Increased hair growth and density following controlled expansion of guinea pig skin and soft tissue

The goal of this study was to investigate the effect of controlled tissue expansion on hair growth and density using the guinea pig model. Thirty white guinea pigs were randomly divided into three groups: a group to undergo expansion (EXP), an operated control group (OC), and a nonoperated control group (NOC). All groups were shaved to create a 1 cm X 2 cm tuft of dorsal hair, which was subsequently dyed. Only the EXP and OC group members underwent construction of a pocket beneath the tuft. Only the EXP group was implanted and expanded over four weeks. The EXP group revealed a significant increase (p less than 0.005) over the controls in both the number of new white hairs produced (W) and density proportion (W/A). The OC group exhibited a significant increase (p less than 0.005) over the NOC group in both W and W/A. Mechanisms to explain the results are postulated. These include the possible roles of increased follicular mitotic activity (hair follicle transformation and cycle dynamics) and improved perifollicular vascularity (capsule formation and the delay phenomenon of skin pocket construction). Clinical implications are discussed.     

Consuming breakfast and exercising longer during high school increases bone mineral density in young adult men

We examined the bone mineral densities (BMDs) of young adult men and analyzed the factors associated with BMD differences. Between 1993 and 2002, all male freshmen in the Wakayama Medical University, Japan were recruited into the present study, which included a self-administrated questionnaire survey, anthropometric measurements, and BMD measurements of the spine and hip. Of a total of 387 freshmen, 382 (98.7 %; mean age, 20.3 years; age range, 18–29 years) completed the study. The mean BMDs of the spine (L2–4) and femoral neck (FN) were 1.21 (standard deviation, 0.13) g/cm² and 1.12 (0.14) g/cm², respectively. The L2–4 BMDs were not associated with age, while FN BMDs were significantly inversely associated with age. The BMDs at L2–4 and FN were significantly associated with body mass index (BMI). After adjustment for age and BMI, multivariate regression analysis indicated that BMDs at L2–4 and FN were associated with current longer exercise duration (L2–4, p = 0.024; FN, p = 0.001), those at L2–4 with milk intake (p = 0.024), and those at FN with consuming breakfast (p = 0.004). Similarly, habits of consuming breakfast and exercising longer (on a weekly basis) during high school were linked with significantly higher L2–4 and FN BMDs. High-impact activities during high school significantly influenced the later BMDs. In conclusion, to maximize peak bone mass, consuming breakfast and completing a longer duration of stronger exercise in the late high school years for at least 10 h per week is recommended.     

Bone mineral density of the proximal tibia following uncemented arthroplasty

Bone mineral density (BMD, g/cm2) was measured using dual-photon absorptiometry (DPA) in selected areas of the proximal tibia following uncemented PCA knee prosthesis. In nine patients with 14 alloplastic operations, measurements were taken at 3-6-month intervals for the first 3 1/2 years after operation. There was a significant increase in BMD of about 15% during the first 6 months after operation. The following year it remained increased, although not significantly, compared with the initial values, then gradually diminished. Increased bone density after arthroplasty may be explained mainly by stimulation of bone formation from weight bearing due to improved walking ability. Stress shielding of the proximal part of the supporting tibial bone did not seem to occur.     

Severe hindlimb ischemia causes periosteal proliferation in the rat tibia

In this rat study, we found tibial periosteal hyperplasia and hypertrophy, and appositional new bone formation 3 days after transient hindlimb ischemia. This response was positively correlated to the extent of muscle necrosis, which was increased either by raising the environmental temperature during ischemia or by prolonging the period of ischemia.

By changing the temperature from 21 °C to 34 °C, the area periost in percent of the total tibial area was increased from 5 to 17, and by changing the duration of ischemia from 3 to 5 hours, it increased from 8 to 18.     

Sport-specific association between exercise loading and the density, geometry, and microstructure of weight-bearing bone in young adult men

Summary

In this population-based study of 24-year-old men, we have investigated the association between sport-specific exercise loading and different bone parameters. We reveal that the association between exercise loading and bone parameters is sport-specific, indicating that nonspecific resistance exercise does not impact bone density, geometry, or microstructure in young men.

Introduction

In this cross-sectional study, the association between nonspecific resistive exercise and areal and volumetric bone density, bone geometry, or bone microstructure was investigated in young adult men.

Methods

A total of 184 male athletes, 24.0?±?0.6 years of age (mean?±?SD), representing nonspecific resistive exercise and soccer (proportion of recreational athletes, 93.4 and 7.7 %, respectively), and 177 nonathletic age-matched controls were measured with dual-energy X-ray absorptiometry. Radius and tibia were measured by peripheral quantitative computed tomography (pQCT) at the diaphysis and by three-dimensional pQCT at the metaphysis.

Results

Men in the nonspecific resistive exercise group had higher grip strength(9.1 % or 0.4 SD) and higher lean mass(5.6 % or 0.5 SD) than those in the nonathletic group(p?<?0.01 and p?<?0.001, respectively). However, men who participated in nonspecific resistive exercise did not have higher bone density or a more favorable bone microstructure or geometry than their nonathletic referents. In contrast, men playing soccer had higher areal bone mineral density (aBMD) at the femoral neck (19.5 % or 1.2 SD) and lumbar spine (12.6 % or 1.0 SD), as well as larger cortical cross-sectional area (16.4 % or 1.1 SD) and higher trabecular bone volume fraction (14.5 % or 0.9 SD), as a result of increased trabecular number (8.7 % or 0.6 SD) and thickness (5.7 % or 0.4 SD) at the tibia than men in the nonathletic group(p?<?0.001).

Conclusions

Weight-bearing exercise with impacts from varying directions (playing soccer) is associated with aBMD and volumetric BMD, cortical bone geometry, as well as trabecular microstructure of weight-bearing bone. Nonspecific recreational resistance exercise does not appear to be a strong determinant of bone density, geometry, or microstructure in young adult men.     

Effect of short-term glucocorticoids on serum osteocalcin in healthy young men

Young healthy men were studied during brief treatment with prednisone to determine the rapidity of the effects of glucocorticoids on serum osteocalcin. Seven subjects were given 60 mg of prednisone orally at 8 a.m. on 5 consecutive days. Serum osteocalcin fell to 68% of the pretreatment level within 24 hours after the first dose was administered (p less than 0.01) and reached a nadir of 37% of baseline between 48 and 96 hours after treatment was begun (p less than 0.005). When prednisone was discontinued, serum osteocalcin returned promptly to pretreatment levels. Similar, though less marked, effects were found with lower doses of prednisone. Serum osteocalcin was not different from baseline after 5 mg of prednisone in five subjects, but after treatment of five subjects each with 10, 15, or 20 mg of prednisone, osteocalcin levels were 83%, 78%, and 74% of baseline, respectively (p less than 0.05). Serum osteocalcin levels fell rapidly with glucocorticoid administration, indicating that the effects of glucocorticoids on bone cells may be demonstrated long before clinical evidence of osteoporosis becomes apparent.     

Long-term changes in the tibia and radius bone mineral density following spinal cord injury

DESIGN: A prospective inception cohort study with an observational analytic design in a spinal cord injury (SCI) centre hospital. OBJECTIVE: To assess changes in trabecular and compact bone of the tibia and radius prospectively in subjects with SCI. SUBJECTS: In total, 10 individuals with an acute SCI. METHODS: Trabecular and compact bone density of the tibia and radius by peripheral quantitative computerised tomography. RESULTS: Analysis of the individual gradients of the curve coefficient showed changes in trabecular bone between -0.19 and -2.46 and in cortical bone between +0.07 and -0.93 in the tibia within 34 months after the SCI. Both trabecular and cortical bone showed a group mean loss of 99 mg/cm(3). No changes were observed in the radius. CONCLUSION: There is a major decrease in tibia mineral density over 3 years; however, no change is observed for the radius mineral content. Large interindividual differences existed in the patterns of loss in the tibia bone substance after SCI. These patterns indicate that there is no steady state of bone mineral density following 3 years of spinal cord injury.     

