Tissue regeneration and the epididymal stem cell.

BACKGROUND: In most pseudostratified epithelia, basal cells represent a multipotent adult stem cell population. These cells generally remain in a quiescent state, until they are stimulated to respond to tissue damage by initiating epithelial regeneration. In the epididymis, cell proliferation occurs at a relatively slow rate under normal physiological conditions. Epididymal basal cells have been shown to share common properties with multipotent adult stem cells. The development of organoids from stem cells represents a novel approach for understanding cellular differentiation and characterization of stem cells. OBJECTIVE: To review the literature on tissue regeneration in the epididymis and demonstrate the presence of an epididymal stem cell population. METHODS: PubMed database was searched for studies reporting on cell proliferation, regeneration, and stem cells in the epididymis. Three-dimensional cell culture of epididymal cells was used to determine whether these can develop into organoids in a similar fashion to stem cells from other tissues. RESULTS: The epididymal epithelium can rapidly regenerate following orchidectomy or efferent duct ligation, in order to maintain epithelial integrity. Studies have isolated a highly purified fraction of rat epididymal basal cells and reported that these cells displayed properties similar to those of multipotent adult stem cells. In two-dimensional cell culture conditions, these cells differentiated into cells which expressed connexin 26, a marker of columnar cells, and cytokeratin 8. Furthermore, three-dimensional cell culture of epididymal cells resulted in the formation of organoids, a phenomenon associated with the proliferation and differentiation of stem cells in vitro. CONCLUSIONS: The rapid proliferation and tissue regeneration of the epididymal epithelium to preserve its integrity following tissue damage as well as the ability of cells to differentiate into organoids in vitro support the notion of a resident progenitor/stem cell population in the adult epididymis.

[Consequences of increasing and ageing population of Basse-Normandie on gynecology and obstetrics activity]. / Effet de l'augmentation et du vieillissement de la population de Basse-Normandie sur l'activité de gynécologie-obstétrique.

INTRODUCTION: In Basse-Normandie, the population over 65 years old will expend more rapidly between 2007 and 2042 (+11.6%) than the rest of the French population (+9.2%). The same population of Basse-Normandie will get old in the 15 years to come. The impact of these demographic changes over the activity in the gynecology-obstetrics field is not clearly identified. Although we cannot predict the technical and scientific developments in the next 15 years, we are presenting a model allowing to hypothesize about changes of gynecology and obstetrics according to population's aging. MATERIALS AND METHODS: We have established a projection model for the realizable surgical acts in obstetrics and gynecology in accordance with the aging of the population in Basse-Normandie. The study was realized based on the acts concerning the cesarean sections (C-section), tubal sterilization, hysteroscopy and hysterectomy as well as ovarectomy and breast surgery. For each activity branch, the codes of the Classification commune des actes médicaux (CCAM) were selected and then removed from the Programme médicalisé des systèmes d'information (PMSI) database. We have used and adapted the Omphale model of the National Statistics and Economical Studies Institute and we have applied it for the period of 2009-2025. RESULTS: Our projection model has permeated to show a 5.5% regression of the C-section acts, a 2% incretion of the hysterectomies and hysteroscopies, 7.7% of ovarectomies as well as a 9.8% augmentation of the breast surgeries. However, we predict a 11.8% diminution of the sterilizations by tubal implants. Globally, the activity in obstetrics and gynecology will remain constant with an insignificant augmentation of 46 acts (0.01%). CONCLUSION: In Basse-Normandie, the surgical activity in gynecology-obstetrics will moderately increase in the next 15 years. This constant activity signifies that there is no need to form more residents than the number of practitioner to retire. The interest of this model is that it is applicable at a national level and it permits to confront the demographic data and the projections of different activities.

[Gynaecology and obstetrics in Basse-Normandy: demographic perspectives in 15 years]. / Gynécologie-obstétrique et gynécologie médicale en Basse-Normandie: perspectives démographiques à 15ans.

OBJECTIVES: The French population is growing and ageing. In this context, it is important to consider the future of gynecologists and obstetricians in Basse-Normandie. The aim of this study was to perform an overview of the demographics of practitioners and estimate the retirements. We also try to project the need of trainees for the next years. MATERIALS AND METHODS: We conducted a demographic and workload survey among 142 practitioners and 35 trainees. We detailed retirements and arrivals of this population. RESULTS: By 2025, nearly two-thirds of practitioners in 2012 will retire, including 100% of medical gynecologists. Otherwise, there will be a lack of 1 to 2 practitioners per year. We also noted the tendance of feminization (86%) and the wish of a multi-practice in public hospital (86%). CONCLUSION: A reflection about the health planning will be necessary in order to answer the demographics difficulty in the region. We will have to take into account the future retirements and also the specific situations in each area.

A new approach to the bending properties of hair fibers.

A new test developed to characterize the bending properties of treated or virgin hair fibers is described. The device consists of a pendulum that bends a sample made up of 39 parallel hair fibers at each swinging stroke. Hair bending stiffness can be assessed by the number of strokes observed until the pendulum stops. The mechanical behavior of natural hair fibers is related to their geometric characteristics. The effects of various hair treatments can be assessed by this method.