Probability of exposure to the wild measles virus in adult population - Estimation from seroepidemiology and historical data

Vaccination against measles is one of the most effective public health interventions which has saved millions of lives and interrupted circulation of the natural virus in the population. However, it is widely accepted that the immunity after vaccination can wane, especially in those who have had no contact with the virus. This study aimed to classify the particular birth cohorts of adults with regard to their exposure to the wild measles virus in the population with a long history of mandatory vaccination. We introduced two methods. In the first, we estimated the probability of exposure to the wild virus through an analysis of antibody levels from the Immunologic Survey performed in the Slovak Republic in 2018, while the second was based on historical epidemiological data. Both methods resulted in similar estimations. Cohorts born in Slovakia before 1964 can be considered to be cohorts in which most people were exposed to the wild measles virus. Cohorts born after 1977 can be designated as cohorts that most likely did not come into the contact with the wild virus. Cohorts born between 1965 and 1976 are composed of a mixture, with a decreasing proportion of people exposed to the wild virus with increasing year of birth. The proposed methods can help identify potential immunity gaps in the adult population. They can be applied in other countries with high measles vaccination coverage to estimate the probability of exposure to the wild measles virus in particular birth cohorts.

Quantification of Waning Immunity After Measles Vaccination-Evidence From a Seroprevalence Study

We aimed to quantify rates of waning immunity after measles vaccination from seroprevalence data collected in a study of a population with high vaccination coverage and a fixed vaccination schedule. Data were collected during a national survey (the Immunological Survey) carried out in the Slovak Republic in 2018. The average rate of waning immunity against measles after the first dose of measles, mumps, and rubella (MMR) vaccine (ages 1.5-10 years) was 9.7% per year from the geometric mean titer value of 2,634 mUI/mL. The average waning rate after the second dose of MMR vaccine (ages 10-33 years) was significantly lower: 4.8% per year from the lower geometric mean titer of 1,331 mUI/mL. This decline in antibody levels suggests that vaccine-induced protection may be compromised and results in an increase in the proportion of seronegative/borderline individuals. These outcomes may provide a valuable source for critical assessment of direct and indirect effects of MMR vaccination.

Overweight and Fertility: What We Can Learn from an Intergenerational Mouse Obesity Model

The aim of this study was to evaluate the effects of being overweight on the ability to conceive, fertilization rate, and in vivo development of embryos in regularly cycling, spontaneously ovulating, and naturally mated female mice. The study was based on statistical analysis of data collected during 14 experiments with identical design, performed on 319 control and 327 obese mice, developed in an intergenerational model of obesity induction which eliminates the impact of aging and high-fat feeding. Six-week-old mice with a vaginal sperm plug were slaughtered on embryonic days 2, 3, or 4, and the flushed contents of the oviducts and uteri were assessed by stereomicroscopy. The results showed no association between being overweight and the proportion of ovulating or fertilized females. On the other hand, a strong association was found between being overweight and ovulation yield. On embryonic day 2, significantly higher numbers of eggs were recovered from the oviducts of fertilized obese mice. Maternal overweight status was also associated with higher developmental capacities of preimplantation embryos. In conclusion, contrary to studies based on the high-fat-diet model, in female mice fed regular chow, being overweight was associated with an increased ovulation quota and higher developmental rate of fertilized oocytes. Being overweight did not impact ability to conceive. On the other hand, as documented in our previous studies, the quality of oocytes and blastocysts recovered from overweight mice developed in an intergenerational model of obesity was low.

Dental Care and Education Facing Highly Transmissible SARS-CoV-2 Variants: Prospective Biosafety Setting: Prospective, Single-Arm, Single-Center Study

With the arrival of the highly transmissible Omicron variants (BA.4 and BA.5), dentistry faces another seasonal challenge to preserve the biosafety of dental care and education. With the aim of protecting patients, students, teachers and healthcare professionals, this paper introduces a prospective sustainable biosafety setting for everyday dental care and education. The setting developed by dental clinicians, epidemiologists, and teachers of dentistry consists of a combination of modern technologies focused on the air-borne part of the viral pathway. The introduced biosafety setting has been clinically evaluated after 18 months of application in the real clinical environment. The protocol has three fundamental pillars: (1) UVC air disinfection; (2) air saturation with certified virucidal essences with nebulizing diffusers; (3) complementary solutions including telehealth and 3D printing. A pseudonymous online smart form was used as the evaluation method. The protocol operates on the premise that everybody is a hypothetical asymptomatic carrier. The results of a clinical evaluation of 115 patient feedbacks imply that no virus transmission from patient to patient or from doctor to nurse was observed or reported using this protocol, and vice versa, although nine patients retrospectively admitted that the clinic visit is likely to be infectious. Despite these promising results, a larger clinical sample and exposition to the current mutated strains are needed for reliable conclusions about protocol virucidal efficiency in current dental environments.

Pretreatment Levels of Chromogranin A and Neuron-specific Enolase in Patients With Gastroenteropancreatic Neuroendocrine Neoplasia

BACKGROUND/AIM

Chromogranin A (CgA) and neuron-specific enolase (NSE) are applied in the diagnosis of neuroendocrine neoplasms (NENs), especially non-functional ones. The aim of this study was to investigate the predictive values of CgA and NSE in long-term survival.

PATIENTS AND METHODS

Our retrospective analysis included 65 patients with histologically verified gastroenteropancreatic NEN between 2005 and 2019. We performed bivariate and multivariable analyses to evaluate the relationship between CgA and NSE values before histological assessment and overall survival. Distribution of time-to-event was analyzed using Kaplan-Meier survival curves and modelled by Cox regression models.

RESULTS

Elevated NSE levels prior to histology were significantly associated with worse survival (HR=1.13, p=0.004) and were associated with low-differentiated NENs (r_s=0.321, p=0.0338). CgA was associated with well-differentiated tumors (r_s=0.233), but not significantly.

CONCLUSION

Pretreatment serum levels of NSE can serve as a valuable additional predictor of long-term survival in patients with NEN.

The role of subtotal and total gastrectomy in the treatment of gastric cancer

The optimal procedure for the lower third gastric adenocarcinoma is still an open question. We performed an analysis of the long-term survival of patients after subtotal (SG) or total gastrectomy (TG) on 164 enrolled patients. Bivariate and multivariable analyses were performed in order to identify characteristics associated with long-term survival. Survival was significantly affected by the number of positive lymph nodes (LN). Patients who have undergone TG had a higher number of total removed LN. The adjusted hazard ratio for the TG group suggests a partial superiority of TG over SG for patients with curative intent. Our data support the importance of extended LN dissection.

Diagnostic ipsilateral central neck dissection may reduce undertreatment of initially low-risk papillary thyroid cancer

Although small papillary thyroid cancer (PTC) patients are considered as low-risk population, approximately 5-20% of these patients relapse after surgery. The objective of this single-center retrospective study was to identify risk factors, which could help to distinguish patients who would need additional treatment after surgery. A total of 268 patients (39 men, 229 women, median age 49 years) underwent surgery between 2007-2015, and fulfilled inclusion criteria: tumor size ≤20 mm, absence of metastatic lymph nodes (LN) in the lateral neck compartment (LC), and absence of local invasion. Total thyroidectomy was performed in 252 cases, in 221 cases with central neck compartment (CC) dissection. The outcome - a more aggressive disease - was defined as the presence of metastases in the LNLC or in distant organs found during follow-up. A median follow-up was 117 months. Overall, 41 patients experienced the outcome with a median time-to-event of 18 months. Male gender (OR=2.2, p=0.049), extra-thyroidal extension ETE (OR=2.61, p=0.015), and metastases in LNCC (OR=4.21, p<0.001) were associated with worse outcome. Multivariable analysis and stratification according to ETE revealed an effect modification with a higher effect of the positive LNCC on the outcome among patients without ETE than in those with ETE. Our findings advocate placing greater emphasis on the role of LNCC metastases in the absence of ETE. In clinically node-negative tumors intraoperative examination of CC on the side of the tumor followed by CC dissection if metastatic lymphadenopathy is present could play an important role in the stratification of patients with small-size PTC.

Omega-3 fatty-acids modulate symptoms of depressive disorder, serum levels of omega-3 fatty acids and omega-6/omega-3 ratio in children. A randomized, double-blind and controlled trial

Omega-3 fatty acids (FA) are a promising adjuvant therapy for depressive disorder (DD) in adults. The objective of this single-centre, randomized, double-blind and controlled study was to compare the efficacy of an omega-3 FA fish oil emulsion with a control oil emulsion alongside the standard treatment for depression in children and adolescents suffering from DD or mixed anxiety depressive disorder (MADD) and to analyse serum fatty acid levels and omega-6/omega-3 FA ratio before and after the intervention. 60 children were randomised 1:1 to the intervention (Om3) or active comparator (Om6) groups. Children's Depression Inventory (CDI) ratings were performed at the baseline, every 2 weeks for a 12-week intervention period. Significant reductions in CDI scores were observed after 6 and 12 weeks of intervention in the Om3 group and in the DD subgroup compared to the Om6 and MADD subgroup. Ratio of omega-6/omega-3 decreased in Om3 but not in Om6 from 24.2/1 to 7.6/1 after 6 weeks, EPA, omega-6/omega-3 ratio, but not DHA, correlated with severity symptoms at the baseline. An omega-3 fatty acid rich fish oil emulsion may be an effective adjuvant supplement during the treatment of depressive disorders in children. Trial registration: ISRCTN 81655012.

RADIATION MACULOPATHY AFTER ONE-DAY SESSION STEREOTACTIC RADIOSURGERY IN PATIENTS WITH CILIARY BODY AND CHOROIDAL MELANOMA

INTRODUCTION

Nowadays radiotherapy is the standard treatment care for patients with uveal melanoma. In Slovakia the only one option is a one-day session stereotactic radiosurgery at linear accelerator LINAC. Irradiation of surrounding tissues of the eye and orbit causes radiation complications. One of the most serious and vision-threatening is the radiation retinopathy, which divides into maculopathy and peripheric retinopathy. The clinical signs include microanerysms, teleangiectases, hard exsudates, cotton wool spots and macular edema, neovascularisation, and vitreous hemorrhage. Radiation macular edema can be classified by optical coherence tomography into cystoid or noncystoid edema. On fluorescein angiography macular edema is divided into non-ischemic and ischemic, while the latter means usually irreversible loss of the visual acuity. This paper is focused on risk factors of radiation retinopathy although it strongly influences functional result of radiotherapy and preservation of the visual acuity.

PURPOSE

By means of bivariate and multivariate analysis to determine the association of radiation dose and other variables with the development of radiation maculopathy.

MATERIAL AND METHODS

The retrospective analysis of 168 patients with ciliary body or choroidal melanoma who performed one-day session stereotactic radiosurgery on a linear accelerator LINAC in a period 2007-2016.

RESULTS

The prevalence of the radiation maculopathy was 29% with the median time from the irradiation to maculopathy 16 months. Median radiation dose on the macula was 37 Gy. Variables statistically significantly associated with the maculopathy were: radiation dose (p = 0.0016), postequatorial location of the tumor (p = 0.0271) and better visual acuity before treatment (p = 0.0007). The tumor touch of the macula was strongly associated with the visual acuity in the bivariate analysis (p = 0.0006), thus it could be omitted from the final model.

DISCUSSION

The radiation dose on a macula is the key determinant for radiation-induced maculopathy, according to other authors and our study approvingly. Other variables were related to proximity of the tumor to the macula, so the radiation dose on the macula was higher indirectly. Better visual acuity before treatment as a risk factor for maculopathy can be a consequence of: a) earlier diagnostics of tumor with proximity to the posterior pole, b) lower enucleation rate; frequency of the enucleation was 1.6 higher in patients without maculopathy. Naturally, on enucleated eyes maculopathy was not diagnosed. Five patients underwent intravitreal application of the bevacizumab as a treatment of the radiation maculopathy, without improvement of the visual acuity.

CONCLUSION

Radiation complications can be vision and eye threatening. Radiation maculopathy is a consequence of higher radiation dose on the macula. The treatment modalities of radiation maculopathy are rather ineffective.

Rooibos tea (Aspalathus linearis) ameliorates the CCl4-induced injury to mitochondrial respiratory function and energy production in rat liver

The rooibos tea (RT) is a source of valuable dietary dihydrochalcones  aspalathin, and nothofagin and other polyphenols. Many in vitro and in vivo studies have shown that RT flavonoids have strong antioxidant effect and significantly reduce oxidative stress. We investigated the antioxidant activity and protective effect of an aqueous extract of RT on the liver mitochondria oxidative phosphorylation in rats with carbon tetrachloride-induced (CCl4-induced) liver damage. Mitochondrial respiration and ATP production was determined amperometrically using a Clark-type oxygen electrode. We found significantly decreased parameters of oxidative phosphorylation in the group having received CCl4 for 10 weeks. Simultaneous administration of RT increased oxygen uptake stimulated with ADP, and the rate of ATP generation in the mitochondria of rats, both having been impaired in rats treated with CCl4 only. Treatment with RT significantly decreased CCl4-induced elevated enzyme levels, improved capacity of the respiratory chain and energy production, presumably due to its potent and direct antioxidant activity, including inhibition of mitochondrial lipid peroxidation. Improved histological features support the view of antioxidant and membrane-stabilizing activity of RT. This fact may play a significant role in the protection of the liver from injury caused by known toxins, and from subsequent development of steatosis and fibrosis..

Support of medication adherence by community pharmacists in Czech and Slovak Republics: a questionnaire survey study

Introduction: Intervention of pharmacists in medication adherence can meaningfully contribute to achieving therapeutic outcomes. Exploring the real-life readiness and opportunities of pharmacists may result in the adoption of measures, which could be seen through improvement of patients’ adherence to pharmacotherapy.

Aim: The aim of the paper was to make a survey on community pharmacists’ potential in medication adherence support in its connectivity to technical and personnel factors, which underline the capacities of pharmacies in dealing with medication adherence.

Methods: The questionnaire survey was conducted from October to December 2014 and involved 158 pharmacists from 117 Czech (CZ) and 41 Slovak (SK) community pharmacies. The structured questionnaire surveyed both technical and personnel factors, including provision of consultancy services related to medication adherence. Non-adherence risk reduction was evaluated by adopting Morisky Scale modified from the pharmacist’s perspective. Questionnaires outcomes were summarised in contingency tables and analyzed for associations between respective categorical variables using χ2 or exact tests and association coefficients. All results are reported as significant at P≤0.05.

Results: The average score of adherence support (CZ/SK 1.95/1.93) was significantly higher as compared to that of persistence or concordance (P<0.001). Reduction of non-adherence risk reached the score of a medium degree (P=0.73, average 2.29 in CZ and 2.22 in SK). These findings were significantly associated with personnel capacities (provision of consultancy, preference for the use of recommended procedures in CZ (P<0.001), number of years of practice in SK (P=0.029)), while significant association with technical equipment (consultancy room) in the SK (P=0.037).

Conclusion: The pharmaceutical care is developing towards the improvement of medication adherence in both countries - assuming a medium degree of adherence support. Further progress may be observed in strengthening the pharmacists’ personnel capacities, and accelerated mainly using information technologies, i.e. through technical capacities.

Fibrinogen Levels Are Associated with Lymph Node Involvement and Overall Survival in Gastric Cancer Patients

BACKGROUND/AIM

Combination of perioperative chemotherapy with gastrectomy with D2 lymphadenectomy improves long-term survival in patients with gastric cancer. The aim of this study was to investigate the predictive value of preoperative levels of CRP, albumin, fibrinogen, neutrophil-to-lymphocyte ratio and routinely used tumor markers (CEA, CA 19-9, CA 72-4) for lymph node involvement.

MATERIALS AND METHODS

This retrospective study was conducted in 136 patients who underwent surgery between 2007 and 2015. Bivariable and multivariable analyses were performed in order to identify important characteristics associated with the risk of lymph node involvement. Kaplan-Meier survival curves and log-rank tests were used to compare overall survival.

RESULTS

Lymph node involvement was significantly affected by preoperative fibrinogen (p=0.008) and albumin (p=0.023). Poor clinical condition, T and N staging and fibrinogen level above 3.5 g/l were significantly associated with worse overall survival.

CONCLUSION

Preoperative fibrinogen and albumin levels are significantly associated with lymphoid metastases in patients with gastric cancer.

Changes in mitochondrial properties may contribute to enhanced resistance to ischemia-reperfusion injury in the diabetic rat heart

Diabetes mellitus, besides having deleterious effects, induces cardiac adaptation that may reduce the heart's susceptibility to ischemia-reperfusion (IR) injury. This study aimed to investigate whether changes in mitochondrial properties are involved in the mechanisms of increased resistance of the diabetic heart to IR. Adult male Wistar rats were made diabetic by a single dose of streptozotocin (65 mg·kg^-1, i.p.), and on the day 8, Langendorff-perfused hearts were subjected to 30 min global ischemia and 40 min reperfusion. Baseline preischemic parameters in the diabetic hearts did not differ markedly from those in the nondiabetic controls, except for lower left ventricular developed pressure, higher mitochondrial membrane fluidity, and protein levels of manganese superoxide dismutase. On the other hand, diabetic hearts showed significantly better post-IR functional restoration and reduced arrhythmogenesis associated with lower reactive oxygen species production as compared with healthy controls. IR decreased membrane fluidity in both experimental groups; however, it led to a complete recovery of mitochondrial Mg²⁺-ATPase activity in diabetics in contrast to its reduction in nondiabetics. These findings indicate that the heart may become adapted to diabetes-induced alterations that might increase its tolerance to an ischemic insult. Preserved mitochondrial function might play a role in the mechanisms of the heart's resistance to IR injury in diabetics.

Emulsified omega-3 fatty-acids modulate the symptoms of depressive disorder in children and adolescents: a pilot study

BACKGROUND

The prevalence of mood disorders in children is a growing global concern. Omega-3 fatty acids (FA) are emerging as a promising adjuvant therapy for depressive disorder (DD) in paediatric patients. The primary objective of this pilot, single-centre, randomized, double-blind controlled study was to compare the efficacy of an Omega-3 FA fish oil emulsion with a control oil emulsion alongside standard treatment for depressive symptoms in children and adolescents suffering from depressive disorder (DD) and mixed anxiety depressive disorder (MADD).

METHODS

38 children (12 patients were treated and diagnosed for at least 1 month before enrolment, 26 patients were first-time diagnosed as DD) aged 11-17 years were randomised 1:1 to the intervention (Omega-3 FA, 19 patients) or active comparator (Omega-6 FA, 19 patients) groups. Children's depression inventory (CDI) ratings were performed at baseline, every 2 weeks for a 12-week intervention period and at 4-week post-intervention. 35 patients (17 in Omega-3 and 18 in Omega-6 groups) who completed the whole intervention period were evaluated. Patients from Omega-3 group were stratified according to diagnosis into two subgroups (DD-10/17 and mixed anxiety depressive disorder (MADD)-7/17 patients) and in the Omega-6 group into DD-10/18 and MADD-8/18 patients. Groups were evaluated separately. Differences between-groups were tested with the Student´s t test or non-parametric Mann-Whitney U test. Two-way ANOVA with repeated measures and Friedman test were used to analyse the Treatment effect for response in CDI score. p < 0.05 was considered significant in all statistical analyses.

RESULTS

Significant reductions in CDI scores in 35 analysed patients who completed 12 weeks intervention were observed after 12 weeks of intervention only in the Omega-3 group (p = 0.034). After stratification to depressive disorder and mixed anxiety depressive disorder subgroups, the DD subgroup receiving the Omega-3 FA fish oil showed statistically greater improvement (score reduction after 8 week treatment of -9.1 CDI, p = 0.0001) when compared to the MADD subgroup (score reduction after 8 week treatment -4.24 CDI, p = 0.271).

CONCLUSIONS

CDI scores were reduced in the Omega-3 group and the depression subgroup had greater improvement than the mixed depressive/anxiety group. An Omega-3 fatty acid rich fish oil emulsion may be an effective adjuvant supplement during the treatment of depressive disorders in children. Trial registration ISRCTN81655012.

Cardioprotection induced by remote ischemic preconditioning preserves the mitochondrial respiratory function in acute diabetic myocardium

A 2×2 factorial design was used to evaluate possible preservation of mitochondrial functions in two cardioprotective experimental models, remote ischemic preconditioning and streptozotocin-induced diabetes mellitus, and their interaction during ischemia/reperfusion injury (I/R) of the heart. Male Wistar rats were randomly allocated into four groups: control (C), streptozotocin-induced diabetic (DM), preconditioned (RPC) and preconditioned streptozotocin-induced diabetic (DM+RPC). RPC was conducted by 3 cycles of 5-min hind-limb ischemia and 5-min reperfusion. DM was induced by a single dose of 65 mg/kg streptozotocin. Isolated hearts were exposed to ischemia/reperfusion test according to Langendorff. Thereafter mitochondria were isolated and the mitochondrial respiration was measured. Additionally, the ATP synthase activity measurements on the same preparations were done. Animals of all groups subjected to I/R exhibited a decreased state 3 respiration with the least change noted in DM+RPC group associated with no significant changes in state 2 respiration. In RPC, DM and DM+RPC group, no significant changes in the activity of ATP synthase were observed after I/R injury. These results suggest that the endogenous protective mechanisms of RPC and DM do preserve the mitochondrial function in heart when they act in combination.

Stimulation of mitochondrial ATP synthase activity - a new diazoxide-mediated mechanism of cardioprotection

Pharmacological preconditioning by diazoxide and a model of experimental streptozotocin-induced acute diabetes mellitus (STZ-DM) provided similar levels of cardioprotection assessed as limiting myocardial infarct size. The aim was to explore the possibility of existence of another in vitro mechanism, which could be contributory to cardioprotection mediated by diazoxide treatment. Mitochondrial membrane fluidity and ATP synthase activity in isolated heart mitochondria were determined under the influence of two factors, STZ-DM condition and treatment with diazoxide. Both factors independently increased the ATP synthase activity (p<0.05), as no interaction effect was observed upon the combination of STZ-DM with diazoxide. On the other hand, the mitochondrial membrane fluidity was significantly increased by STZ-DM only; no significant main effect for diazoxide was found. Based on the results from measurements of enzyme kinetics, we assume a direct interaction of diazoxide with the molecule of ATP synthase stimulated its activity by noncompetitive activation. Our present work revealed, for the first time, that cardioprotection induced by diazoxide may not be caused exclusively by mitochondrial K(ATP) opening, but presumably also by a direct interaction of diazoxide with ATP synthase, although the mechanisms for achieving this activation cannot be fully delineated.

Effect of antihypertensive agents - captopril and nifedipine - on the functional properties of rat heart mitochondria

OBJECTIVES

Investigation of acute effect on cellular bioenergetics provides the opportunity to characterize the possible adverse effects of drugs more comprehensively. This study aimed to investigate the changes in biochemical and biophysical properties of heart mitochondria induced by captopril and nifedipine antihypertensive treatment.

MATERIALS AND METHODS

Male, 12-week-old Wistar rats in two experimental models (in vivo and in vitro) were used. In four groups, the effects of escalating doses of captopril, nifedipine and combination of captopril + nifedipine added to the incubation medium (in vitro) or administered per os to rat (in vivo) on mitochondrial ATP synthase activity and membrane fluidity were monitored.

RESULTS

In the in vitro model we observed a significant inhibitory effect of treatment on the ATP synthase activity (P<0.05) with nonsignificant differences in membrane fluidity. Decrease in the value of maximum reaction rate Vmax (P<0.05) without any change in the value of Michaelis-Menten constant Km, indicative of a noncompetitive inhibition, was presented. At the in vivo level, we did not demonstrate any significant changes in the ATP synthase activity and the membrane fluidity in rats receiving captopril, nifedipine, and combined therapy.

CONCLUSION

In vitro kinetics study revealed that antihypertensive drugs (captopril and nifedipine) directly interact with mitochondrial ATP synthase. In vivo experiment did not prove any acute effect on myocardial bioenergetics and suggest that drugs do not enter cardiomyocyte and have no direct effect on mitochondria.

Participation of heart mitochondria in myocardial protection against ischemia/reperfusion injury: benefit effects of short-term adaptation processes

Acute streptozotocin diabetes mellitus (DM) as well as remote ischemic preconditioning (RPC) has shown a favorable effect on the postischemic-reperfusion function of the myocardium. Cardioprotective mechanisms offered by these experimental models involve the mitochondria with the changes in functional properties of membrane as the end-effector. The aim was to find out whether separate effects of RPC and DM would stimulate the mechanisms of cardioprotection to a maximal level or whether RPC and DM conditions would cooperate in stimulation of cardioprotection. Experiments were performed on male Wistar rats divided into groups: control, DM, RPC and DM treated by RPC (RPC+DM). RPC protocol of 3 cycles of 5-min hind limb ischemia followed by 5-min reperfusion was used. Ischemic-reperfusion injury was induced by 30-min ischemia followed by 40-min reperfusion of the hearts in Langendorff mode. Mitochondria were isolated by differential centrifugation, infarct size assessed by staining with 1 % 2,3,5-triphenyltetrazolium chloride, mitochondrial membrane fluidity with a fluorescent probe DPH, CoQ(9) and CoQ(10) with HPLC. Results revealed that RPC as well as DM decreased the infarct size and preserved mitochondrial function by increasing the mitochondrial membrane fluidity. Both used models separately offered a sufficient protection against ischemic-reperfusion injury without an additive effect of their combination.

Association of p53 and p21 polymorphisms with prostate cancer

Cell cycle deregulation is common in human cancer. Alterations of the tumor-suppressor gene p53 and its downstream effector p21 have been indicated in the development of numerous human malignancies. Therefore, we hypothesize that the p53 codon 72 polymorphism, either on its own or in combination with p21 (C98A and C70T) polymorphisms, modifies the risk of prostate cancer within the Slovak population, and no previous studies have investigated these gene-gene interactions in the pathogenesis of prostate cancer in the Slovak population. Polymerase chain reaction-restriction fragment length polymorphism was used to determine the p53 and p21 genotypes in subjects comprising 300 prostate cancer patients and 446 healthy individuals. These 3 polymorphisms individually did not correlate with the prostate cancer risk. Conversely, the interaction between the p53 and p21 polymorphisms significantly decreased the risk of prostate cancer, with the odds ratio (OR) being 0.49 [95% confidence interval (CI), 0.27-0.86; P<0.05] for subjects carrying the p53 codon 72 arginine (Arg)/proline (Pro)+Pro/Pro and p21 C98A CA genotypes compared to the combined reference genotypes p53 codon 72 Arg/Arg and p21 C98A CC. Neither the p53 genotypes nor the p21 genotypes showed statistically significant differences in Gleason score or serum prostate-specific antigen levels (P>0.05). A decreased risk of prostate cancer association with the p21 C98A CA genotype (OR=0.58; 95% CI, 0.36-0.93; P<0.05) in non-smokers compared to the non-smokers with the p21 C98A CC genotype was observed. Smokers carrying the p53 codon 72 Pro/Pro genotype were not at any significant risk of prostate cancer (OR=2.97; 95% CI, 0.51-17.15) compared to the non-smokers with the Arg/Arg genotype. Taken together, to the best of our knowledge this is the first study to show that a combination of the variant genotypes of p53 codon 72 and p21 C98A may modify the prostate cancer risk within the Slovak population.

An Effect of Oak-Wood Extract (Robuvit®) on Energy State of Healthy Adults-A Pilot Study

The purpose of our study was to examine the psychological benefits of the treatment with Robuvit® (Horphag Research Ltd.) – polyphenolic extract obtained from the wood of oak Quercus robur – on the healthy elderly individuals using energy subscale scores of the Activation – Deactivation Adjective Check List. Analysis was focused on the comparison of pre-post treatment effect of Robuvit on symptoms of fatigue. In the total group of volunteers, significant increase of average question scores was found in three of four subscales of feelings (energy, tiredness, and tension) after 4 weeks of Robuvit administration. Effects of extract were observed mainly after stratification of total group of volunteers according to the level of feeling at the pre-treatment questionnaire. Our results demonstrate positive effect of Robuvit on mental and energy level in healthy human without any unwanted side effects. © 2015 The Authors Phytotherapy Research Published by John Wiley & Sons Ltd.

[Relation between carbonic anhydrase IX serum level, hypoxia and radiation resistance of head and neck cancers]

BACKGROUND

Hypoxia of locally advanced head and neck cancers is one of the main causes of their radiation resistance that presents clinically as a persistence of residual tumor disease after radiation therapy. Therefore, detection of tumor hypoxia could be an important predictor of treatment efficacy. Carbonic anhydrase IX (CA IX) is a protein, coded by a homonymous gene, the expression of which increases in tumor tissues at hypoxic conditions. Hence, CA IX represents an endogenic marker of tumor hypoxia, identifiable in tumor tissues, and its soluble extracellular domain can also be detected in body fluids of the patient. The primary endpoint of this study was to explore whether a correlation exists between CA IX serum level and the residual tumor disease after therapy. The secondary endpoint was to find out how the serum concentration of CA IX changes during the course of fractionated radiation therapy.

MATERIALS AND METHODS

The presented prospective monocentric clinical study evaluated a population of 30 patients with locally advanced squamous cell head and neck cancers, treated by radiation therapy or concurrent chemo radiation therapy with a curative intent. The serum concentration of the soluble form of CA IX was examined from a venous blood sample, using sandwich enzyme linked immunosorbent assay (ELISA). The blood samples were obtained before the treatment initiation, in the middle of radiation therapy, at the time of finishing radiation therapy and six weeks after the treatment completion.

RESULTS

We found a substantial variability in the CA IX levels measured in the examined population, ranging 0- 1,696 pg/ ml. We found no significant changes in the mean value of CA IX concentration during the course of radiation therapy and after the treatment completion. In 11 patients (36.7%), the treatment resulted in complete remission of the disease. In these patients, lower average pretreatment levels of CA IX were noted when compared to patients with persistence of residual tumor disease (37.57 vs 77.47; p = 0.154).

CONCLUSION

The results indicate that serum level of CA IX in patients with locally advanced head and neck cancers does not change significantly during the course of fractionated radiation therapy. The relation between CA IX serum level and residual tumor disease after radiation therapy requires verification on a larger population of patients.

Variation in N-acetyltransferase 2 (NAT2), smoking and risk of prostate cancer in the Slovak population

N-acetyltransferase 2 (NAT2) is an enzyme involved in the biotransformation of xenobiotics, mainly aromatic and heterocyclic amines and hydrazines, all of which represent an important class of carcinogens found in tobacco smoke. Polymorphism in NAT2 gene is reported to be associated with susceptibility to various types of cancer. This study investigated the relationship between the NAT2 polymorphism and the risk of prostate cancer with reference to the link between cigarette smoking and the xenobiotic-metabolizing enzyme NAT2. Overall, 281 cases and 395 controls from Slovakia were studied using polymerase chain reaction-restriction fragment length polymorphism assay. We found no statistically significant association between NAT2 genotypes and prostate cancer risk (slow acetylation vs. rapid acetylation: OR 1.13; 95 % CI 0.83-1.55). We report here a statistically significant correlation between the NAT2*5C/NAT2*6A slow acetylator genotype and the risk for developing prostate cancer (OR 2.91; 95 % CI 1.43-5.94; p = 0.003) when compared with the rapid phenotype. Smokers with NAT2 rapid phenotype had a five percent (5 %) reduced risk of prostate cancer compared with non-smokers carrying the rapid acetylator genotype. The association was reversed among smokers and non-smokers with NAT2 slow phenotype. On the basis of the foregoing, we conclude that the NAT2 phenotypes whether alone or in association with smoking do not correlate with susceptibility to prostate cancer within the Slovak population.

Involvement of membrane fluidity in endogenous protective processes running on subcellular membrane systems of the rat heart

Membrane fluidity is a widely recognized biophysical variable that provides information about structural organization of the subcellular membranes exhibiting physical characteristics of liquid crystals. The term "fluidity" reflects in this case the tightness in packing of acyl parts of the membrane phospholipid molecules, a feature that may influence considerably the molecular mobility and via that also the sensitivity and reactivity of membrane-bound transporters, receptors and enzyme systems. Data presented in this review are aimed to demonstrate the substantial role of changes in membrane fluidity occurring in the processes associated with endogenous protection observed in cardiac sarcolemma and mitochondria in diverse pathologies, particularly in diabetes and hypertension.

Dual influence of spontaneous hypertension on membrane properties and ATP production in heart and kidney mitochondria in rat: effect of captopril and nifedipine, adaptation and dysadaptation

This study deals with changes, induced by hypertension and its treatment, in the function and properties of mitochondria in the heart and kidneys. Male, 16-week-old hypertensive rats were allocated to 3 groups: (i) animals treated daily for 4 weeks with captopril (CAP, 80 mg·(kg body mass)(-1), n = 45), (ii) animals treated with CAP + nifedipine (NIF, 10 mg·kg(-1), n = 45), or (iii) untreated hypertensive controls (n = 96). Wistar rats (n = 96) were used as normotensive controls. Systolic blood pressure (SBP), heart rate (HR), and heart mass / body mass (HW/BW) ratio were measured at the beginning and end of the experiments; measurements for mitochondrial Mg(2+)-ATPase activity, O(2)-consumption (QO(2)), respiratory control index (RCI), ADP/O, oxidative phosphorylation rate (OPR), conjugated diene content (CD), and membrane fluidity (MF) were also taken at different time intervals. In the heart, elevated SBP, HR, and HW/BW accompanied increased QO(2), OPR, and Mg(2+)-ATPase activity, indicating an adaptive response to hypertension-induced increase in the energy demands of the myocardium. Treatments with CAP or with CAP + NIF were very similar in their prevention of increase in SBP, HR, HW/BW, and the rise in OPR (all p < 0.05-0.01). In the kidneys, hypertension induced a drop in OPR; however, antihypertensive therapy aggravated the resulting energy deficiency, whereby treatment with CAP + NIF was more detrimental than treatment with CAP alone. Heart and kidney mitochondria exhibited negligible changes in CD and moderately increased MF, which was more potentiated by treatment with CAP alone than with CAP + NIF.

[Blood pressure changes in chronically haemodialysed patients]

BACKGROUND

Poor blood pressure control in chronically haemodialysed patients leads to increased cardiovascular morbidity and mortality. Information on valid values of blood pressure during haemodialysis and out of office is very important in order to set up adequate treatment.

AIM

To measure blood pressure during the haemodialysis and the subsequent 24-hour period using an ambulatory blood pressure monitoring (ABPM) in patients with normal blood pressure (BP) and patients with high normal BP and hypertension. Relationship between time-dependent blood pressure changes, ultrafiltration (UF) and interdialytic weight gain (IDWG) was analysed.

PATIENTS AND METHODS

Fifty chronically haemodialysed (> 3 months) patients (males/females 33/18) aged 57.5 (53-63; median, interquartile interval) years were studied. Systolic and diastolic pressures (SP, DP) were measured during haemodialysis every hour (H0-H4) and over following 24 hours using Spacelab 90217 monitor. Pulse pressure (PP) values were calculated as a difference between SP and DP. The patients were stratified into two groups based on the cut-off-point calculated as the mean of two mean arterial pressure (MAP) values obtained at the beginning and after the first hour of HD: Group A (n = 25), MAP < 100 mm Hg; Group B (n = 25), MAP 100 mm Hg. Interdialytic weight gain was measured before HD (IDWG1) and after the ABPM (IDWG2); also ultrafiltration (UF) was obtained. The post-dialysis 24-h ABPM period was divided into eight 3-hour intervals (M1-8).

RESULTS

During HD no significant change in SP, DP or PP was found in both group, but there was a significant difference (p = 0.01) between both groups in SP, DP and PP. Values of BP at the end of dialysis were in group A: SP 125 (120-130) mm Hg, DP 75 (60-80) mm Hg and PP 50 (40-60) mm Hg in group B: SP 150 (140-160) mm Hg, DP 80 (80-90) mm Hg a PP 60 (60-70) mm Hg. We did not find any influence of IDWG1 or IDWG2 on SP or DP in both groups. Relationship between UF 3 000 (2 500-4 300) ml and SP (Δ sTK -5 mm Hg) was confirmed only in group A (p = 0.04). In group A, we found a decrease in SP during the third and sixth 3-hour interval (p = 0.01; p = 0.02) including sleeping period, all compared to the end of HD (H4). In group B, such a decrease in SP was found only in the second sleep interval (p = 0.01) and in the sixth 3-hour interval (p = 0.03), all compared to the end of HD (H4). As to DP at the end of dialysis (H4) in group A, it differed only in the third 3-hour interval (p = 0.02), but not during the sleeping period. In group B, the decrease of DP compared to the end HD (H4) was recorded during the two sleep intervals (p = 0.01), and also in the sixth and seventh 3-hour intervals (p = 0.01; p = 0.03). In group A, PP was compared to the end of HD (PPH4) significantly decreased in the first 3-hour interval (p = 0.02) and in seventh and eight 3-hour interval (p = 0.03; p = 0.04). In group B, PP did not significant change from the end of HD. Difference in SP between both groups was maintained over the entire course of ABPM (p = 0.01). However, DP values in both groups were different in the first and third 3-hour intervals (p = 0.01) but in following intervals DP in group B decreased to the level of that in group A. There was no significant difference in the proportion of non-dippers and reverse dippers in both groups.

CONCLUSION

Systolic, diastolic, mean arterial and pulse pressure pressures were not significantly changed during the haemodialysis in both groups. Relationship between ultrafiltration and systolic pressure was confirmed only in group A. No influence of interdialytic weight gain on blood pressure during 24 hours was seen in either group. Systolic pressure decreased in both groups during the nighttime compared to post-HD values, but diastolic pressure decreased only in group B. PP did not decrease during the night in any group. There was no significant difference in the proportion of non-dippers and reverse dippers in both groups.

Healing process of venous ulcers: the role of microcirculation

In order to describe adequately the process of healing in the intermediate degrees, we investigated microcirculatory changes in the venous ulcers at well-defined stages of wound repair. We investigated dynamic changes in microcirculation during the healing process of venous ulcers. Ten venous ulcers were investigated in three consecutive clinical stages of wound healing: non granulation tissue (NGTA), GTA and scar. Subpapillary microcirculation was measured by laser Doppler perfusion (LDP) imaging and expressed using LDP values in arbitrary units. Nutritive perfusion by capillary microscopy and expressed as capillary density (CD) - the number of capillaries per square millimetre. Before the development of GTA the LDP was low (median 1·35; lower-upper quartiles 0·71-1·83) accompanied with zero CD in all but one patient who had a density of 1. With the first appearance of GTA in the same area, the LDP was improved (2·22; 1·12-2·33; P = 0·0024) when compared with NGTA, in combination with a significant increase in CD (1·75; 0-3; P = 0·0054). In scar, the LDP was similar to that in the NGTA (1·03; 0·77-1·83; P = 0·278), combined with the highest CD (5·75; 4·5-8) in comparison with the previous stages of the area (for both pairs, P < 0·0001). Venous ulcers are caused by poor nutritive and subpapillary perfusion. Subpapillary perfusion plays a major role in the formation of GTA. In a scar, the increased nutritive perfusion is sufficient to cover the blood supply and keep skin viable while subpapillary perfusion is low.

Liver mitochondrial respiratory function and coenzyme Q content in rats on a hypercholesterolemic diet treated with atorvastatin

Statins, inhibitors of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase, are effective drugs in the treatment of hypercholesterolemia, however, their undesirable actions are not fully known. We investigated the effects of atorvastatin on the oxidative phosphorylation and membrane fluidity in liver mitochondria, and also on the coenzyme Q (CoQ) content in the mitochondria, liver tissue, and plasma of rats on a standard (C) and hypercholesterolemic (HCh) diet. Atorvastatin was administered at either low (10 mg kg(-1)) or high dose (80 mg kg(-1)) for four weeks. The high dose of the drug decreased the concentrations of total cholesterol and triacylglycerols in the plasma and liver of rats on a HCh diet. Administration of atorvastatin was associated with decreased oxygen uptake (state 3), and oxidative phosphorylation rate in the mitochondria of both C and HCh rats. Further, the drug influenced mitochondrial membrane fluidity and dose-dependently reduced concentrations of oxidized and reduced forms of CoQ in the mitochondria. Our findings point to an association between in vivo administration of atorvastatin and impaired bioenergetics in the liver mitochondria of rats, regardless of diet, in conjunction with simultaneous depletion of oxidized and reduced CoQ forms from the mitochondria. This fact may play a significant role in the development of statin-induced hepatopathy.

Accurate normalization factor for wire myography of rat femoral artery

Wire myograph is a device for the in vitro investigation of both, active and passive properties of arteries. Arteries from a variety of animal species, pathological states, and vascular beds were investigated using this method. We focus on the normalization procedure which is aimed to standardize experimental settings and, in part, to simulate physiological conditions. During normalization, it is determined the internal circumference of a vessel stretched to a tension that corresponds to the transmural pressure of 100 mm Hg (IC100). Once it is determined, the internal circumference is traditionally set to (0.9 IC100). However, this constant 0.9, called also the normalization factor (NF), was experimentally determined for rat small mesenteric arteries only. Therefore, the aim of our work was to show the influence of different NFs on the passive tension and reactivity of both, rat femoral arteries (FA) and the first branches of superior mesenteric arteries (MA). We found out that the maximal active wall tension of the FA was achieved at the NF value of 1.1, and that of the MA at 0.9. Considering the values of the active wall tension we suggest that higher reactivity and better signal-to-noise ratio in FA can be achieved when the NF is set at least to 1.0.

Predictive validity of MRI in detecting and following cholesteatoma

High recurrence rate of the middle ear cholesteatoma requires regular postoperative follow-up. This study evaluated data from the patients investigated with DW MRI to ascertain (1) the strength of the technique in detecting primary, and residual recurrent cholesteatoma, and (2) its accuracy in differentiating cholesteatoma from postoperative tissue changes. The diagnostic accuracy of two different DW imaging (EPI and non-EPI) techniques was evaluated. The data have been collected prospectively from 33 consecutive patients with either primary cholesteatoma, or with suspicious symptoms for potential cholesteatoma recurrence. The findings from non-EPI (HASTE) DW MR and EPI DW MR images were blindly compared with those obtained during a primary or secondary surgery. Preoperative non-EPI (HASTE) DWI pointed to a cholesteatoma in 25 out of 33 patients. In this subgroup, cholesteatoma were confirmed also by the surgery. In five cases, the non-EPI (HASTE) DWI did not show a cholesteatoma in the temporal bone, which agreed with the surgical findings. Three misclassifications were made by non-EPI (HASTE) DWI, all in the subgroup of patients indicated for primary surgery. The resulting pooled sensitivity of non-EPI (HASTE) DW imaging for diagnosing cholesteatoma in our study amounted to 96.15% (95% confidence interval (CI) 80.36-99.9), specificity was 71.43% (95% CI 29.04-96.33). Positive predictive value was 92.59% (95% CI 75.71-99.09) and negative predictive value 83.33% (95% CI 35.88-99.58). In conclusion, we recommend the non-EPI (HASTE) DW MRI as a valid method for diagnosing cholesteatoma and follow-up after cholesteatoma surgery.

Biophysical investigation on left ventricular myocytes in rats with experimentally induced diabetes

Diabetes is a recognized risk factor of heart disease. The abnormalities related to a decreased heart performance probably arise at cellular and molecular levels already in the asymptomatic phase of diabetes. However, the early alterations initiating a sequence of events that culminates in the clinical signs have not been fully elucidated yet. This review deals with some biophysical methods applied to investigation of left ventricular myocytes in rats with streptozotocin diabetes, as well as our most important findings concerning diabetes-induced cell changes which cannot be captured by other techniques. The observed decrease in sarcolemmal membrane fluidity is causatively associated with increased glycation and glycoxidation. On the other hand, an increase in the mitochondrial membrane fluidity may be attributed to augmented energy transduction through the membranes. We reported for the first time concurrent measurements of membrane potential and dynamics, and respiratory chain activities in rat heart mitochondria, as well as calcium transients in the myocytes from diabetic hearts together with the assessed quantitative relationships among these variables. We were able to detect some significant alterations that may underlie myocyte dysfunction and subsequent remodeling of the heart. We suppose that not all these changes reflect mechanisms leading to pathology; some may represent adaptive and compensatory responses to diabetes.

Mitochondrial function in heart and kidney of spontaneously hypertensive rats: influence of captopril treatment

Effect of captopril treatment on capability of heart and kidney mitochondria to produce ATP was investigated in spontaneously hypertensive rats (SHR). Heart mitochondria from SHR responded to hypertension with tendency to compensate the elevated energy demands of cardiac cells by moderate increase in mitochondrial Mg2+-ATPase activity, membrane fluidity (MF) and in majority of functional parameters of the mitochondria (p>0.05). Significant increase exhibited only the oxygen consumption (QO2; p<0.01-0.001) and oxidative phosphorylation rate (OPR; p<0.003) with glutamate+malate (GLUT+MAL) as substrates. Lowering the blood pressure (p<0.02) captopril also eliminated the above compensatory response and impaired the oxidative ATP production by decreasing OPR (p<0.001). Kidney mitochondria of SHR experienced serious disarrangement in parameters of oxidative ATP production: increase in Mg2+-ATPase activity (p<0.05) but, also scattered QO2 values (p<0.03-0.01) leading to decrease in OPR and the ADP:O (p<0.05-0.01) values with both GLUT+MAL and succinate as substrates. Captopril treatment does not alleviated but even worsened the above alterations. Mg2+-ATPase became also decreased and the depression of ADP:O became aggravated (p<0.0001).

Calcium signaling-mediated endogenous protection of cell energetics in the acutely diabetic myocardium

In acute diabetic myocardium, calcium signals propagated by intracellular calcium transients participate in the protection of cell energetics via upregulating the formation of mitochondrial energy transition pores (ETP). Mechanisms coupling ETP formation with an increase in membrane fluidity and a decrease in transmembrane potential of the mitochondria are discussed. Our results indicate that the amplification of calcium transients in the diabetic heart is associated with an increase in their amplitude. Moreover, the signals transferred by calcium transients also regulated ETP formation in nondiabetic myocardium. Evidence for the indispensable role of calcium in the regulation of transition pore formation is provided whereby an exchange of cadmium for calcium ions led to a rapid and dramatic decrease in the amount of ETP. Another possible regulatory factor of the mitochondrial function may be radical-induced damage to the diabetic heart. Nevertheless, our data indicate that radical-induced changes in mitochondria predominantly concern the respiratory chain and have no appreciable effect on the fluidity of the mitochondrial membranes. The residual mitochondrial production of ATP owing to its augmented transfer to the cytosol proved to be adequate to preserve sufficient levels of adenine nucleotides in the acute diabetic myocardium.

[Characteristics of foot ulcers in diabetic patients]

INTRODUCTION

Diabetic foot syndrome is often presented as a skin lesion in diabetics. The aim of our study was to analyse foot ulcerations in diabetics, together with ethiopatogenesis, location and grade of impairment.

METHODS

We analysed foot ulcerations in 124 diabetics who attended outpatient foot clinic, or were hospitalized in the period from 1996 to 2006. Basic neuropathy screening examination was made with cotton wisp, pin-prick, tuning fork, and monofilament. Beside the evaluation of the presence of pedal pulses, the ankle-brachial pressure index was measured. If the infection of foot ulceration was present, bacteriology examinations was performed. Wagner and University of Texas classifications of foot ulcerations were applied, moreover, location of ulcerations was analysed.

RESULTS

Neuropathic ulcer was diagnosed in 46 patients of the total number of 124 (37%), neuroischemic in 76 patients (61%) and pure ischemic ulcer only in 2 patients (2%). Neuropathy was present in 122 (98%) patients with diabetic foot, limb ischemia in 78 patients (63%). Fifty four per cent of foot ulcers were located on toes and 43% ulcers on plantar surface. Foot ulcer infection was detected in 72 patients (58%). We found 48 superficial ulcers (38.7%) and 76 deep ulcers (61.3%). In diabetics without foot ischemia and infection 39% deep ulcers were present whereas in the group with ischemia and infection the proportion amounted to 80% (p < 0.05).

CONCLUSION

Diabetic foot syndrom was present more often in type-2 diabetics with longer disease duration, in those on insulin treatment, in men of older age, further in the diabetics with pure glycemic control and/or with chronic microvascular diabetic complications.

Polymorphisms of glutathione-S-transferase M1, T1, P1 and the risk of prostate cancer: a case-control study

Background

It has been suggested that polymorphisms in glutathione-S-transferases (GST) could predispose to prostate cancer through a heritable deficiency in detoxification pathways for environmental carcinogens. Yet, studies linking GST polymorphism and prostate cancer have so far failed to unambiguously establish this relation in patients. A retrospective study on healthy, unrelated subjects was conducted in order to estimate the population GST genotype frequencies in the Slovak population of men and compare our results with already published data (GSEC project-Genetic Susceptibility to Environmental Carcinogens). A further aim of the study was to evaluate polymorphisms in GST also in patients with prostate cancer in order to compare the evaluated proportions with those found in the control subjects.

Methods

We determined the GST genotypes in 228 healthy, unrelated subjects who attended regular prostate cancer screening between May 2005 and June 2007 and in 129 histologically verified prostate cancer patients. Analysis for the GST gene polymorphisms was performed by PCR and PCR-RFLP.

Results

We found that the GST frequencies are not significantly different from those estimated in a European multicentre study or from the results published by another group in Slovakia. Our results suggest that Val/Val genotype of GSTP1 gene could modulate the risk of prostate cancer, even if this association did not reach statistical significance. We did not observe significantly different crude rates of the GSTM1 and GSTT1 null genotypes in the men diagnosed with prostate cancer and those in the control group.

Conclusion

Understanding the contribution of GST gene polymorphisms and their interactions with other relevant factors may improve screening diagnostic assays for prostate cancer. We therefore discuss issues of study feasibility, study design, and statistical power, which should be taken into account in planning further trials.

Does rooibos tea (Aspalathus linearis) support regeneration of rat liver after intoxication by carbon tetrachloride?

This study evaluates the effect of rooibos tea (RT, Aspalathus linearis) on biochemical and histological parameters during rat liver regeneration after intoxication by carbon tetrachloride (CCl4). From the 10th week, when the administration of CCl4 was terminated, the liver tissue began to regenerate. Seven days later in the regeneration phase, the animals treated by RT during whole period of the experiment, and those which drunk RT only during the regeneration period, exhibited a trend for decrease in the activity of alanine aminotransferase and significant decrease in the activity of aspartate aminotransferase and in total bilirubin content when compared with the water-drinking group. At the same time, the concentration of plasma albumin was elevated and that of tissue malondialdehyde decreased in the both groups drinking RT. After 42 days of regeneration, all biochemical parameters in all three groups reached the level of control healthy animals. In both groups treated with RT, the extent of fibrotic tissue was lower than in the group which received water. We conclude that RT can be recommended not only for the prevention but also as a co-adjuvant for the therapy of liver diseases.

Endogenous protective mechanisms in remodeling of rat heart mitochondrial membranes in the acute phase of streptozotocin-induced diabetes

The aim of present study was to investigate functional and physical alterations in membranes of heart mitochondria that are associated with remodeling of these organelles in acute phase of streptozotocin-induced diabetes and to elucidate the role of these changes in adaptation of the heart to acute streptozotocin-induced diabetes (evaluated 8 days after single dose streptozotocin application to male Wistar rats). Action of free radicals on the respiratory chain of diabetic-heart mitochondria was manifested by 17 % increase (p<0.05) in oxidized form of the coenzyme Q(10) and resulted in a decrease of states S3 and S4 respiration, the respiratory control index, rate of phosphorylation (all p<0.01) and the mitochondrial transmembrane potential (p<0.05), but the ADP/O ratio decreased only moderately (p>0.05). On the contrary, membrane fluidity and the total mitochondrial Mg2+-ATPase activity increased (both p<0.05). In diabetic heart mitochondria, linear regression analysis revealed a reciprocal relationship between the increase in membrane fluidity and decrease in trans-membrane potential (p<0.05, r = 0.67). Changes in membrane fluidity, transmembrane potential, Mg2+-ATPase activity and the almost preserved ADP/O ratio appear as the manifestation of endogenous protective mechanisms participating in the functional remodeling of mitochondria which contributes to adaptation of the heart to diabetes.

Seasonal variations in properties of healthy and diabetic rat heart mitochondria: Mg2+-ATPase activity, content of conjugated dienes and membrane fluidity

Our previous preliminary results pointed to possible seasonal variations in Mg2+-ATPase activity of rat heart mitochondria (MIT). It is not too surprising since seasonal differences were already reported in myocardial function, metabolism and ultrastructure of the intact as well as hemodynamically overloaded rabbit hearts and also in other tissues. The present study is aimed to elucidate whether seasonal differences observed in rat heart MIT Mg2+-ATPase activity will be accompanied with changes in membrane fluidity and in the content of conjugated dienes (CD) in the lipid bilayers of MIT membranes as well as whether the above seasonal differences will also be present in the diabetic heart. Our results revealed that values of Mg2+-ATPase activity in the winter/spring-period (W/S-P) exceeded significantly (p<0.05-0.001) those in the summer/autumn-period (S/A-P). Similar trend was also observed in hearts of animals with acute (8 days) streptozotocin diabetes. With the exception of values of CD in the S/A-P, all values of Mg2+-ATPase activities, membrane fluidity and CD concentrations in diabetic hearts exceeded those observed in the healthy hearts. Our results indicate that seasonal differences may play a decisive role in the evaluation of properties and function of rat heart MIT.

In vitro evaluation of the cytotoxicity and genotoxicity of resorcylidene aminoguanidine in human diploid cells B-HNF-1

RAG belongs to appropriate inhibitors of protein glycation, i.e. formation of advanced glycation end products, which are thought to be responsible for some complications of DM, including neuropathy, angiopathy, retinopathy and nephropathy. In the present study authors have evaluated the genotoxic effect of RAG on the cell culture of human neonatal fibroblasts (B-HNF-1) in regard to its potential clinical application as inhibitor of advanced glycation end products in relationships to the pathogenesis of chronic diabetic complications. The direct contact cytotoxicity assay and micronucleus test were performed. The results showed that RAG in the concentration range of 1 x 10-4 to 1 x 10-6 mol.l-1 did not induce any changes in the morphology of exposed B-HNF-1 cells. The frequency of micronuclei was not significantly increased as well. The inhibitive effect of resorcylidene aminoguanidine was directly proportional to its concentration. It can be concluded that RAG at the selected concentrations has an inhibitive effect on proliferation of the treated cells and, at the same time, does not display any genotoxic effects on B-HNF-1 cells.

Activity of paraoxonase 1 and lipid profile in healthy children

Paraoxonase 1 (PON1) seems to have a relevant role in detoxifying processes and in atherosclerosis. The aim of this study was to determine PON1 activity, the total antioxidant capacity, as well as entire lipid profile in children for screening of possible risk of atherosclerosis development. Serum PON1 arylesterase/paraoxonase activities were determined spectrophotometrically. The total antioxidant capacity of the serum was measured by TEAC method. Parameters of lipid profile were analyzed by routine laboratory methods. It has been shown that PON1 arylesterase/ paraoxonase activities were very similar to values found in adults. In children, no significant correlation between PON1 arylesterase activity and HDL was observed. PON1 paraoxonase activity correlated only with atherogenic index. PON1 arylesterase activity was significantly higher in girls than in boys. The antioxidant capacity was inversely related to the body mass index. In this study, PON1 activity was determined in healthy children aged 11 to 12 years and we found a similarity in PON1 activities of children and adults. Moreover, the results of our study support the hypothesis that higher body weight of children may contribute to a greater risk for development of atherosclerosis in which oxidative stress plays a role.

Functional remodeling of heart mitochondria in acute diabetes: interrelationships between damage, endogenous protection and adaptation

Rats with streptozotocin-diabetes develop mechanisms of endogenous protection (MEP) that participate actively in functional remodeling of cardiac sarcolemma. Remodeling of sarcolemma is a sign of damage but it also protects the cells of the diabetic heart (DH) against additional energy disbalance due to excessive Ca(2+) entry. Since yet, cardiac mitochondria (MIT) were investigated predominantly from the aspect of damage only. Aims of the present study were: i) to distinguish between acute diabetes-induced changes in function of rat heart MIT which clearly belong to damage from those that reflect the MEP and participate in functional remodeling of the MIT; ii) elucidate the significance of MEP-induced changes in heart MIT for cardiac energetics. Acute diabetes (8 days) was induced in adult male Wistar rats by streptozotocin (STZ, 65 mg.kg(-1) i.p., single dose). On the day 8 after STZ administration, the diabetic animals exhibited 300-330 % increase in blood glucose, triacylglycerols and cholesterol as well as 89.6 % increase in glycohemoglobin (all p < 0.01). The blood level of insulin dropped by 53 % (p < 0.02). State 3 and state 4 oxygen consumptions of DH MIT were decreased against the controls, leading to drop of the respiratory control index (17.9 and 7.3 %) and oxidative phosphorylation rate (OPR, 27.5 and 24.6 %; all p < 0.003-0.02). These effects of damage yielding in strained energy balance of the acute DH were partially alleviated by MEP. The latter involved temporary preservation of the ADP : O ratio, with participation of elevated MIT Mg(2+)-ATPase activity as well as increased formation of MIT substrate and energy transition pores (both p < 0.05). Hence, the energy disbalance of the acute DH was finally manifested in 13 % loss in its AMP content only (p < 0.05). Results indicate that MIT in STZ-DH are functionally remodeled. Defective O2 consumption by MIT renders molecular changes suggestive of a mild hypoxic state but an increase in Mg(2+)-ATPase activity and facilitated energy delivery from MIT to the cytoplasm indicate the presence of MEP acting in the MIT and alleviating the effect of decreased oxidative energy production in the acute DH.

Effect of polyphenolic extract, Pycnogenol, on the level of 8-oxoguanine in children suffering from attention deficit/hyperactivity disorder

The purpose of this randomized, double-blind and placebo controlled study was to test the effect of polyphenolic extract of pine bark Pycnogenol (Pyc) on the level of oxidized purines represented by 8-oxo-7,8-dihydroguanine (8-oxoG) and on the total antioxidant status (TAS) in children with attention deficit/hyperactivity disorder (ADHD).We have found significantly increased damage to DNA in ADHD children when compared to controls. 8-oxoG was significantly lower after 1 month of Pyc administration in comparison to the beginning state and to placebo group. TAS in ADHD children was lower in comparison to controls. After Pyc administration, TAS was elevated but statistically significant increase was recorded after 1 month of termination of Pyc application. Improvement of DNA damage and TAS after Pyc administration is associated with the improvement of attention in ADHD children. In conclusion, Pycnogenol(R) administration reduces oxidative damage to DNA, normalizes TAS and improves attention of ADHD children. Explanation of mutual relation between oxidative damage to DNA, TAS and symptoms of ADHD and mechanism of Pyc's action needs further investigations.

Activity of paraoxonase 1 (PON1) and its relationship to markers of lipoprotein oxidation in healthy Slovaks

Low-density lipoproteins (LDLs), when modified by free radicals derived from artery wall cells, induce atherosclerosis. In contrast to oxidized LDL (ox-LDL), high-density lipoproteins (HDLs) are able to prevent atherosclerosis through a protein with antioxidant properties, paraoxonase 1 (PON1). The purpose of this study was to explore the association between the activity of HDL-associated PON1 and circulating ox-LDL as well as to investigate the relationship between ox-LDL and parameters of lipid profile in thirty Slovaks aged 21-73 years because recent studies have presented controversial results concerning PON1 and its role in LDL oxidation. For determination of circulating ox-LDL sandwich ELISA was used and other lipid parameters were determined by routine laboratory analyses. PON1 activities were assayed by two synthetic substrates - paraoxon and phenyl acetate. Lipid peroxides were determined spectrophotometrically. Of the lipid parameters examined, ox-LDL level correlated positively with total (P < 0.0001) and LDL-cholesterol (P < 0.001). Triacylglycerols (TAG) (P < 0.001), lipid peroxides (P < 0.01) and atherogenic index (AI = total cholesterol/HDL) (P < 0.0001) were also strongly correlated with ox-LDL. No inverse relationships were observed between ox-LDL and HDL-cholesterol or arylesterase/paraoxonase activities of PON1. Furthermore, it was found that ox-LDL (P < 0.01) and lipid peroxides (P < 0.05) were significantly higher in men than in women. PON1 arylesterase activity was marginally affected by sex. The results of this study suggest that the anti-atherogenic properties of HDLs are not directly related to their total concentration and that PON1 activity determined towards synthetic compounds (paraoxon and phenyl acetate) reflects no association with markers of oxidative stress. Furthermore, it follows from our results that men are more susceptible to developing atherosclerosis compared to women.

High glucose contributes to aspirin insensitivity in streptozotocin-diabetic rats: a multiparametric aggregation study

The effect of chronic hyperglycaemia on blood platelet response to acetylsalicylic acid was studied in rats with experimental diabetes. Platelet aggregation was determined in non-diabetic and streptozotocin-diabetic rats treated orally with 4 or 40 mg aspirin (ASA)/kg per day (for 8 weeks from the eighth day of diabetes) using whole blood impedance aggregometry with arachidonic acid or ADP as platelet agonists. The dose-dependent effect of ASA 'therapy' on ADP-agonized platelets was significant only in non-diabetic animals, while in diabetic rats both doses were ineffective in reducing ADP-stimulated platelet aggregation. ASA-mediated increased acetylation of platelet proteins favoured reduced platelet aggregation and slower platelet disaggregation (Pr < 0.025 or less). Interestingly, however, the occupation of platelet protein-free amino groups was significantly higher in control rats compared with diabetic rats (P < 0.001), pointing out that proteins of platelets in non-diabetic animals were more vulnerable for the ASA-induced acetylation. We conclude that chronic hyperglycaemia interferes with preventive effects of ASA on platelet reactivity. Our data validate the suggestion that the relationship between aspirin ineffectiveness and poor metabolic control, first revealed in humans, concerns also other animals' platelets and holds regardless of the model or type of diabetes.

Activity of paraoxonase 1 (PON1) and its relationship to markers of lipoprotein oxidation in healthy Slovaks

Low-density lipoproteins (LDLs), when modified by free radicals derived from artery wall cells, induce atherosclerosis. In contrast to oxidized LDL (ox-LDL), high-density lipoproteins (HDLs) are able to prevent atherosclerosis through a protein with antioxidant properties, paraoxonase 1 (PON1). The purpose of this study was to explore the association between the activity of HDL-associated PON1 and circulating ox-LDL as well as to investigate the relationship between ox-LDL and parameters of lipid profile in thirty Slovaks aged 21-73 years because recent studies have presented controversial results concerning PON1 and its role in LDL oxidation. For determination of circulating ox-LDL sandwich ELISA was used and other lipid parameters were determined by routine laboratory analyses. PON1 activities were assayed by two synthetic substrates - paraoxon and phenyl acetate. Lipid peroxides were determined spectrophotometrically. Of the lipid parameters examined, ox-LDL level correlated positively with total (P < 0.0001) and LDL-cholesterol (P < 0.001). Triacylglycerols (TAG) (P < 0.001), lipid peroxides (P < 0.01) and atherogenic index (AI = total cholesterol/HDL) (P < 0.0001) were also strongly correlated with ox-LDL. No inverse relationships were observed between ox-LDL and HDL-cholesterol or arylesterase/paraoxonase activities of PON1. Furthermore, it was found that ox-LDL (P < 0.01) and lipid peroxides (P < 0.05) were significantly higher in men than in women. PON1 arylesterase activity was marginally affected by sex. The results of this study suggest that the anti-atherogenic properties of HDLs are not directly related to their total concentration and that PON1 activity determined towards synthetic compounds (paraoxon and phenyl acetate) reflects no association with markers of oxidative stress. Furthermore, it follows from our results that men are more susceptible to developing atherosclerosis compared to women.

Increased blood plasma hydrolysis of acetylsalicylic acid in type 2 diabetic patients: a role of plasma esterases

Hydrolysis of acetylsalicylic acid (ASA, aspirin), an antiplatelet drug commonly used in the prevention of stroke and myocardial infarction, seems to play a crucial role in its pharmacological action. Thirty-eight healthy volunteers and 38 type 2 diabetic patients were enrolled to test the hypothesis that the enhanced plasma degradation and lowered bioavailability of ASA in diabetic patients is associated with the attenuation of platelet response. Aspirin esterase activities were tested at pH 7.4 and 5.5. A significantly higher overall aspirin esterase activity was noted at pH 7.4 in the diabetic patients (P<0.003), corresponding to faster ASA hydrolysis (P<0.006). This increased activity was attributable to butyrylcholinesterase and probably to albumin, because it was effectively inhibited by eserine and 4-bis-nitrophenyl phosphate (P<0.01). No significant differences between control and diabetic subjects were found at pH 5.5 in either enzymatic activities or ASA hydrolysis rates. The enhanced plasma ASA degradation in diabetic subjects was significantly associated with the refractoriness of blood platelets to ASA (P<0.05) and modulated by plasma cholesterol (P<0.01). No direct effects of plasma pH or albumin were observed. In conclusion, higher aspirin esterase activity contributes to the lowered response of diabetic platelets to ASA-mediated antiplatelet therapy.

The effect of Pycnogenol on the erythrocyte membrane fluidity

In the present study, the in vitro effect of polyphenol rich plant extract, flavonoid--Pycnogenol (Pyc), on erythrocyte membrane fluidity was studied. Membrane fluidity was determined using 1-[4-trimethyl-aminophenyl]-6-phenyl-1,3,5-hexatriene (TMA-DPH), 1,6-diphenyl-1,3,5-hexatriene (DPH) and 12-(9-anthroyloxy) stearic acid (12-AS) fluorescence anisotropy. After Pyc action (50 microg/ml to 300 microg/ml), we observed decreases in the anisotropy values of TMA-DPH and DPH in a dose-dependent manner compared with the untreated erythrocyte membranes. Pyc significantly increased the membrane fluidity predominantly at the membrane surface. Further, we observed the protective effect of Pyc against lipid peroxidation, TBARP generation and oxidative hemolysis induced by H2O2. Pyc can reduce the lipid peroxidation and oxidative hemolysis either by quenching free radicals or by chelating metal ions, or by both. The exact mechanism(s) of the positive effect of Pyc is not known. We assume that Pyc efficacy to modify effectively some membrane dependent processes is related not only to the chemical action of Pyc but also to its ability to interact directly with cell membranes and/or penetrate the membrane thus inducing modification of the lipid bilayer and lipid-protein interactions.

Remodelling of the sarcolemma in diabetic rat hearts: the role of membrane fluidity

The hyperglycaemia and oxidative stress, that occur in diabetes mellitus, cause impairment of membrane functions in cardiomyocytes. Also reduced sensitivity to Ca-overload was reported in diabetic hearts (D). This enhanced calcium resistance is based on remodelling of the sarcolemmal membranes (SL) with down-regulated, but from the point of view of kinetics relatively well preserved Na,K-ATPase and abnormal Mg- and Ca-ATPase (Mg/Ca-ATPase) activities. It was hypothesised that in these changes may also participate the non-enzymatic glycation of proteins (NEG) and the related free radical formation (FRF), that decrease the membrane fluidity (SLMF), which is in reversal relationship to the fluorescence anisotropy (D 0.235 +/- 0.022; controls (C) 0.185 +/- 0.009; p < 0.001). In order to check the true role of SLMF in hearts of the diabetic rats (streptozotocin, single dose, 45 mg/kg i.v.) animals were treated in a special regimen with resorcylidene aminoguanidine (RAG 4 mg/kg i.m.). The treatment with RAG eliminated completely the diabetes-induced decrease in the SLMF (C 0.185 +/- 0.009; D + RAG 0.167 +/- 0.013; p < 0.001) as well as in NEG (fructosamine microg x mg(-1) of protein: C 2.68 +/- 0.14; D 4.48 +/- 0.85; D + RAG 2.57 +/- 0.14; p < 0.001), and FRF in the SL (malondialdehyde: C 5.3 +/- 0.3; D 8.63 +/- 0.2; D + RAG 5.61 +/- 0.53 micromol x g(-1); p < 0.05). Nevertheless, the SL ATPase activity in diabetic animals was not considerably influenced by RAG (increase in D + RAG vs. D 3.3%, p > 0.05). On the other hand, RAG increased considerably the vulnerability of the diabetic heart to overload with external Ca2+ (C 100% of hearts failed, D 83.3%, D + RAG 46.7% of hearts survived). So we may conclude, that: (i) The NEG and FRF caused alterations in SLMF, that accompanied the diabetes-induced remodelling of SL, also seem to participate in the protection of diabetic heart against Ca2+-overload; (ii) Although, the changes in SLMF were shown to influence considerably the ATPase activities in cells of diverse tissues, they seem to be little responsible for changes in ATPases-mediated processes in the SL of chronic diabetic hearts.