Population-based reference values for bone mineral density in young men

Summary Population-based reference values for peak bone mass density in Danish men. BMD of total hip (1.078 ± 0,14 g/cm²) differed significantly from values from National Health and Nutrition Examination Survey III and of total lumbar spine ((1.073 ± 0.125 g/cm²) differed significantly from Hologic values. Introduction Geographic, ethnic, and socio-economic factors are known to affect bone mineral density (BMD) and peak bone mass significantly. Reference values for male peak bone mass are scarce, and the diagnosis of male osteoporosis often relies on values provided by producers of dual-energy X-ray absorptiometry (DXA) equipment. Methods The aim of the present study was 1) to establish population-based reference values for BMD in young men and 2) to study subgroups based on variables with suspected impact on bone metabolism. We included 783 young Caucasian men aged 20 to 30 years in the Odense Androgen Study (OAS). Results Peak BMD was attained within the third decade. Obesity (BMI > 30 kg/m²) was associated with higher BMD. Abuse of anabolic steroids as well as chronic illness was associated with lower BMD. Our population-based reference values for BMD of the total hip (1.078 ± 0.14 g/cm²) differed significantly from published values from National Health and Nutrition Examination Survey III for non-Hispanic white men, while BMD of total lumbar spine (1.073 ± 0.125 g/cm²) differed significantly from Hologic reference values. Conclusions Locally derived reference values are important to avoid false positive or false negative findings during work-up in patients evaluated for osteoporosis.     

Correlates of trabecular and cortical volumetric bone mineral density of the radius and tibia in older men: The osteoporotic fractures in men study

Quantitative computed tomography (QCT) can estimate volumetric bone mineral density (vBMD) and distinguish trabecular from cortical bone. Few comprehensive studies have examined correlates of vBMD in older men. This study evaluated the impact of demographic, anthropometric, lifestyle, and medical factors on vBMD in 1172 men aged 69 to 97 years and enrolled in the Osteoporotic Fractures in Men Study (MrOS). Peripheral quantitative computed tomography (pQCT) was used to measure vBMD of the radius and tibia. The multivariable linear regression models explained up to 10% of the variance in trabecular vBMD and up to 9% of the variance in cortical vBMD. Age was not correlated with radial trabecular vBMD. Correlates associated with both cortical and trabecular vBMD were age (?), caffeine intake (?), total calcium intake (+), nontrauma fracture (?), and hypertension (+). Higher body weight was related to greater trabecular vBMD and lower cortical vBMD. Height (?), education (+), diabetes with thiazolidinedione (TZD) use (+), rheumatoid arthritis (+), using arms to stand from a chair (?), and antiandrogen use (?) were associated only with trabecular vBMD. Factors associated only with cortical vBMD included clinic site (?), androgen use (+), grip strength (+), past smoker (?), and time to complete five chair stands (?). Certain correlates of trabecular and cortical vBMD differed among older men. An ascertainment of potential risk factors associated with trabecular and cortical vBMD may lead to better understanding and preventive efforts for osteoporosis in men. © 2010 American Society for Bone and Mineral Research     

Treatment of congenital pseudarthrosis of the tibia with vascularized fibular periosteal transplant

The vascularized fibular periosteal flap has been recently described and showed solid angio and osteogenic features. We report the use of a free vascularized fibular periosteal transplant in the treatment of a El-Rosasy-Paley Type III congenital pseudarthrosis of the tibia in a 7-year-old boy, with a prior unsuccessful surgery at the age of three. The contralateral fibular periosteum was used to replace two-thirds of the hamartomatous tibial periosteum. We did not proceed to debriding the focus of the pseudarthrosis nor addressed the tibial recurvatum or revised the previous tibial rod. Consolidation was achieved radiologically at 3 months, allowing for the tibial rod to be removed. One year postoperatively, the patient ambulated without the use of a protective orthesis and resumed his sports practice. This novel pathogenesis-based technique showed promising results and a prompt healing of such a difficult orthopedic condition.     

