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Effect on Milk Quality, Causative Agents and Control
Fox, Laurence K.,Bohach, Gregory A.,Lee, Sang-Un,Park, Kun-Taek,Park, Yong-Ho 한국수의공중보건학회 2003 예방수의학회지 Vol.27 No.2
To summarize, mastitis infections attract white blood cells to move into the mammary gland. Their trafficking to the milk will cause a path of secretory cell destruction in their wake. This results in a leaky milk secretory system where components of the blood leak into the milk, reducing milk quality. Control of both contagious and noncontagious pathogens is warranted. There is a need to monitor the mastitis situation as closely as possible, and to root out the problem when it occurs by looking for the fundamental break-down in control. Mycoplasma mastitis seems to be increasing in prevalence. The best method to keep a hand on the pulse of the mycoplasma mastitis situation in a herd is to perform routine bulk tank milk cultures. The appearance of Mycoplasm sp. in the culture indicates that cows have mycoplasma mastitis. However, bulk tank milk cultures may yield false negative results. At times cows with mycoplasma mastitis may be shedding this pathogen at very low levels, not detectable in bulk tank milk. But with routine, perhaps weekly, bulk tank cultures, a dairy manager should feel confident that mycoplasma mastitis problems will be revealed. Once revealed, it is important that managers search and isolate infected cows, since mycoplasma mastitis is contagious. Yet the source of mycoplasma mastitis may not be exclusively the mammary gland. If future research definitively identifies different sources of this pathogen, such as colonization at other body sites, then new strategies need to be developed to control, and prevent, mycoplasma mastitis. The goal of mastitis control is illustrated in Table 1.
Immunosuppression by T regulatory cells in cows infected with Staphylococcal superantigen
박용호,Byoung Sun Chang,Gregory A.Bohach,Sang-Un Lee,William C.Davis,Lawrence K.Fox,Witold A.Ferens,Keun Seok Seo,Hye Cheong Koo,Nam Hoon Kwon 대한수의학회 2005 Journal of Veterinary Science Vol.6 No.3
Our recent study has provided that the in vitro SECinduced proliferation of bovine T cells is preceded by a period of a non-proliferative immunoregulation of T cells that may be associated with cytokine production regulated by type 1 or type 2 T cells. Inversion of CD4+:CD8+ T cell ratio and induction of CD8+ T cells with immunoregulatory activity could increase the probability of intracellular survival of Staphylococcus aureus (S. aureus). The increase of activated CD8+ (ACT2+ BoCD8+) T cells in cows with mastitis caused by S. aureus may be associated with immune-regulatory function in the bovine mammary gland. The difference and similarity between bovine activated CD8+ T cells (CD8+CD26+) and well-established human CD4+CD25+ T regulatory (Tr) cells may help to reveal their unique immune regulatory system in the host infected with S. aureus.
Suppression of bovine T lymphocytes responses by the superantigen staphylococcal enterotoxin C
Witold A. Ferens,Gregory A. Bohach,William C. Davis,Lawrence K. Fox,이상운(Sang Un Lee),박용호(Yong Ho Park) 한국예방수의학회 1998 예방수의학회지 Vol.22 No.3
Staphylococcus aureus에 의한 유방염은 주로 만성으로 경과되며 항생제 치료에 대한 저항성을 나타낸다. 기존의 보고에 의하면, 이 질병은 동일항원 혹은 다른 종류의 항원에 대한 면역반응의 억제와 관련된다고 알려져 있으나, 이러한 효과와 관련된 특이적인 인자는 아직 밝혀지지 않고 있다. 본 실험은 superantigen으로 알려진 포도상구균 장독소가 유방염의 숙주방어기전에 간섭하리라는 가능성을 제시하였다. 본 실험에서 포도상구균 장독소 C형 (SEC)은 in vitro상에서 세포증식의 억제와 CD8⁺T 림프구 표면의 ACT3 marker의 과다 발현에 의해 특징지어지는 소 T 림프구의 일탈된 활성을 유도하였다. SEC에 의한 소 T 림프구의 증식반응은 일시적이었으며, 배양 4일 후에는 ACT1, ACT16 및 IL-2Rα 등 활성세포 표면인자의 증가와 연관되어 왕성한 증식을 나타내었다. 비록 CD4⁺T 림프구와 CD8⁺T림프구는 배양 후 4일과 7일 사이에 증식을 나타내었지만, 상대적으로 CD8⁺T 림프구 아집단의 증식이 더 왕성하였으며 이로 인해 CD4:CD8 비율이 반전되는 결과를 가져왔다.
Superantigen-mediated differentiation of bovine monocytes into dendritic cells
Seo, K. S.,Park, J. Y.,Davis, W. C.,Fox, L. K.,McGuire, M. A.,Park, Y. H.,Bohach, G. A. Wiley (John WileySons) 2009 Journal of Leukocyte Biology Vol.85 No.4
<P>Although many effects of staphylococcal superantigens (SAg) on T cells are well established, less is known about their effects on APC. In this study, bovine PBMC were stimulated with a low dose of staphylococcal enterotoxin C1 (SEC1). The phenotype of adherent cells (Ac) derived from bovine PBMC cultured with SEC1 [SEC1-stimulated Ac (sAc)] for 192 h was CD14(-), CD68(-), CD163(-), dendritic cell (DC)-specific ICAM-3-grabbing nonintegrin(+), MHC class II (MHC II)(high), CD11a(low), CD11b(high), CD11c(high), and CD1b(high), suggesting these cells were dendritic cells (DC). SEC1 also induced transcription of the CXCL1, -2, and -3 family, CXCL6, CCL2, and CCL5 genes in sAc, which increased rapidly but returned to basal levels by 48 h. In contrast, increased transcription of CCL3, CCL8, and CXCL12, responsible for mononuclear cell migration and chronic inflammation, was sustained. In vitro cell migration assays showed vigorous migration of granulocytes, followed by migration of mononuclear cells. The autologous MLR showed that sAc induced a dose-dependent proliferation of CD4(+) T cells and an even stronger proliferation of CD8(+) T cells. This effect was inhibited or reduced by pretreatment with mAb to CD11b, MHC II, or MHC II plus CD18. These results indicate that stimulation of bovine PBMC by SAg induces differentiation of monocytes into DC.</P>