Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 95
Filtrar
1.
Brief Funct Genomics ; 2024 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-38880995

RESUMO

40 years ago, organelle genomes were assumed to be streamlined and, perhaps, unexciting remnants of their prokaryotic past. However, the field of organelle genomics has exposed an unparallel diversity in genome architecture (i.e. genome size, structure, and content). The transcription of these eccentric genomes can be just as elaborate - organelle genomes are pervasively transcribed into a plethora of RNA types. However, while organelle protein-coding genes are known to produce polycistronic transcripts that undergo heavy posttranscriptional processing, the nature of organelle noncoding transcriptomes is still poorly resolved. Here, we review how wet-lab experiments and second-generation sequencing data (i.e. short reads) have been useful to determine certain types of organelle RNAs, particularly noncoding RNAs. We then explain how third-generation (long-read) RNA-Seq data represent the new frontier in organelle transcriptomics. We show that public repositories (e.g. NCBI SRA) already contain enough data for inter-phyla comparative studies and argue that organelle biologists can benefit from such data. We discuss the prospects of using publicly available sequencing data for organelle-focused studies and examine the challenges of such an approach. We highlight that the lack of a comprehensive database dedicated to organelle genomics/transcriptomics is a major impediment to the development of a field with implications in basic and applied science.

2.
Biol Open ; 13(3)2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38427427

RESUMO

The 53rd Ontario Ecology, Ethology, and Evolution Colloquium (OE3C 2023) took place at Western University (London, Canada) on 25-27 May 2023, attracting 160 participants. This Meeting Review aims not only to recapitulate what was discussed during the event, but also to provide a brief synthesis of how biologists can move forward. The event was organised and run by graduate students and postdoctoral researchers from the Department of Biology at Western University. With three international keynote speakers, seventy talks, and fifty poster presentations, the OE3C 2023 spanned a wide range of contemporary research in Ecology, Ethology, and Evolution ("the 3 E's"). The colloquium theme was "Surviving the Anthropocene: future steps for the 3 E's under pressing planetary issues", which was complemented by illustrations depicting the fauna and flora of the "Canadian Anthropocene". Participants discussed what biologists and researchers can do regarding future climate and environmental catastrophes. The meeting culminated in a panel discussion comprising three climate change specialists who examined topics such as the Anthropocene and the Great acceleration, the living planet index, and carbon bombs. Although not exhaustive, these topics served as a starting point for the necessary discussions about how biologists can contribute to the fight for the survival of life on Earth.


Assuntos
Mudança Climática , Etologia , Humanos , Canadá
3.
Anim Behav ; 210: 127-137, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38505105

RESUMO

Motivation to seek social interactions is inherent to all social species. For instance, even with risk of disease transmission in a recent pandemic, humans sought out frequent in-person social interactions. In other social animals, socialization can be prioritized even over water or food consumption. Zebra finches, Taeniopygia guttata, are highly gregarious songbirds widely used in behavioural and physiological research. Songbirds, like humans, are vocal learners during development, which rely on intense auditory learning. Aside from supporting song learning, auditory learning further supports individual identification, mate choice and outcome associations in songbirds. To study auditory learning in a laboratory setting, studies often employ operant paradigms with food restriction and reinforcement and require complete social isolation, which can result in stress and other unintended physiological consequences for social species. Thus, in this work, we designed an operant behavioural method leveraging the sociality of zebra finches for goal-directed behaviours. Our approach relies on visual social reinforcement, without depriving the animals of food or social contact. Using this task, we found that visual social reinforcement was a strong motivational drive for operant behaviour. Motivation was sensitive to familiarity towards the stimulus animal and higher when engaging with a familiar versus a novel individual. We further show that this tool can be used to assess auditory discrimination learning using either songs or synthetic pure tones as stimuli. As birds gained experience in the task, they developed a strategy to maximize reward acquisition in spite of receiving more punishment, i.e. liberal response bias. Our operant paradigm provides an alternative to tasks using food reinforcement and could be applied to a variety of highly social species, such as rodents and nonhuman primates.

4.
eNeuro ; 11(3)2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38467426

RESUMO

Auditory perception can be significantly disrupted by noise. To discriminate sounds from noise, auditory scene analysis (ASA) extracts the functionally relevant sounds from acoustic input. The zebra finch communicates in noisy environments. Neurons in their secondary auditory pallial cortex (caudomedial nidopallium, NCM) can encode song from background chorus, or scenes, and this capacity may aid behavioral ASA. Furthermore, song processing is modulated by the rapid synthesis of neuroestrogens when hearing conspecific song. To examine whether neuroestrogens support neural and behavioral ASA in both sexes, we retrodialyzed fadrozole (aromatase inhibitor, FAD) and recorded in vivo awake extracellular NCM responses to songs and scenes. We found that FAD affected neural encoding of songs by decreasing responsiveness and timing reliability in inhibitory (narrow-spiking), but not in excitatory (broad-spiking) neurons. Congruently, FAD decreased neural encoding of songs in scenes for both cell types, particularly in females. Behaviorally, we trained birds using operant conditioning and tested their ability to detect songs in scenes after administering FAD orally or injected bilaterally into NCM. Oral FAD increased response bias and decreased correct rejections in females, but not in males. FAD in NCM did not affect performance. Thus, FAD in the NCM impaired neuronal ASA but that did not lead to behavioral disruption suggesting the existence of resilience or compensatory responses. Moreover, impaired performance after systemic FAD suggests involvement of other aromatase-rich networks outside the auditory pathway in ASA. This work highlights how transient estrogen synthesis disruption can modulate higher-order processing in an animal model of vocal communication.


Assuntos
Córtex Auditivo , Tentilhões , Feminino , Animais , Masculino , Tentilhões/fisiologia , Aromatase , Reprodutibilidade dos Testes , Vocalização Animal/fisiologia , Estimulação Acústica , Vias Auditivas/fisiologia , Percepção Auditiva/fisiologia , Córtex Auditivo/fisiologia
5.
PLoS One ; 19(3): e0295488, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38502648

RESUMO

This study was carried out to compare the impact of choline supplementation (available from two sources synthetic and natural) on various dosages in broilers. The mode of choline supplementation, via diet and additional sources, synthetic and natural, and the data of performance, carcass quality, blood parameters, and hepatic steatosis were compared. A total of 1050 day-old male Cobb 500 broiler chicks were randomly assigned to 10 treatments, using a completely randomized design model in a factorial scheme, with 6 replicates per treatment and 25 birds per replicate. Choline was supplemented using three sources: synthetic choline chloride 60% (CC), and two sources of natural choline A (NCA), and B (NCB). The Control treatment did not receive any choline supplementation. The diets were supplemented with low, intermediate and high doses of choline sources (400g/t, 800g/t, and 1200g/t of CC; 100g/t, 200g/t, and 300g/t of both NCA and NCB). Data analysis was performed using a factorial model to investigate the effects of choline supplementation (CC, NCA, NCB) and doses on the measured variables. Overall, the results indicated that the the performance of NCA was better than CC & NCB, specifically the dose of 100g/t of NCA outperformed MAR at 100g/t & CC at 400g/t, leading to a significant increase in body weight gain (85.66g & 168.84g respectively), and a noteworthy (9- & 12-point respectively) improvement in feed conversion ratio. Furthermore, NCA contributed to a reduction in steatosis when contrasted with various NCB & CC doses, likely due to the presence of curcumins and catechins in the natural choline source. These findings demonstrated that NCA supplementation yielded superior results compared to CC and NCB across both performance and liver health aspects in broilers aged 1 to 42 days. In conclusion, NCA can be used to replace the CC 60% without compromise on the zootechnical performance in broilers.


Assuntos
Galinhas , Dieta , Animais , Masculino , Ração Animal/análise , Colina/farmacologia , Dieta/veterinária , Suplementos Nutricionais , Aumento de Peso
6.
Phys Chem Chem Phys ; 26(10): 8469-8487, 2024 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-38410922

