Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 60
Filtrar
Mais filtros











Base de dados
Intervalo de ano de publicação
1.
Gene Ther ; 11(12): 949-55, 2004 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-14985792

RESUMO

Glaucoma is a common eye disease associated with elevated intraocular pressure (IOP). Lowering IOP is the only acceptable therapy for glaucoma and slows progression of the disease. Filtration surgery, which introduces a guarded ostomy through the sclera into the anterior chamber of the eye to allow the escape of aqueous humor, is the most reliable method for effective IOP lowering. Success of this surgery is limited by scarring of the ostomy, so this procedure is often accompanied by the use of antimetabolites, such as mitomycin C (MMC), to block the wound healing response. Although effective in preventing scarring, antimetabolites also yield unwanted side effects, such as hypotony and tissue degeneration due to cellular destruction. This study presents an alternative to antimetabolites by using gene therapy to introduce the human gene for p21(WAF-1/cip-1) (p21) to cause cell cycle arrest of surrounding cells rather than their destruction. In this procedure, p21 was delivered using a recombinant adenovirus to ocular hypertensive monkey eyes. These eyes then underwent filtration surgery. Results show that eyes treated with p21 exhibited open surgical ostomies by both functional and histological criteria, and did not display any side effects seen in control animals that were treated with MMC.


Assuntos
Ciclinas/genética , Terapia Genética/métodos , Glaucoma/cirurgia , Trabeculectomia , Cicatrização , Adenoviridae/genética , Animais , Antimetabólitos/uso terapêutico , Ciclo Celular , Inibidor de Quinase Dependente de Ciclina p21 , Vetores Genéticos/administração & dosagem , Glaucoma/terapia , Humanos , Macaca fascicularis , Masculino , Mitomicina/uso terapêutico , Modelos Animais , Distribuição Aleatória , Transdução Genética/métodos
2.
J Ocul Pharmacol Ther ; 18(1): 35-9, 2002 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11858613

RESUMO

3Alpha,5beta-Tetrahydrocortisol (THF) was administered topically and intracamerally to ocular normotensive cynomolgus monkeys to determine whether it affects outflow facility. Monkeys received THF either topically at a dose of 2 x 5 microl drops of 300 microg/10 microl twice daily for 4 days (n = 4) or 3 times daily for 10 days (n = 4) with 10% DMSO as vehicle to the control eye, or intracamerally via 2 ml anterior chamber (AC) exchange of 30 microg/ml THF with vehicle, 0.1% DMSO, to the control eye followed by a second AC exchange using 300 microg/ml THF with vehicle to the control eye. Outflow facility was measured by a two-level constant pressure AC perfusion after administration of eye drops or after baseline outflow facility measurement and AC exchange with THF solution. The results showed no effect on outflow facility in normotensive cynomolgus monkeys.


Assuntos
Humor Aquoso/efeitos dos fármacos , Tetra-Hidrocortisol/farmacologia , Animais , Humor Aquoso/fisiologia , Feminino , Macaca fascicularis , Masculino
3.
Curr Eye Res ; 23(2): 120-7, 2001 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-11840350

RESUMO

PURPOSE: The effects of several serotonergic agonists on aqueous humor formation (AHF), total outflow facility (OF) and intraocular pressure (IOP) were investigated in living cynomolgus monkeys. METHODS: We determined the effect of a single topical unilateral 300 microg or 3 mg dose of the 5-HT agonists serotonin, 5-carboxamidotryptamine (5-CT), sumatripan, gepirone, and 8-hydroxy-2(di-n-propylaminotetralin) (8-OH-DPAT) and a 450 microg dose of flesinoxan on IOP (Goldmann applanation tonometry), AHF (scanning ocular fluorophotometry) and total OF (8-OH-DPAT only, topically and intracamerally). RESULTS: Serotonin, 5-CT, sumatripan or gepirone had no significant effect on IOP or AHF. 8-OH-DPAT caused an AHF increase of approximately 70% over 6 hr in both ipsilateral drug- and contralateral vehicle-treated eyes, but no significant change in IOP compared with baseline measured on a separate occasion in the same animals. 8-OH-DPAT did not increase protein levels or rate of entry of systemically administered fluorescein in the anterior chamber aqueous humor compared to historic controls, and no difference was seen between ipsilateral and contralateral eyes. Flesinoxan had no effect on IOP and produced an insignificant 25% increase in flow in treated eyes compared to baseline. CONCLUSION: The results for 8-OH-DPAT and possibly flexinoxan indicate the presence of a secretion-stimulating 5-HT1A receptor in monkey ciliary epithelium that has little effect on IOP. OF was unchanged following 8-OH-DPAT administered topically or following intracameral exchange.


Assuntos
Humor Aquoso/metabolismo , Corpo Ciliar/efeitos dos fármacos , Agonistas do Receptor de Serotonina/farmacologia , Animais , Barreira Hematoaquosa/efeitos dos fármacos , Corpo Ciliar/metabolismo , Fluorofotometria , Pressão Intraocular/efeitos dos fármacos , Macaca fascicularis , Epitélio Pigmentado Ocular/efeitos dos fármacos , Epitélio Pigmentado Ocular/metabolismo , Receptores de Serotonina/metabolismo , Receptores 5-HT1 de Serotonina
4.
Structure ; 8(2): 175-84, 2000 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-10673436

RESUMO

BACKGROUND: S100C (S100A11) is a member of the S100 calcium-binding protein family, the function of which is not yet entirely clear, but may include cytoskeleton assembly and dynamics. S100 proteins consist of two EF-hand calcium-binding motifs, connected by a flexible loop. Like several other members of the family, S100C forms a homodimer. A number of S100 proteins form complexes with annexins, another family of calcium-binding proteins that also bind to phospholipids. Structural studies have been undertaken to understand the basis of these interactions. RESULTS: We have solved the crystal structure of a complex of calcium-loaded S100C with a synthetic peptide that corresponds to the first 14 residues of the annexin I N terminus at 2.3 A resolution. We find a stoichiometry of one peptide per S100C monomer, the entire complex structure consisting of two peptides per S100C dimer. Each peptide, however, interacts with both monomers of the S100C dimer. The two S100C molecules of the dimer are linked by a disulphide bridge. The structure is surprisingly close to that of the p11-annexin II N-terminal peptide complex solved previously. We have performed competition experiments to try to understand the specificity of the S100-annexin interaction. CONCLUSIONS: By solving the structure of a second annexin N terminus-S100 protein complex, we confirmed a novel mode of interaction of S100 proteins with their target peptides; there is a one-to-one stoichiometry, where the dimeric structure of the S100 protein is, nevertheless, essential for complex formation. Our structure can provide a model for a Ca(2+)-regulated annexin I-S100C heterotetramer, possibly involved in crosslinking membrane surfaces or organising membranes during certain fusion events.


Assuntos
Anexina A1/metabolismo , Cálcio/metabolismo , Proteínas S100/química , Acetilação , Anexina A1/química , Cristalografia por Raios X , Dissulfetos/química , Modelos Moleculares , Conformação Proteica , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo , Proteínas S100/metabolismo , Espectrometria de Fluorescência
5.
Xenobiotica ; 29(8): 793-801, 1999 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-10553720

RESUMO

1. 5'-Hydroxycotinine-N-oxide, 5-(3-pyridyl-N-oxide)-5-hydroxy-1-methyl-pyrrolidone-2, was identified as a new in vivo metabolite of nicotine. 2. The new metabolite was isolated from the urine of rats treated with S-nicotine and characterized using chemical and spectrometric methods. 3. 5'-Hydroxycotinine-N-oxide was synthesized and characterized by MS and by infrared as well as 1H- and 13C-NMR spectroscopy. 4. Identity of the new metabolite with synthetic 5'-hydroxycotinine-N-oxide was demonstrated by comparing the MS and 1H-NMR spectroscopy data as well as by co-chromatography of a spiked urine sample.


Assuntos
Cotinina/análogos & derivados , Nicotina/metabolismo , Animais , Cromatografia Líquida de Alta Pressão , Cotinina/química , Cotinina/urina , Espectroscopia de Ressonância Magnética , Masculino , Espectrometria de Massas , Estrutura Molecular , Nicotina/farmacologia , Ratos , Ratos Sprague-Dawley
6.
J Agric Food Chem ; 47(12): 5133-45, 1999 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-10606585

RESUMO

Thermal transfer to nicotine in the gas phase from neat nicotine, from various nicotine carboxylic acid salts, and from endogenous nicotine in Burley, Bright, and Oriental tobacco samples has been examined by thermogravimetric/differential thermal analysis/mass spectroscopy and evolved gas analysis. Under the conditions used in these studies, the peak transfer temperatures of these substances to nicotine in the gas phase are nicotine and nicotine acetate, both ca. 110-125 degrees C; nicotine malates, ca. 110-210 degrees C for nicotine to malic acid ratios of 1:0.56 and 1:1 and ca. 160-210 degrees C for a nicotine to malic acid ratio of 1:2; (S)-nicotine bis[(2R,3R)-hydrogen tartrate] dihydrate, ca. 195-210 degrees C; and tobacco samples, a range of ca. 160-220 degrees C. These results suggest that nicotine is mostly protonated in tobacco leaf. In all cases, the temperature of the transfer of nicotine to the gas phase was found to be many hundreds of degrees below the temperatures observed around the coal of a burning cigarette (smolder, ca. 500-775 degrees C; dynamic smoking, 600 to over 950 degrees C). Within the narrow zone of a puffing cigarette that encompasses an intermediate temperature range (125-250 degrees C), kinetic data suggest that these temperatures are not sufficient to volatilize significant amounts of nonprotonated nicotine, assuming any exists at all, during the short puff duration (2 s). It is concluded that nonprotonated nicotine and protonated nicotine (salts of nicotine with natural tobacco carboxylic acids) will transfer nicotine to smoke with comparable yields and efficiencies during the smoking process.


Assuntos
Ácidos Carboxílicos/química , Nicotiana/química , Nicotina/química , Plantas Tóxicas , Análise Diferencial Térmica , Gases , Temperatura Alta , Espectrometria de Massas , Termogravimetria
7.
Health Phys ; 77(5): 588-94, 1999 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-10524514

RESUMO

The radiation safety system of the B-Factory accelerator facility at the Stanford Linear Accelerator Center is described. The radiation safety system, which is designed to protect people from prompt radiation exposure due to beam operation, consists of the access control system and the radiation containment system. The access control system prevents people from being exposed to the very high radiation levels inside a beamline shielding enclosure. The access control system consists of barriers, a standard entry module at every entrance, and beam stoppers. The radiation containment system prevents people from being exposed to the radiation outside a shielding enclosure due to either normal or abnormal operation. The radiation containment system consists of power limiting devices, shielding, dump and collimator, and an active radiation monitoring system. The inter-related elements for the access control system and radiation containment system, as well as the associated interlock network, are described. The policies and practices used in establishing the radiation safety system are also compared with the regulatory requirements.


Assuntos
Exposição Ambiental/prevenção & controle , Exposição Ocupacional/prevenção & controle , Saúde Ocupacional , Aceleradores de Partículas , Monitoramento de Radiação/métodos , California , Humanos
8.
J Rheumatol ; 22(11): 2055-61, 1995 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-8596144

RESUMO

OBJECTIVE: To investigate the rate and extent of infection by Epstein-Barr virus (EBV), cytomegalovirus, and herpesvirus 6 in families (affected and nonaffected members) with multiple cases of rheumatoid arthritis (RA). METHODS: Viral DNA was detected by polymerase chain amplification in cells from saliva and peripheral blood. Human leukocyte antigen pedigrees were characterized. RESULTS: Viral DNA, particularly EBV, was detected in increased frequency (p = 0.029) in the patients with RA compare to their nonaffected relatives. CONCLUSION: We suggest that in RA multicase families, increased frequency of viral infection is likely a consequence of the disease state and/or due to gene(s) as yet unidentified.


Assuntos
Artrite Infecciosa/virologia , Artrite Reumatoide/virologia , Infecções por Citomegalovirus/complicações , Saúde da Família , Infecções por Herpesviridae/complicações , Herpesvirus Humano 4 , Herpesvirus Humano 6 , Infecções Tumorais por Vírus/complicações , Idoso , Alelos , Artrite Infecciosa/imunologia , Artrite Reumatoide/imunologia , DNA Viral/análise , Feminino , Antígenos HLA/análise , Antígenos HLA/genética , Herpesviridae/genética , Humanos , Masculino , Pessoa de Meia-Idade , Fenótipo , Reação em Cadeia da Polimerase , Fator Reumatoide/análise
9.
Am Psychol ; 44(8): 1099-109, 1989 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-2672917

RESUMO

This article proposes a model of positive health based on a human-system framework. Such a framework is comprehensive in that (a) it encompasses all of the human system's behavioral subsystems (biochemical, physiological, perceptual, cognitive, and interpersonal), and (b) it permits a higher asymptote of health conceptualization and measurement than that afforded by Western biomedical theory. The article sets forth the conceptual basis of the model and reviews empirical studies that support the model. Finally, the article explores implications of the model for health research, for programs of health enhancement, and for the role of the behavioral sciences in health theory.


Assuntos
Adaptação Psicológica , Comportamentos Relacionados com a Saúde , Nível de Saúde , Saúde , Modelos Psicológicos , Humanos
13.
Folia Biol (Praha) ; 32(3): 218-20, 1986.
Artigo em Inglês | MEDLINE | ID: mdl-3017775

RESUMO

In experiments on rabbits it was found that the subcutaneous injection of cytomegalovirus (CMV) antigen into the draining lymphatic area of the skin allograft caused a decrease in graft survival. The difference of experimental versus control grafts was statistically significant. The finding supports some clinical data regarding the increased incidence of rejection episodes during CMV infection.


Assuntos
Antígenos Virais/administração & dosagem , Citomegalovirus/imunologia , Sobrevivência de Enxerto , Transplante de Pele , Animais , Infecções por Citomegalovirus/imunologia , Feminino , Masculino , Coelhos , Transplante Homólogo
16.
J Pharm Sci ; 73(10): 1472-7, 1984 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-6502500

RESUMO

In this study the relationships between previously reported connectivity indices described by Kier and Hall and steric contributions to the rate constants for several series of reactions are examined. Rate data were examined for four different series of reactions, which were chosen to represent a range of different reaction mechanisms and transition-state structures. For sterically controlled reactions, the relative rates of series of substrates can be correlated either with the connectivity indices of the substrates themselves or with the changes in the indices that accompany formation of transition states. As expected, the significant indices in the correlations are of the cluster and path-cluster types. The connectivity indices should be useful descriptors in helping relate equilibrium properties, chemical reactivities, and pharmacological data to one another.


Assuntos
Piridinas , Brometos , Fenômenos Químicos , Físico-Química , Hidrólise , Cinética , Metilação , Conformação Molecular , Piridinas/metabolismo , Relação Estrutura-Atividade
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA