Topical application of statin affects bone healing around implants

Objectives: 3‐hydroxy‐3‐methylglutaryl coenzyme A reductase inhibitors (statins) are widely used for hyperlipidemia. Recent studies demonstrate that statins stimulate bone morphogenetic protein‐2 expression and lead to bone formation. The aim of this study was to evaluate whether the topical application of statin enhances the osteogenesis around a titanium implant. Materials and methods: Ten‐week‐old female rats received pure titanium rods in both tibiae with or without fluvastatin. Propylene glycol alginate (PGA) was used as a carrier. The rats were divided into five groups: implant‐only group, implant with PGA group, low‐dose group [implant+PGA containing 3 μg of fluvastatin (FS)], medium‐dose group (15 μg of FS), and high‐dose group (75 μg of FS). The animals were sacrificed at 1 and 2 weeks after implantation. Peri‐implant bone formation was assessed by histomorphometric procedures, i.e., measuring the bone–implant contact (BIC) and peri‐implant bone volume (BV). A mechanical push‐out test was also performed to evaluate the implant fixation strength. Statistical differences among the groups were determined by ANOVA and P<0.05 was considered significant. Results: At week 1, there was no significant difference in BIC among the groups, however, BV and the push‐out strength were significantly higher in the high‐dose group than in the implant‐only group. At week 2, BIC and BV had significantly increased in the high‐dose group in comparison with the non‐statin groups. The fluvastatin‐treatment group showed a significant increase in push‐out strength compared with the non‐statin groups. Conclusion: Our histomorphometrical and mechanical evaluations revealed the positive effect of topically applied fluvastatin on the bone around the implant.     

Defective Bone Microstructure in Hydronephrotic Mice: A Histomorphometric Study in ICR/Mlac‐hydro Mice

Chronic renal impairment can lead to bone deterioration and abnormal bone morphology, but whether hydronephrosis is associated with bone loss remains unclear. Herein, we aimed to use computer‐assisted bone histomorphometric technique to investigate microstructural bone changes in Imprinting Control Region (ICR) mice with a spontaneous mutation that was associated with bilateral nonobstructive hydronephrosis (ICR/Mlac‐hydro). The results showed that 8‐week‐old ICR/Mlac‐hydro mice manifested decreases in trabecular bone number and thickness, and an increased trabecular separation, thereby leading to a reduction in trabecular bone volume compared with the wild‐type mice. Furthermore, histomorphometric parameters related to both bone resorption and formation, that is, eroded surface, osteoclast surface, and osteoblast surface, were much lower in ICR/Mlac‐hydro mice than in the wild type. A decrease in moment of inertia was found in ICR/Mlac‐hydro mice, indicating a decrease in bone strength. In conclusion, ICR/Mlac‐hydro mice exhibited trabecular bone loss, presumably caused by marked decreases in both osteoblast and osteoclast activities, which together reflected abnormally low bone turnover. Thus, this mouse strain appeared to be a valuable model for studying the hydronephrosis‐associated bone disease. Anat Rec, 297:208–214, 2014. © 2013 Wiley Periodicals, Inc.     

Changes in bone mass and body composition after bariatric surgery

Abstract

Aim: To analyze the effects of body weight loss on bone mineral density (BMD) on hip (Hip BMD) and lumbar spine (Lumbar BMD) after six months of bariatric surgery. Bariatric surgery is an effective treatment for morbid obesity. Nonetheless, there are scant data on the effect of weight bearing on bone structure.

Material and methods: Seventeen obese women aged 41.2?±?11.3 yrs. who underwent Roux-en-Y gastric bypass (RYGB) were included. Body composition assessments were performed through dual-energy X-ray absorptiometry immediately before and after 6-months RYGB. Data collected pre- and post-RYGB included total body weight, body mass index (BMI), lean body mass (LM), fat mass (FM) and bone mineral content. The pre- (PRE) and post-operative (POST) results were compared.

Results: Lumbar BMD POST presented a non-significant loss of 1.8% whereas Hip BMD POST showed a significant loss of 17.8%. The analysis demonstrated that BMI and LM PRE explained 26% and 49%, respectively, of Hip BMD PRE variability. In addition, LM POST explained 30% of hip BMD POST variability and was not significant for Lumbar BMD POST.

Conclusions: Obesity and rapid weight loss showed direct influence in Hip BMD after six months of bariatric surgery. However, its effect on the lumbar spine area was smaller due to the higher capacity of the spine to dissipate loads through its curvature.     

