Alveolar process | EPFL Graph Search

The alveolar process (ælˈviːələr,_ˌælviˈoʊlər,_ˈælviələr) or alveolar bone is the thickened ridge of bone that contains the tooth sockets on the jaw bones (in humans, the maxilla and the mandible). The structures are covered by gums as part of the oral cavity. The synonymous terms alveolar ridge and alveolar margin are also sometimes used more specifically to refer to the ridges on the inside of the mouth which can be felt with the tongue, either on roof of the mouth between the upper teeth and the hard palate or on the bottom of the mouth behind the lower teeth. The term alveolar (ælˈviːələr) ('hollow') refers to the cavities of the tooth sockets, known as dental alveoli. The alveolar process is also called the alveolar bone or alveolar ridge. The curved portion is referred to as the alveolar arch. The alveolar bone proper, also called bundle bone, directly surrounds the teeth. The term alveolar crest describes the extreme rim of the bone nearest to the crowns of the teeth. The portion of alveolar bone between two adjacent teeth is known as the interdental septum (or interdental bone). The connected, supporting area of the jaw (delineated by the apexes of the roots of the teeth) is known as the basal bone. On the maxilla, the alveolar process is a ridge on the inferior surface, making up the thickest part of the bone. On the mandible it is a ridge on the superior surface. The structures hold the teeth and are encased by gums as part of the oral cavity. Either alveolar process comprises cells, nerves, blood vessels, lymphatic vessels, and periosteum. The alveolar crest terminates uniformly at about the neck of the teeth (within about 1 to 2 mm in a healthy specimen). The alveolar process proper encases the tooth sockets, and contains a lining of compact bone around the roots of the teeth, called the lamina dura. This is attached by the periodontal ligament (PDL) to the root cementum. Although the alveolar process is composed of compact bone, it may be called the cribriform plate because it contains numerous holes where Volkmann's canals pass from the alveolar bone into the PDL.

Hormonal regulation of Stat5 in the mammary gland - from signaling to morphogenesis

Sergio Klinke

The mammary gland development is regulated by steroid and peptide hormones and occurs mainly after birth, compared to the majority of the other organs in the body. The principal hormones responsible for the breast development are the estrogen, the progesterone, the growth hormone, the epidermal growth factor and the prolactin. The latter one is of specific interest since it is required for further development of the gland through pregnancy and lactation. During pregnancy and lactation, alveolar structures develop and differentiate into secretory cells. The signal transducer and activator of transcription 5 (Stat5) is known to be the main effector of prolactin signaling during pregnancy, inducing alveologenesis and differentiation of epithelial cells into secretory cells. I investigated if Stat5 has a role before pregnancy. Protein expression as well as mRNA expression analysis of glands from ovariectomized mice which were artificially stimulated with ovarian hormones (estrogen and progesterone) and control vehicle showed evidences that Stat5 expression can be stimulated by these two hormones. Contrary to the role established until now for stat5 in the mammary gland, I found by fluorescence visualization of Stat5-null epithelium as well as whole mount staining of the same glands that Stat5 is required even before pregnancy since null epithelium showed highly reduced growth already in 3 weeks-old virgin mice. This may indicate a new role for this protein in cell proliferation or survival in early stages of mouse mammary development. Furthermore, transplantation experiment of Stat5-null epithelium into wild-type recipient mice showed that pregnancy state was not able to rescue the normal phenotype. This may be due to complete loss of these cells which happened during the 5 weeks left for the transplanted epithelium to expand the cleared fat pad. This discovery opens a new debate on Stat5 role in the mammary gland development.

2008

Hormonal regulation of Stat5 in the mammary gland - from signaling to morphogenesis

Sergio Klinke

2008