Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 105
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
EMBO J ; 41(15): e110472, 2022 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-35686621

RESUMO

Microtubules tightly regulate various cellular activities. Our understanding of microtubules is largely based on experiments using microtubule-targeting agents, which, however, are insufficient to dissect the dynamic mechanisms of specific microtubule populations, due to their slow effects on the entire pool of microtubules. To overcome this technological limitation, we have used chemo and optogenetics to disassemble specific microtubule subtypes, including tyrosinated microtubules, primary cilia, mitotic spindles, and intercellular bridges, by rapidly recruiting engineered microtubule-cleaving enzymes onto target microtubules in a reversible manner. Using this approach, we show that acute microtubule disassembly swiftly halts vesicular trafficking and lysosomal dynamics. It also immediately triggers Golgi and ER reorganization and slows the fusion/fission of mitochondria without affecting mitochondrial membrane potential. In addition, cell rigidity is increased after microtubule disruption owing to increased contractile stress fibers. Microtubule disruption furthermore prevents cell division, but does not cause cell death during interphase. Overall, the reported tools facilitate detailed analysis of how microtubules precisely regulate cellular architecture and functions.


Assuntos
Microtúbulos , Fuso Acromático , Interfase , Microtúbulos/metabolismo , Fuso Acromático/metabolismo
2.
EMBO Rep ; 24(1): e54935, 2023 01 09.
Artigo em Inglês | MEDLINE | ID: mdl-36314725

RESUMO

The centrosome, a non-membranous organelle, constrains various soluble molecules locally to execute its functions. As the centrosome is surrounded by various dense components, we hypothesized that it may be bordered by a putative diffusion barrier. After quantitatively measuring the trapping kinetics of soluble proteins of varying size at centrosomes by a chemically inducible diffusion trapping assay, we find that centrosomes are highly accessible to soluble molecules with a Stokes radius of less than 5.8 nm, whereas larger molecules rarely reach centrosomes, indicating the existence of a size-dependent diffusion barrier at centrosomes. The permeability of this barrier is tightly regulated by branched actin filaments outside of centrosomes and it decreases during anaphase when branched actin temporally increases. The actin-based diffusion barrier gates microtubule nucleation by interfering with γ-tubulin ring complex recruitment. We propose that actin filaments spatiotemporally constrain protein complexes at centrosomes in a size-dependent manner.


Assuntos
Microtúbulos , Tubulina (Proteína) , Tubulina (Proteína)/metabolismo , Microtúbulos/metabolismo , Actinas/metabolismo , Centrossomo/metabolismo , Citoesqueleto de Actina/metabolismo
3.
J Biomed Sci ; 29(1): 16, 2022 Feb 23.
Artigo em Inglês | MEDLINE | ID: mdl-35197069

RESUMO

BACKGROUND: Docetaxel has been approved by USFDA as a first-line treatment for castration-resistant prostate cancer (CRPC) patients. Patients receiving androgen deprivation therapy along with docetaxel result in superior survival, lower serum prostate specific antigen (PSA) level, and better quality of life. However, a significant proportion of these patients ultimately develop resistance to docetaxel within months. Caffeic acid phenethyl ester (CAPE), one of the main bioactive components extracted from the propolis, has been reported to be effective for repressing the tumor growth, the migration and invasion of prostate cancer (PCa) cells, as well as the downstream signaling and stability of androgen receptor (AR). We hence determined if combination treatment of docetaxel with CAPE can suppress the proliferation and the survival of docetaxel-resistant PCa cells. METHODS: We established docetaxel-resistant PC/DX25 and DU/DX50 CRPC cell lines from PC-3 and DU-145 human PCa cells, respectively. Proliferation assay, MTT assay, flow cytometry with Annexin V staining, Comet Assay, and nude mice xenograft model were applied to determine the effects of combination treatment on cell proliferation and survival of the docetaxel-resistant PCa cells. Micro-Western Array (MWA) and qRT-PCR were used to investigate the molecular mechanism lying underneath. RESULTS: Combination treatment effectively suppressed the proliferation, survival and tumor growth of docetaxel-resistant PCa cells both in vitro and in nude mice. Comet assay and flow cytometry indicated that combination treatment induced apoptosis in docetaxel-resistant PCa cells. MWA and Western blotting assay revealed that combination treatment suppressed protein expression of Bcl-2, AKT2, c-Myc, apoptosis and caspase activation inhibitor (AVEN), pyruvate kinase M2 (PKM2) but increased protein expression of Bax, caspase 3, cytochrome c, glucose-6-phosphate dehydrogenase (G6PD) and acylglycerol kinase (AGK). Overexpression of Bcl-2 in the docetaxel-resistant PCa cells enhanced cell proliferation of docetaxel-resistant PCa cells under combination treatment. Analysis with qRT-PCR suggested that combination treatment decreased cholesterol biosynthesis genes DHCR24 (24-dehydrocholesterol reductase) and LSS (lanosterol synthase) but increased genes involved in glycolysis and TCA cycle. CONCLUSIONS: Combination treatment of docetaxel with CAPE effectively suppressed the proliferation and survival of docetaxel-resistant PCa cells via inhibition of Bcl-2 and c-Myc as well as induction of metabolism interference. Combination treatment can be beneficial for patients with docetaxel-resistant PCa.


