Wireless photodiode for optical and atomic physics experiments

We show the realization of a simple, small footprint, low power system for wireless transmission of data from a photodiode to an oscilloscope or optionally to a computer. It consists of easily accessible standard modules and electronic parts. Optimization of the setup allowed us to build it around very popular 8-bit microcontrollers and with a minimum number of additional components. The system is particularly suitable for real time, continuous monitoring of spectroscopic signals, light power measurements, optical setup adjustments, and optimization. The average current consumption of the battery powered photodiode and transmitter is as low as 5.2 mA. The system is completed with an optional software oscilloscope, allowing one to visualize the photodiode signal on a computer.

The impact of legs fat mass and legs lean fat mass on thigh circumference according cardiovascular risk: a population-based study

Funding Acknowledgements

Type of funding sources: Public Institution(s). Main funding source(s): Medical University of Bialystok, Poland

Introduction A low thigh circumference is associated with an increased risk of high blood pressure, diabetes, cardiovascular diseases, and total mortality.

Objectives The aim of the study was to investigate the relationship between the thigh circumference and cardiovascular (CV) risk classes, and to assess what type of tissue, adipose tissue or muscle tissue affects the thigh circumference.

Methods The longitudinal, population-based, Polish study was conducted in 2017-2020. A total of 931 individuals aged 20-79 were analyzed. Pol-SCORE system was used to assess the 10-year risk of fatal CV based on the following risk factors: age, gender, smoking, systolic blood pressure, and total cholesterol for individuals aged 40-70.  Then, CV risk classes were assessed using the 2019 ESC/EAS guidelines. The measurement of thigh circumference were performed directly below the gluteal fold of the thigh. Both thighs were measured and the mean value was calculated as the final thigh circumference. Body composition was assessed using Dual Energy X-ray Absorptiometry (DEXA).

Results The mean age was 49.1 ± 15.5 years and 43.2% male. The mean thigh circumference was 58.2 ± 5.9 cm, the mean legs fat mass was 7.7 ± 2.8kg, and the mean legs lean mass was 16.9 ± 4.0kg. Lower thigh circumference was associated with higher CV risk classes in univariate linear regression analysis (β -0.516, p = 0.002), as well adjusted by age and sex (β -0.839, p = 0.008), adjusted by age, sex, BMI (β -0.886, p <0.001), and age, sex, WHR (β -0.988, p <0.001). In linear regression analysis legs adipose tissue and muscle tissue were related to the thigh circumference independently of CV risk classes (Model 1) and Pol-SCORE value (Model 2). However, fatty tissue (Model 1: β 0.746, p < 0.001; Model 2: β 0.749, p < 0.001) affects the thigh circumference more than the muscle tissue (Model 1: β 0.479, p < 0.001; Model 2: β 0.442, p < 0.001) (Fig. 1).

Conclusion Smaller thigh circumference was associated with higher CV risk classes. Thigh circumference was more influenced by adipose tissue than by muscle tissue, regardless of the Pol-SCORE  or CV risk classes.

Table 1. Variable Model 1 Model 2 Beta p R2 Beta p R2 Legs fat mass 0.746 <0.001 0.785 0.749 <0.001 0.760 Legs lean mass 0.479 <0.001 0.785 0.442 <0.001 0.760 Model 1: adjusted for Cardiovascular risk classesModel 2: adjusted for Pol-SCOREResults of the linear regression analysis thigh circumference in the general population

Abstract Figure 1.

Very similar cardiometabolic profile in the moderate and high cardiovascular risk classes: a population-based study

Funding Acknowledgements

Type of funding sources: Public Institution(s). Main funding source(s): Medical University of Bialystok, Poland

Background

Cardiovascular disease (CVD) is a major, worldwide problem and remain the dominant cause of premature mortality in the word. Simultaneously the metabolic syndrome is a growing problem. The aim of this study was to investigate the cardiometabolic profile among cardiovascular risk classes, and to estimate CV risk using various calculators.

Methods

The longitudinal, population-based study, was conducted in 2017-2020. A total of 931 individuals aged 20-79 were included. Anthropometric and biochemical profiles were measured according to a standardized protocols. The study population was divided into CV risk classes according to the latest recommendation. Comparisons variables between subgroups were conducted using Dwass-Steele-Critchlow-Fligner test. To estimate CV risk were used: the  Systematic Coronary Risk Estimation system, Framingham Risk Score and LIFEtime-perspective model for individualizing CardioVascular Disease prevention strategies in apparently healthy people (LIFE-CVD).

Results

The mean age was 49.1± 15.5 years, 43.2% were male. Percentages of low-risk, moderate-risk, high-risk and very-high CV risk were 46.1%, 22.8%, 13.5%, 17.6%, respectively. Most of the analyzed anthropometric, body composition and laboratory parameters did not differ between the moderate and high CV risk participants, whereas the low risk group differed significantly. In the moderate and high-risk groups, abdominal distribution of adipose tissue dominated with significantly elevated parameters of insulin resistance. Interestingly, estimating lifetime risk of myocardial infarction, stroke or CV death using LIFE-CVD calculator yielded similar results in moderate and high CV risk classes.

Conclusion

The participants belonging to moderate and high CV risk classes have a very similar unfavorable cardiometabolic profile which may result in the similar lifetime CV risk. This may imply the need for more aggressive pharmacological and non-pharmacological management of CV risk factors in the moderate CV risk population. It would be advisable to consider combining the moderate and high risk classes into one high CV risk class, or it may be worth adding one of the parameters of abdominal fat distribution to the CV risk calculators as an expression of increased insulin resistance.

Abstract Figure 1.

Clinical variables improve efficacy of ECG scores to diagnose the left ventricular hypertrophy in general population

 

Left ventricular hypertrophy (LVH) is an important risk factor of various cardiovascular (CV) diseases and sudden death. Electrocardiography (ECG) is commonly used to detect LVH, but it has poor sensitivity, especially in high cardiovascular risk patients. Although echocardiography (ECHO) is a better, it is less available, and more expensive. Aim: To improve ECG scores to diagnose LVH in a general population.

Methods

The study was conducted in 2017–2019 in a representative sample of area residents. 717 volunteers randomly chosen from the local population were examined. Due to incomplete data, QRS complex duration ≥120ms, fascicular blocks, bundle branch blocks, paced rhythm, 216 people were excluded. Physical examination, ECG, ECHO and laboratory assessment were performed. In ECG LVH defined as >28mm for men, >20mm for women using Cornell index; >17mm for both sexes using Lewis index. In ECHO LV mass was calculated using the Devereux Formula and indexed by body surface area (left ventricular mass index – LVMI). The LVH was defined as LVMI ≥115 g/m2 for man and ≥95 g/m2 for women. Cardiovascular risk was calculated based on the ESC SCORE and additional risk categories published in the latest ESC guidelines. We analyzed 4 models to predict the probability of LVH at ECHO: Model 1: Cornell index; Model 2: Lewis index; Model 3: Cornel index + clinical parameters (age, sex, BMI, office BPs, QRS time, hs-TnT, and HbA1c); Model 4: Lewis index + clinical parameters (age, sex, BMI, office BPs, QRS time, hs-TnT, and HbA1c). Associations between LVH and clinical and biochemical variables were earlier analyzed using multiple linear regression models, these parameters were independently associated with LVH.

