Essam R. Othman

Molecular genetics and racial disparities of uterine leiomyomas

Uterine leiomyomas (ULMs) are benign oestrogen-dependent tumours of the myometrium. They are the most common tumours of the female genital tract, affecting around 77% of the female population. ULMs are more common in Black women than White women. These tumours tend to develop earlier and be more numerous, larger in size and more symptomatic in Black women than other ethnic groups. The molecular mechanism underlying this ethnic disparity is not fully understood. Polymorphism of genes involved in oestrogen synthesis and/or metabolism (COMT, CYP17), variation in the expression levels or function of oestrogen and progesterone receptors or retinoic acid nuclear receptors (retinoid acid receptor-alpha, retinoid X receptor-alpha), or aberrant expression of micro-RNAs are some of the molecular mechanisms that may be involved.

Reassessing the evidence for the link between dioxin and endometriosis: from molecular biology to clinical epidemiology

A 1993 study reporting the link between exposure to dioxin and the risk of developing endometriosis in rhesus monkeys prompted many investigators to look suspiciously at dioxin. Since 1993, many in vitro, animal and epidemiological studies have been published, but the link between dioxin exposure and endometriosis is still unclear. The aim of our review is to present a summary of the biological effects of dioxin and its aryl hydrocarbon receptor, and to reassess the evidence presented in published, in vitro, preclinical and epidemiological studies regarding the association between dioxins and endometriosis. Although in vitro and animal studies provide results in support for a role of dioxins in the pathogenesis of endometriosis, caution should be exercised since these findings are mostly context dependent and since negative findings from these studies are rarely published. On the basis of our review of original epidemiological studies, no significant evidence can be found to support a link between dioxins and endometriosis in women. This observation can be explained by positive publication bias and by significant methodological problems associated with these studies, or by the absence of such a link. In conclusion, it seems that there is insufficient evidence at this moment in support of the hypothesis that dioxin exposure may lead to increased risk of developing endometriosis in women.

Hybrid septate uterus, coexistence of bicornuate and septate varieties: A genuine report

Aim:  To highlight the coexistence of a uterine septum in cases diagnosed as bicornuate uterus on the basis of the external shape of the uterine fundus and to present the outcomes of its hysteroscopic management.

Biomarkers of endometriosis

BACKGROUND Diagnosis of endometriosis is surgical through laparoscopy, which is invasive, costly and associated with potential complications. OBJECTIVES A non-invasive test for diagnosis of endometriosis will focus the use of laparoscopy on women who are highly suspected of having endometriosis. This review includes studies about different biomarkers for endometriosis and their potential for the non-surgical diagnosis of this disease. METHODS This review covers studies that investigated different biomarkers in blood or endometrium. Studies that identified definite cutoff points and evaluated the diagnostic performance of the biomarker as a blood test for endometriosis are focused on. RESULTS/CONCLUSIONS Some of the markers investigated showed a good specificity, none of them showed a high sensitivity. More multi-center studies involving larger numbers of patients are required to identify the most useful biomarker.

Soluble tumor necrosis factor-alpha receptors in the serum of endometriosis patients

INTRODUCTION We examine serum levels sTNFR-I and sTNFR-II in endometriosis patients, and their role as biomarkers of endometriosis. MATERIAL AND METHODS Women were diagnosed with endometriosis during laparoscopy to investigate pelvic pain and/or infertility (N=62). Control group included women with pelvic pain and/or infertility, whose laparoscopy showed no abnormalities (N=55). Serum concentrations of sTNFR-I and sTNFR-II were measured using Bioplex Protein Array system. Non-parametric statistics were used. RESULTS Endometriosis patients had significantly higher levels of sTNFR-I than controls (257.46pg/ml, IQR=2.37-1048.92 versus 130.39pg/ml, IQR=0.99-361.1 respectively, P value=0.01). For TNFR-II, difference between women with (232pg/ml, IQR=0.0-624.4), and women without (132.93pg/ml, IQR=0.0-312.81) endometriosis was not significant (P value=0.05). Early stage endometriosis patients had significantly higher level of sTNFR-I (559.13, IQR=1.82-1289.86) and sTNFR-II (248.8, IQR=0-644.65) than control women (P value is 0.01 for TNFR-I and 0.04 for TNFR-II). Levels of sTNFR-I and sTNFR-II were comparable for advanced endometriosis and controls, and between early and advanced endometriosis. As a biomarker for all- stage endometriosis, sTNFR-I produces AUC of 0.62, sensitivity of 61%, and specificity of 47.3%, at a cutoff of 81.87pg/ml. For early stage disease, sTNFR-I yields AUC of 0.68, sensitivity of 60.7%, specificity of 75%, at a cutoff of 351.22pg/ml. CONCLUSION sTNFR-I is significantly higher in serum of endometriosis patients than controls. As an endometriosis biomarker, sTNFR-I achieves better performance for early stage disease.

Bisphenol A Concentrates Preferentially in Human Uterine Leiomyoma and Induces Proliferation in Rat Myometrium

Objectives: To measure tissue levels of bisphenol A (BPA) in uterine leiomyoma (ULM), adjacent myometrium (Myo-F), and normal myometrium (Myo-N). Also, we tested the effect of BPA treatment on rat myometrium. Methods: Uterine leiomyomas and Myo-F tissues were isolated from hysterectomy specimens done to treat symptomatic ULMs (N = 30). Normal myometrium is isolated from hysterectomies done on ULM-free uteri for other benign indications (N = 25). Bisphenol A was measured in 1 g of tissue using solid-phase extraction and high-performance liquid chromatography, with fluorescence detectors. Experimentally, adult female rats were fed BPA orally at a dose of 50 mg/kg/d for 90 days. Animals were killed, and their myometrial thickness and proliferating cell nuclear antigen (PCNA) immunostaining were evaluated. Results: Tissue concentration of BPA in each of ULM (12.3 ± 2.8 µg/g) and Myo-F (10.1 ± 0.2 µg/g) was significantly higher than that of Myo-N (0.58 ± 0.2 µg/g). There was no statistically significant difference in BPA level between ULM and Myo-F within submucous or interstitial/subserous fibroid groups. Compared to control rats, BPA-treated animals showed significantly higher myometrial thickness (168.67 ± 5.7 µm and 281.6 ± 20.32 µm, respectively, P = .003) and increased myometrial PCNA immunoscores (1.5 ± 0.37 and 10.38 ± 0.67, respectively, P ≤ .001). Conclusion: Bisphenol A concentrates in human ULM tissue and its adjacent Myo-F compared to Myo-N. No significant difference is detected in BPA content of ULM tissue of different subtypes. Bisphenol A increases thickness and induces cellular proliferation in rat myometrium. Taken together, our results support a role of BPA in ULM development/growth.

Stem Cell Markers Describe a Transition From Somatic to Pluripotent Cell States in a Rat Model of Endometriosis

Objective: To study Thy1 as a fibroblast marker, SSEA1 as a marker of intermediate pluripotency, and Oct4 as a marker of established pluripotency in rat model of endometriosis. Design: In vivo animal study. Materials and Methods: Endometriosis was induced in 20 albino female rats through autologous transplantation of one uterine horn to mesentery of intestine. Other 20 rats had their horn removed without transplantation (controls). Rats were sacrificed 4 weeks after induction surgery. Ectopic, eutopic, and control endometria were harvested from endometriosis and control animals respectively. Quantitative syber green based RT-PCR was used to detect expression of Thy-1 (CD90), FUT4 (SSEA1), and POU5F1 (Oct4) genes in tissues. Relative expression was normalized to that of β actin. Thy1, SSEA1, and Oct4 protein expression were detected by immunohistochemistry. Results: Ectopic endometrium expressed significantly higher mRNA of Oct4 and SSEA1 as compared to control endometrium. Expression levels of Oct4 and SSEA1 were comparable between ectopic and eutopic endometria and between eutopic and control endometria. Thy1 (CD90) gene expression level was comparable among ectopic, eutopic, and control endometria. Oct4 immunoscore were significantly higher in ectopic (6.6±0.91) than eutopic (2.5±0.78) or control endometrium (3.7±0.1) (P value 0.02). Thy1 and SSEA1 immunoscores were comparable among all three types of endometria. Conclusions: Using rat model of endometriosis, ectopic endometrium showed significantly higher Oct4, and SSEA1, but similar Thy1 gene expression to that of control endometrium. This indicates increased transition from somatic to pluripotent cell states in ectopic endometrium which may play a role in endometriosis pathogenesis.

Identification and potential role of telocytes in human uterine leiomyoma

BackgroundTelocytes are specialized interstitial tissue cell type. Our aim is to characterize telocytes in human uterine leiomyoma (ULM) and its adjacent myometrium (Myo-F) as well as normal myometrium (Myo-N).MethodsULMs and Myo-F tissues were taken from hysterectomy specimens done to treat symptomatic uterine fibroids (N = 20). Myo-N is isolated from hysterectomies done on ULM- free uteri for other benign indications (N = 15).Telocytes were detected using immunohistochemistry to detect c-Kit (CD-117), as a surface marker expressed on telocytes, and electron microscopic examination to identify telocytes characteristic ultrastructure. Cellular count and electron microscopic features of telocytes in each of the studied tissues were compared.ResultsTelocytes could be detected in ULMs, Myo-F and Myo-N using c-KIT immunostaining. Electron microscopy confirmed the presence of telocytes in the three types of tissues identifying their characteristic features including small triangular or fusiform cell bodies with extensive cellular prolongations. ULM telocytes showed ultrastructural features suggestive of high cellular activities. Cell counts of ULM telocytes (3.35 ± 0.39) were significantly higher (P value = 0.00039) than that of Myo-F (1.39 ± 0.13). Myo-N (2.6 ± 0.36) contained higher telocyte numbers than Myo-F (1.39 ± 0.13), but the difference did not reach statistical significance (P value = 0.19).ConclusionsTelocytes are detected in higher numbers and activity in ULMs than Myo-F or Myo-N. In ULMs, telocytes can work as a hormonal sensors for stem cells, provide scaffold for newly formed myocytes, or control important downstream signaling pathways.

Human uterine leiomyoma contains low levels of 1, 25 dihdroxyvitamin D3, and shows dysregulated expression of vitamin D metabolizing enzymes

OBJECTIVES To evaluate tissue concentration of 1, 25 dihydroxyvitamin D3, and gene expression level of CYP27B1 that codes for 1-α hydroxylase (vitamin D activating enzyme), and CYP24A1 that codes for 24-hydroxylase (vitamin D catabolizing enzyme) in human uterine leiomyoma (ULM), its adjacent myometrium (Myo-F), and normal myometrium (Myo-N). STUDY DESIGN Levels of 1, 25 dihydroxyvitamin D3 were measured using HPLC and Diode detectors whereas CYP27B1, and CYP24A1 expressions were assessed using Real-Time PCR in ULM, Myo-F, and Myo-N. Non-parametric statistics were used. RESULTS ULMs contained significantly less 1, 25 dihydroxy vitamin D3 compared to Myo-F (3.0, IQR: 1.0-9.0 versus 6.0, IQR: 3.0-13.0 μg/ kg, P value is 0.03). No significant difference was detected between ULM and Myo-N, or Myo-F and Myo-N. Intratumoral level of the active form of vitamin D did not differ according to the type of ULM (submucous or interstitial/subserous), or to the ULM volume. CYP27B1 was expressed in ULM (2.17, IQR: 0.65-4.9), Myo-F (4.94, IQR: 1.04-22.59), and Myo-N (0.99, IQR: 0.49-1.71) to a comparable level. CYP24A1 expression was significantly higher in ULM compared to Myo-N (2.00, IQR: 0.69-10.77 versus 0.22, IQR: 00- 0.96, respectively, P value is 0.04). CONCLUSIONS Human ULMs contain significantly lower 1, 25 dihydroxyvitamin D3 than its adjacent myometrium. ULM, Myo-F, and Myo-N express CYP27B1 and CYP24A1. ULMs express significantly higher level of CYP24A1 than normal myometrium indicating that over expression of 24-hydroxylase is a mechanism by which ULMs sustain a relative state of hypovitaminosis D.

Reply to: Misoprostol during cesarean delivery: At which time and by which route?

We appreciate the interest shown by Dr. Shehata in our recently published paper [1]. We would like to thank him for his valuable comments that add much more to our own published findings. Regarding the cost of misoprostol, we disagree with the author that misoprostol is costly than oxytocin wherever in Egypt or worldwide. A recent study demonstrated that the mean cost of misoprostol was significantly lower than the oxytocin (2.0 ± 0.8 vs. 5.1 ± 0.9 US dollars; P < 0.00001) [2]. Additionally, Vlassoff et al., 2016 in reported that misoprostol was more cost effective than oxytocin when given prophylactically after vaginal delivery in low-resource setting; Senegal similar to Egypt [3]. Shehata states that misoprostol costs one Dollar while one oxytocin ampoule costs 0.25 Dollar, although he provides no citations to prove this. Shehata states that the large systematic review by CondeAgudelo et al. [2] reported no statistically significant differences between misoprostol and oxytocin in reducing intraoperative and postoperative bleeding at cesarean delivery. We agree with him, but the review included four clinical trials; one of them showed a significant reduction in the mean postoperative blood loss with sublingual misoprostol (MD 1⁄4 23 ml; P < 0.00001) [4]. In the other 3 studies, there was a lower mean intraoperative blood loss with sublingual misoprostol (MD 1⁄4 55 ml) although it was not statistically significant; P 1⁄4 0.07. This coincides with our study results; however we reported a statistically significant lower blood loss with misoprostol (MD 1⁄4 111 ml, P 1⁄4 0.025) [1]. On the other hand, the mentioned meta-analysis byMousa et al. [5] was evaluating the role of misoprostol in treatment of primary postpartum hemorrhage (PPH), unlike our study which evaluated its prophylactic role in PPH. Finally, Conde-Agudelo et al. [2] reported in their systematic review that equivalence or non-inferiority randomized controlled trials with sufficient statistical power are still needed to compare the