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1.
Gynecol Oncol ; 157(2): 379-385, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32081463

RESUMO

PURPOSE: To evaluate the safety and clinical activity of mirvetuximab soravtansine, an antibody-drug conjugate comprising a humanized anti-folate receptor alpha (FRα) monoclonal antibody, cleavable linker, and the maytansinoid DM4, a potent tubulin-targeting agent, in combination with bevacizumab in patients with FRα-positive, platinum-resistant ovarian cancer. METHODS: Patients with platinum-resistant epithelial ovarian, fallopian tube, or primary peritoneal cancer were administered mirvetuximab soravtansine (6 mg/kg, adjusted ideal body weight) and bevacizumab (15 mg/kg) once every 3 weeks. Eligibility included FRα positivity by immunochemistry and prior bevacizumab exposure was permitted. Adverse events, tumor response, and progression-free survival (PFS) were determined. RESULTS: Sixty-six patients, with a median of 3 prior lines of therapy (range, 1-8), received the combination of mirvetuximab soravtansine and bevacizumab at full dosing during the escalation and expansion stages of the study. Adverse events were generally mild-to-moderate (≤grade 2) with diarrhea, blurred vision, nausea, and fatigue being the most common treatment-related toxicities. Six cases of pneumonitis (9%; all grade 1 or 2), an adverse event of special interest, were observed. The confirmed objective response rate (ORR) was 39%, including 5 complete responses and 21 partial responses, and the median PFS was 6.9 months. The combination was particularly active in the subset of patients (n = 16) who were bevacizumab-naïve, less heavily pretreated (1-2 prior lines), and whose tumors exhibited medium/high FRα expression (ORR, 56% with a median duration of response of 12 months; PFS, 9.9 months). CONCLUSION: The combination of mirvetuximab soravtansine with bevacizumab is well tolerated in patients with platinum-resistant, recurrent ovarian cancer. The encouraging efficacy measures compare favorably to reported outcomes for bevacizumab combined with standard chemotherapy in similar patient populations.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Carcinoma Epitelial do Ovário/tratamento farmacológico , Neoplasias Ovarianas/tratamento farmacológico , Adulto , Idoso , Idoso de 80 Anos ou mais , Anticorpos Monoclonais Humanizados/administração & dosagem , Anticorpos Monoclonais Humanizados/efeitos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Bevacizumab/administração & dosagem , Bevacizumab/efeitos adversos , Carcinoma Epitelial do Ovário/imunologia , Resistencia a Medicamentos Antineoplásicos , Feminino , Receptor 1 de Folato/imunologia , Humanos , Imunoconjugados/administração & dosagem , Imunoconjugados/efeitos adversos , Maitansina/administração & dosagem , Maitansina/efeitos adversos , Maitansina/análogos & derivados , Pessoa de Meia-Idade , Compostos Organoplatínicos/farmacologia , Neoplasias Ovarianas/imunologia , Intervalo Livre de Progressão
2.
Gynecol Oncol ; 151(1): 46-52, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-30093227

RESUMO

PURPOSE: To evaluate the safety profile and preliminary antitumor activity of mirvetuximab soravtansine when administered in combination with carboplatin to relapsed ovarian cancer patients. METHODS: Patients with recurrent, platinum-sensitive epithelial ovarian or fallopian tube cancer were enrolled. Eligibility included a minimum requirement of tumor FRα positivity (≥25% of cells with ≥2+ staining intensity). Patients received escalating doses of mirvetuximab soravtansine and carboplatin on day 1 of a 21-day cycle (once every 3 weeks). Mirvetuximab soravtansine maintenance therapy was permitted, at the investigators discretion, following cessation of carboplatin treatment. Adverse events, tumor response, and progression-free survival (PFS) were determined. RESULTS: Eighteen patients were enrolled and dosed with combination therapy; thirteen continued with mirvetuximab soravtansine maintenance following carboplatin discontinuation. Mirvetuximab soravtansine dosing was escalated from 5 to 6 mg/kg (adjusted ideal body weight) and carboplatin from AUC4 to AUC5. Adverse events were generally mild (≤ grade 2) with nausea, diarrhea, thrombocytopenia, blurred vision, and fatigue being the most common treatment-emergent toxicities. For all evaluable patients (n = 17), the confirmed objective response rate (ORR) was 71%, including three complete responses and nine partial responses, and the median PFS was 15 months. A median duration of response was not reached. CONCLUSION: These data demonstrate that mirvetuximab soravtansine combined with carboplatin is a well-tolerated and highly active regimen in recurrent, platinum-sensitive ovarian cancer. Further evaluation of this combination in a randomized fashion is warranted.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias das Tubas Uterinas/tratamento farmacológico , Receptor 1 de Folato/antagonistas & inibidores , Recidiva Local de Neoplasia/tratamento farmacológico , Neoplasias Ovarianas/tratamento farmacológico , Idoso , Idoso de 80 Anos ou mais , Anticorpos Monoclonais Humanizados/uso terapêutico , Carboplatina/uso terapêutico , Estudos de Coortes , Diarreia/induzido quimicamente , Diarreia/epidemiologia , Intervalo Livre de Doença , Resistencia a Medicamentos Antineoplásicos , Neoplasias das Tubas Uterinas/mortalidade , Neoplasias das Tubas Uterinas/patologia , Fadiga/induzido quimicamente , Fadiga/epidemiologia , Feminino , Humanos , Imunoconjugados/uso terapêutico , Incidência , Dose Máxima Tolerável , Maitansina/análogos & derivados , Maitansina/uso terapêutico , Pessoa de Meia-Idade , Náusea/induzido quimicamente , Náusea/epidemiologia , Recidiva Local de Neoplasia/mortalidade , Recidiva Local de Neoplasia/patologia , Neoplasias Ovarianas/mortalidade , Neoplasias Ovarianas/patologia , Trombocitopenia/induzido quimicamente , Trombocitopenia/epidemiologia , Resultado do Tratamento
3.
Future Oncol ; 14(17): 1669-1678, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29424243

RESUMO

Mirvetuximab soravtansine, an antibody-drug conjugate that binds with high affinity to folate receptor-α to provide tumor-directed delivery of the potent microtubule-disrupting agent DM4, has emerged as a promising investigational agent for the treatment of ovarian cancer, particularly in the setting of platinum-resistant disease. Here we describe the rationale and design of FORWARD I (NCT02631876), the first randomized, multicenter Phase III study to compare the safety and efficacy of mirvetuximab soravtansine versus investigator's choice of chemotherapy in women with folate receptor-α-positive, platinum-resistant epithelial ovarian, primary peritoneal or fallopian tube cancer. Patients will be randomized in a 2:1 ratio. The primary end point is progression-free survival, and key secondary objectives include comparison of overall response rates, overall survival and duration of response.


Assuntos
Anticorpos Monoclonais Humanizados/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Imunoconjugados/uso terapêutico , Maitansina/análogos & derivados , Neoplasias Epiteliais e Glandulares/tratamento farmacológico , Neoplasias Ovarianas/tratamento farmacológico , Platina/farmacologia , Carcinoma Epitelial do Ovário , Feminino , Seguimentos , Humanos , Maitansina/uso terapêutico , Prognóstico , Taxa de Sobrevida
4.
J Appl Biomech ; 28(6): 726-37, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22813601

RESUMO

Recognizing the importance of both the torque-angle and torque-velocity relations, three-dimensional (3D) human strength capabilities (i.e., peak torque as a function of both joint angle and movement velocity) have been increasingly reported. It is not clear, however, the degree to which these surfaces vary between joints, particularly between joints with similar biomechanical configurations. Thus, our goal was to compare 3D strength surfaces between the muscles about the elbow and knee hinge joints in men and women. Peak isometric and isokinetic strength was assessed in 54 participants (30 men) using the Biodex System 3 isokinetic dynamometer. Normalized peak torque surfaces varied significantly between flexion and extension (within each joint) and between joints; however, the normalized 3D torque surfaces did not differ between men and women. These findings suggest the underlying joint biomechanics are the primary influences on these strength surface profiles. Therefore, in applications such as digital human modeling, torque-velocity-angle relationships for each joint and torque direction must be uniquely represented to most accurately estimate human strength capability.


Assuntos
Articulação do Cotovelo/fisiologia , Articulação do Joelho/fisiologia , Modelos Biológicos , Contração Muscular/fisiologia , Músculo Esquelético/fisiologia , Resistência Física/fisiologia , Amplitude de Movimento Articular/fisiologia , Simulação por Computador , Feminino , Humanos , Masculino , Fatores Sexuais , Adulto Jovem
5.
Clin Cancer Res ; 25(6): 1727-1736, 2019 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-30413525

