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1.
Phytochemistry ; 202: 113356, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35934105

RESUMO

Like angiosperms from several other families, the leguminous shrub Gastrolobium bilobum R.Br. produces and accumulates fluoroacetate, indicating that it performs the difficult chemistry needed to make a C-F bond. Bioinformatic analyses indicate that plants lack homologs of the only enzymes known to make a C-F bond, i.e., the Actinomycete flurorinases that form 5'-fluoro-5'-deoxyadenosine from S-adenosylmethionine and fluoride ion. To probe the origin of fluoroacetate in G. bilobum we first showed that fluoroacetate accumulates to millimolar levels in young leaves but not older leaves, stems or roots, that leaf fluoroacetate levels vary >20-fold between individual plants and are not markedly raised by sodium fluoride treatment. Young leaves were fed adenosine-13C-ribose, 13C-serine, or 13C-acetate to test plausible biosynthetic routes to fluoroacetate from S-adenosylmethionine, a C3-pyridoxal phosphate complex, or acetyl-CoA, respectively. Incorporation of 13C into expected metabolites confirmed that all three precursors were taken up and metabolized. Consistent with the bioinformatic evidence against an Actinomycete-type pathway, no adenosine-13C-ribose was converted to 13C-fluoroacetate; nor was the characteristic 4-fluorothreonine product of the Actinomycete pathway detected. Similarly, no 13C from acetate or serine was incorporated into fluoroacetate. While not fully excluding the hypothetical pathways that were tested, these negative labeling data imply that G. bilobum creates the C-F bond by an unprecedented biochemical reaction. Enzyme(s) that mediate such a reaction could be of great value in pharmaceutical and agrochemical manufacturing.


Assuntos
Fluoretação , S-Adenosilmetionina , Fluoracetatos/química , Fluoracetatos/metabolismo , Plantas/metabolismo , Ribose , Serina
2.
BMC Urol ; 22(1): 76, 2022 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-35550071

RESUMO

BACKGROUND: To assess the price range in which fexapotide triflutate (FT), a novel injectable, is cost-effective relative to current oral pharmacotherapy (5 α-reductase inhibitor, α-blocker, 5 α-reductase inhibitor and α-blocker combination therapy) as initial therapy followed by surgery for moderate-to-severe benign prostate hyperplasia patients with lower urinary tract symptoms (BPH-LUTS). METHODS: We developed a microsimulation decision-analytic model to track the progression of BPH-LUTS and associated costs and quality-adjusted life years in the target population. The cost-effectiveness analysis was performed from Medicare's perspective with a time horizon of 4 years using 2019 US dollars for all costs. The microsimulation model considered treatment patterns associated with nonadherence to oral medication and progression to surgery. Model parameters were estimated from large randomized controlled trials, literature and expert opinion. For each initial treatment option, simulations were performed with 1000 iterations, with 1000 patients per iteration. RESULTS: Three upfront oral pharmacotherapy options are close in cost-effectiveness, with combination therapy being the most cost-effective option. Relative to upfront oral pharmacotherapy options, FT slightly increases quality-adjusted life years (QALY) per patient (1.870 (95% CI, 1.868 to 1.872) vs. 1.957 (95% CI, 1.955 to 1.959) QALYs). Under the willingness-to-pay (WTP) threshold of $150,000 per QALY, at price per injection of $14,000, FT is about as cost-effective as upfront oral pharmacotherapy options with net monetary benefit (NMB) $279,168.54. Under the WTP threshold of $50,000 per QALY, at price per injection of $5,000, FT is about as cost-effective as upfront oral pharmacotherapy options with NMB $92,135.18. In an alternative 10-year time horizon scenario, FT price per injection at $11,000 and $4,500 makes FT as cost-effective as oral pharmacotherapies. One-way sensitivity analysis showed this result is most sensitive to upfront therapy prices, FT efficacy and initial IPSS. At price per injections of $5,000, $10,000 and $15,000, the probability that FT is either cost-effective or dominant compared to upfront oral pharmacotherapy options using a WTP threshold of $150,000 per QALY is 100%, 93% and 40%, respectively. CONCLUSIONS: Compared to upfront oral pharmacotherapy options, FT would be cost-effective at a price per injection below $14,000, assuming a WTP threshold of $150,000 per QALY.


Assuntos
Hiperplasia Prostática , Idoso , Colestenona 5 alfa-Redutase , Análise Custo-Benefício , Fluoracetatos , Humanos , Hiperplasia , Masculino , Medicare , Peptídeos , Próstata , Hiperplasia Prostática/cirurgia , Estados Unidos
3.
J Occup Environ Hyg ; 19(7): 411-414, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35544736

RESUMO

This paper presents experimental data on the skin absorption of sodium fluoroacetate from a formulated product using an in vitro approach and human skin. Sodium fluoroacetate is a pesticide, typically applied in formulation (1080) for the control of unwanted vertebrate invasive species. It has been assigned a Skin Notation by the ACGIH, and other international workplace health regulatory bodies, due to its predicted ability to permeate intact and abraded human skin. However, there is a distinct lack of experimental data on the skin absorption of sodium fluoroacetate to support this assignment. This study found that sodium fluoroacetate, as a formulated product, permeated the human epidermis when in direct contact for greater than 10 hr. A steady-state flux (Jss) of 1.31 ± 0.043 µg/cm2/hr and a lag time of 6.1 hr was calculated from cumulative skin permeation data. This study provides important empirical evidence in support of the assignment of a Skin Notation.


Assuntos
Composição de Medicamentos , Fluoracetatos , Absorção Cutânea , Pele , Fluoracetatos/administração & dosagem , Fluoracetatos/metabolismo , Fluoracetatos/farmacocinética , Humanos , Técnicas In Vitro , Rodenticidas/administração & dosagem , Rodenticidas/metabolismo , Rodenticidas/farmacocinética , Pele/metabolismo , Fatores de Tempo
4.
Mol Psychiatry ; 27(3): 1683-1693, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-35027678

RESUMO

The fundamental role of epigenetic regulatory mechanisms involved in neuroplasticity and adaptive responses to traumatic brain injury (TBI) is gaining increased recognition. TBI-induced neurodegeneration is associated with several changes in the expression-activity of various epigenetic regulatory enzymes, including histone deacetylases (HDACs). In this study, PET/CT with 6-([18F]trifluoroacetamido)-1- hexanoicanilide ([18F]TFAHA) to image spatial and temporal dynamics of HDACs class IIa expression-activity in brains of adult rats subjected to a weight drop model of diffuse, non-penetrating, mild traumatic brain injury (mTBI). The mTBI model was validated by histopathological and immunohistochemical analyses of brain tissue sections for localization and magnitude of expression of heat-shock protein-70 kDa (HSP70), amyloid precursor protein (APP), cannabinoid receptor-2 (CB2), ionized calcium-binding adapter protein-1 (IBA1), histone deacetylase-4 and -5 (HDAC4 and HDAC5). In comparison to baseline, the expression-activities of HDAC4 and HDAC5 were downregulated in the hippocampus, nucleus accumbens, peri-3rd ventricular part of the thalamus, and substantia nigra at 1-3 days post mTBI, and remained low at 7-8 days post mTBI. Reduced levels of HDAC4 and HDAC5 expression observed in neurons of these brain regions post mTBI were associated with the reduced nuclear and neuropil levels of HDAC4 and HDAC5 with the shift to perinuclear localization of these enzymes. These results support the rationale for the development of therapeutic strategies to upregulate expression-activity of HDACs class IIa post-TBI. PET/CT (MRI) with [18F]TFAHA can facilitate the development and clinical translation of unique therapeutic approaches to upregulate the expression and activity of HDACs class IIa enzymes in the brain after TBI.


Assuntos
Concussão Encefálica , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Anilidas , Animais , Epigênese Genética , Fluoracetatos , Histona Desacetilases/metabolismo , Ratos
5.
Mol Imaging ; 2021: 7545284, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34934405

RESUMO

Developing sensitive diagnostic methods for a longitudinal evaluation of the status of liver fibrosis is a priority. This study is aimed at assessing the significance of longitudinal positron emission tomography (PET) imaging with 18F-labeling tracers for assessing liver fibrosis in a rat model with bile duct ligation (BDL). Twenty-one 6-week-old Sprague-Dawley male rats were used in this study. Longitudinal PET images using [18F]N-2-(2-fluoroethoxy)benzyl)-N-(4-phenoxypyridin-3-yl)acetamide ([18F]FEPPA) (n = 3), [18F]fluoroacetate ([18F]FAc) (n = 3), and 18F-fluoro-2-deoxy-D-glucose ([18F]FDG) (n = 3) were obtained at 0, 1, and 2 weeks after BDL. Biochemical assays, histological assays, immunohistochemical staining assays, and next generation sequencing analyses were also performed at 0 (n = 3), 1 (n = 3), 2 (n = 3), and 3 (n = 3) weeks after BDL, which demonstrated the severe damage in rat livers after BDL. Regarding [18F]FEPPA and [18F]FDG, there was a significantly higher uptake in the liver after BDL (both P < 0.05), which lasted until week 2. However, the uptake of [18F]FAc in the liver was not significantly different before and after BDL (P = 0.28). Collectively, both [18F]FEPPA and [18F]FDG can serve as sensitive probes for detecting the liver fibrosis. However, [18F]FAc is not recommended to diagnose liver fibrosis.


Assuntos
Fluordesoxiglucose F18 , Cirrose Hepática , Animais , Ductos Biliares/diagnóstico por imagem , Ductos Biliares/patologia , Fluoracetatos , Fígado/diagnóstico por imagem , Fígado/patologia , Cirrose Hepática/diagnóstico por imagem , Cirrose Hepática/patologia , Masculino , Ratos , Ratos Sprague-Dawley
6.
Sci Rep ; 11(1): 23379, 2021 12 03.
Artigo em Inglês | MEDLINE | ID: mdl-34862448

RESUMO

A pathogen inactivation step during collection or processing of clinical samples has the potential to reduce infectious risks associated with diagnostic procedures. It is essential that these inactivation methods are demonstrated to be effective, particularly for non-traditional inactivation reagents or for commercial products where the chemical composition is undisclosed. This study assessed inactivation effectiveness of twenty-four next-generation (guanidine-free) nucleic acid extraction lysis buffers and twelve rapid antigen test buffers against SARS-CoV-2, the causative agent of COVID-19. These data have significant safety implications for SARS-CoV-2 diagnostic testing and support the design and evidence-based risk assessment of these procedures.


