Effects of Clodronate on Cortical and Trabecular Bone in Ovariectomized Rats on a Low Calcium Diet

The aim of this study was to evaluate the contribution of a low calcium diet to the cortical and trabecular osteoporosis seen in ovariectomized rats after 7 weeks on a low calcium diet and to investigate the effects of the bisphosphonate clodronate on this development of osteoporosis. Thirty-six mature, female Wistar rats were randomized into four groups: Ovx−B (bisphosphonate) and Ovx−C (control) were ovariectomized, and Sham−Ca (low calcium) and Sham+Ca (normal calcium) were sham operated. The first three groups were fed a low calcium diet (0.01%) and Sham+Ca normal rat chow (Ca 1.1%). The Ovx−B received 10 mg/kg s.c. clodronate daily for nine weeks, and Ovx−C, Sham−Ca, and Sham+Ca received the same volumes of saline. Bone mineral turnover measured as ⁸⁵Sr-uptake was increased in all low calcium groups compared to Sham+Ca. The Sham+Ca femora had higher dry weight and ash weight than the other groups, and Ovx−C had higher dry weight compared with Ovx−B and Sham−Ca. Calcium content was lower in both Ovx groups compared to both Sham groups. Magnesium was lower in all groups compared to Sham+Ca and higher in Ovx−B compared with Ovx−C. In the femoral shaft, Sham+Ca had significantly higher ultimate bending moment, energy absorption, and deflection compared to the other three groups. Ultimate bending moment was higher in Sham−Ca than in Ovx−C. Stiffness was increased in both Sham+Ca and Ovx−B compared to Ovx−C. The maximum stress in the femoral midshaft was higher in Sham+Ca than in the other groups, and higher in Ovx−B than in Ovx−C. Histomorphometry showed increased medullary area in all low calcium groups compared to Sham+Ca and larger cortical area in Sham+Ca and Ovx−B compared to Ovx−C. Compared to Sham+Ca the trabecular bone volume was decreased to 30% in Sham−Ca and to 9% in Ovx−C, but was unchanged in Ovx−B. The low calcium diet generally increased bone mineral turnover and reduced the tibial bone volume. Femoral changes led to a reduction of cortical fracture strength and maximal stress. Ovariectomy in addition to a low calcium diet reduced femoral strength even more. Daily injections of clodronate to ovariectomized rats on a low calcium diet increased femoral shaft stiffness and maximum stress, and clodronate preserved both trabecular and cortical tibial bone volume completely. Received: 11 June 1996 / Accepted: 5 March 1997     

Bone Mass in Female Volleyball Players: A Comparison of Total and Regional Bone Mass in Female Volleyball Players and Nonactive Females

The purpose of this cross-sectional study was to evaluate bone mass in female athletes participating in an impact loading sport (volleyball), and especially to investigate whether any changes in bone mass might be related to the type and magnitude of weightbearing loading and muscle strength. The volleyball group consisted of 13 first division players (age 20.9 ± 3.7 years) training for about 8 hours/week, and the reference group consisted of 13 nonactive females (age 25.0 ± 2.4 years) not participating in any kind of regular or organized sport activity. The groups were matched according to weight and height. Areal bone mineral density (BMD) was measured in total body, head, lumbar spine, femoral neck, Ward's triangle, trochanter, the whole femur, and humerus using dual-energy-X-ray absorptiometry. Isokinetic concentric peak torque of the quadricep and hamstring muscles was measured using an isokinetic dynamometer. Compared with the controls, the volleyball players had a significantly (P < 0.05–0.01) higher BMD of the total body (6.1%), lumbar spine (13.2%), femoral neck (15.8%), Ward's triangle (17.9%), trochanter (18.8%), nondominant femur (8.2%), and humerus (dominant 9.5%, nondominant 10.0%), but not of the head and the dominant whole femur. The dominant humerus showed significantly higher BMD than the nondominant humerus in both the volleyball and nonactive group (P < 0.05). There was no significant difference in muscle strength of the thigh between the two groups. In the nonactive group, muscle strength in the quadriceps, and especially hamstrings, was correlated to BMD of the adjacent bones (whole femur, hip sites) and also to distant sites (humerus). However, in the volleyball group there were no correlations between muscle strength and BMD of the adjacent bones, but quadricep strength correlated to BMD of the humerus. These results clearly show that young female volleyball players have a high bone mass. The demonstrated high bone mass seems to be related to the type of loading subjected to each BMD site. Muscle strength of the thigh seems to have little impact on BMD in female volleyball players. Received: 18 June 1996 / Accepted: 31 October 1996     

光固化复合树脂修补方法的比较研究

本研究评价了喷砂、氢氟酸(HF)、氢氟酸处理后涂KH-570乙醇液等方法时国产GD光固化复合树脂以及进口VIVADENT复合树脂的修补效果.结果表明:9.6%HF处理国产树脂、喷砂处理进口树脂均获得最大的修补强度,HF KH-570处理方法虽为每种材料中之最小者,但与其它修补方法间无显著性差异.     

Arm function after axillary dissection for breast cancer: a pilot study to provide parameter estimates.

Sixty-three women participated in a study in Calgary, Alberta to assess the rate of arm recovery and factors affecting it up to one year after axillary node dissection for breast cancer. Outcomes included objective measures of swelling, mobility, and strength, and subjective assessments of pain (at rest and with movement) and stiffness. Approximately 42% of women had residual impairment of at least one type one year after surgery, the most common problems being pain (16%) and reduced grip strength (16%). Except for lymphedema, measurements one year after surgery showed little change from measurements at 6 months, suggesting that the shorter follow-up may be appropriate for assessing the long term effects of axillary dissection. Lymphedema was the only sequela which increased over time. The results provide parameter estimates for designing studies to evaluate the role of physiotherapy after axillary dissection.     

Improved Static Compression Behaviors and Tablettabilities of Spherically Agglomerated Crystals Produced by the Spherical Crystallization Technique with a Two-Solvent System

Purpose. Poorly compressible crystals of acebutolol hydrochloride were agglomerated by the spherical crystallization technique with a two-solvent system to improve the compressibility for direct tabletting. The mechanism of improvements in static compression behaviors and tablettabilities of the spherically agglomerated crystals were investigated. Methods. The improvement of static compression behaviors of the agglomerated crystals was determined by measuring the stress relaxations and elastic recoveries of compressed powder of original and agglomerated crystals. The improved tablettability of agglomerated crystals was evaluated by the pressure transmission ratio upon compression, the ejection pressure for releasing the tablet from the die and the tablet strength, i.e., tensile strength required for breaking. Results. The higher relaxation pressure and the lower elastic recovery of the agglomerated crystals than of the original crystals were found. The pressure transmission ratio data showed that the friction pressures of the two crystals were similar during the compression period. The ejection pressure of the agglomerated crystals was lower than that of the original crystals. The tensile strength of the tablet of agglomerated crystals was greater than that of the original crystals. Conclusions. The compressibility and tablettability of the spherically agglomerated crystals prepared by the spherical crystallization technique were much improved due to their increased plastic property and reduced adhesive property compared to the original crystals.     

Similarities in Skeletal Muscle Strength and Exercise Capacity Between Renal Transplant and Hemodialysis Patients

Exercise intolerance is common in hemodialysis (HD) and renal transplant (RTx) patients. Aim of the study was to assess to what extent exercise capacity and skeletal muscle strength of RTx patients differ from HD patients and healthy controls and to elucidate potential determinants of exercise capacity in RTx patients. Exercise capacity, muscle strength, lean body mass (LBM) and physical activity level (PAL) were measured by cycle-ergometry, isokinetic dynamometry, DEXA and Baecke Questionnaire, respectively, in 35 RTx, 16 HD and 21 controls. VO2peak and muscle strength of the RTx patients were significantly lower compared to controls (p<0.01), but not different compared to HD patients. In RTx patients, strength (p<0.001), PAL (p=0.001) and age (p=0.045) were significant predictors of VO2peak. Muscle strength was related to LBM (p=0.001) and age (p=0.001), whereas gender (p<0.001) and renal function (p=0.01) turned out to be significant predictors of LBM. No effects of corticosteroids were observed. Exercise capacity and muscle strength seem equally reduced in RTx and HD patients compared to controls. In RTx patients, muscle strength and PAL are highly related to exercise capacity. Renal function appears to be a significant predictor of LBM, and through the LBM, of muscle strength and exercise capacity.     

含钛合金及Ni-Cr合金与瓷粉结合强度的实验研究

目的:研究含钛合金(4%～6%)[熔附HeraCeramJC瓷粉(A1组)和Vita瓷粉(A2组)]、HeraCeram公司的Ni-Cr合金[熔附HeraCeramJC瓷粉(B1组)和Vita瓷粉(B2组)]及西北有色金属厂的Ni-Cr合金[熔附HeraCeramJC瓷粉(C1组)和Vita瓷粉(C2组)]的金-瓷结合强度,为临床工作提供参考。方法:运用三点弯曲法对各组的金-瓷结合强度进行测试,并对金-瓷结合界面进行电镜观察分析。结果:电镜显示各组瓷粉均与金属基体结合紧密,无明显气泡、中间层等缺陷。结合强度:A1组:(41.08±2.98)MPa,B1组:(46.05±3.16)MPa,C1组:(44.04±3.69)Mpa;A2组:(42.29±3.38)MPa,B2组:(42.05±3.26)MPa,C2组:(47.47±2.92)MPa。①HeraCeramJC瓷粉与3种合金结合的结合强度比较:B1>A1(P<0.05);B1>C1、C1>A1(P>0.05)。②Vita瓷粉与3种合金结合的结合强度比较:C2>A2、C2>B2(P<0.05);A2>B2(P>0.05)。结论:本实验表明临床常用的3种非贵合金与瓷粉的金-瓷结合强度均大于ISO所要求的基本值25MPa,但各组间还存在一定差异,为临床工作中根据患者的具体情况选择合适的烤瓷修复基底材料和瓷粉提供实验依据。     

Estenia瓷树脂复合体制作冠桥的强度测试

目的:探讨Estenia瓷树脂复合体的强度,并与其他几种树脂材料进行比较,为临床选择冠桥树脂材料提供参考。方法:采用Estenia瓷树脂复合体体外模拟下颌第一磨牙单冠和第一磨牙缺失3个单位固定桥的形态,测试单冠的抗压强度和固定桥的抗弯强度,并与Artglass、Solidex、Targis3种树脂材料在相同实验方法下测试得到的结果作比较。结果:Estenia瓷树脂单冠的折裂最大载荷均值为600.20N,Estenia瓷树脂桥的折裂最大载荷均值为302.53N。结论:Estenia瓷树脂复合体的强度高于Artglass﹑Solidex和Targis树脂复合体。     

Muscle Strength and Walking Ability After Laparoscopic Hernioplasty Versus Conventional Repair

Purpose: We examined muscle strength and walking ability after hernia repair to compare the effects of laparoscopic hernioplasty and conventional repair. Methods: Twenty-seven patients with primary inguinal hernias were randomly divided into two groups according to the surgical procedure: 15 patients were treated with laparoscopic hernioplasty and 12 with conventional repair. Two types of muscle testing around the inguinal region, one by manual examination and one using a musculator, were done preoperatively and 1 week postoperatively. Walking exercise tests were performed at the same time as muscle testing. Results: Manual examination showed that the postoperative muscle strength of the iliopsoas muscle was decreased in six patients from the conventional repair group, but not in any of those from the laparoscopic hernioplasty group. The musculator showed decreased strength of the iliopsoas muscle after conventional repair, but not after laparoscopic hernioplasty. The walking exercise test showed that conventional hernia repair influenced walking. Conclusion: A decline in muscle strength of the iliopsoas muscle and walking ability was evident after conventional repair, but not after laparoscopic hernioplasty. Thus, laparoscopic hernioplasty is superior to conventional repair from the perspective of muscle testing and walking ability. Received: March 29, 2002 / Accepted: July 2, 2002 Reprint requests to: N. Murata     

The influence of support conditions in the loading fixture on failure mechanisms in the push-out test: a finite element study

The usefulness of the push-out test as an indicator of interface strength was evaluated using finite element models of intact and partially failed cylindrical push-out specimens loaded against a rigid annular support. The irregular stress distributions that were found in intact specimens depended more on interface conditions at the loading fixture than on a 35% increase in interface area. The maximum stress at the interface was a tensile stress. Critical energy release rates for interface failure were calculated for flawed specimens in which flaw size was either 10 or 100 microns, and for boundary conditions at the loading fixture that were either fixed or slipping in the radial direction. The critical energy release rates depended heavily on the support boundary conditions. Thus, the results of parametric push-out tests can be reasonably compared only for specimens that are very similar in geometry and that are loaded in very carefully controlled fixtures.