Use of Sheep Ovarian Tissue as a Model to Restore Fertility in Young Cancerous Women

Poster (2012, December 10)

Neuroimmune connections in ovine pharyngeal tonsil: potential site for prion neuroinvasion

in Cell & Tissue Research (2012)

Recent studies have proved the possible implication of nasal associated lymphoid tissues, mainly the pharyngeal tonsil, in prion pathogenesis. However, the mechanisms of this neuroinvasion are still being ... [more ▼]

Recent studies have proved the possible implication of nasal associated lymphoid tissues, mainly the pharyngeal tonsil, in prion pathogenesis. However, the mechanisms of this neuroinvasion are still being debated. To determine the potential sites for prion neuroinvasion inside the ovine pharyngeal tonsil, the topography of neurofilaments heavy (200 kDa) (NFH), neurofilaments light (70 kDa) (NFL) and glial fibrillar acidic protein (GFAP) was semi-quantitatively analysed inside the different compartments of the tonsil. The results showed that the most innervated areas were the interfollicular area and the connective tissue located beneath the respiratory epithelium. Even if the germinal centre of the lymphoid follicles was poorly innervated, the existence of rare follicular dendritic cell-nerve synapses inside the germinal centre indicates that this mechanism of neuroinvasion is possible but unlikely to be unique. The host PRNP genotype did not influence the pattern of innervation in these different tonsil compartments, unlike age: an increase of nerve endings in a zone of high trafficking cells beneath the respiratory epithelium occurred with ageing. A minimal age-related increase of innervation inside the lymphoid follicles was also observed. An increase in nerve fibre density around the lymphoid follicles, in an area rich in mobile cells able to transport PrPd, could ensure a more efficient infectivity, not in the early phase but in the advanced phase of lymphoinvasion after amplification of PrPd, or could act as direct site of entry during neuroinvasion. [less ▲]

Is evidence-based medicine so evident in veterinary research and practice? History, obstacles and perspectives.

in Veterinary Journal (2012), 191(1), 28-34

Evidence-based medicine (EBM) refers to the conscientious, explicit and judicious use of current best evidence from research for the care of an individual patient. The concept of EBM was first described ... [more ▼]

Evidence-based medicine (EBM) refers to the conscientious, explicit and judicious use of current best evidence from research for the care of an individual patient. The concept of EBM was first described in human medicine in the early 1990s and was introduced to veterinary medicine 10 years later. However, it is not clear that the EBM approach promulgated in human medicine can be applied to the same extent to veterinary medicine. EBM has the potential to help veterinarians to make more informed decisions, but obstacles to the implementation of EBM include a lack of high quality patient-centred research, the need for basic understanding of clinical epidemiology by veterinarians, the absence of adequate searching techniques and accessibility to scientific data bases and the inadequacy of EBM tools that can be applied to the busy daily practise of veterinarians. This review describes the development of EBM in the veterinary profession, identifies its advantages and disadvantages and discusses whether and how veterinary surgeons should further adopt the EBM approach of human medicine. [less ▲]

Morphological and histological studies of sheep’s brain

Poster (2011, December)

Introduction: The study of normal structures of the sheep’s brain is very important to understand pathological changes caused by the bluetongue virus in the fetus’s brain at various stages of the ... [more ▼]

Introduction: The study of normal structures of the sheep’s brain is very important to understand pathological changes caused by the bluetongue virus in the fetus’s brain at various stages of the gestation. Bluetongue is an arthropod-borne viral disease of domestic and wild ruminants. The serotype 8 is responsible for outbreaks in Northern Europe in 2006. This virus causes lesions in the brain of fetuses as hydrancephaly and porencephaly. The aim of this work is to improve knowledge of anatomy and histology of the central nervous system of the sheep. Methods: Seven heads of adult sheep and one from a fetus aged 4,5 months were used. All heads were first opened in the frontal area using bone’s saw and immerged in a formalin solution for 10 days. After a good fixation, the brains were extracted and sectioned. Transversal, frontal and sagittal sections were realized. The sections of two brains were stained with Berlin-blue and treated to be embedded in methylmetacrylate for gross morphology. The different parts of the 6 resting brains were then embedded in paraffin, cut and the histological sections were stained with haematoxylin/eosin, cresyl violet or by use of silver impregnation. Results: Gross morphological examination of the brains embedded in methylmetacrylate showed the detailed anatomy of the different parts. The staining with haematoxylin/eosin permitted to differentiate the grey matter, the different nucleus and the layers of cerebral and cerebellum cortex. The cresyl violet technique permitted to visualize the Nissl bodies and the silver impregnation revealed nerve fibers. In the fetus brain, blood vessels were very numerous in the brainstem, the cerebellum and the cerebrum. The grey matter was less organized and looser. Conclusion: This work establishes an anatomical and histological approach allowing future studies in ovine fetuses with and without brain lesions potentially caused by the bluetongue virus. [less ▲]

The impact of naturally-occurring, trans-placental bluetongue virus serotype-8 infection on reproductive performance in sheep.

in Veterinary Journal (2011), 187(1), 72-80

Infection with bluetongue virus serotype (BTV)-8 occurred in ruminants in 2006 in Central-Western Europe. The trans-placental passage of this virus has been demonstrated in naturally- and experimentally ... [more ▼]

Infection with bluetongue virus serotype (BTV)-8 occurred in ruminants in 2006 in Central-Western Europe. The trans-placental passage of this virus has been demonstrated in naturally- and experimentally-infected cattle and in experimentally-infected sheep. Trans-placental transmission is potentially important in the 'over-wintering' of this virus and its subsequent impact on reproductive performance. This epidemiological study was carried out on a sheep flock in Belgium that had experienced a severe outbreak of BTV-8 infection, and where the seroprevalence had increased from 1.3% to 88% between January and November 2007. In total, 476 lambs and 26 aborted fetuses from 300 ewes, lambing at four distinct time periods, were investigated between November 2007 and May 2008. The following evidence suggested that BTV-8 infection occurred in utero: (1) positive PCR results from splenic tissue from aborted fetuses (n=4); (2) fetal malformations suggestive of BTV infection (n=10); (3) positive PCR results from red blood cells in-lambs (n=7), and (4) the presence of antibody at birth in viable lambs prior to the intake of colostrum (n=9). The evidence provided by this investigation strongly suggests that trans-placental BTV-8 infection occurs in naturally-infected sheep and the impact of infection on the reproductive performance of such a naive flock was considerable, with up to 25% of ewes aborting and with flock fertility reduced by 50%. The contribution of in utero-infected lambs to the over-wintering of BTV appears limited. [less ▲]

Is evidence-based medicine so evident in veterinary research and practice? : History, obstacles and perspectives

in Veterinary Journal (2011)

Evidence-based medicine (EBM) refers to the conscientious, explicit and judicious use of current best evidence from research for the care of an individual patient. The concept of EBM was first described ... [more ▼]

Evidence-based medicine (EBM) refers to the conscientious, explicit and judicious use of current best evidence from research for the care of an individual patient. The concept of EBM was first described in human medicine in the early 1990s and was introduced to veterinary medicine 10years later. However, it is not clear that the EBM approach promulgated in human medicine can be applied to the same extent to veterinary medicine. EBM has the potential to help veterinarians to make more informed decisions, but obstacles to the implementation of EBM include a lack of high quality patient-centred research, the need for basic understanding of clinical epidemiology by veterinarians, the absence of adequate searching techniques and accessibility to scientific data bases and the inadequacy of EBM tools that can be applied to the busy daily practise of veterinarians. This review describes the development of EBM in the veterinary profession, identifies its advantages and disadvantages and discusses whether and how veterinary surgeons should further adopt the EBM approach of human medicine. [less ▲]

Morphological and histological studies of sheep’s brain

Poster (2010)

Introduction: The study of normal structures of the sheep’s brain is very important to understand pathological changes caused by the bluetongue virus in the fetus’s brain at various stages of the ... [more ▼]

Introduction: The study of normal structures of the sheep’s brain is very important to understand pathological changes caused by the bluetongue virus in the fetus’s brain at various stages of the gestation. Bluetongue is an arthropod-borne viral disease of domestic and wild ruminants. The serotype 8 is responsible for outbreaks in Northern Europe in 2006. This virus causes lesions in the brain of fetuses as hydrancephaly and porencephaly. The aim of this work is to improve knowledge of anatomy and histology of the central nervous system of the sheep. Methods: Seven heads of adult sheep and one from a fetus aged 4,5 months were used. All heads were first opened in the frontal area using bone’s saw and immerged in a formalin solution for 10 days. After a good fixation, the brains were extracted and sectioned. Transversal, frontal and sagittal sections were realized. The sections of two brains were stained with Berlin-blue and treated to be embedded in methylmetacrylate for gross morphology. The different parts of the 6 resting brains were then embedded in paraffin, cut and the histological sections were stained with haematoxylin/eosin, cresyl violet or by use of silver impregnation. Results: Gross morphological examination of the brains embedded in methylmetacrylate showed the detailed anatomy of the different parts. The staining with haematoxylin/eosin permitted to differentiate the grey matter, the different nucleus and the layers of cerebral and cerebellum cortex. The cresyl violet technique permitted to visualize the Nissl bodies and the silver impregnation revealed nerve fibers. In the fetus brain, blood vessels were very numerous in the brainstem, the cerebellum and the cerebrum. The grey matter was less organized and looser. Conclusion: This work establishes an anatomical and histological approach allowing future studies in ovine fetuses with and without brain lesions potentially caused by the bluetongue virus. [less ▲]

A pilot study comparing the antispasmodic effects of inhaled salmeterol, salbutamol and ipratropium bromide using different aerosoldevices on muscarinic bronchoconstriction in healthy cats

in Veterinary Journal (2009), 180

This study compared the duration and magnitude of the antispasmodic effects of salmeterol SLM), salbutamol (SAL), ipratropium bromide (IB) and the combination of SAL and IB (SAL/IB) against carbachol ... [more ▼]

This study compared the duration and magnitude of the antispasmodic effects of salmeterol SLM), salbutamol (SAL), ipratropium bromide (IB) and the combination of SAL and IB (SAL/IB) against carbachol-induced bronchoconstriction in healthy cats, and investigated the gain in efficacy using a two or fourfold increase in drug dosages. The drug regimens used were: (1) LM 25 lg, SAL 100 lg, IB 20 lg and SAL/IB 100 lg/20 lg for bronchodilators delivered by a metered-dose inhaler (MDI); (2) SAL 3.75 mg and IB 62.5 lg for nebulised (NEB) medications. To monitor the bronchodilator effect, airway responsiveness was assessed at different time points using barometric whole-body plethysmography and calculation of the concentration of inhaled carbachol inducing a 300% increase of baseline Penh (enhanced pause), an estimator of airflow limitation Maximum C-Penh300 was recorded 15 min after NEB SAL, IB MDI, NEB IB and 1 h after SAL MDI and 4 h after SLM MDI, respectively. C-Penh300 was significantly different from control values (without treatment) up to 24 h for SLM MDI, 8 h for IB MDI and 4 h for other drugs. In terms of efficacy, SAL/IB MDI showed a synergistic antispasmodic effect at 15 min, 4 h and 8 h after administration. A fourfold increase of the initial dose of IB MDI and NEB IB significantly increased C-Penh300. Despite a fourfold dose increase, SLM displayed the weakest degree of bronchoprotection compared to other bronchodilators. The study provides evidence that inhaled bronchodilators are efficient at preventing muscarinic-induced bronchospasm in healthy cats and that SAL and IB appear to be short-acting bronchodilators in contrast to SLM. [less ▲]

Impact of a natural bluetongue serotype 8 infection on semen quality of Belgian rams in 2007.

in Veterinary Journal (2009), 182(2), 244-51

In 2006, bluetongue (BT) virus serotype 8 emerged in northern Europe and numerous ruminants were affected in the following year. Infertility in males is one of the consequences of BT, although its ... [more ▼]

In 2006, bluetongue (BT) virus serotype 8 emerged in northern Europe and numerous ruminants were affected in the following year. Infertility in males is one of the consequences of BT, although its severity and duration after natural infection has not been documented. In this report, the impact of BT-8 on clinical signs and semen quality of naturally infected rams is described through a longitudinal study of two Belgian ram populations (n=12 and n=24) and a cross sectional study in a further ram population (n=43). Macroscopic semen characteristics, semen concentration, motility, percentage of living and dead spermatozoa were assessed in 167 semen samples collected on 1-6 occasions from 79 BT-8 infected rams within 5-138 days after onset of clinical disease. These were compared with healthy control animals. Significant changes in all variables were observed after natural BT-8 infection. Total recovery occurred around 85 days after clinical disease in animals undergoing a close follow-up of semen quality. Good correspondence between the results of the longitudinal and cross sectional studies suggests that semen quality of BT-8 affected rams reached normal references values 63-138 days after clinical diagnosis of BT. In addition, semen concentration seems to be a sound epidemiological indicator of ram semen quality. [less ▲]

Effects of high and low inspired fractions of oxygen on horse erythrocyte membrane properties, blood viscosity and muscle oxygenation during anaesthesia

in Veterinary Anaesthesia & Analgesia (2009), 36(4), 287-298

To evaluate whether a period of hyperoxia or after a period of hypoxia produced changes attributable to reactive oxygen species in anaesthetized horses. Prospective randomized experimental study. Six ... [more ▼]

To evaluate whether a period of hyperoxia or after a period of hypoxia produced changes attributable to reactive oxygen species in anaesthetized horses. Prospective randomized experimental study. Six healthy (ASA I) geldings, aged 4.5-9.5 years and weighing 510-640 kg(-1). After 30 minutes breathing air as carrier gas for isoflurane, horses were assigned randomly to breathe air as carrier gas (CG0.21) or oxygen as carrier gas (CG1.00) for a further 90 minutes. After an interval of 1 month each horse was re-anaesthetized with the other carrier gas for the 90 minute test period. Ventilation was controlled throughout anaesthesia. Arterial blood was sampled to measure gas tensions, lactate, cholesterol, vitamin E, 4-hydroxy-alkenals, 8-epi-PGF(2 alpha), half haemolysis time, half erythrolysis time, and erythrocyte membrane fluidity. Muscle blood flow and oxygenation were evaluated by near infrared spectroscopy and coloured Doppler. After the first 30 minutes horses were hypoxemic. Subsequently the CG1.00 group became hyperoxaemic (PaO2 similar to 240 mmHg) whereas the CG0.21 group remained hypoxaemic (PaO2 similar to 60 mmHg) and had increased lactate concentration. No significant changes in vitamin E, 4-hydroxy-alkenals, or 8-epi-PGF(2 alpha) concentrations were detected. During the 90 minute test period the CG0.21 group had increased resistance to free-radical-mediated lysis in erythrocytes, whereas the CG1.00 group had slightly decreased resistance of whole blood to haemolysis. CG0.21 induced a progressive muscle deoxygenation whereas CG1.00 induced an increase in muscle oxygen saturation followed by progressive deoxygenation towards baseline. During isoflurane anaesthesia in horses, the hyperoxia induced by changing from air to oxygen induced minimal damage from reactive oxygen species. Using air as the carrier gas decreased skeletal muscle oxygenation compared with using oxygen [less ▲]