Assuntos
Antivirais/farmacologia , Teste Sorológico para COVID-19/métodos , SARS-CoV-2/efeitos dos fármacos , Acetamidas , Tampões (Química) , COVID-19/diagnóstico , COVID-19/virologia , Fluoracetatos , Guanidina/efeitos adversos , Humanos , Inativação de Vírus/efeitos dos fármacos
7.
J Am Chem Soc ; 143(47): 19648-19654, 2021 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-34793157

RESUMO

The installation of gem-difluoromethylene groups into organic structures remains a daunting synthetic challenge despite their attractive structural, physical, and biochemical properties. A very efficient retrosynthetic approach would be the functionalization of a single C-F bond from a trifluoromethyl group. Recent advances in this line of attack have enabled the C-F activation of trifluoromethylarenes, but limit the accessible motifs to only benzylic gem-difluorinated scaffolds. In contrast, the C-F activation of trifluoroacetates would enable their use as a bifunctional gem-difluoromethylene synthon. Herein, we report a photochemically mediated method for the defluorinative alkylation of a commodity feedstock: ethyl trifluoroacetate. A novel mechanistic approach was identified using our previously developed diaryl ketone HAT catalyst to enable the hydroalkylation of a diverse suite of alkenes. Furthermore, electrochemical studies revealed that more challenging radical precursors, namely trifluoroacetamides, could also be functionalized via synergistic Lewis acid/photochemical activation. Finally, this method enabled a concise synthetic approach to novel gem-difluoro analogs of FDA-approved pharmaceutical compounds.


Assuntos
Acetamidas/química , Ésteres/síntese química , Fluoracetatos/química , Alcenos/química , Alquilação , Catálise/efeitos da radiação , Cetonas/química , Cetonas/efeitos da radiação , Estrutura Molecular
8.
Int J Mol Sci ; 22(16)2021 Aug 11.
Artigo em Inglês | MEDLINE | ID: mdl-34445342

RESUMO

Epigenetic regulation by histone deacetylase (HDAC) is associated with synaptic plasticity and memory formation, and its aberrant expression has been linked to cognitive disorders, including Alzheimer's disease (AD). This study aimed to investigate the role of class IIa HDAC expression in AD and monitor it in vivo using a novel radiotracer, 6-(tri-fluoroacetamido)-1-hexanoicanilide ([18F]TFAHA). A human neural cell culture model with familial AD (FAD) mutations was established and used for in vitro assays. Positron emission tomography (PET) imaging with [18F]TFAHA was performed in a 3xTg AD mouse model for in vivo evaluation. The results showed a significant increase in HDAC4 expression in response to amyloid-ß (Aß) deposition in the cell model. Moreover, treatment with an HDAC4 selective inhibitor significantly upregulated the expression of neuronal memory-/synaptic plasticity-related genes. In [18F]TFAHA-PET imaging, whole brain or regional uptake was significantly higher in 3xTg AD mice compared with WT mice at 8 and 11 months of age. Our study demonstrated a correlation between class IIa HDACs and Aßs, the therapeutic benefit of a selective inhibitor, and the potential of using [18F]TFAHA as an epigenetic radiotracer for AD, which might facilitate the development of AD-related neuroimaging approaches and therapies.


Assuntos
Doença de Alzheimer/diagnóstico por imagem , Inibidores de Histona Desacetilases/farmacocinética , Histona Desacetilases/metabolismo , Doença de Alzheimer/genética , Doença de Alzheimer/metabolismo , Doença de Alzheimer/patologia , Anilidas/química , Anilidas/farmacocinética , Animais , Encéfalo/diagnóstico por imagem , Encéfalo/metabolismo , Modelos Animais de Doenças , Epigênese Genética/efeitos dos fármacos , Epigênese Genética/fisiologia , Radioisótopos de Flúor/química , Radioisótopos de Flúor/farmacocinética , Fluoracetatos/química , Fluoracetatos/farmacocinética , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Inibidores de Histona Desacetilases/química , Histona Desacetilases/classificação , Histona Desacetilases/genética , Humanos , Camundongos , Camundongos da Linhagem 129 , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Neuroimagem/métodos , Tomografia por Emissão de Pósitrons/métodos , Células Tumorais Cultivadas
9.
ACS Sens ; 6(6): 2129-2135, 2021 06 25.
Artigo em Inglês | MEDLINE | ID: mdl-34080834

RESUMO

Rapid screening monofluoroacetic acid (FAcOH) is responsible for preventing chemical poisoning and food safety events. Whereas surface enhanced Raman scattering (SERS) spectra is an effective tool for detecting forbidden chemicals, it is difficult to directly detect FAcOH due to its small Raman scattering cross section as well as weak adsorption on SERS substrates. In this work, the metal phenolic supramolecular networks (MPNs, i.e., the tannic acid and Fe3+ complex) were fabricated on the commercial nanoanodic aluminum oxide film (NAAO) for assisting in situ chemical deposition highly uniform Ag nanostructure over large areas (the NAAO@AgNS). The low cost and simple fabrication process made the NAAO@AgNS a single-use consumable. For FAcOH detection, a specific derivative reaction between FAcOH and thiosalicylic acid (TSA) was introduced. By taking TSA as the Raman probe, its SERS signal attenuated constantly with the increasing amount of FAcOH. For improving quantitative accuracy, thiocyanate (SCN-) was introduced on the NAAO@AgNS as an internal standard; thus, the characteristic peak intensity ratios associated with TSA and SCN- (I1035/I2125) were fitted to the concentration of FAcOH. It was demonstrated that the SERS assay achieved good sensitivity and selection toward FAcOH with the limit of quantitation (LOD) as low as 50 nmol L-1. The NAAO@AgNS featured with highly sensitive, uniform, and consistent SERS performances could easily extend to wide SERS applications.


Assuntos
Nanoestruturas , Prata , Óxido de Alumínio , Fluoracetatos
10.
Molecules ; 26(6)2021 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-33802864

RESUMO

The aim and novelty of this paper are found in assessing the influence of inhibitors and antibiotics on intact cell MALDI-TOF mass spectra of the cyanobacterium Synechococcus sp. UPOC S4 and to check the impact on reliability of identification. Defining the limits of this method is important for its use in biology and applied science. The compounds included inhibitors of respiration, glycolysis, citrate cycle, and proteosynthesis. They were used at 1-10 µM concentrations and different periods of up to 3 weeks. Cells were also grown without inhibitors in a microgravity because of expected strong effects. Mass spectra were evaluated using controls and interpreted in terms of differential peaks and their assignment to protein sequences by mass. Antibiotics, azide, and bromopyruvate had the greatest impact. The spectral patterns were markedly altered after a prolonged incubation at higher concentrations, which precluded identification in the database of reference spectra. The incubation in microgravity showed a similar effect. These differences were evident in dendrograms constructed from the spectral data. Enzyme inhibitors affected the spectra to a smaller extent. This study shows that only a long-term presence of antibiotics and strong metabolic inhibitors in the medium at 10-5 M concentrations hinders the correct identification of cyanobacteria by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF).


Assuntos
Antibacterianos/toxicidade , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Synechococcus/química , Synechococcus/efeitos dos fármacos , Antimicina A/análogos & derivados , Antimicina A/toxicidade , Azidas/toxicidade , Respiração Celular/efeitos dos fármacos , Cloranfenicol/toxicidade , Ciclo do Ácido Cítrico/efeitos dos fármacos , Desoxiglucose/toxicidade , Fluoracetatos/toxicidade , Glicólise/efeitos dos fármacos , Malonatos/toxicidade , Biossíntese de Proteínas/efeitos dos fármacos , Piruvatos/toxicidade , Reprodutibilidade dos Testes , Estreptomicina/toxicidade , Synechococcus/isolamento & purificação , Synechococcus/metabolismo , Ausência de Peso
11.
J Chromatogr A ; 1646: 462096, 2021 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-33878620

RESUMO

In the past years, the technology for trace residue analysis of plant protection compounds in plant and animal matrices, soil, and water has gradually changed to meet changing regulatory demands. Generally, from the '70s to the '90s of the last century, the active compounds and only a few major metabolites had to be determined in a typical "residue definition". Step by step and within the framework of product safety assessments of the enforcement of residues in dietary matrices and in the environment, further metabolites have come into the authorities focus. Many active substances were formerly determined via gas chromatography (GC) based detection techniques. The introduction of liquid chromatography tandem mass spectrometry (LC-MS/MS) technology in the '90s and the acceptance of this technique, by official bodies at the end of the '90s, has led to a major change for residue analytical laboratories all over the world. Most of the medium to non-polar active compounds as well as many of the more polar metabolites can be detected with this technique, and today LC-MS/MS is the "workhorse" in many residue analytical laboratories in the industry as well as official enforcement labs responsible for analyzing registration-related field studies. With the demand to analyze further breakdown products, more and more polar compounds, or even (permanently) charged target compounds, have now come into the focus of the registration authorities. This now brings standard LC-based techniques to their limits and requires the application of approaches such as hydrophilic interaction chromatography (HILIC) MS/MS or ion chromatography, however these techniques often incur related uncertainties and problems with matrix samples. The aim of this study was to develop a new CE-MS/MS-based approach to reduce the impact of matrix on the separation and detection of trifluoroacetic acid (TFA) and difluoroacetic acid (DFA) in agrochemical field trials. This project used 7 representative examples of fruit, grain and vegetables which had undergone homogenization and extraction with acetonitrile water and filtration before CE-MS/MS analysis. The CE-MS/MS developed reached the limit of quantitation (LOQ) requirement of current legislation for both TFA and DFA (0.01 mg/kg) in all 7 matrices tested. The mean relative standard deviation (RSD) obtained from the repeat analysis of control field trail samples in all matrices, for both TFA and DFA, was less than 10% meeting GLP guidelines. When compared with LC-MS/MS, using on column loading amounts, the CE-MS/MS was 17 - 43 times more sensitive than a standard method and less matrix effects were observed. The developed method was validated under GLP conditions to provide a GLP-validated residue analytical method for the charged metabolites TFA and DFA in matrix samples from GLP field residue trials.


Assuntos
Eletroforese Capilar/métodos , Fluoracetatos/análise , Resíduos de Praguicidas/análise , Espectrometria de Massas em Tandem/métodos , Ácido Trifluoracético/análise , Animais , Grão Comestível/química , Frutas/química , Cromatografia Gasosa-Espectrometria de Massas , Interações Hidrofóbicas e Hidrofílicas , Verduras
12.
Int J Biol Macromol ; 180: 80-87, 2021 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-33722621

RESUMO

Hydrophobization of cellulosic materials and particularly paper products is a commonly used procedure to render papers more resistant to water and moisture. Here, we explore the hydrophobization of unsized paper sheets via the gas phase. We employed three different compounds, namely palmitoyl chloride (PCl), trifluoroacetic anhydride/acetic anhydride (TFAA/Ac2O)) and hexamethyldisilazane (HMDS) which were vaporized and allowed to react with the paper sheets via the gas phase. All routes yielded hydrophobic papers with static water contact angles far above 90° and indicated the formation of covalent bonds. The PCl and TFAA approach negatively impacted the mechanical and optical properties of the paper leading to a decrease in tensile strength and yellowing of the sheets. The HMDS modified papers did not exhibit any differences regarding relevant paper technological parameters (mechanical properties, optical properties, porosity) compared to the non-modified sheets. XPS studies revealed that the HMDS modified samples have a rather low silicon content, pointing at the formation of submonolayers of trimethylsilyl groups on the fiber surfaces in the paper network. This was further investigated by penetration dynamic analysis using ultrasonication, which revealed that the whole fiber network has been homogeneously modified with the silyl groups and not only the very outer surface as for the PCl and the TFAA modified papers. This procedure yields a possibility to study the influence of hydrophobicity on paper sheets and their network properties without changing structural and mechanical paper parameters.


Assuntos
Celulose/química , Papel , Água/química , Molhabilidade , Anidridos Acéticos/química , Fluoracetatos/química , Compostos de Organossilício/química , Palmitatos/química , Espectroscopia Fotoeletrônica , Porosidade , Espectrofotometria Infravermelho , Resistência à Tração , Ondas Ultrassônicas , Volatilização
13.
Medicine (Baltimore) ; 100(9): e25053, 2021 03 05.
Artigo em Inglês | MEDLINE | ID: mdl-33655984

RESUMO

RATIONALE: With the easy access, rodenticide poisoning has been a public health problem in many countries. Characteristics of central nervous system (CNS) lesions induced by rodenticides are scarcely reported. PATIENT CONCERNS: We presented a case of a 40-year-old man with seizure and consciousness disorder, coagulation dysfunction, and symmetric lesions in white matter and corpus callosum. DIAGNOSIS: He was diagnosed with rodenticide poisoning due to bromadiolone and fluoroacetamide. INTERVENTIONS: He was treated with vitamin K, hemoperfusion, acetamide, and calcium gluconate. OUTCOMES: His leukoencephalopathy was reversed rapidly with the improvement of clinical symptoms. LESSONS: This report presented the impact of rodenticide poisoning on CNS and the dynamic changes of brain lesions, and highlighted the importance of timely targeted treatments.


Assuntos
4-Hidroxicumarinas/envenenamento , Coagulação Sanguínea/efeitos dos fármacos , Fluoracetatos/envenenamento , Leucoencefalopatias/induzido quimicamente , Adulto , Humanos , Leucoencefalopatias/sangue , Masculino , Rodenticidas/envenenamento
14.
Cancer Sci ; 112(5): 1963-1974, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33544933

RESUMO

The emergence of acquired resistance is a major concern associated with molecularly targeted kinase inhibitors. The C797S mutation in the epidermal growth factor receptor (EGFR) confers resistance to osimertinib, a third-generation EGFR-tyrosine kinase inhibitor (EGFR-TKI). We report that the derivatization of the marine alkaloid topoisomerase inhibitor lamellarin N provides a structurally new class of EGFR-TKIs. One of these, lamellarin 14, is effective against the C797S mutant EGFR. Bioinformatic analyses revealed that the derivatization transformed the topoisomerase inhibitor-like biological activity of lamellarin N into kinase inhibitor-like activity. Ba/F3 and PC-9 cells expressing the EGFR in-frame deletion within exon 19 (del ex19)/T790M/C797S triple-mutant were sensitive to lamellarin 14 in a dose range similar to the effective dose for cells expressing EGFR del ex19 or del ex19/T790M. Lamellarin 14 decreased the autophosphorylation of EGFR and the downstream signaling in the triple-mutant EGFR PC-9 cells. Furthermore, intraperitoneal administration of 10 mg/kg lamellarin 14 for 17 days suppressed tumor growth of the triple-mutant EGFR PC-9 cells in a mouse xenograft model using BALB/c nu/nu mice. Thus, lamellarin 14 serves as a novel structural backbone for an EGFR-TKI that prevents the development of cross-resistance against known drugs in this class.