Assuntos
Neoplasias da Próstata , Antagonistas de Androgênios/farmacologia , Animais , Apoptose , Ácidos Cafeicos , Linhagem Celular Tumoral , Proliferação de Células , Docetaxel/farmacologia , Humanos , Masculino , Camundongos , Camundongos Nus , Álcool Feniletílico/análogos & derivados , Qualidade de Vida
4.
J Virol ; 92(4)2018 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-29167343

RESUMO

Virus replication is mediated by interactions between the virus and host. Here, we demonstrate that influenza A virus membrane protein 2 (M2) can be ubiquitinated. The lysine residue at position 78, which is located in the cytoplasmic domain of M2, is essential for M2 ubiquitination. An M2-K78R (Lys78→Arg78) mutant, which produces ubiquitination-deficient M2, showed a severe defect in the production of infectious virus particles. M2-K78R mutant progeny contained more hemagglutinin (HA) proteins, less viral RNAs, and less internal viral proteins, including M1 and NP, than the wild-type virus. Furthermore, most of the M2-K78R mutant viral particles lacked viral ribonucleoproteins upon examination by electron microscopy and exhibited slightly lower densities. We also found that mutant M2 colocalized with the M1 protein to a lesser extent than for the wild-type virus. These findings may account for the reduced incorporation of viral ribonucleoprotein into virions. By blocking the second round of virus infection, we showed that the M2 ubiquitination-defective mutant exhibited normal levels of virus replication during the first round of infection, thereby proving that M2 ubiquitination is involved in the virus production step. Finally, we found that the M2-K78R mutant virus induced autophagy and apoptosis earlier than did the wild-type virus. Collectively, these results suggest that M2 ubiquitination plays an important role in infectious virus production by coordinating the efficient packaging of the viral genome into virus particles and the timing of virus-induced cell death.IMPORTANCE Annual epidemics and recurring pandemics of influenza viruses represent very high global health and economic burdens. The influenza virus M2 protein has been extensively studied for its important roles in virus replication, particularly in virus entry and release. Rimantadine, one of the most commonly used antiviral drugs, binds to the channel lumen near the N terminus of M2 proteins. However, viruses that are resistant to rimantadine have emerged. M2 undergoes several posttranslational modifications, such as phosphorylation and palmitoylation. Here, we reveal that ubiquitination mediates the functional role of M2. A ubiquitination-deficient M2 mutant predominately produced virus particles either lacking viral ribonucleoproteins or containing smaller amounts of internal viral components, resulting in lower infectivity. Our findings offer insights into the mechanism of influenza virus morphogenesis, particularly the functional role of M1-M2 interactions in viral particle assembly, and can be applied to the development of new influenza therapies.


Assuntos
Vírus da Influenza A/genética , Ubiquitinação , Proteínas da Matriz Viral/química , Células A549 , Animais , Apoptose , Cães , Genoma Viral , Células HEK293 , Humanos , Vírus da Influenza A/patogenicidade , Células Madin Darby de Rim Canino , Microscopia Eletrônica , Proteínas da Matriz Viral/genética , Vírion/genética , Vírion/patogenicidade , Montagem de Vírus
5.
Semin Dial ; 32(3): 237-242, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30937954

RESUMO

The gastro-intestinal tract is being increasingly recognized as the site of key pathophysiological processes in the hemodialysis patient. Intestinal dysbiosis, increased intraluminal toxin production, and increased intestinal permeability are commonly observed processes which contribute to the pathogenesis of cardiovascular disease and thus elevated mortality. The acute circulatory effects of dialysis itself may contribute significantly to the development of gastrointestinal dysfunction as a result of both local and distant effects. Additionally, the liver, a relatively unknown entity in this process, has a substantial role as a functional barrier between the portal and systemic circulation and in the metabolism of pathogenic gut-derived uremic toxins. Here we summarize the evidence for acute gastro-intestinal and hepatic effects of hemodialysis and identify gaps in knowledge to date which require further study.


Assuntos
Circulação Hepática/fisiologia , Estresse Oxidativo , Diálise Renal , Insuficiência Renal Crônica/metabolismo , Circulação Esplâncnica/fisiologia , Toxinas Biológicas/efeitos adversos , Humanos , Insuficiência Renal Crônica/fisiopatologia , Insuficiência Renal Crônica/terapia
6.
FASEB J ; 31(12): 5568-5576, 2017 12.
Artigo em Inglês | MEDLINE | ID: mdl-28842423

RESUMO

Liver X receptors (LXRs) are important sensors and regulators for cholesterol, fatty acid, and glucose. LXRs play essential roles in the development and progression of cardiovascular diseases. We examined the effects of T0901317, a potent LXR agonist, on angiogenesis of human umbilical vein endothelial cells (HUVECs). Treatment with T0901317 inhibited the tube formation and migration of HUVECs and reduced the in vivo angiogenesis, as determined by chorioallantoic membrane assay. T0901317 stimulated gene and protein expression of LXR target gene apolipoprotein D (ApoD). Overexpression of ApoD suppressed the tube formation of HUVECs. ApoD interacted with scavenger receptor class B member 1 (SR-B1), while knockdown of SR-B1 blocked suppressive effects of T0901317 on HUVEC migration. T0901317 treatment or overexpression of ApoD lessened expression of proteins regulating angiogenesis, including phospho-eNOS S1177, phospho-Akt T308, phospho-Akt S473, eNOS, mammalian target of rapamycin, VEGF-A, VEGF-C, IL-8, RhoB, matrix metalloproteinase (MMP)-8, -9, and monocyte chemoattractant protein 1. Our study suggested that activation of LXR interferes with angiogenesis through induction of LXR target gene ApoD, which in turn suppresses PI3K-Akt-eNOS signaling, an essential pathway regulating angiogenesis. ApoD may be a potential therapeutic target for tumor angiogenesis.-Lai, C.-J., Cheng, H.-C., Lin, C.-Y., Huang, S.-H., Chen, T.-H., Chung, C.-J., Chang, C.-H., Wang, H.-D., Chuu, C.-P. Activation of liver X receptor suppresses angiogenesis via induction of ApoD.


Assuntos
Apolipoproteínas D/metabolismo , Receptores X do Fígado/metabolismo , Neovascularização Fisiológica/efeitos dos fármacos , Movimento Celular/efeitos dos fármacos , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Células Endoteliais da Veia Umbilical Humana/metabolismo , Humanos , Hidrocarbonetos Fluorados/farmacologia , Interleucina-8/metabolismo , Receptores X do Fígado/agonistas , Óxido Nítrico Sintase Tipo III/metabolismo , Receptores Depuradores Classe B/metabolismo , Transdução de Sinais/efeitos dos fármacos , Sulfonamidas/farmacologia , Serina-Treonina Quinases TOR/metabolismo , Fator A de Crescimento do Endotélio Vascular/metabolismo , Fator C de Crescimento do Endotélio Vascular/metabolismo
7.
BMC Nephrol ; 19(1): 356, 2018 12 12.
Artigo em Inglês | MEDLINE | ID: mdl-30541478

RESUMO

BACKGROUND: The hepatic circulation is involved in adaptive systemic responses to circulatory stress. However, it is vulnerable to both chronic hypervolemia and cardiac dysfunction. The influence of hemodialysis (HD) and ultrafiltration (UF) upon liver water content has been understudied. We conducted a detailed pilot study to characterize the effects of HD upon liver water content and stiffness, referenced to peripheral fluid mobilization and total body water. METHODS: We studied 14 established HD patients without liver disease. Magnetic resonance imaging (MRI) together with ultrasound-based elastography and bioimpedance assessment were employed to measure hepatic water content and stiffness, body composition, and water content in the calf pre- and post-HD. RESULTS: Mean UF volume was 8.13 ± 4.4 mL/kg/hr. Fluid removal was accompanied with effective mobilization of peripheral water (measured with MRI within the thigh) from 0.85 ± 0.21 g/mL to 0.83 ± 0.18 g/mL, and reduction in total body water (38.9 ± 9.4 L to 37.4 ± 8.6 L). However, directly-measured liver water content did not decrease (0.57 ± 0.1 mL/g to 0.79 ± 0.3 m L/g). Liver water content and IVC diameter were inversely proportional (r = - 0.57, p = 0.03), a relationship which persisted after dialysis. CONCLUSIONS: In contrast to the reduced total body water content, liver water content did not decrease post-HD, consistent with a diversion of blood to the hepatic circulation, in those with signs of greater circulatory stress. This novel observation suggests that there is a unique hepatic response to HD with UF and that the liver may play a more important role in intradialytic hypotension and fluid shifts than currently appreciated.


Assuntos
Água Corporal/metabolismo , Fígado/metabolismo , Diálise Renal , Ultrafiltração , Adulto , Idoso , Composição Corporal , Elasticidade , Técnicas de Imagem por Elasticidade , Impedância Elétrica , Feminino , Humanos , Perna (Membro) , Fígado/diagnóstico por imagem , Fígado/fisiopatologia , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Músculo Esquelético/metabolismo , Projetos Piloto , Veia Cava Inferior/diagnóstico por imagem
8.
JAMA ; 319(18): 1870-1879, 2018 05 08.
Artigo em Inglês | MEDLINE | ID: mdl-29801012

RESUMO

Importance: In observational studies, increased water intake is associated with better kidney function. Objective: To determine the effect of coaching to increase water intake on kidney function in adults with chronic kidney disease. Design, Setting, and Participants: The CKD WIT (Chronic Kidney Disease Water Intake Trial) randomized clinical trial was conducted in 9 centers in Ontario, Canada, from 2013 until 2017 (last day of follow-up, May 25, 2017). Patients had stage 3 chronic kidney disease (estimated glomerular filtration rate [eGFR] 30-60 mL/min/1.73 m2 and microalbuminuria or macroalbuminuria) and a 24-hour urine volume of less than 3.0 L. Interventions: Patients in the hydration group (n = 316) were coached to drink more water, and those in the control group (n = 315) were coached to maintain usual intake. Main Outcomes and Measures: The primary outcome was change in kidney function (eGFR from baseline to 12 months). Secondary outcomes included 1-year change in plasma copeptin concentration, creatinine clearance, 24-hour urine albumin, and patient-reported overall quality of health (0 [worst possible] to 10 [best possible]). Results: Of 631 randomized patients (mean age, 65.0 years; men, 63.4%; mean eGFR, 43 mL/min/1.73 m2; median urine albumin, 123 mg/d), 12 died (hydration group [n = 5]; control group [n = 7]). Among 590 survivors with 1-year follow-up measurements (95% of 619), the mean change in 24-hour urine volume was 0.6 L per day higher in the hydration group (95% CI, 0.5 to 0.7; P < .001). The mean change in eGFR was -2.2 mL/min/1.73 m2 in the hydration group and -1.9 mL/min/1.73 m2 in the control group (adjusted between-group difference, -0.3 mL/min/1.73 m2 [95% CI, -1.8 to 1.2; P = .74]). The mean between-group differences (hydration vs control) in secondary outcomes were as follows: plasma copeptin, -2.2 pmol/L (95% CI, -3.9 to -0.5; P = .01); creatinine clearance, 3.6 mL/min/1.73 m2 (95% CI, 0.8 to 6.4; P = .01); urine albumin, 7 mg per day (95% CI, -4 to 51; P = .11); and quality of health, 0.2 points (95% CI, -0.3 to 0.3; P = .22). Conclusions and Relevance: Among adults with chronic kidney disease, coaching to increase water intake compared with coaching to maintain the same water intake did not significantly slow the decline in kidney function after 1 year. However, the study may have been underpowered to detect a clinically important difference. Trial Registration: clinicaltrials.gov Identifier: NCT01766687.


Assuntos
Ingestão de Líquidos , Tutoria , Insuficiência Renal Crônica/terapia , Água/administração & dosagem , Idoso , Progressão da Doença , Feminino , Taxa de Filtração Glomerular , Comportamentos Relacionados com a Saúde , Humanos , Masculino , Pessoa de Meia-Idade , Concentração Osmolar , Educação de Pacientes como Assunto , Insuficiência Renal Crônica/fisiopatologia , Insuficiência Renal Crônica/urina , Urina/química
10.
Pediatr Nephrol ; 32(6): 917-919, 2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-28197886

RESUMO

In a recent article in Pediatric Nephrology, EM Yang and colleagues (Pediatr Nephrol 2017: doi: 10.1007/s00467-016-3587-6 ) published a retrospective cross-sectional study involving a cohort of 442 children with an mean estimated glomerular filtration rate of >60 mL/min/1.73 m2. The authors measured 24-h urine protein excretion (24-h UProt) alongside the morning spot urine protein to creatinine ratio (Prot/Cr) in this group of patients. While the Prot/Cr may be the only feasible way to routinely estimate the daily protein excretion of a young child, inter-individual variability in childrens' urinary creatinine excretion (UCr) may heavily influence the result. The authors sought to determine which equation was the most accurate in predicting UCr. Not only did they discover that the adult Cockcroft-Gault equation worked best, they also found that multiplying the Prot/Cr by the estimated UCr significantly improved the accuracy of the 24-h UProt estimate. In this editorial we discuss both the strengths and limitations of the study by EM Yang and colleagues. We also highlight the importance of adhering to internationally agreed upon reporting guidelines such as the STrengthening the Reporting of OBservational studies in Epidemiology (STROBE) statement.


