Evaluation of dexamethasone treated mesenchymal stem cells for recovery in neurotmesis model of peripheral nerve injury.

OBJECTIVE: Peripheral nerve injuries comprise significant portion of the nervous system injuries. Although peripheral nerves show some capacity of regeneration after injury, the extent of regeneration is not remarkable. The present study aimes to evaluate the regeneration of transected sciatic nerve by a therapeutic value of dexamethasone (DEX) associated with cell therapy (Cell) and biodegradable membrane (Mem) in rat. METHODS: Male Wistar rats (n = 42, 180-200g) were randomly divided into control (Ctrl), Membrane+ Cell, Mem, DEX, DEX+ Cell, DEX+ Mem and DEX+ Cell+ Mem groups. Functional recovery was evaluated at 2, 4, 6, 8 and 12 weeks after surgery using sciatic functional index (SFI), withdrawal reflex latency (WRL) test, electrophysiological and histological analyses. RESULTS: The rats in the DEX+ Cell+ Mem-treated group showed a significant improvement in SFI, WRL and electrophysiological findings during the 2nd to 12th weeks after surgery. In addition, histomorphological findings showed a significant improvement in the DEX+ Cell+ Memtreated group, at 12 weeks after surgery. DISCUSSION: Taken together, use of DEX associated with cell and biodegradable membrane could improve functional and histomorphological properties of the sciatic nerve after injury.

Curcumin and Biodegradable Membrane Promote Nerve Regeneration and Functional Recovery After Sciatic Nerve Transection in Adult Rats.

BACKGROUND: Curcumin has immunomodulatory anti-inflammatory, antioxidant, and neuroprotective properties. The goal of this study was to determine the effects of curcumin and biodegradable membrane on nerve healing in rat sciatic nerve transected injuries. METHODS: Rats were divided into groups: (1) control group (Ctrl), (2) curcumin group (Cur), (3) membrane group (Mem), and (4) membrane and curcumin group (Mem + Cur). Functional recovery was evaluated at 2, 4, 6, and 8 weeks after surgery. At the end of the eighth week after surgery, histological assessments were done. RESULTS: At the end of 8th week after surgery, functional assessments (sciatic nerve index, withdrawal reflex latency, and electromyography) in the Mem + Cur group improved compared with other groups (P < 0.05). Histological results (number of nerve fibers, diameter of nerve fibers, and myelin thickness) improved in the Mem + Cur group compared with the control, Cur, and Mem groups (P < 0.05). CONCLUSION: The present study showed the positive effects of Mem + Cur on nerve regeneration of transected sciatic nerve in rat model.

Evaluation of nerve growth factor (NGF) treated mesenchymal stem cells for recovery in neurotmesis model of peripheral nerve injury.

BACKGROUND: Peripheral nerve damages are a relatively common type of the nervous system injuries. Although peripheral nerves show some capacity of regeneration after injury, the extent of regeneration is not remarkable. The present study aimed to evaluate the effect of NGF treated mesenchymal stem cells on regeneration of transected sciatic nerve. MATERIALS AND METHODS: In this experimental study, forty-two male Wistar.rats (180-200 g) were randomly divided into 6 groups (n = 7) including control, Membrane + Cell (Mem + Cell), NGF group, NGF + Cell group, NGF + Mem group and NGF + Mem + Cell group. Regeneration of sciatic nerve was evaluated using behavioral analysis, electrophysiological assessment and histological examination. RESULTS: The rats in the NGF + Mem + Cell group showed significant decrease in sciatic functional index (SFI) and hot water paw immersion test during the 2nd to 8th weeks after surgery. (p < 0.001). At 8 weeks after surgery, electrophysiological findings showed that amplitude increased and latency decreased significantly in NGF + Mem + Cell group (p < 0.001). Measured histological parameters showed that number of nerve fibers, number of vessels and percent of vessel area also increased significantly in NGF + Mem + Cell group (p < 0.05). CONCLUSION: The present study showed that NGF in accompany with mesenchymal stem cells improved electrophysiological and histological indices.

Chitosan-film associated with mesenchymal stem cells enhanced regeneration of peripheral nerves: A rat sciatic nerve model.

OBJECTIVE: Peripheral nerve injuries comprise significant portion of the nervous system injuries. Although peripheral nerves show some capacity of regeneration after injury, but the extent of regeneration is not remarkable. Regeneration might be through the activity of the mesenchymal stem cells (MSCs) which can release growth factors or extracellular matrix components or by the therapeutic effect of some material with the MSCs. The present study aimed to evaluate the regeneration of transected sciatic nerve by a therapeutic value of mesenchymal stem cells (MSCs) associated with chitosan-film (Cs) in rat. MATERIALS & METHODS: Male Wistar rats (n=42, 180-200g) were randomly divided into intact; control; sham; Cs; MSCs; MSCs + Cs groups. Functional recovery was evaluated at 2, 4, 6 and 8 weeks after surgery using sciatic functional index (SFI), hot water paw immersion test, electrophysiological, histological analyses. RESULTS: The rats in the MSCs+Cs group showed significant decrease in SFI and hot water paw immersion test during the 2nd to 8th weeks after surgery. Electrophysiological findings showed a significant decrease in latency time in the MSCs +Cs group. Amplitude of the nerve impulses also increased. Number of nerve fibers with more than 6 µm diameters increased significantly in MSCs+Cs. The number of nerve fibers with less than 4 µm diameters also increased significantly in MSCs+Cs group. CONCLUSION: Taken together, mesenchymal stem cells associated with Cs could improve functional and histomorphological properties of the sciatic nerve after injury which may have some clinical outcomes as well.

