Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 1.006
Filtrar
Mais filtros

Intervalo de ano de publicação
1.
Immunity ; 56(8): 1910-1926.e7, 2023 08 08.
Artigo em Inglês | MEDLINE | ID: mdl-37478854

RESUMO

Highly effective vaccines elicit specific, robust, and durable adaptive immune responses. To advance informed vaccine design, it is critical that we understand the cellular dynamics underlying responses to different antigen formats. Here, we sought to understand how antigen-specific B and T cells were activated and participated in adaptive immune responses within the mucosal site. Using a human tonsil organoid model, we tracked the differentiation and kinetics of the adaptive immune response to influenza vaccine and virus modalities. Each antigen format elicited distinct B and T cell responses, including differences in their magnitude, diversity, phenotype, function, and breadth. These differences culminated in substantial changes in the corresponding antibody response. A major source of antigen format-related variability was the ability to recruit naive vs. memory B and T cells to the response. These findings have important implications for vaccine design and the generation of protective immune responses in the upper respiratory tract.


Assuntos
Vacinas contra Influenza , Influenza Humana , Humanos , Formação de Anticorpos , Anticorpos Antivirais , Linfócitos T , Antígenos , Organoides
2.
J Biol Chem ; 300(3): 105702, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38301896

RESUMO

Elevated levels of branched chain amino acids (BCAAs) and branched-chain α-ketoacids are associated with cardiovascular and metabolic disease, but the molecular mechanisms underlying a putative causal relationship remain unclear. The branched-chain ketoacid dehydrogenase kinase (BCKDK) inhibitor BT2 (3,6-dichlorobenzo[b]thiophene-2-carboxylic acid) is often used in preclinical models to increase BCAA oxidation and restore steady-state BCAA and branched-chain α-ketoacid levels. BT2 administration is protective in various rodent models of heart failure and metabolic disease, but confoundingly, targeted ablation of Bckdk in specific tissues does not reproduce the beneficial effects conferred by pharmacologic inhibition. Here, we demonstrate that BT2, a lipophilic weak acid, can act as a mitochondrial uncoupler. Measurements of oxygen consumption, mitochondrial membrane potential, and patch-clamp electrophysiology show that BT2 increases proton conductance across the mitochondrial inner membrane independently of its inhibitory effect on BCKDK. BT2 is roughly sixfold less potent than the prototypical uncoupler 2,4-dinitrophenol and phenocopies 2,4-dinitrophenol in lowering de novo lipogenesis and mitochondrial superoxide production. The data suggest that the therapeutic efficacy of BT2 may be attributable to the well-documented effects of mitochondrial uncoupling in alleviating cardiovascular and metabolic disease.


Assuntos
Lipogênese , Doenças Metabólicas , Membranas Mitocondriais , Inibidores de Proteínas Quinases , Espécies Reativas de Oxigênio , Humanos , 2,4-Dinitrofenol/farmacologia , 3-Metil-2-Oxobutanoato Desidrogenase (Lipoamida)/metabolismo , Aminoácidos de Cadeia Ramificada/metabolismo , Lipogênese/efeitos dos fármacos , Inibidores de Proteínas Quinases/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Animais , Camundongos , Ratos , Linhagem Celular , Membranas Mitocondriais/efeitos dos fármacos , Células Cultivadas
3.
Mol Biol Evol ; 41(7)2024 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-38941083

RESUMO

Insect crop pests threaten global food security. This threat is amplified through the spread of nonnative species and through adaptation of native pests to control measures. Adaptations such as pesticide resistance can result from selection on variation within a population, or through gene flow from another population. We investigate these processes in an economically important noctuid crop pest, Helicoverpa zea, which has evolved resistance to a wide range of pesticides. Its sister species Helicoverpa armigera, first detected as an invasive species in Brazil in 2013, introduced the pyrethroid-resistance gene CYP337B3 to South American H. zea via adaptive introgression. To understand whether this could contribute to pesticide resistance in North America, we sequenced 237 H. zea genomes across 10 sample sites. We report H. armigera introgression into the North American H. zea population. Two individuals sampled in Texas in 2019 carry H. armigera haplotypes in a 4 Mbp region containing CYP337B3. Next, we identify signatures of selection in the panmictic population of nonadmixed H. zea, identifying a selective sweep at a second cytochrome P450 gene: CYP333B3. We estimate that its derived allele conferred a ∼5% fitness advantage and show that this estimate explains independently observed rare nonsynonymous CYP333B3 mutations approaching fixation over a ∼20-year period. We also detect putative signatures of selection at a kinesin gene associated with Bt resistance. Overall, we document two mechanisms of rapid adaptation: the introduction of fitness-enhancing alleles through interspecific introgression, and selection on intraspecific variation.


Assuntos
Introgressão Genética , Resistência a Inseticidas , Mariposas , Animais , Mariposas/genética , Resistência a Inseticidas/genética , Sistema Enzimático do Citocromo P-450/genética , América do Norte , Adaptação Biológica/genética , Adaptação Fisiológica/genética , Seleção Genética , Espécies Introduzidas
4.
J Bacteriol ; 206(10): e0023524, 2024 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-39330254

RESUMO

Bacteroides species are successful colonizers of the human colon and can utilize a wide variety of complex polysaccharides and oligosaccharides that are indigestible by the host. To do this, they use enzymes encoded in polysaccharide utilization loci (PULs). While recent work has uncovered the PULs required for the use of some polysaccharides, how Bacteroides utilize smaller oligosaccharides is less well studied. Raffinose family oligosaccharides (RFOs) are abundant in plants, especially legumes, and consist of variable units of galactose linked by α-1,6 bonds to a sucrose (glucose α-1-ß-2 fructose) moiety. Previous work showed that an α-galactosidase, BT1871, is required for RFO utilization in Bacteroides thetaiotaomicron. Here, we identify two different types of mutations that increase BT1871 mRNA levels and improve B. thetaiotaomicron growth on RFOs. First, a novel spontaneous duplication of BT1872 and BT1871 places these genes under the control of a ribosomal promoter, driving high BT1871 transcription. Second, nonsense mutations in a gene encoding the PUL24 anti-sigma factor likewise increase BT1871 transcription. We then show that hydrolases from PUL22 work together with BT1871 to break down the sucrose moiety of RFOs and determine that the master regulator of carbohydrate utilization (BT4338) plays a role in RFO utilization in B. thetaiotaomicron. Examining the genomes of other Bacteroides species, we found homologs of BT1871 in a subset and showed that representative strains of species with a BT1871 homolog grew better on melibiose than species that lack a BT1871 homolog. Altogether, our findings shed light on how an important gut commensal utilizes an abundant dietary oligosaccharide. IMPORTANCE: The gut microbiome is important in health and disease. The diverse and densely populated environment of the gut makes competition for resources fierce. Hence, it is important to study the strategies employed by microbes for resource usage. Raffinose family oligosaccharides are abundant in plants and are a major source of nutrition for the microbiota in the colon since they remain undigested by the host. Here, we study how the model commensal organism, Bacteroides thetaiotaomicron utilizes raffinose family oligosaccharides. This work highlights how an important member of the microbiota uses an abundant dietary resource.


Assuntos
Proteínas de Bactérias , Bacteroides , Regulação Bacteriana da Expressão Gênica , Oligossacarídeos , Rafinose , Rafinose/metabolismo , Oligossacarídeos/metabolismo , Bacteroides/genética , Bacteroides/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Bacteroides thetaiotaomicron/genética , Bacteroides thetaiotaomicron/metabolismo , Bacteroides thetaiotaomicron/enzimologia , alfa-Galactosidase/metabolismo , alfa-Galactosidase/genética , Mutação
5.
BMC Biotechnol ; 24(1): 37, 2024 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-38825715

RESUMO

BACKGROUND: As part of a publicly funded initiative to develop genetically engineered Brassicas (cabbage, cauliflower, and canola) expressing Bacillus thuringiensis Crystal (Cry)-encoded insecticidal (Bt) toxin for Indian and Australian farmers, we designed several constructs that drive high-level expression of modified Cry1B and Cry1C genes (referred to as Cry1BM and Cry1CM; with M indicating modified). The two main motivations for modifying the DNA sequences of these genes were to minimise any licensing cost associated with the commercial cultivation of transgenic crop plants expressing CryM genes, and to remove or alter sequences that might adversely affect their activity in plants. RESULTS: To assess the insecticidal efficacy of the Cry1BM/Cry1CM genes, constructs were introduced into the model Brassica Arabidopsis thaliana in which Cry1BM/Cry1CM expression was directed from either single (S4/S7) or double (S4S4/S7S7) subterranean clover stunt virus (SCSV) promoters. The resulting transgenic plants displayed a high-level of Cry1BM/Cry1CM expression. Protein accumulation for Cry1CM ranged from 5.18 to 176.88 µg Cry1CM/g dry weight of leaves. Contrary to previous work on stunt promoters, we found no correlation between the use of either single or double stunt promoters and the expression levels of Cry1BM/Cry1CM genes, with a similar range of Cry1CM transcript abundance and protein content observed from both constructs. First instar Diamondback moth (Plutella xylostella) larvae fed on transgenic Arabidopsis leaves expressing the Cry1BM/Cry1CM genes showed 100% mortality, with a mean leaf damage score on a scale of zero to five of 0.125 for transgenic leaves and 4.2 for wild-type leaves. CONCLUSIONS: Our work indicates that the modified Cry1 genes are suitable for the development of insect resistant GM crops. Except for the PAT gene in the USA, our assessment of the intellectual property landscape of components presents within the constructs described here suggest that they can be used without the need for further licensing. This has the capacity to significantly reduce the cost of developing and using these Cry1M genes in GM crop plants in the future.


Assuntos
Arabidopsis , Toxinas de Bacillus thuringiensis , Proteínas de Bactérias , Endotoxinas , Proteínas Hemolisinas , Plantas Geneticamente Modificadas , Plantas Geneticamente Modificadas/genética , Arabidopsis/genética , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Proteínas Hemolisinas/genética , Animais , Endotoxinas/genética , Regiões Promotoras Genéticas/genética , Bacillus thuringiensis/genética , Mariposas/genética , Brassica/genética , Controle Biológico de Vetores/métodos , Inseticidas/farmacologia
6.
Planta ; 260(4): 86, 2024 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-39230667

RESUMO

MAIN CONCLUSION: The review offers insights into the current state of research on insect pest-resistant GM crops and the regulations governing the cultivation of GM crops in India. India has a rich crop diversity of more than 160 major and minor crops through its diverse agroclimatic conditions. Insect pests alone cause around USD 36 billion in crop loss annually in India. The last two decades witnessed considerable progress in managing insect pests by adopting innovative techniques including transgenics. In research, significant advancement has been brought in insect pest-resistant transgenics in India since its inception in 2002. However, any events have not been endorsed owing to biosafety impediments, except Bt cotton reaching the commercial release stage. A landmark decision to exempt certain types of gene-edited plants from genetically modified organism (GMO) regulations offers great promise for developing novel insect-resistant crops in India. The article reviews the current research on insect pest-resistant transgenics and its regulations in India.


Assuntos
Produtos Agrícolas , Insetos , Controle Biológico de Vetores , Plantas Geneticamente Modificadas , Produtos Agrícolas/genética , Índia , Plantas Geneticamente Modificadas/genética , Animais , Insetos/genética , Controle Biológico de Vetores/métodos
7.
Appl Environ Microbiol ; 90(10): e0074224, 2024 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-39291983

RESUMO

The resistance to the insecticidal protein Cry1Ac from the bacterium Bacillus thuringiensis (Bt) in the cabbage looper, Trichoplusia ni, has previously been identified to be associated with a frameshift mutation in the ABC transporter ABCC2 gene and with altered expression of the aminopeptidase N (APN) genes APN1 and APN6, shown as missing of the 110-kDa APN1 (phenotype APN1¯) in larval midgut brush border membrane vesicles (BBMV). In this study, genetic linkage analysis identified that the APN1¯ phenotype and the ABCC2 mutation in Cry1Ac-resistant T. ni segregated independently, although they were always associated under Cry1Ac selection. The ABCC2 mutation and APN1¯ phenotype were separated into two T. ni strains respectively. Bioassays of the T. ni strains with Cry1Ac determined that the T. ni with the APN1¯ phenotype showed a low level resistance to Cry1Ac (3.5-fold), and the associated resistance is incompletely dominant in the background of the ABCC2 mutation. Whereas the ABCC2 mutation-associated resistance to Cry1Ac is at a moderate level, and the resistance is incompletely recessive in the genetic background of downregulated APN1. Analysis of Cry1Ac binding to larval midgut BBMV indicated that the midgut in larvae with the APN1¯ phenotype had reduced binding affinity for Cry1Ac, but the number of binding sites remained unchanged, and the midgut in larvae with the ABCC2 mutation had both reduced binding affinity and reduced number of binding sites for Cry1Ac. The reduced Cry1Ac binding to BBMV from larvae with the ABCC2 mutation or APN1¯ phenotype correlated with the lower levels of resistance.IMPORTANCEThe soil bacterium Bacillus thuringiensis (Bt) is an important insect pathogen used as a bioinsecticide for pest control. Bt genes coding for insecticidal proteins are the primary transgenes engineered into transgenic crops (Bt crops) to confer insect resistance. However, the evolution of resistance to Bt proteins in insect populations in response to exposure to Bt threatens the sustainable application of Bt biotechnology. Cry1Ac is a major insecticidal toxin utilized for insect control. Genetic mechanisms of insect resistance to Cry1Ac are complex and require to be better understood. The resistance to Cry1Ac in Trichoplusia ni is associated with a mutation in the ABCC2 gene and also associated with the APN expression phenotype APN1¯. This study identified the genetic independence of the APN1¯ phenotype from the ABCC2 mutation and isolated and analyzed the ABCC2 mutation-associated and APN1¯ phenotype-associated resistance traits in T. ni to provide new insights into the genetic mechanisms of Cry1Ac resistance in insects.


Assuntos
Toxinas de Bacillus thuringiensis , Bacillus thuringiensis , Proteínas de Bactérias , Antígenos CD13 , Endotoxinas , Proteínas Hemolisinas , Resistência a Inseticidas , Mariposas , Proteínas Associadas à Resistência a Múltiplos Medicamentos , Mutação , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Animais , Endotoxinas/genética , Endotoxinas/metabolismo , Endotoxinas/farmacologia , Proteínas Hemolisinas/genética , Proteínas Hemolisinas/farmacologia , Proteínas Hemolisinas/metabolismo , Resistência a Inseticidas/genética , Proteínas Associadas à Resistência a Múltiplos Medicamentos/genética , Proteínas Associadas à Resistência a Múltiplos Medicamentos/metabolismo , Bacillus thuringiensis/genética , Mariposas/genética , Antígenos CD13/genética , Antígenos CD13/metabolismo , Larva/genética , Larva/crescimento & desenvolvimento , Proteína 2 Associada à Farmacorresistência Múltipla , Regulação para Baixo , Inseticidas/farmacologia , Proteínas de Insetos/genética , Proteínas de Insetos/metabolismo
8.
Appl Environ Microbiol ; 90(4): e0177823, 2024 04 17.
Artigo em Inglês | MEDLINE | ID: mdl-38470126

RESUMO

The Bacillus cereus sensu stricto (s.s.) species comprises strains of biovar Thuringiensis (Bt) known for their bioinsecticidal activity, as well as strains with foodborne pathogenic potential. Bt strains are identified (i) based on the production of insecticidal crystal proteins, also known as Bt toxins, or (ii) based on the presence of cry, cyt, and vip genes, which encode Bt toxins. Multiple bioinformatics tools have been developed for the detection of crystal protein-encoding genes based on whole-genome sequencing (WGS) data. However, the performance of these tools is yet to be evaluated using phenotypic data. Thus, the goal of this study was to assess the performance of four bioinformatics tools for the detection of crystal protein-encoding genes. The accuracy of sequence-based identification of Bt was determined in reference to phenotypic microscope-based screening for the production of crystal proteins. A total of 58 diverse B. cereus sensu lato strains isolated from clinical, food, environmental, and commercial biopesticide products underwent WGS. Isolates were examined for crystal protein production using phase contrast microscopy. Crystal protein-encoding genes were detected using BtToxin_Digger, BTyper3, IDOPS (identification of pesticidal sequences), and Cry_processor. Out of 58 isolates, the phenotypic production of crystal proteins was confirmed for 18 isolates. Specificity and sensitivity of Bt identification based on sequences were 0.85 and 0.94 for BtToxin_Digger, 0.97 and 0.89 for BTyper3, 0.95 and 0.94 for IDOPS, and 0.88 and 1.00 for Cry_processor, respectively. Cry_processor predicted crystal protein production with the highest specificity, and BtToxin_Digger and IDOPS predicted crystal protein production with the highest sensitivity. Three out of four tested bioinformatics tools performed well overall, with IDOPS achieving high sensitivity and specificity (>0.90).IMPORTANCEStrains of Bacillus cereus sensu stricto (s.s.) biovar Thuringiensis (Bt) are used as organic biopesticides. Bt is differentiated from the foodborne pathogen Bacillus cereus s.s. by the production of insecticidal crystal proteins. Thus, reliable genomic identification of biovar Thuringiensis is necessary to ensure food safety and facilitate risk assessment. This study assessed the accuracy of whole-genome sequencing (WGS)-based identification of Bt compared to phenotypic microscopy-based screening for crystal protein production. Multiple bioinformatics tools were compared to assess their performance in predicting crystal protein production. Among them, identification of pesticidal sequences performed best overall at WGS-based Bt identification.


Assuntos
Bacillus thuringiensis , Inseticidas , Bacillus thuringiensis/genética , Bacillus thuringiensis/metabolismo , Bacillus cereus/genética , Toxinas de Bacillus thuringiensis , Genoma Bacteriano , Genômica , Inseticidas/metabolismo , Proteínas de Bactérias/química
9.
Strahlenther Onkol ; 200(5): 367-376, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38108835

RESUMO

PURPOSE: Brachytherapy (BT), also known as interventional radiotherapy (IRT), has proven its utility in the treatment of localized tumors. The aim of this review was to examine the efficacy of modern BT in early-stage oral cavity cancer (OCC) in terms of local control (LC), overall survival (OS), disease-free survival (DFS), cancer-specific survival (CSS), and safety. METHODS: The SPIDER framework was used, with sample (S), phenomena of interest (PI), design (D), evaluation (E), and research type (R) corresponding to early-stage oral cavity cancer (S); BT (PI); named types of qualitative data collection and analysis (D); LC, OS, DFS, CSS, and toxicity (E); qualitative method (R). Systematic research using PubMed and Scopus was performed to identify full articles evaluating the efficacy of BT in patients with early-stage OCC. The studies were identified using medical subject headings (MeSH). We also performed a PubMed search with the keywords "brachytherapy oral cavity cancer, surgery." The search was restricted to the English language. The timeframe 2002-2022 as year of publication was considered. We analyzed clinical studies of patients with OCC treated with BT alone only as full text; conference papers, surveys, letters, editorials, book chapters, and reviews were excluded. RESULTS: The literature search resulted in 517 articles. After the selection process, 7 studies fulfilled the inclusion criteria and were included in this review, totaling 456 patients with early-stage node-negative OCC who were treated with BT alone (304 patients). Five-year LC, DFS, and OS for the BT group were 60-100%, 82-91%, and 50-84%, respectively. CONCLUSION: In conclusion, our review suggests that BT is effective in the treatment of early-stage OCC, particularly for T1N0 of the lip, mobile tongue, and buccal mucosa cancers, with good functional and toxicity profiles.


Assuntos
Braquiterapia , Neoplasias Bucais , Braquiterapia/métodos , Neoplasias Bucais/radioterapia , Humanos , Estadiamento de Neoplasias , Intervalo Livre de Doença , Resultado do Tratamento
10.
Anal Biochem ; 693: 115584, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-38843975

RESUMO

Using the amino acid sequences and analysis of selected known structures of Bt Cry toxins, Cry1Ab, Cry1Ac, Cry1Ah, Cry1B, Cry1C and Cry1F we specifically designed immunogens. After antibodies selection, broad-spectrum polyclonal antibodies (pAbs) and monoclonal antibody (namely 1A0-mAb) were obtained from rabbit and mouse, respectively. The produced pAbs displayed broad spectrum activity by recognizing Cry1 toxin, Cry2Aa, Cry2Ab and Cry3Aa with half maximal inhibitory concentration (IC50) values of 0.12-9.86 µg/mL. Similarly, 1A0-mAb showed broad spectrum activity, recognizing all of the above Cry protein (IC50 values of 4.66-20.46 µg/mL) with the exception of Cry2Aa. Using optimizations studies, 1A10-mAb was used as a capture antibody and pAbs as detection antibody. Double antibody sandwich enzyme-linked immunosorbent assays (DAS-ELISAs) were established for Cry1 toxin, Cry2Ab and Cry3Aa with the limit of detection (LOD) values of 2.36-36.37 ng/mL, respectively. The present DAS-ELISAs had good accuracy and precisions for the determination of Cry toxin spiked tap water, corn, rice, soybeans and soil samples. In conclusion, the present study has successfully obtained broad-spectrum pAbs and mAb. Furthermore, the generated pAbs- and mAb-based DAS-ELISAs protocol can potentially be used for the broad-spectrum monitoring of eight common subtypes of Bt Cry toxins residues in food and environmental samples.


Assuntos
Anticorpos Monoclonais , Toxinas de Bacillus thuringiensis , Endotoxinas , Ensaio de Imunoadsorção Enzimática , Proteínas Hemolisinas , Animais , Ensaio de Imunoadsorção Enzimática/métodos , Coelhos , Camundongos , Endotoxinas/análise , Endotoxinas/imunologia , Proteínas Hemolisinas/imunologia , Proteínas Hemolisinas/análise , Proteínas Hemolisinas/química , Anticorpos Monoclonais/imunologia , Anticorpos Monoclonais/química , Proteínas de Bactérias/imunologia , Proteínas de Bactérias/química , Proteínas de Bactérias/análise , Bacillus thuringiensis/química , Camundongos Endogâmicos BALB C
11.
Ann Hematol ; 103(4): 1397-1402, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38367057

RESUMO

B/T mixed phenotype acute leukemia (MPAL), which represents only 2-3% of all MPAL cases, is classified as a high-risk leukemia subtype. Adults diagnosed with B/T MPAL have a notably low 3-year survival rate, estimated at 20-40%. The rarity and undercharacterization of B/T MPAL present substantial challenges in identifying an optimal treatment protocol. This report aims to shed light on this issue by presenting a case in which a patient with a complex karyotype was treated using a combination of venetoclax, azacitidine, and blinatumomab. This novel, chemo-free regimen resulted in the patient achieving both hematologic and molecular complete remission, with no severe organ or hematological toxicity observed. Notably, the patient continued to maintain molecular remission for 1 year following the transplantation. Based on these findings, the combination of venetoclax, azacitidine, and blinatumomab could be considered a potential therapeutic approach for B/T MPAL patients, meriting further investigation.


Assuntos
Anticorpos Biespecíficos , Azacitidina , Compostos Bicíclicos Heterocíclicos com Pontes , Leucemia , Sulfonamidas , Adulto , Humanos , Azacitidina/uso terapêutico , Leucemia/terapia , Doença Aguda
12.
Am J Obstet Gynecol ; 230(3S): S1076-S1088, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37690862

RESUMO

Obstetrical hemorrhage is a relatively frequent obstetrical complication and a common cause of maternal morbidity and mortality worldwide. The majority of maternal deaths attributable to hemorrhage are preventable, thus, developing rapid and effective means of treating postpartum hemorrhage is of critical public health importance. Intrauterine devices are one option for managing refractory hemorrhage, with rapid expansion of available devices in recent years. Intrauterine packing was historically used for this purpose, with historical cohorts documenting high rates of success. Modern packing materials, including chitosan-covered gauze, have recently been explored with success rates comparable to uterine balloon tamponade in small trials. There are a variety of balloon tamponade devices, both commercial and improvised, available for use. Efficacy of 85.9% was cited in a recent meta-analysis in resolution of hemorrhage with the use of uterine balloon devices, with greatest success in the setting of atony. However, recent randomized trials have demonstrated potential harm associated with improvised balloon tamponade use In low resource settings and the World Health Organization recommends use be restricted to settings where monitoring is available and care escalation is possible. Recently, intrauterine vacuum devices have been introduced, which offer a new mechanism for achieving hemorrhage control by mechanically restoring uterine tone via vacuum suction. The Jada device, which is is FDA-cleared and commercially available in the US, found successful bleeding control in 94% of cases in an initial single-arm trial, with recent post marketing registry study described treatment success following hemorrhage in 95.8% of vaginal and 88.2% of cesarean births. Successful use of improvised vacuum devices has been described in several studies, including suction tube uterine tamponade via Levin tubing, and use of a modified Bakri balloon. Further research is needed with head-to-head comparisons of efficacy of devices and assessment of cost within the context of both device pricing and overall healthcare resource utilization.


Assuntos
Dispositivos Intrauterinos , Hemorragia Pós-Parto , Feminino , Humanos , Gravidez , Cesárea/efeitos adversos , Hemorragia Pós-Parto/etiologia , Hemorragia Pós-Parto/prevenção & controle , Resultado do Tratamento , Tamponamento com Balão Uterino , Útero , Ensaios Clínicos como Assunto
13.
Conserv Biol ; 38(2): e14222, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37990833

RESUMO

Intensification in agriculture affects many insect species, including butterflies. Insect-resistant crops, such as Bt (Bacillus thuringiensis) maize, which produces a toxin active against Lepidoptera, are an alternative to insecticide sprays. Genetically modified crops are regulated in most countries and require an environmental risk assessment. In the European Union, such assessments include the use of simulation models to predict the effects on nontarget Lepidoptera (NTL). To support the assessment of protected NTL, we extended an individual-based, stochastic, spatially explicit mathematical model (LepiX) to include a wider range of exposure scenarios, a species-sensitivity distribution, and an option for repeated exposure of individuals. We applied the model to transgenic maize DAS-1507, which expresses a high concentration of Bt toxin in pollen that may be consumed by NTL larvae on their host plants nearby. Even in the most conservative scenario without repeated exposure, mortality estimates for highly sensitive species ranged from 41% to 6% at distances of 10-1000 m from the nearest maize field. Repeated exposure can cause additional mortality and thus is relevant for the overall risk assessment. Uncertainties in both exposure and ecotoxicity estimates strongly influenced the predicted mortalities. Care should be taken to include these uncertainties in the model scenarios used for decision-making. In accordance with other modeling results, our simulations demonstrated that mean mortality may not be safe for protected species. With its high pollen expression, DAS-1507 maize may pose risks to sensitive and protected butterfly and moth species that may be difficult to manage. High expression of Bt toxin in pollen is unnecessary for controlling target pests. Consequently, we suggest that Bt maize with high pollen expression not be cultivated in regions where protected butterflies are to be conserved.


La intensificación en la agricultura afecta a muchas especies de insectos, incluyendo a las mariposas. Los cultivos resistentes a los insectos, como el maíz Bt (Bacillus thuringiensis), el cual produce una toxina activa contra los lepidópteros, son una alternativa a los insecticidas. Los cultivos genéticamente modificados (GM) están regulados en la mayoría de los países y requieren de una evaluación de riesgo ambiental. En la Unión Europea (EU), dichas evaluaciones incluyen el uso de modelos de simulación para pronosticar los efectos sobre los lepidópteros no objetivo (LNO). Para apoyar a la evaluación de LNO protegidos, extendimos un modelo matemático espacialmente explícito, estocástico y basado en el individuo (LepiX) para incluir una mayor gama de escenarios de exposición, una distribución de la sensibilidad de las especies y una opción para la exposición repetida de los individuos. Aplicamos el modelo al maíz transgénico DAS­1507, el cual expresa una alta concentración de toxina Bt en el polen que puede ser consumido por las larvas de LNO en una planta hospedera cercana. Incluso en el escenario más conservador sin una exposición repetida, las estimaciones de mortalidad para las especies altamente sensibles variaron entre el 41% y el 6% en distancias de 10­1000 m a partir del campo de maíz más cercano. La exposición repetida puede causar mortalidad adicional y por lo tanto es relevante para la evaluación general del riesgo. La incertidumbre en las estimaciones de la exposición y la ecotoxicidad influyeron fuertemente sobre la mortalidad pronosticada. Se debe tener cuidado de incluir estas incertidumbres en los escenarios modelados usados para la toma de decisiones. De acuerdo con los resultados de otros modelos, nuestras simulaciones demostraron que la mortalidad media podría no ser segura para las especies protegidas. Con su alta producción de polen, el maíz DAS­1507 podría representar un riesgo difícil de manejar para las especies de mariposas y polillas sensibles y protegidas. No se necesita una expresión elevada de la toxina Bt en el polen para controlar a las plagas. En consecuencia, sugerimos que no se cultive el maíz Bt con una alta producción de polen en las regiones en donde se busca conservar a las mariposas protegidas. Presión del maíz resistente a insectos sobre mariposas y polillas protegidas.


Assuntos
Borboletas , Mariposas , Animais , Borboletas/genética , Mariposas/genética , Zea mays/genética , Zea mays/metabolismo , Toxinas de Bacillus thuringiensis/metabolismo , Produtos Agrícolas , Plantas Geneticamente Modificadas/genética , Conservação dos Recursos Naturais , Insetos , Larva/genética
14.
Clin Chem Lab Med ; 62(12): 2461-2468, 2024 Nov 26.
Artigo em Inglês | MEDLINE | ID: mdl-38753471

RESUMO

OBJECTIVES: Even in the current era of hematology analyzer automation and peripheral equipment, quality control sample measurement remains a manual task, leading to variability in quality control data and increased workload. In this study, we evaluated the performance of quality control measurement using the BT-50 Transportation Unit (BT-50, Sysmex, Kobe, Japan), equipped with a scheduled automatic quality control function, to ensure measurement accuracy and streamline the workflow of hematology testing. METHODS: We evaluated the automatic measurement performance of quality control samples using the BT-50 for six representative blood test parameters: WBC (white blood cell), RBC (red blood cell), HGB (hemoglobin), HCT (hematocrit), PLT (platelet), and RET% (reticulocyte percent). We evaluated the equivalence and compared measurement accuracy between the BT-50 and the manual method. We then compared the variability to other laboratories and confirmed the stability of quality control samples. We also evaluated changes in workflow and staff resources before and after the introduction of the BT-50. RESULTS: The quality control measurement results for the BT-50 and the manual method were found to be equivalent for all six parameters. The variability measured by the BT-50 was lower for some parameters compared to the manual method. Furthermore, the workflow was streamlined by reducing manual processes, resulting in increased efficiency. CONCLUSIONS: We confirmed the performance of quality control measurements using the schedule function of the BT-50. Introducing the BT-50 reduced the operator's workload, improved operational efficiency, and promoted the standardization of quality control measurements.


Assuntos
Controle de Qualidade , Humanos , Automação , Testes Hematológicos/normas , Testes Hematológicos/métodos , Automação Laboratorial/normas
15.
Mol Biol Rep ; 51(1): 832, 2024 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-39037638

RESUMO

BACKGROUND: JAK/STAT signaling plays an important role in regulating cell proliferation. Reducing proliferation and inducing cell death with gene-specific inhibitors such as ruxolitinib, Receptor tyrosine kinases (RTK) inhibitor targeting JAK1/2, are therapeutic approaches. The use of nanoparticles can reduce the toxicity and side effects of drugs, as they act directly on cancer cells and can selectively increase drug accumulation in tumor cells. Poly-ɛ-caprolactone (PCL) is a polymer that is frequently used in drug development. In this study, Rux-PCL-NPs were synthesized to increase the effectiveness of ruxolitinib. In addition, this study aimed to determine the effect of Rux-PCL-NPs on JAK/STAT signaling and apoptotic cell death. METHODS AND RESULTS: Rux-PCL-NPs were synthesized by nanoprecipitation. The Rux-PCL-NPs had a spherical and mean particle size of 219 ± 88.66 nm and a zeta potential of 0.471 ± 0.453 mV. In vitro cytotoxicity and antiproliferative effects were determined by MTT and soft agar colony formation assays, respectively. The effects of ruxolitinib, PCL-NPs, and Rux-PCL-NPs on apoptosis and the JAK/STAT pathway in cells were examined by western blot analysis. PCL-NPs did not have a toxic effect on the cells. The IC50 value of Rux-PCL-NPs was decreased 50-fold compared to that of ruxolitinib. Rux-PCL-NPs promoted cell death by downregulating JAK2 and STAT5, thereby inhibiting the JAK/STAT pathway. CONCLUSIONS: Our results revealed that Rux-PCL-NPs, which increased the efficacy of ruxolitinib, regulated apoptosis and the JAK2/STAT5 pathway.


Assuntos
Apoptose , Neoplasias da Mama , Proliferação de Células , Janus Quinase 2 , Nanopartículas , Nitrilas , Poliésteres , Pirazóis , Pirimidinas , Fator de Transcrição STAT5 , Transdução de Sinais , Nitrilas/farmacologia , Humanos , Pirazóis/farmacologia , Pirimidinas/farmacologia , Janus Quinase 2/metabolismo , Fator de Transcrição STAT5/metabolismo , Transdução de Sinais/efeitos dos fármacos , Linhagem Celular Tumoral , Poliésteres/química , Nanopartículas/química , Feminino , Proliferação de Células/efeitos dos fármacos , Apoptose/efeitos dos fármacos , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo
16.
Environ Res ; 263(Pt 1): 120006, 2024 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-39299448

RESUMO

The impacts of transgenic crops on soil microbiology and fertility are critical in determining their biosafety. While transgenic crops can alter soil microbes, their effects are often context-dependent; therefore, the ecological importance of these changes remains a topic of ongoing research. Using high-throughput sequencing, we investigated the effects of Bacillus thuringiensis (Bt) maize expressing the mcry1Ab and mcry2Ab genes (2A7) on soil nutrient dynamics, as well as the diversity and function of soil microbial communities, including bacteria and fungi, within different soil compartments. Our findings revealed a plant-shaped rhizosphere (RS) microbial community as a result of the selective recruitment of microorganisms from the surrounding environment. The transgene insertion had a significant impact on the RS niche, and several species eventually became associated with Z58 and 2A7 plants. For example, Neocosmospora rubicola fungal and Pantoea dispersa bacterial microorganisms were significantly decreased in the dual Bt-transgenic 2A7 rhizosphere but enriched in the Z58 rhizospheres. The activity of soil enzymes such as urease, invertase, and alkaline phosphatase was boosted by Bt-transgenic 2A7. LefSe analysis identified significant bacterial and fungal biomarker species that were responsible for the differential effects of Bt-transgenic 2A7 and control Z58 within rhizosphere soils. Mantel analysis further demonstrated that the root exudates of 2A7 altered nutrient-acquisition enzymes by influencing biomarker taxa. PICRUSt2 functional characterization revealed a significantly higher abundance of the phosphate-starvation-inducible protein in control Z58 than in Bt-transgenic 2A7. Furthermore, taxonomy, alpha (Shannon diversity), and beta diversity analyses all revealed niche-driven microbial profile differentiation. Niche partitioning also had a significant impact on N- and P-related COGs as well. Our findings suggests that Bt-transgenic 2A7 modulates rhizosphere microbial communities by affecting biomarker taxa and soil enzyme activity. These findings will promote sustainable agriculture practices by advancing our knowledge of the ecological effects of Bt crops on soil microbial communities.

17.
Surg Endosc ; 38(2): 640-647, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38012439

RESUMO

BACKGROUND: Lymph node status is an important factor in determining preoperative treatment strategies for stage T1b-T2 esophageal cancer (EC). Thus, the aim of this study was to investigate the risk factors for lymph node metastasis (LNM) in T1b-T2 EC and to establish and validate a risk-scoring model to guide the selection of optimal treatment options. METHODS: Patients who underwent upfront surgery for pT1b-T2 EC between January 2016 and December 2022 were analyzed. On the basis of the independent risk factors determined by multivariate logistic regression analysis, a risk-scoring model for the prediction of LNM was constructed and then validated. The area under the receiver operating characteristic curve (AUC) was used to assess the discriminant ability of the model. RESULTS: The incidence of LNM was 33.5% (214/638) in our cohort, 33.4% (169/506) in the primary cohort and 34.1% (45/132) in the validation cohort. Multivariate analysis confirmed that primary site, tumor grade, tumor size, depth, and lymphovascular invasion were independent risk factors for LNM (all P < 0.05), and patients were grouped based on these factors. A 7-point risk-scoring model based on these variables had good predictive accuracy in both the primary cohort (AUC, 0.749; 95% confidence interval 0.709-0.786) and the validation cohort (AUC, 0.738; 95% confidence interval 0.655-0.811). CONCLUSION: A novel risk-scoring model for lymph node metastasis was established to guide the optimal treatment of patients with T1b-T2 EC.


Assuntos
Neoplasias Esofágicas , Humanos , Metástase Linfática/patologia , Estudos Retrospectivos , Fatores de Risco , Neoplasias Esofágicas/cirurgia , Neoplasias Esofágicas/patologia , Excisão de Linfonodo , Linfonodos/cirurgia , Linfonodos/patologia
18.
Dig Dis Sci ; 69(9): 3361-3368, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39068378

RESUMO

BACKGROUND: Methanogens are associated with gut dysmotility in animal models but have not been robustly studied in humans. The WMC assesses regional transit time (TT) and pH in the GI tract. AIMS: To study the segmental TT and pH among patients with SIBO or IMO utilizing WMC. METHODS: We conducted a retrospective study of 207 patients who underwent a glucose or lactulose breath test (BT) and WMC from 2010 to 2022. Diagnosis of SIBO and IMO were based on the 2017 North American consensus criteria. TT and pH were extracted from WMC recordings. We tested for differences in means of continuous variables and frequencies of categorical variables using two-sample t tests, Wilcoxon Rank Sum test, Chi-square, and Fisher exact tests. We used R version 3.3.1 (2016-06-21) for all statistical analyses. RESULTS: A total of 196 patients met criteria, mean age 47.4 years and 155 (79.1%) females. Of the 86 (43.9%) patients with a positive BT, 42 (58.3%) had IMO only (meeting only CH4 criteria) and 30 (34.9%) met both H2 and CH4 criteria. Colonic TT was longer in patients with a positive BT compared to negative patients (40 h:29 min vs 28 h:51 min, p = 0.028). Small bowel TT and colonic TT were longer in patients with IMO compared to negative patients (SBTT: 5 h:15 min vs 4 h:32 min, p = 0.021; CTT: 44 h:23 min vs 28 h:51 min, p = 0.030). There were no significant differences in segmental pH compared to negative patients. CONCLUSION: To our knowledge, this is the largest study of patients who have undergone both BT and WMC. A positive BT was associated with delayed CTT, while having IMO only was associated with both delayed CTT and SBTT, but neither with pH. Future investigation is needed to elucidate whether changes in intestinal microbiota affect gut transit.


Assuntos
Trânsito Gastrointestinal , Intestino Delgado , Humanos , Feminino , Masculino , Trânsito Gastrointestinal/fisiologia , Estudos Retrospectivos , Pessoa de Meia-Idade , Adulto , Intestino Delgado/microbiologia , Intestino Delgado/metabolismo , Metano/metabolismo , Metano/análise , Testes Respiratórios/métodos , Endoscopia por Cápsula/métodos , Colo/microbiologia , Colo/metabolismo , Síndrome da Alça Cega/diagnóstico , Síndrome da Alça Cega/fisiopatologia , Concentração de Íons de Hidrogênio , Motilidade Gastrointestinal/fisiologia
19.
J Invertebr Pathol ; 205: 108129, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38754546

RESUMO

Bacillus thuringiensis (Bt) Cry2Aa is a member of the Cry pore-forming, 3-domain, toxin family with activity against both lepidopteran and dipteran insects. Although domains II and III of the Cry toxins are believed to represent the primary specificity determinant through specific binding to cell receptors, it has been proposed that the pore-forming domain I of Cry2Aa also has such a role. Thus, a greater understanding of the functions of Cry2Aa's different domains could potentially be helpful in the rational design of improved toxins. In this work, cry2Aa and its domain fragments (DI, DII, DIII, DI-II and DII-DIII) were subcloned into the vector pGEX-6P-1 and expressed in Escherichia coli. Each protein was recognized by anti-Cry2Aa antibodies and, except for the DII fragment, could block binding of the antibody to Cry2Aa. Cry2Aa and its DI and DI-II fragments bound to brush border membrane vesicles (BBMV) from H. armigera and also to a ca 150 kDa BBMV protein on a far western (ligand) blot. In contrast the DII, DIII and DII-III fragments bound to neither of these. None of the fragments were stable in H. armigera gut juice nor showed any toxicity towards this insect. Our results indicate that contrary to the general model of Cry toxin activity domain I plays a role in the binding of the toxin to the insect midgut.


Assuntos
Toxinas de Bacillus thuringiensis , Proteínas de Bactérias , Endotoxinas , Proteínas Hemolisinas , Mariposas , Animais , Endotoxinas/metabolismo , Proteínas Hemolisinas/metabolismo , Toxinas de Bacillus thuringiensis/metabolismo , Proteínas de Bactérias/metabolismo , Mariposas/metabolismo , Mariposas/microbiologia , Sítios de Ligação , Bacillus thuringiensis/metabolismo , Controle Biológico de Vetores , Domínios Proteicos , Helicoverpa armigera
20.
Proc Natl Acad Sci U S A ; 118(52)2021 12 28.
Artigo em Inglês | MEDLINE | ID: mdl-34930832

RESUMO

Replacing synthetic insecticides with transgenic crops for pest management has been economically and environmentally beneficial, but these benefits erode as pests evolve resistance. It has been proposed that novel genomic approaches could track molecular signals of emerging resistance to aid in resistance management. To test this, we quantified patterns of genomic change in Helicoverpa zea, a major lepidopteran pest and target of transgenic Bacillus thuringiensis (Bt) crops, between 2002 and 2017 as both Bt crop adoption and resistance increased in North America. Genomic scans of wild H. zea were paired with quantitative trait locus (QTL) analyses and showed the genomic architecture of field-evolved Cry1Ab resistance was polygenic, likely arising from standing genetic variation. Resistance to pyramided Cry1A.105 and Cry2Ab2 toxins was controlled by fewer loci. Of the 11 previously described Bt resistance genes, 9 showed no significant change over time or major effects on resistance. We were unable to rule out a contribution of aminopeptidases (apns), as a cluster of apn genes were found within a Cry-associated QTL. Molecular signals of emerging Bt resistance were detectable as early as 2012 in our samples, and we discuss the potential and pitfalls of whole-genome analysis for resistance monitoring based on our findings. This first study of Bt resistance evolution using whole-genome analysis of field-collected specimens demonstrates the need for a more holistic approach to examining rapid adaptation to novel selection pressures in agricultural ecosystems.


Assuntos
Evolução Molecular , Resistência a Inseticidas/genética , Mariposas/genética , Controle Biológico de Vetores , Plantas Geneticamente Modificadas , Animais , Bacillus thuringiensis/genética , Produtos Agrícolas , Genoma de Inseto/genética , Masculino
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA