Effect of systemic creatine monohydrate supplementation on denervated muscle during reinnervation: experimental study in the rat

The purpose of this experimental study was to evaluate possible upgrading effects of systemic creatine monohydrate administration on the reinnervation of denervated muscle. At the same time, the protective effect of the agent on denervated muscle until ultimate reinnervation after nerve repair was quantified. The functional outcome of muscle reinnervation after creatine monohydrate application was compared with a control group. Forty adult Wistar rats weighing 180 to 220 g were used. The right sciatic nerve was dissected, exposed, and cut at the level of the midthigh in all rats. The experimental design consisted of two groups: experimental (animals were fed creatine monohydrate) and control (gavage feeding was provided by saline). Both groups were divided into two subgroups: subgroups A and B for the experimental group, and subgroups C and D for the control group. In subgroups A and C, the nerves were repaired with four 10-0 epineurial stitches. In subgroups B and D, both the proximal and distal ends of the nerves were ligated and no neural anastomosis was performed. In the experimental groups (subgroups A and B), the rats were fed by daily supplementation of oral creatine monohydrate, 300 mg/kg body weight. In the controls (subgroups C and D), oral supplementation was provided by saline. Functional recovery was evaluated using walking track analysis, pinching test, and limb circumference and toe contracture measurements at the end of 6 months, after which the rats were sacrificed and nerve specimens from both ends of the repair sites and the whole gastrocnemius muscle were obtained to document the results of the histomorphometric and histochemical studies, including light microscopic examinations and muscle weight measurements. The mean functional recovery values in subgroups A, B, C, and D were 91 percent, 80 percent, 87 percent, and 59 percent, respectively. Functional recovery improved significantly in the experimental groups (in both the surgically repaired and unrepaired subgroups), compared with the control groups (p<0.05). The pinching test revealed a statistically significant difference in nerve conduction between the experimental and control groups (p<0.05). The limb circumference ratio of the surgically treated side to the untouched side in subgroups A, B, C, and D were noted as 0.95, 0.89, 0.91, and 0.87, respectively, and the difference between the experimental and the control groups was statistically significant (p<0.05). The differences between subgroups A and B, C and D, A and C, and B and D were also significant. The surgically repaired and creatine-supplemented subgroups demonstrated the best results in toe contracture index. The muscle weight measurement results were concordant with the results of the limb circumference ratio. In both surgically repaired subgroups (subgroups A and C), there were qualitatively significant amounts of myelinated fibers in the nerve distal to the anastomotic site; there were no myelinated fibers in the distal stumps of subgroups B and D. Histochemical analyses of the contents of the muscle fiber types also revealed no significant difference. Overall, the results showed the useful effect of oral creatine supplementation on both surgically repaired and unrepaired nerve injuries. The best results were obtained from surgically repaired nerve injuries and also from the systemic creatine-supplemented subgroups. This study confirms that systemic administration of creatine monohydrate has a protective and upgrading effect on the functional properties of denervated muscle, especially in surgically reinnervated subjects.     

Role of N-acetyl cysteine and acetyl-l-carnitine combination treatment on DNA-damage-related genes induced by radiation in HEI-OC1 cells

Abstract

Purpose: The aim of the present study was to evaluate the effect of acetyl-l-carnitine (ALC) and N-acetyl cysteine (NAC) on ionizing radiation (IR)-induced cytotoxicity and change in DNA damage-related genes in House Ear Institute-Organ of Corti 1 (HEI-OC1) cells.

Methods: HEI-OC1 cells were irradiated with 5?Gy radiation and treated by eight combinations of NAC and/or ALC: control, NAC, ALC, IR, NAC?+?IR, ALC?+?NAC, ALC?+?IR, and ALC?+?NAC?+?IR. Cell viability, apoptotic cell death, and DNA damage were measured at the 72nd hour. Eighty-four IR-induced DNA-damage-related genes were determined by RT-PCR gene array and >10-fold changes were considered significant.

Results: IR decreased cell viability by about 50% at 72?hours of incubation. In particular, the ALC and/or NAC combination before IR protected the HEI-OC1 cells (p?<?.05). Single and combination treatment prior to IR led to lower apoptotic cell death (p?<?.05). There was a significant lower DNA damage in ALC?+?NAC?+?IR group compared to IR group (p?<?.05). Expressions of Brca2, Xpc, Mlh3, Rad51, Xrcc2, Hus1, Rad9a, Cdkn1a, Gadd45a which are the DNA-repair genes were found to be significantly higher in NAC?+?ALC?+?IR group than those in individual treatment of ALC or NAC.

Conclusions: ALC and/or NAC treatment prior to IR led to higher cell viability and lower apoptotic cell damage compared to the IR group. The results of the study show that the ALC?+?NAC combination treatment inhibits DNA damage and induces DNA-repair genes to repair radiation damage, and this combination treatment is more effective against radiation-induced DNA damage than NAC or ALC therapy individually.     

Changes in vascularity of cartilage endplate of degenerated intervertebral discs in response to melatonin administration in rats

We carried out an experimental investigation of cartilage endplate vascularity of degenerated intervertebral discs produced by exogenous melatonin (MEL) treatment. Adult Swiss albino rats were divided into three groups: control, operated degeneration, and MEL treatment. There were five rats in each group and, using a posterior approach, cuts were made parallel to the endplates in the posterior annulus fibrosus in five consecutive intervertebral discs between the 5th and 10th vertebral segments of the rats' tails. At 8 weeks, five of these animals were treated with exogenous MEL (s.c. injection of 30 μg/100 g body weight daily for 4 weeks). In each experimental group, one animal was examined using CT scanner to study the density of the cartilage endplate of the disc. To evaluate the bone growth and vascularity of the cartilage endplate region, the animals were killed for subsequent histopathological evaluation. We found that the vascular channel counts and percentage areas from animals treated with MEL were significantly lower than from the operated degeneration animals. Accordingly, the density histogram in the MEL group showed a spike profile for both the vertebral body and the cartilage endplate, indicating an increase in the amount of higher density tissues in these regions. Our results demonstrate that the use of MEL reduces the cartilage endplate vascularity of degenerated intervertebral discs, suggesting that it may have an osteoinductive effect on bone formation. Further studies are needed to characterize fully the relevance of our findings for the treatment of disorders such as postmenopausal osteoporosis.     

Evaluation of genitofemoral nerve motor conduction in inguinoscrotal pathologies

Aim

Inguinoscrotal pathologies are commonly seen in childhood. The genitofemoral nerve (GFN) is responsible for sensitive innervations of scrotal region and the motor innervations of cremasteric muscle. GFN also innervates the afferent and efferent pathways of cremasteric reflex. A prospective study was performed to evaluate the possible relation between inguinoscrotal pathologies and GFN motor functions.

Methods

Patients with inguinal hernia, hydrocele, undescended or retractile testicles, aged between 2-12 years were enrolled in the study. Bilateral latency and duration of GFN motor conductions (GFNMC) were obtained electrophysiologically by surface electrodes. GFNMC recordings of non-pathological sides were assessed as control group. Latency and duration of each group were compared with control group (Mann-Whitney U test). P values lower than .05 were considered significant.

Results

Seventy-three electrophysiologic evaluations were investigated in inguinal hernia (n:18), hydrocele (n:9), undescended testicle (n:14), retractile testicle (n:12) and control (n:20) groups. There was no age difference between groups and controls. Latency was significantly prolonged in inguinal hernia group when compared with control group (P = .028). Although the latencies were shortened in undescended testicle group, no significant difference detected (P > .05).

Conclusion

Prolonged latencies in inguinal hernia may be a result of nerve trap caused by hernia sac. GFN motor functions showed no causative role in other inguinoscrotal pathologies. It can be also suggested that clinical features of other inguinoscrotal pathologies were not affected by GFN motor functions. Electrophysiological studies in younger age groups with large number of patients are needed to support our suggestions.     

Antithrombin III prevents deleterious effects of remote ischemia-reperfusion injury on healing of colonic anastomoses

BACKGROUND: Antithrombin III is known as the most important natural inhibitor of thrombin activity and has been shown to attenuate local harmful effects of ischemia-reperfusion injury in many organs. In recent animal studies, delaying effect of remote organ ischemia-reperfusion injury on healing of intestinal anastomoses has been demonstrated. In this study, we investigated whether antithrombin III reduces deleterious systemic effects of ischemia-reperfusion injury on healing of colonic anastomoses in rats. METHODS: Anastomosis of the left colon was performed in 24 rats that were divided into three groups: sham operated control (group I, n = 8), 30 minutes of intestinal ischemia-reperfusion by superior mesenteric artery occlusion (group II, n = 8), antithrombin III treated group (250 U/kg before and after the ischemia-reperfusion, group III, n = 8). On postoperative day 6, all animals were sacrificed, and bursting pressure and tissue hydroxyproline content of the anastomoses were assessed and compared. RESULTS: On postoperative day 6 the mean bursting pressures were 149.6 +/- 4.8, 69.8 +/- 13.5, and 121.8 +/- 8.7 mm Hg for groups I, II, and III, respectively (P = 0.000). Mean tissue hydroxyproline concentration values were 389.5 +/- 29.6, 263.1 +/- 10.0, and 376.0 +/- 33.8 microg/mg for groups I, II, III respectively (P = 0.005). CONCLUSIONS: This study showed that, antithrombin III treatment significantly prevented the delaying effect of remote organ ischemia-reperfusion injury on anastomotic healing in the colon. Further clinical studies are needed to clarify whether antithrombin may be a useful therapeutic agent to increase the safety of the anastomosis during particular operations where remote organ ischemia-reperfusion injury takes place.     

Dexamethasone down-regulates endothelial expression of intercellular adhesion molecule and impairs the healing of bowel anastomoses.

OBJECTIVE: To find out the role of endothelial expression of intercellular adhesion molecule-1 (ICAM-1) in the healing of intestinal anastomoses in rats, and to establish the effects of peroperative treatment with corticosteroids. DESIGN: Experimental animal study. SETTING: University hospital, Turkey. MATERIAL: 78 Male Wistar rats. INTERVENTIONS: Rats were divided into four groups: Group I, colonic anastomosis only (=18); Group II, colonic anastomosis plus caecal ligation and puncture (=18); Group III, colonic anastomosis plus dexamethasone (=18); and Group IV, colonic anastomosis, plus caecal ligation and puncture, plus dexamethasone (=18). Six animals served as the sham group. The animals underwent bowel transsection and primary anastomosis Infection was produced by caecal ligation and puncture Preoperatively, dexamethasone was given intramuscularly in a dose of 2 mg/kg/day. MAIN OUTCOME MEASURES: After 1, 3 and 5 days, anastomotic healing and endothelial expression of ICAM-1 were measured microscopically. RESULTS: Anastomotic healing was significantly impaired in dexamethasone-treated animals, and endothelial expression of ICAM-1 was reduced. Endothelial expression of ICAM-1 was no higher in the infected group than in controls. Maximum expression of ICAM-1 on endothelial cells was seen on the first day in each group, and declined on the following days, although the sebsequent reduction in expression was not significant. CONCLUSION: Dexamethasone down-regulated expression of ICAM-1, which is important in migration of leucocytes from the circulation to the wound site, and significantly impaired the healing of intestinal anastomoses in rats.     

Effects of topical application of methotrexate on nasal mucosa in rats: a preclinical assessment study.

OBJECTIVE: The aim of this study is to investigate dose-dependent effect of the topical application of methotrexate (MTX) in rats on the normal nasal mucosa, liver tissue, liver enzymes, and hemoglobin levels. STUDY DESIGN: Preclinical animal study. SETTING: Twenty male adult wistar albino rats were randomly divided into 4 groups (n=5). A single puff of MTX (2.5 microg) was applied to both nasal cavities 2 times a day. The animals were given MTX 1 day a week in group 1, 3 days a week in group 2, and 5 days a week in group 3. Control group animals were given 1 puff of physiologic saline to both nasal cavities 5 days a week and 2 times a day. After 28 days, liver biopsies, blood samples, and 5 nasal mucosal biopsies were taken. Histological examination was made with respect to certain parameters semiquantitatively (grade 0-3). The aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels and hemoglobin counts were studied from blood samples. RESULTS: There are no statistically significant differences with respect to histopathological parameters between the control group and the groups 1-3 (P>0.05). Histopathological examination of liver tissue did not reveal any evident difference between the control and study groups. Mean AST and ALT as liver function tests and hemoglobin counts were within normal limits. Topical application of MTX at these doses has no toxic effect on the nasal mucosa, the liver tissue, AST and ALT levels, and hemoglobin level. CONCLUSIONS: These results have been encouraging to investigate use of the topical application of MTX in nasal manifestation of autoimmune disease or addition of the topical application of MTX to the steroid treatment in cases with massive nasal polyposis resistant to steroids and prone to recurrence.     

Isolated hair loss on the eyebrow: five cases with trichoscopic features

Alopecia areta (AA) and trichotillomania (TTM) are common causes for hair loss on the eyebrows. Yellow dots, vellus hairs, anisotrichosis, empty follicular openings, and black dots were observed in the present study’s patients with AA. Split hairs, question mark hairs, broken hairs, flame hairs, black dots, hairs with different lengths, and hemorrhagic areas were found in the patients with TTM. Trichoscopy is a very useful and helpful technic in distinguishing AA and TTM on the eyebrows.