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Lymphatic anatomy: lymphatics of the cervix
Published in Charles F. Levenback, Ate G.J. van der Zee, Robert L. Coleman, Clinical Lymphatic Mapping in Gynecologic Cancers, 2022
Anca Chelariu-Raicu, Katherine C. Kurnit
The cervix is composed of fibrous, elastic, and smooth muscular tissue. It is more fibrous than the corpus, with smooth muscle comprising just 15% of the body of the cervix, primarily at the endocervix. It is lined by columnar and squamous epithelium. The endocervix is lined by a single layer of mucin-producing columnar epithelium, which also lines the many endocervical glands. In this respect, the mucin-producing apparatus is not truly glandular but is a complex infolding of the mucosal surface. The distal extent of this mucosa joins stratified, nonkeratinizing squamous epithelium on or near the exocervix. The location of this abrupt transformation is variable and changes continuously during the reproductive years, responding to the lower vaginal pH after puberty.3 In this process, columnar epithelium undergoes metaplastic change to become more resilient squamous epithelium.4 It is in this transformation zone that most preinvasive and invasive cervical lesions arise. Distally, the exocervical tissue is continuous with the vaginal epithelium.
The Vaginal Microbiome
Published in Carlos Simón, Carmen Rubio, Handbook of Genetic Diagnostic Technologies in Reproductive Medicine, 2022
Shahriar Mowla, Phillip R. Bennett, David A. MacIntyre
There are distinct anatomical, immunological, and morphological differences between the lower (vagina and ectocervix) and upper (uterus and endocervix) reproductive tract that reflect their unique functions (Figure 20.2). For example, the vaginal epithelium consists of multiple protective layers of non-keratinized stratified squamous epithelial cells that can vary in thickness from a few to 45 cells (55). In comparison, the epithelium of the upper reproductive tract consists of a single layer of columnar epithelial cells. In the vagina, cells in the apical layer undergo cornification, a process by which they lose their nuclei and intracellular organelles (56). Regular exfoliation of these cells into the vaginal lumen (55) assists in the removal of invading pathogens (57,58). Mitosis in the basal layer promotes renewal of the epithelium (55) with an estimated turnover of approximately 96h (59).
Factors Affecting the Microflora of the Lower Genital Tract of Healthy Women
Published in Michael J. Hill, Philip D. Marsh, Human Microbial Ecology, 2020
Bacteria found in the endogenous microflora of the lower genital tract of healthy women have been shown to adhere in vitro to exfoliated vaginal epithelial cells.84 However, the mean number of bacteria that adhered per cell was significantly less than organisms considered to be pathogens, such as N. gonorrhoeae, or potential pathogens, such as group B streptococci or G. vaginalis. Adhesion of group B streptococci85 and N. gonorrhoeae86 to vaginal cells and of E. coli to uroepithelial cells87 has been shown to vary over the menstrual cycle and during pregnancy, although there is little evidence that this affects the ability of G. vaginalis88 to adhere to epithelial cells. These studies suggest that the host cell receptor is important and may be influenced by hormones. However, the cells used in most studies have been exfoliated vaginal epithelial cells collected from volunteers which will be a mixed population at different stages of keratinization. Bacteria show enhanced adherence to cells with a high degree of keratinization89,90 and therefore it is difficult to know how closely these experiments mimic the in vivo situation. Sobel et al.91 used human vaginal epithelial cells in tissue culture, which showed morphological features in common with normal vaginal epithelium.91 Bacterial adherence proved to be similar using both tissue culture and exfoliated cells.
Vaginal oxygen plus hyaluronic acid on genito-urinary symptoms of breast cancer survivors
Published in Climacteric, 2023
C. Massarotti, G. Asinaro, M. G. Schiaffino, C. Ronzini, I. Vacca, M. Lambertini, P. Anserini, L. Del Mastro, A. Cagnacci
However, there are also limitations to report. The study was performed in a relatively small cohort of women and without a control group. The effects were rather consistent, but it is unclear whether this treatment is more advantageous than other local non-hormonal therapies. Vaginal health was evaluated by the VHIS but we did not consider any objective evaluation of vaginal epithelium maturation. Vaginal oxygen and hyaluronic acid are not expected to induce epithelium maturation, which mainly depends on estrogen stimulus. Studies investigating the daily administration of hyaluronic acid or other moisturizing agents have shown minimal irrelevant maturation of the epithelium and minimal decreases of pH [21]. Maturation of the epithelium allows vaginal microbiota to produce lactic acid from glycogen of mature cells with the consequence of vaginal pH decrease [28]. In our case, the lack of relevant pH modifications during treatment indicates the absence of a significant maturation of vaginal epithelium.
Clinical manifestations and evaluation of postmenopausal vulvovaginal atrophy
Published in Gynecological Endocrinology, 2021
Faustino R. Pérez-López, Pedro Vieira-Baptista, Nancy Phillips, Bina Cohen-Sacher, Susana C. A. V. Fialho, Colleen K. Stockdale
As a result of hypoestrogenism, the vaginal epithelium becomes thinner, loses glycogen, and thus, the vaginal pH increases. An increased pH is a predictor of VVA, but other factors must be discarded (i.e. bacterial vaginosis, recent intercourse). A change in the resident microbiota occurs commonly, with a decrease in the population of lactobacilli and an increase in bacterial diversity, including more enteric bacteria [11]. In the state of hypoestrogenism, there is a decrease in the number of layers of epithelial cells and degeneration of collagen and elastin fibers in the underlying connective tissue, resulting in less tissue elasticity and greater mucosal fragility. Vascular and non-vascular smooth muscles in the subepithelial layers, as well as neuronal density, are also affected as estrogen decrease is associated with vasoconstriction, dryness, and hypertonia of the vaginal wall [8,17,18].
Vulvovaginal atrophy in women after cancer
Published in Climacteric, 2019
VVA occurs due to decreased estrogenization of the vaginal tissue and is therefore most common after the menopause. This can cause vaginal dryness, soreness, postmenopausal bleeding, and irritation, as well as urinary symptoms such as frequency, urgency, and urge incontinence10. The response of VVA to topical estrogens is rapid and sustained11. Unlike other symptoms and signs of the menopause, VVA is progressive over time. Symptoms are both variable and common, and include a decrease in vaginal rugae, decreased blood flow to the vaginal epithelium, an increase in vaginal pH, and a shift in the vaginal maturation index. The lower urinary tract has the same embryonic origin as the vagina and vulva, and decreased estrogen also leads to urinary symptoms such as dysuria, urgency, and recurrent urinary tract infections11. These symptoms are being increasingly recognized as part of the pathophysiology of VVA, and hence there has been a proposal by the International Society for the Study of Women’s Sexual Health and the North American Menopause Society to use the term genitourinary syndrome of menopause which encompasses both VVA and urinary symptoms12. When this article refers to VVA, both vulvovaginal and urinary symptoms are implied.