RESUMO
Xenotransplantation using genetically modified pig organs could solve the donor organ shortage problem. Two inactivated genes that make humans unique from pigs are GGTA1 and CMAH, the products of which produce the carbohydrate epitopes, aGal and Neu5Gc that attract preformed human antibody. When the GGTA1 and CMAH genes were deleted in pigs, human antibody binding was reduced in preliminary analysis. We analyzed the binding of human IgM and IgG from 121 healthy human serum samples for binding to GGTA1 KO and GGTA1/CMAH KO peripheral blood mononuclear cells (PBMCs). We analyzed a sub population for reactivity toward genetically modified pig PBMCs as compared to chimpanzee and human PBMCs. Deletion of the GGTA1 and CMAH genes in pigs improved the crossmatch results beyond those observed with chimpanzees. Sorting the 121 human samples tested against the GGTA1/CMAH KO pig PBMCs did not reveal a distinguishing feature such as blood group, age or gender. Modification of genes to make pig carbohydrates more similar to humans has improved the crossmatch with human serum significantly.
Assuntos
Anticorpos/química , Galactosiltransferases/genética , Transplante Heterólogo , Adolescente , Adulto , Idoso , Animais , Animais Geneticamente Modificados , Carboidratos/química , Epitopos/química , Feminino , Deleção de Genes , Rejeição de Enxerto , Humanos , Imunoglobulina G/química , Imunoglobulina M/química , Leucócitos Mononucleares/citologia , Masculino , Pessoa de Meia-Idade , Pan troglodytes , Ligação Proteica , SuínosRESUMO
Previous studies have shown that the principal glucose transporter isoform within the blood-brain barrier (BBB) is GLUT1, and that GLUT1 mRNA is upregulated and immunoreactive GLUT1 protein is downregulated in rats with streptozocin (STZ)-induced experimental diabetes. The present studies investigate effects of insulin therapy on both GLUT1 mRNA and immunoreactive GLUT1 protein in brain capillaries isolated from control (CO), diabetic (DM), and insulin-treated diabetic (IRx) rats. The following variables were measured: serum glucose levels, rat brain capillary immunoreactive GLUT1 level by quantitative Western blotting, and rat brain capillary GLUT1 and actin mRNA levels by quantitative Northern blotting. Serum glucose levels were 6.4 +/- 1.2, 30.3 +/- 3.2, and 3.7 +/- 1.7 mmol/L in CO, DM, and IRx rats, respectively. Brain capillary immunoreactive GLUT1 transporter protein level was 53% +/- 13% of CO values in DM rats, and this value was unchanged with insulin treatment. GLUT1 mRNA level in rat brain was increased to 131% +/- 8% of CO values in DM rats and was 80% +/- 5% of CO values in IRx rats. In conclusion, short-term insulin therapy in rats with STZ-induced diabetes normalizes BBB GLUT1 mRNA level, but does not normalize depressed immunoreactive GLUT1 protein level.
Assuntos
Diabetes Mellitus Experimental/metabolismo , Insulina/uso terapêutico , Proteínas de Transporte de Monossacarídeos/análise , Proteínas de Transporte de Monossacarídeos/genética , RNA Mensageiro/análise , Actinas/genética , Animais , Glicemia/análise , Barreira Hematoencefálica , Northern Blotting , Western Blotting , Encéfalo/irrigação sanguínea , Química Encefálica , Capilares/química , Capilares/metabolismo , Diabetes Mellitus Experimental/tratamento farmacológico , Transportador de Glucose Tipo 1 , Isomerismo , Masculino , Proteínas de Transporte de Monossacarídeos/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ratos , Ratos Sprague-Dawley , EstreptozocinaRESUMO
HR 756, the syn derivative of 7-[(2-(2-amino-4-thiazolyl)-2-methoxyimino)acetamido]cephalosporanic acid, is a new semisynthetic cephalosporin. It was 80 times more active than the anti derivative against beta-lactamase-producing strains of gram-negative bacteria. The range of inhibitory concentrations of HR 756 against gram-negative bacteria, including Haemophilus influenzae, susceptible or resistant to penicillins and cephalosporins was from 0.01 to 0.1 mug/ml. This activity was consistently higher than those observed with cephalothin, cephaloridine, cephalexin, and cefazolin. Nevertheless, some strains of Enterobacter cloacae were resistant. HR 756 showed very similar activity to that of ampicillin against group A streptococci and Streptococcus pneumoniae.