This study was conducted to evaluate the usefulness of coronary arterial profiles from normal dogs (11 animals) and canines (six dogs) with experimental myocardial infarction (MI) induced by ligation of the left coronary artery (LCA). Blood velocity of the LCA and right coronary artery (RCA) were evaluated following transthoracic pulsed-wave Doppler echocardiography. The LCA was observed as an infundibular shape, located adjacent to the sinus of Valsalva. The RCA appeared as a tubular structure located 12 o'clock relative to the aorta. In normal dogs, the LCA and RCA mean peak diastolic velocities were 20.84 +/- 3.24 and 19.47 +/- 2.67 cm/sec, respectively. The LCA and RCA mean diastolic deceleration times were 0.91 +/- 0.14 sec and 1.13 +/- 0.20 sec, respectively. In dogs with MI, the LCA had significantly (p < 0.01) lower peak velocities (14.82 +/- 1.61 cm/sec) than the RCA (31.61 +/- 2.34 cm/sec). The RCA had a significantly (p < 0.01) rapid diastolic deceleration time (0.71 +/- 0.06 sec) than that found in the LCA (1.02 +/- 0.22 sec) of MI dogs. In conclusion, these profiles may serve as a differential factor for evaluating cardiomyopathy in dogs.
Animals ; Blood Flow Velocity/*veterinary ; Coronary Vessels/surgery/*ultrasonography ; Dog Diseases/*diagnosis ; Dogs/*physiology ; Echocardiography, Doppler, Pulsed/standards/*veterinary ; Female ; Male ; Myocardial Infarction/diagnosis/*veterinary

OBJECTIVETo observe and compare the effects of two kinds of lung recruitment maneuvers, namely sustained inflation (SI) and incremental positive end-expiratory pressure (PEEP) (IP) on oxygenation, respiratory mechanics, and hemodynamics of dogs with severe smoke inhalation injury.

METHODSAfter being treated with conventional mechanical ventilation, 12 dogs were inflicted with severe smoke inhalation injury. They were divided into group SI and group IP according to the random number table, with 6 dogs in each group. Dogs in group SI were subjected to continuous positive airway pressure ventilation, with inspiratory pressure of 25 cmH2O (1 cmH2o = 0. 098 kPa), and it was sustained for 20 s. PEEP level in group IP was gradually increased by 5 cmH2O every 5 min up to 25 cmH2O, and then it was decreased by 5 cmH2O every 5 min until reaching 2-3 cmH2O. Then the previous ventilation mode was resumed in both groups for 8 hours. Blood gas analysis (pH value, PaO2, and PaCO2), oxygenation index (OI), respiratory mechanics parameters [peak inspiratory pressure (PIP), mean airway pressure, and dynamic lung compliance], and hemodynamic parameters [heart rate, mean arterial pressure (MAP), pulmonary arterial pressure (PAP), and cardiac output (CO)] were recorded or calculated before injury, immediately after injury, and at post ventilation hour (PVH) 2, 4, 6, 8. Data were processed with analysis of variance of repeated measurement and LSD-t test.

RESULTS(1) At PVH 6 and 8, pH values of dogs in group SI were significantly lower than those in group IP (with t values respectively 2. 431 and 2. 261, P values below 0.05); PaO2 levels in group SI [(87 ± 24), (78 ± 14) mmHg, 1 mmHg =0. 133 kPa] were lower than those in group IP [ (114 ± 18) , (111 ± 17) mmHg, with t values respectively 2. 249 and 3.671, P <0.05 or P <0.01]; OI values in group SI were significantly higher than those in group IP (with t values respectively 2.363 and 5.010, P <0.05 or P <0.01). No significant differences were observed in PaCO2 level within each group or between the two groups (with t values from 0. 119 to 1. 042, P values above 0.05). Compared with those observed immediately after injury, the pH values were significantly lowered (except for dogs in group IP at PVH 6 and 8, with t values from 2.292 to 3.222, P <0.05 or P <0.01), PaO2 levels were significantly elevated (with t values from 4. 443 to 6.315, P <0.05 or P <0.01), and OI values were significantly lowered (with t values from 2.773 to 9.789, P <0.05 orP <0.01) in both groups at all the treatment time points. (2) The PIP level at each time point showed no significant differences between two groups (with t values from 0. 399 to 1. 167, P values above 0. 05). At PVH 4 and 8, the mean airway .pressure values of dogs in group SI were significantly higher than those in group IP (with t values respectively 1.926 and 1. 190, P values below 0.05). At PVH 4, 6, and 8, the dynamic lung compliance levels of dogs in group SI [(9.5 ± 1.9), (12.8 ± 2. 1), (13. 1 ± 1.8) mL/cmH2O] were significantly lower than those in group IP [(11.6 ± 1.2), (15.4 ± 1.8), (14.9 ± 0.8) mL/cmH2O], with t values respectively 2. 289, 2. 303, 2. 238, P values below 0.05. Compared with those observed immediately after injury, PIP and the mean airway pressure values of dogs in two groups were significantly lowered at each treatment time point (with t values from 2. 271 to 7. 436, P <0. 05 or P < 0.01); the dynamic lung compliance levels were significantly elevated in both groups at PVH 6 and 8 (with t values from 2. 207 to 4. 195, P < 0.05 or P <0.01). (3) Heart rate, MAP, and PAP levels at each time point between two groups showed no significant differences (with t values from 0. 001 to 1. 170, P values above 0. 05). At PVH 4, 6, and 8, CO levels in group IP [(0. 6 + 0. 3), (0. 6 + 0. 4), (0. 5 + 0. 7) L/min] were significantly lower than those in group SI [(1.5 0.7), (1.8 + 1.1), (1.6 +0.9) L/min], with t values respectively 3. 028, 2.511, 2.363, P values below 0.05. Compared with that observed immediately after injury, CO level in group IP was significantly lowered at PVH 4, 6, or 8 (with t values respectively 2. 363, 2. 302, 2. 254, P values below 0. 05).

CONCLUSIONSBoth lung recruitment maneuvers can effectively improve oxygenation and lung compliance of dogs with severe smoke inhalation injury. IP is more effective in improving lung compliance, while SI shows less impact on the hemodynamic parameters.

Animals ; Blood Gas Analysis ; veterinary ; Dogs ; Hemodynamics ; Lung Compliance ; physiology ; Oxygen ; blood ; Oxygen Consumption ; physiology ; Positive-Pressure Respiration ; methods ; Respiration, Artificial ; Respiratory Mechanics ; Severity of Illness Index ; Smoke ; adverse effects ; Smoke Inhalation Injury ; physiopathology ; therapy

Alternative sources of mesenchymal stem cells (MSCs) for replacing bone marrow (BM) have been extensively investigated in the field of bone tissue engineering. The purpose of this study was to compare the osteogenic potential of canine MSCs derived from adipose tissue (AT), BM, umbilical cord blood (UCB), and Wharton's jelly (WJ) using in vitro culture techniques and in vivo orthotopic implantation assays. After canine MSCs were isolated from various tissues, the proliferation and osteogenic potential along with vascular endothelial growth factor (VEGF) production were measured and compared in vitro. For the in vivo assay, MSCs derived from each type of tissue were mixed with beta-tricalcium phosphate and implanted into segmental bone defects in dogs. Among the different types of MSCs, AT-MSCs had a higher proliferation potential and BM-MSCs produced the most VEGF. AT-MSCs and UCB-MSCs showed greater in vitro osteogenic potential compared to the other cells. Radiographic and histological analyses showed that all tested MSCs had similar osteogenic capacities, and the level of new bone formation was much higher with implants containing MSCs than cell-free implants. These results indicate that AT-MSCs, UCB-MSCs, and WJ-MSCs can potentially be used in place of BM-MSCs for clinical bone engineering procedures.
Adipocytes, White/cytology/physiology ; Alkaline Phosphatase/metabolism ; Animals ; Biocompatible Materials/metabolism/*therapeutic use ; Bone Diseases/*therapy ; Bone Marrow Cells/cytology/physiology ; Calcification, Physiologic ; Calcium/metabolism ; Calcium Phosphates/metabolism/therapeutic use ; Cell Proliferation ; Dogs ; Female ; Fetal Blood/cytology/physiology ; Flow Cytometry ; Male ; Mesenchymal Stromal Cells/cytology/*metabolism ; *Osteogenesis ; Polyesters/metabolism/therapeutic use ; Tissue Engineering/*methods ; Vascular Endothelial Growth Factor A/metabolism

This paper is aimed to investigate the signal source and influential factors in signals of trans-esophageal pulse oxygen saturation (SeO2). The red light of the SeO2 probe was faced directly to the descending aorta (DA) of the mongrel dogs. The readings and waveform of SeO2 signals were recorded under following conditions: before and after DA was shield; before and after the blood supply of esophagus was cut off; under the different touch pressures between the SeO2 probe and the esophageal wall. The readings and waveform of SeO2 signals were also recorded respectively at both different esophageal depth and directions when mechanical ventilation was on and off. The tongue oxygen saturation (StO2) was recorded simultaneously as control. The waveform of SeO2 signals disappeared after DA was shield (P < 0.001). No significant difference was found in the SeO2 signals before and after the blood supply of esophagus was cut off (P > 0.05). Compared with the StO2 readings when the SeO2 probe was placed at different esophageal depth, the waldeyer ring, cervical area and thoracic inlet,the readings of SeOz significantly decreased (P < 0.05) while mechanical ventilation was on and off. However, there was no significant difference in the readings between SeO2 signals from DA, aortic arch (AA) and left subclavian artery and the StO2 signals recorded simultaneously. Mechanical ventilation had a remarkable effect on the SeO2 signals at different esophageal depth (P < 0.05), but the StO2 signals lay in its insensitivity to its influence. The readings of StO2 signals were significantly different from that of StO2 signals when the touch pressure between the SeO2 probe and the esophageal wall below 40 mmHg (P < 0.01). The directions of the optimum SeO2 signals acquired at different esophageal depth were not the same. The SeO2 signals were primarily derived from deeper arteries around the esophagus. All of Mechanical ventilation, location of the SeO2 probe in the esophagus and the touch pressure between the probe and esophageal wall can influence SeO2 signals.
Animals ; Aorta, Thoracic ; physiology ; Biosensing Techniques ; instrumentation ; methods ; Blood Gas Analysis ; instrumentation ; methods ; Dogs ; Esophagus ; blood supply ; Female ; Male ; Oximetry ; instrumentation ; methods ; Oxygen ; blood ; Signal Processing, Computer-Assisted

The present paper aims to investigate the relation between characteristic parameters of transesophageal photoelectric pulse wave in descending aorta and ambulatory artery blood pressure. The chests of ten adult experimental dogs were performed to take the photoelectric pulse wave of descending aorta transesophageally. The concurrent femoral artery invasive blood pressure was recorded simultaneously. Stepwise regression analysis method was used to study the correlation efficient between characteristic parameters of descending aorta pulse wave (H, h, h/H, g/H, At, s, H(1 + ts/td), k)and invasive artery blood pressure. The characteristic parameters, k and h/H (ratio: 90% and 80%) was proved that they had good correlation with systolic pressure; and k, H and s (ratio: 90%, 80% and 70%), had good correlation with diastolic pressure; while k and H (ratio: 90% for both) had good correlation with mean pressure. The mean values of multiple correlation coefficients of the selected characteristic parameters of descending aorta pulse wave with systolic pressure, diastolic pressure and mean pressure of femoral artery were 0.871, 0.900 and 0.856, respectively. The characteristic parameters of descending aorta pulse wave had specific correlation with systolic pressure, diastolic pressure and mean pressure.
Animals ; Aorta, Thoracic ; physiology ; Blood Pressure ; physiology ; Blood Pressure Monitoring, Ambulatory ; methods ; Dogs ; Electrophysiologic Techniques, Cardiac ; methods ; Female ; Femoral Artery ; physiology ; Male ; Pulse Wave Analysis ; methods ; Regression Analysis

OBJECTIVETo explore the protective effect and the mechanism of controlled hypotension induced by transcutaneous electrical acupoint stimulation (TEAS) combined with general anesthesia.

METHODSSixteen male Beagles were randomly divided into a group of controlled hypotension induced by simple general anesthesia (control group) and a group of controlled hypotension induced by TEAS combined with general anesthesia (observation group). All the animals were administered with combination of Isoflurane and Sodium Nitroprusside (SNP) for controlled hypotension without TEAS until the arterial pressure was lowered to 30% basic mean arterial pressure (MAP) for 60 min. In the observation group, TEAS (2 Hz/100 Hz, 3-5 mA) was applied to "Hegu" (LI 4) "Zusanli" (ST 36), "Sanyinjiao" (SP 6) and "Quchi" (LI 11) from the beginning of physiological conditions stability to the end of maintained low MAP for 60 min, but there was no TEAS in control group. The changes of MAP, the left intraventricular pressure (LIVP), T wave and ST-T segment of II lead electrocardiogram (ECG) were monitored with the physiological signal acquisition system, and myocardial apoptosis was detected by TUNEL method.

RESULTSAll the animals could maintain stable required low blood pressure. At one hour after cease of controlled hypotension, MAP of (109.56 +/- 6.14) mmHg returned to the basic level in the observation group, while MAP of (84.91 +/- 6.36) mmHg was still lower than its basic MAP of (111.02 +/- 4.15) mmHg in the control group (P < 0.05), showing significant difference in MAP between the two groups (P < 0.05). -dp/dtmax of (3156.32 +/- 332.82) mmHg/s showed significant lower than its basic value of (4585.33 +/- 638.55) mmHg/s when blood pressure increased for 1 h in the control group (P < 0.05), but there was no difference in the observation group. When the objective low MAP maintaining for 60 min the ST segment was decreased significantly in the control group (P < 0.05), but there was no difference in the observation group. The numbers of positive apoptosis cardiocytes in the observation group were (24.67 +/- 2.45) cells/mm2, which were significantly fewer than (37.89 +/- 1.90) cells/mm2 in the control group (P < 0. 05).

CONCLUSIONSTEAS combined with general anesthesia for controlled hypotension can significantly shorten restoration time of MAP, help to improve myocardial ischemia and the cardiac functional recovery and reduce myocardial apoptosis so as to produce myocardial protection.

Acupuncture Points ; Anesthesia, General ; Anesthetics, General ; pharmacology ; Animals ; Blood Pressure ; drug effects ; Dogs ; Heart ; drug effects ; physiology ; Humans ; Hypotension, Controlled ; Male ; Models, Animal ; Random Allocation ; Transcutaneous Electric Nerve Stimulation

This study aimed to assess the influence of lobectomy and pneumonectomy on cardiac rhythm and on the dimensions and function of the right-side of the heart. Twelve dogs undergoing lobectomy and eight dogs undergoing pneumonectomy were evaluated preoperatively and one month postoperatively with electrocardiography and Doppler echocardiography at rest. Pulmonary artery systolic pressure (PASP) was estimated by the tricuspid regurgitation jet (TRJ) via the pulse wave Doppler velocity method. Systemic inflammatory response syndrome criteria (SIRS) were also evaluated based on the clinical and hematological findings in response to lobectomy and pneumonectomy. Following lobectomy and pneumonectomy, we predominantly detected atrial fibrillation and varying degrees of atrioventricular block (AVB). Dogs that died within seven days of the lobectomy (n = 2) or pneumonectomy (n = 1) had complete AVB. Preoperative right atrial, right ventricular, and pulmonary artery dimensions increased gradually during the 30 days (p<0.05) following pneumonectomy, but did not undergo significant changes during that same period after lobectomy. Mean PASP was 56.0 +/- 4.5 mmHg in dogs having significant TRJ after pneumonectomy. Pneumonectomy, but not lobectomy, could lead to increases (p<0.01) in the SIRS score within the first day post-surgery. In brief, it is important to conduct pre- and postoperative cardiac evaluation of dogs undergoing lung resections because cardiac problems are a common postoperative complication after such surgeries. In particular, complete AVB should be considered a life-threatening complication after pneumonectomy and lobectomy. In addition, pneumonectomy appears to increase the likelihood of pulmonary hypertension development in dogs.
Animals ; Atrial Fibrillation/diagnosis/veterinary ; Atrioventricular Block/diagnosis/*veterinary ; Blood Pressure/physiology ; Dogs ; Echocardiography/veterinary ; Electrocardiography/veterinary ; Pneumonectomy/adverse effects/*veterinary ; Postoperative Care/methods/*veterinary ; Postoperative Complications/diagnosis/*veterinary ; Preoperative Care/methods/*veterinary ; Systemic Inflammatory Response Syndrome/diagnosis/etiology/veterinary ; Tricuspid Valve Insufficiency/diagnosis/etiology/veterinary

PURPOSE: Photoplethysmography (PPG) is a noninvasive optical technology that detects changes in blood volume in the vascular system. This study aimed to investigate the possibilities of monitoring the cardiovascular system status by using PPG. MATERIALS AND METHODS: Forced hemodynamic changes were induced using cardiac stimulants; dopamine and epinephrine, and PPG components were recorded by a noninvasive method at the peripheral blood vessels. The results were compared among 6 dogs. Endotracheal intubation was performed after an intramuscular injection of 25 mg/kg ketamine sulfate, and anesthesia was maintained with 2% enflurane. After stabilizing the animals for 15 min, 16 mg/mL diluted dopamine was injected into a vein for 2 min at 20 microgram/kg.min(-1) by using an infusion pump. Thereafter, the infusion pump was stopped, and 1 mg epinephrine was injected intravenously. Fluid administration was controlled to minimize preload change in blood pressure. RESULTS: After stimulant administration, systolic blood pressure (SBP) and diastolic blood pressures (DBP) increased. The direct current (DC) component, which reflects changes in blood volume, decreased while the alternating current (AC) component, which reflects changes in vascular compliance and resistance, increased. The correlation coefficient between SBP and the foot of the DC component was 0.939 (p < 0.01), while it was 0.942 (p < 0.01) for DBP and the peak of the DC component. The AC component could predict the increase in vascular resistance from a stable pulse blood volume, even with increased pulse pressure. Conclusions: These results support the possibility that PPG components may be used for easy and noninvasive measurement of hemodynamic changes in the cardiovascular system.
Animals ; Blood Pressure/*physiology ; *Blood Pressure Monitors ; Dogs/*physiology ; Humans ; Models, Animal ; Photoplethysmography/*methods

Human umbilical cord blood-derived mesenchymal stem cells (MSCs) are known to possess the potential for multiple differentiations abilities in vitro and in vivo. In canine system, studying stem cell therapy is important, but so far, stem cells from canine were not identified and characterized. In this study, we successfully isolated and characterized MSCs from the canine umbilical cord and its fetal blood. Canine MSCs (cMSCs) were grown in medium containing low glucose DMEM with 20% FBS. The cMSCs have stem cells expression patterns which are concerned with MSCs surface markers by fluorescence-activated cell sorter analysis. The cMSCs had multipotent abilities. In the neuronal differentiation study, the cMSCs expressed the neuronal markers glial fibrillary acidic protein (GFAP), neuronal class III beta tubulin (Tuj-1), neurofilament M (NF160) in the basal culture media. After neuronal differentiation, the cMSCs expressed the neuronal markers Nestin, GFAP, Tuj-1, microtubule-associated protein 2, NF160. In the osteogenic & chondrogenic differentiation studies, cMSCs were stained with alizarin red and toluidine blue staining, respectively. With osteogenic differentiation, the cMSCs presented osteoblastic differentiation genes by RT-PCR. This finding also suggests that cMSCs might have the ability to differentiate multipotentially. It was concluded that isolated MSCs from canine cord blood have multipotential differentiation abilities. Therefore, it is suggested that cMSCs may represent a be a good model system for stem cell biology and could be useful as a therapeutic modality for canine incurable or intractable diseases, including spinal cord injuries in future regenerative medicine studies.
Animals ; *Cell Differentiation ; Chondrogenesis ; Dogs/blood/*physiology ; Fetal Blood/*cytology ; Mesenchymal Stem Cells/*cytology ; Neurons/cytology ; Osteogenesis

OBJECTIVETo evaluate the relationship between myocardial systolic, diastolic functions and perfusion in coronary artery stenosis using velocity vector imaging (VVI) and myocardial contrast echocardiography (MCE).

METHODSStenoses in the anterior descending branch of the coronary artery were induced in 8 dogs. Before and after coronary artery stenosis, two-dimensional images of the left ventricular mastoid muscle section on the short axis at rest and in the peak dose of dobutamine were obtained for evaluation of VVI and MCE. The myocardial blood flow A.beta values, peak systolic strain rate (SRsys) and peak diastolic strain rate (SRdia) in the direction of the circumference of the short axis were measured.

RESULTSAt rest, only severe coronary stenosis resulted in significantly lowered SRsys, SRdia and A.beta value of the stenotic bed compared to the values before the stenosis (-1.1-/+0.50 vs -1.62-/+0.50, 1.19-/+0.48 vs 1.75-/+0.51, 0.4-/+0.21 vs 0.80-/+0.47, P<0.05). In stress, SRsys, SRdia and A.beta value of the stenotic bed gradually decreased as coronary stenosis worsened (-4.31-/+1.14 vs -3.20-/+0.98 vs -1.18-/+0.64, 4.51-/+1.13 vs 3.39-/+0.98 vs 1.37-/+0.64. 3.54-/+1.95 vs 1.81-/+0.89 vs 0.82-/+0.42, P<0.05). Both at rest and in stress, good correlations were noted between SRsys and SRdia (r(rest)=0.88, r(stress)=0.96, P<0.01), between SRsys and the standard A.beta values (r(rest)0.56, r(stress)=0.71, P<0.01), and between SRdia and A.beta (r(rest)=0.57, r(stress)=0.72, P<0.01) in the direction of the circumference of the short axis.

CONCLUSIONSUsing VVI and MCE, the changes in myocardial perfusion and the systolic and diastolic functions in the direction of the circumference can be observed dynamically. VVI may help assess the condition of myocardial perfusion by evaluating the systolic and diastolic function.

Animals ; Blood Flow Velocity ; physiology ; Coronary Circulation ; Coronary Stenosis ; complications ; diagnostic imaging ; physiopathology ; Diastole ; Dogs ; Echocardiography ; methods ; Female ; Male ; Myocardial Contraction ; Ventricular Dysfunction, Left ; diagnostic imaging ; etiology ; physiopathology ; Ventricular Function, Left ; physiology