Рatients with diabetes have more complications and higher mortality from COVID-19. This is due to the fact that diabetes impairs the immune response. Hyperglycemia causes a violation of the immune response, which in turn cannot control the spread of pathogenic microorganisms and therefore patients
with diabetes are more susceptible to infections. The purpose of the work ₋₋ analysis of bibliometric databases of literature on new developments in diabetes and COVID-19 and focused on clinical recommendations for patients with diabetes infected with COVID-19. The search methods included a literature review of scientific articles that studied diabetes and COVID-19. According to the results of the analysis of the articles obtained as a result of the search in the PubMed, SCOPUS, Web of Science, MedScape databases, a combination of the terms “diabetes and SARS-CoV-2”, “diabetes and COVID-19”, “pathogenesis of diabetes in case of COVID-19”, "pancreas", "clinical features", "diagnosis", "treatment", "clinical recommendations", we found 32 messages from 2020 to 2022. The main parameters  of the study were outpatients and inpatients with diabetes and COVID-19 of middle and elderly age starting from 46 years and up to 82 years of age in France, China, the USA, Great Britain, in which a nationwide, retrospective, populationbased study was conducted. The following concomitant diseases are included in the main studies: arterial hypertension, cardiovascular diseases, heart failure, chronic kidney disease, chronic obstructive pulmonary disease, myocardial infarction, cerebrovascular diseases. Issues of pathogenetic mechanisms in DM and COVID-19, as well as management of patients with DM and COVID-19 are highlighted.
Key words. Diabetes mellitus, СOVID-19, SARS-CoV-2, angiotensin-converting enzyme-2, cytokines.

Aim: To study the process of hemoglobin oxidation and the enzymatic reactions associated with it.
Materials and Methods: Heparinized human blood (15 IU/ml) was obtained from the clinical department. The concentration of oxy- and methemoglobin,
auto-oxidation of hemoglobin was determined spectrophotometrically spectrophotometrically. Autooxidation of hemoglobin was recorded spectrophotometrically, and protein concentration was determined by the Lowry method. Monooxygenase activity of hemoglobin was also measured by the method described
by Lowry spectrophotometrically. The concentration of O₂ and H₂O₂ in the reaction media was determined on a biomicroanalyzer OR 210/3 (Redelkis).
Results: The obtained experimental data allow us to propose a mechanism of “spontaneous autooxidation” of oxyhemoglobin, which can be described by
the following equations:
Hb²⁺O₂ = Hb³⁺ + O₂ (1)
Hb²⁺O₂ + 2e^- + 2H⁺ = Hb³⁺ + H₂O₂ (2)
Hb²⁺O₂ + 2e ^- + 2H⁺ = Hb²⁺ + H₂O₂  (3)
Hb²⁺ + O_{2 ⁼}  Hb²⁺O2 (4)
Spectral characteristics of the process of “spontaneous auto-oxidation” indicate the formation of a metform of hemoglobin, the depletion of oxygen by the system was established, at pH 5.6, an increase in the monooxygenase activity of hemoglobin is observed 3-4 times compared to the physiological level.
Сonclusions: In addition to the main, previously known functions of hemoglobin (gas transport, peroxidase, monooxygenase), it catalyzes a two-electron
oxidase reaction in which O₂
 is reduced to H₂O₂. This is confirmed by experimental data on the formation of one of the products of “spontaneous autoxidation”
of oxyhemoglobin _ deoxyform at pH 5.6 _ 8.9.
 KEY WORDS: oxyhemoglobin, methemoglobin, autooxidation, monooxygenase activity, oxidase reaction, ligands

У статті представлено огляд літературних даних щодо метаболізму цинку в організмі людини. Цинк – один із найважливіших мікроелементів, бере участь у численних аспектах клітинного обміну. Необхідний для каталітичної активності ферментів та відіграє роль у забезпеченні імунної функції організму, синтезі білків, синтезі ДНК і клітинному поділі, загоєнні ран, тощо. Цинк також забезпечує нормальний ріст і розвиток організму під час вагітності, дитинства та підліткового віку. Метаболізм цинку тісно пов’язаний з обміном інших хімічних елементів.
Ключові слова: цинк, метаболізм, порушення, імунна система.