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1.
Reprod Biomed Online ; 49(6): 104384, 2024 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-39427473

RESUMO

RESEARCH QUESTION: Are there significant differences between cumulative live birth rates (CLBR) after short or extended embryo culture when comparisons are performed per cycle? DESIGN: This French national study included all IVF cycles performed from January 2016 to December 2019 with at least one cleaved embryo at day 2. The day 2/3 and day 5/6 groups were identified using the National Biomedicine Agency register. Only attempts involving the vitrification method were included. CLBR was assessed with 1 and 2 years of follow-up using a logistic regression model. The evolution of CLBR per cycle was compared over 1 year of follow-up. RESULTS: In total, 133,250 cycles met the inclusion criteria (70,528 and 62,722 in the day 2/3 and day 5/6 groups). In multivariate analysis including several patient and cycle characteristics, the CLBR per cycle was significantly lower in the day 5/6 compared with the day 2/3 group. A significantly higher rate of fresh embryo transfer cancellation was observed in the day 5/6 compared with the day 2/3 group. The evolution of the CLBR was significantly different in favour of the day 2/3 group in cases with three or fewer day 2 embryos, whatever the patient's age, in their two first attempts as well as in their third or further attempts. CONCLUSIONS: Overall, the nationwide results per cycle suggest that extended embryo culture until the blastocyst stage, even when used in combination with vitrification, could not improve live birth rates. Moreover, where three or fewer day 2 embryos are obtained, it might be preferable to use the short embryo culture strategy.

2.
Pharm Res ; 41(6): 1121-1138, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38720034

RESUMO

PURPOSE: The goal was to assess, for lipophilic drugs, the impact of logP on human volume of distribution at steady-state (VDss) predictions, including intermediate fut and Kp values, from six methods: Oie-Tozer, Rodgers-Rowland (tissue-specific Kp and only muscle Kp), GastroPlus, Korzekwa-Nagar, and TCM-New. METHOD: A sensitivity analysis with focus on logP was conducted by keeping pKa and fup constant for each of four drugs, while varying logP. VDss was also calculated for the specific literature logP values. Error prediction analysis was conducted by analyzing prediction errors by source of logP values, drug, and overall values. RESULTS: The Rodgers-Rowland methods were highly sensitive to logP values, followed by GastroPlus and Korzekwa-Nagar. The Oie-Tozer and TCM-New methods were only modestly sensitive to logP. Hence, the relative performance of these methods depended upon the source of logP value. As logP values increased, TCM-New and Oie-Tozer were the most accurate methods. TCM-New was the only method that was accurate regardless of logP value source. Oie-Tozer provided accurate predictions for griseofulvin, posaconazole, and isavuconazole; GastroPlus for itraconazole and isavuconazole; Korzekwa-Nagar for posaconazole; and TCM-New for griseofulvin, posaconazole, and isavuconazole. Both Rodgers-Rowland methods provided inaccurate predictions due to the overprediction of VDss. CONCLUSIONS: TCM-New was the most accurate prediction of human VDss across four drugs and three logP sources, followed by Oie-Tozer. TCM-New showed to be the best method for VDss prediction of highly lipophilic drugs, suggesting BPR as a favorable surrogate for drug partitioning in the tissues, and which avoids the use of fup.


Assuntos
Modelos Biológicos , Humanos , Preparações Farmacêuticas/química , Incerteza , Farmacocinética , Distribuição Tecidual , Triazóis
3.
BMC Health Serv Res ; 23(1): 198, 2023 Feb 24.
Artigo em Inglês | MEDLINE | ID: mdl-36829122

RESUMO

BACKGROUND: The COVID-19 pandemic raised awareness of the need to better understand where and how patient-level costs are incurred in health care organizations, as health managers and other decision-makers need to plan and quickly adapt to the increasing demand for health care services to meet patients' care needs. Time-driven activity-based costing offers a better understanding of the drivers of cost throughout the care pathway, providing information that can guide decisions on process improvement and resource optimization. This study aims to estimate COVID-19 patient-level hospital costs and to evaluate cost variability considering the in-hospital care pathways of COVID-19 management and the patient clinical classification. METHODS: This is a prospective cohort study that applied time-driven activity-based costing (TDABC) in a Brazilian reference center for COVID-19. Patients hospitalized during the first wave of the disease were selected for their data to be analyzed to estimate in-hospital costs. The cost information was calculated at the patient level and stratified by hospital care pathway and Ordinal Scale for Clinical Improvement (OSCI) category. Multivariable analyses were applied to identify predictors of cost variability in the care pathways that were evaluated. RESULTS: A total of 208 patients were included in the study. Patients followed five different care pathways, of which Emergency + Ward was the most followed (n = 118, 57%). Pathways which included the intensive care unit presented a statistically significant influence on costs per patient (p <  0.001) when compared to Emergency + Ward. The median cost per patient was I$2879 (IQR 1215; 8140) and mean cost per patient was I$6818 (SD 9043). The most expensive care pathway was the ICU only, registering a median cost per patient of I$13,519 (IQR 5637; 23,373) and mean cost per patient of I$17,709 (SD 16,020). All care pathways that included the ICU unit registered a higher cost per patient. CONCLUSIONS: This is one of the first microcosting study for COVID-19 that applied the TDABC methodology and demonstrated how patient-level costs vary as a function of the care pathways followed by patients. These findings can be used to develop value reimbursement strategies that will inform sustainable health policies in middle-income countries such as Brazil.


Assuntos
COVID-19 , Procedimentos Clínicos , Humanos , Brasil , Estudos Prospectivos , Pandemias , Fatores de Tempo , Custos Hospitalares , Hospitais , Hospitalização , Custos de Cuidados de Saúde
4.
Rural Remote Health ; 23(1): 8178, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36802799

RESUMO

INTRODUCTION: Climate change is a topic of growing interest and should guide our actions in society. Clinical practice must improve sustainability and ecological behavior as an opportunity. We intend to show how measures were implemented to reduce resource consumption in a health center in Gonçalo, a small village in the center of Portugal, with the support of local government spreading these practices across the community. METHODS: The first step was to account for daily resource use in Gonçalo's Health Center. Opportunities for improvement were listed in a multidisciplinary team meeting and subsequently implemented. Local government was very cooperative in the implementation of such measures, helping us spread the intervention to the community. RESULTS: A considerable reduction in resource consumption was verified, mainly the reduction of consumption of paper. Before this intervention, there was neither separation nor recycling of waste, which was initiated by this program. This change was implemented in the building of the Parish Council, at the Health Center and School Center of Gonçalo, where health education activities were promoted. DISCUSSION: In a rural area, the health center is an integral part of the life of the community in which it operates. Thus, their behaviors have the power to influence that same community. By showing our interventions and through practical examples, we intend to influence other health units to be an agent for change within their communities. By reducing, reusing and recycling, we intend to be a role model.


Assuntos
Educação em Saúde , Humanos , Mudança Climática , Serviços de Saúde Rural , Portugal , Desenvolvimento Sustentável
5.
Rural Remote Health ; 23(1): 8177, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36802825

RESUMO

INTRODUCTION: Gonçalo, a village with 1316 inhabitants of which 573 are 65 years old or older, presents itself as the 'Cradle of Fine Basketry'. Its population, rich in culture and stories to tell, has the support of a day care center for the elderly, where around 20 elderly people spend their days and find social connection. These patients make individual trips to access medical and nursing consultations. METHODS: Creation of a monthly consultation at the day care center for the elderly patients there. RESULTS: Reduction in the number of individual trips by the elderly patients, through the displacement of the family team;Optimizing the management of each individual health plan with the support of the day center's technical director, including therapeutic management and carrying out complementary diagnostic tests;Observation of the elderly patients in a safer way, avoiding traveling and maintaining a familiar space;Closer ties between the elderly patients and healthcare team; and Training of day care center professionals. DISCUSSION: At the heart of the practice of a healthcare team is the health and well-being of each patient. Therefore, meeting their needs, reallocating resources and involving the community will lead to health gains. The 'Consultas em Dia' project reflects this same onjective: the need of each elderly person to have access to GP/family nurse consultations joined with the healthcare team's willingness to provide an adapted response. Together we improved access and care delivery … we improved the health of our community!


Assuntos
Hospital Dia , Atenção à Saúde , Humanos , Idoso , Criança , Creches
6.
J Antimicrob Chemother ; 77(12): 3256-3264, 2022 11 28.
Artigo em Inglês | MEDLINE | ID: mdl-36171717

RESUMO

BACKGROUND: Infections caused by bacterial biofilms are very difficult to treat. The use of currently approved antibiotics even at high dosages often fails, making the treatment of these infections very challenging. Novel antimicrobial agents that use distinct mechanisms of action are urgently needed. OBJECTIVES: To explore the use of [G1K,K8R]cGm, a designed cyclic analogue of the antimicrobial peptide gomesin, as an alternative approach to treat biofilm infections. METHODS: We studied the activity of [G1K,K8R]cGm against biofilms of Staphylococcus aureus, a pathogen associated with several biofilm-related infections. A combination of atomic force and real-time confocal laser scanning microscopies was used to study the mechanism of action of the peptide. RESULTS: The peptide demonstrated potent activity against 24 h-preformed biofilms through a concentration-dependent ability to kill biofilm-embedded cells. Mechanistic studies showed that [G1K,K8R]cGm causes morphological changes on bacterial cells and permeabilizes their membranes across the biofilm with a half-time of 65 min. We also tested an analogue of [G1K,K8R]cGm without disulphide bonds, and a linear unfolded analogue, and found both to be inactive. CONCLUSIONS: The results suggest that the 3D structure of [G1K,K8R]cGm and its stabilization by disulphide bonds are essential for its antibacterial and antibiofilm activities. Moreover, our findings support the potential application of this stable cyclic antimicrobial peptide to fight bacterial biofilms.


Assuntos
Anti-Infecciosos , Infecções Estafilocócicas , Humanos , Staphylococcus aureus , Testes de Sensibilidade Microbiana , Biofilmes , Infecções Estafilocócicas/microbiologia , Peptídeos Catiônicos Antimicrobianos/farmacologia , Antibacterianos/farmacologia , Bactérias , Dissulfetos
7.
Int J Mol Sci ; 23(16)2022 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-36012519

RESUMO

Y55W mutants of non-selective NaK and partly K+-selective NaK2K channels have been used to explore the conformational dynamics at the pore region of these channels as they interact with either Na+ or K+. A major conclusion is that these channels exhibit a remarkable pore conformational flexibility. Homo-FRET measurements reveal a large change in W55-W55 intersubunit distances, enabling the selectivity filter (SF) to admit different species, thus, favoring poor or no selectivity. Depending on the cation, these channels exhibit wide-open conformations of the SF in Na+, or tight induced-fit conformations in K+, most favored in the four binding sites containing NaK2K channels. Such conformational flexibility seems to arise from an altered pattern of restricting interactions between the SF and the protein scaffold behind it. Additionally, binding experiments provide clues to explain such poor selectivity. Compared to the K+-selective KcsA channel, these channels lack a high affinity K+ binding component and do not collapse in Na+. Thus, they cannot properly select K+ over competing cations, nor reject Na+ by collapsing, as K+-selective channels do. Finally, these channels do not show C-type inactivation, likely because their submillimolar K+ binding affinities prevent an efficient K+ loss from their SF, thus favoring permanently open channel states.


