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.     

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.     

微电流与低浓度氯对水中脊髓灰质炎I型病毒的协同灭活效应

目的　观察微电流 (low amperage direct current,LDC)与游离氯 (free chlorine,FC)对水中脊髓灰质炎 I型病毒 (PV1 )的协同灭活效果 .方法　用微电流 0 .4～ 1 .2 m A·cm-2 协同氯 0 .2～ 0 .3 mg· L-1 处理污染 PV1水样 ,比较作用前后灭活率 K值评价灭活效果 ,用 Berenbaum方法判断微电流与氯灭活病毒有无协同效应 ,用蚀斑形成试验 (PFUA)和病毒细胞酶联免疫试验 (VELCIA)检测感染性和抗原性变化 .结果　实验观察到微电流达到 0 .4 m A· cm-2 对水中PV1有弱灭活作用 ,电流密度达到 1 .2 m A· cm-2 与 0 .2mg· L-1氯有协同灭活效应 ,微电流 1 .2 m A· cm-2与氯 0 .3mg· L-1协同消毒 30 min,水中病毒减少 4.0 8个对数级 ,而单独用氯仅减少 1 .93个对数级 ;协同作用后病毒感染性灭活增强 ,而抗原性灭活不明显 .结论　微电流协同氯可提高低浓度氯灭活水中病毒的效果     

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。