Results

A total of 501 patients were included. The average age of patients was 49.0±15.35 years, and 203 probants (40.5%) were male. We developed a novel score to assess the probability of LVH at ECHO in general population based on nine items (age, sex, body mass index, office BPs, Cornell index or Lewis index, QRS time, hs-TnT, and HbA1c). Additional clinical parameters improved sensitivity of Cornell index up to 86.0% (AUC:0.8011; 95% CI:0.748–0.854) from 64.9% (AUC:0.6450; 95% CI:0.573–0.716) in general population, to 92.9% (AUC:0.8423; 95% CI:0.760–0.924) from 64.3% (AUC:0.6481; 95% CI:0.518–0.779) in low CV risk patients, to 69.2% (AUC:0.6767; 95% CI:0.544–0.809) from 38.5% (AUC:0.5284; 95% CI:0.352–0.705) in moderate CV risk, and to 73.3% (AUC:0.7151; 95% CI: 0.609–0.821) of Lewis index from 50.0% (AUC: 0.5630; 95% CI:0.448–0.678) in high and very-high CV risk class.

Conclusions

Addition of clinical parameters to ECG indices in the diagnosis of LVH markedly improves their diagnostic efficacy both in general population and in higher risk groups. The new score may be useful in guiding the appropriateness of ECHO study in general population, and especially in moderate and high CV risk patients, who are not always aware of the increased CV risk.

ROC curves for recognize LVH.

Funding Acknowledgement

Type of funding source: Public Institution(s). Main funding source(s): Medical University of Bialystok for Bialystok PLUS study

Hydrogen peroxide-dependent antibacterial action of Melilotus albus honey

Honey originating from different floral sources exhibits the broad spectrum of antibacterial activity as a result of the presence of hydrogen peroxide as well as nonperoxide bioactive compounds. The mechanisms of antibacterial activity of Polish melilot honey were investigated for the first time. Polish melilot honey samples (Melilotus albus biennial = 3 and annual = 5, Melilotus officinalis = 1) were collected directly from beekeepers and analysed for pollen profile, basic physicochemical parameters, antioxidant capacity, radical scavenging activity, total phenolic contents as well as antibacterial properties against pathogenic bacteria Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Salmonella spp. The physicochemical properties of melilot honey were specific for light-coloured unifloral honey samples and were not dependent on its botanical and geographical origin (P > 0·05). All tested honey samples exhibited inhibitory activity (above 90%) against Gram-positive bacteria at the concentration of 12·5-25%. Above 30-50% of antibacterial activity of melilot honey was connected with glucose oxidase enzyme action and was destroyed in the presence of catalase. Hydrogen peroxide-dependent antibacterial activity of honey was inversely correlated with its radical scavenging activity (r = -0·67) and phenolic compounds (r = -0·61). Antibacterial action of melilot honey depends not only on hydrogen peroxide produced by glucose oxidase, but also on other nonperoxide bioactive components of honey.

SIGNIFICANCE AND IMPACT OF THE STUDY

Melilot honey is used in traditional medicine as an anticoagulant agent due to the possibility of the presence of the coumarin compounds which are specific for Melilotus plant. Melilotus albus is rarely used to produce honey, and antibacterial properties of this variety of honey had not been studied yet. Nine samples of melilot honey produced in different regions of Poland were analysed according to their antibacterial activity which was correlated with physiochemical parameters and antioxidant activity. It was shown that antibacterial activity of melilot honey is created by hydrogen peroxide and other bioactive compounds.

Effect of melatonin supplementation on plasma lipid hydroperoxides, homocysteine concentration and chronic fatigue syndrome in multiple sclerosis patients treated with interferons-beta and mitoxantrone

Multiple sclerosis (MS) prevalence is higher in geographic regions with less sunlight exposure. Melatonin participates in the effects of sunlight in healthy individuals and could play a role in MS pathophysiology. Melatonin crosses the blood-brain barrier and exerts antioxidative, immunomodulatory, and anti-inflammatory effects. Chronic fatigue syndrome concerns 80 - 90% MS patients. The pathophysiology of chronic fatigue syndrome is unknown, however activation of immune, inflammatory, oxidative and nitrosative stress mechanisms and plasma lipid peroxide elevation was reported. Homocysteine increases plasma lipid hydroperoxides levels. The aim was to determine the effect of melatonin supplementation on chronic fatigue syndrome in MS patients and evaluate plasma lipid hydroxyperoxides (LHP) and homocysteine concentrations as a potential biochemical fatigue biomarkers. Into a case-control prospective study 102 MS patients divided according receiving immunomodifying MS treatment into groups: RRMS-pretreated, RRMS-INF-beta, SP/PPMS-mitoxantrone, RRMS-relapse were enrolled. Patients were supplemented with melatonin over 90 days. Plasma LHP, homocysteine concentration, brain MRI and fatigue score were examined. Results show that LHP concentrations were significantly higher in all studied MS groups vs.

CONTROLS

In all MS patient groups melatonin application resulted in significant decrease in plasma LHP concentrations. Plasma homocysteine concentration was similar in healthy people, RRMS-pretreated, RRMS-INF-beta and SP/PP-MS-mitoxantrone groups. However, in the RRMS-relapse group plasma levels of homocysteine were significantly higher compared to the RRMS-pretreated group. There were no significant differences in plasma homocysteine concentration in the studied groups before and after melatonin application. The fatigue score was significantly lower in RRMS pretreated group compared to RRMS-INF-beta and SP/PP MS-mitoxantrone treated patients. Plasma lipid hydroxyperoxides could be potential biochemical chronic fatigue syndrome biomarker in MS patients and homocysteine could be a potential marker of acute phase of MS. Melatonin exerts beneficial effects in MS patients based on its' proved antioxidative properties.

Proopiomelanocortin but not vasopressin or renin-angiotensin system induces resuscitative effects of central 5-HT1A activation in haemorrhagic shock in rats

The aim of this study was to determine the effectory mechanisms: vasopressin, renin-angiotensin system and proopiomelanocortin-derived peptides (POMC), partaking in the effects of serotonin through central serotonin 1A receptor (5-HT1A) receptors in haemorrhagic shock in rats. The study was conducted on male Wistar rats. All experimental procedures were carried out under full anaesthesia. The principal experiment included a 2 hour observation period in haemorrhagic shock. Drugs used - a selective 5-HT1A agonist 8-OH-DPAT (5 μg/5 μl); V1a receptor antagonist [β-mercapto-β, β-cyclo-pentamethylenepropionyl(1),O-me-Tyr(2),Arg(8)]AVP (10 μg/kg); angiotensin type I receptor antagonist (AT1) ZD7155 (0.5 mg/kg, i.v.); angiotensin-converting-enzyme inhibitor captopril (30 mg/kg, i.v.); melanocortin type 4 (MC4) receptor antagonist HS014 (5 μg, i.c.v.). There was no influence of ZD715, captopril or blocking of the V1a receptors on changes in the heart rate (HR), mean arterial pressure (MAP), peripheral blood flow or resistance caused by the central stimulation of 5-HT1A receptors (P≥0.05). However, selective blocking of central MC4 receptors caused a slight, but significant decrease in HR and MAP (P<0.05). POMC derivatives acting via the central MC4 receptor participate in the resuscitative effects of 8-OH-DPAT. The angiotensin and vasopressin systems do not participate in these actions.

Influence of melatonin supplementation on serum antioxidative properties and impact of the quality of life in multiple sclerosis patients

The relationship between the prevalence of multiple sclerosis (MS) and sunlight's ultraviolet radiation was proved. Oxidative stress plays a role in the pathogenic traits of MS. Melatonin possesses antioxidative properties and regulates circadian rhythms. Several studies have reported that the quality of life is worse in patients with MS than in healthy controls, with a higher prevalence of sleep disturbances, depression and fatigue. The aim of study was to evaluate 5 mg daily melatonin supplementation over 90 days on serum malondialdehyde (MDA) concentration and superoxide dismutase (SOD) activity and its' influence on impact of the quality of life of MS patients. A case-control prospective study was performed on 102 MS patients and 20 controls matched for age and sex. The EDSS, MRI examinations and Multiple Sclerosis Impact Scale (MSIS-29) questionnaire was completed. Marked increase in serum MDA concentration in all MS patients groups was observed and after melatonin treatment decreased significantly in interferons-beta and glatiramer acetate-treated groups, but not in mitoxantrone-treated group. A significant increase in SOD activity compared to controls only in glatiramer acetate-treated group was observed. After 3 months melatonin supplementation the SOD activity increased compared to initial values in interferons beta-treated groups. A significant increase in both MSIS-29-PHYS and MSIS-29-PSYCH items mean scores only in the MX group as compared to other groups was observed. There were no significant differences in mean MSIS-29-PHYS was observed before and after melatonin therapy. Melatonin supplementation caused a decrease in mean MSIS-29-PSYCH scores compared to initial values in interferons beta-treated groups. Finding from our study suggest that melatonin can act as an antioxidant and improves reduced quality in MS patients.

Labeled [³H]--thymidine incorporation in the DNA of 3T3-L1 preadipocytes due to MT₂- and not MT₃- melatonin receptor

The discovery of MT₁, MT₂, and MT₃ melatonin receptors on adipose tissue cells gives grounds for considering the possibility of melatonin as a factor which influences energy storage through modulation of metabolism and adipocyte proliferation. To date only a few contradictory studies have been published on the influence of melatonin on preadipocytes. The aim of the present study is to evaluate the influence of melatonin at physiological and supraphysiological concentrations on the proliferation of 3T3-L1 murine preadipocytes after 3 and 24 hours of the experiment and to determine the participation of membrane melatonin MT₂ receptors, and for the first time--MT₃, in its melatonin action during a 24-hour experiment. The 3T3-L1 murine preadipocyte cell line were cultured with or without melatonin at 10⁻³ and 10⁻⁹ mol/L, with or without melatonin antagonists luzindole (10⁻⁴ mol/L) and prazosin (10⁻⁵ mol/L). Cell proliferation was determined by means of labeled [³H]-thymidine incorporation in the DNA of the cell. Melatonin at both physiological and supraphysiological concentrations has a stimulating effect on the number of 3T3-L1 preadipocytes. The application of luzindole inhibits the above effect of melatonin both at 10⁻³ mol/L and 10⁻⁹ mol/L concentrations (P<0.05). The presence of prazosin does not have a statistically significant influence on the effects of melatonin action. Summarizing, it has been proven that melatonin exerts a proproliferative effect on 3T3-L1 preadipocytes at physiological and supraphysiological concentrations, partially by MT₂, and not by MT₃ receptors.

The role of serotonergic 5-HT1A receptors in central cardiovascular regulation in haemorrhagic shock in rats

The bleeding and haemorrhage is strictly related with accidents and many medical procedures. In some conditions it leads to hypovolaemia and further to hypovolaemic shock. Under conditions of haemorrhagic shock, heart rate and blood pressure critically collapse. Reversing the sympathoinhibitory phase of hypovolaemia could be crucial for clinical management of injured patients after haemorrhage. Systemic administration of 5-HT1A agonists seams to produce resuscitating effects. The aim of this study was to investigate the participation of central serotonin and, in particular, 5-HT1A receptors in cardiovascular regulation in haemorrhagic shock in rats. Intracerebroventricular (i.c.v.) administration of serotonin (5-HT) increased the heart rate (HR), mean arterial pressure (MAP) and implicated that all haemorrhaged animals survived for the whole observation time (2 hours). Similar, although significantly more minor, effects were achieved after selective 5-HT1A activation. Moreover, the i.c.v. administration of selective 5-HT1A antagonist before i.c.v. 5-HT injection partially inhibited 5-HT induced changes. The results of the present work indicate that 5-HT plays an important role in the reversal of the haemorrhagic shock in rats. These effects are at least partially dependent on activation of 5-HT1A receptors.

Antioxidative enzymes activity and malondialdehyde concentration during mitoxantrone therapy in multiple sclerosis patients

Mitoxantrone (MX) is approved for the treatment of aggressive relapsing-remitting, secondary-progressive and progressive-relapsing form of multiple sclerosis (MS). The mechanism of its action is multiaxial, however, it is not free from side effects. The causes of the side effects are still unknown and require further investigation. The aim of this study was to investigate the influence of MX therapy on enzymatic parameters of endogenous antioxidative status: manganese and copper/zinc superoxide dismutase (MnSOD, Cu/ZnSOD), catalase (CAT), glutathione peroxidase (GSH-Px) and lipid peroxidation marker--malondialdehyde (MDA) in blood serum and cerebrospinal fluid (CSF) in patients suffering from MS. After the MX therapy serum and the CSF MDA concentrations increased significantly. We reported that MnSOD activities decrease in serum and the CSF, while, surprisingly, the serum Cu/ZnSOD activity increases after the MX therapy. We also noted a marked decrease in CSF CAT and GSH-Px activity after the MX treatment. Our results strongly suggest the influence of MX therapy on oxidation/antioxidation status of serum and the CSF. These findings open up new opportunities for a better understanding of underlying physiopathological events in MS and provide a new insight into MX's mechanisms of action, especially its potent side effects.

Prognostic value of KIT/PDGFRA mutations in gastrointestinal stromal tumours (GIST): Polish Clinical GIST Registry experience

BACKGROUND

Majority of gastrointestinal stromal tumours (GISTs) are characterised by KIT-immunopositivity and the presence of KIT/platelet-derived growth factor receptor alpha (PDGFRA) activating mutations.

PATIENTS AND METHODS

Spectrum and frequency of KIT and PDGFRA mutations were investigated in 427 GISTs. Univariate and multivariate analysis of relapse-free survival (RFS) was conducted in relation to tumours' clinicopathologic features and genotype.

RESULTS

Mutations were found in 351 (82.2%) cases, including 296 (69.3%) KIT and 55 (12.9%) PDGFRA isoforms. Univariate analysis revealed higher 5-year RFS rate in women (37.9%; P = 0.028) and in patients with gastric tumours (46.3%; P < 0.001). In addition a better 5-year RFS correlated with smaller tumour size ≤ 5 cm (62.7%; P < 0.001), tumours with mitotic index ≤ 5/50 high-power fields (60%; P < 0.001), and characterised by (very) low/moderate risk (70.2%; P = 0.006). Patients with GISTs bearing deletions encompassing KIT codons 557/558 had worse 5-year RFS rate (23.8%) than those with any other KIT exon 11 mutations (41.8%; P < 0.001) or deletions not involving codons 557/558 (33.3%; P = 0.007). Better 5-year RFS characterised patients with KIT exon 11 point mutations (50.7%) or duplications (40%). By multivariate analysis, tumours with PDGFRA mutations and KIT exon 11 point mutations/other than 557/558 deletions had lower risk of progression than with KIT exon 11 557/558 deletions (both Ps = 0.001).

CONCLUSIONS

KIT/PDGFRA mutational status has prognostic significance for patients' outcome and may help in management of patients with GISTs.

Role of leptin, ghrelin, angiotensin II and orexins in 3T3 L1 preadipocyte cells proliferation and oxidative metabolism

There is now growing evidence that the reactive oxygen species have an influence on proliferation and antioxidative status of various cell types. The aim of the study was to investigate the effects of different concentrations of leptin, ghrelin, angiotensin II and orexins on proliferation, culture medium malondialdehyde (MDA) levels and antioxidative enzymes activities: superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and catalase (CAT) in 3T3 L1 preadipocytes cell culture. Cell proliferation was measured using [(3)H]tymidine incorporation. In 3T3-L1 cells leptin caused a significant reduction in proliferation (by 36%) compared to control. Ghrelin increased preadipocyte proliferation, and the effect was stronger in higher dose (by 39%), while proproliferatory effect of angiotensin II was stronger in lower doses (by 47%). All used doses of orexin A significantly increased 3T3 L1 cell proliferation (from 21% to 160%), while orexin B caused a marked reduction (from 35% to 70%) of this proliferation. The effects of both orexins were dose-dependent. Leptin and ghrelin increased activity of SOD, CAT, GSH-Px and decreased level of MDA. Angiotensin II treatment stimulated only SOD and CAT activities. Influence of orexins was different on various enzymes. Orexin A increased MDA levels, while orexin B caused a marked decrease in MDA levels. Our results strongly suggest the effects of appetite affecting hormones such as leptin and ghrelin on proliferation and antioxidative enzyme activities of preadipocyte cell lines. Orexin A was found to be the most efficient proliferative-signalling hormone, while orexin B revealed the most significant inhibitory effect on preadipocytes proliferation.

Basal and postprandial plasma levels of PYY, ghrelin, cholecystokinin, gastrin and insulin in women with moderate and morbid obesity and metabolic syndrome

Metabolic syndrome (MS), defined as central obesity, hyperinsulinemia, insulin resistance, hypertension, dyslipidemia and glucose intolerance, has been associated with inflammatory biomarkers and cardiovascular diseases. This study was carried out on three groups of women; lean controls, moderately obese with MS (OB-MS) and morbidly obese with MS (MOB-MS). The main objectives were: 1. to analyze the plasma levels of total and acylated ghrelin, peptide YY(3-36) (PYY(3-36)), cholecystokinin (CCK), gastrin and insulin levels under basal conditions and in response to a standard mixed meal, and 2. to elucidate the relationship between the plasma levels of these gut peptides and metabolic syndrome parameters. Plasma levels of the gut hormones were measured by radioimmunoassays at time 0 just before the meal and at 30, 60 and 120 min after a meal ingestion. Traditional lipid profile and high-sensitivity C reactive protein (hs-CRP), the strongest biomarker of inflammation were also determined in OB-MS and MOB-MS. When compared to OB-MS, MOB-MS exhibited much higher anthropometric parameters such as waist circumference, higher fat mass and higher plasma levels of low density lipoprotein-cholesterol (LDL-C) and hs-CRP. Both these obese groups revealed significantly higher values of body mass index (BMI), fat mass, total cholesterol (TC), LDL-C, fasting glucose, fasting insulin, insulin resistance (IR) calculated from homeostatic model assessment (HOMA) and hs-CRP compared to the values recorded in lean subjects. Fasting PYY(3-36) level was lower, while fasting acylated ghrelin was higher in MOB-MS than in OB-MS. Plasma total and acylated ghrelin levels were significantly lower in OB-MS compared to lean women. In MOB-MS women the fasting PYY(3-36) levels were lower compared to lean controls and OB-MS, whilst postprandially in both OB-MS and MOB-MS, it was much lower than in lean women. The fasting plasma levels of total and acylated ghrelin and their postprandial decrease were significantly smaller in both obese groups compared to lean subjects. Plasma hs-CRP levels correlated positively with BMI, waist circumference, fat mass, fasting glucose, HOMA IR and fasting active ghrelin, whilst it negatively correlated with plasma fasting and total ghrelin. Moreover, plasma fasting acylated ghrelin correlated positively with fat mass. Fasting total ghrelin correlated positively with BMI, HDL-C and negatively with HOMA IR. We conclude that MS features of obesity are closely related to fasting and postprandial alterations of concentrations of PYY(3-36), CCK and ghrelin, suggesting that determination of gut hormones controlling food intake might be considered as a valuable tool to assess the progression of MS to comorbidities of obesity.

Influence of melatonin on cell proliferation, antioxidative enzyme activities and lipid peroxidation in 3T3-L1 preadipocytes--an in vitro study

Melatonin, acting via MT1, MT2 and MT3 membrane receptors, influences central and peripheral regulatory mechanisms of energy homeostasis in mammals. In peripheral tissues, it evokes the pro-proliferative effect in a number of normal cells. Moreover, this hormone inhibits lipolysis in subcutaneous adipocytes in vitro and reduces free oxygen metabolites-induced damage acting directly, as a free radical scavenger, and indirectly, by stimulation of antioxidative enzyme activities. The aim of the study was to examine the effects of melatonin on cell proliferation, antioxidative enzyme activities and malondialdehyde (MDA) concentration in 3T3-L1 preadipocyte cell culture. We found that melatonin (10(-3) and 10(-6) M/L) stimulated cell proliferation in dose- and time-depending manner, and this effect was inhibited by a relatively selective MT2 receptor antagonist - luzindole (10(-4) M/L). Melatonin, increased activities of manganese containing and copper-zinc containing superoxide dismutase (MnSOD and Cu/ZnSOD) isoenzymes, catalase, glutathione reductase and glutathione peroxidase after 24 h of incubation. In contrast, after 48 h of incubation, activities of all studied enzymes were lower than in the control group. There were no changes in MDA concentrations after 24 h of incubation, whereas, in melatonin-treated media, after 48 h of the experiment, MDA level was significantly decreased. Our results demonstrate that melatonin, acting via MT2 receptors, stimulates proliferation of 3T3-L1 preadipocytes and this action could be due to the enhancement in antioxidative enzyme activities and attenuation of lipid peroxidation by this indole.

Effect of extremely low frequency of electromagnetic fields on cell proliferation, antioxidative enzyme activities and lipid peroxidation in 3T3-L1 preadipocytes--an in vitro study

The exposure to extremely low frequency electromagnetic field (ELF-MF, frequencies less than 200-300 Hz) can alter the transcription and translation of genes, influence the cell proliferation rate and affect enzyme activities. Moreover, the hypothesis that ELF-MF increases free oxygen metabolites generation has been proposed. Since recent in vivo studies suggest that electric and magnetic fields are able to affect adipose cells metabolism. The aim of the study was to examine the effects of ELF-MF (frequency of basic impulse 180-195 Hz, induction 120 microT) on cell proliferation, antioxidative enzyme activities and malondialdehyde (MDA) concentration in 3T3-L1 preadipocyte cell culture. We found that ELF-MF application lasting 36 minutes daily failed to influence cell count after 24h and 48 h of incubation. After 24 h, in the ELF-MF treated group, manganese- and copper-zinc-containing superoxide dismutase (MnSOD and Cu/ZnSOD) isoenzymes media activities were decreased, catalase activity was increased, whereas there were no significant differences in glutathione peroxidase (GSH-Px) and glutathione reductase (GSSG-Rd) activities in comparison to the control. After 48 h of incubation, all enzyme activities were reduced, except for GSSG-Rd, in which no changes were noticed. MDA concentration at 24 h after incubation with the exposure to ELF-MF was significantly higher in comparison to the control, without ELF-MF. After 48 h of incubation, MDA levels were significantly lower in both groups with no differences between the groups without and with ELF-MF. We conclude that ELF-MF influences antioxidative enzyme activities and increases lipid peroxidation in 3T3-L1 preadipocyte cultures.

Influence of extremely-low-frequency magnetic field on antioxidative melatonin properties in AT478 murine squamous cell carcinoma culture

Effects of melatonin, extremely-low-frequency magnetic field (ELF-MF), and their combination on AT478 murine squamous cell carcinoma line were studied. Manganese superoxide dismutase (MnSOD), copper-zinc superoxide dismutase (Cu/ZnSOD), and glutathione peroxidase (GSH-Px) were used as markers of cells antioxidative status, and malondialdehyde (MDA) level was used as a marker of lipid peroxidation. After melatonin treatment, antioxidative enzyme activities were increased and MDA level was decreased. Application of ELF-MF on treated cells caused an increase of both superoxide dismutases activity and MDA level, but influence of ELF-MF on GSH-Px activity was negligible. All enzyme activity in culture medium containing melatonin (10(-3), 10(-4), 10(-5) M) after exposure to ELF-MF were significantly diminished compared to cells treated only with melatonin. Also MDA levels after combined treatment with melatonin and ELF-MF were significantly decreased. Observed changes were statistically significant (p<0.05). These results strongly suggest that ELF-MF attenuates antioxidative actions of melatonin on cellular level.