between tinnitus and neuroanatomical features at global-brain and sub-brain levels. RESULTS: Genetic susceptibility to tinnitus was causally associated with increased white matter volume (odds ratio [OR] = 2.361, 95% confidence interval [CI], 1.033 to 5.393) and total brain volume (OR = 2.391, 95% CI, 1.047 to 5.463) but inversely associated with cerebrospinal fluid volume (OR = 0.362, 95% CI, 0.158 to 0.826). A smaller gray matter volume in the left Heschl's gyrus and right insular cortex and larger gray matter volume in the posterior division of the left parahippocampal gyrus may lead to an increased risk for tinnitus (OR = 0.978, 95% CI, 0.961 to 0.996; OR = 0.987, 95% CI, 0.976 to 0.998; and OR = 1.015, 95% CI, 1.001 to 1.028, respectively). CONCLUSIONS: Genetic susceptibility to tinnitus was causally associated with increased white matter volume and total brain volume. Volume alteration in several cortical regions may indicate a higher tinnitus risk, and further research is recommended for causality inference at the level of sub-brain regions. Our findings provide genetic evidence for elucidating the underlying pathophysiological mechanisms of tinnitus-related neuroanatomical abnormalities.
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Estudo de Associação Genômica Ampla , Zumbido , Humanos , Análise da Randomização Mendeliana , Zumbido/genética , Predisposição Genética para Doença , NeuroimagemRESUMO
Chlorothalonil (CTL) is widely used in agricultural production and antifoulant additive globally due to its broad spectrum and non-systemic properties, resulting in its widespread existence in foods, soil and water. Extensive evidence demonstrated that exposure to CTL induced adverse effects on organisms and in particular its reproductive toxicity has been attracted public concern. However, the influences of CTL on oocyte maturation is mysterious so far. In this study, we documented the toxic effects of CTL on oocyte in vitro maturation and the related underlying mechanisms. Exposure to CTL caused continuous activation of spindle assembly checkpoints (SAC) which in turn compromised meiotic maturation in mouse oocyte, featured by the attenuation of polar body extrusion (PBE). Detection of cytoskeletal dynamics demonstrated that CTL exposure weakened the acetylation level of α-tubulin and impaired meiotic spindle apparatus, which was responsible for the aberrant state of SAC. Meanwhile, exposure to CTL damaged the function of mitochondria, inducing the decline of ATP content and the elevation of reactive oxygen species (ROS), which thereby induced early apoptosis and DNA damage in mouse oocytes. In addition, exposure to CTL caused the alteration of the level of histone H3 methylation, indicative of the harmful effects of CTL on epigenetic modifications in oocytes. Further, the CTL-induced oxidative stress activated mitogen-activated protein kinase (MAPK) pathway and injured the maturation of oocytes. In summary, exposure to CTL damaged mouse oocyte in vitro maturation via destroying spindle assembly, inducing oxidative stress and triggering MAPK pathway activation.
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Técnicas de Maturação in Vitro de Oócitos , Proteínas Quinases Ativadas por Mitógeno , Nitrilas , Animais , Camundongos , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Estresse Oxidativo , Oócitos/metabolismo , Espécies Reativas de Oxigênio/metabolismo , ApoptoseRESUMO
BACKGROUND: Metagenomic next-generation sequencing (mNGS) has become a powerful tool for pathogen detection, but the value of human sequencing reads generated from it is underestimated. METHODS: A total of 138 patients with pleural effusion (PE) were diagnosed with tuberculous pleurisy (TBP, N = 82), malignant pleural effusion (MPE, N = 35), or non-TB infection (N = 21), whose PE samples all underwent mNGS analysis. Clinical TB tests including culture, Acid-Fast Bacillus (AFB) test, Xpert, and T-SPOT, were performed. To utilize mNGS for MPE identification, 25 non-MPE samples (20 TBP and 5 non-TB infection) were randomly selected to set human chromosome copy number baseline and generalized linear modeling was performed using copy number variant (CNV) features of the rest 113 samples (35 MPE and 78 non-MPE). RESULTS: The performance of TB detection was compared among five methods. T-SPOT demonstrated the highest sensitivity (61% vs. culture 32%, AFB 12%, Xpert 35%, and mNGS 49%) but with the highest false-positive rate (10%) as well. In contrast, mNGS was able to detect TB-genome in nearly half (40/82) of the PE samples from TBP subgroup, with 100% specificity. To evaluate the performance of using CNV features of the human genome for MPE prediction, we performed the leave-one-out cross-validation (LOOCV) in the subcohort excluding the 25 non-MPE samples for setting copy number standards, which demonstrated 54.1% sensitivity, 80.8% specificity, 71.7% accuracy, and an AUC of 0.851. CONCLUSION: In summary, we exploited the value of human and non-human sequencing reads generated from mNGS, which showed promising ability in simultaneously detecting TBP and MPE.
