Ákos Mérei

A polymorphism within the fructosamine-3-kinase gene is associated with HbA1c levels and the onset of type 2 diabetes mellitus

BACKGROUND Non-enzymatic glycation is a process, which leads to the formation of advanced glycation endproducts. These compounds are involved in the development of diabetic microvascular complications. Fructosamine-3-kinase (FN3K) is an intracellular enzyme that phosphorylates fructosamines resulting in fructosamine-3-phosphate, which subsequently decomposes to inorganic phosphate, 3-deoxyglucasone and the unmodified amine. Recently, the G900C (rs1056534) single nucleotide polymorpism (SNP) of the FN3K gene was found to be associated with the enzyme activity. OBJECTIVE/DESIGN The aim of the study was to investigate the impact of the SNP on clinical and biochemical features and microvascular complications of type 2 diabetes. PATIENTS A total of 859 type 2 diabetic subjects and 265 healthy controls were enrolled in the study and were genotyped with PCR-RFLP method. RESULTS Genotype frequencies were as follows, CC: 5%, GC: 54%, GG: 41% in subjects with type 2 diabetes and CC: 6%, GC: 51%, GG: 43% in the controls. Diabetic subjects with the CC variant had lower HbA (1c) levels compared with the others (CC: 6.48+/-0.05%; GC: 7.66+/-0.09%; GG: 7.68+/-0.09%; p<0.001). Furthermore, in case of the CC allelic variant type 2 diabetes was diagnosed at a later age than in case of GC or GG variants (CC: 56.0+/-1.90 years; GC: 52.0+/-0.62 years; GG: 50.1+/-0.71 years; p<0.05). Logistic regression analysis did not reveal association between CC genotype and diabetic complications, such as diabetic nephropathy, neuropathy and retinopathy (OR=1.036, CI 95% 0.652-1.647, p=0.880; OR=0.985, CI 95% 0.564-1.721 p=0.958; OR=1.213, CI 95% 0.470-3.132, p=0.690, respectively). CONCLUSION We conclude that the G900C polymorphism associates with the level of HbA (1c) and the onset of the disease, but not with either of the diabetic microvascular complications.

Effects of erythropoietin on glucose metabolism

We purposed to determine the impact of erythropoietin on altering glucose metabolism in the settings of in vitro and in vivo experiments. The acute effect of erythropoietin on lowering blood glucose levels was studied in animal experiments. In [³H]-deoxy-D-glucose isotope studies we measured glucose uptake with insulin and erythropoietin using 3T3-L1 cells cultured under normal or high glucose conditions. Altered activation of Akt and ERK pathways was evaluated in immunoblot analyses. Immunocytochemistry was conducted to determine the glucose transporter 4 translocation to the plasma membrane. Addition of erythropoietin significantly lowered blood glucose levels in vivo in rats. The glucose uptake was markedly increased by erythropoietin treatment (at concentrations 0.15, 0.3, and 0.625 ng/ml) in adipocytes grown in high glucose medium (p<0.05), but it remained unaltered in cells under normal glucose conditions. Significant increase of phosphorylation of ERK and Akt was detected due to erythropoietin (p<0.05). Co-administration of erythropoietin and insulin resulted in higher phosphorylation of Akt and [³H]-deoxy-D-glucose uptake in adipocytes than insulin treatment alone. We found that erythropoietin induced the trafficking of glucose transporter 4 to the plasma membrane. Our data showed that erythropoietin significantly decreased blood glucose levels both in vivo and in vitro, in part, by increasing glucose uptake via the activation of Akt pathway. Preliminary data revealed that adipocytes most likely exhibit a specific receptor for erythropoietin.

The effect of Na-selenite treatment on the oxidative stress–antioxidants balance of multiple organ failure

PURPOSE Our study tested the hypothesis that sodium (Na)-selenite expression treatment can reduce oxidative stress and increase plasma antioxidants, whereas modulating white blood cell antigen expression in severe sepsis. Selenite is a well known cofactor of glutathione peroxidases and other antioxidant enzymes; therefore, one may expect an antioxidant effect of treatment. MATERIALS We randomized 40 severe septic patients into treatment and control groups. Treatment group (n = 21) received 1000-μg/2 hours Na-selenite load, followed by a 1000-μg/die medication. Oxidative stress markers, including malondialdehyde, maximal free radical production, and plasma antioxidants: free sulfhydryl groups, glutathione levels, and superoxide dismutase and catalase enzyme activity were measured. RESULTS According to our results, the treatment regime successfully restored serum selenium levels. Treatment group developed a significant malondialdehyde increase by the fifth study day, whereas reactive oxygen species production decreased significantly. Reduced glutathione and plasma sulfhydryl groups showed no significant difference. Treatment group showed deteriorated expression of CD11a and slight increase of CD49d expression on monocytes throughout our study. CONCLUSIONS Although our Na-selenite treatment regime successfully restored the selenium deficiency of severe septic patients, antioxidant and white blood cell antigen expression modulating effect of the therapy was not observed in our patient group.

Measurement of the modification and interference rate of urinary albumin detected by size-exclusion HPLC

The measurement of the excretion of urinary albumin (albuminuria) is an important and well-established method to assess clinical outcomes. A high-performance liquid chromatography (HPLC) method has been introduced to measure albuminuria. Using this method, it was found that commonly used immunological methods do not measure a fraction of urinary albumin. Some authors presumed that the reason of immuno-unreactivity is the modification of urinary albumin; some others presumed that the difference is merely because of interference. In order to decide this question, we established an HPLC method equipped with tandem UV and fluorescent detection to assess the changes in the detectability of albumin with the rate of modification. For this measurement, differently modified forms of albumin were used. Urine samples of diabetic patients were also measured to find a potential connection between the modification rate and clinical parameters. Secondly, we have established a reversed phase HPLC method to assess the interference rate. We conclude that albumin modification does not affect immunoreactivity. The modification rate of urinary albumin in diabetic patients showed a correlation with renal function. The interference rate of the albumin peak was found to be 12.7% on average, which does not explain the difference between the two methods.

Comparison of VividTrac®, Airtraq®, King Vision®, Macintosh Laryngoscope and a Custom-Made Videolaryngoscope for difficult and normal airways in mannequins by novices

BackgroundDirect laryngoscopy remains the gold standard for endotracheal intubation and is preferred by experienced operators. However, an increasing number of reports currently support videolaryngoscopy, particularly for novice users. The widespread use of videolaryngoscopy may be limited due to financial limitations, especially in low-income countries. Therefore, affordable single-use scopes are now becoming increasingly popular. We sought to compare these new scopes with direct laryngoscopes and the previously tested videolaryngoscopes in mannequins by novices.MethodsFifty medical students were recruited to serve as novice users. Following brief, standardized training, students were asked to execute endotracheal intubation with each of the devices, including the Airtraq®, a custom-made videolaryngoscope, the King Vision®, the Macintosh laryngoscope and the VividTrac®, on an airway trainer (Laerdal Airway Management Trainer®) in normal and difficult airway scenarios. We evaluated the time to and the proportion of successful intubation, the best view of the glottis, esophageal intubation, dental trauma and user satisfaction.ResultsWe observed no differences in esophageal intubation. However, intubation-related times, the view of the glottis and operator satisfaction were significantly better throughout the study with the commercial videolaryngoscopes. In comparison, the custom-made videolaryngoscope performance proved to be similar to that of the Macintosh laryngoscope. The VividTrac® performance was similar (P > 0.05) or significantly better than that of the King Vision® in both scenarios.ConclusionsBased upon our results, the Airtraq®, King Vision® and VividTrac® were superior to the Macintosh laryngscope in both normal and difficult airway scencarios for novice users. In particular, our study is the first to report that the VividTrac® shows promise for further clinical evaluation.

Perioperative time course of matrix metalloproteinase-9 (MMP-9), its tissue inhibitor TIMP-1 & S100B protein in carotid surgery

Background & objectives: Ischaemic stroke is a life burdening disease for which carotid endarterectomy (CEA) is considered a gold standard intervention. Pro-inflammatory markers like matrix metalloproteinases (MMPs) and their inhibitors (TIMPs) and S-100 Beta (S100B) may have a role in the early inflammation and cognitive decline following CEA. This study was aimed to describe the perioperative time courses and correlations between of MMP-9, TIMP-1 and S100B following CEA. Methods: Fifty four patients scheduled for CEA were enrolled. Blood samples were collected at four time points, T1: preoperative, T2: 60 min after cross-clamp release, T3: first postoperative morning, T4: third postoperative morning. Twenty atherosclerotic patients were included as controls. Plasma MMP-9, TIMP-1 and S100B levels were estimated by ELISA. Results: TIMP-1 was decreased significantly in the CEA group (P<0.01). Plasma MMP-9 was elevated and remained elevated from T1-4 in the CEA group (P<0.05) with a marked elevation in T3 compared to T1 (P<0.05). MMP-9/TIMP-1 was elevated in the CEA group and increased further by T2 and T3 (P<0.05). S100B was elevated on T2 and decreased on T3-4 compared to T1. Interpretation & conclusions: Our study provides information on the dynamic changes of MMP-9-TIMP-1 system and S100B in the perioperative period. Preoperative reduction of TIMP-1 might be predictive for shunt requirement but future studies are required for verification.

Effects of Mono- and Dual Blockade of the Renin-Angiotensin System on Markers of Cardiovascular Status in Hypertensive Patients with Mild and Moderate Renal Failure

Background/Aims: Dual renin-angiotensin system (RAS) blockade has no more efficiency to decrease cardiovascular mortality than mono-blockade. Our goal was to explore differences between other cardiovascular markers in patients with RAS blockade. Methods: We analyzed two groups of patients treated with a long-term ACE inhibitor (MONO-group, n = 20) and an ACE inhibitor and angiotensin II receptor blocker (DUAL-group, n = 15). Ambulatory blood pressure monitoring, echocardiography, arterial stiffness and levels of catecholamine, endogenous ouabain (EO), pro-brain natriuretic peptide and more types of urinary albumin measurements were performed. Results: In the DUAL-group, we found significantly better cardiac parameters, but the levels of EO and urinary albumins were similar in both groups. The level of EO correlates with nighttime mean arterial blood pressure (R = 0.556, p = 0.032) and arterial β-stiffness (R = 0.512, p = 0.042). Urinary immuno-unreactive albumin showed a relationship with diastolic dysfunction of the heart (R = –0.508, p = 0.045) diurnal index of diastolic blood pressure (R = –0.569, p = 0.021) in the MONO-group. Conclusion: Cardiac parameters were more prosperous in the DUAL-group, but the levels of EO did not differ between groups. The level of EO correlated with blood pressure and arterial stiffness markers in the MONO-group only. The urinary immuno-unreactive albumin may be a new marker of cardiovascular conditions.

Effects of therapeutic hypothermia and kinetics of serum protein S100B after cardiopulmonary resuscitation

Introduction. Post-resuscitation care is regulated by international guidelines. A milestone of these is the application of therapeutic hypothermia (TH). The aims of our study were: to determine the 30-day-mortality for our patients, to monitor the efficacy and effects of TH, and to investigate serum protein S100B – as an early prognostic marker.Materials and Methods. In our study, 57 patients, treated after cardiopulmonary resuscitation (CPR) on a multidisciplinary intensive care unit, were included. Patients were divided into groups who received and who didn’t receive TH. 30-day-mortality was determined as an end-point. Effects of TH were monitored using statistical analysis according to clinical parameters and laboratory tests. Serum protein S100B levels were measured with ELISA technique on 20 randomised patients atadmission and the 1st, 3rd and 5th day after CPR. Results. Total 30-day-mortality was 74%. TH did not reduced the 30-day-mortality (73% vs. 74%, p>0.05). We found a significant correlation between TH and serum lactate concentration after admission (0h,p=0.006) and at 12 (p=0.045) and 36 (p=0.049) hours after CPR. On the3rd (p=0.005) and 4th (p=0.043) day after CPR, as a result of TH, platelet count was significantly higher compared to normothermic samples. There was no significant difference in protein S100B levels between the normothermic and TH group and protein S100B levels did not correlate with 30-day-mortality.Conclusion. Despite recommendations of international guidelines, we cannot prove the beneficial effect of TH, or a correlation of protein S100B levels with a positive outcome.