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1.
J Pharm Pharmacol ; 74(8): 1125-1132, 2022 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-35512448

RESUMO

OBJECTIVES: To explore the effect of Acai berry on the pharmacokinetics of Atorvastatin (ATR), Alogliptin (ALO) and Empagliflozin (EMPA) in SD rats. METHOD: Thirty-six rats were divided into six groups (n = 6). First three groups were treated with Acai berry (PO; 250 mg/kg); fourth, fifth and sixth groups received sodium CMC (vehicle) for 10 days and on eleventh day, first and fourth groups were administered with ATR (PO; 10 mg/kg); second and fifth groups with ALO (PO; 25 mg/kg) and third and sixth groups received EMPA (PO; 25 mg/kg). KEY FINDINGS: Co-intake of ATR with Acai berry resulted in slight decrease in Cmax from 41.78 to 34.65 ng/ml and AUC from 227.66 to 136.31 (µg/ml) *h, while there was an increase in the Cmax from 43.43 to 68.71 ng/ml and AUC from 117.6 to 207.1 (µg/ml) *h in ALO treated groups and Cmax from 173.99 to 250.1 ng/ml and AUC from 400.37 to 518.35 (µg/ml) *h in the EMPA-treated groups. CONCLUSION: There was a significant change in the AUC0-t and Cmax of ATR, ALO and EMPA after co-administration with Acai berry. Further studies are recommended to confirm the clinical significance of these interactions.


Assuntos
Euterpe , Interações Ervas-Drogas , Animais , Atorvastatina , Compostos Benzidrílicos , Glucosídeos , Piperidinas , Ratos , Ratos Sprague-Dawley , Uracila/análogos & derivados
2.
J Healthc Eng ; 2022: 1120242, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35340239

RESUMO

Objective: To explore the effects of systematic diet education combined with multidisciplinary nursing on nutritional status and calcium and phosphorus metabolism in patients with diabetic kidney disease (DKD) in uremic phase after treatment with alogliptin. Methods: A total of 90 DKD patients with uremia admitted to our hospital from January 2020 to January 2021 were selected as the research objects. The subjects were divided into combined group and routine group by random number table method. All patients received alogliptin medication. The combination group received systematic dietary education combined with multidisciplinary nursing after the medication, and the conventional group received conventional intervention. Serum albumin, blood calcium, and other indexes were detected between both groups after intervention. Results: After intervention, compared with the conventional group, all nutritional indexes of the combined group were obviously higher, levels of serum phosphorus and calcium-phosphorus product of the combined group were obviously lower (P < 0.001), the incidence of hypoglycemia and hyperglycemia of the combined group was obviously lower (P < 0.05), the total compliance rate of the combined group was obviously higher (P < 0.05), and the SAS score of the combined group was obviously lower (P < 0.001). Conclusion: With conspicuous intervention effect, systematic diet education combined with multidisciplinary nursing is a reliable method that can improve the nutritional status and levels of calcium and phosphorus metabolism, enhance treatment compliance, and reduce anxiety. Further research will help to provide a better solution for patients. This trial is registered with ChiCTR2200057011.


Assuntos
Diabetes Mellitus , Nefropatias Diabéticas , Cálcio , Nefropatias Diabéticas/tratamento farmacológico , Dieta , Feminino , Humanos , Masculino , Estado Nutricional , Fósforo , Piperidinas , Uracila/análogos & derivados
3.
Front Immunol ; 12: 627173, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33777010

RESUMO

Mucosal-associated invariant T (MAIT) cells are a population of innate-like T cells that utilize a semi-invariant T cell receptor (TCR) α chain and are restricted by the highly conserved antigen presenting molecule MR1. MR1 presents microbial riboflavin biosynthesis derived metabolites produced by bacteria and fungi. Consistent with their ability to sense ligands derived from bacterial sources, MAIT cells have been associated with the immune response to a variety of bacterial infections, such as Mycobacterium spp., Salmonella spp. and Escherichia coli. To date, MAIT cells have been studied in humans, non-human primates and mice. However, they have only been putatively identified in cattle by PCR based methods; no phenotypic or functional analyses have been performed. Here, we identified a MAIT cell population in cattle utilizing MR1 tetramers and high-throughput TCR sequencing. Phenotypic analysis of cattle MAIT cells revealed features highly analogous to those of MAIT cells in humans and mice, including expression of an orthologous TRAV1-TRAJ33 TCR α chain, an effector memory phenotype irrespective of tissue localization, and expression of the transcription factors PLZF and EOMES. We determined the frequency of MAIT cells in peripheral blood and multiple tissues, finding that cattle MAIT cells are enriched in mucosal tissues as well as in the mesenteric lymph node. Cattle MAIT cells were responsive to stimulation by 5-OP-RU and riboflavin biosynthesis competent bacteria in vitro. Furthermore, MAIT cells in milk increased in frequency in cows with mastitis. Following challenge with virulent Mycobacterium bovis, a causative agent of bovine tuberculosis and a zoonosis, peripheral blood MAIT cells expressed higher levels of perforin. Thus, MAIT cells are implicated in the immune response to two major bacterial infections in cattle. These data suggest that MAIT cells are functionally highly conserved and that cattle are an excellent large animal model to study the role of MAIT cells in important zoonotic infections.


Assuntos
Infecções Bacterianas/imunologia , Bovinos/imunologia , Células T Invariantes Associadas à Mucosa/imunologia , Animais , Citocinas/farmacologia , Feminino , Antígenos de Histocompatibilidade Classe I/imunologia , Humanos , Masculino , Camundongos , Antígenos de Histocompatibilidade Menor/imunologia , Fenótipo , Ribitol/análogos & derivados , Ribitol/farmacologia , Uracila/análogos & derivados , Uracila/farmacologia
4.
J Nippon Med Sch ; 88(1): 71-79, 2021 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-32475902

RESUMO

BACKGROUND: Combination therapy with an alpha-glucosidase inhibitor or glinide plus a dipeptidyl peptidase-4 inhibitor is thought to be effective for glycemic control because of its effects on postprandial hyperglycemia. However, no studies have directly compared these two combination therapies in relation to efficacy and safety. METHODS: Eighteen patients with type 2 diabetes were studied. All had diabetes not adequately controlled with diet and exercise therapy, an HbA1c level of ≥7.5%, and were not receiving any medication for diabetes. The patients were randomized to either miglitol- or repaglinide-based combination therapy with alogliptin. Patients received miglitol or repaglinide monotherapy for 3 months (the miglitol and repaglinide groups, respectively), after which alogliptin was added to each group as combination therapy for 3 months. A meal tolerance test (MTT) was performed before the start of treatment and at the end of monotherapy and combination therapy. RESULTS: During the study period, decreases in HbA1c and glycated albumin were significantly greater in the repaglinide group than in the miglitol group; however, there was no significant difference between treatment groups at the end of the study. At the end of monotherapy, insulin secretion relative to glucose elevation (ISG0-30: area under the curve of insulin from 0 to 30 min during MTT [AUC0-30 of IRI]/AUC0-30 of plasma glucose) was significantly higher only in the repaglinide group; ISG0-30 did not significantly increase in either group after the addition of alogliptin. CONCLUSIONS: The addition of alogliptin to repaglinide monotherapy did not cause glucose-independent inappropriate insulin secretion and did not appear to increase the incidence of hypoglycemia.


