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Reconfiguration of amorphous complex oxides provides a readily controllable source of stress that can be leveraged in nanoscale assembly to access a broad range of 3D geometries and hybrid materials. An amorphous SrTiO3 layer on a Si:B/Si1- x Gex :B heterostructure is reconfigured at the atomic scale upon heating, exhibiting a change in volume of ≈2% and accompanying biaxial stress. The Si:B/Si1- x Gex :B bilayer is fabricated by molecular beam epitaxy, followed by sputter deposition of SrTiO3 at room temperature. The processes yield a hybrid oxide/semiconductor nanomembrane. Upon release from the substrate, the nanomembrane rolls up and has a curvature determined by the stress in the epitaxially grown Si:B/Si1- x Gex :B heterostructure. Heating to 600 °C leads to a decrease of the radius of curvature consistent with the development of a large compressive biaxial stress during the reconfiguration of SrTiO3 . The control of stresses via post-deposition processing provides a new route to the assembly of complex-oxide-based heterostructures in 3D geometry. The reconfiguration of metastable mechanical stressors enables i) synthesis of various types of strained superlattice structures that cannot be fabricated by direct growth and ii) technologies based on strain engineering of complex oxides via highly scalable lithographic processes and on large-area semiconductor substrates.
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BACKGROUND: The loss of global functional independence, along with bladder, bowel, and sexual dysfunctions, may contribute to psychological distress and life dissatisfaction after spinal cord injury (SCI). AIM: To explore the relationship of erectile function and androgenic status with life satisfaction, independently from confounders recognizable in spinal cord-injured men. METHODS: 100 consecutive men (49 ± 17 years) admitted to a rehabilitation program because of chronic SCI (≥1 year) underwent clinical/biochemical evaluations, including the assessment of life and sexual satisfaction using the Life-Satisfaction Questionnaire-9 (LiSat-9), erectile function using the International Index of Erectile Function-5 (IIEF-5), global and bowel-bladder functional independence using the Spinal Cord Independence Measure (SCIM) and measurement of total testosterone (TT) levels. The free testosterone level was calculated using the Vermeulen formula. OUTCOMES: The outcomes include the relationship between sexual health and life satisfaction in men with SCI. RESULTS: A LiSat-9 score <4, suggestive for life dissatisfaction, was exhibited by 49% of men. When compared with the life-satisfied group, a significantly higher percentage of them had sexual dissatisfaction and erectile dysfunction (ED); they also exhibited significantly lower levels of TT and calculated free testosterone (cFT) and a more severe impairment of bowel-bladder function. The life satisfaction degree correlated with sexual satisfaction degree, IIEF-5 score, TT, cFT, and bowel-bladder function degree. At the logistic regression model, including sexual LiSat-9 subscore and bowel-bladder SCIM subscore, only the former exhibited a significant negative association with life dissatisfaction. In a further logistic regression model, including the putative key determinants of sexual satisfaction, erectile function, and cFT levels, a higher odd of life dissatisfaction was independently associated both with a lower IIEF-5 score (OR: 0.93; 95% CI: 0.88, 0.98) and lower cFT levels (OR: 0.98; 95% CI: 0.98, 0.99). CLINICAL IMPLICATIONS: In men with chronic SCI, assessment of erectile function and testosterone levels can help to predict life satisfaction. STRENGTHS & LIMITATIONS: This is the first demonstration of the independent association of androgen deficiency and ED with life satisfaction in men with SCI. Prospective studies are warranted to clarify the cause-effect relationships. CONCLUSIONS: In men with SCI, ED and low testosterone levels exhibit a significant independent association with life dissatisfaction; longitudinal intervention studies could explore possible effects of their treatment in improving sexual and life satisfaction in this population. D'Andrea S, Minaldi E, Castellini C, et al. Independent Association of Erectile Dysfunction and Low Testosterone Levels With Life Dissatisfaction in Men With Chronic Spinal Cord Injury. J Sex Med 2020;17:911-918.
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Disfunção Erétil , Traumatismos da Medula Espinal , Disfunção Erétil/etiologia , Humanos , Masculino , Ereção Peniana , Estudos Prospectivos , Traumatismos da Medula Espinal/complicações , TestosteronaRESUMO
Antimonide compounds are fabricated in membrane form to enable materials combinations that cannot be obtained by direct growth and to support strain fields that are not possible in the bulk. InAs/(InAs,Ga)Sb type II superlattices (T2SLs) with different in-plane geometries are transferred from a GaSb substrate to a variety of hosts, including Si, polydimethylsiloxane, and metal-coated substrates. Electron microscopy shows structural integrity of transferred membranes with thickness of 100 nm to 2.5 [Formula: see text]m and lateral sizes from [Formula: see text]m2 to [Formula: see text] cm2 Electron microscopy reveals the excellent quality of the membrane interface with the new host. The crystalline structure of the T2SL is not altered by the fabrication process, and a minimal elastic relaxation occurs during the release step, as demonstrated by X-ray diffraction and mechanical modeling. A method to locally strain-engineer antimonide-based membranes is theoretically illustrated. Continuum elasticity theory shows that up to [Formula: see text]3.5% compressive strain can be induced in an InSb quantum well through external bending. Photoluminescence spectroscopy and characterization of an IR photodetector based on InAs/GaSb bonded to Si demonstrate the functionality of transferred membranes in the IR range.
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INTRODUCTION: Comparative studies on differences in sexual function outcomes between homosexual and heterosexual men are sparse and inconclusive. AIM: To systematically evaluate whether, and to what extent, a statistically significant difference exists in the odds of erectile dysfunction (ED) and premature ejaculation (PE) between homosexual and heterosexual men. METHODS: A thorough search of Medline, SCOPUS, CINAHL, and Web of Science databases was carried out to identify case-control studies comparing the prevalence of ED and PE in homosexual and heterosexual men. Methodological quality of the included studies was assessed using the Newcastle-Ottawa Scale. Odds ratios (ORs) of reporting ED and PE were combined using random effect models. The Cochrane Q and I2 tests were carried out to analyze the between-studies heterogeneity. Funnel plots and trim-and-fill analysis were used to assess publication bias. MAIN OUTCOME MEASURES: The relationship between sexual orientation and odds of ED and PE was assessed by calculating pooled ORs with a 95% CI. RESULTS: 4 studies included in the quantitative analysis collectively provided information on 1,807 homosexual and 4,055 heterosexual men. The pooled ORs indicated that homosexual orientation was associated with 1.5-fold higher odds of reporting ED (OR = 1.49, 95% CI = 1.03-2.16; P = .04) and 28.0% lower odds of reporting PE in comparison to the heterosexual orientation (OR = 0.72, 95% CI = 0.52-1.00; P = .05). However, a significant heterogeneity among the studies was observed. Funnel plots revealed a possible publication bias only for the ED analysis, where the trim-and-fill test detected a putative missing study. Nevertheless, even when the pooled estimate was adjusted for publication bias, there was a significantly higher risk of ED in the homosexual group (adjusted OR = 1.60, 95% CI = 1.10-2.30; P = .01). CLINICAL IMPLICATIONS: These findings can drive future studies on sexual needs and concerns of homosexual men, which might not exactly match those of heterosexual individuals. STRENGTH & LIMITATIONS: This is the first meta-analysis exploring the differences in the prevalence of ED and PE between homosexual and heterosexual men. However, the results should be interpreted with caution, because their generalization could be hindered by the non-probabilistic nature of the samples, and a measurement bias could result from the use of different non-standardized indicators of sexual dysfunctions. CONCLUSION: Homosexual orientation is associated with higher odds of ED and lower odds of PE compared with heterosexual orientation. Further studies are warranted to elucidate the clinical significance of these findings and whether they reflect differences in patterns of sexual lifestyle. Barbonetti A, D'Andrea S, Cavallo F, et al. Erectile Dysfunction and Premature Ejaculation in Homosexual and Heterosexual Men: A Systematic Review and Meta-Analysis of Comparative Studies. J Sex Med 2019;16:624-632.
