Application of Liquid Chromatography Coupled to Mass Spectrometry for Direct Estimation of the Total Levels of Adenosine and Its Catabolites in Human Blood.

Adenosine is a multifunctional nucleoside with several roles across various levels in organisms. Beyond its intracellular involvement in cellular metabolism, extracellular adenosine potently influences both physiological and pathological processes. In relation to its blood level, adenosine impacts the cardiovascular system, such as heart beat rate and vasodilation. To exploit the adenosine levels in the blood, we employed the liquid chromatography method coupled with mass spectrometry (LC-MS). Immediately after collection, a blood sample mixed with acetonitrile solution that is either enriched with 13C-labeled adenosine or a newly generated mixture is transferred into the tubes containing the defined amount of 13C-labeled adenosine. The 13C-enriched isotopic adenosine is used as an internal standard, allowing for more accurate quantification of adenosine. This novel protocol for LC-MS-based estimation of adenosine delivers a rapid, highly sensitive, and reproducible means for quantitative estimation of total adenosine in blood. The method also allows for quantification of a few catabolites of adenosine, i.e., inosine, hypoxanthine, and xanthine. Our current setup did not allow for the detection or quantifying of uric acid, which is the final product of adenosine catabolism. This advancement provides an analytical tool that has the potential to enhance our understanding of adenosine's systemic impact and pave the way for further investigations into its intricate regulatory mechanisms.

Vitamin D insufficiency is not associated with thyroid autoimmunity in Slovak women with Hashimoto´s disease.

The role of vitamin D (VD) in the etiopathogenesis of autoimmune diseases (AI) is extensively studied. However, its association with autoimmune thyroid disease (AITD) is still controversial. AIM of this study was to assess the relationship between the vitamin D status and thyroid autoimmunity in Slovak premenopausal women with newly diagnosed AITD. SUBJECTS AND METHODS: This prospective case-control study included 57 women with AITD and 41 age- and BMI-matched controls. All subjects were examined for summer and winter serum 25(OH)D, thyroid autoantibodies (a-TPO, a-TG), freeT4 and TSH concentrations. Thyroid volume was measured by ultrasound. RESULTS: There were no significant differences in serum 25(OH)D between AITD and control groups. No significant correlation between 25(OH)D and thyroid autoantibodies was found either in the whole cohort or in AITD women. The prevalence of vitamin D insufficiency was 60.31 % in AITD women and 52.5 % in the control group. No significant association between VD and thyroid autoantibodies, thyroid hormones and thyroid volume was detected in this study. CONCLUSION: Authors conclude that VD insufficiency is common in Slovak premenopausal women independently of the presence of AITD. Vitamin D insufficiency is not associated with thyroid autoimmunity in patients with early diagnosis of AITD (Tab. 3, Ref. 31). Text in PDF www.elis.sk Keywords: vitamin D, autoimmune thyroid disease, thyroid autoantibodies.

The Role of Adenosine and Its Degradation Enzymes - Adenosinedeaminase and Adenosinekinase in Pathogenesis of Vasovagal Syncope.

INTRODUCTION: Adenosine is mediator regulating physiological and pathological processes in organism. It probably plays a role in pathogenesis of vasovagal syncopes (VVS), too. Adenosine, its receptors and degradation enzymes- adenosinedeaminase (ADA) and adenosinekinase (ADK), are called the adenosinergic system. AIM: We aimed to evaluate serum levels of adenosine, ADA and ADK in patients with tilt-induced VVS and compare them to tlit-negative controls. Secondary aim was to compare the levels between the types of VVS and correlate them with hemodynamic parameters. SUBJECTS AND METHODS: Altogether 132 individuals were involved in this study (age 39,88±15,64 years, 51 males). All patients underwent head up tilt test (HUTT) in differential diagnosis of syncope. Blood sampling was performed before and after HUTT. Baseline and stimulated serum levels of adenosine, ADA and ADK were evaluated by ELISA method. RESULTS: HUTT was positive in 91 patients (HUTT+), 41 individuals were negative (HUTT-). HUTT+ patients had higher baseline and stimulated adenosine levels, when compared to HUTT- population. The rise in adenosine was higher in HUTT+ group. On the other hand, the increase of ADA was significantly higher in HUTT- subjects. Among HUTT+ group, the highest adenosine was found during vasodepressoric VVS. CONCLUSION: Adenosinergic system may play role in pathogenesis of VVS. Patients with VVS have higher adenosine levels, that may be caused by attenuated degradation. Adenosine seems to be involved predominantly in vasodepressoric type of VVS. Further research evaluating complex function of adenosinergic system in these patients is needed.

Adenosine, adenosine- deaminase and implantable recorder outcome in syncopal patients.

BACKGROUND: Adenosine test was proposed as a tool for identification of syncopal patients who benefit from pacemaker implantation. Aim of the study was to assess the relationship between adenosine levels, the outcome of adenosine test and results of implantable loop recorder (ILR) monitoring in patients with syncope. METHODS: In 29 patients (mean age 59 ± 11 years, 15 men, 14 women) with unexplained syncope ILR was implanted. In addition, adenosine test (intravenous injection of 20 mg adenosine bolus) and assays of plasmatic adenosine and adenosine-deaminase were performed. RESULTS: Adenosine test was positive in 15 patients and negative in 14 patients. Patients with positive adenosine test had lower adenosine levels compared to patients with negative test (8.86 ± 2.07 ng/ml vs. 15.18 ± 2.14 ng/ml, p = .04). No difference was observed in adenosine deaminase levels (16.35 ± 2.20 IU/l vs. 13.20 ± 2.48 IU/l, p = .40). There was a negative correlation between adenosine level and AVB duration during adenosine test (p = .04; R2  = 0.22). Patients with positive adenosine test had more frequent asystole during ILR monitoring than patients with negative test (9 pts vs. 1 pt, p = .005). Adenosine levels were lower in patients with asystolic syncope on ILR compared to vasodepressor syncope 8.20 ± 2.86 ng/ml versus 13.27 ± 7.26 ng/ml, p = .05). CONCLUSIONS: Patients with positive adenosine test have decreased production of endogenous adenosine compared to patients with negative adenosine test. Positivity of adenosine test and low adenosine level in the peripheral blood were associated with more frequent asystolic episodes during ILR monitoring.

Bisphenol A as a Factor in the Mosaic of Autoimmunity.

The population worldwide is largely exposed to bisphenol A (BPA), a commonly used plasticizer, that has a similar molecular structure to endogenous estrogens. Therefore, it is able to influence physiological processes in the human body, taking part in pathophysiology of various endocrinopathies, as well as, cardiovascular, neurological and oncological diseases. BPA has been found to affect the immune system, leading to the development of autoimmunity and allergies, too. In the last few decades, the prevalence of autoimmune diseases has significantly increased that could be explained by a rising exposure of the population to environmental factors, such as BPA. BPA has been found to play a role in the pathogenesis of systemic autoimmune diseases and also organ-specific autoimmunity (thyroid autoimmunity, diabetes mellitus type 1, myocarditis, inflammatory bowel disease, multiple sclerosis, encephalomyelitis etc), but the results of some studies still remain controversial, so further research is needed.

Urinary bisphenol A in women with polycystic ovary syndrome - a possible suppressive effect on steroidogenesis?

OBJECTIVES: There is a growing evidence indicating an impact of endocrine distrupting chemicals such as bisphenol A (BPA) on human reproduction. Its higher levels in serum or urine have been documented in women with polycystic ovary syndrome (PCOS), however the relationship to ovarian steroidogenesis remains unclear. Aim of the study was to compare urinary BPA (U-BPA) concentrations among PCOS women and control group. Second aim was to assess the relationship of U-BPA to ovarian steroidogenesis in the group with PCOS. METHODS: Eighty six Caucasian women (age 28.5 ± 5.1 years) diagnosed with PCOS and 32 controls of age 24.9 ± 4.4 years were included in the study. Fasting blood samples were analyzed for biochemical parameters and steroid hormones. U-BPA was measured in the morning urine sample using high pressure liquid chromatography. RESULTS: PCOS women had significantly higher U-BPA as compared with control group (p=0.0001). Those with high levels of U-BPA (U-BPA ≥2.14 ug/g creatinine) demonstrated higher serum insulin (p=0.029) and HOMA IR (p=0.037), lower serum estrone (p=0.05), estradiol (p=0.0126), FSH (p=0.0056), and FAI (p=0.0088), as compared with low-BPA group (U- BPA <2.14 ug/g creatinine). In PCOS women, U-BPA positively correlated with age (p=0.0026; R2=0.17), negatively with estradiol (p=0.0001, R2=0.5), testosterone (p=0.0078, R2=0.15), free-testosterone (p=0.0094, R2=0.12) and FAI (p=0.0003, R2=0.32), respectively. CONCLUSIONS: PCOS women have significantly higher U-BPA concentrations than healthy controls. U-BPA positively correlates with age and negatively with ovarian steroid hormones suggesting a possible suppressive effect of bisphenol A on ovarian steroidogenesis.

Etiology of syncope in patients with preexisting atrioventricular conduction disorders.

BACKGROUND: The discussion about the feasibility of empiric pacemaker implantation in patients with preexisting atrioventricular (AV) conduction disorders continues. The aim of the study was to determine the etiology of syncope and the need for pacemaker insertion in patients with AV conduction impairment using implantable loop recorder (ILR). METHODS: ILR was implanted after negative diagnostic workup in 37 patients with syncope (24 men, 13 women, age 72 ± 10 years) and preexisting impairment of AV conduction. First-degree AV block (AVB I) was present in 26 patients, and bundle branch block (BBB) in 17 patients. RESULTS: ILR-based diagnosis was made in 28 patients (75%)-sinus arrest in 13 patients, complete AVB in 10 patients, and vasodepressor syncope in five patients. In patients with preexisting BBB, sinus arrest occurred during ILR monitoring significantly more frequently than in patients without BBB (53% vs 20%, P = .03). Complete AVB was significantly less common in patients with preexisting BBB than in patients without BBB (12% vs 40%, P = .04). On multivariate regression analysis, the only independent predictor of AVB occurrence during ILR monitoring was preexisting AVB I (P = .03). The only independent predictor of sinus arrest during ILR monitoring was preexisting BBB (P = .03). CONCLUSIONS: In patients with preexisting AV conduction disorders, prevailing syncopal mechanism during ILR monitoring was asystole. However, sinus arrest occurred more often than complete AVB and was predicted by preexisting BBB. Preexisting AVB was a predictor of complete AVB during ILR monitoring.

[Adenosine - a mediator with multisystemic effects (or a hormone?)]. / Adenozín - mediátor s multisystémovými úcinkami (alebo hormón?).

Adenosine is a nucleoside regulating many physiological and pathological processes in human organism. It is produced by almost all cells and is metabolised by adenosinedeaminase enzyme. Effect of adenosine is mediated by three types of adenosine receptors. Adenosinergic system significantly influences function of cardiovascular system, furthemore it plays a key role in sleep homeostasis, in regulation of bone metabolism and activation of immune system. Adenosine mediates effect of various hormones, but also adenosine itself has its own autocrine, paracrine and systemic effects. Changes in endogenous adenosine levels, or changes of adenosine receptor sensitivity, may play a role in ethiopathogenesis of many diseases. Thus adenosinergic system can become a target for new therapeutical possibilities in many fields of medicine.Key words: adenosine - adenosinedeaminase - cardiovascular system - diabetes mellitus - hormone.

[Diagnostics of polycystic ovary syndrome]. / Diagnostika syndrómu polycystických ovárií.

Polycystic ovary syndrome (PCOS) is the most frequent endocrinopathy among women of reproductive age and the most frequent cause of menstruation cycle disorders. It is marked by a hyperandrogenic state (clinical and/or biochemical) and ovulatory dysfunction (anovulation and/or ultrasonographic finding of polycystic ovaries), which are also criteria for its diagnosis according to Androgen Excess and PCOS Society. The syndrome has multiple phenotypic expressions, among them besides the above characteristics also a metabolic syndrome, primarily obesity and insulin resistance. Diagnosing of PCOS may be rather exacting in clinical practice and it remains to be a diagnosis per exclusionem, following elimination of other causes of hyperandrogenic state and chronic oligo-anovulation. It requires a close cooperation between a gynecologist and endocrinologist and with regard to frequent metabolic complications also with an internist, diabetologist and possibly cardiologist.

[Diagnostics of polycystic ovary syndrome]. / Diagnostika syndrómu polycystických ovárií.

UNLABELLED: Polycystic ovary syndrome (PCOS) is the most frequent endocrinopathy among women of reproductive age and the most frequent cause of menstruation cycle disorders. It is marked by a hyperandrogenic state (clinical and/or biochemical) and ovulatory dysfunction (anovulation and/or ultrasonographic finding of polycystic ovaries), which are also criteria for its diagnosis according to Androgen Excess and PCOS Society. The syndrome has multiple phenotypic expressions, among them besides the above characteristics also a metabolic syndrome, primarily obesity and insulin resistance. Diagnosing of PCOS may be rather exacting in clinical practice and it remains to be a diagnosis per exclusionem, following elimination of other causes of hyperandrogenic state and chronic oligo-anovulation. It requires a close cooperation between a gynecologist and endocrinologist and with regard to frequent metabolic complications also with an internist, diabetologist and possibly cardiologist. KEY WORDS: AES criteria - diagnosis - differential diagnosis - polycystic ovary syndrome.