Study of transected sciatic nerve repair by biodegradable membrane and betamethasone in adult albino wistar rats.

AIM: One of the major injuries of the nervous system is that of peripheral nerves. Although peripheral nerves show some capacity of regeneration after injury, the extent of regeneration is not remarkable. The present study aimed to evaluate the regeneration of the transected sciatic nerve by membrane and betamethasone in rats. MATERIAL AND METHODS: In this study twenty-eight adult male rats were divided into four equal groups including 1. Control group (Ctrl); 2. Betamethasone group (Beta); 3. Membrane group (Mem); 4. Membrane and Betamethasone group (Mem-Beta). Functional recovery was evaluated at 2, 4, 6 and 8 weeks post surgery. At 8 weeks after surgery, electromyographical (EMG) and histological assessments were performed. RESULTS: 8 weeks after surgery, sciatic functional index (SFI) and withdrawl reflex latency (WRL) reaction time were decreased significantly (p 0.05) in Mem+Beta group as compared to the control, beta and Mem groups respectively. In EMG test latency and amplitude of impulses improved in Mem+Beta group compared to other groups (p 0.05). Histological assessments performed at 8 weeks after surgery showed significant increase in the number of nerve fibers, diameter of nerve fibers and myelin thickness in Mem+Beta group as compared to the Ctrl, Beta and Mem groups (p 0.05). CONCLUSION: The results of the present study showed the positive effects of the chitosan membrane together with betamethasone on nerve regeneration of the transected sciatic nerve in a rat model.

Study of Transected Sciatic Nerve Repair by Amniotic Membrane with Betamethasone in Adult Albino Wistar Rats.

BACKGROUND: The aim of this study was to determine the effects of amniotic membrane impregnated with betamethasone on regeneration of transected sciatic nerve injury in adult albino Wister rats. METHODS: In this research, 42 male adult rats were divided into six equal groups. 1) Normal (intact) group: healthy rats without any injury; 2) CONTROL GROUP: sciatic nerve was cut and sutured; 3) Sham group: 0.2 mL culture medium was injected on the epineurium in the injury; 4) Amniotic membrane group (AM): Acellular amniotic membrane was used around the damaged sciatic nerve; 5) Betamethasone group (B): 0.2 mL Betamethasone (4 mg/mL) was injected in the site of damaged nerve and 6) Amniotic membrane group and Betamethasone (AM/B) group: Acellular amniotic membrane impregnated with 0.2 mL betamethasone was used around the damaged sciatic nerve. The rate of recovery was studied by Sciatic Functional Index (SFI), withdrawal reflex latency (WRL) test and electroctrophysiological assessments at 2, 4, 6 and 8 weeks after surgery. Histological assessment was done 8 weeks after surgery. RESULTS: At 8 weeks after surgery, SFI, WRL test and electrophysiological values in AM/B group were significantly improved compared to control and sham groups (P < 0.05). Histological results showed improvement in therapeutic groups, especially AM/B group compared to control and sham groups and other therapeutic groups (P < 0.05). CONCLUSION: The present study showed the positive effects of Amniotic membrane and Betamethasone on nerve regeneration of transected sciatic nerve in a rat model.

Long-term Developmental Effects of Lactational Exposure to Lead Acetate on Ovary in Offspring Wistar Rats.

BACKGROUND: During the last decades, environmental contamination by lead generated from human activities has become an evident concern. The present study assessed the long-term effects of neonatal exposure to different doses of lead acetate on the ovaries of offspring rats. MATERIALS AND METHODS: Pregnant female Wistar rats were randomly divided into a control and three experimental groups. The experimental groups received 20, 100 and 300 mg/L/day lead acetate via drinking water during lactation. Ovaries of the offspring were removed at 30, 60, 90 and 120 days of age, their weights recorded and fixed in Bouin's solution. Following tissue processing, 5 µm serial sections were stained with hematoxylin-eosin, and then, the numbers and diameters of ovarian follicles and corpora lutea were estimated. RESULTS: Ovary weights decreased significantly (p<0.05) in the 300 mg/L/day dose groups at 30, 60 and 90 days postnatal development. Significant dose-related decreases were seen in the numbers of primary, secondary and antral follicles in 100 (p<0.05) and 300 mg/L/day doses groups at 30 and 60 days of age (p<0.01). There was significant decrease in mean number of corpora lutea in the 100 (p<0.05) and 300 (p<0.01) mg/L/day dose groups at 60 days of age. It seems that neonatal lead treatment has transient effects on follicular development in the ovary of offspring and ovarian parameters gradually improve until 90 days of age. CONCLUSION: The present study showed that maternal lead acetate exposure affects prepubertal ovarian follicle development in a dose dependent manner, but ovarian parameters gradually improve during the postpubertal period.