Serum levels of copper and zinc in diabetic retinopathy: Potential new therapeutic targets (Review).

Diabetic retinopathy (DR) is a microvascular disorder occurring due to the long-term effects of diabetes, leading to vision-threatening damage to the retina. The human body has an elaborate system for managing and regulating the number of key trace metals circulating in the blood and stored cells. Inadequate zinc (Zn) and concurrent excess of copper (Cu) levels are associated with an increased level of oxidative stress, which may aggravate the microvascular lesions in diabetes mellitus. Several studies have revealed a significantly lower serum Zn concentration and increased Cu levels in DR when compared with diabetic patients without retinopathy and normal controls. These abnormalities are correlated with the duration of diabetes and higher levels of HbA1C. Multiple pathological mechanisms are proposed to explain these changes including hyperzincuria associated with polyuria, glycosuria, and proteinuria in diabetic patients, as well as impaired absorption of Zn at the gastrointestinal level. Increased levels of free Cu ions may be attributed to glycation and the release of Cu ions from the Cu-binding sites of proteins. Zn supplements and selective Cu chelators may be useful to alleviate oxidative stress and prevent DR progression.

Acute Mesenteric Ischemia in COVID-19 Patients.

Acute mesenteric ischemia is a rare but extremely severe complication of SARS-CoV-2 infection. The present review aims to document the clinical, laboratory, and imaging findings, management, and outcomes of acute intestinal ischemia in COVID-19 patients. A comprehensive search was performed on PubMed and Web of Science with the terms "COVID-19" and "bowel ischemia" OR "intestinal ischemia" OR "mesenteric ischemia" OR "mesenteric thrombosis". After duplication removal, a total of 36 articles were included, reporting data on a total of 89 patients, 63 being hospitalized at the moment of onset. Elevated D-dimers, leukocytosis, and C reactive protein (CRP) were present in most reported cases, and a contrast-enhanced CT exam confirms the vascular thromboembolism and offers important information about the bowel viability. There are distinct features of bowel ischemia in non-hospitalized vs. hospitalized COVID-19 patients, suggesting different pathological pathways. In ICU patients, the most frequently affected was the large bowel alone (56%) or in association with the small bowel (24%), with microvascular thrombosis. Surgery was necessary in 95.4% of cases. In the non-hospitalized group, the small bowel was involved in 80%, with splanchnic veins or arteries thromboembolism, and a favorable response to conservative anticoagulant therapy was reported in 38.4%. Mortality was 54.4% in the hospitalized group and 21.7% in the non-hospitalized group (p < 0.0001). Age over 60 years (p = 0.043) and the need for surgery (p = 0.019) were associated with the worst outcome. Understanding the mechanisms involved and risk factors may help adjust the thromboprophylaxis and fluid management in COVID-19 patients.

Laparoscopic Surgery in COVID-19 Era-Safety and Ethical Issues.

(1) Background: The paper aims to review the available evidence regarding the health risk of the aerosolization induced by laparoscopy induced and impact of the COVID-19 pandemic upon minimally invasive surgery. (2) Materials and methods: A systematic review of the literature was performed on PubMed, Medline and Scopus until 10 July. (3) Results: Chemicals, carcinogens and biologically active materials, such as bacteria and viruses, have been isolated in surgical smoke. However, the only evidence of viral transmission through surgical smoke to medical staff is post-laser ablation of HPV-positive genital warts. The reports of SARS-CoV-2 infected patients who underwent laparoscopic surgery revealed the presence of the virus, when tested, in digestive wall and stools in 50% of cases but not in bile or peritoneal fluid. All surgeries did not result in contamination of the personnel, when protective measures were applied, including personal protective equipment (PPE) and filtration of the pneumoperitoneum. There are no comparative studies between classical and laparoscopic surgery. (4) Conclusions: Previously published data showed there is a possible infectious and toxic risk related to surgical smoke but not particularly proven for SARS-CoV-2. Implementing standardized filtration systems for smoke evacuation during laparoscopy, although increases costs, is necessary to increase the safety and it will probably remain a routine also in the future.