Due to the need for continuous work, the heart uses up to 8% of the total energy expenditure. Due to the relatively low adenosine triphosphate (ATP) storage capacity, the heart’s work is dependent on its production. This is possible due to the metabolic flexibility of the heart, which allows it to use numerous substrates as a source of energy. Under normal conditions, a healthy heart obtains approximately 95% of its ATP by oxidative phosphorylation in the mitochondria. The primary source of energy is fatty acid oxidation, the rest of the energy comes from the oxidation of pyruvate. A failed heart is characterised by a disturbance in these proportions, with the contribution of individual components as a source of energy depending on the aetiology and stage of heart failure. A unique form of cardiac dysfunction is sepsis-induced cardiomyopathy, characterised by a significant reduction in energy production and impairment of cardiac oxidation of both fatty acids and glucose. Metabolic disorders appear to contribute to the pathogenesis of cardiac dysfunction and therefore are a promising target for future therapies. However, as many aspects of the metabolism of the failing heart remain unexplained, this issue requires further research.

Increases in plasma kynurenic acid (KYNA) concentration relate to the severity of inflammation. The aim of this study was to analyse changes in plasma KYNA concentration and neutrophil/lymphocyte ratio (NLR) in cardiac surgery patients. Additionally, the effect of anaesthesia was analysed. Adult cardiac surgery patients under intravenous general anaesthesia were studied. Additionally, some patients received sevoflurane (SEV) prior to cardiopulmonary bypass. Plasma KYNA concentration and NLR were measured before anaesthesia, just after surgery and on postoperative days 1, 2 and 3. Patients were assigned to two groups: patients who did not receive SEV (NonSEV group) and patients who received SEV (SEV group). Forty-three patients were studied. Twenty-four of them received SEV. KYNA increased immediately after surgery and remained elevated through postoperative day 3 in the NonSEV group, whereas it was similar to the preoperative concentration in the SEV group. NLR increased immediately after surgery in both groups, and higher values were noted in the NonSEV group than in the SEV group at postoperative days 2 and 3. Plasma KYNA concentration correlated with NLR in the NonSEV group. Cardiac surgery caused an increase in NLR. Plasma KYNA increased in the NonSEV group and correlated with NLR. Administration of SEV inhibited the increase in KYNA, most likely due to its anti-inflammatory properties.

Data show a local deficit of QUDA in RA patients and suggest its potential role as an endogenous substance controlling synoviocyte viability.

Atherosclerosis together with its cardiovascular consequences is the most common and significant cause of death, particularly in highly developed countries. The process of atherogenesis begins as soon as in childhood and depends on classical risk factors. Atherosclerosis also results from a chronic inflammatory-immune process which takes place in the vascular walls. Furthermore, it has been known for a number of years that the development of atherosclerotic lesions is closely connected with the concentration of homocysteine in serum. Homocysteine is a sulfur amino acid originating from methionine. An increased concentration of homocysteine in blood harmfully influences blood vessels, leading to a higher risk of ischemic heart disease and stroke. Since tackling classical atherosclerosis risk factors is not efficient enough when it comes to protecting the cardiovascular system from diseases, new substances possessing anti-atherogenic properties, especially endogenous ones, are sought. Recently, researchers have paid attention to a connection between homocysteine and an endogenous tryptophan derivative, kynurenic acid. Recently, it was revealed that kynurenic acid counteracts the harmful effects of homocysteine on endothelium cells in vitro. The hypothesis assuming homocysteine-kynurenate interplay suggests the existence of a new mechanism of atherogenesis and gives us an opportunity to use this knowledge in both prevention and treatment of cardiovascular diseases.

Background. hypoparathyroidism is a condition of parathyroid hormone (Pth) deficiency, which can be inherited, but it is also encountered mainly after thyroid or parathyroid gland surgery. Pth stimulates calcium reabsorption in the kidneys and calcium release from the bones. it also stimulates renal production of 1,25-dihydroxyvitamin D (calcitriol) from 25-hydroxyvitamin D. hypocalcaemia caused by Pth deficiency can lead to cramping and twitching of the muscles or tetany and many other symptoms. Objectives. the aim of the study was to retrospectively evaluate, in own material, the prevalence and clinical picture of hypoparathyroidism, caused by various surgical procedures performed on the thyroid gland. Material and methods. the study group involved 145 patients after thyroid surgery, treated for various reasons in the Department of Endocrinology of the Medical University in lublin in the years 2000-2017. the authors analyzed the medical histories and clinical pictures of the patients and the results of laboratory tests, including calcium, phosphorus and Pth concentrations. Results. 32 patients were diagnosed with hypoparathyroidism, and 113 patients without calcium concentration disorders. the analyzed groups did not differ significantly in respect to gender, age and indications for thyroid surgery. we found no correlation between the length of follow up and Pth concentration, a weak negative correlation with total calcium concentration and a quite strong negative correlation with ionized calcium concentration in the subgroup with newly diagnosed hypoparathyroidism. Conclusions. the clinical picture of hypocalcaemia varies, and it is important to take into account the possibility of hypoparathyroidism in a patient after thyroid surgery. Key words: hypoparathyroidism, hypocalcaemia, tetany, thyroid operation.