[Show abstract][Hide abstract] ABSTRACT: Objective. The aim of this study was to find a proper experimental design and to evaluate n-butyl-2-cyanoacrylate (Histoacryl) as a fixation method for a light-weight and large pore PP mesh (Synthetic PP Mesh-1) using the sheep as an animal model. Methods. Posterior vaginal implantation by means of episiotomy was used to implant 8 ewes which were evaluated macroscopically and histologically at 3 months () and 6 months () post-surgery. In previous pilot studies anterior vaginal implantation was evaluated, as well as different synthetic mesh materials, sizes and fixation methods ( to 3) during three weeks. In all cases a clinical evaluation of the animal was performed. Results. A reduction in the mesh size (Synthetic PP Mesh-1) together with precise application of the surgical glue Histoacryl to fix the mesh yielded significantly better histocompatibility results () compared to larger size or other fixation methods. Conclusion. The combination of Synthetic PP Mesh-1 with Histoacryl offered a high degree of graft integration without vaginal ulceration and a minimal foreign body reaction, being the sheep a proper animal model to test these types of medical devices.
BioMed Research International 06/2015; 2015. DOI:10.1155/2015/737683 · 2.71 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Current developments in tissue engineering strategies for articular cartilage regeneration focus on the design of supportive three-dimensional scaffolds and their use in combination with cells from different sources. The challenge of translating initial successes in small laboratory animals into the clinics involves pilot studies in large animal models, where safety and efficacy should be investigated during prolonged follow-up periods. Here we present, in a single study, the long-term (up to 1 year) effect of biocompatible porous scaffolds non-seeded and seeded with fresh ex vivo expanded autologous progenitor cells that were derived from three different cell sources [cartilage, fat and bone marrow (BM)] in order to evaluate their advantages as cartilage resurfacing agents. An ovine model of critical size osteochondral focal defect was used and the test items were implanted arthroscopically into the knees. Evidence of regeneration of hyaline quality tissue was observed at 6 and 12 months post-treatment with variable success depending on the cell source. Cartilage and BM-derived mesenchymal stromal cells (MSC), but not those derived from fat, resulted in the best quality of new cartilage, as judged qualitatively by magnetic resonance imaging and macroscopic assessment, and by histological quantitative scores. Given the limitations in sourcing cartilage tissue and the risk of donor site morbidity, BM emerges as a preferential source of MSC for novel cartilage resurfacing therapies of osteochondral defects using copolymeric poly-D,L-lactide-co-glycolide scaffolds.
[Show abstract][Hide abstract] ABSTRACT: Oocytes from adult goats have better competence to develop up to blastocyst stage than those from prepubertal females. Previous results in our laboratory showed that oocyte developmental competence in prepubertal goats is positively related to follicle diameter, as oocytes from follicles larger than 3mm have the same competence as adult goat ones, demonstrating that follicular environment affects oocyte competence for embryo development. Other studies concluded that fatty acids (FA) in follicular fluid (FF) play an important role in oocyte and embryo development. The aim of this study was to analyse FF composition regarding FA percentage comparing samples from adult (3 years old, forage diet) or prepubertal (1 month suckling) Murciano-Granadina goats. FF samples were recovered from follicles larger and smaller than 3mm by laparoscopy (adult) or aspiration of ovaries collected at slaughterhouse (prepubertal). For the FA analysis, the Sukhija and Palmquist protocol was used with some modifications. Briefly, 200μL of FF sample was vortexed for 60s with 250μL of toluene and 1mL of HCL (5%) and then warmed in water bath for 1h at 70°C. Subsequently, 1.25mL of K2CO3 (12%) and 500μL of toluene was added, vortexed for 30s, and centrifuged for 5min (3000rpm). Finally the supernatant was recovered and dried with Na2SO4. The extracted samples were maintained at -20°C until gas chromatographic analysis (123-2362, Agilent Technologies Inc., Santa Clara, CA). The results are shown in Table 1. The analysis of FA composition in FF showed significantly higher concentrations of C15:0 (pentadecanoic), C16:0 (palmitic), C17:0 (margaric), C18:0 (stearic), linolenic acid (ALA), and EPA (eicosapentanoic) in adult goats compared to prepubertal goats, and C17:0, C18:0 linoleic acid (LA), and ALA in larger follicles of prepubertal females, showing some coincidences in follicular environment that could explain previous studies. These results are in agreement with those of Matoba et al. (2014; Rep. Fertil. Dev. 26, 337) who showed that FF associated with more competent oocytes had a significantly higher concentration in ALA than FF from incompetent oocytes in cattle.
Reproduction Fertility and Development 12/2014; 27(1):180-1. DOI:10.1071/RDv27n1Ab179 · 2.40 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The purpose of this randomised trial was to compare the effects of alfaxalone and propofol on tear production (STT-1), intraocular pressure (IOP) and globe position (GP) in healthy dogs. Fourteen Beagles were randomly divided into two groups; dogs in one group received alfaxalone (3 mg/kg) (n=7) and dogs in the other group received propofol (6 mg/kg) (n=7), both administered intravenously. IOP and GP were evaluated at basal time (Tb) and T2,5,10,15,20,25&30 (minutes after complete drug administration). STT-1 was evaluated at Tb and T10,20&30. STT-1 and IOP results were analysed using analysis of variance and GP was analysed using the likelihood ratio χ(2) test. Dogs in the alfaxalone group showed a significant reduction in STT-1 at T10&20 (P<0.05), while the propofol group did not show statistically significant differences in this parameter over time. Both anaesthetic drugs produced a transient elevation of IOP at T2 (P>0.05), which then decreased (P<0.01). While alfaxalone caused a ventral globe deviation that lasted from T2 to T10 (P<0.05) and was fully recovered at T30, propofol induced a ventral globe deviation from T2 to T5 (P<0.05), being restored at T20. These results suggest that both alfaxalone and propofol can be safely used for intraocular surgery, as they significantly reduce IOP. Furthermore, anaesthetic induction with propofol would be especially recommended for dogs with tear deficiencies.
The Veterinary record 10/2014; 176(3). DOI:10.1136/vr.102621 · 1.49 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Regenerative therapies using adult stem cells have attracted great interest in the recent years and offer a promising alternative to current surgical practices. In this report, we evaluated the safety and efficacy of an autologous cell-based treatment of osteoarthritis using mesenchymal stromal cells expanded from bone marrow aspirates that were administered intra-articularly.
Ten 2-year old ewes were divided in two groups (for analysis at 6 and 12 months, respectively). Full thickness articular cartilage defects of approximately 60 mm2 were created arthroscopically in the medial femorotibial condyles and a meniscal tear in the anterior horn of the medial meniscus in the 20 hind legs. Intra-articular injection of 4 mL of either treatment (a suspension of cells) or control (same as treatment, without cells) were applied one month after generating a chronic condition similar to human pathology. Animals were monitored radiographically, by MRI and ultrasound scanning; and macroscopic and histological analyses were conducted at 6 and 12 months. Furthermore a full necropsy was performed at 12 months post-treatment. The intra-articular injection of autologous MSC was safe, as judged by the lack of local or systemic adverse effects during the clinical follow-up and by a full necropsy performed at 12 months post-treatment. Evidence of regeneration of articular cartilage and meniscus was case-dependent but statistically significant improvement was found in specific macroscopic and histological parameters. Such parameters included colour, rigidity, cell distribution and hyaline quality of the refill tissue as well as the structure of subchondral bone.
New Biotechnology 09/2014; 31(5). DOI:10.1016/j.nbt.2014.07.004 · 2.90 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Clinical translation of emerging technologies aiming at cartilage resurfacing is hindered by neither the appropriate scaffold design nor the optimal cell source having been defined. Here, critical-sized, chondral-only focal defects were created in sheep and treated with clinical-grade, co-polymeric poly-lactide:polyglycolic acid scaffolds either alone or seeded with 3.3 × 10(6) ± 0.4 × 10(6) autologous bone marrow-derived mesenchymal stromal cells and studied over 12 month follow-up. An untreated group was included for comparison. Second-look arthroscopy performed at 4 months post-treatment evidenced the generation of neocartilage of better quality in those defects treated with cells. However, macroscopic scores in the cell-treated group declined significantly from 7.5 ± 2.3 at 4 months to 3.1 ± 2.6 (p = 0.0098) at 12 months post-treatment, whereas the other two experimental groups remained unaltered during 4-12 month post-treatment. The effectiveness of the cell-based approach proposed in this study is thus restricted to between months 1 and 4 post-treatment.
[Show abstract][Hide abstract] ABSTRACT: The aim of the study was to determine the distribution of different volumes of methylene blue solution injected into the epidural space in anaesthetized pregnant and non-pregnant sheep, to evaluate its cranial distribution and to compare between them. Fifteen pregnant and fifteen non-pregnant sheep were included in the study. Sheep were anaesthetized and received 0.05, 0.1, or 0.2 mL/kg of a lumbosacral epidural solution containing 0.12% methylene blue in 0.9% saline. Thirty minutes after the epidural injection, the ewes were euthanized. The extension of the dye within the epidural space was measured, and the correlation between the volume of the dye injected and the number of stained vertebrae was evaluated. The cranial migration of the dye between pregnant and non-pregnant sheep was also compared. The results show that the volume of methylene blue injected epidurally into pregnant and non-pregnant sheep correlated directly with its cephalic distribution into the epidural space; and a volume of 0.1 mL/kg or 0.2 mL/kg stained up to the first lumbar segment in pregnant and non-pregnant sheep, respectively. Also, the results suggest that the volume of drugs administered into the epidural space of pregnant sheep should be half the volume that would be used in non-pregnant sheep.
PLoS ONE 04/2014; 9(4):e92860. DOI:10.1371/journal.pone.0092860 · 3.23 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The “One world, one health” initiative emphasizes the need for new strategies to control human and animal tuberculosis (TB) based on their shared interface. A good example would be the development of novel universal vaccines against Mycobacterium tuberculosis complex (MTBC) infection. This study uses the goat model, a natural TB host, to assess the protective effectiveness of a new vaccine candidate in combination with Bacillus Calmette-Guerin (BCG) vaccine.
Thirty-three goat kids were divided in three groups: Group 1) vaccinated with BCG (week 0), Group 2) vaccinated with BCG and boosted 8 weeks later with a recombinant adenovirus expressing the MTBC antigens Ag85A, TB10.4, TB9.8 and Acr2 (AdTBF), and Group 3) unvaccinated controls. Later on, an endobronchial challenge with a low dose of M. caprae was performed (week 15). After necropsy (week 28), the pulmonary gross pathology was quantified using high resolution Computed Tomography. Small granulomatous pulmonary lesions (< 0.5 cm diameter) were also evaluated through a comprehensive qualitative histopathological analysis. M. caprae CFU were counted from pulmonary lymph nodes.
The AdTBF improved the effects of BCG reducing gross lesion volume and bacterial load, as well as increasing weight gain. The number of Ag85A-specific gamma interferon-producing memory T-cells was identified as a predictor of vaccine efficacy. Specific cellular and humoral responses were measured throughout the 13-week post-challenge period, and correlated with the severity of lesions.
Unvaccinated goats exhibited the typical pathological features of active TB in humans and domestic ruminants, while vaccinated goats showed only very small lesions. The data presented in this study indicate that multi-antigenic adenoviral vectored vaccines boosts protection conferred by vaccination with BCG.
PLoS ONE 11/2013; 8(11):e81317. DOI:10.1371/journal.pone.0081317 · 3.23 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The objective of this study was to determine the pharmacodynamics effects of the anaesthetic alfaxalone in 2-hydroxypropyl- β -cyclodextrin in pregnant sheep after the intravenous injection of a 2 mg/kg weight dose. Six pregnant Ripollesa sheep, weighing 47.1 ± 4.4 kg, were used. Twenty-four hours after instrumentation, sheep were anaesthetized with intravenous alfaxalone in cyclodextrin. Time to standing from anaesthesia was 30.0 ± 10.81 min. Foetal heart rate increased significantly during the first 5 min after alfaxalone administration. Significant differences were observed in maternal diastolic arterial blood pressure between minute 10 and minutes 90, 120, 150, 180, 210, and 240. Significant differences were observed for foetal systolic arterial blood pressure between 5 and 30 min after alfaxalone administration. Significant differences in foetal pH were detected during the entire study period, whereas maternal pH returned to baseline values by 60 min after alfaxalone administration. The present study indicated that alfaxalone in 2-hydroxypropyl- β -cyclodextrin administered as an intravenous bolus at 2 mg/kg body weight produced minimal adverse effects and an uneventful recovery from anaesthesia in pregnant sheep and their foetus.
The Scientific World Journal 10/2013; 2013:189843. DOI:10.1155/2013/189843 · 1.73 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Alfaxalone in a 2-hydroxypropyl-β-cyclodextrin (HPCD) formulation is an intravenous (IV) hypnotic agent characterised by the stability of cardiorespiratory effects after a single-bolus administration. The objective of this study was to investigate the cardiovascular, respiratory, and acid-base effects of alfaxalone-HPCD administered during a continuous rate infusion in six Ripollesa sheep. After instrumentation, a 2mg/kg IV bolus of alfaxalone followed by a continuous infusion of 10mg/kg/h was administered to the sheep. Heart rate, arterial blood pressure, respiratory rate and arterial blood gases were recorded. Occasional side effects and time to standing were also noted. No significant changes were observed in arterial blood pressure, but during the infusion and the initial stages of recovery, a significant increase in heart rate occurred during the last 120min of the study. Significant respiratory depression was detected during the infusion period and the first 15min of recovery. This study showed that a constant rate infusion alfaxalone in un-premedicated sheep produced clinically acceptable haemodynamic results and a mild respiratory depression that may require intermittent positive pressure ventilation.
The Veterinary Journal 10/2012; 196(2). DOI:10.1016/j.tvjl.2012.09.010 · 1.76 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The objective of this prospective study was to determine the effects of a single intravenous bolus of alfaxalone in 2-hydroxypropyl-β-cyclodextrin and propofol on the intraocular pressure (IOP) in sheep. Ten Ripollesa sheep with a bodyweight of 48.5 (6.8) kg (mean [sd]) were used in the study. Twenty-four hours before the experimental procedure, a complete ophthalmic examination was performed in all animals. The day of the study, intravenous alfaxalone (2 mg/kg) or propofol (6 mg/kg) was randomly administered in a cross-over design, with a washout period of two weeks. Measurements of IOP, globe position and pupil size were obtained at basal time, before induction (time 0) and at two, five, 10, 15, 20, 30, 45, 60, 90 and 120 minutes after drug administration. Occasional side effects and time to standing were also noted. Intravenous administration of alfaxalone and propofol in sheep resulted in no alteration of IOP. Nevertheless, a decrease in the pupil size was observed in both groups. This present study shows that alfaxalone and propofol, administrated as a single intravenous bolus, are good options for maintaining IOP during anaesthesia in sheep, although marked miosis was observed after administration.
[Show abstract][Hide abstract] ABSTRACT: Developmental competence of oocytes from prepubertal females is lower than those from adult females. Oocyte development competence is positively related to follicular diameter. Most of the follicles of prepubertal goat ovaries are smaller than 3 mm. The aim of this study was to compare oocytes of two follicle sizes (< 3 mm and ≥ 3 mm) from prepubertal goats with oocytes from adult goats in relation to their in vitro production and quality of blastocysts. Oocytes from prepubertal goats were obtained from slaughterhouse ovaries and selected according to the follicle diameter whereas oocytes from adult goats were recovered in vivo by LOPU technique without prior selection of follicle size. COCs were IVM for 27 h, IVF at the conventional conditions with fresh semen and presumptive zygotes were cultured in SOF medium for 8 days. Blastocysts obtained were vitrified and after warming their blastocoele re-expansion and the ploidy by FISH technique were assessed. We found significant differences between blastocysts yield of oocytes recovered from follicles smaller than 3 mm of prepubertal goats compared to those from adult goats (5.45% vs 20. 83%, respectively) however, these differences disappear if oocytes were recovered form large follicles (18.07%). A total of 28 blastocysts were analysed and 96.43% showed mixoploidy. Age did not affect the number of embryos with abnormal ploidy or blastocyst re-expansion after warming. Furthermore, the percentage of diploid blastomeres per embryo was similar in the 3 groups studied, adult, prepubertal from follicles ≥ 3 mm and < 3 mm (68.6%, 80.8% and 73.6%, respectively). In conclusion, IVP of blastocysts coming from follicles larger than 3 mm of goats 45 days old were not different to the blastocysts produced from adult goats, both in terms of quantity and quality.
[Show abstract][Hide abstract] ABSTRACT: The clinical efficacy of a 70 microg/h transdermal buprenorphine patch and of 20 microg/kg of buprenorphine administered subcutaneously (SC) for the relief of post-operative pain was determined in 24 healthy female dogs undergoing elective ovariohysterectomy (OHE). Dogs were randomly assigned to three groups: (1) a control group that received no analgesics, (2) a BSC group that received buprenorphine SC (20 microg/kg), and (3) a BP group that received buprenorphine by a 70 microg/h transdermal patch. Dogs were scored for signs of pain at 0, 2, 4, 6, 8, 10, 14, 20, 26, 32 and 38 h after extubation using the Numerical Rating Scale (NRS) and a modified University of Melbourne Pain Scale (UMPS). Mean NRS and UMPS scores for dogs in the BSC group (2.56 ± 0.23 and 3.05 ± 0.27, respectively) and the BP group (2.02 ± 0.24 and 2.67 ± 0.23, respectively) were significantly lower (P<0.05) compared with dogs in the control group (5.42 ± 0.38 and 7.89 ± 0.44, respectively), whereas differences between the two buprenorphine treatment groups were not significant. The results indicated that the analgesia produced by the 70 microg/h patch was similar to that induced by SC administration of 20 microg/kg of buprenorphine in dogs undergoing OHE, suggesting that the transdermal buprenorphine patch may be a useful alternative for pain management in dogs.
The Veterinary Journal 01/2011; 187(1):124-8. DOI:10.1016/j.tvjl.2009.11.011 · 1.76 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The objective of the present study was to evaluate the plasma concentrations and pharmacokinetics of buprenorphine after transdermal application in dogs (n = 4). A 70 microg/h transdermal buprenorphine patch was applied to the ventral abdomen of four healthy beagles. Blood samples were collected through a preplaced jugular catheter before and at 1, 2, 4, 8, 12, 24, 36, 48 and every 6 h until 108 h after the patch application. Plasma buprenorphine concentrations were measured using a (125)I-labelled radioimmunoassay (RIA) assay. No adverse effects were observed in any of the dogs. Concentrations of buprenorphine were detected in plasma after the application of the transdermal buprenorphine patch on the four experimental animals. Buprenorphine plasma concentrations increased during the first 36 h and then remained in the 0.7-1.0 ng/mL range during the study period. A decrease in plasma buprenorphine concentration was not observed during the study. Although analgesia could not be demonstrated the present study shows the ability of buprenorphine transdermal delivery systems developed for human use to deliver measurable concetrations of buprenorphine in dogs.
Journal of Veterinary Pharmacology and Therapeutics 10/2009; 32(5):503-5. DOI:10.1111/j.1365-2885.2009.01058.x · 1.19 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Benign prostatic hyperplasia (BPH) is an age-dependent prostatic disease affecting male humans and dogs. In dogs, the combined administration of estrogens and androgens synergistically increases prostate weight, and continued treatment leads to the development of glandular hyperplasia. The aim of the present study was to examine the immunohistochemical expression of androgen receptor (AR), estrogen receptor alpha (ER alpha), and estrogen receptor beta (ER beta) in the different cell types of the prostate gland in an experimental model. Five male beagle dogs were castrated and treated with 25 mg of 5 alpha-androstane-3 alpha and 17beta-diol and 0.25 mg 17beta-estradiol for 30 weeks. Prostate specimens were surgically obtained every 45 days (experimental stages M0 to M6: 0, 12, 18, 24, 30, and 36 weeks from the beginning of the hormonal treatment). The control group consisted of 3 noncastrated dogs treated with a vehicle, from which specimens were only taken at the time points M0, M1, M4, and M6. Immunohistochemical data revealed high AR and ER alpha expression in the epithelial and stromal cell nuclei of all the experimental and control specimens. Weak staining of the cytoplasm was observed only in epithelial cells. The suspension of hormone treatment led to a significant reduction in the expression of both receptors. On the contrary, ER beta was expressed only in epithelial cell nuclei, with no significant differences in the percentages of stained nuclei between control and hormonally treated or atrophic prostates. Results indicate that AR, ER alpha, and ER beta are differently expressed in canine prostate tissue and that they show specific expression patterns in response to the hormonal induction of BPH.
Journal of Andrology 02/2009; 30(3):240-7. DOI:10.2164/jandrol.108.006775 · 2.47 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Etomidate is an intravenous (IV) hypnotic agent characterised by its cardiovascular stability. Although etomidate has been satisfactorily used in veterinary and human obstetrics, little is known about its effects on the fetus. This study determined the cardiovascular and acid-base effects of etomidate administration in the pregnant ewe and her fetus. The effects of etomidate were evaluated in two separate studies. In the first study, etomidate was administered as a 1mg/kg IV bolus; in the second, the drug was administered as a continuous infusion of 100 microg/kg/min for 1h, preceded by a 1mg/kg IV bolus. Etomidate administration did not depress cardiovascular function in the pregnant ewe or fetus. When administered as a continuous infusion, maternal heart rate and blood pressure increased during the second half of the infusion and the initial stages of recovery. Acid-base alterations led to transient but slight respiratory depression in both mother and fetus, probably reflecting the combined effects of etomidate on respiration and the positioning of the animal.
The Veterinary Journal 08/2008; 177(1):94-103. DOI:10.1016/j.tvjl.2007.03.023 · 1.76 Impact Factor