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Annual Review of Cell and Developmental... Oct 2023The uterine lining (endometrium) regenerates repeatedly over the life span as part of its normal physiology. Substantial portions of the endometrium are shed during... (Review)
Review
The uterine lining (endometrium) regenerates repeatedly over the life span as part of its normal physiology. Substantial portions of the endometrium are shed during childbirth (parturition) and, in some species, menstruation, but the tissue is rapidly rebuilt without scarring, rendering it a powerful model of regeneration in mammals. Nonetheless, following some assaults, including medical procedures and infections, the endometrium fails to regenerate and instead forms scars that may interfere with normal endometrial function and contribute to infertility. Thus, the endometrium provides an exceptional platform to answer a central question of regenerative medicine: Why do some systems regenerate while others scar? Here, we review our current understanding of diverse endometrial disruption events in humans, nonhuman primates, and rodents, and the associated mechanisms of regenerative success and failure. Elucidating the determinants of these disparate repair processes promises insights into fundamental mechanisms of mammalian regeneration with substantial implications for reproductive health.
Topics: Female; Animals; Humans; Endometrium; Uterus; Fibrosis; Mammals
PubMed: 37843929
DOI: 10.1146/annurev-cellbio-011723-021442 -
Pathology, Research and Practice Nov 2023The human endometrium is a complex hormone-target tissue consisting of two layers: the lower basalis, and the upper functionalis. The latter of the two goes through a... (Review)
Review
The human endometrium is a complex hormone-target tissue consisting of two layers: the lower basalis, and the upper functionalis. The latter of the two goes through a cycle of thickening and shedding without residual scarring or loss of function. This cycle, known as the menstrual cycle, occurs on a monthly basis in most of healthy reproductive-age women. It is, however, associated with a number of reproductive diseases, endometriosis being one of them. Endometriosis is defined as the presence of endometrium at ectopic sites within the peritoneum or, more rarely, other locations outside the abdominal area. It affects around 6-10% of reproductive-age women in the world and causes debilitating pain, heavy menstrual bleeding, pain during penetrative sex, and infertility. The etiology of the disease is not yet fully understood but the generally accepted theory is that the endometriotic lesions originate from viable eutopic endometrial cells that flow back into the peritoneum through the process of retrograde menstruation. Endometriosis is usually classified into four stages: minimal, mild, moderate, and severe, though it is important to note that the presentation of symptoms does not necessarily correspond to the disease progression. The immune system plays an important role in supporting the viability and growth of ectopic endometriotic tissue, all the while promoting chronic inflammation at the lesion sites, which causes prolonged pain. There is no definitive cure for endometriosis, but there are several options for symptom management, including laparoscopy, hormonal therapy, the use of NSAIDs, dietary changes, exercise, and, in cases when all conservative treatments fail, hysterectomy.
Topics: Female; Humans; Endometriosis; Endometrium; Hysterectomy; Inflammation; Pain
PubMed: 37844487
DOI: 10.1016/j.prp.2023.154847 -
BMJ Sexual & Reproductive Health Jan 2024Heavy menstrual bleeding affects up to one third of menstruating individuals and has a negative impact on quality of life. The diagnosis of heavy menstrual bleeding is...
BACKGROUND
Heavy menstrual bleeding affects up to one third of menstruating individuals and has a negative impact on quality of life. The diagnosis of heavy menstrual bleeding is based primarily on history taking, which is highly dependent on traditional disposable menstrual products such as pads and tampons. Only tampons undergo industry-regulated testing for absorption capacity. As use of alternative menstrual products is increasing, there is a need to understand how the capacity of these products compare to that of standard products.
METHODS
A variety of commercially available menstrual products (tampons, pads, menstrual cups and discs, and period underwear) were tested in the laboratory to determine their maximal capacity to absorb or fill using expired human packed red blood cells. The volume of blood necessary for saturation or filling of the product was recorded.
RESULTS
Of the 21 individual menstrual hygiene products tested, a menstrual disc (Ziggy, Jiangsu, China) held the most blood of any product (80 mL). The perineal ice-activated cold pack and period underwear held the least (<3 mL each). Of the product categories tested, on average, menstrual discs had the greatest capacity (61 mL) and period underwear held the least (2 mL). Tampons, pads (heavy/ultra), and menstrual cups held similar amounts of blood (approximately 20-50 mL).
CONCLUSION
This study found considerable variability in red blood cell volume capacity of menstrual products. This emphasises the importance of asking individuals about the type of menstrual products they use and how they use them. Further understanding of capacity of newer menstrual products can help clinicians better quantify menstrual blood loss, identify individuals who may benefit from additional evaluation, and monitor treatment.
Topics: Female; Humans; Menorrhagia; Menstrual Hygiene Products; Hygiene; Quality of Life; Menstruation; Erythrocytes
PubMed: 37550075
DOI: 10.1136/bmjsrh-2023-201895