In-vitro antiplatelet effect of melatonin in healthy individuals and patients with type 2 diabetes mellitus.

PURPOSE: The incidence of acute myocardial infarctions (AMI) shows circadian variation typically peaking during morning hours with a decline at night. However, this variation does not occur in patients with diabetes mellitus (DM). The night's decline of AMI may be partially explained by melatonin-related platelet inhibition. Whether this effect is absent in diabetic patients is unknown. The aim was to study the effect of melatonin on in-vitro platelet aggregation in healthy individuals and patients with type 2 DM. METHODS: Platelet aggregation was measured in blood samples from healthy individuals (n = 15) and type 2 DM patients (n = 15) using multiple electrode aggregometry. Adenosine diphosphate (ADP), arachidonic acid (ASPI) and thrombin (TRAP) were used as agonists. Aggregability for each subject was tested after adding melatonin in two concentrations. RESULTS: In healthy individuals, melatonin inhibited platelet aggregation in both higher (10-5 M) and lower concentrations (10-9 M) induced by ADP, ASPI, and TRAP (p < 0.001, p = 0.002, p = 0.029, respectively). In DM patients, melatonin did not affect platelet aggregation in both concentrations induced by ADP, ASPI, and TRAP. Melatonin decreased platelet aggregation induced by ADP, ASPI, and TRAP significantly more in healthy individuals compared to patients with DM. (p = 0.005, p = 0.045 and p = 0.048, respectively). CONCLUSION: Platelet aggregation was inhibited by melatonin in healthy individuals. In-vitro antiplatelet effect of melatonin in type 2 DM patients is significantly attenuated.

The importance of coenzyme Q10 and its ratio to cholesterol in the progress of chronic kidney diseases linked to non- -communicable diseases.

OBJECTIVES: The mortality of patients with chronic kidney diseases (CKD) increases with the decrease in glomerular filtration rate (eGFR). In the progress of CKD that is closely linked to non-communicable diseases (NCDs), the role of coenzyme Q10 (CoQ10) is not fully evaluated. We aimed to evaluate the importance of CoQ10, CoQ10/cholesterol ratio, and oxidative stress in the progress of CKD. PATIENTS AND METHODS: The control group was constituted of 19 healthy subjects who volunteered to enrol in the study, CKD group consisted of 58 patients with CKD, of whom 54 had CKD combined with hypertension, 22 had CKD combined with hypertension and diabetes type 2 , and 18 had CKD combined with hypertension and statin therapy. We observed age, BMI, creatinine, uric acid, eGFR, hemoglobin, CRP, glucose, lipids fraction, and liver enzymes. Coenzyme Q10-TOTAL (ubiquinol+ubiquinone) in platelets and plasma were determined using HPLC method with UV detection. Indexed of CoQ10/lipid fractions were evaluated. Oxidative stress was determined as thiobarbituric acid­reactive substances (TBARS). RESULTS: With increased stages of CKD, eGFR and CoQ10 as well as its ratio to lipids were significantly reduced while TBARS increased. CONCLUSION: We assume that lower endogenous CoQ10 level may be one of the reasons of kidney dysfunction. CoQ10/lipids ratio and increase in oxidative stress can predict the progression of CKD in patients with arterial hypertension, diabetes mellitus and dyslipidemia (Tab. 2, Fig. 4, Ref. 49).

Can alpha-1-acid glycoprotein affect the outcome of treatment in a cancer patient?

Alpha-1-acid glycoprotein (AGP) is a glycoprotein found in the alpha-1 globulin fraction of human plasma proteins. AGP is an important representative of acute-phase proteins. Although numerous articles have been devoted to AGP, its exact biological function remains obscure. AGP levels increase with a number of diseases. One of them is a tumor disease. In our paper, we discuss the role of increased AGP levels in cancer patients. We deal with the role of AGP as a drug-binding protein and its effect on the efficacy of chemotherapy in oncological patients. Other problems that are discussed in our paper include the role of AGP as an immunomodulatory protein and its relationship to angiogenesis because angiogenesis plays an important role in the progression of cancer (Ref. 57). Keywords: alpha-1-acid glycoprotein, orosomucoid, cancer, disease marker, immunomodulatory protein,drug-binding protein.

Platelet mitochondrial bioenergetic analysis in patients with nephropathies and non-communicable diseases: a new method.

OBJECTIVES: To test the hypothesis if mitochondrial bioenergetic function analyzed in circulating platelets may represent peripheral signature of mitochondrial dysfunction in nephropathy associated to non-communicable human diseases such as cardiovascular diseases, diabetes and with statins treatment. METHODS: High-resolution respirometry was used for analysis of mitochondrial bioenergetics in human platelets isolated from peripheral blood. This method is less-invasively compared to skeletal muscle biopsy. Patients with nephropathies and in combination with non-communicable diseases were included in the study. RESULTS: This pilot study showed platelet mitochondrial bioenergy dysfunction in patients with nephropathies and non-communicable diseases. Positive effect of treatment with 10 mg atorvastatin on platelet mitochondrial respiratory chain Complex I-linked respiration and ATP production in patients with nephropathies, diabetes and 80 mg atorvastatin in patient with nephropathy and dialysis was found. Positive effect of 80 mg fluvastatin treatment, and negative effect of thrombocytopenia and renal transplantation on platelet mitochondrial bioenergy was determined. CONCLUSION: High-resolution respirometry allowed detection of small changes in platelet mitochondrial function. This method could be used as a sensitive bioenergetic test of mitochondrial function for diagnosis and monitoring the therapy in patients with nephropathy (Tab. 1, Fig. 3, Ref. 39).

Effects of complete water fasting and regeneration diet on kidney function, oxidative stress and antioxidants.

OBJECTIVE: The aim of the study was to observe the influence of 11-days complete water fasting (WF) and regeneration diet (RD) on renal function, body weight, blood pressure and oxidative stress. BACKGROUND: Therapeutic WF is considered a healing method. METHODS: Ten volunteers drank only water for 11 days, followed by RD for the next 11 days. Data on body weight, blood pressure, kidney functions, antioxidants, lipid peroxidation, cholesterols, triacylglycerols and selected biochemical parameters were obtained. RESULTS: WF increased uric acid and creatinine and decreased glomerular filtration rate. After RD, the parameters were comparable to baseline values. Urea was not affected. Lipid peroxidation (TBARS) decreased and maintained stable after RD. Fasting decreased α-tocopherol and increased γ-tocopherol, no significant changes were found after RD. Coenzyme Q10 decreased after RD. HDL-cholesterol decreased in WF. Total- and LDL-cholesterol decreased after RD. Other biochemical parameters were within the range of reference values. CONCLUSIONS: The effect of the complete fasting on kidney function was manifested by hyperuricemia. Renal function was slightly decreased, however maintained within the reference values. After RD, it returned to baseline values. The positive effect of the complete water fasting was in the reduction of oxidative stress, body weight and blood pressure (Tab. 3, Ref. 25).

Alpha-2-macroglobulin and hyaluronic acid as fibromarkers in patients with chronic hepatitis C.

BACKGROUND: Liver fibrosis is the final common pathway of chronic liver diseases of various etiology. From the practical standpoint, it would be ideal to have a noninvasive fibromarker. The aim of our study was to investigate the levels of alpha-2-macroglobulin, potential fibromarker, in correlation to histological staging and another potential fibromarker, hyaluronic acid, in patients with chronic hepatitis C. METHODS: Population groups in this study consisted of 51 healthy volunteers and 54 patients with chronic hepatitis C. Liver biopsies were obtained under ultrasound guidance. Alpha-2-macroglobulin was determined by electroimmunodiffusion and hyaluronic acid with enzyme-linked binding protein assay. RESULTS: Both potential fibromarkers, alpha-2-macroglobulin and hyaluronic acid, were increased in patients with chronic hepatitis C. The alpha-2-macroglobulin levels were not significantly increased in the groups F0-F1. In the groups F2-F4, alpha-2-macroglobulin levels were significantly higher than in the control group. The changes of hyaluronic acid were similar to changes of alpha-2-macroglobulin. Regression analysis showed a significant correlation between hyaluronic acid and alpha-2-macroglobulin levels. CONCLUSIONS: According to the results of our study, it can be concluded that alpha-2-macroglobulin and hyaluronic acid might be useful markers of liver fibrosis (Tab. 2, Ref. 15).

The nonskeletal effects of vitamin D3 and the threshold limit associated with the risk of health complications.

OBJECTIVE: To evaluate the threshold limit of vitamin D3 associated with the risk of nonskeletal health complications in humans. BACKGROUND: Vitamin D3 deficiency is primary caused by a reduced sun exposure, consequent limiting of vitamin D3 production in the skin, and low intake of food with this vitamin. METHODS: Ninety-two adults (25-95 years old) were admitted to III. Internal clinic or examined in outpatient department of The University hospital in Bratislava. Vitamin D3 levels were determined using electrochemical luminescence immunoassay. The least square method for the results processing was used. RESULTS: Vitamin D3 level 16 ng/ml may be threshold limit for the risk of hypertension, ischaemic heart disease, renal insufficiency and diabetes mellitus. A higher occurrence of the observed diseases was in female and male patients with vitamin D3 levels<16 ng/ml.The highest increase of occurrence of diabetes mellitus in women for vitamin D3<16 ng/ml (160%) compared to vitamin D3≥16 ng/ml (40%) was observed. Concerning the men, the highest increase refers to ischaemic heart disease (67%). CONCLUSION: The limit value of vitamin D3, 16 ng/ml, confirmed the association between vitamin D3 insufficiency and the presence of hypertension, ischaemic heart disease, renal insufficiency and diabetes mellitus. Its relation to age, sex and other variables was detected (Tab. 1, Fig. 5, Ref. 27).

Does seasonality of births in diabetes mellitus reflect pathogenetic differences?

OBJECTIVES: This study indicates that the seasonality of births of patients with DM1 and DM2 has occurred in their adolescence or adulthood. BACKGROUND: Patients with Diabetes mellitus type 2 (DM2) with the maturity onset have different seasonal birth patterns from those with Diabetes mellitus type 1 (DM1) with the maturity onset, or DM1children. METHODS: Monthly numbers of births of 81 and 236 children with DM1 and DM2, respectively, in adolescent or adult age, were adapted to different actual length of calendar months. The 12- and 6-month rhythm was tested using the cosinor regression with 95% confidence interval versus the hypothesis of null seasonality. RESULTS: Regarding DM1 with maturity onset, annual and semiannual rhythm was significant in both genders, with the increase in birth numbers from November to January and decrease in March, April and August. In DM2, only female data displayed a significant annual rhythm, with an increase in birth from April to August and decrease from October to December.  CONCLUSION: The birth seasonality related to DM1 in adolescent or adult age appears to be reciprocal, compared to DM1 in childhood. For DM2, the seasonality of births was found only in females. The increase in female fecundity seems to be related to an increase in the risk of DM2 in female offspring. The outcomes could help in identifying environmental and endogenous factors related to seasonality cycle (Tab. 1, Fig. 1, Ref. 18).

Effect of ivabradine, captopril and melatonin on the behaviour of rats in L-nitro-arginine methyl ester-induced hypertension.

Cardiovascular diseases including hypertension are often associated with behavioural alterations. The aim of this study was to show, whether ivabradine, the blocker of If-channel in sinoatrial node, is able to modify the behaviour of rats in L-nitro-arginine methyl ester (L-NAME)-induced hypertension and to compare the effect of ivabradine with captopril and melatonin. 12-week-old male Wistar rats were divided into the following groups: controls, ivabradine (10 mg/kg/24 h), L-NAME (40 mg/kg/24 h), L-NAME + ivabradine, L-NAME + captopril (100 mg/kg/24 h), L-NAME + melatonin (10 mg/kg/24 h). Systolic blood pressure (SBP) and heart rate (HR) were measured by tail-cuff method once a week. The behaviour of rats was investigated during 23-hours in the phenotyper after four weeks of the treatment. Chronic administration of L-NAME induced hypertension without a change in HR. All tested substances partly prevented the increase of SBP, while ivabradine and melatonin also reduced HR. Ivabradine, captopril and melatonin reduced daily food intake, slightly decreased daily water intake and attenuated body weight gain. In L-NAME group, locomotor activity was enhanced by ivabradine, whereas exploratory behaviour was increased by melatonin and captopril. In conclusion, ivabradine, besides its potentially protective hemodynamic actions, does not seem to exert any disturbing effects on behaviour in L-NAME-induced hypertension in rats, while some of its effects were similar to captopril or melatonin. It is suggested that ivabradine used in cardiovascular indications is harmless regarding the effect on behaviour.

Serum cholinesterase activity and proteosynthetic function of liver in patients with diabetes mellitus.

INTRODUCTION: Diabetes mellitus is associated with a lot of changes in intermediary metabolism and several authors reported on higher frequency of liver diseases in patients with diabetes. AIM OF THE STUDY: Was to establish the changes of blood serum cholinesterase, prealbumin and albumin, parameters which are accepted as an index of liver proteosynthetic function, in patients with diabetes mellitus. PATIENTS AND METHODS: The study group consisted of 207 patients with diabetes mellitus (83 patients with type I and 124 patients with type II diabetes mellitus). Control group consisted of 179 healthy subjects. The activity of cholinesterase was assayed by the kinetic method, concentrations of prealbumin and albumin were determined immunochemically. RESULTS: Activity of serum cholinesterase was significantly higher in group of patients with diabetes mellitus than in control group (65.05 vs 73.33 microkat/l). The concentration of prealbumin was lower in blood serum of patients with diabetes than in controls (308.10 vs 285.85 mg/l). Serum levels of albumin were not different in both studied groups. After dividing of patients according to the type of diabetes, 80 % of abnormal values of cholinesterase and prealbumin were present in patients with type II diabetes. CONCLUSIONS: The results of our study showed abnormal values of determined liver tests approximately in 22 % of patients with diabetes mellitus. The character of laboratory changes--increased activity of cholinesterase, decreased concentration of prealbumin and normal levels of albumin, suggests development of liver steatosis in these patients. The most of pathological findings were in patients with diabetes type II (Tab. 3, Ref. 20).

[Present views on indications and techniques in kidney biopsy]. / Súcasný pohl'ad na indikáciu a techniku oblickovej biopsie.

In the current situation there are available many data on renal biopsies. Nevertheless a lot of questions remain unanswered the effectivity and safety of the technique of renal biopsy. We demonstrate the current insight on indications, contraindications and the technique of renal biopsy. A number of studies in recent years have found the biopsy to be of major value in patients with high levels of proteinuria, those with signs of systemic disease, and certain patients with acute renal failure. We demonstrate our technique of localization of the kidney, with marking of location and depth. Continuous ultrasonic guidance is used as the needle is inserted into the kidney. Biopsy of kidney is performed by an automated technique with Biopty instrument for its safety and better effectivity. (Tab. 1, Fig. 6, Ref. 13.)

[Changes in thrombocyte aggregation in patients with type I diabetes]. / Zmeny agregácie trombocytov u pacientov s cukrovkou I. typu.

The authors present the results of evaluation of platelet aggregation by means of an automated system (on line detection of platelet aggregation curves) in 80 patients with diabetes mellitus type I. After global analysis no significant changes were found between controls, patients without diabetic nephropathy, and patients with incipient and clinically manifested nephropathy. However, as a result of our data, the area below the aggregatory curve is minimal in the group of patients with clinically manifested diabetic nephropathy. Additional changes of platelet aggregation were observed after dividing the followed set of patients dividing into homogenous subgroups according to their sex. The sensitivity of platelets after induction by ADP was found to be lower in male diabetics than in male controls. Likewise the area below the aggregatory curve and the transmittance of absolute maximum of platelet aggregation was lower in female diabetics than in female controls. In both cases diabetic nephropathy could have participated in platelet sensitivity changes. The authors' findings in the followed group of patients when compared with the described platelet hyperaggregability in diabetes approves the possibility of the platelet aggregatory polymorphism being present in these patients. With respect to these findings the examination of the platelet aggregation and its general parameters exactly justifies the usefulness of the antiaggregatory therapy. (Fig. 4, Ref. 15.)

[Biochemical and functional study of the liver during treatment of familial hyperlipoproteinemia with Mevacor (lovastatin) and Vasosan S (cholestyramine)]. / Biochemické a funkcné vysetrenie pecene pocas liecby familiárnej hyperlipoproteinémie Mevacorom (lovastatínom) a Vasosanom S (cholestyramínom).

The aim of our study was the biochemical and functional examination of the liver during the therapy of familiar hyperlipoproteinemia by means of MevacorR (lovostatine) in comparison with the treatment by Vasosan S (cholestyramine). We examined 20 patients treated with a daily dose of MevacorR being 20-40 mg and, 18 patients treated with a daily dose of Vasosan S being 16-32 g for the period of 12 weeks. During the therapy the total cholesterol, LDL-cholesterol, HDL-cholesterol, triacylglycerols, hepatic enzymes (AST, ALT, ALP) activity, functional test of the liver, biological half-time of antipyrine (t 1/2 antipyrine) were investigated at the onset and at the end of the study. We discovered that at the end of the treatments by MevacorR and Vasosan S the hypolipidemic effect increased (cholesterol p < 0.001, LDL cholesterol p < 0.001), and there was difference in the effect on HDL-cholesterol and in that on triacylglycerols. During the treatment we discovered that due to both medicaments the liver enzymes activity increased to a different extent. At the beginning of the study the antipyrine biological half-time statistically increased in both investigated groups, namely in comparison with the control group. At the end of the treatments in both groups the antipyrine half-time was prolonged, however not significantly. Prior to long-term therapy by hypolipidemics the authors recommend biochemical and functional examination of the liver. (Tab. 4, Fig. 8, Ref. 7.)

[Fibrinogen and diabetic microangiopathy]. / Fibrinogén a diabetická mikroangiopatia.

Diabetic microangiopathy is in its developed form a serious complication for patients with diabetes, in particular diabetes type 1. An important aspect of prevention of organ damage is early assessment of factors which accelerate the development of microangiopathy. In the submitted paper the authors draw attention assessment of plasma fibrinogen, thrombocyte aggregation in relation to renal functions in type 1 diabetics as well as other indicators which promote the development and acceleration of diabetic nephropathy. In patients with diabetic nephropathy a correlation was found between fibrinogen and thrombocyte aggregation as well as between the rate of urinary albumin excretion, systolic and median blood pressure which are risk factors which increase the mortality of patients with type 1 diabetes.

Peroxisomal enzymes in the liver of rats with experimental diabetes mellitus type 2.

Diabetes mellitus is relatively frequently associated with fatty liver disease. Increased oxidative stress probably plays an important role in the development of this hepatopathy. One of possible sources of reactive oxygen species in liver is peroxisomal system. There are several reports about changes of peroxisomal enzymes in experimental diabetes, mainly enzymes of fatty acid oxidation. The aim of our study was to investigate the possible changes of activities of liver peroxisomal enzymes, other than enzymes of beta-oxidation, in experimental diabetes mellitus type 2. Biochemical changes in liver of experimental animals suggest the presence of liver steatosis. The changes of serum parameters in experimental group are similar to changes in serum of patients with non-alcoholic fatty liver disease. We have shown that diabetes mellitus influenced peroxisomal enzymes by the different way. Despite of well-known induction of peroxisomal beta-oxidation, the activities of catalase, aminoacid oxidase and NADH-cytochrome b(5) reductase were not significantly changed and the activities of glycolate oxidase and NADP-isocitrate dehydrogenase were significantly decreased. The effect of diabetes on liver peroxisomes is probably due to the increased supply of fatty acids to liver in diabetic state and also due to increased oxidative stress. The changes of metabolic activity of peroxisomal compartment may participate on the development of diabetic hepatopathy.