Assuntos
Creatinina , Adulto , Criança , Estudos Transversais , Humanos , Testes de Função Renal , Proteinúria , Estudos Retrospectivos
11.
Clin Nephrol ; 88(8): 79-85, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28502322

RESUMO

AIMS: Many of the secondary effects of high levels of molybdenum (Mo) overlap with symptoms commonly seen in pediatric patients with chronic kidney disease (CKD). We measured plasma Mo levels and examined the relationship between Mo levels and kidney function. MATERIALS AND METHODS: The study was carried out at the London Health Sciences Centre in London, Ontario, Canada with 36 children and adolescents 4 - 18 years of age with CKD. There were 1 - 6 trace element measurements (Mo and copper (Cu)) per patient. We studied the proportion of patients with abnormal trace element levels and the relationship between trace element levels and estimated glomerular filtration rate (eGFR), calculated using the Filler formula. Plasma Mo and Cu levels were measured using High Resolution Sector Field Inductively Coupled Mass Spectrometry. Anthropomorphic data and blood parameters were collected from our electronic chart program. RESULTS: Median eGFR was 51 mL/min/1.73m2 (35, 75). Median Mo level was 2.00 µg/L (1.40, 2.88). 20 patients had at least one set of Mo levels above the published reference interval in either unit, and the results of 46% of the tests were above the interval. There was a strong negative correlation between the Mo levels and the eGFR (Spearman's r = -0.627, p < 0.0001). CONCLUSIONS: Our study suggests that pediatric patients with CKD have elevated plasma levels of Mo, which may cause secondary effects commonly associated with CKD. The elevated Mo levels in our center's catchment area may cause an accumulation of this trace element in patients with impaired renal function.
.


Assuntos
Molibdênio/sangue , Insuficiência Renal Crônica/sangue , Adolescente , Criança , Pré-Escolar , Estudos Transversais , Feminino , Taxa de Filtração Glomerular , Humanos , Estudos Longitudinais , Masculino , Prevalência , Insuficiência Renal Crônica/fisiopatologia
12.
Environ Toxicol ; 32(8): 2053-2063, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28371048

RESUMO

Epithelial-mesenchymal transition (EMT) is a process through which epithelial cells are transformed into mesenchymal cells; EMT diminishes cell polarity and cell-cell adhesion in cancer cells, leading to enhanced migratory and invasive properties. In this experiment, zymography, cell invasion, and migration assays were performed. Results indicated that Duchesnea indica extracts (DIE) inhibited highly metastatic A549 and H1299 cells by reducing the secretions of matrix metalloproteinase-2 and urokinase-type plasminogen activator. Cell adhesion assay also demonstrated that DIE reduced the cell adhesion properties. Western blot analysis showed that DIE down-regulated the expression of N-cadherin, fibronectin, and vimentin, which are mesenchymal markers, and enhanced that of E-cadherin, which is an epithelial marker. In vivo study showed that tumor growth was significantly reduced in BALB/c nude mouse xenograft model administered with oral gavage of DIE. Therefore, DIE could be exhibits potential as a phytochemical-based platform for prevention and treatment of lung cancer. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 2053-2063, 2017.


Assuntos
Adenocarcinoma/tratamento farmacológico , Antineoplásicos Fitogênicos/farmacologia , Transição Epitelial-Mesenquimal/efeitos dos fármacos , Neoplasias Pulmonares/tratamento farmacológico , Extratos Vegetais/farmacologia , Potentilla/química , Adenocarcinoma/patologia , Adenocarcinoma de Pulmão , Animais , Antígenos CD , Antineoplásicos Fitogênicos/uso terapêutico , Caderinas/metabolismo , Adesão Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Fibronectinas/metabolismo , Humanos , Neoplasias Pulmonares/patologia , Metaloproteinase 2 da Matriz/metabolismo , Camundongos Endogâmicos BALB C , Camundongos Nus , Invasividade Neoplásica , Transplante de Neoplasias , Extratos Vegetais/uso terapêutico , Ativador de Plasminogênio Tipo Uroquinase/metabolismo
13.
Kidney Int ; 90(5): 974-984, 2016 11.
Artigo em Inglês | MEDLINE | ID: mdl-27498206

RESUMO

The purpose of this review is to examine the evidence supporting the application of plasma exchange in renal disease. Our review focuses on the following 6 most common renal indications for plasma exchange based on 2014 registry data from the Canadian Apheresis Group: (i) thrombotic thrombocytopenic purpura (TTP)/hemolytic uremic syndrome; (ii) renal transplantation, (iii) anti-neutrophil cytoplasm antibodies-associated vasculitis, (iv) cryoglobulinemia, (v) focal segmental glomerulosclerosis, and (vi) Goodpasture syndrome. The rarity of these diseases and their rapid, often fatal course mean that randomized controlled studies of plasma exchange are rarely conducted. Although evidence from an adequately powered randomized controlled trial supports the use of plasma exchange to treat thrombotic thrombocytopenic purpura, the use of plasma exchange to treat other renal diseases is only supported by observational and mechanistic studies. Larger well-designed trials are needed to clarify the potential role of plasma exchange in renal disease. Growing international collaboration will improve the quality of future studies in this area.


Assuntos
Nefropatias/terapia , Plasmaferese , Crioglobulinemia/terapia , Rejeição de Enxerto/terapia , Humanos , Púrpura Trombocitopênica Trombótica/terapia
14.
Pediatr Transplant ; 20(1): 34-8, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26589470

RESUMO

Although de novo DSA are associated with inferior graft survival, there are no effective strategies to prevent their formation. Underexposure to MPA (prodrug: MMF) also contributes to rejection rates early after transplantation, but the effect of this phenomenon on the formation of DSA long-term post-transplantation is unknown. Data are expressed as mean (standard deviation). All available data from 32 renal transplant recipients (age at transplantation 7.5 [4.5] yr) on tacrolimus and MPA immunosuppression with an average follow-up of 9.4 (s.d. 4.6) yr were analyzed. DSA were measured using the Luminex assay (>500 MFI was considered DSA-positive). Tacrolimus and MPA levels were measured with the Abbot Tacro II and EMIT assay, respectively. Among 1964 MPA and 3462 tacrolimus trough levels, the average MPA trough level was 3.2 (1.5) mg/L and the average tacrolimus level was 6.7 (2.8) ng/mL. At last follow-up, only 5/32 patients had undetectable DSA, with 5/32 having no class I antibodies and 6/32 having no class II antibodies. DSA formation was associated with a lower minimum MPA trough level (0.27 [0.23] vs. 0.47 [0.18] mg) and cystatin C eGFR (48 [21] vs. 70 [23] mL/min/1.73 m(2)) for class I DSA formers. The average eGFR of patients without class I DSA was 70 (23) mL/min/1.73 m(2), whereas the average eGFR of patients with class I DSA was 48 (21) mL/min/1.73 m(2) (p = 0.0071). MPA trough levels <1.3 mg/L long-term post-transplantation are associated with the formation of DSA. The association between the formation of DSA and minimum MPA exposure may support a strategy for preventing the formation of DSA.


Assuntos
Formação de Anticorpos , Ácido Micofenólico/sangue , Ácido Micofenólico/uso terapêutico , Insuficiência Renal/sangue , Insuficiência Renal/cirurgia , Antropometria , Anticorpos/imunologia , Área Sob a Curva , Criança , Estudos de Coortes , Cistatina C/sangue , Monitoramento de Medicamentos , Feminino , Seguimentos , Taxa de Filtração Glomerular , Rejeição de Enxerto/imunologia , Sobrevivência de Enxerto , Humanos , Imunossupressores/uso terapêutico , Estimativa de Kaplan-Meier , Transplante de Rim , Masculino , Insuficiência Renal/imunologia , Tacrolimo/sangue , Tacrolimo/uso terapêutico , Doadores de Tecidos , Transplantados , Resultado do Tratamento
15.
Pediatr Nephrol ; 31(12): 2175-2177, 2016 12.
Artigo em Inglês | MEDLINE | ID: mdl-27647182

RESUMO

Although measuring creatinine to determine kidney function is currently the clinical standard, new markers such as beta-trace protein (BTP) and beta-2-microglobulin (B2M) are being investigated in an effort to measure glomerular filtration rate more accurately. In their recent publication, Inker et al. (Am J Kidney Dis 2015; 67:40-48) explored the use of these two relatively new markers in combination with some commonly available clinical characteristics in a large cohort of adults with chronic kidney disease. Their research led them to develop three formulae using BTP, B2M, and a combination of the two. The combined formula is particularly attractive as it removes all gender bias, which applies to both serum creatinine and cystatin C. Using data from a cohort of 127 pediatric patients from our center, we sought to determine whether these formulae would be equally as effective in children as in adults. Unfortunately, we found that the formulae cannot be applied to the pediatric population.


Assuntos
Biomarcadores/sangue , Taxa de Filtração Glomerular , Oxirredutases Intramoleculares/sangue , Lipocalinas/sangue , Pediatria/normas , Insuficiência Renal Crônica/diagnóstico , Microglobulina beta-2/sangue , Adolescente , Algoritmos , Criança , Pré-Escolar , Estudos de Coortes , Creatinina/sangue , Cistatina C/sangue , Feminino , Humanos , Testes de Função Renal , Masculino , Padrões de Referência , Insuficiência Renal Crônica/sangue , Insuficiência Renal Crônica/fisiopatologia
16.
Semin Dial ; 28(1): 1-5, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25348058

RESUMO

Dialysis patients have high mortality rate and the leading cause of death is cardiovascular disease. Uremic cardiomyopathy differs from that due to conventional atherosclerosis, where cardiovascular changes result in ineffective circulation and lead to tissue ischemia. Modern dialysis has significant limitations with fluid management probably the most challenging. Current evidence suggests that both volume overload and aggressive fluid removal can induce circulatory stress and multi-organ injury. Furthermore, we do not have accurate volume assessment tools. As a result, targeting euvolemia might result in more harm than benefit with conventional hemodialysis therapy. Therefore, it might be time to consider a degree of permissive over-hydration until we have better tools to both determine ideal weight and improve current renal replacement therapy so that the process of achieving it is not so fraught with the current dangers.


Assuntos
Doenças Cardiovasculares/etiologia , Falência Renal Crônica/terapia , Diálise Renal/efeitos adversos , Desequilíbrio Hidroeletrolítico/prevenção & controle , Líquidos Corporais , Peso Corporal , Hidratação , Humanos , Desequilíbrio Hidroeletrolítico/etiologia
17.
Semin Dial ; 28(2): 180-5, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25482159

RESUMO

Cardiovascular disease is the leading cause of mortality in hemodialysis patients. A chronic state of volume and pressure overload contributes, and central to this is the net sodium balance over the course of a hemodialysis. Of recent interest is the contribution of the dialysate sodium concentration (Dial-Na+) to clinical outcomes. Abundant evidence confirms that in thrice-weekly conventional hemodialysis, higher Dial-Na+ associates with increased intradialytic weight gain, blood pressure, and cardiovascular morbidity and mortality. On the other hand, low Dial-Na+ associates with intradialytic hypotension in the same patient population. However, the effect of Dial-Na+ in short hours daily hemodialysis (SHD; often referred to as "quotidian" dialysis), or nocturnal dialysis (FHND) is less well studied. Increased frequency and duration of exposure to a diffusive sodium gradient modulate the way in which DPNa+ alters interdialytic weight gain, predialysis blood pressure, and intradialytic change in blood pressure. Furthermore, increased dialysis frequency appears to decrease the predialysis plasma sodium setpoint (SP), which is considered stable in conventional thrice-weekly patients. This review discusses criteria to determine optimal Dial-Na+ in conventional, SHD and FHND patients, and identifies areas for future research.


Assuntos
Doenças Cardiovasculares , Soluções para Diálise/química , Falência Renal Crônica/terapia , Diálise Renal/estatística & dados numéricos , Sódio/análise , Doenças Cardiovasculares/epidemiologia , Doenças Cardiovasculares/etiologia , Doenças Cardiovasculares/prevenção & controle , Saúde Global , Humanos , Falência Renal Crônica/complicações , Morbidade/tendências , Fatores de Risco , Taxa de Sobrevida/tendências
18.
Pediatr Transplant ; 19(7): 669-74, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26201386

RESUMO

TDM of MPA, the active compound of MMF, is rarely used despite its substantial intra- and interpatient variability. Little is known about the utility of long-term MPA TDM. Data are expressed as mean (one standard deviation). All available data from 27 renal transplant recipients (mean age at transplantation: 7.7 [5.0] yr) with an average follow-up of 9.3 (4.6) yr were analyzed. MPA levels were measured using the EMIT. GFR was measured using cystatin C and eGFR was calculated using the Filler formula. Intrapatient CV of the trough level was calculated as the ratio of the mean divided by one standard deviation. Mean cystatin C eGFR was 56.9 (24.4) mL/min/1.73 m(2) . There was a weak but significant correlation between the MPA trough level and the AUC (Spearman r = 0.6592, p < 0.0001). A total of 1964 MPA trough levels (73 [45]/patient) were measured, as compared to 3462 Tac trough levels (144 [71]/patient). The average MPA trough level was 3.01 (1.26) mg/L and the average trough Tac level was 7.3 (1.8) ng/mL. Intrapatient CV was statistically higher (p = 0.00093) for MPA at 0.68 (0.29) when compared to Tac with a CV of 0.46 (0.12). CV did not correlate with eGFR. Intrapatient MPA trough level CV is significantly higher than for Tac, while CV for both MPA and Tac was high. MPA trough level monitoring may be a feasible monitoring option to improve patient exposure and possibly outcomes.