RESUMO

PURPOSE: Reversible, low-grade ocular adverse events (AE) are associated with administration of mirvetuximab soravtansine, a folate receptor alpha (FRα)-targeted antibody-drug conjugate undergoing phase III clinical evaluation in platinum-resistant ovarian cancer. This study investigated the underlying mechanisms of ocular toxicity and evaluated primary prophylactic use of corticosteroid eye drops in patients receiving mirvetuximab soravtansine. PATIENTS AND METHODS: Target expression in the human eye was determined by IHC. The ocular toxicity profile of mirvetuximab soravtansine was assessed preclinically using Dutch-Belted rabbits. In a phase I clinical study, patients with ovarian cancer were treated with 6 mg/kg mirvetuximab soravtansine intravenously once every 3 weeks, including one expansion cohort with corticosteroid eye drops administered daily for the first 10 days of each treatment cycle. RESULTS: FRα expression was absent from human corneal tissues. Ocular abnormalities in the rabbit eye appeared phenotypically consistent with off-target effects on the cornea. Forty patients were enrolled in the expansion cohort. Reversible grade 1 or 2 blurred vision and keratopathy occurred in 16 (40%) and 12 (30%) patients, respectively; no grade 3/4 ocular events were observed. Compared with those patients who did not receive primary prophylaxis, corticosteroid eye drop use resulted in fewer dose reductions (5% vs. 15%) and none discontinued due to ocular AEs. CONCLUSIONS: Preclinical modeling was predictive of the corneal-related symptoms seen in some patients dosed with mirvetuximab soravtansine. Primary prophylactic use of topical corticosteroid eye drops resulted in a trend toward symptomatic improvement and a reduction in ocular AE-related dose modifications in patients treated with mirvetuximab soravtansine.


Assuntos
Anticorpos Monoclonais Humanizados/efeitos adversos , Doenças da Córnea/prevenção & controle , Glucocorticoides/administração & dosagem , Imunoconjugados/efeitos adversos , Maitansina/análogos & derivados , Neoplasias Ovarianas/tratamento farmacológico , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Anticorpos Monoclonais Humanizados/administração & dosagem , Córnea/efeitos dos fármacos , Córnea/patologia , Doenças da Córnea/induzido quimicamente , Doenças da Córnea/patologia , Esquema de Medicação , Avaliação Pré-Clínica de Medicamentos , Resistencia a Medicamentos Antineoplásicos , Feminino , Receptor 1 de Folato/antagonistas & inibidores , Receptor 1 de Folato/metabolismo , Humanos , Imunoconjugados/administração & dosagem , Infusões Intravenosas , Masculino , Maitansina/administração & dosagem , Maitansina/efeitos adversos , Pessoa de Meia-Idade , Soluções Oftálmicas/administração & dosagem , Neoplasias Ovarianas/patologia , Coelhos , Testes de Toxicidade Subaguda , Resultado do Tratamento
6.
Int J Radiat Oncol Biol Phys ; 94(3): 450-60, 2016 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-26867874

RESUMO

PURPOSE: Whereas post-radiation therapy overreactions (OR) represent a clinical and societal issue, there is still no consensual radiobiological endpoint to predict clinical radiosensitivity. Since 2003, skin biopsy specimens have been collected from patients treated by radiation therapy against different tumor localizations and showing a wide range of OR. Here, we aimed to establish quantitative links between radiobiological factors and OR severity grades that would be relevant to radioresistant and genetic hyperradiosensitive cases. METHODS AND MATERIALS: Immunofluorescence experiments were performed on a collection of skin fibroblasts from 12 radioresistant, 5 hyperradiosensitive, and 100 OR patients irradiated at 2 Gy. The numbers of micronuclei, γH2AX, and pATM foci that reflect different steps of DNA double-strand breaks (DSB) recognition and repair were assessed from 10 minutes to 24 hours after irradiation and plotted against the severity grades established by the Common Terminology Criteria for Adverse Events and the Radiation Therapy Oncology Group. RESULTS: OR patients did not necessarily show a gross DSB repair defect but a systematic delay in the nucleoshuttling of the ATM protein required for complete DSB recognition. Among the radiobiological factors, the maximal number of pATM foci provided the best discrimination among OR patients and a significant correlation with each OR severity grade, independently of tumor localization and of the early or late nature of reactions. CONCLUSIONS: Our results are consistent with a general classification of human radiosensitivity based on 3 groups: radioresistance (group I); moderate radiosensitivity caused by delay of nucleoshuttling of ATM, which includes OR patients (group II); and hyperradiosensitivity caused by a gross DSB repair defect, which includes fatal cases (group III).


Assuntos
Proteínas Mutadas de Ataxia Telangiectasia/metabolismo , Núcleo Celular/metabolismo , Quebras de DNA de Cadeia Dupla , Histonas/metabolismo , Lesões por Radiação/classificação , Tolerância a Radiação/fisiologia , Pele/efeitos da radiação , Análise de Variância , Proteínas Mutadas de Ataxia Telangiectasia/genética , Biópsia , Linhagem Celular , Reparo do DNA , Fibroblastos/efeitos da radiação , Humanos , Testes para Micronúcleos/métodos , Fosforilação , Lesões por Radiação/metabolismo , Lesões por Radiação/patologia , Tolerância a Radiação/genética , Pele/patologia , Fatores de Tempo
7.
Mech Ageing Dev ; 126(2): 263-7, 2005 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-15621206

RESUMO

Our previous work revealed that 88% of centenarians delay or escape the age-related lethal diseases cardiac disease, stroke and diabetes. In the cases of those having a history of cancer we have observed anecdotes of centenarians presenting with large primary tumors that would have otherwise been expected to have metastasized and to have been lethal. However, these tumors were removed without consequence. To better understand the relationship between cancer and exceptional longevity, we quantified age of cancer diagnoses, life-time clinically evident cancer prevalence, tobacco use and family histories through medical record review and interviews. One thousand one hundred and forty-three subjects were studied revealing 20% (N=152) of female and 22% (N=80) of male centenarians with a history of non-skin cancer. The most common cancers were prostate (11.7% of males), breast (8.2% of females), and colon (5.7%). The average age of diagnosis was 80.5 years compared to 63.2 years in the general population according to National Cancer Institute SEER data. Similar delays were noted when age of onset was examined according to specific type of cancer. In conclusion, the age of diagnosis of cancer is relatively delayed in those who live to 100 years. Some cancers are very rare among these individuals suggesting that there are certain cancers that may be incompatible with survival to extreme old age.


Assuntos
Envelhecimento , Neoplasias/patologia , Fatores Etários , Idade de Início , Idoso , Idoso de 80 Anos ou mais , Estudos de Coortes , Suscetibilidade a Doenças , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias/diagnóstico , Neoplasias/epidemiologia , Fenótipo , Fatores de Tempo
8.
Leuk Res ; 28(11): 1137-43, 2004 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-15380336

RESUMO

Inosine-5'-monophosphate-dehydrogenase (IMPDH) regulates the de novo synthesis of guanine ribonucleotides (GNT). IMPDH activity varies inversely with intracellular [GNT] and is linked to cellular proliferation. K562 leukemia cell growth was studied relative to IMPDH expression and activity following culture of the cells with Tiazofurin, an IMPDH inhibitor. Tiazofurin depressed IMPDH activity and [GTP] in K562 cells, and also increased IMPDH mRNA expression. Following exposure to Tiazofurin, K562 cell proliferation, entry into cycle, and sensitivity to cycle-active cytotoxic agents were increased. These findings indicate that the efficacy of standard chemotherapy in bcr-abl positive leukemias might be enhanced if combined sequentially with Tiazofurin.


Assuntos
Antineoplásicos/farmacologia , Inibidores Enzimáticos/farmacologia , IMP Desidrogenase/antagonistas & inibidores , Ribavirina/análogos & derivados , Ribavirina/farmacologia , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , IMP Desidrogenase/genética , IMP Desidrogenase/metabolismo , Técnicas In Vitro , Células K562 , RNA Mensageiro/genética
9.
Leuk Res ; 28(11): 1125-36, 2004 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-15380335

RESUMO

Six patients with bcr-abl positive AML or chronic myelogenous leukemia in blast crisis (CML-BC) were treated with the IMP-dehydrogenase (IMPDH) inhibitor, Tiazofurin, in a Phase-II trial. Tiazofurin was given by IV infusion (2200-2700 mg/m2 per day) for up to 10 days. Leukemia blasts rapidly disappeared from the circulation of patients during treatment, while mature myeloid cells in the marrow increased in number. Although these hematologic responses were transient, persisting less than 3-4 weeks, our findings confirm that Tiazofurin has anti-leukemia activity. This drug warrants further study in combination regimens with other chemotherapeutic agents for the treatment of bcr-abl positive AML and CML-BC.


Assuntos
Antineoplásicos/uso terapêutico , Inibidores Enzimáticos/uso terapêutico , Genes abl , IMP Desidrogenase/antagonistas & inibidores , Leucemia Mieloide Aguda/tratamento farmacológico , Ribavirina/análogos & derivados , Ribavirina/uso terapêutico , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Resultado do Tratamento
10.
Radiat Oncol ; 6: 79, 2011 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-21714935

RESUMO

PURPOSE: To assess treatment toxicity and patients' survival/quality of life (QoL) after volumetric modulated arc therapy (VMAT) with simultaneous in-field boost (SIB) for cancer patients with 1 - 4 brain metastases (BM) treated with or without surgery. METHODS AND MATERIALS: Between March and December 2010, 29 BM patients (total volume BM, < 40 cm3) aged < 80 years, KPS ≥ 70, RPA < III were included in this prospective trial. Whole brain VMAT (30 Gy) and a SIB to the BM (40 Gy) was delivered in 10 fraction. Mean age was 62.1 ± 8.5 years. Fifteen (51.7%) underwent surgery. KPS and MMSE were prospectively assessed. A self-assessed questionnaire was used to assess the QoL (EORTC QLQ-C30 with -BN20 module). RESULTS: As of April 2011 and after a mean FU of 5.4 ± 2.8 months, 14 (48.3%) patients died. The 6-month overall survival was 55.1%. Alopecia was only observed in 9 (31%) patients. In 3-month survivors, KPS was significantly (p = 0.01) decreased. MMSE score remained however stable (p = 0.33). Overall, QoL did decrease after VMAT. The mean QLQ-C30 global health status (p = 0.72) and emotional functional (p = 0.91) scores were decreased (low QoL). Physical (p = 0.05) and role functioning score (p = 0.01) were significantly worse and rapidly decreased during treatment. The majority of BN20 domains and single items worsened 3 months after VMAT except headaches (p = 0.046) and bladder control (p = 0.26) which improved. CONCLUSIONS: The delivery of 40 Gy in 10 fractions to 1 - 4 BM using VMAT was achieved with no significant toxicity. QoL, performance status, but not MMSE, was however compromised 3 months after treatment in this selected cohort of BM patients.


Assuntos
Neoplasias Encefálicas/patologia , Neoplasias Encefálicas/radioterapia , Radioterapia de Intensidade Modulada/métodos , Idoso , Encéfalo/patologia , Feminino , Nível de Saúde , Humanos , Masculino , Pessoa de Meia-Idade , Metástase Neoplásica , Prognóstico , Estudos Prospectivos , Qualidade de Vida , Inquéritos e Questionários , Resultado do Tratamento
11.
J Biomech ; 44(4): 683-93, 2011 Feb 24.
Artigo em Inglês | MEDLINE | ID: mdl-21092968

RESUMO

An optimization-based formulation and solution method are presented to predict asymmetric human gait for a large-scale skeletal model. Predictive dynamics approach is used in which both the joint angles and joint torques are treated as unknowns in the equations of motion. For the optimization formulation, the joint angle profiles are treated as the primary unknowns, and velocities and accelerations are calculated using them. In numerical implementation, the joint angle profiles are discretized using the B-spline interpolation. An algorithm is presented to inversely calculate the joint torques and the ground reaction forces. The sum of the joint-torques squared, called the dynamic effort, is minimized as the human performance measure. Constraints are imposed on the joint strengths (torques) and joint ranges of motion along with other physical constraints. The formulation is validated by simulating a symmetric gait and comparing the results with the experimental data. Then asymmetric gait motion is simulated, where the left and right step lengths are different. The kinematics and kinetics results from the simulation are presented and discussed. Predicted ground reaction forces are explained by using the inverted pendulum model. Predicted kinematics and kinetics have trends that are similar to those reported in the literature. Potential practical applications of the formulation and the solution approach are discussed.


Assuntos
Algoritmos , Marcha/fisiologia , Articulações/fisiologia , Locomoção/fisiologia , Modelos Biológicos , Contração Muscular/fisiologia , Músculo Esquelético/fisiologia , Amplitude de Movimento Articular/fisiologia , Simulação por Computador , Humanos , Torque
12.
C R Biol ; 334(2): 140-57, 2011 Feb.
Artigo em Francês | MEDLINE | ID: mdl-21333944

