Effective Decontamination of Laboratory Animal Rooms with Vapour-phase (“Vaporized”) Hydrogen Peroxide and Peracetic Acid

The purpose of this study was to investigate the decontaminant effects of vapour-phase hydrogen peroxide (VHP) and peracetic acid (PAA) in laboratory animal rooms. Methodologically and microbiologically, both methods were evaluated as an alternative to traditional methods. In the VHP decontamination process, the cycle consisted of 4 phases (dehumidification, conditioning, decontamination and aeration). The residual vapour was catalytically decomposed into water and oxygen. The complete process of room decontamination with VHP took 14-15 hours.In PAA decontamination, the dry fog system produced very fine droplets of disinfectant that were dispersed throughout the laboratory animal rooms. The overall decontamination process by PAA mist took 3 hours, which was much faster than VHP decontamination. In both methods, no corrosion appeared on the material surfaces. The results of chemical and biological indicators showed complete decontamination after exposure to VHP and PAA fumigation. In the airborne microbiological examinations, total colony counts for the surface and environmental microorganisms were minimal. There were no significant differences between VHP and PAA fumigation. In laboratory facilities, conventional decontaminating methods will be gradually converted into VHP or PAA decontamination. This experiment confirmed that the VHP method is suitable for the decontamination of a relatively limited space whereas the PAA method is applicable to the rapid decontamination of spacious laboratory animal rooms. In conclusion, decontamination with VHP and PAA holds great promise as an effective alternative to currently used formaldehyde fumigation.Abbreviations ACC: peracetic acid, BIs: biological indicators, CFU: colony-forming units, CIs: chemical indicators, EPA: Environmental Protection Agency, PDACP: potato dextrose agar with chloramphenicol, SCD: soybean casein digest, SCDLP: soybean casein digest with lecithin and polysorbate 80, and VHP: vapour-phase hydrogen peroxide

Successful Treatment for Idiopathic Thrombocytopenic Purpura in a Japanese Monkey

In human beings and dogs, idiopathic thrombocytopenic purpura (ITP) is a well-known disease in which antibodies bound to the surface platelets result in premature platelet destruction by macrophages. However, there is a paucity of information dealing with ITP in non-human primates, especially the Japanese monkey (Macaca fuscata). The case is described of a female Japanese monkey suffering from ITP in the Center for Experimental Animals. Physical examinations revealed characteristic findings such as mucosal and cutaneous petechiae, ecchymoses and purpura, epistaxis and mucous membrane pallor. The monkey had severe thrombocytopenia (10,000/μl) on initial hematological examination. Immunosuppressive glucocorticoid therapy had remarkable effects on this condition, with the platelet count rapidly reaching the normal range. On tapering the dose of predonisolone, the number of platelets decreased and the monkey suffered a relapse of ITP. Although immunosuppressive therapy was resumed with the initial dose of predonisolone, the monkey was relatively slow to respond. The initial treatment revealed an apparently faster increase in platelet count than the second treatment following the recurrence of ITP. The monkey remained in complete remission for more than one year after cessation of predonisolone treatment. In blood coagulation profiles and serum biochemical findings, there were no marked changes throughout this investigation. Neither endoscopy nor the stool antigen test provided evidence that natural infection with Helicobacter pylori caused ITP in this monkey. This is the first case of successful treatment for idiopathic thrombocytopenic purpura in a Japanese monkey

Significant Improvement in Survival of Tabby Jimpy Mutant Mice by Providing Folded-paper Nest Boxes

There is little scientific evidence that environmental enrichment meets the physiological needs for laboratory  animals. The purpose of this study was to evaluate whether the provision of nest boxes improved the lifespan  of Tabby jimpy (Ta-jp) mutant mice carrying a lethal gene. Nest boxes tested in this study were small  folded-paper trapezoid-shaped houses. The Nest box group was reared in cages with the nest boxes and  the Control group was raised in only standard cages. Weaning results and survival rates in Ta-jp mice were  compared between both groups. By the weaning stage, all of the Ta-jp mice survived in the Nest box group.  There was a significant difference in weaning rates between both groups. The body weight of weanlings  demonstrated a significant difference between both groups. The survival analysis indicated that the Nest  box group (29.9 days) significantly had a longer lifespan than the Control group (25.7 days). The Nest box  group developed few abnormal jumping behaviours. The nest boxes served as shelters from environmental  stimuli. In conclusion, we confirmed that folded-paper nest boxes had a beneficial effect on weaning rates  of Ta-jp mice. Our results revealed that there was significant improvement in survival of Ta-jp mice using  the nest boxes.

International Center of Veterinary Education and Research (iCOVER), Joint Faculty of Veterinary Medicine・Advanced Research Center for Laboratory Animal Science (ARCLAS), Yamaguchi University

Advanced Research Center for Laboratory Animal Science (ARCLAS) within International Center of Veterinary Education and Research (iCOVER), Joint Faculty of Veterinary Medicine, Yamaguchi University was established in January 2015. The purpose of ARCLAS is twofold: first, to provide care and management for laboratory animals in safe and adequate manner and, second, to prepare the education curricula for practical training for laboratory animal science. I will now show the outline of newly developed laboratory facilities, ARCLAS

Accelerating effects of silk fibroin on wound healing in hairless descendants of Mexican hairless dogs

Abstract: We examined the safety of silk fibroin in the subcutaneous tissues. In addition, we macroscopically and histopathologically evaluated its healing effect on the full-thickness wounds in hairless dogs. We prepared 3 types of matrices including amorphous silk fibroin films, and á-and â-type silk fibroin powder. No toxicity was found in the sites injected with silk fibroin solutions. Macroscopically, silk fibroin films had accelerating effects on wound repair, as compared with occlusive dressings (dried porcine skin and hydrocolloid dressings). Histopathological examinations revealed that silk fibroin films facilitate reepithelialization and the formation of granulation tissues, collagens and elastic fibers. The sites treated with the á-type silk fibroin powder were faster in wound repair than those treated with the â-type silk fibroin powder. The á-type silk fibroin powder absorbed excessive exudate. Microscopically, there are epidermal and dermal regeneration in the sites treated with the á-type silk fibroin powder. These results show that silk fibroin is inert in biological tissues, indicating excellent biocompatibility. Silk fibroin films facilitate reepithelialization, remodeling of connective tissues and collagenization. The á-type fibroin powder is a wound dressing that regulates excessive exudate from the wound and provides a proper moist environment. These results suggest that silk fibroin is a useful dressing material in veterinary clinical medicine

bcl-x Prevents Apoptotic Cell Death of Both Primitive and Definitive Erythrocytes at the End of Maturation

bcl-x is a member of the bcl-2 gene family, which regulates apoptotic cell death in various cell lineages. There is circumstantial evidence suggesting that bcl-x might play a role in the apoptosis of erythroid lineage cells, although there is no direct evidence. In this study, we used Bcl-X null mouse embryonic stem (ES) cells, and showed that Bcl-X is indispensable for the production of both embryonic primitive erythrocytes (EryP) and adult definitive erythrocytes (EryD) at the end of their maturation. In vivo, bcl-x−/− ES cells did not contribute to circulating EryD in adult chimeric mice that were produced by blastocyst microinjection of the bcl-x−/− ES cells. bcl-x−/− EryP and EryD were produced by in vitro differentiation induction of ES cells on macrophage colony-stimulating factor–deficient stromal cell line OP9, and further analysis was carried out. The emergence of immature EryP and EryD from bcl-x−/− ES cells was similar to that from bcl-x+/+ ES cells. However, prominent cell death of bcl-x−/− EryP and EryD occurred when the cells matured. The data show that the antiapoptotic function of bcl-x acts at the very end of erythroid maturation

THE OPHTHALMIC ARTERY ARISING FROM THE MIDDLE MENINGEAL ARTERY

The present report describes a case of variation of the ophthalmic artery observed in a 91-year-old Japanese woman at dissection in 1992. It was found that on one side, the ophthalmic artery originate from the middle meningeal artery, and the ophthalmic artery from the internal carotid artery was absent