Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 1.143
Filtrar
Mais filtros

Intervalo de ano de publicação
1.
Blood ; 143(26): 2735-2748, 2024 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-38518105

RESUMO

ABSTRACT: Acute lymphoblastic leukemia (ALL) arises from the uncontrolled proliferation of B-cell precursors (BCP-ALL) or T cells (T-ALL). Current treatment protocols obtain high cure rates in children but are based on toxic polychemotherapy. Novel therapies are urgently needed, especially in relapsed/refractory (R/R) disease, high-risk (HR) leukemias and T-ALL, in which immunotherapy approaches remain scarce. Although the interleukin-7 receptor (IL-7R) plays a pivotal role in ALL development, no IL-7R-targeting immunotherapy has yet reached clinical application in ALL. The IL-7Rα chain (CD127)-targeting IgG4 antibody lusvertikimab (LUSV; formerly OSE-127) is a full antagonist of the IL-7R pathway, showing a good safety profile in healthy volunteers. Here, we show that ∼85% of ALL cases express surface CD127. We demonstrate significant in vivo efficacy of LUSV immunotherapy in a heterogeneous cohort of BCP- and T-ALL patient-derived xenografts (PDX) in minimal residual disease (MRD) and overt leukemia models, including R/R and HR leukemias. Importantly, LUSV was particularly effective when combined with polychemotherapy in a phase 2-like PDX study with CD127high samples leading to MRD-negativity in >50% of mice treated with combination therapy. Mechanistically, LUSV targeted ALL cells via a dual mode of action comprising direct IL-7R antagonistic activity and induction of macrophage-mediated antibody-dependent cellular phagocytosis (ADCP). LUSV-mediated in vitro ADCP levels significantly correlated with CD127 expression levels and the reduction of leukemia burden upon treatment of PDX animals in vivo. Altogether, through its dual mode of action and good safety profile, LUSV may represent a novel immunotherapy option for any CD127+ ALL, particularly in combination with standard-of-care polychemotherapy.


Assuntos
Ensaios Antitumorais Modelo de Xenoenxerto , Animais , Humanos , Camundongos , Receptores de Interleucina-7/antagonistas & inibidores , Camundongos SCID , Fagocitose/efeitos dos fármacos , Subunidade alfa de Receptor de Interleucina-7 , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológico , Leucemia-Linfoma Linfoblástico de Células Precursoras/patologia , Leucemia-Linfoma Linfoblástico de Células Precursoras/imunologia , Feminino , Camundongos Endogâmicos NOD , Anticorpos Monoclonais Humanizados/uso terapêutico , Anticorpos Monoclonais Humanizados/farmacologia , Linhagem Celular Tumoral , Antineoplásicos Imunológicos/farmacologia , Antineoplásicos Imunológicos/uso terapêutico
2.
Proc Natl Acad Sci U S A ; 119(40): e2209139119, 2022 10 04.
Artigo em Inglês | MEDLINE | ID: mdl-36161960

RESUMO

Decrypting the rearrangements that drive mammalian chromosome evolution is critical to understanding the molecular bases of speciation, adaptation, and disease susceptibility. Using 8 scaffolded and 26 chromosome-scale genome assemblies representing 23/26 mammal orders, we computationally reconstructed ancestral karyotypes and syntenic relationships at 16 nodes along the mammalian phylogeny. Three different reference genomes (human, sloth, and cattle) representing phylogenetically distinct mammalian superorders were used to assess reference bias in the reconstructed ancestral karyotypes and to expand the number of clades with reconstructed genomes. The mammalian ancestor likely had 19 pairs of autosomes, with nine of the smallest chromosomes shared with the common ancestor of all amniotes (three still conserved in extant mammals), demonstrating a striking conservation of synteny for ∼320 My of vertebrate evolution. The numbers and types of chromosome rearrangements were classified for transitions between the ancestral mammalian karyotype, descendent ancestors, and extant species. For example, 94 inversions, 16 fissions, and 14 fusions that occurred over 53 My differentiated the therian from the descendent eutherian ancestor. The highest breakpoint rate was observed between the mammalian and therian ancestors (3.9 breakpoints/My). Reconstructed mammalian ancestor chromosomes were found to have distinct evolutionary histories reflected in their rates and types of rearrangements. The distributions of genes, repetitive elements, topologically associating domains, and actively transcribed regions in multispecies homologous synteny blocks and evolutionary breakpoint regions indicate that purifying selection acted over millions of years of vertebrate evolution to maintain syntenic relationships of developmentally important genes and regulatory landscapes of gene-dense chromosomes.