Assuntos
Canais de Potássio , Potássio , Proteínas de Bactérias/metabolismo , Sítios de Ligação , Canais Iônicos/metabolismo , Íons/metabolismo , Potássio/metabolismo , Canais de Potássio/metabolismo , Conformação Proteica , Sódio/metabolismo
8.
Exp Appl Acarol ; 88(2): 191-207, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36346558

RESUMO

This work had the objectives to (1) evaluate the susceptibility of various Rhipicephalus microplus populations to commercial acaricides, and (2) select commercial acaricides (50-80% effective) and evaluate the effects of binary combinations of the phenylpropanoid (E)-cinnamaldehyde with selected commercial acaricides to control R. microplus under laboratory and field conditions. Using adult immersion tests with 116 populations and 14 commercial acaricides, products showing 50-80% effectiveness (percent control) with the lowest number of active ingredients were selected. Acaricides containing amitraz or chlorfenvinphos were tested in combination with (E)-cinnamaldehyde on a field population (strain CM). We found that (E)-cinnamaldehyde enhanced the activity of both commercial acaricides against R. microplus larvae; however, the enhancement was more accentuated when using amitraz. Experiments combining (E)-cinnamaldehyde + amitraz on unfed larvae and engorged females from another population (strain Gyn) were performed, verifying (E)-cinnamaldehyde enhanced the activity of amitraz. In the field experiment, the application of (E)-cinnamaldehyde appeared toxic to the tick hosts (cattle). We concluded that (E)-cinnamaldehyde enhanced the activity of amitraz against unfed larvae and engorged females of R. microplus; however, in the field test this phenylpropanoid caused intoxication in the cattle. Studies searching for new combinations of compounds from essential oils with amitraz deserve attention, as well as studies to develop formulations using amitraz + (E)-cinnamaldehyde that will be efficient and will not have toxic effects in cattle.


Assuntos
Acaricidas , Doenças dos Bovinos , Rhipicephalus , Infestações por Carrapato , Feminino , Bovinos , Animais , Acaricidas/farmacologia , Infestações por Carrapato/veterinária , Resistência a Inseticidas , Larva
9.
Langmuir ; 37(33): 9952-9963, 2021 08 24.
Artigo em Inglês | MEDLINE | ID: mdl-34374545

RESUMO

Lipid hydroperoxides are key mediators of diseases and cell death. In this work, the structural and dynamic perturbations induced by the hydroperoxidized POPC lipid (POPC-OOH) in fluid POPC membranes, at both 23 and 37 °C, were addressed using advanced small-angle X-ray scattering (SAXS) and fluorescence methodologies. Notably, SAXS reveals that the hydroperoxide group decreases the lipid bilayer bending rigidity. This alteration disfavors the bilayer stacking and increases the swelling in-between stacked bilayers. We further investigated the changes in the apolar/polar interface of hydroperoxide-containing membranes through time-resolved fluorescence/anisotropy experiments of the probe TMA-DPH and time-dependent fluorescence shifts of Laurdan. A shorter mean fluorescence lifetime for TMA-DPH was obtained in enriched POPC-OOH membranes, revealing a higher degree of hydration near the membrane interface. Moreover, a higher microviscosity near TMA-DPH and lower order are predicted for these oxidized membranes, at variance with the usual trend of variation of these two parameters. Finally, the complex relaxation process of Laurdan in pure POPC-OOH membranes also indicates a higher membrane hydration and viscosity in the close vicinity of the -OOH moiety. Altogether, our combined approach reveals that the hydroperoxide group promotes alterations in the membrane structure organization, namely, at the level of membrane order, viscosity, and bending rigidity.


Assuntos
Peróxidos Lipídicos , Fosfatidilcolinas , Polarização de Fluorescência , Bicamadas Lipídicas , Espalhamento a Baixo Ângulo , Difração de Raios X
10.
Int J Mol Sci ; 22(21)2021 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-34769082

RESUMO

The blood-brain barrier (BBB) is a barrier that separates the blood from the brain tissue and possesses unique characteristics that make the delivery of drugs to the brain a great challenge. To achieve this purpose, it is necessary to design strategies to allow BBB passage, in order to reach the brain and target the desired anatomic region. The use of nanomedicine has great potential to overcome this problem, since one can modify nanoparticles with strategic molecules that can interact with the BBB and induce uptake through the brain endothelial cells and consequently reach the brain tissue. This review addresses the potential of nanomedicines to treat neurological diseases by using nanoparticles specially developed to cross the BBB.