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Derrame Pleural Maligno , Derrame Pleural , Tuberculose Pleural , Humanos , Tuberculose Pleural/diagnóstico , Derrame Pleural Maligno/diagnóstico , Derrame Pleural Maligno/genética , Sequenciamento de Nucleotídeos em Larga Escala , Metagenômica , Sensibilidade e EspecificidadeRESUMO
The HIV-1 envelope spike [Env; trimeric (gp160)3 cleaved to (gp120/gp41)3] induces membrane fusion, leading to viral entry. It is also the viral component targeted by neutralizing antibodies. Vaccine development requires production, in quantities suitable for clinical studies, of a recombinant form that resembles functional Env. HIV-1 gp140 trimers-the uncleaved ectodomains of (gp160)3-from a few selected viral isolates adopt a compact conformation with many antigenic properties of native Env spikes. One is currently being evaluated in a clinical trial. We report here low-resolution (20 Å) electron cryomicroscopy (cryoEM) structures of this gp140 trimer, which adopts two principal conformations, one closed and the other slightly open. The former is indistinguishable at this resolution from those adopted by a stabilized, cleaved trimer (SOSIP) or by a membrane-bound Env trimer with a truncated cytoplasmic tail (EnvΔCT). The latter conformation is closer to a partially open Env trimer than to the fully open conformation induced by CD4. These results show that a stable, uncleaved HIV-1 gp140 trimer has a compact structure close to that of native Env.IMPORTANCE Development of any HIV vaccine with a protein component (for either priming or boosting) requires production of a recombinant form to mimic the trimeric, functional HIV-1 envelope spike in quantities suitable for clinical studies. Our understanding of the envelope structure has depended in part on a cleaved, soluble trimer, known as SOSIP.664, stabilized by several modifications, including an engineered disulfide. This construct, which is difficult to produce in large quantities, has yet to induce better antibody responses than those to other envelope-based immunogens, even in animal models. The uncleaved ectodomain of the envelope protein, called gp140, has also been made as a soluble form to mimic the native Env present on the virion surface. Most HIV-1 gp140 preparations are not stable, however, and have an inhomogeneous conformation. The results presented here show that gp140 preparations from suitable isolates can adopt a compact, native-like structure, supporting its use as a vaccine candidate.
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Proteína gp120 do Envelope de HIV/química , Proteína gp41 do Envelope de HIV/química , HIV-1/química , Conformação Molecular , Produtos do Gene env do Vírus da Imunodeficiência Humana/química , Produtos do Gene env do Vírus da Imunodeficiência Humana/imunologia , Anticorpos Neutralizantes/imunologia , Microscopia Crioeletrônica , Anticorpos Anti-HIV/imunologia , Proteína gp120 do Envelope de HIV/genética , Proteína gp120 do Envelope de HIV/metabolismo , Proteína gp41 do Envelope de HIV/genética , Proteína gp41 do Envelope de HIV/metabolismo , HIV-1/imunologia , Multimerização Proteica , Estrutura Terciária de Proteína , Proteólise , Solubilidade , Vacinas Sintéticas , Produtos do Gene env do Vírus da Imunodeficiência Humana/genética , Produtos do Gene env do Vírus da Imunodeficiência Humana/metabolismoRESUMO
1,5-Anhydroglucitol (1,5-AG) is sensitive to short-term glucose fluctuations and postprandial hyperglycemia, which has great potential in the clinical application of diabetes as a nontraditional blood glucose monitoring indicator. A large number of studies have found that 1,5-AG can be used to screen for diabetes, manage diabetes, and predict the perils of diabetes complications (diabetic nephropathy, diabetic cardiovascular disease, diabetic retinopathy, diabetic pregnancy complications, diabetic peripheral neuropathy, etc.). Additionally, 1,5-AG and ß cells are also associated with each other. As a noninvasive blood glucose monitoring indicator, salivary 1,5-AG has much more benefit for clinical application; however, it cannot be ignored that its detection methods are not perfect. Thus, a considerable stack of research is still needed to establish an accurate and simple enzyme assay for the detection of salivary 1,5-AG. More clinical studies will also be required in the future to confirm the normal reference range of 1,5-AG and its role in diabetes complications to further enhance the blood glucose monitoring system for diabetes.
