JNK Inhibition Modulates the Cytoskeleton, Hypoxia, and Neurogenesis on the Protein Level in Glioblastoma Cells and Astrocytes: An Immunofluorescence Study.

AIM: To evaluate the effects of c-Jun N-terminal kinase (JNK) inhibition and signal blocking on hypoxia (hypoxia-inducible factor 1-alpha (HIF-1α)), differentiation and neurogenesis (bone morphogenetic protein (BMP4)), and the cytoskeleton (F-actin) in glioblastoma multiforme cells (GBMCs). MATERIAL AND METHODS: We evaluated the differences between GBMCs and astrocytes in terms of the abovementioned parameters and assessed them with the aim of studying human GBMCs (U-87 MG) and astrocytes (SVG p12). The cells were exposed to different doses of the JNK inhibitor, SP600125, for 24, 48, and 72 hours. HIF-1α, BMP4, and F-actin expressions were evaluated using immunofluorescence image analysis. RESULTS: The half-maximal inhibitory concentration value for SP600125 was determined to be 10 µM at 24 hours of exposure. After SP600125 administration, elevated levels of HIF-1α and BMP4 were detected in GBMCs and astrocytes. F-actin level only increased in GBMCs after SP600125 administration. CONCLUSION: JNKs are important for cell proliferation, differentiation, survival, and death; thus, research on JNKs has become important for the treatment of many human diseases, especially brain tumors, Parkinson's disease, and Alzheimer's disease. The results of this study involving immunofluorescence techniques should be investigated and supported by studies that involve comprehensive molecular techniques.

Effects of Dexamethasone Exposure on Neural Crest Cells and Primary and Secondary Neurulation in Chick Embryos.

AIM: To evaluate the effects of dexamethasone (Dex) treatment on neural crest cells and primary and secondary neurulation in chick embryos. MATERIAL AND METHODS: Sixty fertilized eggs with an average weight of 65 ± 2 g were incubated in 60%?70% humidity at 37.2°C ± 0.1°C. After 26 hours of incubation, the control group (n=12) received 0.1 mg/kg physiologic saline (S), group 1 (n=12) received 0.1 mg/kg Dex, group 2 (n=12) received 1 mg/kg Dex, and group 3 (n=12) received 5 mg/kg Dex into each embryonic disc. The eggs were incubated until Hamburger?Hamilton stage (HH) 15, HH18, and HH20. Then, the embryos were dissected and evaluated both macroscopically and microscopically. RESULTS: The mortality rate in the control group, group 1, and groups 2 and 3 was 27%, 48%, and 100%, respectively. The neural tube thicknesses in group 1 significantly increased in HH 15 and HH20 (p < 0.05). The mitosis number in group 1 significantly decreased in each stage (p < 0.05). Wnt-1 expression was significantly lower in group 1 in HH15 (p < 0.05) and HH18 (p < 0.05), but there was no significant difference in HH20 (p > 0.05). Fibroblast growth factor (FGF) expression was significantly lower in group 1 in HH15 (p < 0.05). The expression of N-cadherin was significantly higher in group 1 in HH20 (p < 0.05). Fibronectin expression decreased in group 1 in HH18 (p < 0.01). CONCLUSION: Although the Dex treatment did not result in neural tube closure defect, the mortality rates and neural tube thicknesses increased, whereas mitotic activation and Wnt-1 and FGF signal pathways reduced in some stages.

Effect of suprascapular nerve injury on rotator cuff enthesis.

BACKGROUND: Numerous reports have shown that retracted rotator cuff tears may cause suprascapular nerve injury, and nerve injury causes atrophy and fat accumulation in the rotator cuff muscles. However, the effect of suprascapular nerve injury on rotator cuff enthesis has not been directly defined. This study aimed to investigate the effect of suprascapular nerve injury on rotator cuff enthesis. METHODS: Twenty-four Wistar albino rats underwent bilateral transection of the suprascapular nerve. Additional 6 rats were used as the sham group. Bilateral supraspinatus and infraspinatus entheses were examined after 1, 4, 8, and 12 weeks of nerve transection. Histomorphometric analyses were performed for each zone of enthesis. RESULTS: Compared with normal enthesis, significant and consistent decrease in cellularity were observed in the tendon and bone at all time points (P < .001). Collagen bundle diameter in the tendon also decreased in a similar manner (P < .001). Apart from the tendon and bone zones, fibrocartilage and calcified fibrocartilage zones showed similar response, and significant decrease in cellularity was observed 8 weeks after nerve transection (P < .001). CONCLUSION: This study identifies suprascapular nerve injury as an underlying mechanism leading to compromise of the rotator cuff enthesis structure. Suprascapular nerve injury may be considered as an etiologic factor for the impaired healing after repair of a massive tear.

Effect of L-Arginine Therapy on Vasospasm: Experimental Study in Rats.

OBJECTIVE: Cerebral vasospasm occurring after subarachnoid hemorrhage is a serious cause of morbidity. Cerebral vasospasm-related studies aim to prevent complications after subarachnoid hemorrhage. Nitric oxide affects brain blood flow and local vascular hemodynamics. L-arginine is used in the synthesis of nitric oxide, and hence we have investigated the efficacy of L-arginine treatment by using femoral artery vasospasm model. METHODS: Twenty-four male Sprague-Dawley rats have been divided into 3 groups as vasospasm, vasospasm + L-arginine, and control. In this study, we have preferred the "Rat Femoral Artery Vasospasm Model" described by Okada et al. Rats in the vasospasm + L-arginine group were given 300 mg/kg L-arginine for 7 days. At the end of the study, all samples of rat femoral arteries have been dissected and examined microscopically for histopathologic analysis. Statistical analysis was performed using Kruskal-Wallis and Mann-Whitney U tests, and P < 0.05 value was considered statistically significant. RESULTS: L-arginine treatment reduced the morphometric changes such as irregularity of the elastic lamina, disruption of the endothelial cells, vacuolization, and hemorrhages that are caused by vasospasm. When the wall thickness and lumen diameter measurements were evaluated statistically, significant improvement was observed in the vasospasm + L-arginine group compared with the vasospasm group (P < 0.01). CONCLUSIONS: In our study, the use of L-arginine, as a nitric oxide substrate, improved the experimental vasospasm in rats. Therefore we think that L-arginine therapy can be used in the prevention and treatment of cerebral vasospasm after subarachnoid hemorrhage.

Low pH irrigation fluids have positive effect on intra-articular chondral healing.

PURPOSE: The aim of this study was to evaluate the effect of Ringer's lactate (RL) solutions with different pH values on early histologic healing in a microfracture model in vivo. The null hypothesis of the presented study is that irrigation fluids with lower pH (6.4) have negative effects on fibrous cartilage healing. METHODS: Eighteen Wistar albino rats were randomly divided into three groups. Anterior midline incision was performed. Microfracture procedure was performed with a 1.2 mm k-wire at the lateral femoral condyle of each knee. the skin was sutured and joints were irrigated for 30 min with low pH (6.4) RL in Group 1, high pH (7.6) RL in Group 2 and no irrigation in Group 3. Three rats from each group were randomly selected and killed on the 3rd and 7th day. On the 3rd day, the healed chondral area was examined. On the 3rd and 7th day, the chondral depth and morphology were evaluated. On the 7th day, bone cellularity was assessed with osteoblast; osteoclast number and bone quality were evaluated with trabecular area and the number of trabeculae. RESULTS: Chondral healing area on the 3rd day was significantly higher in Group 1 compared to other groups. Chondral morphology was also qualitatively superior in Group 1 compared to other groups on the 3rd and 7th day. There were no differences in chondral depths between the groups on the 3rd day; however, increased chondral depths were observed in Group 1 on the 7th day. There were statistically significant increases in trabecular area and the number of trabeculae, as well as the number of osteoblasts and osteoclasts in Group 1 on the 7th day. CONCLUSIONS: The presented study revealed that low pH irrigation fluids have positive effects on the healing characteristics of intra-articular fibrous cartilage after microfracture procedure in vivo. In light of this study, we can assume that lower pH solutions could be safely used during microfracture procedures and it can also facilitate intra-articular fibrous cartilage formation and cartilage healing. Selection of irrigation solution is also important for intra-articular fibrous cartilage healing after microfracture procedure in vivo.

Effects of Three Different Frequencies of Aerobic Physical Activity on Heart and Kidney Tissues in Type 2 Diabetes-Induced Rats.

OBJECTIVE: Exercise has many beneficial effects in the treatment and prevention of Type 2 Diabetes Mellitus (T2DM). The aim of this study was to evaluate the effect of physical activities with different frequencies performed within a total total duration of one week on the heart and kidney tissues and vascular endothelial growth factor (VEGF) expressions in experimental T2DM model. METHOD: Rats (n: 30) were divided into sedentary control (SC), sedentary T2DM (SD), T2DM and continuous exercise (DEc, 30 min/day, 5 days/week), T2DM and short bouts exercise (DEsb, 3x10 min/day, 5 days/week), T2DM and weekend warrior exercise (DEww, 35+40 min/day, 2 days/week) groups. Rats were administered streptozotocin (65 mg/kg) and nicotinamide (110 mg/kg) through intraperitoneal route. After 6-weeks of swimming exercise (total duration 150 min/week), biochemical analyzes were performed to measure oral glucose tolerance test, insulin sensitivity and cytokines. Histopathological and immunohistochemical analyses [VEGF, capillary density, Transforming growth factor beta (TGF-ß)] were performed in heart and kidney tissues. RESULTS: Compared with sedentary T2DM rats, significant improvements were observed in all exercise groups in terms of blood glucose level, insulin sensitivity, capillary density in heart tissue, VEGF expressions in tissues, TGF-ß expressions in kidney tissue and all histopathological analysis (p<0.05). CONCLUSION: This study shows that physical activity at various frequencies may significantly ameliorate harmful effects of T2DM on heart and kidney tissue without significant differences between exercise frequencies, provided that the total duration of aerobic exercise remains the same (150 min/week).

Completion repair exhibits increased healing characteristics compared with in situ repair of partial thickness bursal rotator cuff tears.

PURPOSE: Little information is available regarding the healing capacity of in situ and completion repair for the treatment of partial thickness rotator cuff tears. The purpose of the study was to analyze the healing characteristics of both techniques. METHODS: Twenty-four adult Sprague-Dawley rats were operated. Partial thickness bursal side tears were created bilaterally at the supraspinatus tendons. Additional 6 rats were used as the sham group. The right shoulders were repaired in situ, and the left shoulders were repaired using the tear completion technique on the 10th day after detachment surgery. Rats were sacrificed on the 10th and 30th days after repair surgery. Type I collagen, the TNF-α concentrations, the number and diameter of fibroblasts, and neovascularization were examined at two different time points. RESULTS: The collagen concentration (ng/mg total protein) was significantly increased in both groups at T1 and decreased in the in situ group, whereas completion repair continued to increase at T2 (P < 0.05). The mean fibroblast diameter in the completion repair group continued to increase at both time points (P < 0.05). Neovascularization was significantly increased with tear completion compared with in situ repair (P < 0.05) at T1. No significant (n.s.) differences regarding the TNF-α concentration (pg/mg total protein) were noted for both surgical techniques at T2 (P > 0.05). CONCLUSION: Despite the concerns of detaching the intact tendon, the completion repair technique exhibited increased healing characteristics compared with the in situ technique. The reason for this finding might be the refreshing effect of debridement at the chronic degenerated tendon that could improve the healing response.

Effects of different aerobic exercise frequencies on streptozotocin-nicotinamide-induced type 2 diabetic rats: Continuous versus short bouts and weekend warrior exercises.

BACKGROUND: Exercise training is known to have multiple beneficial effects on type 2 diabetes mellitus (T2DM). The aim of this study was to explore the effects of aerobic exercise frequency on diabetic parameters, the histopathological structure of skeletal muscle, diabetic myopathy, and mitochondrial enzyme activity in an experimental model of T2DM. METHODS: Sprague-Dawley rats (n = 35) were rendered diabetic by injection of nicotinamide (110 mg/kg) and streptozotocin (65 mg/kg). Rats with blood glucose concentrations between 7 and 17 mmol/L were used. Diabetic rats were randomly allocated to one of the following groups: (i) control sedentary; (ii) diabetic sedentary; (iii) diabetic with continuous exercise (30 min/day, 5 days/week); (iv) diabetic with short bouts of exercise (3 × 10 min/day, 5 days/week); and (v) diabetic rats as "weekend warriors" (35 + 40 min/day, 2 days/week). After 6 weeks swimming exercise (total duration 150 min/week), biochemical tests were performed to measure insulin, glucose, cytokines, serum and muscle myeloperoxidase (MPO), and malondialdehyde (MDA) levels. Histologic analysis (histomorphometric and mitochondrial enzyme analysis) was also performed. RESULTS: Compared with diabetic sedentary rats, significant improvements were observed in all exercise groups in terms of glucose levels, weight loss, tissue MPO and MDA levels, muscular connective tissue, muscle atrophy, mitochondrial enzyme, and all histomorphometric analyses. CONCLUSIONS: The results of the study emphasize the effects of training on inflammation, increased oxidative stress, myopathy, and mitochondrial damage in a rat model of T2DM, and demonstrate that there is no major difference between exercise modalities provided that the total duration of exercise remains the same.

Treatment with milk thistle extract (Silybum marianum), ursodeoxycholic acid, or their combination attenuates cholestatic liver injury in rats: Role of the hepatic stem cells.

BACKGROUND/AIMS: Cholestasis, which results in hepatic cell death, fibrosis, cirrhosis, and eventually liver failure, is associated with oxidative stress. The aim of this study was to evaluate the effects of milk thistle (MT, Silybum marianum) and ursodeoxycholic acid (UDCA) or their combination on the activation of hepatic stem cells and on the severity of cholestasis liver injury in rats. MATERIALS AND METHODS: Under anesthesia, bile ducts of female Sprague Dawley rats were ligated (BDL) or had sham operation. BDL rats were administered saline, UDCA (15 mg/kg/d), MT (600 mg/kg/d), or UDCA+MT by gavage for 10 days. On the 11th day, rats were sacrificed and blood and liver samples were obtained. Serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), hepatic malondialdehyde (MDA) levels, and myeloperoxidase (MPO) activity were measured. Hepatic injury, a-smooth muscle actin expression, and stem cell markers c-kit, c-Myc, Oct3/4, and SSEA-1 were histologically determined. RESULTS: Histological scores, serum ALT, and hepatic MDA levels were higher in BDL group than in the sham rats, while all treatments significantly reduced these levels. The reduction in ALT was significantly greater in UCDA+MT-treated group than in other treatment groups. c-Kit, c-Myc, Oct3/4, and SSEA-1 were increased in saline-treated BDL group with respect to sham-operated control group, and these markers were significantly reduced in all treatment groups. CONCLUSION: In addition to a modulatory effect on the stem cell-induced regenerative response of the liver, UDCA, MT, and their combination demonstrated similar anti-inflammatory and antiproliferative effects on cholestasis-induced hepatic injury.

The Histological Effects of Ozone Therapy on Sciatic Nerve Crush Injury in Rats.

OBJECTIVE: Peripheral nerve injury is a common, important problem that lacks a definitive, effective treatment. It can cause neurologic deficits ranging from paresthesia to paralysis. This study evaluated the effect of ozone therapy on sciatic nerve crush injury in rats. MATERIALS AND METHODS: Twenty-four male rats were divided into control sham surgery, sciatic nerve injury, and sciatic nerve injury with ozone groups (each n = 8). The sciatic nerve injury was inflicted via De Koning's crush-force method. The sciatic nerve injury group received medical air and the sciatic nerve injury ozone group received 0.7 mg/kg ozone. Sciatic nerve samples were obtained 4 weeks after injury. Vascular congestion, vacuolization, edema formation, S100 expression, and the thicknesses of the perineurium and endoneurium and diameter of the injured sciatic nerves were evaluated. RESULTS: The diameter of the sciatic nerve and thicknesses of the perineurium and epineurium were significantly greater in the sciatic nerve injury group (P < 0.05) and significantly less in the sciatic nerve injury with ozone group (P < 0.001). High S100 immunoreactivity was seen in the sciatic nerve injury group compared with the other 2 groups (P < 0.05). The distributions of vascular congestion and vacuolization were significantly less in the sciatic nerve injury with ozone group (P < 0.05). CONCLUSIONS: Ozone therapy improved sciatic nerve injury recovery without causing an increase in fibrotic tissue. Ozone reduced fibrosis, vascular congestion, vacuolization, and edema in rodents. Ozone treatment might be used to assist in sciatic nerve injury.

Effects of Ozone on Spinal Cord Recovery via the Wnt/ Β-Catenin Pathway Following Spinal Cord Injury in Rats.

AIM: At the cellular level, spinal cord injury (SCI) provokes an inflammatory response that generates substantial secondary damage within the spinal cord but may also contribute to its repair. Besides intracellular antioxydant increase after exactly estimated oxidative stress; oxygen formation and transport is also advanced by ozone. The Wnt family of proteins contributes to the development of the nervous system, influencing cell proliferation. In the present study we evaluated the effect of ozone on spinal cord injury in rats. MATERIAL AND METHODS: Twenty-one male Sprague-Dawley rats were used. The rats were randomly allocated into three groups (control, trauma and trauma+ozone). SCI was inflicted using Allen"s spinal cord trauma method. The study was performed to determine the effects of ozone therapy on rats with SCI in terms of locomotor strength clinically and neuronal injury, white matter cavitation, edema, number of blood vessels, and expression of ß-catenin immunohistochemically. RESULTS: Comparison of the locomotor strength scores revealed a significant improvement on day 7 in trauma+ozone group. The groups were compared with regard to edema, neuronal injury, and white matter cavitation. Average ß-catenin levels were significantly different between the control group (68.11 ± 0.43), trauma+ozone group (37.96 ± 2.16), and trauma group (25.46 ± 1.07) (F = 1677.74, df = 2, p < 0.0005). CONCLUSION: The results of this study indicated that ozone therapy accelerates the healing process, increases vascularity, and reduces neuronal damage in rodents, suggesting that ozone therapy may be an adjuvant treatment in patients with SCI.

The effect of femoral nerve block on fracture healing via expressions of growth factors and ß-catenin.

INTRODUCTION: Many patients of all ages are admitted to hospital due to bone fractures. The etiology of fracture has a very wide spectrum, ranging from motor accidents to pathological conditions such as tumors, osteoporosis, and others. Bone fracture healing is a well-programmed and well-organized process, but is also long and intractable. The outcome of this process is therefore affected by many factors, such as the patient's age, ethnicity, nutritional status, and extent of the fracture. At present, regional analgesic techniques are frequently applied in order to avoid the complications of systemic opioid administration, central block applications. Femoral block is one of the regional analgesic techniques frequently applied by anesthesiologists when the lower extremities are involved. In this study, we evaluated the effect of femoral nerve block on the healing of an experimental non-stabilized femur fracture via expression of TGF-ß, VEGF, and ß-catenin and bone histomorphometry in rats. MATERIAL AND METHODS: In the control group, only the femoral fracture was performed and the bone was not fixated, similarly as in other groups. In the One-Day Block group, a one-time femoral nerve block was applied after the femoral fracture. In the Three-Day Block group, a daily femoral nerve block was performed for three days after the femoral fracture. On Days 4, 7, and 13, femurs were excised. The bone sections were stained with hematoxylin-eosin to evaluate bone tissue and Safranin O to assess callus tissue, cartilaginous tissue, and new bone areas. TGF-ß, VEGF, and ß-catenin were assessed by immunohistochemistry. RESULTS: Histomorphometric analysis revealed that femoral block application had a positive impact on bone healing. TGF-ß expression in the One-Day and Three-Day Block Groups was significantly higher than in the control group at all times, as was also the case with VEGF expression. On day 13, ß-catenin expression was significantly higher in the Three-Day Block group than the others. CONCLUSIONS: The results of the study suggests that the applications of a femoral nerve block for perioperative analgesia, for either one day or three days, resulted in better and more rapid bone healing.

The Effect of Ozone Therapy on Experimental Vasospasm in the Rat Femoral Artery.

AIM: Oxidation products following subarachnoid hemorrhage (SAH) are among the causative substances of cerebral vasospasm and poor outcome. Ozone (O3) is a gas that contains three atoms of oxygen with a cyclic structure. It has been suggested that application of low-dose ozone has an antioxidant effect and provides resistance to oxidative stress. We investigated the effect of oxygen-ozone therapy on rat femoral artery vasospasm. MATERIAL AND METHODS: Twenty-four male Sprague-Dawley rats were randomly separated into vasospasm, vasospasm + ozone and control groups. The femoral artery vasospasm model was used. Rats in the vasospasm + ozone group were given 4 mL of ozone (20 µ/mL) daily for 7 days. Femoral arteries were examined by light microscopy for histological changes and morphometric analysis. Kruskal Wallis test and Mann Whitney U tests were used for the statistical analysis. The values of p < 0.01 and p < 0.05 were recognized as statistically significant. RESULTS: Ozone treatment reduced the morphometric changes as irregularity of the elastic lamina, disruption of the endothelial cells, vacuolization and hemorrhages that caused by vasospasm. The measurements of the wall thickness (p=0.003; p < 0.01) and lumen diameter (p=0.001; p < 0.01) showed statistically significant difference (p < 0.01) between the vasospasm and vasospasm+ozone groups. CONCLUSION: Ozone therapy may be useful in the treatment of post-hemorrhagic vasospasm.

Impact of 1p/19q codeletion on the diagnosis and prognosis of different grades of meningioma.

BACKGROUND: Meningiomas are one of the most common tumours to affect the central nervous system. Genetic mutations are important in meningeal tumourigenesis, progression and prognosis. In this study, we aimed to examine the effect of 1p/19q deletion on the diagnosis and prognosis of meningioma subtypes using the fluorescence in situ hybridization (FISH) method. METHODS: Twenty-four patients with meningioma were retrospectively studied. Tumour samples were obtained from 10 typical, 11 atypical and three anaplastic malignant meningiomas. The most representative tumour sections were screened for 1p/19q deletion using the FISH method. RESULTS: Of the 24 patients, eight were women (33.3%) and 16 (66.7%) were men. The mean age was 56.6 years. The higher-grade meningioma was usually seen in males and had a higher rate of deletion on 1p (p = 0.001). There was a statistically significant difference between the grades and the rate of deletion on 19q (p = 0.042) and between the grades and the rates of polysomy, monosomy and amplification on 19q (p = 0.002; p = 0.001; p = 0.002, respectively). There was no statistical difference between 1p/19q codeletion and the grades of meningioma (p > 0.05). We detected higher level of Ki-67 in the condition of codeletion but did not find a statistical difference (p = 0.0553). CONCLUSION: Deletion on 1p, as well as deletion, polysomy, monosomy and amplification on 19q, are detected more frequently in high grade meningiomas. This amplification is most likely due to the amplification of oncogenes.

Effects of hemostatic polysaccharide agent on epidural fibrosis formation after lumbar laminectomy in rats.

BACKGROUND CONTEXT: Epidural fibrosis is a common adverse outcome of spinal surgery that can compress the dural sac and nerve root. Local hemostatic agents have many indications in numerous types of spinal surgery. As these agents may behave as foreign bodies, inducing inflammation and delaying regeneration, they could enhance the risk of epidural fibrosis. PURPOSE: We evaluated the effects of hemostatic polysaccharide on epidural fibrosis development in laminectomized rats. STUDY DESIGN: This is a randomized controlled trial. OUTCOME MEASURES: One month after surgery, tissues were histopathologically examined. Spinal tissue surrounding the laminectomy site was cut with a microtome and stained with hematoxylin and eosin and Masson trichrome. Slides were evaluated by a pathologist in a blinded fashion. The extent of epidural fibrosis, fibroblast cell density, cartilage, and bone regeneration was evaluated. METHODS: Rats were randomly assigned to receive sham surgery, laminectomy, or laminectomy with hemostatic polysaccharide (seven rats per group). Sham surgery that consisted of a skin incision was performed without laminectomy. Laminectomy was performed at the L1 and L2 vertebrae. In the experimental group, the polysaccharide hemostatic material, HaemoCer was placed in the laminectomy area. RESULTS: The proportion of rats with epidural fibrosis in laminectomized mice (both with and without hemostatic material) was higher than in sham-operated rats (p<.01). There was no difference in fibrosis between the two groups of laminectomized rats (p>.05). CONCLUSIONS: Our study indicates that hemostatic polysaccharide does not enhance epidural fibrosis following laminectomy in rodents, suggesting that absorbable polysaccharides may be appropriate for use in hemostasis during spinal surgery.

Effects of the popular food additive sodium benzoate on neural tube development in the chicken embryo.

AIM: Many more additives have been introduced with the development of processed foods. Neural tube defects are congenital malformations of the central nervous system. More than 300 000 children are born with neural tube defects every year and surviving children remain disabled for life. Sodium benzoate is used intensively in our daily lives. We therefore aimed to evaluate the effects of sodium benzoate on neural tube defects in chicken embryos. MATERIAL AND METHODS: Fertile, specific pathogen-free eggs were used. The study was conducted on five groups. After 30 hours of incubation, the eggs were opened under 4x optical magnification. The embryonic disc was identified and sodium benzoate solution was injected. Eggs were closed with sterile adhesive strips and incubation was continued till the end of the 72nd hour. All eggs were then reopened and embryos were dissected from embryonic membranes and evaluated histopathologically. RESULTS: We found that the development of all embryos was consistent with the stage. We detected neural tube obstruction in one embryo. Neural tube defects were not detected in any embryos. CONCLUSION: This study showed that sodium benzoate as one of the widely used food preservatives has no effect to neural tube defect development in chicken embryos even at high doses.

The effect of organic silicon injection on Achilles tendon healing in rats.

OBJECTIVE: The aim of this study was to assess the efficacy of a soluble absorbable silicon compound on healing of the Achilles tendon. METHODS: The Achilles tendons of 21 Wistar albino rats were cut and repaired. A 0.01 ml organic silicon solution (silanol) was injected peri/intratendinously into the left leg of all rats and the same dose of saline into the right leg postoperatively. Rats were randomly divided into 3 groups for biomechanical testing on Day 10 (7 rats) and Day 20 (7 rats) and histological and immunohistochemical assessment on Day 20 (7 rats). Fibroblast cell count and diameter, tissue vascularity and blood vessel diameter were evaluated by histomorphometry. Basic fibroblast growth factor (bFGF) immunoreactivity was analyzed with immunohistochemistry on Day 20. Failure load and stiffness of the repaired tendons were measured on Days 10 and 20. RESULTS: The number of fibroblasts per area, average fibroblast diameter, number of vessels parallel to collagen bundles per area and average vessel diameter were significantly higher in the organic silicon group than in the control group (p<0.05). Strong immunoreactivity of bFGF in the silicon group was detected. Failure load was significantly higher in the silicon group than in the control group on Day 10 (p=0.041). On Day 20, while a difference still existed, this difference was not significant. There was no effect of the silicon injection on stiffness of healing tendons. CONCLUSION: Organic silicon appears to have a positive effect on tendon healing and is suitable for further studies on host healing response modification.

Stem cell and extracellular matrix-related molecules increase following melatonin treatment in the skin of postmenopausal rats.

The menopause has a negative effect in the skin. Melatonin affects skin functions and structures through actions mediated by cell-surface and putative-nuclear receptors expressed in skin cell. We have therefore determined the effects of melatonin treatment on stem cell in the epidermis and extracellular matrix related molecules in the dermis the skin of postmenopausal rats. A total of 45 female rats were divided into 5 groups: control group, group A [ovariectomy (OVX)], group B (OVX +10 mg/kg/day melatonin), group C (OVX +30 mg/kg/day melatonin), group S (sham operated + 10 mg/kg/day melatonin). Ventral skin samples were excised at 12th week after ovariectomy. Hematoxylin-eosin, periodic acid- methylamine silver, elastic van Gieson staining techniques were used to measure histomorphometrically the thickness of elastic fibers and basement membrane, depths of the epidermis, dermis, and subcutaneous fat layer. Immunohistochemical staining methods were used for fibroblast growth factor ß (FGF ß), collagen type I, fibronectin, ß-catenin, c-kit, c-Myc evaluation. Epidermal thickness, subcutaneous fat layer, and elastic fibers were significantly decreased in group C, and there was a significant increase after melatonin treatment. Although there was no difference in dermal thickness of group C, melatonin also significantly increased the dermal thickness. High FGF ß, type I collagen, fibronectin, ß-catenin, c-Myc immunoreactivity developed following melatonin in all groups. Thus melatonin treatment of postmenopausal rats was mostly due to the decrease of stem cell and extracellular matrix-related molecules in the skin.

Quantitative immunohistochemical analysis of nitric oxide synthases and apoptosis regulator proteins in the fetal rat brain following maternal uterine artery ligation.

The purpose of this study was to determine the relation between nitric oxide synthases (calcium-independent iNOS and calcium-dependent eNOS) and apoptosis regulator proteins (anti-apoptotic Bcl-2, pro-apoptotic p53) of fetal rat brain in experimental intrauterine growth retardation (IUGR) model via quantitative immunohistochemistry. Cortical zone of parietal cerebral cortex and ventricular zone of third ventricle were studied following bilateral uterine artery ligation on gestational day 18. Significant increase in iNOS immunoreactivity was determined in parietal cerebral cortex and ventricular zones as eNOS immunoreactivity increased in ventricular zone of IUGR group. Bcl-2 expression was significantly decreased in ventricular zone; whereas cortical zone of IUGR group expressed p53 immunoreactivity.

Constructive effect of exogenous melatonin against osteoporosis after ovariectomy in rats.

OBJECTIVE: To analyze histomorphometric, densitometric and biochemical effects of melatonin on osteoporosis in ovariectomized rats. STUDY DESIGN: Wistar rats were divided into 6 groups. Group C: control; Group I: bilateral ovariectomy (OVX); Group II: OVX + vehicle; Group III: OVX + 10 mg/kg/day melatonin (MLT); Group IV: OVX + 30 mg/kg/day MLT; Group V: sham + 10 mg/kg/day MLT. Cortex, trabecula, osteoblast and osteoclast numbers were evaluated on vertebra and femur histomorphometrically. Hydroxyproline analysis was used to determine collagen content of femur and vertebrae. Bone mineral density and bone mineral content were measured. RESULTS: Trabecular thickness and trabecular area of vertebra and femur and cortical thickness of femur showed remarkable decrease after OVX, but increased after MLT treatment in the OVX+MLT groups. Following OVX, no statistically significant difference was found in number of osteoblasts or osteoclasts, trabecular number or levels of hydroxyproline after treatment with MLT. OVX caused significant decrease in bone mineral density, but treatment with MLT was unable to reverse this effect. CONCLUSION: MLT may trigger microscopic changes in bone, and time of application is critical for clinical recovery. It can be effective in helping treat postmenopausal osteoporosis. However, it is contraindicated in women who have normal-functioning ovaries.