Animal models experimental studies

Chan, L.S. Robinson, N., and Xu, L. Expression of interleukin-4 in the epidermis of transgenic mice results in a pruritic inflammatory skin disease an experimental animal model to study atopic dermatitis. J. Invest. Dermatol. 117, 977-983 (2001). 

The use of in vitro systems such as cell cultures, tissue slices, and cell lines has become of major importance for several reasons. First of all, the common practice of the use of experimental animal models for studying toxicity of chemicals meets serious and growing criticism for ethical and economic reasons. Toxicity studies aiming at performing a hazard or a risk assessment inevitably will include adverse effects and thus discomfort for the animals involved. Moreover, the cost of running an animal facility and performing toxicity studies is an increasingly important limitation. 

The results obtained using the screening techniques in mentally retarded children prompted us to try to study some inborn errors in animal models . Experimental phenylketonuria, for example, can be simulated by overloading with phenylalanine or by inhibiting the phenylalanine hydroxylase with /7-chlorophenylalanine. We have used both /w hloro-phenylalanine and esculin (to block the dihydropteridine reductase reaction), a treatment which leads to a complete inhibition of the enzyme< > > (Fig. 2). 

Risling, M., Davidsson, J., 2012. Experimental animal models for studies on the mechanisms of blast-induced neurotrauma. Front. Neurol. 3, 30. 

Although there is no evidence that the DA afferents to DLPFC are damaged in schizophrenics, if the cortical pathology does reduce the ability of DA to function there, this would be equivalent to deafferentation and, as in the experimental studies, lead to increased subcortical mesolimbic activity and positive symptoms (Fig. 17.3). Unfortunately there is no good evidence that the nucleus accumbens is more active in schizophrenics or is even the origin of positive symptoms (but see Animal models ). Nevertheless it is a useful working hypothesis. 

As alluded to already, a major problem inherent in neuropharmacologic research is the lack of phenotypic changes that are clearly associated with treatment response this difficulty is particularly evident for mood-stabilizing agents [9]. In the absence of suitable animal models, studies have attempted to overcome this experimental hurdle by employing paradigms that involve the identification of com-... 

Although infection with C. parvum is considered predominantly secretory, histopathologic studies have revealed varying degrees of villous atrophy and infiltration of inflammatory cells beneath the epithelial mucosa [85, 86], Prostaglandins, which are known to induce cAMP-mediated apical chloride secretion and inhibit electroneutral sodium chloride and water absorption in enterocytes, have been demonstrated to be elevated in a porcine model of cryptosporidiosis [87], Inflammatory cytokines such as IL-1, IL-8 and TNF-a are induced in intestinal epithelial cell lines infected with Cryptosporidium and in animal models of cryptosporidiosis and have been postulated to play a role in pathogenesis [88, 89], Expression of TNF-a and IL-1 mRNA in the majority of jejunal biopsies of adult volunteers after experimental infection were also observed, although this did not correlate with the enteric symptoms [90]. 

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