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1.
Opt Lett ; 49(9): 2525-2528, 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38691760

RESUMO

A fundamental parameter to determine how electromagnetic waves interfere is their relative phase, and achieving a fine control over it enables a wide range of interferometric applications. Existing phase control methods rely on modifying the optical path length either by changing the path followed by the light or by altering the thickness or index of refraction of an optical element in the setup. In this Letter, we present a novel, to the best of our knowledge, method, based on acousto-optic modulators (AOMs), which allows adjusting the phase by shifting the frequency of the light in a segment of its path. Since the amount of phase shift depends on the length of the segment, an optical fiber is used to realize a 2π shift. Two experimental implementations are described which deal with different sources of phase fluctuations. The first addresses fluctuations resulting from the optical fiber, while the second tackles unwanted variations originating from the AOMs.

2.
Plant J ; 98(3): 492-510, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30659683

RESUMO

Insight into how plants simultaneously cope with multiple stresses, for example, when challenged with biotic stress from pathogen infection and abiotic stress from drought, is important both for understanding evolutionary trade-offs and optimizing crop responses to these stresses. Mechanisms by which initial plant immune signaling antagonizes abscisic acid (ABA) signal transduction require further investigation. Using a chemical genetics approach, the small molecule [5-(3,4-dichlorophenyl)furan-2-yl]-piperidine-1-ylmethanethione (DFPM) has previously been identified due to its ability to suppress ABA signaling via plant immune signaling components. Here, we have used forward chemical genetics screening to identify DFPM-insensitive loci by monitoring the activity of ABA-inducible pRAB18::GFP in the presence of DFPM and ABA. The ability of DFPM to attenuate ABA signaling was reduced in rda mutants (resistant to DFPM inhibition of ABA signaling). One of the mutants, rda2, was mapped and is defective in a gene encoding a lectin receptor kinase. RDA2 functions in DFPM-mediated inhibition of ABA-mediated reporter expression. RDA2 is required for DFPM-mediated activation of immune signaling, including phosphorylation of mitogen-activated protein kinase (MAPK) 3 (MPK3) and MPK6, and induction of immunity marker genes. Our study identifies a previously uncharacterized receptor kinase gene that is important for DFPM-mediated immune signaling and inhibition of ABA signaling. We demonstrate that the lectin receptor kinase RDA2 is essential for perceiving the DFPM signal and activating MAPKs, and that MKK4 and MKK5 are required for DFPM interference with ABA signal transduction.


Assuntos
Ácido Abscísico/metabolismo , Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Regulação da Expressão Gênica de Plantas/genética , Regulação da Expressão Gênica de Plantas/fisiologia , Transdução de Sinais/genética , Transdução de Sinais/fisiologia
3.
Pediatr Dermatol ; 37(6): 1113-1118, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32853447

RESUMO

BACKGROUND AND OBJECTIVES: Skin diseases are a common reason for emergency department (ED) consultations; however, few studies have focused on pediatric patients. Diagnostic consistency between ED physicians and dermatologists varies from 43% to 58%, meaning many patients seeking emergency care may receive incorrect diagnoses and treatments. We aimed to determine the diagnostic concordance between ED physicians and pediatric dermatologists. METHODS: We conducted a prospective study including all pediatric patients (<18 years) who were seen for a skin condition at the ED from December 1, 2017, to June 1, 2018, and consented to participate. We classified diagnoses according to their etiology. Patients were diagnosed by ED trainees and attending physicians, followed by blinded pediatric dermatology trainees and attending physicians. We evaluated concordance using Fleiss's kappa coefficient (κ) with a 95% confidence interval. We further stratified the data by level of training. RESULTS: We included 185 patients. Inflammatory conditions were the most common reason for consultation, followed by infections; 10 patients required hospitalization. Concordance between diagnoses given at the ED and at the dermatology clinic was moderate (κ 0.472, 95% CI: 0.389-0.455) with 62.7% agreement. Concordance between different diagnostic categories was lowest for autoimmune disorders and drug reactions (κ 0.392 with 95% CI: 0.248-0.536 and κ 0.258 with 95% CI: 0.114-0.402). CONCLUSIONS: Diagnostic concordance between ED physicians and dermatologists was moderate and differed according to training level and diagnoses. Dermatological education for ED providers, specifically focusing on autoimmune disorders and drug reactions, may improve diagnostic accuracy and patient care.


Assuntos
Dermatologistas , Médicos , Criança , Serviço Hospitalar de Emergência , Humanos , México , Estudos Prospectivos , Centros de Atenção Terciária
4.
Arthroscopy ; 34(5): 1621-1627, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29482859

RESUMO

PURPOSE: To report the magnetic resonance imaging (MRI) and clinical outcomes at a minimum 5-year follow-up in a series of patients with postmeniscectomy syndrome and treated with a polyurethane scaffold. METHODS: All consecutive patients operated on from September 2008 to February 2011 for either persistent medial or lateral joint line compartmental pain receiving a polyurethane scaffold due to a previous partial meniscus resection with a minimum 5-year follow-up were included. Functional scores (Knee Injury and Osteoarthritis Outcomes Score, International Knee Documentation Committee, Lysholm, and Tegner) were assessed preoperatively and at the last follow-up. The state of the scaffold as well as postoperative scaffold extrusion and the total remaining meniscal volume was also evaluated in MRI. RESULTS: Thirty-two patients were included. The mean follow-up was 70.8 ± 7.5 months. The functionality of the knees improved in all the scores used (P < .001) except for the Tegner score that stayed steady. Most of meniscal implants showed extrusion of 2.4 mm (95% confidence interval [CI], 1.1-3.7) were smaller and a hyperintensity signal was seen in the MRI. Three scaffolds were resorbed at the last follow-up. The meniscal volume, determined by MRI, was 1.14 cm3 (95% CI, 0.96-1.31) preoperatively and 1.61 cm3 (95% CI, 1.43-1.7) at the last follow-up. No differences were presented. CONCLUSIONS: The use of a polyurethane meniscal scaffold in patients with a symptomatic meniscus deficit had a good functional outcome at 5 years after surgery. However, the implanted scaffolds did not present normal meniscal tissue with MRI, and the implant volume was considerably less than expected. The fact that most of patients included received different concomitant procedures during scaffold implantation introduces a degree of performance bias into the results. LEVEL OF EVIDENCE: Level IV, case series.


Assuntos
Artroscopia/métodos , Imageamento por Ressonância Magnética/métodos , Meniscos Tibiais/cirurgia , Poliuretanos , Lesões do Menisco Tibial/cirurgia , Alicerces Teciduais , Adulto , Feminino , Seguimentos , Humanos , Masculino , Meniscos Tibiais/diagnóstico por imagem , Pessoa de Meia-Idade , Período Pós-Operatório , Lesões do Menisco Tibial/diagnóstico , Fatores de Tempo , Resultado do Tratamento , Adulto Jovem
5.
Connect Tissue Res ; 55 Suppl 1: 134-7, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25158198

RESUMO

Dentin phosphoprotein (DPP) is a protein expressed mainly in dentin and to a lesser extent in bone. DPP has a disordered structure, rich in glutamic acid, aspartic acid and phosphorylated serine/threonine residues. It has a high capacity for binding to calcium ions and to hydroxyapatite (HA) crystal surfaces. We used molecular dynamics (MD) simulations as a method for virtually screening interactions between DPP motifs and HA. The goal was to determine which motifs are absorbed to HA surfaces. For these simulations, we considered five peptides from the human DPP sequence. All-atom MD simulations were performed using GROMACS, the peptides were oriented parallel to the {100} HA crystal surface, the distance between the HA and the peptide was 3 nm. The system was simulated for 20 ns. Preliminary results show that for the unphosphorylated peptides, the acidic amino acids present an electrostatic attraction where their side chains are oriented towards HA. This attraction, however, is slow to facilitate bulk transport to the crystal surface. On the other hand, the phosphorylated (PP) peptides are rapidly absorbed on the surface of the HA with their centers of mass closer to the HA surface. More importantly, the root mean square fluctuation (RMSF) indicates that the average structures of the phosphorylated peptides are very inflexible and elongate, while that of the unphosphorylated peptides are flexible. Radius of gyration (Rg) analysis showed the compactness of un-phosphorylated peptides is lower than phosphorylated peptides. Phosphorylation of the DPP peptides is necessary for binding to HA surfaces.


Assuntos
Durapatita/metabolismo , Proteínas da Matriz Extracelular/metabolismo , Fosfoproteínas/metabolismo , Sialoglicoproteínas/metabolismo , Sequência de Aminoácidos , Humanos , Simulação de Dinâmica Molecular , Peptídeos/química , Peptídeos/metabolismo , Fosforilação , Estrutura Terciária de Proteína
6.
Pediatr Emerg Care ; 30(6): 418-20, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24892682

RESUMO

Chronic granulocytic leukemia (CGL) is a rare hematologic disease in pediatric patients. It usually presents with insidious symptoms. However, some cases may have an atypical presentation. We report herein the case of a 13-year-old female admitted to the emergency department with acute abdomen. She had hyperleukocytosis of 500.0 × 1000 cells/mm suggestive of CGL. A paracentesis was performed due to abdominal compartment syndrome that demonstrated hemoperitoneum. At laparotomy, a ruptured ovarian mass was found with multiple tumor implants in the serosal surface. Pathology revealed a CGL-infiltrated ovary. The patient is currently stable, has finished adjuvant chemotherapy, and is at 24 months of follow-up. To our knowledge, this is the first report of such a case.


Assuntos
Hemoperitônio/diagnóstico , Laparotomia/métodos , Leucemia Mielogênica Crônica BCR-ABL Positiva/diagnóstico , Neoplasias Ovarianas/diagnóstico , Adolescente , Feminino , Hemoperitônio/cirurgia , Humanos , Cariotipagem , Leucemia Mielogênica Crônica BCR-ABL Positiva/cirurgia , Neoplasias Ovarianas/cirurgia , Ovariectomia
7.
ACS Omega ; 9(1): 1216-1229, 2024 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-38222653

RESUMO

Parkinson's disease (PD) is the second most common neurodegenerative disease, affecting the elderly population worldwide. In PD, the misfolding of α-synuclein (α-syn) results in the formation of inclusions referred to as Lewy bodies (LB) in midbrain neurons of the substantia nigra and other specific brain localizations, which is associated with neurodegeneration. There are no approved strategies to reduce the formation of LB in the neurons of patients with PD. Our drug discovery program focuses on the synthesis of urea and thiourea compounds coupled with aminoindole moieties to abrogate α-syn aggregation and to slow down the progression of PD. We synthesized several urea and thiourea analogues with a central 1,4-phenyl diurea/thiourea linkage and evaluated their effectiveness in reducing α-syn aggregation with a special focus on the selective inhibition of oligomer formation among other proteins. We utilized biophysical methods such as thioflavin T (ThT) fluorescence assays, transmission electron microscopy (TEM), photoinduced cross-linking of unmodified proteins (PICUP), as well as M17D intracellular inclusion cell-based assays to evaluate the antiaggregation properties and cellular protection of our best compounds. Our results identified compound 1 as the best compound in reducing α-syn fibril formation via ThT assays. The antioligomer formation of compound 1 was subsequently superseded by compound 2. Both compounds selectively curtailed the oligomer formation of α-syn but not tau 4R isoforms (0N4R, 2N4R) or p-tau (isoform 1N4R). Compounds 1 and 2 failed to abrogate tau 0N3R fibril formation by ThT and atomic force microscopy. Compound 2 was best at reducing the formation of recombinant α-syn fibrils by TEM. In contrast to compound 2, compound 1 reduced the formation of α-syn inclusions in M17D neuroblastoma cells in a dose-dependent manner. Compound 1 may provide molecular scaffolds for the optimization of symmetric molecules for its α-syn antiaggregation activity with potential therapeutic applications and development of small molecules in PD.

