COVID-19, a pandemic disease caused by a viral infection, is associated with a high mortality rate. Most of the signs and symptoms, e.g. cytokine storm, electrolytes imbalances, thromboembolism, etc., are related to mitochondrial dysfunction. Therefore, targeting mitochondrion will represent a more rational treatment of COVID-19. The current work outlines how COVID-19's signs and symptoms are related to the mitochondrion. Proper understanding of the underlying causes might enhance the opportunity to treat COVID-19.

Replication is a fundamental aspect of cancer, and replication is about reproducing all the elements and structures that form a cell. Among them are DNA, RNA, enzymes, and coenzymes. All the DNA is doubled during each S (synthesis) cell cycle phase. This means that six billion nucleic acids must be synthesized in each cycle. Tumor growth, proliferation, and mutations all depend on this synthesis. Cancer cells require a constant supply of nucleotides and other macromolecules. For this reason, they must stimulate de novo nucleotide synthesis to support nucleic acid provision. When deregulated, de novo nucleic acid synthesis is controlled by oncogenes and tumor suppressor genes that enable increased synthesis and cell proliferation. Furthermore, cell duplication must be achieved swiftly (in a few hours) and in the midst of a nutrient-depleted and hypoxic environment. This also means that the enzymes participating in nucleic acid synthesis must work efficiently. pH is a critical factor in enzymatic efficiency and speed. This review will show that the enzymatic machinery working in nucleic acid synthesis requires a pH on the alkaline side in most cases. This coincides with many other pro-tumoral factors, such as the glycolytic phenotype, benefiting from an increased intracellular pH. An increased intracellular pH is a perfect milieu for high de novo nucleic acid production through optimal enzymatic performance.

Background and Aim: The soft tissue defects around the knee are common and represents a challenge for surgeons due to its complexity and desired outcome. Many reconstructive treatment options are available and flaps are recommended. The current study aimed to evaluate the outcome of using saphenous artery (SA)-based flaps for the management of soft tissue defects around the knee. Methodology: Files of 34 patients treated by SA-based flaps were reviewed for outcome and complications. Collected data included patient demographics, etiology, size, site and side of the defect and outcome (flap survival and complications) at the end of the 6th postoperative month. Results: There were 26 males and 8 females. Their age ranged from 18 to 45 years; the mean age was 33.18±6.58 years. The commonest etiology was posttraumatic (64.7%) then post-burn contracture (20.6%). The majority of defects were on the right side (82.4%). The maximum length of the defect ranged between 14 and 20 cm (mean ± SD were 16.56±1.62) while the maximum width ranged between 6 and 10 cm (mean ±SD were 8.59±1.05). The flap survival rate was 97.1%. The overall complications rate was 14.7%, distal flap necrosis reported for 5.9%, wound dehiscence for 2.9% and seroma for 5.9%. All treated conservatively, except that of distal flap necrosis which need reintervention. Conclusion: The saphenous artery-based fasciocutaneous flap is an effective, feasible and safe option for the management of soft tissue defects around the knee.

Introduction and aim: Pilonidal sinus (PNS) is a common inflammatory condition of the gluteal region. Different methods were introduced for treatment. However, recurrence is still a significant problem after surgery and different approaches were described to lower the recurrence rate. But controversy exist regarding the standard surgical intervention. The current work aimed to compare between excision with off midline primary closure versus Limberg flap procedure in the treatment of sacrococcygeal PNS. Methodology: Sixty patients with PNS were included and divided into two equal groups, the first for primary midline excision with closure, and the second treated by Limberg flap. Patients were assessed by clinical evaluation and after surgery, the recurrence rate was documented through the first year. In addition, complications rate and times to restore the normal daily activities were documented and compared between groups. Results: Both groups were comparable regarding all preoperative variables. The operative time was significantly short among group I than group II (31.6± 6.5 vs 51.6± 6.4 minutes). The duration of hospital stay, time to return to work, drainage amount, time to stitch removal, time to walk pain-free and time to painless toilet seat were significantly shorter in group I. However, cosmetic score was significantly higher in group I than group II. Finally, the recurrence rate was significantly higher in group I than group II (20.0% vs 0.0%). The recurrence was significantly associated with hairy skin, positive family history, diabetes mellitus, higher BMI, and history of previous PNS. Conclusion: Primary midline closure of PNS is superior than the Limberg flap in operative time and times to return to normal daily activities. However, it had a higher recurrence rate. Thus, Limberg flap is advocated for PNS.

Bariatric surgery is considered an appropriate method in cases of obesity, such as severe or comorbidities obesity. However, the number of patients requiring bariatric surgery is growing  constantly and rapidly. Opposing that, the anatomical modifications of the gastrointestinal tract often lead to a significant alteration in the pharmacokinetics of orally administered drugs in terms of absorption of drugs and the bioavailability of oral medications required after the surgery. The current study investigates the correlation between reduced body mass following bariatric surgery and the bioavailability of orally administered drugs. Therefore, it is required to warrant through clinical studies that help establish guidelines related to common oral drugs prescribed and monitor the medications that exhibit a small therapeutic window that should be assessed, excluding the clinical endpoint. Furthermore, the use of pharmacokinetic modeling based on a mechanical method to simulate the multivariate nature observed while changes occur during the exposure of drugs will help to serve as an essential tool to understand further the trends in oral exposure of drugs in postoperative cases develop practical clinical guidance.