Assuntos
Encéfalo/metabolismo , Portadores de Fármacos/metabolismo , Sistemas de Liberação de Medicamentos , Nanopartículas/metabolismo , Animais , Barreira Hematoencefálica/efeitos dos fármacos , Barreira Hematoencefálica/metabolismo , Encéfalo/efeitos dos fármacos , Portadores de Fármacos/química , Sistemas de Liberação de Medicamentos/métodos , Humanos , Nanopartículas/química , Doenças Neurodegenerativas/tratamento farmacológico , Doenças Neurodegenerativas/metabolismo , Preparações Farmacêuticas/administração & dosagem , Farmacocinética
11.
Int J Mol Sci ; 22(21)2021 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-34769384

RESUMO

The allosteric coupling between activation and inactivation processes is a common feature observed in K+ channels. Particularly, in the prokaryotic KcsA channel the K+ conduction process is controlled by the inner gate, which is activated by acidic pH, and by the selectivity filter (SF) or outer gate, which can adopt non-conductive or conductive states. In a previous study, a single tryptophan mutant channel (W67 KcsA) enabled us to investigate the SF dynamics using time-resolved homo-Förster Resonance Energy Transfer (homo-FRET) measurements. Here, the conformational changes of both gates were simultaneously monitored after labelling the G116C position with tetramethylrhodamine (TMR) within a W67 KcsA background. At a high degree of protein labeling, fluorescence anisotropy measurements showed that the pH-induced KcsA gating elicited a variation in the homo-FRET efficiency among the conjugated TMR dyes (TMR homo-FRET), while the conformation of the SF was simultaneously tracked (W67 homo-FRET). The dependence of the activation pKa of the inner gate with the ion occupancy of the SF unequivocally confirmed the allosteric communication between the two gates of KcsA. This simple TMR homo-FRET based ratiometric assay can be easily extended to study the conformational dynamics associated with the gating of other ion channels and their modulation.


Assuntos
Proteínas de Bactérias/química , Proteínas de Bactérias/metabolismo , Transferência Ressonante de Energia de Fluorescência/métodos , Ativação do Canal Iônico , Canais de Potássio/química , Canais de Potássio/metabolismo , Potássio/metabolismo , Proteínas de Bactérias/genética , Concentração de Íons de Hidrogênio , Simulação de Dinâmica Molecular , Canais de Potássio/genética , Conformação Proteica
12.
Int J Mol Sci ; 22(2)2021 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-33419017

RESUMO

Alkylammonium salts have been used extensively to study the structure and function of potassium channels. Here, we use the hydrophobic tetraoctylammonium (TOA+) to shed light on the structure of the inactivated state of KcsA, a tetrameric prokaryotic potassium channel that serves as a model to its homologous eukaryotic counterparts. By the combined use of a thermal denaturation assay and the analysis of homo-Förster resonance energy transfer in a mutant channel containing a single tryptophan (W67) per subunit, we found that TOA+ binds the channel cavity with high affinity, either with the inner gate open or closed. Moreover, TOA+ bound at the cavity allosterically shifts the equilibrium of the channel's selectivity filter conformation from conductive to an inactivated-like form. The inactivated TOA+-KcsA complex exhibits a loss in the affinity towards permeant K+ at pH 7.0, when the channel is in its closed state, but maintains the two sets of K+ binding sites and the W67-W67 intersubunit distances characteristic of the selectivity filter in the channel resting state. Thus, the TOA+-bound state differs clearly from the collapsed channel state described by X-ray crystallography and claimed to represent the inactivated form of KcsA.


Assuntos
Proteínas de Bactérias/metabolismo , Canais de Potássio/metabolismo , Compostos de Amônio Quaternário/química , Proteínas de Bactérias/antagonistas & inibidores , Proteínas de Bactérias/genética , Sítios de Ligação , Transferência Ressonante de Energia de Fluorescência , Concentração de Íons de Hidrogênio , Mutagênese Sítio-Dirigida , Potássio/química , Potássio/metabolismo , Canais de Potássio/genética , Estabilidade Proteica , Estrutura Terciária de Proteína , Compostos de Amônio Quaternário/metabolismo , Sódio/química , Sódio/metabolismo , Temperatura
13.
Int J Mol Sci ; 22(21)2021 Oct 29.
Artigo em Inglês | MEDLINE | ID: mdl-34769158

RESUMO

Phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2) is an essential plasma membrane component involved in several cellular functions, including membrane trafficking and cytoskeleton organization. This function multiplicity is partially achieved through a dynamic spatiotemporal organization of PI(4,5)P2 within the membrane. Here, we use a Förster resonance energy transfer (FRET) approach to quantitatively assess the extent of PI(4,5)P2 confinement within the plasma membrane. This methodology relies on the rigorous evaluation of the dependence of absolute FRET efficiencies between pleckstrin homology domains (PHPLCδ) fused with fluorescent proteins and their average fluorescence intensity at the membrane. PI(4,5)P2 is found to be significantly compartmentalized at the plasma membrane of HeLa cells, and these clusters are not cholesterol-dependent, suggesting that membrane rafts are not involved in the formation of these nanodomains. On the other hand, upon inhibition of actin polymerization, compartmentalization of PI(4,5)P2 is almost entirely eliminated, showing that the cytoskeleton network is the critical component responsible for the formation of nanoscale PI(4,5)P2 domains in HeLa cells.


Assuntos
Citoesqueleto/metabolismo , Fosfatidilinositol 4,5-Difosfato/metabolismo , Membrana Celular/metabolismo , Transferência Ressonante de Energia de Fluorescência , Células HeLa , Humanos , Microdomínios da Membrana/metabolismo , Microscopia , Fosfatidilinositol 4,5-Difosfato/análise
14.
Mol Pharmacol ; 97(4): 295-303, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32102968

RESUMO

The main objective of this study was to clarify the topical mechanisms underlying diclofenac-induced gastric toxicity by considering for the first time both ionization states of this nonsteroidal anti-inflammatory drug. 1,2-Dimyristoyl-sn-glycero-3-phosphocholine (DMPC) liposomes were the model system chosen to mimic the protective phospholipid layers of the gastric mucosa and to describe the interactions with diclofenac, considering the pH gradient found in the gastric mucosa (3 < pH < 7.4). Complementary experimental techniques were combined to evaluate the drug's affinity for DMPC bilayers, as well as to assess the drug's effects on the structural properties of the phospholipid bilayer. The diclofenac-DMPC interactions were clearly dependent on the drug's ionization state. Neutral diclofenac displayed greater affinity for DMPC bilayers than anionic diclofenac. Moreover, the protonated/neutral form of the drug induced more pronounced and/or distinct alterations in the structure of the DMPC bilayer than the deprotonated/ionized form, considering similar membrane concentrations. Therefore, neutral diclofenac-induced changes in the structural properties of the external phospholipid layers of the gastric mucosa may constitute an additional toxicity mechanism of this worldwide-used drug, which shall be considered for the development of safer therapeutic strategies. SIGNIFICANCE STATEMENT: Neutral or anionic diclofenac exerted distinct alterations in phosphatidylcholine bilayers, which are used in this work as models for the protective phospholipid layers of the gastric mucosa. Remarkable changes were induced by neutral diclofenac in the structural properties of the phospholipid bilayer, suggesting that both ionized and neutral states of nonsteroidal anti-inflammatory drugs must be considered to clarify their mechanisms of toxicity and to ultimately develop safer anti-inflammatory drugs.


Assuntos
Anti-Inflamatórios não Esteroides/toxicidade , Diclofenaco/toxicidade , Dimiristoilfosfatidilcolina/química , Mucosa Gástrica/efeitos dos fármacos , Bicamadas Lipídicas/química , Mucosa Gástrica/química , Concentração de Íons de Hidrogênio , Lipossomos/química , Estrutura Molecular , Espalhamento a Baixo Ângulo , Difração de Raios X
15.
Hum Genet ; 139(6-7): 833, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32445039

RESUMO

In the original article publication, the affiliation of the author Ana Coutinho is incorrect.