RESUMO

Individual response to ionizing radiation is an important information required to apply an efficient radiotherapy treatment against tumour and to avoid any adverse effects in normal tissues. In 1981, Fertil and Malaise have demonstrated that the post-irradiation local tumor control determined in vivo is correlated with clonogenic cell survival assessed in vitro. Furthermore, these authors have reminded the relevance of the concept of intrinsic radiosensitivity that is specific to each individual organ (Fertil and Malaise, 1981) [1]. To date, since clonogenicity assays are too time-consuming and do not provide any other molecular information, a plethora of research groups have attempted to determine the molecular bases of intrinsic radiosensitivity in order to propose reliable and faster predictive assays. To this aim, several approaches have been developed. Notably, the recent revolution in genomic and proteomic technologies is providing a considerable number of data but their link with radiosensitivity still remains to be elucidated. On another hand, the systematic screening of some candidate genes potentially involved in the radiation response is highlighting the complexity of the molecular and cellular mechanisms of DNA damage sensoring and signalling and shows that an abnormal radiation response is not necessarily due to the impairment of one single protein. Finally, more modest approaches consisting in focusing some specific functions of DNA repair seem to provide more reliable clues to predict over-acute reactions caused by radiotherapy. In this review, we endeavoured to analyse the contributions of these major approaches to predict human radiosensitivity.


Assuntos
Variação Genética , Tolerância a Radiação/genética , Radiação Ionizante , Animais , Morte Celular/efeitos da radiação , Hipóxia Celular , Cromossomos Humanos/efeitos da radiação , Células Clonais/efeitos da radiação , Ensaio de Unidades Formadoras de Colônias , DNA/efeitos da radiação , Reparo do DNA/genética , Relação Dose-Resposta à Radiação , Estudos de Associação Genética , Predisposição Genética para Doença , Humanos , Camundongos , Neoplasias/genética , Neoplasias/radioterapia , Lesões por Radiação/genética , Lesões por Radiação/prevenção & controle , Tolerância a Radiação/fisiologia , Radiometria , Radioterapia/efeitos adversos , Resultado do Tratamento
13.
J Biomech Eng ; 130(3): 031002, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18532851

RESUMO

Since humans can walk with an infinite variety of postures and limb movements, there is no unique solution to the modeling problem to predict human gait motions. Accordingly, we test herein the hypothesis that the redundancy of human walking mechanisms makes solving for human joint profiles and force time histories an indeterminate problem best solved by inverse dynamics and optimization methods. A new optimization-based human-modeling framework is thus described for predicting three-dimensional human gait motions on level and inclined planes. The basic unknowns in the framework are the joint motion time histories of a 25-degree-of-freedom human model and its six global degrees of freedom. The joint motion histories are calculated by minimizing an objective function such as deviation of the trunk from upright posture that relates to the human model's performance. A variety of important constraints are imposed on the optimization problem, including (1) satisfaction of dynamic equilibrium equations by requiring the model's zero moment point (ZMP) to lie within the instantaneous geometrical base of support, (2) foot collision avoidance, (3) limits on ground-foot friction, and (4) vanishing yawing moment. Analytical forms of objective and constraint functions are presented and discussed for the proposed human-modeling framework in which the resulting optimization problems are solved using gradient-based mathematical programming techniques. When the framework is applied to the modeling of bipedal locomotion on level and inclined planes, acyclic human walking motions that are smooth and realistic as opposed to less natural robotic motions are obtained. The aspects of the modeling framework requiring further investigation and refinement, as well as potential applications of the framework in biomechanics, are discussed.


Assuntos
Modelos Biológicos , Caminhada/fisiologia , Simulação por Computador , Retroalimentação Psicológica , Análise de Elementos Finitos , Pé/fisiologia , Fricção , Marcha/fisiologia , Sensação Gravitacional , Humanos , Articulações/fisiologia , Matemática , Movimento/fisiologia , Contração Muscular , Músculo Esquelético/fisiologia , Dinâmica não Linear , Equilíbrio Postural/fisiologia , Postura/fisiologia , Fatores de Tempo , Estudos de Tempo e Movimento , Torque
14.
Am J Hematol ; 82(5): 363-7, 2007 May.
Artigo em Inglês | MEDLINE | ID: mdl-17205535

RESUMO

Acquired loss of functional von Willebrand factor (VWF) has been termed the acquired von Willebrand syndrome (AVWS). AVWS is a rare adult-onset bleeding diathesis that is clinically similar to congenital von Willebrand disease (VWD), and occurs with a variety of autoimmune, lymphoproliferative, or myeloproliferative disorders. We have identified four patients with AVWS in association with immunoglobulin light chain (AL) amyloidosis. These patients, lacking any pre-existing or family history of abnormal bleeding, developed cutaneous, mucosal, or gastrointestinal bleeding in the course of their disease without deficiency of clotting factor X or other factors; the activated partial thromboplastin time (aPTT) was prolonged in three out of the four cases. Despite normal VWF antigen levels, VWF ristocetin cofactor activity (VWF:RCo) was low. Electrophoresis patterns of high molecular weight (HMW) VWF multimers were abnormal in two of the four cases. Two of the patients were treated with high-dose intravenous melphalan followed by autologous stem cell transplantation (HDM/SCT) and achieved hematologic remission. In these two patients, the bleeding diathesis improved and the coagulation parameters normalized, confirming a causal relationship between the plasma cell dyscrasia and the AVWS. AVWS should be considered in AL amyloidosis patients with hemorrhagic diatheses and normal clotting factor levels.


Assuntos
Amiloidose/complicações , Doenças de von Willebrand/etiologia , Adulto , Amiloidose/sangue , Amiloidose/tratamento farmacológico , Amiloidose/cirurgia , Antígenos/análise , Eletroforese das Proteínas Sanguíneas , Eletroforese em Gel de Ágar , Hemorragia/etiologia , Humanos , Cadeias Leves de Imunoglobulina/análise , Masculino , Melfalan/uso terapêutico , Peso Molecular , Tempo de Tromboplastina Parcial , Transplante de Células-Tronco de Sangue Periférico , Indução de Remissão , Ristocetina/farmacologia , Transplante Autólogo , Doenças de von Willebrand/imunologia , Fator de von Willebrand/imunologia
15.
Blood ; 108(12): 3945-7, 2006 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-16926284

RESUMO

Recently, protocols using high-dose melphalan chemotherapy and autologous peripheral blood stem cell transplantation (HDM/SCT) have been developed for the treatment of patients with immunoglobulin light chain (AL) amyloidosis. Although peritransplantation mortality is greater than for other hematologic diseases, treatment leads to durable hematologic complete responses, improvements in organ function and quality of life, and extended survival in a substantial proportion of patients. To determine whether this treatment can be applied to older patients, we have analyzed HDM/SCT treatment outcomes for 65 patients (aged 65 years or older) with AL amyloidosis compared with outcomes for 280 younger patients. For patients over age 65 years who meet the same eligibility criteria as younger patients, toxicity, hematologic remission rate, and survival were not significantly different from those observed in younger patients, indicating that older patients should not be excluded a priori from consideration for HDM/SCT treatment.


Assuntos
Envelhecimento , Amiloidose/terapia , Antineoplásicos Alquilantes/administração & dosagem , Cadeias Leves de Imunoglobulina , Melfalan/administração & dosagem , Transplante de Células-Tronco de Sangue Periférico , Adulto , Idoso , Amiloidose/mortalidade , Antineoplásicos Alquilantes/efeitos adversos , Intervalo Livre de Doença , Feminino , Humanos , Masculino , Melfalan/efeitos adversos , Pessoa de Meia-Idade , Transplante de Células-Tronco de Sangue Periférico/efeitos adversos , Transplante de Células-Tronco de Sangue Periférico/mortalidade , Qualidade de Vida , Recuperação de Função Fisiológica , Indução de Remissão , Estudos Retrospectivos , Taxa de Sobrevida , Transplante Autólogo
16.
J Biomech Eng ; 127(6): 934-45, 2005 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-16438230

RESUMO

This paper presents the design and prototyping of an inherently compliant lightweight hand mechanism. The hand mechanism itself has 15 degrees of freedom and five fingers. Although the degrees of freedom in each finger are coupled, reducing the number of independent degrees of freedom to 5, the 15 degrees of freedom of the hand could potentially be individually actuated. Each joint consists of a novel flexing mechanism that is based on the loading of a compression spring in the axial and transverse direction via a cable and conduit system. Currently, a bench top version of the prototype is being developed; the three joints of each finger are coupled together to simplify the control system. The current control scheme under investigation simulates a control scheme where myoelectric signals in the wrist flexor and extensor muscles are converted in to x and y coordinates on a control scheme chart. Static load-deformation analysis of finger segments is studied based on a 3-dimensional model without taking the stiffener into account, and the experiment validates the simulation.


Assuntos
Biomimética/instrumentação , Articulações dos Dedos/fisiologia , Força da Mão/fisiologia , Mãos/fisiologia , Modelos Biológicos , Robótica/instrumentação , Biomimética/métodos , Simulação por Computador , Elasticidade , Desenho de Equipamento , Análise de Falha de Equipamento , Estudos de Viabilidade , Humanos , Projetos Piloto , Robótica/métodos , Estresse Mecânico
17.
Ergonomics ; 47(13): 1386-405, 2004 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-15513715

RESUMO

Significant attention in recent years has been given towards obtaining a better understanding of human joint ranges, measurement, and functionality, especially in conjunction with commands issued by the central nervous system. Studies of those commands often include computer algorithms to describe path trajectories. These are typically in "open-form" with specific descriptions of motions, but not "closed form" mathematical solutions of the full range of possibilities. This paper proposes a rigorous "closed form" kinematic formulation to model human limbs, understand their workspace (also called the reach envelope), and delineate barriers therein where a path becomes difficult or impossible owing to physical constraints. The novel ability to visualize barriers in the workspace emphasizes the power of these closed form equations. Moreover, this formulation takes into account joint limits in terms of ranges of motion and identifies barriers therein where a person is required to attain a different posture. Examples include the workspaces of a typical forearm and a typical finger. The wrist's range of motion is used to illustrate the visualization of the progress in the functionality of a wrist undergoing rehabilitation.


Assuntos
Braço/fisiologia , Fenômenos Biomecânicos/métodos , Modelos Biológicos , Movimento/fisiologia , Humanos , Amplitude de Movimento Articular , Articulação do Punho/fisiologia
18.
Med Care ; 42(7): 700-6, 2004 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-15213495

RESUMO

OBJECTIVES: The objectives of this study were to determine whether tamoxifen recommendation differs by physician specialty, to determine whether perception affects tamoxifen recommendation, and to investigate the association between the physician's specialty and the perception of risks and benefits of tamoxifen. METHODS: We enrolled a cohort of geographically diverse women aged 65 and older with stage I through IIIa breast cancer in a prospective cohort study. We recruited their surgeons and, when applicable, their medical oncologists to provide patient-specific information about their perceptions of the risks and benefits of tamoxifen and whether they recommended tamoxifen. Each physician also completed a questionnaire regarding his or her demographic and practice characteristics. Patient data were collected through medical record review and a patient interview 3 months after definitive breast cancer surgery. RESULTS: We collected physician treatment recommendation forms for 585 women. Oncologists were 2.5 times more likely to recommend tamoxifen, compared with surgeons, after adjusting for patient and tumor characteristics (95% confidence interval, 1.5-4.2). For both specialties, their perceptions of the risks and benefits of tamoxifen were strong predictors of tamoxifen recommendation. However, there were differences in perception by physician specialty. Distant metastases and tolerance of tamoxifen side effects were more important to oncologists, whereas local recurrence and risk of cataracts were more important to surgeons. CONCLUSION: Physicians' perceptions of the risks and benefits of tamoxifen therapy for older women are important in their decision-making process.


Assuntos
Antineoplásicos Hormonais/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Medicina , Seleção de Pacientes , Especialização , Tamoxifeno/uso terapêutico , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Neoplasias da Mama/patologia , Quimioterapia Adjuvante , Tomada de Decisões , Feminino , Humanos , Modelos Logísticos , Masculino , Medicina/estatística & dados numéricos , Estudos Prospectivos , Medição de Risco , Estados Unidos
19.
Blood ; 104(6): 1888-93, 2004 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-15155460

RESUMO

Treatment of AL amyloidosis patients with high-dose melphalan chemotherapy followed by autologous peripheral blood stem cell transplantation (HDM/SCT) can produce hematologic complete responses (CRs) and improvement in organ function. To determine whether these responses are accompanied by improvement in quality of life (QOL), we employed the Medical Outcomes Study (MOS) 36-item Short Form General Health Survey (SF-36) questionnaire for 544 patients evaluated between 1994 and 2002. At baseline, the scores were significantly lower on all 8 SF-36 scales compared with age-matched population norms: the composite physical component summary (PCS) for the AL patients was 34.5 versus the population norm of 46.8, and the mental component summary (MCS) was 45.0 versus the norm of 51.5. All SF-36 scores improved at 1 year, with the MCS reaching the population norm. The PCS, though improved, was still lower than normal but was greater in the subgroup of patients who achieved a hematologic CR; the PCS normalized at 2 years in these patients. Thus, treatment of AL amyloidosis patients with HDM/SCT produces measurable and sustained improvements in quality of life, particularly in those patients who achieve hematologic CR.


Assuntos
Amiloidose/tratamento farmacológico , Amiloidose/cirurgia , Melfalan/administração & dosagem , Melfalan/uso terapêutico , Qualidade de Vida , Transplante de Células-Tronco , Seguimentos , Inquéritos Epidemiológicos , Humanos , Pessoa de Meia-Idade , Inquéritos e Questionários , Taxa de Sobrevida , Resultado do Tratamento
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