Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 88
Filtrar
Mais filtros

Tipo de documento
Intervalo de ano de publicação
1.
Cell ; 178(3): 653-671.e19, 2019 07 25.
Artigo em Inglês | MEDLINE | ID: mdl-31348890

RESUMO

Nociceptin and its receptor are widely distributed throughout the brain in regions associated with reward behavior, yet how and when they act is unknown. Here, we dissected the role of a nociceptin peptide circuit in reward seeking. We generated a prepronociceptin (Pnoc)-Cre mouse line that revealed a unique subpopulation of paranigral ventral tegmental area (pnVTA) neurons enriched in prepronociceptin. Fiber photometry recordings during progressive ratio operant behavior revealed pnVTAPnoc neurons become most active when mice stop seeking natural rewards. Selective pnVTAPnoc neuron ablation, inhibition, and conditional VTA nociceptin receptor (NOPR) deletion increased operant responding, revealing that the pnVTAPnoc nucleus and VTA NOPR signaling are necessary for regulating reward motivation. Additionally, optogenetic and chemogenetic activation of this pnVTAPnoc nucleus caused avoidance and decreased motivation for rewards. These findings provide insight into neuromodulatory circuits that regulate motivated behaviors through identification of a previously unknown neuropeptide-containing pnVTA nucleus that limits motivation for rewards.


Assuntos
Motivação/efeitos dos fármacos , Peptídeos Opioides/farmacologia , Recompensa , Área Tegmentar Ventral/metabolismo , Potenciais de Ação , Animais , Comportamento Animal/efeitos dos fármacos , Feminino , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Neurônios/fisiologia , Técnicas de Patch-Clamp , Precursores de Proteínas/genética , Receptores Opioides/agonistas , Receptores Opioides/deficiência , Receptores Opioides/genética , Receptor de Nociceptina , Nociceptina
2.
Nature ; 615(7953): 712-719, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36922590

RESUMO

Mitochondria are critical to the governance of metabolism and bioenergetics in cancer cells1. The mitochondria form highly organized networks, in which their outer and inner membrane structures define their bioenergetic capacity2,3. However, in vivo studies delineating the relationship between the structural organization of mitochondrial networks and their bioenergetic activity have been limited. Here we present an in vivo structural and functional analysis of mitochondrial networks and bioenergetic phenotypes in non-small cell lung cancer (NSCLC) using an integrated platform consisting of positron emission tomography imaging, respirometry and three-dimensional scanning block-face electron microscopy. The diverse bioenergetic phenotypes and metabolic dependencies we identified in NSCLC tumours align with distinct structural organization of mitochondrial networks present. Further, we discovered that mitochondrial networks are organized into distinct compartments within tumour cells. In tumours with high rates of oxidative phosphorylation (OXPHOSHI) and fatty acid oxidation, we identified peri-droplet mitochondrial networks wherein mitochondria contact and surround lipid droplets. By contrast, we discovered that in tumours with low rates of OXPHOS (OXPHOSLO), high glucose flux regulated perinuclear localization of mitochondria, structural remodelling of cristae and mitochondrial respiratory capacity. Our findings suggest that in NSCLC, mitochondrial networks are compartmentalized into distinct subpopulations that govern the bioenergetic capacity of tumours.


Assuntos
Carcinoma Pulmonar de Células não Pequenas , Metabolismo Energético , Neoplasias Pulmonares , Mitocôndrias , Humanos , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Carcinoma Pulmonar de Células não Pequenas/patologia , Carcinoma Pulmonar de Células não Pequenas/ultraestrutura , Ácidos Graxos/metabolismo , Glucose/metabolismo , Gotículas Lipídicas/metabolismo , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patologia , Neoplasias Pulmonares/ultraestrutura , Microscopia Eletrônica , Mitocôndrias/metabolismo , Mitocôndrias/ultraestrutura , Fosforilação Oxidativa , Fenótipo , Tomografia por Emissão de Pósitrons
4.
Nature ; 575(7782): 380-384, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31666695

RESUMO

Mitochondria are essential regulators of cellular energy and metabolism, and have a crucial role in sustaining the growth and survival of cancer cells. A central function of mitochondria is the synthesis of ATP by oxidative phosphorylation, known as mitochondrial bioenergetics. Mitochondria maintain oxidative phosphorylation by creating a membrane potential gradient that is generated by the electron transport chain to drive the synthesis of ATP1. Mitochondria are essential for tumour initiation and maintaining tumour cell growth in cell culture and xenografts2,3. However, our understanding of oxidative mitochondrial metabolism in cancer is limited because most studies have been performed in vitro in cell culture models. This highlights a need for in vivo studies to better understand how oxidative metabolism supports tumour growth. Here we measure mitochondrial membrane potential in non-small-cell lung cancer in vivo using a voltage-sensitive, positron emission tomography (PET) radiotracer known as 4-[18F]fluorobenzyl-triphenylphosphonium (18F-BnTP)4. By using PET imaging of 18F-BnTP, we profile mitochondrial membrane potential in autochthonous mouse models of lung cancer, and find distinct functional mitochondrial heterogeneity within subtypes of lung tumours. The use of 18F-BnTP PET imaging enabled us to functionally profile mitochondrial membrane potential in live tumours.


Assuntos
Carcinoma Pulmonar de Células não Pequenas/fisiopatologia , Neoplasias Pulmonares/fisiopatologia , Potencial da Membrana Mitocondrial , Células A549 , Animais , Carcinoma Pulmonar de Células não Pequenas/diagnóstico por imagem , Humanos , Neoplasias Pulmonares/diagnóstico por imagem , Camundongos , Camundongos Transgênicos , Compostos Organofosforados , Tomografia por Emissão de Pósitrons
5.
World J Urol ; 42(1): 322, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38747982

RESUMO

PURPOSE: Utility of prostate-specific antigen density (PSAd) for risk-stratification to avoid unnecessary biopsy remains unclear due to the lack of standardization of prostate volume estimation. We evaluated the impact of ellipsoidal formula using multiparametric magnetic resonance (MRI) and semi-automated segmentation using tridimensional ultrasound (3D-US) on prostate volume and PSAd estimations as well as the distribution of patients in a risk-adapted table of clinically significant prostate cancer (csPCa). METHODS: In a prospectively maintained database of 4841 patients who underwent MRI-targeted and systematic biopsies, 971 met inclusions criteria. Correlation of volume estimation was assessed by Kendall's correlation coefficient and graphically represented by scatter and Bland-Altman plots. Distribution of csPCa was presented using the Schoots risk-adapted table based on PSAd and PI-RADS score. The model was evaluated using discrimination, calibration plots and decision curve analysis (DCA). RESULTS: Median prostate volume estimation using 3D-US was higher compared to MRI (49cc[IQR 37-68] vs 47cc[IQR 35-66], p < 0.001). Significant correlation between imaging modalities was observed (τ = 0.73[CI 0.7-0.75], p < 0.001). Bland-Altman plot emphasizes the differences in prostate volume estimation. Using the Schoots risk-adapted table, a high risk of csPCa was observed in PI-RADS 2 combined with high PSAd, and in all PI-RADS 4-5. The risk of csPCa was proportional to the PSAd for PI-RADS 3 patients. Good accuracy (AUC of 0.69 and 0.68 using 3D-US and MRI, respectively), adequate calibration and a higher net benefit when using 3D-US for probability thresholds above 25% on DCA. CONCLUSIONS: Prostate volume estimation with semi-automated segmentation using 3D-US should be preferred to the ellipsoidal formula (MRI) when evaluating PSAd and the risk of csPCa.


Assuntos
Antígeno Prostático Específico , Próstata , Neoplasias da Próstata , Humanos , Masculino , Neoplasias da Próstata/patologia , Neoplasias da Próstata/diagnóstico por imagem , Antígeno Prostático Específico/sangue , Idoso , Pessoa de Meia-Idade , Tamanho do Órgão , Próstata/patologia , Próstata/diagnóstico por imagem , Medição de Risco , Biópsia Guiada por Imagem/métodos , Imageamento por Ressonância Magnética/métodos , Tomada de Decisão Clínica , Imageamento por Ressonância Magnética Multiparamétrica , Estudos Prospectivos
6.
World J Urol ; 42(1): 372, 2024 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-38866949

RESUMO

PURPOSE: Magnetic resonance imaging (MRI) is a promising tool for risk assessment, potentially reducing the burden of unnecessary prostate biopsies. Risk prediction models that incorporate MRI data have gained attention, but their external validation and comparison are essential for guiding clinical practice. The aim is to externally validate and compare risk prediction models for the diagnosis of clinically significant prostate cancer (csPCa). METHODS: A cohort of 4606 patients across fifteen European tertiary referral centers were identified from a prospective maintained database between January 2016 and April 2023. Transrectal or transperineal image-fusion MRI-targeted and systematic biopsies for PI-RADS score of ≥ 3 or ≥ 2 depending on patient characteristics and physician preferences. Probabilities for csPCa, defined as International Society of Urological Pathology (ISUP) grade ≥ 2, were calculated for each patients using eight models. Performance was characterized by area under the receiver operating characteristic curve (AUC), calibration, and net benefit. Subgroup analyses were performed across various clinically relevant subgroups. RESULTS: Overall, csPCa was detected in 2154 (47%) patients. The models exhibited satisfactory performance, demonstrating good discrimination (AUC ranging from 0.75 to 0.78, p < 0.001), adequate calibration, and high net benefit. The model described by Alberts showed the highest clinical utility for threshold probabilities between 10 and 20%. Subgroup analyses highlighted variations in models' performance, particularly when stratified according to PSA level, biopsy technique and PI-RADS version. CONCLUSIONS: We report a comprehensive external validation of risk prediction models for csPCa diagnosis in patients who underwent MRI-targeted and systematic biopsies. The model by Alberts demonstrated superior clinical utility and should be favored when determining the need for a prostate biopsy.


Assuntos
Imageamento por Ressonância Magnética , Próstata , Neoplasias da Próstata , Humanos , Masculino , Neoplasias da Próstata/patologia , Neoplasias da Próstata/diagnóstico por imagem , Medição de Risco/métodos , Idoso , Imageamento por Ressonância Magnética/métodos , Pessoa de Meia-Idade , Próstata/patologia , Próstata/diagnóstico por imagem , Biópsia Guiada por Imagem/métodos , Valor Preditivo dos Testes
7.
Tob Control ; 2023 Aug 11.
Artigo em Inglês | MEDLINE | ID: mdl-37567601

RESUMO

INTRODUCTION: Tobacco is one of the world's largest preventable causes of premature death, accounting for more than 8 million deaths and costing the global economy US$1.4 trillion each year. Smoking is a global problem with 1.3 billion people using tobacco worldwide, who will face harmful effects on health and on people's current and future financial situations and quality of life.This article aims to be the first study to generate evidence on the effects of smoking on household expenditure and the number of people living under the poverty threshold by studying the crowding out and impoverishing effect in Mexico. METHODS: Through econometric methods and maximising a household utility function we estimate the crowding out and impoverishing effect of tobacco consumption in México based on household's income and spending survey from 2020. RESULTS: Spending on tobacco crowds out household spending on other goods and services. In Mexico, spending on tobacco results in decreased spending on essential goods and services, like education and healthcare, and increased spending on harmful goods such as alcoholic beverages. These effects are common across all income levels but are more pronounced in low-income households. When spending on tobacco increases, for example, following regular price increases made by the tobacco industry, the crowding out effect is exacerbated.In addition, smoking has an impoverishing effect on the population. This is because some families find that their remaining income level falls below the poverty line after deducting money spent on tobacco (a concept known as secondary poverty). In Mexico, 909 132 people are left with a disposable income level below the extreme poverty line because of expenditure on tobacco and smoking-related diseases. CONCLUSIONS: Smoking affects individual health and the finances of households in Mexico, particularly those of low-income people. By increasing tobacco taxes, those who quit smoking increase their quality of life and well-being. However, those who continue to smoke and increase their tobacco spending are affected by a shift in their spending on other goods and services.The increase in tobacco taxes must be accompanied by public policies that help reduce tobacco consumption and compensate the crowding out on goods and services relevant to the development of households.

8.
Int J Mol Sci ; 24(19)2023 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-37834216

RESUMO

Only a small number of infected people are highly susceptible to schistosomiasis, showing high levels of infection or severe liver fibrosis. The susceptibility to schistosome infection is influenced by genetic background. To assess the genetic basis of susceptibility and identify the chromosomal regions involved, a backcross strategy was employed to generate high variation in schistosomiasis susceptibility. This strategy involved crossing the resistant C57BL/6J mouse strain with the susceptible CBA/2J strain. The resulting F1 females (C57BL/6J × CBA/2J) were then backcrossed with CBA/2J males to generate the backcross (BX) cohort. The BX mice exhibited a range of phenotypes, with disease severity varying from mild to severe disease, lacking a fully resistant group. We observed four levels of infection intensity using cluster and principal component analyses and K-means based on parasitological, pathological, and immunological trait measurements. The mice were genotyped with 961 informative SNPs, leading to the identification of 19 new quantitative trait loci (QTL) associated with parasite burden, liver lesions, white blood cell populations, and antibody responses. Two QTLs located on chromosomes 15 and 18 were linked to the number of granulomas, liver lesions, and IgM levels. The corresponding syntenic human regions are located in chromosomes 8 and 18. None of the significant QTLs had been reported previously.