Assuntos
Compostos Heterocíclicos de 4 ou mais Anéis/farmacologia , Inibidores de Proteínas Quinases/farmacologia , Acrilamidas/farmacologia , Compostos de Anilina/farmacologia , Animais , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/genética , Ensaios de Seleção de Medicamentos Antitumorais/métodos , Receptores ErbB/antagonistas & inibidores , Receptores ErbB/genética , Receptores ErbB/metabolismo , Fluoracetatos , Expressão Gênica , Compostos Heterocíclicos de 4 ou mais Anéis/química , Xenoenxertos , Humanos , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Terapia de Alvo Molecular , Moluscos/química , Mutagênese Sítio-Dirigida , Mutação , Inibidores de Proteínas Quinases/química
15.
Rev. med. Risaralda ; 26(2): 166-171, jul.-dic. 2020. tab, graf
Artigo em Inglês | LILACS, COLNAL | ID: biblio-1150026

RESUMO

Abstract Introduction: Sodium fluoroacetate, known as compound 1080, was discovered in Germany during the Second World War. It is usually used as a rodenticide, it is an odorless and tasteless substance, with a lethal dose in humans of 2 mg / kg that is why it was withdrawn from the market in some countries, including Colombia; however, it is obtained illegally. This substance has biochemical and physiological effects at the cellular level that alter the transport of citrate at the mitochondrial level, generating accumulation of lactic acid and alteration of the glucose use. The clinical manifestations are nonspecific since there is no any cardinal symptom. Therefore, its diagnosis is made due to high clinical suspicion associated with establishment of exposure to the compound in view of the difficulty to obtain paraclinical confirmation in a timely manner. Methods: We present a case report of intentional ingestion of sodium fluoroacetate in an adolescent that is associated with an infection added to the bloodstream by methicillin- sensitive Staphylococcus aureus (MSSA). The patient developed multiple complications that lead to support in the Intensive Care Unit (ICU) with a satisfactory outcome. In view of the lack of a specific antidote, she was treated with ethanol in order to increase the level of acetate; thus, offering an alternative substrate to the Krebs cycle. It is suggested that the ethanol offers benefits in the acute treatment of these patients. Results: The patient with sodium fluoroacetate poisoning and kidney failure received renal replacement therapy with a favorable evolution and survival at discharge from the intensive care unit of a third-level hospital in the city of Pereira, Risaralda, Colombia. Conclusions: Sodium fluoroacetate poisoning is relatively rare and can cause acute kidney injury and multi-organ failure with a high rate of complications and death. A case of self-inflicted poisoning that received a timely manner continuous renal replacement therapy with a favorable outcome in terms of ICU survival was presented.


Resumen Introducción: El fluoroacetato de sodio ⎯conocido como compuesto 1080⎯, fue descubierto en Alemania durante la segunda guerra mundial, suele ser utilizado como raticida y se caracteriza por ser una sustancia inodora e insabora. En humanos, una dosis de 2 a mg/kg es letal; debido a su toxicidad fue retirado del mercado en algunos países, incluyendo Colombia, no obstante, se consigue de forma ilegal. Esta sustancia tiene efectos bioquímicos y fisiológicos a nivel celular que altera el transporte del citrato a nivel mitocondrial, generando acumulación de ácido láctico y alteración en la utilización de la glucosa. Las manifestaciones clínicas son inespecíficas y no existe un síntoma cardinal. Por ende, su diagnóstico se realiza por alta sospecha clínica, asociado al establecimiento de la exposición al compuesto, ya que la confirmación paraclínica es difícil de realizar oportunamente. Métodos: Se presenta un reporte de caso de ingestión intencional en un adolescente, asociado con infección agregada al torrente sanguíneo por Estafilococos Aureos Meticilino Sensible (EAMS). El paciente desarrolló múltiples complicaciones y requirió asistencia en Unidad de Cuidados Intensivos (UCI) con desenlace satisfactorio. Ya que no se cuenta con antídoto específico , se le dio tratamiento con etanol para aumentar el nivel de acetato, ofreciendo así un sustrato alterno al ciclo de Krebm. Se estima que el etanol puede ofrecer beneficios en el tratamiento agudo de estos pacientes. Resultados: Paciente con intoxicación por fluoroacetato de sodio e insuficiencia renal, recibe terapia de reemplazo renal con un evolución favorable y supervivencia al alta de la Unidad de Cuidados Intensivos de un hospital de tercer nivel en la ciudad de Pereira, Risaralda, Colombia. Conclusiones: La intoxicación por fluoroacetato de sodio es relativamente poco frecuente y puede causar injuria renal aguda y falla multiorgánica con alta tasa de complicaciones y muerte. Se presentó un caso de intoxicación autoinfligida que recibió terapia de reemplazo renal continua temprana con un desenlace favorable en términos de supervivencia en la UCI.


Assuntos
Humanos , Masculino , Adolescente , Staphylococcus aureus , Toxicidade , Fluoracetatos , Meticilina , Acetatos , Rodenticidas , Ciclo do Ácido Cítrico , Ácido Cítrico , Ácido Láctico , Diagnóstico , Etanol , Ingestão de Alimentos , Injúria Renal Aguda , Colecionismo , Sobrevivência , Terapia de Substituição Renal Contínua , Glucose , Hospitais , Unidades de Terapia Intensiva , Chumbo
16.
Sci Rep ; 10(1): 20539, 2020 11 25.
Artigo em Inglês | MEDLINE | ID: mdl-33239700

RESUMO

Dichapetalum cymosum produces the toxic fluorinated metabolite, fluoroacetate, presumably as a defence mechanism. Given the rarity of fluorinated metabolites in nature, the biosynthetic origin and function of fluoroacetate have been of particular interest. However, the mechanism for fluorination in D. cymosum was never elucidated. More importantly, there is a severe lack in knowledge on a genetic level for fluorometabolite-producing plants, impeding research on the subject. Here, we report on the first transcriptome for D. cymosum and investigate the wound response for insights into fluorometabolite production. Mechanical wounding studies were performed and libraries of the unwounded (control) and wounded (30 and 60 min post wounding) plant were sequenced using the Illumina HiSeq platform. A combined reference assembly generated 77,845 transcripts. Using the SwissProt, TrEMBL, GO, eggNOG, KEGG, Pfam, EC and PlantTFDB databases, a 69% annotation rate was achieved. Differential expression analysis revealed the regulation of 364 genes in response to wounding. The wound responses in D. cymosum included key mechanisms relating to signalling cascades, phytohormone regulation, transcription factors and defence-related secondary metabolites. However, the role of fluoroacetate in inducible wound responses remains unclear. Bacterial fluorinases were searched against the D. cymosum transcriptome but transcripts with homology were not detected suggesting the presence of a potentially different fluorinating enzyme in plants. Nevertheless, the transcriptome produced in this study significantly increases genetic resources available for D. cymosum and will assist with future research into fluorometabolite-producing plants.


Assuntos
Fluoracetatos/metabolismo , Magnoliopsida/genética , Folhas de Planta/genética , Estresse Mecânico , Transcriptoma/genética , Vias Biossintéticas/genética , Regulação para Baixo/genética , Regulação da Expressão Gênica de Plantas , Ontologia Genética , Anotação de Sequência Molecular , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Regulação para Cima/genética
17.
Cancer Chemother Pharmacol ; 86(5): 693-699, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-33011861

RESUMO

PURPOSE: Hyperammonemia is an important adverse event associated with 5-fluorouracil (5FU) from 5FU metabolite accumulation. We present a case of an advanced gastric cancer patient with chronic renal failure, who was treated with 5FU/leucovorin (LV) infusion chemotherapy (2-h infusion of LV and 5FU bolus followed by 46-h 5FU continuous infusion on day 1; repeated every 2 weeks) and developed hyperammonemia, with the aim of exploring an appropriate hemodialysis (HD) schedule to resolve its symptoms. METHODS: The blood concentrations of 5FU and its metabolites, α-fluoro-ß-alanine (FBAL), and monofluoroacetate (FA) of a patient who had hyperammonemia from seven courses of palliative 5FU/LV therapy for gastric cancer were measured by liquid chromatography-mass spectrometry. RESULTS: On the third day of the first cycle, the patient presented with symptomatic hyperammonemia relieved by emergency HD. Thereafter, the 5FU dose was reduced; however, in cycles 2-4, the patient developed symptomatic hyperammonemia and underwent HD on day 3 for hyperammonemia management. In cycles 5-7, the timing of scheduled HD administration was changed from day 3 to day 2, preventing symptomatic hyperammonemia. The maximum ammonia and 5FU metabolite levels were significantly lower in cycles 5-7 than in cycles 2-4 (NH3 75 ± 38 vs 303 ± 119 µg/dL, FBAL 13.7 ± 2.5 vs 19.7 ± 2.0 µg/mL, FA 204.0 ± 91.6 vs 395.9 ± 12.6 ng/mL, mean ± standard deviation, all p < 0.05). After seven cycles, partial response was confirmed. CONCLUSION: HD on day 2 instead of 3 may prevent hyperammonemia in 5FU/LV therapy.


Assuntos
Antimetabólitos Antineoplásicos/efeitos adversos , Fluoruracila/efeitos adversos , Hiperamonemia/terapia , Diálise Renal , Neoplasias Gástricas/tratamento farmacológico , Idoso de 80 Anos ou mais , Amônia/sangue , Antimetabólitos Antineoplásicos/administração & dosagem , Antimetabólitos Antineoplásicos/sangue , Antimetabólitos Antineoplásicos/metabolismo , Esquema de Medicação , Fluoracetatos/sangue , Fluoracetatos/metabolismo , Fluoruracila/administração & dosagem , Fluoruracila/sangue , Fluoruracila/metabolismo , Humanos , Hiperamonemia/sangue , Hiperamonemia/induzido quimicamente , Hiperamonemia/diagnóstico , Masculino , Fatores de Tempo , Resultado do Tratamento , beta-Alanina/análogos & derivados , beta-Alanina/sangue , beta-Alanina/metabolismo
18.
J Pharm Biomed Anal ; 190: 113579, 2020 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-32871420

RESUMO

Bisphosphonates (BPs) have broad medical applications against osteoporosis, bone metastasis and Paget's disease. The BP-related jaw osteonecrosis limits their use extensively and has a causal relationship with the process of drug disposition, such as deposition on bone and slow elimination rate. Thus it is imperative to accurately determine BP levels in either clinical or pharmacological/toxicological studies. The ability of trimethylsilyl diazomethane (TMSD) to alkylate the hydroxyls in phosphoric groups is an advantage in terms of decreasing polarity and enhancing mass response of BPs. There are, however, practical limitations to the cumbersome sample preparation procedure, the prolonged reaction time, the by-products and the obstacle to ionization. To overcome these disadvantages, a simplified and rapid precolumn derivatization method with N-(tert-Butyldimethylsilyl)-N-methyl-trifluoroacetamide (MTBSTFA) to quantify etidronate, clodronate, alendronate and zoledronate BPs in rat plasma was established in this work. The derivatization reaction was conducted within 2 min at room temperature, and the unitary di-tert-butyldimethylsilyl (di-tBDMS) derivative was obtained for each BP. Derivatives were separated on a XTerra® MS C8 column (2.1 × 50 mm, 3.5 µm) with the mobile phase of 5 mM ammonium acetate buffer (pH 8.5) and acetonitrile, then detected using electrospray ionization tandem mass spectrometry in negative mode. An easy extraction process instead of the time-consuming solid-phase extraction (SPE) was employed for plasma treatment. The proposed method showed good linearity for BPs over the range of 2-500 ng/mL in 20 µL plasma and high sensitivity owing to the larger molecular ions, higher ionization capacity and more stable fragments of di-tBDMS derivatives. The intra- and inter-batch precision were <13.1 %, and the accuracy ranged within ±10 %. The extraction recovery varied from 75.4 to 88.0 %. The optimized method was successfully applied to characterize the pharmacokinetic profile of zoledronate in rats. Moreover, it is a promising approach for the determination of other phosphoric acid-containing metabolites.


Assuntos
Difosfonatos , Preparações Farmacêuticas , Acetamidas , Animais , Cromatografia Líquida , Fluoracetatos , Ratos , Reprodutibilidade dos Testes
19.
Biomolecules ; 10(7)2020 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-32630260

RESUMO

Fluoroacetamide (FAM) is a small (77 Da) and highly toxic chemical, formerly used as a rodenticide and potentially as a poison by terrorists. Poisoning with FAM has occurred in humans, but few reliably rapid detection methods and antidotes have been reported. Therefore, producing a specific antibody to FAM is not only critical for the development of a fast diagnostic but also a potential treatment. However, achieving this goal is a great challenge, mainly due to the very low molecular weight of FAM. Here, we design two groups of FAM haptens for the first time, maximally exposing the fluorine or amino groups, with the aid of linear aliphatic or phenyl-contained spacer arms. Interestingly, whereas the hapten with fluorine at the far end of the hapten did not induce an antibody response to FAM, the hapten with an amino group at the far end and phenyl-contained spacer arm triggered a significantly specific antibody response. Finally, a monoclonal antibody (mAb) named 5D11 was successfully obtained with an IC50 value of 97 µg mL-1 and negligible cross-reactivities to the other nine functional and structural analogs.


Assuntos
Anticorpos Monoclonais/metabolismo , Fluoracetatos/antagonistas & inibidores , Haptenos/administração & dosagem , Animais , Fluoracetatos/envenenamento , Haptenos/química , Haptenos/imunologia , Imunização , Concentração Inibidora 50 , Camundongos , Camundongos Endogâmicos BALB C , Estrutura Molecular , Baço/imunologia
20.
FEMS Microbiol Ecol ; 96(7)2020 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-32353874

RESUMO

Among the natural halogenic compounds, the plant toxin fluoroacetate (FA) causes livestock fatalities in southern hemisphere countries. Here, we report on the isolation of a rumen bacterium, strain C12-8 that degrades FA under anaerobic conditions. 16S rRNA gene sequence analysis showed this bacterium belonged to the Pyramidobacter genus within the Synergistetes phylum and was 98% similar to Pyramidobacter piscolens W5455 isolated from the human oral cavity. Transmission electron microscopy showed the cell envelope to be unusual, with only one membrane and no obvious external wall. Growth and FA degradation were enhanced by peptide-rich protein hydrolysates but not carbohydrates. End products of metabolism were mainly acetate, propionate/isovalerate and isobutyrate. Strain C12-8 preferentially used peptide-bound amino acids rather than free amino acids. Glycine, serine, threonine, leucine, histidine and isoleucine were utilized as free and peptide-bound amino acids, but there was minimal utilization of alanine, proline, methionine, aspartic acid, lysine and arginine in either form. A survey of several cattle properties in northern Australia showed that strain C12-8 and other FA degrading bacteria affiliated with Cloacibacillus porcorum strain MFA1 were endemic to cattle in the northern beef herd and may help to reduce toxicity.


Assuntos
Fluoracetatos , Rúmen , Animais , Arginina , Austrália , Bactérias , Composição de Bases , Bovinos , DNA Bacteriano/genética , Humanos , Leucina , Filogenia , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Inquéritos e Questionários
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