Effects of different rates of propofol with or without S-ketamine on ventricular function in healthy cats - a randomized study.

Propofol is used for anesthetic induction in cats and procedural sedation in countries where alfaxalone is not available. Studies have reported propofol-related effects in echocardiography variables in dogs and humans. However, there is a lack of echocardiography studies investigating propofol-related effects on cats. This study aimed to use echocardiography to investigate echocardiographic changes in three protocols using propofol: propofol-slow (2 mg/kg/min, PS); propofol-fast (8 mg/kg/min, PF); propofol-ketamine (S-ketamine 2 mg/kg bolus followed by propofol 2 mg/kg/min; PK) in healthy premedicated (gabapentin-buprenorphine-acepromazine; 200 mg/cat, 0.4, and 0.1 mg/kg, respectively), non-intubated cats. Echocardiographic measurements were obtained at three time points: baseline (before the administration of propofol), end of propofol titration (end-point, T0), and 15 min after T0 (T15). Propofol at a lower rate continued from T0 to T15. Echocardiographic and physiological variables included fractional shortening (FS%), ejection fraction (EF%), HR, BP, and others. Propofol requirements at T0 for PF, PS, and PK groups were 5.0 ± 0.9, 3.8 ± 0.7, and 2.4 ± 0.5 mg/kg, respectively. EF% neither change over time nor between groups. PF and PK showed a reduction in FS% at T0 (47 ± 6 to 34 ± 6 and 42 ± 6 to 36 ± 5, respectively). BP reduced significantly in PF and PS groups (136 ± 26 to 105 ± 13 and 137 ± 22 to 115 ± 15 mmHg, respectively). It is unclear whether changes in echocardiography variables were of clinical relevance related to treatment groups or a result of within-group individual responses.

Evaluation of the anesthetic depth and bispectral index during propofol sequential target-controlled infusion in dogs.

Background and Aim: The use of anesthetic infusions based on pharmacokinetic values associated with anesthetic plan and bispectral index in dogs have not been well-documented in the literature. This study aimed to evaluate the bispectral index (BIS) change based on pre-propofol and establish clinical anesthetic depth changes during propofol sequential target-controlled infusion (STCI) in dogs with a plasma target of 5 µg/mL. Materials and Methods: Twenty healthy male dogs aged 1-3 years and weighing 9.8-44 kg were recruited. These dogs were pre-medicated intramuscularly with methadone (0.2 mg/kg) and acepromazine (0.03 mg/kg). After 30 min, propofol anesthetic induction and maintenance were initiated using STCI according to dog pharmacokinetic (PK) parameters. Subsequently, the target plasma concentration of propofol was set at 5 µg/mL for both anesthetic induction and the 120 min maintenance. Then, TivaTrainer v.9.1 software was used to calculate anesthetic infusion rates in a TCI plasmatic concentration mode using the PKs model optimized by covariates for propofol TCI in dogs. The BIS value was recorded every 5 min from the beginning of induction until the end of anesthesia. Finally, analysis of variance was performed on numerical data using the Friedman test, followed by the Bonferroni adjustment (p<0.05). Results: A statistical difference was observed between the baseline BIS value (T0), with a median value of 84.5 (81-97), and BIS after every 15 min (T15) of inducing anesthesia. Surgical anesthetic depth was also reached in 18 of 20 dogs after 10 min of infusion and in all dogs after 20 min, with a median BIS value of 72 (53-89) at the time of surgical anesthesia depth. Results also showed no BIS variation (p<0.05) between anesthetic moments after anesthetic induction with a substantial amplitude of BIS in the surgical anesthetic depth. Moreover, the maximum depth of anesthesia in all dogs by clinical evaluation was reached after 20 min of anesthesia and then remained stable throughout the anesthetic period. Conclusion: This study suggested that most dogs (90%) attained a surgical depth of anesthesia within 15 min of STCI onset, with a plasma target of 5 µg/mL and no change in anesthetic depth throughout the period anesthesia lasted. Furthermore, median BIS values remained high even after dogs reached the surgical depth of anesthesia, indicating that the comparison of BIS values of dogs and humans should not be considered for classifying anesthetic and hypnotic depths in dogs.