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Disfunção Erétil/fisiopatologia , Ejaculação Precoce/fisiopatologia , Comportamento Sexual , Heterossexualidade , Homossexualidade , Humanos , Estilo de Vida , Masculino , PrevalênciaRESUMO
DNA double-strand breaks (DSBs) are known to be powerful inducers of homologous recombination (HR), but single-strand breaks (nicks) have also been shown to trigger HR. Both DSB- and nick-induced HR ((nick)HR) are exploited in advanced genome-engineering approaches based on the bacterial RNA-guided nuclease Cas9. However, the mechanisms of (nick)HR are largely unexplored. Here, we applied Cas9 nickases to study (nick)HR in mammalian cells. We find that (nick)HR is unaffected by inhibition of major damage signaling kinases and that it is not suppressed by nonhomologous end-joining (NHEJ) components, arguing that nick processing does not require a DSB intermediate to trigger HR. Relative to a single nick, nicking both strands enhances HR, consistent with a DSB intermediate, even when nicks are induced up to â¼1kb apart. Accordingly, HR and NHEJ compete for repair of these paired nicks, but, surprisingly, only when 5' overhangs or blunt ends can be generated. Our study advances the understanding of molecular mechanisms driving nick and paired-nick repair in mammalian cells and clarify phenomena associated with Cas9-mediated genome editing.
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Quebras de DNA de Cadeia Dupla , Endonucleases/metabolismo , Recombinação Homóloga , Reparo de DNA por Recombinação , Animais , Linhagem Celular , Dano ao DNA , Reparo do DNA por Junção de Extremidades , Replicação do DNA , Técnicas de Inativação de Genes , Humanos , Camundongos , Motivos de Nucleotídeos , Troca de Cromátide IrmãRESUMO
OBJECTIVES: To determine (1) whether the serum concentration of 25-hydroxy vitamin D (25(OH)D3) was associated with depression levels in people with chronic spinal cord injury (SCI) and (2) whether any observed association was independent of potential confounders. DESIGN: Cross-sectional study. SETTING: Rehabilitation institute. PARTICIPANTS: Patients with chronic SCI (N=100) recruited consecutively. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Patients underwent clinical and biochemical evaluations, including assessment of 25(OH)D3 levels and the presence and severity of depressive symptoms, by using the interviewer-assisted self-report Beck Depression Inventory-II (BDI-II). RESULTS: Depression (BDI-II score ≥14) was observed in 15 of 28 women (53.6%) and 18 of 72 men (25.0%) of the study population. They exhibited significantly lower 25(OH)D3 levels, lower functional independence degree in performing activities of daily living, poorer engagement in leisure time physical activity, and higher body mass index. Lower 25(OH)D3 levels were associated with higher BDI-II scores as well as with the occurrence of depression. These associations persisted after adjustment for all significant predictors of the BDI-II score that were selected, as possible confounders, by univariate analysis. In receiver operating characteristic analysis, a 25(OH)D3 level of <9.99ng/mL had the highest accuracy in discriminating patients with depression. CONCLUSIONS: In people with chronic SCI, an inverse association exists between serum 25(OH)D3 levels and depressive symptoms, widely independent of potential confounders, especially those, peculiar to this population, that can mediate the effects of depression on vitamin D levels.
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Depressão/sangue , Depressão/epidemiologia , Traumatismos da Medula Espinal/epidemiologia , Vitamina D/análogos & derivados , Atividades Cotidianas , Adulto , Idoso , Idoso de 80 Anos ou mais , Índice de Massa Corporal , Doença Crônica , Estudos Transversais , Feminino , Humanos , Relações Interpessoais , Masculino , Pessoa de Meia-Idade , Escalas de Graduação Psiquiátrica , Índice de Gravidade de Doença , Vitamina D/sangueRESUMO
Friedreich ataxia is an inherited neurodegenerative disease that leads to progressive disability. There is currently no effective treatment and patients die prematurely. The underlying genetic defect leads to reduced expression of the mitochondrial protein frataxin. Frataxin insufficiency causes mitochondrial dysfunction and ultimately cell death, particularly in peripheral sensory ganglia. There is an inverse correlation between the amount of residual frataxin and the severity of disease progression; therefore, therapeutic approaches aiming at increasing frataxin levels are expected to improve patients' conditions. We previously discovered that a significant amount of frataxin precursor is degraded by the ubiquitin/proteasome system before its functional mitochondrial maturation. We also provided evidence for the therapeutic potential of small molecules that increase frataxin levels by docking on the frataxin ubiquitination site, thus preventing frataxin ubiquitination and degradation. We called these compounds ubiquitin-competing molecules (UCM). By extending our search for effective UCM, we identified a set of new and more potent compounds that more efficiently promote frataxin accumulation. Here we show that these compounds directly interact with frataxin and prevent its ubiquitination. Interestingly, these UCM are not effective on the ubiquitin-resistant frataxin mutant, indicating their specific action on preventing frataxin ubiquitination. Most importantly, these compounds are able to promote frataxin accumulation and aconitase rescue in cells derived from patients, strongly supporting their therapeutic potential.
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Aconitato Hidratase/metabolismo , Ataxia de Friedreich/tratamento farmacológico , Ataxia de Friedreich/metabolismo , Proteínas de Ligação ao Ferro/metabolismo , Fármacos Neuroprotetores/farmacologia , Sítios de Ligação , Linhagem Celular , Desenho de Fármacos , Fluorescência , Células HEK293 , Humanos , Immunoblotting , Proteínas de Ligação ao Ferro/química , Proteínas de Ligação ao Ferro/genética , Simulação de Acoplamento Molecular , Mutação , Fármacos Neuroprotetores/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Ubiquitinação/efeitos dos fármacos , FrataxinaRESUMO
Müller cell activation is an early finding in diabetic retinopathy (DR), but its physiopathologic role in the disease is still unclear, especially in the early phases. We investigated on Müller glial activation in primary rat retinal cultures, exposed to High Glucose (HG), and in retinas from streptozotocin (stz)-induced diabetic rats. First of all, we checked if the presence of Müller glia influenced HG neurotoxicity. In mixed glial/neuronal retinal cultures, a single HG administration (sHG) for 48 h induced activation of Müller glia, in absence of neuronal damage. In contrast, in pure neuronal cultures, a marked neurotoxic effect was detected, suggesting that in this cell model Müller glia protect neurons from HG neurotoxicity. To better mimic the diabetic milieu, where retinal cells are constantly bathed in hyperglycemic fluid, and to further characterize astrocytic neuroprotective ability, mixed retinal cultures were exposed to repeated daily replacement of HG (rHG). In this paradigm, starting from 48 h, increased apoptosis and synaptic loss were observed, even in the presence of Müller cells. Phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2), whose activation triggers a prosurvival pathway, was increased by sHG, while it was down-regulated by rHG, suggesting that ERK1/2 activation is involved in neuroprotection. Consistently, in presence of ERK1/2 inhibitor PD98059, sHG exerted a proapoptotic effect also in glial/neuronal retinal cultures. In line with the in vitro data, early changes in diabetic retinas from stz-injected rats included Müller cell activation and increased pERK1/2 levels, but no signs of neuronal damage. These results suggest that, in the early phases of DR, Müller glial activation does not contribute to neurodegeneration, but may indeed have a neuroprotective activity against HG-induced neurotoxicity through a mechanism involving pERK1/2.
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Diabetes Mellitus Experimental , Retinopatia Diabética/fisiopatologia , Células Ependimogliais/fisiologia , Sistema de Sinalização das MAP Quinases/fisiologia , Retina/efeitos dos fármacos , Animais , Apoptose/efeitos dos fármacos , Western Blotting , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Retinopatia Diabética/induzido quimicamente , Células Ependimogliais/efeitos dos fármacos , Glucose/toxicidade , Masculino , Ratos , Ratos Sprague-DawleyRESUMO
p21 is a well-established regulator of cell cycle progression. The role of p21 in DNA repair, however, remains poorly characterized. Here, we describe a critical role of p21 in a replication-coupled DNA double-strand break (DSB) repair that is mechanistically distinct from its cell cycle checkpoint function. We demonstrate that p21-deficient cells exhibit elevated chromatid-type aberrations, including gaps and breaks, dicentrics and radial formations, following exposure to several DSB-inducing agents. p21-/- cells also exhibit an increased DNA damage-inducible DNA-PKCS S2056 phosphorylation, indicative of elevated non-homologous DNA end joining. Concomitantly, p21-/- cells are defective in replication-coupled homologous recombination (HR), exhibiting decreased sister chromatid exchanges and HR-dependent repair as determined using a crosslinked GFP reporter assay. Importantly, we establish that the DSB hypersensitivity of p21-/- cells is associated with increased cyclin-dependent kinase (CDK)-dependent BRCA2 S3291 phosphorylation and MRE11 nuclear foci formation and can be rescued by inhibition of CDK or MRE11 nuclease activity. Collectively, our results uncover a novel mechanism by which p21 regulates the fidelity of replication-coupled DSB repair and the maintenance of chromosome stability distinct from its role in the G1-S phase checkpoint.
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Inibidor de Quinase Dependente de Ciclina p21/fisiologia , Quebras de DNA de Cadeia Dupla , Reparo do DNA , Replicação do DNA , Animais , Proteína BRCA2/metabolismo , Camptotecina/toxicidade , Instabilidade Cromossômica , Reagentes de Ligações Cruzadas/toxicidade , Inibidor de Quinase Dependente de Ciclina p21/genética , Reparo do DNA por Junção de Extremidades , Enzimas Reparadoras do DNA/metabolismo , Proteínas de Ligação a DNA/metabolismo , Etoposídeo/toxicidade , Pontos de Checagem da Fase G1 do Ciclo Celular , Células HCT116 , Células HeLa , Humanos , Proteína Homóloga a MRE11 , Camundongos , Mitomicina/toxicidade , Fosforilação , Reparo de DNA por Recombinação , Inibidores da Topoisomerase/toxicidadeRESUMO
Proteolysis-targeting chimeras (PROTACs) describe compounds that bind to and induce degradation of a target by simultaneously binding to a ubiquitin ligase. More generally referred to as bifunctional degraders, PROTACs have led the way in the field of targeted protein degradation (TPD), with several compounds currently undergoing clinical testing. Alongside bifunctional degraders, single-moiety compounds, or molecular glue degraders (MGDs), are increasingly being considered as a viable approach for development of therapeutics, driven by advances in rational discovery approaches. This review focuses on drug discovery with respect to bifunctional and molecular glue degraders within the ubiquitin proteasome system, including analysis of mechanistic concepts and discovery approaches, with an overview of current clinical and pre-clinical degrader status in oncology, neurodegenerative and inflammatory disease.
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Descoberta de Drogas , Oncologia , Citoplasma , Complexo de Endopeptidases do Proteassoma , Proteólise , UbiquitinaRESUMO
We have designed an integrated device that couples input and output coaxial horn antennas with a self-assembled helical slow-wave structure cradled in a v-groove on a silicon-on-insulator wafer. These devices will potentially enable the characterization of cold parameters and beam-wave interaction in slow-wave structures on a wafer level, i.e., without having to dice and package individual devices. In addition, such vertically integrated antennas and helical slow-wave structures may form the basis of compact and low-cost traveling-wave tube amplifiers operating at THz frequencies.
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Mobile health applications, which employ wireless technology for healthcare, can aid behaviour change and subsequently improve health outcomes. Mobile health applications have been developed to increase physical activity, but are rarely grounded on behavioural theory and employ simple techniques for personalisation, which has been proven effective in promoting behaviour change. In this work, we propose a theoretically driven and personalised behavioural intervention delivered through an adaptive knowledge-based system. The behavioural system design is guided by the Behavioural Change Wheel and the Capability-Opportunity-Motivation behavioural model. The system exploits the ever-increasing availability of health data from wearable devices, point-of-care tests and consumer genetic tests to issue highly personalised physical activity and sedentary behaviour recommendations. To provide the personalised recommendations, the system firstly classifies the user into one of four diabetes clusters based on their cardiometabolic profile. Secondly, it recommends activity levels based on their genotype and past activity history, and finally, it presents the user with their current risk of developing cardiovascular disease. In addition, leptin, a hormone involved in metabolism, is included as a feedback biosignal to personalise the recommendations further. As a case study, we designed and demonstrated the system on people with type 2 diabetes, since it is a chronic condition often managed through lifestyle changes, such as physical activity increase and sedentary behaviour reduction. We trained and simulated the system using data from diabetic participants of the UK Biobank, a large-scale clinical database, and demonstrate that the system could help increase activity over time. These results warrant a real-life implementation of the system, which we aim to evaluate through human intervention.
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INTRODUCTION: The weight of erectile dysfunction (ED) among the various determinants of psychological distress in men with spinal cord injury (SCI) remains to be clarified. AIM: The aim of this article was to evaluate psychological distress features in SCI men with or without ED. METHODS: Forty consecutive patients with neurologically stable SCI were included in the study. Functional independence (FI) was assessed by Barthel Index (BI), which was divided into global score (questions 1-10) and bowel/bladder subscore (questions 5 and 6). Erectile function was evaluated with Sexual Health Inventory for Men (SHIM). MAIN OUTCOME MEASURES: Psychological distress was assessed with the Symptom Checklist-90-revised (SCL-90-R), scoring nine primary dimensions and their combination as Global Severity Index, a global index of psychological distress. RESULTS: All SCL-90-R scores and the percentage of patients with scores >75th percentile of the entire study population were significantly higher in the group with ED (N=21) than without ED (N=19). Most of SCL-90-R subscales were inversely correlated with SHIM score. ED was exhibited by a high proportion (84%) of men with thoracolumbar lesions but by no patients with cervical lesions. Men with cervical lesions exhibited significantly lower SCL-90-R scores than those with thoracolumbar lesions, in spite of lower FI. However, the thoracolumbar group also reported a more severe bowel/bladder dysfunction. At multivariate logistic regression analysis, ED score significantly explained the variance of most of SCL-90-R dimension scores, whereas no association was revealed between global BI and any score of SCL-90-R dimensions. Bowel/bladder BI explained only to a very low extent the variance of depressive symptoms. CONCLUSIONS: Healthcare providers should be aware of the importance of managing ED in spinal cord-injured men, as it represents a major determinant of their psychological distress, independently of the degree of FI impairment.
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Disfunção Erétil/psicologia , Traumatismos da Medula Espinal/complicações , Estresse Psicológico/etiologia , Adulto , Humanos , Masculino , Pessoa de Meia-Idade , Traumatismos da Medula Espinal/psicologiaRESUMO
The negative effect of sedentary behaviour on type 2 diabetes markers is established, but the interaction with measures of physical activity is still largely unknown. Previous studies have analysed associations with single-activity models, which ignore the interaction with other behaviours. By including results from various analytical approaches, this review critically summarises the effects of sedentary behaviour on diabetes markers and the benefits of substitutions and compositions of physical activity. Ovid Medline, Embase and Cochrane Library databases were systematically searched. Studies were selected if sedentary behaviour and physical activity were measured by accelerometer in the general population, and if associations were reported with glucose, insulin, HOMA-IR, insulin sensitivity, HbA1c, diabetes incidence, CRP and IL-6. Forty-five studies were included in the review. Conclusive detrimental associations with sedentary behaviour were determined for 2-h insulin (6/12 studies found associations), fasting insulin (15/19 studies), insulin sensitivity (4/6 studies), diabetes (3/4 studies) and IL-6 (2/3 studies). Reallocating sedentary behaviour to light or moderate-to-vigorous activity has a beneficial effect for 2-h glucose (1/1 studies), fasting insulin (3/3 studies), HOMA-IR (1/1 studies) and insulin sensitivity (1/1 studies). Compositional measures of sedentary behaviour were found to affect 2-h glucose (1/1 studies), fasting insulin (2/3 studies), 2-h insulin (1/1 studies), HOMA-IR (2/2 studies) and CRP (1/1 studies). Different analytical methods produced conflicting results for fasting glucose, 2-h glucose, 2-h insulin, insulin sensitivity, HOMA-IR, diabetes, hbA1c, CRP and IL-6. Studies analysing data by quartiles report independent associations between sedentary behaviour and fasting insulin, HOMA-IR and diabetes only for high duration of sedentary time (7-9 hours/day). However, this review could not provide sufficient evidence for a time-specific cut-off of sedentary behaviour for diabetes biomarkers. While substituting sedentary behaviour with moderate-to-vigorous activity brings greater improvements for health, light activity also benefits metabolic health. Future research should elucidate the effects of substituting and combining different activity durations and modalities.
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Diabetes Mellitus Tipo 2 , Resistência à Insulina , Biomarcadores , Glicemia/metabolismo , Exercício Físico , Glucose/metabolismo , Hemoglobinas Glicadas , Humanos , Insulina/metabolismo , Interleucina-6 , Comportamento SedentárioRESUMO
This paper presents a fully automated point-of-care device for protein quantification using short-DNA aptamers, where no manual sample preparation is needed. The device is based on our novel aptamer-based methodology combined with real-time polymerase chain reaction (qPCR), which we employ for very sensitive protein quantification. DNA amplification through qPCR, sensing and real-time data processing are seamlessly integrated into a point-of-care device equipped with a disposable cartridge for automated sample preparation. The system's modular nature allows for easy assembly, adjustment and expansion towards a variety of biomarkers for applications in disease diagnostics and personalised medicine. Alongside the device description, we also present a new algorithm, which we named PeakFluo, to perform automated and real-time quantification of proteins. PeakFluo achieves better linearity than proprietary software from a commercially available qPCR machine, and it allows for early detection of the amplification signal. Additionally, we propose an alternative way to use the proposed device beyond the quantitative reading, which can provide clinically relevant advice. We demonstrate how a convolutional neural network algorithm trained on qPCR images can classify samples into high/low concentration classes. This method can help classify obese patients from their leptin values to optimise weight loss therapies in clinical settings.
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Aptâmeros de Nucleotídeos , Sistemas Automatizados de Assistência Junto ao Leito , Humanos , Técnicas de Amplificação de Ácido Nucleico/métodos , Reação em Cadeia da Polimerase em Tempo Real/métodos , SoftwareRESUMO
Convergent evidence associates exposure to endocrine disrupting chemicals (EDCs) with major human diseases, even at regulation-compliant concentrations. This might be because humans are exposed to EDC mixtures, whereas chemical regulation is based on a risk assessment of individual compounds. Here, we developed a mixture-centered risk assessment strategy that integrates epidemiological and experimental evidence. We identified that exposure to an EDC mixture in early pregnancy is associated with language delay in offspring. At human-relevant concentrations, this mixture disrupted hormone-regulated and disease-relevant regulatory networks in human brain organoids and in the model organisms Xenopus leavis and Danio rerio, as well as behavioral responses. Reinterrogating epidemiological data, we found that up to 54% of the children had prenatal exposures above experimentally derived levels of concern, reaching, for the upper decile compared with the lowest decile of exposure, a 3.3 times higher risk of language delay.
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Disruptores Endócrinos/toxicidade , Transtornos do Desenvolvimento da Linguagem/epidemiologia , Transtornos do Neurodesenvolvimento/epidemiologia , Efeitos Tardios da Exposição Pré-Natal , Transcriptoma/efeitos dos fármacos , Animais , Transtorno do Espectro Autista/epidemiologia , Transtorno do Espectro Autista/genética , Encéfalo/efeitos dos fármacos , Encéfalo/embriologia , Pré-Escolar , Estrogênios/metabolismo , Feminino , Fluorocarbonos/análise , Fluorocarbonos/toxicidade , Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Ontologia Genética , Humanos , Locomoção/efeitos dos fármacos , Células-Tronco Neurais/efeitos dos fármacos , Transtornos do Neurodesenvolvimento/genética , Organoides , Fenóis/análise , Fenóis/toxicidade , Ácidos Ftálicos/análise , Ácidos Ftálicos/toxicidade , Gravidez , Medição de Risco , Hormônios Tireóideos/metabolismo , Xenopus laevis , Peixe-ZebraRESUMO
Testicular germ cell tumors (TGCTs) are typically exquisitely sensitive to DNA interstrand cross-link (ICLs) agents. ICLs covalently link both strands of the DNA duplex, impeding fundamental cellular processes like DNA replication to cause cell death. A leading drug used for the treatment of TGCTs is cisplatin, which introduces ICLs and leads to formation of double strand breaks (DSBs), a DNA lesion that can be repaired in the S/G2 phases of the cell cycle by homologous recombination (HR, also termed homology-direct repair). Although most TGCTs respond to cisplatin-induced ICLs, a fraction is resistant to treatment. One proposed mechanism of TGCT resistance to cisplatin is an enhanced ability to repair DSBs by HR. Other than HR, repair of the ICL-lesions requires additional DNA repair mechanisms, whose action might also be implemented in therapy-resistant cells. This chapter describes GFP assays to measure (a) HR proficiency following formation of a DSB by the endonuclease I-SceI, and (b) HR repair induced by site-specific ICL formation involving psoralen. These experimental approaches can be used to determine the proficiency of TGCT cell lines in DSB repair by HR in comparison to HR repair of ICLs, providing tools to better characterize their recombination profile. Protocols of these assays have been adapted for use in Embryonal Carcinoma (EC) TGCT cell lines. Assays only require transient introduction of plasmids within cells, affording the advantage of testing multiple cell lines in a relatively short time.