Assuntos
Neoplasias Hepáticas , Esquistossomose mansoni , Esquistossomose , Humanos , Masculino , Feminino , Camundongos , Animais , Esquistossomose mansoni/genética , Camundongos Endogâmicos C57BL , Modelos Genéticos , Schistosoma mansoni/genética , Camundongos Endogâmicos CBA , Suscetibilidade a Doenças , Genômica
9.
Eur J Neurol ; 29(7): 2015-2023, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35247022

RESUMO

BACKGROUND AND PURPOSE: The aim was to evaluate whether adaptive NKG2C+ natural killer (NK) cells, characterized by enhanced antibody-dependent cell cytotoxicity (ADCC), may influence time to B cell repopulation after rituximab treatment in multiple sclerosis (MS) patients. METHODS: This was a prospective observational study of MS patients treated with rituximab monitoring peripheral B cells for repeated doses. B cell repopulation was defined as CD19+ cells above 2% of total lymphocytes, classifying cases according to the median time of B cell repopulation as early or late (≤9 months, >9 months, respectively). Basal NK cell immunophenotype and in vitro ADCC responses induced by rituximab were assessed by flow cytometry. RESULTS: B cell repopulation in 38 patients (24 relapsing-remitting MS [RRMS]; 14 progressive MS) was classified as early (≤9 months, n = 19) or late (>9 months, n = 19). RRMS patients with late B cell repopulation had higher proportions of NKG2C+ NK cells compared to those with early repopulation (24.7% ± 16.2% vs. 11.3% ± 10.4%, p < 0.05), and a direct correlation between time to B cell repopulation and percentage of NKG2C+ NK cells (R 0.45, p < 0.05) was observed. RRMS cases with late repopulation compared with early repopulation had a higher secretion of tumor necrosis factor α and interferon γ by NK cells after rituximab-dependent NK cell activation. The NK cell immunophenotype appeared unrelated to B cell repopulation in progressive MS patients. CONCLUSIONS: Adaptive NKG2C+ NK cells in RRMS may be associated with delayed B cell repopulation after rituximab, a finding probably related to enhanced depletion of B cells exerted by NK-cell-mediated ADCC, pointing to the use of personalized regimens with anti-CD20 monoclonal antibody therapy in some patients.


Assuntos
Esclerose Múltipla , Anticorpos Monoclonais/farmacologia , Citotoxicidade Celular Dependente de Anticorpos , Humanos , Células Matadoras Naturais , Esclerose Múltipla/tratamento farmacológico , Rituximab/farmacologia , Rituximab/uso terapêutico
10.
Int J Mol Sci ; 23(20)2022 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-36292921

RESUMO

Metabolic changes that facilitate tumor growth are one of the hallmarks of cancer. These changes are not specific to tumors but also take place during the physiological growth of tissues. Indeed, the cellular and tissue mechanisms present in the tumor have their physiological counterpart in the repair of tissue lesions and wound healing. These molecular mechanisms have been acquired during metazoan evolution, first to eliminate the infection of the tissue injury, then to enter an effective regenerative phase. Cancer itself could be considered a phenomenon of antagonistic pleiotropy of the genes involved in effective tissue repair. Cancer and tissue repair are complex traits that share many intermediate phenotypes at the molecular, cellular, and tissue levels, and all of these are integrated within a Systems Biology structure. Complex traits are influenced by a multitude of common genes, each with a weak effect. This polygenic component of complex traits is mainly unknown and so makes up part of the missing heritability. Here, we try to integrate these different perspectives from the point of view of the metabolic changes observed in cancer.


Assuntos
Neoplasias , Animais , Neoplasias/genética , Fenótipo , Biologia de Sistemas
11.
Rev Esp Enferm Dig ; 113(1): 45-47, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33054282

RESUMO

We present the case of a 76-year-old male with a history of acute cholecystitis who underwent a scheduled laparoscopic cholecystectomy. Chronic cholecystitis with a thickened cystic duct was observed intraoperatively. The anatomic pathology report found high-grade dysplasia that affected the distal edge of the cystic duct. In view of these findings, an endoscopic retrograde cholangiopancreatography (ERCP) was performed with SpyGlass® and an excrescent lesion suggestive of malignancy adjacent to the cystic-common bile duct junction was observed. A resection of the extrahepatic bile duct was performed with lymphadenectomy of the hepatic hilum and hepaticojejunostomy in a subsequent procedure. The definitive pathology report confirmed pancreaticobiliary intraductal papillary mucinous neoplasia with high-grade dysplasia and free margins.


Assuntos
Neoplasias dos Ductos Biliares , Ductos Biliares Extra-Hepáticos , Neoplasias Pancreáticas , Idoso , Neoplasias dos Ductos Biliares/cirurgia , Colangiopancreatografia Retrógrada Endoscópica , Hepatectomia , Humanos , Masculino , Neoplasias Pancreáticas/diagnóstico por imagem , Neoplasias Pancreáticas/cirurgia
12.
Med Oral Patol Oral Cir Bucal ; 26(3): e361-e367, 2021 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-33037795

RESUMO

BACKGROUND: Primary stability is an important key determinant of implant osseointegration. We investigated approaches to improve primary implant stability using a new drilling technique termed osseodensification (OD), which was compared with the conventional under-drilling (UD) method utilized for low-density bones. MATERIAL AND METHODS: We placed 55 conical internal connection implants in each group, in 30 low-density sections of pig tibia. The implants were placed using twist drill bits in both groups; groups Under Drilling (UD) and Osseodensification (OD) included bone sections subjected to conventional UD and OD drilling, respectively. Before placing the implants, we randomized the bone sections that were to receive these implants to avoid sample bias. We evaluated various primary stability parameters, such as implant insertion torque and resonance frequency analysis (RFA) measurements. RESULTS: The results showed that compared with implants placed using the UD technique, those placed using the OD technique were associated with significantly higher primary stability. The mean insertion torque of the implants was 8.87±6.17 Ncm in group 1 (UD) and 21.72±17.14 Ncm in group 2 (OD). The mean RFA was 65.16±7.45 ISQ in group 1 (UD) and 69.75±6.79 ISQ in group 2 (OD). CONCLUSIONS: The implant insertion torque and RFA values were significantly higher in OD group than in UD. Therefore, compared with UD, OD improves primary stability in low-density bones (based on torque and RFA measurements).


Assuntos
Implantes Dentários , Animais , Densidade Óssea , Implantação Dentária Endóssea , Retenção em Prótese Dentária , Osseointegração , Análise de Frequência de Ressonância , Suínos , Torque
13.
Nature ; 505(7481): 117-20, 2014 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-24284625

RESUMO

N(6)-methyladenosine (m(6)A) is the most prevalent internal (non-cap) modification present in the messenger RNA of all higher eukaryotes. Although essential to cell viability and development, the exact role of m(6)A modification remains to be determined. The recent discovery of two m(6)A demethylases in mammalian cells highlighted the importance of m(6)A in basic biological functions and disease. Here we show that m(6)A is selectively recognized by the human YTH domain family 2 (YTHDF2) 'reader' protein to regulate mRNA degradation. We identified over 3,000 cellular RNA targets of YTHDF2, most of which are mRNAs, but which also include non-coding RNAs, with a conserved core motif of G(m(6)A)C. We further establish the role of YTHDF2 in RNA metabolism, showing that binding of YTHDF2 results in the localization of bound mRNA from the translatable pool to mRNA decay sites, such as processing bodies. The carboxy-terminal domain of YTHDF2 selectively binds to m(6)A-containing mRNA, whereas the amino-terminal domain is responsible for the localization of the YTHDF2-mRNA complex to cellular RNA decay sites. Our results indicate that the dynamic m(6)A modification is recognized by selectively binding proteins to affect the translation status and lifetime of mRNA.


Assuntos
Adenosina/análogos & derivados , Estabilidade de RNA , RNA Mensageiro/química , RNA Mensageiro/metabolismo , Proteínas de Ligação a RNA/metabolismo , Adenosina/metabolismo , Adenosina/farmacologia , Sequência de Bases , Proteínas de Ligação a DNA/genética , Células HeLa , Humanos , Antígenos de Histocompatibilidade Menor , Motivos de Nucleotídeos , Organelas/genética , Organelas/metabolismo , Ligação Proteica , Biossíntese de Proteínas , Estabilidade de RNA/efeitos dos fármacos , Transporte de RNA , RNA não Traduzido/química , RNA não Traduzido/metabolismo , Proteínas de Ligação a RNA/química , Proteínas de Ligação a RNA/classificação , Especificidade por Substrato
14.
J Chem Phys ; 152(12): 124119, 2020 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-32241132

RESUMO

Over the last few years, extraordinary advances in experimental and theoretical tools have allowed us to monitor and control matter at short time and atomic scales with a high degree of precision. An appealing and challenging route toward engineering materials with tailored properties is to find ways to design or selectively manipulate materials, especially at the quantum level. To this end, having a state-of-the-art ab initio computer simulation tool that enables a reliable and accurate simulation of light-induced changes in the physical and chemical properties of complex systems is of utmost importance. The first principles real-space-based Octopus project was born with that idea in mind, i.e., to provide a unique framework that allows us to describe non-equilibrium phenomena in molecular complexes, low dimensional materials, and extended systems by accounting for electronic, ionic, and photon quantum mechanical effects within a generalized time-dependent density functional theory. This article aims to present the new features that have been implemented over the last few years, including technical developments related to performance and massive parallelism. We also describe the major theoretical developments to address ultrafast light-driven processes, such as the new theoretical framework of quantum electrodynamics density-functional formalism for the description of novel light-matter hybrid states. Those advances, and others being released soon as part of the Octopus package, will allow the scientific community to simulate and characterize spatial and time-resolved spectroscopies, ultrafast phenomena in molecules and materials, and new emergent states of matter (quantum electrodynamical-materials).

15.
Rev Esp Enferm Dig ; 112(10): 814-815, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32954783

RESUMO

Liver failure (LF) is a severe entity, which represents a diagnostic challenge for clinicians. Knowing the etiology of liver aggression is key for its management. We present a rare case of cholestatic LF secondary to primary AL (kappa-light chain) amyloidosis as a presentation associated to multiple myeloma.


Assuntos
Amiloidose , Falência Hepática , Mieloma Múltiplo , Amiloidose/complicações , Humanos , Falência Hepática/etiologia , Mieloma Múltiplo/complicações
17.
Bioessays ; 38(7): 664-73, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-27241833

RESUMO

Diseases of complex origin have a component of quantitative genetics that contributes to their susceptibility and phenotypic variability. However, after several studies, a major part of the genetic component of complex phenotypes has still not been found, a situation known as "missing heritability." Although there have been many hypotheses put forward to explain the reasons for the missing heritability, its definitive causes remain unknown. Complex diseases are caused by multiple intermediate phenotypes involved in their pathogenesis and, very often, each one of these intermediate phenotypes also has a component of quantitative inheritance. Here we propose that at least part of the missing heritability can be explained by the genetic component of intermediate phenotypes that is not detectable at the level of the main complex trait. At the same time, the identification of the genetic component of intermediate phenotypes provides an opportunity to identify part of the missing heritability of complex diseases.


Assuntos
Doenças Genéticas Inatas/genética , Variação Genética , Genética Médica , Modelos Genéticos , Fenótipo , Animais , Doenças Genéticas Inatas/etiologia , Doenças Genéticas Inatas/patologia , Predisposição Genética para Doença , Humanos
18.
J Electrochem Soc ; 164(9): G99-G103, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28890550

RESUMO

Electrochemical fluorination of methyl(phenylthio)acetate was achieved using tetrabutylammonium fluoride (TBAF). Electrochemical fluorination was performed under potentiostatic anodic oxidation using an undivided cell in acetonitrile containing TBAF and triflic acid. The influence of several parameters including: oxidation potential, time, temperature, sonication, TBAF concentration and triflic acid concentration on fluorination efficiency were studied. It was found that the triflic acid to TBAF concentration ratio plays a key role in the fluorination efficiency. Electrochemical fluorination resulted in formation of mono-fluorinated methyl 2-fluoro-2-(phenylthio)acetate verified by gas chromatography-mass spectrometry (GC-MS) and nuclear magnetic resonance (NMR) Spectroscopy. Under optimum conditions 44 ± 3% mono fluorination yield was obtained after a 30 min electrolysis. Electrochemical radiofluorination for the synthesis of methyl 2-[18F]fluoro-2-(phenothio) acetate was also achieved with the same optimized electrochemical cell parameters where TBAF was first passed through an anion exchange resin containing fluorine-18. A radiochemical fluorination efficiency of 7 ± 1% was achieved after 30 min of electrolysis.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA