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1.
Med Dosim ; 2024 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-38368183

RESUMO

Peer review is an important component of any radiation oncology continuous quality improvement program. While limited guidelines exist, there is no consensus about how peer review should be performed, and large variations exist among different institutions. The purpose of this report is to describe our experience with peer review at a busy Radiation Oncology clinic and to evaluate the difference between prospective and retrospective peer review. We also performed a failure modes and effects analysis (FMEA) of the peer review process. Starting in 2015, every peer review session was tracked, including recommended changes to treatment plans. We reviewed the frequency, types and severity of these changes. A team of physicians and physicists conducted an FMEA of the peer review process. Between April 2015 and June 2020, a total of 3,691 patients were peer-reviewed. Out of those, 1,903 were prospective reviews (51.6%). Plans reviewed before treatment were almost 4.5 times more likely to be changed by peer review than those reviewed after the start of treatment (0.9% vs 0.2%). Plan changes after the start of treatment had a higher severity than changes prior to the start of treatment. FMEA identified several critical components of peer review. While there is no national standard for peer review, it is evident that prospective peer review is preferable. There may be a subconscious reluctance to change plans already underway, which could be a barrier to improving plans with the peer review process. Rather than reviewing in a group setting, it would be ideal to individually assign review tasks that are embedded in the clinical flow, assuring prospective review for all patients prior to final physician approval. Individual review rather than group review may be more candid, due to interpersonal concerns about publicly disagreeing with colleagues.

2.
Int J Radiat Oncol Biol Phys ; 111(4): 856-864, 2021 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-34058256

RESUMO

PURPOSE: Delivering linguistically competent care is critical to serving patients who have limited English proficiency (LEP) and represents a key national strategy to help reduce health disparities. Current acceptable standards of communication with patients who have LEP include providers communicating through professional interpretive services or bilingual providers speaking the patients' preferred language directly. This randomized clinical trial tests the effect of patient-provider language concordance on patient satisfaction. METHODS AND MATERIALS: Eighty-three adult Spanish-speaking patients with cancer were randomly assigned to receive care from either (1) 1 of 2 bilingual physicians speaking to the patient directly in Spanish or (2) the same physicians speaking English and using a professional interpreter service. Validated questionnaires were administered to assess patient-reported satisfaction with both provider communication and overall care. Transcripts of initial consultations were analyzed for content variations. RESULTS: Compared with patients receiving care through professional interpretive services, patients cared for in direct Spanish reported significantly improved general satisfaction, technical quality of care (mean composite score [MCS], 4.41 vs 4.06; P = .005), care team interpersonal manner (MCS, 4.37 vs 3.88; P = .004), communication (MCS, 4.50 vs 4.25; P = .018), and time spent with patient,(MCS, 4.30 vs 3.92; P = .028). Specific to physician communication, patients rated direct-Spanish care more highly in perceived opportunity to disclose concerns (MCS 4.91 vs 4.62; P = .001), physician empathy (MCS, 4.94 vs 4.59; P <.001), confidence in physician abilities (MCS, 4.84 vs 4.51; P = .001), and general satisfaction with their physician (MCS, 4.88 vs 4.59; P <.001). Analyzing the content of consultation encounters revealed differences between study arms, with the direct-Spanish arm having more physician speech related to patient history verification (mean number of utterances, 13 vs 9; P = .01) and partnering activities (mean utterances, 16 vs 5; P <.001). Additionally, patients in the direct-Spanish arm were more likely to initiate unprompted speech (mean utterances, 11 vs 3; P <.001) and asked their providers more questions (mean utterances, 11 vs 4; P = .007). CONCLUSIONS: This study shows improved patient-reported satisfaction among patients with cancer who had LEP and were cared for in direct Spanish compared with interpreter-based communication. Further research into interventions to mitigate the patient-provider language barrier is necessary to optimize care for this population.


Assuntos
Idioma , Neoplasias , Adulto , Barreiras de Comunicação , Hispânico ou Latino , Humanos , Neoplasias/terapia , Satisfação do Paciente , Relações Médico-Paciente
3.
J Appl Clin Med Phys ; 22(4): 115-120, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33764663

RESUMO

PURPOSE: To assess the dosimetric performance of an automated breast planning software. METHODS: We retrospectively reviewed 15 breast cancer patients treated with tangent fields according to the RTOG 1005 protocol and 30 patients treated off-protocol. Planning with electronic compensators (eComps) via manual, iterative fluence editing was compared to an automated planning program called EZFluence (EZF) (Radformation, Inc.). We compared the minimum dose received by 95% of the volume (D95%), D90%, the volume receiving at least 105% of prescription (V105%), V95%, the conformity index of the V95% and PTV volumes (CI95%), and total monitor units (MUs). The PTV_Eval structure generated by EZF was compared to the RTOG 1005 breast PTV_Eval structure. RESULTS: The average D95% was significantly greater for the EZF plans, 95.0%, vs. the original plans 93.2% (P = 0.022). CI95% was less for the EZF plans, 1.18, than the original plans, 1.48 (P = 0.09). D90% was only slightly greater for EZF, averaging at 98.3% for EZF plans and 97.3% for the original plans (P = 0.0483). V105% (cc) was, on average, 27.8cc less in the EZF breast plans, which was significantly less than for those manually planned. The average number of MUs for the EZF plans, 453, was significantly less than original protocol plans, 500 (P = 8 × 10-6 ). The average difference between the protocol PTV volume and the EZF PTV volume was 196 cc, with all but two cases having a larger EZF PTV volume (P = 0.020). CONCLUSION: EZF improved dose homogeneity, coverage, and MU efficiency vs. manually produced eComp plans. The EZF-generated PTV eval is based on the volume encompassed by the tangents, and is not appropriate for dosimetric comparison to constraints for RTOG 1005 PTV eval. EZF produced dosimetrically similar or superior plans to manual, iteratively derived plans and may also offer time and efficiency benefits.


Assuntos
Neoplasias da Mama , Planejamento da Radioterapia Assistida por Computador , Mama , Neoplasias da Mama/diagnóstico por imagem , Neoplasias da Mama/radioterapia , Feminino , Humanos , Fator 4 Semelhante a Kruppel , Dosagem Radioterapêutica , Estudos Retrospectivos , Software
4.
Brachytherapy ; 17(6): 990-994, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30217433

RESUMO

PURPOSE: To evaluate changes in the percent depth dose (PDD) and effective depth of treatment due to force applied by the applicator during treatments of nonmelanoma skin cancer with the Xoft electronic brachytherapy system. METHODS: To simulate compressible tissue, a 5-mm tissue-equivalent bolus was used. A soft x-ray ion chamber was used for output measurements, which were performed for all Xoft surface applicators with plastic endcaps in place. Output was first measured at 5 mm depth with minimal pressure from the applicator on the bolus and then repeated after applying uniform pressure on the applicator to calculate the change in PDD and effective treatment depth. RESULTS: For the 10-mm cone, a moderate force of 5 N changed the PDD by more than 20%. The effect was also pronounced for the 20-mm cone, while minimal for the 35- and 50-mm cones. Even when only a moderate force was applied, the effective prescription depth changed by several millimeters, on the order of a typical prescription depth. CONCLUSION: Based on the results of this simulation, excessive pressure applied on the skin by the applicator can drastically alter the PDD and effective treatment depth. The effect is most pronounced for the 10- and 20-mm cones, which tend to be used most frequently. Inappropriate applicator placement may therefore result in significant consequences such as excessive dose to the target, severe skin reaction, permanent discoloration, skin indentation, and poor overall cosmesis upon completion of treatment.


Assuntos
Braquiterapia/métodos , Planejamento da Radioterapia Assistida por Computador/métodos , Neoplasias Cutâneas/radioterapia , Humanos , Radiometria/métodos , Dosagem Radioterapêutica , Pele/patologia , Pele/efeitos da radiação , Resultado do Tratamento
5.
Brachytherapy ; 17(4): 702-708, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29773330

RESUMO

PURPOSE: To develop an improved Xoft electronic skin brachytherapy process and identify areas of further improvement. METHODS AND MATERIALS: A multidisciplinary team conducted a failure modes and effects analysis (FMEA) by developing a process map and a corresponding list of failure modes. The failure modes were scored for their occurrence, severity, and detectability, and a risk priority number (RPN) was calculated for each failure mode as the product of occurrence, severity, and detectability. Corrective actions were implemented to address the higher risk failure modes, and a revised process was generated. The RPNs of the failure modes were compared between the initial process and final process to assess the perceived benefits of the corrective actions. RESULTS: The final treatment process consists of 100 steps and 114 failure modes. The FMEA took approximately 20 person-hours (one physician, three physicists, and two therapists) to complete. The 10 most dangerous failure modes had RPNs ranging from 336 to 630. Corrective actions were effective at addressing most failure modes (10 riskiest RPNs ranging from 189 to 310), yet the RPNs were higher than those published for alternative systems. Many of these high-risk failure modes remained due to hardware design limitations. CONCLUSIONS: FMEA helps guide process improvement efforts by emphasizing the riskiest steps. Significant risks are apparent when using a Xoft treatment unit for skin brachytherapy due to hardware limitations such as the lack of several interlocks, a short source lifespan, and variability in source output. The process presented in this article is expected to reduce but not eliminate these risks.


Assuntos
Braquiterapia/instrumentação , Planejamento da Radioterapia Assistida por Computador/métodos , Neoplasias Cutâneas/radioterapia , Dispositivos Eletrônicos Vestíveis , Desenho de Equipamento , Humanos
6.
Pract Radiat Oncol ; 5(3): 183-187, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25413394

RESUMO

PURPOSE: In contrast to studies of adults, there are limited published data regarding palliative radiation therapy (RT) for children, and further study is greatly needed. METHODS AND MATERIALS: We performed a retrospective review of all pediatric patients referred to our radiation oncology department over a 5-year span from January 1, 2007, to December 31, 2011. RESULTS: Of 244 total pediatric patients referred, a subset of 45 (18.4%) were treated specifically with palliative intent for a total of 83 courses of RT. Follow-up data until study closure or death were available for 98% of patients. The median survival after initiation of palliative RT was 6.5 months. Overall, 23% of the children were alive at last follow-up visit, and 77% were deceased. The prescribed RT was completed in 93% of courses; 7% of courses were discontinued because of clinical deterioration due to systemic disease progression. The overall symptom response rate (partial or complete) was 72%. Overall response rate by symptom was 80% for bone pain, 55% for dyspnea or chest pain, 58% for neurologic symptoms, 50% for bleeding, and 100% for liver pain or ascites. Response rates by histology were 100% for leukemias, 91% for neuroblastoma, 76% for Ewing sarcoma, 64% for rhabdomyosarcoma, 54% for osteosarcoma, and 50% for primary central nervous system neoplasms. For responders, the median time from RT initiation to response was 1 week. For 7% of patients, a repeat course of RT for the same site and symptom was performed. No patients experienced RTOG (Radiation Therapy Oncology Group) grade 3 or greater acute or late toxicities. CONCLUSIONS: RT is a useful palliative tool for pediatric patients that merits continued use and further study.


Assuntos
Neoplasias/radioterapia , Cuidados Paliativos/métodos , Adolescente , Neoplasias Ósseas/radioterapia , Neoplasias Ósseas/secundário , Neoplasias Ósseas/cirurgia , Criança , Pré-Escolar , Dispneia/radioterapia , Feminino , Seguimentos , Humanos , Lactente , Masculino , Neoplasias/etiologia , Neoplasias/patologia , Neoplasias/cirurgia , Dor/radioterapia , Radiocirurgia , Radioterapia Conformacional , Radioterapia de Intensidade Modulada , Estudos Retrospectivos , Resultado do Tratamento
7.
Int J Radiat Oncol Biol Phys ; 90(5): 1202-7, 2014 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-25442045

RESUMO

PURPOSE: To report on the use of an incident learning system in a radiation oncology clinic, along with a review of staff participation. METHODS AND MATERIALS: On September 24, 2010, our department initiated an online real-time voluntary reporting system for safety issues, called the Radiation Oncology Quality Reporting System (ROQRS). We reviewed these reports from the program's inception through January 18, 2013 (2 years, 3 months, 25 days) to assess error reports (defined as both near-misses and incidents of inaccurate treatment). RESULTS: During the study interval, there were 60,168 fractions of external beam radiation therapy and 955 brachytherapy procedures. There were 298 entries in the ROQRS system, among which 108 errors were reported. There were 31 patients with near-misses reported and 27 patients with incidents of inaccurate treatment reported. These incidents of inaccurate treatment occurred in 68 total treatment fractions (0.11% of treatments delivered during the study interval). None of these incidents of inaccurate treatment resulted in deviation from the prescription by 5% or more. A solution to the errors was documented in ROQRS in 65% of the cases. Errors occurred as repeated errors in 22% of the cases. A disproportionate number of the incidents of inaccurate treatment were due to improper patient setup at the linear accelerator (P<.001). Physician participation in ROQRS was nonexistent initially, but improved after an education program. CONCLUSIONS: Incident learning systems are a useful and practical means of improving safety and quality in patient care.