8.
Results Chem ; 52023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37346091

RESUMO

Alzheimer's disease (AD) is a multifactorial, chronic neurodegenerative disease characterized by the presence of extracellular ß-amyloid (Aß) plaques, intraneuronal neurofibrillary tangles (NFTs), activated microglial cells, and an inflammatory state (involving reactive oxygen species production) in the brain. NFTs are comprised of misfolded and hyperphosphorylated forms of the microtubule-binding protein tau. Interestingly, the trimeric form of the 2N4R splice isoform of tau has been found to be more toxic than the trimeric 1N4R isoform in neuron precursor cells. Few drug discovery programs have focused on specific tau isoforms. The present drug discovery project is centered on the anti-aggregation effect of a series of seventeen 4- or 5-aminoindole carboxamides on the 2N4R isoform of tau. The selection of the best compounds was performed using α-synuclein (α-syn). The anti-oligomer and -fibril activities of newly synthesized aminoindole carboxamide derivatives were evaluated with biophysical methods, such as thioflavin T fluorescence assays, photo-induced cross-linking of unmodified proteins, and transmission electron microscopy. To evaluate the reduction of inclusions and cytoprotective effects, M17D neuroblastoma cells expressing inclusion-forming α-syn were treated with the best amide representatives. The 4-aminoindole carboxamide derivatives exhibited a better anti-fibrillar activity compared to their 5-aminoindole counterparts. The amide derivatives 2, 8, and 17 exerted anti-oligomer and anti-fibril activities on α-syn and the 2N4R isoform of tau. At a concentration of 40 µM, compound 8 reduced inclusion formation in M17D neuroblastoma cells expressing inclusion-prone αSynuclein3K::YFP. Our results demonstrate the potential of 4-aminoindole carboxamide derivatives with regard to inhibiting the oligomer formation of α-syn and tau (2N4R isoform) for further optimization prior to pre-clinical studies.

9.
ACS Omega ; 8(22): 20102-20115, 2023 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-37305264

RESUMO

Protein misfolding results in a plethora of known diseases such as Alzheimer's disease, Parkinson's disease, Huntington's disease, transthyretin-related amyloidosis, type 2 diabetes, Lewy body dementia, and spongiform encephalopathy. To provide a diverse portfolio of therapeutic small molecules with the ability to reduce protein misfolding, we evaluated a set of 13 compounds: 4-(benzo[d]thiazol-2-yl)aniline (BTA) and its derivatives containing urea (1), thiourea (2), sulfonamide (3), triazole (4), and triazine (5) linker. In addition, we explored small modifications on a very potent antioligomer 5-nitro-1,2-benzothiazol-3-amine (5-NBA) (compounds 6-13). This study aims to define the activity of BTA and its derivatives on a variety of prone-to-aggregate proteins such as transthyretin (TTR81-127, TTR101-125), α-synuclein (α-syn), and tau isoform 2N4R (tau 2N4R) through various biophysical methods. Thioflavin T (ThT) fluorescence assay was used to monitor fibril formation of the previously mentioned proteins after treatment with BTA and its derivatives. Antifibrillary activity was confirmed using transmission electron microscopy (TEM). Photoreactive cross-linking assay (PICUP) was utilized to detect antioligomer activity and lead to the identification of 5-NBA (at low micromolar concentration) and compound 13 (at high concentration) as the most promising in reducing oligomerization. 5-NBA and not BTA inhibited the inclusion formation based on the cell-based assay using M17D neuroblastoma cells that express inclusion-prone αS-3K::YFP. 5-NBA abrogated the fibril, oligomer, and inclusion formation in a dose-dependent manner. 5-NBA derivatives could be the key to mitigate protein aggregation. In the future, the results made from this study will provide an initial platform to generate more potent inhibitors of α-syn and tau 2N4R oligomer and fibril formation.

10.
J Funct Biomater ; 14(9)2023 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-37754881

RESUMO

The goal of this study is to evaluate the influence of the concentration of silver on the structural and antimicrobial in vitro properties of silver-doped hydroxyapatite powders obtained using the precipitation method. Different concentrations of silver were evaluated to assess the antimicrobial properties. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, scanning electron microscopy (SEM), and dispersive energy spectroscopy (EDS) were used to characterize the powders. XRD and FTIR showed that the hydroxyapatite structure is not affected by the incorporation of silver; on the other hand, EDS showed the presence of silver in the powders. Antibacterial studies showed the efficiency of hydroxyapatite powders in inhibiting bacterial growth as silver concentration increases. According to the results, silver-doped hydroxyapatite powders are suggested for use in the prevention and treatment of infections in bone and dental tissues.

11.
ACS Chem Neurosci ; 14(21): 3913-3927, 2023 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-37818657

RESUMO

Alzheimer's disease (AD) is the most prevalent neurodegenerative disorder underlying dementia in the geriatric population. AD manifests by two pathological hallmarks: extracellular amyloid-ß (Aß) peptide-containing senile plaques and intraneuronal neurofibrillary tangles comprised of aggregated hyperphosphorylated tau protein (p-tau). However, more than half of AD cases also display the presence of aggregated α-synuclein (α-syn)-containing Lewy bodies. Conversely, Lewy bodies disorders have been reported to have concomitant Aß plaques and neurofibrillary tangles. Our drug discovery program focuses on the synthesis of multitarget-directed ligands to abrogate aberrant α-syn, tau (2N4R), and p-tau (1N4R) aggregation and to slow the progression of AD and related dementias. To this end, we synthesized 11 compounds with a triazine-linker and evaluated their effectiveness in reducing α-syn, tau isoform 2N4R, and p-tau isoform 1N4R aggregation. We utilized biophysical methods such as thioflavin T (ThT) fluorescence assays, transmission electron microscopy (TEM), photoinduced cross-linking of unmodified proteins (PICUP), and M17D intracellular inclusion cell-based assays to evaluate the antiaggregation properties and cellular protection of our best compounds. We also performed disaggregation assays with isolated Aß-plaques from human AD brains. Our results demonstrated that compound 10 was effective in reducing both oligomerization and fibril formation of α-syn and tau isoform 2N4R in a dose-dependent manner via ThT and PICUP assays. Compound 10 was also effective at reducing the formation of recombinant α-syn, tau 2N4R, and p-tau 1N4R fibrils by TEM. Compound 10 reduced the development of α-syn inclusions in M17D neuroblastoma cells and stopped the seeding of tau P301S using biosensor cells. Disaggregation experiments showed smaller Aß-plaques and less paired helical filaments with compound 10. Compound 10 may provide molecular scaffolds for further optimization and preclinical studies for neurodegenerative proteinopathies.


Assuntos
Doença de Alzheimer , Doença por Corpos de Lewy , Idoso , Humanos , Proteínas tau/metabolismo , alfa-Sinucleína/metabolismo , Doença de Alzheimer/metabolismo , Peptídeos beta-Amiloides/metabolismo , Isoformas de Proteínas
12.
Rev Med Inst Mex Seguro Soc ; 61(Suppl 3): S460-S467, 2023 Oct 02.
Artigo em Espanhol | MEDLINE | ID: mdl-37934928

RESUMO

Background: Gestational diabetes mellitus (GDM) refers to diabetes diagnosed in the second or third trimester of pregnancy. Assessing the weight gain in each pregnant women's appointment is a common task of primary care during their visit. However, the implications of this increase in weight for the development of GDM are unknown. Objective: Evaluate if the greater than expected weight gain (HEWG) in pregnancy is a risk factor for the development of GDM. Methods: Analytical, observational, longitudinal, retrolective study, which included pregnant women between 15 and 40 years of age with complete follow-up of the preg-nancy with > 2 prenatal check-ups, somatometry and complete medical history was made. During follow-up, the GPME was determined. Odds ratio (OR) and 95% confi-dence intervals (95% CI) were calculated. Variables with significance were entered into a multiple logistic regression model (MLR), where the dependent variable was DMG. The sample size calculation was for convenience. Results: 1000 pregnant women with a median age of 28 years were included. In the MLR The pre-gestational body mass index (BMI) with overweight had an RM of 1.3 (95% CI 0.86-1.98), BMI with obesity an OR of 2.57 (95% CI 1.6-4.14), the HEWG during pregnancy had an OR 1.14 95% CI (0.71-1.81), Age> 30 years shows an RM of 2.24 (95% CI 1.55-3.25). Conclusions: HEWG during pregnancy is not an independent risk factor for the devel-opment of GDM. The main ones are age> 30 years and pre-gestational obesity.


Introducción: la diabetes mellitus gestacional (DMG) se refiere a la diabetes diagnosti-cada a partir del segundo trimestre del embarazo. Evaluar el incremento de peso de mu-jeres embarazadas es una labor habitual en la consulta del primer nivel de atención. Sin embargo, se desconocen las implicaciones que tiene este incremento ponderal para el desarrollo de DMG. Objetivo: evaluar si la ganancia ponderal mayor a la esperada (GPME) en el embarazo es factor de riesgo para el desarrollo de DMG. Métodos: estudio analítico, observacional, longitudinal, retrolectivo, que incluyó a em-barazadas de 15 a 40 años con seguimiento completo del embarazo con más de dos consultas de control prenatal, somatometría e historia clínica completa. Durante el se-guimiento se determinó la GPME. Se calculó razón de momios (RM) e intervalos de confianza del 95% (IC95%). Las variables con significancia se ingresaron a un modelo de regresión logística múltiple (RLM), en donde la variable de desenlace fue DMG. Resultados: se incluyeron a 1000 embarazadas con mediana de edad de 28 años. En la RLM el índice de masa corporal (IMC) pre-gestacional con sobrepeso tuvo una RM de 1.3 (IC95%: 0.86-1.98), IMC con obesidad una RM de 2.57 (IC95%: 1.6-4.14), la GPME durante el embarazo tuvo una RM de 1.14 (IC95%: 0.71-1.81) y la edad > 30 años una RM de 2.24 (IC95%: 1.55-3.25). Conclusiones: la GPME durante el embarazo no es un factor de riesgo independiente para el desarrollo de DMG. Los principales son la edad >30 años y la obesidad preges-tacional.


Assuntos
Diabetes Gestacional , Gravidez , Feminino , Humanos , Adulto , Diabetes Gestacional/diagnóstico , Diabetes Gestacional/etiologia , Aumento de Peso , Obesidade/complicações , Sobrepeso , Fatores de Risco , Índice de Massa Corporal
13.
Langmuir ; 28(43): 15278-85, 2012 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-23002810

RESUMO

We have studied the adsorption of thioacetic acid (TAAH) on Au(111) from solution deposition. The close proximity of the SH groups to CO groups makes this molecule very attractive for exploring the effect of the functional group on the stability of the S-C and S-Au bonds. Although thioacetic acid was supposed to decompose slowly in water by hydrolysis supplying hydrogen sulfide, this behavior is not expected in nonpolar solvents such as toluene or hexane. Therefore, we have used these solvents for TAAH self-assembly on the Au(111) surface. The characterization of the adsorbates has been done by electrochemical techniques, X-ray photoelectron spectroscopy (XPS), and scanning tunneling microscopy (STM). We have found that even in nonpolar solvents thioacetic acid decomposes to S. The results have been discussed on the basis that the adsorbed species suffer a cleavage on the Au surface, leaving the S attached to it. The dissociation is a spontaneous process that reaches the final state very fast once it is energetically favorable, as can be interpreted from DFT calculations. The thioacetic acid adsorption reveals the strong effect that produces a functional group and the key role of the S-H bond cleavage in the self-assembly process.

14.
Biochem Biophys Rep ; 31: 101284, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35664543

RESUMO

AA amyloidosis is the result of overproduction and aberrant processing of acute-phase serum amyloid A1 (SAA1) by hepatocytes. Proteolytic cleavage of SAA1 is believed to play a central role in AA amyloid formation. The SAA1 protein undergoes a cleavage of 18 residues consisting of the signal peptide at the N-terminal region. To better understand the mechanism behind systemic amyloidosis in the SAA1 protein, we studied the misfolding propensity of the signal peptide region. We first examined the signal peptide amino acid SAA derived from different animal species. A library of 16 peptides was designed to evaluate the propensity of aggregation. The amyloidogenic potential of each SAA1 signal peptide homolog was assessed using in silico Tango program, thioflavin T (ThT) fluorescence, transmission electron microscopy (TEM), and seeding with misfolded human SAA1 signal peptide. After 7 days of incubation, most of the SAA1 signal peptide fragments had the propensity to form fibrils at a concentration of 100 µM in 50 mM Tris buffer at 37 °C by TEM. All peptides were able to generate fibrils at a higher concentration, i.e 500 µM in 25 mM Tris buffer with 50% HFIP, by ThT. All SAA1 signal synthetic peptides designed from the different animal species had the propensity to misfold and form fibrils, particularly in species with low occurrence of systemic amyloidosis. The human SAA1 signal peptide region was capable to seed the SAA1 1-25 and 32-47 peptide regions. Characterizing fibrillar conformations are relevant for seeding intact and/or fragmented SAA, which may contribute, to the mechanism of protein misfolding. This research signifies the importance of the signal peptide region and its possible contribution to the misfolding of aggregation-prone proteins.

15.
Antioxidants (Basel) ; 11(9)2022 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-36139800

RESUMO

Anthopleura hermaphroditica is an intertidal anemone that lives semi-buried in soft sediments of estuaries and releases its brooded embryos directly to the benthos, being exposed to potentially detrimental ultraviolet radiation (UVR) levels. In this study, we investigated how experimental radiation (PAR: photosynthetically active radiation; UVA: ultraviolet A radiation; and UVB: ultraviolet B radiation) influences burrowing (time, depth and speed) in adults and juveniles when they were exposed to PAR (P, 400-700 nm), PAR + UVA (PA, 315-700 nm) and PAR + UVA + UVB (PAB, 280-700 nm) experimental treatments. The role of sediment as a physical shield was also assessed by exposing anemones to these radiation treatments with and without sediment, after which lipid peroxidation, protein carbonyls and total antioxidant capacity were quantified. Our results indicate that PAB can induce a faster burial response compared to those anemones exposed only to P. PAB increased oxidative damage, especially in juveniles where oxidative damage levels were several times higher than in adults. Sediment offers protection to adults against P, PA and PAB, as significant differences in their total antioxidant capacity were observed compared to those anemones without sediment. Conversely, the presence or absence of sediment did not influence total antioxidant capacity in juveniles, which may reflect that those anemones have sufficient antioxidant defenses to minimize photooxidative damage due to their reduced tolerance to experimental radiation. Burrowing behavior is a key survival skill for juveniles after they have been released after brooding.

16.
MEDICC Rev ; 23(1): 64-71, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33780425

RESUMO

INTRODUCTION: With a global adult prevalence of 24%, non-alcoholic fatty liver disease is a global health problem that parallels the worldwide increase of obesity. Its frequency, clinical characteristics and related diseases in Cuba remain unknown. OBJECTIVE: Describe the clinical characteristics, comorbidities and personal habits of patients with non-alcoholic fatty liver disease who are being treated in secondary and tertiary health facilities in seven Cuban provinces. METHODS: A cross-sectional, multicenter study was carried out in 6601 adults seen at gastroenterology outpatient clinics of nine hospitals in seven Cuban provinces from September 2018 through May 2019. Non-alcoholic fatty liver disease was diagnosed by abdominal ultrasound. The study included 1070 patients who met the diagnostic and study criteria and agreed to participate. Their personal habits and anthropometric and clinical characteristics, comorbidities and other aspects of their medical histories were recorded. RESULTS: Of the 1070 participants, 60.7% (649) were women. Participants' average age was 54.5 years and average body mass index was 30.5 kg/m2. A total of 397 (37.1%) were overweight and 574 (53.6%) were obese, 945 (88.3%) led a sedentary lifestyle, 564 (52.7%) had high blood pressure, 406 (37.9%) had lipid disorders and 301 (28.1%) were diabetic. While 484 (45.2%) of patients were asymptomatic, the most frequent clinical signs and symptoms were fatigue (262; 24.5%), dyspepsia (209; 19.5%), abdominal pain (306; 28.5%) and hepatomegaly (189; 17.7%). Liver cirrhosis was present in 37 (3.5%) patients at the time of diagnosis. Family history of type 2 diabetes mellitus and obesity were identified in 391 (36.5%) and 279 (26.1%) of participants, respectively. CONCLUSIONS: Prevalence of non-alcoholic fatty liver disease in these Cuban patients coincides with that reported in the Caribbean region, which has high levels of obesity, overweight and sedentary lifestyles. Most were asymptomatic, female or had metabolism-related comorbidities such as high blood pressure, type 2 diabetes mellitus and dyslipidemia.


Assuntos
Hepatopatia Gordurosa não Alcoólica/epidemiologia , Índice de Massa Corporal , Estudos Transversais , Cuba/epidemiologia , Diabetes Mellitus Tipo 2/epidemiologia , Dislipidemias/epidemiologia , Feminino , Humanos , Hipertensão/epidemiologia , Masculino , Pessoa de Meia-Idade , Prevalência , Fatores de Risco
17.
J Neural Eng ; 17(2): 026011, 2020 03 27.
Artigo em Inglês | MEDLINE | ID: mdl-32109906

RESUMO

Myocontrol, that is, control of a prosthesis via muscle signals, is still a surprisingly hard problem. Recent research indicates that surface electromyography (sEMG), the traditional technique used to detect a subject's intent, could proficiently be replaced, or conjoined with, other techniques (multi-modal myocontrol), with the aim to improve both on dexterity and reliability. Objective. In this paper we present an online assessment of multi-modal sEMG and force myography (FMG) targeted at hand and wrist myocontrol. Approach. Twenty sEMG and FMG sensors in total were used to enforce simultaneous and proportional control of hand opening/closing, wrist pronation/supination and wrist flexion/extension of 12 intact subjects. Main results and Significance. We found that FMG yields in general a better performance than sEMG, and that the main drawback of the sEMG array we used is not the inability to perform a desired action, but rather action interference, that is, the undesired concurrent activation of another action. FMG, on the other hand, causes less interference.


Assuntos
Membros Artificiais , Eletromiografia , Humanos , Miografia , Reprodutibilidade dos Testes , Punho
18.
Front Chem ; 8: 605307, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33490037

RESUMO

The development of drug carriers based in lipid nanoparticles (LNPs) aims toward the synthesis of non-toxic multifunctional nanovehicles that can bypass the immune system and allow specific site targeting, controlled release and complete degradation of the carrier components. Among label free techniques, Surface Plasmon Resonance (SPR) biosensing is a versatile tool to study LNPs in the field of nanotherapeutics research. SPR, widely used for the analysis of molecular interactions, is based on the immobilization of one of the interacting partners to the sensor surface, which can be easily achieved in the case of LNPs by hydrophobic attachment onto commercial lipid- capture sensor chips. In the last years SPR technology has emerged as an interesting strategy for studying molecular aspects of drug delivery that determines the efficacy of the nanotherapeutical such as LNPs' interactions with biological targets, with serum proteins and with tumor extracelullar matrix. Moreover, SPR has contributed to the obtention and characterization of LNPs, gathering information about the interplay between components of the formulations, their response to organic molecules and, more recently, the quantification and molecular characterization of exosomes. By the combination of available sensor platforms, assay quickness and straight forward platform adaptation for new carrier systems, SPR is becoming a high throughput technique for LNPs' characterization and analysis.

19.
Science ; 369(6509)2020 09 11.
Artigo em Inglês | MEDLINE | ID: mdl-32913074

RESUMO

Telomere shortening is a hallmark of aging. Telomere length (TL) in blood cells has been studied extensively as a biomarker of human aging and disease; however, little is known regarding variability in TL in nonblood, disease-relevant tissue types. Here, we characterize variability in TLs from 6391 tissue samples, representing >20 tissue types and 952 individuals from the Genotype-Tissue Expression (GTEx) project. We describe differences across tissue types, positive correlation among tissue types, and associations with age and ancestry. We show that genetic variation affects TL in multiple tissue types and that TL may mediate the effect of age on gene expression. Our results provide the foundational knowledge regarding TL in healthy tissues that is needed to interpret epidemiological studies of TL and human health.


Assuntos
Envelhecimento/genética , Homeostase do Telômero/genética , Encurtamento do Telômero/genética , Telômero/fisiologia , Marcadores Genéticos , Variação Genética , Humanos , Especificidade de Órgãos
20.
Biochem Biophys Res Commun ; 384(1): 49-54, 2009 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-19393626

RESUMO

Cementum protein 1 (CEMP1) has been recently cloned, and in vitro experiments have shown functions as regulator of cementoblast behavior and inducer of differentiation of non-osteogenic cells toward a cementoblastic/osteoblastic phenotype. In this study, we have produced a full-length human recombinant CEMP1 protein in a human gingival fibroblast cell line. The purified protein (hrCEMP1) has a M(r) 50,000. Characterization of hrCEMP1 indicates that its secondary structure is mainly composed of beta-sheet (55%), where random coil and alpha helix conformations correspond to 35% and 10%, respectively. It was found that hrCEMP1 is N-glycosylated, phosphorylated and possesses strong affinity for hydroxyapatite. Even more important, our results show that hrCEMP1 plays a role during the biomineralization process by promoting octacalcium phosphate (OCP) crystal nucleation. These features make CEMP1 a very good candidate for biotechnological applications in order to achieve cementum and/or bone regeneration.


Assuntos
Calcificação Fisiológica , Proteínas/metabolismo , Proteínas Recombinantes/biossíntese , Durapatita/química , Fibroblastos/metabolismo , Gengiva/citologia , Gengiva/metabolismo , Glicosilação , Humanos , Fosforilação , Estrutura Secundária de Proteína , Proteínas/química , Proteínas/genética , Proteínas Recombinantes/química , Proteínas Recombinantes/genética
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