Heterogeneity in epithelium-dependent responses

The airway epithelium exerts a profound influence on the responsiveness of bronchial smooth muscle to both contracting and relaxing agents. This may be due to the release of an epithelium-derived factor or factors. There is a considerable heterogeneity in the effects of the epithelium between orders of bronchi, between species, and between pharmacologic agents. Such heterogeneity may reflect variations in the release and/or effect of the epithelium-derived relaxing factor(s). This report demonstrates that: (1) there is a basal and a stimulated release of the factor, (2) the prominence of different types of release varies between species, (3) the effect of the epithelium on relaxation of bronchial smooth muscle is greatest in the presence of high degrees of cholinergic tone, (4) the effects of the epithelium are not mediated via cyclic GMP, and (5) the epithelium-derived relaxing factor is not nitric oxide.     

犬囊状动脉瘤微弹簧圈栓塞治疗前后的超声研究

目的探讨囊状动脉瘤模型的声像图和血流动力学特征以及超声对其血管内栓塞效果的评价。方法利用用显微外科技术于犬颈总动脉制成三种类似于人类的囊状动脉瘤模型，其中侧壁型12例、分叉型4例、末端型6例。术后7～14d彩超观察瘤腔、载瘤动脉及瘤体内血流动力学改变。栓塞后再行彩超检查观察其疗效，并与MRA、DSA及病理检查结果对比。结果三种类型动脉瘤均有相似的血流模式，瘤腔内血流分为三个血流区：1)沿远侧瘤壁进入的流人区；2)沿近侧瘤壁出去的流出区和3)中心缓慢涡流区。流人区峰速高于流出区。②侧壁型动脉瘤内血流速较慢，易形成部分性血栓，而分叉型和末端型动脉瘤内血流速高。③血管内治疗后，血流显示19例动脉瘤腔闭塞，2例瘤颈部有残腔，1例弹簧圈略脱出瘤颈导致载瘤动脉狭窄。④超声结果与MRA、DSA及病理结果完全一致。结论①各型动脉瘤模型有相似的血流模式。②侧壁型动脉瘤顶部易形成部分血栓。③双功超声能观察载瘤动脉及瘤体内血流动力学改变，可作为动脉瘤及栓塞治疗效果无创评价的方法之一。     

Sequence analysis of a canine parvovirus isolated from a red panda (<Emphasis Type="Italic">Ailurus fulgens</Emphasis>) in China

Canine parvovirus (CPV) was first recognized in the late 1970 s in dogs and has mutated and spread throughout the world in canid and felid species since then. In this study, a novel CPV was isolated from the endangered red panda (Ailurus fulgens) in China. Nucleotide and phylogenetic analysis of the capsid protein VP2 gene classified the red panda parvovirus (RPPV) as a CPV-2a type. Substitution of Val for Gly at the conserved 300 residue in RPPV presents an unusual variation in the CPV-2a amino acid sequence and is further evidence for the continuing evolution of the virus. The 300 residue is important in distinguishing the antigenicity and host range of CPVs. The clinical significance and population impact of RPPV infection in captive red pandas in China is unknown and is an important topic for future research.     

Adaptation of canine distemper virus to canine footpad keratinocytes modifies polymerase activity and fusogenicity through amino acid substitutions in the P/V/C and H proteins

The wild-type canine distemper virus (CDV) strain A75/17 induces a non-cytocidal infection in cultures of canine footpad keratinocytes (CFKs) but produces very little progeny virus. After only three passages in CFKs, the virus produced 100-fold more progeny and induced a limited cytopathic effect. Sequence analysis of the CFK-adapted virus revealed only three amino acid differences, of which one was located in each the P/V/C, M and H proteins. In order to assess which amino acid changes were responsible for the increase of infectious virus production and altered phenotype of infection, we generated a series of recombinant viruses. Their analysis showed that the altered P/V/C proteins were responsible for the higher levels of virus progeny formation and that the amino acid change in the cytoplasmic tail of the H protein was the major determinant of cytopathogenicity.     

犬急性心肌梗塞早期左肾动脉和左颈总动脉血流动力学变化

目的：研究犬急性心肌梗塞（ＡＭＩ）时的左肾动脉（ＬＲＡ）和左颈总动脉（ＬＣＣＡ）的血流动力学变化。方法：用二维超声动图及多普勒血流图（ＤＥ）检测冠脉支结扎前后ＬＲＡ、ＬＣＣＡ收缩期最大肌梗塞后ＬＲＡ、ＬＣＣＡ的ＲＩ、ＰＩ值显著升高（ＬＣＣＡＰ〈０．０１；ＬＲＡ，０．０５〉Ｐ〉０．０１），Ｖｍａｘ、ＴＶＩ、ＨＲ参数值有变化但无统计学差异。且心梗后３０和６０分钟时的参数值接近。结论：ＡＭＩ后ＬＲＡ、Ｌ     

迷走神经对心房有效不应期离散度影响的实验研究

目的用动物实验模拟快速房率来观察迷走神经对心房有效不应期离散度(dAERP)变化的影响.方法用8只杂种犬自身随机对照,每只犬进行2次实验,分非迷走神经阻断组与迷走神经阻断组,每组包括全部8只杂种犬.第1次实验在快速刺激前后监测心率变异性和心房有效不应期(AERP),2周后进行第2次实验,刺激前静脉应用阿托品,快速刺激前后监测AERP.观察不同状态下和用药物时犬的迷走神经张力和dAERP的变化以及之间的关系.结果①非迷走神经阻断组800次/分的快速心房刺激很快引起AERP缩短,dAERP无明显变化.停止刺激后AERP恢复很快,dAERP从刺激终止时(21.0±5.3)ms升高到7 h后的(40.0±7.4)ms(P＜0.05).②非迷走神经阻断组心率变异性参数在刺激终止7 h后与刺激终止时相比明显升高(P＜0.05).③刺激前应用阿托品,AERP和dAERP无明显变化,快速刺激仍能引起AERP缩短,刺激终止后dAERP从(21.0±4.1)ms升高到(28.0±5.1)ms(P＞0.05).结论阻断迷走神经不能阻止电重构的发生,但迷走神经张力升高是dAERP升高的主要原因.     

Orthodontic management of a dilacerated central incisor and partially impacted canine with unilateral extraction – A case report

Aim

To align a dilacerated maxillary central incisor and partially impacted canine with unilateral extraction in a young patient with skeletal deep bite.

Evaluation of an attenuated strain of Ehrlichia canis as a vaccine for canine monocytic ehrlichiosis

Canine monocytic ehrlichiosis is an important tick-borne disease worldwide. No commercial vaccine for the disease is currently available and tick control is the main preventive measure against the disease. The aim of this study was to evaluate the potential of a multi-passaged attenuated strain of Ehrlichia canis to serve as a vaccine for canine monocytic ehrlichiosis, and to assess the use of azithromycin in the treatment of acute ehrlichiosis. Twelve beagle dogs were divided into 3 groups of 4 dogs. Groups 1 and 2 were inoculated (vaccinated) with an attenuated strain of E. canis (#611A) twice or once, respectively. The third group consisted of naïve dogs which served as controls. All 3 groups were challenged with a wild virulent strain of E. canis by administering infected dog-blood intravenously. Transient thrombocytopenia was the only hematological abnormality observed following inoculation of dogs with the attenuated strain. Challenge with the virulent strain resulted in severe disease in all 4 control dogs while only 3 of 8 vaccinated dogs presented mild transient fever. Furthermore, the mean blood rickettsial load was significantly higher in the control group (27–92-folds higher during days 14–19 post challenge with the wild the strain) as compared to the vaccinated dogs. The use of azithromycin was assessed as a therapeutic agent for the acute disease. Four days treatment resulted in further deterioration of the clinical condition of the dogs. Molecular comparison of 4 genes known to express immunoreactive proteins and virulence factors (p30, gp19, VirB4 and VirB9) between the attenuated strain and the challenge wild strain revealed no genetic differences between the strains. The results of this study indicate that the attenuated E. canis strain may serve as an effective and secure future vaccine for canine ehrlichiosis.