Resveratrol shows vasoprotective effect reducing oxidative stress without affecting metabolic disturbances in insulin-dependent diabetes of rabbits.

PURPOSE: Resveratrol has been shown to have vasoprotective effects by upregulating oxidative defense mechanisms in a variety of pathophysiological conditions. However, the effect of resveratrol on diabetic oxidative stress and vascular and metabolic abnormalities is not completely understood. Therefore, this study was designed to evaluate whether long-term resveratrol supplementation has a protective effect on vascular function and integrity in association with metabolic parameters and oxidative stress in insulin-dependent diabetes. METHODS: Diabetes was induced in rabbits with alloxan and maintained for 8 weeks. We used a resveratrol dose of 5 mg/L (10 weeks, starting 14 days before alloxan injection) and 50 mg/L (8 or 10 weeks, starting concomitantly or 14 days before alloxan injection) in the drinking water of rabbits. RESULTS: Relaxation to acetylcholine was impaired (control 75.6 ± 3.59%, versus diabetic 42.23 ± 2.53%) and contractions to phenylephrine increased (control 136.89 ± 2.27%, versus diabetic 159.37 ± 6.27%) in aortas from diabetic animals. These changes were associated with increased basal or NAD(P)H-induced superoxide production, as well as lipid peroxide and superoxide dismutase (SOD) levels in the aortic samples. The maximal relaxation to acetylcholine improved by 75.74 ± 9.04% in diabetic rabbits treated with resveratrol. The increased contractions to phenylephrine were not restored to control values after resveratrol treatments, but sensitivity to the contractions tended to decrease. Resveratrol increased nitrite/nitrate levels and suppressed basal or NAD(P)H-induced superoxide production and lipid peroxide levels in the aortas. Importantly, resveratrol increased serum insulin levels without affecting blood glucose and the lipid profile in diabetic rabbits. Using electron microscopic examinations, resveratrol was found to markedly protect the endothelial integrity from diabetes. CONCLUSION: Overall, there was no noticeable difference between resveratrol treatment groups on the recovery from diabetes. Our results indicate that resveratrol alleviates type 1 diabetes-induced vasculopathy by decreasing vascular oxidative stress and thereby increasing the bioavailability of nitric oxide without changing metabolic abnormalities.

Validation and reliability of the Turkish version of the fear avoidance beliefs questionnaire in patients with low back pain.

AIM: The aim of this study was to translate the questionnaire into Turkish and to investigate the test-retest reliability, construct validity and its sensitivity to change following physical therapy. METHODS: The questionnaire was translated into Turkish using the forward and backward translation technique. Test-retest reliability was assessed with the correlation coefficients. Scale analysis for internal validity, the Cronbach's alpha score was calculated. Construct validity was tested with principal components analysis and was also tested with divergent validity. Following three weeks of treatment, sensitivity to change and responsiveness of the questionnaire was assessed. RESULTS: The questionnaire was applied on 55 patients and high correlations were found on the repeated items 48 hours later. In the scale analysis, the Cronbach's alpha score was found as 0.911 for the total questionnaire. Two factors were found compatible with the original questionnaire with principal components analysis. These two factors explain 61.647% of the total variance in the questionnaire performed on 150 patients. In divergent validity, the fear avoidance beliefs were found in low correlation with the clinical variables. Sensitivity to change and responsiveness of the FABQ was found to be low. CONCLUSIONS: FABQ has sufficient psychometric features for its applicability in the Turkish population with subacute and chronic low back pain.

A comparison of various vascularization-perfusion venous nerve grafts with conventional nerve grafts in rats.

Peripheral nerves with defective segments can only be repaired using nerve grafts. Among the various nerve graft options, the outcome of vascularized grafts has been shown to be better, especially when used in the hypovascular and scarred recipient bed. The purpose of this study was to compare the regeneration capacities of various types of venous nerve grafts in a rat model. Forty adult male Wistar albino rats were divided into four groups. A 2-cm-long segment of femoral sheath was isolated from the surrounding tissue without disturbing the unity of the femoral sheath contents. Four different nerve graft models were applied: flow-through venous, arterialized venous, prefabricated venous, and conventional nerve graft (control). All nerve grafts were closed with silicone sheets. These neurovascular segments were reopened in postoperative week 10 to determine the viability of the grafted nerves and to assess the degree of nerve healing. Histopathologic examinations, morphometric analysis, and electrophysiological measurements were performed. The degree of nerve healing in the flow-through venous nerve grafts was similar to that observed in the arterialized nerve grafts. Prefabricated flow-through venous grafts were not as successful as flow-through venous grafts or arterialized nerve grafts. All of the vascularized nerve grafts showed better results than the conventional nerve grafts.

Electron microscopic examination of the myelinated axons of corpus callosum in perfused young and old rats.

In this study, the myelinated axons of parts of the corpus callosums of young and old rats were examined under the electron microscope and a grading system was performed for quantitating the ultrastructural pathological changes of these axons. Except the old splenium group, the only ultrastructural pathological change, observed in the myelinated axons was the separation in myelin configuration. In addition to this finding, in the old splenium group, in some of the myelinated axons, an interruption was observed in the myelin configuration. Additionally, these ultrastructural pathological findings were present in the larger sized myelinated axons of the corpus callosum.

Serum IgG, IgA, IgM, and IgE levels after electroacupuncture and diet therapy in obese women.

We investigated the effect of acupuncture therapy on obese women's body weight and peripheral blood levels of serum immunoglobulin G (IgG), immunoglobulin A (IgA), immunoglobulin M (IgM), and immunoglobulin E (IgE). Sixty-three healthy women were assigned into 3 groups: placebo electroacupuncture (n = 13; mean age, 40.5 +/- 4.2 years; body mass index [BMI], 33.5 +/- 4.2), diet restriction (n = 23; mean age, 42.9 +/- 4.0 years; BMI, 34.6 +/- 2.9), and electroacupuncture (n = 24; mean age, 40.1 +/- 5.9 years; BMI, 33.9 +/- 2.7). Electroacupuncture was applied to the Hunger and Shen Men ear points and to the LI 4, LI 11, St 36, St 44, and Ren 6 body points for 30 min once daily for 20 days. A restricted diet of 1400 kilocalories was given to participants in all 3 groups for 20 days. Weight was lost significantly in subjects in the electroacupuncture group compared to those in the diet restriction and placebo electroacupuncture groups (p < 0.000, Tukey test). Modulations in serum IgG (p < 0.001) were apparent in women treated with electroacupuncture compared with women treated with placebo electroacupuncture and restricted diet only. No significant changes were seen in serum IgA, IgM, and IgE levels among the 3 groups. Our results suggest that electroacupuncture can be effectively used to treat obesity. We also observed a modulating effect of serum IgG, which is associated with weight loss, in patients in the electroacupuncture group.

Prevention of doxorubicin-induced cardiotoxicity by melatonin.

Anthracyclines, such as doxorubicin and daunorubicin, are highly effective anticancer agents. Cardiotoxicity made by these agents develops as a complication of the cancer chemotherapy. Melatonin, the chief secretory product of the pineal gland, was recently found to be a free radical scavenger and antioxidant. We decided to evaluate the tissue-protective effect of melatonin against myocardial toxic effects of doxorubicin in six groups of rats. Rats were given doxorubicin (Dx) (45 mg/kg dose) and melatonin (MEL) (10 mg/kg), first doxorubicin and then melatonin (DM), first melatonin and then doxorubicin (MD). The degree of cardiac muscle cell alterations were examined either histologically (mean total score technique) or biochemically. In doxorubicin-treated group, malondialdehyde (MDA) levels of the heart tissue were significantly increased, glutathione (GSH) levels were decreased compared to the control rats. In the group in which first doxorubicin and then melatonin was given, MDA levels were significantly decreased and glutathione (GSH) levels were increased compared to the doxorubicin-treated group. During ultrastructural analysis, in doxorubicin-treated group, cellular edema, mitochondrial deformation, decreased glycogen stores, and disordered myofibrillary structure were observed. In contrast, in first doxorubicin and then melatonin-treated group, normal cellular structure was observed. But, first melatonin and then doxorubicin-treated group was not significantly preserved from the doxorubicin-induced changes. By preventing lipid peroxidation and myocardial lesions, melatonin may be highly effective in protecting against doxorubicin-induced cardiotoxicity.

Formation of the cochlear nerve in the modiolus of the guinea pig and human cochleae.

BACKGROUND: Central processes of the bipolar neurons in the spiral ganglion converge in the modiolus to form the initial portion of the auditory branch (cochlear nerve) of the eighth cranial nerve. This occurs before the cochlear nerve passes through the internal auditory meatus. The neurons of the spiral ganglion send their central processes towards the internal acoustic meatus, through a single canal to form the cochlear nerve. These processes are described in many textbooks as running through numerous longitudinal small canals called canales longitudinales modioli before entering the internal acoustic meatus. Results of this study indicated that the term; "canalis longitudinalis modioli" was considered to be more appropriate than the former. METHODS: Central processes of the bipolar neurons in the spiral ganglion of the guinea pig and human cochleae were investigated using stereo, light and electron microscopy. RESULTS: Detailed examination of the guinea pig and human cochleae by light, electron and stereomicroscopy did not reveal multiple longitudinal canals but a single canal for the cochlear nerve. CONCLUSIONS: The singular term canalis longitudinalis modioli is more appropriate than canales longitudinales modioli.

Erythropoietin exerts neuroprotection after acute spinal cord injury in rats: effect on lipid peroxidation and early ultrastructural findings.

Lipid peroxidation has been reported to play an important role in spinal cord injury (SCI). Erythropoietin (EPO) is a hematopoietic growth factor that stimulates proliferation and differentiation of erythroid precursor cells and is also known to exert neurotrophic activity in the central nervous system. The purpose of this study was to investigate the effectiveness of recombinant human EPO in attenuating the severity of experimental SCI. Rats were divided into seven groups. Controls (1) received only laminectomy. The trauma-only group (2) underwent 50-g/cm contusion injury and had no medication. In group 3, 30 mg/kg of methylprednisolone was introduced. The vehicle group (4) received vehicle solution containing human serum albumin, which is a solvent of EPO. Groups 5, 6, and 7 received 100 IU/kg, 1,000 IU/kg, and 5,000 IU/kg of EPO, respectively. All treatments were given as single doses, intraperitoneally, immediately after injury. Thiobarbituric acid-reactive substances were estimated to demonstrate lipid peroxidation, and ultrastructure was evaluated by electron microscopy. The results showed that lipid peroxidation by-products increased after injury. Administration of EPO and methylprednisolone sodium succinate (MPSS) reduced thiobarbituric acid-reactive substances after trauma. The best biochemical results were obtained with 5,000 IU/kg of EPO. Electron microscopic findings showed that EPO protected the spinal cord from injury. Although 1,000 IU/kg and 5,000 IU/kg of EPO inhibited lipid peroxidation better than MPSS, ultrastructural neuroprotection was similar.

Determination of the width of the presacral space on magnetic resonance imaging.

Presacral space enlargement may be the first sign of certain diseases. The normal width of the presacral space has not been widely investigated and in all previous studies was calculated from lateral radiographs obtained at barium enema examination. Our study determined the normal width of the presacral space on MRI and investigated a possible difference between men and women. The width of the presacral space was measured retrospectively from sagittal T2-weighted MR images of 193 patients (87 males; 106 females, aged 18-83 years). Presacral space width was measured separately for S1, S2, and S3 vertebral levels from the anterior surface of the vertebral bodies to the closest part of the posterior wall of the rectum. Differences between male and female subjects were analyzed by t-tests. Normal mean widths of the presacral space in men and women were 16.2 mm and 11.9 mm for S1, 14.9 mm and 11.2 mm for S2, and 13.0 mm and 10.6 mm for S3, respectively. Measurements of the presacral space width in men were significantly larger than in women at all three levels (P < 0.001 for S1, P < 0.001 for S2, P = 0.006 for S3). In summary, the presacral space width measured on MRI was found to be significantly larger in the male than in the female population.

Three-dimensional reconstruction of the lentiform nucleus from serial sections in man.

Three-dimensional (3-D) reconstruction of the lentiform nucleus was performed by using serial macroscopic anatomic sections, taken from a human cadaver. When the rendered form of this wire-frame reconstruction was examined, it was found that both the putamen and globus pallidus had upper and lower poles. The distances between the upper and lower poles were 2.23 cm in the putamen and 1.45 cm in the globus pallidus. The lower poles of the putamen and globus pallidus were about the same level but the upper pole of the putamen was 0.78 cm higher than in the globus pallidus. The vertical dimension of the lentiform nucleus was 22.9 mm. This is the first study reporting the three-dimensional reconstruction and the dimensions of the lentiform nucleus of the human brain. We believe that this study will be of help in future studies concerning the lentiform nucleus and its relations.

Effect of trapidil in ischemia/reperfusion injury of peripheral nerves.

OBJECTIVE: Ischemia plays an important role in the development of pathological changes in nerve tissue, and restoration of blood flow results in injury (ischemia/reperfusion [I/R] injury) mediated by toxic oxygen free radicals. Trapidil is currently used as a coronary artery vasodilating agent and is also used for the prevention of ischemic symptoms of cerebral vasospasm. The purpose of this study was to determine the effects of trapidil on I/R injury and the ischemic tolerance of rat peripheral nerves. METHODS: Preischemia or prereperfusion administration of trapidil (8 mg/kg) was evaluated in the rat sciatic nerve I/R injury model. Nerve tissue samples from the I/R injury site were assayed for malondialdehyde (MDA), nitrites, and nitrates, as markers of I/R injury, and pathological changes were evaluated by electron microscopy. RESULTS: I/R resulted in an increase in MDA levels, which remained elevated for 2 weeks in control nerves. Rats that received trapidil before ischemia exhibited decreased MDA levels, and rats that received trapidil after the standard 3 hours of ischemia demonstrated increased tolerance to reperfusion, as reflected in significantly decreased MDA levels. Nitrite and nitrate levels in trapidil-treated rats were significantly higher than those in control animals. Histological evaluations of the sciatic nerve segments demonstrated that preischemia and postischemia trapidil treatments had a sparing effect against the myelin damage and axonal edema that are consistently noted in untreated ischemic reperfused nerves. CONCLUSION: The results confirm that pretreatment with trapidil before the ischemic insult or before reperfusion provides marked protection against I/R injury in peripheral nerves.

Ultrastructural scoring of graded acute spinal cord injury in the rat.

OBJECT: There is a need for an accurate quantitative histological technique that also provides information on neurons, axons, vascular endothelium, and subcellular organelles after spinal cord injury (SCI). In this paper the authors describe an objective, quantifiable technique for determining the severity of SCI. The usefulness of ultrastructural scoring of acute SCI was assessed in a rat model of contusion injury. METHODS: Spinal cords underwent acute contusion injury by using varying weights to produce graded SCI. Adult Wistar rats were divided into five groups. In the first group control animals underwent laminectomy only, after which nontraumatized spinal cord samples were obtained 8 hours postsurgery. The weight-drop technique was used to produce 10-, 25-, 50-, and 100-g/cm injuries. Spinal cord samples were also obtained in the different trauma groups 8 hours after injury. Behavioral assessment and ultrastructural evaluation were performed in all groups. When the intensity of the traumatic injury was increased, behavioral responses showed a decreasing trend. A similar significant negative correlation was observed between trauma-related intensity and ultrastructural scores. CONCLUSIONS: In the present study the authors characterize quantitative ultrastructural scoring of SCI in the acute, early postinjury period. Analysis of these results suggests that this method is useful in evaluating the degree of trauma and the effectiveness of pharmacotherapy in neuroprotection studies.

Antioxidant actions and early ultrastructural findings of thiopental and propofol in experimental spinal cord injury.

Thiopental and propofol are effective antioxidant agents. The current study was undertaken to examine the neuroprotective effects of a single intraperitoneal dose of thiopental and propofol. Effects of the drugs were evaluated by lipid peroxidation and ultrastructural findings. Fifty male Wistar rats were divided into five groups. Group 1 was the control group. Rats underwent laminectomy only, and nontraumatized spinal cord samples were obtained 1 hour after surgical intervention. All other rats sustained a 50-g/cm contusion injury by the weight drop technique. Group 2 rats underwent spinal cord injury alone, group 3 rats received 1 mL intralipid solution intraperitoneally immediately after trauma as the vehicle group, group 4 rats received a 15-mg/kg single dose of thiopental, and group 5 rats received a 40-mg/kg single dose of propofol intraperitoneally following the trauma. Samples from groups 2, 3, 4, and 5 were obtained 1 hour after injury. Lipid peroxidation was determined by measuring the concentration of malondialdehyde in the spinal cord tissue. The ultrastructure of the spinal cord was determined by electron microscopy. The contusion injury was associated with a rise in lipid peroxidation. Compared with the trauma group there was significant attenuation in lipid peroxidation of groups 4 and 5. Ultrastructural findings showed that the rats of group 4 sustained minor damage after spinal cord injury, but there was more evident damage in group 5 rats. These results indicate that thiopental decreases lipid peroxidation and improves ultrastructure, whereas propofol decreases lipid peroxidation without improving ultrastructure 1 hour after spinal cord injury in rats.