The role of melatonin as an antioxidant in the follicle

Melatonin (N-acetyl-5-methoxytryptamine) is secreted during the dark hours at night by pineal gland, and it regulates a variety of important central and peripheral actions related to circadian rhythms and reproduction. It has been believed that melatonin regulates ovarian function by the regulation of gonadotropin release in the hypothalamus-pituitary gland axis via its specific receptors. In addition to the receptor mediated action, the discovery of melatonin as a direct free radical scavenger has greatly broadened the understanding of melatonin's mechanisms which benefit reproductive physiology. Higher concentrations of melatonin have been found in human preovulatory follicular fluid compared to serum, and there is growing evidence of the direct effects of melatonin on ovarian function especially oocyte maturation and embryo development. Many scientists have focused on the direct role of melatonin on oocyte maturation and embryo development as an anti-oxidant to reduce oxidative stress induced by reactive oxygen species, which are produced during ovulation process. The beneficial effects of melatonin administration on oocyte maturation and embryo development have been confirmed by in vitro and in vivo experiments in animals. This review also discusses the first application of melatonin to the clinical treatment of infertile women and confirms that melatonin administration reduces intrafollicular oxidative damage and increase fertilization rates. This review summarizes our recent works and new findings related to the reported beneficial effects of melatonin on reproductive physiology in its role as a reducer of oxidative stress, especially on oocyte maturation and embryo development

Luteal blood flow in patients undergoing GnRH agonist long protocol

<p>Abstract</p> <p>Background</p> <p>Blood flow in the corpus luteum (CL) is closely related to luteal function. It is unclear how luteal blood flow is regulated. Standardized ovarian-stimulation protocol with a gonadotropin-releasing hormone agonist (GnRHa long protocol) causes luteal phase defect because it drastically suppresses serum LH levels. Examining luteal blood flow in the patient undergoing GnRHa long protocol may be useful to know whether luteal blood flow is regulated by LH.</p> <p>Methods</p> <p>Twenty-four infertile women undergoing GnRHa long protocol were divided into 3 groups dependent on luteal supports; 9 women were given ethinylestradiol plus norgestrel (Planovar) orally throughout the luteal phase (control group); 8 women were given HCG 2,000 IU on days 2 and 4 day after ovulation induction in addition to Planovar (HCG group); 7 women were given vitamin E (600 mg/day) orally throughout the luteal phase in addition to Planovar (vitamin E group). Blood flow impedance was measured in each CL during the mid-luteal phase by transvaginal color-pulsed-Doppler-ultrasonography and was expressed as a CL-resistance index (CL-RI).</p> <p>Results</p> <p>Serum LH levels were remarkably suppressed in all the groups. CL-RI in the control group was more than the cutoff value (0.51), and only 2 out of 9 women had CL-RI values < 0.51. Treatments with HCG or vitamin E significantly improved the CL-RI to less than 0.51. Seven of the 8 women in the HCG group and all of the women in the vitamin E group had CL-RI < 0.51.</p> <p>Conclusion</p> <p>Patients undergoing GnRHa long protocol had high luteal blood flow impedance with very low serum LH levels. HCG administration improved luteal blood flow impedance. This suggests that luteal blood flow is regulated by LH.</p

Entanglement of single-photons and chiral phonons in atomically thin WSe2_2

Quantum entanglement is a fundamental phenomenon which, on the one hand, reveals deep connections between quantum mechanics, gravity and the space-time; on the other hand, has practical applications as a key resource in quantum information processing. While it is routinely achieved in photon-atom ensembles, entanglement involving the solid-state or macroscopic objects remains challenging albeit promising for both fundamental physics and technological applications. Here, we report entanglement between collective, chiral vibrations in two-dimensional (2D) WSe$_2$ host --- chiral phonons (CPs) --- and single-photons emitted from quantum dots (QDs) present in it. CPs which carry angular momentum were recently observed in WSe$_2$ and are a distinguishing feature of the underlying honeycomb lattice. The entanglement results from a "which-way" scattering process, involving an optical excitation in a QD and doubly-degenerate CPs, which takes place via two indistinguishable paths. Our unveiling of entanglement involving a macroscopic, collective excitation together with strong interaction between CPs and QDs in 2D materials opens up ways for phonon-driven entanglement of QDs and engineering chiral or non-reciprocal interactions at the single-photon level

Transverse vaginal septum in a teenager with a history of imperforate hymen: A case report

Introduction: Imperforate hymen and transverse vaginal septum are conditions characterized by obstructive defects, typically leading to hematometrocolpos detected around the time of puberty. We encountered a patient who had undergone hymenotomy in infancy to treat pyocolpos due to an imperforate hymen and later developed hematometrocolpos in puberty due to a transverse vaginal septum. Case presentation: A 13-year-old female presented with hypomenorrhea and hematometrocolpos-induced dysmenorrhea. She had a history of pyocolpos with a urinary tract infection at 3 months of age. At that time, no vaginal opening was found on perineal examination, and imperforate hymen was diagnosed. When hymenotomy was performed, the external cervical os was not detected by intravaginal bronchoscopic examination. However, this abnormal finding was not fully investigated. The postoperative course after hymenotomy was free of complications, and the patient remained asymptomatic until menarche. When she presented 3 months after menarche, genital examination revealed a bulging transverse septum inside the vagina, 5 cm from the hymen. Ultrasound and magnetic resonance imaging revealed a distended uterus, distended upper vagina, and collapsed lower vagina. Transverse vaginal septum was considered, and vaginoscopy was performed to exclude vaginal reclosure or adhesion caused by the previous surgery. A diagnosis of transverse vaginal septum was confirmed, and total excision of the septum was performed. The patient underwent regular postoperative follow-ups for stenosis prevention. Conclusion: Considering the rarity of these concurrent conditions, clinicians must always consider the possibility of several complex anomalies. Vaginoscopy using a hysteroscope may be useful for definitive diagnosis and determining appropriate treatments

Bilateral ovarian endometriomas after laparoscopic hysterectomy following adjuvant tamoxifen therapy for breast cancer: A case report

Tamoxifen, a selective estrogen receptor modulator, is widely used as adjunctive therapy for women with breast cancer. However, tamoxifen has an agonistic effect on the endometrium and may be associated with endometrial proliferation, hyperplasia, polyp formation and carcinoma. The case report describes a 50-year-old woman who developed bilateral ovarian endometriomas while taking tamoxifen for breast cancer after total laparoscopic hysterectomy. She had undergone total laparoscopic hysterectomy for multiple uterine fibroids with no ovarian pathology at age 48 years, had been diagnosed with breast cancer and had commenced tamoxifen as post-mastectomy adjuvant therapy. One year after starting tamoxifen, she developed bilateral ovarian swelling accompanied by acute abdominal pain. At laparoscopic bilateral salpingo-oophorectomy, endometriomas were visible on both ovaries. Pathological examination confirmed endometriotic cysts with no evidence of malignancy. Postoperatively, anastrozole (an aromatase inhibiter) was substituted for tamoxifen as adjuvant therapy for her breast cancer

Contact Geometry and Pathway Determined Carriers Transport through Microscale Perovskite Crystals

Abstract With the miniaturization of crystals‐based photoelectric devices, electrode contact‐geometries may play a critical role in determining the device performance. However, investigation of the role of electrode contact geometries in situ faces great challenges due to the electrode contact geometry is typically unmodifiable. To this end, a kind of liquid metal is employed as an adaptive‐deformable electrode to study the carrier transport through perovskite microcrystals, in which the electrode contacts geometries/positions and thus the carrier‐pathways can be adjusted. Under light illumination, a spike feature of photocurrent is observed when carriers transport along the perovskite microcrystal surface upon an edge‐contact geometry, which is absent as the carrier mainly transport through crystal interior upon a top‐contact geometry. Switching, rectifying, and memristor functions are selectively realized just by modifying the contact geometry. The underlying mechanism for the observations is further elucidated. This study provides a platform for studying carrier transport through microscale crystals with adjustable contact geometry and supplies an approach for fabricating diverse functional devices by changing the electrode contact‐geometries

Genome-wide DNA methylation analysis reveals a potential mechanism for the pathogenesis and development of uterine leiomyomas.

BACKGROUND: The pathogenesis of uterine leiomyomas, the most common benign tumor in women, remains unclear. Since acquired factors such as obesity, hypertension and early menarche place women at greater risk for uterine leiomyomas, uterine leiomyomas may be associated with epigenetic abnormalities that are caused by unfavorable environmental exposures. PRINCIPAL FINDINGS: Profiles of genome-wide DNA methylation and mRNA expression were investigated in leiomyomas and in myometrium with and without leiomyomas. Profiles of DNA methylation and mRNA expression in the myometrium with and without leiomyomas were quite similar while those in leiomyomas were distinct. We identified 120 genes whose DNA methylation and mRNA expression patterns differed between leiomyomas and the adjacent myometrium. The biological relevance of the aberrantly methylated and expressed genes was cancer process, including IRS1 that is related to transformation, and collagen-related genes such as COL4A1, COL4A2 and COL6A3. We also detected 22 target genes of estrogen receptor (ER) alpha, including apoptosis-related genes, that have aberrant DNA methylation in the promoter, suggesting that the aberrant epigenetic regulation of ER alpha-target genes contributes to the aberrant response to estrogen. CONCLUSIONS: Aberrant DNA methylation and its related transcriptional aberration were associated with cancer processes, which may represent a critical initial mechanism that triggers transformation of a single tumor stem cell that will eventually develop into a monoclonal leiomyoma tumor. The aberrant epigenetic regulation of ER alpha-target genes also may contribute to the aberrant response to estrogen, which is involved in the development of uterine leiomyomas after menarche