著者

Mineo HAYASAKI

出版者

JAPANESE SOCIETY OF VETERINARY SCIENCE

雑誌

Journal of Veterinary Medical Science (ISSN:09167250)

巻号頁・発行日

pp.19-0156, (Released:2019-12-25)

被引用文献数

3

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Microfilariae (Mfs) of filarial nematode parasites exhibit nocturnal periodicity, with their numbers in peripheral blood peaking at night and decreasing during the day. However, the reason for their appearance at night remains unknown. In this study, in vitro photobiostimulation experiments showed that Mfs exhibited positive phototaxis toward infrared light with lower photon flux densities of infrared light at wavelengths of 890 and 700 nm, in particular, mediating paradoxically higher velocity than intense ones. Microarray analysis revealed that infrared light stimulation influenced gene expression in Mfs and induced significant upregulation of genes, with phosphorylation- and neurogenesis-related genes being highly enriched. Weaker natural infrared beams from the atmosphere only at midnight may induce microfilaria periodicity, and the nature of the periodic pattern is innate and plastic, as demonstrated by artificially changing the light-dark cycle. This is the first report of positive phototaxis toward infrared light in Dirofilaria immitis Mfs. The notable finding is that they moved in union despite the lack of a fluid current inside the container, indicating that infrared light appears to control nocturnal periodicity in D. immitis Mfs. The newly developed culture medium and the adoption of charge-coupled device (CCD) camera and time-lapse VHS videocassette recorder used in this study made possible to be a long observation.

著者

Azusa INUI Kazuhito ITAMOTO Tetsuya TAKUMA Hideki TSUTSUMI Manabu TANIGAWA Mineo HAYASAKI Yasuho TAURA Koichi MAMBA

出版者

公益社団法人 日本獣医学会

雑誌

Journal of Veterinary Medical Science (ISSN:09167250)

巻号頁・発行日

vol.66, no.6, pp.599-609, 2004 (Released:2004-07-05)

参考文献数

43

被引用文献数

12 19

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Bone mineral density (BMD), distribution of its density and bone histomorphometric parameters were evaluated in lumbar vertebra of normally growing miniature pigs. The fourth lumbar vertebra (L4) of the Göttingen miniature pig were used in this cross-sectional study in vitro. The BMD of the miniature pig was similar to that of humans in tendency of gender differences and some growth patterns during puberty. In these regards this animal appears useful as a model for human bone study. However, the trabecular and cortical BMDs of lumbar spine were extremely high value (399.43 ± 26.36 mg/cm3 in female trabeculae; 973.06 ± 69.55 mg/cm3 in female cortical bone; 419.04 ± 34.84 mg/cm3 in male trabeculae; 1038.81 ± 125.72 mg/cm3 in male cortical bone in pigs 30 months or more). Furthermore, histomorphometric analysis yielded values that were remarkably different from those found in humans. From these results, it was revealed that miniature pig had a higher bone mass and denser trabecular network than human, indicating that its bone is probably stronger. Therefore, care should be taken in choosing the miniature pig as a bone study model.

著者

Mineo HAYASAKI Mikako UENO Hiroyasu EJIMA Akira MUNAKATA Yukio TAMURA

出版者

公益社団法人 日本獣医学会

雑誌

Journal of Veterinary Medical Science (ISSN:09167250)

巻号頁・発行日

pp.12-0206, (Released:2012-10-15)

被引用文献数

1 2

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A dog was suspected of suffering from ectopic Dirofilaria immitis infection, because a large white nematode worm was detected in the anterior chamber of the left eye. A cylinder-shaped fibrin sac in the anterior chamber was found in the eye of the dog by slit lamp microscopy. After successful surgical removal of the worm, the corneal wound produced by the keratotomy healed in a short period. The worm was estimated to be extremely young, 5th-stage-immature male D. immitis, equivalent to a 90–120-day-old worm postinfection, by close morphological measurement and an experimental infection study. Thus, an immature worm can exhibit erratic parasitism in a host’s eye. The fibrin sac was considered to be a trace of the invasion route, and the cornea may have been the port of entry into the anterior chamber of the eye in the erratic migration of D. immitis.