Expression of β-catenin and MSX1 proteins during parrot pseudoteeth and goose denticulations and giant filiform papillae's early development.

Objective: To use immunohistochemistry to analyse the expression of MSX1 and β-catenin proteins during parrot pseudoteeth development and goose denticulations and giant filiform papillae ontogeny.

Material And Methods: Eggs were purchased from stockbreeders. Embryos from selected stages were removed and sliced.

Healing of particulate allografts mixed with platelet concentrates in ridge preservation and sinus lift: a prospective histomorphometric study.

The objective of the present study was to evaluate the bone quality of sinus and alveolar grafts following filling with particulate allogenous bone (DFDBA 300-500μm) and platelet concentrate (platelet-rich fibrin, PRF). A prospective interventional clinical study was carried out. A total of 40 bone cores, 2mm in diameter, were taken from 21 patients: 22 from grafted alveoli, 7 from grafted sinus sites, and 11 from native bone used as a control.

Are birds pseudoteeth and denticulations related to touch papilla? An investigation in parrot, goose, and chicken.

We first studied the morphology and the development of goose denticulations, which develop mainly by a ripple process, and the touch papillae of the bill tip organ, which appears through an evagination process at the end of the beak. During their development, we observed the specific expression of PAX9, PITX2, and BMP4, while SHH was expressed mainly in the basal layer of the epithelium in a non-specific manner. Adult goose denticulations are associated with numerous columns.

Evolution and development of parrot pseudoteeth.

Parrot embryos carry peculiar appendages at their developing beak that have been described as pseudoteeth. To better characterize the pattern of development responsible for the emergence of these dental appendages, we examined parrot embryos combining conventional histology and microtomography approaches. Using immunohistochemistry, we observed the epithelial and mesenchymal expression of several proteins involved in tooth development in mammals.

Quantification of the relative orientation and position of the mandibular condyles.

The human temporomandibular joint (TMJ) is involved in vital functions such as feeding and talking, while its disorder prevalence is reported to be between 5% and 12%. Functional evaluation using quantitative motion analysis tools is interesting in order to better understand normal and abnormal TMJ behavior. But, for the same mandibular displacement, left and right condyles will most certainly give different motion representation: both condyles showing a different shape and volume, being most of the time asymmetric and highly individual.

Effects of HSP90 inhibition on primordial germ cells migration: A study in the gonad of the chick embryo.

Introduction: Primordial Germ Cells (PGCs) differentiate into spermatozoa or oocytes. They appear early during embryonic development before migrating to the gonadal ridges. Because of their long migration, PGCs have been proposed as a valuable model to study long distance cell migration.

Is Vasa such a highly specific marker for primordial germ cells? A comparison of VASA and HSP90 proteins expression in young chicken embryos.

Introduction: Primordial germ cells (PGCs) have been studied since the 19 century with several different methods. The earliest works were based on the morphological criteria of these cells associated or not with a particular staining. Different markers have been proposed in immunohistochemistry among which we can quote the Stage-specific embryonic antigene-1 (SSEA-1), the embryonic mouse antigen-1 (EMA-1) or the heat shock protein 90.

A reviewed chronology of primordial germ cells migration in the chick embryo.

Introduction: Primordial Germ Cells (PGCs) are present in all sexually reproducing animals. They differentiate into spermatozoa or oocytes and are therefore responsible for the transmission of genetic and epigenetic information across generations. In birds, PGCs are first observed in the center of the blastodisc at stage Eyal-Giladi X.

Triceps, quadriceps or pentaceps femoris? Need for proper muscle definition.

Introduction: Over the last years, the definition of quadriceps femoris (QF) has evolved somewhat and some authors now define a fifth head: the tensor of vastus intermedius (TVI). Descriptions of the different components of QF in textbooks and recent findings remain confusing. Therefore, the aim of this study is to obtain more information on this possible fifth head.

External and computed tomography analysis of a strophocephalic lamb.

Context: The Museum of Anatomy and Embryology Louis Deroubaix attached to the Laboratory of Anatomy, Biomecanics and Organogenesis, ULB, Brussels, possesses in its liquid collections a cephalic extremity of a lamb suffering from strophocephaly. The origins have not been determined. The trunk and the limbs are resected.

Hox-A2 protein expression in mouse embryo middle ear ossicles.

The origin of the mammalian middle ear ossicles from mandibular and hyoid pharyngeal arches remains controversial and discussed. Two adverse theories are proposed. The first claims that malleus and incus derive from the Meckel's cartilage of the mandibular arch, and stapes from Reichert's cartilage of the hyoid arch.

[Contributions of embryology and comparative anatomy for teaching of cranial nerves].

Some authors propose a global approach, including imaging, to describe cranial nerves from a clinical point of view. If we can agree to a certain extent with this proposal, we consider that the use of a medical point of view can neglect histological and embryological features which contribute to a better understanding of nerve function. For example, it is false to consider totally "nerves" I and II as "sensory cranial nerves".

Geldanamycin administration reduces the amount of primordial germ cells in the mouse embryo.

Introduction: Heat shock proteins (HSPs) are expressed or overexpressed in response to exposure to stress. They act as molecular chaperones, ensuring the correct folding of numerous client proteins. HSP90 is one of the most conserved HSPs.

[Not Available].

Trained in the ULB, pupil of Albert Brachet, Ernest Van Campenhout frequented successively the Université Libre de Bruxelles (ULB), the Yale University and the Montreal University, to settle definitively in the Université Catholique de Louvain (UCL), where he becomes professor of anatomy, histology and embryology. Despite the fact that his most interest was the autonomic innervation of the digestive tract, he examined a lot of problems, and his severe and rigorous teaching impressed a number of student's generations.

Body mass prediction from femoral volume and sixteen other femoral variables in the elderly: BMI and adipose tissue effects.

Objectives: The frequently used prediction equations of body mass do not seem appropriate for elderly individuals. Here, we establish the relationship between femoral dimensions and known body mass in elderly individuals in order to develop prediction formulas and identify the factors affecting their accuracy.

Materials And Methods: The body mass linear least-squares regression is based on 17 femoral dimensions, including femoral volume, and 66 individuals.

Further consideration of the curvature of the Neandertal Femur.

Objectives: Neandertal femora are particularly known for having a marked sagittal femoral curvature. This study examined femoral curvature in Neandertals in comparison to a modern human population from Belgium by the use of three-dimensional (3D) quadric surfaces modeled from the bone surface. 3D models provide detailed information and enabled femoral curvature to be analyzed in conjunction with other morphological parameters.

[The dorsoventral inversion: An attempt of synthesis].

The invertebrates, with known exception of echinoderms, are hyponeurian and protostomian. By contrast, echinoderms, chordates and vertebrate are epineurian and deuterostomian. Convinced of the uniqueness origin of all species, Etienne Geoffroy Saint Hilaire (1772-1844), had postulated a complete inversion of body plan to explain this difference.

How different are the Kebara 2 ribs to modern humans?

This study analyses rib geometric parameters of individual ribs of 14 modern human subjects (7 males and 7 females) in comparison to the reconstructed ribs of the Kebara 2 skeleton which was taken from the reconstruction of a Neandertal thorax by Sawyer & Maley (2005). Three-dimensional (3D) models were segmented from CT scans and each rib vertex cloud was placed into a local coordinate system defined from the rib principal axes. Rib clouds were then analysed using best fitting ellipses of the external contours of the cross-section areas.

[Hermann Joris (1875-1910), a forgotten histologist].

Hermann Joris (1875-1910) was professor of histology at the Medical college of the Université libre de Bruxelles between 1908 and 1910. At the time of its nomination, its work relating to the pituitary gland and the neurons was the object of critical sharp by Albert Brachet. The author analyzes in what these criticisms rested certainly on sometimes debatable interpretations scientific, but betray also a quarrel between two generations of teachers of the University.