Alcoholism-associated spinal and femoral bone loss in abstinent male alcoholics,as measured by dual X-ray absorptiometry

Although alcoholism is a known risk factor for osteoporosis, there are few published reports on alcoholism-associated bone loss. To study alcoholism-associated bone loss, this study used a dual X-ray absorptiometry (DXA) densitometer to measure lumbar and femoral bone mineral density (BMD) in a previously little-studied population: 32 relatively healthy, nonhospitalized, Caucasian, alcoholic men with a period of abstinence longer than that previously studied (median abstinence 4.0 months, range 3 days–36 months). DXA is a new, highly precise densitometric method with many advantages over the methods used in previous studies. The subjects had statistically significant bone loss at three sites: lumbar spine, femoral neck, and Ward's triangle (multiple correction adjusted two-tailed P < 0.008). Compared to the mean BMD of sex-, age-, and race-matched norms, the subjects' average femoral neck, Ward's triangle, and lumbar BMDs were, respectively, 0.56, 0.69, and 0.57 standard deviations (SDs) below the normative values.This study was partially funded by a National Institutes of Health Short Term Research Training Grant (PHSHL 07491) to K.C.     

Association of a genetic polymorphism in human apolipoprotein B-100 with intermediate density lipoprotein concentrations

Immunochemical techniques have been used to identify five antigenic (Ag) sites on apolipoprotein B-100 (apoB), the major protein constituent of very low density (VLDL), intermediate density (IDL), and low density lipoproteins (LDL). Each Ag site results from allelic variation at a specific locus of the apoB gene. In the present study, we assessed whether variations in the five Ag loci were associated with concentrations of plasma lipids or lipoprotein fractions measured by analytical ultracentrifugation in a group of 44 healthy men. Pair-wise analyses of the Ag markers revealed that Ag(a1/d), in association with either Ag(x/y) or Ag(t/z), is significantly related to plasma IDL-mass concentrations. In this cohort we detected no significant associations of the Ag alleles (singly or in combination) with plasma total cholesterol, triglycerides, LDL-cholesterol, HDL-cholesterol, or mass of total VLDL or LDL. These results suggest that genetic variations in the apoB molecule may predispose to variations in concentrations of IDL that could have consequences for atherosclerotic risk.     

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.     

延边地区警察人群血脂水平

目的了解延边地区警察人群的血脂水平。方法将382例（男350例，女32例；朝鲜族165例，汉族217例）延边少数民族自治州公安局职工作为观察组，将100例健康人群作为对照组，应用日立7600生化分析仪分别测定甘油三酯（TG）、总胆固醇（CHO）、高密度脂蛋白胆固醇（HDL—C）、低密度脂蛋白胆固醇（LDL—C），并进行对比分析。结果观察组检出血脂异常者220例，占58．9％；对照组28例，占28％，两者差异有统计学意义（Х^2=27．78，P〈0．01），观察组明显高于对照组。此外，观察组中朝鲜族与汉族的血脂异常率差异无统计学意义（P〉0．05），但男女差异显著（P〈0．01）。结论延边地区警察人群的血脂代谢异常率明显高于普通人群，无民族差异，提示该人群应及早加强健康教育和其他预防措施。     

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.     

饮水锶对大鼠骨骼生长发育影响的实验研究

研究了高锶饮水对大鼠骨骼生长发育的影响。结果表明，饮水中锶浓度为５～５００ｍｇ／Ｌ达１２周可引起Ｗｉｓｔａｒ大鼠血清、尿、股骨、颌骨和牙齿中锶含量增高，呈明显的剂量－反应关系。同时，锶还可使骨骼钙含量降低，牙齿钙含量和骨骼的骨密度增高，以及除第１２周雌性大鼠外血清钙水平下降。尚未发现锶对动物体重、体长、血清ＡＫＰ活性、尿钙水平以及股骨弯曲断裂载荷的影响。然而，锶对动物骨骼生长发育影响性别之间存在差异，如在第１２周染锶组雄性大鼠血清钙含量降低，而雌性大鼠升高；在第４周和第８周时，仅雄性大鼠尿Ｈｏｐ／Ｃｒ比值增高，而雌性大鼠维持于正常水平；Ｓｒ２＋还使雄性大鼠颌骨骨密度增加，而雌性大鼠股骨骨密度增加。上述改变提示可能是动物性别之间在内分泌调节和代谢过程上不同的结果。     

利塞膦酸钠在防治绝经后骨质疏松症中的作用

目的　观察利塞膦酸钠防治绝经后骨质疏松症的疗效。方法　绝经后骨质疏松症共4 8例 ,随机分为 2组 ,对照组 2 4例 ,服安慰剂 ;试验组 2 4例 ,服利塞膦酸钠 5mg/d。另外 ,两组患者每日均服钙维生素D3 合剂 (凯思立 ) 1片 ,两组共服药 12个月 ,试验后 0、1、3、6、9、12个月进行随访。结果　利塞膦酸钠组腰椎、股骨颈及大粗隆的骨密度均明显升高 (P <0 0 5 ) ,其中腰椎骨密度治疗前为 0 80± 0 0 9,治疗后 6个月及 12个月均达到 0 82± 0 0 9,增加率为 2 93%及 2 85 % ,均明显高于对照组 (P <0 0 5 )。 6个月及 12个月治疗总有效率试验组为 80 95 %及 71 4 3% ,显著高于对照组的4 5 4 5 %及 31 82 % (P <0 0 5 )。两组患者均无严重副作用。结论　利塞膦酸钠能明显提高绝经后骨质疏松症患者的骨密度 ,副作用轻。     

糖皮质激素对肾小球疾病患者骨代谢影响因素的研究

目的　探讨长期应用糖皮质激素 (GC)治疗对肾小球疾病患者骨代谢影响的因素。方法　 2 0 7例肾小球疾病患者 ,应用常规剂量GC治疗 ,于治疗前及治疗后每隔 3～ 6个月 ,进行了 35 7例次腰椎和股骨近端骨密度 (BMD)、血钙、血磷和骨钙素浓度测定。结果　①用GC后骨钙素浓度明显降低 (P均 <0 0 0 5 ) ,但其不能预测BMD下降。②用药 15个月后男性各部位BMD均减少 (32 2～111 5 )mg/cm2 ,以L1 4和股骨粗隆更明显 (P均 <0 0 5 ) ,骨丢失率 3 3%～ 10 3% ;女性L1 4BMD均减少(4 3 8～ 76 0 )mg/cm2 ,以L1更明显 (P <0 0 5 ) ,骨丢失率 3 9%～ 7 9%。③年龄与各部位BMD变化呈负相关 ,但不影响GC造成的骨丢失。男性各部位、女性L1 4BMD减少与GC累计剂量和GC用药时间负相关。④用GC15个月 (GC累计剂量 10g以上 ) ,男性L1 4BMD正常的比例从 3/ 4至 3/ 5 ;女性L1和L2 BMD正常者从 3/ 4减少到 1/ 2。结论　长期口服糖皮激素导致与剂量和用药时间相关的腰椎和男性股骨粗隆骨丢失 ,年龄偏大和男性患者骨丢失更明显。