Assuntos
Erros Médicos/estatística & dados numéricos , Garantia da Qualidade dos Cuidados de Saúde/estatística & dados numéricos , Melhoria de Qualidade , Radioterapia (Especialidade)/estatística & dados numéricos , Erros de Configuração em Radioterapia/estatística & dados numéricos , Gestão de Riscos/métodos , Segurança/estatística & dados numéricos , Braquiterapia/instrumentação , Humanos , Erros Médicos/prevenção & controle , Corpo Clínico/educação , Corpo Clínico/estatística & dados numéricos , Radioterapia (Especialidade)/instrumentação , Radioterapia (Especialidade)/normas , Radioterapia/instrumentação , Segurança/normas , Interface Usuário-Computador
8.
Ther Adv Respir Dis ; 8(1): 3-12, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24334338

RESUMO

PURPOSE/OBJECTIVE: Treatment of presumed early-stage lung cancer with definitive radiation therapy in the absence of a pathologically confirmed specimen frequently occurs. However, it is not well described in the literature, and there are few North American series reporting on this patient population. We report outcomes in patients treated with stereotactic body radiotherapy (SBRT) for presumed lung cancer and compare them to outcomes in patients treated with SBRT with pathologically confirmed non-small cell lung cancer (NSCLC). MATERIALS/METHODS: This study is based on a retrospective review of 55 patients with presumed or confirmed lung cancer: 23 patients had nondiagnostic or absent pathologic specimens while 32 patients had pathologically confirmed NSCLC. All patients had hypermetabolic primary lesions on a positron emission tomography (PET) or PET/computed tomography (CT) scan. SBRT was delivered as 48-56 Gy in four to five fractions via a four-dimensional CT treatment plan. RESULTS: Of the patients without pathological confirmation, the mean age was 78 (range 63-89 years) and 17 (74%) were men. The mean tumor size was 2.5 cm (range 1.0-5.1). Reasons for not having confirmed pathologic diagnosis included indeterminate biopsy specimen or an inability to tolerate a biopsy procedure due to poor respiratory status. SBRT was chosen due to noncandidacy for surgery in 17 patients (74%) or patient refusal of surgery in six (26%). Median follow up was 24.2 months (range 1.9-64.6): 2 of the 23 patients (8.7%) had local failure at the site of SBRT and 3 (13%) had regional failure. The actuarial 12-month overall survival was 83%. The median overall survival was 30.2 months. At last follow up, 12 patients (52%) were alive up to 64.6 months after treatment. SBRT was tolerated well in this series. Acute toxicity was noted in two patients (8.7%) and chronic toxicity in three (13%). These patient characteristics and results were shown to be similar to the 32 patients with pathologically confirmed NSCLC. On Kaplan-Meier analysis, there was no significant difference (p = 0.27) in overall survival between patients with pathologically confirmed NSCLC and those with presumed lung cancer (which was deemed most likely NSCLC). CONCLUSION: While biopsy confirmation remains a goal in the workup of suspected NSCLC, SBRT without pathologic confirmation may represent a safe and effective option for the treatment of presumed NSCLC among patients who cannot tolerate or refuse surgery.


