Preliminary study on the effect of parenteral naloxone, alone and in association with calcium gluconate, on bone healing in an ovine "drill hole" model system

BACKGROUND: Several diseases affect bone healing and physiology. Many drugs that are commonly used in orthopaedics as "analgesics" or anti-inflammatory agents impair bone healing. Stressful conditions are associated with decreased serum osteocalcin concentration. High endorphin levels alter calcium metabolism, blocking the membrane channels by which calcium normally enters cells. The consequent decrease of intracellular calcium impairs the activities of calcium-related enzymes. Naloxone is a pure opioid antagonist. Morphine-induced osteocalcin inhibition was abolished when osteoblasts were incubated with naloxone. Naloxone restored the altered cellular and tissue physiology by removing beta-endorphins from specific receptors. However, this is only possible if the circulating Ca concentration is adequate. The aim of the present study was to evaluate the efficacy of parenteral naloxone administration in inducing fast mineralization and callus remodelling in a group of sheep with a standardised bone lesion. METHODS: Twenty ewes were randomly assigned to 4 treatment groups. Group A acted as control, group B received a solution of calcium gluconate, group C a solution of naloxone, and group D a solution of calcium gluconate and naloxone. A transverse hole was drilled in the left metacarpus, including both cortices, then parenteral treatment was administered intramuscularly, daily for four weeks. Healing was evaluated by weekly radiographic examination for eight weeks. For quantitative evaluation, the ratio of the radiographic bone density between the drill area and the adjacent cortical bone was calculated. After eight weeks the sheep were slaughtered and a sample of bone was collected for histopathology RESULTS: Group D showed a higher radiographic ratio than the other groups. Sheep not treated with naloxone showed a persistently lower ratio in the lateral than the medial cortex (P < 0.01). Histopathology of bone samples showed more caverns and fewer osteoblasts in group D than in the other groups (P </= 0.001). CONCLUSION: A low-dose parenteral regimen of naloxone enhances mineralization and remodelling of the callus in healing cortical defects in sheep, especially if associated with calcium gluconate

An Ultrasound Assisted Anchoring Technique (BoneWelding® Technology) for Fixation of Implants to Bone – A Histological Pilot Study in Sheep

The BoneWelding® Technology offers new opportunities to anchor implants within bone. The technology melted the surface of biodegradable polymer pins by means of ultrasound energy to mould material into the structures of the predrilled bone. Temperature changes were measured at the sites of implantation in an in vitro experiment. In the in vivo part of the study two types of implants were implanted in the limb of sheep to investigate the biocompatibility of the method. One implant type was made of PL-DL-lactide (PLA), the second one was a titanium core partially covered with PLA. Healing period was 2 and 6 months, with 3 sheep per group. Bone samples were evaluated radiologically, histologically and histomorphometrically for bone remodeling and inflammatory reactions. Results demonstrated mild and short temperature increase during insertion. New bone formed at the implant without evidence of inflammatory reaction. The amount of adjacent bone was increased compared to normal cancellous bone. It was concluded that the BoneWelding® Technology proved to be a biocompatible technology to anchor biodegradable as well as titanium-PLA implants in bone

Semiquantitave histopathological evaluation of the samples obtained after eight weeks from surgery

<p><b>Copyright information:</b></p><p>Taken from "Preliminary study on the effect of parenteral naloxone, alone and in association with calcium gluconate, on bone healing in an ovine "drill hole" model system"</p><p>http://www.biomedcentral.com/1471-2474/8/43</p><p>BMC Musculoskeletal Disorders 2007;8():43-43.</p><p>Published online 22 May 2007</p><p>PMCID:PMC1891106.</p><p></p> (A) Microphotograph (10 ×; Toluidine Blue) of a slide obtained from a sheep of group A (Control); (B) Microphotograph (10 ×; Toluidine Blue) of a slide obtained from a sheep of group D (Naloxon and Calcium gluconate). Comparing the images is particularly evident the diffence in the number and area of the caverns surrounding the "drill hole" a. Parent bone; b. New bone; c. Fibrous tissue

Comparison of a dorsopalmar radiography of the metacarpus of a sheep from Group A (control) and one of Group D (naloxone and calcium gluconate) at T6

<p><b>Copyright information:</b></p><p>Taken from "Preliminary study on the effect of parenteral naloxone, alone and in association with calcium gluconate, on bone healing in an ovine "drill hole" model system"</p><p>http://www.biomedcentral.com/1471-2474/8/43</p><p>BMC Musculoskeletal Disorders 2007;8():43-43.</p><p>Published online 22 May 2007</p><p>PMCID:PMC1891106.</p><p></p> The difference in radiodensity at the drill hole site is evident and is statistically significant

Variations in rates of severe perineal tears and episiotomies in 20 European countries: a study based on routine national data in Euro-Peristat Project.

To access publisher's full text version of this article click on the hyperlink at the bottom of the pageRates of severe perineal tears and episiotomies are indicators of obstetrical quality of care, but their use for international comparisons is complicated by difficulties with accurate ascertainment of tears and uncertainties regarding the optimal rate of episiotomies. We compared rates of severe perineal tears and episiotomies in European countries and analysed the association between these two indicators.We used aggregate data from national routine statistics available in the Euro-Peristat project. We compared rates of severe (third- and fourth-degree) tears and episiotomies in 2010 by mode of vaginal delivery (n = 20 countries), and investigated time trends between 2004 and 2010 (n = 9 countries). Statistical associations were assessed with Spearman's ranked correlations (rho).In 2010 in all vaginal deliveries, rates of severe tears ranged from 0.1% in Romania to 4.9% in Iceland, and rates of episiotomies from 3.7% in Denmark to 75.0% in Cyprus. A negative correlation between the rates of episiotomies and severe tears was observed in all deliveries (rho = -0.66; p = 0.001), instrumental deliveries (rho = -0.67; p = 0.002) and non-instrumental deliveries (rho = -0.72; p < 0.001). However there was no relation between time trends of these two indicators (rho = 0.43; p = 0.28).The large variations in severe tears and episiotomies and the negative association between these indicators in 2010 show the importance of improving the assessment and reporting of tears in each country, and evaluating the impact of low episiotomy rates on the perineum.info:eu-repo/grantAgreement/EC/FP7/20101301, 2007114, 2003131, 6646