Assuntos
1-Desoxinojirimicina/análogos & derivados , Carbamatos/administração & dosagem , Diabetes Mellitus Tipo 2/tratamento farmacológico , Inibidores da Dipeptidil Peptidase IV/administração & dosagem , Inibidores de Glicosídeo Hidrolases/administração & dosagem , Piperidinas/administração & dosagem , Uracila/análogos & derivados , 1-Desoxinojirimicina/administração & dosagem , 1-Desoxinojirimicina/efeitos adversos , Adulto , Idoso , Carbamatos/efeitos adversos , Quimioterapia Combinada , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Piperidinas/efeitos adversos , Segurança , Resultado do Tratamento , Uracila/administração & dosagem , Uracila/efeitos adversos , Adulto Jovem
5.
PLoS One ; 15(12): e0240338, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33306682

RESUMO

Thyroid hormones are important modulators of metabolic activity in mammals and alter cholesterol and fatty acid levels through activation of the nuclear thyroid hormone receptor (THR). Currently, there are several THRß agonists in clinical trials for the treatment of non-alcoholic steatohepatitis (NASH) that have demonstrated the potential to reduce liver fat and restore liver function. In this study, we tested three THRß-agonism-based NASH treatment candidates, GC-1 (sobetirome), MGL-3196 (resmetirom), and VK2809, and compared their selectivity for THRß and their ability to modulate the expression of genes specific to cholesterol and fatty acid biosynthesis and metabolism in vitro using human hepatic cells and in vivo using a rat model. Treatment with GC-1 upregulated the transcription of CPT1A in the human hepatocyte-derived Huh-7 cell line with a dose-response comparable to that of the native THR ligand, triiodothyronine (T3). VK2809A (active parent of VK2809), MGL-3196, and VK2809 were approximately 30-fold, 1,000-fold, and 2,000-fold less potent than T3, respectively. Additionally, these relative potencies were confirmed by quantification of other direct gene targets of THR, namely, ANGPTL4 and DIO1. In primary human hepatocytes, potencies were conserved for every compound except for VK2809, which showed significantly increased potency that was comparable to that of its active counterpart, VK2809A. In high-fat diet fed rats, a single dose of T3 significantly reduced total cholesterol levels and concurrently increased liver Dio1 and Me1 RNA expression. MGL-3196 treatment resulted in concentration-dependent decreases in total and low-density lipoprotein cholesterol with corresponding increases in liver gene expression, but the compound was significantly less potent than T3. In conclusion, we have implemented a strategy to rank the efficacy of THRß agonists by quantifying changes in the transcription of genes that lead to metabolic alterations, an effect that is directly downstream of THR binding and activation.


Assuntos
Hepatopatia Gordurosa não Alcoólica/tratamento farmacológico , Receptores beta dos Hormônios Tireóideos/agonistas , Transcrição Gênica/efeitos dos fármacos , Acetatos/farmacologia , Acetatos/uso terapêutico , Proteína 4 Semelhante a Angiopoietina/metabolismo , Animais , Linhagem Celular Tumoral , LDL-Colesterol/sangue , LDL-Colesterol/metabolismo , Dieta Hiperlipídica/efeitos adversos , Modelos Animais de Doenças , Avaliação Pré-Clínica de Medicamentos , Hepatócitos , Humanos , Iodeto Peroxidase/genética , Iodeto Peroxidase/metabolismo , Fígado/efeitos dos fármacos , Fígado/metabolismo , Fígado/patologia , Malato Desidrogenase/genética , Malato Desidrogenase/metabolismo , Masculino , Hepatopatia Gordurosa não Alcoólica/sangue , Hepatopatia Gordurosa não Alcoólica/etiologia , Hepatopatia Gordurosa não Alcoólica/patologia , Organofosfonatos/farmacologia , Organofosfonatos/uso terapêutico , Fenóis/farmacologia , Fenóis/uso terapêutico , Cultura Primária de Células , Piridazinas/farmacologia , Piridazinas/uso terapêutico , Ratos , Uracila/análogos & derivados , Uracila/farmacologia , Uracila/uso terapêutico
6.
Molecules ; 25(18)2020 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-32932702

RESUMO

In this study, novel derivatives based on 6-methyluracil and condensed uracil were synthesized, namely, 2,4-quinazoline-2,4-dione with ω-(ortho-nitrilebenzylethylamino) alkyl chains at the N atoms of the pyrimidine ring. In this series of synthesized compounds, the polymethylene chains were varied from having tetra- to hexamethylene chains, and secondary NH, tertiary ethylamino, and quaternary ammonium groups were introduced into the chains. The molecular modeling of the compounds indicated that they could function as dual binding site acetylcholinesterase inhibitors, binding to both the peripheral anionic site and active site. The data from in vitro experiments show that the most active compounds exhibit affinity toward acetylcholinesterase within a nanomolar range, with selectivity for acetylcholinesterase over butyrylcholinesterase reaching four orders of magnitude. In vivo biological assays demonstrated the potency of these compounds in the treatment of memory impairment using an animal model of Alzheimer disease.


Assuntos
Acetilcolinesterase/química , Doença de Alzheimer/tratamento farmacológico , Butirilcolinesterase/química , Inibidores da Colinesterase/farmacologia , Transtornos da Memória/tratamento farmacológico , Uracila/química , Compostos de Amônio/química , Animais , Ânions , Comportamento Animal , Sítios de Ligação , Barreira Hematoencefálica/efeitos dos fármacos , Domínio Catalítico , Modelos Animais de Doenças , Desenho de Fármacos , Avaliação Pré-Clínica de Medicamentos , Humanos , Concentração Inibidora 50 , Aprendizagem em Labirinto , Camundongos , Simulação de Acoplamento Molecular , Escopolamina , Uracila/análogos & derivados
7.
Food Funct ; 11(7): 5782-5787, 2020 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-32618294

RESUMO

Methylglyoxal (MGO) is the main antimicrobial determinant associated with using Manuka Honey as a topical dressing. While direct mechanisms of Manuka honey MGO's antimicrobial activity have been demonstrated, such as disruption of bacterial fimbria and flagella, no interaction of Manuka honey-derived MGO with antimicrobial effector cells of the immune system, such as mucosal-associated invariant T cells (MAIT cells), has yet been reported. MAIT cells are an abundant subset of human T cells, critical for regulating a diverse range of immune functions, including antimicrobial defense mechanisms but also mucosal barrier integrity. MAIT cells become activated by recognition of an important microbial metabolite, 5-amino-6-d-ribitylaminouracil (5-A-RU), which is produced by a wide range of microbial pathogens and commensals. Recognition is afforded when 5-A-RU condenses with mammalian-cell derived MGO to form the potent MAIT cell activator, 5-(2-oxopropylideneamino)-6-d-ribitylaminouracil (5-OP-RU). Formation of 5-OP-RU and its subsequent presentation to MAIT cells by major histocompatibility (MHC)-related molecule 1 (MR1) facilitates host-pathogen and host-commensal interactions. While MGO is a metabolite naturally present in mammalian cells, it is unclear whether exogenous dietary MGO sources, such as those obtained from Manuka honey intake, can contribute to 5-OP-RU formation and enhance MAIT cell activation. In this work, we report that endogenous MGO is the rate-limiting substrate for converting microbial 5-A-RU to 5-OP-RU and that Manuka honey-derived MGO significantly enhances MAIT cell activation in vitro. Our findings posit a novel mechanism by which intake of a food item, such as Manuka honey, can potentially support immune homeostasis by enhancing MAIT cell-specific microbial sensing.


Assuntos
Mel , Fatores Imunológicos/farmacologia , Leptospermum , Ativação Linfocitária/efeitos dos fármacos , Células T Invariantes Associadas à Mucosa/metabolismo , Aldeído Pirúvico/farmacologia , Antibacterianos/farmacologia , Apiterapia , Humanos , Aldeído Pirúvico/metabolismo , Ribitol/análogos & derivados , Ribitol/metabolismo , Uracila/análogos & derivados , Uracila/metabolismo
8.
Cancer Chemother Pharmacol ; 86(1): 45-54, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32529295

RESUMO

PURPOSE: Several clinical guidelines recommend genetic screening of DPYD, including coverage of the variants c.1905 + 1G>A(DPYD*2A), c.1679T>G(DPYD*13), c.2846A>T, and c.1129-5923C>G, before initiating treatment with fluoropyrimidines. However, this screening is often inadequate at predicting the occurrence of severe fluoropyrimidine-induced toxicity in patients. METHODS: Using a complementary approach combining whole DPYD exome sequencing and in silico and structural analysis, as well as phenotyping of DPD by measuring uracilemia (U), dihydrouracilemia (UH2), and the UH2/U ratio in plasma, we were able to characterize and interpret DPYD variants in 28 patients with severe fluoropyrimidine-induced toxicity after negative screening. RESULTS: Twenty-five out of 28 patients (90%) had at least 1 variant in the DPYD coding sequence, and 42% of the variants (6/14) were classified as potentially deleterious by at least 2 of the following algorithms: SIFT, Poly-Phen-2, and DPYD varifier. We identified two very rare deleterious mutations, namely, c.2087G>A (p.R696H) and c.2324T>G (p.L775W). We were able to demonstrate partial DPD deficiency, as measured by the UH2/U ratio in a patient carrying the variant p.L775W for the first time. CONCLUSION: Whole exon sequencing of DPYD in patients with suspicion of partial DPD deficiency can help to identify rare or new variants that lead to enzyme inactivation. Combining different techniques can yield abundant information without increasing workload and cost burden, thus making it a useful approach for implementation in patient care.


Assuntos
Antimetabólitos Antineoplásicos/efeitos adversos , Deficiência da Di-Hidropirimidina Desidrogenase/induzido quimicamente , Deficiência da Di-Hidropirimidina Desidrogenase/genética , Di-Hidrouracila Desidrogenase (NADP)/genética , Variantes Farmacogenômicos/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Capecitabina/efeitos adversos , Simulação por Computador , Di-Hidrouracila Desidrogenase (NADP)/química , Di-Hidrouracila Desidrogenase (NADP)/metabolismo , Feminino , Fluoruracila/administração & dosagem , Fluoruracila/efeitos adversos , Humanos , Masculino , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único , Estudos Retrospectivos , Uracila/análogos & derivados , Uracila/sangue
9.
Plant Cell Rep ; 39(8): 1013-1028, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32328702

RESUMO

KEY MESSAGE: Induction of biphasic interphase-mitotic cells and PCC is connected with an increased level of metabolism in root meristem cells of Allium cepa. Previous experiments using primary roots of Allium cepa exposed to low concentrations of hydroxyurea have shown that long-term DNA replication stress (DRS) disrupts essential links of the S-M checkpoint mechanism, leading meristem cells either to premature chromosome condensation (PCC) or to a specific form of chromatin condensation, establishing biphasic organization of cell nuclei with both interphase and mitotic domains (IM cells). The present study supplements and extends these observations by describing general conditions under which both abnormal types of M-phase cells may occur. The analysis of root apical meristem (RAM) cell proliferation after prolonged mild DRS indicates that a broad spectrum of inhibitors is capable of generating PCC and IM organization of cell nuclei. These included: 5-aminouracil (5-AU, a thymine antagonist), characterized by the highest efficiency in creating cells with the IM phenotype, aphidicolin (APH), an inhibitor of DNA polymerase α, 5-fluorodeoxyuridine (FUdR), an inhibitor of thymidylate synthetase, methotrexate (MTX), a folic acid analog that inhibits purine and pyrimidine synthesis, and cytosine arabinoside (Ara-C), which inhibits DNA replication by forming cleavage complexes with topoisomerase I. As evidenced using fluorescence-based click chemistry assays, continuous treatment of onion RAM cells with 5-AU is associated with an accelerated dynamics of the DNA replication machinery and significantly enhanced levels of transcription and translation. Furthermore, DRS conditions bring about an intensified production of hydrogen peroxide (H2O2), depletion of reduced glutathione (GSH), and some increase in DNA fragmentation, associated with only a slight increase in apoptosis-like programmed cell death events.


Assuntos
Replicação do DNA/efeitos dos fármacos , Interfase/efeitos dos fármacos , Meristema/citologia , Mitose/efeitos dos fármacos , Cebolas/citologia , Uracila/análogos & derivados , Apoptose/efeitos dos fármacos , Núcleo Celular/efeitos dos fármacos , Núcleo Celular/metabolismo , Dano ao DNA , Fragmentação do DNA/efeitos dos fármacos , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Glutationa/metabolismo , Peróxido de Hidrogênio/metabolismo , Cebolas/genética , Biossíntese de Proteínas/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Plântula/efeitos dos fármacos , Plântula/metabolismo , Transcrição Gênica/efeitos dos fármacos , Uracila/farmacologia
10.
Molecules ; 25(8)2020 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-32344516

RESUMO

There has been much effort to exploit fluorescence techniques in the detection of nucleic acids. Canonical nucleic acids are essentially nonfluorescent; however, the modification of the nucleobase has proved to be a fruitful way to engender fluorescence. Much of the chemistry used to prepare modified nucleobases relies on expensive transition metal catalysts. In this work, we describe the synthesis of biaryl quinazolinone-uracil nucleobase analogs prepared by the condensation of anthranilamide derivatives and 5-formyluracil using inexpensive copper salts. A selection of modified nucleobases were prepared, and the effect of methoxy- or nitro- group substitution on the photophysical properties was examined. Both the dihydroquinazolinone and quinazolinone modified uracils have much larger molar absorptivity (~4-8×) than natural uracil and produce modest blue fluorescence. The quinazolinone-modified uracils display higher quantum yields than the corresponding dihydroquinazolinones and also show temperature and viscosity dependent emission consistent with molecular rotor behavior. Peptide nucleic acid (PNA) monomers possessing quinazolinone modified uracils were prepared and incorporated into oligomers. In the sequence context examined, the nitro-substituted, methoxy-substituted and unmodified quinazolinone inserts resulted in a stabilization (∆Tm = +4.0/insert; +2.0/insert; +1.0/insert, respectively) relative to control PNA sequence upon hybridization to complementary DNA. All three derivatives responded to hybridization by the "turn-on" of fluorescence intensity by ca. 3-to-4 fold and may find use as probes for complementary DNA sequences.


Assuntos
Corantes Fluorescentes/química , Ácidos Nucleicos Peptídicos/química , Quinazolinonas/química , Uracila/química , Técnicas de Química Sintética , Modelos Moleculares , Conformação Molecular , Estrutura Molecular , Técnicas de Síntese em Fase Sólida , Análise Espectral , Uracila/análogos & derivados , Uracila/síntese química
11.
Oncol Res Treat ; 43(5): 237-244, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32146471

RESUMO

BACKGROUND: Metastatic colorectal carcinoma (mCRC) is one of the most prevalent types of cancer worldwide. After tumor progression with first- and second-line treatment, trifluridine (FTD) and tipiracil (TPI) has been shown to be a treatment option. SUMMARY: Data from a pivotal phase 3 trial (RECOURSE) and an ongoing phase 3b trial (PRECONNECT) have shown that, in mCRC patients who experienced disease progression after 2 lines of standard therapy, treatment with FTD/TPI is safe and efficacious. Other third-line options include regorafenib, rechallenge with previous treatment lines or personalized approaches based on comprehensive molecular profiling. Randomized trials or sequential studies aiming for the right treatment sequence or predefined subtypes for FTD/TPI or regorafenib as well for rechallenge are missing. However, FTD/TPI as well as regorafenib are recommended by the current ESMO, German S3, and National Comprehensive Cancer Network (NCCN) guidelines in the same situation, thus offering physicians a number of alternatives for the treatment of mCRC patients after the second progression. Key Message: This narrative review summarizes published data and their impact for FTD/TPI as well for regorafenib and rechallenge chemotherapy in clinical practice settings of refractory situations of colorectal cancer.


Assuntos
Neoplasias Colorretais/tratamento farmacológico , Compostos de Fenilureia/uso terapêutico , Piridinas/uso terapêutico , Pirrolidinas/uso terapêutico , Trifluridina/uso terapêutico , Uracila/análogos & derivados , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Ensaios Clínicos Fase III como Assunto , Neoplasias Colorretais/mortalidade , Neoplasias Colorretais/patologia , Progressão da Doença , Combinação de Medicamentos , Humanos , Metástase Neoplásica , Taxa de Sobrevida , Suíça , Timina , Resultado do Tratamento , Uracila/uso terapêutico
12.
J Clin Endocrinol Metab ; 105(3)2020 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-31750515

RESUMO

BACKGROUND: Inconsistent associations between coffee consumption and bone mineral density (BMD) have been observed in epidemiological studies. Moreover, the relationship of bioactive components in coffee with BMD has not been studied. The aim of the current study is to identify coffee-associated metabolites and evaluate their association with BMD. METHODS: Two independent cohorts totaling 564 healthy community-dwelling adults from the Hong Kong Osteoporosis Study (HKOS) who visited in 2001-2010 (N = 329) and 2015-2016 (N = 235) were included. Coffee consumption was self-reported in an food frequency questionnaire. Untargeted metabolomic profiling on fasting serum samples was performed using liquid chromatography-mass spectrometry platforms. BMD at lumbar spine and femoral neck was measured by dual-energy X-ray absorptiometry. Multivariable linear regression and robust regression were used for the association analyses. RESULTS: 12 serum metabolites were positively correlated with coffee consumption after Bonferroni correction for multiple testing (P < 4.87 × 10-5), with quinate, 3-hydroxypyridine sulfate, and trigonelline (N'-methylnicotinate) showing the strongest association. Among these metabolites, 11 known metabolites were previously identified to be associated with coffee intake and 6 of them were related to caffeine metabolism. Habitual coffee intake was positively and significantly associated with BMD at the lumbar spine and femoral neck. The metabolite 5-acetylamino-6-formylamino-3-methyluracil (AFMU) (ß = 0.012, SE = 0.005; P = 0.013) was significantly associated with BMD at the lumbar spine, whereas 3-hydroxyhippurate (ß = 0.007, SE = 0.003, P = 0.027) and trigonelline (ß = 0.007, SE = 0.004; P = 0.043) were significantly associated with BMD at the femoral neck. CONCLUSIONS: 12 metabolites were significantly associated with coffee intake, including 6 caffeine metabolites. Three of them (AFMU, 3-hydroxyhippurate, and trigonelline) were further associated with BMD. These metabolites could be potential biomarkers of coffee consumption and affect bone health.


Assuntos
Densidade Óssea/efeitos dos fármacos , Cafeína/sangue , Café/efeitos adversos , Ingestão de Líquidos/fisiologia , Absorciometria de Fóton , Alcaloides/sangue , Café/metabolismo , Inquéritos sobre Dietas , Feminino , Colo do Fêmur/diagnóstico por imagem , Hipuratos/sangue , Hong Kong/epidemiologia , Humanos , Vida Independente , Modelos Lineares , Vértebras Lombares/diagnóstico por imagem , Masculino , Metaboloma , Pessoa de Meia-Idade , Osteoporose/epidemiologia , Osteoporose/etiologia , Estudos Prospectivos , Uracila/análogos & derivados , Uracila/sangue
13.
Clin Colorectal Cancer ; 18(2): 159-166.e3, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31060856

RESUMO

BACKGROUND: Current guidelines of the National Comprehensive Cancer Network and the European Society of Medical Oncology recommend regorafenib or trifluridine/tipiracil (TAS-102) for third-line therapy of metastatic colorectal cancer (mCRC). We evaluated the impact of regorafenib and TAS-102 treatment on skeletal muscle dynamics and sarcopenia. PATIENTS AND METHODS: This retrospective analysis was based on unselected, consecutive mCRC patients treated with regorafenib and/or TAS-102 during third or later line of therapy at our tertiary-care cancer center in Salzburg, Austria. The skeletal muscle index (SMI, cm2/m2) and sarcopenia were evaluated from cross-sectional computed tomographic images at the level of the third lumbar vertebra. RESULTS: Between January 2013 and April 2018, a total of 45 patients had received regorafenib and/or TAS-102. At initial mCRC diagnosis and at initiation of third-line therapy, 24% and 54% of patients presented with sarcopenia. A statistically significant skeletal muscle loss was observed during regorafenib treatment (median SMI change: -2.75 cm2/m2 [-6.3%]; P < .0001), which was not the case during TAS-102 therapy (-1.5 cm2/m2 [-3.5%]; P = .575). Furthermore, subclassification of patients into 3 groups-normal muscle mass, stable sarcopenia, and new-onset sarcopenia-at initiation of third-line therapy permitted discrimination of overall survival, with 1-year overall survival rates of 61%, 29%, and 16%, respectively (P = .04). CONCLUSION: The frequency of sarcopenia increases during the course of mCRC and negatively affects survival. In contrast to TAS-102, regorafenib is associated with increased skeletal muscle loss during mCRC treatment and should therefore be used with caution in mCRC patients with preexisting sarcopenia or a history of recent weight loss.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Neoplasias Colorretais/tratamento farmacológico , Compostos de Fenilureia/efeitos adversos , Piridinas/efeitos adversos , Pirrolidinas/efeitos adversos , Terapia de Salvação/efeitos adversos , Sarcopenia/epidemiologia , Trifluridina/efeitos adversos , Uracila/análogos & derivados , Adulto , Idoso , Idoso de 80 Anos ou mais , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Áustria , Neoplasias Colorretais/complicações , Neoplasias Colorretais/mortalidade , Combinação de Medicamentos , Feminino , Seguimentos , Humanos , Vértebras Lombares , Masculino , Pessoa de Meia-Idade , Músculo Esquelético/diagnóstico por imagem , Músculo Esquelético/efeitos dos fármacos , Compostos de Fenilureia/administração & dosagem , Piridinas/administração & dosagem , Pirrolidinas/administração & dosagem , Estudos Retrospectivos , Terapia de Salvação/métodos , Sarcopenia/diagnóstico , Sarcopenia/etiologia , Índice de Gravidade de Doença , Taxa de Sobrevida , Timina , Tomografia Computadorizada por Raios X , Trifluridina/administração & dosagem , Uracila/administração & dosagem , Uracila/efeitos adversos
14.
Gastroenterol Hepatol ; 42(3): 164-170, 2019 Mar.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-30293914

RESUMO

INTRODUCTION: In the interferon era, the treatment of hepatitis C virus (HCV) infection in patients on haemodialysis (HD) was limited due to the significant number of treatment-related adverse events (AEs). Direct-acting antivirals (DAAs) have demonstrated their efficacy and safety in the treatment of HCV in patients with advanced chronic kidney disease on haemodialysis. The objective of the study was to evaluate the success in eliminating HCV infection from our dialysis unit using DAAs, and to assess the impact of HCV elimination on clinical and analytical outcomes. PATIENTS AND METHODS: This is a prospective, interventional, single-center study at Hospital Clínic de Barcelona. All HCV-RNA positive patients who received antiviral therapy with DAAs within a 3-year period (2014-2017) were analyzed (n=20). Data on virologic response, adverse events, and biochemical and hematological parameters during and after DAA therapy were analyzed. RESULTS: All patients achieved sustained virologic response (SVR) and only 40% of patients presented with mild AEs. None of the patients presented with HCV reinfection after a 1-year follow-up period, and thus HCV was eliminated from our HD unit. SVR was associated with a significant increase in hemoglobin and hematocrit, and a tendency toward the need for lower doses of iron supplementation with no changes in darbepoetin dose. CONCLUSION: HCV infection can be safely eliminated from HD units with the use of DAAs, preventing new infections in patients and healthcare staff. In the short term, the achievement of SVR is associated with an improvement in the control of anemia.


Assuntos
Anemia/tratamento farmacológico , Antivirais/uso terapêutico , Hepatite C/tratamento farmacológico , Diálise Renal , Insuficiência Renal Crônica/terapia , Resposta Viral Sustentada , 2-Naftilamina , Anemia/etiologia , Anilidas , Carbamatos , Ciclopropanos , Darbepoetina alfa/administração & dosagem , Feminino , Hematínicos/administração & dosagem , Hematócrito , Hemoglobina A , Humanos , Lactamas Macrocíclicas , Compostos Macrocíclicos/uso terapêutico , Masculino , Pessoa de Meia-Idade , Prolina/análogos & derivados , Estudos Prospectivos , Insuficiência Renal Crônica/complicações , Ritonavir/uso terapêutico , Sulfonamidas/uso terapêutico , Uracila/análogos & derivados , Uracila/uso terapêutico , Valina
15.
Eur J Pharm Sci ; 123: 452-458, 2018 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-30077713

RESUMO

Uracil-tegafur (UFT) is an oral anticancer drug containing uracil and 5­fluorouracil prodrug tegafur and is widely used for adjuvant chemotherapy of colorectal cancer. Although clinical data show circadian variations in plasma 5­fluorouracil concentrations during its long-term infusion, and feasibility studies of chronomodulated administration have been previously reported, the circadian pattern in plasma 5­fluorouracil concentration after UFT administrations remains unclear. The aim of this study was to identify factors causing circadian variations in UFT pharmacokinetics and estimate circadian patterns of plasma 5­fluorouracil concentration corresponding to UFT dosing time in rats. Rats were orally administered UFT (15 mg/kg as tegafur) at three different times of the day: 07:00 (23 h after light onset, HALO), 13:00 (5 HALO), or 19:00 (11 HALO), and then plasma concentrations of tegafur, 5­fluorouracil, and uracil were measured after UFT administration. We found that the area under the plasma concentration-time curves (AUC0-∞) of 5­fluorouracil depended on the UFT dosing time of day with a 2.4-fold difference between the peak (at 19:00: 13.7 ±â€¯1.4 µmol·h/L) and trough (at 13:00: 5.6 ±â€¯1.3 µmol·h/L). The simulated population mean clearance of 5­fluorouracil followed a 24-h cosine circadian curve, with the highest value in the early light phase being 2.2-fold higher than the lowest value in the early dark phase, which was an inverse circadian pattern compared to the plasma 5­fluorouracil concentration. The plasma tegafur levels suggested that circadian variation in tegafur absorption and conversion to 5­fluorouracil are factors causing variations in plasma 5­fluorouracil levels following UFT administration. In conclusion, the circadian pattern of 5­fluorouracil clearance and circadian variations in tegafur pharmacokinetics are important determinants of plasma 5­fluorouracil concentrations following UFT administration. This knowledge could help in developing a chronomodulated administration strategy of UFT for improving clinical outcomes.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/farmacocinética , Ritmo Circadiano , Tegafur/administração & dosagem , Tegafur/farmacocinética , Uracila/administração & dosagem , Uracila/farmacocinética , Administração Oral , Animais , Protocolos de Quimioterapia Combinada Antineoplásica/sangue , Biotransformação , Esquema de Medicação , Cronofarmacoterapia , Combinação de Medicamentos , Masculino , Modelos Biológicos , Ratos Wistar , Tegafur/análogos & derivados , Tegafur/sangue , Uracila/análogos & derivados , Uracila/sangue
16.
Crit Rev Oncol Hematol ; 124: 1-10, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29548480

RESUMO

Fluoropyrimidines (5-fluorouracil and capecitabine) are antimetabolite drugs, widely used for the treatment of a variety of cancers, both in adjuvant and in metastatic setting. Although the most common toxicities of these drugs have been extensively studied, robust data and comprehensive characterization still lack concerning fluoropyrimidine-induced cardiotoxicity (FIC), an infrequent but potentially life-threatening toxicity. This review summarizes the current state of knowledge of FIC with special regard to proposed pathogenetic models (coronary vasospasm, endothelium and cardiomyocytes damage, toxic metabolites, dihydropyrimidine dehydrogenase deficiency); risk and predictive factors; efficacy and usefulness in detection of laboratory markers, electrocardiographic changes and cardiac imaging; and specific treatment, including a novel agent, uridine triacetate. The role of alternative chemotherapeutic options, namely raltitrexed and TAS-102, is discussed, and, lastly, we overview the most promising future directions in the research on FIC and development of diagnostic tools, including microRNA technology.


Assuntos
Doenças Cardiovasculares/induzido quimicamente , Fluoruracila/efeitos adversos , Neoplasias/tratamento farmacológico , Pirimidinas/efeitos adversos , Acetatos/uso terapêutico , Capecitabina/uso terapêutico , Cardiotoxicidade/prevenção & controle , Doenças Cardiovasculares/prevenção & controle , Combinação de Medicamentos , Fluoruracila/uso terapêutico , Humanos , Pirimidinas/uso terapêutico , Pirrolidinas , Quinazolinas/uso terapêutico , Tiofenos/uso terapêutico , Timina , Trifluridina/uso terapêutico , Uracila/análogos & derivados , Uracila/uso terapêutico , Uridina/análogos & derivados , Uridina/uso terapêutico
17.
Expert Opin Drug Saf ; 17(3): 235-241, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29325476

RESUMO

OBJECTIVE: To explore the effectiveness and safety of ombitasvir/paritaprevir/ritonavir and dasabuvir (OBV/PTV/r+DSV) for 12 weeks without ribavirin in adults with chronic HCV genotype 1b infection and compensated cirrhosis. METHODS: Observational study of a prospective cohort of adult patients with HCV genotype 1b infection and compensated cirrhosis who received 12 weeks of OBV/PTV/r and DSV without ribavirin. Effectiveness was assessed by recording the percentage of patients achieving sustained virological response at week 12 post-treatment (SVR12). Safety outcomes were based on the incidence of adverse events. RESULTS: Seventy-eight patients were included. The SVR12 rate was 96.1% (95%CI 89.2-99.2). Adverse events were recorded in 78.0% of patients. Of these, 97.7% were grade 1/2. One patient discontinued treatment prematurely owing to adverse events. Eighty-six interactions were detected in 43 patients (55.1%). Overall, 81.4% of interactions required close monitoring, alteration of drug dosage, or timing of administration. In 7.0% of cases, the interactions arose from contraindications that required the suspension of the concomitant drug. In 11.6% of cases, medicinal plants or foods were withdrawn. CONCLUSIONS: The simplified regimen of OBV/PTV/r+DSV administered for 12 weeks is effective and safe in patients with chronic HCV genotype 1b infection and compensated cirrhosis. No adverse reactions related to drug-drug interactions were recorded.


Assuntos
Antivirais/administração & dosagem , Hepacivirus/genética , Hepatite C Crônica/tratamento farmacológico , Cirrose Hepática/tratamento farmacológico , 2-Naftilamina , Idoso , Anilidas/administração & dosagem , Anilidas/efeitos adversos , Antivirais/efeitos adversos , Carbamatos/administração & dosagem , Carbamatos/efeitos adversos , Estudos de Coortes , Ciclopropanos , Interações Medicamentosas , Quimioterapia Combinada , Feminino , Genótipo , Hepatite C Crônica/virologia , Humanos , Lactamas Macrocíclicas , Cirrose Hepática/virologia , Compostos Macrocíclicos/administração & dosagem , Compostos Macrocíclicos/efeitos adversos , Masculino , Pessoa de Meia-Idade , Prolina/análogos & derivados , Estudos Prospectivos , Ritonavir/administração & dosagem , Ritonavir/efeitos adversos , Sulfonamidas/administração & dosagem , Sulfonamidas/efeitos adversos , Resultado do Tratamento , Uracila/administração & dosagem , Uracila/efeitos adversos , Uracila/análogos & derivados , Valina
18.
Cochrane Database Syst Rev ; 7: CD008398, 2017 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-28752564

RESUMO

BACKGROUND: Patients prefer oral to intravenous (IV) palliative chemotherapy, provided that oral therapy is not less effective. We compared the efficacy and safety of oral and IV fluoropyrimidines for treatment of colorectal cancer (CRC). OBJECTIVES: To compare the effects of oral and IV fluoropyrimidine chemotherapy in patients treated with curative or palliative intent for CRC. SEARCH METHODS: We searched the Cochrane Central Register of Controlled Trials (CENTRAL; 2016, Issue 5), along with OVID MEDLINE, OVID Embase, and Web of Science databases, in June 2016. We also searched five clinical trials registers, several conference proceedings, and reference lists from study reports and systematic reviews. We contacted pharmaceutical companies to identify additional studies. SELECTION CRITERIA: We included randomised controlled trials (RCTs) comparing oral and IV fluoropyrimidine chemotherapy in patients treated with curative or palliative intent for CRC. DATA COLLECTION AND ANALYSIS: Three review authors extracted data and assessed risk of bias independently. We assessed the seven domains in the Cochrane 'Risk of bias' tool and three additional domains: schedules of outcome assessment and/or follow-up; use of intention-to-treat analysis; and baseline comparability of treatment arms. MAIN RESULTS: We included nine RCTs (total of 10,918 participants) that examined treatment with curative intent for CRC with neoadjuvant and/or adjuvant chemotherapy. We included 35 RCTs (total of 12,592 participants) that examined treatment with palliative intent for inoperable advanced or metastatic CRC with chemotherapy (31 first-line studies, two second-line studies, and two studies of first- or second-line chemotherapy). All studies included male and female participants, and no studies included participants younger than 18 years of age. Patients treated with curative intent for CRC with neoadjuvant and/or adjuvant chemotherapy • Disease-free survival (DFS): DFS did not differ between participants treated with oral versus IV fluoropyrimidines (hazard ratio (HR) 0.93, 95% confidence interval (CI) 0.87 to 1.00; seven studies, 8903 participants; moderate-quality evidence).• Overall survival (OS): OS did not differ between participants treated with oral versus IV fluoropyrimidines (HR 0.92, 95% CI 0.84 to 1.00; seven studies, 8902 participants analysed; high-quality evidence).• Grade ≥ 3 adverse events (AEs): Participants treated with oral fluoropyrimidines experienced less grade ≥ 3 neutropenia/granulocytopenia (odds ratio (OR) 0.14, 95% CI 0.11 to 0.16; seven studies, 8087 participants; moderate-quality evidence), stomatitis (OR 0.21, 95% CI 0.14 to 0.30; five studies, 4212 participants; low-quality evidence), and any grade ≥ 3 AEs (OR 0.82, 95% CI 0.74 to 0.90; five studies, 7741 participants; low-quality evidence). There was more grade ≥ 3 hand foot syndrome (OR 4.59, 95% CI 2.97 to 7.10; five studies, 5731 participants; low-quality evidence) in patients treated with oral fluoropyrimidines. There were no differences between participants treated with oral versus IV fluoropyrimidines in occurrence of grade ≥ 3 diarrhoea (OR 1.12, 95% CI 0.99 to 1.25; nine studies, 9551 participants; very low-quality evidence), febrile neutropenia (OR 0.59, 95% CI 0.18 to 1.90; four studies, 2925 participants; low-quality evidence), vomiting (OR 1.05, 95% CI 0.83 to 1.34; eight studies, 9385 participants; low-quality evidence), nausea (OR 1.21, 95% CI 0.97 to 1.51; seven studies, 9233 participants; low-quality evidence), mucositis (OR 0.64, 95% CI 0.25 to 1.62; four studies, 2233 participants; very low-quality evidence), and hyperbilirubinaemia (OR 1.67, 95% CI 0.52 to 5.38; three studies, 2757 participants; very low-quality evidence). Patients treated with palliative intent for inoperable advanced or metastatic CRC with chemotherapy • Progression-free survival (PFS): Overall, PFS was inferior in participants treated with oral versus IV fluoropyrimidines (HR 1.06, 95% CI 1.02 to 1.11; 23 studies, 9927 participants; moderate-quality evidence). Whilst PFS was worse in participants treated with oral compared with IV fluoropyrimidines when UFT/Ftorafur or eniluracil with oral 5-fluorouracil (5-FU) was used, PFS did not differ between individuals treated with oral versus IV fluoropyrimidines when capecitabine, doxifluridine, or S-1 was used.• OS: Overall, OS did not differ between participants treated with oral versus IV fluoropyrimidines (HR 1.02, 95% CI 0.99 to 1.05; 29 studies, 12,079 participants; high-quality evidence). OS was inferior in participants treated with oral versus IV fluoropyrimidines when eniluracil with oral 5-fluorouracil (5-FU) was used.• Time to progression (TTP): TTP was inferior in participants treated with oral versus IV fluoropyrimidines (HR 1.07, 95% CI 1.01 to 1.14; six studies, 1970 participants; moderate-quality evidence).• Objective response rate (ORR): ORR did not differ between participants treated with oral versus IV fluoropyrimidines (OR 0.98, 95% CI 0.90 to 1.06; 32 studies, 11,115 participants; moderate-quality evidence).• Grade ≥ 3 AEs: Participants treated with oral fluoropyrimidines experienced less grade ≥ 3 neutropenia/granulocytopenia (OR 0.17, 95% CI 0.15 to 0.18; 29 studies, 11,794 participants; low-quality evidence), febrile neutropenia (OR 0.27, 95% CI 0.21 to 0.36; 19 studies, 9407 participants; moderate-quality evidence), stomatitis (OR 0.26, 95% CI 0.20 to 0.33; 21 studies, 8718 participants; low-quality evidence), mucositis (OR 0.17, 95% CI 0.12 to 0.24; 12 studies, 4962 participants; low-quality evidence), and any grade ≥ 3 AEs (OR 0.83, 95% CI 0.74 to 0.94; 14 studies, 5436 participants; low-quality evidence). There was more grade ≥ 3 diarrhoea (OR 1.66, 95% CI 1.50 to 1.84; 30 studies, 11,997 participants; low-quality evidence) and hand foot syndrome (OR 3.92, 95% CI 2.84 to 5.43; 18 studies, 6481 participants; moderate-quality evidence) in the oral fluoropyrimidine arm. There were no differences between oral and IV fluoropyrimidine arms in terms of grade ≥ 3 vomiting (OR 1.18, 95% CI 1.00 to 1.40; 23 studies, 9528 participants; low-quality evidence), nausea (OR 1.16, 95% CI 0.99 to 1.36; 25 studies, 9796 participants; low-quality evidence), and hyperbilirubinaemia (OR 1.62, 95% CI 0.99 to 2.64; nine studies, 2699 participants; low-quality evidence). AUTHORS' CONCLUSIONS: Results of this review should provide confidence that treatment for CRC with most of the oral fluoropyrimidines commonly used in current clinical practice is similarly efficacious to treatment with IV fluoropyrimidines. Treatment with eniluracil with oral 5-FU was associated with inferior PFS and OS among participants treated with palliative intent for CRC, and eniluracil is no longer being developed. Oral and IV fluoropyrimidines have different patterns of side effects; future research may focus on determining the basis for these differences.


Assuntos
Antineoplásicos/administração & dosagem , Neoplasias Colorretais/tratamento farmacológico , Pirimidinas/administração & dosagem , Administração Oral , Adulto , Antineoplásicos/efeitos adversos , Camptotecina/administração & dosagem , Camptotecina/análogos & derivados , Capecitabina/administração & dosagem , Quimioterapia Adjuvante , Neoplasias Colorretais/mortalidade , Neoplasias Colorretais/patologia , Intervalo Livre de Doença , Feminino , Floxuridina/administração & dosagem , Fluoruracila/administração & dosagem , Humanos , Injeções Intravenosas , Irinotecano , Masculino , Terapia Neoadjuvante , Compostos Organoplatínicos/administração & dosagem , Cuidados Paliativos , Piridinas/administração & dosagem , Ensaios Clínicos Controlados Aleatórios como Assunto , Tegafur/administração & dosagem , Uracila/administração & dosagem , Uracila/análogos & derivados
19.
Free Radic Biol Med ; 104: 249-261, 2017 03.
Artigo em Inglês | MEDLINE | ID: mdl-28108278

RESUMO

Selenium is present in proteins in the form of selenocysteine, where this amino acid serves catalytic oxidoreductase functions. The use of selenocysteine in nature is strongly associated with redox catalysis. However, selenium is also found in a 2-selenouridine moiety at the wobble position of tRNAGlu, tRNAGln and tRNALys. It is thought that the modifications of the wobble position of the tRNA improves the selectivity of the codon-anticodon pair as a result of the physico-chemical changes that result from substitution of sulfur and selenium for oxygen. Both selenocysteine and 2-selenouridine have widespread analogs, cysteine and thiouridine, where sulfur is used instead. To examine the role of selenium in 2-selenouridine, we comparatively analyzed the oxidation reactions of sulfur-containing 2-thiouracil-5-carboxylic acid (s2c5Ura) and its selenium analog 2-selenouracil-5-carboxylic acid (se2c5Ura) using 1H-NMR spectroscopy, 77Se-NMR spectroscopy, and liquid chromatography-mass spectrometry. Treatment of s2c5Ura with hydrogen peroxide led to oxidized intermediates, followed by irreversible desulfurization to form uracil-5-carboxylic acid (c5Ura). In contrast, se2c5Ura oxidation resulted in a diselenide intermediate, followed by conversion to the seleninic acid, both of which could be readily reduced by ascorbate and glutathione. Glutathione and ascorbate only minimally prevented desulfurization of s2c5Ura, whereas very little deselenization of se2c5Ura occurred in the presence of the same antioxidants. In addition, se2c5Ura but not s2c5Ura showed glutathione peroxidase activity, further suggesting that oxidation of se2c5Ura is readily reversible, while oxidation of s2c5Ura is not. The results of the study of these model nucleobases suggest that the use of 2-selenouridine is related to resistance to oxidative inactivation that otherwise characterizes 2-thiouridine. As the use of selenocysteine in proteins also confers resistance to oxidation, our findings suggest a common mechanism for the use of selenium in biology.


Assuntos
Selênio/metabolismo , Selenocisteína/metabolismo , Enxofre/metabolismo , Uracila/metabolismo , Glutationa/metabolismo , Peróxido de Hidrogênio/farmacologia , Espectroscopia de Ressonância Magnética , Compostos Organosselênicos/química , Compostos Organosselênicos/metabolismo , Oxirredução , Estresse Oxidativo , RNA de Transferência/química , RNA de Transferência/metabolismo , Selênio/química , Selenocisteína/química , Enxofre/química , Uracila/análogos & derivados , Uracila/química , Uridina/análogos & derivados , Uridina/química , Uridina/metabolismo
20.
Cancer J ; 22(3): 205-10, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27341600

RESUMO

Increasingly prolonged survival in metastatic colorectal cancer has paralleled the approval of new agents alone and in combination. Most recently, several new agents have sought approval in the heavily pretreated setting, after treatment with standard chemotherapies, alone and in combination, and with anti-vascular endothelial growth factor receptor and anti-epidermal growth factor receptor (for patients with RAS wild-type tumors). These agents have included the multitargeted tyrosine kinase inhibitor (TKI), regorafenib, and the novel antimetabolite combination, TAS-102. Both of these showed improvement in progression-free survival and overall survival compared with placebo controls and were approved in the United States and the rest of the world. Benefits of treatment and toxicities are discussed. Nintedanib, another multitargeted TKI, is already approved by the European Medicines Evaluation Agency for non-small cell lung cancer and has been studied in a similar phase III trial. Results are pending. The risks and benefits of each agent are discussed.


Assuntos
Antineoplásicos/uso terapêutico , Neoplasias Colorretais/tratamento farmacológico , Animais , Antineoplásicos/administração & dosagem , Antineoplásicos/efeitos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Ensaios Clínicos como Assunto , Neoplasias Colorretais/mortalidade , Neoplasias Colorretais/patologia , Combinação de Medicamentos , Avaliação Pré-Clínica de Medicamentos , Humanos , Terapia de Alvo Molecular , Inibidores de Proteínas Quinases/administração & dosagem , Inibidores de Proteínas Quinases/efeitos adversos , Inibidores de Proteínas Quinases/uso terapêutico , Pirrolidinas , Retratamento , Timina , Resultado do Tratamento , Trifluridina/farmacologia , Trifluridina/uso terapêutico , Uracila/análogos & derivados , Uracila/farmacologia , Uracila/uso terapêutico
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