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Desoxiglucose , Complicações do Diabetes , Humanos , Complicações do Diabetes/diagnóstico , Complicações do Diabetes/sangue , Complicações do Diabetes/metabolismo , Glicemia/análise , Glicemia/metabolismo , Diabetes Mellitus/sangue , Diabetes Mellitus/diagnóstico , Diabetes Mellitus/metabolismo , Automonitorização da Glicemia/métodos , Biomarcadores/sangue , Biomarcadores/análiseRESUMO
This paper uses green innovation and environmental pollution as the mediating variables to construct a mediating effect model to investigate whether China's carbon emission trading policy can improve regional eco-efficiency by reducing regional environmental pollution and stimulating green innovation. This study is based on panel data from 30 provinces and municipalities directly under China's central government and autonomous regions from 2003 to 2019. The eco-efficiency of these provinces is measured using the super-efficiency DEA model and the difference-in-difference method (DID). The results show that (1) China's emission trading policy significantly improves regional ecological efficiency and the per capita GDP. The improvement can effectively improve regional ecological efficiency. (2) The mediating effect of green innovation and environmental pollution is significant. That is, China's carbon emission trading policy further improves regional ecological efficiency by stimulating more green innovation and reducing the synergy brought by environmental pollution. (3) There are differences in the feedback of this impact mechanism between different regions: It shows the characteristics of the western region being more significant than the eastern region. The central region has no significant effect. The research conclusion can provide a policy reference for the subsequent unified promotion of the construction of a carbon emission trading market nationwide and a theoretical basis for helping to achieve the "dual carbon" goal.
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Carbono , Poluição Ambiental , China , Política AmbientalRESUMO
Diabetic retinopathy is the major cause of blindness in diabetic patients, with limited treatment options that do not always restore optimal vision. Retinal nerve degeneration and vascular degeneration are two primary pathological processes of diabetic retinopathy. The retinal nervous system and vascular cells have a close coupling relationship. The connection between neurodegeneration and vascular degeneration is not yet fully understood. Recent studies have found that microRNA plays a role in regulating diabetic retinal neurovascular degeneration and can help delay the progression of the disease. This article will review how microRNA acts as a bridge connecting diabetic retinal neurodegeneration and vascular degeneration, focusing on the mechanisms of apoptosis, oxidative stress, inflammation, and endothelial factors. The aim is to identify valuable targets for new research and clinical treatment of diabetic retinopathy.
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Retinopatia Diabética , MicroRNAs , Estresse Oxidativo , Humanos , MicroRNAs/genética , Retinopatia Diabética/genética , Retinopatia Diabética/patologia , Retinopatia Diabética/metabolismo , Animais , Degeneração Retiniana/genética , Degeneração Retiniana/patologia , Apoptose , Vasos Retinianos/patologia , Retina/patologia , Retina/metabolismoRESUMO
BACKGROUND: Drug-resistant tuberculosis (TB), especially multidrug-resistant tuberculosis (MDR-TB), constitutes a major obstacle to fulfill end TB strategy globally. Although fluoroquinolones (FQs), linezolid (LZD) and bedaquiline (BDQ) were classified as Group A drugs for MDR-TB treatment, our knowledge of the prevalence of TB which were resistant to Group A drugs in China is quite limited. METHODS: In this study, we conducted a prospective multicenter surveillance study in China to determine the proportion of TB patients that were resistant to Group A drugs. A total of 1877 TB patients were enrolled from 2022 at four TB specialized hospitals. The drug susceptibility of isolated strains was conducted using the MGIT 960 system and the molecular mechanisms conferring drug resistance were investigated by Sanger sequencing. RESULTS: 12.9% of isolates were resistant to levofloxacin (LFX), 13.2% were resistant to moxifloxacin (MOX), 0.2% were resistant to bedaquiline (BDQ), and 0.8% were resistant to linezolid (LZD). Totally, 14.0% and 0.4% were classified as multidrug resistant- (MDR-) and extensively drug resistant- (XDR-) TB. The drug resistance was more common in retreated TB cases compared to new cases. In addition, 70.0% of fluoroquinolone (FQ)-resistant isolates harbored mutations in the gyrA and gyrB gene. By contrast, the common drug-resistant mutations were only found in 50% BDQ-resistant and 20% LZD-resistant isolates. CONCLUSIONS: Our data demonstrate that approximate half of MDR -TB patients are resistant to fluoroquinolones, with extremely low prevalence of initial BDQ and LZD resistance. Findings from this study provide important implications for the current management of MDR-TB patients.
