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Hormonal physiology of lactation
Published in Nadia Barghouthi, Jessica Perini, Endocrine Diseases in Pregnancy and the Postpartum Period, 2021
Rawan El-Amin, Loren Custer, Jennifer Silk
Breast tissue is comprised of epithelial and stromal components. The epithelial component contains branching ducts to connect the lobules to the nipple. Each mammary gland is composed of lobes containing lobules with numerous alveoli. The epithelium of the alveoli produces milk. The alveoli are surrounded by myoepithelial cells, which contract and allow milk flow along the ducts of the nipple. The stroma contains adipose and fibrous connective tissue.
Oncogenesis and Metastasis
Published in Karl H. Pang, Nadir I. Osman, James W.F. Catto, Christopher R. Chapple, Basic Urological Sciences, 2021
Cell are supported by surrounding connective tissue—stroma.Stroma has a structural and supportive role.Connects different cell populations.Source of nutrients—vascular network.Allows immune cells to weave through to their target.
Comparative Anatomy and Physiology of the Mammalian Eye
Published in David W. Hobson, Dermal and Ocular Toxicology, 2020
The choroidal stroma varies from being darkly pigmented to a complete absence of pigmentation depending on the species, breed, and individual. In those animals lacking pigmentation, the fundic reflex appears red and on ophthalmoscopic examination the choroidal vessels are visible. The stroma itself is composed of collagen fibrils, melanocytes, fibroblasts, nerves, and larger blood vessels.3,33 The majority of the vessels are veins with arteries situated among them. The arteries have a capillary-free zone surrounding them. Associated with the arteries are nonmyelinated nerve fibers, most of which are motor fibers to the smooth muscle of the arteries.
Bilateral juvenile nasopharyngeal angiofibroma: A rare case report
Published in Acta Oto-Laryngologica Case Reports, 2021
Marlinda Adham, Kartika Hajarani, Lisnawati Rachmadi, Indrati Suroyo
The triad clinical presentation of JNA are unilateral nasal obstruction, recurrent epistaxis and nasal discharge. In this case, patient experienced all the symptoms and also felt a mass on his left cheek. MRI dan CT imaging shows both were hypervascular mass suggesting an angiofibroma, in which right mass is more contrast-enhanced than the left one. Histologically, angiofibroma is composed of fibrocollagenous stromal proliferation with an admixture of variably vascular space. Vascular component is comprised of thin-walled, small to large vessels varying on appearance from stellate to staghorn to barely conspicuous, owing to mark compression by stromal fibrous tissue. Stroma is composed of fibrous tissue with fine or coarse collagen fibers whereas its cells are spindle shaped and stellate with plump nuclei, and tend to radiate around vessels [11]. In this case, histologic examination also showed us that both masses showed similar picture: vascular channels lack the surrounding smooth muscle, innervation of normal blood vessels, and stromal fibrous from spindle to stellate shaped which was concluded to be angiofibroma. However, the mass on the left side shows more fibrous stoma tissue and less vascular component rather that the right one and vice versa.
Comparison of Topical Pigment Epithelium-Derived Factor (PEDF) with Topical Bevacizumab for Accelerating the Regression of Corneal Neovascularization in an Experimental Model of Rabbit Corneal Angiogenesis
Published in Ocular Immunology and Inflammation, 2021
Raziyeh Mahmoudzadeh, Saeed Heidari-Keshel, Mohammad Mehrpour, Fahimeh Asadi Amoli, Leila Aghajanpour, Alireza Lashay
Specimens of all groups did not show any endothelial cells degeneration and deposition. The central portion of cornea in all specimens was free of histopathological changes except the presence of edema seen in three eyes of PEDF group and four eyes of the bevacizumab group compared with the saline group. As mentioned above, vascularization and severity of inflammation in the eyes were scored by the pathologist as grade of 0 to 3 (Figure 2). Table 3 describes the mean score of vascularization and severity of inflammation. Mean score of vascularization in PEDF group (1.17 ± 0.41) was lower than bevacizumab group (1.33 ± 0.52) and saline group (1.58 ± 0.51). However, this difference was not statistically significant among three groups (P = .06) (Table 3, Figure 3). Intra stromal hemorrhage was not seen in PEDF group and bevacizumab group. However, it was found in three eyes (50%) of saline group. Nevertheless, these differences were not statistically significant among groups (P = .07) (Table 3).
Reexamining the role of tissue inflammation in radiation carcinogenesis: a hypothesis to explain an earlier onset of cancer
Published in International Journal of Radiation Biology, 2021
The stroma is a tissue which supports the normal functions of epithelial cells. However, cancers (malignancies derived from epithelial tissue) often accompany the overgrowth of fibroblasts (CAFs) (Shimoda et al. 2010), especially in cancers of the breast, colon, stomach, and pancreas, and the stroma may comprise over 90% of the tumor mass (Dvorak 1986). Interestingly, normal fibroblasts are activated when incubated in the presence of culture supernatants from cancer cells and become myofibroblasts (i.e., they undergo epigenetic changes). Similar changes are also observed following the incubation of fibroblasts with TGF-β, PDGF, FGF2 etc. (Shimoda et al. 2010; Kalluri 2016). Furthermore, not only CAFs but also senescent appearing flat fibroblasts (stellate fibroblasts which may contain unrepaired DNA damage) can support the growth of pre-malignant or malignant, but not normal epithelial cells when these cells are co-cultured in vitro, or co-transplanted into host animals (Krtolica et al. 2001; Orimo et al. 2005; Kojima et al. 2010; Yoshida et al. 2019). The growth stimulation effect in vitro was attributed at least partly to soluble and insoluble factors derived from senescent cells (Krtolica et al. 2001). In this context, it is noted that TGF-β is released not only from myofibroblasts to support their own growth in an autocrine fashion, but also by cancer cells to support the growth of CAFs (Kojima et al. 2010). Cancer cells and CAFs exist in a mutually beneficial relationship.