Adam Kemeny-Beke

Resveratrol: A Multifunctional Cytoprotective Molecule

Several recent studies have shown the protective effects of resveratrol in various experimental conditions and pathological animal models. Clinical studies also indicate the beneficial effects of resveratrol in different human diseases. Resveratrol produces a cascade against of events from the initial death-provoking signal, DNA fragmentation, and cell death. Researchers recognized the beneficial effect of resveratrol, as an important component, of the overall injury that occurs in various disorders such as oxidative stress, myocardial injury, anticancer activity, antidiabetic activity, and antihypercholesterolemic effects. Many mechanisms have been proposed for the initiation of protective effects of resveratrol in various pathological events, and considerable evidence exists to indicate that many mediators are involved in the resveratrol-induced protection. The present review focuses on the history, and the beneficial effects and mechanisms of resveratrol in oxidative stress, myocardial injury, anticancer-, antidiabetic- and antihypercholesterolemic activities, and discusses those therapeutic tools, which warrant becoming clinically important.

PACAP Improves Functional Outcome in Excitotoxic Retinal Lesion: An Electroretinographic Study

Pituitary adenylate cyclase-activating polypeptide (PACAP) and its receptors occur throughout the nervous system, including the retina. PACAP exerts diverse actions in the eye: it influences ocular blood flow, contraction of the ciliary muscle, and has retinoprotective effects. This has been proven in different models of retinal degeneration. The in vivo protective effects of PACAP have been shown in retinal degeneration induced by kainic acid, optic nerve transection and ischemia. We have previously shown by morphological, morphometrical and immunohistochemical analyses that intravitreal PACAP administration protects against monosodium glutamate (MSG)-induced damage in neonatal rats. The question was raised whether these apparent morphological improvements by PACAP administration also lead to functional amelioration in MSG-induced retinal damage. The aim of the present study was to investigate the functional consequences of MSG treatment and the subsequent PACAP administration using electroretinographic measurements. The histological and morphometrical analyses supported the earlier findings that PACAP protected the retina in MSG-induced excitotoxicity. ERG recordings revealed a marked decrease in both the b- and a-wave values, reflecting the function of the inner retinal layers and the photoreceptors, respectively. In retinas receiving intravitreal PACAP treatment, these values were significantly increased. Thus, the functional outcome, although not parallel with the morphology, was significantly improved after PACAP treatment. The present observations are important from the clinical point of view showing, for the first time, that PACAP treatment is able to improve the functional properties of the retina in excitotoxic damage.

Increased production of asymmetric dimethylarginine (ADMA) in ankylosing spondylitis: Association with other clinical and laboratory parameters

OBJECTIVE Asymmetric dimethylarginine (ADMA) has been associated with atherosclerosis, vascular diseases and, recently, also with arthritis including rheumatoid arthritis (RA) and ankylosing spondylitis (AS). METHODS Serum ADMA, arginine and symmetric dimethylarginine (SDMA) levels were assessed by liquid chromatography in 61 AS and 26 osteoarthritis (OA) patients with no known cardiovascular disease. RESULTS Serum ADMA levels were significantly increased in AS compared to OA patients (0.95 ± 0.17 μM versus 0.70 ± 0.25 μM; p < 0.001). There were no differences in serum arginine and SDMA levels. Serum ADMA levels also positively correlated with age (R = 0.258; p = 0.043), body mass index (R = 0.368; p = 0.003), erythrocyte sedimentation rate (R = 0.329; p = 0.009) and ADMA levels negative correlated with chest expansion (R = -0.251; p = 0.04). No correlations were found between ADMA levels and disease duration, pain intensity, BASDAI, BASFI, BASMI, quality of life, CRP, HLA-B27 positivity, endothelial dysfunction or carotid atherosclerosis. CONCLUSION ADMA may serve as a marker of systemic inflammation and may reflect functional immobility in AS. Further studies are needed to assess the possible role of ADMA in AS and AS-related vascular disease.

Postischemic cardiac recovery in heme oxygenase-1 transgenic ischemic/reperfused mouse myocardium

Heme oxygenase‐1 (HO‐1) transgenic mice (Tg) were created using a rat HO‐1 genomic transgene. Transgene expression was detected by RT‐PCR and Western blots in the left ventricle (LV), right ventricle (RV) and septum (S) in mouse hearts, and its function was demonstrated by the elevated HO enzyme activity. Tg and non‐transgenic (NTg) mouse hearts were isolated and subjected to ischemia/reperfusion. Significant post‐ischemic recovery in coronary flow (CF), aortic flow (AF), aortic pressure (AOP) and first derivative of AOP (AOPdp/dt) were detected in the HO‐1 Tg group compared to the NTg values. In HO‐1 Tg hearts treated with 50 μmol/kg of tin protoporphyrin IX (SnPPIX), an HO enzyme inhibitor, abolished the post‐ischemic cardiac recovery. HO‐1 related carbon monoxide (CO) production was detected in NTg, HO‐1 Tg and HO‐1 Tg + SnPPIX treated groups, and a substantial increase in CO production was observed in the HO‐1 Tg hearts subjected to ischemia/reperfusion. Moreover, in ischemia/reperfusion‐induced tissue Na+ and Ca2+ gains were reduced in HO‐1 Tg group in comparison with the NTg and HO‐1 Tg + SnPPIX treated groups; furthermore K+ loss was reduced in the HO‐1 Tg group. The infarct size was markedly reduced from its NTg control value of 37 ± 4% to 20 ± 6% (P < 0.05) in the HO‐1 Tg group, and was increased to 47 ± 5% (P < 0.05) in the HO‐1 knockout (KO) hearts. Parallel to the infarct size reduction, the incidence of total and sustained ventricular fibrillation were also reduced from their NTg control values of 92% and 83% to 25% (P < 0.05) and 8% (P < 0.05) in the HO‐1 Tg group, and were increased to 100% and 100% in HO‐1 KO−/− hearts. Immunohistochemical staining of HO‐1 was intensified in HO‐1 Tg compared to the NTg myocardium. Thus, the HO‐1 Tg mouse model suggests a valuable therapeutic approach in the treatment of ischemic myocardium.

In vivo studies with a Candida tropicalis isolate exhibiting paradoxical growth in vitro in the presence of high concentration of caspofungin

We investigated the activity of caspofungin against a Candida tropicalis clinical isolate showing paradoxical growth in vitro. BALB/c mice immunosuppressed by cyclophosphamide were infected intraperitoneally using 107 CFU/mouse. Caspofungin was administered intraperitoneally once daily for 5 days or as a single dose using the following doses: 0.12, 0.25, 1, 2, 3, 5, and 15 mg/kg. The single dose of caspofungin was effective only at 5 and 15 mg/kg concentrations (100% survival). Five-day caspofungin treatment led to 100% survival at doses of 1 mg/kg or higher. Caspofungin treatment significantly decreased the number of viable yeasts in the peritoneal lavage samples as well as in the infected abscesses at doses 1, 3, 5, and 15 mg/kg caspofungin as compared to the untreated control (P<0.001 in all cases), and even to the group treated with 0.12 mg/kg caspofungin (P<0.05 in all cases). At 2 mg/kg caspofungin dose, sterilization of the internal organs was reproducibly incomplete, suggesting that the role of paradoxical growth in the late clinical failure cannot be excluded.

Anti-mutated citrullinated vimentin (anti-MCV) and anti-65 kDa heat shock protein (anti-hsp65): New biomarkers in ankylosing spondylitis

INTRODUCTION Citrullination as well as anti-citrullinated protein/peptide antibodies (ACPA) have been implicated in the pathogenesis of rheumatoid arthritis (RA). While ACPAs are specific and sensitive markers for RA, there have been hardly any reports regarding ACPAs in ankylosing spondylitis (AS). The possible role of antibodies to Mycobacterial 65 kDa heat shock protein (hsp65) has not been characterized in AS. As new laboratory biomarkers of AS are needed, we investigated the prevalence of anti-mutated citrullinated vimentin (MCV) and anti-hsp65 antibodies in AS. METHODS Altogether 43 AS and 44 healthy controls were included in the study. Anti-MCV and anti-hsp65 were determined in sera by commercial and in-house ELISA, respectively. Serum autoantibody levels were correlated with ESR, CRP, HLA-B27 status, smoking habits, pain intensity, BASDAI, BASFI and BASMI indices. RESULTS Patients with AS had significantly higher serum anti-MCV levels (17.3 U/mL, range: 8.3-31.5 U/mL) in comparison to healthy subjects (8.9 U/mL, range: 5.4-13.3 U/mL) (p<0.01). Sixteen of the 43 AS patients (37%) and none of the 44 healthy controls (0%) were anti-MCV positive using the cut-off value recommended by the manufacturer (>20 U/mL). The mean anti-hsp65 concentration in AS sera was 124.8 AU/mL (range: 27.2-1000 AU/mL), while controls exerted significantly lower anti-hsp65 levels (mean: 51.8 AU/mL; range: 22.5-88.5 AU/mL) (p<0.001). Correlation analysis revealed that both anti-MCV positivity (r=0.613; p=0.012) and absolute serum anti-MCV levels (r=0.553; p=0.021) correlated with anti-hsp65 levels. Anti-MCV positivity also correlated with ESR (r=0.437; p=0.03). CONCLUSIONS Anti-MCV and anti-hsp65 may be novel biomarkers in AS.

Protective Effect of Alpha-Melanocyte-Stimulating Hormone (α-MSH) on the Recovery of Ischemia/Reperfusion (I/R)-Induced Retinal Damage in A Rat Model

The present study demonstrates capacity of α-MSH to augment recovery from ischemia/reperfusion (I/R)-induced retinal damage in vivo and correlation of its protective effects with expression of heme oxygenase-1 (HO-1). Used techniques include ocular ischemia and reperfusion, electroretinography, histology, electron microscopy, and molecular-biological techniques. The results demonstrate the α-MSH-mediated inhibition of I/R-induced functional deterioration of the retina. Outcomes suggest that the protective effects of α-MSH occur mainly through HO-1-dependent pathways but HO-1-independent mechanisms may also contribute to protection. The observation that post-ischemic treatment with α-MSH exhibits therapeutic efficacy in the same range as pre-ischemic treatment, is a novel result. This outcome suggests a highly conserved protective role for α-MSH as a major stress response mechanism—and offers the possibility for development of novel therapeutic strategies utilizing this hormone, in particular in treatment of conditions resulting from I/R injury, such as deterioration of retinal microcirculation. The merit of the study lies in the fact that I/R injury contribute significantly to the severity of retinopathies. However, currently there are no evidence-based treatments for retinal I/R injury available for clinical use. Our finding suggests that α-MSH may have a very wide range of uses in the prevention of I/R-mediated pathologies.

Antiproliferative effect of 4-thiouridylate on OCM-1 uveal melanoma cells

PURPOSE Brachytherapy is a well-established, effective treatment for uveal melanoma with a failure rate of 15%. The fatal consequence of unsuccessful treatments offers reason for improvement of the method. The authors propose using an apoptosis inducing agent locally, concomitantly with the well-established therapy, to sensitize the tumor cells. The authors propose a new nontoxic moderately active apoptosis inducing agent, 4-thio-uridylate (s4UMP), for this purpose. METHODS OCM-1 uveal melanoma cells were treated with various concentrations of s4UMP and its effect was monitored by measuring the cell viability (MTT assay). The following apoptosis detecting methods were performed to reveal the mechanism of decreased cell viability: light microscopy, DNA fragmentation assay, determination of caspase 9 activity, and FACS analysis. RESULTS The viability of uveal melanoma cells was decreased by 32%, 40%, and 9% after 24, 48, and 72 hours of treatment with 10 g/mL (30 M) s4UMP. The effect was not dose dependent; it rather followed a saturation-type inhibition and the cells at lower drug concentration recovered after 72 hours. Characteristic apoptotic cell morphology and DNA fragmentation was detected in treated cells. The caspase-9 was activated upon treatment showing maximal activity at 48 hours suggesting the induction of apoptosis. The annexin binding activity further verified the apoptogenic activity of s4UMP. CONCLUSIONS Uveal melanoma, more than other solid tumors, is resistant to most of the chemotherapeutic protocols as indicated by the high mortality rate of metastatic disease. The authors showed that s4UMP, a naturally occurring nucleotide, could induce apoptosis in uveal melanoma cells, suggesting a potential supplementary therapeutic application of the compound.

Different effect of hyperglycemia on stroke outcome in non-diabetic and diabetic patients - a cohort study

Abstract Objectives: Relationship between hyperglycemia and stroke outcome is unclear, partly due to the small sample size in most studies, and partly due to lack of consensus concerning the cutoff level for hyperglycemia. Methods: In a cohort study, we investigated whether on-admission hyperglycemia is an independent predictor for 30-day case fatality by analyzing data of 2496 consecutive computed tomography (CT) verified acute ischemic stroke patients (2077 non-diabetic and 419 diabetic) included in the prospective, hospital-based Debrecen Stroke Database. Instead of using an arbitrary cutoff level for hyperglycemia, quartiles of on-admission glucose level were used for Kaplan–Meier survival curves and Cox proportional hazard modeling. Results: The four quartiles of serum glucose level were in the range as follows: <5·2 mmol/l, 5·201–6·1 mmol/l, 6·101–7·5 mmol/l, and >7·501 mmol/l (n = 664, 618, 597, and 617, respectively). Among all 2496 participants, the adjusted hazard ratios for death increased with each quartile of admission glucose 1·96 [95% confidence interval (CI): 1·07–3·60; P = 0·03], 1·56 (95% CI: 0·83–2·94; P = 0·17), and 3·04 (95% CI: 1·70–5·44; P<0·0001) for the second, third, and fourth quartiles, respectively). Upon stratification with respect to diabetes, we found similarly high risk for poor outcome among non-diabetic patients, while the risk was considerably lower among diabetic patients. Discussion: These data suggest that even mild elevation of on-admission glucose levels is an independent predictor of 30-day case fatality. So, we propose that the ideal target blood glucose level is lower for non-diabetic than diabetic patients.

Prior transient ischemic attack is independently associated with lesser in-hospital case fatality in acute stroke

Aim:  Ischemic preconditioning has been well established in healthy human hearts, but limited information is available about its occurrence or its integrity in the brain. The aim of the present study was therefore to investigate whether a prior cerebral ischemic episode (stroke or transient ischemic attack [TIA]) is able to confer protection against ischemic stroke, reflected by in‐hospital case fatality.