Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 2 de 2
Filtrar
Mais filtros











Base de dados
Intervalo de ano de publicação
1.
Biologicals ; 43(4): 242-9, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25962339

RESUMO

Plasma-originated commercial intravenous immunoglobulin, which is used for a variety of clinical purposes, has been studied to determine the effect of virus-inactivating doses of gamma irradiation on the structural-functional characteristics of the protein. A detailed analysis has been performed in response to a concern that the use of conventional gamma irradiation may damage biologically active proteins. The results demonstrate that although gamma irradiation of the IgG may have some impact on protein structure, the damage can be reduced or even prevented by appropriate irradiation conditions. At the virucidal dose of gamma irradiation (50 kGy) and a temperature of -80 °C, the integrity of the polypeptide chain of immunoglobulin and the secondary structure of IgG can be completely protected, while conformational changes in tertiary structure are significantly minimized to a level that preserves functional activity. The irradiated IgG retains specific antigen-binding properties and F(c)-binding activity, indicating that the conformational integrity of the most important structural regions is not affected by γ-irradiation. These results present strong evidence that gamma irradiation treatment can be effectively implemented for inactivation of pathogens in IgG solutions that are used for intravenous injection.


Assuntos
Raios gama , Imunoglobulina G/efeitos da radiação , Eletroforese em Gel de Poliacrilamida , Ensaio de Imunoadsorção Enzimática , Imunoglobulina G/sangue , Imunoglobulina G/química , Conformação Proteica , Estabilidade Proteica , Espectrofotometria Infravermelho
2.
Mutat Res ; 711(1-2): 142-9, 2011 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-21185842

RESUMO

Hibernation is an established strategy used by some homeothermic organisms to survive cold environments. In true hibernation, the core body temperature of an animal may drop to below 0°C and metabolic activity almost cease. The phenomenon of hibernation in humans is receiving renewed interest since several cases of victims exhibiting core body temperatures as low as 13.7°C have been revived with minimal lasting deficits. In addition, local cooling during radiotherapy has resulted in normal tissue protection. The experiments described in this paper were prompted by the results of a very limited pilot study, which showed a suppressed DNA repair response of mouse lymphocytes collected from animals subjected to 7-Gy total body irradiation under hypothermic (13°C) conditions, compared to normothermic controls. Here we report that human BJ-hTERT cells exhibited a pronounced radioprotective effect on clonogenic survival when cooled to 13°C during and 12h after irradiation. Mild hypothermia at 20 and 30°C also resulted in some radioprotection. The neutral comet assay revealed an apparent lack on double strand break (DSB) rejoining at 13°C. Extension of the mouse lymphocyte study to ex vivo-irradiated human lymphocytes confirmed lower levels of induced phosphorylated H2AX (γ-H2AX) and persistence of the lesions at hypothermia compared to the normal temperature. Parallel studies of radiation-induced oxidatively clustered DNA lesions (OCDLs) revealed partial repair at 13°C compared to the rapid repair at 37°C. For both γ-H2AX foci and OCDLs, the return of lymphocytes to 37°C resulted in the resumption of normal repair kinetics. These results, as well as observations made by others and reviewed in this study, have implications for understanding the radiobiology and protective mechanisms underlying hypothermia and potential opportunities for exploitation in terms of protecting normal tissues against radiation.


Assuntos
Sobrevivência Celular , Temperatura Baixa , Reparo do DNA , Linhagem Celular , Células Cultivadas , Dano ao DNA , Histonas/genética , Humanos , Hipotermia Induzida , Linfócitos/efeitos da radiação
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA