Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 107
Filtrar
Mais filtros

Bases de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Nature ; 630(8015): 181-188, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38778098

RESUMO

Digital pathology poses unique computational challenges, as a standard gigapixel slide may comprise tens of thousands of image tiles1-3. Prior models have often resorted to subsampling a small portion of tiles for each slide, thus missing the important slide-level context4. Here we present Prov-GigaPath, a whole-slide pathology foundation model pretrained on 1.3 billion 256 × 256 pathology image tiles in 171,189 whole slides from Providence, a large US health network comprising 28 cancer centres. The slides originated from more than 30,000 patients covering 31 major tissue types. To pretrain Prov-GigaPath, we propose GigaPath, a novel vision transformer architecture for pretraining gigapixel pathology slides. To scale GigaPath for slide-level learning with tens of thousands of image tiles, GigaPath adapts the newly developed LongNet5 method to digital pathology. To evaluate Prov-GigaPath, we construct a digital pathology benchmark comprising 9 cancer subtyping tasks and 17 pathomics tasks, using both Providence and TCGA data6. With large-scale pretraining and ultra-large-context modelling, Prov-GigaPath attains state-of-the-art performance on 25 out of 26 tasks, with significant improvement over the second-best method on 18 tasks. We further demonstrate the potential of Prov-GigaPath on vision-language pretraining for pathology7,8 by incorporating the pathology reports. In sum, Prov-GigaPath is an open-weight foundation model that achieves state-of-the-art performance on various digital pathology tasks, demonstrating the importance of real-world data and whole-slide modelling.


Assuntos
Conjuntos de Dados como Assunto , Processamento de Imagem Assistida por Computador , Aprendizado de Máquina , Patologia Clínica , Humanos , Benchmarking , Processamento de Imagem Assistida por Computador/métodos , Neoplasias/classificação , Neoplasias/diagnóstico , Neoplasias/patologia , Patologia Clínica/métodos , Masculino , Feminino
2.
Nat Prod Rep ; 41(3): 331-346, 2024 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-37743806

RESUMO

Covering: 2018 to Jun of 2023The efficiency of traditional antibiotics has been undermined by the proliferation of antibiotic-resistant pathogenic microorganisms, necessitating the pursuit of innovative therapeutic agents. Antimicrobial peptides (AMPs), which are part of host defence peptides found ubiquitously in nature, exhibiting a wide range of activity towards bacteria, fungi, and viruses, offer a highly promising candidate solution. The efficacy of AMPs can frequently be augmented via alterations to their amino acid sequences or structural adjustments. Given the vast reservoir of marine life forms and their distinctive ecosystems, marine AMPs stand as a burgeoning focal point in the quest for alternative peptide templates extracted from natural sources. Advances in identification and characterization techniques have accelerated the discoveries of marine AMPs, thereby stimulating AMP customization, optimization, and synthesis research endeavours. This review presents an overview of recent discoveries related to the intriguing qualities of marine AMPs. Emphasis will be placed upon post-translational modifications (PTMs) of marine AMPs and how they may impact functionality and potency. Additionally, this review considers ways in which marine PTM might support larger-scale, heterologous AMP manufacturing initiatives, providing insights into translational applications of these important biomolecules.


Assuntos
Anti-Infecciosos , Anti-Infecciosos/farmacologia , Anti-Infecciosos/química , Peptídeos Antimicrobianos , Organismos Aquáticos/química , Ecossistema , Peptídeos Catiônicos Antimicrobianos/química , Antibacterianos
3.
Ann Hematol ; 103(7): 2381-2391, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38165416

RESUMO

Blastoid or pleomorphic mantle cell lymphoma (B/P-MCL) is characterized by high invasiveness and unfavorable outcomes, which is still a challenge for treating MCL. This retrospective study was performed to comprehensively analyze the clinical, genomic characteristics and treatment options of patients with B/PMCL from multicenter in China. Data were obtained from 693 patients with B/PMCL from three centers in China between April 1999 and December 2019. Seventy-four patients with BMCL (n = 43) or PMCL (n = 31) were included in the analysis. The median age of the cohort was 60.0 years with a male-to-female ratio of 2.89:1. The 3-year progression-free survival (PFS) and overall survival (OS) rates were 44.1% and 46.0%, respectively. Mutations of TP53, ATM, NOTCH1, NOTCH2, NSD2, SMARCA4, CREBBP, KMT2D, FAT1, and TRAF2 genes were the most common genetic changes in B/P-MCL. Progression of disease within 12 months (POD12) could independently predict the poor prognosis of patients with blastoid and pleomorphic variants. Patients with POD12 carried a distinct mutation profile (TP53, SMARCA4, NSD2, NOTCH2, KMT2D, PTPRD, CREBBP, and CDKN2A mutations) compared to patients with non-POD12. First-line high-dose cytosine arabinoside exposure obtained survival benefits in these populations, and BTKi combination therapy as the front-line treatment had somewhat improvement in survival with no significant difference in the statistic. In conclusion, B/P-MCL had inferior outcomes and a distinct genomic profile. Patients with POD12 displayed a distinct mutation profile and a poor prognosis. New therapeutic drugs and clinical trials for B/P-MCL need to be further explored.