Anestesia total intravenosa para tratamento endodôntico em Panthera leo ­ relato de caso / Total intravenous anesthesia for endodontic treatment in Panthera leo ­ case report

Animais presentes em zoológicos frequentemente necessitam de captura e anestesia para a realização de procedimentos clínicos e cirúrgicos. A anestesia total intravenosa apresenta vantagens como redução do estresse cirúrgico e menor depressão cardiovascular e respiratória. Entretanto, ainda são escassas as pesquisas dedicadas dentro deste contexto. Nesse sentido, o objetivo deste relato foi avaliar o protocolo anestésico empregado, visando um procedimento seguro e passível de reversão para a espécie silvestre selecionada. Acompanhou-se a anestesia de um leão (Panthera leo), macho, adulto, proveniente do Zoológico Municipal de Curitiba, submetido a procedimento endodôntico. A medicação pré-anestésica constituiu-se de dexmedetomidina (6 µg/kg), metadona (0,2 mg/kg), midazolam (0,1 mg/kg) e tiletamina-zolazepam (1,2 mg/kg). A indução foi realizada com propofol (1,5 mg/kg) e o animal foi intubado. Visando promover analgesia local, foi realizado bloqueio infraorbitário esquerdo com 5 mL de lidocaína a 2%. A manutenção foi realizada por meio do fornecimento de propofol (0,02-0,1 mg/kg/h), dexmedetomidina (0,5 µg/kg/h) e remifentanil (5 µg/kg/h). O paciente apresentou sedação profunda e foi mantido em plano anestésico cirúrgico; todos os parâmetros fisiológicos monitorados permaneceram estáveis durante todo o procedimento. Após 55 minutos de anestesia o paciente apresentava sustentação espontânea da cabeça, quando foi novamente transportado ao zoológico para soltura no recinto. A ambulação foi considerada normal pelos observadores no zoológico seis horas após a anestesia. Pôde-se concluir que o protocolo realizado se mostrou tanto eficaz quanto seguro para a referida espécie encaminhada ao procedimento em questão.

Zoo animals often require capture and anesthesia in order to undergo clinical and surgical procedures. Total intravenous anesthesia has advantages such as reduced surgical stress and less cardiovascular and respiratory depression. However, specific research on this matter is still scarce. Therefore, the present report aims to evaluate the anesthetic protocol employed, seeking a safe and reversible procedure for the selected wild species. A male adult lion (Panthera leo), from the Zoológico Municipal de Curitiba, was subjected to an endodontic anesthesia, under close monitoring. The pre-anesthetic medication consisted of dexmedetomidine (6 µg/kg), methadone (0.2 mg/kg), midazolam (0.1 mg/kg) and tiletamine-zolazepam (12 mg/kg). Induction was performed with propofol (1 mg/kg) and the animal was intubated. In order to promote local analgesia, a left infraorbital block was implemented with 5 mL of 2% lidocaine. Maintenance was undertaken by supplying propofol (0.02-0.1 mg/kg/min), dexmedetomidine (0.5 µg/kg/h) and remifentanil (5 µg/kg/h). The patient exhibited deep sedation and followed the surgical anesthetic plan; all the monitored physiological parameters remained stable throughout the procedure. After 55 minutes of anesthesia the patient showed spontaneous head support, when it was transported back to the zoo. The ambulation was considered normal by the zoo observers 6 hours after the anesthesia. It was concluded that the protocol was both effective and safe for the referred species undergone the procedure reported.

Ophthalmic findings in sheep treated with closantel in Curitiba, Brazil.

BACKGROUND AND AIM: Closantel is a widely used anti-parasitic drug that is known to cause ophthalmic problems that lead to blindness. The aim of this study was to investigate the possible electroretinographic changes in sheep that received closantel. MATERIALS AND METHODS: Twenty-four 30-day-old Suffolk sheep were split into control group (12 animals) and closantel group (12 animals). The latter group received 15 mg/kg of closantel subcutaneously immediately after the first electroretinography (ERG). The ISCEV protocol was used to perform the ERGs pre-dose (0), 7, and 30 days after treatment. Statistical analyses to compare ERG responses using t-test and analysis of variance were performed (p<0.05). Three months later, the animals were euthanized and the eyes and a part of optic nerve were collected for histopathology. Photography of the retina and optic nerve was taken, and measures of the retinal layers were made and analyzed by paired t-test. RESULTS: Closantel group showed a significant increase of the mean scotopic a-wave amplitude from 0 to 7 days after closantel administration, using a stimulus of 10,000 mcd.s/m2 and a decrease of the mean scotopic and photopic a-wave amplitude (from 7 to 30 days) using the same flash intensity, as well as a decrease in mean photopic b-wave amplitude (from 7 to 30 days) within the group. Control group showed a significant increase of the mean scotopic b-wave implicit time from pre to 30 days after treatment and an increase of the mean scotopic a-wave implicit time from pre to 7 days after treatment, with the stimulus of 10,000 mcd.s/m2. This group also showed a decrease in mean photopic b-wave implicit time (from pre to 30 days after treatment), using a stimulus of 10,000 mcd.s/m2 and a decrease in mean photopic a-wave implicit time from pre to 30 days after treatment, using a stimulus of 3000 mcd.s/m2. The no difference was found in images neither in the measurements of the retina layers. CONCLUSION: As observed by ERG responses and the histopathology, a dose of 15 mg/kg of closantel does not significantly affect retinal and optic nerve structures in sheep but the electroretinographic results, however, showed alterations on the phototransduction.

Comparison between total intravenous anesthesia with propofol and intermittent bolus of tiletamine-zolazepam in capuchin monkey (Sapajus apella) / Comparação entre anestesia total intravenosa com propofol e bolus intermitente de tiletamina-zolazepam em macaco-prego (Sapajus apella)

Dissociative anesthesia results in stressful and long recovery periods in monkeys and use of injectable anesthetics in medical research has to be refined. Propofol has promoted more pleasure wake up from anesthesia. The objectives of this study were to investigate the use of intravenous anesthetic propofol, establishing the required infusion rate to maintain surgical anesthetic level and comparing it to tiletamine-zolazepam anesthesia in Sapajus apella. Eight healthy capuchin monkeys, premedicated with midazolam and meperidine, were anesthetized with propofol (PRO) or tiletamine-zolazepam (TZ) during 60 minutes. Propofol was infused continually and rate was titrated to effect and tiletamine-zolazepam was given at 5mg/kg IV bolus initially and repeated at 2.5mg/kg IV bolus as required. Cardiopulmonary parameters, arterial blood gases, cortisol, lactate and quality and times to recovery were determined. Recovery quality was superior in PRO. Ventral recumbency (PRO = 43.0±21.4 vs TZ = 219.3±139.7 min) and normal ambulation (PRO = 93±27.1 vs TZ = 493.7±47.8 min) were faster in PRO (p<0.05). Cardiopulmonary effects did not have marked differences between groups. Median for induction doses of propofol was 5.9mg/kg, varying from 4.7 to 6.7mg/kg, Mean infusion rate was 0.37±0.11mg/kg/min, varying during the one-hour period. In TZ, two animals required three and five extra doses. Compared to tiletamine-zolazepam, minor post-anesthetic adverse events should be expected with propofol anesthesia due to the faster and superior anesthetic recovery. (AU)

A anestesia dissociativa em primatas resulta em recuperação anestésica lenta e estressante, e, portanto, o uso de anestesia injetável em pesquisas médicas precisa ser refinado. Por outro lado, o propofol promove recuperação mais suave. Os objetivos desse estudo foram investigar o uso do anestésico intravenoso propofol, estabelecer a taxa de infusão contínua necessária para manter anestesia cirúrgica, e comparar tal técnica com a dissociativa tiletamina-zolazepam em Sapajus apella. Oito macacos-prego saudáveis foram pré-medicados com midazolam e meperidina, e posteriormente anestesiados com propofol (PRO) ou tiletamina-zolazepam (TZ) durante 60 minutos. O propofol foi administrado em infusão contínua, e a taxa foi titulada ao efeito, já a tiletamina-zolazepam foi administrada em 5mg/kg IV como bolus inicial, e repiques de 2,5mg/kg IV conforme necessário. Os parâmetros cardiopulmonares, hemogasometria arterial, cortisol, e lactato, além da qualidade e duração da recuperação anestésica foram determinados. A qualidade da recuperação anestésica foi superior em PRO. O tempo para atingir decúbito ventral (PRO = 43,0±21,4 vs TZ = 219,3±139,7 min) e ambulação normal (PRO = 93±27,1 vs TZ = 493,7±47,8 min) foram mais rápidos em PRO (p<0,05). As variáveis cardiopulmonares não diferiram entre os grupos. A mediana para dose de indução com propofol foi de 5,9mg/kg, variando de 4,7 a 6,7mg/kg. A taxa de infusão contínua média de propofol foi de 0,37±0,11mg/kg/min, variando ao longo dos 60 minutos. Em TZ, dois animais necessitaram de três e cinco repiques. Comparado à tiletamina-zolazepam, menos efeitos adversos pós-anestésicos devem ser esperados com o propofol, devido à recuperação mais suave e rápida.(AU)

Sedative and electrocardiographic effects of low dose dexmedetomidine in healthy cats / Efeitos sedativos e eletrocardiográficos da baixa dose de dexmedetomidina em gatos saudáveis

In feline veterinary practice sedation is often needed to perform diagnostic or minimally invasive procedures, minimize stress, and facilitate handling. The mortality rate of cats undergoing sedation is significantly higher than dogs, so it is fundamental that the sedatives provide good cardiovascular stability. Dexmedetomidine (DEX) is an α2-adrenergic receptor agonist utilized in cats to provide sedation and analgesia, although studies have been utilized high doses, and markedly hemodynamic impairments were reported. The aim of this study was to prospectively investigate how the sedative and electrocardiographic effects of a low dose of DEX performing in cats. Eleven healthy cats were recruited; baseline sedative score, systolic arterial pressure, electrocardiography, and vasovagal tonus index (VVTI) were assessed, and repeated after ten minutes of DEX 5μg/kg intramuscularly (IM). A smooth sedation was noticed, and emesis and sialorrhea were common adverse effects, observed on average seven minutes after IM injection. Furthermore, electrocardiographic effects of a low dose of DEX mainly include decreases on heart rate, and increases on T-wave amplitude. The augmentation on VVTI and appearance of respiratory sinus arrhythmia, as well as sinus bradycardia in some cats, suggesting that DEX enhances parasympathetic tonus in healthy cats, and therefore will be best avoid in patients at risk for bradycardia.(AU)

Na rotina clínica da medicina veterinária felina a sedação é frequentemente requerida para realização de procedimentos diagnósticos ou minimamente invasivos, para minimizar o estresse e facilitar o manuseio dos pacientes. A taxa de mortalidade de gatos submetidos à sedação é mais elevada do que em cães, por esse motivo, é fundamental que os sedativos confiram estabilidade hemodinâmica. A dexmedetomidina (DEX) é um α2-agonista utilizado em felinos para promover sedação e analgesia, porém os estudos têm utilizado doses elevadas, e com isso prejuízos hemodinâmicos importantes foram relatados. O objetivo desta investigação foi avaliar os efeitos sedativos e eletrocardiográficos da baixa dose de DEX em gatos. Para tal, onze felinos saudáveis foram recrutados, foram obtidos valores basais para escore de sedação, pressão arterial sistólica e eletrocardiografia, além do índice de tônus vaso vagal (ITVV). Após dez minutos da aplicação intramuscular (IM) de DEX 5μg/kg todos os exames foram repetidos. Após a DEX, sedação suave foi detectada, e a êmese e sialorreia foram efeitos adversos comuns, observados em média 7 minutos após a injeção IM. Ademais, os principais efeitos eletrocardiográficos foram redução na frequência cardíaca e aumento na amplitude da onda T. O ITVV mais elevado e surgimento de arritmia sinusal respiratória, bem como bradicardia sinusal em alguns gatos, sugerem que a DEX eleva o tônus parassimpático, e por esse motivo deve ser utilizada com cautela em pacientes com predisposição à bradicardia.(AU)

Dexmedetomidine low dose followed by constant rate infusion and antagonism by atipamezole in isoflurane-anesthetized cats: an echocardiographic study.

OBJECTIVE: To investigate the effects of a low dose of dexmedetomidine (DEX) followed by constant rate infusion (CRI) and reversal with atipamezole on systolic and diastolic functions in isoflurane-anesthetized healthy cats. STUDY DESIGN: Prospective cohort study. ANIMALS: A group of 11 client-owned adult cats. METHODS: Baseline transthoracic echocardiography (TTE) was performed, followed by intramuscular (IM) administration of DEX (5 µg kg-1). After 10 minutes, sedation was scored, adverse effects were recorded and another TTE performed. Approximately 40 minutes after DEX administration, anesthesia was induced by isoflurane mask and maintained with 1.2% end-tidal isoflurane and DEX CRI (1 µg kg-1 hour-1) for 80 minutes. Physiological variables were recorded every 10 minutes, and TTE was repeated 10, 30 and 60 minutes after the start of anesthesia. CRI was stopped, atipamezole (30 µg kg-1) was administered IM and a final TTE was performed after 10 minutes. Repeated measures over time were submitted to one-way analysis of variance or Kruskal-Wallis test according to data distribution; significance was assumed at p < 0.05. RESULTS: After DEX premedication, mild sedation and a slight but significant increase in systolic arterial pressure occurred, and vomiting was a common adverse effect. The cardiac output (CO) and heart rate decreased during anesthesia, with no changes after administration of atipamezole. Trivial valvular insufficiencies were commonly seen after DEX premedication and during CRI. Myocardial radial and longitudinal systolic functions were not affected by sedation or by anesthesia. The late phase of diastole on both right and left ventricles was affected by isoflurane-DEX CRI. Global left ventricular myocardial performance was not impaired. CONCLUSIONS: and clinical relevance Decreased CO and late diastolic impairment were observed in healthy cats administered a low dose of DEX for premedication followed by anesthesia with isoflurane and DEX CRI.

Continuous infusion of propofol or intermittent bolus of tiletamine-zolazepam in squirrel monkeys (Saimiri sciureus).

OBJECTIVE: To investigate an infusion of propofol for anesthesia in comparison to tiletamine-zolazepam anesthesia, evaluating physiological variables and recovery in squirrel monkeys. STUDY DESIGN: Prospective non-blinded randomized study. ANIMALS: Eight healthy squirrel monkeys (Saimiri sciureus), aged 3 years and weighing 0.340-0.695 kg. METHODS: Premedication was intramuscular midazolam (0.5 mg) and meperidine (4 mg). Anesthesia was induced with intravenous (IV) propofol (4 mg kg(-1)  minute(-1) ) and maintained with propofol starting at 0.4 mg kg(-1)  minute(-1) (PRO, n = 4) or IV tiletamine-zolazepam (5 mg kg(-1) ) and maintained with supplementary doses of TZ (TZ, n = 4). Cardiopulmonary variables were measured continuously. Arterial blood gases and lactate concentration were measured at the end of anesthesia. Quality and times of recovery were determined. Repeatedly measured data for significant differences were tested between groups with t-test and within groups by anova. RESULTS: Median time for induction of anesthesia in PRO was 180 seconds. Mean maintenance infusion rate of propofol was 0.43 ± 0.05 mg kg(-1)  minute(-1) , varying during the 1 hour period. One monkey died after administration of TZ; others required 1, 4, or 8 supplemental doses. Cardiopulmonary variables were similar between groups, but hypotension was recorded. Recovery times to ventral recumbency in PRO (32 ± 17 minutes) and TZ (84 ± 11 minutes) and normal ambulation in PRO (58 ± 22 minutes) and TZ (358 ± 109minutes) were significantly different (p < 0.05). Recovery quality was superior in PRO, with less ataxia and fewer unsuccessful attempts to stand. Lactate concentration was not different between treatments. CONCLUSIONS AND CLINICAL RELEVANCE: Cardiopulmonary variables were similar between protocols, aside from the higher incidence of hypotension in PRO, indicating that further studies with a larger number of animals are required. Compared to tiletamine-zolazepam, propofol anesthesia provided faster and superior anesthetic recovery in these animals.

Successful implantation of a decellularized equine pericardial patch into the systemic circulation.

BACKGROUND: In the past, successful use of decellularized xenogenic tissue was shown in the pulmonary circulation. This study, however, evaluates a newly developed decellularized equine pericardial patch under high pressure circumstances. MATERIAL AND METHODS: Seven decellularized equine pericardial scaffolds were implanted into the descending aorta of the juvenile sheep. The implanted patches were oversized to evaluate the durability of the decellularized tissue under high surface tension (Law of Laplace). After 4 months of implantation, all decellularized patches were inspected by gross examination, light microscopy (H&E, Serius red, Gomori, Weigert, and von Kossa straining), and immunohistochemical staining. RESULTS: The juvenile sheep showed fast recovery after surgery. There was no mortality during follow-up. At explantation, only limited adhesion was seen at the surgical site. Gross examination showed a smooth and pliable surface without degeneration, as well as absence of aneurysmatic dilatation. Light microscopy showed a well preserved extracellular scaffold with a monolayer of endothelial cells covering the luminal side of the patch. On the outside part of the patch, a well developed neo-vascularization was seen. Host fibroblasts were seen in all layers of the scaffolds. There was no evidence for structural deterioration or calcification of the decellularized equine pericardial scaffolds. CONCLUSIONS: In the juvenile sheep, decellularized equine tissue showed no structural deterioration, but regeneration and remodeling processes at systemic circulation.

Continuous infusion of propofol or intermittent bolus of tiletamine-zolazepam in feline night monkeys (Aotus infulatus).

BACKGROUND: Although commonly used, dissociative anesthesia results in unsatisfactory and long recovery periods. The intravenous anesthetic propofol seems to be the most advantageous solution. The objectives of this study were to investigate the required infusion rate of propofol to maintain surgical anesthesia and to compare it to tiletamine-zolazepam in Aotus infulatus. METHODS: Eight healthy feline night monkeys were anesthetized with propofol (PRO) or tiletamine-zolazepam (TZ) during 60 minutes. Cardiopulmonary parameters, arterial blood gases and lactate and quality and times to recovery were determined. RESULTS: Mean infusion rate of propofol was 0.53 ± 0.10 mg/kg/minute. Cardiopulmonary effects did not show marked differences between groups. Times for hanging, ventral recumbency, and normal ambulation were lower in PRO. Establishment of desirable anesthetic depth was easier, recovery quality was superior, and lactate levels were lower in PRO. CONCLUSIONS: Compared with tiletamine-zolazepam, minor post-anesthetic adverse events should be expected with propofol anesthesia, as well as faster and better anesthetic recovery.

An outbreak of tuberculosis by Mycobacterium bovis in coatis (Nasua nasua).

Mycobacterium tuberculosis complex, which includes Mycobacterium bovis, infrequently causes severe or lethal disease in captive wildlife populations. A dead coati from a wildlife triage center showing pulmonary lesions compatible with tuberculosis had raised suspicion of a potential disease caused by mycobacteria species and was further investigated. Four native coatis (Nasua nasua) with suspected mycobacterial infection were sedated, and bronchoalveolar lavages and tuberculin skin tests (TSTs) were performed. All animals tested positive upon TST. Mycobacterial culturing, Ziehl-Neelsen staining, and genetic testing were performed on postmortem samples and the etiologic agent was identified as M. bovis. Molecular genetic identification using a polymerase chain reaction panel was crucial to achieving a definitive diagnosis.

Bilateral phacoemulsification in an orangutan (Pongo pygmaeus).

A 14-year-old, female, captive-born orangutan (Pongo pygmaeus) developed bilateral cataracts. Ultrasonography, electroretinography and cataract correction using phacoemulsification were performed bilaterally. This case report aims to describe the ophthalmic procedures performed in this animal critically endangered of extinction. The surgery successfully restored vision and normal activity to the patient.

Toxoplasma gondii in Capybara (Hydrochaeris hydrochaeris) antibodies and DNA detected by IFAT and PCR.

Toxoplasmosis is considered nowadays as one of the most important foodborne diseases in the world. One of the emerging risks in acquiring infection with Toxoplasma gondii is the increasing popularity of wild animals and game meat. Capybara (Hydrochaeris hydrochaeris) is the world's largest extant rodent and is used for human consumption in many areas of South America, and in case it carries T. gondii cysts, it may act as a source of infection. In the present study, we detected infection with T. gondii in capybaras from the south of Brazil. Antibodies to T. gondii were assayed in the serum of capybaras using the indirect fluorescent antibody test (IFAT > or = 1:16). Blood, liver, heart, lymph nodes, and spleen tissues were collected and tested by polymerase chain reaction (PCR) for B1 gene and ITS1 region. The results showed that 61.5% (16/26) capybaras were seropositive to T. gondii. Titers of specific antibodies to T. gondii ranged from 1:16 to 1:512. Among the feral rodents studied, 7.7% (2/26) were PCR positive for B1 gene assay and 11.5% (3/26) were positive for ITS1 PCR assay; for both test, the prevalence was 15.4%. Liver, heart, and blood tissues were those which tested positive for the apicomplexan. Our findings show a high percentage of infection with T. gondii in asymptomatic capybaras. Based on those data, we hypothesize that the consumption of raw or undercooked capybara meat could be a source of infection for humans.

Detection of Neospora caninum DNA in capybaras and phylogenetic analysis.

The role of rodents in the sylvatic cycle of Neospora sp. and in the neosporosis epidemiology is still uncertain. The aim of the present work was to detect Neospora caninum and to determine its prevalence in capybaras (Hydrochaeris hydrochaeris), to help elucidate the role of this rodent in the life cycle of the parasite. N.caninum DNA was detected by PCR using 4 different sets of primers specific to the Nc5 and ITS1 sequences. The parasite was found in the lymph nodes, heart, liver, and blood of 23% of the twenty-six capybaras studied. Sequencing the amplified DNA revealed 98% of similarity with N. caninum sequences deposited in the Genbank. Our findings provide the first molecular evidence of N. caninum infection in capybaras, supporting the hypothesis that these rodents can act as reservoirs of N. caninum and play a role in the life cycle of this parasite.

Decellularized heterografts versus cryopreserved homografts: experimental study in sheep model.

OBJECTIVES: The aim of this study is to assess the biological behaviour of porcine decellularized heterografts (Desc group) compared with cryopreserved homografts (Crio group) implanted in juvenile sheep. METHODS: Decellularized porcine pulmonary heterografts were implanted in five animals and cryopreserved pulmonary homografts in another five. The animals were followed-up for a mean of 280 +/- 14 days. The valve diameter was measured by echocardiography, which was performed at the 30th postoperative day, and before the explantation. The valves were also assessed macroscopically. Histological evaluation was performed using H.E., Gomori and Weigert staining. Immunohistochemistry specified different cell types (Factor VIII, CD3, Vimentin and CD68). Calcium quantity was analyzed using atomic absortion spectometry. RESULTS: There was one death in the Desc group due to endocarditis. The valves of Crio group showed decrease in the cellularity whereas the valves of Desc group showed matrix repopulation with endothelial and interstitial cells. Loss of collagen density and disarrangement of the normal fiber architecture was observed in Crio group. Calcium content demonstrated higher levels on the cusps and conduits in Crio group comparatively with Desc group. (P=0.016). The mean valvular diameter at the explantation was significantly increased (P=0.025) in the Desc group. CONCLUSIONS: Decellularized heterografts had a different biological behaviour when compared to cryopreserved homografts and become repopulated by cells with fibroblasts and endothelial cells characteristics. The matrix was preserved and some regenerative potential was present.

Análise do comportamento biológico de heteroenxertos descelularizados e homoenxertos criopreservados: estudo em ovinos / Decellularized heterografts versus cryopreserved homografts: experimental study in sheep model

OBJETIVO: Este estudo avalia o comportamento biológico dos heteroenxertos porcinos descelularizados (Grupo Desc) comparados com os homoenxertos criopreservados (Grupo Crio) implantados em carneiros jovens. MÉTODOS: Foram implantados em cinco animais heteroenxertos pulmonares porcinos descelularizados e em outros cinco, homoenxertos pulmonares criopreservados. Os animais apresentaram seguimento médio de 280 ± 14 dias. O diâmetro valvar foi medido por ecocardiografia, a qual foi realizada no 30º pós-operatório e antes do explante. As valvas foram também avaliadas macroscopicamente. A avaliação histológica foi realizada utilizando-se coloração de H.E., Gomori e Weigert e imunohistoquímica (Fator VIII, CD3, Vimentina e CD68). A quantificação de cálcio foi realizada utilizando-se espectrometria de absorção atômica. RESULTADOS: Houve um óbito no Grupo Desc por endocardite. As valvas do Grupo Crio apresentaram decréscimo na celularidade, enquanto que as valvas do Grupo Desc demonstraram repovoamento da matriz com células endoteliais e intersticiais. No grupo Crio, observou-se perda na densidade e desarranjo da arquitetura das fibras colágenas. A espectrometria de absorção atômica demonstrou maior calcificação no conduto e nas cúspides dos enxertos criopreservados quando comparados aos descelularizados (P=0,016). O diâmetro médio valvar no explante foi significantemente maior no Grupo Desc (P=0,025). CONCLUSÃO: Heteroenxertos descelularizados apresentam um comportamento biológico diferente quando comparados aos homoenxertos criopreservados, tornando-se repovoados por células com características de fibroblastos e células endoteliais. A matriz permaneceu bem preservada, o que possibilitou um processo de regeneração celular.

OBJECTIVES: The aim of this study is to assess the biological behaviour of porcine decellularized heterografts (Desc group) compared with cryopreserved homografts (Crio group) implanted in juvenile sheep. METHODS: Decellularized porcine pulmonary heterografts were implanted in five animals and cryopreserved pulmonary homografts in another five. The animals were followed-up for a mean of 280 ± 14 days. The valve diameter was measured by echocardiography, which was performed at the 30th postoperative day, and before the explantation. The valves were also assessed macroscopically. Histological evaluation was performed using H.E., Gomori and Weigert staining. Immunohistochemistry specified different cell types (Factor VIII, CD3, Vimentin and CD68). Calcium quantity was analyzed using atomic absortion spectometry. RESULTS: There was one death in the Desc group due to endocarditis. The valves of Crio group showed decrease in the cellularity whereas the valves of Desc group showed matrix repopulation with endothelial and interstitial cells. Loss of collagen density and disarrangement of the normal fiber architecture was observed in Crio group. Calcium content demonstrated higher levels on the cusps and conduits in Crio group comparatively with Desc group. (P=0.016). The mean valvular diameter at the explantation was significantly increased (P=0.025) in the Desc group. CONCLUSIONS: Decellularized heterografts had a different biological behaviour when compared to cryopreserved homografts and become repopulated by cells with fibroblasts and endothelial cells characteristics. The matrix was preserved and some regenerative potential was present

The capybara eye: clinical tests, anatomic and biometric features.

PURPOSE: To carry out a descriptive investigation of the capybara (Hydrochaeris hydrochaeris) eye and to perform selected ophthalmic diagnostic tests with the aim of establishing normal physiological reference values for this species. METHOD: A total of 22 healthy, capybaras were used to test most of the parameters in this investigation. Ages varied from 2 to 4 years of age. Selected diagnostic ocular tests were performed including Schirmer tear test, tonometry using an applanation tonometer (Tonopen), central corneal thickness using an ultrasonic pachymeter (Sonomed, Micropach, Model 200P +), axial globe length and culture of the normal conjunctival bacterial flora. RESULTS AND DISCUSSION: Capybara's normal ocular features include: dorsal and ventral puncta, vestigial third eyelid, true cilia only at the upper eyelid margins. The bulbar conjunctiva is noticeably densely pigmented with a brown to bronze color. The capybara's pupil is oval in shape and vertical in position No tapetum lucidum is present in this species and the retinal blood vessels are almost absent. Results for selected ocular diagnostic tests investigated were: Intraocular pressure: 18.4 +/- 3.8 mmHg; Schirmer tear test: 14.9 +/- 5.1 mm/min; Central corneal thickness: 0.46 +/- 0.03 mm; Axial globe length: 22.20 +/- 1.71 mm. No statistically significant differences between ages or genders were found for any of the results. Corynebacterium sp., Micrococcus sp., Bacillus sp. and Staphylococcus sp. were isolated from healthy conjunctiva, suggesting they are normal constituents of the conjunctival flora of the capybara eye. The corneal epithelium of the capybara possesses a thin and discrete Bowman's layer. Results and parameters obtained in this investigation exposed unique anatomic features of the capybara eye and will help veterinary ophthalmologists to more accurately diagnose discrete or unusual pathological changes of the capybara eye. Furthermore, corneal thickness and axial length of the capybara are similar to that of human beings, revealing that the world's largest living rodent might be an excellent biological model for ophthalmic studies.

Reference values for selected ophthalmic diagnostic tests of the capuchin monkey (Cebus apella).

PURPOSE: To perform selected ophthalmic diagnostic tests in healthy capuchin monkeys (Cebus apella) with the aim of establishing normal physiological reference values for this species. METHODS: A total of 15 healthy, capuchin monkeys were used to test most of the parameters in this investigation. Five of the 15 monkeys were used for the evaluation of normal conjunctival flora. Ages varied from 6 to 20 years of age. Selected diagnostic ocular tests were performed including Schirmer tear test (STT), tonometry using an applanation tonometer (Tonopen), central corneal thickness (CCT) using an ultrasonic pachymeter (Sonomed, Micropach), Model 200P+) and culture of the normal conjunctival bacterial flora. RESULTS AND DISCUSSION: Results for selected ocular diagnostic tests investigated here for the capuchin monkey eye were as follows: IOP: 18.4 +/- 3.8 mmHg; STT: 14.9 +/- 5.1 mm/min; CCT: 0.46 +/- 0.03 mm. No statistically significant differences between ages or genders were found for any of the results. Streptococcus sp. and Corynebacterium sp. were isolated from healthy conjunctival and eyelid margins, suggesting they are normal constituents of the conjunctival flora of the capuchin monkey. The data obtained in this investigation will help veterinary ophthalmologists and laboratory animal medicine specialists to more accurately diagnose ocular diseases in the capuchin monkey. These ophthalmic reference values will be particularly useful to diagnose discrete or unusual pathological changes of the capuchin monkey eye.

Histological evaluation of tissue-engineered heart valves implanted in the juvenile sheep model: is there a need for in-vitro seeding?

BACKGROUND AND AIM OF THE STUDY: A new-generation heart valve was developed to improve long-term durability. The study aim was to evaluate the need for in-vitro autologous endothelial cell seeding of a decellularized valve scaffold. METHODS: A seeded (group I, n = 6) or non-seeded (group II, n=6) decellularized valve was implanted into the right ventricular outflow tract of 12 juvenile sheep. In group I, a jugular vein was harvested to characterize and expand endothelial cells (ECs). The scaffold was seeded in vitro, using a sedimentation technique. In group II, non-seeded decellularized scaffolds were implanted and explantation was performed at three and six months. Valves were evaluated by echocardiography, gross pathology, X-radiography, histology, and immunohistochemistry. RESULTS: In group I, the EC seeding density was 1.06 +/- 0.01 x 10(5) cells/cm2, with a cell viability of 95.7 +/- 1.4%. No regurgitation was visualized by echocardiography. Gross pathology showed smooth leaflets without retraction; calcification was absent at X-radiography, and this was confirmed by von Kossa staining. Histologically, group I valves showed a persistence of ECs, whereas a monolayer of host ECs was seen at six months in group II valves. Host fibroblasts were available in both groups, and numbers increased over time. Differences were identified in the recellularization density of in-vitro-seeded and non-seeded valves for up to three months, but no such difference was seen after six months. CONCLUSION: Based on results of studies in a sheep model, there appears to be no need for in-vitro cell seeding of decellularized scaffolds.