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1.
Proc Natl Acad Sci U S A ; 113(13): 3557-62, 2016 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-26979952

RESUMO

Many experiments have shown that local biodiversity loss impairs the ability of ecosystems to maintain multiple ecosystem functions at high levels (multifunctionality). In contrast, the role of biodiversity in driving ecosystem multifunctionality at landscape scales remains unresolved. We used a comprehensive pan-European dataset, including 16 ecosystem functions measured in 209 forest plots across six European countries, and performed simulations to investigate how local plot-scale richness of tree species (α-diversity) and their turnover between plots (ß-diversity) are related to landscape-scale multifunctionality. After accounting for variation in environmental conditions, we found that relationships between α-diversity and landscape-scale multifunctionality varied from positive to negative depending on the multifunctionality metric used. In contrast, when significant, relationships between ß-diversity and landscape-scale multifunctionality were always positive, because a high spatial turnover in species composition was closely related to a high spatial turnover in functions that were supported at high levels. Our findings have major implications for forest management and indicate that biotic homogenization can have previously unrecognized and negative consequences for large-scale ecosystem multifunctionality.


Assuntos
Biodiversidade , Florestas , Simulação por Computador , Bases de Dados Factuais , Ecossistema , Europa (Continente) , Agricultura Florestal , Modelos Biológicos , Árvores
2.
Angiogenesis ; 21(3): 533-543, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29502220

RESUMO

Vascular endothelial growth factors (VEGFs) regulate blood and lymph vessel development upon activation of three receptor tyrosine kinases (VEGFRs). The extracellular domain of VEGFRs consists of seven Ig-homology domains, of which D2-3 form the ligand-binding site, while the membrane proximal domains D4-7 are involved in homotypic interactions in ligand-bound receptor dimers. Based on low-resolution structures, we identified allosteric sites in D4-5 and D7 of vascular endothelial growth factor receptor 2 (VEGFR-2) accomplishing regulatory functions. Allosteric inhibition of VEGFR-2 signaling represents an attractive option for the treatment of neovascular diseases. We showed earlier that DARPin® binders to domains D4 or D7 are potent VEGFR-2 inhibitors. Here we investigated in detail the allosteric inhibition mechanism of the domain D4 binding inhibitor D4b. The 2.38 Å crystal structure of D4b in complex with VEGFR-2 D4-5, the first high-resolution structure of this VEGFR-2 segment, indicates steric hindrance by D4b as the mechanism of inhibition of receptor activation. At the cellular level, D4b triggered quantitative internalization of VEGFR-2 in the absence of ligand and thus clearance of VEGFR-2 from the surface of endothelial cells. The allosteric VEGFR-2 inhibition was sufficiently strong to efficiently inhibit the growth of human endothelial cells at suboptimal dose in a mouse xenograft model in vivo, underlining the therapeutic potential of the approach.


Assuntos
Inibidores da Angiogênese , Sistemas de Liberação de Medicamentos , Células Endoteliais da Veia Umbilical Humana , Neovascularização Patológica , Transdução de Sinais , Fator A de Crescimento do Endotélio Vascular , Regulação Alostérica/efeitos dos fármacos , Sítio Alostérico , Inibidores da Angiogênese/química , Inibidores da Angiogênese/farmacologia , Animais , Cristalografia por Raios X , Células HEK293 , Xenoenxertos , Células Endoteliais da Veia Umbilical Humana/metabolismo , Células Endoteliais da Veia Umbilical Humana/patologia , Células Endoteliais da Veia Umbilical Humana/transplante , Humanos , Camundongos , Camundongos SCID , Neovascularização Patológica/tratamento farmacológico , Neovascularização Patológica/metabolismo , Neovascularização Patológica/patologia , Ligação Proteica , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/genética , Suínos , Transplante Heterólogo , Fator A de Crescimento do Endotélio Vascular/antagonistas & inibidores , Fator A de Crescimento do Endotélio Vascular/química , Fator A de Crescimento do Endotélio Vascular/metabolismo , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/antagonistas & inibidores , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/química , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/metabolismo
3.
Am J Addict ; 26(3): 215-220, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28240800

RESUMO

BACKGROUND AND OBJECTIVES: Exposure to traumatic events is common among patients with substance use disorders (SUD). In patients with non-substance-related disorders, especially with gambling disorders (GD) and internet addiction (IA), traumatic childhood experiences have not been investigated extensively. The objective of this study was to compare trauma histories in patients with GD and IA to patients with heroin dependence. METHODS: Cross-sectional surveys including the childhood trauma questionnaire (CTQ) and clinical data among 107 participants; 59 patients with non-substance-related disorders (GD [n = 39]; IA [n = 20]) were compared to 28 patients prescribed injectable heroin for opioid dependence in heroin-assisted treatment (HAT) and to a healthy control group (HC) (n = 20). RESULTS: The findings revealed a high prevalence of trauma exposure in all three clinical groups, with 74.4% of patients with GD, 80.0% of patients with IA, and 93.0% of patients in HAT compared to 40% in HC. All three groups (GD, IA, HAT) reported significantly higher levels of "emotional neglect" compared to HC. CONCLUSIONS AND SCIENTIFIC SIGNIFICANCE: The results provide clinically relevant information suggesting that the burden of childhood traumatic experiences may be as common in patients with GD and IA as in patients with heroin dependence. These findings could pose an important starting-point for treatment. (Am J Addict 2017;26:215-220).


Assuntos
Adultos Sobreviventes de Eventos Adversos na Infância/psicologia , Comportamento Aditivo/psicologia , Jogo de Azar/psicologia , Dependência de Heroína/psicologia , Transtornos Relacionados ao Uso de Opioides/psicologia , Adulto , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Psicopatologia , Inquéritos e Questionários
4.
RNA ; 20(4): 429-39, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24572808

RESUMO

mRNA transport coupled with translational control underlies the intracellular localization of many proteins in eukaryotic cells. This is exemplified in Drosophila, where oskar mRNA transport and translation at the posterior pole of the oocyte direct posterior patterning of the embryo. oskar localization is a multistep process. Within the oocyte, a spliced oskar localization element (SOLE) targets oskar mRNA for plus end-directed transport by kinesin-1 to the posterior pole. However, the signals mediating the initial minus end-directed, dynein-dependent transport of the mRNA from nurse cells into the oocyte have remained unknown. Here, we show that a 67-nt stem-loop in the oskar 3' UTR promotes oskar mRNA delivery to the developing oocyte and that it shares functional features with the fs(1)K10 oocyte localization signal. Thus, two independent cis-acting signals, the oocyte entry signal (OES) and the SOLE, mediate sequential dynein- and kinesin-dependent phases of oskar mRNA transport during oogenesis. The OES also promotes apical localization of injected RNAs in blastoderm stage embryos, another dynein-mediated process. Similarly, when ectopically expressed in polarized cells of the follicular epithelium or salivary glands, reporter RNAs bearing the oskar OES are apically enriched, demonstrating that this element promotes mRNA localization independently of cell type. Our work sheds new light on how oskar mRNA is trafficked during oogenesis and the RNA features that mediate minus end-directed transport.


Assuntos
Regiões 3' não Traduzidas/genética , Proteínas de Drosophila/genética , Drosophila melanogaster/genética , Embrião não Mamífero/fisiologia , Microtúbulos/metabolismo , Oócitos/fisiologia , RNA Mensageiro/genética , Animais , Pareamento de Bases , Sequência de Bases , Polaridade Celular , Células Cultivadas , Drosophila melanogaster/crescimento & desenvolvimento , Dineínas/metabolismo , Embrião não Mamífero/citologia , Feminino , Imunofluorescência , Hibridização In Situ , Cinesinas/metabolismo , Dados de Sequência Molecular , Conformação de Ácido Nucleico , Oócitos/citologia , Folículo Ovariano/citologia , Folículo Ovariano/fisiologia , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Glândulas Salivares/citologia , Glândulas Salivares/fisiologia , Homologia de Sequência do Ácido Nucleico
5.
Proc Natl Acad Sci U S A ; 110(32): 12960-5, 2013 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-23878260

RESUMO

Vascular endothelial growth factors (VEGFs) and their receptors (VEGFRs) are key drivers of blood and lymph vessel formation in development, but also in several pathological processes. VEGF-C signaling through VEGFR-3 promotes lymphangiogenesis, which is a clinically relevant target for treating lymphatic insufficiency and for blocking tumor angiogenesis and metastasis. The extracellular domain of VEGFRs consists of seven Ig homology domains; domains 1-3 (D1-3) are responsible for ligand binding, and the membrane-proximal domains 4-7 (D4-7) are involved in structural rearrangements essential for receptor dimerization and activation. Here we analyzed the crystal structures of VEGF-C in complex with VEGFR-3 domains D1-2 and of the VEGFR-3 D4-5 homodimer. The structures revealed a conserved ligand-binding interface in D2 and a unique mechanism for VEGFR dimerization and activation, with homotypic interactions in D5. Mutation of the conserved residues mediating the D5 interaction (Thr446 and Lys516) and the D7 interaction (Arg737) compromised VEGF-C induced VEGFR-3 activation. A thermodynamic analysis of VEGFR-3 deletion mutants showed that D3, D4-5, and D6-7 all contribute to ligand binding. A structural model of the VEGF-C/VEGFR-3 D1-7 complex derived from small-angle X-ray scattering data is consistent with the homotypic interactions in D5 and D7. Taken together, our data show that ligand-dependent homotypic interactions in D5 and D7 are essential for VEGFR activation, opening promising possibilities for the design of VEGFR-specific drugs.


Assuntos
Multimerização Proteica , Estrutura Terciária de Proteína , Fator C de Crescimento do Endotélio Vascular/química , Receptor 3 de Fatores de Crescimento do Endotélio Vascular/química , Sequência de Aminoácidos , Sítios de Ligação/genética , Ligação Competitiva , Cristalografia por Raios X , Eletroforese em Gel de Poliacrilamida , Humanos , Ligantes , Microscopia Eletrônica , Modelos Moleculares , Dados de Sequência Molecular , Complexos Multiproteicos/química , Complexos Multiproteicos/metabolismo , Complexos Multiproteicos/ultraestrutura , Mutação , Ligação Proteica , Espalhamento a Baixo Ângulo , Homologia de Sequência de Aminoácidos , Termodinâmica , Fator C de Crescimento do Endotélio Vascular/genética , Fator C de Crescimento do Endotélio Vascular/metabolismo , Receptor 3 de Fatores de Crescimento do Endotélio Vascular/genética , Receptor 3 de Fatores de Crescimento do Endotélio Vascular/metabolismo , Difração de Raios X
6.
Mycologia ; 116(3): 381-391, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38573224

RESUMO

The importance of mushrooms as a food source is continually increasing. To investigate how environmental factors affect the nutritional value of mushrooms, we harvested them in eastern Poland, south-central Germany, and northwestern Belgium in plots with similar environmental conditions but varying in tree species composition and richness. We used gas chromatography-mass spectrometry (GC-MS) to analyze the fatty acid (FA) content of the mushrooms. Fungal species identity explained the largest part (40%) of the total variation in FA concentration and composition. Environmental factors accounted for 1-12% of variation. The concentration of FA, especially saturated fatty acids, decreased with increasing understory cover and increasing nitrogen concentration in the topsoil. The effect of tree species richness or tree species identity was negligible. Our results suggest that the nutritional value of mushrooms depends mainly on the species identity of fungi, but that their FA content is slightly higher in forests with less undergrowth and in nitrogen-poor soils.


Assuntos
Agaricales , Ácidos Graxos , Florestas , Cromatografia Gasosa-Espectrometria de Massas , Ácidos Graxos/análise , Agaricales/química , Agaricales/classificação , Alemanha , Polônia , Bélgica , Nitrogênio/análise , Nitrogênio/metabolismo , Árvores/química , Valor Nutritivo , Solo/química
7.
Commun Chem ; 6(1): 106, 2023 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-37264098

RESUMO

The Gs protein-coupled adenosine A2A receptor (A2AAR) represents an emerging drug target for cancer immunotherapy. The clinical candidate Etrumadenant was developed as an A2AAR antagonist with ancillary blockade of the A2BAR subtype. It constitutes a unique chemotype featuring a poly-substituted 2-amino-4-phenyl-6-triazolylpyrimidine core structure. Herein, we report two crystal structures of the A2AAR in complex with Etrumadenant, obtained with differently thermostabilized A2AAR constructs. This led to the discovery of an unprecedented interaction, a hydrogen bond of T883.36 with the cyano group of Etrumadenant. T883.36 is mutated in most A2AAR constructs used for crystallization, which has prevented the discovery of its interactions. In-vitro characterization of Etrumadenant indicated low selectivity versus the A1AR subtype, which can be rationalized by the structural data. These results will facilitate the future design of AR antagonists with desired selectivity. Moreover, they highlight the advantages of the employed A2AAR crystallization construct that is devoid of ligand binding site mutations.

8.
J Biol Chem ; 286(25): 22622-31, 2011 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-21525003

RESUMO

The extracellular region of the thyrotropin receptor (TSHR) can be subdivided into the leucine-rich repeat domain (LRRD) and the hinge region. Both the LRRD and the hinge region interact with thyrotropin (TSH) or autoantibodies. Structural data for the TSHR LRRD were previously determined by crystallization (amino acids Glu(30)-Thr(257), 10 repeats), but the structure of the hinge region is still undefined. Of note, the amino acid sequence (Trp(258)-Tyr(279)) following the crystallized LRRD comprises a pattern typical for leucine-rich repeats with conserved hydrophobic side chains stabilizing the repeat fold. Moreover, functional data for amino acids between the LRRD and the transmembrane domain were fragmentary. We therefore investigated systematically these TSHR regions by mutagenesis to reveal insights into their functional contribution and potential structural features. We found that mutations of conserved hydrophobic residues between Thr(257) and Tyr(279) cause TSHR misfold, which supports a structural fold of this peptide, probably as an additional leucine-rich repeat. Furthermore, we identified several new mutations of hydrophilic amino acids in the entire hinge region leading to partial TSHR inactivation, indicating that these positions are important for intramolecular signal transduction. In summary, we provide new information regarding the structural features and functionalities of extracellular TSHR regions. Based on these insights and in context with previous results, we suggest an extracellular activation mechanism that supports an intramolecular agonistic unit as a central switch for activating effects at the extracellular region toward the serpentine domain.


Assuntos
Espaço Extracelular/metabolismo , Receptores da Tireotropina/química , Receptores da Tireotropina/metabolismo , Sequência de Aminoácidos , Substituição de Aminoácidos , Animais , Células COS , Bovinos , Chlorocebus aethiops , Sequência Conservada , AMP Cíclico/metabolismo , Regulação da Expressão Gênica , Humanos , Interações Hidrofóbicas e Hidrofílicas , Fosfatos de Inositol/metabolismo , Modelos Moleculares , Dados de Sequência Molecular , Mutagênese Sítio-Dirigida , Mutação , Dobramento de Proteína , Estrutura Secundária de Proteína , Estrutura Terciária de Proteína , Receptores da Tireotropina/genética , Tireotropina/metabolismo
9.
Clin Endocrinol (Oxf) ; 73(6): 815-20, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-20846293

RESUMO

OBJECTIVE: Constitutively activating mutations (CAMs) of the TSHR are the major cause for nonautoimmune hyperthyroidism. Re-examination of constitutive activity previously determined in CHO cell lines recently demonstrated the caveats for the in vitro determination of constitutive TSHR activity, which leads to false positive conclusions regarding the molecular origin of hyperthyroidism or hot thyroid carcinomas. DESIGN: Mutations L677V and T620I identified in hot thyroid carcinomas were previously characterized in CHO and in 3T3-Vill cell lines, respectively, stably expressing the mutant without determination of TSHR expression. F666L identified in a patient with hot thyroid nodules, I691F in a family with nonautoimmune hyperthyroidism and F631I identified in a hot thyroid carcinoma were not characterized for their in vitro function. Therefore, we decided to (re)evaluate the in vitro function of these five TSHR variants by determination of cell surface expression, and intracellular cAMP and inositol phosphate levels and performed additionally linear regression analyses to determine basal activity independently from the mutant's cell surface expression in COS-7 and HEK(GT) cells. RESULTS AND CONCLUSIONS: Only one (F631I) of the five investigated TSHR variants displayed constitutive activity for G(α) s signalling and showed correlation with the clinical phenotype. The previous false classification of T620I and L677V as CAMs is most likely related to the fact that both mutations were characterized in cell lines stably expressing the mutated receptor construct without assessing the respective receptor number per cell. Other molecular aetiologies for the nonautoimmune hyperthyroidism and/or hot thyroid carcinomas in these three patients and one family should be elucidated.


Assuntos
Hipertireoidismo/genética , Receptores da Tireotropina/genética , Receptores da Tireotropina/metabolismo , Neoplasias da Glândula Tireoide/genética , Animais , Células COS , Linhagem Celular , Chlorocebus aethiops , AMP Cíclico/metabolismo , Citometria de Fluxo , Humanos , Mutagênese Sítio-Dirigida , Mutação
10.
Biomed Chromatogr ; 24(7): 752-8, 2010 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-19908207

RESUMO

Biomarkers are an increasingly important constituent of the drug development process, offering the potential of increased efficiency through reduced compound attrition and earlier proof of mechanism and/or efficacy. Assays developed for compound screening that can be directly translated for clinical trials are especially valuable, but their successful adoption requires a careful balance between assay performance and implementation costs. One such 'fit-for-purpose' biomarker assay, the indirect measurement of pharmacological modulation of sphingolipid biosynthesis and disposition, is presented here. Among sphingolipids, numerous ceramide species are readily detectable in different lipoprotein fractions of mammalian plasma, but their parallel quantification can be prohibitively expensive and time consuming. Ceramides differ in their fatty acid moiety, which is readily removed by hydrolysis, yielding a common sphingosine derivative, the measurement of which serves as an indicator of total ceramide. When followed by liquid chromatography tandem mass spectrometry (LC/MS/MS) for detection, robust analyte quantification becomes relatively straightforward. The practical utility of a method developed to be fit for the purpose of rapidly and quantitatively measuring treatment-induced variations in total ceramide from hamster plasma and individual lipoprotein fractions is described. With a linear calibration range from 0.003 to 33.4 microm sphingosine, precision and accuracy error in plasma-based quality controls spiked with ceramides was less than 15%. The specificity of the assay for ceramides was also assessed. The simplicity of the method would allow for its potential translation to other preclinical species, as well as for clinical applications in later-stage drug development.


Assuntos
Ceramidas/análise , Cromatografia Líquida/métodos , Espectrometria de Massas/métodos , Esfingosina/análise , Pesquisa Translacional Biomédica , Animais , Ceramidas/sangue , Cricetinae , Masculino , Mesocricetus , Esfingosina/sangue
11.
Integr Environ Assess Manag ; 16(6): 885-897, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32589785

RESUMO

While the Middle East and North African (MENA) region is facing challenges to sustain water security, water reclamation has received increasing consideration as a favorable mitigating solution. Despite the availability of adequate technologies, economic, political, legal, social, and environmental constraints often hamper stakeholders, and especially decision makers, from exploiting the existing potential into solution implementation. In the present paper, a comprehensive assessment for water reclamation and reuse was developed. This assessment consisted of 4 objectives: 1) apply a decision-support tool (DST) for water reclamation potential for municipal wastewater, 2) apply a DST for simulating and estimating the lifecycle costs of project-related technologies for water reclamation (municipal and industrial wastewater, as well as drainage canal water), 3) assess the national-level conditions for water reuse with a multicriteria decision analysis (MCA), and 4) establish exemplary strategies, barriers, and measures for water reuse. The present MCA considered 6 thematic subjects: policy and institution, economy, society, water management, legislation, and environment. The assessment was applied to food and nonfood crop irrigation in Egyptian, Moroccan, and Tunisian case studies. For all defined case studies, adapted treatment trains that could treat wastewater to the desired quality at reasonable costs were identified and are presented in the present paper. Results showed that technological options are available for water reuse, but the concept is not widely implemented in Egypt, Morocco, and Tunisia. The present paper identifies key barriers and drivers for the implementation of water reclamation for irrigation. In particular, the considered countries showed different characteristics regarding efficient water management, water pricing, subsidies and wastewater tariffs, implementation of monitoring and reporting systems, or legal aspects regarding the use of reclaimed water for food crop irrigation. Further exploration of case studies on high potential water reuse and financially affordable wastewater reclamation, particularly case studies that explore the impacts of policies and practices across countries, would be useful for helping the MENA region improve their water security situation. Integr Environ Assess Manag 2020;16:885-897. © 2020 SETAC.


Assuntos
Purificação da Água , Conservação dos Recursos Naturais , Egito , Humanos , Marrocos , Distribuição Aleatória , Tunísia , Eliminação de Resíduos Líquidos , Águas Residuárias , Água , Abastecimento de Água
12.
FASEB J ; 22(8): 2798-808, 2008 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-18381815

RESUMO

The mechanisms governing transition of the thyroid stimulating hormone (TSH) receptor (TSHR) from basal to active conformations are poorly understood. Considering that constitutively activating mutations (CAMs) and inactivating mutations in each of the extracellular loops (ECLs) trigger only partial TSHR activation or inactivation, respectively, we hypothesized that full signaling occurs via multiple extracellular signal propagation events. Therefore, individual CAMs in the extracellular region were combined to create double and triple mutants. In support of our hypothesis, combinations of mutants in the ECLs are in some cases additive, while in others they are even synergistic, with triple mutant I486A/I568V/V656F exhibiting a 70-fold increase in TSH-independent signaling. The proximity but likely different spatial orientation of the residues of activating and inactivating mutations in each ECL supports a dual functionality to facilitate signal induction and conduction, respectively. This is the first report for G-protein coupled receptors, suggesting that multiple and cooperative signal propagating events at all three ECLs are required for full receptor activation. Our findings provide new insights concerning molecular signal transmission from extracellular domains toward the transmembrane helix bundle of the glycoprotein hormone receptors.


Assuntos
Receptores da Tireotropina/química , Receptores da Tireotropina/metabolismo , Transdução de Sinais/fisiologia , Sequência de Aminoácidos , Animais , Sítios de Ligação/genética , Células COS , Chlorocebus aethiops , AMP Cíclico/biossíntese , Humanos , Cinética , Modelos Moleculares , Dados de Sequência Molecular , Mutagênese Sítio-Dirigida , Conformação Proteica , Estrutura Terciária de Proteína , Receptores da Tireotropina/genética , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Homologia de Sequência de Aminoácidos
13.
Diagn Cytopathol ; 47(6): 589-593, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30677251

RESUMO

Sclerosing mucoepidermoid carcinoma with eosinophilia (SMECE) is a rare primary cancer of the thyroid. This tumor is analogous to other primary tumors of the salivary glands, breast, pancreas, and esophagus. We present a case of this rare tumor with characteristic clinical features, ultrasound images, cytopathology, histopathology, and a heretofore undocumented somatic gene mutation. Additionally, we provide a succinct review of the controversial literature for this uncommon lesion.


Assuntos
Carcinoma Mucoepidermoide/genética , Carcinoma Mucoepidermoide/patologia , Eosinofilia/genética , Eosinofilia/patologia , Mutação/genética , Glândula Tireoide/patologia , Neoplasias da Glândula Tireoide/genética , Neoplasias da Glândula Tireoide/patologia , Biópsia , Carcinoma Mucoepidermoide/diagnóstico por imagem , Eosinofilia/diagnóstico por imagem , Feminino , Humanos , Pessoa de Meia-Idade , Glândula Tireoide/diagnóstico por imagem , Neoplasias da Glândula Tireoide/diagnóstico por imagem
14.
Thyroid ; 18(5): 499-508, 2008 May.
Artigo em Inglês | MEDLINE | ID: mdl-18466076

RESUMO

BACKGROUND: Up to date, three thyroid-stimulating hormone receptor (TSHR) germline variants have been reported for which no functional consequences have been detected by in vitro characterizations. However, familial nonautoimmune hyperthyroidism and hot nodules are clearly associated with constitutively activating TSHR germline mutations. We describe a family with a new TSHR germline mutation that is associated with euthyroidism in 13 family members and hyperthyroidism in 1 family member. METHODS: Mutation analysis of the TSHR gene was performed by denaturing gradient gel electrophoresis. TSHR constructs were characterized by determination of cell surface expression, 3'-5'-cyclic adenosine monophosphate (cAMP) accumulation, and constitutive cAMP activity. RESULTS: A novel TSHR germline mutation (N372T) was found in a man who presented with thyrotoxicosis. The mutation was also detected in 13 family members, all of whom were euthyroid. Interestingly, an additional constitutively active somatic mutation (S281N) was identified on the second parental TSHR allele of the hyperthyroid index patient. Linear regression analysis showed a lack of constitutive activity for N372T. Moreover, coexpression studies of N372T with S281N did not reveal any evidence for a functional influence of N372T on the constitutively active mutation (CAM). CONCLUSIONS: N372T is unlikely to cause altered thyroid function. This is consistent with the finding that only the index patient with the additional somatic mutation S281N was hyperthyroid.


Assuntos
Mutação em Linhagem Germinativa/genética , Hipertireoidismo/genética , Receptores da Tireotropina/genética , Adolescente , Adulto , Idoso , Criança , AMP Cíclico/metabolismo , Análise Mutacional de DNA , Feminino , Seguimentos , Predisposição Genética para Doença , Humanos , Modelos Lineares , Masculino , Pessoa de Meia-Idade , Linhagem , Tireotoxicose/genética
15.
Bioorg Med Chem Lett ; 18(2): 546-53, 2008 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-18063367

RESUMO

Cholesterol absorption inhibition (CAI) represents an important treatment option for hypercholesterolemia. Herein, we report the design and evaluation of a series of substituted oxazolidinones as ligands for the Niemann Pick C1 Like 1 (NPC1L1) protein, a key mediator of cholesterol transport. Novel analogs were initially evaluated in a brush border membrane NPC1L1 binding assay; subsequently, promising compounds were evaluated in vivo for acute inhibition of cholesterol absorption. These studies identified analogs with low micromolar NPC1L1 binding affinity and acute in vivo efficacy of >50% absorption inhibition at 3mg/kg.


Assuntos
Colesterol/metabolismo , Absorção Intestinal/efeitos dos fármacos , Proteínas de Membrana Transportadoras/metabolismo , Oxazolidinonas/farmacologia , Animais , Ligantes , Microvilosidades/metabolismo , Oxazolidinonas/química , Oxazolidinonas/metabolismo , Oxazolidinonas/farmacocinética , Ratos , Difração de Raios X
16.
Diagn Cytopathol ; 46(4): 340-344, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29193882

RESUMO

Fine needle aspiration is frequently used as the initial diagnostic procedure in the work-up of head and neck lesions, including soft tissue masses and salivary gland neoplasms. Giant cell tumors (GCTs), both osseous and extraosseous, are benign tumors that occur, albeit rarely, in the head and neck region. Extraosseous GCTs may be further classified based on their tissue of origin and specific anatomic location. Regardless of location, giant cell tumors are morphologically similar and share cytologic and histologic diagnostic criteria. Evaluation of imaging is therefore essential to the correct classification of these tumors. Accurate diagnosis is crucial since the clinical behavior and treatment is significantly different among the subtypes of GCTs. The case presented herein illustrates the diagnostic dilemma between two uncommon entities in an unusual site: GCT of parotid gland and tenosynovial GCT.


Assuntos
Tumores de Células Gigantes/patologia , Neoplasias Mandibulares/patologia , Neoplasias Parotídeas/patologia , Transtornos da Articulação Temporomandibular/patologia , Adulto , Diagnóstico Diferencial , Feminino , Tumores de Células Gigantes/diagnóstico por imagem , Humanos , Neoplasias Mandibulares/diagnóstico por imagem , Neoplasias Parotídeas/diagnóstico por imagem , Transtornos da Articulação Temporomandibular/diagnóstico por imagem
17.
Waste Manag ; 68: 534-546, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28624336

RESUMO

An increasing number of geochemically scarce metallic raw materials are entering into our lives via new technologies. A reversal of this trend is not foreseeable, leading to concerns regarding the security of their supply. However, the evaluation of raw material supply is currently hampered by inconsistent use of fundamental terminologies and incomplete assessment criteria. In this paper, we aim to establish a consistent framework for evaluating raw material supply from both anthropogenic and geological sources. A method for concept extraction was applied to evaluate systematically the use of fundamental terms in the evaluation of raw material supply. The results have shown that 'availability' is commonly used in raw material supply evaluations, whilst other researchers suggest that raw material supply should be evaluated based on 'accessibility'. It was revealed that 'accessibility' actually comprises two aspects: 'availability' and 'approachability'. Raw material 'approachability' has not previously been explicitly addressed at a system level. A novel, consistent framework for evaluating raw material supply was therefore developed. To demonstrate the application of the established framework, we evaluated the raw material supply of four rare earth element case studies. Three case studies are End-of-Life products (the anthroposphere) from Switzerland: (i) phosphors in fluorescent lamps, (i) permanent magnets in the drive motors of electric cars and (iii) fibre optic cable. The fourth case study source is the Earth's crust (the geosphere): Mount Weld deposit in Australia. The framework comprises a comprehensive evaluation of six components relating to raw material mining and processing: their geological knowledge, eligibility, technology, economic, societal and environmental impacts. Our results show that metals are not considered to be fully accessible in any of the case studies due to a lack of necessary technologies and potential societal and environmental impacts. The framework presented here can serve as a starting point for the development of an evaluation framework for raw material accessibility at an early project development stage.


Assuntos
Conservação dos Recursos Naturais , Metais Terras Raras , Mineração , Austrália , Meio Ambiente , Suíça
18.
Dev Cell ; 41(1): 72-81.e6, 2017 04 10.
Artigo em Inglês | MEDLINE | ID: mdl-28399403

RESUMO

Human susceptibility to obesity is mainly genetic, yet the underlying evolutionary drivers causing variation from person to person are not clear. One theory rationalizes that populations that have adapted to warmer climates have reduced their metabolic rates, thereby increasing their propensity to store energy. We uncover here the function of a gene that supports this theory. THADA is one of the genes most strongly selected during evolution as humans settled in different climates. We report here that THADA knockout flies are obese, hyperphagic, have reduced energy production, and are sensitive to the cold. THADA binds the sarco/ER Ca2+ ATPase (SERCA) and acts on it as an uncoupler. Reducing SERCA activity in THADA mutant flies rescues their obesity, pinpointing SERCA as a key effector of THADA function. In sum, this identifies THADA as a regulator of the balance between energy consumption and energy storage, which was selected during human evolution.


Assuntos
Proteínas de Transporte/metabolismo , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/metabolismo , Metabolismo Energético , Temperatura Alta , Proteínas de Neoplasias/metabolismo , Animais , Sequência Conservada , Retículo Endoplasmático/metabolismo , Feminino , Técnicas de Inativação de Genes , Células HeLa , Humanos , Mutação/genética , Obesidade/metabolismo , Obesidade/patologia , Ligação Proteica , ATPases Transportadoras de Cálcio do Retículo Sarcoplasmático/metabolismo
19.
Structure ; 25(2): 341-352, 2017 02 07.
Artigo em Inglês | MEDLINE | ID: mdl-28111021

RESUMO

Vascular endothelial growth factors (VEGFs) regulate blood and lymph vessel development upon activation of three receptor tyrosine kinases: VEGFR-1, -2, and -3. Partial structures of VEGFR/VEGF complexes based on single-particle electron microscopy, small-angle X-ray scattering, and X-ray crystallography revealed the location of VEGF binding and domain arrangement of individual receptor subdomains. Here, we describe the structure of the full-length VEGFR-1 extracellular domain in complex with VEGF-A at 4 Å resolution. We combined X-ray crystallography, single-particle electron microscopy, and molecular modeling for structure determination and validation. The structure reveals the molecular details of ligand-induced receptor dimerization, in particular of homotypic receptor interactions in immunoglobulin homology domains 4, 5, and 7. Functional analyses of ligand binding and receptor activation confirm the relevance of these homotypic contacts and identify them as potential therapeutic sites to allosterically inhibit VEGFR-1 activity.


Assuntos
Fator A de Crescimento do Endotélio Vascular/química , Receptor 1 de Fatores de Crescimento do Endotélio Vascular/química , Sequência de Aminoácidos , Sítios de Ligação , Clonagem Molecular , Cristalografia por Raios X , Expressão Gênica , Humanos , Ligantes , Microscopia Eletrônica , Modelos Moleculares , Ligação Proteica , Conformação Proteica em alfa-Hélice , Conformação Proteica em Folha beta , Domínios e Motivos de Interação entre Proteínas , Multimerização Proteica , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Alinhamento de Sequência , Homologia de Sequência de Aminoácidos , Termodinâmica , Fator A de Crescimento do Endotélio Vascular/genética , Fator A de Crescimento do Endotélio Vascular/metabolismo , Receptor 1 de Fatores de Crescimento do Endotélio Vascular/genética , Receptor 1 de Fatores de Crescimento do Endotélio Vascular/metabolismo
20.
Atherosclerosis ; 189(2): 264-72, 2006 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-16458317

RESUMO

Plasma sphingomyelin (SM) has been suggested as a risk factor for coronary heart disease independent of cholesterol levels. A decrease of SM in lipoproteins is known to improve the activities of lecithin:cholesterol acyltransferase (LCAT) and lipoprotein lipase (LPL) in vitro. Inhibition of SM biosynthesis may reduce lipoprotein SM content and thus improve cholesterol distribution in lipoproteins by enhancing reverse cholesterol transport and clearance of triglyceride-rich lipoproteins. To examine this hypothesis, ApoE KO mice were fed a western diet and treated for 4 weeks with various concentrations of myriocin, a specific inhibitor of serine palmitoyltransferase. Myriocin treatment lowered plasma cholesterol and TG levels in a dose-dependent manner. In addition, myriocin treatment reduced cholesterol contents in VLDL and LDL and elevated HDL-cholesterol. Observed lipid-lowering effects of myriocin were associated with suppression of HMG CoA reductase and fatty acid synthase via reduced levels of SREBP-1 RNA and protein. Induction of apoAI and lecithin:cholesterol acytransferase (LCAT) in the liver by myriocin was associated with an increased HDL. Lesion area and macrophage area were also diminished in the cuffed femoral artery of ApoE KO mice. In conclusion, inhibition of sphingolipid biosynthesis can be a novel therapeutic target for dyslipidemia and atherosclerosis.


Assuntos
Aterosclerose/tratamento farmacológico , Aterosclerose/metabolismo , Ácidos Graxos Monoinsaturados/uso terapêutico , Esfingomielinas/antagonistas & inibidores , Esfingomielinas/biossíntese , Animais , Apolipoproteínas E/deficiência , Western Blotting , HDL-Colesterol/sangue , LDL-Colesterol/sangue , VLDL-Colesterol/sangue , Modelos Animais de Doenças , Regulação da Expressão Gênica , Imunossupressores/uso terapêutico , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Reação em Cadeia da Polimerase , RNA/genética , Proteína de Ligação a Elemento Regulador de Esterol 1/efeitos dos fármacos , Proteína de Ligação a Elemento Regulador de Esterol 1/genética , Proteína de Ligação a Elemento Regulador de Esterol 1/metabolismo
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