Scanning electron microscopy of endometriotic lesions in the pelvic peritoneum and the histogenesis of endometriosis

Estrogen restricts the apoptosis of endometrial stromal cells by promoting TSLP secretion

Endometriosis (EMS) is a female hormone‑ dependent disease with controversial reports of its etiology and pathogenesis. Apoptosis is particularly important in the human endometrium due to the dynamic cycles of proliferation and shedding. Estrogen possessed antiapoptotic effects on endometrial stromal cells (ESCs), which appears to be exacerbated in women with EMS; however, the underlying mechanism of the antiapoptotic effects of estrogen on ESC remains unknown. The present study aimed to determine whether estrogen regulates the apoptosis of ESCs via thymic stromal lymphopoietin (TSLP) and the associated mechanism. An ELISA was conducted to detect TSLP content in the ESC culture medium treated with estrogen. Subsequently, the early apoptotic rate and expression of B‑cell lymphoma (Bcl‑2) of ESCs were analyzed by flow cytometry in the presence of recombinant human TSLP, anti‑human TSLP neutralizing antibody or estrogen. In the present study, it was reported that ESCs exhibited basal TSLP secretion in the absence of estrogen as reported in previous studies, and that estrogen promoted TSLP secretion of ESCs in a dose‑dependent manner. The results demonstrated that estrogen suppressed the apoptosis of ESCs associated with the promotion of Bcl‑2 expression, which may be partly reversed by inhibiting TSLP. Therefore, the findings of the present study revealed a novel mechanism of estrogen‑dependent apoptotic suppression of ESCs associated with TSLP secretion and Bcl‑2 regulation. Endogenous and estrogen‑induced endometrial TSLP may promote the initiation and development of EMS via the inhibition of apoptosis.

Intraoperative detection of subtle endometriosis: a novel paradigm for detection and treatment of pelvic pain associated with the loss of peritoneal integrity

Endometriosis is a common disease affecting 40 to 70% of reproductive-aged women with chronic pelvic pain (CPP) and/or infertility. The purpose of this study was to demonstrate the use of a blue dye (methylene blue) to stain peritoneal surfaces during laparoscopy (L/S) to detect the loss of peritoneal integrity in patients with pelvic pain and suspected endometriosis. Forty women with CPP and 5 women without pain were evaluated in this pilot study. During L/S, concentrated dye was sprayed onto peritoneal surfaces, then aspirated and rinsed with Lactated Ringers solution. Areas of localized dye uptake were evaluated for the presence of visible endometriotic lesions. Areas of intense peritoneal staining were resected and some fixed in 2.5% buffered gluteraldehyde and examined by scanning (SEM) electron microscopy. Blue dye uptake was more common in women with endometriosis and chronic pelvic pain than controls (85% vs. 40%). Resection of the blue stained areas revealed endometriosis by SEM and loss of peritoneal cell-cell contact compared to normal, non-staining peritoneum. Affected peritoneum was associated with visible endometriotic implants in most but not all patients. Subjective pain relief was reported in 80% of subjects. Based on scanning electron microscopy, we conclude that endometrial cells extend well beyond visible implants of endometriosis and appear to disrupt the underlying mesothelium. Subtle lesions of endometriosis could therefore cause pelvic pain by disruption of peritoneal integrity, allowing menstrual or ovulatory blood and associated pain factors access to underlying sensory nerves. Complete resection of affected peritoneum may provide a better long-term treatment for endometriosis and CPP. This simple technique appears to improve detection of subtle or near invisible endometriosis in women with CPP and minimal visual findings at L/S and may serve to elevate diagnostic accuracy for endometriosis at laparoscopy.

Assessment of endometrial receptivity

OBJECTIVE

To provide a focused review of the scientific literature pertaining to endometrial receptivity.

DESIGN

Review of the literature and appraisal of relevant articles.

SETTING

Academic teaching hospital.

PATIENT(S)

Women with infertility.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Critical review of the literature.

RESULT(S)

Although a consensus has been achieved regarding the existence of a temporally defined period during which embryo attachment and invasion can occur (called the "window of implantation"), reliable methods to assess "receptivity" have not been established or adequately validated. In women with certain gynecologic disorders, including endometriosis, tubal disease, and polycystic ovary syndrome, endometrial receptivity seems to be compromised, leading to infertility and pregnancy loss. The establishment of reliable biomarkers for the detection of defects in endometrial receptivity has been a long-sought goal that remains an elusive target. The validation of endometrial biomarkers will require properly designed and implemented studies based on the recognition that endometrial receptivity defects are not equally distributed in women with endometriosis or these other conditions.

CONCLUSION(S)

Rapidly advancing technologies are bringing new biomarkers to the clinical arena that promise to further reveal the complexities of the implantation process.

A serial section study of visually normal posterior pelvic peritoneum from baboons (Papio cynocephalus, Papio anubis) with and without spontaneous minimal endometriosis

OBJECTIVES

To determine if microscopic endometriosis exists in visually normal pelvic peritoneum from baboons with and without endometriosis.

DESIGN

Observational histologic study at Institute of Primate Research, Nairobi, Kenya.

SUBJECTS

Seventeen baboons including 13 adult females (5 with histologically proven endometriosis, 8 with a normal pelvis) and 4 juveniles (1 female and 3 males).

INTERVENTIONS

Diagnostic laparoscopy with identification of visually normal pelvic peritoneum before euthanasia, followed by laparotomy with excision of a large area (at least 4 x 6 cm or 24 cm2 per animal, 408 cm2 surface in all baboons) of this visually normal-appearing peritoneum.

MAIN OUTCOME MEASURE

Presence of microscopic endometriosis (endometrial glands and stroma) in serial sections of visually normal pelvic peritoneum.

RESULTS

Two adjacent glandular structures compatible with endometriosis were found in normal peritoneum obtained during menses from one female baboon without macroscopic disease. Microscopic endometriosis was not detected in the other female primates with or without macroscopic disease or in male animals.

CONCLUSION

Microscopic endometriosis was found in only 1 of 14 female baboons (prevalence 7%; 95% confidence interval 0% to 33%) with visually normal pelvic peritoneum. These findings suggest that, with the paucity of human data available, more studies are needed before concluding that massive microscopic disease exists in visually normal-appearing peritoneum of women.