RESUMO
We present a two-stage model for the study of chronic hind limb ischemia in rats. In the area of ischemia, sclerotic changes with atrophic rhabdomyocytes and reduced vascularization were revealed. CD31 expression in the endothelium increased proportionally to the number of vessels in the ischemic zone, and at the same time, focal expression of ßIII-tubulin was detected in the newly formed nerve fibers. These histological features are equivalent to the development of peripheral arterial disease in humans, which allows using our model in the search for new therapeutic strategies.
Assuntos
Modelos Animais de Doenças , Membro Posterior , Isquemia , Músculo Esquelético , Animais , Ratos , Músculo Esquelético/patologia , Músculo Esquelético/metabolismo , Músculo Esquelético/irrigação sanguínea , Membro Posterior/irrigação sanguínea , Membro Posterior/patologia , Isquemia/patologia , Isquemia/metabolismo , Isquemia/fisiopatologia , Masculino , Ratos Wistar , Molécula-1 de Adesão Celular Endotelial a Plaquetas/metabolismo , Tubulina (Proteína)/metabolismo , Doença Arterial Periférica/patologia , Doença Arterial Periférica/metabolismo , Doença Arterial Periférica/fisiopatologiaRESUMO
Type 2 diabetes mellitus develops due to a combination of genetic and environmental factors. C57BL/6 mice prone to obesity and leptin resistance were kept on a high-fat diet for 21 weeks. The animals showed a significant increase in fasting and postprandial glucose levels and body weight, the development of insulin resistance, and by week 18, an increase in the serum TNFα level. Metformin therapy at a dose of 250 mg/kg was effective against the background of disturbances in carbohydrate metabolism: animals showed a significant decrease in insulin resistance and TNFα level.
Assuntos
Diabetes Mellitus Tipo 2 , Resistência à Insulina , Camundongos , Animais , Diabetes Mellitus Tipo 2/genética , Dieta Hiperlipídica/efeitos adversos , Insulina , Fator de Necrose Tumoral alfa/genética , Glicemia , Camundongos Endogâmicos C57BL , Fatores de RiscoRESUMO
Among the panel of monoclonal antibodies to the recombinant protein HlyIICTD Bacillus cereus an antibody was found capable of forming an immune complex with a thrombin recognition region, the amino acid sequence of which is located inside the recombinant HlyIICTD. Localization of the epitope was carried out using peptide phage display methods, as well as enzyme immunoassay and immunoblotting for interaction with recombinant proteins, either containing or not containing individual components HlyIICTD. The identified epitope is located in the region of the thrombin site and retains the ability to interact with the antibody after the proteolyotic attack of the protein by thrombin.
RESUMO
L-Glycero-D-manno-heptopyranose is a characteristic compound of many lipopolysaccharide (LPS) core structures of Gram-negative bacteria. In Escherichia coli two heptosyltransferases, namely WaaC and WaaF, are known to transfer L-glycero-D-manno-heptopyranose to Re-LPS and Rd(2)-LPS, respectively. It had been proposed that both reactions involve ADPL-glycero-D-manno-heptose as a sugar donor; however, the structure of this nucleotide sugar had never been completely elucidated. In the present study, ADPL-glycero-D-manno-heptose was isolated from a heptosyltransferase-deficient E. coli mutant, and its structure was determined by nuclear magnetic resonance spectroscopy and matrix-assisted laser-desorption/ionization time-of-flight mass spectrometry as ADPL-glycero-beta-D-manno-heptopyranose. This compound represented the sole constituent of the bacterial extract that was accepted as a sugar donor by heptosyltransferases I and II in vitro.
Assuntos
Glicosiltransferases/metabolismo , Açúcares de Adenosina Difosfato/metabolismo , Escherichia coli/enzimologia , Heptoses/química , Heptoses/metabolismo , Ressonância Magnética Nuclear Biomolecular , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Especificidade por Substrato/fisiologiaRESUMO
The monosaccharide allyl 7-O-carbamoyl-L-glycero-alpha-D-manno- heptopyranoside, the reducing disaccharide 7-O-carbamoyl-L-glycero-alpha-D- manno-heptopyranosyl-(1-->3)-L-glycero-D-manno-heptopyranose and the disaccharides allyl 7-O-carbamoyl-L-glycero-alpha-D-manno-heptopyranosyl-(1-->3)-L-glycero- beta- and alpha-D-manno-heptopyranoside were prepared in good yields. The 7-O-carbamoyl substituent was regioselectively introduced via NH3-NH4HCO3 treatment of a 6,7-O-carbonate group. Glycosylation steps were carried out using Me3SiOTf or BF3.Et2O promoted coupling of allyl alcohol with trichloroacetimidate or fluoride glycosyl donors, respectively. The deprotected allyl glycosides were reacted with cysteamine to afford spacer glycosides which were subsequently linked to bovine serum albumin. The artificial antigens which are related to the dephosphorylated heptose region of the lipopolysaccharide core region from Pseudomonas aeruginosa classified into RNA group I may be used for the characterization of monoclonal antibodies directed against inner core epitopes of human-pathogenic Pseudomonas species.
