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2.
Ann Hematol ; 102(4): 749-754, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36732419

RESUMO

Intensive chemotherapy (IC) is commonly used to achieve remission in patients with acute myeloid leukemia (AML). Venetoclax plus azacitidine (VEN-AZA) is FDA-approved to treat patients with AML aged ≥ 75 years or who are ineligible for IC. This retrospective analysis used de-identified electronic health records from the US-based Flatiron Health database from patients diagnosed 11/21/2018 to 10/31/2021 to compare treatment outcomes with VEN-AZA vs. IC. Patients were 1:1 propensity score-matched ([Formula: see text]). Assessments included rates of complete remission (CR) and hematopoietic stem cell transplant (HSCT), overall survival (OS), and relapse-free survival (RFS). CR and HSCT rates were higher with IC than with VEN-AZA (60.9% vs. 44.2% [P = 0.006] and 18.1% vs. 8.0% [P = 0.012], respectively). Median OS was 17.7 months in patients treated with IC and 11.3 months with VEN-AZA without censoring (P = 0.278) and 13.7 vs. 10.6 months, respectively, with censoring at HSCT (P = 0.584). Median RFS was 12.0 months in patients treated with IC vs. 9.5 months with VEN-AZA without censoring (P = 0.431) and 6.4 vs. 7.4 months, respectively, with censoring at HSCT (P = 0.444). No OS or RFS differences observed between the two arms reached statistical significance. Randomized controlled trials comparing the two approaches are warranted, as are novel approaches to reduce relapse rates following CR.


Assuntos
Registros Eletrônicos de Saúde , Leucemia Mieloide Aguda , Humanos , Estados Unidos/epidemiologia , Estudos Retrospectivos , Azacitidina/uso terapêutico , Leucemia Mieloide Aguda/terapia , Compostos Bicíclicos Heterocíclicos com Pontes/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico
3.
Leuk Lymphoma ; 62(6): 1411-1421, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33430673

RESUMO

To describe real-world treatment patterns and outcomes among adult patients with myelodysplastic syndromes (MDS) treated with hypomethylating agents (HMA), patients were identified in the SEER-Medicare database (01/2006-12/2016); 3,046 patients with MDS treated with HMA were included. An algorithm was developed to categorize patients into MDS risk groups: the majority of patients were classified as Higher-risk (70.9%), 8.0% as Intermediate-risk, and 21.1% as Unknown-risk. Overall, 77.4% of patients initiated azacitidine and 22.6% decitabine; they received an average of 5.1 index-HMA cycles, of which 90.9% were complete with a median cycle duration of 28 days. Median survival was 11.6, 18.4, and 19.1 months for the Higher-risk, Intermediate-risk, and Unknown-risk groups, respectively. Median time-to-AML transformation was 19.3 months for the Higher-risk group and 50.4 months for the Intermediate-risk group (not reached for Unknown-risk). Data highlight the unmet medical needs of patients with MDS treated with HMA, particularly for the Higher-risk MDS group.


Assuntos
Antimetabólitos Antineoplásicos , Síndromes Mielodisplásicas , Adulto , Idoso , Antimetabólitos Antineoplásicos/uso terapêutico , Azacitidina/uso terapêutico , Decitabina/uso terapêutico , Humanos , Medicare , Síndromes Mielodisplásicas/tratamento farmacológico , Resultado do Tratamento , Estados Unidos/epidemiologia
4.
J Med Econ ; 24(1): 234-243, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33472483

RESUMO

AIMS: To describe healthcare resource utilization (HRU) and costs in patients with myelodysplastic syndromes (MDS) treated with hypomethylating agents (HMA) based on HMA-treatment response. MATERIALS AND METHODS: SEER-Medicare data (January 2006-December 2016) were used to identify adults diagnosed with MDS (SEER: January 2009-December 2015) initiated on HMA (index date). HMA-treatment success (indicators: ≥7 HMA cycles, stem cell transplantation, and transfusion independence) or failure (indicators: acute myeloid leukemia [AML], AML-like treatment, and death) was determined using a claim-based algorithm. HRU and costs were assessed from the index date to 1-year post-index, overall and stratified by HMA-treatment success or failure. Among patients with HMA-treatment failure, HRU and costs were also assessed from failure to 1-year post-failure. RESULTS: The study included 3,046 patients (mean age: 77.4 years; females: 36.8%). Rates of HMA-treatment success and failure were 44.4% and 76.2%, respectively (20.6% had HMA-treatment success then failure). Overall, patients had 15.2 inpatient admissions per-100-patients-per-month (median follow-up: 5.9 months). Patients with HMA-treatment success had 7.5 inpatient admissions per-100-patients-per-month (median follow-up: 12.0 months), while those with HMA-treatment failure had 20.4 and 35.3 admissions per-100-patients-per-month pre- and post-HMA-treatment failure, respectively (median follow-up: 4.3 and 1.8 months, pre- and post-HMA-treatment failure, respectively). Mean total healthcare costs were $12,494 per-patient-per-month overall, $8,069 per-patient-per-month among patients with HMA-treatment success, and $13,809 and $19,242 per-patient-per-month pre- and post-HMA-treatment failure, respectively. Outpatient costs (68.3%) were the main contributor of total healthcare costs overall, while inpatient costs (80.3%) were the main cost driver post-HMA-treatment failure. LIMITATIONS: Without available laboratory test results, clinical indicators observed in claims were used to assess HMA-treatment response. CONCLUSIONS: Over 75% of patients with MDS failed HMA-treatment within 6 months of initiation and were observed with more inpatient admissions than those with HMA-treatment success, translating into substantially higher healthcare costs. HMA-treatment failure results in an important economic burden in MDS patients.


Assuntos
Leucemia Mieloide Aguda , Síndromes Mielodisplásicas , Idoso , Feminino , Custos de Cuidados de Saúde , Humanos , Leucemia Mieloide Aguda/tratamento farmacológico , Medicare , Síndromes Mielodisplásicas/tratamento farmacológico , Aceitação pelo Paciente de Cuidados de Saúde , Estudos Retrospectivos , Estados Unidos
5.
Bone Marrow Transplant ; 56(5): 1180-1189, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33288862

RESUMO

We evaluated standard-of-care (SOC) treatment with or without midostaurin to prevent relapse following allogeneic hematopoietic stem cell transplant (alloHSCT) in patients with acute myeloid leukemia (AML) harboring internal tandem duplication (ITD) in FLT3. Adults (aged 18-70 years) who received alloHSCT in first complete remission, had achieved hematologic recovery, and were transfusion independent were randomized to receive SOC with or without midostaurin (50 mg twice daily) continuously in twelve 4-week cycles. The primary endpoint was relapse-free survival (RFS) 18 months post-alloHSCT. Sixty patients were randomized (30/arm); 30 completed all 12 cycles (midostaurin + SOC, n = 16; SOC, n = 14). The estimated 18-month RFS (95% CI) was 89% (69-96%) in the midostaurin arm and 76% (54-88%) in the SOC arm (hazard ratio, 0.46 [95% CI, 0.12-1.86]; P = 0.27); estimated relapse rates were 11% and 24%, respectively. Inhibition of FLT3 phosphorylation to <70% of baseline (achieved by 50% of midostaurin-treated patients) was associated with improved RFS. The most common serious adverse events were diarrhea, nausea, and vomiting. Rates of graft-vs-host disease were similar between both arms (midostaurin + SOC, 70%; SOC, 73%). The addition of midostaurin maintenance therapy following alloHSCT may provide clinical benefit in some patients with FLT3-ITD AML. (ClinicalTrials.gov identifier: NCT01883362).


