Clinical Outcomes of Fixation of Depressed Posterolateral Tibial Plateau Fractures Using a Direct Lateral Approach.

Introduction: Fixation of plateau posterolateral fracture (PLF) is challenging because the fracture site is mostly covered by vital neurovascular structures. We operated on 15 cases of PLF using a direct lateral approach. This study aims to report on clinical results. Material and methods: Between 2017 and 2019, 15 cases of PLFs were fixed with a direct lateral approach and a tricortical autologous bone graft from the iliac crest. A depression of more than 2 mm was indicated for the surgical treatment. Clinical evaluation included Lysholm score, International Knee Documentation Committee Score (IKDC) score, and Tegner activity scale after two years follow-up. Results: The last follow-up was at 24 months after the operation. The mean postoperative Tegner activity scale did not change significantly compared to before the injury (6.5 (6-7) vs. 7 (6-8, p = 0.5)). The postoperative IKDC and Lysholm scores improved significantly compared to before the operation (p < 0.001). The full range of motion was seen in all patients except one who was manipulated after three months. Conclusions: Surgical treatment using a direct lateral approach is a safe procedure for PLFs that results in good, short-term clinical and radiologic outcomes without fibular osteotomy or compromising the important neurovascular structures. Level of evidence: IV.

Assessment of electrocardiogram interpretation competency among healthcare professionals and students of Ardabil University of Medical Sciences: a multidisciplinary study.

BACKGROUND: Electrocardiogram (ECG) interpretation is a core clinical skill that helps to rapid diagnosis of potentially life-threatening diseases. Misinterpretation of the electrocardiogram can lead to inappropriate clinical decisions with adverse outcomes. The main aim of this survey was to assess the competency of electrocardiogram interpretation and related factors among healthcare professionals and students of Ardabil University of Medical Sciences. METHODS: This descriptive cross-sectional study included 323 staff and students of Ardabil University of Medical Sciences in northwestern Iran. Data were collected randomly from November to January 1400 using the Badell-Coll ECG Interpretation Competency Questionnaire and analyzed using SPSS V.14. Statistical analysis included descriptive statistics, independent t-test, ANOVA, Pearson correlation coefficient and multiple linear regression. RESULTS: The results showed that the mean and standard deviation of electrocardiogram interpretation competency of health professional staff and students was 5.13 ± 2.25 (maximum score = 10). The large number of participants wasn't able to identify normal sinus rhythm (n = 251, 77.3%), acute myocardial infarction (n = 206, 63.8%) and pathological Q waves (n = 201, 62.2%). The results of multiple linear regression showed that the variables of education level, self-assessment of electrocardiogram interpretation competence, work experience, and type of hospital were able to predict the competence of ECG interpretation in participants. CONCLUSIONS: Our findings showed that the participants' level of electrocardiogram interpretation competency was low. Hence, regular, standard training and education are recommended. Also, managers and educators of the health system should consider the role of positive self-assessment and exposure to ECG interpretation in improving the competence of staff and students to interpret ECG.

Topical Tranexamic Acid versus Phenylephrine-lidocaine for the Treatment of Anterior Epistaxis in Patients Taking Aspirin or Clopidogrel; a Randomized Clinical Trial.

INTRODUCTION: Epistaxis is one of the most prevalent complaints in the emergency department (ED), especially in patients who take antiplatelet agents. This study aimed to compare the effect of topical use of tranexamic acid (TXA) with phenylephrine-lidocaine anterior nasal packing (PANP) in controlling epistaxis of patients who take aspirin or clopidogrel. METHODS: This prospective, double-blind, parallel-group, randomized clinical trial was conducted to compare the effect of topical use of intravenous (IV) TXA compared with PANP on controlling anterior epistaxis in patients who take aspirin or clopidogrel. RESULTS: One hundred patients with the mean age of 59.24 ± 7.75 (45 - 75) years were studied (52% male). Two groups were similar in terms of age (p=0.81) and sex (p=0.23) distribution, diabetes mellitus (p=0.54), and hypertension (p = 0.037). The mean time to stop bleeding was 6.70 ± 2.35 minutes in the TXA group and 11.50±3.64 minutes in the PANP group (p=0.002). Bleeding recurrence occurred in 3 (6%) cases of the TXA group and 10 (20%) cases of the PANP group (p =0.03). Time to discharge from ED in the TXA group was significantly lower than the PANP group (p<0.001). The absolute risk reduction (ARR), relative risk reduction, and number needed to harm of treatment with TXA for anterior nasal bleeding were 14.00% (95%CI: 1.11 - 26.89), 17.50% (95%CI: 0.60 - 37.27), and 7.14 (95%CI: 3.71 -90.43), respectively. CONCLUSION: Topical TXA is an appropriate treatment option in bleeding cessation, and reducing re-bleeding and duration of hospital stay in patients with epistaxis who take antiplatelet agents.

A non-monotone pattern search approach for systems of nonlinear equations.

In this paper, a new pattern search is proposed to solve the systems of nonlinear equations. We introduce a new non-monotone strategy which includes a convex combination of the maximum function of some preceding successful iterates and the current function. First, we produce a stronger non-monotone strategy in relation to the generated strategy by Gasparo et al. [Nonmonotone algorithms for pattern search methods, Numer. Algorithms 28 (2001), pp. 171-186] whenever iterates are far away from the optimizer. Second, when iterates are near the optimizer, we produce a weaker non-monotone strategy with respect to the generated strategy by Ahookhosh and Amini [An efficient nonmonotone trust-region method for unconstrained optimization, Numer. Algorithms 59 (2012), pp. 523-540]. Third, whenever iterates are neither near the optimizer nor far away from it, we produce a medium non-monotone strategy which will be laid between the generated strategy by Gasparo et al. [Nonmonotone algorithms for pattern search methods, Numer. Algorithms 28 (2001), pp. 171-186] and Ahookhosh and Amini [An efficient nonmonotone trust-region method for unconstrained optimization, Numer. Algorithms 59 (2012), pp. 523-540]. Reported are numerical results of the proposed algorithm for which the global convergence is established.

Topically-administered acetyl-L-carnitine increases sciatic nerve regeneration and improves functional recovery after tubulization of transected short nerve gaps.

BACKGROUND: Peripheral nerve injuries repair is still among the most challenging and concern-raising tasks in neurosurgery. The effect of an acetyl-L-carnitin-loaded silicone tube as an in-situ delivery system in defects bridging was studied using a rat sciatic nerve regeneration model. METHODS: A 10-mm sciatic nerve defect was bridged using a silicone tube (SIL/ALC) filled with 10 µL acetyl-L-carnitine (100 ng/mL). In the control group (SIL), the tube was filled with the same volume of the phosphate-buffered solution. The regenerated fibers were studied 4, 8, 12 and 16 weeks after surgery. RESULTS: The functional study confirmed faster recovery of the regenerated axons in acetyl-L-carnitine treated than control group (P<0.05). The mean ratios of gastrocnemius muscles weight were measured. There was a statistically significant difference between the muscle weight ratios of SIL/ALC and SIL groups (P<0.05). Morphometric indices of regenerated fibers showed that the number and diameter of the myelinated fibers in SIL/ALC were significantly higher than in the control group. In immuohistochemistry, the location of reactions to S-100 in the SIL/ALC group was clearly more positive than in the SIL group. CONCLUSIONS: Acetyl-L-carnitine, when loaded in a silicone tube, can bring to an improvement in functional recovery and quantitative morphometric indices of sciatic nerve.

Association of increased rate of condemnation of broiler carcasses due to hepatic abnormalities with immunosuppressive diseases in the broiler chicken industry in Saskatchewan.

The objective of this study was to identify the causative agents of hepatitis observed in broiler chickens at processing. Livers of chickens from 16 broiler farms in Saskatchewan with gross lesions of hepatitis were collected at processing. In addition to routine bacterial isolation and histopathological examination, serologic studies for infectious bursal disease virus (IBDV) and Chicken anaemia virus (CAV), calculation of the ratio of the weight of the bursa of Fabricius (BF) to body weight (BBW), and histopathological examination of the BF were done. Of the 264 livers with gross lesions, 83% had multifocal to coalescing necrotizing hepatitis, 16% had perihepatitis, and 1% had hemorrhages. No definitive causative microorganisms were isolated from the hepatic lesions; however, no significant bacterial isolations were made. Bursal atrophy, low BBW ratio, and high titer of antibody against IBDV each correlated with the rate of total condemnations (P = 0.0188, P = 0.0001, and P = 0.0073, respectively). Nucleotide sequencing of IBDV isolated from the BF identified the variant strains Delaware-E and 586. Condemnation because of hepatic lesions was correlated with titer of antibody against IBDV and BBW (P = 0.016 and P = 0.027). The results of this study demonstrate that hepatic lesions in Saskatchewan chickens are not currently caused by a primary bacterial pathogen but are associated with indicators of immunosuppression that is likely due to variant IBDV.

L'objectif de la présente étude était d'identifier les agents causals de l'hépatite observée chez des poulets à griller au moment de la transformation. Les foies de poulets provenant de 16 fermes de poulets à griller en Saskatchewan avec des lésions macroscopiques d'hépatite furent prélevés. En plus de l'isolement bactérien de routine et de l'examen histopathologique, on effectua des analyses sérologiques pour le virus de la bursite infectieuse aviaire (VBIA) et le virus de l'anémie du poulet (VAP), le calcul du ratio du poids de la bourse de Fabricius (BF) sur le poids corporel (BPC), et l'examen histopathologique de la BF. Sur les 264 foies ayant des lésions macroscopiques, 83 % avaient des lésions multifocales à coalescentes d'hépatite nécrosante, 16 % de la péri-hépatite et 1 % des hémorragies. Aucun agent causal définitif ne fut isolé des lésions hépatiques; toutefois, aucun agent bactérien significatif ne fut isolé. Une atrophie de la bourse, un faible ratio BPC, et un titre élevé d'anticorps dirigé contre VBIA corrélaient tous avec le taux de condamnation totale (P = 0,0188, P = 0,0001, et P = 0,0073, respectivement). Le séquençage nucléotidique des VBIA isolés des BF identifia les souches variantes Delaware-E et 586. La condamnation due aux lésions hépatiques était corrélée avec le titre d'anticorps contre VBIA et le BPC (P = 0,016 et P = 0,027, respectivement). Les résultats de la présente étude démontrent que les lésions hépatiques chez les poulets de la Saskatchewan ne sont pas actuellement causées par un agent bactérien pathogène primaire mais sont associées à des indicateurs d'immunosuppression qui est probablement causée par un variant de VBIA.(Traduit par Docteur Serge Messier).

Alpha-lipoic acid loaded in chitosan conduit enhances sciatic nerve regeneration in rat.

OBJECTIVES: To investigate the effect of topical administration of alpha-lipoic acid into chitosan conduit on peripheral nerve regeneration using a rat sciatic nerve transection model. MATERIALS AND METHODS: Forty five Wistar rats were divided into three experimental groups randomly. A 10-mm gap of sciatic nerve was bridged with a chitosan conduit following surgical preparation and anesthesia. In treatment group, the conduit was filled with 30 µl alpha-lipoic acid (10 mg/kg/bw).It was filled with 30 µl phosphate buffered saline solution in control group. In Sham group sciatic nerve was just exposed. RESULTS: The recovery of nerve function was faster in treatment group than in control, at 4 and 8 weeks after surgery (P-value<0.05). Conduction velocity was better in treatment group than in control group at 4 and 12 weeks (P-value<0.05). Recovery index was higher in treatment group than the control group, 8 weeks after surgery (P-value <0.05). Greater nerve fiber diameter, axon diameter, and myelin sheath thickness were observed in treatment group compared to control group at 8 and 12 weeks after surgery (P-value<0.05). The immunoreactivity of regenerated axons and myelin sheath in treatment group were far more similar to sham group. CONCLUSION: Alpha-lipoic acid when loaded in a chitosan conduit could improve transected sciatic nerve regeneration in rat.

Guided bone regeneration of mandibles using chitosan scaffold seeded with characterized uncultured omental adipose-derived stromal vascular fraction: an animal study.

PURPOSE: The aim of this study was to assess the effect of characterized uncultured omental adipose-derived stromal vascular fraction (SVF) on bone regeneration in a circular mandibular bone defect. A chitosan scaffold was used to maintain the cells in situ. MATERIALS AND METHODS: Seventy-five healthy male white Wistar rats were randomized into three experimental groups. In the control group, a surgical bone defect was created in the body of the mandible. In the scaffold group, a chitosan scaffold was placed into the defect. In the scaffold/SVF group, a scaffold was implanted and seeded with 10-µL SVF aliquots (2.19 ± 0.43 x 10(7) cells). RESULTS: Microscopic and histomorphometric analyses showed improved and earlier regeneration of bone defects in the scaffold/SVF group compared to the scaffold-only group. CONCLUSION: In this animal model, the use of a chitosan scaffold with SVF aliquots resulted in significantly earlier regeneration of bone than the use of the scaffold alone.

Sciatic nerve regeneration induced by transplantation of in vitro bone marrow stromal cells into an inside-out artery graft in rat.

Traumatic injury to peripheral nerves results in considerable motor and sensory disability. Several research groups have tried to improve the regeneration of traumatized nerves by invention of favorable microsurgery. Effect of undifferentiated bone marrow stromal cells (BMSCs) combined with artery graft on peripheral nerve regeneration was studied using a rat sciatic nerve regeneration model. A 10-mm sciatic nerve defect was bridged using an artery graft (IOAG) filled with undifferentiated BMSCs (2 × 10(7) cells/mL). In control group, the graft was filled with phosphated buffer saline alone. The regenerated fibers were studied 4, 8 and 12 weeks after surgery. Assessment of nerve regeneration was based on behavioral, functional (Walking Track Analysis), electrophysiological, histomorphometric and immuohistochemical (Schwann cell detection by S-100 expression) criteria. The behavioral, functional and electrophysiological studies confirmed significant recovery of regenerated axons in IOAG/BMSC group (P < 0.05). Quantitative morphometric analyses of regenerated fibers showed the number and diameter of myelinated fibers in IOAG/BMSC group were significantly higher than in the control group (P < 0.05). This demonstrates the potential of using undifferentiated BMSCs combined with artery graft in peripheral nerve regeneration without limitations of donor-site morbidity associated with isolation of Schwann cells. It is also cost saving due to reduction in interval from tissue collection until cell injection, simplicity of laboratory procedures compared to differentiated BMSCs and may have clinical implications for the surgical management of patients after facial nerve transection.

Transplantation of undifferentiated bone-marrow stromal cells into a vein graft accelerates sciatic nerve regeneration in streptozotocin induced diabetic rats.

Influence of undifferentiated bone marrow stromal cells (BMSCs) combined with vein graft on transected sciatic nerve repair was studied in diabetic rats. A nerve segment, 10 mm, was excised and a vein graft (VG) was used to bridge the gap. 10 microliter undifferentiated BMSCs (2 x 10(7) cells /mL) were administered into the graft in treatment group (VG/BMSC). Phosphate buffered saline was only administered into the graft in control group. The regenerated nerve fibers were studied in three time points of 4, 8 and 12 weeks after surgery. Evaluation of the repair process was based on behavioral, functional (Walking Track Analysis), electrophysiological, histomorphometrical and immunohistochemical criteria. The behavioral, functional and electrophysiological studies indicated that there was significant recovery in regeneration of axons in VG/BMSC group (P < 0.05). Morphometric evaluations showed that the number and diameter of myelinated fibers in VG /BMSC group were significantly higher than those in the control group (P < 0.05). This indicates the potential of using undifferentiated BMSCs combined with vein graft in peripheral nerve repair in diabetic rats with no restrictions of donor-site morbidity associated with isolation of Schwann cells. This technique is also cost saving because of decrease in interval from tissue harvest until administration of the cells and simplicity of laboratory techniques in comparison with undifferentiated BMSCs. It may have clinical implications for the surgical management of diabetic patients after nerve transection.

Functional effect of local administration of glial derived neurotrophic factor combined with inside-out artery graft on sciatic nerve regeneration in rat.

Effect of local glial derived neurotrophic factor (GDNF) on nerve regeneration was assessed. Eighty male Wistar rats were divided into four experimental groups (n = 20), randomly: In transected group left sciatic nerve was transected and stumps were fixed in adjacent muscle. In treatment group defect was bridged using an artery graft filled with 10 µL GDNF. In artery group graft was filled with phosphate-buffered saline. In normal control group sciatic nerve was exposed and manipulated. Each group was subdivided into four subgroups of five animals each and nerve fibers were studied in a 16-week period. Behavioral, functional, electrophysiological and gastrocnemius muscle mass findings and morphometric indices confirmed faster recovery of regenerated axons in IOAG/GDNF than in IOAG group (p < 0.05). Immunohistochemical reactions to S-100 in IOAG/GDNF were more positive than that in IOAG group. GDNF improved functional recovery and morphometric indices of sciatic nerve. It could be considered as an effective treatment for peripheral nerve repair in practice.

The mesenchymal stem cell-derived microvesicles enhance sciatic nerve regeneration in rat: a novel approach in peripheral nerve cell therapy.

BACKGROUND: The accomplishment for desired functional peripheral nerve regeneration is still challenging despite various materials and methods. The effects of local application of omental adipose mesenchymal stromal cell-derived microvesicles (MVs) on peripheral nerve regeneration were studied using a rat sciatic nerve transection model. METHODS: A 10-mm gap of sciatic nerve was bridged with a chitosan conduit. The rats were divided into five experimental groups randomly as follows: cultured undifferentiated omental adipose-derived stromal cells, rest mesenchymal stem cell-derived MVs (c-MVs), anti-inflammatory mesenchymal stem cell-derived MVs (anti-MVs), proinflammatory mesenchymal stem cell-derived MVs (pro-MVs), and negative control (Chit). RESULTS: The functional assessment of nerve regeneration (walking track analyses), electrophysiologic measurements, muscle mass measurements, as well as histomorphometrical and immunohistochemical indices showed drastic improvement in nerve regeneration in c-MVs and anti-MVs animals compared with pro-MVs animals (p < 0.05). CONCLUSION: The anti-inflammatory stem cell-derived MVs can be used as an alternative for the improvement of rat sciatic nerve regeneration.

Effect of local administration of cyclosporine A on peripheral nerve regeneration in a rat sciatic nerve transection model.

OBJECTIVE: To assess the effect of cyclosporine A (CsA) loaded in chitosan conduit on bridging the sciatic nerve defects in a rat model. METHODS: A 10 mm sciatic nerve defect was bridged using a chitosan conduit filled with 10 µl carrier-drug dilution (10 µg/L CsA). In control group, the conduit was filled with the same volume of carrier dilution alone. The regene-rated fibers were studied 4, 8 and 12 weeks after surgery. RESULTS: The functional study confirmed faster recovery of the regenerated axons in treatment group than control group (P<0.05). There was statistically significant difference of the gastrocnemius muscle weight ratios between treatment and control groups (P<0.05). Morphometric indices of regenerated fibers showed that the number and diameter of the myelinated fibers in CsA-treated animals were significantly higher than those in control group. In immunohistochemistry, the location of reactions to S-100 in CsA group was clearly more positive than control group. CONCLUSION: CsA loaded in a chitosan conduit results in improvement of functional recovery and quantitative morphometric indices of sciatic nerve. It is easily available without any complications compared with its systemic administration.

Repair of nerve defect with chitosan graft supplemented by uncultured characterized stromal vascular fraction in streptozotocin induced diabetic rats.

Regenerative properties of stem cells at the service of nerve repair have been initiated during recent decades. Effects of transplantation of characterized uncultured stromal vascular fraction (SVF) on peripheral nerve regeneration were studied using a rat sciatic nerve transection model. A 10-mm sciatic nerve defect was bridged using a chitosan conduit filled with SVF. In control group, chitosan conduit was filled with phosphate-buffered saline alone. The regenerated nerve fibers were studied 4 weeks, 8 weeks, and 12 weeks after surgery. In sham-operated group, the sciatic nerve was only exposed and manipulated. Behavioral and Functional studies confirmed faster recovery of regenerated axons in SVF transplanted animals than in control group (P < 0.05). Gastrocnemius muscle mass in SVF transplanted animals was found to be significantly more than that in control group. Morphometric indices of the regenerated fibers showed the number and diameter of the myelinated fibers were significantly higher in SVF transplanted animals than in control group. In immunohistochemistry, location of reactions to S-100 in SVF transplanted animals was clearly more positive than that in control group. SVF transplantation combined with chitosan conduit could be considered as a readily accessible source of stromal cells that improve functional recovery of sciatic nerve.

Peripheral nerve regeneration following transection injury to rat sciatic nerve by local application of adrenocorticotropic hormone.

The objective of this study was to assess local effect of adrenocorticotropic hormone (ACTH) on the functional recovery of the sciatic nerve in a transection model. Sixty male healthy white Wistar rats were randomized into four experimental groups of 15 animals each: In the sham-operated group (SHAM), the sciatic nerve was exposed and manipulated. In the transected group (TC), the left sciatic nerve was transected and the cut nerve ends were fixed in the adjacent muscle. In the silicone graft group (SIL) a 10-mm defect was made and bridged using a silicone tube. The graft was filled with phosphated-buffer saline alone. In the treatment group a silicone tube (SIL/ACTH) was filled with 10 µL ACTH (0.1 mg/mL). Each group was subdivided into three subgroups of five animals each and regenerated nerve fibres were studied at 4, 8 and 12 weeks post operation. Behavioral testing, functional, gastrocnemius muscle mass and morphometric indices showed earlier regeneration of axons in SIL/ACTH than in SIL group (p < 0.05). Immunohistochemistry clearly showed more positive location of reactions to S-100 in SIL/ACTH than in SIL group. ACTH improved functional recovery and morphometric indices of sciatic nerve. This finding supports role of ACTH after peripheral nerve repair and may have clinical implications for the surgical management of patients after nerve transection.

Improvement of functional recovery of transected peripheral nerve by means of chitosan grafts filled with vitamin E, pyrroloquinoline quinone and their combination.

Effects of vitamin E and pyrroloquinoline quinone on peripheral nerve regeneration were studied using a rat sciatic nerve transection model. Ninety male healthy White Wistar rats were divided into three experimental groups (n = 15), randomly: Sham-operation (SHAM), transected control (TC), chitosan conduit (Chit) and three treatment groups (Vit E, PQQ and PQQ + Vit E). In SHAM group after anesthesia, left sciatic nerve was exposed through a gluteal muscle incision and after homeostasis muscle was sutured. In Chit group left sciatic nerve was exposed the same way and transected proximal to tibio-peroneal bifurcation leaving a 10-mm gap. Proximal and distal stumps were each inserted into a chitosan tube. In treatment groups the tube was implanted the same way and filled with Vit E, PQQ and PQQ + Vit E. Each group was subdivided into three subgroups of six animals each and were studied 4, 8, 12 weeks after surgery. Functional and electrophysiological studies, and gastrocnemius muscle mass measurement confirmed faster and better recovery of regenerated axons in Vit E + PQQ combination compared to Vit E or PQQ solely (P < 0.05). Morphometric indices of regenerated fibers showed number and diameter of the myelinated fibers in PQQ + Vit E was significantly higher than in other treatment groups. In immunohistochemistry, location of reactions to S-100 in PQQ + Vit E was clearly more positive than in other treatment groups. Response to PQQ + Vit E treatment demonstrates that it influences and improves functional recovery of peripheral nerve regeneration.

Ketoprofen combined with artery graft entubulization improves functional recovery of transected peripheral nerves.

The objective was to assess the local effect of ketoprofen on sciatic nerve regeneration and functional recovery. Eighty healthy male white Wistar rats were randomized into four experimental groups of 20 animals each: In the transected group (TC), the left sciatic nerve was transected and nerve cut ends were fixed in the adjacent muscle. In the treatment group the defect was bridged using an artery graft (AG/Keto) filled with 10 microliter ketoprofen (0.1 mg/kg). In the artery graft group (AG), the graft was filled with phosphated-buffer saline alone. In the sham-operated group (SHAM), the sciatic nerve was exposed and manipulated. Each group was subdivided into four subgroups of five animals each and regenerated nerve fibres were studied at 4, 8, 12 and 16 weeks post operation. Behavioural testing, sciatic nerve functional study, gastrocnemius muscle mass and morphometric indices showed earlier regeneration of axons in AG/Keto than in AG group (p < 0.05). Immunohistochemical study clearly showed more positive location of reactions to S-100 in AG/Keto than in AG group. When loaded in an artery graft, ketoprofen improved functional recovery and morphometric indices of the sciatic nerve. Local usage of this easily accessible therapeutic medicine is cost saving and avoids the problems associated with systemic administration.

Vascular endothelial growth factor promotes peripheral nerve regeneration after sciatic nerve transection in rat.

OBJECTIVE: To evaluate the local effect of vascular endothelial growth factor (VEGF) on transected sciatic nerve regeneration. METHODS: Sixty male white Wistar rats were divided into four experimental groups randomly (n equal to 15). In transected group the left sciatic nerve was transected and the stump was fixed to adjacent muscle. In treatment group the defect was bridged using a silicone graft filled with 10 microlitre VEGF. In silicone group the graft was filled with phosphate-buffered saline. In sham-operated group the sciatic nerve was exposed and manipulated. Each group was subdivided into three subgroups with five animals in each and nerve fibers were studied 4, 8 and 12 weeks after operation. RESULTS: Behavioral test, functional study of sciatic nerve, gastrocnemius muscle mass and morphometric indices confirmed a faster recovery of regenerated axons in VEGF group than in silicone group (P less than 0.05). In immunohistochemical assessment, reactions to S-100 in VEGF group were more positive than that in silicone group. CONCLUSION: Local administration of VEGF will improve functional recovery and morphometric indices of sciatic nerve.

Improvement of peripheral nerve defects using a silicone conduit filled with hepatocyte growth factor.

OBJECTIVE: To assess local effects of hepatocyte growth factor (HGF) on peripheral nerve repair in a rat sciatic nerve transection model. STUDY DESIGN: Sixty male, healthy, white Wistar rats were randomized into 4 experimental groups: In the sham-operated group, sciatic nerve was exposed and manipulated. In the transected control group, the left sciatic nerve was transected. In the silicone graft group (SIL), a 10-mm defect was made and bridged using a silicone tube. The graft was filled with phosphate-buffered saline in the SIL group and with HGF in the SIL/HGF group. RESULTS: Behavioral testing, sciatic nerve functional study, gastrocnemius muscle mass measurement, and morphometric indices found earlier regeneration of axons in the SIL/HGF than in the SIL group (P < .05). Immunohistochemical study clearly found more positive location of reactions to S-100 in the SIL/HGF group than in the SIL group. CONCLUSIONS: HGF may have clinical implications for the surgical management of patients after facial nerve transection.

Acetyl salicylic acid locally enhances functional recovery after sciatic nerve transection in rat.

Local effect of acetyl salicylic acid (ASA) on peripheral nerve regeneration was studied using a rat sciatic nerve transection model. Forty-five male healthy White Wistar rats were divided into three experimental groups (n = 15), randomly: Sham-operation (SHAM), control (SIL), and ASA-treated (SIL/ASA) groups. In SHAM group after anesthesia left sciatic nerve was exposed through a gluteal muscle incision and after homeostasis the muscle was sutured. In SIL group the left sciatic nerve was exposed the same way and transected proximal to tibio-peroneal bifurcation leaving a 10-mm gap. Proximal and distal stumps were each inserted into a silicone tube and filled with 10 µl phosphate buffered solution. In SIL/ASA group defect was bridged using a silicone tube filled with 10 µl acetyl salisylic acid (0.1 mg/ml). Each group was subdivided into three subgroups of five animals each and were studied 4, 8, and 12 weeks after surgery. Data were analyzed statistically by factorial analysis of variance (ANOVA) and the Bonferroni test for pair-wise comparisons. Functional study confirmed faster and better recovery of regenerated axons in SIL/ASA than in SIL group (p < 0.05). Gastrocnemius muscle mass in SIL/ASA was significantly more than in SIL group. Morphometric indices of regenerated fibers showed that the number and diameter of the myelinated fibers in SIL/ASA were significantly higher than in control group. In immuohistochemistry, location of reactions to S-100 in SIL/ASA was clearly more positive than in SIL group. Response to local treatment of ASA demonstrates that it influences and improves functional recovery of peripheral nerve regeneration.