Assuntos
Evolução Molecular , Cariótipo , Mamíferos , Sintenia , Animais , Bovinos/genética , Cromossomos de Mamíferos/genética , Eutérios/genética , Humanos , Mamíferos/genética , Filogenia , Bichos-Preguiça/genética , Sintenia/genética
3.
J Biol Chem ; 299(9): 105119, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37527778

RESUMO

Serratia marcescens is an opportunistic human pathogen involved in antibiotic-resistant hospital acquired infections. Upon contact with the host epithelial cell and prior to internalization, Serratia induces an early autophagic response that is entirely dependent on the ShlA toxin. Once Serratia invades the eukaryotic cell and multiples inside an intracellular vacuole, ShlA expression also promotes an exocytic event that allows bacterial egress from the host cell without compromising its integrity. Several toxins, including ShlA, were shown to induce ATP efflux from eukaryotic cells. Here, we demonstrate that ShlA triggered a nonlytic release of ATP from Chinese hamster ovary (CHO) cells. Enzymatic removal of accumulated extracellular ATP (eATP) or pharmacological blockage of the eATP-P2Y2 purinergic receptor inhibited the ShlA-promoted autophagic response in CHO cells. Despite the intrinsic ecto-ATPase activity of CHO cells, the effective concentration and kinetic profile of eATP was consistent with the established affinity of the P2Y2 receptor and the known kinetics of autophagy induction. Moreover, eATP removal or P2Y2 receptor inhibition also suppressed the ShlA-induced exocytic expulsion of the bacteria from the host cell. Blocking α5ß1 integrin highly inhibited ShlA-dependent autophagy, a result consistent with α5ß1 transactivation by the P2Y2 receptor. In sum, eATP operates as the key signaling molecule that allows the eukaryotic cell to detect the challenge imposed by the contact with the ShlA toxin. Stimulation of P2Y2-dependent pathways evokes the activation of a defensive response to counteract cell damage and promotes the nonlytic clearance of the pathogen from the infected cell.


Assuntos
Autofagia , Interações Hospedeiro-Patógeno , Integrina alfa5beta1 , Receptores Purinérgicos P2Y2 , Serratia , Toxinas Biológicas , Animais , Cricetinae , Trifosfato de Adenosina/metabolismo , Autofagia/efeitos dos fármacos , Células CHO , Cricetulus , Exocitose/efeitos dos fármacos , Interações Hospedeiro-Patógeno/efeitos dos fármacos , Integrina alfa5beta1/antagonistas & inibidores , Integrina alfa5beta1/metabolismo , Receptores Purinérgicos P2Y2/metabolismo , Serratia/química , Serratia/efeitos dos fármacos , Serratia/fisiologia , Toxinas Biológicas/farmacologia , Humanos
4.
Blood ; 140(1): 45-57, 2022 07 07.
Artigo em Inglês | MEDLINE | ID: mdl-35452517

RESUMO

Acute lymphoblastic leukemia (ALL) is the most common malignant disease affecting children. Although therapeutic strategies have improved, T-cell acute lymphoblastic leukemia (T-ALL) relapse is associated with chemoresistance and a poor prognosis. One strategy to overcome this obstacle is the application of monoclonal antibodies. Here, we show that leukemic cells from patients with T-ALL express surface CD38 and CD47, both attractive targets for antibody therapy. We therefore investigated the commercially available CD38 antibody daratumumab (Dara) in combination with a proprietary modified CD47 antibody (Hu5F9-IgG2σ) in vitro and in vivo. Compared with single treatments, this combination significantly increased in vitro antibody-dependent cellular phagocytosis in T-ALL cell lines as well as in random de novo and relapsed/refractory T-ALL patient-derived xenograft (PDX) samples. Similarly, enhanced antibody-dependent cellular phagocytosis was observed when combining Dara with pharmacologic inhibition of CD47 interactions using a glutaminyl cyclase inhibitor. Phase 2-like preclinical in vivo trials using T-ALL PDX samples in experimental minimal residual disease-like (MRD-like) and overt leukemia models revealed a high antileukemic efficacy of CD47 blockade alone. However, T-ALL xenograft mice subjected to chemotherapy first (postchemotherapy MRD) and subsequently cotreated with Dara and Hu5F9-IgG2σ displayed significantly reduced bone marrow infiltration compared with single treatments. In relapsed and highly refractory T-ALL PDX combined treatment with Dara and Hu5F9-IgG2σ was required to substantially prolong survival compared with single treatments. These findings suggest that combining CD47 blockade with Dara is a promising therapy for T-ALL, especially for relapsed/refractory disease harboring a dismal prognosis in patients.


Assuntos
Leucemia-Linfoma Linfoblástico de Células Precursoras , Leucemia-Linfoma Linfoblástico de Células T Precursoras , Animais , Anticorpos Monoclonais/farmacologia , Anticorpos Monoclonais/uso terapêutico , Antígeno CD47 , Humanos , Camundongos , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológico , Leucemia-Linfoma Linfoblástico de Células T Precursoras/tratamento farmacológico
5.
Glob Chang Biol ; 30(4): e17274, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38605677

RESUMO

Climate change and other anthropogenic disturbances are increasing liana abundance and biomass in many tropical and subtropical forests. While the effects of living lianas on species diversity, ecosystem carbon, and nutrient dynamics are receiving increasing attention, the role of dead lianas in forest ecosystems has been little studied and is poorly understood. Trees and lianas coexist as the major woody components of forests worldwide, but they have very different ecological strategies, with lianas relying on trees for mechanical support. Consequently, trees and lianas have evolved highly divergent stem, leaf, and root traits. Here we show that this trait divergence is likely to persist after death, into the afterlives of these organs, leading to divergent effects on forest biogeochemistry. We introduce a conceptual framework combining horizontal, vertical, and time dimensions for the effects of liana proliferation and liana tissue decomposition on ecosystem carbon and nutrient cycling. We propose a series of empirical studies comparing traits between lianas and trees to answer questions concerning the influence of trait afterlives on the decomposability of liana and tree organs. Such studies will increase our understanding of the contribution of lianas to terrestrial biogeochemical cycling, and help predict the effects of their increasing abundance.


Assuntos
Ecossistema , Clima Tropical , Florestas , Árvores , Carbono
6.
Sensors (Basel) ; 24(11)2024 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-38894353

RESUMO

The paper introduces a computer vision methodology for detecting pitting corrosion in gas pipelines. To achieve this, a dataset comprising 576,000 images of pipelines with and without pitting corrosion was curated. A custom-designed and optimized convolutional neural network (CNN) was employed for binary classification, distinguishing between corroded and non-corroded images. This CNN architecture, despite having relatively few parameters compared to existing CNN classifiers, achieved a notably high classification accuracy of 98.44%. The proposed CNN outperformed many contemporary classifiers in its efficacy. By leveraging deep learning, this approach effectively eliminates the need for manual inspection of pipelines for pitting corrosion, thus streamlining what was previously a time-consuming and cost-ineffective process.

7.
Rev Neurol (Paris) ; 180(4): 314-325, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38485630

RESUMO

Neurofeedback is a brain-computer interface tool enabling the user to self-regulate their neuronal activity, and ultimately, induce long-term brain plasticity, making it an interesting instrument to cure brain disorders. Although this method has been used successfully in the past as an adjunctive therapy in drug-resistant epilepsy, this approach remains under-explored and deserves more rigorous scientific inquiry. In this review, we present early neurofeedback protocols employed in epilepsy and provide a critical overview of the main clinical studies. We also describe the potential neurophysiological mechanisms through which neurofeedback may produce its therapeutic effects. Finally, we discuss how to innovate and standardize future neurofeedback clinical trials in epilepsy based on evidence from recent research studies.


Assuntos
Interfaces Cérebro-Computador , Epilepsia , Neurorretroalimentação , Humanos , Neurorretroalimentação/métodos , Epilepsia/terapia , Epilepsia/psicologia , Interfaces Cérebro-Computador/tendências , Plasticidade Neuronal/fisiologia , Autocontrole , Encéfalo/fisiologia , Encéfalo/fisiopatologia
8.
Semin Cancer Biol ; 79: 44-57, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-32623044

RESUMO

This review focuses on immune checkpoint inhibitors - immunomodulatory agents that aim to relieve tumour-mediated immune-cell suppression. Immune checkpoint proteins can be expressed on the tumour-cell or immune-cell populations. Immune checkpoint proteins dampen the immune response by inactivating immune cells capable of tumour destruction. Blockade of immune checkpoints has shown impressive results in a range of solid cancers, particularly melanoma and non-small cell lung cancer. The potential benefit of this class of drugs is widespread across most cancer types and an unprecedented number of clinical studies are underway to examine the benefit of these agents. The aims of this review are to: provide an overview of the key early immune checkpoint inhibitor trials involving drugs targeting programmed cell death-1 (PD-1), programmed cell death ligand-1 (PD-L1) and cytotoxic T-lymphocyte antigen-4 (CTLA-4) in multiple disease types; provide an overview of emerging therapies aimed at these targets; and provide a detailed exploration of the status of immune checkpoint inhibitors in breast cancer.


Assuntos
Antígeno B7-H1/antagonistas & inibidores , Neoplasias da Mama/tratamento farmacológico , Antígeno CTLA-4/antagonistas & inibidores , Inibidores de Checkpoint Imunológico/uso terapêutico , Receptor de Morte Celular Programada 1/antagonistas & inibidores , Biomarcadores Tumorais/antagonistas & inibidores , Feminino , Humanos , Imunoterapia/métodos
9.
Evol Dev ; 25(6): 335-352, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37317654

RESUMO

We compare and contrast two theoretical perspectives on adaptive evolution-the orthodox Modern Synthesis perspective, and the nascent Agential Perspective. To do so, we develop the idea from Rasmus Grønfeldt Winther of a 'countermap', as a means for comparing the respective ontologies of different scientific perspectives. We conclude that the modern Synthesis perspective achieves an impressively comprehensive view of a universal set of dynamical properties of populations, but at the considerable cost of radically distorting the nature of the biological processes that contribute to evolution. For its part, the Agential Perspective offers the prospect of representing the biological processes of evolution with much greater fidelity, but at the expense of generality. Trade-offs of this sort are endemic to science, and inevitable. Recognizing them helps us to avoid the pitfalls of 'illicit reification', i.e. the mistake of interpreting a feature of a scientific perspective as a feature of the non-perspectival world. We argue that much of the traditional Modern Synthesis representation of the biology of evolution commits this illicit reification.


Assuntos
Evolução Biológica
10.
Br J Cancer ; 129(6): 1022-1031, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37507543

RESUMO

BACKGROUND: The phase II neo-adjuvant clinical trial ICORG10-05 (NCT01485926) compared chemotherapy in combination with trastuzumab, lapatinib or both in patients with HER2+ breast cancer. We studied circulating immune cells looking for alterations in phenotype, genotype and cytotoxic capacity (direct and antibody-dependent cell-mediated cytotoxicity (ADCC)) in the context of treatment response. METHODS: Peripheral blood mononuclear cells (PBMCs) were isolated from pre- (n = 41) and post- (n = 25) neo-adjuvant treatment blood samples. Direct/trastuzumab-ADCC cytotoxicity of patient-derived PBMCs against K562/SKBR3 cell lines was determined ex vivo. Pembrolizumab was interrogated in 21 pre-treatment PBMC ADCC assays. Thirty-nine pre-treatment and 21 post-treatment PBMC samples were immunophenotyped. Fc receptor genotype, tumour infiltrating lymphocyte (TIL) levels and oestrogen receptor (ER) status were quantified. RESULTS: Treatment attenuated the cytotoxicity/ADCC of PBMCs. CD3+/CD4+/CD8+ T cells increased following therapy, while CD56+ NK cells/CD14+ monocytes/CD19+ B cells decreased with significant post-treatment immune cell changes confined to patients with residual disease. Pembrolizumab-augmented ex vivo PBMC ADCC activity was associated with residual disease, but not pathological complete response. Pembrolizumab-responsive PBMCs were associated with lower baseline TIL levels and ER+ tumours. CONCLUSIONS: PBMCs display altered phenotype and function following completion of neo-adjuvant treatment. Anti-PD-1-responsive PBMCs in ex vivo ADCC assays may be a biomarker of treatment response.


Assuntos
Antineoplásicos , Neoplasias , Humanos , Citotoxicidade Celular Dependente de Anticorpos , Antineoplásicos/uso terapêutico , Linhagem Celular Tumoral , Leucócitos Mononucleares/metabolismo , Terapia Neoadjuvante , Neoplasias/tratamento farmacológico , Fenótipo , Receptor ErbB-2/genética , Receptor ErbB-2/metabolismo , Trastuzumab/farmacologia
11.
Antimicrob Agents Chemother ; 67(1): e0128122, 2023 01 24.
Artigo em Inglês | MEDLINE | ID: mdl-36541767

RESUMO

Taniborbactam is a novel cyclic boronate ß-lactamase inhibitor in clinical development in combination with cefepime. We assessed the in vitro activity of cefepime-taniborbactam and comparators against a 2018-2020 collection of Enterobacterales (n = 13,731) and Pseudomonas aeruginosa (n = 4,619) isolates cultured from infected patients attending hospitals in 56 countries. MICs were determined by CLSI broth microdilution. Taniborbactam was tested at a fixed concentration of 4 µg/mL. Isolates with cefepime-taniborbactam MICs of ≥16 µg/mL underwent whole-genome sequencing. ß-lactamase genes were identified in meropenem-resistant isolates by PCR/Sanger sequencing. Against Enterobacterales, taniborbactam reduced the cefepime MIC90 value by >64-fold (from >16 to 0.25 µg/mL). At ≤16 µg/mL, cefepime-taniborbactam inhibited 99.7% of all Enterobacterales isolates; >97% of isolates with multidrug-resistant (MDR) and ceftolozane-tazobactam-resistant phenotypes; ≥90% of isolates with meropenem-resistant, difficult-to-treat-resistant (DTR), meropenem-vaborbactam-resistant, and ceftazidime-avibactam-resistant phenotypes; 100% of VIM-positive, AmpC-positive, and KPC-positive isolates; 98.7% of extended-spectrum ß-lactamase (ESBL)-positive; 98.8% of OXA-48-like-positive; and 84.6% of NDM-positive isolates. Against P. aeruginosa, taniborbactam reduced the cefepime MIC90 value by 4-fold (from 32 to 8 µg/mL). At ≤16 µg/mL, cefepime-taniborbactam inhibited 97.4% of all P. aeruginosa isolates; ≥85% of isolates with meropenem-resistant, MDR, and meropenem-vaborbactam-resistant phenotypes; >75% of isolates with DTR, ceftazidime-avibactam-resistant, and ceftolozane-tazobactam-resistant phenotypes; and 87.4% of VIM-positive isolates. Multiple potential mechanisms, including carriage of IMP, certain alterations in PBP3, permeability (porin) defects, and possibly, upregulation of efflux were present in most isolates with cefepime-taniborbactam MICs of ≥16 µg/mL. We conclude that cefepime-taniborbactam exhibited potent in vitro activity against Enterobacterales and P. aeruginosa and inhibited most carbapenem-resistant isolates, including those carrying serine carbapenemases or NDM/VIM metallo-ß-lactamases (MBLs).


Assuntos
Antibacterianos , Farmacorresistência Bacteriana , Cefepima/farmacologia , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Meropeném/farmacologia , Tazobactam/farmacologia , beta-Lactamases/genética , Pseudomonas aeruginosa , Bactérias Gram-Negativas , Compostos Azabicíclicos/farmacologia , Testes de Sensibilidade Microbiana
12.
Chemistry ; 29(17): e202203835, 2023 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-36581566

RESUMO

The reliable self-assembly of microporous metal-phosphonate materials remains a longstanding challenge. This stems from, generally, more coordination modes for the functional group allowing more dense structures, and stronger bonding driving less crystalline products. Here, a novel orthogonalized aryl-phosphonate linker, 1,3,5-tris(4'-phosphono-2',6'-dimethylphenyl) benzene (H6 L3) has been used to direct formation of open frameworks. The peripheral aryl rings of H6 L3 are orthogonalized relative to the central aromatic ring giving a tri-cleft conformation of the linker in which small aromatic molecules can readily associate. When coordinated to magnesium ions, a series of porous crystalline metal-organic, and hydrogen-bonded metal-organic frameworks (MOFs, HMOFs) are formed (CALF-41 (Mg), HCALF-42 (Mg), -43 (Mg)). While most metal-organic frameworks are tailored based on choice of metal and linker, here, the network structures are highly dependent on the inclusion and structure of the guest aromatic compounds. Larger guests, and a higher stoichiometry of metal, result in increased solvation of the metal ion, resulting in networks with connectivities increasingly involving hydrogen-bonds rather than direct phosphonate coordination. Upon thermal activation and aromatic template removal, the materials exhibit surface areas ranging from 400-600 m2 /g. Self-assembly in the absence of aromatic guests yields mixtures of phases, frequently co-producing a dense 3-fold interpenetrated structure (1). Interestingly, a series of both more porous (530-900 m2 /g), and more robust solids is formed by complexing with trivalent metal ions (Al, Ga, In) with aromatic guest; however, these are only attainable as microcrystalline powders. The polyprotic nature of phosphonate linkers enables structural analogy to the divalent analogues and these are identified as CALF-41 analogues. Finally, insights to the structural transformations during metal ion desolvation in this family are gained by considering a pair of structurally related Co materials, whose hydrogen-bonded (HCALF-44 (Co)) and desolvated (CALF-44 (Co)) coordination bonded networks were fully structurally characterized.

13.
BMC Pregnancy Childbirth ; 23(1): 54, 2023 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-36690977

RESUMO

BACKGROUND: The prevalence and impact of fistulas are more common in developing countries with limited access to emergency obstetric care. As a result, women in these settings often experience adverse psychosocial factors. The purpose of this study was to describe the characteristics of Congolese women who developed urogenital fistula following Cesarean sections (CS) to determine the characteristics associated with two etiologies: (1) prolonged obstructed labor; and (2) a complication of CS following obstructed labor. METHODS: We performed a cross-sectional study on abstracted data from all patients with urogenital fistula following CS who received care during a surgical campaign in a remote area of the Democratic Republic of the Congo (DRC). Descriptive analyses characterized patients with fistula related to obstructed labor versus CS. Univariate and multivariate logistic regression models identified factors associated with obstetric fistula after cesarean delivery following obstructed labor. Variables were included in the logistic regression models based upon biological plausibility. RESULTS: Among 125 patients, urogenital fistula etiology was attributed to obstructed labor in 77 (62%) and complications following CS in 48 (38%). Women with a fistula, attributed to obstructed labor, developed the fistula at a younger age (p = .04) and had a lower parity (p = .02). Attempted delivery before arriving at the hospital was associated with an increased risk of obstetric fistula after cesarean delivery following obstructed labor (p < .01). CONCLUSION: CS are commonly performed on women who arrive at the hospital following prolonged obstructed labor and fetal demise, and account for almost 40% of urogenital fistula. Obstetric providers should assess maternal status upon arrival to prevent unnecessary CS and identify women at risk of developing a fistula.


Assuntos
Distocia , Complicações do Trabalho de Parto , Fístula Vesicovaginal , Gravidez , Humanos , Feminino , Cesárea/efeitos adversos , Estudos Transversais , Fístula Vesicovaginal/epidemiologia , Fístula Vesicovaginal/etiologia , Fístula Vesicovaginal/prevenção & controle , Complicações do Trabalho de Parto/epidemiologia , Paridade , Distocia/etiologia
14.
Biochemistry (Mosc) ; 88(2): 253-261, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37072330

RESUMO

Some restriction-modification systems contain two DNA methyltransferases. In the present work, we have classified such systems according to the families of catalytic domains present in the restriction endonucleases and both DNA methyltransferases. Evolution of the restriction-modification systems containing an endonuclease with a NOV_C family domain and two DNA methyltransferases, both with DNA_methylase family domains, was investigated in detail. Phylogenetic tree of DNA methyltransferases from the systems of this class consists of two clades of the same size. Two DNA methyltransferases of each restriction-modification system of this class belong to the different clades. This indicates independent evolution of the two methyltransferases. We detected multiple cross-species horizontal transfers of the systems as a whole, as well as the cases of gene transfer between the systems.


Assuntos
Enzimas de Restrição-Modificação do DNA , Metiltransferases , Enzimas de Restrição do DNA/genética , Enzimas de Restrição-Modificação do DNA/genética , Filogenia , Metiltransferases/genética , DNA
15.
Int J Mol Sci ; 24(18)2023 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-37762271

RESUMO

During transition into a dormant state, Mycolicibacterium (Mycobacterium) smegmatis cells are able to accumulate free porphyrins that makes them sensitive to photodynamic inactivation (PDI). The formation of dormant cells in a liquid medium with an increased concentration of magnesium (up to 25 mM) and zinc (up to 62 µM) resulted in an increase in the total amount of endogenous porphyrins in dormant M. smegmatis cells and their photosensitivity, especially for bacteria phagocytosed by macrophages. To gain insight into possible targets for PDI in bacterial dormant mycobacterial cells, a proteomic profiling with SDS gel electrophoresis and mass spectrometry analysis were conducted. Illumination of dormant forms of M. smegmatis resulted in the disappearance of proteins in the separating SDS gel. Dormant cells obtained under an elevated concentration of metal ions were more sensitive to PDI. Differential analysis of proteins with their identification with MALDI-TOF revealed that 45.2% and 63.9% of individual proteins disappeared from the separating gel after illumination for 5 and 15 min, respectively. Light-sensitive proteins include enzymes belonging to the glycolytic pathway, TCA cycle, pentose phosphate pathway, oxidative phosphorylation and energy production. Several proteins involved in protecting against oxygen stress and protein aggregation were found to be sensitive to light. This makes dormant cells highly vulnerable to harmful factors during a long stay in a non-replicative state. PDI caused inhibition of the respiratory chain activity and destroyed enzymes involved in the synthesis of proteins and nucleic acids, the processes which are necessary for dormant cell reactivation and their transition to multiplying bacteria. Because of such multiple targeting, PDI action via endogenous porphyrins could be considered as an effective approach for killing dormant bacteria and a perspective to inactivate dormant mycobacteria and combat the latent form of mycobacteriosis, first of all, with surface localization.


Assuntos
Anti-Infecciosos , Proteômica , Mycobacterium smegmatis , Ciclo do Ácido Cítrico , Transporte de Elétrons
16.
Afr J Reprod Health ; 27(12): 79-85, 2023 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-38158865

RESUMO

This study assesses the risk that rape survivors have of developing cervical cancer in the context of conflict. A cross-sectional and descriptive study conducted in Bunyakiri and Kavumu, a conflict region in the east of the Democratic Republic of the Congo during the period from September 1 to 10, 2022, including 47 women survivors of sexual violence, 41 of whom were selected on the basis of certain criteria with age ranging from 18 to 50 years. Speculum examination was performed with visual inspection with acetic acid (VIA). After collecting data, the latter were encoded in the Excel file and grouped in the form of tables then analyzed after calculating the percentage. Ages of 21-30 years was the most represented, i.e., 56%. Among them, 34.1% were married and 31.7% were abandoned. Majority was in secondary school (46.3%) and illiterates (34.1%). 36.5% complained of pelvic pain and 36.5% reported first sexual intercourse at the age range of 13-15 years, of which 25 cases, i.e., 61% were sexually active. 39% reported having had 3 sexual partners in their life. VIA was negative in 97.5% of cases. It should be mentioned in this study that the environment of conflict zone, the circumstances of rape and the risky sexual behavior of survivors are an ecosystem that predisposes them to cervical cancer.


Cette étude évalue le risque qu'ont les survivantes de viol de développer un cancer du col de l'utérus dans un contexte de conflit. Une étude transversale et descriptive menée à Bunyakiri et Kavumu, région de conflit à l'est de la République Démocratique du Congo durant la période du 1er au 10 septembre 2022, incluant 47 femmes survivantes de violences sexuelles, dont 41 ont été sélectionnées sur la base de certains critères avec un âge allant de 18 à 50 ans. L'examen au spéculum a été réalisé avec inspection visuelle à l'acide acétique (VIA). Après collecte des données, ces dernières ont été encodées dans le fichier Excel et regroupées sous forme de tableaux puis analysées après calcul du pourcentage. La tranche d'âge de 21 à 30 ans était la plus représentée, soit 56 %. Parmi eux, 34,1% étaient mariés et 31,7% étaient abandonnés. La majorité était scolarisée dans le secondaire (46,3%) et analphabète (34,1%). 36,5% se plaignaient de douleurs pelviennes et 36,5% rapportaient leurs premiers rapports sexuels entre 13 et 15 ans, dont 25 cas, soit 61% étaient sexuellement actifs. 39 % déclarent avoir eu 3 partenaires sexuels dans leur vie. VIA était négatif dans 97,5 % des cas. Il convient de mentionner dans cette étude que l'environnement de la zone de conflit, les circonstances du viol et le comportement sexuel à risque des survivantes constituent un écosystème qui les prédispose au cancer du col de l'utérus.


Assuntos
Estupro , Delitos Sexuais , Neoplasias do Colo do Útero , Humanos , Feminino , Adolescente , Adulto Jovem , Adulto , Pessoa de Meia-Idade , Neoplasias do Colo do Útero/diagnóstico , Neoplasias do Colo do Útero/epidemiologia , República Democrática do Congo/epidemiologia , Estudos Transversais , Ecossistema , Guerra , Detecção Precoce de Câncer , Ácido Acético , Sobreviventes , Fatores de Risco
17.
Persoonia ; 50: 158-310, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38567263

RESUMO

Novel species of fungi described in this study include those from various countries as follows: Australia, Aschersonia mackerrasiae on whitefly, Cladosporium corticola on bark of Melaleuca quinquenervia, Penicillium nudgee from soil under Melaleuca quinquenervia, Pseudocercospora blackwoodiae on leaf spot of Persoonia falcata, and Pseudocercospora dalyelliae on leaf spot of Senna alata. Bolivia, Aspicilia lutzoniana on fully submersed siliceous schist in high-mountain streams, and Niesslia parviseta on the lower part and apothecial discs of Erioderma barbellatum on a twig. Brazil, Cyathus bonsai on decaying wood, Geastrum albofibrosum from moist soil with leaf litter, Laetiporus pratigiensis on a trunk of a living unknown hardwood tree species, and Scytalidium synnematicum on dead twigs of unidentified plant. Bulgaria, Amanita abscondita on sandy soil in a plantation of Quercus suber. Canada, Penicillium acericola on dead bark of Acer saccharum, and Penicillium corticola on dead bark of Acer saccharum. China, Colletotrichum qingyuanense on fruit lesion of Capsicum annuum. Denmark, Helminthosphaeria leptospora on corticioid Neohypochnicium cremicolor. Ecuador (Galapagos), Phaeosphaeria scalesiae on Scalesia sp. Finland, Inocybe jacobssonii on calcareous soils in dry forests and park habitats. France, Cortinarius rufomyrrheus on sandy soil under Pinus pinaster, and Periconia neominutissima on leaves of Poaceae. India, Coprinopsis fragilis on decaying bark of logs, Filoboletus keralensis on unidentified woody substrate, Penicillium sankaranii from soil, Physisporinus tamilnaduensis on the trunk of Azadirachta indica, and Poronia nagaraholensis on elephant dung. Iran, Neosetophoma fici on infected leaves of Ficus elastica. Israel, Cnidariophoma eilatica (incl. Cnidariophoma gen. nov.) from Stylophora pistillata. Italy, Lyophyllum obscurum on acidic soil. Namibia, Aureobasidium faidherbiae on dead leaf of Faidherbia albida, and Aureobasidium welwitschiae on dead leaves of Welwitschia mirabilis. Netherlands, Gaeumannomycella caricigena on dead culms of Carex elongata, Houtenomyces caricicola (incl. Houtenomyces gen. nov.) on culms of Carex disticha, Neodacampia ulmea (incl. Neodacampia gen. nov.) on branch of Ulmus laevis, Niesslia phragmiticola on dead standing culms of Phragmites australis, Pseudopyricularia caricicola on culms of Carex disticha, and Rhodoveronaea nieuwwulvenica on dead bamboo sticks. Norway, Arrhenia similis half-buried and moss-covered pieces of rotting wood in grass-grown path. Pakistan, Mallocybe ahmadii on soil. Poland, Beskidomyces laricis (incl. Beskidomyces gen. nov.) from resin of Larix decidua ssp. polonica, Lapidomyces epipinicola from sooty mould community on Pinus nigra, and Leptographium granulatum from a gallery of Dendroctonus micans on Picea abies. Portugal, Geoglossum azoricum on mossy areas of laurel forest areas planted with Cryptomeria japonica, and Lunasporangiospora lusitanica from a biofilm covering a biodeteriorated limestone wall. Qatar, Alternaria halotolerans from hypersaline sea water, and Alternaria qatarensis from water sample collected from hypersaline lagoon. South Africa, Alfaria thamnochorti on culm of Thamnochortus fraternus, Knufia aloeicola on Aloe gariepensis, Muriseptatomyces restionacearum (incl. Muriseptatomyces gen. nov.) on culms of Restionaceae, Neocladosporium arctotis on nest of cases of bag worm moths (Lepidoptera, Psychidae) on Arctotis auriculata, Neodevriesia scadoxi on leaves of Scadoxus puniceus, Paraloratospora schoenoplecti on stems of Schoenoplectus lacustris, Tulasnella epidendrea from the roots of Epidendrum × obrienianum, and Xenoidriella cinnamomi (incl. Xenoidriella gen. nov.) on leaf of Cinnamomum camphora. South Korea, Lemonniera fraxinea on decaying leaves of Fraxinus sp. from pond. Spain, Atheniella lauri on the bark of fallen trees of Laurus nobilis, Halocryptovalsa endophytica from surface-sterilised, asymptomatic roots of Salicornia patula, Inocybe amygdaliolens on soil in mixed forest, Inocybe pityusarum on calcareous soil in mixed forest, Inocybe roseobulbipes on acidic soils, Neonectria borealis from roots of Vitis berlandieri × Vitis rupestris, Sympoventuria eucalyptorum on leaves of Eucalyptus sp., and Tuber conchae from soil. Sweden, Inocybe bidumensis on calcareous soil. Thailand, Cordyceps sandindaengensis on Lepidoptera pupa, buried in soil, Ophiocordyceps kuchinaraiensis on Coleoptera larva, buried in soil, and Samsoniella winandae on Lepidoptera pupa, buried in soil. Taiwan region (China), Neophaeosphaeria livistonae on dead leaf of Livistona rotundifolia. Türkiye, Melanogaster anatolicus on clay loamy soils. UK, Basingstokeomyces allii (incl. Basingstokeomyces gen. nov.) on leaves of Allium schoenoprasum. Ukraine, Xenosphaeropsis corni on recently dead stem of Cornus alba. USA, Nothotrichosporon aquaticum (incl. Nothotrichosporon gen. nov.) from water, and Periconia philadelphiana from swab of coil surface. Morphological and culture characteristics for these new taxa are supported by DNA barcodes. Citation: Crous PW, Osieck ER, Shivas RG, et al. 2023. Fungal Planet description sheets: 1478-1549. Persoonia 50: 158- 310. https://doi.org/10.3767/persoonia.2023.50.05.

18.
Clin Infect Dis ; 75(8): 1462-1466, 2022 10 12.
Artigo em Inglês | MEDLINE | ID: mdl-36130226

RESUMO

Coronavirus disease 2019 (COVID-19) in pregnancy is associated with excess maternal and infant morbidity and mortality in both African and higher-resource settings. Furthermore, mounting evidence demonstrates the safety and efficacy of COVID-19 vaccination for pregnant women and infants. However, national guidelines in many African countries are equivocal or lack recommendations on COVID-19 vaccine in pregnancy. We summarize key data on COVID-19 epidemiology and vaccination among pregnant African women to highlight major barriers to vaccination and recommend 4 interventions. First, policymakers should prioritize pregnant women for COVID-19 vaccination, with a target of 100% coverage. Second, empirically supported public health campaigns should be sustainably implemented to inform and support pregnant women and their healthcare providers in overcoming vaccine hesitancy. Third, COVID-19 vaccination for pregnant women should be expanded to include antenatal care, obstetrics/gynecology, and targeted mass vaccination campaigns. Fourth, national monitoring and evaluation of COVID-19 vaccine uptake, safety, surveillance, and prospective outcomes assessment should be conducted.


Assuntos
COVID-19 , COVID-19/prevenção & controle , Vacinas contra COVID-19 , Feminino , Humanos , Lactente , Gravidez , Gestantes , Estudos Prospectivos , Vacinação
19.
Clin Infect Dis ; 75(11): 1950-1961, 2022 11 30.
Artigo em Inglês | MEDLINE | ID: mdl-36130257

RESUMO

BACKGROUND: Few data are available on COVID-19 outcomes among pregnant women in sub-Saharan Africa (SSA), where high-risk comorbidities are prevalent. We investigated the impact of pregnancy on SARS-CoV-2 infection and of SARS-CoV-2 infection on pregnancy to generate evidence for health policy and clinical practice. METHODS: We conducted a 6-country retrospective cohort study among hospitalized women of childbearing age between 1 March 2020 and 31 March 2021. Exposures were (1) pregnancy and (2) a positive SARS-CoV-2 RT-PCR test. The primary outcome for both analyses was intensive care unit (ICU) admission. Secondary outcomes included supplemental oxygen requirement, mechanical ventilation, adverse birth outcomes, and in-hospital mortality. We used log-binomial regression to estimate the effect between pregnancy and SARS-CoV-2 infection. Factors associated with mortality were evaluated using competing-risk proportional subdistribution hazards models. RESULTS: Our analyses included 1315 hospitalized women: 510 pregnant women with SARS-CoV-2, 403 nonpregnant women with SARS-CoV-2, and 402 pregnant women without SARS-CoV-2 infection. Among women with SARS-CoV-2 infection, pregnancy was associated with increased risk for ICU admission (adjusted risk ratio [aRR]: 2.38; 95% CI: 1.42-4.01), oxygen supplementation (aRR: 1.86; 95% CI: 1.44-2.42), and hazard of in-hospital death (adjusted sub-hazard ratio [aSHR]: 2.00; 95% CI: 1.08-3.70). Among pregnant women, SARS-CoV-2 infection increased the risk of ICU admission (aRR: 2.0; 95% CI: 1.20-3.35), oxygen supplementation (aRR: 1.57; 95% CI: 1.17-2.11), and hazard of in-hospital death (aSHR: 5.03; 95% CI: 1.79-14.13). CONCLUSIONS: Among hospitalized women in SSA, both SARS-CoV-2 infection and pregnancy independently increased risks of ICU admission, oxygen supplementation, and death. These data support international recommendations to prioritize COVID-19 vaccination among pregnant women.


Assuntos
COVID-19 , Complicações Infecciosas na Gravidez , Feminino , Gravidez , Humanos , Lactente , COVID-19/epidemiologia , SARS-CoV-2 , Estudos Retrospectivos , Mortalidade Hospitalar , Vacinas contra COVID-19 , Estudos de Coortes , África Subsaariana/epidemiologia
20.
J Am Chem Soc ; 144(28): 12632-12637, 2022 07 20.
Artigo em Inglês | MEDLINE | ID: mdl-35786956

RESUMO

The scission of a C(sp3)-H bond to form a new metal-alkyl bond is a fundamental step in coordination chemistry and catalysis. However, the extent of C-H bond weakening when this moiety interacts with a transition metal is poorly understood and quantifying this phenomenon could provide insights into designing more efficient C-H functionalization catalysts. We present a nickel complex with a robust adamantyl reporter ligand that enables the measurement of C-H acidity (pKa) and bond dissociation free energy (BDFE) for a C(sp3)-H agostic interaction, showing a decrease in pKa by dozens of orders of magnitude and BDFE decrease of about 30 kcal/mol upon coordination. X-ray crystallographic data is provided for all molecules, including a distorted square planar NiIII metalloradical and "doubly agostic" NiII(κ2-CH2) complex.


Assuntos
Metais , Níquel , Catálise , Cristalografia por Raios X , Ligantes , Níquel/química
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA