Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 237
Filtrar
1.
Aliment Pharmacol Ther ; 44(11-12): 1183-1198, 2016 12.
Artigo em Inglês | MEDLINE | ID: mdl-27778367

RESUMO

BACKGROUND: Non-alcoholic steatohepatitis (NASH) and resultant liver fibrosis is a major health problem without approved pharmacotherapy. Pre-clinical results of GR-MD-02, a galectin-3 inhibitor, suggested potential efficacy in NASH with advanced fibrosis/cirrhosis and prompted initiation of a clinical development programme in NASH with advanced fibrosis. AIM: To evaluate the safety, pharmacokinetics and exploratory pharmacodynamic markers of GR-MD-02 in subjects having NASH with bridging fibrosis. METHODS: The GT-020 study was a first-in-human, sequential dose-ranging, placebo controlled, double-blinded study with the primary objective to assess the safety, tolerability and dose limiting toxicity of GR-MD-02, in subjects with biopsy-proven NASH with advanced fibrosis (Brunt stage 3). The secondary objectives were to characterise first-dose and multiple-dose pharmacokinetic profiles and to evaluate changes in potential serum biomarkers and liver stiffness as assessed by FibroScan. RESULTS: GR-MD-02 single and three weekly repeated of 2, 4 and 8 mg/kg revealed no meaningful clinical differences in treatment emergent adverse events, vital signs, electrocardiographic findings or laboratory tests. Pharmokinetic parameters showed a dose-dependent relationship with evidence of drug accumulation following 8 mg/kg (~twofold). CONCLUSIONS: GR-MD-02 doses were in the upper range of the targeted therapeutic dose determined from pre-clinical data and were safe and well tolerated with evidence of a pharmacodynamic effect. These results provide support for a Phase 2 development programme in advanced fibrosis due to NASH.


Assuntos
Galectina 3/antagonistas & inibidores , Cirrose Hepática/tratamento farmacológico , Hepatopatia Gordurosa não Alcoólica/tratamento farmacológico , Pectinas , Adulto , Idoso , Biomarcadores/sangue , Método Duplo-Cego , Feminino , Galectina 3/sangue , Humanos , Cirrose Hepática/sangue , Masculino , Pessoa de Meia-Idade , Hepatopatia Gordurosa não Alcoólica/sangue , Pectinas/efeitos adversos , Pectinas/sangue , Pectinas/farmacocinética , Pectinas/farmacologia
2.
Med Oral Patol Oral Cir Bucal ; 21(4): e413-9, 2016 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-27031069

RESUMO

BACKGROUND: To adequately perform rehabilitation of edentulous patients by a complete removable dental prosthesis (CRDP) is from basic interest to dentists to understand the morphologic changes caused by re-establishment of a physiologic jaw relationship. Anthropometric analyses of standardized frontal view and profile photographs may help elucidate such changes. MATERIAL AND METHODS: Photographs of 31 edentulous patients were compared in relaxed lip closure and after insertion of a CRDP in stable occlusion. 2232 anthropometric distances were raised. Eighteen anthropometric indices reflecting the perioral morphology and its integration in the vertical facial harmony were investigated. RESULTS: The intercanthal - mouth width index (p>.001), medial - lateral cutaneous upper lip height index (p=.007), lower vermilion contour index (p=.022), vermilion - total upper lip height index (p=.018), cutaneous - total upper lip height index (p=.023), upper lip - nose height index (p=.001), nose - upper face height index (p=.002), chin - mandible height index (p=.013), upper lip - mandible height index (p=.045), nose - lower face height index (p=.018), and nose - face height index (p=.029) showed significant pre- to post-treatment changes. CONCLUSIONS: The investigated anthropometric indices presented reproducible results related to an increase in occlusal vertical dimension. Their application may be helpful in assessment, planning, and explanation of morphologic effects of CRDPs on the perioral and overall facial morphology, which may helps to improve the aesthetic outcome.


Assuntos
Prótese Dentária , Estética Dentária , Cefalometria , Face , Humanos , Arcada Edêntula , Lábio
3.
Child Care Health Dev ; 40(6): 840-52, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24261547

RESUMO

BACKGROUND: Limited capacity for social engagement is a core feature of autism spectrum disorder (ASD), often evident early in the child's development. While these skills are difficult to train, there is some evidence that active involvement in music-making provides unique opportunities for social interaction between participants. Family-centred music therapy (FCMT) endeavours to support social engagement between child and parent within active music-making, yet the extent of benefits provided is unknown. AIM: This study investigated the impacts of FCMT on social engagement abilities. METHODS: Twenty-three children (36-60 months) with severe ASD received either 16 weeks of FCMT in addition to their early intervention programmes (n = 12), or their early intervention programme only (n = 11). Change in social engagement was measured with standardized parent-report assessments, parent interviews and clinician observation. RESULTS: Intention-to-treat analysis for the Vineland Social Emotional Early Childhood Scale indicated a significant effect in favour of FCMT. Thematic qualitative analysis of the parent interviews showed that the parent-child relationship grew stronger. CONCLUSION: FCMT improves social interactions in the home and community and the parent-child relationship, but not language skills or general social responsiveness. This study provides preliminary support for the use of FCMT to promote social engagement in children with severe ASD.


Assuntos
Transtornos Globais do Desenvolvimento Infantil/psicologia , Transtornos Globais do Desenvolvimento Infantil/terapia , Intervenção Educacional Precoce , Terapia Familiar , Relações Interpessoais , Musicoterapia , Pais/psicologia , Criança , Pré-Escolar , Comunicação , Feminino , Humanos , Masculino , Relações Pais-Filho , Pais/educação , Resultado do Tratamento
4.
Dent Mater ; 24(1): 9-17, 2008 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-17379295

RESUMO

OBJECTIVES: The purpose of this study was to analyze the stress distribution through the thickness of bilayered dental ceramics subjected to both thermal stresses and ring-on-ring tests and to systematically examine how the individual layer thickness influences this stress distribution and the failure origin. METHODS: Ring-on-ring tests were performed on In-Ceram Alumina/Vitadur Alpha porcelain bilayered disks with porcelain in the tensile side, and In-Ceram Alumina to porcelain layer thickness ratios of 1:2, 1:1, and 2:1 were used to characterize whether failure originated at the surface or the interface. Based on (1) the thermomechanical properties and thickness of each layer, (2) the difference between the test temperature and the glass transition temperature, and (3) the ring-on-ring loading configuration, the stress distribution through the thickness of the bilayer was calculated using closed-form solutions. Finite element analyses were also performed to verify the analytical results. RESULTS: The calculated stress distributions showed that the location of maximum tension during testing shifted from the porcelain surface to the In-Ceram Alumina/porcelain interface when the relative layer thickness ratio changed from 1:2 to 1:1 and to 2:1. This trend is in agreement with the experimental observations of the failure origins. SIGNIFICANCE: For bilayered dental ceramics subjected to ring-on-ring tests, the location of maximum tension can shift from the surface to the interface depending upon the layer thickness ratio. The closed-form solutions for bilayers subjected to both thermal stresses and ring-on-ring tests allow the biaxial strength of the bilayer to be evaluated.


Assuntos
Porcelana Dentária , Análise do Estresse Dentário , Facetas Dentárias , Análise do Estresse Dentário/métodos , Análise de Elementos Finitos , Temperatura Alta , Teste de Materiais , Maleabilidade , Propriedades de Superfície , Resistência à Tração , Temperatura de Transição
5.
Food Addit Contam ; 24 Suppl 1: 47-59, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17687699

RESUMO

In March 2006, a joint workshop was organized by the European Commission and the Confederation of EU Food and Drink Industries (CIAA) to discuss current knowledge and achievements in the reduction of acrylamide levels. This paper focuses on the progress made with cereal products. At present, the reduction options available are applicable to a limited number of cereal products and are product-specific. The following are the most promising: * Adjustment of time and temperature during baking. * Extend fermentation times where feasible. * Substitution of ammonium bicarbonate with alternatives where feasible. * Avoid or minimise use of reducing sugars where possible. * Maintenance of uniform control of the colour and avoidance of very high baking temperature where possible. The most promising near-term technical solution is the use of asparaginase. This enzyme has the potential to achieve a 60-90% reduction for some products made from dough or batter, which can be held for a time. In the longer term, the optimisation of agronomy and plant breeding for wheat has the potential to reduce acrylamide in all foods on any scale, whether domestic or industrial. Importantly, nutritional and toxicological issues, other than acrylamide, must also be considered so as to ensure that the steps taken to reduce acrylamide levels do not have other adverse effects on diet.


Assuntos
Acrilamida/análise , Carcinógenos Ambientais/análise , Grão Comestível/química , Contaminação de Alimentos/análise , Asparaginase/metabolismo , Asparagina/análise , Pão/análise , Culinária/métodos , Fermentação , Contaminação de Alimentos/prevenção & controle , Manipulação de Alimentos/métodos , Avaliação Nutricional , Medição de Risco/métodos
6.
J Dent ; 35(7): 600-6, 2007 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-17543439

RESUMO

OBJECTIVES: The purpose of this study was to compare three existing sets of formulas predicting stresses in a thin circular plate subjected to biaxial moment loading, such that limitations for each set of formulas could be understood. These formulas include American Society for Testing and Materials (ASTM) formulas for monolayered plates, Roark's formulas for bilayered plates, and Hsueh et al.'s formulas for multilayered plates. METHODS: The three sets of formulas were summarized and appraised. Biaxial moment loading is generally achieved using biaxial flexure tests, and the plate is placed on a support ring and loaded in the central region. While both ASTM and Hsueh et al.'s formulas predict stresses through the thickness of the plate, Roark's formulas predict stresses only on the top and the bottom surfaces of the plate. Also, a simply supported plate at its edge is considered in Roark's formulas. We modified Roark's formulas to include the overhang region of the plate to more closely simulate the actual loading configuration. Then, the accuracy of formulas was examined by comparing with finite element results of monolayered and bilayered plates subjected to ring-on-ring loading. RESULTS: Monolayer is a special case of bilayer, and both monolayer and bilayer are special cases of multilayer. For monolayered plates, ASTM and Hsueh et al.'s formulas are identical, and both are in excellent agreement with finite element results. For bilayered plates, Hsueh et al.'s formulas are in excellent agreement with finite element results. For both monolayered and bilayered plates, Roark's formulas deviate from finite element results while the modified Roark's formulas are accurate. CONCLUSIONS: Roark's formulas for evaluating the biaxial strength of bilayered dental ceramics will result in errors in predicted stresses which depend on the size of the overhang region of the plate in the actual loading configuration. Also, Roark's formulas are limited to predicting stresses on the top and the bottom surfaces of the plate. On the other hand, Hsueh et al.'s formulas are for multilayered plates and predict stresses through the plate thickness.


Assuntos
Cerâmica/química , Análise do Estresse Dentário/métodos , Análise de Elementos Finitos , Modelos Teóricos , Maleabilidade , Suporte de Carga
7.
Rev. biol. trop ; 55(supl.1): 131-140, jun. 2007. graf, tab
Artigo em Inglês | LILACS | ID: lil-473837

RESUMO

Se estudió la dinámica y estructura poblacional de Excirolana armata en tres playas arenosas de la provincia de Buenos Aires (Argentina), de enero de 2004 a marzo de 2005. Se seleccionaron playas sometidas a distintos tipos de influencias antropogénicas. Los parámetros de la función de crecimiento de von Bertalanffy fueron determinados en cada playa. Esta especie mostró una notable fluctuación en su crecimiento, con tasas más bajas a fines de otoño y en invierno. La población de la playa con mayor grado de erosión antropogénica presentó los valores menores y más estables de densidad y biomasa, la más alta tasa de mortalidad y la menor longevidad. Las variaciones temporales del coeficiente alométrico de la relación longitud-peso seco indicaron un patron cíclico, con los menores valores en otoño-invierno y los mayores en verano. Las hembras predominaron en la población ebido a la corta duración de la temporada reproductiva. Las poblaciones argentinas y uruguayas tienen índices similares en el crecimiento, pero difieren en los valores de abundancia y densidad, probablemente como respuesta a variaciones en la orfodinámica de las playas y en las interacciones biológicas.


The population dynamics and structure of the cirolanid isopod Excirolana armata were studied from January 2004 through March 2005 in three sandy beaches of Buenos Aires Province (Argentina). Beaches with different types of anthropogenic influences were selected. The von Bertalanffy’s growth function parameters were determined for each population. There was a marked fluctuation in growth, with lowest rates in late autumn and winter. The isopod population of the beach exposed to the highest degree of anthropogenic erosion had thelowest and most stable values of abundance and biomass, the highest mortality rate and the shortest life span.Temporal fluctuations of the allometric coefficient of the length‑dry weight relationship indicated a cycling pattern,with lowest values during the autumn‑winter period and peak values in the summer. Females predominatedin the populations due to the short duration of the reproductive season. Argentine and Uruguayan populationsshowed similar growth performance indices, but differed in their abundance and biomass values, probably asa response to variations in beach morphodynamics and biological interactions.


Assuntos
Animais , Masculino , Feminino , Ecossistema , Isópodes/crescimento & desenvolvimento , Análise de Variância , Argentina , Praias , Isópodes/classificação , Dinâmica Populacional
8.
J Dent Res ; 84(12): 1172-7, 2005 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-16304449

RESUMO

Oral biofilms are mixed-species microbial communities, and their uncontrolled outgrowth can express as oral diseases. Antimicrobial peptides represent alternative classes of antimicrobials that exhibit selectivity for prokaryotes. We wanted to test the effect of a synthetic decapeptide antimicrobial, KSL, on the development of oral biofilms formed by isolated human salivary bacteria. We used differential interference contrast microscopy, coupled with a dual-flow cell system, to determine the effect of KSL on oral biofilm development. We used reductions of viable counts and confocal microscopy to assess the bactericidal activity of KSL on mature oral biofilms. KSL effectively blocked biofilm development. A significant effect on the viability of mature biofilms was observed when KSL was used in the presence of a surface-active agent, or after biofilms were mechanically disrupted. This study shows that KSL may be a useful adjunct for conventional oral hygiene to prevent plaque-mediated dental diseases.


Assuntos
Antibacterianos/farmacologia , Biofilmes/efeitos dos fármacos , Depsipeptídeos/farmacologia , Saliva/microbiologia , Anti-Infecciosos Locais/farmacologia , Aderência Bacteriana/efeitos dos fármacos , Compostos de Benzalcônio/farmacologia , Biofilmes/crescimento & desenvolvimento , Clorexidina/farmacologia , Contagem de Colônia Microbiana , Durapatita , Germânio , Humanos , Viabilidade Microbiana/efeitos dos fármacos , Microscopia Confocal , Microscopia de Interferência , Tensoativos/farmacologia
9.
Bull Entomol Res ; 95(5): 449-55, 2005 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-16197565

RESUMO

DL-beta-aminobutyric acid (BABA) is a non-protein amino acid that is an effective inducer of resistance against a variety of plant pathogens. However, examples of BABA-induced resistance against insect herbivores have not been reported. We applied BABA as a soil drench to legumes and monitored its effects on the pea aphid Acyrthosiphon pisum (Harris). On tic bean (Vicia faba var. minor), BABA increased aphid mortality, caused a reduction in the mean relative growth rate of individual insects and lessened the intrinsic rate of population increase (rm). BABA also caused significant reductions in the growth rate of A. pisum on pea (Pisum sativa), broad bean (Vicia faba var. major), runner bean (Phaseolus coccineus), red clover (Trifolium pratense) and alfalfa (Medicago sativa). No direct toxic effects of BABA against A. pisum were found, and no phytotoxic effects that may have caused a reduction in aphid performance were detected. Possible mechanisms behind this BABA-induced inhibition of aphid performance are discussed.


Assuntos
Aminobutiratos/farmacologia , Afídeos/efeitos dos fármacos , Afídeos/crescimento & desenvolvimento , Fabaceae/efeitos dos fármacos , Inseticidas/farmacologia , Raízes de Plantas/efeitos dos fármacos , Animais , Afídeos/fisiologia , Ninfa/efeitos dos fármacos , Reprodução/efeitos dos fármacos , Solo
10.
J Pharm Sci ; 94(9): 2084-95, 2005 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-16052551

RESUMO

The metabolic fate of azimilide in man is unusual as it undergoes a cleavage in vivo resulting in the formation of two classes of structurally distinct metabolites. During a metabolite profiling study conducted in human volunteers to assess the contribution of all pathways to the clearance of (14)C-azimilide, greater than 82% of radioactivity was recovered in urine (49%-58%) and feces (33%). Urine, feces, and plasma were profiled for metabolites. A cleaved metabolite, 4-chloro-2-phenyl furoic acid was present at high concentration in plasma (metabolite/parent AUC ratio approx. 4), while other plasma metabolites, azimilide N-oxide (metabolite/parent AUC ratio 0.001), and a cleaved hydantoin metabolite (metabolite/parent AUC ratio = 0.3) were present at lower concentrations than azimilide. In urine, the cleaved metabolites were the major metabolites, (> 35% of the dose) along with phenols (as conjugates, 7%-8%), azimilide N-oxide (4%-10%), a butanoic acid metabolite (2%-3%), and desmethyl azimilide (2%). A limited investigation of fecal metabolites indicated that azimilide (3%-5%), desmethyl azimilide (1%-3%), and the butanoic acid metabolite (< 1%) were present. Contributing pathways for metabolism of azimilide, identified through in vitro and in-vivo studies, were CYPs 1A1 (est. 28%), 3A4/5 (est. 20%), 2D6 (< 1%), FMO (est. 14%), and cleavage (35%). Enzyme(s) involved in the cleavage of azimilide were not identified.


Assuntos
Antiarrítmicos/farmacocinética , Imidazolidinas/farmacocinética , Microssomos Hepáticos/metabolismo , Piperazinas/farmacocinética , Adulto , Antiarrítmicos/sangue , Antiarrítmicos/urina , Área Sob a Curva , Radioisótopos de Carbono , Citocromo P-450 CYP1A1/metabolismo , Citocromo P-450 CYP2D6/metabolismo , Citocromo P-450 CYP3A , Sistema Enzimático do Citocromo P-450/metabolismo , Fezes/química , Humanos , Hidantoínas , Imidazolidinas/sangue , Imidazolidinas/urina , Técnicas In Vitro , Masculino , Microssomos Hepáticos/enzimologia , Piperazinas/sangue , Piperazinas/urina , Fatores de Tempo
11.
Clin Pharmacol Ther ; 70(4): 370-83, 2001 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11673753

RESUMO

BACKGROUND: Pharmacokinetic (PK) and pharmacodynamic (PD) models for azimilide were developed and validated with sparse blood sampling and QTc interval data obtained during three clinical trials of azimilide for prevention of supraventricular arrhythmia recurrence. METHODS: Patients were orally administered placebo or azimilide dihydrochloride, 35, 50, 75, 100, or 125 mg/d, for 6 to 9 months. NONMEM was used for data fitting and assessment of selected patient covariates and concomitant medication classes for PK/PD relationships. RESULTS: Results indicate that azimilide clearance (CL) was dependent on body weight (WTKG), gender, and current tobacco use, where CL (L/h) = 3.92 x (WTKG - 43)(0.208), with a 17% increase for male subjects and a 15.5% increase for current tobacco use. Volume of distribution (V) was also dependent on WTKG and total bilirubin (BIL), where V (L) = 9.88 x (WTKG - 43) + 717 x (BIL)(0.348). The PK/PD analysis indicated that the baseline QTc interval was dependent on gender, New York Heart Association Class, digoxin, and paced artificial pacemaker spike, whereas the 50% effective concentration (EC(50)) was dependent on the serum potassium (K) level, where EC(50) = 107 x K. The change in EC(50) was not clinically significant within the normal range for potassium. The mean E(max) (maximum increase in the QTc interval for the E(max) models) was a 61.7 ms increase from baseline. At 125 mg/d the predicted percent increase in the QTc interval at the maximum plasma drug concentration at steady state was 9% and 10% for male and female patients, respectively. The values of the median prediction error were -3% and -0.4% for the PK and PK/PD models, respectively, and the values of the absolute prediction error were 21% and 4% for the PK and PK/PD models, respectively, indicating that both models are essentially unbiased and acceptably accurate. CONCLUSIONS: Azimilide PK parameters are dependent on body weight, gender, smoking status, and bilirubin and are independent of the coadministration of digoxin, warfarin, and cytochrome P4503A4 inhibitors and inducers. The relationship between azimilide concentration and change in QTc is primarily dependent on serum potassium.


Assuntos
Antiarrítmicos/farmacologia , Antiarrítmicos/farmacocinética , Imidazóis/farmacologia , Imidazóis/farmacocinética , Imidazolidinas , Piperazinas/farmacologia , Piperazinas/farmacocinética , Taquicardia Supraventricular/tratamento farmacológico , Análise de Variância , Bilirrubina/sangue , Peso Corporal , Ensaios Clínicos Fase III como Assunto , Relação Dose-Resposta a Droga , Método Duplo-Cego , Eletrocardiografia/efeitos dos fármacos , Etnicidade , Feminino , Humanos , Hidantoínas , Masculino , Pessoa de Meia-Idade , Modelos Estatísticos , Potássio/sangue , Reprodutibilidade dos Testes , Fatores Sexuais , Fumar , Taquicardia Supraventricular/sangue , Taquicardia Supraventricular/prevenção & controle
12.
Cell Stress Chaperones ; 6(3): 247-55, 2001 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-11599566

RESUMO

The Hsp70-interacting protein Hip binds to the adenosine triphosphatase domain of Hsp70, stabilizing it in the adenosine 5'-diphosphate-ligated conformation and promoting binding of target polypeptides. In mammalian cells, Hip is a component of the cytoplasmic chaperone heterocomplex that regulates signal transduction via interaction with hormone receptors and protein kinases. Analysis of the complete genome sequence of the model flowering plant Arabidopsis thaliana revealed 2 genes encoding Hip orthologs. The deduced sequence of AtHip-1 consists of 441 amino acid residues and is 42% identical to human Hip. AtHip-1 contains the same functional domains characterized in mammalian Hip, including an N-terminal dimerization domain, an acidic domain, 3 tetratricopeptide repeats flanked by a highly charged region, a series of degenerate GGMP repeats, and a C-terminal region similar to the Sti1/Hop/p60 protein. The deduced amino acid sequence of AtHip-2 consists of 380 amino acid residues. AtHip-2 consists of a truncated Hip-like domain that is 46% identical to human Hip, followed by a C-terminal domain related to thioredoxin. AtHip-2 is 63% identical to another Hip-thioredoxin protein recently identified in Vitis labrusca (grape). The truncated Hip domain in AtHip-2 includes the amino terminus, the acidic domain, and tetratricopeptide repeats with flanking charged region. Analyses of expressed sequence tag databases indicate that both AtHip-1 and AtHip-2 are expressed in A thaliana and that orthologs of Hip are also expressed widely in other plants. The similarity between AtHip-1 and its mammalian orthologs is consistent with a similar role in plant cells. The sequence of AtHip-2 suggests the possibility of additional unique chaperone functions.


Assuntos
Proteínas de Arabidopsis/genética , Arabidopsis/genética , Chaperonas Moleculares/genética , Sequência de Aminoácidos , Animais , Arabidopsis/metabolismo , Proteínas de Arabidopsis/química , Proteínas de Arabidopsis/metabolismo , Proteínas de Choque Térmico HSP70/metabolismo , Humanos , Chaperonas Moleculares/química , Chaperonas Moleculares/metabolismo , Dados de Sequência Molecular , Estrutura Terciária de Proteína , Sequências Repetitivas de Ácido Nucleico/genética , Alinhamento de Sequência , Vitis/genética
13.
Pharm Res ; 18(2): 166-70, 2001 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11405286

RESUMO

PURPOSE: To determine the pharmacokinetics and absolute bioavailability of risedronate after single-dose oral administration of 30 mg risedronate as a tablet and an aqueous solution, and 0.3 mg risedronate as an intravenous infusion. METHODS: This study was a randomized, three-treatment, four-period, partial replicate crossover study involving 33 healthy volunteers. Treatments were administered 7 weeks apart, and the third treatment was repeated during the fourth period. Serum and urine were collected over 72 hours and 672 hours, respectively. RESULTS: Following intravenous administration, renal clearance accounted for 87% of total clearance, with 65% of the dose excreted within 24 hours and 85% of the dose excreted within four weeks. The absolute bioavailability was approximately 0.62% after both oral formulations, and the relative bioavailability of the tablet compared with the oral solution was 104%. The rate and extent of absorption from the two formulations were bioequivalent based on the range proposed for highly variable drugs. Intrasubject variability following oral administration was 50-80%, and was primarily associated with absorption. CONCLUSION: The majority of the total clearance after intravenous administration of risedronate was renal clearance, indicating that only a small percentage of a systemic dose is potentially incorporated, or "cleared," into bone. The absolute bioavailability of orally administered risedronate is approximately 0.6%, and is independent of formulation. Variability in the pharmacokinetics following oral administration is primarily associated with intrasubject variability in absorption.


Assuntos
Bloqueadores dos Canais de Cálcio/farmacocinética , Ácido Etidrônico/análogos & derivados , Ácido Etidrônico/farmacocinética , Administração Oral , Adulto , Análise de Variância , Área Sob a Curva , Estudos Cross-Over , Feminino , Humanos , Infusões Intravenosas , Masculino , Taxa de Depuração Metabólica , Pessoa de Meia-Idade , Ácido Risedrônico
14.
Plant Physiol ; 125(2): 1074-85, 2001 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11161062

RESUMO

Little is known about molecular responses in plants to phloem feeding by insects. The induction of genes associated with wound and pathogen response pathways was investigated following green peach aphid (Myzus persicae) feeding on Arabidopsis. Aphid feeding on rosette leaves induced transcription of two genes associated with salicylic acid (SA)-dependent responses to pathogens (PR-1 and BGL2) 10- and 23-fold, respectively. Induction of PR-1 and BGL2 mRNA was reduced in npr1 mutant plants, which are deficient in SA signaling. Application of the SA analog benzothiadiazole led to decreases in aphid reproduction on leaves of both wild-type plants and mutant plants deficient in responsiveness to SA, suggesting that wild-type SA-dependent responses do not influence resistance to aphids. Two-fold increases occurred in mRNA levels of PDF1.2, which encodes defensin, a peptide involved in the jasmonate (JA)-/ethylene-dependent response pathway. Transcripts encoding JA-inducible lipoxygenase (LOX2) and SA/JA-inducible Phe-ammonia lyase increased 1.5- to 2-fold. PDF1.2 and LOX2 induction by aphids did not occur in infested leaves of the JA-resistant coi1-1 mutant. Aphid feeding induced 10-fold increases in mRNA levels of a stress-related monosaccharide symporter gene, STP4. Phloem feeding on Arabidopsis leads to stimulation of response pathways associated with both pathogen infection and wounding.


Assuntos
Afídeos/fisiologia , Afídeos/patogenicidade , Arabidopsis/parasitologia , Imunidade Inata/fisiologia , Animais , Arabidopsis/genética , Arabidopsis/fisiologia , Comportamento Alimentar , Doenças das Plantas/parasitologia , Folhas de Planta/fisiologia , Fatores de Tempo
15.
Planta ; 212(2): 155-62, 2001 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-11216835

RESUMO

Vascular exudates of Cucurbita maxima (Duch.) contain a group of highly conserved serine proteinase inhibitors collectively called Pumpkin Fruit Trypsin Inhibitors (PFTIs) that prevent proteolytic activity of trypsin or chymotrypsin. Polyclonal antibodies raised against PFTIs were used to immunolocalize these low-molecular-weight proteins within the phloem tissue and to study their developmental expression. The inhibitors were translocated throughout the transport phloem and were present in vascular exudates collected from both source and sink tissues throughout the plant. During the early stages of vascular development, PFTIs accumulated specifically in sieve element-companion cell complexes of the phloem tissue. Transcripts were initially detected by reverse transcription-polymerase chain reaction in seedlings 1 d after germination and the protein detected 24 h later. Pumpkin fruit trypsin inhibitors were present in both cell types of differentiating and translocating sieve element-companion cell complexes. The inhibitors were detected in the phloem of the bicollateral vascular bundles, but the protein was most consistently localized within the cortical and bundle-associated extrafascicular phloem.


Assuntos
Inibidores da Tripsina/metabolismo , Verduras/metabolismo , Sequência de Bases , Primers do DNA , Inibidores da Tripsina/genética
17.
J Physiol ; 526 Pt 2: 231-40, 2000 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-10896714

RESUMO

1. Kir2.1 channels are blocked by Rb+ and Cs+ in a voltage-dependent manner, characteristic of many inward rectifier K+ channels. Mutation of Ser165 in the transmembrane domain M2 to Leu (S165L) abolished Rb+ blockage and lowered Cs+ blocking affinity. At negative voltages Rb+ carried large inward currents. 2. A model of the Kir2.1 channel, built by homology with the structure of the Streptomyces lividans K+ channel KcsA, suggested the existence of an intersubunit hydrogen bond between Ser165 and Thr141 in the channel pore-forming P-region that helps stabilise the structure of this region. However, mutations of Thr141 and Ser165 did not produce effects consistent with a hydrogen bond between these residues being essential for blockage. 3. An alternative alignment between the M2 regions of Kir2.1 and KcsA suggested that Ser165 is itself a pore-lining residue, more directly affecting blockage. We were able to replace Ser165 with a variety of polar and non-polar residues, consistent with this residue being pore lining. Some of these changes affected channel blockage. 4. We tested the hypothesis that Asp172 - a residue implicated in channel gating by polyamines - formed an additional selectivity filter by using the triple mutant T141A/S165L/D172N. Large Rb+ and Cs+ currents were measured in this mutant. 5. We propose that both Thr141 and Ser165 are likely to provide binding sites for monovalent blocking cations in wild-type channels. These residues lie beyond the carbonyl oxygen tunnel thought to form the channel selectivity filter, which the blocking cations must therefore traverse.


Assuntos
Permeabilidade da Membrana Celular/fisiologia , Césio/farmacologia , Canais de Potássio Corretores do Fluxo de Internalização , Canais de Potássio/fisiologia , Rubídio/farmacologia , Sequência de Aminoácidos , Substituição de Aminoácidos , Animais , Proteínas de Bactérias/química , Células CHO , Permeabilidade da Membrana Celular/efeitos dos fármacos , Cricetinae , Leucina , Camundongos , Dados de Sequência Molecular , Mutagênese Sítio-Dirigida , Canais de Potássio/química , Canais de Potássio/efeitos dos fármacos , Estrutura Secundária de Proteína , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo , Alinhamento de Sequência , Homologia de Sequência de Aminoácidos , Serina , Transfecção
18.
Dent Mater ; 16(4): 235-43, 2000 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-10831777

RESUMO

OBJECTIVES: The purpose of this study was to examine the influence of testing method (uniaxial and biaxial) and relative layer heights on the failure origin and failure mode of bilayered ceramic composite beams and disks composed of In-Ceram and Vitadur Alpha porcelain. METHODS: Beams and disks were fabricated, with relative layer heights of 1:2, 1:1, and 2:1, respectively, for In-Ceram and Vitadur Alpha porcelain. Ninety specimens each (thirty 1:2, thirty 1:1, and thirty 2:1) were tested in 3-point, 4-point-1/4-point, and biaxial ring-on-ring testing apparatuses. Fractography was used to categorize failure origins as either surface or interfacial, and failure modes as delamination or nondelamination. RESULTS: Surface and interfacial failure origins were observed in 3-point and biaxial disk test specimens, but not 4-point-1/4-point specimens where only surface failures occurred. None of the "clinically similar" specimens (1:2) failed at the interface. All testing methods resulted in delamination of Vitadur Alpha from the In-Ceram, while only 3-point and biaxial disk testing methods resulted in crack propagation through the composite interface without delamination. SIGNIFICANCE: Varying relative layer heights or varying testing method in laminate composite tensile specimens can affect failure mode and failure origin.


Assuntos
Cerâmica/química , Porcelana Dentária/química , Adesividade , Algoritmos , Óxido de Alumínio/química , Análise de Variância , Distribuição de Qui-Quadrado , Análise do Estresse Dentário/instrumentação , Humanos , Teste de Materiais , Microscopia Eletrônica de Varredura , Maleabilidade , Estresse Mecânico , Propriedades de Superfície , Resistência à Tração
19.
Prog Lipid Res ; 39(1): 19-39, 2000 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-10729606

RESUMO

Increasing numbers of plant proteins are being shown to have posttranslationally-attached lipids. The modifications include N-myristoylation, S-palmitoylation, prenylation by farnesyl or geranylgeranyl moieties, or attachment of glycosylphosphatidylinositol anchors. This report summarizes recent findings regarding the structure, metabolism and physiological functions of these important protein-linked lipids.


Assuntos
Proteínas de Plantas/química , Glicosilfosfatidilinositóis/química , Glicosilfosfatidilinositóis/metabolismo , Glicosilfosfatidilinositóis/fisiologia , Miristatos/química , Miristatos/metabolismo , Palmitatos/química , Palmitatos/metabolismo , Proteínas de Plantas/metabolismo , Proteínas de Plantas/fisiologia , Prenilação de Proteína/fisiologia
20.
J Clin Pharmacol ; 40(3): 258-65, 2000 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-10709154

RESUMO

Risedronate is a pyridinyl bisphosphonate approved for the treatment of Paget's disease (US-FDA) and in development for the treatment and prevention of osteoporosis. This study examined risedronate pharmacokinetics and tolerability after oral administration using a randomized, double-blind, parallel-group design. Healthy male and female volunteers (n = 22-23 subjects per dose) received a single oral dose of 2.5, 5, or 30 mg risedronate. Serum and urine samples were collected for 72 and 672 hours, respectively, and risedronate concentrations were determined by ELISA. Safety was evaluated by monitoring adverse events, clinical laboratory measurements, vital signs, and electrocardiograms. Mean Cmax (0.41, 0.94, and 5.1 ng/mL for 2.5, 5, and 30 mg, respectively), AUC (1.8, 3.9, and 21 ng.h/mL for 2.5, 5, and 30 mg, respectively), and urinary excretion (22, 63, and 260 micrograms for 2.5, 5, and 30 mg, respectively) were dose proportional, and there were no significant differences in tmax or CLR among the three doses. All doses were well tolerated; no serious adverse events occurred, and all but one of the adverse events were mild or moderate in severity. There was no evidence of an acute phase reaction occurring after oral administration of risedronate.


Assuntos
Ácido Etidrônico/análogos & derivados , Administração Oral , Adulto , Relação Dose-Resposta a Droga , Ácido Etidrônico/administração & dosagem , Ácido Etidrônico/efeitos adversos , Ácido Etidrônico/farmacocinética , Feminino , Humanos , Masculino , Ácido Risedrônico
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...