A 14-year-old girl diagnosed as Crohn's disease had lymphoid hyperplasia throughout the large bowel. Biopsy specimens from the lymphoid hyperplasia demonstrated non-caseous granulomas within the lymph follicles. An immuno-histochemical study of biopsy specimens showed that HLA-DR antigens were expressed on epithelium close to the lymph follicle, which was observed in all specimens containing th...

The murine primordial follicle pool develops largely within 3 days after birth through germline nest breakdown and enclosure of oocytes within pregranulosa cells. The mechanisms that trigger primordial follicle formation likely are influenced by a transition from the maternal to fetal hormonal milieu at the time of birth. High levels of maternal estrogen maintain intact germline nest in fetal o...

In mammals, immature oocytes are surrounded by a layer of flattened cells. At this early stage of development, these "follicle cells" and the plasma membrane of the oocyte are in close proximity. As the oocyte matures, the follicle cells multiply and become cuboidal or radially elongated, and a jelly-like substance containing polysaccharides (1) appears between the oocyte cortex and the follicl...

Rupture of the ovarian follicle releases the oocyte at ovulation, a timed event that is critical for fertilization. It is not understood how the protease activity required for rupture is directed with precise timing and localization to the outer surface, or apex, of the follicle. We hypothesized that vasoconstriction at the apex is essential for rupture. The diameter and blood flow of individua...

The hair follicle produces a terminally differentiated keratinized end product, the hair shaft, that is eventually shed. The follicle undergoes cyclical regeneration with at least 10 different epithelial and mesenchymal cell lineages. Hair is formed by rapidly proliferating matrix keratinocytes in the bulb located at the base of the growing (anagen) follicle. The duration of anagen varies great...

Follicular cysts are the most critical reproductive disorder in dairy cows and disturb normal ovarian cycle, resulting in the prolonged interval from calving to conception. Therefore, this condition causes significant economic losses to the dairy industry. Two direct causal factors of cyst are suggested in this review; the disorder of ovulation and the delay of regression. The disorder of ovula...

The interovulatory intervals of mares contain various combinations of minor follicular waves (largest follicle does not become dominant) and major waves (largest follicle becomes dominant). After emergence of an ovulatory follicular wave, the follicles grow in a common-growth phase until the beginning of deviation. At deviation, the dominant follicle continues to grow and the subordinate follic...

In this short review, I introduce an integrated vision of human hair follicle behavior and describe opposing influences that control hair follicle homeostasis, from morphogenesis to hair cycling. The interdependence and complementary roles of these influences allow us to propose that the hair follicle is a true paradigm of a "Yin Yang" type, that is a cold/slow-hot/fast duality. Moreover, a new...

Ovarian follicle development continues in a wave-like manner during the bovine oestrous cycle giving rise to variation in the duration of ovulatory follicle development. The objectives of the present study were to determine whether a relationship exists between the duration of ovulatory follicle development and pregnancy rates following artificial insemination (AI) in dairy cows undergoing spon...

Adult stem cells are multipotent and can be induced experimentally to differentiate into various cell lineages. Such cells are therefore a key part of achieving the promise of tissue regeneration. The most studied stem cells are those of the hematopoietic and mesenchymal lineages. Recently, mesenchymal stem cells were demonstrated in dental tissues, including dental pulp, periodontal ligament, ...