Bisphosphonates suppress periosteal osteoblast activity independently of resorption in rat femur and tibia

Recent studies demonstrate that bisphosphonates suppress bone resorption by leading to apoptosis of the osteoclast and inhibiting the differentiation to mature osteoclasts. The influence of bisphosphonates on bone formation is unknown, although it has been hypothesized that bisphosphonates inhibit osteoblast apoptosis and stimulate osteoblast proliferation and differentiation in vitro, leading to increased bone formation. The purpose of this study was to investigate the effect of bisphosphonates on bone formation. We administered risedronate at 0.05, 0.5 or 5.0 microg/kg/day or alendronate at 0.1, 1.0 or 10 microg/kg/day subcutaneously for 17 days to 6-month-old female Sprague-Dawley rats. Control rats were given a daily subcutaneous injection of saline. Following sacrifice, the femoral and tibial mid-diaphyses were harvested and mineralizing surface (MS/BS), mineral apposition rate (MAR) and bone formation rate (BFR/BS) were measured on periosteal and endocortical surfaces. In the femur, periosteal MAR was significantly lower in all treatment groups (22-29% for risedronate, 26-36% for alendronate) than in control. In the tibia, periosteal MAR and BFR of all treatment groups were significantly lower (41-50% for risedronate, 43-52% for alendronate) than in the control group. Because the periosteal surfaces of these bones are only undergoing bone formation in modeling mode, our results show that bisphosphonates suppress bone formation independently of bone resorption. Because this effect is seen on periosteal MAR rather than on periosteal MS/BS, we hypothesize that bisphosphonates affect the activity of individual osteoblasts at the cell level. This may help to explain the reason that the anabolic effects of teriparatide are blunted when administered concurrently with or following a course of bisphosphonates in humans.     

健康青年男子体成分及全身骨密度相关分析研究

目的　调查我国青年健康男子的体成分和骨密度 (BMD) ,为骨质疏松预防、诊断、治疗提供科学依据。方法　应用DEXA测定了 15 5例年龄为 18.0～ 2 3.9岁健康青年男子的体成分、全身及腰椎和前臂的BMD。结果　上肢的BMD有随年龄而增长的趋势 ,全身及其他各部位的骨矿 (BMC)和BMD各年龄组间差异无显著性 (P >0 . 0 5 ) ;全身各部位的BMD除腰椎外 ,均随着体重指数 (BMI)的增高而增加 (P <0 .0 1) ;腰椎2 4BMD与瘦体重的相关系数达到 0 .6 89(P <0 .0 1) ,与体脂含量的相关系数只有0 12 7(P >0 . 0 5 ) ;当BMI在 18. 5～ 2 4 . 9时 ,瘦体重随着BMI的增加而增加 ,当BMI升至 2 5时 ,瘦体重不再增加。结论　瘦体重可能是影响BMD的重要因素。     

加压训练搭配振动训练对老年男性骨质代谢和骨密度影响

目的探讨加压训练搭配振动训练对老年人骨质代谢、骨密度、下肢肌力的影响。方法本研究招募55~75岁男性受试者80人,其中69人最终完成实验,受试者随机分为振动训练组、加压训练组、振动搭配加压训练组、对照组、所有受试者进行为期36周,每周4次训练干预。振动训练组:受试者在振动频率30 Hz、振幅2 mm的振动平台,执行训练方案;加压训练组:受试者左右腿,股四头肌、股二头肌、腓肠肌进行局部加压150mmgh,在平地执行训练方案;加压搭配振动训练组:受试者左右腿,股四头肌、股二头肌、腓肠肌进行局部加压150mmgh,在振动频率30 Hz、振幅2 mm的振动平台,执行训练方案;对照组在平地执行训练方案,受试者在第0、36、46周接受肌力、骨密度、生化指标、骨质代谢检测。结果振动训练组、加压训练组、加压搭配振动组、对照组均通过36周运动干预,股骨颈骨密度、大转子骨密度、Ward三角骨密度、下肢肌力、GH、IGF-1、BGP、BALP等指标均得到提高(P0.05),加压搭配振动组受试者对骨密度和肌力的提高显著高于另外三组(P0.05)、而采用单纯采用振动或加压的两组改善效果基本一致。采用传统方式运动的对照组也具有一定改善效果,其程度显著低于其余三组(P0.05)。结论单纯通过加压训练和振动训练进行长期训练均可以达到改善下肢骨密度的效果,加压搭配振动训练对于下肢骨密度和肌力的改善则更为显著。加压搭配振动训练能够有效刺激人体内生长激素和胰岛素样生长因子-1水平提升刺激骨组织生长,在停止训练后能够较长时间维持骨密度。     

Arterial vascularization of the tibia in the adult]

The arterial vascularization of the tibia in an adult is examined by microangiography (with micropaque).--The proximal epiphysis vessels originate in the periarticular circle of the knee; some are vertical, others horizontal; the condylus medialis is more vascularized than the condylus lateralis.--The metaphysis is vascularized by the arteria nutriciae terminal branches and by numerous vessels originating in the periosteal system.--The diaphysis depends on the nutrition (arteria nutriciae tibialis) and periosteal systems: these two systems are equally important in the two upper thirds but in the lower third the nutrition system is more important.--The proximal metaphysis receives numerous arteries coming from the periosteal system; they anastomose with the terminal ramifications of the arteria nutriciae.--The distal epiphysis is vascularized by three pedicles: anterior, posterior, and medial, whose branches anastomose. These pedicles are provided by the perimalleolar circle.     

Isoflavones prevent bone loss following ovariectomy in young adult rats

Soy protein, a rich source of phytoestrogens, exhibit estrogen-type bioactivity. The purpose of this study was to determine if ingestion of isoflavones before ovariectomy can prevent bone loss following ovariectomy. Twenty-four nulliparous Wistar rats were randomly divided into four groups. In the normal diet groups, a sham operation was performed on Group A, while ovariectomy was performed on Group B. For Groups C and D, all rats were fed with an isoflavone-rich (25 mg/day) diet for one month, then bilateral ovariectomy were performed. In the rats in Group C, a normal diet was begun following the ovariectomy. The rats in Groups D continued to receive the isoflavone-rich diet for two additional months postoperatively. All rats were sacrificed 60 days after surgery. The weight of bone ash of the long bones and whole lumbar spine were determined. A histological study of cancellous bone was done and biochemical indices of skeletal metabolism were performed and analyzed. The markers of bone metabolism exhibited no significant changes. When compared with the sham-operated rats fed a normal diet, the bone mass of ovariectomized rats decreased significantly; pre-ovariectomy ingestion of an isoflavone-rich diet did not prevent bone loss. The bone mass of rats treated with an isoflavone-rich diet for three months was higher than controls two months after ovariectomy.     

Recent isolated fractures of the tibia in the adult

A series of 80 cases of recent isolated fracture of tibia in adults demonstrated the specific problems raised by this type of fracture, related for the most part to the integrity of the fibular splint. A resulting therapeutic attitude is based on a biomechanical study, the place of osteotomy of the fibula being discussed: orthopaedic treatment is suggested for fractures without displacement, under strict radiologic surveillance, and surgical treatment for fractures with primary or secondary displacement. The indications for fibular osteotomy are reviewed.     

青年男性高尿酸血症患者生活方式干预对骨密度的影响

目的探讨青年男性血尿酸水平与骨密度的关系以及高尿酸血症患者生活方式干预措施对骨密度的影响。方法选取体检人群中青年男性作为受试者,应用Pearson相关分析检验受试者尿酸与骨密度的相关性。将受试者根据尿酸水平分为正常组及高尿酸血症组,对高尿酸血症者进行为期1年的生活方式干预,对两组人群1年前后的临床指标进行组内及组间比较。结果相关分析显示,受试者血尿酸水平与骨密度呈正相关关系(P0.05)。分组后,两组受试者尿酸与腰椎骨密度均呈正相关关系(P0.05)。按提前设定的措施进行生活方式干预后,高尿酸血症组受试者的尿酸、三酰甘油及低密度脂蛋白胆固醇较前下降,与干预前比较,差异有统计学意义(P0.05);骨密度与干预前比较,差异无统计学意义(P0.05)。正常组与高尿酸血症组在受试1年后各项指标的差异无统计学意义。结论对青年男性通过改善生活方式的措施来控制尿酸水平,可同时改善脂代谢,短期内未造成对骨密度的不利影响。