Assuntos
Carcinoma Pulmonar de Células não Pequenas/cirurgia , Neoplasias Pulmonares/cirurgia , Radiocirurgia/métodos , Idoso , Idoso de 80 Anos ou mais , Carcinoma Pulmonar de Células não Pequenas/diagnóstico , Carcinoma Pulmonar de Células não Pequenas/patologia , Feminino , Seguimentos , Humanos , Estimativa de Kaplan-Meier , Neoplasias Pulmonares/diagnóstico , Neoplasias Pulmonares/patologia , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Tomografia por Emissão de Pósitrons/métodos , Radiocirurgia/efeitos adversos , Estudos Retrospectivos , Taxa de Sobrevida , Tomografia Computadorizada por Raios X/métodos , Resultado do Tratamento
9.
Clin Lung Cancer ; 15(2): 131-5, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24157245

RESUMO

BACKGROUND: The purpose of this study was to describe our clinical experience using stereotactic body radiation therapy (SBRT) to treat medically inoperable stage I non-small-cell lung cancer (NSCLC) in very elderly patients. PATIENTS AND METHODS: Twenty-four consecutive octogenarians with stage I NSCLC were treated with SBRT between 2007 and 2011 at a single center. Median prescription dose was 48 Gy (range, 48-56). Follow-up clinical examination and computed tomography (CT) were performed every 2 to 3 months. RESULTS: Median age was 85 years (range, 80-89). Twenty-three (96%) patients had peripheral tumors, and median tumor size was 22 mm (range, 11-49). Tissue diagnosis was obtained in 16 (67%) patients. Median follow-up for all patients was 27.6 months (range, 4.3-61.2). The 24-month disease-free survival was 77% (95% confidence interval [CI], 61%-97%). The 24-month overall survival (OS) was 74% (95% CI, 57%-94%). No local failure (LF) was observed during the period of observation. Nodal failure (NF) and distant failure (DF) occurred in 2 and 4 patients, respectively. The cumulative incidence of competing mortality at 24 months was estimated at 13% (95% CI, 3%-30%). No difference in outcomes with or without tissue diagnosis was observed. No grade ≥ 3 early or late treatment-related toxicities were observed. CONCLUSION: Octogenarians tolerate SBRT well, which makes it an attractive treatment option.


Assuntos
Carcinoma Pulmonar de Células não Pequenas/cirurgia , Neoplasias Pulmonares/cirurgia , Radiocirurgia , Idoso de 80 Anos ou mais , Carcinoma Pulmonar de Células não Pequenas/mortalidade , Carcinoma Pulmonar de Células não Pequenas/patologia , Feminino , Seguimentos , Humanos , Neoplasias Pulmonares/mortalidade , Neoplasias Pulmonares/patologia , Masculino , Estadiamento de Neoplasias , Prognóstico , Estudos Retrospectivos , Taxa de Sobrevida
10.
J Radiosurg SBRT ; 2(2): 135-140, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-29296352

RESUMO

OBJECTIVES: To review the literature and report our experience with the use of stereotactic body radiation therapy (SBRT) to treat multiple primary lung cancers (MPLCs). METHODS: A retrospective review of 18 patients with 36 separate MPLC lesions (6 synchronous pairs and 12 metachronous pairs) was performed. Of these 18 patients, 16 were not surgical candidates and 2 declined to have surgery. Of the 36 lesions treated, 27 received SBRT, 6 had received prior fractionated RT, and 3 had prior surgical resection. Radiotherapy doses for SBRT ranged from 48 to 56 Gy (Median = 50 Gy) in 4 to 13 fractions (Median = 5 fractions) and treatment plans used 4D-CT simulation scans in all patients. RESULTS: The median follow-up was 20 months after initial SBRT. We observed local control in 22 of 27 (81.5%) of the lesions treated with SBRT. The actuarial overall survival at 2 years from completion of initial SBRT course was 62%. Metastatic disease occurred in 3 of the 6 deceased patients. Clinically evident pneumonitis was observed in 3 of the 18 pts (17%), which resolved completely with steroid therapy. CONCLUSIONS: SBRT appears to be a safe and effective treatment for MPLC both solely or after prior fractionated RT or surgical resection. SBRT for MPLC is a reasonable treatment option for patients who are not optimal candidates for surgery or who decline surgery.

11.
Cancer ; 117(2): 414-20, 2011 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-20830691

RESUMO

BACKGROUND: Circadian cell-cycle progression causes fluctuating radiosensitivity in many tissues, which could affect clinical outcomes. The purpose of this study was to determine whether outcomes of single-session gamma knife radiosurgery (GKRS) for metastatic nonsmall cell lung cancer (NSCLC) differ based on treatment time. METHODS: Fifty-eight patients received GKRS between 10:00 am and 12:30 pm and 39 patients received GKRS between 12:30 pm and 3:00 pm. The mean peripheral dose was 18.6 Gy. The mean tumor size was 7.3 cm³. Magnetic resonance imaging was used to score local control at 3 months. Cause of death (COD) was categorized as central nervous system (CNS)-related or systemic. RESULTS: Demographic and disease characteristics of the 2 groups were similar. Local control at 3 months was achieved in 97% (35/36) of patients who underwent GKRS early in the day versus 67% (8/12) of patients who underwent GKRS later in the day (chi-square, P = .014). Early GKRS was associated with better survival (median 9.5 months) than late GKRS (median 5 months) (Kaplan-Meier log-rank test, P = .025). Factors contributing to better survival in a Cox regression model included early treatment time (P = .004) and recursive partition analysis class (P < .001). Cause of death in the early treatment group was CNS-related in 6% (3/47) of patients versus 24% (8/34) of patients in the late treatment group (chi-square test, P = .026). CONCLUSIONS: GKRS for metastatic NSCLC had better local control, better survival, and a lower rate of CNS-related cause of death when given earlier in the day versus later in the day. These retrospective data should encourage future study in brain radiosurgery and non-CNS stereotactic body radiotherapy series.


Assuntos
Neoplasias Encefálicas/secundário , Neoplasias Encefálicas/cirurgia , Carcinoma Pulmonar de Células não Pequenas/patologia , Neoplasias Pulmonares/patologia , Radiocirurgia/métodos , Neoplasias Encefálicas/mortalidade , Neoplasias Encefálicas/patologia , Ritmo Circadiano , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Resultado do Tratamento
12.
J Commun Disord ; 41(6): 485-500, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18433765

RESUMO

UNLABELLED: Nineteen PD patients who received deep brain stimulation (DBS), 10 non-surgical (control) PD patients, and 11 non-pathologic age- and gender-matched subjects performed sustained vowel phonations. The following acoustic measures were obtained on the sustained vowel phonations: correlation dimension (D2), percent jitter, percent shimmer, SNR, F0, vF0, and vAm. The results indicated the following: The mean D2 of control PD patients was significantly higher than the mean D2 of non-pathologic subjects and patients who received deep brain stimulation. These results suggest an improvement in PD voice in treated patients. Many PD vocal samples in this study have type 2 signals containing subharmonics that may not be suitable for perturbation analysis but are suitable for nonlinear dynamic analysis, making the D2 results more reliable. These findings show that DBS may provide measurable improvement in patients with severe vocal impairment. LEARNING OUTCOMES: Readers will be able to: (1) identify the advantages of nonlinear dynamic analysis as a clinical tool to evaluate the aperiodic voice commonly found in patients with Parkinson's disease, (2) describe in general the method of obtaining a correlation dimension measure from a voice sample and the significance of this measure in terms of specific voice signal properties, (3) consider the preliminary implications from nonlinear dynamic analysis of a positive DBS effect on Parkinsonian voice and the potential for further investigations using nonlinear dynamic analysis on the influence of gender, severity of disease, and combined treatments on Parkinsonian voice improvement.


Assuntos
Estimulação Encefálica Profunda/métodos , Doença de Parkinson/terapia , Fonética , Acústica da Fala , Percepção da Fala , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Modelos Estatísticos , Inquéritos e Questionários
13.
Mol Pharmacol ; 71(6): 1695-702, 2007 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-17387142

RESUMO

Thiazolidinediones alter cell energy metabolism. They are used to treat or are being considered for the treatment of disorders that feature mitochondrial impairment. Their mitochondrial effects, however, have not been comprehensively studied under long-term exposure conditions. We used the human neuron-like NT2 cell line to directly assess the long-term effects of a thiazolidinedione drug, pioglitazone, on mitochondria. At micromolar concentrations, pioglitazone increased mitochondrial DNA (mtDNA) content, levels of mtDNA and nuclear-encoded electron transport chain subunit proteins, increased oxygen consumption, and elevated complex I and complex IV V(max) activities. Pioglitazone treatment was also associated with increased cytoplasmic but reduced mitochondrial peroxide levels. Our data suggest that pioglitazone induces mitochondrial biogenesis and show that pioglitazone reduces mitochondrial oxidative stress in a neuron-like cell line. For these reasons pioglitazone may prove useful in the treatment of mitochondriopathies.


Assuntos
Mitocôndrias/efeitos dos fármacos , Neurônios/efeitos dos fármacos , Tiazolidinedionas/farmacologia , Linhagem Celular , Respiração Celular/efeitos dos fármacos , DNA Mitocondrial , Transporte de Elétrons/efeitos dos fármacos , Humanos , Mitocôndrias/fisiologia , Neurônios/citologia , Neurônios/fisiologia , Estresse Oxidativo/efeitos dos fármacos , Estresse Oxidativo/fisiologia , Pioglitazona , Espécies Reativas de Oxigênio/metabolismo
14.
J Voice ; 21(1): 64-71, 2007 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-16377130

RESUMO

Many persons with Parkinson's disease (PD) will eventually experience vocal impairment as their condition advances. Using standard perturbation analyses (parameters like jitter and shimmer) to measure fluctuations in phonatory signal may inhibit researchers from recognizing severely disordered patterns that seem to be present in the voices of some PD patients. Nonlinear dynamic analysis can quantify these aperiodic patterns, which indicate severe pathology that is usually characterized perceptually by hoarseness. Here, sustained vowel phonations of a heterogeneous group of PD subjects (20 women and 21 men) were compared with those of a control group (22 women and 18 men) based on results of nonlinear dynamic analyses (D(2)) and perturbation analyses. Results showed PD subjects as a whole to have significantly higher D(2) values than control subjects (P = 0.016), which indicates increased signal complexity in PD vocal pathology. Differences in the comparison of these two groups were significant in jitter (P = 0.014) but nonsignificant in shimmer (P = 0.695). Furthermore, the performance on these three measures was affected by subject sex. Nonlinear dynamic analysis showed significantly higher D(2) in the female PD group than in the female control group (P = 0.001), but jitter and shimmer did not show such a difference. The male PD group had statistically higher jitter than the male control group (P = 0.036), but these groups did not differ in D(2) or shimmer. Overall, nonlinear dynamic analysis may be a valuable method for the diagnosis of Parkinsonian laryngeal pathology.


Assuntos
Doença de Parkinson/epidemiologia , Distúrbios da Voz/diagnóstico , Distúrbios da Voz/epidemiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Índice de Gravidade de Doença , Acústica da Fala , Distúrbios da Voz/fisiopatologia , Qualidade da Voz
15.
Chaos ; 15(3): 33903, 2005 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-16252994

RESUMO

A nonlinear model is applied to study pathologic vocal vibratory characteristics and voice treatments of Parkinson's disease. We find that a number of pathologic vocal characteristics commonly observed in Parkinson's disease, including reduced vibratory intensity, incomplete vocal closure, increased phonation threshold pressure, glottal tremor, subharmonics, and chaotic vocal fold vibrations, can be studied with this nonlinear model. We also find that two kinds of clinical voice treatments for Parkinson's disease, including respiratory effort treatment and Lee Silverman voice treatment can be studied with this computer model. Results suggest that respiratory effort treatment, in which subglottal pressure is increased, might aid in enhancing vibratory intensity, improving glottal closure, and avoiding vibratory irregularity. However, the Lee Silverman voice treatment, in which both subglottal pressure and vocal fold adduction are increased, might be better than respiratory effort treatment. Increasing vocal fold thickness would be further helpful to improve these pathologic characteristics. The model studies show consistencies with clinical observations. Computer models may be of value in understanding the dynamic mechanism of disordered voices and studying voice treatment effects in Parkinson's disease.


Assuntos
Modelos Biológicos , Doença de Parkinson/fisiopatologia , Paralisia das Pregas Vocais/fisiopatologia , Paralisia das Pregas Vocais/terapia , Prega Vocal/fisiopatologia , Distúrbios da Voz/fisiopatologia , Distúrbios da Voz/terapia , Treinamento da Voz , Simulação por Computador , Humanos , Dinâmica não Linear , Doença de Parkinson/complicações , Distúrbios da Fala/etiologia , Distúrbios da Fala/fisiopatologia , Distúrbios da Fala/terapia , Medida da Produção da Fala/métodos , Fonoterapia/métodos , Terapia Assistida por Computador/métodos , Resultado do Tratamento , Vibração , Paralisia das Pregas Vocais/etiologia , Distúrbios da Voz/etiologia
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