心力衰竭犬心房电生理特性的研究

为观察心力衰竭 (简称心衰 )犬心房肌电生理特性的改变 ,探讨充血性心衰时心房颤动 (AF)发生机制。选择14只犬随机分为起搏组 (n =7)和假手术组 (n =7) ,在左、右房各缝植 4对电极 ,电极尾端经皮下由犬背部穿出。假手术组犬埋置起搏器后不起搏。起搏组犬置入实验用VOO型起搏器快速心室起搏 (2 2 0次 /分 ) 6周 ,建立心衰犬模型 ,分别于起搏前、起搏 6周后 ,测定心房有效不应期 (AERP)、AERP离散度 (AERPd)、房内和房间传导时间及心房肌传导速度 ,记录AF诱发情况。结果 :①假手术组犬术前与术后比较 ,心功能和心房电生理特性均无明显变化。②心室快速起搏 6周犬AERP较起搏前略延长 ,但差异无显著性。起搏 6周犬AERPd较起搏前明显增大 (4 0 .4±15 .6msvs 2 2 .6± 10 .2ms,P <0 .0 5 )。与起搏前比较 ,起搏 6周犬房内及房间传导时间明显延长 (CTRA5 4 .7± 7.2msvs 33.1± 9.5ms ;CTLA5 2 .3± 8.9msvs 31.7± 6 .3ms ;CTRA LA6 9.7± 8.2msvs 4 2 .8± 7.9ms,P均 <0 .0 5 ) ,心房肌传导速度显著减慢 (CVRA5 4 .8± 7.9cm/svs 90 .7± 8.4cm/s ;CVLA5 7.4± 9.6cm/svs 94 .6± 10 .2cm/s,P均 <0 .0 5 )。③心衰犬AF诱发率、诱发次数、AF持续时间较起搏前明显增加。假手术组犬术前、术后比较AF诱发情况无?     

一种介入技术制作的局灶性脑栓塞溶栓实验模型

目的运用介入技术建立一种能够符合影像学研究和溶栓的局灶性脑栓塞动物模型。材料与方法13只成年家犬,采用随机数字表法分成对照组(A组)3只和实验组10只,实验组又按照导管插入颈内动脉的不同位置分成B、C组,每组各5只,经股动脉插管注入自体动脉血栓制作犬的局灶脑栓塞动物模型。每组分别行数字减影血管造影(DSA)、磁共振扩散加权成像(DWI)扫描、神经功能评分、脑组织病理切片评价效果,并做统计分析。结果A组未见异常改变。B、C组血管实时造影示颈内动脉主干栓塞,B1、B4、B5延迟造影阻塞血管显示再通,B2、B3、C组延迟造影阻塞血管无再通,B、C组模型成功率分别为40%、100%;两组神经功能评分分别为5.2±4.438、7.2±1.923;阻塞血管无再通者DWI1h均出现梗死灶;HE染色:自溶组出现大量神经元细胞坏死性改变,C组神经元细胞形态改变程度较轻,残存细胞数目明显增多。结论运用介入技术导管插入颈内动脉内制作局灶性脑栓塞溶栓实验模型,造模稳定,动物创伤小,适合溶栓实验研究。     

Man’s best friend? Infective endocarditis due to Capnocytophaga canimorsus

Infective endocarditis caused by zoonotic microorganisms is an uncommon clinical entity. A 55-year-old man was diagnosed with endocarditis due to Capnocytophaga canimorsus, a commensal bacterium contained in the saliva of dogs, that involved the aortic and tricuspid valves and was complicated by a para-aortic valve abscess and aorta-to-right atrial fistula. The patient was successfully treated with antibiotic therapy and surgical intervention. C canimorsus endocarditis should be considered in patients with culture-negative endocarditis, particularly in immunosuppressed, asplenic or alcoholic individuals who have recently suffered a dog bite or have had close contact with dogs.     

In Vitro inhibitory potential of decursin and decursinol angelate on the catalytic activity of cytochrome P-450 1A1/2, 2D15, and 3A12 isoforms in canine hepatic microsomes

Danggui is one of the most popular herbal medicines consumed by patients in different clinical settings in Asian countries. In this study, the two major pyranocoumarin compounds extracted from the Korean Angelica gigas root decursin (DC) and decursinol angelate (DA) were examined in vitro with regard to their abilities to inhibit hepatic CYP1A1/2, CYP2D15, and CYP3A12 catalytic activities in canine liver microsomes. The two components were capable of inhibiting CYP1A1/2, CYP2D15, and CYP3A12 catalytic activities, but the potencies varied. DC and DA selectively and noncompetitively inhibited CYP1A1/2 activity, with K _i values of 90.176 and 67.560 μM, respectively. On the other hand, they exhibited slight inhibitory effects on CYP2D15 and CYP3A12 with K _i values of 666.180 and 872.502 μM, 990.500 and 909.120 μM (1’hydroxymidazolam, MDZ1’H), and 802.800 and 853.920 μM (4-hydroxymidazolam, MDZ4H), respectively. Additionally, they showed increased inhibition after preincubation, which suggests the involvement of a mechanism-based inhibition. In sum, this in vitro data should be heeded as a signal of possible in vivo interactions. The use of human liver preparations would considerably strengthen the practical impact of the data generated from this study. The two authors contributed equally to this paper.     

无泵体外肺辅助技术对犬急性呼吸窘迫综合征血流动力学的影响

目的 探讨无泵型体外肺辅助技术（Pecla）对犬急性呼吸窘迫综合征（ARDS）模型血流动力学的影响,寻找安全的分流范围.方法 建立犬ARDS模型,连接Pecla装置,将12只杂种犬随机分为两组,A组采用心排量的25%,20%,15%,10%的分流量顺序进行分流,B组采用心排量的10%,15%,20%,25%的分流量顺序进行分流,各分流量持续1小时,分别记录Pecla模型在模型建成后稳定一小时和各分流量末时的体循环血压,心率,肺循环血压.结果 两组的体循环血压,心率,肺循环血压均有轻度变化,但无显著差异（P＞0.05）.结论 Pecla使用25%的分流量不会对血流动力学产生严重影响.     

Novel After-loading Interstitial Photodynamic Therapy of Canine Transmissible Sarcoma with Photofrin II and Excimer Dye Laser

Novel after-loading interstitial photodynamic therapy was performed in a canine transmissible sarcoma (CTS) model, utilizing photofrin II and an excimer dye laser. First, photofrin II was injected intravenously at a dose of 5 mg/kg, then 48 h later, laser-proof plastic tubing was inserted into the CTS, followed by photoradiation of the tumor from the inside. The mean diameter of tumor necrosis rapidly increased in parallel with increase in total irradiation energy below 240 J/cm; the mean diameter of tumor necrosis was 20.7 mm at an energy of 120 J/cm, and 24.5 mm at 240 J/cm. Beyond 240 J/cm, the diameter gradually increased to 26 mm at 960 J/cm. As a side effect, cutaneous tissue showed a deep open ulcer at 240 J/cm, a shallow open ulcer at 180 J/cm, and a scar healing at 120 J/cm. The thermal effect of laser light is considered negligible below 480 J/cm.     

Phase-dependent expression of matrix metalloproteinases and their inhibitors in demyelinating canine distemper encephalitis

Matrix metalloproteinases (MMPs) are zinc- and calcium-dependent enzymes that cleave molecules of the extracellular matrix, and thus are able to open the blood-brain-barrier and affect myelin. Their inhibitors (TIMPs) are important candidates for the therapy of demyelinating diseases. To establish an immunohistochemical profile of MMP and TIMP expression in plaque variants in dogs with spontaneous demyelinating distemper encephalitis, paraffin-embedded cerebella were studied employing the avidin-biotin-peroxidase complex method with a panel of nine polyclonal (anti-MMP-1, -3, -7, -9, -12, -13, -14, -TIMP-1, and -2) and two monoclonal antibodies (anti-latent MMP-2, and -MMP-11). All MMPs and TIMPs were prominently up-regulated in acute and subacute non-inflammatory lesions, and double-labeling techniques showed that they were mainly expressed by astrocytes and brain macrophages/microglia. In subacute inflammatory and chronic plaques, a moderate to strong decrease of MMP and TIMP expression compared to acute lesions was observed. In these phases MMP-11, -12, and -13 were still moderately present. In addition to astro- and microglia, invading perivascular mononuclear cells were positive for MMPs and TIMPs. In summary, there seems to be a phase-dependent expression of MMPs and TIMPs in demyelinating canine distemper encephalitis, and an MMP-TIMP imbalance might account for the lesion progression in this disease.     

免疫酶标法检测犬脑组织狂犬病毒的实验研究

目的 用免疫酶标技术对犬脑组织狂犬病毒抗原进行分析。方法 应用单克隆抗体和免疫酶标技术标记犬脑组织中狂犬病毒抗原。结果 在以HE法检测全部阴性的48例狗脑组织中，有2例呈阳性反应，阳性率为4.17％。大脑、海马区出现明显的弥漫型和局灶型阳性颗粒，结论 免疫组化单克隆抗体标记狂犬病毒其敏感度高，可提高狂犬病毒的诊断率；对研究狂犬病毒在犬脑组织神经细胞的分布有一定的意义。     

上颌尖牙及矫治器三维有限元模型的建立

目的:建立上颌尖牙的三维有限元模型,为分析上颌尖牙的生物力学性质提供数字模型.方法:螺旋CT扫描原始模型,运用Mimics软件对DICOM数据进行三维影像重建,将处理后的数据导人到PRO/E wildfire 2.0,建立尖牙牙体、牙周膜、牙槽骨以及矫治器的实体模型.采用MSC.Patran进行网格划分、参数设定,获得上颌尖牙的三维有限元模型.结果:建立了左侧上颌尖牙的三维有限元模型.建成的模型具有良好的形态,模型包括牙体、牙周膜、牙槽骨、托槽、弓丝、标尺.该模型采用四面体单元划分,共有节点36528个,组成219690个单元.结论:建立上颌尖牙的三维有限元模型,该模型结构完整,层次清晰,具有良好的几何相似性,可以满足对上颌尖牙进行各种力学分析的需要.     

Instrumented measurement of in vivo anterior-posterior translation in the canine knee to assess anterior cruciate integrity.

This study was designed to objectively quantify in vivo anterior-posterior canine knee translation relative to anterior cruciate ligament (ACL) integrity. Tibial translation was determined in one knee of 43 crossbreed hounds from radiographs performed while a set anterior and then posterior force was applied to the tibia using a custom designed device. The total (TTT), anterior (ATT), and posterior (PTT) tibial translation were measured (absolute) and normalized to the width of the tibia (normalized). Absolute and normalized TTT was significantly greater in ruptured ACL knees than in partially disrupted (PD) ACL knees, which were significantly greater than in intact ACL knees. ATT and PTT was significantly greater in ruptured ACL knees than in PD or intact ACL knees, which were not significantly different. The sensitivity and specificity of normalized TTT to distinguish knees with intact from PD ACLs were both 100%. Normalized TTT to distinguish knees with PD from ruptured ACLs had a sensitivity and specificity of 100% and 92%, respectively. Intra- and inter-observer intra-class correlation coefficients were 0.84 or higher for all translations. This precise non-invasive technique to assess canine knee translational stability and ACL integrity permits repetitive, objective measurements for diagnostic use and to assess therapeutic intervention efficacy.