RESUMO

Efficient surface passivation and toxic lead (Pb) are known obstacles to the photovoltaic application of perovskite-based solar cells. A possible solution for these problems is to use thin-films of two-dimensional (2D) perovskite-based materials and the replacement of Pb with alternative divalent cations (B); however, our atomistic understanding of the differences between (3D) three-dimensional and 2D perovskite-based materials is far from satisfactory. Herein, we report a systematic theoretical investigation based on ab initio density functional theory (DFT) calculations for both 3D MABX3 and the Ruddlesden-Popper 2D (BA)2(MA)B2X7 (B = Ge, Sn, Pb, and X = Cl, Br, I) compounds to investigate the differences (contrasts) in selected physical-chemical properties, i.e., structural parameters, energetic stability, electronic, and optical properties. We found an increased cation/anion charge separation because of the presence of organic spacers, which results in stronger Coulomb interactions in the inorganic framework, and hence, it enhances the cohesive energy (stability) within the inorganic layer. The inorganic layer constitutes the optically active region that contributes to the superior performance of perovskite-based solar cells. We quantified this effect by comparing the average electronic charges at the X sites in both 2D and 3D perovskites. This comparison is then correlated with variations in BX6-octahedron volumes, resulting in a monotonic relation. Moreover, the electronic structure characterization demonstrates that Ge-based systems present weakly sensitive band gaps to dimensionality due to a compensatory effect between Jahn-Teller distortions and quantum confinement. Lead-free GeI-, SnBr-, and SnI-based perovskites have DFT band gaps closer to the optimal value used in photovoltaic applications. Finally, as expected, the 2D systems absorption coefficients show pronounced anisotropy.

7.
J Chem Inf Model ; 64(4): 1306-1318, 2024 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-38347752

RESUMO

Chiral organic-inorganic perovskites exhibit unique physicochemical properties driven by the symmetry of monovalent organic cations. However, an atomistic understanding of how chiral cations transfer their chirality to the inorganic framework and the role played by van der Waals (vdW) interactions in this process is still incomplete. In this work, we report a theoretical investigation, based on density functional theory calculations within the Perdew-Burke-Ernzerhof (PBE) formulation for the exchange-correlation functional, into the role of the vdW interactions in the chirality transfer process. For that, we selected several vdW corrections, namely, Grimme (D2, D3, D3(BJ)), Tkatchenko-Scheffler (TS, TS+SCS, TS+HSI), density-dependent energy correction (dDsC), and many-body scattering (MBD) energy method correction. For the chiral perovskite systems, we selected a set of chiral organic-inorganic perovskites with several dimensions, namely, from zero-dimensional to three-dimensional, each having enantiomers with R and S configurations. Based on a statistical treatment of the relative errors of all lattice parameters with respect to experimental data, we found that D3, D3(BJ), TS, TS+SCS, TS+HSI, and MBD vdW are the most accurate corrections to describe the equilibrium structural properties of chiral perovskites using the PBE method. We identify chirality-induced sequential asymmetries of distorted octahedrons and propose angular descriptors to quantify them, where the orientations of these distortions depend on the R or S nature of the chiral cations. Furthermore, we demonstrate the importance of accurate vdW interactions in precisely describing these asymmetric distortions. By means of binding energies and charge-transfer analysis, we show that the impact of vdW corrections on the charge distribution leads to a subtle strengthening of hydrogen bonds between chiral cations and inorganic octahedra, resulting in an increase in the binding energy. Finally, we identified that the Rashba-Dresselhaus effect in two-dimensionality is refined by vdW interactions.


Assuntos
Compostos de Cálcio , Óxidos , Titânio , Teoria da Densidade Funcional , Ligação de Hidrogênio , Cátions
8.
Trends Plant Sci ; 29(6): 626-629, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38360479

RESUMO

Plant mitochondrial and plastid genomes typically show pervasive, genome-wide transcription. Little is known, however, about the utility of organelle noncoding RNAs, which often make up most of the transcriptome. Here, we suggest that long-read sequencing data combined with dedicated RNA databases could help identify putative functional organelle noncoding transcripts.


Assuntos
Genoma de Planta , Transcriptoma , Transcriptoma/genética , Genoma de Planta/genética , RNA não Traduzido/genética , Genoma Mitocondrial/genética , Transcrição Gênica , RNA de Plantas/genética , Plantas/genética
9.
Rev. bras. educ. méd ; 48(1): e003, 2024. graf
Artigo em Português | LILACS-Express | LILACS | ID: biblio-1529765

RESUMO

Resumo Introdução: Atualmente o Brasil mostra um expressivo aumento da sobrevida e consequente elevação do número de idosos na sua população. Do ponto de vista de propostas para a melhoria da qualidade de vida deles, a sexualidade deve ser compreendida a partir do princípio holístico, não somente do fator biológico. Nesse cenário, novas reflexões de profissionais da saúde tornam-se indispensáveis para o planejamento de ações específicas, objetivando a atenção integral à saúde do idoso. Relato de experiência: O presente relato de experiência traz o início de um diálogo com acadêmicos de Medicina de uma universidade pública sobre a complexidade da sexualidade e infecções sexualmente transmissíveis (IST) em idosos, buscando identificar o conhecimento desses discentes sobre o assunto e idealizar propostas de ação ao público-alvo. Para isso, estruturou-se uma estratégia de ensino-aprendizagem cuja abordagem consistiu na adaptação e aplicação da metodologia do Arco de Maguerez para o debate sobre IST no contexto da saúde pública brasileira, o qual foi realizado com base nas diretrizes do ensino remoto emergencial. Nossos resultados vão de encontro à literatura que visa compreender as representações sociais acerca da sexualidade dos idosos. Neles, verificou-se que as representações sociais acerca da sexualidade na terceira idade assemelham-se à descrição científica, apresentado similitude entre o senso comum e o conhecimento erudito. Discussão: Diante da discrepância descrita na literatura quanto aos conceitos errôneos por parte dos idosos e dos familiares e pelos profissionais de saúde acerca da sexualidade na terceira idade, são imprescindíveis a realização de campanhas e o desenvolvimento de medidas e estratégias preventivas voltadas para idosos, a fim reduzir a incidência de IST nessa comunidade. Para isso, são fundamentais estratégias de educação em saúde no ensino acadêmico e de educação profissional continuada para sedimentar os conhecimentos necessários na idealização de propostas eficazes. Conclusão: A partir da formação médica adequada e por meio da discussão dos aspectos complexos sobre o assunto, serão possíveis a construção, a implementação e a avaliação de políticas públicas de saúde para o enfrentamento das IST, de modo a diminuir as barreiras relacionadas à prevenção de doenças e à promoção de saúde sexual na população idosa.


Abstract Introduction: Brazil is currently reporting a significant increase in survival and consequent rise in its elderly population. From the point of view of proposals to improve their quality of life, sexuality should be understood from a holistic, and not just a biological, perspective. In this scenario, new reflections by health professionals become indispensable for the planning of specific actions aimed at providing comprehensive health care for the elderly. Experience report: This experience report describes the beginning of a dialogue with medical students from a public university about the complexity of sexuality and sexually transmitted infections among the elderly, seeking to identify their knowledge of the subject and devise proposals for action with the target audience. To this end a teaching-learning strategy was structured based on an approach that adapted and applied the Arc of Maguerez methodology to the debate on sexually transmitted infections (STIs) in the context of Brazilian public health, which was conducted out within the guidelines of emergency remote learning. Our results are in line with the literature that seeks to understand the social representations about sexuality among the elderly. It was found that the social representations about sexuality in the elderly are similar to the scientific description, with similarities between common sense and scholarly knowledge. Discussion: Given the discrepancy described in the literature regarding the misconceptions on the part of the elderly, family members and health professionals about sexuality in old age, it is essential that campaigns be conducted, and preventive measures and strategies developed for the elderly to reduce the incidence of STIs in this community. Hence, health education strategies are needed in academic teaching and continuing professional education to consolidate the knowledge required to devise effective proposals. Conclusions: Based on fit-for-purpose medical education, the discussion of complex aspects about this subject will support the construction, implementation, and evaluation of public health policies to tackle STIs, reducing barriers related to the prevention and promotion of sexual health in the elderly population.

10.
Front Immunol ; 14: 1206979, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37876932

RESUMO

Introduction: Infection by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) induces rapid production of IgM, IgA, and IgG antibodies directed to multiple viral antigens that may have impact diverse clinical outcomes. Methods: We evaluated IgM, IgA, and IgG antibodies directed to the nucleocapsid (NP), IgA and IgG to the Spike protein and to the receptor-binding domain (RBD), and the presence of neutralizing antibodies (nAb), in a cohort of unvaccinated SARS-CoV-2 infected individuals, in the first 30 days of post-symptom onset (PSO) (T1). Results: This study included 193 coronavirus disease 2019 (COVID-19) participants classified as mild, moderate, severe, critical, and fatal and 27 uninfected controls. In T1, we identified differential antibody profiles associated with distinct clinical presentation. The mild group presented lower levels of anti-NP IgG, and IgA (vs moderate and severe), anti-NP IgM (vs severe, critical and fatal), anti-Spike IgA (vs severe and fatal), and anti-RBD IgG (vs severe). The moderate group presented higher levels of anti-RBD IgA, comparing with severe group. The severe group presented higher levels of anti-NP IgA (vs mild and fatal) and anti-RBD IgG (vs mild and moderate). The fatal group presented higher levels of anti-NP IgM and anti-Spike IgA (vs mild), but lower levels of anti-NP IgA (vs severe). The levels of nAb was lower just in mild group compared to severe, critical, and fatal groups, moreover, no difference was observed among the more severe groups. In addition, we studied 82 convalescent individuals, between 31 days to 6 months (T2) or more than 6 months (T3), PSO, those: 12 mild, 26 moderate, and 46 severe plus critical. The longitudinal analyzes, for the severe plus critical group showed lower levels of anti-NP IgG, IgA and IgM, anti-Spike IgA in relation T3. The follow-up in the fatal group, reveals that the levels of anti-spike IgG increased, while anti-NP IgM levels was decreased along the time in severe/critical and fatal as well as anti-NP IgG and IgA in several/critical groups. Discussion: In summary, the anti-NP IgA and IgG lower levels and the higher levels of anti-RBD and anti-Spike IgA in fatal compared to survival group of individuals admitted to the intensive care unit (ICU). Collectively, our data discriminate death from survival, suggesting that anti-RBD IgA and anti-Spike IgA may play some deleterious effect, in contrast with the potentially protective effect of anti-NP IgA and IgG in the survival group.


Assuntos
COVID-19 , Humanos , SARS-CoV-2 , Anticorpos Antivirais , Anticorpos Neutralizantes , Nucleocapsídeo , Imunoglobulina G , Imunoglobulina A , Imunoglobulina M
11.
Front Oncol ; 13: 1237170, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37746264

RESUMO

Purpose: Medulloblastomas are the most common primary malignant brain tumors in children. They are divided into molecular subgroups: WNT-activated, SHH-Activated, TP53 mutant or wild type, and non-WNT/non-SHH (Groups 3 and 4). WNT-activated medulloblastomas are usually caused by mutations in the CTNNB1 gene (85%-90%), and most remaining cases of CTNNB1 wild type are thought to be caused by germline mutations in APC. So far, the frequencies of CTNNB1 have been reported mainly in North American and European populations. The aim of this study was to report the frequency of CTNNB1 mutations in WNT-activated medulloblastomas in a Latin-Iberian population and correlate with their clinicopathological characteristics. Methods: A total of 266 medulloblastomas from seven different institutions from Brazil (n=211), Portugal (n=38), and Argentina (n=17) were evaluated. Following RNA and DNA isolation from formalin-fixed, paraffin-embedded (FFPE) tumor tissues, the molecular classification and CTNNB1 mutation analysis were performed by nCounter and Sanger sequencing, respectively. Results: WNT-activated medulloblastomas accounted for 15% (40/266) of the series. We observed that 73% of WNT-activated medulloblastomas harbored CTNNB1 mutations. CTNNB1 wild-type cases (27%) were more prevalent in female individuals and suggested to be associated with a worse outcome. Among the CTNNB1 wild-type cases, the available analysis of family history revealed two cases with familiar adenomatous polyposis, harboring APC germline variants. Conclusion: We observed a lower incidence of CTNNB1 mutations in WNT-activated medulloblastomas in our Latin-Iberian cohort compared to frequencies previously described in other populations. Considering that CTNNB1 wild-type cases may exhibit APC germline mutations, our study suggests a higher incidence (~30%) of hereditary WNT-activated medulloblastomas in the Latin-Iberian population.

12.
Int J Mol Sci ; 24(15)2023 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-37569410

RESUMO

Breast cancer (BC) is the most common cancer in women, with metastatic BC being responsible for the highest number of deaths. A frequent site for BC metastasis is the brain. Brain metastasis derived from BC involves the cooperation of multiple genetic, epigenetic, angiogenic, and tumor-stroma interactions. Most of these interactions provide a unique opportunity for development of new therapeutic targets. Potentially targetable signaling pathways are Notch, Wnt, and the epidermal growth factor receptors signaling pathways, all of which are linked to driving BC brain metastasis (BCBM). However, a major challenge in treating brain metastasis remains the blood-brain barrier (BBB). This barrier restricts the access of unwanted molecules, cells, and targeted therapies to the brain parenchyma. Moreover, current therapies to treat brain metastases, such as stereotactic radiosurgery and whole-brain radiotherapy, have limited efficacy. Promising new drugs like phosphatase and kinase modulators, as well as BBB disruptors and immunotherapeutic strategies, have shown the potential to ease the disease in preclinical studies, but remain limited by multiple resistance mechanisms. This review summarizes some of the current understanding of the mechanisms involved in BC brain metastasis and highlights current challenges as well as opportunities in strategic designs of potentially successful future therapies.


Assuntos
Neoplasias Encefálicas , Neoplasias da Mama , Radiocirurgia , Feminino , Humanos , Neoplasias da Mama/genética , Barreira Hematoencefálica/patologia , Neoplasias Encefálicas/genética
13.
J Exp Zool A Ecol Integr Physiol ; 339(9): 887-897, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37522484

RESUMO

Ocypode quadrata, a Ghost crab species found along the western Atlantic coast, is considered a bioindicator of anthropogenic impact on sandy beaches. Ghost Crabbing, a touristic activity in which ghost crabs are chased just for fun, is a potentially threatening activity for this crab. In crustaceans, metabolites such as glucose and lactate, and the gene expression of crustacean hyperglycemic hormone (CHH) and heat shock proteins (HSPs) increase when the animals are exposed to several types of stress, including alterations in temperature, salinity, or exposure to xenobiotics. This work was developed to identify if being chased by humans would affect these markers of stress in this species of crab. The effects of chasing stress on hemolymph and tissue metabolites and the gene expression levels of CHH and HSP70 were investigated. The levels of lactate in the hemolymph of stressed crabs were six times higher than those of control crabs immediately after chasing and decreased progressively during recovery, indicating an active anaerobic metabolism during the stress. On the contrary, glucose levels in the hemolymph of the stressed crabs increased progressively from 30 to 60 min after chasing, indicating an inverse correlation between glucose and lactate and the conversion of lactate to glucose by gluconeogenesis. In stressed crabs, the levels of triglycerides in the hemolymph decreased 30 min after chasing, while the opposite tended to occur in the hepatopancreas, indicating that during recovery, the crabs use triglycerides as energy source to sustain aerobic metabolism. Finally, this study demonstrates that ghost crabs are stressed by minimum human contact and that "ghost crabbing" must not be encouraged as a tourist activity.


Assuntos
Braquiúros , Humanos , Animais , Braquiúros/fisiologia , Glucose/metabolismo , Triglicerídeos , Lactatos
14.
Biomed J ; 46(3): 100539, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35598733

RESUMO

BACKGROUND: Type 1 diabetes mellitus is a prevalent autoimmune disease worldwide. The knowledge of female particularities in metabolic dysfunction is of fundamental importance, leading to better choices for human therapy candidates. The aim of this study is to investigate the glucose flux peculiarities of female rats submitted to two classic experimental diabetes protocols. METHODS: Female Wistar rats, 60 days old, were used to evaluate biochemical and hormonal serum parameters, in addition to skeletal muscle and liver energy stocks and 14C-glucose and 14C-alanine flux. Two different protocols, multiple (25 mg/kg dose) and single (65 mg/kg dose) intraperitoneal streptozotocin, were compared considering the alterations presented 48 h and 30 days after the drug administration. RESULTS: The results showed few indicators of muscle and liver metabolic imbalance. High-single streptozotocin dose promoted 97% and 41% lower glycogen levels in liver and muscle respectively. Multiple-low streptozotocin dose promoted 63% lower lipid synthesis in liver. After 30 days, diabetic animals presented hyperglycaemia in both protocols, 589.5 (529.3/642.3) mg/dL to high-single dose and 374.2 (339.3/530.6) mg/dL to multiple-low dose. However, they did not present lower insulin levels, alterations on muscle glucose uptake, nor higher hepatic gluconeogenesis. CONCLUSION: In conclusion, this study demonstrates that females, at least Wistar rats, are less responsive to classic diabetes protocols established in literature, so mechanisms of experimental diabetes for females need more investigation. After which, therapeutic candidates should be evaluated in such a way sex bias does not present itself as a factor that hinders reproducibility in human studies.


Assuntos
Diabetes Mellitus Experimental , Glucose , Humanos , Ratos , Feminino , Animais , Glucose/metabolismo , Ratos Wistar , Glicemia , Estreptozocina/metabolismo , Estreptozocina/uso terapêutico , Reprodutibilidade dos Testes , Diabetes Mellitus Experimental/tratamento farmacológico , Diabetes Mellitus Experimental/metabolismo , Fígado/metabolismo
15.
Poult Sci ; 102(2): 102320, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36508950

RESUMO

Oxidative stress significantly compromises the production efficiency of laying hens. It has been reported in literature that selenium (Se) in poultry diets has a positive effect on mitigating these effects. This study has been carried out to evaluate the effects of Se supplementation in feeds, from either an inorganic or a hydroxy-selenomethionine (OH-SeMet) source, on the performance and physiological traits of 50- to 70-wk-old Dekalb Brown laying hens under heat stress, and on their egg quality after different storage durations. The treatments consisted in supplementing 0.3 ppm of Se as sodium selenite (SS; 45%-0.7g/ton) or OH-SeMet (2%-15g/ton) in twelve 16-bird replicates. Supplementation with OH-SeMet resulted in a better performance of the laying hens than with SS: -5% feed conversion ratio and +3.6% of egg mass. A reduction in egg quality was observed with prolonged egg storage, which was mitigated with the use of OH-SeMet in laying hen diets. The use of OH-SeMet increased the antioxidant capacity of the birds, which showed higher glutathione peroxidase levels in the blood, kidneys, liver, and intestinal mucosa, in addition to a higher Se content in the eggs and a greater bone resistance. Thus, supplementing feeds with 0.3 ppm of OH-SeMet to 50- to 70-wk-old semi-heavy laying hens enhances their antioxidant capacity and leads to a higher egg quality and productivity than SS supplementation.


Assuntos
Selênio , Selenometionina , Animais , Feminino , Selenometionina/farmacologia , Antioxidantes , Galinhas , Óvulo , Selênio/farmacologia , Dieta/veterinária , Resposta ao Choque Térmico , Ração Animal/análise , Suplementos Nutricionais
16.
bioRxiv ; 2023 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-38187685

RESUMO

Sensory perception is dynamic, quickly adapting to sudden shifts in environmental or behavioral context. Though decades of work have established that these dynamics are mediated by rapid fluctuations in sensory cortical activity, we have a limited understanding of the brain regions and pathways that orchestrate these changes. Neurons in the orbitofrontal cortex (OFC) encode contextual information, and recent data suggest that some of these signals are transmitted to sensory cortices. Whether and how these signals shape sensory encoding and perceptual sensitivity remains uncertain. Here, we asked whether the OFC mediates context-dependent changes in auditory cortical sensitivity and sound perception by monitoring and manipulating OFC activity in freely moving animals under two behavioral contexts: passive sound exposure and engagement in an amplitude modulation (AM) detection task. We found that the majority of OFC neurons, including the specific subset that innervate the auditory cortex, were strongly modulated by task engagement. Pharmacological inactivation of the OFC prevented rapid context-dependent changes in auditory cortical firing, and significantly impaired behavioral AM detection. Our findings suggest that contextual information from the OFC mediates rapid plasticity in the auditory cortex and facilitates the perception of behaviorally relevant sounds. Significance Statement: Sensory perception depends on the context in which stimuli are presented. For example, perception is enhanced when stimuli are informative, such as when they are important to solve a task. Perceptual enhancements result from an increase in the sensitivity of sensory cortical neurons; however, we do not fully understand how such changes are initiated in the brain. Here, we tested the role of the orbitofrontal cortex (OFC) in controlling auditory cortical sensitivity and sound perception. We found that OFC neurons change their activity when animals perform a sound detection task. Inactivating OFC impairs sound detection and prevents task-dependent increases in auditory cortical sensitivity. Our findings suggest that the OFC controls contextual modulations of the auditory cortex and sound perception.

17.
Foods ; 11(23)2022 Nov 24.
Artigo em Inglês | MEDLINE | ID: mdl-36496600

RESUMO

Insects present great potential for the food industry due to their easier rearing conditions and high nutritional value, in comparison with traditional livestock. However, there is a lack of evaluation of the technological status of food products developed with edible insects. Therefore, this study aims to analyze the emergent technological and scientific applications of edible insects in the food industry through a prospective study of patent documents and research articles. Espacenet was used as a research tool, applying the terms Insect, Pupa, Larva, or Nymph and the codes A23L33 and A23V2002. A total of 1139 documents were found-341 were related to the study. Orbit® was used to evaluate technological domains and clusters of concepts. Scopus database research was performed to assess the prevalence of insect research, with the term "edible and insect*". The main insects used were silkworms, bees, beetles, mealworms, crickets, and cicadas. Protein isolates were the predominant technology, as they function as an ingredient in food products or supplements. A diverse application possibility for insects was found due to their nutritional composition. The insect market is expected to increase significantly in the next years, representing an opportunity to develop novel high-quality/sustainable products.

18.
Front Genet ; 13: 921324, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36147510

RESUMO

Hearing loss (HL) is a common sensory deficit in humans and represents an important clinical and social burden. We studied whole-genome sequencing data of a cohort of 2,097 individuals from the Brazilian Rare Genomes Project who were unaffected by hearing loss to investigate pathogenic and likely pathogenic variants associated with nonsyndromic hearing loss (NSHL). We found relevant frequencies of individuals harboring these alterations: 222 heterozygotes (10.59%) for sequence variants, 54 heterozygotes (2.58%) for copy-number variants (CNV), and four homozygotes (0.19%) for sequence variants. The top five most frequent genes and their corresponding combined allelic frequencies (AF) were GJB2 (AF = 1.57%), STRC (AF = 1%), OTOA (AF = 0.69%), TMPRSS3 (AF = 0.41%), and OTOF (AF = 0.29%). The most frequent sequence variant was GJB2:c.35del (AF = 0.72%), followed by OTOA:p. (Glu787Ter) (AF = 0.61%), while the most recurrent CNV was a microdeletion of 57.9 kb involving the STRC gene (AF = 0.91%). An important fraction of these individuals (n = 104; 4.96%) presented variants associated with autosomal dominant forms of NSHL, which may imply the development of some hearing impairment in the future. Using data from the heterozygous individuals for recessive forms and the Hardy-Weinberg equation, we estimated the population frequency of affected individuals with autosomal recessive NSHL to be 1:2,222. Considering that the overall prevalence of HL in adults ranges from 4-15% worldwide, our data indicate that an important fraction of this condition may be associated with a monogenic origin and dominant inheritance.

19.
Biomedicines ; 10(9)2022 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-36140400

RESUMO

Telomere maintenance is key during cancer development. Malignant cells can either use telomerase or an alternative lengthening of telomere (ALT) pathway to maintain their telomere length. In Hodgkin's Lymphoma (HL), the presence of telomerase activation is established. The activation of ALT has been reported recently. Our data confirm this notion describing co-localization of the phosphorylated form of telomeric repeat-binding factor 1 (pT371-TRF1) with ALT-associated promyelocytic leukemia bodies. Surprisingly, to our knowledge, there are no published studies targeting both telomere maintenance pathways in HL. Consequently, we investigated, for the first time, the effects of both telomerase and ALT inhibition on HL cell viability: We inhibited telomerase and/or ALT, given either individually, simultaneously, or consecutively. We report that the inhibition of telomerase using BIBR1532 followed by ALT inhibition, using trabectedin, caused a decrease of greater than 90% in cell viability in three patient-derived HL cell lines. Our results suggest that HL cells are most vulnerable to the consecutive inhibition of telomerase followed by ALT inhibition.

20.
Foods ; 11(12)2022 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-35741873

RESUMO

The world is currently undergoing a demographic change towards an increasing number of elderly citizens. Aging is characterized by a temporal decline in physiological capacity, and oxidative stress is a hallmark of aging and age-related disorders. Such an oxidative state is linked to a decrease in the effective mechanisms of cellular repair, the incidence of post-translational protein glycation, mitochondrial dysfunction, and neurodegeneration, just to name some of the markers contributing to the establishment of age-related reduction-oxidation, or redox, imbalance. Currently, there are no prescribed therapies to control oxidative stress; however, there are strategies to elevate antioxidant defenses and overcome related health challenges based on the adoption of nutritional therapies. It is well known that herbal teas such, as hibiscus, rooibos, and yerba mate, are important sources of antioxidants, able to prevent some oxidation-related stresses. These plants produce several bioactive metabolites, have a pleasant taste, and a long-lasting history as safe foods. This paper reviews the literature on hibiscus, rooibos, and yerba mate teas in the context of nutritional strategies for the attenuation of oxidative stress-related glycoxidation and neurodegeneration, and, here, Alzheimer's Disease is approached as an example. The focus is given to mechanisms of glycation inhibition, as well as neuroprotective in vitro effects, and, in animal studies, to frame interest in these plants as nutraceutical agents related to current health concerns.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...