Examination of the effect of curcumin in experimental liver damage created by diethylnitrosamine in Swiss albino mice to superoxide dismutase and catalase activities and glutathione, malondialdehyde, and advanced oxidation protein products levels.

In this study, the effects of curcumin, glutathione (GSH), malondialdehyde (MDA) levels, advanced protein oxidation products (AOPP), superoxide dismutase (SOD), and catalase (CAT) activities in experimental liver damage with diethylnitrosamine (DEN) in Swiss albino mice were investigated. The subjects (n = 9) used in the study were divided into 5 groups as tumor control 1, tumor control 2, curcumin protective, curcumin treatment and healthy control groups Curcumin oral gavage (in 150 mg/kg of ethylalcohol) was given to the protecting group for 19 days, 5 days before the administration of DEN, and 24 h after the administration of DEN. Hundred microliters of ethylalcohol oral gavage was given to the healthy group for 19 days. While MDA levels decreased significantly in the curcumin preservative group (p < 0.05), (p = 0.002), the decrease was not significant in the treatment groups (p > 0.05), (p = 0.128). AOPP levels decreased significantly in the curcumin protective group (p < 0.05), (p = 0.009) but the decrease in the treatment group was not found significant (p > 0.05), (p = 0.073). SOD activities increased significantly in both groups. It was found as (p < 0.05), (p = 0.001) and (p < 0.05), (p = 0.002), respectively. GSH levels decreased but these reductions were not found statistically significant. CAT activities increased significantly in both groups. It was determined as (p < 0.05), (p = 0.001) for both groups.

A New Method Involving Percutaneous Application in the Treatment of Deep Venous Insufficiency: An Experimental Study With Internal Compression Therapy in a Porcine Model.

INTRODUCTION: To study the efficiency of internal compression therapy (ICT), a new and promising method of treatment for deep venous insufficiency, how that efficiency is achieved, and its potential side-effects, in a porcine model. MATERIAL AND METHODS: The femoral vein diameters of 4 pigs were first measured. ICT was then applied such as to reduce the diameter of these veins by 50%. The femoral vein diameters of 2 pigs were re-measured after 1 month. The femoral vein and its surrounding tissue were excised for immunohistopathological and genetic examination. The same procedures were applied to the remaining 2 pigs 3 months subsequently. Collagen I and IV immunohistochemical staining and Masson's trichrome and Alcian blue histochemical staining were applied during immunohistopathological examination. Collagen I, III, and IV and connective tissue growth factor (CTGF) mRNA expressions were examined for genetic examination. RESULTS: The femoral vein diameters decreased by approximately 50% after ICT application. This decrease persisted after the first and third months. Histopathological examination revealed loose connective tissue around the venous tissue after the operation, particularly in the third month, together with perivascular fibrosis and increased collagen in connective tissue. No difference was observed between regions with and without ICT application in terms of mucinous degeneration, an indicator of tissue injury, during Alcian blue staining. Genetic examination revealed an increase in collagen I and IV and CTGF mRNA expression in perivascular tissue resulting from ICT application. CONCLUSION: ICT is effective both in terms of creating a durable tissue around the vein and of increasing collagen tissue and stimulating fibrosis, and has no deleterious side-effects on tissue.

Beneficial effects of rolipram, a phosphodiesterase 4 specific inhibitor, on testicular torsion-detorsion injury in rats.

INTRODUCTION: The aim of the study is to investigate the effect of Rolipram, a selective phosphodiesterase 4 inhibitor, on testicular torsion - detorsion injury. METHODS: Sixty young male rats were divided into five groups. In each group, the right testes of six rats were removed four hours after detorsion for biochemical analysis, and the right testes of the remaining six rats were removed 24 h after detorsion for pathological analysis. In group 1 (sham-operated) right orchiectomy was performed without torsion, and right testes were sent to the laboratory for biochemical and pathologic analyses. In group 2 (control) torsion was applied to the right testes for 60 min, and detorsion was performed without the administration of Rolipram. In group 3 torsion was applied to the right testes for 60 min. 1 mg/kg Rolipram was administered 30 min before detorsion. In group 4 torsion was applied to the right testes for 60 min, and 1 mg/kg Rolipram was administered during detorsion. In group 5 torsion was applied to the right testes for 60 min. 1 mg/kg Rolipram was administered 30 min after detorsion. The malondialdehyde and nitric oxide levels were determined. The rates of necrosis and apoptosis were evaluated by histopathological examination. RESULTS: The level of malondialdehyde was higher in the torsioned groups (Group 2, 3, 4, 5) than that in group 1 (p = 0.004). There was no statistically significant difference between the groups regarding the level of nitric oxide (p = 0.182). Apoptosis was higher in groups 2, 3 and 4 than in group 1; however, apoptosis was similar in group 1 and group 5 (p = 0.122). The level of necrosis in group 1 was similar to that in groups 4 and 5 (p = 0.194 and p = 0.847, respectively). CONCLUSION: We suggest that the administration of Rolipram can decrease the rate of necrosis and apoptosis in testicular ischaemia-reperfusion injury.

Impact of intranasal application of nerve growth factor on the olfactory epithelium in rats with chemically induced diabetes.

Recent studies suggest that nerve growth factor (NGF) protects olfactory cells and axons from injury in vitro. Eighteen Wistar-Albino rats randomly divided into three groups: control group, diabetic group without NGF, and diabetic with NGF. Intranasal NGF (6 µg/day) was administered over a 5-day period. At the end of 30 days, the olfactory epithelium (OE) of NGF-applied diabetic rats regenerated, the epithelium thickness was significantly higher, and caspase-3 expression was not significantly different from the control. The current results demonstrate that intranasally administered NGF significantly reversed OE morphological changes in diabetes by decreasing diabetes-related cell death and inflammation.

Effects of vitamin D on ovary in DHEA-treated PCOS rat model: A light and electron microscopic study.

AIM: The aim of this study was to investigate the effects of vitamin D treatment on ovary in experimentally designed polycystic ovary syndrome of female rats using light and electron microscopic techniques. METHODS: Twenty-four female pre-pubertal rats were divided into control, DHEA and DHEA+Vit.D groups. In DHEA group, the PCOS rat model was developed by 6mg/kg/day dehydroepiandrosterone administration as subcutaneously injections. In DHEA+Vit.D group, 6 mg/kg/day DHEA and 120ng/100g/week 1,25(OH)2D3 was performed simultaneously. Controls were injected with vehicle alone. At the end of the 28 days, blood samples were collected and the ovarian tissues were taken for histological examinations. RESULTS: FSH, LH levels, LH/FSH ratio, and testosterone levels showed a significant increase in DHEA group when compared with the control group. Moreover, these measurements were lower in the treatment group than the DHEA group. In DHEA group, increased number of atretic follicles and cystic follicles were seen with light microscopic analysis. Cystic follicles with attenuated granulosa cell layers and thickened theca cell layers and lipid accumulation in interstitial cells were observed by electron microscope. It is observed that atretic and cystic follicles were decreased as a result of vitamin D treatment. CONCLUSION: Our results indicate the curative role of vitamin D treatment on the androgen excess in PCOS rat model which causes abnormalities in ovarian morphology and functions. Vitamin D has positive effects on the hormonal and structural changes observed in PCOS, but it has been concluded that long-term use may be more beneficial.

Delay by Staged Elevation of Flaps and Importance of Inclusion of the Perforator Artery.

"Surgical delay" is aimed at increasing blood flow to adjacent angiosomes by opening choke vessels, to obtain larger and more reliable flaps. We hypothesized that staged elevation (delay) from distal to proximal, in addition to preservation perforator artery near the base will improve survival. Thirty-two Sprague-Dawley rats were divided into 4 groups and 3x8cm caudal McFarlane flaps were elevated. In "delay" groups the 3 × 4 cm distal part was elevated and sutured back, with complete elevation (3 × 8 cm) after 4 days. The deep circumflex iliac artery (DCIA) at the base was either preserved or transected. The groups were: group A (Delay/DCIA preserved), group B (Delay/DCIA transected), group C (No Delay/DCIA preserved), group D (No Delay/DCIA transected). The percentage of surviving flap area was measured after 7 days with digital planimetrics. Statistics were done with ANOVA and unpaired T-test. The survivals were: 98.44 ± 3.13 %(group A), 69.33 ± 5.51 %(group B), 76.50 ± 8.91 %(group C) and 52.89 ± 3.15 %(group D). Delay lead to a greater degree of survival whether the arteries were preserved (p = 0.002) or transected (p = 0.01). In groups where the DCIA was preserved, the delay lead to a greater area of survival (p = 0.002). Inclusion of arteries lead to a greater degree of survival whether delay was performed (p = 0.003) or not (p = 0.005). Necropsy showed that the DCIAs were dilated bilaterally when preserved with vascular arcades reaching all viable areas. When the DCIA was transected, the gluteal perforators were dilated bilaterally with the vascular arcades reaching all viable areas. Staged elevation is an effective method of delay in both random and rando-axial flaps. When this is combined with preserving the perforator artery, survival rates are further enhanced.

Effects of bovine lactoferrin in surgically created bone defects on bone regeneration around implants.

The aim of this experimental study was to evaluate the effect of bovine lactoferrin (bLF)-loaded gelatin microspheres (GM) used in combination with anorganic bovine bone on bone regeneration in surgically created bone defects around tooth implants. Twenty-four uniform bone defects were created in the frontal bone via an extraoral approach in 12 domestic pigs. Twenty-four implants were placed at the center of the defects. In eight animals one of these defects was filled with 0.3 mL anorganic bovine bone while the other was left empty. In four animals, all defects were filled with 3 mg/defect bLF-loaded GM and anorganic bovine bone. All the defects were covered with collagen membranes. All animals were sacrificed after 10 weeks of healing, and the implants with the surrounding bone defects were removed en bloc. Undecalcified sections were prepared for histomorphometric analysis. The mean total area of hard tissue was 26.9 ± 6.0% in the empty defect group, 31.8 ± 8.4% in the graft group, and 47.6 ± 5.0% in the lactoferrin group (P < 0.001). The mean area of newly formed bone was 26.9 ± 6.0% in the empty defect group, 22.4 ± 8.2% in the graft group, and 46.1 ± 5.1% in the lactoferrin group (P < 0.001). The mean residual graft area was 9.4 ± 3.2% in the graft group and 1.5 ± 0.6% in the lactoferrin group (P < 0.001). The mean proportion of bone-implant contact in the defect region was 21.9 ± 8.4% in the empty defect group, 26.9 ± 10.1% in the graft group and 29.9 ± 10.3% in the lactoferrin group (P = 0.143). These data indicate that a combination of 3 mg bLF-loaded GM and bovine-derived HA promotes bone regeneration in defects around implants.

Straight versus S-shaped sternotomy: a histologic study in the sheep model.

INTRODUCTION: Straight sternotomy is the most common access for open heart surgery. Techniques have been proposed for maximizing sternal stability in high-risk patients. This trend implies a growing need for newer surgical techniques. The aim of this experimental study in the sheep model is to evaluate median vs. S shaped sternotomy the feasibility of using a special device to accelerate the sternal instability and bone healing. MATERIALS AND METHODS: We enrolled 31 sheep, weighing 18-30 kg. For all animals a midline skin incision was made. In group I (n = 16 animals), straight median sternotomy and in group II (n = 15 animals), S-shaped incision was marked on the periosteum of the sternum by new created device for standard S-shaped sternotomy. Sternum biopsies were performed on second surgery month for all survived animals from the sternum and the surrounding soft tissue. RESULTS: No early superficial wound complications were observed. Overall mortality in the initial approach group was 19.3% (6 sheep). In group I; 3 sheep had died on first surgery day, the reason may be hemorrhage and in group II; 3 sheep developed intractable VF during surgery procedure or immediately afterwards so died. There were statistically significant differences in the scores of bone healing between group 1 and group 2 (4.2 vs.7.3, ANOVA, p < 0.001). DISCUSSION: Our work is based on the use of a standard S-shaped sternotomy procedure on sheep sternum. In our experience with the sternal healing in the sheep model, the process of new bone formation was accelerated with S- shaped cut than straight sternotomy procedure.

Investigating the clinical significance of mesh peritonization in abdominal vault suspension surgery using a comparative rabbit model.