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Mycobacterium tuberculosis , Tuberculose Resistente a Múltiplos Medicamentos , Humanos , Antituberculosos/farmacologia , Antituberculosos/uso terapêutico , Linezolida/farmacologia , Linezolida/uso terapêutico , Estudos Prospectivos , Farmacorresistência Bacteriana Múltipla/genética , Tuberculose Resistente a Múltiplos Medicamentos/tratamento farmacológico , Tuberculose Resistente a Múltiplos Medicamentos/epidemiologia , Tuberculose Resistente a Múltiplos Medicamentos/microbiologia , Fluoroquinolonas/farmacologia , Fluoroquinolonas/uso terapêutico , China/epidemiologia , Testes de Sensibilidade MicrobianaRESUMO
Eastern equine encephalitis virus (EEEV) is the most virulent alphavirus that infects humans, and many survivors develop neurological sequelae, including paralysis and intellectual disability. Alphavirus spike proteins comprise trimers of heterodimers of glycoproteins E2 and E1 that mediate binding to cellular receptors and fusion of virus and host cell membranes during entry. We recently identified very-low density lipoprotein receptor (VLDLR) and apolipoprotein E receptor 2 (ApoER2) as cellular receptors for EEEV and a distantly related alphavirus, Semliki Forest virus (SFV). Here, we use single-particle cryo-electron microscopy (cryo-EM) to determine structures of the EEEV and SFV spike glycoproteins bound to the VLDLR ligand-binding domain and found that EEEV and SFV interact with the same cellular receptor through divergent binding modes. Our studies suggest that the ability of LDLR-related proteins to interact with viral spike proteins through very small footprints with flexible binding modes results in a low evolutionary barrier to the acquisition of LDLR-related proteins as cellular receptors for diverse sets of viruses.
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Microscopia Crioeletrônica , Vírus da Encefalite Equina do Leste , Receptores de LDL , Receptores de LDL/metabolismo , Receptores de LDL/química , Vírus da Encefalite Equina do Leste/metabolismo , Vírus da Encefalite Equina do Leste/ultraestrutura , Humanos , Animais , Vírus da Floresta de Semliki/metabolismo , Ligação Proteica , Receptores Virais/metabolismo , Receptores Virais/química , Proteínas do Envelope Viral/metabolismo , Proteínas do Envelope Viral/química , Proteínas do Envelope Viral/ultraestrutura , Modelos MolecularesRESUMO
Background: Breast cancer is a common cause of cancer-related death worldwide. Chemotherapy plays an indispensable role in the conventional treatment of breast cancer, bringing some physical burdens and discomfort on cancer patients. Consequently, more and more patients turn to seeking the help of Complementary and Alternative Medicine (CAM), mainly traditional Chinese medicine (TCM). Xiaoyao san (XYS), a classical formula, has been shown to improve symptoms of breast cancer. An increasing number of researches suggest that compared to chemotherapy alone, Chinese herbal medicine combined with chemotherapy could increase effectiveness and reduce toxicity caused by chemotherapy. Emerging experimental research continuously demonstrated some of the components in XYS could stop breast cancer tumor cells from growing. However, the efficacy and safety of modified XYS combined with chemotherapy remain to be determined. Therefore, it is essential to evaluate the comparative effectiveness and safety of modified XYS combined with chemotherapy in-depth, thus providing clinicians and policymakers with evidence-based guidance and new treatment options. Objective: To comprehensively evaluate the efficacy and safety of modified XYS in conjunction with chemotherapy in treating breast cancer by conducting a meta-analysis. Methods: 8 databases were systemically searched until April 3, 2022, including Web of Science PubMed, EMBASE, Cochrane Library, China National Knowledge Infrastructure (CNKI), Wanfang, Chinese Scientific Journals Database (VIP), and Chinese Biological Medical Database (CBM). Relevant randomized controlled trials (RCTs) comparing modified XYS in combination with chemotherapy versus chemotherapy alone were included. For the evaluation of methodological quality, Cochrane Collaboration was considered. Software Review Manager (version 5.4) was used for data analysis. Software STATA (version 15.0) was employed for sensitivity analysis and publication bias. Results: Altogether, 17 RCTs involving 1207 patients were investigated in the current review. The findings revealed that modified XYS combined with chemotherapy could lead to beneficial improvements compared to chemotherapy alone. More specifically, the combined therapy could enhance the short-term efficacy in the treatment of solid tumors (OR: 1.74; 95% CI 1.27 to 2.39; P = 0.0006; I2 = 0%); improve QOL (quality of life) (OR: 3.75; 95% CI 2.58 to 5.44; P < 0.00001; I2 = 0%); reduce clinical symptoms (OR: 3.69; 95% CI 1.43 to 9.49; P = 0.007; I2 = 53%); ease depression (MD: -12.96; 95% CI -16.09 to -9.83; P < 0.00001; I2 = 0%); increase leukocytes (OR: 0.32; 95% CI 0.20 to 0.50; P < 0.00001; I2 = 0%) and platelets (OR: 0.37; 95% CI 0.20 to 0.67; P = 0.001; I2 = 0%); reduce nausea and vomiting (OR: 0.26; 95% CI 0.15 to 0.44; P < 0. 00001; I2 = 0%); mitigate cardiotoxicity (OR: 0.16; 95% CI 0.07 to 0.36; P<0.00001; I2 = 0%); prolong survival time (OR: 2.19; 95% CI 1.03 to 4.66; P = 0.04; I2 = 0%), compared to chemotherapy alone. Unfortunately, there was no statistically significant difference in damage to the liver and kidney (OR: 0.59; 95% CI 0.29 to 1.21; P = 0.15; I2 = 0%). Conclusion: The existing evidence suggests modified XYS combined with chemotherapy leads to beneficial improvements in the management of breast cancer, which may serve as a promising therapy for breast cancer in clinical practice. Given the limited number of high quality RCTs, more rigorous, scientific, double-blinded, large-scale, multi-center clinical trials are warranted further. Systematic review registration: https://www.crd.york.ac.uk/PROSPERO/, identifier CRD42022357860.
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This study systematically investigated the performance of MeltPro and next-generation sequencing in the diagnosis of fluoroquinolone (FQ) resistance among multidrug-resistant tuberculosis patients and explored the relationship between nucleotide alteration and the level of phenotypic susceptibility to FQs. From March 2019 to June 2020, a feasibility and validation study with both MeltPro and next-generation sequencing was performed in 126 patients with multidrug-resistant tuberculosis. Using phenotypic drug susceptibility testing as the gold standard, 95.3% (82 of 86) of ofloxacin-resistant isolates were identified correctly by MeltPro. In addition, whole-genome sequencing was able to detect 83 phenotypically ofloxacin-resistant isolates. The isolates with an individual gyrB mutation outside the quinolone resistance-determining region (QRDR) had minimum inhibitory concentrations (MICs) of ≤2 µg/mL. Despite showing low MICs close to the breakpoint for isolates carrying only gyrA_Ala90Val, the combined mutation gyrB_Asp461Asn caused the ofloxacin MIC to be eight higher than that obtained in Mycobacterium tuberculosis (MTB) isolates with the Ala90Val mutation alone (median, 32 µg/mL; P = 0.038). Heteroresistance was observed in 12 of 88 isolates harboring mutations in the QRDRs. In conclusion, our data show that MeltPro and the whole-genome sequencing assay correctly can identify FQ resistance caused by mutations in the gyrA QRDR. The combined gyrB_Asp461Asn mutation may significantly decrease in vitro FQ susceptibility of MTB isolates with low-level-resistance-associated gyrA mutations.
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Mycobacterium tuberculosis , Tuberculose Resistente a Múltiplos Medicamentos , Humanos , Fluoroquinolonas/farmacologia , Testes de Sensibilidade Microbiana , Farmacorresistência Bacteriana/genética , DNA Girase/genética , Tuberculose Resistente a Múltiplos Medicamentos/diagnóstico , Tuberculose Resistente a Múltiplos Medicamentos/tratamento farmacológico , Tuberculose Resistente a Múltiplos Medicamentos/microbiologia , Ofloxacino/farmacologia , Mutação , Sequenciamento de Nucleotídeos em Larga Escala , Antituberculosos/farmacologiaRESUMO
Background: Sputum culture result at the sixth month is essential for predicting therapeutic response to longer multidrug-resistant tuberculosis (MDR-TB) regimens. This study aimed to construct a predictive model using cavity-based radiomics to predict sputum status at the sixth month for MDR-TB patients treated with longer regimens. Methods: This retrospective study recruited 315 MDR-TB patients treated with longer regimens from two centers (250 patients from center 1 and 65 patients from center 2), who were divided into persistently positive and conversion to negative sputum culture groups according to sputum results. Radiomics features were extracted based on the cavity, and a radiomics model was selected and established using a random forest classifier. The clinical characteristics and primary CT signs with significant differences were integrated to build a clinical model. A combined model was generated using the radiomics and clinical model. ROC curves, F1-score and DCA curves were used to assess the predictive performance of the models. Results: Twenty-eight radiomics features were selected to build a radiomics model for predicting the sputum status. The radiomics model achieved good performance, with AUCs of 0.892 and 0.839 in the training and testing cohort, respectively, which was similar to the performance of the combined model (0.913 and 0.815) and much higher than that of the clinical model (0.688 and 0.525) in the two cohorts. Conclusion: The cavity-based radiomics model has the potential to predict sputum culture status for MDR-TB patients receiving longer regimens, which could guide follow-up treatment effectively.
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BACKGROUND: Nocardia species can cause local or disseminated infection. Prompt diagnosis and appropriate treatment of nocardiosis are required, because it can cause significant morbidity and mortality. Knowledge of local species distribution and susceptibility patterns is important to appropriate empiric therapy. However, knowledge on the epidemiology and antimicrobial susceptibility profiles of clinical Nocardia species remains limited in China. METHODS: The data of isolation of Nocardia species were collected from databases such as Pubmed, Web of Science, Embase as well as Chinese databases (CNKI, Wanfang and VIP). Meta-analysis was performed using RevMan 5.3 software. Random effect models were used and tested with Cochran's Q and I2 statistics taking into account the possibility of heterogeneity between studies. RESULTS: In total, 791 Nocardia isolates were identified to 19 species levels among all the recruited studies. The most common species were N. farcinica (29.1%, 230/791), followed by N. cyriacigeorgica (25.3%, 200/791), N. brasiliensis (11.8%, 93/791) and N. otitidiscaviarum (7.8%, 62/791). N. farcinica and N. cyriacigeorgica were widely distributed, N. brasiliensis mainly prevalent in the south, N. otitidiscaviarum mainly distributed in the eastern coastal provinces of China. Totally, 70.4% (223/317) Nocardia were cultured from respiratory tract specimens, 16.4% (52/317) from extra-pulmonary specimens, and 13.3% (42/317) from disseminated infection. The proportion of susceptible isolates as follows: linezolid 99.5% (197/198), amikacin 96.0% (190/198), trimethoprim-sulfamethoxazole 92.9% (184/198), imipenem 64.7% (128/198). Susceptibility varied by species of Nocardia. CONCLUSIONS: N. farcinica and N. cyriacigeorgica are the most frequently isolated species, which are widely distributed in China. Pulmonary nocardiosis is the most common type of infection. Trimethoprim-sulfamethoxazole can still be the preferred agent for initial Nocardia infection therapy due to the low resistance rate, linezolid and amikacin could be an alternative to treat nocardiosis or a choice in a combination regimen.
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Nocardiose , Nocardia , Humanos , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Combinação Trimetoprima e Sulfametoxazol/uso terapêutico , Linezolida/uso terapêutico , Amicacina/uso terapêutico , Testes de Sensibilidade Microbiana , Farmacorresistência Bacteriana , Nocardiose/tratamento farmacológico , Nocardiose/epidemiologia , China/epidemiologiaRESUMO
BACKGROUND AND OBJECTIVE: Imbalance of oxidative stress has been detected in a range of fibrotic diseases. Melatonin as an indoleamine hormone plays an important role in regulating the circadian rhythm of human, while in recent years, its antioxidant effect has also attracted increasing attention. This study aimed to perform a systematic review and meta-analysis to comprehensively evaluate the antioxidant effect of melatonin in animal models of fibrosis. METHODS: The PubMed, Cochrane Library, EMBASE, Web of Science, China National Knowledge Infrastructure (CNKI), Wanfang database, China Science and Technology Journal Database (VIP), and SinoMed databases were searched from inception to March 1st, 2022 to retrieve eligible studies that evaluated the effect of melatonin supplementation on the levels of malondialdehyde (MDA), lipid peroxidation (LPO), nitric oxide (NO), superoxide dismutase (SOD), glutathione (GSH), glutathione peroxidase (GPx), and catalase (CAT) in animal models of fibrosis. RESULTS: A total of 64 studies were included in this meta-analysis. The results showed that melatonin supplementation significantly reduced the levels of oxidative indicators including MDA (P < 0.00001), LPO (P < 0.00001) and NO (P < 0.0001), and elevated the levels of antioxidant indicators including GSH (P < 0.00001), GPx (P < 0.00001) and SOD (P < 0.00001) in fibrotic diseases. CONCLUSIONS: Our research findings showed that melatonin supplementation could significantly reduce the levels of oxidative indicators including MDA, LPO and NO and elevate the levels of antioxidant indicators including GSH, GPx and SOD so as to correct oxidative stress in animal models of fibrosis. However, no significant changes were observed in CAT level. More clinical studies are needed to further confirm the beneficial role of melatonin in fibrotic diseases.
Assuntos
Antioxidantes , Melatonina , Animais , Humanos , Antioxidantes/farmacologia , Antioxidantes/metabolismo , Melatonina/farmacologia , Estresse Oxidativo , Catalase/metabolismo , Glutationa/metabolismo , Superóxido Dismutase/metabolismo , Fibrose , Óxido Nítrico/farmacologia , Modelos Animais , Glutationa Peroxidase/metabolismo , Malondialdeído/farmacologiaRESUMO
Doxorubicin (DOX) is a broad-spectrum chemotherapeutic drug used in clinical treatment of malignant tumors. It has a high anticancer activity but also high cardiotoxicity. The aim of this study was to explore the mechanism of Tongmai Yangxin pills (TMYXPs) in ameliorating DOX-induced cardiotoxicity through integrated metabolomics and network pharmacology. In this study, first, an ultrahigh-performance liquid chromatography-quadrupole-time-of-flight/mass spectrometry (UPLC-Q-TOF/MS) metabonomics strategy was established to obtain metabolite information and potential biomarkers were determined after data processing. Second, network pharmacological analysis was used to evaluate the active components, drug-disease targets, and key pathways of TMYXPs to alleviate DOX-induced cardiotoxicity. Targets from the network pharmacology analysis and metabolites from plasma metabolomics were jointly analyzed to select crucial metabolic pathways. Finally, the related proteins were verified by integrating the above results and the possible mechanism of TMYXPs to alleviate DOX-induced cardiotoxicity was studied. After metabolomics data processing, 17 different metabolites were screened, and it was found that TMYXPs played a role in myocardial protection mainly by affecting the tricarboxylic acid (TCA) cycle of myocardial cells. A total of 71 targets and 20 related pathways were screened out with network pharmacological analysis. Based on the combined analysis of 71 targets and different metabolites, TMYXPs probably played a role in myocardial protection through regulating upstream proteins of the insulin signaling pathway, MAPK signaling pathway, and p53 signaling pathway, as well as the regulation of metabolites related to energy metabolism. They then further affected the downstream Bax/Bcl-2-Cyt c-caspase-9 axis, inhibiting the myocardial cell apoptosis signaling pathway. The results of this study may contribute to the clinical application of TMYXPs in DOX-induced cardiotoxicity.
RESUMO
BACKGROUND: In this study, we utilized whole genome sequencing (WGS) of clinical extremely drug-resistant tuberculosis (EDR-TB) strains collected during 2014-2020 in Beijing to detect clustered strains. METHODS: A retrospective cohort study was conducted by inclusion of EDR-TB patients with positive cultures in Beijing between 2014 and 2020. RESULTS: A total of 95 EDR-TB patients were included in our analysis. Up on the WGS based genotyping, 94 (94/95, 98.9%) out of 95 were identified as lineage 2 (East Asia). The pairwise genomic distance analysis identified 7 clusters, ranging in size from 2 to 5 isolates. The clustering rate of EDR-TB was 21.1%; while no patients had significantly higher odds of clustering. All isolates harbor rpoB RRDR mutations that confer RIF resistance and katG or inhA promoter mutations that confer INH resistance. Of 95 EDR-TB isolates, a total of 15 mutation types were recorded in the transcriptional regulator mmpR5. In vitro susceptibility testing results revealed that 14 (14/15, 93.3%) out of 15 mutation types were resistant to CFZ; whereas only 3 (3/15, 20.0%) showed resistance to BDQ. Interestingly, 12 isolates harbored mutations within rrl locus, whereas only mutations at positions 2294 and 2296 conferred CLA resistance. Favorable outcomes of EDR-TB patients were positively associated with more effective drugs in the regimes. CONCLUSION: WGS data demonstrate limited transmission of EDR-TB in this metropolis city. WGS-based drug susceptibility predictions will bring benefits to EDR-TB patients to formulate optimal therapeutic regimens.
Assuntos
Tuberculose Extensivamente Resistente a Medicamentos , Mycobacterium tuberculosis , Tuberculose Resistente a Múltiplos Medicamentos , Humanos , Antituberculosos/farmacologia , Antituberculosos/uso terapêutico , Tuberculose Extensivamente Resistente a Medicamentos/tratamento farmacológico , Tuberculose Extensivamente Resistente a Medicamentos/epidemiologia , Tuberculose Resistente a Múltiplos Medicamentos/tratamento farmacológico , Tuberculose Resistente a Múltiplos Medicamentos/epidemiologia , Tuberculose Resistente a Múltiplos Medicamentos/diagnóstico , Pequim/epidemiologia , Estudos Retrospectivos , China/epidemiologia , Mutação , Testes de Sensibilidade Microbiana , Farmacorresistência Bacteriana Múltipla/genéticaRESUMO
Alphaviruses are arthropod-borne enveloped RNA viruses that include several important human pathogens with outbreak potential. Among them, eastern equine encephalitis virus (EEEV) is the most virulent, and many survivors develop neurological sequelae, including paralysis and intellectual disability. The spike proteins of alphaviruses comprise trimers of heterodimers of their envelope glycoproteins E2 and E1 that mediate binding to cellular receptors and fusion of virus and host cell membranes during entry. We recently identified very-low density lipoprotein receptor (VLDLR) and apolipoprotein E receptor 2 (ApoER2), two closely related proteins that are expressed in the brain, as cellular receptors for EEEV and a distantly related alphavirus, Semliki forest virus (SFV) 1 . The EEEV and SFV spike glycoproteins have low sequence homology, and how they have evolved to bind the same cellular receptors is unknown. Here, we used single-particle cryo-electron microscopy (cryo-EM) to determine structures of the EEEV and SFV spike glycoproteins bound to the VLDLR ligand-binding domain. The structures reveal that EEEV and SFV use distinct surfaces to bind VLDLR; EEEV uses a cluster of basic residues on the E2 subunit of its spike glycoprotein, while SFV uses two basic residues at a remote site on its E1 glycoprotein. Our studies reveal that different alphaviruses interact with the same cellular receptor through divergent binding modes. They further suggest that the ability of LDLR-related proteins to interact with viral spike proteins through very small footprints with flexible binding modes results in a low evolutionary barrier to the acquisition of LDLR-related proteins as cellular receptors for diverse sets of viruses.