High dietary salt intake attenuates nitric oxide mediated endothelium-dependent vasodilation and increases oxidative stress in pregnancy

OBJECTIVE

This study aimed to investigate the impact of dietary salt intake during normal pregnancy on maternal microvascular and macrovascular endothelium-dependent reactivity and oxidative stress level.

MATERIALS AND METHODS

In this cross-sectional study, based on their 24-h urinary sodium excretion, pregnant women (37-40 weeks of gestation) were divided into three groups: normal salt (<5.75 g/day, N  = 12), high salt (5.75-10.25 g/day, N  = 36), and very high salt (VHS;>10.25 g/day, N  = 17). Forearm skin microvascular reactivity in response to vascular occlusion, local heating (LTH) and iontophoresis of acetylcholine (AChID), as well as brachial artery flow mediated dilation (FMD) were measured. Serum nitric oxide, endocan, 8-iso-prostaglandin F2α (8-iso-PGF2α), thiobarbituric acid reactive substances (TBARS), and ferric-reducing ability of plasma assay were measured as biomarkers of endothelial function/activation and oxidative stress.

RESULTS

Brachial artery FMD, microvascular AChID, and LTH were significantly decreased in VHS compared with NS group, while LTH was also decreased in normal salt compared with high salt group. Nitric oxide was significantly decreased in both high salt and VHS groups compared with normal salt. Endocan, 8-iso-PGF2α, and TBARS were significantly increased in VHS compared with the normal salt group.

CONCLUSION

High dietary salt intake is associated with decreased nitric oxide mediated endothelium-dependent vasodilation in peripheral microcirculation and macrocirculation of healthy pregnant women due to increased oxidative stress.

Early Low-Grade Inflammation Induced by High-Salt Diet in Sprague Dawley Rats Involves Th17/Treg Axis Dysregulation, Vascular Wall Remodeling, and a Shift in the Fatty Acid Profile

BACKGROUND/AIMS

Unrestricted increased table salt (NaCl) intake is associated with oxidative stress and inflammation, leading to endothelial dysfunction and atherosclerosis. However, data on salt-induced immunomodulatory effects in the earliest phase of salt loading are scarce.

METHODS

In the present study, an animal model of short-term salt loading was employed, including male Sprague Dawley rats consuming a high-salt diet (HSD; 4% NaCl) or standard laboratory chow (low-salt; LSD; 0.4% NaCl) during a 7-day period. The contribution of angiotensin II (ANGII) suppression was tested by adding a group of rats on a high-salt diet receiving ANGII infusions. Samples of peripheral blood/mesenteric lymph node leukocytes, brain blood vessels, and serum samples were processed for flow cytometry, quantitative real-time PCR, total proteome analysis, and multiplex immunoassay.

RESULTS

Data analysis revealed the up-regulation of Il 6 gene in the microcirculation of high-salt-fed rats, accompanied by an increased serum level of TNF-alpha cytokine. The high-salt diet resulted in increased proportion of serum mono-unsaturated fatty acids and saturated fatty acids, reduced levels of linoleic (C18:2 ω-6) and α-linolenic (C18:3 ω-3) acid, and increased levels of palmitoleic acid (C16:1 ω-7). The high-salt diet had distinct, lymphoid compartment-specific effects on leukocyte subpopulations, which could be attributed to the increased expression of salt-sensitive SGK-1 kinase. Complete proteome analysis revealed high-salt-diet-induced vascular tissue remodeling and perturbations in energy metabolism. Interestingly, many of the observed effects were reversed by ANGII supplementation.

CONCLUSION

Low-grade systemic inflammation induced by a HSD could be related to suppressed ANGII levels. The effects of HSD involved changes in Th17 and Treg cell distribution, vascular wall remodeling, and a shift in lipid and arachidonic acid metabolism.

Enhanced Microvascular Adaptation to Acute Physical Stress and Reduced Oxidative Stress in Male Athletes Who Consumed Chicken Eggs Enriched with n-3 Polyunsaturated Fatty Acids and Antioxidants-Randomized Clinical Trial

This randomized interventional study aimed to determine the effects of n-3 polyunsaturated fatty acids, selenium, vitamin E, and lutein supplementation in the form of enriched chicken egg consumption on microvascular endothelium-dependent vasodilation, oxidative stress, and microvascular response to an acute strenuous training session (ASTS) in competitive athletes. Thirty-one male athletes were assigned to a control (n = 17) or a Nutri4 group (n = 14) who consumed three regular or enriched chicken eggs per day, respectively, for 3 weeks. Significantly enhanced endothelium-dependent responses to vascular occlusion (PORH) and iontophoresis of acetylcholine (AChID) were observed in the Nutri4 group but not in the control group after egg consumption. Formation of peroxynitrite and hydrogen peroxide in peripheral blood mononuclear cells, as well as serum concentration of 8-iso prostaglandin F2α, decreased in the Nutri4 group while remaining unchanged in controls. PORH and AChID were reduced post-ASTS compared with pre-ASTS, both before and after the diets, in both groups. However, the range of PORH responsiveness to ASTS (ΔPORH) increased after consumption of enriched eggs. These results suggest that consumption of enriched chicken eggs has a beneficial effect on microvascular endothelium-dependent vasodilation and the reduction of oxidative stress levels in competitive athletes. Also, microvascular adaptation to the ASTS was improved after consumption of Nutri4 eggs.

Tff3-/- Knock-Out Mice with Altered Lipid Metabolism Exhibit a Lower Level of Inflammation following the Dietary Intake of Sodium Chloride for One Week

A high salt intake causes hemodynamic changes and promotes immune response through cell activation and cytokine production, leading to pro-inflammatory conditions. Transgenic Tff3^-/- knock-out mice (TFF3ko) (n = 20) and wild-type mice (WT) (n = 20) were each divided into the (1) low-salt (LS) group and (2) high-salt (HS) group. Ten-week-old animals were fed with standard rodent chow (0.4% NaCl) (LS) or food containing 4% NaCl (HS) for one week (7 days). Inflammatory parameters from the sera were measured by Luminex assay. The integrin expression and rates of T cell subsets of interest from the peripheral blood leukocytes (PBLs) and mesenteric lymph nodes (MLNs) were measured using flow cytometry. There was a significant increase in high-sensitivity C reactive protein (hsCRP) only in the WT mice following the HS diet, while there were no significant changes in the serum levels of IFN-γ, TNF-α, IL-2, IL-4, or IL-6 as a response to treatment in either study groups. The rates of CD4⁺CD25⁺ T cells from MLNs decreased, while CD3⁺γδTCR⁺ from peripheral blood increased following the HS diet only in TFF3ko. γδTCR expressing T cell rates decreased in WT following the HS diet. The CD49d/VLA-4 expression decreased in the peripheral blood leukocytes in both groups following the HS diet. CD11a/LFA-1 expression significantly increased only in the peripheral blood Ly6C^-CD11a^high monocytes in WT mice following salt loading. In conclusion, salt-loading in knock-out mice caused a lower level of inflammatory response compared with their control WT mice due to gene depletion.

Consumption of Nutritionally Enriched Hen Eggs Enhances Endothelium-Dependent Vasodilation via Cyclooxygenase Metabolites in Healthy Young People-A Randomized Study

OBJECTIVE

The present study aimed to evaluate the effects of enriched hen egg consumption on endothelium-dependent vasodilation (EDV) and the role of cyclooxygenases in EDV in the microcirculation of young healthy individuals. This study hypothesizes that Nutri4 eggs will improve endothelial function, which will be manifested by changes in microcirculatory flow measured by a laser Doppler flowmeter (LDF) during reactive hyperemia in response to vascular occlusion, in which n-3 PUFA plays an important role as well as its degradation pathway by cyclooxygenases.

MATERIALS AND METHODS

Participants consumed three eggs per day for three weeks: The control group (CTRL, n = 14) consumed regular hen eggs (approximately 0.330 mg of lutein, 1.785 mg of vitamin E, 0.054 mg of selenium and 438 mg of n-3 PUFAs daily) and Nutri4 group (n = 20) consumed enriched eggs (approximately 1.85 mg of lutein, 0.06 mg of selenium, 3.29 mg of vitamin E, and 1026 mg of n-3 PUFAs daily). Skin microvascular blood flow in response to EDV (post-occlusive reactive hyperemia (PORH) and iontophoresis of acetylcholine (AChID)) and sodium nitroprusside (SNPID; endothelium-independent) was assessed by laser Doppler flowmetry before and after dietary protocol and in a separate group of participants who were administered perorally 100 mg of indomethacin before microvascular response assessment. Arterial blood pressure, heart rate, serum lipid, and liver enzymes, anthropometric measurements, protein expression of cyclooxygenase 1 (COX-1), cyclooxygenase 2 (COX-2), neuronal nitric oxide synthases (nNOS), inducible nitric oxide synthases (iNOS), and endothelial nitric oxide synthases (eNOS) were measured before and after dietary protocol.

RESULTS

PORH and AChID were significantly enhanced, and SNPID remained unchanged in the Nutri4 group, while none was changed in the CTRL following a respective diet. PORH decreased after administration of indomethacin in Nutri4 after dietary protocol. Protein expression of COX-2 was significantly higher in the Nutri4 group compared to the CTRL after the dietary protocol.

CONCLUSION

Consumption of enriched eggs improves microvascular EDV in healthy young subjects. Results suggest an element of n-3 PUFAs metabolites via the cyclooxygenases pathway in enhanced reactive hyperemia.

Estimation of Salt Intake in Normotensive and Hypertensive Children: The Role of Body Weight

OBJECTIVE

The connection between increased dietary salt intake and arterial hypertension has been recognized for a long time, even in children. This study aimed to investigate salt consumption in normotensive and hypertensive children and evaluate their dietary habits.

MATERIALS AND METHODS

A total of fifty participants were included in this cross-sectional study: twenty-five normotensive children and 25 children of both sexes with essential arterial hypertension from 12-17 years old. Subjects' body mass index, waist-to-hip ratio, body composition and arterial blood pressure were measured, and their daily salt intake was calculated from 24-h urine samples. Using the food frequency questionnaire (FFQ), the data on the average daily total energy and food intakes were collected and analyzed using a suitable program.

RESULTS

Estimated daily salt intake was significantly higher in hypertensive compared to normotensive children, and this is positively associated with blood pressure and body mass index (BMI). Hypertensive children had significantly higher BMIs, which also positively correlated with blood pressure. Consistently, resting metabolic rate (kcal) is higher in hypertensive children compared to normotensive, and this is also associated with blood pressure. Reported energy intake is also enlarged in hypertensive compared to normotensive children and for both groups, levels are significantly higher than the recommended values.

CONCLUSIONS

Our study results confirm the relationship between daily salt consumption, blood pressure and body weight. Sodium consumption related to blood pressure and body weight among children. Cardiovascular disease prevention should start in early childhood by reducing salt intake and preventing overweight/obesity since these are two of the most important modifiable risk factors for hypertension.

Consumption of Hen Eggs Enriched with n-3 Polyunsaturated Fatty Acids, Selenium, Vitamin E and Lutein Incites Anti-Inflammatory Conditions in Young, Healthy Participants - A Randomized Study

BACKGROUND

Dietary supplementation with compounds that possess antioxidant and anti-inflammatory properties (n-3 polyunsaturated fatty acids (PUFAs), selenium, vitamin E, lutein), has been shown to positively correlate with improvements in chronic conditions, although understanding of these combined effects in healthy humans is limited. The study aimed to evaluate the effects of enriched eggs consumption on oxidative status and inflammatory conditions in healthy volunteers. We hypothesized that a three-week diet containing enriched eggs can alter the immune response of healthy adults towards anti-inflammatory conditions.

METHODS

34 participants consumed 3 hard-boiled hen eggs per day (21 days): Control group-regular hen eggs (n-3 PUFAs = 438 mg, selenium = 0.054 mg, lutein = 0.330 mg and vitamin E = 1.785 mg) (N = 14); 4Nutri group-hen eggs enriched with 4 nutrients (n-3 PUFAs = 1026 mg, selenium = 0.06 mg, lutein = 1.85 mg and vitamin E = 3.29 mg) (N = 20). Samples were taken before and after the protocol. Serum concentrations of lipid mediators and cytokines were measured with enzyme-linked immunosorbent assay (ELISA) and antibody-based, magnetic bead reagent kits on the Luminex platform, respectively. Serum oxidative stress and antioxidant capacity were measured using standardized methods, while gene expression in peripheral blood mononuclear cells (PBMCs) was measured via real-time PCR.

RESULTS

Decreased serum levels of pro-inflammatory interleukin 17A (IL-17A) and an increased neuronal nitric oxide synthase (nNOS) expression in the 4Nutri group, together with alteration of metabolites produced via cyclooxygenase (COX) pathways in the Control group, suggest a shift towards anti-inflammatory conditions in participants who consumed enriched hen eggs.

CONCLUSIONS

Present results suggest that the combined action of n-3 PUFAs and antioxidants may have a protective role in resting, non-inflammatory conditions.

CLINICAL TRIAL REGISTRATION

NCT04564690.

Does the Endothelium of Competitive Athletes Benefit from Consumption of n-3 Polyunsaturated Fatty Acid-Enriched Hen Eggs?

The present study aimed to determine the effect of n-3 polyunsaturated fatty acid (PUFA)-enriched hen eggs on microvascular vasodilation, microvascular responsiveness to a stress challenge and markers of oxidative stress in competitive athletes. Competitive athletes (n=23) were divided to a control group (n=9), who consumed three regular hens’ eggs daily (249 mg n-3 PUFAs/d), and n-3 PUFAs group (n=14), who consumed three n-3 PUFA-enriched hen eggs daily (1,053 g n-3 PUFAs/d) for 3 weeks. Endothelium-dependent responses [post-occlusive reactive hyperemia (PORH) and acetylcholine-induced dilation (AChID)] and endothelium-independent responses [sodium nitroprusside-induced dilation (SNPID)] of skin microvascular blood flow were assessed by laser Doppler flowmetry in pre- and post-acute exhausting exercise (AEE) sessions. Blood pressure, serum lipid, free fatty acids profiles, and biomarkers of oxidative stress were measured before and after each dietary protocol. Consumption of serum n-3 PUFAs significantly decreased the n-6/n-3 ratio and enhanced PORH and AChID, but did not affect SNPID at rest. Furthermore, serum glutathione peroxidase and superoxide dismutase activities were significantly decreased in the n-3 PUFAs group but remained unchanged in the control group. In both groups, PORH, AChID, and SNP were significantly reduced post-AEE compared with pre-AEE, both before and after consumption of each diet. Only AChID responsiveness to AEE (ΔAChID) significantly increased following consumption of n-3 PUFAs. Overall, n-3 PUFAs supplementation as n-3 PUFA-enriched hen eggs enhanced microvascular endothelial function at rest and may contribute to adaptation to AEE in competitive athletes.

Effects of n-3 Polyunsaturated Fatty Acid-Enriched Hen Egg Consumption on the Inflammatory Biomarkers and Microvascular Function in Patients with Acute and Chronic Coronary Syndrome—A Randomized Study

Simple Summary

There is a strong potential of n-3 polyunsaturated fatty acid (n-3 PUFA) consumption to reduce cardiovascular risk and prevent adverse outcomes in existing cardiovascular diseases. This study aimed to test the effect of n-3 PUFA supplementation in the form of enriched hen eggs on serum lipid and free fatty acid profiles, inflammatory and oxidative stress biomarkers, and microvascular reactivity in patients with acute and chronic coronary artery disease. Consumption of three n-3 PUFA-enriched hen eggs for three weeks had a favorable effect on serum free fatty acid profile (a lower n-6/n-3 PUFA ratio) and mild anti-inflammatory effects but did not significantly affect microvascular reactivity in patients with coronary artery disease. Because consumption of both regular and n-3 PUFA eggs had no negative effects on any of the measured biological and functional vascular parameters, the results of the present study indicate that eggs can be safely consumed in the daily diet of patients with coronary artery disease.

Abstract

This study aimed to test the effect of n-3 polyunsaturated fatty acid (PUFA)-enriched hen egg consumption on serum lipid and free fatty acid profiles, inflammatory and oxidative stress biomarkers, and microvascular reactivity in patients with coronary artery disease (CAD). Forty CAD patients participated in this study. Of those, 20 patients had acute CAD (Ac-CAD), and 20 patients had chronic CAD (Ch-CAD). The control group (N = 20) consumed three regular hen eggs/daily (249 mg n-3 PUFAs/day), and the n-3 PUFAs group (N = 20) consumed three n-3 PUFA-enriched hen eggs/daily (1053 g n-3 PUFAs/day) for 3 weeks. Serum n-3 PUFA concentration significantly increased (in all CAD patients), while LDL cholesterol and IL-6 (in Ac-CAD patients), and hsCRP and IL-1a (in all CAD patients) significantly decreased in the n-3 PUFAs group. Glutathione peroxidase (GPx) activity significantly decreased, and forearm skin microvascular reactivity in response to vascular occlusion (postocclusive reactive hyperemia (PORH)) remained unchanged in both the n-3 PUFAs and control groups in total CAD, Ac-CAD, and Ch-CAD patients. Potentially, n-3 PUFA-enriched hen eggs can change the free fatty acid profile to a more favorable lower n6/n3 ratio, and to exhibit mild anti-inflammatory effects but not to affect microvascular reactivity in CAD patients.

Carnosine, Small but Mighty-Prospect of Use as Functional Ingredient for Functional Food Formulation

Carnosine is a dipeptide synthesized in the body from β-alanine and L-histidine. It is found in high concentrations in the brain, muscle, and gastrointestinal tissues of humans and is present in all vertebrates. Carnosine has a number of beneficial antioxidant properties. For example, carnosine scavenges reactive oxygen species (ROS) as well as alpha-beta unsaturated aldehydes created by peroxidation of fatty acid cell membranes during oxidative stress. Carnosine can oppose glycation, and it can chelate divalent metal ions. Carnosine alleviates diabetic nephropathy by protecting podocyte and mesangial cells, and can slow down aging. Its component, the amino acid beta-alanine, is particularly interesting as a dietary supplement for athletes because it increases muscle carnosine, and improves effectiveness of exercise and stimulation and contraction in muscles. Carnosine is widely used among athletes in the form of supplements, but rarely in the population of cardiovascular or diabetic patients. Much less is known, if any, about its potential use in enriched food. In the present review, we aimed to provide recent knowledge on carnosine properties and distribution, its metabolism (synthesis and degradation), and analytical methods for carnosine determination, since one of the difficulties is the measurement of carnosine concentration in human samples. Furthermore, the potential mechanisms of carnosine's biological effects in musculature, metabolism and on immunomodulation are discussed. Finally, this review provides a section on carnosine supplementation in the form of functional food and potential health benefits and up to the present, neglected clinical use of carnosine.

The effect of n-3 polyunsaturated fatty acids enriched hen eggs consumption on IgG and total plasma protein N-glycosylation in healthy individuals and cardiovascular patients

OBJECTIVE

This study determined the effect of n-3 PUFAs enriched hen eggs consumption on IgG and total plasma protein N-glycan profiles and inflammatory biomarkers level in healthy individuals (N = 33) and cardiovascular (CV) patients (N = 21).

MATERIALS AND METHODS

Subjects were divided to Control-Healthy and Control-CV subgroups (consumed three regular hens' eggs/daily (249 mg n-3 PUFAs/day)), and n-3-PUFAs-Healthy and n-3-PUFAs-CV subgroups (consumed three n-3 PUFAs enriched hen eggs/daily (1053 mg n-3 PUFAs/day)) for 3 weeks. Serum free fatty acids profile and high-sensitivity C reactive protein (hsCRP), interleukin 6 and 10 (IL-6, IL-10) and tumor necrosis factor alpha were measured. Total plasma protein and IgG N-glycome have been profiled before and after dietary protocols.

RESULTS

Serum n-3 PUFAs concentration significantly increased following n-3 PUFAs hen eggs consumption in both n-3-PUFAs-Healthy and n-3-PUFAs-CV. IL-10 significantly increased in both Healthy subgroups, while no change occurred in CV subgroups. Derived IgG N-glycan traits: bisecting GlcNAc (B) significantly decreased in n-3-PUFAs-Healthy, while agalactosylation (G0) and core fucosylation (CF) significantly increased in Control-Healthy. Derived total plasma protein N-glycan traits: high branching glycans (HB), trigalactosylation (G3), tetragalactosylation (G4), trisialylation (S3), tetrasialylation (S4) and antennary fucosylation (AF) significantly decreased, while G0, monogalactosylation (G1), neutral glycans (S0), B, CF and oligomannose structures (OM) significantly increased in n-3 PUFAs-CV. Digalactosylation (G2) significantly decreased, and G0, G1, S0, disialylation (S2), B and CF significantly increased in Control-CV.

CONCLUSIONS

n-3 PUFAs consumption alters IgG N-glycan traits and IL-10 in healthy individuals, and total plasma protein N-glycan traits in CV patients, by shifting them toward less inflammatory N-glycosylation profile.

Dietary Intake of n-3 PUFA-Enriched Hen Eggs Changes Inflammatory Markers' Concentration and Treg/Th17 Cells Distribution in Blood of Young Healthy Adults-A Randomised Study

In the present study, we aimed to determine the effects of n-3 polyunsaturated acid (PUFA) supplementation (~1053 mg/per day), i.e., α-linolenic (~230 mg), eicosapentaenoic (~15 mg), and docosahexaenoic acid (~105 mg), through hen eggs, on pro- and anti-inflammatory parameters in healthy individuals (23.8 ± 2.57 years old). Here, we demonstrate differential effects of regular hen eggs (N = 21; W/M = 10/11) and n-3 PUFA-enriched hen eggs (N = 19; W/M = 10/9) consumption on the serum levels of lipid mediators, representation of peripheral T helper cell subsets (recently activated T-helper cells, nTreg, Th17 and non-Th17-IL-17A secreting T-helper lymphocytes) and their functional capacity for cytokine secretion. Both diets significantly altered systemic levels of pro-inflammatory and inflammation resolving lipid mediators; however, only the n-3 PUFAs group showed a significant shift towards anti-inflammatory prostanoids and increased levels of pro-resolving oxylipins. Both study groups showed reduced frequencies of peripheral nTreg lymphocytes and decreased rates of peripheral Th17 cells. Their functional capacity for cytokine secretion was significantly altered only in the n-3 PUFAs group in terms of increased transforming growth factor β-1 and reduced interleukin 6 secretion. Diet supplemented with n-3 PUFAs alters immune response towards inflammation resolving conditions through effects on lipid mediators and cytokine secretion by T lymphocytes in human model without underlying comorbidities.

Anti-Inflammatory Potential of n-3 Polyunsaturated Fatty Acids Enriched Hen Eggs Consumption in Improving Microvascular Endothelial Function of Healthy Individuals-Clinical Trial

The effects of consumption of n-3 polyunsaturated fatty acids (n-3 PUFAs) enriched hen eggs on endothelium-dependent and endothelium-independent vasodilation in microcirculation, and on endothelial activation and inflammation were determined in young healthy individuals. Control group (N = 21) ate three regular hen eggs/daily (249 mg n-3 PUFAs/day), and n-3 PUFAs group (N = 19) ate three n-3 PUFAs enriched hen eggs/daily (1053 g n-3 PUFAs/day) for 3 weeks. Skin microvascular blood flow in response to iontophoresis of acetylcholine (AChID; endothelium-dependent) and sodium nitroprusside (SNPID; endothelium-independent) was assessed by laser Doppler flowmetry. Blood pressure (BP), body composition, body fluid status, serum lipid and free fatty acids profile, and inflammatory and endothelial activation markers were measured before and after respective dietary protocol. Results: Serum n-3 PUFAs concentration significantly increased, AChID significantly improved, and SNPID remained unchanged in n-3 PUFAs group, while none was changed in Control group. Interferon-γ (pro-inflammatory) significantly decreased and interleukin-10 (anti-inflammatory) significantly increased in n-3 PUFAs. BP, fat free mass, and total body water significantly decreased, while fat mass, interleukin-17A (pro-inflammatory), interleukin-10 and vascular endothelial growth factor A significantly increased in the Control group. Other measured parameters remained unchanged in both groups. Favorable anti-inflammatory properties of n-3 PUFAs consumption potentially contribute to the improvement of microvascular endothelium-dependent vasodilation in healthy individuals.

Enhanced Antioxidative Defense by Vitamins C and E Consumption Prevents 7-Day High-Salt Diet-Induced Microvascular Endothelial Function Impairment in Young Healthy Individuals

This study aimed to examine whether the oral supplementation of vitamins C and E during a seven-day high salt diet (HS; ~14 g salt/day) prevents microvascular endothelial function impairment and changes oxidative status caused by HS diet in 51 (26 women and 25 men) young healthy individuals. Laser Doppler flowmetry measurements demonstrated that skin post-occlusive reactive hyperemia (PORH), and acetylcholine-induced dilation (AChID) were significantly impaired in the HS group, but not in HS+C+E group, while sodium nitroprusside-induced dilation remained unaffected by treatments. Serum oxidative stress markers: Thiobarbituric acid reactive substances (TBARS), 8-iso prostaglandin-F2α, and leukocytes’ intracellular hydrogen peroxide (H₂O₂) production were significantly increased, while ferric-reducing ability of plasma (FRAP) and catalase concentrations were decreased in the HS group. All these parameters remained unaffected by vitamins supplementation. Matrix metalloproteinase 9, antioxidant enzymes Cu/Zn SOD and glutathione peroxidase 1, and leukocytes’ intracellular superoxide production remained unchanged after the protocols in both HS and HS+C+E groups. Importantly, multiple regression analysis revealed that FRAP was the most powerful predictor of AChID, while PORH was strongly predicted by both FRAP and renin-angiotensin system activity. Hereby, we demonstrated that oxidative dis-balance has the pivotal role in HS diet-induced impairment of endothelial and microvascular function in healthy individuals which could be prevented by antioxidative vitamins consumption.

Impact of High Salt Diet on Cerebral Vascular Function and Stroke in Tff3-/-/C57BL/6N Knockout and WT (C57BL/6N) Control Mice

High salt (HS) dietary intake leads to impaired vascular endothelium-dependent responses to various physiological stimuli, some of which are mediated by arachidonic acid (AA) metabolites. Transgenic Tff3^−/− gene knockout mice (Tff3^−/−/C57BL/6N) have changes in lipid metabolism which may affect vascular function and outcomes of stroke. We aimed to study the effects of one week of HS diet (4% NaCl) on vascular function and stroke induced by transient occlusion of middle cerebral artery in Tff3^−/− and wild type (WT/C57BL/6N) mice. Flow-induced dilation (FID) of carotid artery was reduced in WT-HS mice, but not affected in Tff3^−/−-HS mice. Nitric oxide (NO) mediated FID. NO production was decreased with HS diet. On the contrary, acetylcholine-induced dilation was significantly decreased in Tff3^−/− mice on both diets and WT-HS mice. HS intake and Tff3 gene depletion affected the structural components of the vessels. Proteomic analysis revealed a significant effect of Tff3 gene deficiency on HS diet-induced changes in neuronal structural proteins and acute innate immune response proteins’ expression and Tff3 depletion, but HS diet did not increase the stroke volume, which is related to proteome modification and upregulation of genes involved mainly in cellular antioxidative defense. In conclusion, Tff3 depletion seems to partially impair vascular function and worsen the outcomes of stroke, which is moderately affected by HS diet.

The Physiological Effect of n-3 Polyunsaturated Fatty Acids (n-3 PUFAs) Intake and Exercise on Hemorheology, Microvascular Function, and Physical Performance in Health and Cardiovascular Diseases; Is There an Interaction of Exercise and Dietary n-3 PUFA Intake?

Physical activity has a beneficial effect on systemic hemodynamics, physical strength, and cardiac function in cardiovascular (CV) patients. Potential beneficial effects of dietary intake of n-3 polyunsaturated fatty acids (n-3 PUFAs), such as α-linolenic acid, eicosapentaenoic acid, and docosahexaenoic acid on hemorheology, vascular function, inflammation and potential to improve physical performance as well as other CV parameters are currently investigated. Recent meta-analysis suggests no effect of n-3 PUFA supplementation on CV function and outcomes of CV diseases. On the other hand, some studies support beneficial effects of n-3 PUFAs dietary intake on CV and muscular system, as well as on immune responses in healthy and in CV patients. Furthermore, the interaction of exercise and dietary n-3 PUFA intake is understudied. Supplementation of n-3 PUFAs has been shown to have antithrombotic effects (by decreasing blood viscosity, decreasing coagulation factor and PAI-1 levels and platelet aggregation/reactivity, enhancing fibrinolysis, but without effects on erythrocyte deformability). They decrease inflammation by decreasing IL-6, MCP-1, TNFα and hsCRP levels, expression of endothelial cell adhesion molecules and significantly affect blood composition of fatty acids. Treatment with n-3 PUFAs enhances brachial artery blood flow and conductance during exercise and enhances microvascular post-occlusive hyperemic response in healthy humans, however, the effects are unknown in cardiovascular patients. Supplementation of n-3 PUFAs may improve anaerobic endurance and may modulate oxygen consumption during intense exercise, may increase metabolic capacity, enhance endurance capacity delaying the onset of fatigue, and improving muscle hypertrophy and neuromuscular function in humans and animal models. In addition, n-3 PUFAs have anti-inflammatory and anti-nociceptive effects and may attenuate delayed-onset muscle soreness and muscle stiffness, and preserve joint mobility. On the other hand, effects of n-3 PUFAs were variably observed in men and women and they vary depending on dietary protocol, type of supplementation and type of sports activity undertaken, both in healthy and cardiovascular patients. In this review we will discuss the physiological effects of n-3 PUFA intake and exercise on hemorheology, microvascular function, immunomodulation and inflammation and physical performance in healthy persons and in cardiovascular diseases; elucidating if there is an interaction of exercise and diet.

Seven-Day Salt Loading Impairs Microvascular Endothelium-Dependent Vasodilation without Changes in Blood Pressure, Body Composition and Fluid Status in Healthy Young Humans

OBJECTIVES

We aimed to assess whether a 7-day high-salt (HS) diet affects endothelium-dependent and/or endothelium-independent microvascular function in the absence of changes in arterial blood pressure (BP), and to determine whether such microvascular changes are associated with changes in body composition and fluid status in healthy young humans.

MATERIALS AND METHODS

Fifty-three young healthy individuals (28 women and 25 men) were assigned to a 7-day low-salt diet (<3.5 g salt/day) followed by a 7-day HS diet (∼14 g salt/day). Skin microvascular blood flow in response to iontophoresis of acetylcholine (ACh) and sodium nitroprusside (SNP) was assessed by laser Doppler flowmetry, and BP, heart rate (HR), plasma renin activity (PRA), serum aldosterone, serum and 24 h-urine sodium, potassium, urea and creatinine levels, together with body composition and fluid status measurement with a 4-terminal portable impedance analyzer were measured before and after diet protocols.

RESULTS

BP, HR, body composition and fluid status were unchanged, and PRA and serum aldosterone level were significantly suppressed after HS diet. ACh-induced dilation (AChID) was significantly impaired, while SNP-induced dilation was not affected by HS diet. Impaired AChID and increased salt intake, as well as impaired AChID and suppressed renin-angiotensin system were significantly positively correlated. Changes in body composition and fluid status parameters were not associated with impaired AChID.

CONCLUSION

7-day HS diet impairs microvascular reactivity by affecting its endothelium-dependent vasodilation in young healthy individuals. Changes are independent of BP, body composition changes or fluid retention, but are the consequences of the unique effect of HS on endothelial function.

The Role of Epoxyeicosatrienoic Acids in Diabetes Mellitus-Induced Impaired Vascular Relaxation of Aortic Rings in Ovariectomized Sprague-Dawley Rats

AIM

The present study was aimed at determining if type 1 diabetes mellitus (DM) affects vascular function and at elucidating the mechanisms mediating vasorelaxation in both nonovariectomized and ovariectomized Sprague-Dawley (SD) rats.

MATERIALS AND METHODS

Eighty female SD rats were divided into four groups: nonovariectomized healthy (non-OVX-CTR) and diabetic (non-OVX-DM) rats and ovariectomized healthy (OVX-CTR) and diabetic (OVX-DM) rats. Bilateral ovariectomy was performed at the age of 5 weeks, and type 1 DM was induced by streptozotocin at the age of 6 weeks. At the age of 12 weeks, acetylcholine-induced relaxation (AChIR) was assessed in aortic rings in the absence/presence of L-NAME, Indomethacin, and MS-PPOH. Aortic tissue mRNA expression of eNOS, iNOS, COX-1, COX-2, thromboxane synthase 1 (TBXAS1), CYP4A1, CYP4A3, and CYP2J3, as well as plasma oxidative stress, was measured.

RESULTS

AChIR did not differ in non-OVX-DM rats compared to non-OVX-CTR ones. AChIR was significantly reduced in the OVX-DM group compared to the OVX-CTR group. MS-PPOH did not reduce AChIR in OVX-DM rats as it did in OVX-CTR ones. CYP4a3 mRNA expression in OVX-DM rats was significantly lower compared to that in the OVX-CTR group.

CONCLUSIONS

Female sex hormones may protect vasorelaxation in type 1 diabetic rats. Type 1 diabetes impairs vasorelaxation in response to ACh in ovariectomized rats (but not in nonovariectomized rats) by affecting vasorelaxation pathways mediated by EETs.

Emergence patterns and ecological associations of some haematophagous blackfly species along an oligotrophic hydrosystem

Emergence patterns of blackflies (Diptera: Simuliidae) were investigated for 2 years at nine sites in the Plitvice Lakes area of Croatia, using pyramid-type traps. A total of 38 012 specimens representing 10 haematophagous species were collected. The dominant species was Simulium angustipes Edwards, 1915, a vector transmitting avian trypanosomes. Water temperature, alkalinity, conductivity and habitat type represented the factors with the greatest degree of influence on blackfly species composition, structure and distribution along a longitudinal gradient of this oligotrophic karstic hydrosystem. Simulium angustipes was highly associated with lake outlets. The blackfly communities at all sites were dominated by species typical of the rhithral zone, but there was a shift in species composition along a longitudinal gradient from the hypocrenal-epirhithral to the epirhithral-metarhithral zone. Multiple generations per year were detected in S. angustipes, whereas in Simulium costatum Friederichs, 1920, the number of generations differed between sites with constant and those with variable water temperature.

First description of postweaning multisystemic wasting syndrome (PMWS) in wild boar (Sus scrofa) in Croatia and phylogenetic analysis of partial PCV2 sequences

This report describes the first case of postweaning multisystemic wasting syndrome (PMWS) in wild boar in Croatia. During the winter season of 2004, eight wild young piglets (of approximately 2 to 5 months of age) were found dead in a fenced hunting area. Polymerase chain reaction (PCR) was carried out on mesenteric lymph nodes and all animals yielded positive results. In one of these animals diagnosis of PMWS was established based on the three key diagnostic criteria including the clinical manifestation, moderate lymphoid lesions consisting of lymphocyte depletion and granulomatous inflammation, and detection of the presence of PCV2 genome within the lymphoid lesions by in situ hybridisation (ISH). Three additional wild piglets had also mild PMWS-like lesions and a low amount of PCV2 was also found. No PMWS-like lesions or PCV2 genome were detected in the rest of the wild piglets studied. Three PCR-positive isolates were partially sequenced, which confirmed the diagnosis of PCV2 and demonstrated that the three sequences were genetically identical. The phylogenetic analysis of a representative PCV2 isolate indicated that its sequence (DQ875444) is grouped in a separate branch with Hungarian isolate (AY256460) and differs from any of the annotated sequences.

Comparison of trichinelloscopy with a digestion method for the detection of Trichinella larvae in muscle tissue from naturally infected pigs with low level infections

The identification of Trichinella infection in pigs in Croatia has traditionally been done by inspection of individual carcasses. In response to outbreaks of human trichinellosis in the last decade, the Croatian Ministry of Agriculture and Forestry instituted compulsory trichinelloscopic examination of tissue from both commercially and privately slaughtered swine. The purpose of this study was to compare trichinelloscopy and artificial digestion for use in samples containing low numbers of larvae. Each assay was used to test 1,769 field positive samples, 290 of which contained 6 or less larvae per gram of muscle tissue. The sensitivity and specificity of trichinelloscopy with 6 or less l pg was 43.4 and 88%, respectively. kappa-Value as a measure of agreement between trichinelloscopy and artificial digestion was 0.27%. It is noteworthy that a considerable number of the 103 (52%) negative animals on trichinelloscopy contained>or=6l pg which is enough to cause clinical trichinellosis. These findings support other studies that indicate trichinelloscopy is not a method of choice and that it is necessary to implement more sensitive procedures such as artificial digestion.

Evaluation of ELISA for detection of Trichinella antibodies in muscle juice samples of naturally infected pigs

The performance characteristics of an ELISA test for trichinellosis in pigs applied to muscle juice was assessed using 314 samples collected from pigs located in endemic areas of Croatia. Peptic digestion was used as the reference method. The diagnostic accuracy of the two compared dilutions (1:10 and 1:100) was considered to be high because the area under the curve (AUC) index was 0.922 and 0.920 for each dilution, respectively. In this study the two graph-receiver operating characteristic (TG-ROC) analysis was used as a tool for selecting cut-off points. Sensitivity, specificity, likelihood ratios, efficiency and Youden's index were used as indices of test accuracy. The cut-off values that minimize overall misclassification cost under an assumption of 3% prevalence were calculated. Our results indicate that the ELISA applied to muscle juice is a highly accurate test and can be adapted to process a large number of samples.

A seroepidemiologic survey of canine visceral leishmaniosis among apparently healthy dogs in Croatia

Cross-sectional investigation was done on seroprevalence of Leishmania sp. infection among apparently healthy dogs in an area where canine leishmaniosis is endemic. Survey included 68 dogs living in the coastal city of Split, and 238 dogs living in 12 villages scattered in the hinterland. Each dog was clinically examined for the presence of some discrete signs compatible with leishmaniosis and by dot-ELISA modification determined the presence of anti-Leishmania antibodies. The titre 1:600 and higher was regarded as positive in the study. The seroprevalence ranged from 0 to 42.85%, depending on the location. 54.34% of the seropositive dogs had moderately enlarged lymph nodes and/or some discrete changes on the skin. In our parasitological study, Leishmania sp. was isolated from several seropositive animals that had some clinical signs and from a few which did not have any. Data analysis revealed that serological positivity to Leishmania sp. was not associated with a dog's outdoor lifestyle and utility, but was associated with the gender and age.

Organization and work of the War Hospital in Sturba near the town of Livno, Bosnia and Herzegovina

The work of the Croatian Defense Council (armed forces of the Croatian citizens of Bosnia and Herzegovina) War Hospital at Sturba, outskirts of the town of Livno, is described. The hospital was established in the beginning of April and worked until September 1992. It provided services for the battlefield of approximately 100 km of a very difficult mountainous terrain. The hospital was situated in a concrete dugout taken from the Yugoslav Federal Army. It was well equipped and supplied exclusively by numerous donations. Medical personnel were recruited partly from local medical professionals and partly from volunteers from Croatia. During the 5-month period, 597 patients (571 soldiers and 26 civilians) were admitted. A total of 314 operations, 141 in general and 173 in regional anesthesia, were performed. None of the patients died in the hospital. There was not a single epidemic either among soldiers or civilians in the area.