References of "Piret, Joëlle"
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See detailMechanoreceptors in the anterior horn of the equine medial meniscus: an immunohistochemical approach.
Nemery, Elodie ULg; Gabriel, Annick ULg; Piret, Joëlle ULg et al

Poster (2014)

Mechanoreceptors are “encapsulated sensory end-organs” involved in proprioceptive function. Given the high incidence of meniscal injuries in horses, the clinical interest in these mechanoreceptors ... [more ▼]

Mechanoreceptors are “encapsulated sensory end-organs” involved in proprioceptive function. Given the high incidence of meniscal injuries in horses, the clinical interest in these mechanoreceptors, particularly in the meniscus, and the lack of information concerning them in equine menisci, our objective was to study these corpuscles in the anterior horn of the equine medial meniscus, which is the most common localization reported for equine meniscal injuries. An immunohistochemical approach to detect Schwann cells and nerve fibres allowed us to localize and identify these corpuscles within the meniscus. Three types of mechanoreceptors were identified and localized between the abaxial quarter and the abaxial third of the meniscus: the Ruffini, Pacini and Golgi corpuscles. In conclusion, from a purely fundamental point of view, our work highlights for the first time the presence of MCR at the level of the anterior horn of the equine medial meniscus and proposes a classification based on specific immunocytochemical techniques. This morphological approach could serve as a basis for clinical studies, in order to evaluate the impact of these corpuscles on the poor sportive prognosis in equine meniscal tears. [less ▲]

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See detailDevelopment of Astrocytes in the Sheep Cerebellum
Salouci, Moustafa ULg; Antoine, Nadine; Shikh Al Sook, Mohamad Khir ULg et al

Poster (2013, October 11)

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See detailThree-dimensional reconstruction of the pharyngeal tonsil innervation pattern in sheep
Toppets, Vinciane ULg; Piret, Joëlle ULg; Gabriel, Annick ULg et al

in Journal of Neuroimmunology (2013), (262), 79-84

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See detailMorphometric analyses of the normal suspensory ligament in Standardbreds
Shikh Al Sook, Mohamad Khir ULg; Antoine, Nadine ULg; Piret, Joëlle ULg et al

Poster (2013, July)

The suspensory ligament (SL) is composed of connective tissue (CT) with a variable proportion of muscle (MT) and adipose tissue (AT). The aim of our study is to quantify the CT, MT and AT within the SL in ... [more ▼]

The suspensory ligament (SL) is composed of connective tissue (CT) with a variable proportion of muscle (MT) and adipose tissue (AT). The aim of our study is to quantify the CT, MT and AT within the SL in sound horses. Right limbs from 11 horses were collected. Samples from 6 levels of the SL were embedded in paraffin or in Tissue-Tek®. Most of the paraffin sections were shredded. Using the cryosection, some artefacts appeared. Cryoprotection was carried out, which produced the best results. Hematoxylin–phloxine–saffron and Hematoxylin–eosin gave a good contrast of colours between the tissues allowing the use of an image analysis programme. The percentage of MT and AT decreased significantly (P < 0.0001), whereas the percentage of CT increased significantly (P < 0.0001) with age and when descending from the proximal to the distal level of the SL. The percentage of MT was significantly higher (P < 0.0001) in females than males, while the percentage of CT was significantly higher (P < 0.0001) in males than females. The percentage of AT was significantly higher (P = 0.0278) in pelvic limbs than in thoracic limbs. These results confirm the variation in tissue composition within the SL of sound horses. [less ▲]

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See detailMorphometric analyses of the body and the branches of the normal third interosseous muscle (suspensory ligament) in Standardbreds
Shikh Al Sook, Mohamad Khir ULg; Antoine, Nadine ULg; Piret, Joëlle ULg et al

in Anatomia, Histologia, Embryologia (2013)

The third interosseous muscle (suspensory ligament, TIOM) is composed of connective tissue (CT) with a variable proportion of muscle (MT) and adipose tissue (AT). The aim of our study is to quantify the ... [more ▼]

The third interosseous muscle (suspensory ligament, TIOM) is composed of connective tissue (CT) with a variable proportion of muscle (MT) and adipose tissue (AT). The aim of our study is to quantify the CT, MT and AT within the body and the branches of right thoracic and pelvic limbs TIOM in sound horses to determine whether there are differences in CT, MT and AT between age, sex, limbs and levels. Right limbs from 11 sound horses were collected. Samples from 6 levels of the TIOM were embedded in paraffin or in Tissue-Tek®. Most of the paraffin sections were shredded. Using the cryosection, some artefacts appeared. Cryoprotection was carried out, which produced the best results. Hematoxylin–phloxine–saffron and Hematoxylin–eosin gave a good contrast of colours between the tissues observed allowing the use of an image analysis programme to calculate percentage of each tissue within the TIOM. The percentage of MT and AT decreased significantly (P < 0.0001), whereas the percentage of CT increased significantly (P < 0.0001) with age and when descending from the proximal to the distal level of the TIOM. The percentage of MT was significantly higher (P < 0.0001) in females than males, while the percentage of CT was significantly higher (P < 0.0001) in males than females. The percentage of AT was significantly higher (P = 0.0278) in pelvic limbs than in thoracic limbs. These results confirm the variation in tissue composition within the TIOM of sound horses. [less ▲]

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See detailLong term culture and characterization of chicken primordial germ cells
Tonus, Céline ULg; Waroux, Olivier ULg; Cloquette, Karine et al

Poster (2012, November)

Avian primordial germ cells (PGCs), can keep their germ cells properties and are foreseen as promising tools for developing avian transgenesis and preservation of genetic resources of endangered species ... [more ▼]

Avian primordial germ cells (PGCs), can keep their germ cells properties and are foreseen as promising tools for developing avian transgenesis and preservation of genetic resources of endangered species. We have developed original methods that allow long term (20 month) expansion of primary cultures of undifferentiated PGCs and their efficient cryopreservation. Blood samples were collected from stage 13-18 embryos, pooled, deposited in cell culture inserts and co-cultivated in the presence of irradiated BRL cells. This physically separated co-culture system along with selective culture medium promoted emergence, selection and proliferation of undifferentiated PGCs lines. Overall, 35% of blood samples gave rise to PGCs cell lines originating from three commercial layer breeds and two Belgian endangered breeds. PGCs lines were first characterised for the expression of the stem cells and PGCs characteristic marker SSEA-1 by FACS (expression rate: 90-99%). RT-PCR confirmed expression of germ-line specific markers (CVH, CDH, DAZL), pluripotency markers (cPouV, cSox2, cNanog), telomerase and CXCR4 receptor. In addition, by means of a quantitative PCR amplification of a chromosome W specific sequence, we demonstrated a drift of all our lines towards the male sex (WL), while they were initially isolated from pooled blood samples with statistically equivalent numbers of male and female embryos (35 females: 29 males). PGCs were subsequently efficiently cryopreserved by slow freezing or by a newly developed vitrification method. Labelled PGCs from 10 lines were injected in recipient embryos. Colonization of the genital ridges confirmed that PGCs retain their gonadal migratory ability, both after long-term culture (min 3, max 20 month) and after cryopreservation. [less ▲]

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See detailThe three-dimensional reconstruction of the innervation pattern in the lymphoid compartment of the ovine pharyngeal tonsil highlighted a possible way of neuro-invasion by the scrapie agent.
Toppets, Vinciane ULg; Piret, Joëlle ULg; Grobet, Luc ULg et al

in Proceedings of the 2nd Scientific Meeting of the Faculty of Veterinary Medicine, ULg, Belgium, October 19, 2012 (2012, October 19)

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See detailMorphological and morphometric analyses of the suspensory ligament in Standardbreds
Shikh Al Sook, Mohamad Khir ULg; Antoine, Nadine ULg; Piret, Joëlle ULg et al

Poster (2012, October)

Ultrasound techniques allow examination of some parts of the suspensory ligament (SL) but "anomalies" are regularly observed. Their significance is not known. Few studies have described the relationship ... [more ▼]

Ultrasound techniques allow examination of some parts of the suspensory ligament (SL) but "anomalies" are regularly observed. Their significance is not known. Few studies have described the relationship between ultrasonographic appearance and the exact morphology in histological sections. The aim of this study is to develop good techniques for cutting, staining, and showing the variation in the tissue composition within the SL. The SLs from the right limbs of 11 horses were collected. Samples were taken from cross-sections at six levels of the SL and they were embedded in paraffin or in Tissue-Tek®. Most of the paraffin sections were shredded. By using the cryosection technique, some freezing artifacts (holes) appeared. Therefore, a technique of freezing with cryoprotection was carried out, which produced the best results. Hematoxylin-phloxine-saffron gives a good contrast of colors between the tissues observed allowing the use of an image analysis program. The percentage of each tissue within the SL for each section and for six levels of the ligament was calculated. Results were analyzed by SAS software. The muscle tissue (PMT) and adipose tissue (PAT) decreased significantly (p < 0.0001), whereas the connective tissue (PCT) increased significantly (p < 0.0001) with age and when descending from the proximal to the distal level of the SL. The PMT was significantly higher (p < 0.0001) in females than males, while the PCT was significantly higher (p < 0.0001) in males than females. The PAT was significantly higher (p = 0.0278) in hindlimbs than in forelimbs. [less ▲]

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See detailNeuroimmune connections in ovine pharyngeal tonsil: potential site for prion neuroinvasion
Toppets, Vinciane ULg; Piret, Joëlle ULg; Kirschvink, Nathalie et al

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 ▲]

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See detailPrevalence of naturally occuring cartilage defects in the ovine stifle
Pierson, Audrey ULg; Muylkens, Benoît ULg; Hontoir, Fanny et al

Poster (2012)

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See detailFeatures of follicular dendritic cells in ovine pharyngeal tonsil: An in vivo and in vitro study in the context of scrapie pathogenesis
Toppets, Vinciane ULg; Defaweux, Valérie ULg; Piret, Joëlle ULg et al

in Veterinary Immunology and Immunopathology (2011), 141

Although the alimentary tract has been suggested as the most likely portal of entry in natural scrapie, a growing amount of data indicates that the respiratory system and more specifically the pharyngeal ... [more ▼]

Although the alimentary tract has been suggested as the most likely portal of entry in natural scrapie, a growing amount of data indicates that the respiratory system and more specifically the pharyngeal tonsils serve as a natural portal of entry for scrapie. This study describes for the first time the broad cell populations in the lymphoid compartment of pharyngeal tonsils and more specifically inside the lymphoid follicles where the scrapie agent accumulates during the period of latency. Follicular dendritic cells (FDCs), stromal cells located in the light zone of the germinal centre of lymphoid follicles, seem to be the principal causal factor in the accumulation of the infectious agent in transmissible spongiform encephalopathy (TSE) diseases. Knowing that efficient lymphoreticular prion propagation requires PrPc expression, we analysed the expression of PrPc with the mouse monoclonal antibody Pri 909 both in situ and on FDC-cluster-enriched cell suspensions. In situ, a positive staining was observed in the germinal centre of pharyngeal lymph follicles. The germinal centre labelling was due to the presence of a follicular dendritic network as revealed after immunogold staining of isolated FDC clusters. Our results suggest that the pharyngeal lymphoreticular system and more specifically PrPc expressing follicular dendritic cells could serve as a prion “reservoir” during the latency phase, thus playing a key role during the scrapie lymphoinvasion. [less ▲]

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See detailMorphology of the suspensory ligament (interosseous muscle III) of the horse
Shikh Al Sook, Mohamad Khir ULg; Espinosa, Jennifer; Piret, Joëlle ULg et al

Poster (2011)

Introduction: The injuries of the suspensory ligament (SL) are important causes of lameness and financial losses in the equine industry. Ultrasound examination permitted to visualize some parts of the SL ... [more ▼]

Introduction: The injuries of the suspensory ligament (SL) are important causes of lameness and financial losses in the equine industry. Ultrasound examination permitted to visualize some parts of the SL. The significance of “abnormal” findings is however not sufficiently known. Until now, few studies described the relationship between the ultrasonographic appearance and the exact morphology in histological sections. The aim of this study is to develop good techniques for cutting and staining the SL and to improve knowledge about the normal morphology of the SL. Methods: In this study, the SL of eight <sound> horses were collected. The body of the SL was divided in 3 thirds and sampling was realised within each third and between the thirds. The samples were embedded in paraffin or in Tissue-Tek for cryosections. The sections were stained with hematoxylin/eosin or Masson's trichrome. For 3 SL, ultrasounds were performed before sampling. The digital tip was maintained in physiological position owing to a press. Results: Most of the paraffin sections were shredded because of the hardness of the tissue. Cryosection revealed a better preservation of tissues. Only some freezing artifacts (holes) appeared on a few sections. Muscles fibers surrounded by adipose tissue containing blood vessels were present mainly in the proximal and medium third of the SL whereas they were not found in the distal third. The remaining structure look like a tendon and was composed of collagen fibers, stained in green with the Masson's trichrome coloration. Conclusions: This study permitted to develop cutting and staining techniques for the SL and helped to map the adipose, muscular and tendinous parts within the SL. It lays down the bases of subsequent studies that will concern ultrasonographically examined digital tips of sound and pathological horses of different breeds and ages. [less ▲]

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See detailMorphology of the digital sheath in horses
Strzalkowski, A; Espinosa, J; Jacqmot, O et al

in Anatomia, Histologia, Embryologia (2010, August), 39(4), 288

Introduction: The digital sheath is located in the palmar (plantar) face of the distal limb. It consists of a synovium, divided into intimate and vascularised supportive layers, and ligaments that ... [more ▼]

Introduction: The digital sheath is located in the palmar (plantar) face of the distal limb. It consists of a synovium, divided into intimate and vascularised supportive layers, and ligaments that strengthen the tendon sheath in its palmar (plantar) face. The synovium surrounds the digital flexor tendons during their passage within the sheath. The synovium fluid, produced by the filtering of the blood and by the intima cells, allows lubrification within the sheath. Lameness, originating from digital sheath pathology is not rare, and it is important, for any equine practitioner, to know its normal morphology. The aim of this study is to precise the morphology of the digital sheath, particularly its synovium because the literature is not unanimous. Methods: The digitals tips of 7 "sound" horses were collected. Samples were taken within the 3 annular ligaments (Proximal, Digital Proximal, Digital Distal). The digital flexor tendons were sampled with the visceral sheath of the synovial membrane at the level of the proximal sesamoïd bones and just proximal to the medium scutum. All these samples were embedded in tissue-tek and freezed for cryosectioning. The proximal and distal recessus of the synovial membrane were also sampled, fixed in formalin and embedded in paraffin. Sections were stained with haematoxylin/eosin. One sample of the synovial membrane was taken for electronic microscopy and embedded in? Results: Annular ligaments are composed of dense connective tissue but are transversal strengthening of the fascia rather than true ligaments. The digital flexor tendons showed the typical organisation of the collagen network. Type III fibrocytes were observed within the deep digital flexor tendon. The synovial membrane showed two layers: an intima (with visceral and parietal sheath) with fibroblast-like cells and macrophagic cells, and a sub-intima composed of fibrous tissue that was sometime so thickened that it was difficult to cut! The recessus contained large synovial fringe with adipose tissue. Conclusion: This study permitted to precise the morphology of the digital sheath in horse which may help to better understand the pathological changes. [less ▲]

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See detailMorphology of the suspensory ligament (interosseous muscle III) of the horse
Shikh Al Sook, Mohamad Khir ULg; Espinosa, Jennifer; Piret, Joëlle ULg et al

Poster (2010)

Introduction: The injuries of the suspensory ligament (SL) are important causes of lameness and financial losses in the equine industry. Ultrasound examination permitted to visualize some parts of the SL ... [more ▼]

Introduction: The injuries of the suspensory ligament (SL) are important causes of lameness and financial losses in the equine industry. Ultrasound examination permitted to visualize some parts of the SL. The significance of “abnormal” findings is however not sufficiently known. Until now, few studies described the relationship between the ultrasonographic appearance and the exact morphology in histological sections. The aim of this study is to develop good techniques for cutting and staining the SL and to improve knowledge about the normal morphology of the SL. Methods: In this study, the SL of eight <sound> horses were collected. The body of the SL was divided in 3 thirds and sampling was realised within each third and between the thirds. The samples were embedded in paraffin or in Tissue-Tek for cryosections. The sections were stained with hematoxylin/eosin or Masson's trichrome. For 3 SL, ultrasounds were performed before sampling. The digital tip was maintained in physiological position owing to a press. Results: Most of the paraffin sections were shredded because of the hardness of the tissue. Cryosection revealed a better preservation of tissues. Only some freezing artifacts (holes) appeared on a few sections. Muscles fibers surrounded by adipose tissue containing blood vessels were present mainly in the proximal and medium third of the SL whereas they were not found in the distal third. The remaining structure look like a tendon and was composed of collagen fibers, stained in green with the Masson's trichrome coloration. Conclusions: This study permitted to develop cutting and staining techniques for the SL and helped to map the adipose, muscular and tendinous parts within the SL. It lays down the bases of subsequent studies that will concern ultrasonographically examined digital tips of sound and pathological horses of different breeds and ages. [less ▲]

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