Pathophysiological changes occurring during Escherichia coli endotoxin and Pasteurella multocida challenge in piglets: relationship with cough and temperature and predicitive value for intensity of lesions.

The aims of this study were (1) to correlate cough and body temperature (BT) with the severity of bronchopneumonia in pigs, (2) to determine whether these clinical signs can be used to early diagnose bronchopneumonia and (3) to assess the predictive values of cough and BT regarding lung lesions. Bronchopneumonia was induced by administering E. coli endotoxin (LPS) combined with Pasteurella multocida type A (PmA) in the trachea of 13 piglets. Saline-instilled negative controls (n = 8), PmA inoculated (n = 6) and LPS instilled (n = 5) groups were also constituted. Cough and BT were recorded daily while the bronchopneumonia severity was assessed using bronchoalveolar lavage fluid (BALF) cytology, cytokines and measurement of lung lesion volume. Changes in expiratory breathing pattern were also measured (Penh). The combination of LPS and PmA induced a subacute bronchopneumonia characterised by macrophage, neutrophil, and lymphocyte infiltration, changes in Penh and an increase in the mRNA level of IFN-gamma while IL8, IL-18 and TNF-alpha mRNA levels remained unchanged. The daily body weight gain of infected animals was significantly reduced. Cough and BT changes were proportional to the intensity of the lung inflammatory process, functional respiratory changes and to the extent of macroscopic lesions. When comparing the individual values of cough and BT to thresholds defined for both parameters, an early diagnosis of pneumonia was possible. Considering the pooled data of each group, it was possible to define thresholds allowing an early segregation between the groups of diseased and healthy piglets. The daily values of cough and BT were predictive for the volume of lung lesions recorded at the end of the trial. In conclusion, cough and BT appear as potential indicators for the intensity and the evolution of the respiratory disease. They also seem to be good predictors for the magnitude of lung lesions and weight gain recorded at the study endpoint

La croissance de la mandibule humaine : conception actuelle

Thèse d'agrégation de l'enseignement supérieur (Faculté de médecine) -- UCL, 198

The function of Meckel's and secondary cartilages in the histomorphogenesis of the cat mandibular symphysis

Cat mandibular symphysis was investigated with histological methods in animals of ages between 3 weeks of intra-uterine life and 56 days post-natal. As in rodents, carnivores and insectivores, Meckel's cartilages fuse in the midline and form a cartilaginous nodule which persists in the symphysis until birth. This nodule, which we have called the symphyseal Meckelian islet, is isolated from Meckel's cartilage, of which only very small calcified islets are left as intramandibular traces after endochondral ossification. Both hemimandibles are bordered by secondary cartilage, which undergoes endochondral ossification, and by chondroid tissue, which is less abundant than in man. At birth, secondary cartilage of both hemimandibles forms a synchondrosis, the lingual part of which undergoes gradual resorption in the 4-week-old cat. The vestibular part is still present at 8 weeks

Transversal mandibular body growth during prefuctional intraosseous eruption of permanent premolars in dogs

Objectives. In order to investigate how the mandibulary morphogenesis has evolved during the prefunctional intraosseous eruption of permanent premolars in dog. Materials and Methods. 10 young mongrel dogs aged from 12 to 16 weeks at the beginning of the experiment were given two intraperitoneal injections of oxytetracycline (50mg/kg and 35mg/kg 2 weeks later) and a final injection of Alizarin red S 2 weeks later. Animals, distributed in pairs from the same litter, were killed with an overdose of Nembutal at 16, 17, 18, 19 and 20 weeks of age. The growth of transversal diameters was measured by means of microradiography and fluorescence microscopy. Conclusions. It was demonstrated that the increase of diameters of the mandible was only subjected, at this stage of the growth, to the effect of variations in the speed of apposition, according to sites and periods studied

Metopic sutural closure in the human skull.

The present study reveals the presence in the sutural area of secondary cartilage, assuring the passive growth of the bones and undergoing an endochondral ossification, but without playing a direct role in the synostosis. The chondroid tissue is responsible for the growth of each frontal bone towards the other and constitutes the first bridge of union between the two bones. It is the most important finding in this study, which provides a description of the closure of the metopic suture and of the maintenance of an open sutural space by a process of active resorption. This new knowledge will help to understand better the whole process of suture closure and its pathology