Assuntos
Transplante de Células-Tronco Hematopoéticas , Leucemia Mieloide Aguda , Adolescente , Adulto , Idoso , Humanos , Leucemia Mieloide Aguda/terapia , Pessoa de Meia-Idade , Mutação , Estaurosporina/análogos & derivados , Estaurosporina/uso terapêutico , Transplante de Células-Tronco , Adulto Jovem , Tirosina Quinase 3 Semelhante a fms/genética
6.
Leuk Lymphoma ; 61(13): 3146-3153, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-32812818

RESUMO

Approval of midostaurin, a multikinase inhibitor, in combination with chemotherapy for the treatment of adults with newly diagnosed FLT3 mutation-positive acute myeloid leukemia, was based on the phase 3 RATIFY trial results. RADIUS-X (NCT02624570) was an expanded access program providing access to midostaurin during regulatory review and extending the understanding of the safety and tolerability of midostaurin. Patients aged ≥18 years received midostaurin with 1-2 cycles of induction therapy (cytarabine plus daunorubicin or idarubicin) and ≤4 cycles of high-dose cytarabine consolidation chemotherapy or as single-agent maintenance therapy. The study enrolled 103 patients. No new safety events were observed; toxicities were not influenced by age, anthracycline choice, or coadministration of CYP3A4 inhibitors. The most common adverse events (AEs) were febrile neutropenia, nausea, and diarrhea. During maintenance, 46% of patients reported AEs. Midostaurin demonstrated a manageable safety profile and was associated with high transplant and low on-treatment relapse rates.


Assuntos
Leucemia Mieloide Aguda , Rádio (Anatomia) , Adolescente , Adulto , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Humanos , Leucemia Mieloide Aguda/diagnóstico , Leucemia Mieloide Aguda/tratamento farmacológico , Leucemia Mieloide Aguda/genética , Mutação , Inibidores de Proteínas Quinases/efeitos adversos , Estaurosporina/análogos & derivados , Tirosina Quinase 3 Semelhante a fms/genética
7.
Leuk Res ; 87: 106262, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31756575

RESUMO

INTRODUCTION: Identification of cytogenetic and molecular abnormalities has become vital for the appropriate treatment of acute myeloid leukemia (AML). One of the most common molecular alterations in AML is the constitutive activation by internal tandem duplication of FMS-like tyrosine kinase 3 (FLT3). METHODS: This observational, retrospective, cohort study at the Huntsman Cancer Institute (HCI) had two time periods: 1) a historical pre-midostaurin time period which consisted of the FLT3 mutated (FLT3m) and FLT3 wild type (FLT3wt) cohorts from January 1, 2007, to December 31, 2016, and 2) a post-midostaurin cohort which consisted of the FLT3 mutated midostaurin-user cohort (early mido) from May 01, 2017 to December 31, 2018. RESULTS: In total, 39 patients were included in the FLT3m cohort, 61 in the FLT3wt cohort, and seven in the early mido cohort. FLT3m patients spent fewer days in the hospital during the first consolidation regimen and received fewer consolidation cycles compared to FLT3wt patients. Overall survival (OS) was similar between FLT3m and FLT3wt patients. For patients without hematopoietic stem cell transplant, OS was significantly shorter for FLT3m patients compared to FLT3wt patients. Mean AML related inpatient charges and physician charges for FLT3m patients were significantly higher than FLT3wt patients. CONCLUSION: The FLT3 mutation is historically associated with a shorter time to transplant and increased total health care charges. More information is needed to evaluate the real-world treatment strategies for FLT3-mutated patients in the presence of FLT3 inhibitors and the impact of these treatment strategies on clinical and economic outcomes.


Assuntos
Leucemia Mieloide Aguda/diagnóstico , Leucemia Mieloide Aguda/tratamento farmacológico , Leucemia Mieloide Aguda/economia , Mutação , Estaurosporina/análogos & derivados , Tirosina Quinase 3 Semelhante a fms/genética , Adulto , Idoso , Estudos de Coortes , Assistência Integral à Saúde/economia , Feminino , Custos de Cuidados de Saúde , Humanos , Leucemia Mieloide Aguda/genética , Masculino , Pessoa de Meia-Idade , Prognóstico , Inibidores de Proteínas Quinases/economia , Inibidores de Proteínas Quinases/uso terapêutico , Estudos Retrospectivos , Estaurosporina/economia , Estaurosporina/uso terapêutico , Resultado do Tratamento
8.
Sci Rep ; 9(1): 2599, 2019 02 22.
Artigo em Inglês | MEDLINE | ID: mdl-30796301

RESUMO

Modulation by neuropeptides enhances several functions of acid-sensing ion channels (ASICs), such as pain sensation and acid-induced neuronal injury. The acid-induced opening of ASICs is transient, because of a rapid desensitization. Neuropeptides containing an Arg-Phe-amide motif affect ASIC desensitization and allow continuous activity of ASICs. In spite of the importance of the sustained ASIC activity during prolonged acidification, the molecular mechanisms of ASIC modulation by neuropeptides is only poorly understood. To identify the FRRFa (Phe-Arg-Arg-Phe-amide) binding site on ASIC1a, we carried out an in silico docking analysis and verified functionally the docking predictions. The docking experiments indicated three possible binding pockets, located (1) in the acidic pocket between the thumb, finger, ß-ball and palm domains, (2) in a pocket at the bottom of the thumb domain, and (3) in the central vestibule along with the connected side cavities. Functional measurements of mutant ASIC1a confirmed the importance of residues of the lower palm, which encloses the central vestibule and its side cavities, for the FRRFa effects. The combined docking and functional experiments strongly suggest that FRRFa binds to the central vestibule and its side cavities to change ASIC desensitization.


Assuntos
Canais Iônicos Sensíveis a Ácido , Dipeptídeos/metabolismo , Neuropeptídeos/metabolismo , Canais Iônicos Sensíveis a Ácido/química , Canais Iônicos Sensíveis a Ácido/metabolismo , Animais , Sítios de Ligação , Simulação de Acoplamento Molecular/métodos , Oócitos , Ligação Proteica , Domínios Proteicos , Xenopus laevis
9.
Pharmacoeconomics ; 37(2): 239-253, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30382485

RESUMO

OBJECTIVES: The aim of this study was to assess the cost effectiveness of midostaurin + cytarabine + daunorubicin (midostaurin arm) versus placebo + cytarabine + daunorubicin (placebo arm) in the treatment of adult patients with newly diagnosed FLT3-mutated acute myeloid leukemia (AML) who are eligible for standard cytarabine + daunorubicin chemotherapy, from a US third-party payer perspective. METHODS: A lifetime partitioned survival model with four health states (active disease, complete remission [CR], relapse, and death) was constructed. Efficacy inputs (time to CR or death, time to relapse or death, and overall survival) were estimated using data from the RATIFY trial (NCT00651261). Costs (inflated to 2016 US dollars) included treatment, drug monitoring, stem cell transplantation (SCT), adverse events costs, and medical costs associated with health states. Incremental costs per quality-adjusted life-year (QALY) and life-year (LY) gained were estimated. Deterministic (DSA) and probabilistic sensitivity analyses (and PSA) were performed to assess model robustness. RESULTS: In the base case, patients in the midostaurin arm incurred higher total direct costs over a lifetime compared with the placebo arm ($4,043,470 vs. $3,959,741), resulting in an incremental cost of $83,729; however, the midostaurin arm had better effectiveness, with 1.59 more LYs and 1.37 more QALYs. These led to a base-case incremental cost-effectiveness ratio (ICER) of $52,596 per LY, or $61,167 per QALY. Results were robust in the DSA. In the PSA, the probability of the midostaurin arm being cost-effective compared with the placebo arm was 65.9%, at a willingness to pay of $150,000/QALY. CONCLUSIONS: This analysis suggests that midostaurin is a cost-effective treatment for adult patients with newly diagnosed FLT3-mutated AML, from a US third-party payer perspective.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Leucemia Mieloide Aguda/tratamento farmacológico , Modelos Teóricos , Tirosina Quinase 3 Semelhante a fms/genética , Adulto , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/economia , Análise Custo-Benefício , Citarabina/administração & dosagem , Daunorrubicina/administração & dosagem , Método Duplo-Cego , Feminino , Custos de Cuidados de Saúde , Humanos , Leucemia Mieloide Aguda/economia , Leucemia Mieloide Aguda/genética , Masculino , Pessoa de Meia-Idade , Anos de Vida Ajustados por Qualidade de Vida , Estaurosporina/administração & dosagem , Estaurosporina/análogos & derivados , Taxa de Sobrevida , Resultado do Tratamento , Estados Unidos
10.
Health Qual Life Outcomes ; 16(1): 193, 2018 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-30241538

RESUMO

BACKGROUND: Preference valuations of health status are essential in health technology and economic appraisal. This study estimated utilities for treatment-related health states of acute myeloid leukemia (AML) and disutilities of severe adverse events (SAEs) using a representative sample of adults from the general population in the United States (US). METHODS: Treatment-related AML health states, defined based on literature and interviews with clinicians, included complete remission (CR), no CR, relapse, stem cell transplant (SCT), and post SCT short-term recovery. Six attributes with varying levels, including fever, lack of energy, problems with daily function, anxiety/depression, blood transfusions, and hospitalization, were used to define health states. An online survey using discrete choice experiment methodology was designed to capture preferences for health status scenarios including the identified attributes and key grade 3/4 chemotherapy-related SAEs. Health state utilities and SAE disutilities were generated from a conditional logistic regression with generalized estimating equations. RESULTS: Of the 300 survey participants, the demographic distributions were within a 3% margin of those in the 2010 US Census. CR had the highest utility value (0.875), followed by post-SCT short-term recovery (0.398), relapse (0.355), no CR (0.262), and SCT (0.158). Of the SAEs, serious infection had the highest decline in utility (0.218), followed by severe diarrhea (0.176), abnormally low blood cell counts (0.100), and severe redness/skin peeling (0.060). CONCLUSIONS: AML and treatments can result in reduced quality of life and impaired ability to perform daily activities. Findings of this study underline the value that society places on treatment-related AML health states and SAEs.


Assuntos
Nível de Saúde , Leucemia Mieloide Aguda/complicações , Leucemia Mieloide Aguda/terapia , Adolescente , Adulto , Idoso , Feminino , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Qualidade de Vida , Inquéritos e Questionários , Resultado do Tratamento , Estados Unidos , Adulto Jovem
11.
J Med Econ ; 21(6): 556-563, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29304724

RESUMO

OBJECTIVE: To describe the setting, duration, and costs of induction and consolidation chemotherapy for adults with newly-diagnosed acute myeloid leukemia (AML), who are candidates for standard induction chemotherapy, in the US. METHODS: Adults newly-diagnosed with AML who received standard induction chemotherapy in an inpatient setting were identified from the Truven Health Analytics MarketScan (2006-2015) and SEER-Medicare (2007-2011) databases. Patients were observed from induction therapy start to the first of hematopoietic stem cell transplant, 180 days after induction discharge, health plan enrollment/data availability end, or death. Induction and consolidation chemotherapy were identified using Diagnosis-Related Group codes (chemotherapy with acute leukemia) or procedure codes for AML chemotherapy administration. AML treatment episode setting (inpatient or outpatient), duration, and costs (2015 USD, payers' perspective) were described for commercially insured patients and Medicare beneficiaries. RESULTS: In total, 459 commercially insured patients and 563 Medicare beneficiaries (mean age = 54 and 66 years; 53% and 54% male; respectively) were identified. For induction therapy, mean costs were $145,189 for commercially insured patients and $85,734 for Medicare beneficiaries, and median inpatient duration was 31 days (both). Following induction, 64% of commercially insured patients and 53% of Medicare beneficiaries had ≥1 consolidation cycle; 75% and 65% of consolidation cycles were in an inpatient setting, respectively. For consolidation cycles, in the inpatient setting, mean costs were $28,137 for commercially insured patients and $28,843 for Medicare beneficiaries, median cycle duration was 6 days (both); in the outpatient setting, mean costs were $11,271 for commercially insured patients and $5,803 Medicare beneficiaries, median duration was 5 days (both). LIMITATIONS: Granular information on chemotherapy type administered was unavailable. CONCLUSIONS: This is the first exploratory study providing a complete picture of recent AML treatment patterns and management costs among commercially insured patients and Medicare beneficiaries. There is substantial heterogeneity in the management and costs of AML.


Assuntos
Gastos em Saúde/estatística & dados numéricos , Recursos em Saúde/economia , Recursos em Saúde/estatística & dados numéricos , Quimioterapia de Indução/economia , Seguro Saúde/estatística & dados numéricos , Leucemia Mieloide Aguda/tratamento farmacológico , Idoso , Feminino , Humanos , Seguro Saúde/economia , Tempo de Internação , Masculino , Medicare/economia , Medicare/estatística & dados numéricos , Pessoa de Meia-Idade , Modelos Econométricos , Características de Residência , Estudos Retrospectivos , Estados Unidos
12.
Proc Natl Acad Sci U S A ; 114(14): 3768-3773, 2017 04 04.
Artigo em Inglês | MEDLINE | ID: mdl-28320963

RESUMO

Acid-sensing ion channels (ASICs) are proton-activated Na+ channels expressed in the nervous system, where they are involved in learning, fear behaviors, neurodegeneration, and pain sensation. In this work, we study the role in pH sensing of two regions of the ectodomain enriched in acidic residues: the acidic pocket, which faces the outside of the protein and is the binding site of several animal toxins, and the palm, a central channel domain. Using voltage clamp fluorometry, we find that the acidic pocket undergoes conformational changes during both activation and desensitization. Concurrently, we find that, although proton sensing in the acidic pocket is not required for channel function, it does contribute to both activation and desensitization. Furthermore, protonation-mimicking mutations of acidic residues in the palm induce a dramatic acceleration of desensitization followed by the appearance of a sustained current. In summary, this work describes the roles of potential pH sensors in two extracellular domains, and it proposes a model of acidification-induced conformational changes occurring in the acidic pocket of ASIC1a.


Assuntos
Canais Iônicos Sensíveis a Ácido/química , Canais Iônicos Sensíveis a Ácido/metabolismo , Sódio/metabolismo , Toxinas Biológicas/metabolismo , Canais Iônicos Sensíveis a Ácido/genética , Sítios de Ligação , Humanos , Concentração de Íons de Hidrogênio , Modelos Moleculares , Mutação , Estrutura Terciária de Proteína
13.
J Biol Chem ; 290(29): 17956-17966, 2015 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-26070563

RESUMO

Acid-sensing ion channels (ASICs) are neuronal, voltage-independent Na(+) channels that are transiently activated by extracellular acidification. They are involved in pain sensation, the expression of fear, and in neurodegeneration after ischemic stroke. Our study investigates the role of extracellular subunit interactions in ASIC1a function. We identified two regions involved in critical intersubunit interactions. First, formation of an engineered disulfide bond between the palm and thumb domains leads to partial channel closure. Second, linking Glu-235 of a finger loop to either one of two different residues of the knuckle of a neighboring subunit opens the channel at physiological pH or disrupts its activity. This suggests that one finger-knuckle disulfide bond (E235C/K393C) sets the channel in an open state, whereas the other (E235C/Y389C) switches the channel to a non-conducting state. Voltage-clamp fluorometry experiments indicate that both the finger loop and the knuckle move away from the ß-ball residue Trp-233 during acidification and subsequent desensitization. Together, these observations reveal that ASIC1a opening is accompanied by a distance increase between adjacent thumb and palm domains as well as a movement of Glu-235 relative to the knuckle helix. Our study identifies subunit interactions in the extracellular loop and shows that dynamic changes of these interactions are critical for normal ASIC function.


Assuntos
Canais Iônicos Sensíveis a Ácido/química , Canais Iônicos Sensíveis a Ácido/metabolismo , Sequência de Aminoácidos , Animais , Galinhas , Humanos , Modelos Moleculares , Dados de Sequência Molecular , Conformação Proteica , Subunidades Proteicas/química , Subunidades Proteicas/metabolismo , Alinhamento de Sequência , Xenopus
14.
FASEB J ; 28(11): 4748-63, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25122557

RESUMO

In the present bed rest (BR) study, 23 volunteers were randomized into 3 subgroups: 60 d BR control (Ctr); BR with resistive exercise (RE; lower-limb load); and resistive vibration exercise (RVE; RE with superimposed vibration). The aim was to analyze by confocal and electron microscopy the effects of vibration on myofibril and filament integrity in soleus (Sol) and vastus lateralis (VL) muscle; differential proteomics of contractile, cytoskeletal, and costameric proteins (TN-C, ROCK1, and FAK); and expression of PGC1α and atrophy-related master genes MuRF1 and MuRF2. RVE (but not RE) preserved myofiber size and phenotype in Sol and VL by overexpressing MYBPC1 (42%, P ≤ 0.01), WDR1 (39%, P ≤ 0.01), sarcosin (84%, P ≤ 0.01), and CKM (20%, P ≤ 0.01) and prevented myofibrillar ultrastructural damage as detectable by MuRF1 expression. In Sol, cytoskeletal and contractile proteins were normalized by RVE, and TN-C increased (59%, P ≤ 0.01); the latter also with RE (108%, P ≤ 0.01). In VL, the outcomes of both RVE (acting on sarcosin and desmin) and RE (by way of troponinT-slow and MYL2) were similar. RVE appears to be a highly efficient countermeasure protocol against muscle atrophy and ultrastructural and molecular dysregulation induced by chronic disuse.


Assuntos
Terapia por Exercício , Músculo Esquelético/metabolismo , Atrofia Muscular/metabolismo , Proteômica , Adulto , Repouso em Cama/métodos , Humanos , Masculino , Pessoa de Meia-Idade , Contração Muscular/fisiologia , Músculo Esquelético/patologia , Atrofia Muscular/terapia , Vibração , Adulto Jovem
15.
J Gen Physiol ; 143(1): 105-18, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24344244

RESUMO

Acid-sensing ion channels (ASICs) are neuronal Na(+)-conducting channels activated by extracellular acidification. ASICs are involved in pain sensation, expression of fear, and neurodegeneration after ischemic stroke. Functional ASICs are composed of three identical or homologous subunits, whose extracellular part has a handlike structure. Currently, it is unclear how protonation of residues in extracellular domains controls ASIC activity. Knowledge of these mechanisms would allow a rational development of drugs acting on ASICs. Protonation may induce conformational changes that control the position of the channel gate. We used voltage-clamp fluorometry with fluorophores attached to residues in different domains of ASIC1a to detect conformational changes. Comparison of the timing of fluorescence and current signals identified residues involved in movements that preceded desensitization and may therefore be associated with channel opening or early steps leading to desensitization. Other residues participated in movements intimately linked to desensitization and recovery from desensitization. Fluorescence signals of all mutants were detected at more alkaline pH than ionic currents. Their midpoint of pH dependence was close to that of steady-state desensitization, whereas the steepness of the pH fluorescence relationship was closer to that of current activation. A sequence of movements was observed upon acidification, and its backward movements during recovery from desensitization occurred in the reverse order, indicating that the individual steps are interdependent. Furthermore, the fluorescence signal of some labeled residues in the finger domain was strongly quenched by a Trp residue in the neighboring ß-ball domain. Upon channel activation, their fluorescence intensity increased, indicating that the finger moved away from the ß ball. This extensive analysis of activity-dependent conformational changes in ASICs sheds new light on the mechanisms by which protonation controls ASIC activity.


Assuntos
Canais Iônicos Sensíveis a Ácido/metabolismo , Ativação do Canal Iônico , Prótons , Canais Iônicos Sensíveis a Ácido/química , Canais Iônicos Sensíveis a Ácido/genética , Sequência de Aminoácidos , Animais , Humanos , Concentração de Íons de Hidrogênio , Simulação de Dinâmica Molecular , Dados de Sequência Molecular , Mutação , Estrutura Terciária de Proteína , Xenopus
16.
Proteomics ; 10(21): 3756-74, 2010 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-20957755

RESUMO

The present investigation, the first in the field, was aimed at analyzing differentially, on individual samples, the effects of 55 days of horizontal bed rest, a model for microgravity, on myosin heavy and myosin light chain isoforms distribution (by SDS) and on the proteome (by 2-D DIGE and MS) in the vastus lateralis (VL), a mixed type II/I (∼50:50%) head of the quadriceps and in the calf soleus (SOL), a predominantly slow (∼35:65%) twitch muscle. Two separate studies were performed on six subjects without (BR) and six with resistive vibration exercise (RVE) countermeasures, respectively. Both VL and SOL underwent in BR decrements of ∼15% in cross-sectional area and of ∼22% in maximal torque that were prevented by RVE. Myosin heavy chain distribution showed increased type I and decreased type IIA in BR both in VL and in SOL, the opposite with RVE. A substantial downregulation of proteins involved in aerobic metabolism characterized both in SOL and VL in BR. RVE reversed the pattern more in VL than in SOL, whereas proteins involved in anaerobic glycolysis were upregulated. Proteins from the Z-disk region and from costamers were differently dysregulated during bed rest (both BR and RVE), particularly in VL.


Assuntos
Repouso em Cama/efeitos adversos , Músculo Esquelético/metabolismo , Cadeias Pesadas de Miosina/metabolismo , Cadeias Leves de Miosina/metabolismo , Proteômica/métodos , Vibração/uso terapêutico , Adulto , Eletroforese em Gel Bidimensional , Terapia por Exercício/métodos , Humanos , Immunoblotting , Masculino , Cadeias Pesadas de Miosina/química , Cadeias Leves de Miosina/química , Isoformas de Proteínas/química , Isoformas de Proteínas/metabolismo , Músculo Quadríceps/metabolismo , Transdução de Sinais , Espectrometria de Massas em Tandem
17.
Exp Oncol ; 26(3): 192-5, 2004 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-15494686

RESUMO

Acute venous thromboembolism (VTE) is a common and potentially fatal complication that frequently occurs in cancer patients. Few data are currently available about the optimal management of this category of high-risk patients. In clinical practice, physicians have to deal with many problems related to cancer patients with acute VTE. For instance, cancer patients with deep vein thrombosis (DVT) are frequently admitted to the hospital since their high rate of recurrent thrombotic events and/or bleeding-related therapy; however, most of them would prefer alternatives to prolonged hospitalisation. Then, it is not clearly whether data coming from a non-cancer population (such as that regarding the use of D-dimer test and/or pre-test clinical probability [PCP]), can be reliable applied in cancer patients. Finally, scanty information is present on the feasibility of the "home-treatment program" for DVT in this category of high-risk patients. In our review we present data on a population of cancer patients evaluated at the Emergency Care in whom we have evaluated: 1) the diagnostic accuracy of PCP and D-dimer test; 2) the safety and efficacy of low molecular weight heparins (LMWH) as "protective anticoagulation" in case of deferred imaging for VTE and 3) the safety and efficacy of home treatment.


Assuntos
Anticoagulantes/uso terapêutico , Heparina de Baixo Peso Molecular/uso terapêutico , Assistência Domiciliar , Neoplasias/complicações , Autocuidado , Tromboembolia/tratamento farmacológico , Trombose Venosa/tratamento farmacológico , Doença Aguda , Adulto , Idoso , Idoso de 80 Anos ou mais , Anticoagulantes/efeitos adversos , Biomarcadores , Feminino , Produtos de Degradação da Fibrina e do Fibrinogênio/análise , Hemorragia/induzido quimicamente , Hemorragia/prevenção & controle , Heparina de Baixo Peso Molecular/administração & dosagem , Hospitalização , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Embolia Pulmonar/sangue , Embolia Pulmonar/tratamento farmacológico , Embolia Pulmonar/etiologia , Estudos Retrospectivos , Autoadministração , Sensibilidade e Especificidade , Tromboembolia/sangue , Tromboembolia/etiologia , Resultado do Tratamento , Trombose Venosa/sangue , Trombose Venosa/etiologia
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