Assuntos
Rejeição de Enxerto/prevenção & controle , Imunossupressores/farmacocinética , Transplante de Rim , Ácido Micofenólico/análogos & derivados , Ácido Micofenólico/sangue , Adolescente , Área Sob a Curva , Biomarcadores/sangue , Criança , Pré-Escolar , Monitoramento de Medicamentos , Seguimentos , Humanos , Imunossupressores/uso terapêutico , Ácido Micofenólico/farmacocinética , Ácido Micofenólico/uso terapêutico , Estudos Retrospectivos
19.
Int J Mol Sci ; 16(5): 10748-66, 2015 May 12.
Artigo em Inglês | MEDLINE | ID: mdl-25984601

RESUMO

Head and neck cancers, which affect 650,000 people and cause 350,000 deaths per year, is the sixth leading cancer by cancer incidence and eighth by cancer-related death worldwide. Oral cancer is the most common type of head and neck cancer. More than 90% of oral cancers are oral and oropharyngeal squamous cell carcinoma (OSCC). The overall five-year survival rate of OSCC patients is approximately 63%, which is due to the low response rate to current therapeutic drugs. In this review we discuss the possibility of using caffeic acid phenethyl ester (CAPE) as an alternative treatment for oral cancer. CAPE is a strong antioxidant extracted from honeybee hive propolis. Recent studies indicate that CAPE treatment can effectively suppress the proliferation, survival, and metastasis of oral cancer cells. CAPE treatment inhibits Akt signaling, cell cycle regulatory proteins, NF-κB function, as well as activity of matrix metalloproteinase (MMPs), epidermal growth factor receptor (EGFR), and Cyclooxygenase-2 (COX-2). Therefore, CAPE treatment induces cell cycle arrest and apoptosis in oral cancer cells. According to the evidence that aberrations in the EGFR/phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt) signaling, NF-κB function, COX-2 activity, and MMPs activity are frequently found in oral cancers, and that the phosphorylation of Akt, EGFR, and COX-2 correlates to oral cancer patient survival and clinical progression, we believe that CAPE treatment will be useful for treatment of advanced oral cancer patients.


Assuntos
Ácidos Cafeicos/uso terapêutico , Neoplasias Bucais/tratamento farmacológico , Álcool Feniletílico/análogos & derivados , Animais , Humanos , Álcool Feniletílico/uso terapêutico
20.
Ther Drug Monit ; 36(3): 353-7, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24365986

RESUMO

Concomitant immunosuppression may affect the mycophenolate mofetil exposure. Astellas developed a once-daily modified release formulation of tacrolimus (TacMR) with the potential to reduce the likelihood of nonadherence. It is unknown whether mycophenolic acid (MPA) area under the concentration-time curve (AUC) differs between the 2 tacrolimus (Tac) formulations. In a 2-by-2 crossover design, 20 stable renal transplant recipients on twice-daily Tac either continued their usual Tac therapy (n = 10, group 1) or switched to TacMR for a 12-week period (n = 10, group 2), after which the patients crossed over to the other formulation for another 12-week period. Pharmacokinetic profiles using limited sampling strategies were obtained before randomization (visit 1), and at 12 (visit 2) and 24 weeks (visit 3) at steady state. MPA AUC was calculated using the Pawinski formula. When analyzing visits on Tac, TacMR, and back on Tac combined, the MPA AUC for all 20 patients at baseline was 42.24 (16.98), 37.18 (13.75), and 40.09 (16.69) mg·h·L(-1), respectively, which was not statistically significant using repeated measures (P = 0.1327, R(2) = 0.1109). We conclude that MPA pharmacokinetic profiles are not altered when converting patients from Tac to TacMR.


Assuntos
Imunossupressores/farmacologia , Imunossupressores/farmacocinética , Transplante de Rim , Ácido Micofenólico/análogos & derivados , Tacrolimo/administração & dosagem , Tacrolimo/farmacologia , Adulto , Idoso , Área Sob a Curva , Estudos Cross-Over , Preparações de Ação Retardada , Quimioterapia Combinada , Feminino , Humanos , Imunossupressores/administração & dosagem , Masculino , Pessoa de Meia-Idade , Ácido Micofenólico/farmacocinética
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA