RESUMEN
The toxic effects of ACR monomer include carcinogenesis, cellular genotoxic, and neurotoxicity. In this study, we examined the effect of acrylamide on biochemical and hematologic parameters in Wistar rats and explored the renal and hepatic function of these animals through a complementary anatomopathologic study. For it, thirty female Wistar rats aged 4 weeks and weighing 100 ± 10 g were housed six animals per cage and divided as follows: two groups were exposed for 2 months to drinking water containing 5 mg (Group 2) or 10 mg acrylamide (Group 3); one group of 12 rats received the median lethal dose of acrylamide by gavage (Group 4); and the control group (Group 1) received pure water. The results clearly showed that acrylamide affects various biochemical parameters, such as creatinine, urea, and serum globulin levels and the lipid balance, which are directly related to renal and hepatic dysfunction and disruption of the hematologic system. In addition, the data revealed changes in the complete blood count (CBC); significant increases in the number of leukocytes (9.95 ± 1.44 and 10.44 ± 1.21) and lymphocytes (6.11 ± 0.48 and 6.33 ± 0.76) in Groups 3 and 4, respectively; and decreases in total protein (88.95 ± 6.36), albumin (37.65 ± 1.65) and α-1 globulin levels (24.84 ± 2.10) in Group 3. The anatomopathologic study confirmed liver damage in the animals administered an acrylamide containing diet compared with those in the control group. The present study confirmed the effects of acrylamide on different hematologic, biochemical and immunologic parameters, with a specific focus on the liver and kidney, and on the induction of neurotoxic disorders. The results showed that oral exposure to acrylamide via drinking water or gavage induces kidney damage, hepatocellular insufficiency and chronic liver disease, resulting in primary immunodeficiency and activation of the immune system following the possible expression of certain immunoreaction genes.
Asunto(s)
Acrilamida/toxicidad , Acrilamida/administración & dosificación , Administración Oral , Animales , Proteínas Sanguíneas/análisis , Creatinina/sangre , Femenino , Riñón/efectos de los fármacos , Riñón/metabolismo , Recuento de Leucocitos , Hígado/efectos de los fármacos , Hígado/metabolismo , Recuento de Linfocitos , Ratas , Ratas Wistar , Albúmina Sérica/análisis , Seroglobulinas/análisis , Urea/sangreRESUMEN
A Staphylococcus aureus strain, isolated from an Algerian biotope, secretes a non-induced lipase in the culture medium. The S. aureus lipase (SAL) was purified to homogeneity. Pure SAL is a monomeric protein (43 kDa). The 20 N-terminal amino acid residues showed a high degree of homology with other staphylococcal lipase sequences. SAL presents specific activities of about 1600 and 555 U mg-1 using tributyrin and olive oil emulsion as substrates, respectively. In contrast to other staphylococcal lipases previously characterized, SAL was stable at a pH range from 6 to 9 after 1 h incubation, and retained 50% of its activity after 10 min incubation at 50 °C. The purified enzyme was also characterized using monolayer technique. Lipase activity can be measured only when the surface pressure exceeds 15 mN m-1 . The critical surface pressure (πc ) measured with egg-PC films was estimated at 33 mN m-1 . SAL showed a preference for the distal ester groups of the diglyceride isomers at low surface pressure, for the adjacent ester groups at high surface pressure and a preference for the sn-3 position of the 2,3-sn-enantiomer of dicaprin. Cloned and sequenced gene part, encoding the mature lipase shows, in comparison with S. aureus lipase 3 (SAL3), a deletion of three residues (LKA) at the N-terminal extremity and a substitution of glycine 208 and isoleucine 226 with an arginine and leucine, respectively.
Asunto(s)
Lipasa/genética , Lipasa/metabolismo , Staphylococcus aureus/enzimología , Secuencia de Aminoácidos , Sustitución de Aminoácidos , Clonación Molecular , Medios de Cultivo/química , Emulsiones , Estabilidad de Enzimas , Concentración de Iones de Hidrógeno , Cinética , Lipasa/química , Aceite de Oliva/metabolismo , Presión , Staphylococcus aureus/genética , Staphylococcus aureus/metabolismo , Estereoisomerismo , Especificidad por Sustrato , Tensoactivos/química , Tensoactivos/aislamiento & purificación , Triglicéridos/metabolismoRESUMEN
A considerable variation is noticed between the different species studied and even between the strains of the same species, in the assimilation of cholesterol in synthetic media, in presence of different concentrations of bile salts and under anaerobiosis conditions. The obtained results show that certain strains of Streptococcus thermophilus and Lactobacillus bulgaricus resist bile salts and assimilate appreciable cholesterol quantities in their presence. The study of associations shows that only strains assimilating cholesterol in a pure state remain active when they are put in associations, but there is no additional effect. However, the symbiotic effect between Streptococcus thermophilus and Lactobacillus bulgaricus of yogurt, with regard to bile salts, is confirmed. The lactic fermenters of yogurt (Y2) reduce the levels of total cholesterol, HDL-cholesterol and LDL-cholesterol, in a well-balanced way. In all cases, the assimilated quantity of HDL-cholesterol is lower than that of LDL-cholesterol. Moreover, yogurt Y2 keeps a significant number of bacteria, superior to 10(8) cells ml(-1), and has a good taste 10 days after its production.