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71.
E. I. Barengolts M. Berman S. C. Kukreja T. Kouznetsova C. Lin E. V. Chomka 《Calcified tissue international》1998,62(3):209-213
Estrogen deficiency is a risk factor for osteoporosis and coronary artery disease. Osteoporosis can be evaluated by measuring
bone mineral density (BMD). Coronary atherosclerotic burden can be evaluated by measuring coronary calcium using electron
beam computed tomography (EBT) of the heart. We compared coronary calcium scores in 45 asymptomatic postmenopausal women with
normal and low BMD. BMD of the lumbar spine and proximal femur was measured by dual X-ray absorptiometry (DXA), and coronary
calcium was measured quantitatively by EBT. Women were divided into control, osteopenia, and osteoporosis groups based on
the T score of the lumbar spine. Women were similar in age, years since menopause, height, weight, and body mass index (BMI).
BMD ± SD (g/cm2) of L1–L4 was 0.96 ± 0.11, 0.83 ± 0.03, and 0.73 ± 0.05, in control, osteopenia, and osteoporosis group, respectively. The
total coronary calcium score ± SD (relative units) was 41.9 ± 83.1, 115.1 ± 181.9, and 221.7 ± 355.4 for control, osteopenia,
and osteoporosis group, respectively; the score was significantly higher in the osteoporosis than in the control group. This
study provides initial data suggesting that women with osteoporosis may have a higher risk of developing coronary atherosclerosis. 相似文献
72.
Fast and slow twitch muscle fibers have distinct contractile properties. Here we determined that membrane excitability also varies with fiber type. Na+ currents (INA) were studied with the loose-patch voltage clamp technique on 29 histochemically classified human intercostal skeletal muscle fibers at the endplate border and <200 μm from the endplate (extrajunctional). Fast and slow twitch fibers showed slow inactivation of endplate border and extrajunctional INA and had increased INA at the endplate border compared to extrajunctional membrane. The voltage dependencies of INA were similar on the endplate border and extrajunctional membrane, which suggests thatboth regions have physiclogically similar channels. Fast twitch fibers had larger INA on the endplate border and extrajunctional membrane and manifest fast and slow inactivation of INA at more negative potentials than slow twitch fibers. For normal muscle, the differences between INA on fast and slow twitch fibers might: (1) enable fast twitch fibers to operate at high firing frequencies for brief periods; and (2) enable slow twitch fibers to operate at low firing frequencies for prolonged times. Disorders of skeletal membrane excitability, such as the periodic paralyses and myotonias, may impact fast and slow twitch fibers differently due to the distinctive Na+ channel properties of each fiber type. © 1993 John Wiley & Sons, Inc. 相似文献
73.
Clanton C. Shipp Paul S. Berger Manya S. Deehr Bess Dawson-Hughes M.D. 《Calcified tissue international》1988,42(5):287-292
Summary Precision of dual-photon absorptiometry (DPA) measurements was determined in a lumbar spine phantom and in humans. Approximately
half of the measurements were made before and half after a153gadolinium source change. The phantom was measured with different amounts of acrylic, which simulates human soft tissue, in
order to evaluate the influence of body thickness on bone mineral density (BMD). Results of scans analyzed with two software
versions from Lunar Radiation Corp., the widely used 08B and a prototype 08C, are compared. DPA with a cold source significantly
overestimated BMD in the phantom in the presence of large amounts (more than 25 cm) of soft tissue equivalent with version
08B but not with the newer version 08C. Similiarly, in nine subjects, there was a significant decrease in spine BMD after
a source change when scans were analyzed with version 08B (mean difference 0.026 g/cm2,P=0.002) but not with 08C (0.01 g/cm2,P=0.234). No systematic effect of source change on femoral BMD measurements was observed. The SD of the mean difference of
two measurements of the nine subjects was 0.019 g/cm2 (1.6% of the mean value) for the spine with software version 08B and 0.024 g/cm2 (2.0%) with version 08C, 0.03 g/cm2 (3.3%) for the femur neck, 0.03 g/cm2 (4.0%) for the greater trochanter, and 0.04 g/cm2 (4.9%) for Ward's triangle region of the proximal femur. The spine phanton was scanned on two other commercial bone densitometers
in order to assess inter-instrument variation. Phantom measurements of L2-4 BMD made on two Lunar Radiation Corp model DP3
scanners which differed by 2% were 10 and 12% higher than those with a Norland Corp. model 2600 scanner. 相似文献
74.
固生蛋白tenascin对肝细胞癌血管生成及浸润转移的影响 总被引:1,自引:0,他引:1
目的 探讨固生蛋白(tenascin ,TN)在肝细胞癌(hepatocellularcarcinoma ,HCC)中的表达和与HCC血管生成及浸润转移的关系。方法 应用免疫组织化学法检测4 2例HCC、10例肝硬化和7例正常肝组织内TN的表达情况,观察与HCC病理学特点及微血管密度(microvesseldensity ,MVD)之间的关系。结果 ①TN在HCC中的阳性表达率和强度显著高于肝硬化和正常肝脏组织( χ2 =4 15 ,P <0 0 5 ;t=2 4 73,P <0 0 5 ) ;②TN在有包膜侵犯组、病理分级Ⅲ~Ⅳ组及有转移HCC中的阳性表达率及强度明显高于无包膜侵犯组( χ2 =5 4 7,P <0 0 5 ;t=2 138,P <0 0 5 )、病理分级Ⅰ~Ⅱ级组( χ2 =6 87,P <0 0 1;t=2 4 79,P <0 0 5 )以及无转移组( χ2 =10 6 ,P <0 0 1;t=2 6 93,P <0 0 1) ;③肝癌>5cm、有包膜侵犯、有转移、病理分级Ⅲ~Ⅳ级组的MVD值明显高于肝癌≤5cm(t=2 0 36 ,P <0 0 5 )、无包膜侵犯(t =2 32 8,P <0 0 5 )、无转移(t =2 4 94 ,P <0 0 5 )及病理分级Ⅰ~Ⅱ级组(t =2 2 71,P <0 0 5 )。④TN阳性表达HCC中的MVD值明显高于TN阴性表达HCC中的MVD值(t =2 4 87,P <0 0 5 )。结论 TN在HCC组织中的表达上调与其血管生成和浸润转移有关 相似文献
75.
彭勃 《齐齐哈尔医学院学报》2004,25(3):250-251
目的 联合应用影像学(胸部X线和CT)提高纤支镜对肺癌的诊断。方法选择我院纤支镜后组织病理学确诊的肺癌177例,全部病例在做纤支镜前1周内进行胸部X线或CT检查,并将影像学征象与纤支镜下表现及其病理学类型进行对照分析。结果中央型肺癌165例,周围型肺癌12例;纤支镜下主要表现有:外向型生长98例,浸润型生长63例,仅见间接征象5例,未见异常12例;组织病理学类型:鳞癌117例,腺癌29例,小细胞癌24例,其它肿瘤7例;影像学征象表现有:肺部肿块影116例,阻塞性肺炎表现为主27例,以局限性肺不张表现为主19例,片状模糊的阴影12例,两肺多发结节影3例。结论 纤支镜和影像学征象对肺癌的诊断各有特点,两者联合应用,可取长补短,提高肺癌的诊断。 相似文献
76.
目的探讨低密度及氧化低密度脂蛋白对内皮细胞分泌肾上腺髓质素(ADM)的影响.方法利用培养的内皮细胞株ECV-304细胞,分别与不同浓度的低密度(50 100mg/L)、氧化低密度脂蛋白(50 100mg/L)及低密度脂蛋白(50 mg/L) 氧化低密度脂蛋白(50 mg/L)进行孵育,24 h后分别收集培养上清及细胞,用放免分析检测上清及细胞内肾上腺髓质素的含量.结果低密度脂蛋白对肾上腺髓质素的分泌无影响,而氧化型低密度脂蛋白能明显刺激ADM的分泌,二者合用的作用接近于100mg/L的OX-LDL.结论OX-LDL可能具有氧化LDL使其成为OX-LDL的作用,ADM的分泌可能是对细胞损伤的一种反应. 相似文献
77.
Christina Djokoto George Tomlinson Stephen Waldman Marc Grynpas Angela M. Cheung 《Journal of clinical densitometry》2004,7(4):448-456
Dual-energy X-ray absorptiometry (DXA) and quantitative ultrasound (QUS) are the accepted modalities for the evaluation of fracture risk in the clinical setting. However, neither method provides a direct measurement of bone mechanics. In this study, we investigated a prototype device, known as a mechanical response tissue analyzer (MRTA), which provides direct mechanical measurements of mechanical properties of bone. A total of 56 healthy volunteers (20 men and 36 women) between the ages of 18 and 83 were recruited. The MRTA was used to measure the cross-sectional bending stiffness (EI) of the ulna bone. Axial speed of sound (SOS) at the ulna bone was determined by QUS; bone mineral content (BMC) and bone mineral density (BMD) were determined by DXA. Correlations, regression analysis, and analyses of variance (ANOVAs) were used to compare the three modalities. These analyses revealed that although there are strong linear relationships among the data collected by the various technologies, the bone properties reflected by MRTA are not fully explained by DXA and QUS. We conclude that the total information conveyed by MRTA measurements is unique. Further research is needed to delineate the different qualities of bone strength that are captured by MRTA, but not by DXA or QUS. 相似文献
78.
目的 :探讨胃癌组织中微血管密度 (MVD)与胃癌生物学行为的关系。方法 :应用免疫组织化学S -P法和抗人因子Ⅷ相关抗原 (FⅧ -RAg)的抗体 ,标记 6 8例胃癌组织中的微血管 ,检测MVD。分析其与胃癌组织学类型、分化水平、浸润深度及淋巴结转移的关系。结果 :6 8例胃癌组织中FⅧ -RAg阳性表达 5 2例 ,占 76 .4 7%。FⅧ -RAg和MVD与分化水平、浸润深度 (P <0 .0 1)及淋巴结转移 (P <0 .0 0 1)密切相关。不同组织学类型中FⅧ-RAg的表达具有显著相关性 (P <0 .0 1) ,而MVD则与胃癌组织学类型无显著差异 (P >0 .0 5 )。 结论 :血管生成对胃癌的发展具有一定作用 ,FⅧ -RAg的检测和MVD可作为判断胃癌恶性程度和预后的生物学指标。 相似文献
79.
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. 相似文献
80.
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. 相似文献