Campylorrhinus lateralis, Bilateral microphthalmia and odontoma temporalis in an Oldenburg Foal.

An Oldenburg colt with wry nose was autopsied after having lived for only 30 min. It presented cyanotic oral mucosae, underdeveloped eyes and a right-sided temporal osseous mass. The applicable nomenclature for the defects is discussed, and the potential etiopathogenesis is explored by describing the normal embryonic development of the affected body parts.

Stereology and computer assisted three-dimensional reconstruction as tools to study probiotic effects of Aeromonas hydrophila on the digestive tract of germ-free Artemia franciscana nauplii.

AIMS: Validation of stereology and three-dimensional reconstruction for monitoring the probiotic effect of Aeromonas hydrophila on the gut development of germ-free Artemia franciscana nauplii. METHODS AND RESULTS: Germ-free Artemia nauplii were cultured using Baker's yeast and dead Aer. hydrophila. Live Aer. hydrophila were added on the first day to the treatment group. The gut length and volume were monitored on days two and four using stereology and three-dimensional reconstruction. Both methods showed comparable results. Stereology was least labour intensive to estimate volumes, while three-dimensional reconstructions rendered architectural and topographical data of the gut. Moreover, a positive effect of probiotic bacterium, Aer. hydrophila is likely. CONCLUSION: Slight increment in the growth of the digestive tract of A. franciscana nauplii exerted by probiotic bacteria could be detected using stereology and three-dimensional reconstruction. SIGNIFICANCE AND IMPACT OF THE STUDY: The gnotobiotic Artemia rearing system is unique to investigate the effects of micro-organisms on the development of nauplii. However, in the base of this model system, only survival counts and length measurements exist as monitoring tools. Therefore, additional tools such as stereology and three-dimensional reconstruction are prerequisite to obtain more powerful analysis.

Locations of gut-associated lymphoid tissue in the 3-month-old chicken: a review.

The lymphoid tissue that is associated with the intestinal tract, the so-called gut-associated lymphoid tissue (GALT), is well developed in the chicken. Depending on the location, it is present as aggregations of lymphoid cells, or organized in lymphoid follicles and tonsils. From proximal to distal, the intestinal tract contains a pharyngeal tonsil, diffuse lymphoid tissue and lymphoid follicles in the cervical and thoracic parts of the oesophagus, an oesophageal tonsil, diffuse lymphoid tissue in the proventriculus, a pyloric tonsil, Peyer's patches, Meckel's diverticulum, two caecal tonsils, diffuse lymphoid tissue in the rectum, the bursa of Fabricius, and diffuse lymphoid tissue in the wall of the proctodeum. The lymphoid tissues are frequently covered by a lympho-epithelium that is infiltrated by lymphoid cells. Such an epithelium often contains M or microfold cells, which are specialized in antigen sampling and transport antigens to the underlying lymphoid tissue. A solid knowledge of the avian GALT could contribute to the development of vaccines to be administered orally. Additionally, immune stimulation via pre- and probiotics is based on the presence of a well-developed intestinal immune system.

Transsplenic portal catheterization combined with a jugular double-lumen catheter for pharmacokinetic and presystemic metabolization studies in pigs.

The reliability of a silicone double-lumen catheter implanted into the external jugular vein and tunnelled towards the neck region was investigated in eight pigs. Surgery was uneventful without interference with the normal homoeostasis during 8 days. After injection of amoxicillin/clavulanic acid through the distal port of the catheter, analysis of drug components in the simultaneous blood samples obtained by the proximal port and a Venoject system were comparable in one pig. Histological control of the catheterized jugular veins pointed to an acceptable tissue reaction while bacteriological examination of the tip of the catheters was negative in only three animals. A moulding of the intestinal veins was made in a pig cadaver to determine the optimal length of insertion of a silicone portal catheter from the splenic vein towards the portal vein. Surgery was straightforward in four pigs whereby the catheter was exteriorized towards the back region. No complications were encountered during and after surgery for 9 days. The technique of a double-lumen catheter placed into the jugular vein and a transsplenic portal catheter is a useful tool for the study of the pharmacokinetics and also the first-pass effect of drugs in experimental pigs.

Hair or salivary cortisol analysis to identify chronic stress in piglets?

Hair cortisol might better represent chronic stress than salivary cortisol in piglets. To test this hypothesis, 24 female, 7-day old piglets were allocated to two groups and artificially reared. The piglets in the stressed group were exposed to overcrowding (0.10m2/piglet) and frequent mixing with unfamiliar piglets until the age of 28 days. The control group remained in an unchanging group at a density of 0.29m2/piglet. After 3 weeks, stressed animals had gained significantly less weight (median, here and throughout, 7.58kg) than the control animals (6.43kg; P=0.021). Additionally, hair from the stressed group contained significantly higher cortisol concentrations (87.29 vs. 75.60pg/mg hair; P=0.005), whereas salivary cortisol concentrations did not significantly differ between groups (0.30 vs. 0.25 µg/dL saliva; P=0.447). Weight gain and hair cortisol concentrations were significantly correlated (P=0.036, r=-0.430), but neither of these parameters were correlated with salivary cortisol concentrations (P=0.929, r=0.019 and P=0.904, r=0.026, respectively).

Absence of arterial phenotype in mice with homozygous slc2A10 missense substitutions.

Arterial tortuosity syndrome (ATS, MIM# 208050) is a rare autosomal recessive connective tissue disease, mainly characterized by widespread arterial involvement with elongation, tortuosity, and aneurysms of the large and middle-sized arteries (Callewaert et al., 2008, Hum Mutat 29:150-158). Recently, mutations were identified in the SLC2A10 gene encoding the facilitative glucose transporter GLUT10 (Coucke et al., 2006, Nat Genet 38:452-457). It was hypothesized that loss-of-function of the transporter results in upregulation of the transforming growth factor beta (TGFbeta) signaling pathway (Coucke et al., 2006, Nat Genet 38:452-457). We anticipated that a mouse model would help to gain more insight in the complex pathophysiological mechanism of human ATS. Here, we report that two mouse models, homozygous respectively for G128E and S150F missense substitutions in glut10 do not present any of the vascular, anatomical, or immunohistological abnormalities as encountered in human ATS patients. We conclude that these mouse strains do not phenocopy human ATS and cannot help the further elucidation of pathogenetic mechanisms underlying this disease.

Anatomy of the lower respiratory tract in domestic birds, with emphasis on respiration.

This manuscript describes the anatomy of the lower respiratory tract in domestic bird species including the chicken and pigeon. The here described anatomical structures play a major role avian respiration, which is fundamentally different from respiration in mammals. During inspiration and expiration, a continuous caudocranial airflow is present within the tertiary bronchi of the Paleopulmo, while the Neopulmo, which is only present in phylogenetically recent species, is characterized by tidal respiration. Various anatomical structures and aerodynamic mechanisms have been described in an attempt to explain the proposed mechanism of respiration. The air sac system that is essential for avian respiration usually comprises an unpaired clavicular air sac and paired cervical, cranial and caudal thoracic, and abdominal air sacs. The latter are by far the larger and are interwoven with the abdominal organs.

Anatomy of the upper respiratory tract in domestic birds, with emphasis on vocalization.

This work reviews the anatomy of the upper respiratory tract in domestic birds including the chicken and pigeon. Non-exhaustive additional information on other bird species, illustrating the extraordinary diversity in the biological class Aves, can be found in several footnotes. The described anatomical structures are functionally considered in view of avian sound production. In particular, the Syrinx is invaluable. Its most important structures are the Labia and the lateral and medial tympaniform membranes in non-songbirds and songbirds, respectively. These structures produce sound by vibrating during expiration and eventually inspiration.

Effect of artificial rearing of piglets on the volume densities of M cells in the tonsils of the soft palate and ileal Peyer's patches.

The high prolificacy of modern hybrid sows has increased the mean litter size during the last decades. However, rearing large litters is challenging and has increased the use of alternative management strategies such as euthanasia of weak piglets, cross-fostering, supplementing piglets with milk, split-nursing and split-weaning. The latter includes artificial rearing on brooders where piglets have ad libitum access to milk replacer. The effect of this artificial rearing on the immune system of the piglet is the subject of various studies. The present study focused on the M cells in the tonsil of the soft palate and in the ileal Peyer's patch (iPP). These epithelial cells are specialized in antigen sampling and play a pivotal role in the induction of adaptive immune responses. The volume densities of the M cells were assessed by stereological analysis of tissue samples from piglets of 0, 3, 8 and 19days of age. During the first three days, piglets suckled the sow, permitting them to ingest colostrum. At the third day, the piglets were either allowed to continue to suckle the sow or were transferred to brooders. The six experimental groups, each containing six piglets, thus consisted of newborn piglets, 3-day-old sow-suckled piglets, and conventionally and artificially reared piglets of 8 and 19days of age. To identify M cells, tissue samples were immersed in 4% phosphate-buffered paraformaldehyde and paraffin sections were immunohistochemically stained against cytokeratin 18. The volume densities of M cells in both the crypt epithelium of the tonsils of the soft palate and the follicle-associated epithelium of the iPPs did not show any difference between the various age groups of conventionally reared piglets. However, values were twice as high in the iPPs compared to the tonsils of the soft palate. In contrast, a decrease in volume densities of M cells was observed in the iPPs of piglets after they had been transferred to commercial brooders (P=0.05), resulting in significantly lower values (P=0.04) in comparison with the age-matched sow-suckled groups. However, this observation did not translate to values of the tonsils where M cell volume densities remained the same in all age and rearing groups. Based on these results, it appears that antigen sampling is possible from birth onwards and is more advanced in the small intestine than in the oropharynx, but possibly lags behind in artificially reared piglets.

Left Retrocaval Ureter around the Ipsilateral Limb of a Double Caudal Vena Cava in a Cat.

Necropsy examination of an adult neutered male cat, which was humanely destroyed as it had feline immunodeficiency virus (FIV) infection, demonstrated the presence of a left retrocaval ureter that was entrapped around the left limb of a double caudal vena cava. These associated anomalies originate from the complex embryofetal development of the caudal vena cava. Since no clinical signs had been reported and no gross lesions related to this anomaly were observed, this manifestation should be simply considered as an anatomical variation.

The ligaments of the canine hip joint revisited.

Numerous conventional anatomical textbooks describe the canine hip joint, but many contradictions, in particular regarding the ligament of the femoral head, are present. This paper presents a brief overview of the different literature descriptions. These are compared with own observations that have resulted in a revised description of the anatomy of the ligament of the femoral head in the dog. To this purpose, the hip joints of 41 dogs, euthanized for reasons not related to this study and devoid of lesions related to hip joint pathology, were examined. It was observed that the ligament of the femoral head is not a single structure that attaches only to the acetabular fossa, as generally accepted, but it also connects to the transverse acetabular ligament and is complemented by a strong accessory ligament that courses in caudal direction to attach in the elongation of the acetabular notch that extends on the cranioventral surface of the body of the ischium. The description of this accessory ligament in conventional anatomical handbooks is incomplete. This description of the accessory ligament of the femoral head could support the research unravelling the etiopathogenesis of hip instability.

Lymph drainage from the ovine tonsils: an anatomical study of the tonsillar lymph vessels.

Although the tonsils of sheep have gained much attention during the last decade, only few data are available on their lymph vessel architecture. Tonsillar lymph vessels are immunologically important as they form the efferent routes for locally activated immune cells to reach the draining lymph nodes. To gain insight into the tonsillar lymph drainage in the sheep, Indian ink and a casting polymer were injected into the interstitium of the five tonsils present in the heads of slaughtered sheep. This enabled us to determine the draining lymph node and to examine the microscopic organization of lymph vessels using light and scanning electron microscopy. No lymph vessels were observed within the tonsillar lymphoid follicles. The corrosion casts demonstrated that the lymphoid follicles are surrounded by numerous sacculated lymph sinuses that drain into a dense interfollicular lymph vessel network. From here, the lymph flows into single small lymph vessels that in turn drain into larger lymph vessels extending towards the medial retropharyngeal lymph node. The presented results can be valuable for immunological studies, for example during oral or intranasal vaccine development.

Lymphangiogenesis in canine mammary tumours: a morphometric and prognostic study.

Canine mammary tumours (CMTs) are the most common tumours of entire female dogs and represent a promising model for human breast cancer. Little is known about the presence and prognostic value of lymphangiogenesis in CMTs. The aims of the present study were to analyze selected characteristics of lymphatic vessels in CMTs, to evaluate their prognostic significance and to compare these results with studies of human breast cancer. Fifty-six benign CMTs, 55 malignant CMTs and 13 control samples of normal canine mammary gland tissue were studied. Serial immunohistochemical labelling with the lymphatic marker prox-1 and the proliferation marker Ki67 was performed. In intratumoural (IT) and peritumoural (PT) regions, the lymphatic vessel density (LVD), mean lymphatic vessel perimeter (LVP) and relative area occupied by lymphatic vessels (LVA) were analyzed. Lymphatic endothelial cell proliferation (LECP) and tumour cell proliferation (TCP) were also measured. Lymphatic vessels were identified in IT and PT regions and lymphangiogenesis was present in both regions. The IT lymphatic vessels were smaller, less numerous and occupied a smaller relative area compared with those of the PT region. Although no differences in lymphatic vessel parameters were observed between benign and malignant tumours, control tissue differed significantly from neoplastic tissue. None of the lymphatic vessel parameters showed a prognostic value, except for LECP in PT regions of benign tumours. The findings were in accordance with results of investigations into human breast cancer, which supports the use of dogs with spontaneously occurring CMTs as an animal model in comparative oncology trials.

Angiogenesis in canine mammary tumours: a morphometric and prognostic study.

Angiogenesis in canine mammary tumours (CMTs) has been described previously; however, only the intratumoural (IT) region has been studied and information on peritumoural (PT) angiogenesis is lacking. In this study, the blood vessel density (BVD), blood vessel perimeter (BVP) and blood vessel area (BVA) in IT and PT regions of 56 benign CMTs, 55 malignant CMTs and 13 samples of normal mammary gland tissue were analyzed. In addition, the blood endothelial cell proliferation (BECP) as an indicator of ongoing angiogenesis was investigated. The prognostic value of each parameter was also examined. Blood vessels and proliferating blood endothelial cells were present in IT and PT regions of both benign and malignant tumours. The vessels in the PT region had a significantly higher area and perimeter compared with those in the IT region. Malignant tumours showed significantly more vessels with a smaller total BVA and a higher BECP compared with benign tumours and control tissue. In the PT regions there was a significantly higher BVD, BVA and BVP compared with the vessels in control tissue. Only the IT and PT BVD and PT BECP in benign tumours allowed prediction of survival. The morphology of blood vessels in CMTs shows similarities with those in human breast cancer, which strengthens the case for the use of dogs with CMTs in comparative oncology trials.

Supplementing formula-fed piglets with a low molecular weight fraction of bovine colostrum whey results in an improved intestinal barrier.

To test the hypothesis that a low molecular weight fraction of colostral whey could affect the morphology and barrier function of the small intestine, 30 3-d-old piglets (normal or low birth weight) were suckled (n = 5), artificially fed with milk formula (n = 5), or artificially fed with milk formula with a low molecular weight fraction of colostral whey (n = 5) until 10 d of age. The small intestine was sampled for histology (haematoxylin and eosin stain; anti-KI67 immunohistochemistry) and enzyme activities (aminopeptidase A, aminopeptidase N, dipeptidylpeptidase IV, lactase, maltase, and sucrase). In addition, intestinal permeability was evaluated via a dual sugar absorption test and via the measurement of occludin abundance. Artificially feeding of piglets reduced final BW (P < 0.001), villus height (P < 0.001), lactase (P < 0.001), and dipeptidylpeptidase IV activities (P < 0.07), whereas crypt depth (P < 0.001) was increased. No difference was observed with regard to the permeability measurements when comparing artificially fed with naturally suckling piglets. Supplementing piglets with the colostral whey fraction did not affect BW, enzyme activities, or the outcome of the dual sugar absorption test. On the contrary, the small intestines of supplemented piglets had even shorter villi (P = 0.001) than unsupplemented piglets and contained more occludin (P = 0.002). In conclusion, at 10 d of age, no differences regarding intestinal morphology and permeability measurements were observed between the 2 BW categories. In both weight categories, the colostral whey fraction affected the morphology of the small intestine but did not improve the growth performances or the in vivo permeability. These findings should be acknowledged when developing formulated milk for neonatal animals with the aim of improving the performance of low birth weight piglets.

Age-related differences in mucosal barrier function and morphology of the small intestine in low and normal birth weight piglets.

To test the hypothesis that the mucosal maturation of the small intestine is altered in low birth weight piglets, pairs of naturally suckled low birth weight (LBW, n = 20) and normal birth weight (NBW, n = 20) littermate piglets were selected and sampled after 0, 3, 10, and 28 d of suckling. In vivo intestinal permeability was evaluated via a lactulose-mannitol absorption test. Other indirect measurements for mucosal barrier functioning included sampling for histology and immunohistochemistry (intestinal trefoil factor [ITF]), measuring intestinal alkaline phosphatase (IAP) activity, and immunoblotting for occludin, caspase-3, and proliferating cell nuclear antigen (PCNA). The lactulose-mannitol ratio did not differ between NBW and LBW piglets, but a significant increase in this ratio was observed in 28-d-old piglets (P = 0.001). Small intestinal villus height did not differ with age (P = 0.02) or birth weight (P = 0.20). In contrast, villus width (P = 0.02) and crypt depth (P < 0.05) increased gradually with age, but no birth-weight-related differences were observed. LBW piglets had significantly (P = 0.03) more ITF immunoreactive positive cells per villus area compared to NBW piglets, whereas no age (P = 0.82) or region-related (P = 0.13) differences could be observed. The activity of IAP in the small intestine was higher in newborn piglets compared to the older piglets. No significant differences in cell proliferation in the small intestine was observed (P = 0.47) between NBW and LBW piglets; the highest proliferation was seen in piglets of 28 d of age (P = 0.01). Newborn piglets had significantly fewer apoptotic cells, whereas more apoptotic cells were seen in piglets of 10 d of age (P < 0.01). In conclusion, birth weight did not affect the parameters related to intestinal barrier function investigated in this study, suggesting that the mucosal barrier function is not altered in LBW piglets. Nevertheless, these results confirm that the mucosal barrier function in the small intestine of piglets alters with age.

Enteric and serological distribution of serotonin and its precursor tryptophan in perinatal low and normal weight piglets.

Perinatal mortality is high among small-for-gestational age (SGA) piglets and continues to be an economic burden and threat to animal welfare. As the physiological role of serotonin (5-hydroxytryptamine, 5-HT) in perinatal development and gastrointestinal function in the pig remains unknown, the aim of this study was to assess the enteric distribution of 5-HT cells and to determine 5-HT together with its precursor tryptophan in the serum of perinatal normal and SGA piglets. For this purpose, proximal and distal parts of the small intestine (SI) were processed for immunohistochemical analysis to assess the presence of 5-HT endocrine cells. Serum 5-HT was measured with ELISA, whereas its precursor, that is, the free fraction of tryptophan (FFT) together with albumin-bound tryptophan and total tryptophan, were analysed with HPLC in postnatal piglets. In addition, the morphological growth patterns of the different intestinal tissue layers of both normal and SGA piglets were stereologically analysed. The stereological volume density of 5-HT enteroendocrine cells showed a significant interaction effect between age and region. Indeed, the amount of 5-HT cells in both the proximal and distal part of the SI tended to decrease according to age, with the lowest values detected at day 3 postpartum. No differences could be observed related to BW. Interestingly, the serum concentration of 5-HT was higher in normal piglets compared with SGA piglets. Moreover, the ratio of FFT to total tryptophan was significantly affected by age and BW. Normal piglets had, on average, a lower FFT/total tryptophan ratio compared with SGA piglets. An approximate linear decrease was observed with increasing age. Finally, the immaturity of the intestinal system of the SGA piglets was not reflected in altered volume densities of the different intestinal layers. To conclude, although no BW effect could be detected in the distribution of enteric 5-HT cells, serum 5-HT and the ratio of FFT to total tryptophan ratio showed significant differences between normal piglets and their SGA littermates.

Time-of-flight magnetic resonance angiography (TOF-MRA) of the normal equine head.

REASONS FOR PERFORMING STUDY: Noncontrast magnetic resonance angiography (MRA) is widely used in human and small animal medicine. However, this technique has not yet been described in the horse, and compared to other angiographic techniques MRA could be more cost efficient and potentially safer. OBJECTIVES: The aim of this study was to provide a comprehensive anatomical reference of the normal equine head vasculature using a noncontrast MRA technique, on both low- and high-field MRI. METHODS: Five healthy adult horses were examined, 4 with a low-field magnet (0.23T) and the remaining one with a high-field magnet (1.5T). The magnetic resonance angiography sequence used was TOF (time-of-flight) 2D-MRA and CT images of a vascular corrosion cast were subsequently used as anatomical references. RESULTS: The MRA imaging protocol provided good visualisation of all major intra- and extracranial vessels down to a size of approximately 2 mm in diameter on both low- and high-field systems. This resulted in identification of vessels to the order of 3rd-4th branches of ramification. The visibility of the arteries was higher than of the veins, which showed lower signal intensity. Overall, MRA obtained with the high-field protocol provided better visualisation of the arteries, showing all the small arterial branches with a superior resolution. CONCLUSIONS: The use of a specific vascular sequence such as TOF 2D-MRA allows good visualisation of the equine head vasculature and eliminates the need for contrast media for MRA. POTENTIAL RELEVANCE: Magnetic resonance angiography allows for visualisation of the vasculature of the equine head. Vessel morphology, symmetry and size can be evaluated and this may possibly play a role in preoperative planning or characterisation of diseases of the head, such as neoplasia or guttural pouch mycosis.