The effect of systemic rifampicin treatment on inferior alveolar nerve regeneration in rats following crush injury.

Axonal regeneration of the inferior alveolar nerve (IAN) is a therapeutic target for functional recovery after peripheral nerve injury. Rifampicin exerts anti-apoptotic, anti-inflammatory, and anti-oxidant effects on nerve tissues that may enhance functional recovery after peripheral nerve injury. The aim of the present study was to evaluate the therapeutic effects of systemic rifampicin following IAN crush injury. Following the nerve crush injuries of the IAN, 24 Sprague-Dawley rats were randomly divided into three groups to receive daily intraperitoneal injections of either vehicle, 5 mg kg-1 rifampicin, or 20 mg kg-1 rifampicin. Twenty-four days after induction of nerve injuries, Fluorogold (FG) was injected over the mental foramen for the evaluation of neuronal survival. At the end of the four-week period, histologic and histomorphometric examination of IAN samples were performed and FG positive cells were counted in the trigeminal ganglion sections. FG positive cells were significantly more frequent in the 20 and 5 mg kg-1 rifampicin groups than in the vehicle-treated group. Electron microscopic analyses revealed that the percentage of axons with optimum g-ratio was significantly lower in the vehicle group than in both treatment groups. In conclusion, systemic rifampicin treatment can enhance peripheral nerve regeneration.

Comparative effects of photobiomodulation therapy at wavelengths of 660 and 808 nm on regeneration of inferior alveolar nerve in rats following crush injury.

The aim of the present study was to investigate the therapeutic effects of 660-nm and 880-nm photobiomodulation therapy (PBMT) following inferior alveolar nerve (IAN) crush injury. Following the nerve crush injuries of IAN, 36 Wistar rats were randomly divided into three groups as follows: (1) control, (2) 660-nm PBMT, and (3) 808-nm PBMT (GaAlAs laser, 100 J/cm2, 70 mW, 0.028-cm2 beam). PBMT was started immediately after surgery and performed once every 3 days during the postoperative period. At the end of the 30-day treatment period, histopathological and histomorphometric evaluations of tissue sections were made under a light and electron microscope. The ratio of the inner axonal diameter to the total outer axonal diameter (g-ratio) and the number of axons per square micrometer were evaluated. In the 808-nm PBMT group, the number of nerve fibers with suboptimal g-ratio ranges of 0-0.49 (p < 0.001) is significantly lower than expected, which indicates better rate of myelinization in the 808-nm PBMT group. The number of axons per square micrometer was significantly higher in the 808-nm PBMT group when compared with the control (p < 0.001) and 660-nm PBMT group (p = 0.010). The data and the histopathological investigations suggest that the PBMT with the 808-nm wavelength along with its settings was able to enhance IAN regeneration after nerve crush injury.

Evaluation of the Effects of Low-Level Laser Therapy on Diabetic Bone Healing.

The aim of the present study was to evaluate the effects of low-level laser therapy (LLLT) and biphasic alloplastic bone graft material on diabetic bone healing. Induction of diabetes was performed in 14 male Sprague-Dawley rats by intraperitoneal injection of a 50 mg/kg dose of streptozotocin. Two bilaterally symmetrical non-critical-sized bone defects were created in the parietal bones in each rat. Right defects were filled with biphasic alloplastic bone graft. Rats were randomly divided into 2 groups, with 1 group receiving 10 sessions of LLLT (GaAlAs, 78.5 J/cm, 100mW, 0.028 cm beam). The LLLT was started immediately after surgery and once every 3 days during postoperative period. At the end of treatment period, new bone formation and osteoblast density were determined using histomorphometry. Empty (control), graft-filled, LLLT-treated and both graft-filled and LLLT-treated bone defects were compared. New bone formation was higher in the graft treatment samples compared with the control (P = 0.009) and laser samples (P = 0.029). In addition, graft-laser combination treatment samples revealed higher bone formation than control (P = 0.008) and laser (P = 0.026) samples. Osteoblast density was significantly higher in the laser treatment (P <0.001), graft treatment (P = 0.001) and graft-laser combination treatment (P <0.001) samples than control samples. In addition, significantly higher osteoblast density was observed in the graft-laser combination treatment samples compared to the graft treatment samples (P = 0.005). The LLLT was effective to stimulate osteoblastogenesis but failed to increase bone formation. Graft augmentation for treatment of bone defects seems essential for proper bone healing in diabetes, regeneration may be supported by the LLLT to enhance osteoblastogenesis.

Effects of Platelet-Rich Fibrin Membrane on Sciatic Nerve Regeneration.

Alternative treatment approaches to improve the regeneration capacity of damaged peripheral nerves are currently under investigation. The objective of the present study was to evaluate the effects of platelet-rich fibrin (PRF) membrane after sciatic nerve crush injury in rabbits by histomorphometric and electromyographic analysis. The left sciatic nerves of 20 male Vienna rabbits were clamped for 30 seconds to induce crush injuries. Animals were randomly divided into 2 groups: PRF and control. For each animal in the PRF group, a PRF membrane was wrapped around the injured part of the sciatic nerve to form a tube. No additional treatment was performed in the control group. After a 12-week healing period, tissue samples from the injured nerve region were harvested and the g-ratio of axons, axon density, and impulse transmission changes were evaluated. Analysis revealed that axon density differences were not statistically significant between groups (P = 0.139). The rate of nerve fibers with optimum g-ratio was significantly lower in the PRF group than in the control group (P = 0.02). Conduction velocity differences between groups were not statistically significant. Although PRF application has previously shown positive regeneration effects on maxillofacial tissues, local PRF membrane application in tube form did not show any histomorphometric or functional improvement in peripheral nerve crush injury recovery.

Histological and Biomechanical Effects of Local Anesthetics and Steroids on Achilles Tendon: A Study in Rats.

BACKGROUND: Peritendinous injection of local anesthetics, alone or in combination with corticosteroids, is widely used in the treatment of tendinopathies. Toxicity of local anesthetics has been demonstrated in many cells, including myocytes, chondrocytes, and neurons. Bupivacaine and lidocaine are known to have time- and dose-dependent cytotoxicity in these cells. The effects of these agents on the tendon remain unknown. PURPOSE: To show histological and biomechanical effects after the injection of different local anesthetics and steroids, both single and combined, at different concentrations into the peritendinous sheath of rat Achilles tendon. STUDY DESIGN: Controlled laboratory study. METHODS: In the study, 100 rats were divided into 10 groups with equal body weights. Inflammation was induced in both Achilles tendons of each rat by means of the ball drop technique; 7 hours later, injections were made into the peritendinous sheaths of both Achilles tendons using lidocaine, bupivacaine, and dexamethasone as appropriate for the rat's group. At the end of the first week, the right Achilles tendons of the rats were removed for histological study. Left Achilles tendons were evaluated in terms of biomechanics. RESULTS: Histological findings demonstrated that the group with the most toxicity to the tendon was the group that received injection of dexamethasone alone. The groups with the least toxicity were those receiving dexamethasone combined with low- or high-dose bupivacaine. Biomechanical findings showed that the experimental groups had similar results to each other with the exception of the groups receiving 0.25% bupivacaine alone and dexamethasone alone, in which tendons revealed higher tensile strength. CONCLUSION: Local anesthetic and steroid applications have different histological and biomechanical effects on the tendon. Although the dexamethasone-injected group was the most affected in terms of histology, these changes could not be demonstrated biomechanically. CLINICAL RELEVANCE: In future clinical studies, the effect of steroids on the tendon should be investigated more comprehensively. Whether biomechanical results overlap with histological results should be investigated further.

Assessment of right ventricular endocardial dysfunction in mild-to-moderate mitral stenosis patients using velocity vector imaging.

