Histology and histomorphometry of the tibial diaphyseal growth in two turkey strains during the first six weeks after hatching.

The comparative cortical growth of the tibio-tarsus was studied during the first six weeks after hatching in two turkey strains, a light and a heavy one. At one day post-hatching the cortical appeared to be constituted in both strains of an embryonic non-active fibrous bone tissue which had completely disappeared at one week. On and after one week the cortex was constituted of a fibrolamellar adult bone tissue elaborated on the periosteal part of the cortex. Its vascular pattern depended on the strain and on the thickness of the cortical faces. The histomorphometric studies showed that the growth in thickness was earlier and faster in the heavy strain with a Total Diaphyseal Surface twice larger at 6 weeks but a Diaphyseal Cortical Ratio not significantly different since 3 weeks of age.

[Comparative study of the diaphyseal osseous growth of the tibia between 3 and 12 weeks in 2 strains of turkey: histological and histomorphometric aspects]. / Etude comparée de la croissance osseuse diaphysaire du tibia entre 3 et 12 semaines dans 2 souches de dindes: aspects histologiques et histomorphométriques.

The comparative cortical growth of the tibiotarsus was studied in 2 turkey strains, one light, one heavy, between 3 and 12 weeks of age, using histological and histomorphometrical methods. The growth in thickness started earlier and was much faster and larger in the heavier turkey strain. The early ovoid shape of the cortex of the heavier strain and the difference between the thickness of the narrow and the thick cortical faces seemed to be related to the action of strong mechanical strains. Nevertheless the diaphyseal cortical ratio remained not significantly different in the 2 strains from the age of 3 weeks. The light strain exhibited during all the studied periods indicated a more variable mineral apposition rate and earlier and more extensive bone remodelling phenomena. Most of the growth in thickness parameters were significantly higher in the heavier strain when turkeys of the 2 strains were compared at an equivalent weight.

Hematological parameters and visceral lesions relationships in rabbit viral hemorrhagic disease.

Twenty rabbits were inoculated with a suspension of Viral Hemorrhagic Disease virus. Hemostatic functions were assessed every sixth hour from 6 to 60 hours post-inoculation. Tissue samples obtained at the same intervals allowed the study of the development of lesions throughout the experiment. Biological signs of Disseminated Intravascular Coagulation (DIC) were detected on and after 30 h post-inoculation and consisted of prolonged One Stage Prothrombin Time and Activated Partial Thrombin Time, the decrease of factors V, VII, and X and high levels of soluble fibrin monomer complexes and D-dimers. A reduction of thrombocyte numbers, heterophils and lymphocytes was associated. The close association of DIC and necrotizing hepatitis lesions suggested the hepatic lesions to be the most important DIC triggering factor. Other mechanisms are discussed.

Proviral rearrangements and overexpression of a new cellular gene (nov) in myeloblastosis-associated virus type 1-induced nephroblastomas.

Histological and anatomopathological studies performed on 152 independent myeloblastosis-associated virus type 1 (MAV1)-induced nephroblastomas allowed us to precisely define the chronology of tumor development in chickens. Three tumors representing increasing developmental stages were used to construct genomic libraries and to study both the state of proviral genomes and the sites of MAV1 integration in genomic DNA. We established that increasing levels of proviral rearrangement, eventually leading to the elimination of infectious MAV genomes, were associated with tumor progression and that 22 individual tumors, representative of different developmental stages, did not contain any common MAV1 integration site. Cloning of cellular fragments flanking the MAV1-related proviruses in tumor DNA showed that each one of eight nephroblastomas tested expressed a high level of an as yet unidentified cellular gene (nov) whose transcription is normally arrested in adult kidney cells. Cloning of the normal nov gene established that in one tumor, fused long terminal repeat-truncated nov mRNA species were expressed, indicating that at least in that case, the high level of nov expression was under the control of the MAV long terminal repeat promoter. The normal nov gene encodes a putative 32-kDa secreted polypeptide, which is a member of a new family of proteins likely to be involved in cell growth regulation. We also showed that the expression of an amino-terminal-truncated nov product in chicken embryo fibroblasts was sufficient to induce their transformation.

[Isolation of an adenovirus responsible for a case of pancreatitis in guinea fowl]. / Isolement d'un adénovirus responsable d'un cas de pancréatite chez la pintade.

Necrotizing pancreatitis is observed in 2 to 4 week-old guinea poult. Virus isolation was attempted from the pancreata of naturally affected birds. The isolate was identified as a type 1 adenovirus, and it reproduced the disease when inoculated to sensible guinea fowl.

Late clinical expression of lameness related to associated osteomyelitis and tibial dyschondroplasia in male breeding turkeys.

A sudden outbreak of lameness related to transport stress is described in a flock of male breeding turkeys. Most of the affected turkeys exhibited obvious unilateral leg disorders. All were affected with tibial or metatarsal dyschondroplasia with at least one lesion associated with a large focus of necrosis. By histological examinations, bone lesions showed the typical feature of osteomyelitis. The inflammatory bone lesions appeared at only single isolated sites and were always associated with obvious sequestra of dyschondroplastic retained cartilage. Osteomyelitis seems to be an unexpected acute complication of previous dyschondroplasia in relation with different breeding stress situations. The resulting pain of the associated lesions could be the main cause of clinical expression of lameness. The pathogenesis of the phenomenon remains uncertain.

Toxic effects for lambs of cytotoxic necrotising factor from Escherichia coli.

The lethal effect, clinical signs and lesions caused by the intravenous inoculation into six lambs (seven to 10 days old) of a partly purified preparation of cytotoxic necrotising factor (CNF) from Escherichia coli, strain BM2-1, were investigated. Two control preparations were also tested in two lambs each: (i) the same as above but heated for one hour at 60 degrees C, a treatment which inactivates CNF and preserves residual endotoxic activity; and (ii) purified material from a CNF-defective mutant of BM2-1. Whereas none of the lambs in either of the control groups died or showed significant clinical signs or lesions, all the lambs inoculated with partly purified CNF developed severe clinical signs starting six hours after inoculation which consisted mainly of neurological signs and mucoid diarrhoea. The most striking lesions were oedema and haemorrhages in the central nervous system, and foci of coagulation necrosis in the myocardium. Mucus hypersecretion in the gastrointestinal tract was not associated with cellular inflammation.