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1.
Neurobiol Dis ; 194: 106463, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38485095

RESUMO

Mutations in NR2E3, a gene encoding an orphan nuclear transcription factor, cause two retinal dystrophies with a distinct phenotype, but the precise role of NR2E3 in rod and cone transcriptional networks remains unclear. To dissect NR2E3 function, we performed scRNA-seq in the retinas of wildtype and two different Nr2e3 mouse models that show phenotypes similar to patients carrying NR2E3 mutations. Our results reveal that rod and cone populations are not homogeneous and can be separated into different sub-classes. We identify a previously unreported cone pathway that generates hybrid cones co-expressing both cone- and rod-related genes. In mutant retinas, this hybrid cone subpopulation is more abundant and includes a subpopulation of rods transitioning towards a cone cell fate. Hybrid photoreceptors with high misexpression of cone- and rod-related genes are prone to regulated necrosis. Overall, our results shed light on the role of NR2E3 in modulating photoreceptor differentiation towards cone and rod fates and explain how different mutations in NR2E3 lead to distinct visual disorders in humans.


Assuntos
Receptores Nucleares Órfãos , Retina , Camundongos , Animais , Humanos , Receptores Nucleares Órfãos/metabolismo , Retina/metabolismo , Células Fotorreceptoras Retinianas Cones/metabolismo , Diferenciação Celular , Regulação da Expressão Gênica
2.
Genome Res ; 31(6): 981-994, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-34006569

RESUMO

Chromatin architecture mapping in 3D formats has increased our understanding of how regulatory sequences and gene expression are connected and regulated in a genome. The 3D chromatin genome shows extensive remodeling during embryonic development, and although the cleavage-stage embryos of most species lack structure before zygotic genome activation (pre-ZGA), zebrafish has been reported to have structure. Here, we aimed to determine the chromosomal architecture in paternal/sperm zebrafish gamete cells to discern whether it either resembles or informs early pre-ZGA zebrafish embryo chromatin architecture. First, we assessed the higher-order architecture through advanced low-cell in situ Hi-C. The structure of zebrafish sperm, packaged by histones, lacks topological associated domains and instead displays "hinge-like" domains of ∼150 kb that repeat every 1-2 Mbs, suggesting a condensed repeating structure resembling mitotic chromosomes. The pre-ZGA embryos lacked chromosomal structure, in contrast to prior work, and only developed structure post-ZGA. During post-ZGA, we find chromatin architecture beginning to form at small contact domains of a median length of ∼90 kb. These small contact domains are established at enhancers, including super-enhancers, and chemical inhibition of Ep300a (p300) and Crebbpa (CBP) activity, lowering histone H3K27ac, but not transcription inhibition, diminishes these contacts. Together, this study reveals hinge-like domains in histone-packaged zebrafish sperm chromatin and determines that the initial formation of high-order chromatin architecture in zebrafish embryos occurs after ZGA primarily at enhancers bearing high H3K27ac.


Assuntos
Cromatina , Peixe-Zebra , Animais , Cromatina/genética , Cromatina/metabolismo , Cromossomos/genética , Desenvolvimento Embrionário/genética , Regulação da Expressão Gênica no Desenvolvimento , Masculino , Espermatozoides/metabolismo , Peixe-Zebra/genética , Zigoto
3.
Clin Infect Dis ; 76(11): 2027-2037, 2023 06 08.
Artigo em Inglês | MEDLINE | ID: mdl-36975712

RESUMO

We assessed whether low CD4 count and high viral load (VL) affect the response to currently preferred ART. We performed a systematic review of randomized, controlled clinical trials that analyzed preferred first-line ART and a subgroup analysis by CD4 count (≤ or >200 CD4/µL) or VL (≤ or >100 000 copies/mL). We computed the odds ratio (OR) of treatment failure (TF) for each subgroup and individual treatment arm. Patients with ≤200 CD4 cells or VL ≥100 000 copies/mL showed an increased likelihood of TF at 48 weeks: OR, 1.94; 95% confidence interval (CI): 1.45-2.61 and OR, 1.75; 95% CI: 1.30-2.35, respectively. A similar increase in the risk of TF was observed at 96 weeks. There was no significant heterogeneity regarding integrase strand transfer inhibitor or nucleoside reverse transcriptase inhibitor backbone. Our results show that CD4 <200 cells/µL and VL ≥100,000 copies/mL impair ART efficacy in all preferred regimens.


Assuntos
Fármacos Anti-HIV , Infecções por HIV , Humanos , Infecções por HIV/tratamento farmacológico , Fármacos Anti-HIV/uso terapêutico , Carga Viral , Antirretrovirais/uso terapêutico , Contagem de Linfócito CD4 , HIV
4.
Gastroenterol Hepatol ; 46(5): 350-359, 2023 May.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-36174797

RESUMO

BACKGROUND AND AIMS: A dysfunctional immune response is key to the pathogenesis of acute-on-chronic liver failure (ACLF). It has been suggested that treatment with granulocyte colony-stimulating factor (G-CSF) increases survival in patients with ACLF by improving immune cell dysfunction and promoting liver regeneration. The aim of the study is to evaluate the survival benefit associated with G-CSF administration compared with standard medical therapy (SMT) in ACLF. METHODS: Systematic review and meta-analysis of randomized controlled trials. The primary outcome was survival at 60-90 days. We searched Ovid Medline, EMBASE, and Cochrane Central Register of Controlled Trials from inception to August 2021. Manual searches of reference lists in relevant articles and conference proceedings were also included. The revised Cochrane risk-of-bias tool was used for quality and risk of bias assessment. Two independent investigators extracted the data, and disagreements were solved by a third collaborator. RESULTS: The initial search identified 142 studies. Four randomized controlled trials were selected for quantitative analysis including 310 patients (154 G-CSF and 156 SMT). Significant heterogeneity was observed (I2=74%, Chi2=11.57, p=0.009). G-CSF administration did not improve survival in patients with ACLF (random-effects model, risk ratio=0.64 [95% CI 0.39, 1.07]). However, when considering only the results from the studies performed in Asia, a significant decrease on mortality was observed (risk ratio=0.53 [95% CI 0.35, 0.81]). Severity scores (MELD and Child) and CD34+ peripheral cells mobilization did not significantly improve with G-CSF. CONCLUSION: In a systematic review and meta-analysis, G-CSF administration did not significantly improve overall survival compared to SMT in patients with ACLF. The beneficial effects observed in Asian studies, as opposed to the European region, suggest that specific populations may benefit from further research aiming to identify certain subgroups with favourable outcomes when using G-CSF.


Assuntos
Insuficiência Hepática Crônica Agudizada , Criança , Humanos , Insuficiência Hepática Crônica Agudizada/tratamento farmacológico , Ensaios Clínicos Controlados Aleatórios como Assunto , Fator Estimulador de Colônias de Granulócitos/uso terapêutico , Granulócitos , Ásia
5.
BMC Med Res Methodol ; 22(1): 107, 2022 04 10.
Artigo em Inglês | MEDLINE | ID: mdl-35399050

RESUMO

BACKGROUND: Systematic reviews (SRs) are valuable resources as they address specific clinical questions by summarizing all existing relevant studies. However, finding all information to include in systematic reviews can be challenging. Methodological search filters have been developed to find articles related to specific clinical questions. To our knowledge, no filter exists for finding studies on the role of prognostic factor (PF). We aimed to develop and evaluate a search filter to identify PF studies in Ovid MEDLINE that has maximum sensitivity. METHODS: We followed current recommendations for the development of a search filter by first identifying a reference set of PF studies included in relevant systematic reviews on the topic, and by selecting search terms using a word frequency analysis complemented with an expert panel discussion. We evaluated filter performance using the relative recall methodology. RESULTS: We constructed a reference set of 73 studies included in six systematic reviews from a larger sample. After completing a word frequency analysis using the reference set studies, we compiled a list of 80 of the frequent methodological terms. This list of terms was evaluated by the Delphi panel for inclusion in the filter, resulting in a final set of 8 appropriate terms. The consecutive connection of these terms with the Boolean operator OR produced the filter. We then evaluated the filter using the relative recall method against the reference set, comparing the references included in the SRs with our new search using the filter. The overall sensitivity of the filter was calculated to be 95%, while the overall specificity was 41%. The precision of the filter varied considerably, ranging from 0.36 to 17%. The NNR (number needed to read) value varied largely from 6 to 278. The time saved by using the filter ranged from 13-70%. CONCLUSIONS: We developed a search filter for OVID-Medline with acceptable performance that could be used in systematic reviews of PF studies. Using this filter could save as much as 40% of the title and abstract screening task. The specificity of the filter could be improved by defining additional terms to be included, although it is important to evaluate any modification to guarantee the filter is still highly sensitive.


Assuntos
Pesquisa , Coleta de Dados , Humanos , MEDLINE , Prognóstico , Revisões Sistemáticas como Assunto
6.
Dermatol Ther ; 34(1): e13466, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33015928

RESUMO

Hair-pulling disorder (Trichotillomania) is a disabling mental disorder. Patient's behavior is characterized by the recurrent pulling of own hair with hair loss and a marked dysfunction in various areas of daily life. Trichotillomania is a relatively common disorder with pediatric onset, often associated with significant morbidity, comorbidity, and functional decline. Surprisingly, children or adolescents have been little studied in the research studies on the pathophysiology and psychopathology of trichotillomania. Furthermore, more evidences regarding the effective and evidence-based pharmacological interventions for the treatment of this condition are encouraged. This narrative review will report on the etiopathogenesis and clinical manifestations of trichotillomania including criteria for diagnosis and treatment issues of this complex mental disorder.


Assuntos
Doenças do Cabelo , Tricotilomania , Adolescente , Criança , Comorbidade , Humanos , Tricotilomania/diagnóstico , Tricotilomania/terapia
7.
Int J Mol Sci ; 22(6)2021 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-33808880

RESUMO

Peroxisome proliferator activated receptor beta/delta (PPARß/δ) is a nuclear receptor ubiquitously expressed in cells, whose signaling controls inflammation. There are large discrepancies in understanding the complex role of PPARß/δ in disease, having both anti- and pro-effects on inflammation. After ligand activation, PPARß/δ regulates genes by two different mechanisms; induction and transrepression, the effects of which are difficult to differentiate directly. We studied the PPARß/δ-regulation of lipopolysaccharide (LPS) induced inflammation (indicated by release of nitrite and IL-6) of rat pulmonary artery, using different combinations of agonists (GW0742 or L-165402) and antagonists (GSK3787 or GSK0660). LPS induced release of NO and IL-6 is not significantly reduced by incubation with PPARß/δ ligands (either agonist or antagonist), however, co-incubation with an agonist and antagonist significantly reduces LPS-induced nitrite production and Nos2 mRNA expression. In contrast, incubation with LPS and PPARß/δ agonists leads to a significant increase in Pdk-4 and Angptl-4 mRNA expression, which is significantly decreased in the presence of PPARß/δ antagonists. Docking using computational chemistry methods indicates that PPARß/δ agonists form polar bonds with His287, His413 and Tyr437, while antagonists are more promiscuous about which amino acids they bind to, although they are very prone to bind Thr252 and Asn307. Dual binding in the PPARß/δ binding pocket indicates the ligands retain similar binding energies, which suggests that co-incubation with both agonist and antagonist does not prevent the specific binding of each other to the large PPARß/δ binding pocket. To our knowledge, this is the first time that the possibility of binding two ligands simultaneously into the PPARß/δ binding pocket has been explored. Agonist binding followed by antagonist simultaneously switches the PPARß/δ mode of action from induction to transrepression, which is linked with an increase in Nos2 mRNA expression and nitrite production.


Assuntos
PPAR delta/química , PPAR beta/química , Animais , Benzamidas/química , Benzamidas/farmacologia , Sítios de Ligação , Biomarcadores , Expressão Gênica , Mediadores da Inflamação/metabolismo , Ligantes , Lipopolissacarídeos/efeitos adversos , Lipopolissacarídeos/imunologia , Masculino , Conformação Molecular , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Óxido Nítrico/metabolismo , PPAR delta/agonistas , PPAR delta/antagonistas & inibidores , PPAR delta/genética , PPAR beta/agonistas , PPAR beta/antagonistas & inibidores , PPAR beta/genética , Ligação Proteica , Artéria Pulmonar/efeitos dos fármacos , Artéria Pulmonar/metabolismo , Ratos , Relação Estrutura-Atividade , Sulfonas/química , Sulfonas/farmacologia , Tiazóis/química , Tiazóis/farmacologia
8.
Health Info Libr J ; 38(1): 72-76, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33684264

RESUMO

Teaching students how to conduct bibliographic searches in health sciences' databases is essential training. One of the challenges librarians face is how to motivate students during classroom learning. In this article, two hospital libraries, in Spain, used Escape rooms as a method of bringing creativity, teamwork, communication and critical thinking into bibliographic search instruction. Escape rooms are a series of puzzles that must be solved to exit the game. This article explores the methods used for integrating escape rooms into training programmes and evaluates the results. Escape Rooms are a useful tool that can be integrated into residents' training to support their instruction on bibliographic searches. This kind of learning stablishes competences like logical thinking and deductive approaching. These aspects aid participants to make their own decision and to develop social and intellectual skills.


Assuntos
Disseminação de Informação/métodos , PubMed/normas , Humanos , PubMed/instrumentação , PubMed/tendências
9.
Angew Chem Int Ed Engl ; 60(18): 10089-10094, 2021 04 26.
Artigo em Inglês | MEDLINE | ID: mdl-33559939

RESUMO

Atomic-level control over the position and growth of a single and continuous metal chain is an ambitious goal that often requires complex and costly processes. Herein, we demonstrate that 1Pd-DNA molecules, comprising a continuous single chain of PdII ions, can be prepared by a simple self-assembly reaction between the complex [Pd(Cheld)(CH3 CN)] (1Pd_CH3 CN) (Cheld=chelidamic acid) and single-stranded DNA homopolymers (ss-DNA) containing adenine (A) or 7-deazaadenine (X) bases. The single PdII -base pairs [1Pd(N1-A)] and [1Pd(N1-X)] were synthesized and characterized in solution and solid-state (X-ray diffraction) revealing an arrangement similar to that of natural Watson-Crick base pairs. Subsequently, 1Pd-DNA hybrids were prepared, characterized, and their structures studied by small-angle X-ray scattering (SAXS) and ab-initio calculations. The results indicate that the 1Pd-DNA structures resemble that of double-stranded DNA, with one strand being replaced by a supramolecular stack of continuous PdII complexes.

10.
Inorg Chem ; 59(13): 9325-9338, 2020 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-32551611

RESUMO

The formation of copper(II)-mediated base pairs involving pyridine-2,6-dicarboxylate derivatives and canonical nucleosides has proven to be a smart approach to introduce copper(II) ions at specific locations of DNA duplexes. However, the structural characteristics of these metalized base pairs have not yet been revealed, and their effect on DNA structures is difficult to assess. Herein, for the first time, we report on the different structural details of copper-mediated base pairs formed by themselves and in DNA duplexes. The individual base pairs [Cu(mcheld)(N3-Cyt)(H2O)]·3H2O (1Cu_Cyt), [Cu(mcheld)(N7-Ade)(H2O)2]·2H2O (1Cu_Ade), [Cu(mcheld)(N7-Gua)(H2O)] (1Cu_Gua), and [Cu(mcheld)(N1-7CAde)(H2O)]·H2O (1Cu_7CAde) were obtained from the reaction of the metal complex [Cu(mcheld)(H2O)2] (1Cu) (mcheld = 4-methoxypyridine-2,6-dicarboxylic acid) with model nucleosides (Cyt = N1-methylcytosine, Ade = N9-ethyladenine, Gua = N9-propylguanine, 7CAde = N9-propyl-7-deazaadenine). The crystal structure of the five complexes was determined by means of single-crystal X-ray diffraction. Furthermore, the formation of the 1Cu_Cyt and 1Cu_Gua base pairs in the middle of DNA duplexes, duplex DNA15 (917 atoms) and DNA10 (649 atoms), respectively, was studied using highly demanding ab initio computational calculations. These theoretical studies aimed to validate, from a structural point of view, whether base pairs of the kind 1Cu_nucleosides can be included in a DNA double helix and how this situation affects the double-helical structure. The results indicate that the 1Cu_Cyt and 1Cu_Gua base pairs can be formed in a DNA molecule without significant structural constraints. In addition, the double-helix DNA structure remains virtually unchanged when it contains these Cu(II)-mediated base pairs.


Assuntos
Pareamento de Bases , Complexos de Coordenação/química , DNA/química , Complexos de Coordenação/síntese química , Cobre/química , Cristalografia por Raios X , Modelos Químicos , Estrutura Molecular , Nucleosídeos/síntese química , Nucleosídeos/química
11.
Dermatol Ther ; 33(4): e13661, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32447793

RESUMO

Excoriation disorder (ED) is a primary psychiatric disorder characterized by recurrent skin picking, which may lead to self-induced cutaneous lesions and significant distress or functional impairment. The affected patient is aware of his/her self-destructive behavior but feels unable to give up this habit, despite having made repeated attempts to decrease or stop it. ED is a relatively frequent disorder, of notable heterogeneity and phenomenological complexity, accompanied by significant emotional and physical consequences. Therefore, further research is necessary to enhance the knowledge on its clinical manifestations, epidemiology, and comorbidities. This article presents an update regarding the etiopathogenesis, clinical aspects, and treatment options of ED to provide an up-to-date review for psychiatrists, dermatologists, and general practitioners.


Assuntos
Transtornos Mentais , Comportamento Autodestrutivo , Dermatopatias , Comorbidade , Feminino , Humanos , Masculino , Transtornos Mentais/diagnóstico , Transtornos Mentais/epidemiologia , Transtornos Mentais/terapia , Comportamento Autodestrutivo/diagnóstico , Comportamento Autodestrutivo/epidemiologia , Comportamento Autodestrutivo/terapia , Pele , Dermatopatias/diagnóstico , Dermatopatias/epidemiologia , Dermatopatias/terapia
12.
Proc Natl Acad Sci U S A ; 114(6): E941-E950, 2017 02 07.
Artigo em Inglês | MEDLINE | ID: mdl-28115725

RESUMO

Understanding environmental influences on sex ratios is important for the study of the evolution of sex-determining mechanisms and for evaluating the effects of global warming and chemical pollution. Fishes exhibit sexual plasticity, but the underlying mechanisms of environmental effects on their reproduction are unclear even in the well-established teleost research model, the zebrafish. Here we established the conditions to study the effects of elevated temperature on zebrafish sex. We showed that sex ratio response to elevated temperature is family-specific and typically leads to masculinization (female-to-male sex reversal), resulting in neomales. These results uncovered genotype-by-environment interactions that support a polygenic sex determination system in domesticated (laboratory) zebrafish. We found that some heat-treated fish had gene expression profiles similar to untreated controls of the same sex, indicating that they were resistant to thermal effects. Further, most neomales had gonadal transcriptomes similar to that of regular males. Strikingly, we discovered heat-treated females that displayed a normal ovarian phenotype but with a "male-like" gonadal transcriptome. Such major transcriptomic reprogramming with preserved organ structure has never been reported. Juveniles were also found to have a male-like transcriptome shortly after exposure to heat. These findings were validated by analyzing the expression of genes and signaling pathways associated with sex differentiation. Our results revealed a lasting thermal effect on zebrafish gonads, suggesting new avenues for detection of functional consequences of elevated temperature in natural fish populations in a global warming scenario.


Assuntos
Gônadas/metabolismo , Temperatura Alta , Diferenciação Sexual/genética , Transcriptoma , Peixe-Zebra/genética , Animais , Feminino , Regulação da Expressão Gênica no Desenvolvimento , Ontologia Genética , Gônadas/embriologia , Gônadas/crescimento & desenvolvimento , Masculino , Modelos Animais , Razão de Masculinidade , Temperatura , Testículo/embriologia , Testículo/crescimento & desenvolvimento , Testículo/metabolismo , Proteínas de Peixe-Zebra/genética
13.
J Exp Biol ; 220(Pt 6): 1056-1064, 2017 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-28082617

RESUMO

The zebrafish (Danio rerio) has become a well-established experimental model in many research fields but the loss of the primary sex-determining region during the process of domestication renders laboratory strains of zebrafish susceptible to the effects of environmental factors on sex ratios. Further, an essential husbandry aspect - the optimal rearing density to avoid stress-induced masculinization - is not known. We carried out two experiments: the first focusing on the effects of density on survival, growth and sex ratio by rearing zebrafish at different initial densities (9, 19, 37 and 74 fish per litre) for 3 months (6-90 days post-fertilization, dpf), and the second focusing on the effects of cortisol during the sex differentiation period (15-45 dpf) for zebrafish reared at low density. The results showed an increase in the number of males in groups subjected to the two highest initial rearing densities; we also observed a reduction of survival and growth in a density-dependent manner. Furthermore, zebrafish treated with cortisol during the sex differentiation period showed a complete masculinization of the population; treatment with the cortisol synthesis inhibitor metyrapone negated the effects of exogenous cortisol. Our results indicate that the process of sex differentiation in domesticated zebrafish can be perturbed by elevated stocking density and that this effect is likely to be mediated by an increase in cortisol through the stress response. However, the underlying mechanism needs further study.


Assuntos
Estresse Fisiológico , Peixe-Zebra/crescimento & desenvolvimento , Animais , Aglomeração , Feminino , Gônadas/fisiologia , Hidrocortisona/metabolismo , Masculino , Densidade Demográfica , Diferenciação Sexual , Razão de Masculinidade , Peixe-Zebra/fisiologia
14.
Prostaglandins Other Lipid Mediat ; 122: 18-27, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26686607

RESUMO

Prostacyclin (PGI2) is a key mediator involved in cardiovascular homeostasis, acting predominantly on two receptor types; cell surface IP receptor and cytosolic peroxisome proliferator activated receptor (PPAR) ß/δ. Having a very short half-life, direct methods to determine its long term effects on cells is difficult, and little is known of its interactions with nuclear receptors. Here we used computational chemistry methods to investigate the potential for PGI2, beraprost (IP receptor agonist), and GW0742 (PPARß/δ agonist), to bind to nuclear receptors, confirmed with pharmacological methods. In silico screening predicted that PGI2, beraprost, and GW0742 have the potential to bind to different nuclear receptors, in particular thyroid hormone ß receptor (TRß) and thyroid hormone α receptor (TRα). Docking analysis predicts a binding profile to residues thought to have allosteric control on the TR ligand binding site. Luciferase reporter assays confirmed that beraprost and GW0742 display TRß and TRα antagonistic properties; beraprost IC50 6.3 × 10(-5)mol/L and GW0742 IC50 4.9 × 10(-6) mol/L. Changes to triiodothyronine (T3) induced vasodilation of rat mesenteric arteries measured on the wire myograph were measured in the presence of the TR antagonist MLS000389544 (10(-5) mol/L), beraprost (10(-5) mol/L) and GW0742 (10(-5) mol/L); all significantly inhibited T3 induced vasodilation compared to controls. We have shown that both beraprost and GW0742 exhibit TRß and TRα antagonist behaviour, and suggests that PGI2 has the ability to affect the long term function of cells through binding to and inactivating thyroid hormone receptors.


Assuntos
Simulação por Computador , Epoprostenol/farmacologia , Receptores Citoplasmáticos e Nucleares/antagonistas & inibidores , Receptores dos Hormônios Tireóideos/antagonistas & inibidores , Animais , Ligação Competitiva/efeitos dos fármacos , Relação Dose-Resposta a Droga , Epoprostenol/análogos & derivados , Epoprostenol/química , Epoprostenol/metabolismo , Humanos , Ligantes , Masculino , Artérias Mesentéricas/efeitos dos fármacos , Artérias Mesentéricas/fisiologia , Modelos Moleculares , Miografia/métodos , Domínios Proteicos , Ratos Wistar , Receptores Citoplasmáticos e Nucleares/agonistas , Receptores Citoplasmáticos e Nucleares/metabolismo , Receptores dos Hormônios Tireóideos/química , Receptores dos Hormônios Tireóideos/metabolismo , Tiazóis/química , Tiazóis/metabolismo , Tiazóis/farmacologia , Receptores alfa dos Hormônios Tireóideos/antagonistas & inibidores , Receptores alfa dos Hormônios Tireóideos/química , Receptores alfa dos Hormônios Tireóideos/metabolismo , Receptores beta dos Hormônios Tireóideos/antagonistas & inibidores , Receptores beta dos Hormônios Tireóideos/química , Receptores beta dos Hormônios Tireóideos/metabolismo , Tri-Iodotironina/metabolismo , Tri-Iodotironina/farmacologia , Vasodilatação/efeitos dos fármacos
15.
Angew Chem Int Ed Engl ; 55(21): 6170-4, 2016 05 17.
Artigo em Inglês | MEDLINE | ID: mdl-27005864

RESUMO

The oligonucleotide d(TX)9 , which consists of an octadecamer sequence with alternating non-canonical 7-deazaadenine (X) and canonical thymine (T) as the nucleobases, was synthesized and shown to hybridize into double-stranded DNA through the formation of hydrogen-bonded Watson-Crick base pairs. dsDNA with metal-mediated base pairs was then obtained by selectively replacing W-C hydrogen bonds by coordination bonds to central silver(I) ions. The oligonucleotide I adopts a duplex structure in the absence of Ag(+) ions, and its stability is significantly enhanced in the presence of Ag(+) ions while its double-helix structure is retained. Temperature-dependent UV spectroscopy, circular dichroism spectroscopy, and ESI mass spectrometry were used to confirm the selective formation of the silver(I)-mediated base pairs. This strategy could become useful for preparing stable metallo-DNA-based nanostructures.


Assuntos
Adenina/análogos & derivados , DNA/química , Prata/química , Timina/química , Adenina/química , Adenina/metabolismo , Pareamento de Bases , Dicroísmo Circular , DNA/metabolismo , Ligação de Hidrogênio , Conformação de Ácido Nucleico , Espectrometria de Massas por Ionização por Electrospray , Espectrofotometria Ultravioleta , Temperatura , Timina/metabolismo
16.
BMC Genomics ; 16: 679, 2015 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-26338702

RESUMO

BACKGROUND: Sex in fish is plastic and in several species can be influenced by environmental factors. In sensitive species, elevated temperatures have a masculinizing effect. Previous studies on the effects of temperature on gene expression have been restricted to a few cognate genes, mostly related to testis or ovarian development, and analyzed in gonads once they had completed the process of sex differentiation. However, studies on the effect of temperature at the whole gonadal transcriptomic level are scarce in fish and, in addition, temperature effects at the time of sex differentiation at the transcriptomic level are also unknown. Here, we used the European sea bass, a gonochoristic teleost with a polygenic sex determination system influenced by temperature, and exposed larvae to elevated temperature during the period of early gonad formation. Transcriptomic analysis of the gonads was carried out about three months after the end of temperature exposure, shortly after the beginning of the process of sex differentiation. RESULTS: Elevated temperature doubled the number of males with respect to untreated controls. Transcriptomic analysis of early differentiating female gonads showed how heat caused: 1) an up-regulation of genes related to cholesterol transport (star), the stress response (nr3c1) and testis differentiation (amh, dmrt, etc.), 2) a decrease in the expression of genes related to ovarian differentiation such as cyp19a1a, and 3) an increase in the expression of several genes related to epigenetic regulatory mechanisms (hdac11, dicer1, ehmt2, jarid2a, pcgf2, suz12, mettl22). CONCLUSIONS: Taken together, the results of this study contribute to the understanding of how the early environment sets permanent changes that result in long-lasting consequences, in this case in the sexual phenotype. Results also show the usefulness of comparing the effects of heat on the behavior of cognate genes related to sex differentiation as well as that of genes involved in establishing and maintaining cell identity through epigenetic mechanisms.


Assuntos
Bass/genética , Gônadas/metabolismo , Diferenciação Sexual/genética , Temperatura , Transcriptoma , Animais , Análise por Conglomerados , Biologia Computacional , Epigênese Genética , Feminino , Expressão Gênica , Perfilação da Expressão Gênica , Masculino , Característica Quantitativa Herdável , Reprodutibilidade dos Testes , Reprodução/genética , Análise para Determinação do Sexo , Razão de Masculinidade , Estresse Fisiológico/genética
17.
PLoS Genet ; 7(12): e1002447, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22242011

RESUMO

Sex ratio shifts in response to temperature are common in fish and reptiles. However, the mechanism linking temperature during early development and sex ratios has remained elusive. We show in the European sea bass (sb), a fish in which temperature effects on sex ratios are maximal before the gonads form, that juvenile males have double the DNA methylation levels of females in the promoter of gonadal aromatase (cyp19a), the enzyme that converts androgens into estrogens. Exposure to high temperature increased the cyp19a promoter methylation levels of females, indicating that induced-masculinization involves DNA methylation-mediated control of aromatase gene expression, with an observed inverse relationship between methylation levels and expression. Although different CpGs within the sb cyp19a promoter exhibited different sensitivity to temperature, we show that the increased methylation of the sb cyp19a promoter, which occurs in the gonads but not in the brain, is not a generalized effect of temperature. Importantly, these effects were also observed in sexually undifferentiated fish and were not altered by estrogen treatment. Thus, methylation of the sb cyp19a promoter is the cause of the lower expression of cyp19a in temperature-masculinized fish. In vitro, induced methylation of the sb cyp19a promoter suppressed the ability of SF-1 and Foxl2 to stimulate transcription. Finally, a CpG differentially methylated by temperature and adjacent to a Sox transcription factor binding site is conserved across species. Thus, DNA methylation of the aromatase promoter may be an essential component of the long-sought-after mechanism connecting environmental temperature and sex ratios in vertebrate species with temperature-dependent sex determination.


Assuntos
Aromatase/genética , Bass/genética , Metilação de DNA/genética , Gônadas/enzimologia , Processos de Determinação Sexual/genética , Razão de Masculinidade , Animais , Aromatase/metabolismo , Sequência de Bases , Bass/fisiologia , Ilhas de CpG/genética , Europa (Continente) , Feminino , Expressão Gênica , Masculino , Dados de Sequência Molecular , Regiões Promotoras Genéticas , Temperatura
18.
Artigo em Inglês | MEDLINE | ID: mdl-38697392

RESUMO

BACKGROUND: The risk of Trypanosoma cruzi reactivation is poorly understood. Previous studies evaluating the risk of reactivation report imprecise findings, and recommendations for monitoring and management from clinical guidelines rely on consensus opinion. OBJECTIVES: We conducted a systematic review and meta-analysis to estimate the cumulative T. cruzi reactivation incidence in immunosuppressed adults, summarize the available evidence on prognostic factors for reactivation, and examine its prognostic effect on mortality. DATA SOURCES: MEDLINE, Embase, LILACS, Clinical Trials, and CENTRAL from inception to 4 July 2022. STUDY ELIGIBILITY CRITERIA: Studies reporting the incidence of T. cruzi reactivation. PARTICIPANTS: Immunosuppressed adults chronically infected by T. cruzi. METHODS: Two authors independently extracted data (including, but not limited to, incidence data, reactivation definition, follow-up, treatment, monitoring schedule, examined prognostic factors) and evaluated the risk of bias. We pooled cumulative incidence using a random-effects model. RESULTS: Twenty-two studies (806 participants) were included. The overall pooled incidence of T. cruzi reactivation was 27% (95% CI, 19-36), with the highest pooled proportion in the sub-group of transplant recipients (36%; 95% CI, 25-48). The highest risk period was in the first 6 months after transplant (32%; 95% CI, 17-58), decreasing drastically the number of new cases later. People living with HIV and patients with autoimmune diseases experienced significantly lower cumulative reactivation incidences (17%; 95% CI, 8-29 and 18%; 95% CI, 9-29, respectively). A single study explored the independent effect of benznidazole and found benefits for preventing reactivations. No studies evaluated the independent association between reactivation and mortality, while sensitivity analysis results using unadjusted estimates were inconclusive. The heterogeneity of diagnostic algorithms was substantial. CONCLUSIONS: Reactivation occurs in three out of ten T. cruzi-seropositive immunosuppressed adults. These findings can assist clinicians and panel guidelines in tailoring monitoring schedules. There is a great need for an accurate definition of reactivation and targeted monitoring.

19.
Front Immunol ; 15: 1343124, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38361925

RESUMO

Background: In people living with HIV (PLHIV), the CD4/CD8 ratio has been proposed as a useful marker for non-AIDS events. However, its predictive ability on mortality over CD4 counts, and the role of CD8+ T-cell counts remain controversial. Methods: We conducted a systematic review and meta-analysis of published studies from 1996 to 2023, including PLHIV on antiretroviral treatment, and reporting CD4/CD8 ratio or CD8+ counts. The primary outcome was non-AIDS mortality or all-cause mortality. We performed a standard random-effects pairwise meta-analysis comparing low versus high CD4/CD8 ratio with a predefined cut-off point of 0.5. (CRD42020170931). Findings: We identified 2,479 studies for screening. 20 studies were included in the systematic review. Seven studies found an association between low CD4/CD8 ratio categories and increased mortality risk, with variable cut-off points between 0.4-1. Four studies were selected for meta-analysis, including 12,893 participants and 618 reported deaths. Patients with values of CD4/CD8 ratio below 0.5 showed a higher mortality risk (OR 3.65; 95% CI 3.04 - 4.35; I2 = 0.00%) compared to those with higher values. While the meta-analysis of CD8+ T-cell counts was not feasible due to methodological differences between studies, the systematic review suggests a negative prognostic impact of higher values (>1,138 to 1,500 cells/uL) in the long term. Conclusions: Our results support the use of the CD4/CD8 ratio as a prognostic marker in clinical practice, especially in patients with values below 0.5, but consensus criteria on ratio timing measurement, cut-off values, and time to event are needed in future studies to get more robust conclusions. Systematic review registration: https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42020170931, identifier CRD42020170931.


Assuntos
Infecções por HIV , Humanos , Prognóstico , Infecções por HIV/tratamento farmacológico , Relação CD4-CD8 , Linfócitos T CD8-Positivos , Contagem de Linfócito CD4
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