PURPOSE: Right ventricular (RV) function plays an important role in the development of clinical symptoms, exercise capacity, prognosis, and survival in patients with mitral stenosis (MS). The purpose of this study was to evaluate global and regional RV systolic functions using a novel technique, VVI, in mild-to-moderate MS patients without clinical symptoms of heart failure. METHODS: The study population consisted of 60 patients (mean age 51.7 ± 11.6 years; 85% female) with isolated rheumatic mitral valve stenosis and 40 age- and sex-matched control subjects (mean age 49.1 ± 10.5 years; 76.7% female). Conventional echocardiography, tissue Doppler imaging (TDI), strain (S), and strain rate (SRs) analysis were performed in all patients. RESULTS: Transmitral mean pressure gradient was 6.1 ± 3.0 mmHg and mean mitral valve area was 1.41 ± 0.31 cm(2) in patients with MS. TDI systolic velocity was significantly lower in MS patients compared to control subjects (0.13 ± 0.03 m/sec vs. 0.17 ± 0.03 m/sec; P < 0.0001). RV-isovolumic acceleration was reduced in MS patients (3.75 ± 1.09 m/sec(2) vs. 4.62 ± 1.0 m/sec(2) ; P = 0.006). RV-myocardial performance index was significantly increased in patients with MS (0.75 ± 0.05 in MS and 0.29 ± 0.04 in controls; P < 0.0001) revealing impaired RV systolic and diastolic function. The mean longitudinal peak systolic S and SR were significantly reduced in patients with MS (P < 0.0001). CONCLUSION: Our data revealed that RV systolic performance is reduced in patients with mild-to-moderate MS.

Effects of topical Coenzyme Q10, Xanthan Gum and Sodium Hyaluronate on corneal epithelial wound healing.

CLINICAL RELEVANCE: Effective treatment of corneal epithelial defects is crucial to prevent secondary infectious keratitis and visual impairment due to loss of corneal transparency. Therefore, it is important to determine the effect of different topical agents on corneal wound healing response. BACKGROUND: The aim was to compare the effects of three different eye drops on corneal epithelial wound healing in an experimental model. METHODS: Twenty-four eyes of 24 female BALB/c mice were included. A 2 mm central corneal epithelial defect was created. Topical Coenzyme Q10 + Vitamin E D-α-TPGS 4 × 1 was applied to Group A (n = 6), topical Sodium hyaluronate + Xanthan Gum + 0.3% Nethylmicine 4 × 1 to Group B (n = 6) and topical Sodium hyaluronate 4 × 1 to Group C (n = 6). Group D (n = 6) was the control group without treatment. Clinical scoring according to corneal fluorescein staining and histopathological evaluations was performed. RESULTS: Clinical scores according to corneal fluorescein staining were similar in all groups on days 1 (p = 0.05), 2 (p = 0.15) and 3 (p = 0.62). Electron microscopy revealed disruption of intercellular junctions between corneal epithelial cells and intracellular vacuole formation in all groups except Group A. Corneal epithelial thickness and superficial epithelial microvillus arrangement were close to normal in Group A. CONCLUSION: Although there was no difference in clinical scores between groups, electron microscopy revealed a better organised epithelium with normal configuration of microvilli and less vacuolisation in Group A.

Mesenchymal stem cell therapy in necrotizing enterocolitis: a rat study.

We evaluated the potential therapeutic use of exogenous human bone marrow-derived mesenchymal stem cells (hBM-MSCs) in an experimental rat model of necrotizing enterocolitis (NEC). Thirty-six newborn Sprague-Dawley rats were randomly divided into three groups: NEC, NEC + hBM-MSC, and a control (control and control + hBM-MSC). NEC was induced by enteral formula feeding, exposure to hypoxia-hyperoxia, and cold stress. After NEC was induced, iron-labeled hBM-MSCs were administered by intraperitoneal injection. All pups were killed on the fourth day following injection, and the terminal ileum was excised for a histopathological and immunohistochemical evaluation. The pups in the NEC + hBM-MSC group showed significant weight gains and improvements in their clinical sickness scores (p < 0.01). Bowel damage severity observed in the histopathological evaluation was significantly lower in the NEC + hBM-MSC group than that in the NEC group (p = 0.012). The number of MSCs homing to the bowel was significantly higher in the NEC + hBM-MSC group than that in the control + hBM-MSC group. In conclusion, this is the first study that has evaluated the effectiveness of hBM-MSCs in a neonatal rat NEC model. MSCs reduced histopathological damage significantly.

Antiproliferative and Mitochondrial Protective Effects of Apigenin in an Oxygen-Induced Retinopathy In Vivo Mouse Model.

Purpose: To investigate the effects of a common dietary flavonoid apigenin on retinal endothelial cell proliferation, retinal morphological structure, and apoptotic cell death in an oxygen-induced retinopathy (OIR) mouse model to evaluate the possibility of the use of apigenin in the treatment of ocular neovascular diseases (ONDs). Methods: Ninety-six newborn C57BL/6J mice were included. Eight groups were randomized, each including 12 mice. Two negative control groups were kept in room air: the first without any injection and the second received intravitreal (IV) dimethyl sulfoxide (DMSO), which is the solvent we used. The OIR groups were exposed to 75% ± 2% oxygen from postnatal days (PD) 7 to 12. On PD 12, the mice were randomly assigned to 6 groups: 2 OIR control groups (1 received no injection, 1 received IV-DMSO), 2 IV-apigenin groups (10 and 20 µg/mL), and 2 intraperitoneal (IP)-apigenin groups (10 and 20 mg/kg). We quantified retinal endothelial cell proliferation by counting neovascular tufts in cross-sections and examined histological and ultrastructural changes through light and electron microscopy. We evaluated apoptosis by terminal deoxynucleotidyl transferase-mediated nick end-labeling (TUNEL). Results: We detected a significant increase in endothelial cell proliferation in the OIR groups. Groups receiving apigenin, both IP and IV, had significant decreases in endothelial cells, atypical mitochondrion count, and apoptotic cells compared with the groups receiving no injections. None of the apigenin-injected groups revealed cystic degeneration or cell loss. Conclusions: Apigenin suppresses neovascularization, has antiapoptotic and antioxidative effects in an OIR mouse model, and can be considered a promising agent for treating OND. Clinical trial (Project number: DA15/19).

Role of autophagy and evaluation the effects of microRNAs 214, 132, 34c and prorenin receptor in a rat model of focal segmental glomerulosclerosis.

AIMS: Focal segmental glomerulosclerosis (FSGS) is the common cause of chronic renal disease worldwide. Although there are many etiologic factors which have common theme of podocyte injury conclusive etiology is not clearly understood. In this study, we aimed to explore the role of autophagy in the pathogenesis of podocyte injury, which is the key point in disease progression, and the roles of intrarenal microRNAs and the prorenin receptor (PRR) in the 5/6 nephrectomy and adriamycin nephropathy models of FSGS. MAIN METHODS: For experimental FSGS model, 5/6 nephrectomy and adriamycin nephropathy models were created and characterized in adult Sprague Dawley rats. Microarray analysis was performed on FSGS and control groups that was confirmed by q-RT-PCR. Beclin1, LC3B, PRR, ATG7 and ATG5 expression were evaluated by western blotting and immunohistochemistry. Also, Beclin1 and PRR expression were measured by ELISA. Glomerular podocyte isolation was performed and autophagic activity was evaluated in podocytes before and after transfection with miRNA mimic and antagonists. KEY FINDINGS: Glomerular expression of Beclin1, LC3B, PRR, ATG7 and ATG5 were significantly lower in the 5/6 nephrectomy than adriamycin nephropathy group and in both groups lower when compared to control groups. Western blot results were consistent with immunohistochemical data. Electron microscopy revealed signs of impaired autophagy in FSGS. Autophagic activity decreased significantly after miR-214, miR-132 and miR-34c mimics and increased after transfection with antagonists. SIGNIFICANCE: These results showed that the role of autophagic activity and decreased expression of PRR in FSGS pathogenesis and miR-34c, miR-132 and miR-214 could be a potential treatment strategy by regulating autophagy.

The effects of resveratrol on cyclooxygenase-1 and cyclooxygenase-2 mRNA and protein levels in diabetic rat kidneys.

Cyclooxygenase (COX), which have the isoforms of COX-1 and COX-2, is the key enzyme of prostaglandins biosynthesis. Especially, COX-2 is induced in inflammatory disease such as Diabetes Mellitus (DM). Resveratrol (RSV), a natural antioxidant, has a beneficial role in prevention of inflammatory disease. We investigated the changes of COX-1 and COX-2 mRNA expression and protein level in diabetic rat kidney after RSV treatment. Three months-old, 44 Wistar albino male rats, which were divided into six groups such as control group, sodium citrate buffer (sham control) group, diabetic group (DM), Dimethyl Sulfoxide induced control group, RSV treated sham control group (RSV) and RSV treated diabetic group (DM + RSV) were used for the study. Experimental diabetes was induced by intraperitoneal injection of 55 mg/kg Streptozotocin. After the induction of chronic diabetes 10 mg/kg per day RSV was administered intraperitoneally for 4 weeks. In this study. RSV has no significant effect on COX-1 mRNA expression in diabetic rat kidney (P > 0.05). Immunohistochemical study showed that COX-1 expression was slightly inhibited in RSV group and was not significantly supressed in DM + RSV group. When comparing control and treated groups, there were no significant differences in COX-2 mRNA or protein levels (P > 0.05). In conclusion, our results indicate that resveratrol do not significantly affect COX gene and protein expression. Therefore, different therapy strategies such as combination with other antidiabetic drugs may tried in STZ induced animal model for reducing diabetic symptoms and altering COX-1 and COX-2 mRNA or protein levels.

The morphological evaluation of ipsilateral and contralateral vasa deferentia in a rat model of unilateral spermatic cord torsion.

AIM: Spermatic cord torsion is a surgical emergency that requires early intervention to protect the effected testicle. The literature review about this ischemic reperfusion (I/R) injury reveals not only ipsilateral, but also contralateral testicular and epididymal injuries in a broad fashion. However, there is no data about vas deferens injury related with this surgical emergency. The aim of the study is to evaluate the morphological changes of the vas deferens due to testicular I/R injury. MATERIALS AND METHODS: Eighteen Wistar-Albino rats were allocated to three groups. Bilateral vasa deferentia of control group (Gr C, n = 6) were harvested without any surgical intervention. The torsion group was subjected to 2 h torsion and 2 h detorsion of the left testicle (Gr T, n = 6) and the third group underwent sham operations (Gr S, n = 6). Bilateral vasa deferentia of Gr T and S were harvested after surgery. The either side of the vas deferens was divided into three equal segments and these regions (adjacent to urinary bladder, medial and adjacent to testicle) were evaluated histopathologically. RESULTS: The electron microscopic evaluation of bilateral vasa deferentia of Gr T revealed different degrees of degeneration on either side. The region adjacent to testicle of the contralateral vas deferens was the most effected segment when compared with the other segments. CONCLUSION: In the light of these findings, it can be said that testicular I/R injury effects not only testis and epididymis, but also the adjacent vas deferens. This effect seems to be bilateral, like the testis and epididymis injury. Moreover, it mostly seems to depend on the apoptotic processes.

High dose cotinine may induce neural tube defects in a chick embryo model.

AIM: Nicotine is a well-known agent among 4000 chemicals in cigarettes. About 70 to 80% of nicotine is converted to cotinine, a major metabolite. The aim of the present study is to investigate the effect of cotinine on neural tube development in a chick embryo model. MATERIAL AND METHODS: Sixty fertile, specific pathogen free eggs were divided into 6 groups for this study. In the first group, a fixed cotinine concentration for each egg was calculated just to simulate the concentration of a smoker's blood level. A second experimental group was designed at a higher cotinine concentration. Embryos that succeeded to reach Hamburger-Hamilton stage 12 from each group were then embedded into paraffin for permanent sections. These two groups were compared with eggs subjected to vehicle (standard alcohol and ten times more alcohol concentration) and control groups (saline and sham groups). RESULTS: Embryos of the cotinine (regular dose), vehicle and control groups were normal, but embryos subjected to higher cotinine concentrations were malformed at the cranial part of the thoracic neural tube. CONCLUSION: Association of cotinine with neural tube defects was demonstrated in the present study. Cigarette smoking may induce hazardous effects on neural tube development.

Effect of intravitreal and intraperitoneal cyanidin-3-glucoside injection in oxygen-induced retinopathy mouse model.

Purpose: To evaluate the effect of cyanidin-3-glucoside (C3G) in oxygen-induced retinopathy (OIR) mouse model. Methods: In this experimental study, 10 C57BL / 6J type mice exposed to room air comprised two control groups (n = 5 each; a negative control and a group receiving intravitreal sterile dimethyl sulfoxide [IVS DMSO]). Thirty C57BL / 6J type mice exposed to 75% ± 2% oxygen from postnatal day 7 to postnatal day 12 comprised the OIR groups. On postnatal day 12, these mice were randomized into six groups (n = 5 each): two OIR control groups (negative control and IVS DMSO), two intravitreal C3G groups (300 and 600 ng/µL), and two intraperitoneal C3G groups (0.05 and 0.1 mg/kg). We quantified neovascularization by counting endothelial cell proliferation on the vitreal side of the inner limiting membrane of the retina and examined histological and ultrastructural changes via light and electron microscopy and apoptosis by terminal deoxynucleotidyl transferase deoxy-UTP-nick end labeling. Results: The intravitreal C3G groups yielded lower endothelial cell counts compared with the intravitreal DMSO group. The intraperitoneal high-dose group had lower cell counts compared with the OIR control groups. Electron microscopy revealed significantly less mitochondrial dysmorphology in intravitreal groups and the high-dose intraperitoneal mice. We noted no difference in apoptotic cell count between the controls, low-dose intravitreal, and both intraperitoneal groups. However, apoptotic cell count was significantly higher in the high-dose intravitreal group. Conclusion: C3G suppresses endothelial cell proliferation in an OIR mouse model, leads to a reduced hyperoxia-induced mitochondrial dysmorphology, but increases apoptotic cell death in high concentrations.

Antiproliferative and anti-apoptotic effect of astaxanthin in an oxygen-induced retinopathy mouse model.

OBJECTIVE: To evaluate the impact of intravitreal (IV) and intraperitoneal (IP) astaxanthin (AST) injections on neovascular development (ND), retinal morphology, and apoptotic activity in a C57BL/6J mouse model with hyperoxia-induced retinopathy (HIR). DESIGN: C57BL/6J mouse model. METHODS: Two negative control groups (n = 6 each; one of which received IV sterile dimethyl sulfoxide [DMSO]) of C57BL/6J-type mice were exposed to room air. The HIR groups included 36 C57BL/6J-type mice exposed to 75% ± 2% oxygen from postnatal day (PD) 7 to PD 12. On PD 12, these mice were randomized into 6 groups (n = 6 each): 2 HIR control groups (one of which received IV-DMSO), 2 IV-AST groups (10 and 100 µg/mL), and 2 IP-AST groups (0.5 and 5 mg/kg). We measured ND by counting neovascular tufts in cross sections and examined histological, ultrastructural changes via light and electron microscopy. Apoptosis was detected using terminal deoxynucleotidyl transferase-mediated nick end-labeling. RESULTS: No ND was detected in the negative control groups. ND levels were not significantly different between high- and low-dose AST for either means of administration. However, ND levels were significantly lower in the AST groups, regardless of delivery, compared to the control groups. The means of delivery (IP versus IV) also yielded significant differences in ND. The incidence of mitochondrial dysmorphology and apoptosis were lower in groups receiving AST. CONCLUSIONS: AST seems to suppress ND and has anti-apoptotic activity in the HIR mouse model.

Effect of Creatine on Rat Sciatic Nerve Injury: A Comparative Ultrastructural Study.

AIM: Creatine is an endogenous molecule synthesized in the liver, kidney and pancreas from glycine and arginine and is important for mitochondrial metabolism. It is widely used as a supplement for improving muscle mass and function for many years. As it is expected to prevent apoptosis and diminish oxidative stress, it is also studied in a number of neurodegenerative diseases for its beneficial effect in recent years. We studied the effect of creatine on the peripheral nerve injury in an experimental rat crush injury model to obtain ultrastructural evidence. MATERIAL AND METHODS: Animals were randomly divided into 3 groups having 5 animals in each group. Group 1 was the control group, Group 2 the trauma group and Group 3 the trauma+creatine group. The first group served as sham control. In group 2 and group 3, sciatic nerves of the rats received crush injury using aneurysm clips. In group 3, daily 2 g/kg creatine monohydrate was administered via gavage after the trauma. Nerve samples were obtained at the 28th day after trauma for light and electron microscopic evaluation. RESULTS: Our comparative analysis results suggest a possible positive effect of creatine supplement on peripheral nerve regeneration as statistical analysis revealed significant differences between group 2 and group 3. Though our finding does not represent a miracle of regenerative support, beneficial usage of creatine is documented in the present study. CONCLUSION: Creatine supplement helps to diminish the harmful effects of peripheral nerve crush injury which is also supported by electron microscopy findings.

Comparative evaluation of the electrophysiological, functional and ultrastructural effects of alpha lipoic acid and cyanocobalamin administration in a rat model of sciatic nerve injury.

BACKGROUND: Vitamin B12 and alpha lipoic acid (ALA) are known to promote functional and morphological recovery after peripheral nerve injury. OBJECTIVE: To compare the regenerative and neuroprotective effects of vitamin B12 and ALA treatment after sciatic nerve injury. METHODS: A total of 40 rats were randomly assigned to control (sciatic nerve exposure without injury or anastomosis), sham (sciatic nerve injury and epineural anastomosis were performed but no treatment was administered), PS (isotonic saline was administered for 12 weeks after surgery), ALA (2 mg/kg ALA was administered for 12 weeks after surgery), and vitamin B12 groups (2 mg/kg cyanocobalamin was administered for 12 weeks after surgery). Functional recovery was determined by footprint analysis, in vivo neurophysiology, and ex vivo histopathological examination. RESULTS: ALA treatment produced significant improvements in sciatic functional index values and non-significant improvements on electroneuromyography compared to vitamin B12 treatment. Upon histopathological examination, the regenerative effects of ALA were relevant to axonal structural recovery whereas vitamin B12 produced greater improvements in edema and myelination. CONCLUSIONS: While both vitamin B12 and ALA produced improvements after sciatic nerve injury, ALA was more functionally effective. The unique ultrastructural effects of vitamin B12 and ALA treatment should be considered in future studies.

Histomorphometric and Ultrastructural Evaluation of Long-Term Alpha Lipoic Acid and Vitamin B12 Use After Experimental Sciatic Nerve Injury in Rats.

AIM: To analyze the therapeutic effects of long-term alpha lipoic acid (A-LA) and vitamin B12 use via histomorphometric methods and electron microscopy in the transected sciatic nerves of rats. MATERIAL AND METHODS: Forty rats were randomized into five groups (n=8/group). In group I, 1 cm segment of sciatic nerve was resected without any other intervention. In group II (sham), following right sciatic nerve transection, primary epineurial anastomosis was performed by placing the edges of the nerve end-to-end. In group III (saline), after right sciatic nerve transection, the ends of the nerves were brought together and closed after application of intraperitoneal physiologic saline. In group IV, 2 mg/kg of alpha lipoic acid and in group V, 2 mg/kg of vitamin B12 was administered intraperitoneally before surgical intervention. RESULTS: Histomorphometric and electron microscopic analyses revealed that vitamin B12 did not prevent structural changes, abnormal myelination and g-ratio deviations regarding the functional aspects of the sciatic nerve. Alpha lipoic acid was more effective in restructuring the histomorphometric and structural aspects of the nerve with more myelinated fibers with optimal values (0.55-0.68) than vitamin B12 groups, in which the number of myelinated nerve fibers significantly decreased at optimal intervals (0.55-0.68). CONCLUSION: A-LA administration following peripheral nerve transection injury is more effective in promoting nerve healing regarding the structural aspects of the sciatic nerve compared to vitamin B12 and also myelination of nerve fibers by increasing g-values.

Adipose-Derived Stem Cells Enhance Axonal Regeneration through Cross-Facial Nerve Grafting in a Rat Model of Facial Paralysis.

BACKGROUND: Cross-face nerve grafting combined with functional muscle transplantation has become the standard in reconstructing an emotionally controlled smile in complete irreversible facial palsy. However, the efficacy of this procedure depends on the ability of regenerating axons to breach two nerve coaptations and reinnervate endplates in denervated muscle. The current study tested the hypothesis that adipose-derived stem cells would enhance axonal regeneration through a cross-facial nerve graft and thereby enhance recovery of the facial nerve function. METHODS: Twelve rats underwent transection of the right facial nerve, and cross-facial nerve grafting using the sciatic nerve as an interpositional graft, with coaptations to the ipsilateral and contralateral buccal branches, was carried out. Rats were divided equally into two groups: a grafted but nontreated control group and a grafted and adipose-derived stem cell-treated group. Three months after surgery, biometric and electrophysiologic assessments of vibrissae movements were performed. Histologically, the spectra of fiber density, myelin sheath thickness, fiber diameter, and g ratio of the nerve were analyzed. Immunohistochemical staining was performed for the evaluation of acetylcholine in the neuromuscular junctions. RESULTS: The data from the biometric and electrophysiologic analysis of vibrissae movements, immunohistochemical analysis, and histologic assessment of the nerve showed that adipose-derived stem cells significantly enhanced axonal regeneration through the graft. CONCLUSION: These observations suggest that adipose-derived stem cells could be a clinically translatable route toward new methods to enhance recovery after cross-facial nerve grafting.

Bio-engineered synovial membrane to prevent tendon adhesions in rabbit flexor tendon model.

During tendon injuries, the tendon sheath is also damaged. This study aims to test effectiveness of engineered tendon synovial cell biomembrane on prevention of adhesions. Forty New Zealand Rabbits enrolled into four study groups. Engineered synovial sheath was produced by culturing cell suspension on fabricated collagen matrix membrane. Study groups were: tendon repair (group A), tendon repair zone covered with plane matrix (Group B), synovial suspension injection into the zone of repair over matrix (Group C), and biomembrane application (Group D). Biomechanical evaluations of tendon excursion, metacarpophalangeal and proximal interphalangeal joints range of motion, H&E and Alcian Blue with neutral red staining, and adhesion formation graded for histological assessments were studied. Ten non-operated extremities used as control. Tendon excursions and range of motions were significantly higher and close to control group for Group D, p < 0.05. Adhesion formation was not different among Groups C, D, and Control, p > 0.005. Hyaluronic acid synthesis was demonstrated at groups C and D at the zone of injury. Application of synovial cells into the tendon repair zone either by cell suspension or within a biomembrane significantly decreases the adhesion formation. Barrier effect of collagen matrix and restoration of hyaluronic acid synthesis can explain the possible mechanism of action.