Evaluation of Serum Levels of Lactate Dehydrogenase Isoenzymes in COVID- 19 Patients

Background: This study aimed to determine the serum levels of lactate dehydrogenase isoenzymes (LDH1, LDH2, LDH3, LDH4, and LDH5) and their contribution to the total lactate dehydrogenase enzyme elevation observed in COVID-19 patients. Design of study: This study was conducted in collaboration between Al-Nahrain University/College of Medicine/Chemistry and Biochemistry Department and Al- Yarmouk Teaching Hospital, Baghdad, Iraq. The study included 90 patients with confirmed COVID-19 infection: 45 with severe symptoms, and 45 with mild symptoms during the period from February 2021 to June 2021. The different LDH isoenzymes (LDH1, LDH2, LDH3, LDH4, and LDH5) were determined by enzyme-linked immunosorbent assay (ELISA) kits. Results: This study showed high correlation between total lactate dehydrogenase (LDH) enzyme and disease progression and severity in patients with COVID-19. The study also showed significantly higher levels of the lactate dehydrogenase isoenzymes (LDH1, LDH3, and LDH4) in patients with severe symptoms. Conclusion: This study suggests that elevation of serum lactate dehydrogenase (LDH) in patients with COVID-19 may be associated with the release of more than one of LDH isoenzymes into the bloodstream, therefore the use of total LDH as a specific biomarker for lung affectation in patients with COVID-19 is not specific, but the assay of all LDH isoenzymes could give a better understanding of the tissues most affected by the virus.

Protective Effect of Flaxseed on the Health of Experimental Animals Exposed to Xylene

Xylene is mainly used as a solvent in the printing, tire and leather industries. It is also used as: a facility cleaner, paint and varnish thinner, component of fuel, and chemical for the laboratory processing of histological preparations. For these reasons people are frequently exposed to xylene and the risk of intoxication is high. This study focused on the protective effect of flaxseed on mice experimentally intoxicated with xylene. The experiment lasted 14 days. The mice used in this study (n = 60) were allocated to 3 groups: the control group (C) received only the standard diet; the xylene group (X) was fed a standard diet and was administered xylene p. o. (10 µl daily); and the xylene + flaxseed group (XF) received the standard feed, crushed flaxseed and xylene at the same dose as group X. The observations involved changes in: body weight, liver enzyme levels, and caspase activity in the liver of the mice. The administration of additives resulted in significant changes in the body weight of the mice on day 7 of the experiment (P < 0.05). The highest weight gain was observed in mice from the XF group. In contrast, the body weight of the mice from group X exposed only to xylene was the lowest. The biochemical analysis of the liver cells of the xylene intoxicated mice showed elevated levels of: aspartate aminotransferase (AST), De Ritis ratio (AST/ALT ratio), and lactate dehydrogenase isoenzymes LDH-3 and LDH-5. Caspase-3, the marker of apoptosis, was increased in the XF group. Thus, the administration of flaxseed in our experiment had a beneficial effect on the clinical and metabolic parameters of mice intoxicated with xylene. Our results indicated that the administration of flaxseed, may act as a preventative measure with respect to xylene intoxication of animals; however, further analyses are needed to confirm this assumption.

Applicability of the protein-lipid profile and activity of lactate dehydrogenase isoenzymes for diagnosing nutritional muscular dystrophy in calves

Introduction: In calves, hyposelenosis degenerates skeletal muscles in different parts of the body. The extent of damage to muscle cells can be diagnosed by determining the activity of creatine kinase (CK), aspartate aminotransferase (AST), and lactate dehydrogenase (LDH). The aim of this study was to analyse variations in the serum levels of LDH isoenzymes in calves with nutritional muscular dystrophy (NMD), to determine the applicability of this parameter for diagnosing NMD, and to describe the influence of hyposelenosis on total protein (TP), triglyceride (TG), and cholesterol (CHOL) levels.Material and Methods: Two groups of calves (n = six animals per group) were used. After birth, control group calves (SC) were intramuscularly administered 10 ml of a preparation containing selenium (Se) and vitamin E, and experimental group animals (SE) that were not injected. Blood was collected after 5, 15, and 25 days, and the concentrations of Se, vitamin E, TP, TG, and CHOL and the activity of glutathione peroxidase (GSH-Px), CK, and LDH fractions were determined.Results: Hypocholesterolaemia and elevated TG levels were found in SE group calves whose LDH fractions revealed a significant increase in LDH4 and LDH5 activity and a decrease in LDH1 activity when electrophoretically separated.Conclusions: Nutritional muscular dystrophy is accompanied by hypocholesterolaemia and elevated TG levels caused by muscle lipolysis. LDH4 and LDH5 activity parameters assist early diagnosis of NMD in calves.