Fine structure of Egyptian buffalo oocytes (Bubalus bubalis) during different in vitro maturation periods using transmission electron microscopy (TEM)

This study was carried out to illustrate the ultrastructure of Egyptian buffalo oocytes through in vitro maturation (IVM) period (24 h). Selected cumulus oocytes complexes (COCs) were divided into three groups in relation to the time of maturation (8, 16 and 24 h >). After different maturation intervals, the matured oocytes were examined by light and transmission electron microscope (TEM). Results showed that the cumulus cells were close to each other and zona plucida (ZP) in the first group than the second and third group, lipid droplets (LD) appeared normal and nearly from plasma membrane in the group of oocytes matured in vitro for 8 h than oocytes matured in vitro for 24 h, microvilli (Mv) appeared with more number, higher thickness and penetrating the ZP and cytoplasm in the first group than other two groups, and mitochondria (M) in the first group were located near the plasma membrane, while in the third group it appeared as individual and scattered through the oocyte cell. Finally, the first polar body was observed in the third group only. This study showed the ultra-structural concepts of Egyptian buffalo oocytes during different IVM periods, and provided insights about the changes that occurred in oocytes during maturation process in the bovine species.Keywords: Egyptian buffalo, oocytes, in vitro maturation (IVM), ultra structura

The impact of surgical delay on resectability of colorectal cancer: An international prospective cohort study

AIM: The SARS-CoV-2 pandemic has provided a unique opportunity to explore the impact of surgical delays on cancer resectability. This study aimed to compare resectability for colorectal cancer patients undergoing delayed versus non-delayed surgery. METHODS: This was an international prospective cohort study of consecutive colorectal cancer patients with a decision for curative surgery (January-April 2020). Surgical delay was defined as an operation taking place more than 4 weeks after treatment decision, in a patient who did not receive neoadjuvant therapy. A subgroup analysis explored the effects of delay in elective patients only. The impact of longer delays was explored in a sensitivity analysis. The primary outcome was complete resection, defined as curative resection with an R0 margin. RESULTS: Overall, 5453 patients from 304 hospitals in 47 countries were included, of whom 6.6% (358/5453) did not receive their planned operation. Of the 4304 operated patients without neoadjuvant therapy, 40.5% (1744/4304) were delayed beyond 4 weeks. Delayed patients were more likely to be older, men, more comorbid, have higher body mass index and have rectal cancer and early stage disease. Delayed patients had higher unadjusted rates of complete resection (93.7% vs. 91.9%, P = 0.032) and lower rates of emergency surgery (4.5% vs. 22.5%, P < 0.001). After adjustment, delay was not associated with a lower rate of complete resection (OR 1.18, 95% CI 0.90-1.55, P = 0.224), which was consistent in elective patients only (OR 0.94, 95% CI 0.69-1.27, P = 0.672). Longer delays were not associated with poorer outcomes. CONCLUSION: One in 15 colorectal cancer patients did not receive their planned operation during the first wave of COVID-19. Surgical delay did not appear to compromise resectability, raising the hypothesis that any reduction in long-term survival attributable to delays is likely to be due to micro-metastatic disease

Ultra-structural study of Egyptian Buffalo oocytes before and after in vitro maturation

The purpose of this study was to describe the changes occurring in the cytoplasmic organelles of the buffalo oocytes before and after in vitro maturation. The total number of oocytes used in this experiment was 250 oocytes; 50 in vivo matured oocytes, 100 immature oocytes, and the other 100 was in vitro matured oocytes cultured in TCM-199 + LH. The oocytes examined in this study showed normal ultra-structure of mitochondria, smooth endoplasmic reticulum (SER), zona pellucida (ZP), lipid droplets, vesicles and Golgi in the good type meanwhile, some differences and abnormalities in denuded oocytes were recorded. The most remarkable changes observed in the two different categories of oocytes (good and denuded) after maturation was the different complexes consisting endoplasmic reticulum, mitochondria (M), lipid droplets (L), vesicles (V) and ZP. Concerning the polar body (PB), group of in vitro matured oocytes showed a normal PB formation, vesicles, whereas mitochondria were dislocated towards the site of the PB. In vitro matured oocytes showed clusters of cortical granules which existed in aggregates throughout the peripheral ooplasm just beneath the oolemma. In vitro maturation of Egyptian buffalo oocytes could be elucidated by alterations that occurred in the cytoplasmic organelles of the oocytes as shown by transmission electron microscopy (TEM).Keywords: Egyptian buffalo, oocytes, in vitro maturation, ultra-structur