The Antigen-Processing Pathway via Major Histocompatibility Complex I as a New Perspective in the Diagnosis and Treatment of Endometriosis.

Endometriosis is a debilitating gynecological disease defined as the presence of endometrium-like epithelium and/or stroma outside the uterine cavity. The most commonly affected sites are the pelvic peritoneum, ovaries, uterosacral ligaments, and the rectovaginal septum. The aberrant tissue responds to hormonal stimulation, undergoing cyclical growth and shedding similar to appropriately located endometrial tissue in the uterus. Common symptoms of endometriosis are painful periods and ovulation, severe pelvic cramping, heavy bleeding, pain during sex, urination and bowel pain, bleeding, and pain between periods. Numerous theories have been proposed to explain the pathogenesis of endometriosis. Sampson's theory of retrograde menstruation is considered to be the most accepted. This theory assumes that endometriosis occurs due to the retrograde flow of endometrial cells through the fallopian tubes during menstruation. However, it has been shown that this process takes place in 90% of women, while endometriosis is diagnosed in only 10% of them. This means that there must be a mechanism that blocks the immune system from removing endometrial cells and interferes with its function, leading to implantation of the ectopic endometrium and the formation of lesions. In this review, we consider the contribution of components of the Major Histocompatibility Complex (MHC)-I-mediated antigen-processing pathway, such as the ERAP, TAP, LMP, LNPEP, and tapasin, to the susceptibility, onset, and severity of endometriosis. These elements can induce significant changes in MHC-I-bound peptidomes that may influence the response of immune cells to ectopic endometrial cells.

The role of anti-Mullerian hormone and other correlates in patients with polycystic ovary syndrome.

BACKGROUND: Anti-Müllerian hormone (AMH) has recently emerged as a promising biomarker for the detection of polycystic ovarian morphology. In polycystic ovary syndrome (PCOS), an elevated level of AMH has been suggested to add value to the Rotterdam criteria in cases of diagnostic uncertainty. In this study, we evaluated the correlation between AMH and PCOS, and the potential role of AMH in PCOS diagnosis. METHODS: A case-control study was performed on a total of 200 females, 100 of which were diagnosed with PCOS as per Rotterdam revised criteria (2003) and 100 as the control (non-PCOS group). Patient medical records were therefore retrieved for clinical, biochemical and ultrasound markers for PCOS diagnosis. Sensitivity, specificity, area under receiver operating characteristic (AUROC) curve, and multivariate linear regression models were applied to analyze our data. RESULTS: Mean serum levels of LH and AMH, and LH/FSH ratio were significantly different between compared groups. In the PCOS group, the mean serum AMH level was 6.78 ng/mL and LH/FSH ratio was 1.53 while those of controls were 2.73 ng/mL and 0.53, respectively (p < .001). The most suitable compromise between 81% specificity and 79% sensitivity was obtained with a cutoff value of 3.75 ng/mL (26.78 pmol/L) serum AMH concentration for PCOS prediction, with an AUROC curve of 0.9691. CONCLUSION: Serum AMH cutoff level of 3.75 ng/mL was identified as a convenient gauge for the prediction of PCOS and an adjuvant to the Rotterdam criteria.

Value of Early Laparoscopic Exploration for Primary Infertile Patients with Patent Fallopian Tubes Complicated with Pelvic Effusion.

BACKGROUND Endometriosis is a progressive disease, and early detection and early treatment are particularly important. The purpose of this study was to investigate the effect of the timing of laparoscopy on the spontaneous pregnancy rate of primary infertile patients complicated with pelvic effusion within 6 months after surgery. MATERIAL AND METHODS We enrolled 330 primary infertile patients with pelvic effusion and bilateral patent fallopian tubes. They were divided into 3 groups based on retrospective analysis of clinical data. Study Group 1 underwent laparoscopy 1 month after hysterosalpingography (HSG), Study Group 2 received laparoscopy after trying to conceive for 3 months, and the Control Group did not undergo laparoscopy. According to the specific conditions during laparoscopy, repair and plastic surgery of fallopian tube, electrocautery of endometriosis and uterine suspension were performed. The main observation indicators were proportions of retrograde menstruation, peritoneal endometriosis, and tubal adhesions in laparoscopy groups, and spontaneous pregnancy rates within 6 months. RESULTS The proportions of retrograde menstruation were 92.2% and 93.1% in Study Group 1 and Study Group 2, respectively, with no statistical significance. The proportions of peritoneal endometriosis were 51.0% and 64.7%, with a statistically significant difference. The proportions of tubal adhesions were 31.4% and 36.2%, with no statistical significance. The pregnancy rates within 6 months were 73.9%, 52.6%, and 13.1%, with a statistically significant difference for pairwise comparisons. CONCLUSIONS The pregnancy rate of primary infertile patients with patent fallopian tubes complicated with pelvic effusion can be significantly improved through early laparoscopic surgery (exploration and treatment).

Effects of hormone replacement therapy on glucose and lipid metabolism in peri- and postmenopausal women with a history of menstrual disorders.

BACKGROUND: Previous studies have indicated that women with a history of menstrual disorders have an increased risk of metabolic and cardiovascular diseases. This has been attributed to the high proportion of polycystic ovary syndrome (PCOS) among this group. The favorable effects of hormone replacement therapy (HRT) on serum lipid profiles and glucose homeostasis in postmenopausal women is widely accepted. Whether HRT can also show positive effects on metabolic homeostasis in menopausal women with prior menstrual disorders (a putative PCOS phenotype) has not been reported yet. The aim of the study was to compare the effects of HRT on glucose and lipid metabolism in peri- and postmenopausal women with prior menstrual disorders and controls who did not have prior menstrual disorders. METHODS: A retrospective multicenter study was conducted including 595 peri- and postmenopausal women who received HRT at four hospitals in the Zhejiang Province from May 31, 2010 to March 8, 2021. Participants were divided into the Normal menstruation group and the Menstrual disorders group according to their prior usual menstrual cycle pattern. Glucose and lipid metabolism indicators were assessed at baseline and after HRT. The results were compared between and within the groups, and data from peri- and postmenopausal women were analyzed separately. RESULTS: HRT significantly decreased fasting insulin and homeostasis model assessment of insulin resistance in perimenopausal users, and fasting plasma glucose levels in postmenopausal users with prior menstrual disorders, compared with baseline. Furthermore, HRT decreased low-density lipoprotein cholesterol, total cholesterol, fasting insulin, fasting plasma glucose and homeostasis model assessment of insulin resistance in both peri- and postmenopausal controls, compared with baseline. Nevertheless, no significant differences were observed in any of the glucose or lipid metabolism indicators at baseline and follow-up, as well as changes from baseline levels between menopausal women with and without prior menstrual disorders. CONCLUSIONS: HRT shows more obvious within-group improvements in glucose and lipid metabolism in controls, but there is no significant between-group difference. Further prospective studies are required for confirmation.

Endometrial epithelial-mesenchymal transition (EMT) by menstruation-related inflammatory factors during hypoxia.

Endometriosis is characterised by inflammation and fibrotic changes. Our previous study using a mouse model showed that proinflammatory factors present in peritoneal haemorrhage exacerbated inflammation in endometriosis-like grafts, at least in part through the activation of prostaglandin (PG) E2 receptor and protease-activated receptor (PAR). In addition, hypoxia is a well-known inducer of fibrosis that may be associated with epithelial-mesenchymal transition (EMT). However, the complex molecular interactions between hypoxia and proinflammatory menstruation-related factors, PGE2 and thrombin, a PAR1 agonist, on EMT in endometriosis have not been fully characterised. To explore the effects of hypoxia and proinflammatory factors on EMT-like changes in endometrial cells, we determined the effects of PGE2 and thrombin (P/T) on EMT marker expression and cell migration in three dimensional cultured human endometrial epithelial cells (EECs) and endometrial stromal cells (ESCs). Treatment of EECs with P/T under hypoxia stimulated cell migration, increased the expression of mesenchymal N-cadherin, vimentin and C-X-C chemokine receptor type 4 (CXCR4), and reduced the expression of epithelial E-cadherin. Furthermore, treatment with C-X-C motif chemokine ligand 12 (CXCL12), a ligand for CXCR4, increased EMT marker expression and cell migration. In ESCs, P/T or oestrogen treatment under hypoxic conditions increased the expression and secretion of CXCL12. Taken together, our data show that hypoxic and proinflammatory stimuli induce EMT, cell migration and inflammation in EECs, which was increased by CXCL12 derived from ESCs. These data imply that inflammatory mediators in retrograde menstrual fluid contribute to ectopic endometrial EMT and migration in the presence of peritoneal hypoxia.

The female medical workforce.

In the UK, the proportion of female medical students has remained static over the last decade, at around 55%; however, at consultant level, only 36.6% of doctors are women. The reasons for this drop in numbers are not clear. Given the increase in number of female doctors in training, the proportion of female doctors at consultant level is lower than might be expected. This article discusses issues affecting the female medical workforce in anaesthesia, intensive care and pain medicine. It explores how gender stereotypes and implicit gender bias can affect the way women are perceived in the workplace, especially in leadership positions, and discusses health issues particular to the female medical workforce. While the issues in this article may not affect all women, the cumulative effect of being subject to gender stereotypes within a workplace not designed to accommodate the health needs of women may contribute to a work environment that may promote the attrition of women from our specialties.

Menstrual disorders associated with sirolimus treatment.

INTRODUCTION: Sirolimus has become a pillar in the treatment of vascular anomalies due to its inhibition of the mammalian target of rapamycin (mTOR). Adverse effects include metabolic and hematologic disorders among others, although menstrual disorders have not been well described. MATERIALS AND METHODS: Retrospective review of patients with vascular anomalies on sirolimus treatment was performed. Patients presenting menstrual alterations were included. MAIN RESULTS: One hundred and thirty-six patients with vascular anomalies on treatment with sirolimus were reviewed, finding seven women out of 74 (9.4%) who presented menstrual alterations attributable to the treatment. These seven patients presented with different vascular malformations and three showed pathogenic variants in phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA) in affected tissue. Partial response in six and stability in one patient was obtained after treatment, administered for an average of 27.5 months (6-48). Five patients have completed treatment and two patients continue on after 12 and 15 months, respectively. All patients reported regular menstrual cycles prior to sirolimus treatment. One patient presented with amenorrhea for 4 months after treatment initiation that later spontaneously resolved. The other six patients presented with hypermenorrhea, four of them associating metrorrhagia. Most patients presented with mild menstrual alterations, without needing dose reduction or withdrawal, although one discontinued sirolimus due to hypermenorrhea, metrorrhagia, and hematuria. After sirolimus withdrawal, regular menstrual cycles were restored in five patients. CONCLUSION: Sirolimus treatment can produce menstrual disorders as adverse effects. Although mild and reversible upon dose reduction or cessation of treatment, patients and physicians should be aware on this potential side effect.

[A 14-year-old girl with cyclical abdominal pain]. / Een 14-jarig meisje met cyclische buikpijn.

In thisarticle, we present the case of a 14-year-old girl withcyclicalabdominalpainand a palpablemass in thelower abdomen duetoanimperforate hymen.

Disparate effects of methicillin-resistant Staphylococcus aureus infection on renal function in IgA-dominant infection-associated glomerulonephritis and menstrual toxic shock syndrome: a case report and literature review.

The sudden outbreak of severe acute respiratory syndrome coronavirus 2 pneumonia posed a significant challenge to medical professionals because treatment of critically ill patients requires the efforts of a multidisciplinary team. To highlight this principle, we examined acute kidney injury (AKI) in IgA-dominant infection-associated glomerulonephritis (GN) and menstrual toxic shock syndrome (mTSS). Both GN and mTSS are rare diseases caused by staphylococcal infection, and renal function is frequently impaired. The resulting AKIs are disparate pathological entities driven by distinct immune mechanisms. We begin by describing the case of a diabetic man with pyopneumothorax following methicillin-resistant Staphylococcus aureus (MRSA). He had endocapillary proliferative GN with in situ IgA-dominant immune-complex formation in the mesangium accompanied by complement C3 deposition in the glomerular capillary wall. By contrast, acute tubular necrosis was observed in a case of mTSS; the patient's immune response was stimulated differently by MRSA enterotoxin and exotoxin resulting in aberrant IgA deposition, complement activation, and insufficient antibody production. As a multidisciplinary communication covering the fields of nephrology, immunology, and pathology, this report may help clinicians to understand these distinct renal lesions and make optimal therapeutic decisions expeditiously.

[Prevalence of Menstrual Disorders according to Body Mass Index and Lifestyle Factors: The National Health Insurance Service-National Health Screening Cohort in Korea, 2009~2016].

PURPOSE: This study was performed to identify the prevalence of menstrual disorders in Korean women based on body mass index (BMI) and lifestyle factors, by utilizing the Korean National Health Insurance Database. METHODS: A retrospective observational study design was used for the secondary data analysis. Data of women aged 15 to 49 years who were diagnosed with menstrual disorders were extracted from The National Health Insurance Service-National Health Screening Cohort in Korea from 2009 to 2016. The age-standardized prevalence rate of menstrual disorders was calculated using SAS version 9.4, and a Chi-square test and Cochran-Armitage test were performed. RESULTS: In total, 2,219,445 cases were extracted from the database. The prevalence of menstrual disorders significantly increased from 8.6% to 11.6% (Z=135.16, p for trend <.001) over the past eight years. In particular, it was higher in underweight women than in women with normal weight across all years (Z=-4.18~-14.72, p<.001). Moreover, statistically significant differences in the prevalence of menstrual disorders were found to be associated with drinking and smoking in all years and with physical activity levels in part (p<.05~.001). CONCLUSION: These findings present compelling evidence on the prevalence of menstrual disorders based on a national database. Since the prevalence of menstrual disorders has steadily increased and differs based on BMI and lifestyle factors, educational and clinical interventions are necessary to promote risk awareness and appropriate behavioral changes among Korean women.

Association between nutritional level, menstrual-related symptoms, and mental health in female medical students.

OBJECTIVE: Research suggests that medical students as well as women are at greater risk of depression compared to the general population and men. This suggests that female medical students are crucial targets requiring specific monitoring for mental health disorder prevention and intervention. However, little is known regarding the risk factors for poor mental health among this population. Therefore, we investigated whether menstrual symptoms and nutritional status are associated with psychological distress in Japanese female medical students. METHODS: This cross-sectional study assessed 326 female medical students who attended a school medical check-up, which included blood sampling in 2018. The levels of psychological distress were evaluated using the Japanese General Health Questionnaire (J-GHQ)-30. We defined high GHQ scores as GHQ-30 ≥7. We checked dysmenorrhea levels and assessed menstrual symptoms according to the presence of premenstrual syndrome (PMS). Dysmenorrhea was evaluated according to quartiles of the sum of the Menstrual Distress Questionnaire (MDQ). PMS was assessed using the Premenstrual Symptoms Questionnaire (PSQ). We evaluated levels of serum albumin, hemoglobin, ferritin, and lipid metabolite as nutritional factors. A multivariate logistic regression analysis was used to identify the association between menstrual-related symptoms or nutritional factors and the levels of psychological distress. RESULTS: A total of 45 female medical students (15%) experienced psychological distress. Serum albumin levels were associated with psychological distress, while lipid metabolite levels were not. The intensity of dysmenorrhea and the presence of PMS were associated with psychological distress, independent of nutritional status. CONCLUSION: Both menstrual symptoms and nutrition markers were associated with the levels of psychological distress in Japanese female medical students. School doctors and nurses can help improve the mental health of young female medical students by encouraging a healthy diet and checking for the presence of menstrual symptoms.

Anti-Müllerian Hormone and Ovarian Morphology in Women With Hypothalamic Hypogonadism.

CONTEXT: Different phenotypical features of women with hypothalamic hypogonadism (HH), also known as World Health Organization-1 anovulation, including ovarian morphology, have been scarcely described in large cohorts. Some studies have reported increased levels of anti-Müllerian hormone (AMH) in women with HH. OBJECTIVE: To assess whether women with HH, compared with healthy controls, have increased serum levels of AMH and what proportion of these women erroneously meet the Rotterdam Criteria for Polycystic Ovarian Syndrome (PCOS). DESIGN, SETTING AND PARTICIPANTS: Retrospective cohort study in a Dutch academic medical center including 83 women with neither anovulation nor menstrual cycle disorders (healthy controls), 159 women with HH and 3640 women with PCOS. Age matching was used between the HH and PCOS group (1:2 ratio) to create a second group consisting of 318 age-matched women with PCOS. INTERVENTION: None. MAIN OUTCOME MEASURES: AMH levels and ovarian morphology. RESULTS: Median AMH serum levels for the HH group were 3.8 (<0.1-19.8), compared with 7.5 (<0.1-81.0) in the PCOS group and 1.9 (<0.1-21.5) in the control group (P < 0.001). In the HH group, 58 (36%) erroneously met the Rotterdam Criteria for PCOS (meeting 2 of 3 criteria). CONCLUSIONS: AMH levels are increased in women with HH. We hypothesize that this increase, although there was no increase in follicle count, may be explained by the presence of a relatively large pool of antral follicles smaller than 2 mm in diameter, that are undetectable by transvaginal ultrasound. This study highlights the importance of measuring gonadotropins and estradiol before diagnosing a patient with PCOS.

Energy Availability Is Associated With Luteinizing Hormone Pulse Frequency and Induction of Luteal Phase Defects.

OBJECTIVE: Determine the interrelations between reductions in energy availability (EA), luteinizing hormone (LH) pulse frequency, and the induction of menstrual disturbances in previously sedentary, ovulatory women. METHODS: Secondary analysis of a randomized controlled trial consisting of a 3-month controlled diet and supervised exercise program. EA was calculated daily by measured energy intake (kcal) and exercise energy expenditure (kcal) normalized to fat-free mass (kg) and averaged during baseline and each of 3 intervention menstrual cycles. Blood samples were obtained every 10 minutes for 24 hours in the early follicular phase before the intervention and after 3 months of diet and exercise (n = 14). LH pulse dynamics were assessed by Cluster. Linear mixed models determined whether EA predicts LH pulse frequency and LH pulse frequency predicts luteal phase defects (LPDs). RESULTS: Subjects were 20 ± 1 years old, 165.1 ± 1.4 cm tall, and weighed 58.9 ± 1.5 kg. LH pulse frequency decreased from 0.82 ± 0.06 pulses/h to 0.63 ± 0.09 pulses/h (P = 0.048) as a result of the intervention which produced modest (-3.2 ± 0.6 kg) weight loss. EA, averaged across a menstrual cycle, predicted LH pulse frequency (P = 0.003) such that a single-unit decrease in EA was associated with a 0.017 pulses/h decrease in LH pulse frequency. LH pulse frequency in cycles with LPDs was 49% of that observed in cycles with no menstrual disturbances and for every 0.1-unit decrease in LH pulse frequency, the odds of having an LPD were 22× greater than having an optimal ovulatory cycle (P = 0.01). CONCLUSIONS: Modest reductions in EA over a prolonged period are associated with decreased LH pulse frequency and the induction of menstrual disturbances.

Prostatic-specific antigen (PSA) levels in patients with polycystic ovary syndrome (PCOS): a meta-analysis.

PURPOSE: The polycystic ovary syndrome (PCOS) is a reproductive endocrine disorder, clinically characterized by oligo-ovulation/chronic anovulation, menstrual irregularities, hyperandrogenism (such as hirsutism, acne), hyperinsulinemia, and obesity. Prostatic-specific antigen (PSA) has been identified as a potential new marker in PCOS women. Although the precise role of PSA in PCOS patients still remains undetermined, PSA might serve as a useful clinical marker and might even represent a new diagnostic criterion of hyperandrogenemia in females of PCOS. METHODS: A meta-analysis was performed in the study to identify the association between the polycystic ovary syndrome and prostatic-specific antigen. To identify eligible original articles, we searched a range of computerized databases, including Medline via PubMed, EMBASE, CNKI and Web of Science with a systematic searching strategy. The characteristics of each study and standard mean differences (SMD) with corresponding confidence intervals (CIs) were calculated and subgroup analysis was performed to analyze heterogeneity. RESULTS: A total of 532 patients from seven articles were included in the meta-analysis. We identified a significant relationship between polycystic ovary syndrome and prostatic-specific antigen, with a pooled SMD of 0.81 (95% CI: 0.58 to 1.04; P < 0.01). The pooled data were calculated with the random-effects model as a moderate significant heterogeneity was found among the studies. CONCLUSIONS: The meta-analysis suggested that there was a significant association between the polycystic ovary syndrome and prostatic-specific antigen and we should not ignore the role of PSA in the PCOS patients in clinical.

Characteristics of carcinogenic HPV genotypes in North China Plain and the association with cervical lesions.

Human papillomavirus (HPV) infection is a crucial health problem and caused substantial malignancy diseases among female worldwide. We aim to investigate the distribution of HPV subtype and the status of cervical cancer and precancerous lesions caused by HPV infection in North China Plain population. A total of 61,870 samples of outpatients and inpatients from January 2015 to May 2017 at the Affiliated Hospital of Jining Medical University were collected. All of the samples were tested by rapid flow-through hybridization HPV genotyping. Approximately 17,280 of the cases tested positive for HPV, indicating an infection rate of 27.9%. Approximately 7009 cases were compared to the results of cytological diagnosis. The top five HPV genotypes were HPV-16 (4.5%), HPV-52 (2.9%), HPV-58 (2.8%), HPV-53 (1.9%), and HPV-81 (1.9%). The youngest age group (age < 20 years) showed the highest infection rate (59.9%), and then decreased with age. As the degree of cervical lesions worsened gradually, the rate of high-risk HPV infection increased, such as 24.3% (322/1324) in the Cervicitis, 31.30% (560/1785) in the CINI, 54.1% (568/1050) in the CINII, 80.1% (693/865) in the CIN III, and 99.5% (428/430) in the cervical cancer group. These findings were significantly different from the 9.7% (155/1555) observed in the normal medical examination group (P < .05). This is the first study to demonstrate the characteristics of HPV and the association with cervical lesions in North China Plain population.

Abnormal menstruation after radical trachelectomy and its effects on fertility.

AIM: To evaluate and identify the risk factors for abnormal menstruation after radical trachelectomy. METHODS: This study included 58 patients who underwent radical trachelectomy at our hospital between April 2005 and January 2018. Patients were divided into groups of those with no change in postoperative menstruation (regular [R] group; n = 46) and those with abnormal menstruation such as amenorrhea or hypomenorrhea (irregular [I] group; n = 12). The perioperative characteristics and fertility of the groups were compared retrospectively. The data were statistically analyzed using Student's t-test, Fisher's exact test and Mann-Whitney U test for univariate analysis and logistic regression analysis for multivariate analysis, with the level of statistical significance set at P < 0.05. RESULTS: Based on Federation of Gynecology and Obstetrics staging, 54 patients had stage IB1, 2 had stage IB2 and 2 had stage IIA1 cervical cancer. Eight patients received neoadjuvant chemotherapy. Pretreatment tumor size, residual uterine cavity length and neoadjuvant and postoperative chemotherapy use were not significantly different between the groups. Abnormal menstruation was significantly more common in patients with postoperative pelvic infection (R group, 13.0%; I group, 58.3%) and cervical stenosis (R group, 15.2%; I group, 58.3%). CONCLUSION: To maintain healthy menstruation even after radical trachelectomy, it is important to prevent postoperative pelvic infection and cervical stenosis.

Geometric and "True" Densitometric Characteristics of Bones in Athletes with Stress Fracture and Menstrual Disturbances: A Systematic Review.

BACKGROUND: Stress fractures can lead to short- and long-term consequences, impacting participation in sport and general health. Recognizing which skeletal characteristics render bones susceptible to stress fracture may aid stress-fracture prevention. Menstrual disturbances among exercising women are a known risk factor for stress fracture; therefore, assessing skeletal commonalities between women with stress fractures and women with menstrual disturbances may increase our understanding of why menstrual disturbances put athletes at greater risk for stress fracture. Three-dimensional (3D) bone imaging tools provide detailed information about volumetric bone mineral density (vBMD) and bone structure that cannot be obtained using traditional two-dimensional (2D) techniques. OBJECTIVES: This systematic review serves to: (1) evaluate the current literature available on vBMD, bone geometry, and bone structure in exercising women with menstrual disturbances and exercising women with stress fractures, and (2) assess the common skeletal characteristics between both conditions. Our aim is to reveal bone properties beyond 2D areal BMD that may indicate increased susceptibility to stress fracture among exercising women with menstrual disturbances. SEARCH METHODS: A search of the PubMed/Medline database was completed in May 2018. ELIGIBILITY CRITERIA: Eligible articles included those that reported vBMD, bone geometry, or bone structure obtained from 3D imaging techniques or estimated from 2D imaging techniques. Only studies conducted in premenopausal exercising women and girls who had a stress fracture, a menstrual disturbance, or both were included. RESULTS: Twenty-four articles met the inclusion criteria. Bone area and cortical thickness at the tibia were identified as altered both in women with menstrual disturbances and in women with stress fractures; however, there was inconsistency in the results observed for all bone parameters. The majority of skeletal parameters of the lower extremities were not significantly different between exercising women with and without stress fractures and between those with and without menstrual disturbances. DISCUSSION: Most studies were moderate or low quality based on study design, and only one article combined both conditions to explore vBMD and bone geometry in athletes with menstrual disturbances and a history of stress fracture. These findings highlight the need for more skeletal research on the intersection of these health conditions in exercising women. The lack of observed differences in skeletal parameters suggests that risk factors other than bone geometry and structure may be the primary causes of stress fracture in these women.

Abnormally located SSEA1+/SOX9+ endometrial epithelial cells with a basalis-like phenotype in the eutopic functionalis layer may play a role in the pathogenesis of endometriosis.

STUDY QUESTION: Is endometriosis associated with abnormally located endometrial basalis-like (SSEA1+/SOX9+) cells in the secretory phase functionalis and could they contribute to ectopic endometriotic lesion formation? SUMMARY ANSWER: Women with endometriosis had an abnormally higher number of basalis-like SSEA1+/SOX9+ epithelial cells present in the stratum functionalis and, since these cells formed 3D structures in vitro with phenotypic similarities to ectopic endometriotic lesions, they may generate ectopic lesions following retrograde menstruation. WHAT IS KNOWN ALREADY: Endometrial basalis cells with progenitor potential are postulated to play a role in the pathogenesis of endometriosis and SSEA1 and nuclear SOX9 (nSOX9) mark basalis epithelial cells that also have some adenogenic properties in vitro. Induction of ectopic endometriotic lesions in a baboon model of endometriosis produces characteristic changes in the eutopic endometrium. Retrograde menstruation of endometrial basalis cells is proposed to play a role in the pathogenesis of endometriosis. STUDY DESIGN, SIZE, DURATION: This prospective study included endometrial samples from 102 women with and without endometriosis undergoing gynaecological surgery and from six baboons before and after induction of endometriosis, with in vitro assays examining the differentiation potential of human basalis-like cells. PARTICIPANTS/MATERIALS, SETTING, METHODS: The study was conducted at a University Research Institute. SSEA1 and SOX9 expression levels were examined in human endometrial samples from women aged 18-55 years (by immunohistochemistry (IHC) and qPCR) and from baboons (IHC). The differential gene expression and differentiation potential was assessed in freshly isolated SSEA1+ endometrial epithelial cells from women with and without endometriosis (n = 8/group) in vitro. In silico analysis of selected published microarray datasets identified differential regulation of genes of interest for the mid-secretory phase endometrium of women with endometriosis relative to that of healthy women without endometriosis. MAIN RESULTS AND THE ROLE OF CHANCE: Women with endometriosis demonstrated higher number of basalis-like cells (SSEA1+, nSOX9+) in the functionalis layer of the eutopic endometrium compared with the healthy women without endometriosis in the secretory phase of the cycle (P < 0.05). Induction of endometriosis resulted in a similar increase in basalis-like epithelial cells in the eutopic baboon endometrium. The isolated SSEA1+ epithelial cells from the eutopic endometrium of women with endometriosis had higher expression of OCT4, NANOG, FUT4 mRNA (P = 0.05, P = 0.007, P = 0.018, respectively) and they differentiated into ectopic endometriotic gland-like structures in 3D culture, but not into mesodermal lineages (adipose or bone cells). LARGE SCALE DATA: N/A. LIMITATIONS, REASONS FOR CAUTION: Small sample size. Bioinformatics analysis and results depends on the quality of published microarray datasets and the stringency of patient selection criteria employed. Differentiation of SSEA-1+ cells was only examined for two mesodermal lineages (adipogenic and osteogenic). WIDER IMPLICATIONS OF THE FINDINGS: Since endometrial epithelial cells with SSEA1+/nSOX9+ basalis-like phenotype generate endometriotic gland-like structures in vitro, they may potentially be a therapeutic target for endometriosis. An in depth analysis of the function of basalis-like eutopic endometrial epithelial cells might provide insights into their potential deregulation in other disorders of the endometrium including heavy menstrual bleeding and endometrial cancer where their function may be aberrant. STUDY FUNDING/COMPETING INTEREST(S): We acknowledge the support by Wellbeing of Women project grant RG1073 (D.K.H., C.E.G.) and R01 HD083273 from the National Institutes of Health (A.T.F.). We also acknowledge the support of Liverpool Women's Hospital Foundation Trust (J.D.), Institute of Translational Medicine (L.D.S., H.A.L., A.J.V., D.K.H.), University of Liverpool, the National Health and Medical Research Council of Australia ID 1042298 (C.E.G.) and the Victorian Government Operational Infrastructure Support Fund. All authors declare no conflict of interest.