16.
Hum Genet ; 139(6-7): 821-831, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32277285

RESUMO

Schistosomes induce severe hepatic disease, which is fatal in 2-10% of cases, mortality being higher in cases of co-infection with HBV or HCV. Hepatic disease occurs as a consequence of the chronic inflammation caused by schistosome eggs trapped in liver sinusoids. In certain individuals, the repair process leads to a massive accumulation of fibrosis in the periportal spaces. We and others have shown that genetic variants play a crucial role in disease progression from mild to severe fibrosis and explain why hepatic fibrosis progresses rapidly in certain subjects only. We will review here published findings concerning the strategies that have been used in the analysis of hepatic fibrosis in schistosome-infected individuals, the genetic variants that have associated with fibrosis, and variants in new pathways crucial for fibrosis progression. Together, these studies show that the development of fibrosis is under the tight genetic control of various common variants with moderate effects. This polygenic control has made it possible to develop models that identify schistosome-infected individual at risk of severe hepatic disease. We discuss the performances and limitations of these models.


Assuntos
Algoritmos , Marcadores Genéticos , Hepatopatias Parasitárias/diagnóstico , Medicina de Precisão , Schistosoma/genética , Esquistossomose/complicações , Índice de Gravidade de Doença , Animais , Progressão da Doença , Humanos , Hepatopatias Parasitárias/etiologia , Hepatopatias Parasitárias/genética , Schistosoma/imunologia , Schistosoma/patogenicidade , Esquistossomose/imunologia , Esquistossomose/parasitologia
17.
Mol Microbiol ; 109(3): 385-400, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29989674

RESUMO

Haem is an essential cofactor in central metabolic pathways in the vast majority of living systems. Prokaryotes acquire haem via haem biosynthesis pathways, and some also utilize haem uptake systems, yet it remains unclear how they balance haem requirements with the paradox that free haem is toxic. Here, using the model pathogen Staphylococcus aureus, we report that IsdG, one of two haem oxygenase enzymes in the haem uptake system, inhibits the formation of haem via the internal haem biosynthesis route. More specifically, we show that IsdG decreases the activity of ferrochelatase and that the two proteins interact both in vitro and in vivo. Further, a bioinformatics analysis reveals that a significant number of haem biosynthesis pathway containing organisms possess an IsdG-homologue and that those with both biosynthesis and uptake systems have at least two haem oxygenases. We conclude that IsdG-like proteins control intracellular haem levels by coupling the two pathways. IsdG is thus a target for the treatment of S. aureusinfections.


Assuntos
Heme/biossíntese , Oxigenases/metabolismo , Infecções Estafilocócicas/microbiologia , Staphylococcus aureus/enzimologia , Animais , Linhagem Celular , Ferroquelatase/genética , Ferroquelatase/metabolismo , Genes Bacterianos/genética , Humanos , Ferro/metabolismo , Macrófagos/microbiologia , Camundongos , Oxigenases/genética , RNA Bacteriano/genética , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Staphylococcus aureus/genética
18.
J Antimicrob Chemother ; 74(9): 2617-2625, 2019 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-31127270

RESUMO

OBJECTIVES: To investigate the mechanism of action at the molecular level of pepR, a multifunctional peptide derived from the Dengue virus capsid protein, against Staphylococcus aureus biofilms. METHODS: Biofilm mass, metabolic activity and viability were quantified using conventional microbiology techniques, while fluorescence imaging methods, including a real-time calcein release assay, were employed to investigate the kinetics of pepR activity at different biofilm depths. RESULTS: Using flow cytometry-based assays, we showed that pepR is able to prevent staphylococcal biofilm formation due to a fast killing of planktonic bacteria, which in turn resulted from a peptide-induced increase in the permeability of the bacterial membranes. The activity of pepR against pre-formed biofilms was evaluated through the application of a quantitative live/dead confocal laser scanning microscopy (CLSM) assay. The results show that the bactericidal activity of pepR on pre-formed biofilms is dose and depth dependent. A CLSM-based assay of calcein release from biofilm-embedded bacteria was further developed to indirectly assess the diffusion and membrane permeabilization properties of pepR throughout the biofilm. A slower diffusion and delayed activity of the peptide at deeper layers of the biofilm were quantified. CONCLUSIONS: Overall, our results show that the activity of pepR on pre-formed biofilms is controlled by its diffusion along the biofilm layers, an effect that can be counteracted by an additional administration of peptide. Our study sheds new light on the antibiofilm mechanism of action of antimicrobial peptides, particularly the importance of their diffusion properties through the biofilm matrix on their activity.


