The effects of the pulsed magnetic field on sepsis-induced liver tissue injury in rats.

Sepsis is the host's response to infection and can lead to severe and life-threatening cases. We aimed to investigate the effects of pulsed magnetic field (PMF) on septic liver tissue injury. A total of 28 adult Wistar albino rats were divided equally into four study groups: Sham, PMF-1, PMF-2, and Sepsis, with seven rats in each. Sepsis was performed using the CLP method. PMF-1 and PMF-2 were exposed to 7.5 Hz and 15 Hz PMF, respectively, for 24 hours. After having their livers removed, liver tissues were analysed using histological techniques. We observed remarkable healing in PMF groups. Apoptotic cells decreased in the PMF-treated groups compared with the Sepsis group (p < 0.05). Immune expressions of Acas-3, Bax, and HIF-1 increased in the Sepsis group, while Bcl-2 expression decreased (p < 0.05). The results imply that PMF application has anti-apoptotic, antiinflammatory, and therapeutic effects on septic liver tissue injury.

Effects of Diclofenac Sodium on Seizure Activity in Rats with Pentylenetetrazole-Induced Convulsions.

Epilepsy is a disease which affects between 1 and 2% of the population, and a large proportion of these people do not react to currently available anticonvulsant medications, indicating the need for further research into novel pharmacological therapies. Numerous studies have demonstrated that oxidative stress and inflammation occur during epilepsy and may contribute to its development and progression, indicating higher levels of oxidative and inflammatory parameters in experimental models and clinical patients. This research aimed to assess the impact of diclofenac sodium, a nonsteroidal anti-inflammatory medicine, on seizure and levels of oxidative stress and inflammatory biomarkers in a rat model of epilepsy triggered by pentylenetetrazole (PTZ). 60 rats were randomly allocated to one of two groups: electroencephalography (EEG) recordings or behavioral evaluation. Rats received diclofenac sodium at three various doses (25, 50, and 75 mg/kg) intraperitoneally (IP) or a placebo, followed by intraperitoneal (IP) pentylenetetrazole, a powerful seizure-inducing medication. To investigate if diclofenac sodium had antiseizure properties, seizure activity in rats was evaluated using EEG recordings, the Racine convulsion scale (RCS) behaviour score, the duration of the first myoclonic jerk (FMJ), and the levels of MDA, TNF-α, and SOD. The average percentage of EEG spike waves decreased from 76.8% (placebo) to 64.1% (25 mg/kg diclofenac), 55.9% (50 mg/kg diclofenac), and 37.8% (75 mg/kg diclofenac). FMJ had increased from a mean of 58.8 s (placebo), to 93.6 s (25 mg/kg diclofenac), 185.8 s (50 mg/kg diclofenac) and 231.7 s (75 mg/kg diclofenac). RCS scores decreased from a mean score of 5.6 (placebo), to 3.75 (25 mg/kg diclofenac), 2.8 (50 mg/kg diclofenac) and 1.75 (75 mg/kg diclofenac). MDA levels reduced from 14.2 ng/gr (placebo) to 9.6 ng/gr (25 mg/kg diclofenac), 8.4 ng/gr (50 mg/kg diclofenac) and 5.1 ng/gr (75 mg/kg diclofenac). Likely, TNF-α levels decreased from 67.9 ng/gr (placebo) to 48.1 ng/gr (25 mg/kg diclofenac), 33.5 ng/gr (50 mg/kg diclofenac) and 21.3 ng/gr (75 mg/kg diclofenac). SOD levels, however, enhanced from 0.048 U/mg (placebo) to 0.055 U/mg (25 mg/kg diclofenac), 0.14 U/mg (50 mg/kg diclofenac), and 0.18 U/mg (75 mg/kg diclofenac). Diclofenac sodium (25, 50, and 75 mg/kg i.p.) effectively lowered the spike percentages and RCS scores linked with PTZ-induced epilepsy in rats, as well as significantly decreased MDA, TNF-α, IL-1ß, PGE2 and increased SOD levels. Probably as a result of its anti-oxidative and anti-inflammatory effects, diclofenac sodium dramatically lowered seizure activity at both doses compared to placebo control. Each of these results were significant, with p-values of < 0.01, < 0.05. Therefore, the therapeutic application diclofenac sodium as a potential anticonvulsant should be investigated further.

Does anti-IgE therapy prevent chronic allergic asthma-related bone deterioration in asthmatic mice?

Current evidence on the association between allergic diseases and bone metabolism indicates asthma may be a potential risk factor for bone health. Using anti-IgE has been proven effective in allergic asthma treatment with a good safety profile; however, its effects on bone health are unknown. Thus, we aimed to investigate whether: (i) chronic allergic asthma (CAA) causes any meaningful changes in bone, and if any, (ii) anti-IgE therapy prevents any CAA-induced adverse alteration. A murine model was used to study CAA. Thirty-two BALB/c male-mice were assigned into four groups (eight-mice/group): Control, CAA (treated with saline), CAA + 100 µg of anti-IgE (CAA + 100AIgE), and CAA + 200 µg of anti-IgE (CAA + 200AIgE) groups. After immunization, saline or anti-IgE was performed intraperitoneally for 8-weeks (in five-sessions at 15-days interval). Three-point bending test was used for the mechanical analysis. Bone calcium (Ca2+) and phosphorus (P3-) as well as Ca/P ratio were evaluated using inductively-coupled plasma-mass-spectrometer (ICP-MS). Compared to control, reductions observed in yield and ultimate moments, rigidity, energy-to-failure, yield and ultimate stresses, elastic modulus, toughness, and post-yield toughness parameters of the CAA group were found significant (P < 0.05). Similar declines were also detected regarding bone Ca2+, P3- and Ca/P ratio (P < 0.05). Compared to control, we observed that 200 µg administration of anti-IgE in CAA + 200AIgE group hindered CAA-related impairments in mineral and mechanical characteristics of bone, while 100 µg in CAA + 100AIgE failed to do so. Our results showed CAA may cause bone loss, leading to a decrease in bone strength, and anti-IgE administration may dose-dependently inhibit these impairments in bone.

Comparison of the Effects of Pulsed Electromagnetic Field and Extracorporeal Shockwave Therapy in a Rabbit Model of Experimentally Induced Achilles Tendon Injury.

Achilles tendon injuries are a common cause of complications including adhesions and tendon degeneration. As a result of these complications, the biomechanical properties are lost. Extracorporeal shockwave therapy (ESWT) and pulsed electromagnetic field (PEMF) recover the injured tendon structure; however, detailed studies of changes in tendon biomechanical properties are limited. We hypothesized that PEMF application would improve Achilles tendon biomechanical properties similar to ESWT. The curative effects of a PEMF 4-week application (15 Hz, 1 mT, 260 µs, 1 h/day) and ESWT (3 doses/28 days, 1st dose: 0.12 mJ/mm2 , 15 Hz, 300 impulses; 2nd dose: 0.14 mJ/mm2 , 15 Hz, 500 impulses; 3rd dose: 0.14 mJ/mm2 , 15 Hz, 500 impulses) on rabbits with Achilles tendon injury were investigated in terms of histopathological and biomechanical properties. The clinical feasibility of PEMF application was evaluated by comparing the results of both methods. Fifty New Zealand female rabbits were divided into two groups to be used in either biomechanical or immunohistochemical studies. Each of the two groups was further divided into five groups: C (Control), SH (Sham), TI (tendon injury), TI + ESWT, and TI + PEMF. Biomechanical evaluations revealed that maximum load, toughness, and maximum stress averages of the TI + PEMF group significantly increased (P < 0.05). When immunohistochemical images of the TI + PEMF group were compared with those of the TI group, the amount of fibrous tissue was less, the homogeneity of collagen fibers recovered, and collagen organization was more uniform. We conclude that both ESWT and PEMF are equally efficient for Achilles tendon recovery. PEMF application is effective and can be used in the clinic as a painless alternative treatment method. © 2020 Bioelectromagnetics Society.

Electrocardiography (ECG) analysis and a new feature extraction method using wavelet transform with scalogram analysis.

Electrocardiography (ECG) signals and the information obtained through the analysis of these signals constitute the main source of diagnosis for many cardiovascular system diseases. Therefore, accurate analyses of ECG signals are very important for correct diagnosis. In this study, an ECG analysis toolbox together with a user-friendly graphical user interface, which contains the all ECG analysis steps between the recording unit and the statistical investigation, is developed. Furthermore, a new feature calculation methodology is proposed for ECG analysis, which carries distinct information than amplitudes and durations of ECG main waves and can be used in artificial intelligence studies. Developed toolbox is tested using both Massachusetts Institute of Technology-Beth Israel Hospital (MIT-BIH) Arrhythmia ECG Database and an experimentally collected dataset for performance evaluation. The results show that ECG analysis toolbox presented in this study increases the accuracy and reliability of the ECG main wave detection analysis, highly fasten the process duration compared to manual ones and the new feature set can be used as a new parameter for decision support systems about ECG based on artificial intelligence.

Does Levetiracetam Administration Prevent Cardiac Damage in Adulthood Rats Following Neonatal Hypoxia/Ischemia-Induced Brain Injury?

Cardiovascular abnormalities are widespread when a newborn is exposed to a hypoxic-ischemic injury in the neonatal period. Although the neuroprotective effects of levetiracetam (LEV) have been reported after hypoxia, the cardioprotective effects of LEV have not been documented. Therefore, we aimed to investigate whether levetiracetam (LEV) has a protective effect on cardiac-contractility and ultrastructure of heart muscle in rats exposed to hypoxia-ischemia (HI) during the neonatal period. A total of 49 seven-day-old rat pups were separated into four groups. For HI induction, a combination of right common carotid artery ligation with 8% oxygen in seven-day-old rat pups for 2 h was performed for saline, LEV100, and LEV200 groups. Just after hypoxia, LEV100 and LEV200 groups were administered with 100 mg/kg and 200 mg/kg of LEV, respectively. The arteries of rats in the control group were only detected; no ligation or hypoxia was performed. At the end of the 16th week after HI, cardiac mechanograms were recorded, and samples of tissue were explored by electronmicroscopy.While ventricular contractility in the control group was similar to LEV100, there were significant decreases in both saline and LEV200 groups (p < 0.05). Although ventricular contractile duration of the control and saline groups was found to be similar, durations in the LEV100 and LEV200 groups were significantly higher (p < 0.05). After HI, mitochondrial damage and ultrastructural deteriorative alterations in ventricles and atriums of the LEV-administered groups were significantly less severe than the saline group. The present study showed that neonatal HI caused long-term cardiac dysfunction and ultrastructural deteriorations in cardiac muscles. LEV administration just after HI might possess some protective effects against myocardial damage and contractility.

The Protective Effects of Pulsed Magnetic Field and Melatonin on Testis Torsion and Detorsion Induced Rats Indicated by Scintigraphy, Positron Emission Tomography/Computed Tomography and Histopathological Methods.

PURPOSE: The aim of the present study was to show the protective effect of pulsed magnetic field (PMF) application and melatonin administration on damage in testis in a one-sided torsion detorsion induced rat model using testicular scintigraphy with 99mTc pertechnetate, PET/CT with 18F-FDG and histopathological methods. MATERIALS AND METHODS: Sixty male rats were used in the study; 30 rats were randomly divided into five groups for one day applications of sham control, torsion, melatonin, pulsed magnetic field (PMF) and melatonin plus PMF. Similarly, for one week group, the other 30 rats were divided into the same five group (n=6), but the animals were sacrificed after one week. Rats were exposed to 50 Hz, 1 mT PMF for two hours. PET/CT with 37 MBq 18F-FDG and testicular scintigraphy with and 37 MBq 99mTc pertechnetate examinations were carried out, and testicular tissue was examined using histopathological methods.  Results: In one day treatment, melatonin administration significantly increased perfusion and glucose metabolism compared to torsion group (p<0.01). Perfusion and glucose metabolism was also higher in the PMF and melatonin plus PMF groups than torsion group (p<0.01). In one week treatment, melatonin administration resulted in a significant higher perfusion rate and glucose metabolism rate compared to torsion group (p<0.01 and p<0.001, respectively). In addition, perfusion and glucose metabolism significantly increased in PMF and melatonin plus PMF groups compared to torsion group (p<0.01 and p<0.001, respectively). Furthermore, caspase-3 immunoreactivity and pathological changes increased in the torsion group (p<0.05). Melatonin and melatonin plus PMF treatment reduced the rate of immunoreactivity and pathological findings compared to the torsion group (p<0.05). CONCLUSION: According to these results it can be concluded that PMF application had a therapeutic benefit as effective as melatonin administering. In addition, it was indicated that PET/CT with 18F-FDG and testicular scintigraphy with 99mTc pertechnetate could be efficiently used in determining the treatment efficiency in testicular torsion.

miRNA expression profile is altered differentially in the rat brain compared to blood after experimental exposure to 50 Hz and 1 mT electromagnetic field.

Common complex diseases are a result of host and environment interactions. One such putative environmental factor is the electromagnetic field exposure, especially the occupational extremely low frequency (ELF) magnetic field, 50 Hz, 1 mT, whose neurobiological relevance remains elusive. We evaluated the effects of long-term (60 days) ELF-MF exposure on miRNAs previously related to brain and human diseases (miR-26b-5p, miR-9-5p, miR-29a-3p, miR-106b-5p, miR-107, miR-125a-3p). A total of 64 young (3 weeks-old) and mature (10 weeks-old) male/female Wistar-Albino rats were divided into sham and ELF-MF exposed groups. After sacrifice of the animals, blood samples from rat's tail vein and brain tissues were collected. The expression levels of miRNAs were investigated with Real-Time PCR technique and TaqMan probe Technology. All miRNA expression levels of the young female rats show a significant decrease in blood according to brain samples (p < 0.05), but fewer miRNAs displayed a similar significant decrease in the blood. In conclusion, these new observations might inform future clinical biological psychiatry studies of long-term electromagnetic field exposure, and the ways in which host-environment interactions contribute to brain diseases.

Rebaudioside A inhibits pentylenetetrazol-induced convulsions in rats.

The safety of patients with epilepsy consuming sweetening agents, which is becoming increasingly prevalent for various reasons, is a topic that should be emphasized as sensitively as it is for other diseases. Patients with epilepsy consume sweetening agents for different reasons such being diabetic or overweight. They can occasionally be exposed to sweetening agents unrestrainedly through consuming convenience food, primarily beverages. This study aimed to investigate the effects of rebaudioside A (Reb-A), which is a steviol glycoside produced from the herb Stevia rebaudiana (Bertoni), on epileptic seizures and convulsions induced by pentylenetetrazole (PTZ). Forty-eight male rats were used. Twenty-four rats were administered 35 mg/kg PTZ to trigger epileptiform activity; the remaining 24 rats were administered 70 mg/kg PTZ to trigger the convulsion model. The epileptiform activity was evaluated by spike percentage, whereas convulsion was evaluated by Racine's Convulsion Scale and the onset time of the first myoclonic jerk. Statistical analysis revealed a statistically significant decrease in the Racine's Convulsion Scale score and increase in the latency of first myoclonic jerk in a dose-dependent manner for the rat groups in which PTZ epilepsy had been induced and Reb-A had been administered. For the groups that were administered Reb-A, the spike decrease was apparent in a dose-dependent manner, based on the spike percentage calculation. These results indicated that Reb-A has positive effects on PTZ-induced convulsions.

Melatonin can Ameliorate Radiation-Induced Oxidative Stress and Inflammation-Related Deterioration of Bone Quality in Rat Femur.

The aim of the present study was to evaluate the radioprotective effects of melatonin on the biomechanical properties of bone in comparison to amifostine (WR-2721). Forty Sprague Dawley rats were divided equally into 5 groups namely; control (C), irradiation (R; single dose of 50 Gy), irradiation + WR-2721 (R + WR-2721; irradiation + 200 mg/kg WR-2721) radiation + melatonin 25 mg/kg (R + M25; irradiation + 25 mg/kg melatonin), and radiation + melatonin 50 mg/kg (R + M50; irradiation + 50 mg/kg melatonin). In order to measure extrinsic (organ-level mechanical properties of bone; the ultimate strength, deformation, stiffness, energy absorption capacity) and intrinsic (tissue-level mechanical properties of bone; ultimate stress, ultimate strain, elastic modulus, toughness) features of the bone, a three-point bending (TPB) test was performed for biomechanical evaluation. In addition, a bone mineral density (BMD) test was carried out. The BMD and extrinsic properties of the diaphyseal femur were found to be significantly higher in the R + M25 group than in group R (p < 0.05). A significant increase was observed in R + M50 (p < 0.05) in comparison to group R in the cross-sectional area of the femoral shaft and elastic modulus parameter. The protective effect of melatonin was similar to that of WR-2721. Thus, biomechanical quality of irradiated bone can be ameliorated by free radical scavenger melatonin.

Inhibition of Radiation-Induced Oxidative Damage in the Lung Tissue: May Acetylsalicylic Acid Have a Positive Role?

The lung is relatively sensitive to irradiation. It is shown that acetylsalicylic acid (ASA) might reduce oxidative injury and that it has a place in protection from cancer. The aim of this study is to evaluate the potential radioprotective effects of ASA. Whole-body irradiation (6 Gy, single dose) was applied to the rats. Glutathione (GSH), malondialdehyde (MDA), myeloperoxidase (MPO), and nitric oxide (NO) levels in the lung tissue were measured. Control (C), Radiation (R), Radiation + ASA (R + ASA; received irradiation and 25 mg/kg of ASA intraperitoneally (i.p.)), and Radiation + Amifostine (R + WR-2721; received irradiation and 200 mg/kg of WR-2721 i.p.) groups were used. The MPO levels decreased statistically significantly in the group administered ASA. Histopathologically, a radioprotective effect of ASA was more evident in the R + ASA group. ASA is an agent which has not been used as a radioprotector in the clinic yet, and it is worth supporting with more advanced studies.

Effects of a tumor necrosis factor-alpha inhibitor (etanercept) on the sciatic nerve in a hypoxic ischemia-induced neonatal rat model.

BACKGROUND: Neonatal hypoxic-ischemic (HI) injury has been considered to have acute and long term deleterious effects on many tissues, including the peripheral nerve. OBJECTIVES: In this study, the effects of a tumor necrosis factor-alpha (TNF-a) inhibitor (etanercept) on peripheral nerve damage and the ultrastructure of the sciatic nerve and gastrocnemius muscle in rats exposed to HI during the neonatal period were examined. MATERIAL AND METHODS: In this study, 45 seven-day-old rats were used and they were divided into three groups. The right carotid arteries of the rats in the saline and etanercept groups were ligated and put in a hypoxia chamber containing 8% oxygen for two hours. Just after hypoxia, the etanercept group was given 10 mg/kg etanercept, but the saline group had only saline intraperitoneally. The sham group rats' carotid arteries were not ligated or put in hypoxia. The amplitude, area and latency of sciatic nerve compound motor action potential (CMAP), which mainly reflects axonopathy and myelinopathy, were measured using standard techniques in the seventeenth week following the HI. Sciatic nerve and gastrocnemius muscle were evaluated with a transmission electron microscope, and grading for myelin sheath damage was done to all groups. RESULTS: Neuropathy was seen in rats after HI. While treatment with etanercept showed a protective effect for the axons of sciatic nerve, demyelination could not be recovered with etanercept. CONCLUSIONS: This study is the first in literature to show a partial interruption of the signal through the peripheral nerve fibers caused by axonal and myelin dysfunction continuation in rats exposed to HI after birth, in the 17th week.

Determination of the effects of pulmonary arterial hypertension and therapy on the cardiovascular system of rats by impedance cardiography.

AIM: To evaluate the effects of bosentan, sildenafil, and combined therapy on the cardiovascular system using impedance cardiography (ICG) in rats with monocrotaline (MCT)-induced pulmonary arterial hypertension (PAH). METHODS: Seventy male Wistar-albino rats were randomized into five groups. A single dose of MCT was given to all rats, except to the control group. After 4 weeks, bosentan, sildenafil, and combined treatment was started and lasted for 3 weeks. The last group that developed PAH did not receive any medication. Echocardiographic evaluation was performed to determine the PAH development. Thoracic fluid content index (TFCI), stroke volume index (SI), heart rate (HR), cardiac index (CI), and myocardial contractility index (IC) were determined. All procedures were performed at the baseline and after 4 and 7 weeks. RESULTS: Echocardiographic parameters showed that the all MCT-injected rats developed PAH. There were no significant inter- and intra-group differences in TFCI, SI, and IC (P>0.05), but at the 7th week, CI value in the sildenafil-treated PAH rats was significantly higher than in other groups and HR of PAH rats with combined therapy was significantly lower than in other groups. CONCLUSION: PAH did not have an effect on LV function of rats, or if it did, the effect was compensated by physiological processes. Also, sildenafil treatment deteriorated the LV cardiac index.

Adaptation of heart to training: a comparative study using echocardiography & impedance cardiography in male & female athletes.

BACKGROUND & OBJECTIVES: Intensive regular physical exercise training is associated with a physiological changes in left ventricular (LV) morphology and functions. This cardiac remodeling observed in the athletes is associated with the specific haemodynamic requirements of the exercise undertaken. The main objective of this study is to evaluate the effect of endurance training on cardiac morphology, systolic and diastolic LV functions and haemodynamic parameters both in male and female athletes. METHODS: Seventy nine healthy athletes (age 20.0 ± 2.6 yr; 49% male) and 82 healthy sedentary adolescent (age 20.8 ± 2.2 yr, 49% male) volunteered to participate in this study. All subjects underwent transthoracic echocardiography and impedance cardiography. RESULTS: Both female and male athletes had greater LV end-diastolic cavity sizes, LV mass and stroke volume (SV) values when compared with controls. Also, in male athletes, LV mass index was higher than in female athletes. While male athletes had lower resting heart rate compared to female athletes, they had higher mean arterial blood pressure. In male athletes, basal septal and mid septal strain values were higher compared to controls. There were no significant differences in strain and peak systolic strain rate values between female athletes and controls. In male athletes, there was a weak positive correlation between SV and LV mass, basal lateral and septal strain values. In female athletes, only a weak positive correlation was found between SV and basal septal strain values. INTERPRETATION & CONCLUSIONS: Endurance-trained male and female athletes had higher LV mass, LV cavity dimensions and SV compared to sedentary controls. Although there was no difference in diastolic cardiac functions between athletes and controls, local enhanced systolic function was found with increase of SV. Both morphologic and haemodynamic differences were more evident in male athletes.

The effect of insulin therapy on biomechanical deterioration of bone in streptozotocin (STZ)-induced type 1 diabetes mellitus in rats.

AIMS: To investigate the effect of insulin therapy on biomechanical properties of bone in streptozotocin (STZ)-induced type 1 diabetes mellitus (T1DM) in rats. METHODS: A total of 28 male Wistar-Albino rats (12-week-old; 210-300g) were divided into 4 groups (n=7 for each) including control [C; no treatment], sham [Sh; distilled water i.p., for 8 weeks], diabetes [T1DM; 65mg/kg of STZ, single i.p.] and diabetes+insulin treatment [T1DM+I; 65mg/kg of STZ, single i.p.+insulin; 2-4UI/day/rat, i.p., for 8 weeks] groups. Body weight, blood glucose levels (BGLs), bone mineral density (BMD) and geometric/mechanical properties of bone tissue were evaluated. RESULTS: BGLs in diabetic rats were significantly increased compared to non-diabetic rats, while the body weights were decreased (p<0.05). Femur length and cross-sectional area of femur were significantly decreased in both T1DM and T1DM+I groups (p<0.05). The significant reduction obtained in BMD in T1DM rats compared with C and Sh (p<0.05) groups was reversed by insulin treatment (p<0.05). Displacement, absorbed energy, maximum load, ultimate stress and toughness were significantly decreased inT1DM and T1DM+I groups compared to C and Sh groups (p<0.05). CONCLUSIONS: In conclusion, insulin treatment seems to be ineffective in restoration of biomechanical deterioration of bone specific to STZ-induced T1DM.

Deterioration of bone quality by streptozotocin (STZ)-induced type 2 diabetes mellitus in rats.

Patients with diabetes mellitus (DM) have various skeletal disorders and bone quality can be impaired in DM leading to fractures. Wistar albino male rats (270-300 g; n = 16) were assigned randomly to nondiabetic and diabetic rats (single dose intravenous injection of 45 mg/kg streptozotocin). All rats in each group were perpetuated for 8 weeks, and blood glucose levels as well as body weights were measured once weekly. Biomechanical measurements were performed at the mid-diaphysis of the left femur with tensile test. Extrinsic and intrinsic properties were measured or calculated. Bone mineral density (BMD) was also evaluated and measured by dual-energy X-ray absorptiometry. Cross-sectional area of the femoral shaft was evaluated by computerized tomography. Blood glucose levels in diabetic rats were significantly increased compared to that of the nondiabetic rats, while the body and femur weights were decreased (P < 0.05). In respect to the BMD, cross-sectional area and femur length, there were no statistically significant differences between the nondiabetic and diabetic rats (P > 0.05). The maximum load, ultimate stress, and toughness endpoints in diabetic rats were significantly decreased compared to that of the nondiabetics (P < 0.05). There were no statistically significant differences between the nondiabetic and diabetic rats with regard to the displacement and stiffness (P > 0.05). Femurs of diabetic rats had less absorbed energy than that in nondiabetics (P < 0.05). Ultimate strain was lower in diabetic rats than that in nondiabetics, while the elastic modulus was higher (P > 0.05). The bone quality of rats is decreased by streptozotocin-induced type 2 diabetes mellitus.

The effect of long-term extremely low-frequency magnetic field on geometric and biomechanical properties of rats' bone.

Bone is composed of a mineral matrix reinforced by a network of collagen that governs the biomechanical functions of the skeletal system in the body. The purpose of the study was to investigate the possible effect of extremely low-frequency magnetic field (ELF-MF) on geometric and biomechanical properties of rats' bone. In this study, 30 male Sprague-Dawley rats were used. The rats were divided into three groups: two experimental and one control sham. The first and second experimental group (n=10) were exposed to 100 microT and 500 microT-MF during 10 months, 2 h a day, respectively, and the third (sham) (n=10) group was treated like experimental group except ELF-MF exposure in methacrylate boxes. After ELF-MF and sham exposure, geometric and the biomechanical properties of rats' bone, such as cross-sectional area of the femoral shaft, length of the femur, cortical thickness of the femur, ultimate tensile strength (maximum load), displacement, stiffness, energy absorption capacity, elastic modulus, and toughness of bone were determined. The geometric and biomechanical analyses showed that a significant decrease in rats exposed to 100 microT-MF in comparison to sham and 500 microT-MF exposed rats about the values of cross-sectional area of the femoral shaft (P<0.05). Maximum load increased in 100 muT-MF and 500 microT-MF exposed rats when compared to that of the sham rats (P<0.05). The cortical thickness of the femurs of MF-exposed rats (100 microT and 500 microT) were significantly decreased in comparison to that of sham groups' rats (P<0.05 and P<0.001). However, no significant differences were found in the other biomechanical endpoints between each other groups, such as: length of the femur, displacement, stiffness, energy absorption capacity, elastic modulus, and toughness of bone (P>0.05). These experiments demonstrated that 100 microT-MF and 500 microT-MF can affect biomechanical and geometrical properties of rats' bone.

Effect of N-acetylcysteine on radiation-induced genotoxicity and cytotoxicity in rat bone marrow.

The aim of this study is to evaluate the potential radioprotective effects of N-acetylcysteine (NAC) against genotoxicity and cytotoxicity. The effect of WR-2721, as a representative of clinically used radioprotector, was compared with that of NAC, using the chromosomal aberration (CA) and micronucleus (MN) test systems in the irradiated rat's femoral bone marrow cells. We also investigated the mitotic index (MI), and the ratio of polychromatic erythrocytes (PCEs) to normochromatic erythrocytes (NCEs). The rats (n = 16) were divided randomly and equally into four groups: Control (C), Radiation (R), R+NAC (received irradiation and 1000 mg/kg NAC) and R+WR-2721 (received irradiation and 200 mg/kg WR-2721) rats. All the irradiated groups received whole-body gamma irradiation as a single dose of 6 Gy. Group R showed higher CA and MN formation when compared to C. Group R showed higher frequency of MN formation when compared to both R+NAC and R+WR-2721. The mean MI and PCE/NCE ratios were lower in Group R when compared to those of Group C. The mean MI and PCE/NCE ratios of both R+NAC and R+WR-2721 groups were lower when compared to those of Group C. The MI in Group R was lower when compared to that of both R+NAC and R+WR-2721 groups. In this study, the results give clues about the beneficial effects of NAC against radiation-induced genotoxicity and cytotoxicity in rat bone marrow and its effect may be comparable to that observed for WR-2721.

Effects of long-term exposure of extremely low frequency magnetic field on oxidative/nitrosative stress in rat liver.

Thirty-two adult Wistar-Albino female and male rats were used to investigate the long-term (45 days) effects of extremely low frequency magnetic field (ELF-MF; 50Hz, 1mT, 4h/day) exposure on oxidative/nitrosative stress in liver tissues of rats. The rats were divided randomly into four groups: female control (FC; n = 8) and MF-exposed female rats (F-MF; n = 8); male control (MC; n = 8) and MF-exposed male rats (M-MF; n = 8). Liver tissue from each animal was harvested and utilized for malondialdehyde (MDA) and 3-nitrotyrosine (3-NT) detection. MDA levels were measured by MDA-TBA method, while the 3-NT levels were determined by the HPLC-UV system. There were no significant differences between the MDA levels of the control (FC; MC) and MF-exposed (F-MF; M-MF) rats (P > 0.05). In the F-MF rats, 3-NT levels were significantly increased when compared to those of the FC rats (P < 0.05). There were no significant differences between the 3-NT levels of the MC and M-MF rats. In conclusion, our study suggests that the long-term ELF-MF exposure may enhance the oxidative/nitrosative stress in liver tissue of the female rats and could have a deteriorative effect on cellular proteins rather than lipids by enhancing 3-NT formation.