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.     

Treatment of osteoporosis in men

Osteoporosis in men is recognised worldwide as an important and increasing public health problem. The causes are more heterogeneous than those in women. About 50% are diagnosed as secondary cases. In some secondary forms of osteoporosis the specific diagnosis results in additional therapeutic options (e.g. androgen therapy in proven hypogonadism). The basic therapy for osteoporosis in men is no different to that in postmenopausal women, namely recommendations for counteracting modifiable risk factors, especially with regard to diet, physical exercise, and calcium and vitamin D supplementation. Concerning specific drug medications, however, even today there is still a therapeutic dilemma in male osteoporosis. While older substances (e.g. calcitonin, fluoride, alfacalcidol) are approved for both sexes, all newer medications have primarily been approved for the treatment of postmenopausal osteoporosis. Health authorities request studies in purely male populations. For new drugs, fracture data are necessary while for new substances within a class (e.g. bisphosphonates), at the very least consistent effects on bone mineral density (BMD) and bone turnover markers are requested. Due to these regulatory rules, ibandronate, teriparatide and strontium ranelate are not approved in the European Union. Some years ago, alendronate was the first bisphosphonate that was approved for the treatment of men with osteoporosis, based on consistent results from two independent male studies using a daily 10 mg dosage. Very recently risedronate was approved by the FDA and EMEA. A randomised, placebo-controlled multicentre trial of 285 male patients showed, after 2 years, a 5.8% increase in lumbar spine BMD in the risedronate 35 mg once weekly group vs 1.2% in the placebo group. In a prospective controlled study on 316 men with primary or secondary osteoporosis we found, after 12 months, a lumbar spine BMD of +4.7% vs +1.0% in controls. The number of patients with one or more new vertebral fractures was 8 in the risedronate group and 20 in the placebo group (a fracture reduction of 60%). Furthermore, we found a significantly smaller decrease in height and a steeper decrease in back pain in the risedronate group. Risedronate is the first oral bisphosphonate available for men with the more comfortable once weekly dosage.     

过氧化物酶体增殖物激活受体γC161T基因多态性与糖皮质激素性骨质疏松症的关系

目的 探讨中国人过氧化物酶体增殖物激活受体γ(PPARγ)基因外显子6 C161T多态性与糖皮质激素性骨质疏松症(GIO)的相关关系。方法 应用聚合酶链反应-限制性片段长度多态性(PCR-RELP)方法测定208例正常健康人（Ⅰ组）、168例非GIO患者（Ⅱ组）和104例GIO患者（Ⅲ组）PPARγ基因外显子6 C161T的基因型。应用双能X线骨密度仪(DEXA)测定股骨、腰椎等部位的骨密度。 结果 外显子6 C161T有CC、CT、TT 3种基因型。GIO组CC基因型频率显著低于正常对照组；CT和TT基因型频率显著高于正常对照组。非GIO组、应用激素组（GIO组＋非GIO组）与正常对照组比较，各基因型频率差异均无统计学意义。正常对照组C161T的CC基因型组各部位的骨密度有高于CT和TT基因型组的趋势，但差异无统计学意义。非GIO组和GIO组C161T的CC基因型组腰椎的骨密度明显高于CT和TT基因型组 (P ＜ 0.05)，分别为非GIO组CC型（1.04±0.17） g/cm2，CT+TT型（1.02±0.07） g/cm2；GIO组CC型（0.94±0.12） g/cm2，CT+TT型（0.83±0.08） g/cm2。经年龄、体重指数等因素校正后，差异仍有统计学意义(P ＜ 0.05）。 结论 PPARγ基因C161T基因型在正常人和应用激素患者之间无明显差异，它可能与肾小球肾炎的发病无关。C161T基因型在GIO组和正常对照组之间差异有统计学意义，它可能与糖皮质激素性骨质疏松症的发病有关。PPARγ基因C161T多态性与应用糖皮质激素患者腰椎的骨密度有关。等位基因C可能是骨量的保护因子，它可能与应用糖皮质激素后骨量的丢失有关。     

体表面积、体质量指数对老年骨质疏松的影响

目的探讨体表面积（BS）、体质量、体质量指数（BMI）对老年人骨密度（BMD）的影响。方法用双能X线骨密度仪测定1794例老年人腰椎、髋关节的BMD值，并对其与BS等指标进行相关回归分析。结果BS大的老年人其BMD大于BS小者，有显著性差异。在各种指标与BMD的相关性比较中，BS与BMD的相关性最好，其后依次为：体质量、身高、OSTA得分（亚洲人自我骨质疏松筛查工具）、BMI。结论BS比BMI等指标更能反映出人体体型对老年人BMD的影响。     

In vivo detection of single cells by MRI.

The use of high-relaxivity, intracellular contrast agents has enabled MRI monitoring of cell migration through and homing to various tissues, such as brain, spinal cord, heart, and muscle. Here it is shown that MRI can detect single cells in vivo, homing to tissue, following cell labeling and transplantation. Primary mouse hepatocytes were double-labeled with green fluorescent 1.63-microm iron oxide particles and red fluorescent endosomal labeling dye, and injected into the spleens of recipient mice. This is a common hepatocyte transplantation paradigm in rodents whereby hepatocytes migrate from the spleen to the liver as single cells. One month later the animals underwent in vivo MRI and punctuated, dark contrast regions were detected scattered through the livers. MRI of perfused, fixed samples and labeled hepatocyte phantoms in combination with histological evaluation confirmed the presence of dispersed single hepatocytes grafted into the livers. Appropriate controls were used to determine whether the observed contrast could have been due to dead cells or free particles, and the results confirmed that the contrast was due to disperse, single cells. Detecting single cells in vivo opens the door to a number of experiments, such as monitoring rare cellular events, assessing the kinetics of stem cell homing, and achieving early detection of metastases.     

与铁稳态有关的生物分子

根据近几年来发表的与铁稳态有关的生物分子的研究文献 ,将这些生物分子根据其与铁的吸收、转运、储存以及对铁稳态的监控调节等方面的关系 ,对这些生物分子进行了分类。特别是对细胞膜载体、运铁蛋白受体、铁调蛋白及铁反应元件等作了较为详细地论述     

超细α-FeOOH制备过程研究 Ⅰ.制备工艺

以制备晶形、粒度、轴比等满足高性能磁粉要求的铁黄为目标,研究了碱法超细α-FeOOH合成的工艺配方和工艺条件对粒子性能的影响,包括碱比、气量、转速、Fe(OH)_2结晶条件、熟化时间等工艺参数的影响规律。重复稳定地制备出三类超微粒α-FeOOH粒子,其粒度分别为0.18、0.28、0.39μm,分布均匀,无枝叉。     

铁骨晶对大鼠钙代谢、骨密度的影响及临床观察

本实验以铁骨晶（多肽钙），进口脱脂奶粉，活性钙冲剂，贝壳钙为钙源添加于大鼠正常饲料中。观察结果表明：上述４组钙的吸收率分别为６４．４％，６９．１％，５９．９％，５１．６％；钙的储留率分别为８９．８％，９３．３％，８５．２％，７９．０％；钙的存留率分别为４３．６％，４９．０％，３２．４％，２６．８％；股骨指数分别为７．０２×１０（－３），６．４３×１０（－３），６．８４×１０（－３）。６．８８×１０（－３）；折断力（牛顿）分别为６０．５４±１２．５５，４６．８１±９．３２，４３．２６±１６．６２，３８．２４±１０．７９。同时以铁骨晶为钙源对７０例（５～６岁）儿童进行了血清Ｃａ，Ｆｅ，Ｚｎ，Ｈｂ及生长发育的检测。铁骨晶组的身高，体重，胸围分别比对照组增加。铁骨晶组血清Ｃａ，Ｆｅ，Ｚｎ，Ｈｂ也均有较好的改善。这表明铁骨晶具有较好的促进钙吸收利用作用，同时能增加骨强度作用。     

Bone mineral density in patients with prostatic cancer treated with orchidectomy and with estrogens

Bone mineral density (BMD) and bone mineral content (BMC) were measured in the femoral neck area, trochanteric area and Wards triangle, and in the distal radius of the left forearm before and after 1 year of endocrine treatment in 27 patients with prostatic cancer. Eleven of the patients were treated with orchidectomy and 16 with combined oral and intramuscular estrogens. The patients were free from metastases during the entire observation period. In the orchidectomized patients, BMD and BMC of the distal radius decreased significantly following treatment, whereas no changes were observed in the estrogen-treated patients. These preliminary results demonstrate that estrogens may protect bone in male subjects also and may merit further investigations on larger groups of patients.