OBJECTIVE: To investigate the clinical significance of mesh peritonization in an experimental rabbit model. STUDY DESIGN: Twenty rabbits were randomly assigned to two groups. A sacrouteropexy operation was performed in both groups using a polypropylene mesh. In the first group, the pelvic peritoneum was not closed over the mesh, and in the second group, the mesh was buried throughout the pelvic retroperitoneal tunnel. One month after mesh implantation, the abdomen was opened and the previous surgical site was explored. The primary outcome was intraabdominal adhesion formation; the secondary outcome was the histologic degree of tissue remodeling. RESULTS: There were no statistically significant differences between the two groups in terms of adhesion scores and collagen organization (P=0.692, P=0.097, respectively). There was a greater degree of inflammation in the second group as identified by significantly higher scores for eosinophils-neutrophils, macrophages-foreign body giant cells and mononuclear cells (P=0.002, P=0.001 and P=0.002, respectively). CONCLUSIONS: Similar adhesion and collagen organization patterns were found in both groups, but indicators of the inflammatory process were significantly higher in the second group.

The protective effect of hesperidin on methotrexate-induced intestinal epithelial damage in rats: an experimental study.

OBJECTIVE: The purpose of this experimental study was to evaluate the efficacy of hesperidin (HES) in protecting against methotrexate (MTX)-induced intestinal damage using histopathological and immunohistochemical techniques. MATERIALS AND METHODS: Seventy-eight male Wistar albino rats were divided into 4 groups that received (a) saline only (control group), n = 19; (b) HES only, n = 19; (c) MTX only, n = 19, and (d) MTX plus HES, n = 21. On the first day of the study, a single dose of MTX (20 mg/kg) was administered intraperitoneally to group 3 and 4 rats. The HES (200 mg/kg) was administered by gavage for 5 days. For the MTX plus HES group, HES (200 mg/kg) was administered by gavage for 5 days after MTX treatment. Rats were sacrificed on the 2nd, 4th and 6th day of the study. Tissue samples from the jejunum were taken for histopathological and immunohistochemical analysis. RESULTS: On the 4th day, crypt injury in the MTX plus HES group (1.00 ± 0.00) was less than that in the MTX group (2.00 ± 0.89; p < 0.05). The small intestinal damage score was lower in the MTX plus HES group (6.33 ± 0.82) as compared to the MTX group (8.00 ± 2.37). Inducible nitric oxide synthase and interleukin-8 levels were lower in the MTX plus HES group (65 and 25%, respectively) as compared to the corresponding values of the MTX group (80 and 52.5%, respectively). On the 6th day, the Ki-67 proliferation index in the MTX group (45%) was lower than that in the MTX plus HES group (76.67%) and the control group (p < 0.05). The small intestinal damage score was high in the HES group on the 4th day due to increased cellular infiltration. On the 6th day, the Ki-67 proliferation index rose in parallel with the decrease in cellular infiltration and therefore histopathological scoring. The proliferation-enhancing effect of HES also appeared in healthy rats. CONCLUSION: HES seemed to have a protective effect against MTX-induced intestinal injury.

Effects of the fusionless instrumentation on the disks and facet joints of the unfused segments: a pig model.

BACKGROUND: Growing rod (GR) is a state-of-the-art procedure favored when curvatures of the spine cannot be managed nonoperatively in early-onset scoliosis. Although some postulate that multiple distractions and/or relative immobilization of the unfused segments affect the health of disk and facet joint (FJ) and cause degeneration and/or spontaneous fusion, this has not thoroughly been investigated. In this study, changes in the unfused segment after a spine-based fusionless instrumentation (SBFI) are investigated and compared with the control (CG) and instrumented fusion (IF) groups. METHODS: A total of 13 piglets, 10 to 14 weeks of age, were used. SBFI and IF were performed on 7 and 3 piglets, respectively, and 3 formed the CG. In SBFI, lengthening procedures of 5 mm were applied once monthly for 3 months, and, after 4 months, all piglets were euthanized. Histologic sections of the unfused disks and FJ were analyzed, and morphometric histologic analysis was performed. RESULTS: On the basis of the Gries criteria, unfused disk median grades were 1, 2, and 4 for control, SBFI, and IF, respectively, that revealed a statistical difference (P<0.001). Unfused FJ median grades were 1 and 2 for control and SBFI, respectively, that revealed a statistical difference (P<0.001). The mean hypertrophic zone (HZ) heights were 69.78, 84.20, and 66.14 µm; HZ chondrocyte cell widths were 19.03, 18.76, and 17.36 µm; and HZ chondrocyte cell heights were 15.01, 15.04, and 12.42 µm in the CG, SBFI, and IF groups, respectively. Statistically, for HZ heights, SBFI was different compared with CG and IF (P<0.001), and, for HZ chondrocyte cell widths and heights, IF was different compared with CG and SBFI (P<0.001). CONCLUSIONS: Morphometric analysis in this study supports the findings that SBFI preserves the growth potential of the spine. Furthermore, changes in the HZ heights show that distractive forces stimulate the apophyseal growth of the axial skeleton describing how the growth rate of the spine in GR might surpass the normal growth rate. Overall, although some degenerative changes are observed, SBFI and repeated distractions alone are not solely responsible for FJ arthrosis and disk degeneration, given that they are structurally preserved. CLINICAL RELEVANCE: GR and regular lengthening procedures do not impair disk health and preserve the growth potential of the spine if it is applied with a meticulous technique.

Fusionless instrumentation in growing spine and adjacent segment problems: an experimental study in immature pigs.

STUDY DESIGN: Experimental study. OBJECTIVE: To compare the effects of fusionless instrumentation (FI) and instrumented fusion (IF) on the adjacent segment in an immature pig model. SUMMARY OF BACKGROUND DATA: Observations reveal proximal junctional kyphosis after FI. Possible reasons are stress concentration, repeated distractive forces, and/or soft tissue damage done in the index surgery. It was speculated that FI can decrease stressors to the junctional area by preserving the spinal mobility in some manner; however, this has not been proven to date. METHODS: Thirteen piglets of 10- to 14-week age were used. FI and IF were performed on 7 and 3 piglets, respectively, and 3 piglets formed the control group. Control piglets did not undergo any surgical procedures. T11-L4 instrumentation, decortication, and grafting were applied to IF piglets. In FI groups, however, L1-L2 was left uninstrumented and unfused using T11-T12 and L3-L4 levels as anchors to the growing construct. A total of 4 lengthening procedures were performed: 1 in the index operation and 3 more, once in each lengthening procedure monthly, for 3 months. Four months after the index operations, all piglets were killed and the adjacent segment motion capabilities, disc, and facets were evaluated with radiographical, magnetic resonance imaging, biomechanical, and histological analyses. RESULTS: Comparison of proximal junctional Cobb angles of the postindex (mean: 21, range: 17-27) and presacrification (mean: 21, range: 11-31) radiographs in the FI group revealed no difference (P> 0.05). In magnetic resonance imaging, both surgical group proximal adjacent discs showed degeneration to some degree that was statistically indifferent (P = 0.903). Biomechanical evaluation revealed restriction of adjacent segment motion in all directions for both groups; however, this negative effect was significantly less in FI group (P < 0.01). Degeneration observed in histological evaluation in adjacent discs and facets of FI group was significantly lower (P = 0.00). CONCLUSION: In this quadruped straight spine model, in comparison with IF applications, FI is closer to normal physiology even after several lengthening procedures regarding the adjacent segment discs, facet joints, and motion, when interpreting the radiological, biomechanical, and histological results altogether.

The effectiveness of heliox in acute respiratory distress syndrome.

INTRODUCTION: The management of acute respiratory distress syndrome (ARDS) was investigated with the use of heliox in an experimental model. OBJECTIVES: To investigate whether heliox can be considered a new therapeutic approach in ARDS. METHODS: ARDS was designed in Wistar albino male rats, 250-300 g in weight, by intratracheal instillation of physiological saline solution. Anesthezied and tracheotomized rats with ARDS were pressure-controlled ventilated. At the end of 210 min, helium gas was tried. All rats were assigned to two groups: Group 1 (n = 10) was the control group, and was given no treatment; group 2 (n = 7) was given heliox (He: O(2) = 50:50). The heliox group received heliox for 1 h continously. Rats were continued to be kept on a ventilator through the experiment. Two hours after the last inhalation, both lungs of the rats were excised for both histopathological examination and immunohistochemical evaluation. STATISTICAL ANALYSIS USED: Histopathological grading were expressed as median interquartile range. Mann-Whitney U-test was used to assess the relationships between the variables. RESULTS: The infiltation of neutrophils were decreased in rats treated with heliox. Edema in the interstitial and intraalveolar areas was less than that of the control rats. Also, the diminishing of perivascular and/or intraalveolar hemorrhage was apperant. Hyaline membrane (HM) formation decreased in the heliox group compared with the control group. Decreased inducible nitric oxide synthase expression was shown via immunohistochemical examination in the heliox group. CONCLUSION: The present study histopathologically indicated the effectiveness of heliox in the decreasing of neutrophil infiltation, interstitial/intraalveolar edema, perivascular and/or intraalveolar hemorrhage and HM formation in ARDS. Besides the known effect of heliox in obstructive lung disease, inhaled heliox therapy could be associated with the improvement of inflamation in ARDS.

The effect of levetiracetam on neuronal apoptosis in neonatal rat model of hypoxic ischemic brain injury.

BACKGROUND: Hypoxic-ischemic brain injury (HIBI) is a common cause of neonatal mortality and morbidity. The use of levetiracetam (LEV), as a potential neuroprotective in brain ischemia, receives an increasingly high attention, and it could have a crucial role in the regulation of epileptogenesis and neuroprotection. Potential effects of LEV on neuronal apoptosis in HIBI have not previously been reported in literature. OBJECTIVES: The aim of this study is to evaluate the possible effects of LEV on neuronal apoptosis in neonatal rat model of HIBI. METHODS: Seven-day-old Wistar rat pups were subjected to right common carotid artery ligation and hypoxia (92% nitrogen and 8% oxygen) for 2h. The pups were treated with LEV or saline after hypoxia. In sham group rats, neither ligation, nor hypoxia was performed. Neuronal apoptosis was evaluated by the terminal deoxynucleotidyl-transferase- mediated dUTP nick-end labeling (TUNEL) methods. RESULTS: The counts of apoptotic cells in both hippocampus and cerebral cortex were significantly higher in the saline treatment group than in the sham group. The counts of apoptotic cells in both hippocampus and cerebral cortex were similar to those in the sham group and in the LEV treatment group. The number of apoptotic cells decreased significantly in the LEV-treated group compared with the saline group. CONCLUSIONS: These results show that LEV administration after hypoxia reduces neuronal apoptosis. Thus, we propose that LEV, as an effective antiepileptic and antiapoptotic drug, may be a viable choice for the control of seizure activity in neonates with HIBI.

A pig model for the histomorphometric evaluation of hard tissue around dental implants.

This study aimed to evaluate the frontal bone of Swiss Domestic pigs as an animal model for the histologic-histomorphometric examination of bony tissue around dental implants. We inserted SLA surface implants 4.1 mm in diameter and 10 mm in length into the frontal bones of 9 Swiss-Domestic pigs. Histologic and histomorphometric studies were conducted on the undecalcified sections. Histologic examinations showed that the specimens contain a sufficient amount of bone to provide homogenous bone coverage for standard diameter dental implant placement. The mean bone to implant contact was 61.9% ± 8.7%. Other histomorphometric parameters revealed the regular trabecular architecture at this site. Pigs' frontal bone appears to be a suitable animal model in short-term dental implant studies because it provides a sufficient amount of bone and favorable bone microarchitecture.

Effects of sodium selenite and amiloride on calvarial calcification in closing small cranial defects.

OBJECT: Fresh autogenous bone graft is the most preferred osteoplastic material, whether the purpose is cosmetic, psychological, or for the protection of the brain. These grafts are not rejected and do not react immunologically. The aim of this study was to evaluate the efficacy of autogenous fat rolled with bone dust derived from the bur hole in closing small cranial defects. Additionally, the authors examined the morphological and biochemical effects of Na selenite and amiloride on calvarial calcification. METHODS: The study group consisted of 20 domestic pigs. These animals were randomly divided into 4 groups. A bur hole with a diameter of 10 mm was made at the right parietal region in all animals, and then the periosteum around the bur hole was cauterized following exposure of the dura mater. The dura was coagulated with bipolar cautery. Group 1 (controls): only a bur hole was opened, and it was then closed with a mixture of the bone dust that had been created during the opening of the bur hole and fat tissue that was taken from the animal's neck. Group 2 (amiloride): 1 nmol/g body weight of amiloride was applied subcutaneously within 15 minutes after closure of the bur hole with bone dust and fat, and then amiloride was applied once a day for 4 weeks. Group 3 (Na selenite): 30 nmol/g body weight of Na selenite was applied subcutaneously within 30 minutes after closure of the bur hole with bone dust and fat, and then Na selenite was applied once a day for 4 weeks. Group 4 (amiloride and Na selenite): 1 nmol/g body weight of amiloride was applied subcutaneously at 15 minutes, and 30 nmol/g body weight of Na selenite was applied subcutaneously at 30 minutes after closure of the bur hole with bone dust and fat, and these 2 injections were repeated once a day for 4 weeks. At the end of 4 weeks, the animals were anesthetized to evaluate the closure of the bur hole. Tissue samples were obtained for ultrastructural and biochemical examination. RESULTS: The defect was covered with diffuse connective tissue in the control group. Although multiple capillary vessels were present, the authors did not observe osteogenic differentiation. Histological examination of the second group revealed osteogenic changes. Although new matrix was formed, calcification was not detected. The authors observed fibroblast, collagen fibers, and dense connective tissue filled with capillary in the third group of pigs, which had undergone Na selenite application. Calcification was not detected in this group. Both connective and osteogenic tissue were observed in specimens obtained in the fourth group, which had undergone amiloride and Na selenite application. CONCLUSIONS: The authors experimentally evaluated the supplementary osteogenic effects of Na selenite and amiloride by using them separately and together. The findings seem promising as a lead-in to new studies in restoring cranial defects.

Effect of zoledronic acid on osseointegration of titanium implants: an experimental study in an ovariectomized rabbit model.

PURPOSE: Zoledronic acid (ZA), a new-generation intravenous bisphosphonate, exhibits the greatest affinity for bone mineral with the longest retention, thereby leading to its ability to be dosed at annual intervals in the treatment of osteoporosis. The purpose of this preliminary study was to evaluate the effects of systemic administration of a single dose of ZA on osseointegration and bone healing around titanium dental implants. MATERIALS AND METHODS: Thirty-six female New Zealand rabbits (aged 6-12 months) were used in this study. Rabbits were randomly assigned to 1 of 3 groups: sham control group (SH), ovariectomy group (OVX), and OVX and ZA group (OVX + ZA). Animals in the OVX and OVX + ZA groups were subjected to bilateral ovariectomy, whereas animals in the SH group were sham operated. Eight weeks later, 1 implant was placed in each tibia of the animals. ZA was administered in the OVX + ZA group during the implantation, whereas the OVX and SH groups received saline solution infusions. All of the subjects were sacrificed 8 weeks after the implantation, and tibial specimens were harvested. Histomorphometric bone-to-implant contact analysis, resonance frequency analysis, removal torque testing, and digital radiographic absorptiometry were administered, and the data were statistically analyzed. RESULTS: Histomorphometric, resonance frequency, and radiodensitometric analyses showed significant improvement in osseointegration of implants in the OVX + ZA group compared with the OVX group. However, the differences in removal torque results between the groups were not statistically significant. CONCLUSIONS: The results of this study suggest that systemic ZA administration may improve osseointegration of titanium implants placed in estrogen-deficient states of bone.

The effect of dilation of immature pedicles on pullout strength of the screws: Part 2: In vivo study.

STUDY DESIGN: Experimental study. OBJECTIVE: To evaluate the biomechanical stability of screws placed in expanded pedicles, and to compare those with the screws placed in the nonexpanded pedicles in an in vivo model. SUMMARY OF BACKGROUND DATA: Pullout strength of a pedicle screw increases as the diameter of the screw gets larger. Small pedicles of pediatric patients prevent the use of large size pedicle screws in this age group. As shown in an in vitro study one option to overcome this problem is to dilate and use larger screw in immature spine. But dilation reduces the pullout strength of pedicle screws in in vitro model. METHODS: Six-week-old 3 pigs were used. One of them was lost in the postoperative period. After posterior subperiosteal exposure of lumbar segments (L1-L5), 4.0 mm diameter and 20 mm long pedicle screws were placed on the left. The right pedicles were dilated with stainless steel dilators and instrumented with screws of same dimension. At the end of 3 months the pigs were killed and the pull out strength of each screw were measured. RESULTS: The average pull out strength of the expanded and nonexpanded screws was 378.7 +/- 73 (542-308) Newton and 397 +/- 80 (535-289) Newton, respectively. There was no statistically significant difference between the 2 groups. CONCLUSION: The biomechanical stability of the same size screws inserted at the expanded and nonexpanded pedicles are the same after 3 months. Even dilation of the pedicle decreases the pullout strength of the screw at the beginning, and the pull out strength of both sides became equal after 3 months. The remodeling capacity of pedicles and overgrowth of bone on screws may have an effect on this result.

Detection of cocaine and benzoylecgonine in formalin fixed rat tissues.

The stability of drugs in formalin solution is an important factor in forensic investigation. Tissues (liver, lung, kidney, brain) taken from rats, which have been poisoned acutely with cocaine, were preserved in two different conditions, analyzed by GC-MS, and then compared. Organs of the first group were preserved and stored at -20 degrees C without adding formalin, whereas the organs of the second group were preserved and stored in formalin solution at room temperature (25 degrees C). Serum samples were taken immediately after poisoning and studied as well. In specimens stored at -20 degrees C, cocaine and its metabolite benzoylecgonine were detected in the tissues. Only benzoylecgonine was detected both in tissues and their formalin solution. It was observed that the distribution of cocaine in tissues had differed depending on the preservation conditions. The formalin solution in which benzoylecgonine was mostly detected was from liver. As a result, cocaine was detected in tissues stored at -20 degrees C. It is recommended that both the formalin-fixed tissues and formalin solution should be analyzed concurrently to assure the accurate results (LOD = 3 ng/ml).

The effect of anterior spinal fusion on spinal canal development in an immature porcine model.

STUDY DESIGN: Experimental study. OBJECTIVE: To investigate whether anterior spine fusion in the immature porcine spine has an adverse effect on the development of spinal canal. SUMMARY OF BACKGROUND DATA: Neurocentral cartilage (NCC) is located in the posterior vertebral body and responsible for the development of posterior aspect of the spinal canal. Injury to the NCC interferes with the development of the spinal canal. METHODS: Twelve 8-week-old domestic pigs were used to develop an anterior fusion model. A standard procedure as L3-L4, L4-L5 discectomy, and L3-L5 anterior instrumented spine fusion was performed. To evaluate the development of the spinal canal, all subjects had computed tomography scans before the procedure and at the final follow-up. The spinal canal area was measured at the control level (CL) (L2), arthrodesis level (AL) (L4), superior (L3), and inferior (L5) instrumented level (SIL and IIL). Percent change in spinal canal area from before surgery to final follow-up was also calculated. RESULTS.: Eleven subjects were available for the study. All subjects developed local kyphosis over the fused segments. The average area of L2 (CL) was 0.56 +/- 0.06 cm before surgery. The average areas of the L3 (SIL), L4 (AL), and L5 (IIL) were 0.62, 0.70, and 0.77 cm, respectively. At the final follow-up the average area of L2 was 1.20 cm. The average areas of the SIL, AL, and IIL were 1.16, 1.19, and 1.33 cm, respectively. The percent increase in spinal canal area at the CL was 116.6% whereas it was 85.8%, 71.0%, and 71.2% at SIL, AL, and IIL, respectively. CONCLUSION: Anterior spinal arthrodesis in the immature porcine spine results in iatrogenic retardation on spinal canal growth. This effect is most likely related to the tethering effect of the interbody fusion over the NCC. Although, it is difficult to directly extrapolate these findings to clinical practice, the spine surgeons operating on pediatric patients should be aware of this possibility.