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OBJECTIVE: Cardioplegic solutions are indispensable for open-heart surgeries, including mitral valve repair (MVR), a potentially curative treatment for myxomatous mitral valve disease in dogs. However, procedural methodologies are not fully established, and complications are yet to be comprehensively understood. Cardioplegic solutions contain various substances to protect the myocardium under temporal cardiac arrest. Nevertheless, ventricular fibrillation (VF) occurs as a common complication after releasing the crossclamp. Based on these backgrounds, the search for optimal cardioplegic solutions in dogs undergoing MVR is an urgent issue. This study aims to evaluate the occurrence of VF in dogs treated with blood cardioplegia (BCP) versus crystalloid cardioplegia (CCP) during MVR. ANIMALS: A total of 251 client-owned dogs who underwent MVR from November 2015 to November 2017 were included. METHODS: We retrospectively assessed the relationship between VF and type of cardioplegia (CCP or BCP) based on surgical records, including VF incidence, transfusion use, crossclamp time, and echocardiographic measurements. RESULTS: Logistic regression analysis showed that the CCP group was associated with the occurrence of VF (OR, 2.378; CI, 1.133-4.992; P = .022). In addition, the CCP group was associated with transfusion use (OR, 2.586; CI, 1.232-5.428, P = .022). There was no difference between the groups for the pre- and postoperative echocardiographic measurements. CLINICAL RELEVANCE: The BCP group had a lower incidence of VF and less transfusion use than the CCP group. This finding indicates that BCP may be a superior cardioplegic technique for MVR in dogs.
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Transfusión Sanguínea , Soluciones Cardiopléjicas , Soluciones Cristaloides , Enfermedades de los Perros , Paro Cardíaco Inducido , Válvula Mitral , Fibrilación Ventricular , Perros , Animales , Paro Cardíaco Inducido/métodos , Paro Cardíaco Inducido/veterinaria , Enfermedades de los Perros/prevención & control , Estudios Retrospectivos , Fibrilación Ventricular/veterinaria , Fibrilación Ventricular/prevención & control , Masculino , Femenino , Soluciones Cardiopléjicas/farmacología , Transfusión Sanguínea/veterinaria , Soluciones Cristaloides/administración & dosificación , Soluciones Cristaloides/uso terapéutico , Válvula Mitral/cirugía , Insuficiencia de la Válvula Mitral/veterinaria , Insuficiencia de la Válvula Mitral/cirugíaRESUMEN
Hypoglycemia has not been previously reported as a postoperative complication of mitral valve repair (MVR) in dogs; however, the authors have encountered cases of hypoglycemia after MVR. This study aimed to determine the incidence of hypoglycemia in dogs after MVR and investigate its causes. Blood glucose levels were measured at multiple timepoints in dogs undergoing MVR. Simultaneously, insulin and glucagon blood concentrations in dogs with hypoglycemia preoperatively and postoperatively were compared to verify the physiological responses to hypoglycemia. Furthermore, risk factors for hypoglycemia, using variables selected based on the characteristics of MVR and dogs undergoing MVR, were examined prospectively. The incidence of hypoglycemia after MVR was 14.2%, and plasma glucagon concentrations increased in these dogs (mean: 260 pg/mL and 644 pg/mL pre- and postoperatively, p < 0.001), whereas serum insulin concentrations decreased (median: 0.50 ng/mL and 0.29 ng/mL pre- and postoperatively, p = 0.002). Therefore, hyperinsulinemia or hypoglucagonemia is unlikely to be the cause of postoperative hypoglycemia. The identified risk factors for hypoglycemia included low body weight and asymptomatic myxomatous mitral valve disease. Monitoring blood glucose levels after MVR should be included in the standard hospitalization plan to prevent hypoglycemic emergencies in dogs.
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OBJECTIVE: The Lewis lead is an EGC configuration used to detect atrial activity and its relationship with ventricular activity. However, no equivalent configuration has been proposed in veterinary medicine. Therefore, this study explored new bipolar lead configurations to evaluate atrial depolarization and investigated their characteristics by comparing them with conventional leads. The authors hypothesized that a lead with a high absolute value of the P wave (|P|) and a high ratio of the P wave to the QRS complex (|P|/|QRS|) might be an appropriate configuration. ANIMALS: 6 laboratory Beagles were used. PROCEDURES: Electrocardiograms were recorded using bipolar limb leads (I, II, III, aVL, aVF, and aVR) and unipolar precordial leads (C2, C3, C4, C5, C6, M1, M2, M5, M6, 1st-R, CV6LL, and V10) in the standing position. The new bipolar leads were attached in the following configuration: the negative electrode was attached to M6, and the positive electrode was sequentially applied to M1 and M2. The leads were named M6M1 and M6M2. RESULTS: The waveforms obtained using the new bipolar leads M6M1 and M6M2 showed significantly higher |P|/|QRS| and |P| values than those obtained using conventional limb leads and precordial leads. CLINICAL RELEVANCE: The new leads achieved a specific enhancement of atrial activity conducted at a reduced ventricular amplitude and increased atrial amplitude, similar to the Lewis lead in human medicine. These findings suggest that M6M1 and M6M2 could be supplemental lead configurations to identify P waves without amplifying the QRS waves compared to conventional methods.
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Electrocardiografía , Humanos , Animales , Perros , Electrocardiografía/veterinaria , ElectrodosRESUMEN
In small-breed dogs, myxomatous mitral valve disease (MMVD) is a common disease which may lead to chronic heart failure. Mitral valve repair is an optimal surgical treatment that is currently available in limited veterinary facilities globally because it requires a special surgery team and specific devices. Therefore, some dogs must travel overseas to undergo this surgery. However, a question arises regarding the safety of dogs when traveling by air with a heart disease. We aimed to evaluate the effect of flight journey on dogs with mitral valve disease, including survival rates, symptoms during the trip, laboratory test results, and operational outcomes. All dogs stayed near the owner in the cabin during the flight. The survival rate after the flight was 97.5% in 80 dogs. The surgical survival rates (96.0% and 94.3%) and hospitalization periods (7 days and 7 days) were similar between overseas and domestic dogs. This report shows that taking air flights in the cabin may not have a significant effect on dogs with MMVD, on the premise that their overall conditions are stable under cardiac medication.
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Enfermedades de los Perros , Insuficiencia Cardíaca , Enfermedades de las Válvulas Cardíacas , Perros , Animales , Japón , Enfermedades de los Perros/cirugía , Enfermedades de las Válvulas Cardíacas/cirugía , Válvula MitralRESUMEN
In the typical left-to-right patent ductus arteriosus (PDA), the shunt flows from the ductus arteriosus towards the pulmonary valve. Although hemodynamic changes have been carefully studied in dogs with PDA, there is very little information on the outcomes of the pulmonary valve after surgical correction of PDA. This study aimed to visualize the pulmonary valve by transthoracic echocardiography in dogs with PDA before and after surgical ligation. Prior to surgery, the movement of the anterior semilunar cusp of the pulmonary valve was obstructed by the shunted blood flow during systole in all nine dogs with PDA in this study. M-mode echocardiography revealed a continuous trajectory of the cusp, because the cusp was pushed towards the right ventricle during the whole cardiac cycle by the shunted flow. Epicardial echocardiography performed in one dog during surgical ligation of the ductus arteriosus revealed that the movement of the anterior semilunar cusp normalized immediately after ligation. B- and M-mode echocardiography may be used to support the diagnosis of PDA through observation of the pulmonary valve when color Doppler echography is not available. The findings in this study may be of importance in distinguishing PDA from PDA-mimicking diseases worth considering before the treatment process (e.g. aorticopulmonary fistulas or aberrant arteriovenous shunts).
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Enfermedades de los Perros , Conducto Arterioso Permeable , Discinesias , Válvula Pulmonar , Perros , Animales , Conducto Arterioso Permeable/diagnóstico por imagen , Conducto Arterioso Permeable/cirugía , Conducto Arterioso Permeable/veterinaria , Válvula Pulmonar/diagnóstico por imagen , Ecocardiografía/veterinaria , Sístole , Discinesias/veterinaria , Enfermedades de los Perros/diagnóstico por imagen , Enfermedades de los Perros/cirugíaRESUMEN
Situational syncope, which includes rectally mediated reflexes, is defined as syncope induced by a specific situation. Its pathogenesis generally involves disorders of the autonomic nervous system. However, the mechanisms and preventive strategies are not yet well understood. Therefore, we hypothesized that a tachykinin neurokinin-1 receptor might be involved in the autonomic nervous system, and that a neurokinin-1 receptor antagonist could mitigate reflex syncope. This study used a rat model in which the reflex was induced by afferent vagal stimulation with colorectal distension (CRD). In the study, the rats were divided into three groups: non-CRD, CRD, and CRD with a neurokinin-1 receptor antagonist. First, we examined the effect of fosaprepitant, a neurokinin-1 receptor antagonist, on the circulatory response in this model. We then determined the brain regions that showed increased numbers of c-Fos immunoreactive cells in the respective groups. Our results suggest that the colorectal distension procedure reduced blood pressure and that fosaprepitant lowered this response. In addition, the number of c-Fos immunoreactive cells was increased in the caudal ventrolateral medullary region with colorectal distension, and this number was decreased by the administration of fosaprepitant. In conclusion, fosaprepitant might be involved in the vagal reflex pathway and potentially suppress the circulatory response to colorectal distension.
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Cardiac fibroblasts participate in the inflammatory process of heart diseases as sentinel cells of the cardiac tissue. In this study, we investigated the effect of the proinflammatory cytokine, interleukin 1ß (IL-1ß), on the expression of interleukin 8 (IL-8), which contributes to the induction of innate immunity via the activation and recruitment of innate immune cells, such as neutrophils, to the site of inflammation in canine cardiac fibroblasts. IL-1ß mediates IL-8 mRNA expression and protein release in a dose- and time-dependent manner. The IL-ß-mediated IL-8 protein release and mRNA expression were inhibited by 2-[(aminocarbonyl)amino]-5-(4-fluorophenyl)-3-thiophenecarboxamide, an inhibitor of the transcription factor, nuclear factor (NF)-κB. In cells treated with IL-1ß, NF-κB p65 and p105 were transiently phosphorylated, indicating the activation of NF-κB. However, IL-1ß failed to induce IL-8 mRNA expression in the cells transfected with p65 small interfering RNA (siRNA), but not in those transfected with p105 siRNA. These observations suggest that IL-1ß induces IL-8 expression via the activation of NF-κB p65 in canine cardiac fibroblasts.
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Interleucina-8 , FN-kappa B , Animales , Perros , Fibroblastos/metabolismo , Interleucina-1beta/metabolismo , Interleucina-8/metabolismo , FN-kappa B/metabolismo , ARN Mensajero/metabolismo , ARN Interferente Pequeño/metabolismoRESUMEN
BACKGROUND: In both humans and animals, anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA) is a rare congenital coronary artery anomaly. In veterinary medicine, ALCAPA is reported to be discovered only during autopsy or necropsy, and diagnostic methods and prognosis remain poorly understood in dogs. CASE PRESENTATION: A 6-month-old Kaninchen Dachshund was diagnosed with functional mitral valve regurgitation and ALCAPA. Echocardiography identified anomalous vessels in the left ventricular wall and abnormal origin of the left coronary artery from the pulmonary artery. Further evaluation with coronary computed tomographic angiography demonstrated the left coronary artery arising from the posterior aspect of the main pulmonary artery together with the characteristic findings of ALCAPA. The right coronary artery was found to be dilated and tortuous. Furthermore, dilated coronary collateral arteries within the ventricular septum and along the epicardial surface were observed. The dog underwent surgery, but the origin of the anomalous artery could not be ligated, and it died from pulmonary edema 5 months after surgery. CONCLUSION: Anomalous origin of the left coronary artery from the pulmonary artery is overlooked in clinical practice due to its rarity. Coronary computed tomographic angiography was useful to definitively diagnose ALCAPA in a low-invasive manner. Antemortem diagnosis of ALCAPA was shown to be possible in dogs for the first time, and presence of unexplained mitral valve regurgitation should raise concern to this anomaly.
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Síndrome de Bland White Garland , Enfermedades de los Perros , Animales , Síndrome de Bland White Garland/diagnóstico por imagen , Síndrome de Bland White Garland/veterinaria , Angiografía por Tomografía Computarizada , Enfermedades de los Perros/diagnóstico por imagen , Perros , Ecocardiografía/veterinaria , Arteria Pulmonar/diagnóstico por imagenRESUMEN
OBJECTIVES: Unilateral diaphragmatic paralysis (UDP) due to phrenic nerve injury is a potential complication of thoracic surgery. This study evaluated the prevalence of UDP associated with surgical mitral valve repair (MVR) and its effect on surgical outcomes in dogs. ANIMALS, MATERIALS AND METHODS: Two hundred ninety-four dogs that underwent MVR were included in the study. A retrospective review of medical records was performed for dogs surviving surgery. Diagnosis of UDP was based on preoperative and postoperative thoracic dorsoventral radiographs. RESULTS: A total of 284 dogs survived until the day after surgery. The prevalence of UDP on the day after surgery, on the day of discharge, and after the first postoperative month was 30%, 24%, and 9%, respectively. One case of UDP was observed at 3 months after surgery. Unilateral diaphragmatic paralysis was exhibited by nine of the 21 patients that died in the hospital. The proportion of patients with UDP was higher in dogs that died of respiratory failure than in dogs that died of other causes (p = 0.002). Most dogs whose deaths were suspected to have been related to respiratory failure also had pre-existing respiratory diseases. The occurrence of UDP did not relate to the lengths of stay in the intensive care unit or the hospital. CONCLUSIONS: Our findings suggest that UDP is a common complication in dogs after MVR and that the prevalence of UDP decreases with time after surgery. Unilateral diaphragmatic paralysis is a risk factor for postoperative death, especially in patients with pre-existing respiratory disease.
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Procedimientos Quirúrgicos Cardíacos/veterinaria , Enfermedades de los Perros/cirugía , Válvula Mitral/cirugía , Parálisis Respiratoria/veterinaria , Animales , Procedimientos Quirúrgicos Cardíacos/efectos adversos , Perros , Complicaciones Posoperatorias/veterinaria , Parálisis Respiratoria/epidemiología , Parálisis Respiratoria/etiología , Estudios Retrospectivos , Resultado del TratamientoRESUMEN
BACKGROUND: The Evaluation of pimobendan in dogs with cardiomegaly caused by preclinical myxomatous mitral valve disease (EPIC) study monitored dogs with myxomatous mitral valve disease (MMVD) as they developed congestive heart failure (CHF). OBJECTIVES: To describe the changes in clinical and radiographic variables occurring as dogs with MMVD and cardiomegaly develop CHF, compared to similar dogs that do not develop CHF. ANIMALS: One hundred and thirty-five, and 73 dogs that did or did not develop CHF, respectively. MATERIALS AND METHODS: The following variables were evaluated in 2 groups of dogs (dogs that did or did not develop CHF): Heart rate (HR), clinic respiratory rate (RR), home-measured resting respiratory rate (RRR), rectal temperature (RT), body weight (BW), and vertebral heart sum (VHS). Absolute value and rate of change of each variable were calculated for each day a dog was in study. Daily means were calculated and plotted against time. The onset of CHF or last visit before leaving the study were set as reference time points. RESULTS: The most extreme values and rate of change occurred in variables immediately before onset of CHF. Vertebral heart sum increased earliest. Heart rate, RR, and RRR also increased. Rectal temperature and BW decreased. Increases in RR and RRR were most extreme and occurred immediately before CHF. CONCLUSIONS AND CLINICAL IMPORTANCE: Dogs with MMVD and cardiomegaly experience increases in HR, RR, RRR, and VHS, and decreases in BW and RT as they develop CHF. The variables with highest absolute change and rate of change were RR and RRR. These findings reinforce the value of RR and RRR as indicators of impending or incipient CHF.
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Enfermedades de los Perros/diagnóstico , Insuficiencia Cardíaca/veterinaria , Enfermedades de las Válvulas Cardíacas/veterinaria , Insuficiencia de la Válvula Mitral/veterinaria , Animales , Cardiomegalia/veterinaria , Enfermedades de los Perros/diagnóstico por imagen , Perros , Femenino , Corazón/diagnóstico por imagen , Insuficiencia Cardíaca/complicaciones , Insuficiencia Cardíaca/patología , Frecuencia Cardíaca , Enfermedades de las Válvulas Cardíacas/patología , Masculino , Válvula Mitral/patología , Insuficiencia de la Válvula Mitral/complicaciones , Insuficiencia de la Válvula Mitral/patología , Radiografía Torácica/veterinaria , Frecuencia RespiratoriaRESUMEN
This report, issued by the ACVIM Specialty of Cardiology consensus panel, revises guidelines for the diagnosis and treatment of myxomatous mitral valve disease (MMVD, also known as endocardiosis and degenerative or chronic valvular heart disease) in dogs, originally published in 2009. Updates were made to diagnostic, as well as medical, surgical, and dietary treatment recommendations. The strength of these recommendations was based on both the quantity and quality of available evidence supporting diagnostic and therapeutic decisions. Management of MMVD before the onset of clinical signs of heart failure has changed substantially compared with the 2009 guidelines, and new strategies to diagnose and treat advanced heart failure and pulmonary hypertension are reviewed.
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Enfermedades de los Perros/diagnóstico , Enfermedades de los Perros/terapia , Insuficiencia de la Válvula Mitral/veterinaria , Animales , Perros , Insuficiencia Cardíaca/diagnóstico , Insuficiencia Cardíaca/terapia , Insuficiencia Cardíaca/veterinaria , Hipertensión Pulmonar/diagnóstico , Hipertensión Pulmonar/terapia , Hipertensión Pulmonar/veterinaria , Insuficiencia de la Válvula Mitral/diagnóstico , Insuficiencia de la Válvula Mitral/terapiaRESUMEN
The aim of this study was to evaluate the efficacy of pimobendan with conventional therapies on survival and reocurrence of pulmonary edema in dogs with congestive heart failure (CHF) caused by myxomatous mitral valve disease (MMVD). Records of 197 client-owned dogs from 14 veterinary hospitals were included in this study. Dogs were administered conventional treatments with or without pimobendan. Sixty-four dogs received a standard dose of pimobendan (0.20-0.48 mg/kg every 12 hr (q12hr)), 49 dogs received a low dose of pimobendan (0.05-0.19 mg/kg q12hr), and 84 dogs received conventional therapy alone. Dogs in the standard-dose and low-dose pimobendan groups had significantly longer median survival times than dogs in the conventional group (334, 277 and 136 days, respectively; P<0.001). The reoccurrence rate of pulmonary edema in the standard-dose group was significantly lower than in the low-dose and conventional groups (43%, 59% and 62%, respectively; P<0.05). Combination of pimobendan with a conventional treatment regimen significantly prolonged survival time after an initial episode of pulmonary edema in dogs with CHF caused by MMVD. There was no difference in survival between dogs administered standard and low doses of pimobendan, but pimobendan did prevent the reoccurrence of pulmonary edema in a dose-dependent manner.
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Cardiotónicos/uso terapéutico , Enfermedades de los Perros/prevención & control , Insuficiencia Cardíaca/veterinaria , Insuficiencia de la Válvula Mitral/veterinaria , Edema Pulmonar/veterinaria , Piridazinas/uso terapéutico , Animales , Enfermedades de los Perros/mortalidad , Perros , Femenino , Insuficiencia Cardíaca/etiología , Insuficiencia Cardíaca/mortalidad , Insuficiencia Cardíaca/prevención & control , Masculino , Insuficiencia de la Válvula Mitral/complicaciones , Insuficiencia de la Válvula Mitral/tratamiento farmacológico , Insuficiencia de la Válvula Mitral/mortalidad , Edema Pulmonar/etiología , Edema Pulmonar/mortalidad , Edema Pulmonar/prevención & control , Recurrencia , Estudios Retrospectivos , Análisis de SupervivenciaRESUMEN
BACKGROUND: In heart failure patients, chronic hyperactivation of sympathetic signaling is known to exacerbate cardiac dysfunction. In this study, the cardioprotective effect of vidarabine, an anti-herpes virus agent, which we identified as a cardiac adenylyl cyclase inhibitor, in dogs with pacing-induced dilated cardiomyopathy (DCM) was evaluated. In addition, the adverse effects of vidarabine on basal cardiac function was compared to those of the ß-blocker, carvedilol.MethodsâandâResults:Vidarabine and carvedilol attenuated the development of pacing-induced systolic dysfunction significantly and with equal effectiveness. Both agents also inhibited the development of cardiac apoptosis and fibrosis and reduced the Na+-Ca2+exchanger-1 protein level in the heart. Importantly, carvedilol significantly enlarged the left ventricle and atrium; vidarabine, in contrast, did not. Vidarabine-treated dogs maintained cardiac response to ß-AR stimulation better than carvedilol-treated dogs did. CONCLUSIONS: Vidarabine may protect against pacing-induced DCM with less suppression of basal cardiac function than carvedilol in a dog model. (Circ J 2016; 80: 2496-2505).
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Antivirales/farmacología , Cardiomiopatía Dilatada , Insuficiencia Cardíaca , Vidarabina/farmacología , Animales , Carbazoles/farmacología , Cardiomiopatía Dilatada/tratamiento farmacológico , Cardiomiopatía Dilatada/fisiopatología , Carvedilol , Modelos Animales de Enfermedad , Perros , Femenino , Insuficiencia Cardíaca/tratamiento farmacológico , Insuficiencia Cardíaca/fisiopatología , Herpesviridae , Humanos , Propanolaminas/farmacologíaRESUMEN
There is a severe shortage of donor cornea for transplantation in many countries. Collagenous connective tissue membranes, named BIOSHEETs, grown in vivo were successfully implanted in rabbit corneal stroma for in vivo evaluation of their suitability as a corneal stromal substitute to solve this global donor shortage. BIOSHEETs were prepared by embedding silicone moulds into dorsal subcutaneous pouches in rabbits for 1 month and stored in glycerol. After re-swelling in saline and trephining, disk-shaped BIOSHEETs (4 mm diameter) were allogeneically implanted into stromal pockets prepared in the right cornea of seven rabbits. Clinical tests for corneal thickness and transparency, and tissue analyses were performed. Because the BIOSHEETs (thickness, 131 ± 14 µm) obtained were opaque immediately after implantation, the transparency of the cornea decreased. The total thickness of the BIOSHEET-implanted cornea increased from 364 ± 21.0 µm to 726 ± 131 µm. After 4 weeks' implantation, the thickness of the cornea stabilized (493 ± 80 µm at 4 weeks and 447 ± 46 µm at 8 weeks). The transparency of the cornea increased progressively with time of implantation. The random orientation of collagen fibrils in the original BIOSHEETs tended to be homogeneous, similar to that of the native stroma. No inflammatory cells accumulated and fibroblast-like cells infiltrated the implant. The BIOSHEETs showed high biocompatibility with stromal tissues; however, further studies are needed to test its functional aspects. Although this research is only intended as a proof of concept, BIOSHEETs may be considered a feasible corneal stromal replacement, especially for treating visual impairment caused by stromal haze. Copyright © 2013 John Wiley & Sons, Ltd.
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Córnea/metabolismo , Córnea/cirugía , Fibroblastos/metabolismo , Membranas Artificiales , Ingeniería de Tejidos , Animales , ConejosRESUMEN
UNLABELLED: Currently, there are no reports of inflammatory responses to CPB in dogs. We investigated the time course of pro- and anti-inflammatory cytokine levels during and after CPB. ANIMALS: The study group included 11 dogs that underwent mitral valve repair with CPB, and the control group included 7 healthy dogs that underwent ovariohysterectomy. METHODS: Blood samples from the study group dogs were collected before, during and after surgery and analyzed for plasma levels of interleukin-6 (IL-6), tissue necrosis factor-α (TNF-α), interleukin-10 (IL-10), white blood cells (WBC), and C-reactive protein (CRP). Each inflammatory parameter was also compared with that of the control group dogs. RESULTS: After CPB, plasma levels of IL-6, WBC counts, and CRP levels were significantly higher than preoperative levels, and IL-6 levels in the study group were significantly higher than those in the control group. CONCLUSIONS: CPB induces a systemic inflammatory response in dogs.
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Puente Cardiopulmonar/veterinaria , Citocinas/sangre , Válvula Mitral/cirugía , Síndrome de Respuesta Inflamatoria Sistémica/veterinaria , Animales , Proteína C-Reactiva/metabolismo , Puente Cardiopulmonar/efectos adversos , Perros , Interleucina-10/sangre , Interleucina-6/sangre , Recuento de Leucocitos/veterinaria , Síndrome de Respuesta Inflamatoria Sistémica/sangre , Síndrome de Respuesta Inflamatoria Sistémica/etiología , Factores de Tiempo , Factor de Necrosis Tumoral alfa/sangreRESUMEN
OBJECTIVE: To compare the diuretic effects of subcutaneous (s.c.) administration of furosemide to conventional methods of administration including intravenous (i.v.), per os (p.o.), and constant rate infusion (CRI) in healthy dogs. DESIGN: Prospective, randomized, cross-over study. SETTING: Veterinary university research facility. ANIMALS: Seven healthy, adult mongrel dogs (3 males, 4 females). INTERVENTION: Each dog in the study was randomly assigned to receive a 2 mg/kg dose of furosemide via a single s.c., i.v., or p.o. dose at the beginning (time 0) of an 8-hour study, or via CRI during an 8-hour study period. Urine was collected by emptying the bladder using an indwelling catheter and blood samples were obtained via venipuncture at time 0 for baseline measurements and at 1, 2, 4, 6, and 8 hours into the study. Hourly urine output was calculated in all dogs for each study. Complete blood count, plasma total protein, blood urea nitrogen, creatinine, and renin concentration were measured for each sample. MEASUREMENTS AND MAIN RESULTS: The s.c. administration of furosemide resulted in a urine output per hour (UOP/h) that peaked at 1 hour with UOP/h returning to baseline at 4 hours after injection. Following i.v. administration, UOP/h also peaked at 1 hour but returned more rapidly to baseline levels at 2 hours after injection. With p.o. administration, UOP/h reached a maximum UOP/h at 2 hours but time to return to baseline levels was prolonged to 6 hours after administration. With CRI administration, the time to the maximum UOP/h was delayed to 4 hours after injection but UOP/h was then maintained throughout the study period. CONCLUSIONS: Total urine output following s.c. administration of furosemide in healthy dogs was similar when compared to the i.v. and p.o. route. Subcutaneous route may be an effective means for administration of furosemide in dogs, particularly when i.v. access is difficult.
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Diuréticos/farmacología , Perros/metabolismo , Furosemida/farmacología , Administración Oral , Animales , Estudios Cruzados , Diuréticos/administración & dosificación , Perros/orina , Esquema de Medicación/veterinaria , Femenino , Furosemida/administración & dosificación , Infusiones Intravenosas/veterinaria , Inyecciones Subcutáneas/veterinaria , Masculino , Estudios ProspectivosRESUMEN
OBJECTIVES: To evaluate the functionality of an autologous heart valve with stent (Stent-biovalve or SBV) after implantation in the pulmonic valve position in beagle dogs. ANIMALS: Five beagle dogs. METHODS: A mold with an aperture of a tri-leaflet structure was constructed from a pair of concave and convex rods to which a nitinol (NiTi) stent was mounted. This mold was embedded in a dorsal subcutaneous pouch in beagle dogs for 4 weeks. At the time of the removal, the surfaces of the molds were completely covered with connective tissues, tri-leaflet valves were formed and the NiTi stent was tightly connected to the structure. RESULTS: The mean burst strength of the SBV leaflet was 2710 mmHg (range 2280-3116 mmHg), which was approximately equal to that of the native pulmonic valve leaflet. After implantation in the pulmonary position, the SBV showed good functionality as a pulmonic valve. At 84 days after implantation, the SBV was replaced with autologous fibroblasts and collagenous tissues, and showed organization similar to that of native heart valves. CONCLUSION: Stent-Biovalves achieved good valvular function with laminar flow in the pulmonic valve position of beagle dogs.
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Bioingeniería/métodos , Bioprótesis , Perros , Ensayo de Materiales , Stents/veterinaria , Animales , Fenómenos Biomecánicos , Tejido ConectivoRESUMEN
We designed a novel method for constructing an autologous heart valve with a stent, called a stent-biovalve. In constructing completely autologous heart valves, named biovalves, which used in-body tissue architecture technology, tissues for leaflets were formed via ingrowths into narrow apertures in the preparation molds, frequently leading to delayed or incomplete biovalve preparation. In this technique, self-expandable nitinol stents after everting were mounted on an acrylic column-shaped part and partially covered with an acrylic cylinder-shaped part with three slits. This assembled mold was placed into subcutaneous abdominal pouches in beagles or goats for 4 weeks. Upon removing the acrylic parts after harvesting and trimming of capsulated tissues, a tubular hollow structure with three pocket-flaps of membranous tissue rigidly fixed to the stent's outer surface was obtained. Then, the stent was turned inside out to the original form, thus moving the pocket-flaps from outside to the inside. Stent-biovalves with a sufficient coaptation area were thus obtained with little tissue damage in all cases. The valve opened smoothly, and high aperture ratio was noted. This novel technique was thus highly effective in constructing a robust, completely autologous stent-biovalve with adequate valve function.
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Aleaciones , Bioprótesis , Prótesis Valvulares Cardíacas , Válvulas Cardíacas/metabolismo , Válvulas Cardíacas/trasplante , Stents , Animales , Autoinjertos , Perros , Femenino , Válvulas Cardíacas/patología , MasculinoRESUMEN
It has been reported that mature adipocyte-derived dedifferentiated fat (DFAT) cells show multilineage differentiation potential similar to that observed in mesenchymal stem cells. Since DFAT cells can be prepared from a small quantity of adipose tissue, they could facilitate cell-based therapies in small companion animals such as cats. The present study examined whether multipotent DFAT cells can be generated from feline adipose tissue, and the properties of DFAT cells were compared with those of adipose-derived stem cells (ASCs). DFAT cells and ASCs were prepared from the floating mature adipocyte fraction and the stromal vascular fraction, respectively, of collagenase-digested feline omental adipose tissue. Both cell types were evaluated for growth kinetics, colony-forming unit fibroblast (CFU-F) frequency, immunophenotypic properties, and multilineage differentiation potential. DFAT cells and ASCs could be generated from approximately 1g of adipose tissue and were grown and subcultured on laminin-coated dishes. The frequency of CFU-Fs in DFAT cells (35.8%) was significantly higher than that in ASCs (20.8%) at passage 1 (P1). DFAT cells and ASCs displayed similar immunophenotypes (CD44(+), CD90(+), CD105(+), CD14(-), CD34(-) and CD45(-)). Alpha-smooth muscle actin-positive cells were readily detected in ASCs (15.2±7.2%) but were rare in DFAT cells (2.2±3.2%) at P1. Both cell types exhibited adipogenic, osteogenic, chondrogenic, and smooth muscle cell differentiation potential in vitro. In conclusion, feline DFAT cells exhibited similar properties to ASCs but displayed higher CFU-F frequency and greater homogeneity. DFAT cells, like ASCs, may be an attractive source for cell-based therapies in cats.
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Adipocitos/citología , Tejido Adiposo/citología , Gatos , Células Madre/citología , Adipocitos/fisiología , Animales , Técnicas de Cultivo de Célula , Desdiferenciación Celular , Femenino , Osteogénesis , Células Madre/fisiología , Andamios del TejidoRESUMEN
The aim of this study was to retrospectively assess the clinical usefulness of plasma atrial natriuretic peptide (ANP) concentrations for determining the severity of myxomatous mitral valve disease (MMVD) in dogs. Plasma ANP levels were found to be significantly higher in dogs with MMVD compared to healthy dogs, and plasma ANP levels increased significantly in dogs with progressive heart failure. In dogs with MMVD, stepwise regression analysis revealed that the left atrium/aorta ratio and fractional shortening could be used to predict the plasma ANP concentration. These results indicated that plasma ANP rose with an increase in the volume overload of the left side of the heart. Plasma ANP discriminated cardiomegaly from non-cardiomegaly caused by asymptomatic MMVD. We conclude, therefore, that plasma ANP concentrations may be a clinically useful tool for early diagnosis of asymptomatic MMVD in dogs.