Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 453
Filtrar
Mais filtros

Bases de dados
Tipo de documento
Intervalo de ano de publicação
1.
Liver Int ; 44(3): 838-847, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38263707

RESUMO

BACKGROUND AND AIMS: Haemochromatosis is characterized by progressive iron overload affecting the liver and can cause cirrhosis and hepatocellular carcinoma. Most haemochromatosis patients are homozygous for p.C282Y in HFE, but only a minority of individuals with this genotype will develop the disease. The aim was to assess the penetrance of iron overload, fibrosis, hepatocellular carcinoma and life expectancy. METHODS: A total of 8839 individuals from the Austrian region of Tyrol were genotyped for the p.C282Y variant between 1997 and 2021. Demographic, laboratory parameters and causes of death were assessed from health records. Penetrance, survival, and cancer incidence were ascertained from diagnosed cases, insurance- and cancer registry data. Outcomes were compared with a propensity score-matched control population. RESULTS: Median age at diagnosis in 542 p.C282Y homozygous individuals was 47.8 years (64% male). At genotyping, the prevalence of iron overload was 55%. The cumulative penetrance of haemochromatosis defined as the presence of provisional iron overload was 24.2% in males and 10.5% in females aged 60 years or younger. Among p.C282Y homozygotes of the same ages, the cumulative proportion of individuals without fibrosis (FIB-4 score < 1.3) was 92.8% in males and 96.7% in females. Median life expectancy was reduced by 6.8 years in individuals homozygous for p.C282Y when compared with population-matched controls (p = .001). Hepatocellular carcinoma incidence was not significantly higher in p.C282Y homozygotes than in controls matched for age and sex. CONCLUSION: Reduced survival and the observed age-dependent increase in penetrance among p.C282Y homozygotes call for earlier diagnosis of haemochromatosis to prevent complications.


Assuntos
Carcinoma Hepatocelular , Hemocromatose , Sobrecarga de Ferro , Neoplasias Hepáticas , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Hemocromatose/epidemiologia , Hemocromatose/genética , Hemocromatose/complicações , Penetrância , Carcinoma Hepatocelular/epidemiologia , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/complicações , Estudos de Coortes , Incidência , Antígenos de Histocompatibilidade Classe I/genética , Proteína da Hemocromatose/genética , Sobrecarga de Ferro/complicações , Homozigoto , Cirrose Hepática/complicações , Neoplasias Hepáticas/epidemiologia , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/complicações , Mutação
2.
Malar J ; 23(1): 188, 2024 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-38880870

RESUMO

BACKGROUND: Effective testing for malaria, including the detection of infections at very low densities, is vital for the successful elimination of the disease. Unfortunately, existing methods are either inexpensive but poorly sensitive or sensitive but costly. Recent studies have shown that mid-infrared spectroscopy coupled with machine learning (MIRs-ML) has potential for rapidly detecting malaria infections but requires further evaluation on diverse samples representative of natural infections in endemic areas. The aim of this study was, therefore, to demonstrate a simple AI-powered, reagent-free, and user-friendly approach that uses mid-infrared spectra from dried blood spots to accurately detect malaria infections across varying parasite densities and anaemic conditions. METHODS: Plasmodium falciparum strains NF54 and FCR3 were cultured and mixed with blood from 70 malaria-free individuals to create various malaria parasitaemia and anaemic conditions. Blood dilutions produced three haematocrit ratios (50%, 25%, 12.5%) and five parasitaemia levels (6%, 0.1%, 0.002%, 0.00003%, 0%). Dried blood spots were prepared on Whatman™ filter papers and scanned using attenuated total reflection-Fourier Transform Infrared (ATR-FTIR) for machine-learning analysis. Three classifiers were trained on an 80%/20% split of 4655 spectra: (I) high contrast (6% parasitaemia vs. negative), (II) low contrast (0.00003% vs. negative) and (III) all concentrations (all positive levels vs. negative). The classifiers were validated with unseen datasets to detect malaria at various parasitaemia levels and anaemic conditions. Additionally, these classifiers were tested on samples from a population survey in malaria-endemic villages of southeastern Tanzania. RESULTS: The AI classifiers attained over 90% accuracy in detecting malaria infections as low as one parasite per microlitre of blood, a sensitivity unattainable by conventional RDTs and microscopy. These laboratory-developed classifiers seamlessly transitioned to field applicability, achieving over 80% accuracy in predicting natural P. falciparum infections in blood samples collected during the field survey. Crucially, the performance remained unaffected by various levels of anaemia, a common complication in malaria patients. CONCLUSION: These findings suggest that the AI-driven mid-infrared spectroscopy approach holds promise as a simplified, sensitive and cost-effective method for malaria screening, consistently performing well despite variations in parasite densities and anaemic conditions. The technique simply involves scanning dried blood spots with a desktop mid-infrared scanner and analysing the spectra using pre-trained AI classifiers, making it readily adaptable to field conditions in low-resource settings. In this study, the approach was successfully adapted to field use, effectively predicting natural malaria infections in blood samples from a population-level survey in Tanzania. With additional field trials and validation, this technique could significantly enhance malaria surveillance and contribute to accelerating malaria elimination efforts.


Assuntos
Malária Falciparum , Plasmodium falciparum , Humanos , Malária Falciparum/diagnóstico , Malária Falciparum/sangue , Malária Falciparum/parasitologia , Plasmodium falciparum/isolamento & purificação , Parasitemia/diagnóstico , Parasitemia/parasitologia , Anemia/diagnóstico , Anemia/sangue , Anemia/parasitologia , Espectrofotometria Infravermelho/métodos , Aprendizado de Máquina , Carga Parasitária , Adulto , Inteligência Artificial , Sensibilidade e Especificidade , Feminino , Adulto Jovem , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Adolescente , Masculino , Pessoa de Meia-Idade , Programas de Rastreamento/métodos
3.
Nature ; 561(7723): 416-419, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-30209390

RESUMO

CRISPR-Cas genome-editing nucleases hold substantial promise for developing human therapeutic applications1-6 but identifying unwanted off-target mutations is important for clinical translation7. A well-validated method that can reliably identify off-targets in vivo has not been described to date, which means it is currently unclear whether and how frequently these mutations occur. Here we describe 'verification of in vivo off-targets' (VIVO), a highly sensitive strategy that can robustly identify the genome-wide off-target effects of CRISPR-Cas nucleases in vivo. We use VIVO and a guide RNA deliberately designed to be promiscuous to show that CRISPR-Cas nucleases can induce substantial off-target mutations in mouse livers in vivo. More importantly, we also use VIVO to show that appropriately designed guide RNAs can direct efficient in vivo editing in mouse livers with no detectable off-target mutations. VIVO provides a general strategy for defining and quantifying the off-target effects of gene-editing nucleases in whole organisms, thereby providing a blueprint to foster the development of therapeutic strategies that use in vivo gene editing.


Assuntos
Proteínas Associadas a CRISPR/metabolismo , Sistemas CRISPR-Cas/genética , Edição de Genes/métodos , Edição de Genes/normas , Genoma/genética , Mutação , Especificidade por Substrato/genética , Animais , Proteínas Associadas a CRISPR/genética , Feminino , Humanos , Mutação INDEL , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Pró-Proteína Convertase 9/genética , Transgenes/genética
4.
Diabetologia ; 66(12): 2320-2331, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37670017

RESUMO

AIMS/HYPOTHESIS: Metformin is increasingly used therapeutically during pregnancy worldwide, particularly in the treatment of gestational diabetes, which affects a substantial proportion of pregnant women globally. However, the impact on placental metabolism remains unclear. In view of the association between metformin use in pregnancy and decreased birthweight, it is essential to understand how metformin modulates the bioenergetic and anabolic functions of the placenta. METHODS: A cohort of 55 placentas delivered by elective Caesarean section at term was collected from consenting participants. Trophoblasts were isolated from the placental samples and treated in vitro with clinically relevant doses of metformin (0.01 mmol/l or 0.1 mmol/l) or vehicle. Respiratory function was assayed using high-resolution respirometry to measure oxygen concentration and calculated [Formula: see text]. Glycolytic rate and glycolytic stress assays were performed using Agilent Seahorse XF assays. Fatty acid uptake and oxidation measurements were conducted using radioisotope-labelled assays. Lipidomic analysis was conducted using LC-MS. Gene expression and protein analysis were performed using RT-PCR and western blotting, respectively. RESULTS: Complex I-supported oxidative phosphorylation was lower in metformin-treated trophoblasts (0.01 mmol/l metformin, 61.7% of control, p<0.05; 0.1 mmol/l metformin, 43.1% of control, p<0.001). The proton efflux rate arising from glycolysis under physiological conditions was increased following metformin treatment, up to 23±5% above control conditions following treatment with 0.1 mmol/l metformin (p<0.01). There was a significant increase in triglyceride concentrations in trophoblasts treated with 0.1 mmol/l metformin (p<0.05), particularly those of esters of long-chain polyunsaturated fatty acids. Fatty acid oxidation was reduced by ~50% in trophoblasts treated with 0.1 mmol/l metformin compared with controls (p<0.001), with no difference in uptake between treatment groups. CONCLUSIONS/INTERPRETATION: In primary trophoblasts derived from term placentas metformin treatment caused a reduction in oxidative phosphorylation through partial inactivation of complex I and potentially by other mechanisms. Metformin-treated trophoblasts accumulate lipids, particularly long- and very-long-chain polyunsaturated fatty acids. Our findings raise clinically important questions about the balance of risk of metformin use during pregnancy, particularly in situations where the benefits are not clear-cut and alternative therapies are available.


Assuntos
Metformina , Placenta , Humanos , Feminino , Gravidez , Metformina/farmacologia , Metformina/uso terapêutico , Metformina/metabolismo , Trofoblastos/metabolismo , Cesárea , Ácidos Graxos/metabolismo , Ácidos Graxos Insaturados/metabolismo
5.
Hum Mol Genet ; 31(1): 10-17, 2021 12 17.
Artigo em Inglês | MEDLINE | ID: mdl-34254124

RESUMO

Vascular malformations are most often caused by somatic mutations of the PI3K/mTOR and the RAS signaling pathways, which can be identified in the affected tissue. Venous malformations (VMs) commonly harbor PIK3CA and TEK mutations, whereas arteriovenous malformations (AVMs) are usually caused by BRAF, RAS or MAP2K1 mutations. Correct identification of the underlying mutation is of increasing importance, since targeted treatments are becoming more and more relevant, especially in patients with extensive vascular malformations. However, variants of unknown significance (VUSs) are often identified and their pathogenicity and response to targeted therapy cannot be precisely predicted. Here, we show that zebrafish embryos can be used to rapidly assess the pathogenicity of novel VUSs in TEK, encoding for the receptor TIE2, present on endothelial cells of VMs. Endothelium-specific overexpression of TEK mutations leads to robust induction of VMs, whereas MAP2K1 mutations cause AVMs in our zebrafish model. TEK mutations are often found as double mutations in cis; using our model, we show that double mutations have an additive effect in inducing VMs compared with the respective single variants. The clinically established mTOR-inhibitor sirolimus (rapamycin) efficiently abrogates the development of VMs in this zebrafish model. In summary, endothelium-specific overexpression of patient-derived TEK variants in the zebrafish model allows assessment of their pathogenic significance as well as testing of candidate drugs in a personalized and mutation-specific approach.


Assuntos
Receptor TIE-2 , Malformações Vasculares , Peixe-Zebra , Animais , Células Endoteliais/metabolismo , Endotélio/metabolismo , Endotélio/patologia , Humanos , Mutação , Receptor TIE-2/genética , Malformações Vasculares/genética , Peixe-Zebra/genética , Peixe-Zebra/metabolismo
6.
Chemistry ; 28(2): e202103135, 2022 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-34767667

RESUMO

The 4-anilino-6,7-ethylenedioxy-5-fluoroquinazoline scaffold is presented as a novel model system for the characterization of the weak NH⋅⋅⋅F hydrogen bonding (HB) interaction. In this scaffold, the aniline NH proton is forced into close proximity with the nearby fluorine (dH,F ∼2.0 Å, ∠∼138°), and a through-space interaction is observed by NMR spectroscopy with couplings (1h JNH,F ) of 19±1 Hz. A combination of experimental (NMR spectroscopy and X-ray crystallography) and theoretical methods (DFT calculations) were used for the characterization of this weak interaction. In particular, the effects of conformational rigidity and steric compression on coupling were investigated. This scaffold was used for the direct comparison of fluoride with methoxy as HB acceptors, and the susceptibility of the NH⋅⋅⋅F interaction to changes in electron distribution and resonance was probed by preparing a series of molecules with different electron-donating or -withdrawing groups in the positions para to the NH and F. The results support the idea that fluorine can act as a weak HB acceptor, and the HB strength can be modulated through additive and linear electronic substituent effects.


Assuntos
Fluoretos , Flúor , Eletrônica , Ligação de Hidrogênio , Conformação Molecular
7.
J Intern Med ; 290(6): 1219-1232, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34342064

RESUMO

BACKGROUND: Metabolic syndrome with its key components insulin resistance, central obesity, dyslipidaemia, and hypertension is associated with a high risk for cardiovascular events and all-cause mortality in the general population. However, evidence that these findings apply to patients with chronic kidney disease (CKD) with moderately reduced estimated glomerular filtration rate and/or albuminuria is limited. OBJECTIVES: We aimed to investigate the association between metabolic syndrome and its components with all-cause mortality and cardiovascular outcomes in CKD patients. METHODS: Prospective observation of a cohort of 5110 CKD patients from the German Chronic Kidney Disease study with 3284 (64.3%) of them having a metabolic syndrome at baseline. RESULTS: During the follow-up of 6.5 years, 605 patients died and 650 patients experienced major cardiovascular events. After extended data adjustment, patients with a metabolic syndrome had a higher risk for all-cause mortality (hazard ratio [HR] = 1.26, 95% confidence interval [CI]: 1.04-1.54) and cardiovascular events (HR = 1.48, 95% CI: 1.22-1.79). The risk increased steadily with a growing number of metabolic syndrome components (increased waist circumference, glucose, triglycerides, hypertension and decreased HDL cholesterol): HR per component = 1.09 (95% CI: 1.02-1.17) for all-cause mortality and 1.23 (95% CI: 1.15-1.32) for cardiovascular events. This resulted in hazard ratios between 1.50 and 2.50 in the case when four or five components are present. An analysis of individual components of metabolic syndrome showed that the glucose component led to the highest increase in risk for all-cause mortality (HR = 1.68, 95% CI: 1.38-2.03) and cardiovascular events (HR = 1.81, 95% CI: 1.51-2.18), followed by the HDL cholesterol and triglyceride components. CONCLUSIONS: We observed a high prevalence of metabolic syndrome among patients with moderate CKD. Metabolic syndrome increases the risk for all-cause mortality and cardiovascular events. The glucose and lipid components seem to be the main drivers for the association with outcomes.


Assuntos
Doenças Cardiovasculares , Hipertensão , Síndrome Metabólica , Mortalidade , Insuficiência Renal Crônica , Doenças Cardiovasculares/epidemiologia , HDL-Colesterol , Taxa de Filtração Glomerular , Glucose , Humanos , Hipertensão/epidemiologia , Síndrome Metabólica/complicações , Síndrome Metabólica/epidemiologia , Estudos Prospectivos , Insuficiência Renal Crônica/complicações , Fatores de Risco , Triglicerídeos
8.
J Sleep Res ; 30(6): e13365, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-33902162

RESUMO

Altitude exposure induces hypoxaemia in patients with chronic obstructive pulmonary disease (COPD), particularly during sleep. The present study tested the hypothesis in patients with COPD staying overnight at high altitude that nocturnal arterial hypoxaemia is associated with impaired cerebral tissue oxygenation (CTO). A total of 35 patients with moderate-to-severe COPD, living at <800 m (mean [SD] age 62.4 [12.3] years, forced expiratory volume in 1 s [FEV1 ] 61 [16]% predicted, awake pulse oximetry ≥92%) underwent continuous overnight monitoring of pulse oximetry (oxygen saturation [SpO2 ]) and near-infrared spectroscopy of prefrontal CTO, respectively, at 490 m and 2,590 m. Regression analysis was used to evaluate whether nocturnal arterial desaturation (COPDDesat , SpO2 <90% for >30% of night-time) at 490 m predicted CTO at 2,590 m when controlling for baseline variables. At 2,590 m, mean nocturnal SpO2 and CTO were decreased versus 490 m, mean change -8.8% (95% confidence interval [CI] -10.0 to -7.6) and -3.6% (95% CI -5.7 to -1.6), difference in change ΔCTO-ΔSpO2 5.2% (95% CI 3.0 to 7.3; p < .001). Moreover, frequent cyclic desaturations (≥4% dips/hr) occurred in SpO2 and CTO, mean change from 490 m 35.3/hr (95% CI 24.9 to 45.7) and 3.4/hr (95% CI 1.4 to 5.3), difference in change ΔCTO-ΔSpO2 -32.8/hr (95% CI -43.8 to -21.8; p < .001). Regression analysis confirmed an association of COPDDesat with lower CTO at 2,590 m (coefficient -7.6%, 95% CI -13.2 to -2.0; p = .007) when controlling for several confounders. We conclude that lowlanders with COPD staying overnight at 2,590 m experience altitude-induced hypoxaemia and periodic breathing in association with sustained and intermittent cerebral deoxygenation. Although less pronounced than the arterial deoxygenation, the altitude-induced cerebral tissue deoxygenation may represent a risk of brain dysfunction, especially in patients with COPD with nocturnal hypoxaemia at low altitude.


Assuntos
Altitude , Doença Pulmonar Obstrutiva Crônica , Humanos , Hipóxia , Pessoa de Meia-Idade , Oximetria , Oxigênio , Doença Pulmonar Obstrutiva Crônica/complicações
9.
Clin Exp Immunol ; 200(1): 61-72, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-31799703

RESUMO

In addition to their detection in typical X-linked severe combined immunodeficiency, hypomorphic mutations in the interleukin (IL)-2 receptor common gamma chain gene (IL2RG) have been described in patients with atypical clinical and immunological phenotypes. In this leaky clinical phenotype the diagnosis is often delayed, limiting prompt therapy in these patients. Here, we report the biochemical and functional characterization of a nonsense mutation in exon 8 (p.R328X) of IL2RG in two siblings: a 4-year-old boy with lethal Epstein-Barr virus-related lymphoma and his asymptomatic 8-month-old brother with a Tlow B+ natural killer (NK)+ immunophenotype, dysgammaglobulinemia, abnormal lymphocyte proliferation and reduced levels of T cell receptor excision circles. After confirming normal IL-2RG expression (CD132) on T lymphocytes, signal transducer and activator of transcription-1 (STAT-5) phosphorylation was examined to evaluate the functionality of the common gamma chain (γc ), which showed partially preserved function. Co-immunoprecipitation experiments were performed to assess the interaction capacity of the R328X mutant with Janus kinase (JAK)3, concluding that R328X impairs JAK3 binding to γc . Here, we describe how the R328X mutation in IL-2RG may allow partial phosphorylation of STAT-5 through a JAK3-independent pathway. We identified a region of three amino acids in the γc intracellular domain that may be critical for receptor stabilization and allow this alternative signaling. Identification of the functional consequences of pathogenic IL2RG variants at the cellular level is important to enable clearer understanding of partial defects leading to leaky phenotypes.


Assuntos
Códon sem Sentido , Subunidade gama Comum de Receptores de Interleucina/genética , Fator de Transcrição STAT5/metabolismo , Linfócitos T/metabolismo , Doenças por Imunodeficiência Combinada Ligada ao Cromossomo X/genética , Animais , Células COS , Pré-Escolar , Chlorocebus aethiops , Análise Mutacional de DNA/métodos , Feminino , Humanos , Lactente , Masculino , Fenótipo , Fosforilação , Irmãos , Doenças por Imunodeficiência Combinada Ligada ao Cromossomo X/diagnóstico
10.
Phys Rev Lett ; 125(4): 048104, 2020 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-32794805

RESUMO

The RNA world scenario posits replication by RNA polymerases. On early Earth, a geophysical setting is required to separate hybridized strands after their replication and to localize them against diffusion. We present a pointed heat source that drives exponential, RNA-catalyzed amplification of short RNA with high efficiency in a confined chamber. While shorter strands were periodically melted by laminar convection, the temperature gradient caused aggregated polymerase molecules to accumulate, protecting them from degradation in hot regions of the chamber. These findings demonstrate a size-selective pathway for autonomous RNA-based replication in natural nonequilibrium conditions.


Assuntos
Ecossistema , RNA/química , RNA/genética , Catálise , DNA/química , DNA/genética , DNA/metabolismo , Replicação do DNA , RNA Polimerases Dirigidas por DNA/química , RNA Polimerases Dirigidas por DNA/metabolismo , Planeta Terra , Evolução Molecular , Temperatura Alta , Biossíntese de Proteínas/genética , RNA/metabolismo
11.
Nucleic Acids Res ; 46(16): 8417-8434, 2018 09 19.
Artigo em Inglês | MEDLINE | ID: mdl-30032200

RESUMO

The mutation patterns at Cas9 targeted sites contain unique information regarding the nuclease activity and repair mechanisms in mammalian cells. However, analytical framework for extracting such information are lacking. Here, we present a novel computational platform called Rational InDel Meta-Analysis (RIMA) that enables an in-depth comprehensive analysis of Cas9-induced genetic alterations, especially InDels mutations. RIMA can be used to quantitate the contribution of classical microhomology-mediated end joining (c-MMEJ) pathway in the formation of mutations at Cas9 target sites. We used RIMA to compare mutational signatures at 15 independent Cas9 target sites in human A549 wildtype and A549-POLQ knockout cells to elucidate the role of DNA polymerase θ in c-MMEJ. Moreover, the single nucleotide insertions at the Cas9 target sites represent duplications of preceding nucleotides, suggesting that the flexibility of the Cas9 nuclease domains results in both blunt- and staggered-end cuts. Thymine at the fourth nucleotide before protospacer adjacent motif (PAM) results in a two-fold higher occurrence of single nucleotide InDels compared to guanine at the same position. This study provides a novel approach for the characterization of the Cas9 nucleases with improved accuracy in predicting genome editing outcomes and a potential strategy for homology-independent targeted genomic integration.


Assuntos
Proteína 9 Associada à CRISPR/metabolismo , Reparo do DNA por Junção de Extremidades , Mutação INDEL , Software , Células A549 , Algoritmos , Sequência de Bases , Linhagem Celular , DNA Polimerase Dirigida por DNA/deficiência , DNA Polimerase Dirigida por DNA/metabolismo , Conjuntos de Dados como Assunto , Francisella/enzimologia , Humanos , Motivos de Nucleotídeos , Polimorfismo de Nucleotídeo Único , Proteínas Recombinantes/metabolismo , Streptococcus pyogenes/enzimologia , Especificidade por Substrato , DNA Polimerase teta
12.
BMC Biol ; 17(1): 4, 2019 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-30646909

RESUMO

BACKGROUND: Plasma concentration of low-density lipoprotein (LDL) cholesterol is a well-established risk factor for cardiovascular disease. Inhibition of proprotein convertase subtilisin/kexin type 9 (PCSK9), which regulates cholesterol homeostasis, has recently emerged as an approach to reduce cholesterol levels. The development of humanized animal models is an important step to validate and study human drug targets, and use of genome and base editing has been proposed as a mean to target disease alleles. RESULTS: To address the lack of validated models to test the safety and efficacy of techniques to target human PCSK9, we generated a liver-specific human PCSK9 knock-in mouse model (hPCSK9-KI). We showed that plasma concentrations of total cholesterol were higher in hPCSK9-KI than in wildtype mice and increased with age. Treatment with evolocumab, a monoclonal antibody that targets human PCSK9, reduced cholesterol levels in hPCSK9-KI but not in wildtype mice, showing that the hypercholesterolemic phenotype was driven by overexpression of human PCSK9. CRISPR-Cas9-mediated genome editing of human PCSK9 reduced plasma levels of human and not mouse PCSK9, and in parallel reduced plasma concentrations of total cholesterol; genome editing of mouse Pcsk9 did not reduce cholesterol levels. Base editing using a guide RNA that targeted human and mouse PCSK9 reduced plasma levels of human and mouse PCSK9 and total cholesterol. In our mouse model, base editing was more precise than genome editing, and no off-target editing nor chromosomal translocations were identified. CONCLUSIONS: Here, we describe a humanized mouse model with liver-specific expression of human PCSK9 and a human-like hypercholesterolemia phenotype, and demonstrate that this mouse can be used to evaluate antibody and gene editing-based (genome and base editing) therapies to modulate the expression of human PCSK9 and reduce cholesterol levels. We predict that this mouse model will be used in the future to understand the efficacy and safety of novel therapeutic approaches for hypercholesterolemia.


Assuntos
Colesterol/sangue , Hipercolesterolemia/genética , Fígado/metabolismo , Pró-Proteína Convertase 9/genética , Animais , Modelos Animais de Doenças , Edição de Genes , Genoma , Humanos , Hipercolesterolemia/metabolismo , Camundongos , Camundongos Transgênicos
13.
Chemistry ; 23(26): 6357-6369, 2017 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-28256758

RESUMO

We report on a series of electron donor-acceptor conjugates incorporating a ZnII -porphyrin-based electron donor and a variety of non-conjugated rigid linkers connecting to push-pull chromophores as electron acceptors. The electron acceptors comprize multicyanobutadienes or extended tetracyanoquinodimethane analogues with first reduction potentials ranging from -1.67 to -0.23 V vs. Fc+ /Fc in CH2 Cl2 , which are accessible through a final-step cycloaddition-retroelectrocyclization (CA-RE) reaction. Characterization of the conjugates includes electrochemistry, spectroelectrochemistry, DFT calculations, and photophysical measurements in a range of solvents. The collected data allows for the construction of multiple Marcus curves that consider electron-acceptor strength, linker length, and solvent, with data points extending well into the inverted region. The enhancement of electron-vibration couplings, resulting from the rigid spacers and, in particular, multicyano-groups in the conformationally highly fixed push-pull acceptor chromophores affects the charge-recombination kinetics in the inverted region drastically.

14.
Environ Sci Technol ; 51(8): 4494-4502, 2017 04 18.
Artigo em Inglês | MEDLINE | ID: mdl-28297602

RESUMO

Electronic devices contain important resources, including precious and critical raw materials. For an efficient management of these resources, it is important to know where the devices are located, how long they are used and when and how they are disposed of. In this article, we explore the past and current quantities of electronic devices in the in-use stock and storage stock in Switzerland and quantify the flows between the use, storage and disposal phase with dynamic material flow analysis (MFA). Devices included are mobile phones, desktop and laptop computers, monitors, cathode ray tube and flat panel display televisions, DVD players, and headphones. The system for the dynamic MFA was developed as a cascade model dividing the use phase in first, second and further use, with each of these steps consisting of an in-use stock and a storage stock for devices. Using a customized software tool, we apply Monte Carlo simulation to systematically consider data uncertainty. The results highlight the importance of the storage stock, which accounts for 25% (in terms of mass) or 40% (in terms of pieces) of the total stock of electronic devices in 2014. Reuse and storage significantly influence the total lifetime of devices and lead to wide and positively skewed lifetime distributions.


Assuntos
Tubo de Raio Catódico , Eletrônica , Microcomputadores , Modelos Teóricos , Eliminação de Resíduos , Suíça
15.
Nervenarzt ; 88(2): 141-147, 2017 Feb.
Artigo em Alemão | MEDLINE | ID: mdl-28083684

