Immunization with crude antigens plus aluminium hydroxide protects cattle from Fasciola hepatica infection.

The ability of total homogenate (TH) of Fasciola hepatica conjugated with aluminium hydroxide (alum) or Freund's complete adjuvant (FCA) to protect cattle against experimental fasciolosis was evaluated. Compared with the infected group, the immunized animals with alum-TH and FCA-TH presented a significant reduction in fluke burden (85.9% and 96.8%, respectively), a higher percentage of short-sized worms, a marked reduction in the released eggs in faeces (89% and 57%, respectively), as well as an increased production of specific antibodies before infection. The alum-TH immunized group also showed a significant increase in the antigen-specific proliferation of peripheral blood mononuclear cells (PBMC) as early as 4 weeks before infection. Although both immunized groups (alum-TH and FCA-TH) were able to develop an efficient protective immune response to metacercarial challenge, an earlier PBMC response, lower hepatic damage and less effect on weight gain were found in alum-immunized animals. Therefore, alum is a good candidate for future immunization against bovine fasciolosis.

Glutamatergic ionotropic blockade within accumbens disrupts working memory and might alter the endocytic machinery in rat accumbens and prefrontal cortex.

Effects of blocking N-methyl-D-aspartic acid (NMDA) and non-NMDA glutamatergic receptors on performance in the hole board test was studied in male rats bilaterally cannulated into the nucleus accumbens (Acc). Rats, divided into 5 groups, received either 1 microl injections of saline, (+/-) 2-amino-7-phosphonoheptanoic acid (AP-7) (0.5 or 1 microg) or 2,3-dioxo-6-nitro-1,2,3,4,tetrahydrobenzo-(f)quinoxaline-7-sulphonamide disodium (NBQX, 0.5 or 1 microg) 10 min before testing. An increase by AP-7 was observed in ambulatory movements (0.5 microg; p < 0.05), non-ambulatory movements and number of movements (1 microg; p < 0.05); sniffing and total exploration (1 microg; p < 0.01). When holes were considered in order from the first to the fifth by the number of explorations, the most visited holes (first and second) of the AP-7 group were significantly higher than the corresponding holes of saline group (p < 0.05 for 0.5 microg and p < 0.001 for 1 microg). When the second hole was compared with the first of his group, a difference was only observed in the AP-7 1 microg group (p < 0.001). Increasing differences between the other holes and the first were observed by drug treatment. At molecular level, it was observed that AP-7 induced an increase of the coat protein AP-2 expression in Acc, but not AP-180 neither the synaptic protein synaptophysin. The increase of AP-2 was also observed in the medial prefrontal cortex by the action of AP-7 but not NBQX. We conclude that NMDA glutamatergic blockade might induce an activation of the endocytic machinery into the Acc, leading to stereotypies and perseverations, lacking cortical intentional direction.