Australian Equine Laminitis Research Unit, School of Veterinary Science, the University of Queensland, Gatton, Queensland, Australia.
Department of Veterinary Clinical Sciences, College of Veterinary Medicine, the Ohio State University, Columbus, Ohio, USA.
Equine Vet J. 2019 Sep;51(5):658-664. doi: 10.1111/evj.13072. Epub 2019 Feb 7.
Continuous digital hypothermia can prevent the development and progression of laminitis associated with sepsis but its effects on laminitis due to hyperinsulinaemia are unknown.
To determine the effects of continuous digital hypothermia on laminitis development in the euglycaemic hyperinsulinaemic clamp model.
Randomised, controlled (within subject), blinded, experiment.
Eight clinically normal Standardbred horses underwent laminitis induction using the euglycaemic hyperinsulinaemic clamp model (EHC). At initiation of the EHC, one forelimb was continuously cooled (ICE), with the other maintained at ambient temperature (AMB). Dorsal lamellar sections (proximal, middle, distal) were harvested 48 h after initiation of the EHC and were analysed using histological scoring (0-3) and histomorphometry. Cellular proliferation was quantified by counting epidermal cell nuclei staining positive with an immunohistochemical proliferation marker (TPX2).
Severe elongation and disruption of SEL with dermo-epidermal separation (score of 3) was observed in all AMB feet at one or more section locations, but was not observed in any ICE sections. Overall 92% of the AMB sections received the most severe histological score (grade 3) and 8% were grade 2, whereas ICE sections were classified as either grade 1 (50%) or grade 2 (50%). Relative to AMB feet, ICE sections were 98% less likely to exhibit grades 2 or 3 (OR: 0.02, 95% CI 0.001, 0.365; P<0.01). Histomorphometry measurements of total and nonkeratinised primary epidermal lamellar length were significantly increased (P<0.01) in AMB limbs compared with ICE. TPX2 positive cell counts were significantly increased (P<0.01) in AMB limbs compared with ICE.
Continuous digital hypothermia was initiated before recognition of laminitis and therefore the clinical applicability requires further investigation.
Continuous digital hypothermia reduced the severity of laminitis in the EHC model and prevented histological lesions compatible with lamellar structural failure.
持续的数字式冷敷可以预防与脓毒症相关的蹄叶炎的发展和进展，但它对由于高胰岛素血症引起的蹄叶炎的影响尚不清楚。
确定在正常血糖高胰岛素血症夹闭模型中持续数字式冷敷对蹄叶炎发展的影响。
随机、对照（自身对照）、盲法实验。
8 匹临床正常的标准马通过正常血糖高胰岛素血症夹闭模型（EHC）诱导蹄叶炎。在 EHC 开始时，一只前肢连续冷却（ICE），另一只保持环境温度（AMB）。EHC 开始后 48 小时采集背侧蹄叶切片（近端、中间、远端），并进行组织学评分（0-3）和组织形态计量学分析。通过计数表皮细胞核用免疫组织化学增殖标志物（TPX2）染色阳性的细胞来量化细胞增殖。
在所有 AMB 脚的一个或多个切片位置都观察到严重的 SEL 伸长和破坏，伴有表皮-真皮分离（评分 3），但在任何 ICE 切片中均未观察到。总体而言，92%的 AMB 切片获得了最严重的组织学评分（等级 3），8%为等级 2，而 ICE 切片被分类为等级 1（50%）或等级 2（50%）。与 AMB 脚相比，ICE 脚出现 2 级或 3 级的可能性低 98%（OR：0.02，95%CI 0.001，0.365；P<0.01）。与 ICE 相比，AMB 肢体的总表皮和非角质化初级表皮板层长度的组织形态计量学测量明显增加（P<0.01）。AMB 肢体的 TPX2 阳性细胞计数明显增加（P<0.01）。
在认识到蹄叶炎之前开始进行持续的数字式冷敷，因此其临床适用性需要进一步研究。
持续的数字式冷敷降低了 EHC 模型中蹄叶炎的严重程度，并防止了与板层结构失效一致的组织学病变。