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Testes Genéticos , Recombinação Homóloga , Neoplasias Embrionárias de Células Germinativas/genética , Reparo de DNA por Recombinação , Neoplasias Testiculares/genética , Técnicas de Cultura de Células , Linhagem Celular Tumoral , Dano ao DNA , Replicação do DNA , Ficusina , Expressão Gênica , Genes Reporter , Testes Genéticos/métodos , Humanos , Masculino , Neoplasias Embrionárias de Células Germinativas/diagnóstico , Neoplasias Testiculares/diagnósticoRESUMO
Depression is the most prevalent psychological issue after a spinal cord injury (SCI) and is associated with noticeable disability, mortality and health expenditure. As SCI mainly occurs in sexually active men at a young age, and can lead to them suffering from an organic neurogenic erectile dysfunction (ED), we supposed that ED could be a major correlate of depressive status in men with SCI. As documented by a Beck Depression Inventory-II (BDI-II) score ≥14, depression was reported in 17 out of 57 men with a chronic SCI (29.8%). They exhibited a significantly higher prevalence of ED and a more severe bowel and bladder dysfunction when compared to the group without depression. At the multiple logistic regression analysis, depression showed a significant independent association with ED (OR = 19.0, 95% CI: 3.1, 203.3; p = 0.004) and, to a lesser extent, with a severe impairment of bowel and bladder function (OR = 0.84; 95% CI: 0.72, 0.94; p = 0.01). Depression was observed in 43.7% of men with ED and only in 12.0% of those without ED (p = 0.002). In conclusion, healthcare providers should give the right level of importance to the management of ED in men with SCI, as this represents a major independent correlate of depression, which, in turn, might hinder physical rehabilitation and exacerbate physical health issues related to SCI.
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Protein quantification is traditionally performed through enzyme-linked immunosorbent assay (ELISA), which involves long preparation times. To overcome this, new approaches use aptamers as an alternative to antibodies. In this paper, we present a new approach to quantify proteins with short DNA aptamers through polymerase chain reaction (PCR) resulting in shorter protocol times with comparatively improved limits of detection. The proposed method includes a novel way to quantify both the target protein and the corresponding short DNA-aptamers simultaneously, which also allows us to fully characterize the performance of aptasensors. Human leptin is used as a target protein to validate this technique, because it is considered an important biomarker for obesity-related studies. In our experiments, we achieved the lowest limit of detection of 100 pg/mL within less than 2 h, a limit affected by the dissociation constant of the leptin aptamer, which could be improved by selecting a more specific aptamer. Because of the simple and inexpensive approach, this technique can be employed for Lab-On-Chip implementations and for rapid "on-site" quantification of proteins.
Assuntos
Aptâmeros de Nucleotídeos , DNA/genética , Ensaio de Imunoadsorção Enzimática , Humanos , Leptina/genética , Reação em Cadeia da PolimeraseRESUMO
Despite germ cell tumors (GCTs) responding to cisplatin-based chemotherapy at a high rate, a subset of patients does not respond to treatment and have significantly worse prognosis. The biological mechanisms underlying the resistance remain unknown. In this study, by using two TGCT cell lines that have acquired cisplatin resistance after chronic exposure to the drug, we identified some key proteins and mechanisms of acquired resistance. We show that cisplatin-resistant cell lines had a non-homologous end-joining (NHEJ)-less phenotype. This correlated with a reduced basal expression of TP53-binding protein 1 (53BP1) and DNA-dependent protein kinase (DNA-PKcs) proteins and reduced formation of 53BP1 foci after cisplatin treatment. Consistent with these observations, modulation of 53BP1 protein expression altered the cell line's resistance to cisplatin, and inhibition of DNA-PKcs activity antagonized cisplatin cytotoxicity. Dampening of NHEJ was accompanied by a functional increase in the repair of DNA double-strand breaks (DSBs) by the homologous recombination repair pathway. As a result, cisplatin-resistant cells were more resistant to PARP inhibitor (PARPi) monotherapy. Moreover, when PARPi was given in combination with cisplatin, it exerted an additive/synergistic effect, and reduced the cisplatin dose for cytotoxicity. These results suggest that treatment of cisplatin-refractory patients may benefit from low-dose cisplatin therapy combined with PARPi.