Spinal Trabecular Bone Loss and Fracture in American and Japanese Women

This study examined trabecular bone mineral density (BMD) in Japanese women with and without spinal fracture, and compared the results to American women with and without fracture. The quantitative computed tomography (QCT) systems used at the University of California, San Francisco (UCSF) and at Nagasaki University were cross-calibrated. Normative BMD was assessed with the K₂HPO₄ liquid phantom in 538 Americans aged 20–85 years, and with the B-MAS200 phantom in 577 Japanese aged 20–83 years. These BMD were adjusted for use with the Image Analysis solid phantom using the result of cross-calibration. The trabecular BMD in 111 postmenopausal American women (55 with fracture), and in 185 postmenopausal Japanese women (67 with fracture) were compared for investigation of the difference in BMD values relative to fracture status. The absolute BMD values in Japanese were lower than those in Americans, and the differences were greater with advancing age. The magnitude of the BMD difference was 8.6, 20.5, 38.1 mg/cm³ in women aged 20–24 years, 40–44 years, 60–64 years, respectively. In premenopausal women, BMD began to decrease at the age of 20 in Japanese, whereas the peak bone mass was maintained until the age of 35 in the American women. In immediate postmenopausal women, BMD significantly decreased in both populations. In later postmenopausal women, BMD significantly decreased with age in the Japanese women but decreased less rapidly in the American women. The aging decrease of BMD was 1.4% and 2.2% per year in the later postmenopausal American and Japanese women, respectively. The fracture threshold is considered to be lower in Japanese women. However, the BMD difference between American and Japanese women with fracture was similar to that without fracture. The Z-scores of fracture subjects versus controls were 2.9 in American and 1.8 in Japanese women. In conclusion, Japanese women were found to have a lower BMD and lower fracture threshold than American women. The significant decrease of spinal trabecular BMD in late postmenopause is potentially responsible for the higher prevalence of spinal fracture in Japanese women. Received: 18 December 1995 / Accepted: 23 September 1996     

Associations of Early Premenopausal Fractures with Subsequent Fractures Vary by Sites and Mechanisms of Fractures

In a retrospective population-based study we assessed whether and how self-reported former fractures sustained at the ages of 20–34 are associated with subsequent fractures sustained at the ages of 35–57. The 12,162 women who responded to fracture questions of the baseline postal enquiry (in 1989) of the Kuopio Osteoporosis Study, Finland formed the study population. They reported 589 former and 2092 subsequent fractures. The hazard ratio (HR), with 95% confidence interval (CI), of a subsequent fracture was 1.9 (1.6–2.3) in women with the history of a former fracture compared with women without such a history. A former low-energy wrist fracture was related to subsequent low-energy wrist [HR = 3.7 (2.0–6.8)] and high-energy nonwrist [HR = 2.4 (1.3–4.4)] fractures, whereas former high-energy nonwrist fractures were related only to subsequent high-energy nonwrist [HR = 2.8 (1.9–4.1)] but not to low-energy wrist [HR = 0.7 (0.3–1.8)] fractures. The analysis of bone mineral density (BMD) data of a subsample of premenopausal women who underwent dual x-ray absorptiometry (DXA) during 1989–91 revealed that those with a wrist fracture due to a fall on the same level at the age of 20–34 recorded 6.5% lower spinal (P= 0.140) and 10.5% lower femoral (P= 0.026) BMD than nonfractured women, whereas the corresponding differences for women with a former nonwrist fracture due to high-energy trauma were −1.8% (P= 0.721) and −2.4% (P= 0.616), respectively. Our results suggest that an early premenopausal, low-energy wrist fracture is an indicator of low peak BMD which predisposes to subsequent fractures in general, whereas early high-energy fractures are mainly indicators of other and more specific extraskeletal factors which mainly predispose to same types of subsequent fractures only. Received: 21 February 1996 / Accepted: 24 September 1996     

钙和鸡冠花黄酮提取物对大鼠废用性骨质疏松的作用

目的探讨钙和鸡冠花黄酮提取物对废用性骨质疏松大鼠的作用,为骨质疏松的防治提供依据.方法选用健康SD大鼠40只,雄性.随机分为5组,第1、2组分别为正常对照和阳性对照,灌胃蒸馏水5 ml/(kg@d),第2～5组制造废用性骨质疏松大鼠模型,第3、4、5组为预防组,分别灌胃等量鸡冠花提取物,碳酸钙,鸡冠花提取物加钙溶液.实验8周后,测骨密度(BMD),股骨CT值,测血清MDA、SOD及24 h尿钙、羟脯氨酸(HOP)、尿肌酐含量等.结果阳性组与正常对照组比较股骨重、灰分重、CT值、血清钙下降,尿钙、尿HOP升高(P＜0.05或0.01),预防组与阳性组比较股骨重、CT值显著增加,碳酸钙组、鸡冠花加钙组灰分重显著增加(P＜0.05).与阳性组比较各预防组血清钙增加,尿钙、尿HOP减少(P＜0.05或＜0.01).鸡冠花组、鸡冠花加钙组与阳性组比较股骨BMD、血清SOD升高,MDA降低,单纯补钙组仅BMD升高(P＜0.05或＜0.01).结论鸡冠花提取物、钙对废用性骨质疏松大鼠骨质代谢均有促进作用,两者合用具有更好的预防效果,能延缓或减轻废用性骨质疏松的发生.     

Quantitation of T2′ anisotropic effects on magnetic resonance bone mineral density measurement

In this paper, the authors quantitate the anisotropy of susceptibility effects in an uniaxial trabecular bone model and show its relevance to clinical MR bone mineral density measurements. A physical model is described that quantitates the anisotropic MR behavior of uniaxial trabecular bone. To test the model, a phantom of parallel polyethylene filaments was scanned every 15° between 0° and 90° with respect to the system's main magnetic field (B₀). The distal radial metaphysis of a healthy female volunteer was scanned in orthogonal projections. The signal from each phantom image and each radial image was separated in a pixel-wise fashion into R₂ and R₂′ maps. As predicted, R₂′ relaxation showed anisotropic behavior and changed according to sin² (?), confirming that columnar structures parallel with B₀ will cause no MR susceptibility effects. Scans of the distal radius showed that R₂′ relaxation was twice as great with the forearm perpendicular to B₀ as when it was parallel to it, demonstrating different contributions from struts and columns. For both phantom and radial bone scans, R₂ relaxation was isotropic and did not change with object orientation.     

Bone mineral status in paraplegic patients who do or do not perform standing

Bone mineral density (BMD) was assessed by dual-photon X-ray absorptiometry at the lumbar spine (L3, L4), the proximal femur and the femoral shaft, and by single-photon absorptiometry at the forearm in 53 patients with complete traumatic paraplegia of at least 1 year's duration and in age- and sex-matched healthy controls. The patients did (n=38) or did not (n=15) regularly perform passive weightbearing standing with the aid of a standing device. Compared with the controls, the BMD of paraplegic patients was preserved in the lumbar spine and was markedly decreased in the proximal femur (33%) and the femoral shaft (25%). When considering all patients performing standing, they had a better-preserved BMD at the femoral shaft (p=0.009), but not at the proximal femur, than patients not performing standing. BMD at the lumbar spine (L3,L4) was marginally higher in the standing group (significant only for L3;p=0.040). A subgroup of patients performing standing with use of long leg braces had a significantly higher BMD at the proximal femur than patients using a standing frame or a standing wheelchair (p=0.030). The present results suggest that passive mechanical loading can have a beneficial effect on the preservation of bone mass in osteoporosis found in paraplegics.     

Evaluation of vertebral volumetric vs. areal bone mineral density during growth

Bone mineral “density” (BMD) measured by dual-energy X-ray absorptiometry (DEXA) does not represent the volumetric density (grams per cubic centimeter), but rather the areal density (grams per square centimeter). This distinction is important during growth. The purpose of this study was to measure vertebral dimensions in cadavers of young pigtail macaques (Macaca nemestrina), and to derive equations to predict the volumetric bone density from noninvasive measurements. We measured the areal bone density by DEXA, vertebral volume by underwater weighing, mineral content by ashing, dimensions of lumbar vertebrae by calipers, and dimensions of vertebrae by radiography. Somatometric measurements of the female lumbar vertebral bodies showed that the shape changed during growth. The bone mineral content from the densitometer correlated significantly with the ash weight (r = 0.99, error 8.7%). The correlation coefficient between the volumetric bone mineral density and areal BMD measurement was significant (r = 0.68, p < 0.0001) with a 9.5% error; this improved significantly to 0.82 (7.2% error) when the BMD was divided by the vertebral depth from the radiograph. Areal BMD showed a strong correlation with age (r = 0.82, p < 0.0001), with an average increase of 7.4%/year. In contrast, volumetric mineral density showed a weak relationship with age (r = 0.43, p < 0.01), for an average increase of 1.5%/year. When studying bone mineral density during growth, the differences between volumetric and areal bone mineral density should be taken into consideration. (     

Loading anticancer drugs into HDL as well as LDL has little affect on properties of complexes and enhances cytotoxicity to human carcinoma cells

Low density lipoprotein (LDL) has been found to represent a suitable carrier for cytotoxic drugs that may target them to cancer. This study investigated whether very low density lipoprotein (VLDL), LDL and high density lipoprotein (HDL) can be used to effectively incorporate four cytotoxic drugs, 5-fluorouracil (5-FU), 5-iododeoxyuridine (IUdR), doxorubicin (Dox) and vindesine; characterized the complexes; and examined the effect of incorporation on drug cytotoxicity against HeLa cervical and MCF-7 breast carcinoma cells. Significant drug loading was achieved into all three classes of lipoproteins, consistent with the sizes and hydrophobicity of the drugs. The relative loading efficiency was found to be vindesine>IUdR>Dox>5-FU for all three classes of lipoproteins. As shown by electron microscopy (EM), drug incorporation did not affect the size or morphology of the lipoproteins. Differential scanning calorimetry (DSC) showed that drug loading did not significantly change the thermal transition temperature of core lipids in the lipoproteins. The transition enthalpy was changed only for LDL–Dox and LDL–vindesine. The drugs remained stable in the lipoproteins as determined by high performance liquid chromatography (HPLC). EM, DSC and HPLC data suggest that drugs were incorporated into lipoproteins without disrupting their integrity and drugs remained in their stable forms inside lipoproteins. Compared with free drugs in cytotoxicity assays, the IC₅₀ values of LDL– and HDL–drug complexes were significantly lower (2.4- to 8.6-fold for LDL complexes and 2.5- to 23-fold for HDL complexes). All free or lipoprotein-bound drug formulations were comparably more cytotoxic against MCF-7 than HeLa cells. Upregulating the lipoprotein receptors enhanced, and downregulating them inhibited, the cytotoxicity, indicating the mechanistic involvement of lipoprotein receptor pathways. Complexes of all four drugs with VLDL, in contrast to LDL and HDL, had the same cytotoxicity as the four corresponding free drugs. Our results suggest that further studies are required of the potential of HDL to be a cancer targeting drug carrier.     

微波与X线联合辐射对人体血液系统的影响

本文调查了微波与X线同时接触工人49名(联合组)、单微波接触工人48名(微波组)以及两者均不接触的工人46名(对照组)。联合组和微波组工人的微波辐射剂量每日平均约300μw/cm~2,联合组工人接触的X线剂量,每年小于5rem。结果显示:联合组中性粒细胞ACP、AKP活性以及中性粒细胞核棘突出现率均较微波组和对照组明显增高(P<0.01),糖原含量则较其它两组明显下降(P<0.01)。调查表明,低强度微波与低剂量X线联合辐射比单独微波辐射对人体的潜在危害更大。因此,对雷达等发射设备周围的工作人员,除必要的微波防护外。同时需要对X线进行防护。     

Ki67、P53及微血管密度在大肠肿瘤中的表达

目的 研究Ki67、P53及微血管密度(microvessel density,MVD)在大肠肿瘤中的表达,探讨其与大肠肿瘤癌变的关系及作为早期癌变生物学标志物的可能性。方法 采用免疫组化技术分别测定正常大肠黏膜、大肠息肉及大肠癌组织标本中Ki67、P53及MVD值,共80例,分析其变化规律及相关性。结果 在正常黏膜、大肠息肉、大肠癌组中的Ki67标记指数逐渐增高(分别为11.00±10.70、39.64±17.70、52.96±26.40),组间比较差异显著(P=0.0001)。正常黏膜组P53蛋白均为阴性,大肠癌组P53蛋白表达的阳性率明显高于息肉组(P=0.0001)。Ki67、P53蛋白表达与性别、年龄、病程、病变部位、大小、大肠癌的病理类型、Dukes分期均无相关性。正常黏膜、大肠息肉、大肠癌组的MVD值(14.80±5.10、19.70±7.84、36.56±20.40)逐渐上升,3组差别显著(P=0.0001)。大肠癌中Dukes C、D期的MVD值(40.56±3.49)明显高于A、B期(29.50±2.45)(P=0.016)。Ki67与P53在各种组织中的表达呈正相关(r=0.5149,P=0.015)。联合检测Ki67及P53鉴别大肠良恶性病变的敏感度(70.37％)低于单侧Ki67(96.30％),但特异度(94.34％)明显增高。结论 Ki67标记指数可反映细胞增殖状态,指数高的大肠腺瘤易发生癌变。MVD值高的大肠癌易发生转移,MVD可作为判断大肠癌预后的参考指     

Study on Bone Mineral Density and its Influencing Factors among 1 214 Older Adults in Xuhui District, Shanghai

Osteoporosis is a common disease in older adults. The basic evidence for the diagnosisof osteoporosis is the decrease of bone mineral density (BMD) [1]. Studies showed that the risk of fractures would rise as the bone mineral density decreased, and the me…