强骨康疏胶囊对去卵巢骨质疏松大鼠骨细微结构及骨代谢的影响

目的:观察强骨康疏胶囊对去卵巢骨质疏松大鼠的骨密度、OPG及RANKL蛋白表达、骨组织形态计量学参数及骨组织细微结构的影响。方法:制备去卵巢骨质疏松大鼠模型后,分组:正常对照组、模型空白组、中药低剂量预防组、中药高剂量预防组、雌激素预防组。给药1月后,检测各组股骨骨密度值,显微镜下观察股骨骨小梁的结构变化,并检测骨组织形态计量学参数。采用免疫组织化学染色法检测大鼠股骨OPG及RANKL蛋白表达。结果:模型空白组大鼠股骨骨密度减少,骨小梁厚度、面积、面积百分数均减少,骨小梁间距增大,股骨OPG蛋白平均光密度值显著降低,RANKL蛋白平均光密度值明显增高;雌激素预防组、中药低剂量组、中药高剂量组对上述指标均有明显改善。结论:强骨康疏胶囊能有效提高骨量,维持骨小梁立体空间结构,改善大鼠股骨远端松质骨的显微结构,能够提高骨OPG蛋白表达及抑制RANKL蛋白表达。     

Bone histomorphometry using free and commonly available software

Egan K P, Brennan T A & Pignolo R J
(2012) Histopathology
Bone histomorphometry using free and commonly available software Aims: Histomorphometric analysis is a widely used technique to assess changes in tissue structure and function. Commercially available programs that measure histomorphometric parameters can be cost‐prohibitive. In this study, we compared an inexpensive method of histomorphometry to a current proprietary software program. Methods and results: Image J and Adobe Photoshop^® were used to measure static and kinetic bone histomorphometric parameters. Photomicrographs of Goldner’s trichrome‐stained femurs were used to generate black‐and‐white image masks, representing bone and non‐bone tissue, respectively, in Adobe Photoshop^®. The masks were used to quantify histomorphometric parameters (bone volume, tissue volume, osteoid volume, mineralizing surface and interlabel width) in Image J. The resultant values obtained using Image J and the proprietary software were compared and differences found to be statistically non‐significant. Conclusions: The wide‐ranging use of histomorphometric analysis for assessing the basic morphology of tissue components makes it important to have affordable and accurate measurement options available for a diverse range of applications. Here we have developed and validated an approach to histomorphometry using commonly and freely available software that is comparable to a much more costly, commercially available software program.     

Bone formation with various bone graft substitutes in critical-sized rat calvarial defect

Objective: This histomorphometric study compared the efficacy of a new bone graft substitute (N-HA) derived from hen eggshell, consisted of submicron scale porous hydroxyapatite structure, in the healing of 8 mm diameter critical size defects in rat calvaria. We compared N-HA alone or in combination with calcium sulfate (CS), with a commercial bone substitute, anorganic bovine bone (Bio-Oss, BO).
Material and methods: Critical size defects were created in calvaria of 56 adult Sprague–Dawley rats. Animals were divided into four groups and treated with (1) unfilled defects, (2) N-HA grafts, (3) BO grafts and (4) N-HA/CS grafts. The percentage of new bone formed (NB%) was evaluated histomorphometrically after 6 and 12 weeks.
Results: The N-HA group exhibited more new bone formation compared with other groups at 6 and 12 weeks. Histomorphometric analysis showed greater NB% in N-HA group (11.2% at 4 weeks and 19.2% at 12 weeks) compared with those in unfilled (3.9% at 6 weeks and 6.4% at 12 weeks), BO-treated (6.4% at 6 weeks and 8.2% at 12 weeks) and N-HA/CS-treated (6.3% at 6 weeks and 12.6% at 12 weeks) groups. The N-HA group showed significant differences in NB% compared with unfilled group at 6 weeks ( P =0.016), unfilled and BO-treated groups at 12 weeks ( P =0.001). The addition of CS did not enhance the NB% compared with defects grafted with N-HA alone.
Conclusion: N-HA was an osteoconductive bone substitute for treating osseous defects in critical size defects of rat calvaria.     

Immediate replacement of single upper posterior teeth: a report of cases

Background: The immediate replacement of upper molar teeth with implants poses a significant challenge to the clinician because of its sinus involvement. Purpose: The purpose of this article is to report a protocol in which single molar teeth are replaced immediately with implants, minimizing the need for other surgical procedures. Materials and Methods: This protocol has been employed in eight cases. Briefly, the teeth are extracted atraumatically, the sockets evaluated, an osteotomy performed following the direction of the socket, and a wide diameter implant placed using the socket walls and sinus floor to anchor it. A grafting material is placed when the space between implant and socket wall is considerably large. Three cases are reviewed here, and all eight are summarized. Results: All cases have excellent soft and hard tissue healing after 6 months. Furthermore, the overall time needed to restore the cases has been considerably reduced and the need for sinus management eliminated. Conclusion: The cases presented support the use of the described protocol in the placement of implants in maxillary molar areas without any other sinus procedures.     

Improving Metabolic Control Reverses the Histomorphometric and Biomechanical Abnormalities of an Experimentally Induced Bone Defect in Spontaneously Diabetic Rats

Insulin-dependent type 1 diabetes mellitus (IDDM) has been shown to alter the properties of bone and to impair fracture-healing in both humans and animals. The objective of this study was to examine changes in the histomorphometric and mechanical parameters of bone and remodeling during bone-defect healing, depending on the diabetic metabolic state in spontaneously diabetic BB/O(ttawa)K(arlsburg) rats, a rat strain that represents a close homology to IDDM in humans.A standardized bone-defect model was chosen and based on blood-glucose values at the time of surgery (mg%), postoperative blood-glucose course (mg%), and postoperative insulin requirements (IU/kg). A total of 120 spontaneously diabetic BB/OK rats were divided into groups with a well-compensated (n = 60; 169 ± 102 mg%; 230 ± 126 mg%; and 2.2 ± 1.1 IU/kg) or poorly compensated (n = 60; 380 ± 159 mg%; 359 ± 89 mg%; and 5.4 ± 1.1 IU/kg) metabolic state. Sixty LEW.1A rats served as the normoglycemic controls (93 ± 19 mg%). Fifteen animals from each group were killed on postoperative days 7, 14, 24, and 42, and specimens were processed undecalcified for quantitative bone histomorphometry and for biomechanical testing.Our study showed in terms of bone histomorphometry, within the first 14 days, that severe mineralization disorders occurred exclusively in the rats with a poorly compensated diabetic metabolic state with a highly significant (P < 0.001) or significant (P < 0.01) decrease of all fluorochrome-based parameters of mineralization, apposition, formation and timing of mineralization, as well as significantly decreased values of biomechanical properties (P < 0.05) in comparison to the spontaneously diabetic rats with a well-compensated metabolic state and to the control rats.Bone-defect healing in spontaneously diabetic BB/OK rats is retarded exclusively in a poorly compensated diabetic metabolic state. This study suggests that strictly controlled insulin treatment resulting in a well-compensated diabetic metabolic state will ameliorate the impaired early and late parameters of IDDM bone-defect healing.     

Colonic mucosa in patients with portal hypertension

BACKGROUND AND AIMS: To do a histomorphometric study of vascular changes in colonic mucosa of patients with portal hypertension (PHT) and to find their association with clinical and upper and lower gastrointestinal endoscopic observations. METHODS: Full length colonoscopy was carried out in 55 patients with portal hypertension and 25 controls. Hemorrhoids, anorectal varices and colopathy were carefully looked for and recorded. Two biopsies each were taken from the caecum, ascending colon, transverse colon, descending colon and rectum. Sections from all the five sites were examined for histopathological changes with special reference to changes in mucosal capillaries. Morphometric assessment of the diameter of the capillary and thickness of the capillary wall was performed. These histomorphometric changes were correlated with clinical parameters and findings of upper and lower gastrointestinal endoscopic findings. RESULTS: Dilated and congested capillaries as well as capillaries with irregular thickening of the wall were seen in a significantly higher number of sections from patients than controls in biopsies from all the five sites from caecum to rectum. On morphometry, the diameter of the capillaries and the thickness of the capillary wall in biopsies from all the five sites in patients was significantly higher than that in the control group. Apart from vascular changes, edema and inflammatory infiltrate in lamina propria were the other significant histological features noted. No significant association between clinical and endoscopic features and histomorphometric assessment was found. CONCLUSION: Dilated tortuous mucosal capillaries with irregular thickening of wall, edema of lamina propria and mild chronic inflammatory infiltrate are the major histopathological changes seen in colonic biopsies of patients with PHT, showing that PHT produces changes in the colonic mucosa similar to those seen in the mucosa of upper GI tract. However, the histological changes had no correlation with the clinical or endoscopic findings except that the thickness of the capillary wall was higher in patients who had undergone endoscopic sclerotherapy as opposed to those who had not received sclerotherapy.