Cell culture systems for the protozoan Eimeria are not yet available. The present study was conducted to develop an animal model system by inoculating animals with a live Eimeria vaccine. This study was conducted on 3-day-old chickens (n = 20) pretreated with cyclophosphamide. The chickens were divided into 2 groups: the control group (n = 10) and the inoculated group that received the live Eimeria vaccine (n = 10). During the study period, we compared the clinical signs, changes in body weight, and number of oocysts shed in the feces of the control and inoculated group. This study showed that oocyst shedding was significantly higher in the chickens inoculated with live Eimeria oocysts than in the control chickens. Moreover, body weight gain was lesser in the animals in the inoculated group than in the control animals. Fecal oocyst shedding was observed in the inoculated animals. On the basis of these findings, we suggest that live Eimeria vaccination with cyclophosphamide pretreatment may be used to obtain an effective animal model for studying protozoan infections. This animal study model may eliminate the need for a tedious continuous animal inoculation process every 6 months because the live coccidiosis vaccine contains live oocysts.

The aim of this study was to evaluate the expression of galectin-3, one of beta-galactoside-binding proteins, in the experimental autoimmune encephalomyelitis(EAE) model of Lewis rats or non-obese diabetic (NOD) mice. Western blot analysis showed that galectin-3 was weakly expressed in the spinal cords of complete Freund's adjuvant(CFA) immunized control rats. In EAE, however, galectin-3 expression was significantly increased at the peak stage(days 14 post-immunization), while it was decreased slightly at the recovery stage(day 21 post-immunization).

Hydrocephalus is an intractable disease characterized by the excessive accumulation of cerebrospinal fluid (CSF) in the cerebral ventricles. There are many cases in both human and animals; however, the cause and mechanism of its development is not clearly understood. In this study, differences of cerebral ventricles in 5 inbred mice strains (MRL/MpJ, C57BL/6, C3H/He, DBA/2 and BALB/c) were investigated by histological techniques to determine the possibility of a new animal model for hydrocephalus. Our analysis showed that significant differences in the volume and the surface area of lateral ventricles in the 5 inbred strains, with MRL/MpJ mice having the largest lateral, third, aqueduct and fourth ventricles. In addition, when MRL/MpJ mice were compared to BALB/c mice on 0 day after birth, the former already had larger lateral ventricles than the latter. Although there was no significant difference in the ratios of ependymal cell types in MRL/MpJ mice and BALB/c mice, the number and the diameter of lipid droplets in MRL/MpJ mice were, interestingly, smaller than those in BALB/c mice. It is well known that ependymal cells absorb nutritional substances in CSF by endocytosis, suggesting the possibility that their decrease may relate to the larger cerebral ventricles in MRL/MpJ. In conclusion, MRL/ MpJ mice have greater volumes in cerebral ventricles than other strains and may be useful for a model showing high susceptibility to hydrocephalus.

Mx1 (Myxovirus resistance protein) and Oas1b (Oligoadenylate synthetase-1), induced by type 1 interferon (IFN), play a role in early antiviral innate immunity by inhibiting the replication of viruses. In mice, Mx1 and Oas1b confer resistance to the infection of orthomyxoviruses including influenza viruses and flaviviruses including West Nile viruses, respectively. Laboratory mice have been used to study the mechanisms of the pathogenesis of these virus infections; however, it is possible that they are not a suitable model system to study these viruses, since most of the inbred laboratory mouse strains lack both genes. It has been reported that feral mouse-derived inbred strains show resistance to the infection of these viruses due to the presence of intact both genes. In this study, we generated congenic strains in which the Mx or Oas locus of the MSM/Mx (MSM) mouse was introduced to the most widely used mouse strain, C57BL/6J (B6). B6.MSM-Ms mice showed resistance to the infection of influenza virus but not of West Nile virus. On the other hand, B6.MSM-Oas mice showed resistance to the infection of West Nile virus but not of influenza virus. Our results indicate that Mx1 and Oas1b show highly antiviral specificity in mice possessing the same genetic background. Therefore, these congenic mice are useful for not only infection study but also investigation of host defense mechanism to these viruses.