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1.
Cell ; 185(18): 3290-3306.e25, 2022 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-35988542

RESUMO

In vitro cultured stem cells with distinct developmental capacities can contribute to embryonic or extraembryonic tissues after microinjection into pre-implantation mammalian embryos. However, whether cultured stem cells can independently give rise to entire gastrulating embryo-like structures with embryonic and extraembryonic compartments remains unknown. Here, we adapt a recently established platform for prolonged ex utero growth of natural embryos to generate mouse post-gastrulation synthetic whole embryo models (sEmbryos), with both embryonic and extraembryonic compartments, starting solely from naive ESCs. This was achieved by co-aggregating non-transduced ESCs, with naive ESCs transiently expressing Cdx2 or Gata4 to promote their priming toward trophectoderm and primitive endoderm lineages, respectively. sEmbryos adequately accomplish gastrulation, advance through key developmental milestones, and develop organ progenitors within complex extraembryonic compartments similar to E8.5 stage mouse embryos. Our findings highlight the plastic potential of naive pluripotent cells to self-organize and functionally reconstitute and model the entire mammalian embryo beyond gastrulation.


Assuntos
Células-Tronco Embrionárias , Gastrulação , Animais , Diferenciação Celular/fisiologia , Embrião de Mamíferos/fisiologia , Desenvolvimento Embrionário , Endoderma , Mamíferos , Camundongos
2.
Brain Behav Immun ; 117: 399-411, 2024 03.
Artigo em Inglês | MEDLINE | ID: mdl-38309639

RESUMO

BACKGROUND: Autoantibodies against the potassium voltage-gated channel subfamily A member 2 (KCNA2) have been described in a few cases of neuropsychiatric disorders, but their diagnostic and pathophysiological role is currently unknown, imposing challenges to medical practice. DESIGN / METHODS: We retrospectively collected comprehensive clinical and paraclinical data of 35 patients with KCNA2 IgG autoantibodies detected in cell-based and tissue-based assays. Patients' sera and cerebrospinal fluid (CSF) were used for characterization of the antigen, clinical-serological correlations, and determination of IgG subclasses. RESULTS: KCNA2 autoantibody-positive patients (n = 35, median age at disease onset of 65 years, range of 16-83 years, 74 % male) mostly presented with cognitive impairment and/or epileptic seizures but also ataxia, gait disorder and personality changes. Serum autoantibodies belonged to IgG3 and IgG1 subclasses and titers ranged from 1:32 to 1:10,000. KCNA2 IgG was found in the CSF of 8/21 (38 %) patients and in the serum of 4/96 (4.2 %) healthy blood donors. KCNA2 autoantibodies bound to characteristic anatomical areas in the cerebellum and hippocampus of mammalian brain and juxtaparanodal regions of peripheral nerves but reacted exclusively with intracellular epitopes. A subset of four KCNA2 autoantibody-positive patients responded markedly to immunotherapy alongside with conversion to seronegativity, in particular those presenting an autoimmune encephalitis phenotype and receiving early immunotherapy. An available brain biopsy showed strong immune cell invasion. KCNA2 autoantibodies occurred in less than 10 % in association with an underlying tumor. CONCLUSION: Our data suggest that KCNA2 autoimmunity is clinically heterogeneous. Future studies should determine whether KCNA2 autoantibodies are directly pathogenic or develop secondarily. Early immunotherapy should be considered, in particular if autoantibodies occur in CSF or if clinical or diagnostic findings suggest ongoing inflammation. Suspicious clinical phenotypes include autoimmune encephalitis, atypical dementia, new-onset epilepsy and unexplained epileptic seizures.


Assuntos
Doenças Autoimunes do Sistema Nervoso , Autoimunidade , Encefalite , Doença de Hashimoto , Animais , Humanos , Masculino , Adolescente , Adulto Jovem , Adulto , Pessoa de Meia-Idade , Idoso , Idoso de 80 Anos ou mais , Feminino , Estudos Retrospectivos , Autoanticorpos , Convulsões , Mamíferos , Canal de Potássio Kv1.2
3.
Am J Med Genet A ; 194(5): e63523, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38164622

RESUMO

The FMR1 5' regulation gene region harbors a CGG trinucleotide repeat expansion (CGG-TRE) that causes Fragile X syndrome (FXS) when it expands to more than 200 repetitions. Ricaurte is a small village in southwestern Colombia, with an FXS prevalence of 1 in 38 men and 1 in 100 women (~100 times higher than the worldwide reported prevalence), defining Ricaurte as the largest FXS cluster in the world. In the present study, using next-generation sequencing of whole exome capture, we genotype 55 individuals from Ricaurte (49 with either full mutation or with premutation), four individuals from neighboring villages (with either the full mutation or with the premutation), and one unaffected woman, native of Ricaurte, who did not belong to any of the affected families. With advanced clustering and haplotype reconstruction, we modeled a common haplotype of 33 SNPs spanning 83,567,899 bp and harboring the FMR1 gene. This reconstructed haplotype was found in all the men from Ricaurte who carried the expansion, demonstrating that the genetic conglomerate of FXS in this population is due to a founder effect. The definition of this founder effect and its population outlining will allow a better prediction, follow-up, precise and personalized characterization of epidemiological parameters, better knowledge of the disease's natural history, and confident improvement of the clinical attention, life quality, and health interventions for this community.


Assuntos
Síndrome do Cromossomo X Frágil , Masculino , Humanos , Feminino , Síndrome do Cromossomo X Frágil/epidemiologia , Síndrome do Cromossomo X Frágil/genética , Efeito Fundador , Epidemiologia Molecular , Proteína do X Frágil da Deficiência Intelectual/genética , Expansão das Repetições de Trinucleotídeos , Mutação
4.
Epilepsia ; 65(2): 511-526, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38052475

RESUMO

OBJECTIVE: This study was undertaken to assess reproducibility of the epilepsy outcome and phenotype in a lateral fluid percussion model of posttraumatic epilepsy (PTE) across three study sites. METHODS: A total of 525 adult male Sprague Dawley rats were randomized to lateral fluid percussion-induced brain injury (FPI) or sham operation. Of these, 264 were assigned to magnetic resonance imaging (MRI cohort, 43 sham, 221 traumatic brain injury [TBI]) and 261 to electrophysiological follow-up (EEG cohort, 41 sham, 220 TBI). A major effort was made to harmonize the rats, materials, equipment, procedures, and monitoring systems. On the 7th post-TBI month, rats were video-EEG monitored for epilepsy diagnosis. RESULTS: A total of 245 rats were video-EEG phenotyped for epilepsy on the 7th postinjury month (121 in MRI cohort, 124 in EEG cohort). In the whole cohort (n = 245), the prevalence of PTE in rats with TBI was 22%, being 27% in the MRI and 18% in the EEG cohort (p > .05). Prevalence of PTE did not differ between the three study sites (p > .05). The average seizure frequency was .317 ± .725 seizures/day at University of Eastern Finland (UEF; Finland), .085 ± .067 at Monash University (Monash; Australia), and .299 ± .266 at University of California, Los Angeles (UCLA; USA; p < .01 as compared to Monash). The average seizure duration did not differ between UEF (104 ± 48 s), Monash (90 ± 33 s), and UCLA (105 ± 473 s; p > .05). Of the 219 seizures, 53% occurred as part of a seizure cluster (≥3 seizures/24 h; p >.05 between the study sites). Of the 209 seizures, 56% occurred during lights-on period and 44% during lights-off period (p > .05 between the study sites). SIGNIFICANCE: The PTE phenotype induced by lateral FPI is reproducible in a multicenter design. Our study supports the feasibility of performing preclinical multicenter trials in PTE to increase statistical power and experimental rigor to produce clinically translatable data to combat epileptogenesis after TBI.


Assuntos
Lesões Encefálicas Traumáticas , Epilepsia Pós-Traumática , Epilepsia , Animais , Masculino , Ratos , Lesões Encefálicas Traumáticas/complicações , Lesões Encefálicas Traumáticas/diagnóstico por imagem , Modelos Animais de Doenças , Epilepsia/etiologia , Epilepsia Pós-Traumática/etiologia , Epilepsia Pós-Traumática/patologia , Percussão , Fenótipo , Ratos Sprague-Dawley , Reprodutibilidade dos Testes , Convulsões
5.
Inorg Chem ; 63(11): 5040-5051, 2024 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-38428017

RESUMO

The effect of Eu doping in the Tsai quasicrystal (QC) GdCd7.88 and its periodic 1/1 approximant crystal (AC) GdCd6 are investigated. This represents the first synthesis of Eu-containing stable QC samples, where three samples with the final composition Gd1-xEuxCd7.6±α at Eu doping concentrations x = 0.06, 0.13, and 0.19 are obtained (α ∼ 0.2). They are compared to two 1/1 ACs with compositions Gd1-xEuxCd6 (x = 0.12, 0.16). In addition, a new type of 1/1 AC, differing only by the inclusion of extra Cd sites unique to the Eu4Cd25 1/1 AC, has been discovered and synthesized for the concentrations Gd1-xEuxCd6+δ (x = 0.25, 0.33, 0.45, 0.69, 0.73, and 0 < δ ≤ 0.085). Due to the preferred cube morphology of its single grains, we refer to them as c-type 1/1 ACs and to the conventional standard ones as s-type. In both QCs and s-type ACs, the Eu content appears to saturate at a concentration of ∼20%. On the other hand, any Gd| Eu ratio is allowed in the c-type ACs, varying continuously between GdCd6 and Eu4Cd25. We describe and contrast the changes in composition, atomic structure, specific heat, and magnetic properties induced by Eu doping in the quasicrystalline phase and the s-type and c-type 1/1 ACs. By comparing our results to the literature data, we propose that the occupancy of the extra Cd sites can be used to predict the stability of Tsai-type quasicrystalline phases.

6.
Nanomedicine ; 58: 102749, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38719107

RESUMO

New adjuvant strategies are needed to improve protein-based subunit vaccine immunogenicity. We examined the potential to use nanostructure of 6-O-ascorbyl palmitate to formulate ovalbumin (OVA) protein and an oligodeoxynucleotide (CpG-ODN) (OCC). In mice immunized with a single dose, OCC elicited an OVA-specific immune response superior to OVA/CpG-ODN solution (OC). Rheological studies demonstrated OCC's self-assembling viscoelastic properties. Biodistribution studies indicated that OCC prolonged OVA and CpG-ODN retention at injection site and lymph nodes, reducing systemic spread. Flow-cytometry assays demonstrated that OCC promoted OVA and CpG-ODN co-uptake by Ly6ChiCD11bhiCD11c+ monocytes. OCC and OC induced early IFN-γ in lymph nodes, but OCC led to higher concentration. Conversely, mice immunized with OC showed higher serum IFN-γ concentration compared to those immunized with OCC. In mice immunized with OCC, NK1.1+ cells were the IFN-γ major producers, and IFN-γ was essential for OVA-specific IgG2c switching. These findings illustrate how this nanostructure improves vaccine's response.


Assuntos
Nanoestruturas , Oligodesoxirribonucleotídeos , Ovalbumina , Vacinas de Subunidades Antigênicas , Animais , Nanoestruturas/química , Vacinas de Subunidades Antigênicas/imunologia , Vacinas de Subunidades Antigênicas/química , Vacinas de Subunidades Antigênicas/farmacocinética , Camundongos , Oligodesoxirribonucleotídeos/química , Oligodesoxirribonucleotídeos/farmacocinética , Ovalbumina/imunologia , Ovalbumina/química , Feminino , Camundongos Endogâmicos C57BL , Adjuvantes Imunológicos/química , Adjuvantes Imunológicos/farmacocinética , Interferon gama/metabolismo , Distribuição Tecidual , Ácido Ascórbico/análogos & derivados
7.
Sensors (Basel) ; 24(8)2024 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-38676053

RESUMO

Wearable Biosensor Technology (WBT) has emerged as a transformative tool in the educational system over the past decade. This systematic review encompasses a comprehensive analysis of WBT utilization in educational settings over a 10-year span (2012-2022), highlighting the evolution of this field to address challenges in education by integrating technology to solve specific educational challenges, such as enhancing student engagement, monitoring stress and cognitive load, improving learning experiences, and providing real-time feedback for both students and educators. By exploring these aspects, this review sheds light on the potential implications of WBT on the future of learning. A rigorous and systematic search of major academic databases, including Google Scholar and Scopus, was conducted in accordance with the PRISMA guidelines. Relevant studies were selected based on predefined inclusion and exclusion criteria. The articles selected were assessed for methodological quality and bias using established tools. The process of data extraction and synthesis followed a structured framework. Key findings include the shift from theoretical exploration to practical implementation, with EEG being the predominant measurement, aiming to explore mental states, physiological constructs, and teaching effectiveness. Wearable biosensors are significantly impacting the educational field, serving as an important resource for educators and a tool for students. Their application has the potential to transform and optimize academic practices through sensors that capture biometric data, enabling the implementation of metrics and models to understand the development and performance of students and professors in an academic environment, as well as to gain insights into the learning process.


Assuntos
Técnicas Biossensoriais , Dispositivos Eletrônicos Vestíveis , Técnicas Biossensoriais/instrumentação , Humanos , Eletroencefalografia/métodos , Eletroencefalografia/instrumentação , Educação , Estudantes , Aprendizagem
8.
J Infect Dis ; 227(10): 1164-1172, 2023 05 12.
Artigo em Inglês | MEDLINE | ID: mdl-36729177

RESUMO

BACKGROUND: Breakthrough infections of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are well documented. The current study estimates breakthrough incidence across pandemic waves, and evaluates predictors of breakthrough and severe breakthrough infections (defined as those requiring hospitalization). METHODS: In total, 89 762 participants underwent longitudinal antibody surveillance. Incidence rates were calculated using total person-days contributed. Bias-corrected and age-adjusted logistic regression determined multivariable predictors of breakthrough and severe breakthrough infection, respectively. RESULTS: The incidence was 0.45 (95% confidence interval [CI], .38-.50) during pre-Delta, 2.80 (95% CI, 2.25-3.14) during Delta, and 11.2 (95% CI, 8.80-12.95) during Omicron, per 10 000 person-days. Factors associated with elevated odds of breakthrough included Hispanic ethnicity (vs non-Hispanic white, OR = 1.243; 95% CI, 1.073-1.441), larger household size (OR = 1.251 [95% CI, 1.048-1.494] for 3-5 vs 1 and OR = 1.726 [95% CI, 1.317-2.262] for more than 5 vs 1 person), rural versus urban living (OR = 1.383; 95% CI, 1.122-1.704), receiving Pfizer or Johnson & Johnson versus Moderna, and multiple comorbidities. Of the 1700 breakthrough infections, 1665 reported on severity; 112 (6.73%) were severe. Higher body mass index, Hispanic ethnicity, vaccine type, asthma, and hypertension predicted severe breakthroughs. CONCLUSIONS: Breakthrough infection was 4-25 times more common during the Omicron-dominant wave versus earlier waves. Higher burden of severe breakthrough infections was identified in subgroups.


Assuntos
COVID-19 , SARS-CoV-2 , Humanos , Adulto , Infecções Irruptivas , COVID-19/epidemiologia , COVID-19/prevenção & controle , Incidência , Vacinação
9.
J Infect Dis ; 227(2): 193-201, 2023 01 11.
Artigo em Inglês | MEDLINE | ID: mdl-35514141

RESUMO

Understanding the duration of antibodies to the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus that causes COVID-19 is important to controlling the current pandemic. Participants from the Texas Coronavirus Antibody Response Survey (Texas CARES) with at least 1 nucleocapsid protein antibody test were selected for a longitudinal analysis of antibody duration. A linear mixed model was fit to data from participants (n = 4553) with 1 to 3 antibody tests over 11 months (1 October 2020 to 16 September 2021), and models fit showed that expected antibody response after COVID-19 infection robustly increases for 100 days postinfection, and predicts individuals may remain antibody positive from natural infection beyond 500 days depending on age, body mass index, smoking or vaping use, and disease severity (hospitalized or not; symptomatic or not).


Assuntos
Anticorpos Antivirais , COVID-19 , SARS-CoV-2 , Humanos , Anticorpos Antivirais/imunologia , Formação de Anticorpos/imunologia , COVID-19/epidemiologia , COVID-19/imunologia , SARS-CoV-2/imunologia , Glicoproteína da Espícula de Coronavírus , Texas/epidemiologia , Fatores de Tempo
10.
Inorg Chem ; 62(36): 14668-14677, 2023 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-37642644

RESUMO

Gd14AuxAl86-x Tsai-type 1/1 quasicrystal approximants (ACs) exhibit three magnetic orders that can be finely tuned by the valence electron concentration (e/a ratio). This parameter has been considered to be crucial for controlling the long-range magnetic order in quasicrystals (QCs) and ACs. However, the nonlinear trend of the lattice parameter as a function of Au concentration suggests that Gd14AuxAl86-x 1/1 ACs are not following a conventional solid solution behavior. We investigated Gd14AuxAl86-x samples with x values of 52, 53, 56, 61, 66, and 73 by single-crystal X-ray diffraction. Our analysis reveals that increasing Au/Al ordering with increasing x leads to distortions in the icosahedral shell built of the Gd atoms and that trends observed in the interatomic Gd-Gd distances closely correlate with the magnetic property changes across different x values. Our results demonstrate that the e/a ratio alone may be an oversimplified concept for investigating the long-range magnetic order in 1/1 ACs and QCs and that the mixing behavior of the nonmagnetic elements Au and Al plays a significant role in influencing the magnetic behavior of the Gd14AuxAl86-x 1/1 AC system. These findings will contribute to improved understanding towards tailoring magnetic properties in emerging materials.

11.
Mem Inst Oswaldo Cruz ; 117: e220162, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36651455

RESUMO

BACKGROUND: Costa Rica has a history of neglecting prevention, control and research of leishmaniasis, including limited understanding on Leishmania species causing human disease across the country and a complete lack of knowledge on the Leishmania RNA virus, described as a factor linked to the worsening and metastasis of leishmanial lesions. OBJECTIVES: The aim of this work was to describe a case of cutaneous leishmaniasis by Leishmania (Viannia) guyanensis, bearing infection with Leishmaniavirus 1 (LRV1) in Costa Rica, raising the suspicion of imported parasites in the region. METHODS: The Leishmania strain was previously identified by routine hsp70 polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) in Costa Rica and subsequently characterised by isoenzyme electrophoresis and Sanger sequencing in Brazil. Screening for LRV1 was conducted with a dual RT-PCR approach and sequencing of the fragment obtained. FINDINGS: Since 2016 Costa Rica performs Leishmania isolation and typing as part of its epidemiological surveillance activities. Amongst 113 strains typed until 2019, only one was characterised as a L. (V.) guyanensis, corresponding to the first confirmed report of this species in the country. Interestingly, the same strain tested positive for LRV1. Sequencing of the viral orf1 and 2, clustered this sample with other LRV1 genotypes of South American origin, from the Northeast of Brazil and French Guiana. MAIN CONCLUSION: The unique characteristics of this finding raised the suspicion that it was not an autochthonous strain. Notwithstanding its presumed origin, this report points to the occurrence of said endosymbiont in Central American Leishmania strains. The possibility of its local dispersion represents one more challenge faced by regional health authorities in preventing and controlling leishmaniasis.


Assuntos
Leishmania guyanensis , Leishmaniose Cutânea , Leishmaniavirus , Humanos , Brasil/epidemiologia , Costa Rica , Guiana Francesa , Genótipo , Leishmania guyanensis/genética , Leishmaniose Cutânea/parasitologia , Leishmaniavirus/genética
12.
J Food Sci Technol ; 60(10): 2659-2669, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37599839

RESUMO

Pathogenic bacteria in food are a public health problem worldwide. Polyphenolic bioactive compounds with antimicrobial activity and antioxidant capacity represent a tangible alternative to overcome this problem. To preserve the biological functions of phenolic compounds such as tannic acid, which has been described to possess antioxidant and antimicrobial activity, this study describes the synthesis of a zinc nanohydroxide to stabilize its properties. Characterization by XRD, FT-IR, SEM, DLS, and UV-vis evidenced the presence of tannic acid in the nanohybrid TA-Zn-LHS which was further confirmed by DPPH, ABTS and FRAP antioxidant activity techniques. Bacterial growth inhibition of Escherichia coli ATCC 8739, Salmonella Enteritidis, and Staphylococcus aureus ATCC 25923 was over 80% at 50 mg/mL of the TA-Zn-LHS and over 90% with Zn-LHS. Antibiofilm evaluation of these same strains showed biofilm formation inhibition > 90% and > 80% for Zn-LHS and TA-Zn-LHS, respectively. The toxicity evaluation of the materials in Artemia salina showed a classification of the materials as non-toxic to slightly toxic in concentrations up to 1 mg/mL. These results allow us to introduce a new nanohybrid useful for food safety with safe biological functions.

13.
Epilepsia ; 63(7): 1835-1848, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35366338

RESUMO

OBJECTIVE: We examined whether posttraumatic epilepsy (PTE) is associated with measurable perturbations in gut microbiome. METHODS: Adult Sprague Dawley rats were subjected to lateral fluid percussion injury (LFPI). PTE was examined 7 months after LFPI, during 4-week continuous video-electroencephalographic monitoring. 16S ribosomal RNA gene sequencing was performed in fecal samples collected before LFPI/sham-LFPI and 1 week, 1 month, and 7 months thereafter. Longitudinal analyses of alpha diversity, beta diversity, and differential microbial abundance were performed. Short-chain fatty acids (SCFAs) were measured in fecal samples collected before LFPI by liquid chromatography with tandem mass spectrometry. RESULTS: Alpha diversity changed over time in both LFPI and sham-LFPI subjects; no association was observed between alpha diversity and LFPI, the severity of post-LFPI neuromotor impairments, and PTE. LFPI produced significant changes in beta diversity and selective changes in microbial abundances associated with the severity of neuromotor impairments. No association between LFPI-dependent microbial perturbations and PTE was detected. PTE was associated with beta diversity irrespective of timepoint vis-à-vis LFPI, including at baseline. Preexistent fecal microbial abundances of four amplicon sequence variants belonging to the Lachnospiraceae family (three enriched and one depleted) predicted the risk of PTE, with area under the curve (AUC) of .73. Global SCFA content was associated with the increased risk of PTE, with AUC of .722, and with 2-methylbutyric (depleted), valeric (depleted), isobutyric (enriched), and isovaleric (enriched) acids being the most important factors (AUC = .717). When the analyses of baseline microbial and SCFA compositions were combined, AUC to predict PTE increased to .78. SIGNIFICANCE: Whereas LFPI produces no perturbations in the gut microbiome that are associated with PTE, the risk of PTE can be stratified based on preexistent microbial abundances and SCFA content.


Assuntos
Lesões Encefálicas Traumáticas , Epilepsia Pós-Traumática , Epilepsia , Microbioma Gastrointestinal , Animais , Lesões Encefálicas Traumáticas/complicações , Ácidos Graxos Voláteis , Microbioma Gastrointestinal/genética , Humanos , Ratos , Ratos Sprague-Dawley
14.
Death Stud ; 46(10): 2366-2375, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34184616

RESUMO

The present instrumental study evaluated the psychometric properties of the Coronavirus Anxiety Scale with 421 Colombian adults in full lockdown of coronavirus. The reliability was excellent, obtained through the Cronbach's Alpha coefficient (α = 0.83). The results of the confirmatory factor analysis identified satisfactory indicators for the scale's one-dimensional model. The correlations obtained in the discriminant analysis of the items have a moderate level of correlation with values between 0.74 and 0.81. These findings demonstrate that the Coronavirus Anxiety Scale is a valid and reliable instrument to evaluate dysfunctional anxiety related to coronavirus in Colombian population.


Assuntos
Coronavirus , Adulto , Ansiedade/diagnóstico , Colômbia , Humanos , Psicometria , Reprodutibilidade dos Testes , Inquéritos e Questionários
15.
Soft Matter ; 17(24): 5941-5949, 2021 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-34046658

RESUMO

A chemical actuator was developed taking advantage of the internal microstructure of a plant stem. Stem xylems of Cucurbita moschata were chemically modified with a pH-responsive polymer to obtain an intelligent hydraulic valve. The chemical composition of the device was based mainly on biological scaffolds combined with a minimum content of a tailor-made synthetic copolymer. A pH-sensitive hydrogel composed of a copolymer of acrylic acid was grafted on the inner surface of stem microchannels, assessing the physicochemical properties and the response of the developed actuator under different pressure and pH conditions. Variation of average microcapillary diameter in response to pH stimuli was estimated using Poiseuille's model. This microfluidic device demonstrated the pH-responsive properties and efficient control of flux, showing its open/close transition at pH 3.25 and mechanical stability until pressures of 1.75 meters of water column (mH2O). This actuator has adequate response to open/close cycling and relevance to be evaluated as a pH-response valve of aqueous systems. This kind of actuator is a research topic of high interest with potential application to technology demands.


Assuntos
Cucurbita , Hidrogéis , Concentração de Íons de Hidrogênio , Microfluídica , Xilema
16.
Andrologia ; 53(4): e13886, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33550605

RESUMO

The cryopreservation of spermatozoa has the main purpose of preserving male fertility. However, current preservation techniques have shown to produce lesions in the structure and alter sperm functions, probably due to the production of reactive oxygen species (ROS) during cryopreservation. To overcome the damage provoked by ROS, we introduced a novel antioxidant called EmbryORP® in a vitrification protocol and compared eight fertility parameters: motility, viability, morphology, concentration, the semen pH, the oxidation-reduction potential (ORP), the spontaneous acrosomal reaction (AR) and the mitochondrial membrane potential (MMP), in the presence or absence of EmbryORP® . We analysed 20 samples from healthy human sperm donors and observed that the antioxidant significantly decreased the semen pH as well as the MMP and the ORP affecting the balance of ROS. The antioxidant also lowered the motility and viability of the cells, but preserved the acrosome and sperm morphology in general. We concluded that EmbryORP® lowered the ORP, but to a suboptimal level that may be harmful to spermatozoa. Despite these results, our work opens new perspectives on how to improve cryopreservation media. Therefore, we recommend exploring the EmbryORP® potential benefit by reducing its concentration or changing the exposure time during the cryopreservation protocol.


Assuntos
Preservação do Sêmen , Antioxidantes/farmacologia , Criopreservação , Fertilidade , Humanos , Masculino , Motilidade dos Espermatozoides , Espermatozoides
17.
Exp Eye Res ; 197: 108114, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32561484

RESUMO

The corneal endothelium is the inner cell monolayer involved in the maintenance of corneal transparence by the generation of homeostatic dehydration. The glycosaminoglycans of the corneal stroma develop a continuous swelling pressure that should be counteracted by the corneal endothelial cells through active transport mechanisms to move the water to the anterior chamber. Protein transporters for sodium (Na+), potassium (K+), chloride (Cl-) and bicarbonate (HCO3-) are involved in this endothelial "pump function", however despite its physiological importance, the efflux mechanism is not completely understood. There is experimental evidence describing transendothelial diffusion of water in the absence of osmotic gradients. Therefore, it is important to get a deeper understanding of alternative models that drive the fluid transport across the endothelium such as the electrochemical gradients. Three transcriptomic datasets of the corneal endothelium were used in this study to analyze the expression of genes that encode proteins that participate in the transport and the reestablishment of the membrane potential across the semipermeable endothelium. Subsequently, the expression of the identified channels was validated in vitro both at mRNA and protein levels. The results of this study provide the first evidence of the expression of KCNN2, KCNN3 and KCNT2 genes in the corneal endothelium. Differences among the level of expression of KCNN2, KCNT2 and KCNN4 genes were found in a differentially expressed gene analysis of the dataset. Taken together these results underscore the potential importance of the ionic channels in the pathophysiology of corneal diseases. Moreover, we elucidate novel mechanisms that might be involved in the pivotal dehydrating function of the endothelium and in others physiologic functions of these cells using in silico pathways analysis.


Assuntos
Simulação por Computador , Endotélio Corneano/metabolismo , Regulação da Expressão Gênica , Potenciais da Membrana/fisiologia , Canais de Potássio Ativados por Sódio/genética , RNA Mensageiro/genética , Endotélio Corneano/citologia , Humanos , Transporte de Íons , Canais de Potássio Ativados por Sódio/biossíntese , Transdução de Sinais
18.
Inorg Chem ; 59(13): 9152-9162, 2020 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-32525660

RESUMO

Tsai-type quasicrystals and approximants are distinguished by a cluster unit made up of four concentric polyhedral shells that surround a tetrahedron at the center. Here we show that for Tsai-type 1/1 approximants in the RE-Au-Si systems (RE = Gd, Tb, Ho) the central tetrahedron of the Tsai clusters can be systematically replaced by a single RE atom. The modified cluster is herein termed a "pseudo-Tsai cluster" and represents, in contrast to the conventional Tsai cluster, a structural motif without internal symmetry breaking. For each system, single-phase samples of both pseudo-Tsai and Tsai-type 1/1 approximants were independently prepared as millimeter-sized, faceted, single crystals using the self-flux synthesis method. The full replacement of tetrahedral moieties by RE atoms in the pseudo-Tsai 1/1 approximants was ascertained by a combination of single-crystal and powder diffraction studies, as well as energy dispersive X-ray spectroscopy (EDX) analyses with a scanning electron microscope (SEM). Differential scanning calorimetry (DSC) studies revealed distinctly higher decomposition temperatures, by 5-35 K, for the pseudo-Tsai phases. Furthermore, the magnetic properties of pseudo-Tsai phases are profoundly and consistently different from the Tsai counterparts. The onset temperatures of magnetic ordering (Tmag) are lowered in the pseudo-Tsai phases by ∼30% from 24 to 17 K, 11.5 to 8 K, and 5 to 3.5 K in the Gd-Au-Si, Tb-Au-Si, and Ho-Au-Si systems, respectively. In addition, the Tb-Au-Si and Ho-Au-Si systems exhibit some qualitative changes in their magnetic ordering, indicating decisive changes in the magnetic state/structure by a moment-bearing atom at the cluster center.

19.
BMC Ophthalmol ; 20(1): 333, 2020 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-32807111

RESUMO

BACKGROUND: 22q11.2 duplication syndrome (Dup22q11.2) has reduced penetrance and variable expressivity. Those affected may have intellectual disabilities, dysmorphic facial features, and ocular alterations such as ptosis, hypertelorism, nystagmus, and chorioretinal coloboma. The prevalence of this syndrome is unknown, there are only approximately 100 cases reported. However Dup22q11.2 should have a similar prevalence of DiGeorge syndrome (1 in each 4000 new-borns), in which the same chromosomal region that is duplicated in Dup22q11.2 is deleted. CASE PRESENTATION: We report a patient with intellectual disability, psychomotor development delay, hearing loss with disyllable pronunciation only, hyperactivity, self-harm, hetero-aggressive behaviour, facial dysmorphism, left facial paralysis, post-axial polydactyly, and for the first time in patients with Dup22q11.2, optic nerve coloboma and dysplasia in optic nerve. Array comparative genomic hybridization showed a 22q11.23 duplication of 1.306 million base pairs. CONCLUSIONS: New ocular findings in Dup22q11.2 syndrome, such as coloboma and dysplasia in the optic nerve, are reported here, contributing to the phenotypic characterization of a rarely diagnosed genetic syndrome. A complete characterization of the phenotype is necessary to increase the rate of clinical suspicion and then the genetic diagnostic. In addition, through bioinformatics analysis of the genes mapped to the 22q11.2 region, it is proposed that deregulation of the SPECC1L gene could be implicated in the development of ocular coloboma.


Assuntos
Anormalidades Múltiplas , Coloboma , Anormalidades Múltiplas/genética , Coloboma/diagnóstico , Coloboma/genética , Hibridização Genômica Comparativa , Humanos , Nervo Óptico/anormalidades , Fenótipo
20.
Sensors (Basel) ; 20(10)2020 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-32429400

RESUMO

This paper proposes a teleophthalmology support system in which we use algorithms of object detection and semantic segmentation, such as faster region-based CNN (FR-CNN) and SegNet, based on several CNN architectures such as: Vgg16, MobileNet, AlexNet, etc. These are used to segment and analyze the principal anatomical elements, such as optic disc (OD), region of interest (ROI) composed by the macular region, real retinal region, and vessels. Unlike the conventional retinal image quality assessment system, the proposed system provides some possible reasons about the low-quality image to support the operator of an ophthalmoscope and patient to acquire and transmit a better-quality image to central eye hospital for its diagnosis. The proposed system consists of four steps: OD detection, OD quality analysis, obstruction detection of the region of interest (ROI), and vessel segmentation. For the OD detection, artefacts and vessel segmentation, the FR-CNN and SegNet are used, while for the OD quality analysis, we use transfer learning. The proposed system provides accuracies of 0.93 for the OD detection, 0.86 for OD image quality, 1.0 for artefact detection, and 0.98 for vessel segmentation. As the global performance metric, the kappa-based agreement score between ophthalmologist and the proposed system is calculated, which is higher than the score between ophthalmologist and general practitioner.


Assuntos
Oftalmologia , Disco Óptico , Telemedicina , Algoritmos , Humanos , Retina
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