Assuntos
Linfoma de Célula do Manto , Mutação , Humanos , Linfoma de Célula do Manto/genética , Linfoma de Célula do Manto/mortalidade , Linfoma de Célula do Manto/tratamento farmacológico , Masculino , Feminino , Pessoa de Meia-Idade , China/epidemiologia , Estudos Retrospectivos , Idoso , Adulto , Prognóstico , Taxa de Sobrevida , Idoso de 80 Anos ou mais
4.
Cryobiology ; 114: 104860, 2024 03.
Artigo em Inglês | MEDLINE | ID: mdl-38340888

RESUMO

During the freeze-thaw process, human spermatozoa are susceptible to oxidative stress, which may cause cryodamage and reduce sperm quality. As a novel mitochondria-targeted antioxidant, Mito-tempo has been used for sperm cryopreservation. However, it is currently unknown what role it will play in the process of sperm ultra-rapid freezing. The purpose of this study was to investigate whether Mito-tempo can improve sperm quality during ultra-rapid freezing. In this study, samples with the addition of Mito-tempo (0, 5, 10, 20, and 40 µM) to sperm freezing medium were selected to evaluate the changes in sperm quality, antioxidant capacity and ultrastructure after ultra-rapid freezing. After ultra-rapid freezing, the quality and antioxidant function of the spermatozoa were significantly reduced and the spermatozoa ultrastructure was destroyed. The addition of 10 µM Mito-tempo significantly increased post thaw sperm motility, viability, plasma membrane integrity and mitochondrial membrane potential (P < 0.05). Moreover, the DNA fragmentation index (DFI), ROS levels and MDA content were reduced, and the antioxidant enzyme (CAT and SOD) activities were enhanced in the 10 µM Mito-tempo group (P < 0.05). Moreover, Mito-tempo protected sperm ultrastructure from damage. In conclusion, Mito-tempo improved the quality and antioxidant function of sperm after ultra-rapid freezing while reducing freezing-induced ultrastructural damage.


Assuntos
Antioxidantes , Preservação do Sêmen , Masculino , Humanos , Antioxidantes/farmacologia , Congelamento , Criopreservação/métodos , Motilidade dos Espermatozoides , Crioprotetores/farmacologia , Sêmen , Espermatozoides , Mitocôndrias
5.
Chem Biodivers ; 21(6): e202400327, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38446672

RESUMO

Four new isocoumarins, alternariethers A-C (1-3) and alternariester (4) were separated from the fermentation of the fungus Alternaria malorum FL39, purified from Myoporum bontioides. Their structures were ascertained using NMR and HR-ESI-MS spectroscopy. For compound 4, the absolute configuration was solved with the help of ECD calculation and the DP4+ method. Compared with the positive control triadimefon, compound 1 showed more potent antifungal effects on Colletotrichum musae. The antifungal effects of compounds 1, 2, and 3 on Fusarium oxysporum and Fusarium graminearum, of compound 4 on F. oxysporum, were equal to those of triadimefon. Except for compound 4 which was inactive against Escherichia coli with O78 serotype, all compounds showed moderate or weak antibacterial activity against Staphylococcus aureus ATCC 6538 and E. coli with O6 or O78 serotype.


Assuntos
Alternaria , Antibacterianos , Escherichia coli , Fusarium , Isocumarinas , Testes de Sensibilidade Microbiana , Staphylococcus aureus , Alternaria/química , Alternaria/efeitos dos fármacos , Staphylococcus aureus/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Isocumarinas/química , Isocumarinas/farmacologia , Isocumarinas/isolamento & purificação , Antibacterianos/farmacologia , Antibacterianos/química , Antibacterianos/isolamento & purificação , Fusarium/efeitos dos fármacos , Colletotrichum/efeitos dos fármacos , Antifúngicos/farmacologia , Antifúngicos/química , Antifúngicos/isolamento & purificação , Myoporum/química , Myoporum/metabolismo
6.
Sichuan Da Xue Xue Bao Yi Xue Ban ; 55(2): 309-314, 2024 Mar 20.
Artigo em Zh | MEDLINE | ID: mdl-38645869

RESUMO

Objective: To explore the application effect of intelligent health education based on the health belief model on patients with postoperative kinesophobia after surgical treatment of cervical spondylosis. Methods: A prospective cohort study was conducted with patients who underwent anterior cervical discectomy, decompression, and fusion surgery with a single central nerve and spine center, and who had postoperative kinesophobia, ie, fear of movement. The patients made voluntary decisions concerning whether they would receive the intervention of intelligent health education. The patients were divided into a control group and an intelligent education group and the intervention started on the second day after the surgery. The intelligent education group received intelligent education starting from the second day after surgery through a WeChat widget that used the health belief model as the theoretical framework. The intelligent health education program was designed according to the concept of patient problems, needs, guidance, practice, and feedbacks. It incorporated four modules, including knowledge, intelligent exercise, overcoming obstacles, and sharing and interaction. It had such functions as reminders, fun exercise, shadowing exercise, monitoring, and documentation. Health education for the control group also started on the second day after surgery and was conducted by a method of brochures of pictures and text and WeChat group reminder messages. The participants were surveyed before discharge and 3 months after their surgery. The primary outcome measure compared between the two groups was the degree of kinesophobia. Secondary outcome measures included differences in adherence to functional exercise (Functional Exercise Adherence Scale), pain level (Visual Analogue Scale score), degree of cervical functional impairment (Cervical Disability Index), and quality of life (primarily assessed by the Quality of Life Short Form 12 [SF-12] scale for psychological and physiological health scores). Results: A total of 112 patients were enrolled and 108 patients completed follow-up. Eventually, there were 53 cases in the intelligent education group and 55 cases in the control group. None of the patients experienced any sports-related injuries. There was no statistically significant difference in the primary and secondary outcome measures between the two groups at the time of discharge. At the 3-month follow-up after the surgery, the level of kinesophobia in the intelligent education group (25.72±3.90) was lower than that in the control group (29.67±6.16), and the difference between the two groups was statistically significant (P<0.05). In the intelligent education group, the degree of pain (expressed in the median [25th percentile, 75th percentile]) was lower than that of the control group (0 [0, 0] vs. 1 [1, 2], P<0.05), the functional exercise adherence was better than that of the control group (63.87±7.26 vs. 57.73±8.07, P<0.05), the psychological health was better than that of the control group (40.78±3.98 vs. 47.78±1.84, P<0.05), and the physical health was better than that of the control group (43.16±4.41 vs. 46.30±3.80, P<0.05), with all the differences being statistically significant. There was no statistically significant difference in the degree of cervical functional impairment between the two groups (1 [1, 2] vs. 3 [2, 7], P>0.05). Conclusion: Intelligent health education based on the health belief model can help reduce the degree of kinesophobia in patients with postoperative kinesophobia after surgical treatment of cervical spondylosis and improve patient prognosis.


Assuntos
Vértebras Cervicais , Espondilose , Humanos , Espondilose/cirurgia , Estudos Prospectivos , Vértebras Cervicais/cirurgia , Transtornos Fóbicos/psicologia , Feminino , Masculino , Discotomia/métodos , Educação de Pacientes como Assunto/métodos , Descompressão Cirúrgica/métodos , Medo , Pessoa de Meia-Idade , Educação em Saúde/métodos , Fusão Vertebral/métodos , Cinesiofobia
7.
Chem Biodivers ; 20(12): e202301217, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37870539

RESUMO

The binding of pseudallecin A (PA), a potential antibiotic with strong inhibitory activities against Gram-positive Escherichia coli and Gram-negative Staphylococcus aureus, to human serum albumin (HSA) was explored. The interaction between them was assessed by multi-spectroscopic analysis, binding site competitive analysis, molecular docking and molecular dynamic simulation, showing the results as follows: PA effectively quenched the innate fluorescence of HSA by a static quenching process, formed a complex at a molar ratio of approximately 1 : 1 and performed an effective non-radiative energy transfer; the binding of PA to HSA was a spontaneous exothermic reaction driven by enthalpy with strong affinity and had a slight effect on the conformation of HSA; PA bound at site III of HSA and hydrogen bonds were the major binding forces to maintain the stability of the PA-HSA complex. Molecular dynamic simulation was performed to calculate the root mean square deviation (RMSD), root mean square fluctuation (RMSF) and radius of gyration (Rg) for this complex and effectively supported the spectroscopic outcome. These results meant that the delivery and distribution of PA as a water-insoluble molecule can be efficiently accomplished via HSA in human blood and, it has a good potential for future drug application and pharmacological development.


Assuntos
Simulação de Dinâmica Molecular , Albumina Sérica Humana , Humanos , Albumina Sérica Humana/metabolismo , Simulação de Acoplamento Molecular , Ligação Proteica , Sítios de Ligação , Termodinâmica , Dicroísmo Circular , Espectrometria de Fluorescência
8.
BMC Oral Health ; 23(1): 409, 2023 06 21.
Artigo em Inglês | MEDLINE | ID: mdl-37344797

RESUMO

BACKGROUND: Using a rotary instrument or ultrasonic instrument for tooth preparation is a basic operation in the dental clinic that can produce a significant number of droplets and aerosols. The dental droplet and aerosol can lead to the transfer of harmful germs. The goal of this study was to analyze the properties of microbiological aerosol created by droplets and aerosol generated by three common tooth-preparation instruments. METHODS: Streptococcus mutans UA159 was used as the biological tracer to visualize the droplets and aerosols. The passive sampling method was used to map the three-dimensional spatial distribution and the six-stage Andersen microbial sampler (AMS) was used as the active sampling method to catch aerosol particles at a specific time. RESULTS: The aerosol concentration is related to instruments, three-dimensional spatial distribution, and dissipation time. Most aerosols were generated by air turbines. More microorganisms are concentrated at the 1.5 m plane. The majority of the post dental procedure contamination was detected within the 0-10-min period and it decreased rapidly within 30 min. CONCLUSION: This study is conducive to the proposal and improvement of relevant infection control measures in dental procedures and provides a basis for the assessment of measures, reducing the risk of nosocomial infection.


Assuntos
Infecção Hospitalar , Humanos , Aerossóis , Infecção Hospitalar/prevenção & controle , Controle de Infecções , Atenção à Saúde
9.
Small ; 18(14): e2106657, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35023632

RESUMO

Mapping technique has been the powerful tool for the design of next-generation energy storage devices. Unlike the traditional ion-insertion based lithium batteries, the Li-S battery is based on the complex conversion reactions, which require more cooperation from mapping techniques to elucidate the underlying mechanism. Therefore, in this review, the representative works of mapping techniques for Li-S batteries are summarized, and categorized into the studies of lithium metal anode and sulfur cathode, with sub-sections based on shared characterization mechanisms. Due to specific features of mapping techniques, various aspects such as compositional distribution, in-plain/cross section characterization, coin cell/pouch cell configuration, and structural/mechanical analysis are emphasized in each study, aiming for the guidance for developing strategies to improve the battery performances. Benefited from the achieved progresses, suggestions for future studies based on mapping techniques are proposed to accelerate the development and commercialization of the Li-S battery.

10.
Molecules ; 27(9)2022 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-35566042

RESUMO

Mangrove endophytic fungi represent significant and sustainable sources of novel metabolites with unique structures and excellent biological activities, attracting extensive chemical investigations. In this research, two novel heterodimeric tetrahydroxanthones, aflaxanthones A (1) and B (2), dimerized via an unprecedented 7,7'-linkage, a sp3-sp3 dimeric manner, were isolated from the mangrove endophytic fungus Aspergillus flavus QQYZ. Their structures were elucidated through high resolution electrospray ionization mass spectroscopy (HRESIMS) and nuclear magnetic resonance (NMR) spectroscopy, the absolute configurations of them were determined by a single-crystal X-ray diffraction combined with calculated electronic circular dichroism (ECD) spectra and a 1D potential energy scan. These compounds were evaluated for antifungal activities in vitro and exhibited broad-spectrum and potential antifungal activities against several pathogenic fungi with minimum inhibitory concentration (MIC) values in the range of 3.13-50 µM. They also performed moderate antibacterial activities against several bacteria with MIC values in the range of 12.5-25 µM. This research enriched the resources of lead compounds and templates for marine-derived antimicrobial drugs.


Assuntos
Antifúngicos , Aspergillus flavus , Antibacterianos/química , Antifúngicos/metabolismo , Antifúngicos/farmacologia , Aspergillus/química , Fungos , Estrutura Molecular
11.
Entropy (Basel) ; 24(6)2022 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-35741471

RESUMO

The issue of monitoring and early warning of rock instability has received increasing critical attention in the study of rock engineering. To investigate the damage evolution process of granite under triaxial compression tests, acoustic emission (AE) tests were performed simultaneously. This study firstly introduced two novel parameters, i.e., the coefficient of variation (CoV) of the information entropy and correlation dimension of the amplitude data from the AE tests, to identify the precursor of the failure of granite. Then the relationship between the changes in these parameters and the stress-time curve was compared and analyzed. The results of this study show that: (1) There is a strong correlation between the CoV of the information entropy and the failure process of granite. The granite failed when the CoV curve raised to a plateau, which could be used as an indicator of rock instability. (2) The fluctuation of the correlation dimension indicates the different stages during the loading process, i.e., the initial compaction stage, the linear elastic stage, the yield stage, and the failure stage. Each stage contains a descending and a rising process in the correlation dimension curve, and the exhibited starting point or the bottom point at the correlation dimension curve could be selected as the indicator point for the rock instability. (3) The combined analysis of the Information entropy and Correlation dimension can improve the accuracy of rock instability prediction. This study provides new insights into the prediction of rock instability, which has theoretical implications for the stability of subsurface engineering rock masses.

12.
Zhongguo Zhong Yao Za Zhi ; 47(17): 4658-4664, 2022 Sep.
Artigo em Zh | MEDLINE | ID: mdl-36164872

RESUMO

The endophytic fungus Nigrospora sphaerica S5 derived from the semi-mangrove plant Myoporum bontioides was fermented. Its metabolites were purified by column chromatography. Nine compounds were obtained and identified as terezine P(1), 3-(1-hydroxyethyl)-4-methyl dihydrofuran-2(3H)-one(2), methylhydroheptelidate(3), hydroheptelidic acid(4), 5, 7-dimethoxy-4, 6-dimethylphthalide(5),(3R,4S)-(-)-4-hydroxymellein(6), pestalopyrone(7), indole-3-formaldehyde(8) and p-hydroxybenzaldehyde(9) by spectroscopic techniques. Terezine P(1) was a new alkaloid belonging to the terezine class with a pyrazine ring. Compounds 2-7 were lactones, of which 3 and 4 belonged to sesquiterpenes. Compounds 8 and 9 were indole alkaloids and phenols, respectively. Compounds 3-6 were purified from Nigrospora sp. for the first time. These compounds showed different degrees of antibacterial activity against Staphylococcus aureus, Escherichia coli of O6 serotype and E. coli of O78 serotype.


Assuntos
Alcaloides , Ascomicetos , Myoporum , Sesquiterpenos , Antibacterianos/farmacologia , Ascomicetos/química , Escherichia coli , Formaldeído , Indóis/farmacologia , Lactonas , Estrutura Molecular , Myoporum/química , Myoporum/microbiologia , Fenóis , Pirazinas
13.
Bioorg Chem ; 115: 105232, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34371373

RESUMO

The strategy "IEMAHC" (Induction of Endophyte Metabolism by Adding Host Components) was applied to the fermentation of the endophytic fungus Epicoccum sorghinum L28 from Myoporum bontioides by introducing guaiol, an ingredient of M. bontioides, into the cultivation medium, which resulted in the purification of nine new diphenyl ethers, epicoccethers A-I (1-9). Their structures were determined by overall spectroscopic analysis. HPLC-MS analysis revealed that compounds 5-7 were products generated by induction of guaiol. Compounds 6 and 7 are the first members containing an ester moiety formed by the natural long-chain fatty acid and the hydroxyl group in the phenylmethanol unit of the diphenyl ether class. The antifungal activities of compounds 1, 2, and 4-7 against Fusarium oxysporum were 1, 1, 2, 1, 2 and 4 times as high as those of the positive control triadimefon, respectively. Compounds 4 and 5 showed 1.6 times the antifungal activities of triadimefon towards Colletotrichum musae.


Assuntos
Antifúngicos/farmacologia , Ascomicetos/química , Colletotrichum/efeitos dos fármacos , Fusarium/efeitos dos fármacos , Éteres Fenílicos/farmacologia , Antifúngicos/química , Antifúngicos/isolamento & purificação , Relação Dose-Resposta a Droga , Testes de Sensibilidade Microbiana , Estrutura Molecular , Éteres Fenílicos/química , Éteres Fenílicos/isolamento & purificação , Relação Estrutura-Atividade
14.
Nanotechnology ; 31(37): 375402, 2020 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-32480386

RESUMO

Transition metal element doping into semiconducting materials has been a promising method for the preparation of active photocatalysts for the efficient use of solar energy. In this study, we report the facile synthesis of Fe doped SrWO4 nanoparticles by a solvothermal method for photocatalytic nitrogen reduction. The intrinsic bandgap of SrWO4 is greatly narrowed by the Fe-dopant which not only extends the light absorption from UV to visible light range, but also reduces the charge recombination. The narrowed band structure still fulfils the thermodynamic requirements of nitrogen reduction reaction. At optimal doping concentration, Fe doped SrWO4 shows much higher photocatalytic nitrogen fixation performance. The present study provides a route toward the development of active photocatalysts for nitrogen fixation.

15.
Bioorg Chem ; 104: 104300, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-33011529

RESUMO

To check whether the endophytic fungus from the host plant could produce novel bioactive metabolites induced by the host-derived chemical components, a strategy called "Induction of Endophyte Metabolism by Adding Host Components" (IEMAHC) was put up and applied. Cultivation of the endophytic fungus Botryosphaeria ramosa L29 derived from Myoporum bontioides after adding (2R, 3R)-3, 5, 7-trihydroxyflavanone 3-acetate, a constituent of the same plant, into the culture medium, led to the separation of three new chromones, 5-hydroxy-2, 3-dihydroxymethyl-7-methoxychromone (1), 5-hydroxy-3-acetoxymethyl-2-methyl-7- methoxychromone (2), 5, 7-dihydroxy-3-hydroxymethyl-2-methylchromone (3), one new isocoumarin, 8-hydroxy-3-hydroxymethyl-6-methoxy-7-methylisocoumarin (4), two new δ-lactones, botryopyrone (8) and (5S, 8R)-simplicilopyrone (9), one new naturally rare 2 (7H)-oxepinone, botroxepinone (10), and three known compounds (5-7). They were identified through comprehensive analysis of spectroscopic data. HPLC comparative analysis indicated that compounds 8-10 were induced products after adding (2R, 3R)-3, 5, 7-trihydroxyflavanone 3-acetate as an inducer. Compound 3 exhibited more potent inhibitory activities on Fusarium oxysporum, Fusarium graminearum, Penicillium italicum, and Colletotrichum musae than triadimefon. Compounds 1, 2, 4-7 and 9 displayed potent antifungal activities towards two or three tested fungi with MIC values equal or superior to triadimefon. The induced products 9 and 10 both showing strong inhibitory activity against C. musae, might play a role in strengthening the host defense against the common mangrove invasive pathogenic fungal genera Colletotrichum.


Assuntos
Antifúngicos/farmacologia , Ascomicetos/química , Flavanonas/farmacologia , Antifúngicos/química , Antifúngicos/metabolismo , Ascomicetos/metabolismo , Colletotrichum/efeitos dos fármacos , Relação Dose-Resposta a Droga , Fermentação , Flavanonas/química , Flavanonas/metabolismo , Fusarium/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Estrutura Molecular , Penicillium/efeitos dos fármacos , Relação Estrutura-Atividade
16.
Med Sci Monit ; 26: e918746, 2020 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-32319429

RESUMO

With the increasing incidence of male infertility, routine detection of semen is insufficient to accurately assess male fertility. Infertile men, who have lower odds of conceiving naturally, exhibit high levels of sperm DNA fragmentation (SDF). The mechanisms driving SDF include abnormal spermatogenesis, oxidative stress damage, and abnormal sperm apoptosis. As these factors can induce SDF and subsequent radical changes leading to male infertility, detection of the extent of SDF has become an efficient routine method for semen analysis. Although it is still debated, SDF detection has become a research hotspot in the field of reproductive medicine as a more accurate indicator for assessing sperm quality and male fertility. SDF may be involved in male infertility, reproductive assisted outcomes, and growth and development of offspring. The effective detection methods of SDF are sperm chromatin structure analysis (SCSA), terminal transferase-mediated dUTP end labeling (TUNEL) assay, single-cell gel electrophoresis (SCGE) assay, and sperm chromatin dispersion (SCD) test, and all of these methods are valuable for assisted reproductive techniques. Currently, the preferred method for detecting sperm DNA integrity is SCSA. However, the regulation network of SDF is very complex because the sperm DNA differs from the somatic cell DNA with its unique structure. A multitude of molecular factors, including coding genes, non-coding genes, or methylated DNA, participate in the complex physiological regulation activities associated with SDF. Studying SDF occurrence and the underlying mechanisms may effectively improve its clinical treatments. This review aimed to outline the research status of SDF mechanism and detection technology-related issues, as well as the effect of increased SDF rate, aiming to provide a basis for clinical male infertility diagnosis and treatment.


Assuntos
Infertilidade Masculina/genética , Análise do Sêmen/métodos , Espermatozoides/citologia , DNA/genética , Fragmentação do DNA , Humanos , Infertilidade Masculina/metabolismo , Masculino , Técnicas de Reprodução Assistida , Sêmen/citologia , Sêmen/metabolismo
17.
J Assist Reprod Genet ; 37(7): 1711-1718, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32445153

RESUMO

PURPOSE: To explore the whole-chromosome status, origins, and mechanisms of chromosomal abnormalities in good-quality cleavage embryos using multiple annealing and looping-based amplification cycle (MALBAC) sequencing. METHODS: The embryos studied came from7 patients (maternal aged 26-35) who had healthy birth from the same IVF cycles. These 21 frozen day 3 good-quality embryos were thawed and disaggregated into individual blastomere. Each blastomere was collected and analyzed by MALBAC sequencing. RESULTS: Conclusive results were obtained from a high percentage of blastomeres (95.3%). A total of 46.6% of blastomeres were diploid, 53.4% were abnormal, and 28.0% had complex aneuploidy. Out of 21 embryos, 3 (14.3%) were normal and 18 (85.7%) were mosaics, showing the occurrence of mitotic errors; aneuploidy was confirmed in all cells of 4 of the 18 embryos, which showed the coexistence of meiotic errors. Conclusive results were obtained from all blastomeres of 15 embryos (71.4%, 15/21), which enabled us to reconstruct the cell lineage on the basis of the chromosomal content of the blastomeres in each division. There were 9 mitotic errors (8.7%, 9/103): nondisjunction accounted for 88.9% (8/9), and endoreplication accounted for 11.1% (1/9). CONCLUSIONS: In good-quality embryos, there was a high rate and diverse array of chromosomal abnormalities. Morphological evaluation does not appear to assist in the reduction in meiotic errors from parental origins. Mitotic errors were common, and nondisjunction was found to be the main mechanism causing malsegregation during the cleavage divisions.


Assuntos
Aneuploidia , Blastômeros/citologia , Blastômeros/fisiologia , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Diagnóstico Pré-Implantação/métodos , Adulto , Aberrações Cromossômicas , Feminino , Fertilização in vitro , Humanos , Masculino , Idade Materna , Mosaicismo , Ploidias
18.
Zhonghua Yi Xue Yi Chuan Xue Za Zhi ; 37(9): 934-937, 2020 Sep 10.
Artigo em Zh | MEDLINE | ID: mdl-32820502

RESUMO

OBJECTIVE: To apply single cell sequencing based on multiple annealing and looping amplification cycles (MALBAC) for the determination of the rate and type of mosaicisms of high-quality embryos at cleavage stage. METHODS: After thawing and removing of zona pellucida by enzymatic digestion, blastomeres were collected the high-quality embryos donated by couples whom had given birth to healthy offspring by intracytoplasmic sperm injection and embryo transfer. The whole genome of single cell was amplified and subjected to next generation sequencing. RESULTS: From a total of 23 embryos, 184 blastomeres were collected. 175 (95.1%) of the blastomeres were successfully sequenced, of which 100 (57.1%) were found to harbor chromosomal aneuploidies. Among the 23 embryos, 3 (13.0%) were diploid, 20 (87.0%) were mosaicisms, which included 5 (21.7%) aneuploid mosaicisms, 7 (30.4%) diploid-aneuploid mosaicisms, 5 (21.7%) abnormal mosaicisms, and 3 (13.0%) irregular segregations. CONCLUSION: There is a high rate of chromosomal mosaicisms in high-quality cleavage embryos. Mosaicisms of complex chromosomal abnormality or with high proportion of abnormal cells may be an important factor affecting the potential of embryonic development.


Assuntos
Testes Genéticos , Mosaicismo , Diagnóstico Pré-Implantação , Análise de Célula Única , Aneuploidia , Blastômeros , Hibridização Genômica Comparativa , Feminino , Fertilização in vitro , Humanos , Gravidez
19.
Lab Invest ; 99(4): 483-498, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30487595

RESUMO

Polyploid giant cancer cells (PGCCs) are key contributors to cancer heterogeneity, and the formation of PGCCs is associated with changes in the expression of cell-cycle-related proteins. This study investigated the intracellular localization and expression level of multiple cell-cycle-related proteins in PGCCs derived from BT-549 and HEY cells. In addition, the formation of PGCCs and the clinicopathological significance of cell-cycle-related proteins in human breast and ovarian cancer were examined. The expression levels of cell-cycle-related proteins, including cyclin B1, CDC25B, CDC25C, and other cell cycle phosphoproteins, including Chk2, and Aurora-A kinase, were determined using immunostaining and western blotting both in vitro and in vivo. Migration, invasion, and proliferation in control cells, cyclin B1 knockdown cells and their PGCCs following CoCl2 treatment were compared. In addition, human breast and ovarian cancer samples were collected to determine the correlation of number of PGCCs, expression of cell-cycle-related proteins, and tumor pathologic grade and metastasis. Our results confirm that cyclin B1 was localized in the cytoplasm of PGCCs and in the nuclei of their budding daughter cells. The phosphorylated proteins Chk2 and Aurora-A kinase regulated the expression and subcellular localization of cyclin B1, CDC25B, and CDC25C. The rate of positive cytoplasmic staining of cyclin B1 and positive nuclear staining of both CDC25B and CDC25C increased with increase in tumor grade and lymph node metastasis. Cell-cycle-related proteins, including cyclin B1, CDC25B, and CDC25C play an important role in regulating the formation of PGCCs. The inhibition of cyclinB1 and CoCl2 treatment significantly promoted cell proliferation, invasion, and migration abilities. The subcellular localization of these cell-cycle-related proteins was regulated by other cell cycle phosphoproteins, and was associated with pathologic grade and metastasis of tumors in cases of human breast and ovarian cancer.


Assuntos
Neoplasias da Mama , Proteínas de Ciclo Celular/metabolismo , Ciclina B1/metabolismo , Neoplasias Ovarianas , Fosfatases cdc25/metabolismo , Neoplasias da Mama/química , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Neoplasias da Mama/fisiopatologia , Proteínas de Ciclo Celular/análise , Linhagem Celular Tumoral , Ciclina B1/análise , Feminino , Humanos , Espaço Intracelular/metabolismo , Processos Neoplásicos , Neoplasias Ovarianas/química , Neoplasias Ovarianas/metabolismo , Neoplasias Ovarianas/patologia , Neoplasias Ovarianas/fisiopatologia , Poliploidia , Fosfatases cdc25/análise
20.
J Nat Prod ; 82(8): 2268-2278, 2019 08 23.
Artigo em Inglês | MEDLINE | ID: mdl-31365251

RESUMO

Eleven new ophiobolin-type sesterterpenoids, asperophiobolins A-K (1-11), along with 12 known analogues (12-23) were isolated from the cultures of the mangrove endophytic fungus Aspergillus sp. ZJ-68. The structures of the new compounds were elucidated through spectroscopic analyses, and their absolute configurations were assigned by a combination of Mo2(AcO)4-induced electronic circular dichroism spectra and quantum chemical calculations. Asperophiobolins A-D (1-4) represent the first examples possessing a five-membered lactam unit between C-5 and C-21 in ophiobolin derivatives. In the bioactivity assays, compounds 8-10 and 14-17 exhibited inhibitory effects on lipopolysaccharide-induced nitric oxide production in RAW 264.7 macrophage cells with IC50 values ranging from 9.6 to 25 µM, and compound 8 was found to show comparable inhibition of Mycobacterium tuberculosis protein tyrosine phosphatase B with an IC50 value of 19 µM.


Assuntos
Aspergillus/química , Rhizophoraceae/microbiologia , Sesterterpenos/isolamento & purificação , Animais , Camundongos , Células RAW 264.7 , Sesterterpenos/farmacologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA