Enhanced external counterpulsation improves common carotid artery blood flow in sudden cardiac arrest dogs

AIM: To investigate the effects of enhanced external counterpulsation (EECP) on intracranial pressure (ICP), cerebral perfusion pressure (CPP), common carotid artery blood flow following sudden cardiac arrest (SCA) and successful return of spontaneous circulation (ROSC) by cardiopulmonary resuscitation (CPR) in dogs. METHODS: Dog SCA model was induced with alternating current, then 10 dogs were randomly divided into EECP group (n=6) and control group (n=4) after successful ROSC. The arterial blood pressure (BP), quantity of right common carotid artery blood flow (Q) and intracranial pressure (ICP) were measured. Cerebral perfusion pressure (CCP) equaled to BP minus ICP. Resistance of common carotid artery equaled to mean BP/mean Q. RESULTS: The animal model of SCA-ROSC in 10 dogs were successfully established. No significant difference of mean blood pressure (MBP), maximum systolic pressure (MSP), mean ICP, systolic ICP, diastolic ICP, mean CPP and maximum systolic CPP at all time points between the 2 groups was observed. Compared with control group, the maximum diastolic pressure (MDP) and maximum diastolic CPP was significantly elevated, the resistance of common carotid artery was significantly decreased, and right common carotid artery blood flow was significantly increased in EECP group. CONCLUSION: EECP does not affect MBP, MSP, ICP, mean CPP and systolic CPP,but improves common carotid artery blood flow possibly by increasing diastolic BP, diastolic CPP and reducing the resistance of common carotid artery or other mechanisms.     

Cardiopulmonary bypass influences the plasma levels of calcitonin gene-related peptides in dogs: effects of hemofiltration and hemodilution

Calcitonin gene-related peptides (CGRP), which are potent vasodilators, are elevated during cardiopulmonary bypass (CPB) in humans. We evaluated the plasma levels of CGRP in dogs during CPB with hemofiltration with and without hemodilution. Female beagles were divided into control (n=5) and hemodilution (n=5) groups. The CPB with hemofiltration was performed with or without hemodilution. For the measurement of CGRP, blood samples were collected pre-CPB, during CPB, and post-CPB. The concentrations of CGRP in the hemofiltration solution were measured. Although the CPB elevated the plasma CGRP levels in both groups, its elevation was significant in the hemodilution group when compared to the pre-CPB levels. CGRP levels returned to normal post-CPB. Significant differences were found between the two groups in the CGRP amount in hemofiltration. The results show that hemofiltration should be used during CPB to decrease the plasma levels of CGRP.     

Angiostrongylus vasorum and Eucoleus aerophilus in foxes (Vulpes vulpes) in Great Britain

The nematode parasite Angiostrongylus vasorum is a source of increasing concern in several parts of the world, where it causes significant disease in dogs. Wild canids, especially foxes, are likely to have a role in the epidemiology of canine infection, and the parasite could also affect fox health and population dynamics. The heart and pulmonary vasculature of 546 foxes culled mostly by gamekeepers in Great Britain in 2005–2006 were examined by dissection and a modified flushing technique. Forty foxes were found to be infected, giving an overall prevalence in the UK fox population of 7.3% (5.3–9.9). Prevalence varied widely between regions, from 0% (0–3) in Scotland and northern England to 23% (16–32) in south-east England. This closely matches the perceived incidence of disease in dogs, which is commonly diagnosed in the south-east but rarely in the north. In the Midlands, where disease has recently appeared in dogs, prevalence in foxes was 4.8% (2–11). Close geographical overlap of parasite distribution in foxes and dogs does not necessarily indicate an important wildlife reservoir of infection, but does suggest that A. vasorum might be spreading northwards. The hearts of infected foxes had thicker right ventricles than those of uninfected foxes, suggesting that the parasite could affect fox health and fitness. Burdens ranged from 1 to 59 adult nematodes. Sex, age and body condition were not significantly associated with infection. Eucoleus aerophilus and Crenosoma vulpis, nematode parasites of the respiratory system, were found in 213 and 11 foxes respectively, with slightly higher prevalence of E. aerophilus in the south and east. No specimens of the heartworm Dirofilaria immitis were found, giving an upper 95% confidence interval for prevalence of 0.84%.     

Effects of cell-cycle arrest agents on cleavage and development of loach (Misgurnus anguillicaudatus) embryos

The aim of this study was to determine the lowest concentration of nocodazole and colchicine to arrest blastomere division during the cleavage stage of loach embryos and to assess the reversibility and toxicity of the treatments in the treated embryos. Eight-cell loach embryos were incubated for 4, 8, 12, or 16 h in 1/10× Holtfreter supplemented with either nocodazole, an inhibitor of tubulin polymerization, or colchicine, an inhibitor of tubulin assembly. Complete arrest of cell cycle was observed, at a colchicine concentration of 0.996 mM and at a nocodazole concentration of 0.275 μM, respectively (the lowest effective concentration). No major morphological alteration in chromatin was observed. Reversibility and toxicity of both agents were dose and exposure period dependent. For both agents, prolonging cleavage arrest for more than 4 h (at the effective concentrations) is detrimental to development of embryos. Nocodazole treatment was less cytotoxic, whereas the concentrations of colchicine which induce cleavage arrest were detrimental to development beyond the blastula stage. Toxic effects beyond the blastula stage could be minimized for both agents by reducing the period of treatment and concentration. This revised version was published online in August 2006 with corrections to the Cover Date.     

Electrocardiographic findings in miniature schnauzers with syncope

Objective: The purpose of this study was to examine a population of miniature schnauzers exhibiting syncope as their primary presenting complaint and to correlate their electrocardiographic (ECG) findings with the criteria for the diagnosis of sick sinus syndrome (SSS) reported in the human and veterinary literature. Design: Retrospective study. Patients: Case records of 31 miniature schnauzers with syncope during the period 1996–2000 were reviewed. Measurements and results: This study supported two previous studies finding that females were more predisposed to ECG abnormalities associated with SSS than males. It was also noted that females were slightly older (10.1 years) when compared to males (8.9 years) at the time of diagnosis. A heart murmur was present in 61% of the dogs and this was most likely secondary to mitral valve endocardiosis and regurgitation. The primary rhythm disturbance seen was sinus arrest/sinoatrial block in 48.5% of the cases; sinus bradycardia was the second most common arrhythmia noted. Conclusion: In miniature schnauzers with syncope, SSS should be considered as a primary etiology if abnormal ECG findings are noted.     

地下工程现浇混凝土加强带设计中应注意的问题

随着现代城市高层建筑的发展,地下工程现浇混凝土加强带的使用日益增多;这不但对施工质量、而且对设计质量也提出了更高的要求;尤其是对地下工程现浇混凝土加强带设计中应注意的问题,更应重视,以确保工程质量。     

Dirofilaria immitis infection in dogs: cardiopulmonary biomarker levels

Cardiopulmonary biomarkers are biological parameters that can be objectively measured and quantified as indicators of pathogenic processes (heartworm disease) or as indicators of response to therapeutic intervention. To determine levels of cardiopulmonary biomarkers in canine dirofilariasis, measurements of cardiac troponin T, cardiac troponin I, myoglobin, and D-dimer concentrations were performed for dogs with and without evidence of adult heartworm infection. The results showed that levels of cardiac troponin T were undetectable in all dogs studied while levels of cardiac troponin I were higher in dogs infected with Dirofilaria immitis. In healthy dogs, levels of myoglobin and D-dimer were below detection limits of the instrument and were significantly higher in heartworm-infected dogs, notably in microfilaremic dogs. The results suggest the possibility of using troponin I and myoglobin as markers for cardiac damage and the D-dimer as a supportive tool for a diagnosis of pulmonary thromboembolism in dogs with cardiopulmonary dirofilariasis.