Homocysteinylation of low-density lipoproteins (LDL) from subjects with Type 1 diabetes: effect on oxidative damage of human endothelial cells.

BACKGROUND: Homocysteine (Hcy) is an independent risk factor for cardiovascular disease (CVD). Individuals with Type 1 and Type 2 diabetes are more susceptible to the effects of homocysteine than non-diabetic subjects. The interaction between homocysteine-thiolactone (Hcy-thiolactone), a reactive product of Hcy, and low-density lipoproteins (LDL) induces the formation of homocystamide-LDL adducts (Hcy-LDL) and it has been suggested that homocysteinylation could increase atherogenicity of lipoproteins. AIM: The aim of the study was to compare the effect of in vitro homocysteinylation of LDL isolated from healthy control subjects (C-LDL) and from Type 1 diabetic patients (DM-LDL) and to investigate the effect of homocysteinylated LDL (Hcy-C-LDL and Hcy-DM-LDL) on peroxynitrite production of endothelial cells. METHODS: The in vitro homocysteinylation of LDL isolated from control (n = 12) and DM subjects (n = 12) was carried out by incubating lipoproteins with Hcy-thiolactone. The reaction was verified by quantifying the increase in sulphydryl groups (-SH groups) in Hcy-LDL with respect to control LDL. Control and homocysteinylated LDL were incubated with human aortic endothelial cells (HAEC) in culture. Peroxynitrite production in cells treated in different experimental conditions was assayed by a fluorimetric method. RESULTS: The increase in -SH groups after incubation with homocysteine was greater in LDL from diabetic subjects compared with LDL from control subjects (P < 0.001). In addition, peroxynitrite production from HAEC incubated with Hcy-LDL from diabetic patients was greater than after incubation with Hcy-LDL from control subjects and untreated LDL from diabetic patients (P < 0.001). CONCLUSIONS: These results show that LDL from diabetic patients is more susceptible to in vitro homocysteinylation than LDL from non-diabetic individuals and demonstrate that the compositional changes in Hcy-LDL from diabetic subjects have cytotoxic effects on human endothelial cells.     

肿瘤微血管密度与肝癌病理及预后关系

目的 探讨肿瘤微血管密度（MVD）与肝细胞性肝癌临床病理及预后的关系。方法对30例肝细胞性肝癌根治性切除病理组织切片进行苏木精伊红染色．并用CD34单克隆抗体进行免疫组化染色，计数被CD34抗体染色的肿瘤血管内皮细胞数，以测定MVD。对MVD与临床病理因素及术后生存率关系进行分析。结果 单因素分析结果表明．MVD水平与肿瘤大小、TNM分期都是影响肝细胞性肝癌预后的因素；多因素分析结果表明．肝癌大小及肿瘤分期是肝细胞性肝癌独立预后因素。结论 MVD是肝细胞性肝癌一种预后因素。     

Cyclic tensile stretch load and oxidized low density lipoprotein synergistically induce lectin-like oxidized ldl receptor-1 in cultured bovine chondrocytes, resulting in decreased cell viability and proteoglycan synthesis.

Mechanical stimulation is known to be an essential factor in the regulation of cartilage metabolism. We tested the hypothesis that expression of lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) can be modulated by cyclic tensile stretch load in chondrocytes. Cyclic loading of repeated stretch stress at 10 cycles per minute with 10 kPa of stress for 6 h induced expression of LOX-1 to 2.6 times control in cultured bovine articular chondrocytes, equivalent to the addition of 10 microg/mL oxidized low density lipoprotein (ox-LDL) (2.4 times control). Application of the cyclic load to the chondrocytes along with 10 microg/mL ox-LDL resulted in synergistically increased LOX-1 expression to 6.3 times control. Individual application of cyclic loading and 10 microg/mL ox-LDL significantly suppressed chondrocytes viability (84.6% +/- 3.4% and 80.9% +/- 3.2% of control at 24 h, respectively; n = 3; p < 0.05) and proteoglycan synthesis [81.0% +/- 7.1% and 85.7% +/- 5.2% of control at 24 h, respectively; p < 0.05 when compared with 94.6% +/- 4.6% for native-LDL (n = 3)]. Cyclic loading and 10 microg/mL ox-LDL synergistically affected cell viability and proteoglycan synthesis, which were significantly suppressed to 45.6% +/- 4.9% and 48.7% +/- 6.7% of control at 24 h, respectively (n = 3; p < 0.01 when compared with individual application of cyclic loading or 10 microg/mL ox-LDL). In this study, we demonstrated synergistic effects of cyclic tensile stretch load and ox-LDL on cell viability and proteoglycan synthesis in chondrocytes, which may be mediated through enhanced expression of LOX-1 and which has important implications in the progression of cartilage degeneration in osteoarthritis.     

胶片剂量测量和验证方法的研究

目的设计和实现基于通用激光扫描仪的胶片剂量测量和验证系统。方法采用胶片饱和冲洗、非线性光学校正、多分辨率阈值滤波、离散傅里叶逆变换图像复原等方法,消除了普通扫描仪用于胶片剂量学定量处理中的各种伪影、噪声和畸变;采用过响应系数校正方法消除测量胶片对低能散射光子的过响应,改善了胶片剂量测量的准确性;采用γ结合NAT指标的方法对放疗计划进行二维定量验证,给出可视化图形表达和具有定量数据的验证结果。结果和三维水箱系统、VeriSoft胶片测量系统相比较,研制系统对放疗剂量的测量结果在±2%内符合一致,对IMRT放疗计划的定量验证结果在±3%内符合一致。结论该系统能够实现对放疗剂量的高精度测量和对适形调强放疗计划剂量的可靠验证。     

脑星形细胞瘤中血管内皮生长因子表达与肿瘤血管形成的关系

目的 研究脑星形细胞肿瘤中血管内皮生长因子(VEGF)蛋白的表达及其与微血管密度(MVD)间的相关性。方法 采用免疫组织化学S—P法检测60例脑星形细胞肿瘤中VEGF蛋白的表达，计数肿瘤MVD，分析其意义及两者间的相关性。结果 VEGF总阳性率为63．3％(36／60例)，其中Ⅱ、Ⅲ、Ⅳ级星形细胞瘤中VEGF阳性率分别为42．1％(8/19例)、71．4％(20／28例)、76．9％(10／13例)。间变性星形细胞瘤和多形性胶质母细胞瘤明显高于弥漫性星形细胞瘤(P＜0．05)；在Ⅱ、Ⅲ、Ⅳ级肿瘤各级别间MVD的差异有显著性(P＜0．05)，而且肿瘤从低度恶性向高度恶性转变过程中，微血管形态由窦状扩张为主变为以芽状和细索状为主，而球状血管丛仅出现在胶质母细胞瘤中。VEGF表达与肿瘤MVD呈正相关(P＜0．05)。结论 联合检测VEGF、MVD可作为判断脑星形细胞瘤恶性潜能的重要生物学指标，同时对了解肿瘤血管形成机制有一定意义。     

卡维地洛对冠心病患者血浆氧化修饰低密度脂蛋白的影响

目的 :观察临床应用卡维地洛能否降低冠心病患者血浆氧化修饰低密度脂蛋白 (Ox LDL)水平。方法 :选择确诊冠心病患者及年龄、性别相匹配的正常对照组各 30例。冠心病组卡维地洛平均用量为 (10± 2 .5 )mg/d ,共 4个月 ,于服药前、服药后2个月及 4个月 ,分别采集清晨空腹血 ,以检测Ox LDL ,丙二醛 (MDA)。结果 :冠心病组的Ox LDL、MDA水平显著高于对照组 ,在用药后 2及 4个月冠心病组Ox LDL较用药前有显著降低 (P <0 .0 5 ) ,MDA显示出类似的趋势 (P <0 .0 1)。结论 :卡维地洛具有抗氧化作用 ,可以降低冠心病患者血浆Ox LDL水平。     

Changes in muscle morphology in dialysis patients after 6 months of aerobic exercise training.

BACKGROUND: In the present study we investigated the effect of a 6-month aerobic exercise programme on the morphology of the gastrocnemius muscle of end-stage renal disease (ESRD) patients. METHODS: Twenty-four ESRD patients volunteered to participate in the training programme and underwent muscle biopsy before training. Eighteen patients completed the training programme of whom nine agreed to a post-training biopsy (one woman and eight men, mean age 56 +/- 15 years). Data are presented for the nine subjects who were biopsied before (PRE) and after training (POST) and separately for the 15 subjects for whom we only have a biopsy before training (cross-sectional group). RESULTS: There were no significant differences (P > 0.05) in fibre type distribution or myosin heavy chain (MyHC) expression between the cross-sectional and PRE/POST groups. The mean cross-section fibre area after training (POST) increased by 46% compared with the PRE training status (P < 0.01). The proportion of atrophic fibres decreased significantly after training in type I, IIa and IIx fibre populations (from 51 to 15%, 58 to 21% and 62 to 32%, respectively). Significant differences were also found in capillary contact per fibre (CC/F), with the muscle having 24% (P < 0.05) more CC/F compared with the PRE training status. No significant differences in cytochrome c oxidase concentration were found between the groups. CONCLUSIONS: In conclusion, exercise appeared to be beneficial in renal rehabilitation by correcting the fibre atrophy, increasing the cross-section fibre area and improving the capillarization in the skeletal muscle of renal failure patients.     

辽宁省家栖鼠种类组成与数量动态的研究

本文以1985～1991年城乡家栖鼠鼠情监测资料为主要依据,揭示了辽宁省城乡家栖鼠种类组成与数量的月变动及七年来年变动趋势。城乡1年内均有两个数量商峰,城市数量高峰为4～5月与9～10月,农村数量高峰为3～4月与10～11月。城市家鼠数量明显呈下降趋势,鼠密度被控制在1%以下;农村鼠密度也下降,但平均密度高于2%。     

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.