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1.
Langmuir ; 25(20): 12380-6, 2009 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-19778027

RESUMO

Galactitol dehydrogenase (GatDH) from Rhodobacter sphaeroides is a multifunctional enzyme that catalyzes in the presence of oxidized beta-nicotinamide adenine dinucleotide (NAD(+)) the interconversion of various multivalent aliphatic alcohols to the corresponding ketones. The recombinant GatDH was provided with an N-terminal His(6)-tag to which distally up to three cysteine residues were attached. This protein construct maintained nearly full enzymatic activity, and it could be covalently immobilized via thiol bonds onto the surface of a gold electrode. Binding of GatDH onto the gold electrode was verified by SPR measurements, and residual enzyme activity was measured by cyclic voltammetry using 1,2-hexanediol as substrate, the cofactor NAD(+) and the redox mediator CTFM (4-carboxy-2,5,7-trinitrofluorenyliden-malonnitrile) in solute form. The results demonstrate the possibility of a directed functional immobilization of proteins on gold surfaces, which represents a proof-of-concept for the development of reactors for electrochemical synthon preparation using dehydrogenases.


Assuntos
Enzimas Imobilizadas/química , Enzimas Imobilizadas/genética , Ouro/química , Polímeros/química , Rhodobacter sphaeroides/enzimologia , Desidrogenase do Álcool de Açúcar/química , Desidrogenase do Álcool de Açúcar/genética , Cloreto de Cálcio/metabolismo , Domínio Catalítico , Cisteína/metabolismo , Eletroquímica , Eletrodos , Transporte de Elétrons , Enzimas Imobilizadas/isolamento & purificação , Enzimas Imobilizadas/metabolismo , Mutação , NAD/metabolismo , Engenharia de Proteínas , Desidrogenase do Álcool de Açúcar/isolamento & purificação , Desidrogenase do Álcool de Açúcar/metabolismo , Compostos de Sulfidrila/química , Propriedades de Superfície
2.
Chemphyschem ; 7(7): 1535-43, 2006 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-16789040

RESUMO

The present work shows, for the first time, a comparative experimental study on the electrodeposition of aluminium in three different water and air stable ionic liquids, namely 1-butyl-1-methylpyrrolidinium-bis(trifluoromethylsulfonyl)imide ([BMP]Tf2N), 1-ethyl-3-methylimidazolium-bis(trifluoromethylsulfonyl)imide ([EMIm] Tf2N), and trihexyl-tetradecyl-phosphoniumbis(trifluoromethylsulfonyl)imide (P(14,6,6,6) Tf2N). The ionic liquids [BMP]Tf2N and [EMIm]Tf2N show biphasic behaviour in the AlCl3 concentration range from 1.6 to 2.5 mol L(-1) and 2.5 to 5 mol L(-1), respectively. The biphasic mixtures become monophasic at temperatures >/=80 degrees C. It was found that nanocrystalline aluminium can be electrodeposited in the ionic liquid [BMP]Tf2N saturated with AlCl3. The deposits obtained are generally uniform, dense, shining, and adherent with very fine crystallites in the nanometer size regime. However, coarse cubic-shaped aluminium particles in the micrometer range are obtained in the ionic liquid [EMIm]Tf2N. In this liquid the particle size significantly increases as the temperature rises. A very thin, mirrorlike aluminium film containing very fine crystallites of about 20 nm is obtained in the ionic liquid [trihexyl-tetradecyl-phosphonium]Tf(2)N at room temperature. At 150 degrees C, the average grain size is found to be 35 nm.

3.
Phys Rev Lett ; 86(5): 842-5, 2001 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-11177954

RESUMO

Measurements of grain growth in nanocrystalline Fe reveal a linear dependence of the grain size on annealing time, contradicting studies in coarser-grained materials, which find a parabolic (or power-law) dependence. When the grain size exceeds approximately 150 nm, a smooth transition from linear to nonlinear growth kinetics occurs, suggesting that the rate-controlling mechanism for grain growth depends on the grain size. The linear-stage growth rate agrees quantitatively with a model in which boundary migration is controlled by the redistribution of excess volume localized in the boundary cores.

4.
Med Care ; 37(1): 15-26, 1999 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-10413388

RESUMO

OBJECTIVES: Recent trials of amyotrophic lateral sclerosis (ALS) therapies have included the Sickness Impact Profile (SIP) to evaluate health-related quality of life (HQL). The purpose of this study was to assess the feasibility, psychometric properties, and interpretation of the Sickness Impact Profile in this setting. METHODS: The Sickness Impact Profile was administered at baseline, 3, 6, and 9 months during a double-blind, placebo-controlled study of recombinant human insulin-like growth factor I. The frequency of missing Sickness Impact Profile data and administration time were recorded. Patients' scores on the Appel ALS (AALS) Rating Scale were used to identify a stable subgroup for reliability testing and clinically distinct groups for validity testing. Internal consistency reliability and reproducibility were evaluated using Cronbach's alpha and intraclass correlation coefficients, respectively. Analysis of variance (ANOVA) models and t tests were used to assess validity. Effect sizes and the responsiveness index were used to assess responsiveness. RESULTS: At baseline, 259 (97%) patients completed a 30-minute Sickness Impact Profile interview. At subsequent assessments, response rates ranged from 92% to 97% and mean administration times ranged from 25 to 27 minutes. The overall Sickness Impact Profile score demonstrated alpha reliability and 3-month stability coefficients of 0.94 and 0.80, respectively. Baseline overall Sickness Impact Profile scores discriminated between patients in the two AALS-defined groups with a mean of 13.0+/-7.8 and 24.0+/-11.7 in the better and worse AALS groups, respectively. Similarly, mean overall SIP change scores discriminated patients progressing at different rates (slow to moderate = 4.00+/-7.97; rapid = 10.74+/-8.76). With few exceptions, dimension and category scores met similar criteria. Responsiveness statistics for the physical and overall Sickness Impact Profile scores were lower at 3 months and higher at 6 and 9 months. CONCLUSIONS: The feasibility, psychometric, and interpretive findings support the validity of the Sickness Impact Profile for assessing outcomes of amyotrophic lateral sclerosis and its treatment. Based on these findings, we recommend including the Sickness Impact Profile in future amyotrophic lateral sclerosis clinical trials.


Assuntos
Esclerose Lateral Amiotrófica/psicologia , Ensaios Clínicos como Assunto/psicologia , Qualidade de Vida , Perfil de Impacto da Doença , Atividades Cotidianas , Esclerose Lateral Amiotrófica/fisiopatologia , Esclerose Lateral Amiotrófica/terapia , Análise de Variância , Efeitos Psicossociais da Doença , Análise Discriminante , Progressão da Doença , Estudos de Viabilidade , Feminino , Humanos , Fator de Crescimento Insulin-Like I/uso terapêutico , Masculino , Pessoa de Meia-Idade , Psicometria , Reprodutibilidade dos Testes
5.
Pharmacoeconomics ; 15(2): 179-95, 1999 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-10351191

RESUMO

OBJECTIVE: Amyotrophic lateral sclerosis (ALS) is a fatal, degenerative neuromuscular disease characterised by a progressive loss of voluntary motor activity. Recombinant human insulin-like growth factor I (rhIGF-I) has been shown to be useful in treating ALS. The purpose of this study was to examine the cost effectiveness of rhIGF-I therapy in patients who have ALS. DESIGN: We performed a cost-effectiveness analysis from the societal perspective on 177 patients who received treatment with rhIGF-I or placebo in a North American randomised clinical trial. We estimated the incremental cost-effectiveness ratio of rhIGF-I using resource utilisation and functional status measurements from the clinical trial. Costs were estimated from 1996 US Medicare reimbursement schedules. Utility weights were elicited from ALS healthcare providers using the standard gamble technique. MAIN OUTCOME MEASURES AND RESULTS: The overall cost per quality-adjusted life-year (QALY) gained for rhIGF-I therapy compared with placebo was $US67,440. For the subgroups of patients who were progressing rapidly or were in earlier stages of disease at enrolment, rhIGF-I cost $US52,823 and $US43,197 per QALY gained, respectively. CONCLUSIONS: Treatment with rhIGF-I is most cost effective in ALS patients who are either in earlier stages of the disease or progressing rapidly. The cost effectiveness of rhIGF-I therapy compares favourably with treatments for other chronic progressive diseases.


Assuntos
Esclerose Lateral Amiotrófica/tratamento farmacológico , Esclerose Lateral Amiotrófica/economia , Fator de Crescimento Insulin-Like I/economia , Fator de Crescimento Insulin-Like I/uso terapêutico , Proteínas Recombinantes/economia , Proteínas Recombinantes/uso terapêutico , Adulto , Idoso , Análise Custo-Benefício , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Qualidade de Vida , Sensibilidade e Especificidade
6.
Neurology ; 49(6): 1621-30, 1997 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-9409357

RESUMO

The objective of this study was to investigate the safety and efficacy of recombinant human insulinlike growth factor-I (rhIGF-I) in the treatment of sporadic ALS. A double-blind, placebo-controlled, randomized study of 266 patients was conducted at eight centers in North America. Placebo or rhIGF-I (0.05 mg/kg/day or 0.10 mg/kg/day) was administered for 9 months. The primary outcome measure was disease symptom progression, assessed by the rate of change (per patient slope) in the Appel ALS rating scale total score. The Sickness Impact Profile (SIP), a patient-perceived, health-related quality of life assessment, was a secondary outcome variable. Progression of functional impairment in patients receiving high-dose (0.10 mg/kg/day) rhIGF-I was 26% slower than in patients receiving placebo (p = 0.01). The high-dose treatment group was less likely to terminate the study due to protocol-defined markers of disease symptom progression, and members in this group exhibited a slower decline in quality of life, as assessed by the SIP. Patients receiving 0.05 mg/kg/day of rhIGF-I exhibited trends similar to those associated with high-dose treatment, suggesting a dose-dependent response. The incidence of clinically significant adverse experiences was comparable among the three treatment groups. Recombinant human insulin-like growth factor-I slowed the progression of functional impairment and the decline in health-related quality of life in patients with ALS with no medically important adverse effects.


Assuntos
Esclerose Lateral Amiotrófica/fisiopatologia , Esclerose Lateral Amiotrófica/terapia , Fator de Crescimento Insulin-Like I/uso terapêutico , Progressão da Doença , Relação Dose-Resposta a Droga , Método Duplo-Cego , Feminino , Seguimentos , Humanos , Fator de Crescimento Insulin-Like I/efeitos adversos , Masculino , Pessoa de Meia-Idade , Placebos , Proteínas Recombinantes , Índice de Gravidade de Doença , Perfil de Impacto da Doença , Análise de Sobrevida , Resultado do Tratamento
8.
J Forensic Sci ; 40(5): 900-2, 1995 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-7595336

RESUMO

We report the case of a 21-year-old male who sustained an uncal herniation and subsequent brain death following general anesthesia, for a minor orthopedic procedure, owing to the presence of a large, unsuspected temporal glioma. The possible factors responsible for the precipitation of this event are appraised.


Assuntos
Anestesia Geral/efeitos adversos , Astrocitoma/complicações , Encefalopatias/etiologia , Neoplasias Encefálicas/complicações , Lobo Temporal , Adulto , Astrocitoma/diagnóstico , Morte Encefálica , Neoplasias Encefálicas/diagnóstico , Evolução Fatal , Cefaleia/etiologia , Hérnia/etiologia , Humanos , Pressão Intracraniana , Masculino
9.
Brain Res ; 621(1): 111-5, 1993 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-8221061

RESUMO

In the present study, in situ hybridization was used to examine the expression of nerve growth factor (NGF) receptor (p75NGFR), trk (p140trk) and trkB (p145trkB) mRNA in spinal cord sections from patients with amyotrophic lateral sclerosis (ALS). We report that the expression of p75NGFR and p145trkB mRNA is elevated in alpha motoneurons in ALS sections. However, p140trk mRNA was not expressed in either ALS or control sections.


Assuntos
Esclerose Lateral Amiotrófica/metabolismo , Neurônios Motores/metabolismo , Proteínas Proto-Oncogênicas/genética , RNA Mensageiro/biossíntese , Receptores Proteína Tirosina Quinases/genética , Receptores de Fator de Crescimento Neural/genética , Medula Espinal/metabolismo , Adulto , Humanos , Pessoa de Meia-Idade , Receptor trkA , Medula Espinal/citologia
10.
Neurology ; 39(7): 991-2, 1989 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-2739929

RESUMO

We studied the relative frequency of cavum septum pellucidum (CSP) by CT. Six of 9 men with CSP were boxers or had head trauma. We conclude that some cases of CSP are not congenital variants, but rather may serve as an indicator of prior head trauma, especially in boxers. In such instances, CSP may be a CT sign of traumatic encephalopathy.


Assuntos
Traumatismos em Atletas/diagnóstico por imagem , Boxe , Lesões Encefálicas/diagnóstico por imagem , Septo Pelúcido/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Adolescente , Adulto , Traumatismos Craniocerebrais/diagnóstico por imagem , Feminino , Humanos , Masculino , Valores de Referência
11.
Pediatr Neurol ; 2(6): 356-8, 1986.
Artigo em Inglês | MEDLINE | ID: mdl-3508709

RESUMO

To evaluate malignant hyperthermia (MH) susceptibility in X-linked muscular dystrophies, halothane and caffeine contracture tests were performed on muscle fiber bundles from five patients with Duchenne muscular dystrophy (DMD) and two patients with Becker muscular dystrophy (BMD). Two DMD patients and one BMD patient had positive contracture tests. Since a positive contracture test is currently the best indicator of anesthetic susceptibility in the MH population, and episodes of MH in dystrophic patients have been reported, patients with DMD and BMD may be at risk for developing similar anesthetic complications. Awareness of this potential anesthetic risk is of importance because orthopedic interventions are increasingly more common in these patients.


Assuntos
Ligação Genética , Distrofias Musculares/genética , Aberrações dos Cromossomos Sexuais/genética , Cromossomo X , Adolescente , Cafeína , Criança , Halotano , Humanos , Contração Muscular/efeitos dos fármacos
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