RESUMO

BACKGROUND: Specialized neurological treatment decreases the mortality and morbidity of stroke patients. In many regions of the world an extensive coverage is not available. The cooperation between the Krankenhaus Nordwest (KHNW, Frankfurt, Germany) and the Government of Brunei Darussalam describes the set-up process of a specialized neurological center, including stroke unit, science and rehabilitation center. AIM: The aim of this project called to teach to treat - to treat to teach was to set up a center of excellence in neurology in Brunei Darussalam over a distance of 12,000 km. Treatment options were elucidated by teaching and taught by case examples. MATERIAL AND METHODS: The construction of the Brunei Neuroscience Stroke and Rehabilitation Center (BNSRC) began in July 2010. To overcome the large distance between the department of neurology and neuroradiology at the KHNW and the BNSRC, a telemedical network was established. We provided daily teleteaching for all professions involved in patient care as well as 24/7 availability of teleneurological services from Germany to support the local team on site. RESULTS: In the BNSRC unit over 1000 patients with ischemic and hemorrhagic stroke and all the various acute neurological conditions were treated from July 2010 until July 2016 as inpatients and over 5000 were treated as outpatients. Since 2010, a total of 52 patients with stroke were treated by thrombolysis within the thrombolytic window and 81 hemicraniectomies were performed. CONCLUSION: The project has shown that it is possible to convey specialized neurological knowledge over large distances to provide significant benefits for patients and caregivers.


Assuntos
Educação a Distância/organização & administração , Educação Médica Continuada/organização & administração , Neurologia/educação , Neurologia/organização & administração , Centros de Reabilitação/organização & administração , Reabilitação do Acidente Vascular Cerebral , Brunei , Instrução por Computador/métodos , Alemanha
16.
Chemistry ; 20(1): 202-16, 2014 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-24339058

RESUMO

The synthesis, electrochemical, and photophysical properties of five multicomponent systems featuring a Zn(II) porphyrin (ZnP) linked to one or two anilino donor-substituted pentacyano- (PCBD) or tetracyanobuta-1,3-dienes (TCBD), with and without an interchromophoric bridging spacer (S), are reported: ZnP-S-PCBD (1), ZnP-S-TCBD (2), ZnP-TCBD (3), ZnP-(S-PCBD)2 (4), and ZnP-(S-TCBD)2 (5). By means of steady-state and time-resolved absorption and luminescence spectroscopy (RT and 77 K), photoinduced intramolecular energy and electron transfer processes are evidenced, upon excitation of the porphyrin unit. In systems equipped with the strongest acceptor PCBD and the spacer (1, 4), no evidence of electron transfer is found in toluene, suggesting ZnP→PCBD energy transfer, followed by ultrafast (<10 ps) intrinsic deactivation of the PCBD moiety. In the analogous systems with the weaker acceptor TCBD (2, 5), photoinduced electron transfer occurs in benzonitrile, generating a charge-separated (CS) state lasting 2.3 µs. Such a long lifetime, in light of the high Gibbs free energy for charge recombination (ΔG(CR)=-1.39 eV), suggests a back-electron transfer process occurring in the so-called Marcus inverted region. Notably, in system 3 lacking the interchromophoric spacer, photoinduced charge separation followed by charge recombination occur within 20 ps. This is a consequence of the close vicinity of the donor-acceptor partners and of a virtually activationless electron transfer process. These results indicate that the strongly electron-accepting cyanobuta-1,3-dienes might become promising alternatives to quinone-, perylenediimide-, and fullerene-derived acceptors in multicomponent modules featuring photoinduced electron transfer.

17.
Environ Sci Technol ; 48(4): 2102-13, 2014 Feb 18.
Artigo em Inglês | MEDLINE | ID: mdl-24494583

RESUMO

Dynamic material flow analysis (MFA) is a frequently used method to assess past, present, and future stocks and flows of metals in the anthroposphere. Over the past fifteen years, dynamic MFA has contributed to increased knowledge about the quantities, qualities, and locations of metal-containing goods. This article presents a literature review of the methodologies applied in 60 dynamic MFAs of metals. The review is based on a standardized model description format, the ODD (overview, design concepts, details) protocol. We focus on giving a comprehensive overview of modeling approaches and structure them according to essential aspects, such as their treatment of material dissipation, spatial dimension of flows, or data uncertainty. The reviewed literature features similar basic modeling principles but very diverse extrapolation methods. Basic principles include the calculation of outflows of the in-use stock based on inflow or stock data and a lifetime distribution function. For extrapolating stocks and flows, authors apply constant, linear, exponential, and logistic models or approaches based on socioeconomic variables, such as regression models or the intensity-of-use hypothesis. The consideration and treatment of further aspects, such as dissipation, spatial distribution, and data uncertainty, vary significantly and highly depends on the objectives of each study.


Assuntos
Metais/análise , Modelos Teóricos , Fatores de Tempo , Incerteza
18.
Xenobiotica ; 44(9): 827-41, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24666335

RESUMO

The disposition and metabolism of a Chk-1 inhibitor (LY2603618) was characterized following a 1-h intravenous administration of a single 250-mg dose of [14C]LY2603618 (50 µCi) to patients with advanced or metastatic solid tumors. LY2603618 was well tolerated with no clinically significant adverse events. Study was limited to three patients due to challenges of conducting ADME studies in patients with advanced cancer. Plasma, urine and feces were analyzed for radioactivity, LY2603618 and metabolites. LY2603618 had a half-life of 10.5 h and was the most abundant entity in plasma, accounting for approximately 69% of total plasma radioactivity. The second most abundant metabolites, H2 and H5, accounted for <10% of total circulating radioactivity. The major route of clearance was via CYP450 metabolism. The mean total recovery of radioactivity was 83%, with approximately 72% of the radioactivity recovered in the feces and approximately 11% in the urine. LY2603618 represented approximately 6% and 3% of the administered dose in feces and urine, respectively. A total of 12 metabolites were identified. In vitro phenotyping indicated that CYP3A4 was predominantly responsible for the metabolic clearance of LY2603618. Additionally, aldehyde oxidase was involved in the formation of a unique human and non-human primate metabolite, H5.


Assuntos
Neoplasias/tratamento farmacológico , Compostos de Fenilureia/farmacocinética , Pirazinas/farmacocinética , Administração Intravenosa , Idoso , Cromatografia Líquida , Relação Dose-Resposta a Droga , Interações Medicamentosas , Fezes/química , Feminino , Meia-Vida , Humanos , Masculino , Taxa de Depuração Metabólica , Microssomos Hepáticos/efeitos dos fármacos , Microssomos Hepáticos/metabolismo , Pessoa de Meia-Idade , Compostos de Fenilureia/administração & dosagem , Pirazinas/administração & dosagem , Espectrometria de Massas em Tandem
19.
JDR Clin Trans Res ; 9(2): 185-189, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37565570

RESUMO

KNOWLEDGE TRANSFER STATEMENT: The EU DELIVER project aims to enhance the quality of oral health care through codevelopment and coproduction of solutions together with citizens/patients, providers, and policymakers. The unique multicountry nature of the project will facilitate fast-track prototype development and testing of innovative QI approaches in select countries. Reflective learning regarding the transferability of findings between different countries and settings offers unique opportunities to drive progress toward context-specific implementation of innovative oral health care QI approaches. The collective knowledge gained from the 7 European countries involved in DELIVER can also generate knowhow for improving the quality of oral health care in other countries around the globe.


Assuntos
Aprendizagem , Qualidade da Assistência à Saúde , Humanos , Europa (Continente)
20.
Hypertension ; 81(2): 319-329, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38018457

RESUMO

BACKGROUND: The chronic hypoxia of high-altitude residence poses challenges for tissue oxygen supply and metabolism. Exposure to high altitude during pregnancy increases the incidence of hypertensive disorders of pregnancy and fetal growth restriction and alters placental metabolism. High-altitude ancestry protects against altitude-associated fetal growth restriction, indicating hypoxia tolerance that is genetic in nature. Yet, not all babies are protected and placental pathologies associated with fetal growth restriction occur in some Andean highlanders. METHODS: We examined placental metabolic function in 79 Andeans (18-45 years; 39 preeclamptic and 40 normotensive) living in La Paz, Bolivia (3600-4100 m) delivered by unlabored Cesarean section. Using a selection-nominated approach, we examined links between putatively adaptive genetic variation and phenotypes related to oxygen delivery or placental metabolism. RESULTS: Mitochondrial oxidative capacity was associated with fetal oxygen delivery in normotensive but not preeclamptic placenta and was also suppressed in term preeclamptic pregnancy. Maternal haplotypes in or within 200 kb of selection-nominated genes were associated with lower placental mitochondrial respiratory capacity (PTPRD [protein tyrosine phosphatase receptor-δ]), lower maternal plasma erythropoietin (CPT2 [carnitine palmitoyl transferase 2], proopiomelanocortin, and DNMT3 [DNA methyltransferase 3]), and lower VEGF (vascular endothelial growth factor) in umbilical venous plasma (TBX5 [T-box transcription factor 5]). A fetal haplotype within 200 kb of CPT2 was associated with increased placental mitochondrial complex II capacity, placental nitrotyrosine, and GLUT4 (glucose transporter type 4) protein expression. CONCLUSIONS: Our findings reveal novel associations between putatively adaptive gene regions and phenotypes linked to oxygen delivery and placental metabolic function in highland Andeans, suggesting that such effects may be of genetic origin. Our findings also demonstrate maladaptive metabolic mechanisms in the context of preeclampsia, including dysregulation of placental oxygen consumption.


Assuntos
Placenta , Pré-Eclâmpsia , Humanos , Gravidez , Feminino , Placenta/metabolismo , Cesárea , Retardo do Crescimento Fetal , Fator A de Crescimento do Endotélio Vascular/metabolismo , Hipóxia/metabolismo , Oxigênio/metabolismo , Fenótipo , Genômica
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA