Influence of Tacrolimus (FK506) on Nerve Regeneration Using Allografts: A Rat Sciatic Nerve Model.

PURPOSE: FK506 is an immunosuppressant agent used to prevent rejection after organ transplantation. The aim of the present study was to assess effects of tacrolimus (FK506) on peripheral nerve regeneration using allografts in a rat sciatic nerve model. MATERIALS AND METHODS: Thirty male white Wistar rats were divided randomly into a normal control (NC) group (n = 10), an allograft (ALLO) group (n = 10), and an FK506-treated (ALLO/FK506) group (n = 10). In the NC group, the left sciatic nerve was exposed through a gluteal muscle incision and, after homeostasis, the muscle was sutured. In the ALLO group, the left sciatic nerve was exposed through a gluteal muscle incision and transected proximal to the tibioperoneal bifurcation, where a 10-mm segment was excised. The same procedure was performed in the ALLO/FK506 group. The harvested nerves of the ALLO group served as allografts for the ALLO/FK506 group and vice versa. The NC and ALLO groups received sterile olive oil 300 µL intraperitoneally once a day for 1 week and the ALLO/FK506 group received FK506 300 µL (1 mg/kg) intraperitoneally once a day for 1 week. RESULTS: Behavioral, functional, and biomechanical recovery and gastrocnemius muscle mass showed earlier regeneration of axons in the ALLO/FK506 than in the ALLO group (P < .05). Histomorphometric and immunohistochemical studies also showed earlier regeneration of axons in the ALLO/FK506 than in the ALLO group (P < .05). CONCLUSIONS: Administration of FK506 could accelerate functional recovery of the sciatic nerve after nerve allografting. It could have clinical implications for the surgical management of patients after facial nerve transection.

Protective effects of propolis on ischemia-reperfusion injury in a rat testicular torsion and detorsion model.

The torsion model of testis in a rat was adopted for evaluation of possible effects of propolis (Prop) on ischemia-reperfusion (IS/REP) injury. The healthy male Wistar rats (totally 24 animals) were randomized into four groups (n = 6) and animals experienced bilateral testicular torsions as follows: In sham group just, laparotomy was performed and in IS group, animals experienced a 3 hr period testicular IS. In IS/REP group, a 3 hr period of IS followed by a 3 hr period of testicular REP for left testis and a one-week testicular REP for right testis were done. In this group animals were gavaged by 1.00 mL normal saline 1 hr before the onset of IS. In IS/REP/ Prop group, the same procedures for IS/REP animals were followed as well as gavage of 1.00 mL Prop extract solution 1 hr before the onset of IS. Analyses of biochemistry, histology, inflammatory biomarkers and sperm parameters were carried out. In IS/REP/Prop group, nitric oxide synthase malondialdehyde, myeloperoxidase and 8-hydroxy-2 deoxyguanine in IS/REP/Prop group were significantly decreased and, superoxide dismutase, total glutathione, glutathione peroxidase, glutathione reductase and glutathione S-transferase were significantly increased compared to the other animals. In IS/REP/Prop group, seminiferous tubules (with normal spermatogenesis) showed all stages of spermatogenic cells with plentiful spermatozoa. Tubular deterioration and atrophy and spermatogenic cell loss in were seen in a limited extent. The mean concentrations of Interleukin-1 beta and tumor necrosis factor alpha in IS/REP/Prop were significantly decreased. Sperm quality was significantly improved by Prop in IS/REP/Prop group. It was concluded that Prop could be supportive in diminishing IS/REP injury in testicular tissue exposed to ischemia.

Influence of Systemic Administration of Coq10 Nanoparticles on Ischemia-Reperfusion Injury on Ovaries in Rat.

Using a rat ovary model, effects of COQ10 nanoparticles (NCOQ10) were studied on ischemia-reperfusion injury. In the present experimental study, following randomization of thirty healthy female Wistar rats ∼250 g, the animals were subjected to five experimental groups (n = 6): group SHAM : only laparotomy was performed, group IS: only a 3-hour ischemia was performed, group IS/REP: the procedure included a 3-hour ischemia followed by a 3-hour reperfusion, and 50 µL soybean oil (solvent of NCOQ10) was administered 30 min before cessation of reperfusion, group IS/NCOQ10: the procedure included a 3-hour ischemia only and 50 µL (0.3 mmol/lit/IP) of NCOQ10 30 min before cessation of ischemia, and group IS/REP/NCOQ10: the procedure included a 3-hour ischemia, a 3-hour reperfusion, and 20 µL (0.3 mmol/lit) of NCOQ10 30 min before cessation of ischemia. Significantly amended development of ischemia/reperfusion tissue injury was observed in animals treated with NCOQ10 compared to those of other groups (P=0.001). Mean values of biochemical indices were significantly higher than those observed for other groups (P=0.001). Significantly lower values of MDA were observed in IS/REP/NCOQ10 animals compared to those of other groups (P=0.001).Where ovarian tissue is exposed to ischemia, intraperitoneal administration of NCOQ10 could bear clinical benefits in diminishing ischemia-reperfusion injury.

Assessments of regenerative potential of silymarin nanoparticles loaded into chitosan conduit on peripheral nerve regeneration: a transected sciatic nerve model in rat.

PURPOSE: It is compulsory to make a tension-free, end-to-end repair in transected injuries. However, when it comes to longer defects, placement of an autograft or nerve conduits is required. The present study was designed to assess regenerative potential of silymarin nanoparticles loaded into chitosan conduit on peripheral nerve regeneration in a transected sciatic nerve model in rat. METHODS: In NML group left sciatic nerve was exposed through a gluteal muscle incision and after careful hemostasis skin was closed. In TSC group left sciatic nerve was transected and stumps were fixed in adjacent muscle. In CTN group, 10-mm sciatic nerve defects were bridged using a chitosan. In CTN/NSLM group, 10-mm sciatic nerve defects were bridged using a chitosan conduit and 100 µL silymarin nanoparticles were administered into the conduit. The regenerated fibers were studied 4, 8, and 12 weeks after surgery. Assessment of nerve regeneration was based on behavioral, functional, biomechanical, histomorphometric, and immuohistochemical criteria. RESULTS: The behavioral, functional, electrophysiological, and biomechanical studies confirmed significant recovery of regenerated axons in CTN/NSLM group (P < 0.05). Quantitative morphometric analyses of regenerated fibers showed number and diameter of myelinated fibers in CTN/NSLM group were significantly higher than in CTN group (P < 0.05). DISCUSSION: This demonstrated potential of using chitosan-silymarin nanoparticles in peripheral nerve regeneration without limitations of donor-site morbidity associated with isolation of autograft. It is also cost saving and may have clinical implications for surgical management of patients after peripheral nerve transection.

Fabrication and transplantation of chitosan-selenium biodegradable nanocomposite conduit on transected sciatic nerve: a novel study in rat model.

Purpose: The improvement of techniques using conduits that connects the ends of damaged nerves and guides the growth of nerve fibers between the stumps, including adoption of natural or synthetic materials still is a challenge in peripheral nerve repair. The aim of the present novel study was to fabricate and transplant chitosan-selenium biodegradable nanocomposite conduit on transected sciatic nerve in rat model.Methods: In NORMAL group, the left sciatic nerve was exposed through a gluteal muscle incision and after careful hemostasis skin was closed. In TRANSECTED group left sciatic nerve was transected and stumps were fixed in adjacent muscle. In CHITOSAN and CSBNC groups, 10-mm sciatic nerve defects were bridged using a chitosan and chitosan-selenium biodegradable nanocomposite conduits, respectively. The regenerated fibers were studied 4, 8 and 12 weeks after surgery. Assessment of nerve regeneration was based on behavioral, functional, biomechanical, histomorphometric and immunohistochemical criteria.Results: The behavioral, functional and biomechanical studies confirmed significant recovery of regenerated axons in CSBNC group (P < 0.05). Quantitative morphometric analyses of regenerated fibers showed the number and diameter of myelinated fibers in CSBNC group were significantly higher than in the CHITOSAN group (P < 0.05).Discussion: This demonstrates the potential of using CSBNC in peripheral nerve regeneration without limitations of donor-site morbidity associated with isolation autograft. It is also cost saving and may have clinical implications for the surgical management of patients after facial nerve transection.

Interaperitoneal Administration of Αlpha-Tocopherol Loaded Nanoparticles Improves Ischemia-Reperfusion Injury in Rat Ovaries Torsion and Detorsion Model.

OBJECTIVE: To investigate effects of intraperitoneally administration of α-tocopherol loaded nanoparticles (TNP) on ischemia-reperfusion injury in ovaries. METHODS: Thirty-five healthy female Wistar rats ~250g were randomized into seven experimental groups (n = 5): Group SHAM: The rats underwent only laparotomy. Group Ischemia: A 3- hour ischemia only. Group I/R: A 3-hour ischemia and a 3-hour reperfusion. Group I/T: A 3-hour ischemia only and 100 mg/kg intraperitoneal administration (IP) of α-tocopherol 2.5 hours after induction of ischemia. Group I/R/T: A 3-hour ischemia, a 3-hour reperfusion and 100 mg/kg IP of α-tocopherol 2.5 hours after induction of ischemia. Group I/TNP: A 3-hour ischemia only and 1 mg/kg IP of TNP 2.5 hours after induction of ischemia. Group I/R/TNP: A 3-hour ischemia, a 3-hour reperfusion and 1 mg/kg IP of TNP 2.5 hours after induction of ischemia. RESULTS: Animals treated with αTNP showed significantly ameliorated development of ischemia and reperfusion tissue injury compared to those of other groups (p=0.001). The significant higher values of SOD, tGSH, GPO, GSHRd and GST were observed in I/R/NC animals compared to those of other groups (p=0.001). Damage indicators (NOS, MDA, MPO and DNA damage level) were significantly lower in I/R/NC animal compared to those of other groups (p=0.001). CONCLUSION: Intraperitoneal administration of TNP could be helpful in minimizing ischemia-reperfusion injury in ovarian tissue exposed to ischemia.

Assessment of Neuroprotective Effects of Local Administration of 17- Beta- Estradiol on Peripheral Nerve Regeneration in Ovariectomized Female Rats.

OBJECTIVE: To assess the neuroprotective effects of local administration of 17- beta- estradiol on nerve regeneration. METHODS: Sixty female Wistar rats were overiectomized and divided into four experimental groups (n = 15), randomly: In autograft group a segment of sciatic nerve was transected and re-implanted reversely. In sham-surgery group sciatic nerve was exposed and manipulated. In transected group left sciatic nerve was transected and stumps were fixed in adjacent muscle. In treatment group defect was bridged using a silicon conduit filled with 10 µL (0.1 mg/mL) 17- beta- estradiol. Each group was subdivided into four subgroups of five animals each and nerve fibers were studied in a 12-week period. RESULTS: Behavioral, functional, biomechanical, electrophysiological and gastrocnemius muscle mass findings and morphometric indices confirmed faster recovery of regenerated axons in treatment group than in other groups (p<0.05). Immunohistochemical reactions to S-100 in treatment group were more positive than that in other groups. CONCLUSION: Local administration of 17-beta-estradiol improved functional recovery and morphometric indices of sciatic nerve. It could have clinical implications for the surgical management of patients after facial nerve transection.

Local Effect of Heparin Binding Neurotrophic Factor Combined With Chitosan Entubulization on Sciatic Nerve Repair in Rats.

OBJECTIVE: To assess the effect of on sciatic nerve regeneration in animal model of rat. METHODS: Seventy-five male Wistar rats were divided into five experimental groups randomly (each group containing 15 animals): Sham operation group (SHAM), autograft group (AUTO), transected control (TC), chitosan conduit (CHIT) and heparin binding neurotrophic factor treated group (CHIT/HBNF). In AUTO group a segment of sciatic nerve was transected and reimplanted reversely. In SHAM group sciatic nerve was exposed and manipulated. In transected group left sciatic nerve was transected and stumps were fixed in adjacent muscle (TC). In treatment group defect was bridged using a chitosan conduit (CHIT) filled with 10 µL HBNF (CHIT/HBNF). Each group was subdivided into four subgroups of five animals each and nerve fibers were studied in a 12-week period. RESULTS: Behavioral, functional, biomechanical, electrophysiological and gastrocnemius muscle mass findings and morphometric indices confirmed faster recovery of regenerated axons in treatment group than in CHIT group (P=0.001). Immunohistochemical reactions to S-100 in treatment group were more positive than that in CHIT group. CONCLUSION: Local administration of improved functional recovery and morphometric indices of sciatic nerve. It could be considered as an effective treatment for peripheral nerve repair in practice.

Local administration of prostaglandin E1 combined with silicone chamber improves peripheral nerve regeneration.

The aim of this study was to assess the effect of locally administered prostaglandin E1 on peripheral nerve regeneration and functional recovery. Sixty male healthy white Wistar rats were divided into four experimental groups (n = 15), randomly: In transected group (TC), left sciatic nerve was transected and stumps were fixed in the adjacent muscle. In treatment group defect was bridged using silicone graft (SIL/PE) filled with 10 µL prostaglandin E1. In silicone graft group (SIL), the graft was filled with phosphate-buffered saline alone. In sham-operated group (SHAM), sciatic nerve was exposed and manipulated. Each group was subdivided into three subgroups of five animals each and regenerated nerve fibers were studied 4, 8 and 12 weeks after surgery. Behavioral testing, sciatic nerve functional study, gastrocnemius muscle mass and morphometric indices confirmed faster recovery of regenerated axons in SIL/PE than SIL group (p < 0.05). In immunohistochemistry, location of reactions to S-100 in SIL/PE was clearly more positive than that in SIL group. When loaded in a silicone graft, prostaglandin E1 improved functional recovery and morphometric indices of sciatic nerve. Local application of prostaglandin E1 improved functional recovery and morphometric indices of sciatic nerve.

Follicular Viability and Histological Alterations after Auto-transplantation of Dog Ovaries by Experimentally Inducing Blood Sinus on Stomach.

BACKGROUND: Currently, chemotherapy and radiotherapy are considered most effective methods for cancer treatment, however these strategies often result in fertility problems. A favorable alternative to prevent fertility loss in cancer patients is the cryopreservation and transplantation of sexual tissues (ovaries and/or testes). There is a low rate of fertilization following cryopreservation of ovaries prior to implantation. Therefore, in our opinion, this low rate is caused by instable blood flow during organ transplantation. Thus, this study researches a canine ovarian model that focuses on direct exposure of ovaries with blood in an experimentally induced sinus-like cavity. We implanted this tissue on the muscular layer of the stomach, which is its most vascularized region. MATERIALS AND METHODS: Ovarian transplantation was conducted on T1 animals (n=5), bilateral ovariectomy was performed on T2 animals (n=5), unilateral ovariectomy was conducted on T3 cases and animals in the control-sham group (n=5) did not undergo ovariectomy or transplantation. RESULTS: All isotransplanted ovaries survived. Ovaries resumed follicular growth and revascularization. Transplanted ovaries contained 75%-76% of survived small follicles (pre antral) after 60 days. The ovarian granulosa cells showed considerable resistance against ischemia. After day 30 no statistically significant differences in the level of estradiol and progesterone were observed between T1 animals and the T3 group. T1 animals showed considerably high levels of progesterone and estradiol in comparison to T2 cases. CONCLUSION: This study showed that using blood sinus method for ovarian isotransplantation helps ovarian tissue to survive from post implantation ischemia which confirms with normal follicles presentation and intact endocrine function of the implanted ovaries.