Assuntos
Antibacterianos/farmacologia , Peptídeos Catiônicos Antimicrobianos/farmacologia , Biofilmes/efeitos dos fármacos , Vírus da Dengue/genética , Infecções Estafilocócicas/tratamento farmacológico , Staphylococcus aureus/efeitos dos fármacos , Proteínas do Capsídeo/genética , Infecções Estafilocócicas/microbiologia
19.
Mar Drugs ; 17(12)2019 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-31766498

RESUMO

The use of marine-origin polysaccharides has increased in recent research because they are abundant, cheap, biocompatible, and biodegradable. These features motivate their application in nanotechnology as drug delivery systems; in tissue engineering, cancer therapy, or wound dressing; in biosensors; and even water treatment. Given the physicochemical and bioactive properties of fucoidan and chitosan, a wide range of nanostructures has been developed with these polysaccharides per se and in combination. This review provides an outline of these marine polysaccharides, including their sources, chemical structure, biological properties, and nanomedicine applications; their combination as nanoparticles with descriptions of the most commonly used production methods; and their physicochemical and biological properties applied to the design of nanoparticles to deliver several classes of compounds. A final section gives a brief overview of some biomedical applications of fucoidan and chitosan for tissue engineering and wound healing.


Assuntos
Organismos Aquáticos/química , Quitosana/química , Sistemas de Liberação de Medicamentos , Polissacarídeos/química , Antibacterianos/administração & dosagem , Antibacterianos/química , Materiais Biocompatíveis/química , Composição de Medicamentos/métodos , Humanos , Interações Hidrofóbicas e Hidrofílicas , Nanomedicina/métodos , Nanopartículas/química , Polifenóis/administração & dosagem , Polifenóis/química , Engenharia Tecidual/métodos
20.
Nutr J ; 17(1): 66, 2018 07 06.
Artigo em Inglês | MEDLINE | ID: mdl-29980231

RESUMO

BACKGROUND: Findings available in literature indicate that metabolic syndrome (MetS) diagnosed in young ages tends to remain in adulthood. The aim of the study was to identify demographic, nutritional, anthropometric and behavioral correlates of MetS in a sample of adolescents from Dourados, Mato Grosso do Sul, Brazil. METHODOLOGY: This is a cross-sectional school-based study involving 274 participants aged 12-18 years (186 girls and 88 boys). Anthropometric measurements were performed and a questionnaire with structured questions was applied for data collection. MetS was identified according to criteria proposed by the International Diabetes Federation. Data were statistically treated using bivariate analysis and hierarchical multiple regression. RESULTS: The proportion of adolescents identified with MetS was equivalent to 4.7% [95% CI (3.6-6.0)]. Multivariate analysis showed that older age (OR = 1.22 [1.04-1.73]) and higher economic class (OR = 1.25 [1.07-1.96]) were significantly associated with MetS. Among behavioral factors, longer recreational screen time (OR = 1.26 [1.05-1.94]) and low fruits/vegetables intake (OR = 1.49 [1.23-2.41]) were independently associated with MetS. Likewise, excess body weight (OR = 1.52 [1.24-2.41]) was significantly associated with the outcome. CONCLUSION: The high proportion of adolescents with MetS and the identification of their correlates reinforce the need for early life style intervention and awareness programs in this population group.


Assuntos
Síndrome Metabólica/epidemiologia , Adolescente , Comportamento do Adolescente , Fatores Etários , Brasil/epidemiologia , Criança , Estudos Transversais , Dieta , Feminino , Frutas , Promoção da Saúde , Humanos , Estilo de Vida , Masculino , Fatores Socioeconômicos , Inquéritos e Questionários , Verduras
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