Recovery of opercular anomalies in gilthead sea bream, Sparus aurata L.: morphological and morphometric analysis.

Opercular anomalies are very frequent in reared gilthead sea bream and these can negatively influence the product value. Field observations have suggested that opercular malformations can recover over time. In order to verify this hypothesis, 140-day-old gilthead sea bream with monolateral opercular anomalies were divided into three groups, according to the type and increasing seriousness of the opercular malformations, and another group was composed of fish with bilateral opercular anomalies. All groups were monitored for 16 months. In the group with monolateral anomalies, the opercular recovery process was documented by morphological (stereomicroscope) and morphometric analysis. For the latter analysis, two relevant areas, A and T, were identified in the cephalic region. The ratio (T - A)/T, tending to 1, represents the recovery index (RI) of anatomical integrity and quantifies the recovery level of opercular complex anomalies. Results suggested that the recovery process was considerable over the 16 months of investigation but should not be considered complete. At the end of the study, 61% of the gilthead sea bream population with monolateral opercular defects recovered external integrity, whereas the population with bilateral defects showed a poorer recovery capability.

[Selective dorsal T1-T6 fusion of the thoracic spine and effects on thorax growth: experimental study in prepuberal New Zealand White rabbits]. / Influence de l'arthrodèse vertébrale dorsale sélective T1-T6 sur la croissance thoracique: étude expérimentale chez des lapins New Zealand White prépubertaires.

PURPOSE OF THE STUDY: The purpose of this study is to assess the consequences brought by selective dorsal arthrodesis of thoracic spine (T1-T6) to the growth of spine and thoracic volume in operated and sham-operated New Zealand White rabbits, between prepubertal age and the end of somatic growth, through the study of computerised tomography (CT) scans periodically carried out on them after arthrodesis surgery. MATERIAL AND METHODS: Nine female rabbits were subjected to surgery for selective dorsal arthrodesis of the upper thoracic spine and three were sham-operated. Surgery was performed at age nine weeks, before the onset of puberty. Two "C"-shaped titanium bars were placed beside the spinous processes of the thoracic vertebrae to obtain a selective posterior arthrodesis of the first six thoracic vertebrae. Under general anesthesia, three CT scans were performed, 10 (t1), 55 (t2) and 139 (t3) days after surgery. Measures were obtained by Myrian Pro software for three different groups: group 1 with complete fusion, group 2 with incomplete fusion, group 3 sham-operated. RESULTS: The total dorsal and ventral lengths of thoracic vertebral bodies in the spinal segment T1-T6 was smaller in group 1 and group 2 than in group 3, whereas no differences were observed between the three groups in the T7-T12 segment. The average of the dorsoventral/laterolateral thoracic diameter ratio at fused levels was less than 1 in group 1 as well as in group 2; on the contrary, in group 3 it was greater than 1. The sternum and lung volume grow less. CONCLUSIONS: Vertebral arthrodesis in the treatment of progressive idiopathic scoliosis in prepubertal patients is not ideal, but is still a choice in treating major deformities of the spine. Postoperative assessment of spinal deformity is essential, feasible and recordable through CT scans. Dorsal arthrodesis in prepubertal rabbits changes thoracic growth patterns. In operated rabbits, the dorsoventral thoracic diameter grows more slowly than the laterolateral thoracic diameter. The sternum, the total lengths of thoracic vertebral bodies in the spinal segment T1-T6 and lungs grow less. The Crankshaft phenomenon is evident at the fused vertebral levels where there is a reduction of thoracic kyphosis.

Morphometric analysis of the scleral bony ring with different numbers of ossicles in the eye of Coturnix coturnix japonica.

The scleral bony ring (s.b.r.) of Coturnix coturnix japonica was examined and evaluated morphometrically in its characteristic formations (scleral ossicles, overlapping sectors). The modal class 14-14, the most representative, was compared to others having minor or major numbers of ossicles with complex or simple overlaps in the left and right eyes. It was observed that the ossicles, numbered as in the literature, are ordered in a characteristic manner to form the s.b.r. The ossicle dimensions are different and numbers 4 and 7 are always smaller and larger. The s.b.r. with different numbers of ossicles compared to the model class 14-14 (0,0) showed an evident compensatory behaviour in all classes. In fact, when the ossicle number decreased, single ossicle area increased, retaining a constant s.b.r. area.

[Structure and vascularization of the dental pulp in horse incisors]. / Structure et vascularisation de la pulpe dentaire des incisives du cheval.

The dental pulp of 34 horses aged between 4 months and 20 years has been studied on India ink injected and on paraffin embedded specimens. The pulp dimensions of the first and especially of the second dentition decrease with age. This reduction is accompanied by pronounced changes of structure; the mucous connective tissue becomes a dense, irregular connective tissue. The vessels are numerous and make a network particularly rich at the margins of the pulp; they diminish with advancing age. The reduction of the pulp volume and the regression of its vascular network are particularly pronounced at the crown level whose pulp cavity is progressively filled with secondary dentin. The regression of the vascular network precedes the reduction of the pulp volume.