Cutaneous microvascular reactivity and aortic elasticity in coronary artery disease: Comparison of the laser Doppler flowmetry and echocardiography.

BACKGROUND AND AIM: Decreased vascular reactivity in atherosclerosis was previously shown. In our study, it was aimed to demonstrate the decreased vascular functions in both microvascular and macrovascular tissues and to estimate any correlation between them. METHODS: Twenty-five control outpatients with no coronary artery disease (CAD) history and 26 outpatients with CAD history were enrolled in the study. Local cutaneous post-occlusive reactive hyperemia (PORH) responses after three minutes of brachial occlusion with a pneumatic cuff were recorded noninvasively by a Perimed Periflux 5010 laser Doppler flow system. Aortic distensibility and stiffness indexes were recorded noninvasively by a two-dimensional Doppler echocardiography machine (Vivid S6 GE Medical System, Horten, Norway). RESULTS: Except for the medication history of subjects, there were no significant demographic differences between the CAD and control groups. Peak flow (PF), resting flow (RF) and biological zero(BZ) laser Doppler measurements were not decreased, but PF-RF/RF (%), PF-BZ/BF (%), hyperemia repayment and PORH indexes were significantly decreased in the CAD group (P=0.005, P=0.024, P=0.017, P=0.006, respectively) with laser Doppler measurements. Aortic strain (%) and aortic distensibility (cm3/dyn-1) measurements were significantly decreased in the CAD group (P=0.005, P=0.013). However, there was no correlation between microvascular indexes (hyperemia repayment index, PORH index) and macrovascular indexes (aortic strain and aortic distensibility). DISCUSSION: Different corrupted vascular tonus regulator systems in arteries of varying diameter, different major reactive responses to the stimuli or, finally, the lack of a number of subjects to obtain a significant level may be responsible for the irrelevant correlation analysis. CONCLUSION: The differences in arterial beds (both aorta and microcirculation) may be examined to assess the cardiovascular risk in patients with history of CAD.

Effects of electromagnetic field exposure on the heart: a systematic review.

The use of electrical devices has gradually increased throughout the last century, and scientists have suggested that electromagnetic fields (EMF) generated by such devices may have harmful effects on living creatures. This work represents a systematic review of collective scholarly literature examining the effects of EMFs on the heart. Although most works describing effects of EMF exposure have been carried out using city electric frequencies (50-60 Hz), a consensus has not been reached about whether long- or short-term exposure to 50-60 Hz EMF negatively affects the heart. Studies have indicated that EMFs produced at cell-phone frequencies cause no-effect on the heart. Differences between results of studies may be due to a compensatory response developed by the body over time. At greater EMF strengths or shorter exposures, the ability of the body to develop compensation mechanisms is reduced and the potential for heart-related effects increases. It is noteworthy that diseases of heart tissues such as myocardial ischemia can also be successfully treated using EMF. Despite the substantial volume of data that has been collected on heart-related effects of EMFs, additional studies are needed at the cellular and molecular level to fully clarify the subject. Until the effects of EMF on heart tissue are more fully explored, electronic devices generating EMFs should be approached with caution.

The relationship between hypertension and plasma allantoin, uric acid, xanthine oxidase activity and nitrite, and their predictive capacity in severe preeclampsia.

It is controversial that uric acid (UA) levels are related to the severity of hypertension in preeclampsia (PE). Our aim in this study was to determine whether UA, xanthine oxidase activity (XOA), allantoin and nitrite levels are related to arterial blood pressure (BP) in PE. We formed a control group (n = 20) and a PE group (n = 20) for the study. Their BPs and plasma UA, XOA, allantoin and nitrite levels were measured. The values from the control and PE pregnant women were assessed via a Wilcoxon matched-pairs test. A Pearson correlation test was also performed. In addition, the diagnostic value of these tests was evaluated via receiver operating characteristic (ROC) analysis. The BP, UA, XOA and allantoin levels in the PE patients were found to be higher when compared with those of the pregnant controls. The UA, XOA and allantoin levels showed high correlations with BP in cases of PE. However, there was no superiority among the correlations. No differences were observed between the groups in terms of nitrite levels and the relationship between nitrite and BP. UA, XOA and allantoin levels may be high due to placental cell death because of abnormal trophoblastic activity observed in PE. Moreover, the reactive oxygen products that are created during the genetic material degradation may explain how UA, XOA and allantoin levels are related to BP. According to ROC analysis, UA, XOA and allantoin assays are reliable predictors for the determination of PE.

Investigation of effects of short-term exposure to 50 HZ magnetic field on central, peripheral, and autonomic nervous systems in rats.

Although a large number of exposure studies have been carried out to investigate possible detrimental effects of a power-line frequency magnetic field (PF-MF; 50-60 Hz) on living organisms, there is no consensus in reported results. Recent research suggested that short-term exposure to a 50 Hz PF-MF can have a greater effect than long-term exposure. In our study, we aimed to investigate the possible effect of short-term 50 Hz PF-MF exposure on central, peripheral, and autonomic nervous systems through electroencephalogram (EEG), nerve conduction velocity (NCV), and heart rate variability (HRV) measurements. To that end, Wistar albino rats and sciatic nerves gathered from the rats were exposed to a 50 Hz, 0.3 mT MF, and changes on EEG, NCV, and HRV were investigated. According to data we gathered, MF frequency and magnetic flux density that we applied did not affect EEG, NCV, or HRV. The reason for conflicting results gathered from MF exposure studies may be that the nervous system can be affected by a specific MF frequency and magnetic flux density, but that different MF exposures do not affect it. Moreover, exposure duration to MF may also have influenced results.

Investigation of the oxidative effect of chronic hyperammonemia on the kidney and the possible protective effect of allopurinol.

Although there have been many studies on this topic, the molecular mechanism of the toxic effects of hyperammonemia on cells has not yet been fully explained. Recent studies have held oxidative stress mechanisms responsible for hyperammonemia-induced cell damage. Kidney functions are affected in diseases associated with an increase in ammonia in the blood. Our study tries to determine whether oxidative stress mechanisms are responsible for kidney damage in chronic hyperammonemia. We also investigated whether kidney damage is dependent on possible reactive oxygen products associated with the xanthine oxidase (XO) enzyme and whether the possible association can be inhibited with allopurinol, an XO enzyme inhibitor. The study took into consideration the enzyme activities of XO, xanthine dehydrogenase (XDH), superoxide dismutase (SOD), glutathione-S-transferase (GST), as well as protein thiol (P-SH) and malondialdehyde (MDA) levels. The data found demonstrated that chronic hyperammonemia had oxidative stress effects on the kidney, and that kidney XO and XDH activity changed. However, it was not possible to inhibit this oxidative stress in the kidney using allopurinol. Thus, we could not conclude that oxidative stress is an XO-dependent mechanism. The outcomes of the study suggested that this oxidative situation arising in hyperammonemia occurred through a mechanism other than the XO enzyme.

Effects of 50 Hertz-1 mT magnetic field on action potential in isolated rat sciatic nerve.

The aim of this study was to investigate possible effects of 50 Hz-1 mT magnetic field (MF) on action potential in isolated rat sciatic nerve. We used 16 Wistar rats in the study. They were divided into control (n = 10) and MF (n = 6) groups. The sciatic nerve of left legs in the MF group was exposed to 50 Hz-1 mT MF for 30 min by using a Helmholtz applicator and then action potentials in control and experimental groups were recorded extracellularly. Maximum amplitude and hyperpolarization time and action potential were significantly (p ≤ 0.025) lower in the MF group than in control. However, conduction time, minimum amplitude, depolarization and repolarization times of the action potential was not different between control and MF groups evaluated. In conclusion, 50-1 mT MF caused to decrease amplitude value and hyperpolarization time of action potential in the rat nerve.

The effects of allopurinol on rat liver and spleen tissues in a chronic hyperammonemia animal model.

OBJECTIVE: To investigate whether hyperammonemia can lead to any structural change in liver and spleen tissues or biochemical changes in blood and if allopurinol (ALLO) has a protective effect in hyperammonemia. METHODS: This study was conducted between April and May 2006. Thirty-six females Wistar Albino rats were randomly divided into 3 equal groups: Controls, administered with ammonia (NH3) and administered with NH3 + ALLO groups. Ammonium acetate (2.5 mmole/kg/day) was injected to NH3 group intraperitoneally (IP) for 28 days. The other group received ammonium acetate (2.5 mmole/kg) plus ALLO (50 mg/kg) IP for 28 days. After finishing the study, blood and tissue samples were collected to perform histopathological and biochemical analysis. RESULTS: Liver and spleen tissues were normal in the control group. In NH3 group, liver tissues were minimally vacuolar and granular degenerations and moderate mononuclear cell infiltration. However, there was no histopathological change in NH3 + ALLO group. Spleen tissues were normal in NH3 group. In biochemical analysis, there was no significant difference between the groups (p>0.05). CONCLUSION: The ammonium acetate may cause minimal structural changes in rat liver and ALLO can prevent this. We found that biochemical parameters do not necessarily correlate with the histopathological findings.

The efficacy of Aesculus hippocastanum seeds on diabetic nephropathy in a streptozotocin-induced diabetic rat model.

Cytokines, such as transforming growth factor (TGF)-ß1, and increased oxidative stress are considered to be responsible for the development of diabetic nephropathy. We hypothesized that Aesculus hippocastanum (AH) seeds may have preventive effects on oxidative stress and TGF-ß-related diabetic nephropathy in streptozotocin (STZ)-induced diabetic nephropathy in rats. Twenty-one male Sprague-Dawley albino rats were divided into three groups (n=7). Except for the control group, they all had diabetic nephropathy induced by an intraperitoneal injection of STZ. While the diabetes group did not receive any medication, the diabetes+AH group was given the medication for 4 weeks. After the experiment, analyses were performed to evaluate the glomerular area, severity of sclerosis, and fibronectin immunoexpression, as well as levels of malondialdehyde (MDA), TGF-ß, blood urea nitrogen (BUN), blood glucose, creatinine, and proteinuria. It was found that glomerular area, severity of sclerosis, fibronectin immunoexpression, and levels of MDA, TGF-ß, BUN, creatinine, and proteinuria were decreased in the diabetes+AH group. It is known that diabetic nephropathy is induced, to a large extent, by hyperglycemia. In the present study, AH extract ameliorated diabetic nephropathy without decrease in blood glucose levels. In the study, AH seeds showed beneficial effects on the functional properties of the kidney and microscopic improvements in diabetic nephropathy.

Physiological parameters as a tool in the diagnosis of fibromyalgia syndrome in females: A preliminary study.

AIMS: Although fibromyalgia (FM) syndrome is associated with many symptoms, there is as yet no specific finding or laboratory test diagnostic of this syndrome. The physical examination and laboratory tests may be helpful in figuring out this syndrome. MATERIALS AND METHODS: The heart rate, respiration rate, body temperature (TEMP), height, body weight, hemoglobin level, erythrocyte sedimentation rate, white blood cell count, platelet count (PLT), rheumatoid factor and C-reactive protein levels and electrocardiograms (ECG) of FM patients were compared with those of control individuals. In addition, the predictive value of these tests was evaluated via receiver operating characteristic (ROC) analysis. KEY FINDINGS: The results showed that the TEMP and the PLT were higher in the FM group compared with the control group. Also, ST heights in ECGs which corresponds to a period of ventricle systolic depolarization, showed evidence of a difference between the FM and the control groups. There was no difference observed in terms of the other parameters. According to the ROC analysis, PLT, TEMP and ST height have predictive capacities in FM. SIGNIFICANCE: Changes in hormonal factors, peripheral blood circulation, autonomous system activity disorders, inflammatory incidents, etc., may explain the increased TEMP in the FM patients. The high PLT level may signify a thromboproliferation or a possible compensation caused by a PLT functional disorder. ST depression in FM patients may interrelate with coronary pathology. Elucidating the pathophysiology underlying the increases in TEMP and PLT and the decreases in ST height may help to explain the etiology of FM.

Investigation of the relationship between anxiety and heart rate variability in fibromyalgia: A new quantitative approach to evaluate anxiety level in fibromyalgia syndrome.

BACKGROUND: Fibromyalgia syndrome (FMS) is identified by widespread musculoskeletal pain, sleep disturbance, nonrestorative sleep, fatigue, morning stiffness and anxiety. Anxiety is very common in Fibromyalgia and generally leads to a misdiagnosis. Self-rated Beck Anxiety Inventory (BAI) and doctor-rated Hamilton Anxiety Inventory (HAM-A) are frequently used by specialists to determine anxiety that accompanies fibromyalgia. However, these semi-quantitative anxiety tests are still subjective as the tests are scored using doctor-rated or self-rated scales. METHOD: In this study, we investigated the relationship between heart rate variability (HRV) frequency subbands and anxiety tests. The study was conducted with 56 FMS patients and 34 healthy controls. BAI and HAM-A test scores were determined for each participant. ECG signals were then recruited and 71 HRV subbands were obtained from these ECG signals using Wavelet Packet Transform (WPT). The subbands and anxiety tests scores were analyzed and compared using multilayer perceptron neural networks (MLPNN). RESULTS: The results show that a HRV high frequency (HF) subband in the range of 0.15235Hz to 0.40235Hz, is correlated with BAI scores and another HRV HF subband, frequency range of 0.15235Hz to 0.28907Hz is correlated with HAM-A scores. The overall accuracy is 91.11% for HAM-A and 90% for BAI with MLPNN analysis. CONCLUSION: Doctor-rated or self-rated anxiety tests should be supported with quantitative and more objective methods. Our results show that the HRV parameters will be able to support the anxiety tests in the clinical evaluation of fibromyalgia. In other words, HRV parameters can potentially be used as an auxiliary diagnostic method in conjunction with anxiety tests.

Effect of oral tamoxifen on the healing of corrosive oesophageal burns in an experimental rat model.

OBJECTIVES: Corrosive oesophagitis is a common health problem in children. Scar tissue can develop during the recovery period, and as a result, serious narrowing of the oesophagus can develop, in turn causing morbidity and mortality. In previous studies, it was argued that tamoxifen (TAM) may have antifibrotic effects beyond its oestrogen antagonist or agonist properties. We aimed to examine the possible effects of TAM on fibrosis and stricture formation, which are complications of corrosive oesophagitis. METHODS: Three study groups were formed as follows: a non-oesophageal burn group (NON-EB, n = 6), an oesophageal burn group (EB, n = 6) and an oesophageal burn + tamoxifen group (EB-TAM, n = 6). In the NON-EB rats, the oesophageal lumen was washed with 0.9% NaCl while, in the EB and EB-TAM rats, the distal oesophagus was burned with a 50% NaOH solution. After application of this solution to the EB-TAM group rats, 0.4 mg/kg/day of TAM was administered via gavage for 7 days. Twenty-two days later, the rat oesophagi were examined histopathologically for inflammation, granulation, collagen deposition and stenosis. RESULTS: In the EB group rats, the inflammation, collagen deposition and stenosis scores increased compared with those of the other groups. In the EB-TAM group, these three scores were lower compared with those of the EB group rats, but higher compared with those of the NON-EB group rats. No significant difference was observed in the granulation scores between the EB and EB-TAM groups. It was also observed that the EB-TAM group rats gained more weight than those in the EB group. CONCLUSIONS: According to the data obtained, TAM use prevents inflammation, collagenization and stricture development. TAM may be a useful medicine in the treatment of corrosive oesophagitis.

Effects of short-term exposure to powerline-frequency electromagnetic field on the electrical activity of the heart.

ABSTRACT The heart is a contractile organ that can generate its own rhythm. The contraction, or the rhythm, of the heart may be influenced by electromagnetic field (EMF) exposure, because of the heart's excitability characteristic. In previous studies, different methods have been used to study the possible effects of an extremely low frequency electromagnetic field (ELF-EMF) on the heart. But the studies' designs were not similar, and the results were also different. Recent studies have shown some evidence that short-term EMF exposure can influence the heart more than long-term exposure. This study investigated how the heart is affected in the first EMF exposure. In a simulation of the daily exposure of humans to a power frequency, Wistar albino rats were used. By utilizing the Helmholtz-coil set, we obtained a 50-Hz, 1-µT EMF and examined rat heart activity during short-term EMF exposure. No effect was observed under this exposure condition. The results obtained do not confirm a possible mechanism in the electrical activity of the rat heart model.