The oocyte is recognised as the largest cell in mammalian species and other multicellular organisms. Mitochondria represent a high proportion of the cytoplasm in oocytes and mitochondrial architecture is different in oocytes than in somatic cells, characterised by a rounder appearance and fragmented network. Although the number of mitochondria per oocyte is higher than in any other mammalian cell, their number and activity decrease with advancing age. Mitochondria integrate numerous processes essential for cellular function, such as metabolic processes related to energy production, biosynthesis, and waste removal, as well as Ca2+ signalling and reactive oxygen species (ROS) homeostasis. Further, mitochondria are responsible for the cellular adaptation to different types of stressors such as oxidative stress or DNA damage. When these stressors outstrip the adaptive capacity of mitochondria to restore homeostasis, it leads to mitochondrial dysfunction. Decades of studies indicate that mitochondrial function is multifaceted, which is reflected in the oocyte, where mitochondria support numerous processes during oocyte maturation, fertilization, and early embryonic development. Dysregulation of mitochondrial processes has been consistently reported in ageing and age-related diseases. In this review, we describe the functions of mitochondria as bioenergetic powerhouses and signal transducers in oocytes, how dysfunction of mitochondrial processes contributes to reproductive ageing, and whether mitochondria could be targeted to promote oocyte rejuvenation.

Introduction: Lipomas of the gastrointestinal tract are a rare condition. Only 5% are of gastric origin, and this corresponds to 2% to 3% of all benign tumors of the stomach and less than 1% of all gastric neoplasms. It is our purpose to report an unusual presentation of a giant gastric lipoma in an oligosymptomatic patient and highlight the importance of discussing differential diagnosis in this situation. A review of the literature has shown that this is one of the largest gastric lipomas described. Case presentation: We describe a rare case of a benign gastric tumor with uncommon features in a 63-year-old Caucasian woman. She was admitted with abdominal discomfort, nausea, and upper abdominal fullness after eating. The lesion was suspicious of malignancy because of its dimension and central contrast enhancement on computed tomography. Conventional upper digestive endoscopy revealed a large bulging mass in the gastric posterior wall and three ulcerated areas. In this procedure, a technical limitation due to the location of the mass in the submucosa prevented an adequate biopsy from being obtained. The fragments obtained from the ulcers revealed nothing but necrotic mucosa. Our patient underwent a subtotal gastrectomy and D1 lymphadenectomy with a Roux-en-Y reconstruction. Macroscopic findings revealed a 12 × 8 × 6cm mass with a volume of 576cm³, and the histological pattern demonstrated well-differentiated mature adipose tissue surrounded by a fibrous capsule, confirming the diagnosis of gastric submucosal lipoma. Conclusions: Gastric lipoma is a rare benign disease that eventually simulates a malignant tumor.

To evaluate the overall performance and oocyte quality of follicular phase stimulation (FPS) vs. luteal phase stimulation (LPS) among patients undergoing double ovarian stimulation (DuoStim). Obser...