乙型肝炎患者TNF-α和PDGF水平及其与肝纤维化的关系

目的 研究乙型肝炎患者血清细胞因子水平与肝纤维化的关系。方法 检测８０例乙型肝炎患者及２０例正常对照的血清肿瘤坏死因子（ＴＮＦ－α和血小板源生长因子（ＰＤＧＦ）水平。结果 急性肝炎、慢怀肝炎和肝硬化患者的ＴＮＦ－α和ＰＤＧＦ的活性明显高于正常对照组,且与患者的血清Ⅲ型前胶原肽（ＰＣⅢ）含量密切相关（ｒ＝０．６６,ｒ＝０．７５）。结论 ＴＮＦ－α和ＰＤＧＦ活性的变化可能与肝纤维化的发病机理有关,在慢     

Ⅱ型糖尿病合并高血压患者高胰岛素血症和舒血管前列腺素关系的探讨

对２３例非胰岛素依赖型糖尿病（ＮＩＤＤＭ）患者、１８例ＮＩＤＤＭ合并高血压的和平共１８例正常人在糖耐量试验期间血胰岛素、６－酮－前列腺素Ｆ＿（１α）（６－ｋｅｔｏ－ＰＧＦ＿（１α）和前列腺素Ｅ＿２（ＰＧＥ＿２）水平进行了测定。ＮＩＤＤＭ并高血压组基值和糖负荷后血清胰岛素水平显著升高，６－ｋｅｔｏ－ＰＧＦ＿（１α）和ＰＧＥ＿（２）浓度显著下降，尤以胰岛素释放高峰为明显。胰岛素与６－Ｋｅｔｏ－ＰＧＦ＿（１α）浓度呈显著负相关。提示ＮＩＤＤＭ合并高血压可能与高胰岛素血症抑制舒血管前列腺素合成有关。     

高胆固醇血症患者载脂蛋白B-100缺陷的检测

目的　研究家族性载脂蛋白Ｂ－ １００ 缺陷症（ＦＤＢ） 在广东地区高胆固醇血症病人中的发生率及其与血脂水平的关系。方法　以病人外周血白细胞提取ＤＮＡ,采用ＰＣＲ技术扩增ＡＰＯＢ 基因中１０５４９ ～１０８９５ 号核苷酸的ＤＮＡ片段,用Ｄｉｇ－ ｄｄＵＴＰ末端标记一对等位基因特异寡核苷酸片段作为探针进行斑点杂交。结果　对２１４ 例原发性高胆固醇血症患者进行探查,未发现一例ＦＤＢ先证者。结论　可能该病在广东地区的发生率较低,有待予扩大样本含量继续研究。     

冠心病患者红细胞变形能力与红细胞膜脂质成分和PAF－AH活性关系的研究

本文检测了１１２例冠心病（ＣＨＤ）患者红细胞变形能力（ＥＤ）和膜脂质成分及血小板激活因子乙酰水解酶（ＰＡＦ－ＡＨ）活性变化。结果显示，ＣＨＤ病人红细胞滤过指数（ＩＦ）较对照组明显增高（Ｐ＜０．００１）；膜胆固醇（Ｃｈ）、脂质过氧化物（ＭＤＡ）和Ｃｈ／磷脂（Ｃｈ／ＰＬ）明显增高，而膜ＰＬ和ＰＡＦ－ＡＨ活性明显降低，与对照组相比差异有显著性意义（Ｐ＜０．００１）。ＣＨＤ患者ＩＦ与膜Ｃｈ、ＭＤＡ和ＣＵＰＬ呈正相关，与膜ＰＬ和ＰＡＦ－ＡＨ呈负相关。提示ＣＨＤ患者ＥＤ降低与红细胞膜脂质成分异常和ＰＡＦ－ＡＨ活性降低有关。     

原发性高血压伴高胰岛素血症者饮食控制和氨酰心安治疗效果

研究胰岛素抵抗、高胰岛素血症与高血压的关系。方法对１２例原发性高血压伴高胰岛素血症者进行饮食控制和降低交神经活性的治疗。结果血压，尤其ＤＢＰ与胰岛素敏感指数（ＳＩ）Ｐ〈０．０５，胰岛素曲线下面积（ＡＵＣ２），Ｐ〈０．０２５，及游脂肪酸（ＦＦＡ）Ｐ〈０．０５有密切关联；ＦＦＡ的增高，可为脂肪代谢紊乱较绵一个指标。结论通过限制热卡摄入，降低交感神经活性，可以改善胰岛素掐抗；降低高胰岛素血症；减少ＦＦＡ     

老年人胰岛素样生长因子轴与血脂水平关系

生长激素（ＧＨ）－胰岛素样生长因子（ＩＧＦ）轴的活性随年龄增加而减低。成人ＧＨ缺乏可引起高胆固醇血症,导致心血管疾病发病率增加。本研究目的旨在了解老年人ＧＨ－ＩＧＦ轴的活性及其与血脂水平的关系。对象与方法１３２名健康志愿者（男５２,女８０）,年龄６０...     

高胆固醇血症低密度脂蛋白受体基因点突变的研究

目的：建立低密度脂蛋白－受体（ＬＤＬ－Ｒ）基因点突变监测方法,从基因水平对３０例原发性高胆固醇血症患者进行筛选、明确诊断。 方法：将聚合酶链式反应－单链构象多态性（ＰＣＲ－ＳＳＣＰ）与银染技术相结合,用１９对引物对ＬＤＬ－Ｒ基因的全部１８个外显子进行检测,３０例患者中,对筛查出的突变用ＰＣＲ产物直接测序或克隆测序的方法明确突变的性质和位置。 结果：确立的ＰＣＲ－ＳＳＣＰ条件稳定,银染方法灵敏度高、重复性好,且避免了同位素污染。３０例患者中,发现１例定位于外显子１４的杂合子点突变患者,ＰＣＲ产物直接测序证实第６７１位密码子发生错义突变：ＣＣＣ→ＣＧＣ,导致脯氨酸→精氨酸;１例纯合子家族性高胆固醇血症患者外显子７发生点突变,克隆测序证实密码子３０８位发生错义突变：ＴＡＣ→ＴＧＣ,导致半胱氨酸→酪氨酸;２例杂合子患者外显子４的３’部分ＳＳＣＰ出现相同异常带型。查阅文献,测序证实的突变皆是新的突变。 结论：建立的ＰＣＲ－ＳＳＣＰ方法可用于高胆固醇血症患者ＬＤＬＲ基因点突变的筛检。研究结果从基因水平证实中国家族性高胆固醇血症患者ＬＤＬ－Ｒ基因突变具有多样性的特点。     

血小板来源生长因子在活动性狼疮性肾炎肾小球病理改变的作用

血小板来源生长因子（ＰＤＧＦ）是肾小球肾炎炎症反应中的一个重要介质。为了进一步探讨ＰＤＧＦ与狼疮性肾炎病变活动的关系，用反转录－多聚酶链反应（ＲＴ－ＰＣＲ）和四层ＰＡＰ免疫组化染色技术，对９例狼疮性肾炎患者（７例活动性，２例非活动性）肾小球内ＰＤＧＦ－Ａ、Ｂ链ｍＲＮＡ和蛋白质以及ＰＤＧＦ－Ｂ受体蛋白表达变化进行了观察。发现活动性狼疮性肾炎患者肾小球ＰＤＧＦ及其Ｂ受体表达较非活动性病变者显著增高。该现象与狼疮性肾炎肾脏活动性病变以及血尿的程度呈正相关。表明ＰＤＧＦ是导致狼疮性肾炎肾脏病变活动的重要介质之一。值得指出的是，ＰＤＧＦ对这类病人肾小球固有细胞的增殖并无明显影响，提示狼疮性肾炎肾小球病变活动期可能伴有拮抗ＰＤＧＦ增殖作用的物质存在。     

高甘油三酯血症患者血浆对氧磷酶1活性降低(摘要)

最近研究发现 ,高脂喂养使家兔血浆脂质升高、对氧磷酶 1(ｐａｒａｏｘｏｎａｓｅ 1,ＰＯＮ 1)活性降低。高甘油三酯血症 (ｈｙｐｅｒｔｒｉｇｌｙｃｅｒｉｄｅｍｉａ ,ＨＴＧ )患者血清ＰＯＮ 1活性的改变国内外尚未见报道。本文初步探讨了ＨＴＧ患者血清ＰＯＮ 1活性的改变。1　对象与方法自愿者 117人 ,年龄 36～ 74岁。测定空腹 12～14ｈ血浆甘油三酯和总胆固醇含量。从中选择出没患其它疾病、没服用降脂药和任何激素、血脂符合诊断标准的人员分别作为ＨＴＧ患者和正常对照。按常规方法测定血浆甘油三酯和总胆固醇。用沉淀法除去血浆中…     

胰岛素抵抗、糖尿病与冠心病间关系的研究

本研究探讨胰岛素抵抗、高胰岛素血症、Ⅱ型糖尿病之高血糖状态等对冠状动脉 (冠脉 )粥样硬化的影响。一、对象与方法1.病例选择 :2 48例 (总组 )行冠状动脉造影病人 ,其中造影阳性 16 5例 (ＣＨＤ组 ) ,阴性 83例 (非ＣＨＤ组 )。从总组中随机抽取 5 8例为抽样组。2 .临床及生化测定 :所有患者测空腹静脉血浆糖 (ＦＰＧ) ;抽样组测身高、体重 ,行 75ｇ口服葡萄糖耐量试验 (ＯＧＴＴ)及胰岛素释放实验 (ＩＲＴ) ,并测胆固醇 (Ｃｈ)、甘油三酯 (ＴＧ)、低密度脂蛋白 胆固醇 (ＬＤＬ Ｃｈ)、高密度脂蛋白 胆固醇 (ＨＤＬ Ｃｈ)、载脂蛋白Ａ1(…     

Platelet-derived growth factor agonist activity of a secreted form of the v-sis oncogene product.

We have compared the functional properties of a growth factor partially purified from medium conditioned by simian sarcoma virus-transformed cells with those of platelet-derived growth factor (PDGF). The factor mimicked the effects induced by PDGF: it bound to and activated human fibroblast PDGF receptors and stimulated DNA synthesis. These activities were specifically inhibited by PDGF antibodies and thus elicited by a factor(s) immunologically related to PDGF. The factor behaved as a secretory protein, since about 95% of the receptor-binding activity was found in the medium after a 48-hr serum-free incubation. Structural characterization of the PDGF-like activity revealed a Mr 24,000 intracellular protein and two polypeptides of Mr 13,000 and 11,500 released into the medium. The Mr 13,000 component bound to human fibroblasts; this binding was competitively inhibited by PDGF. The data support the possibility that oncogene products may elicit transforming activity by interacting with the normal cellular mitogenic pathway.     

Platelet-derived growth factor stimulates low density lipoprotein receptor activity in cultured human fibroblasts.

Human platelets contain a mitogen, the platelet-derived growth factor (PDGF), that stimulates the proliferation of a variety of cell types in culture and that may play a role in atherogenesis. Studies were conducted to explore the effects of PDGF on low density lipoprotein (LDL) receptor activity of cultured human fibroblasts. The PDGF utilized in these studies was partially purified from human platelet-rich plama by ion exchange chromatography and gel filtration. LDL receptor activity was assessed by both specific binding of 125I-labeled LDL to the fibroblast's surface at 4 degrees C, and the incorporation of [14C]oleate into cholesteryl esters. Exposure of normal human fibroblasts to increasing amounts of PDGF (0.1-10 microgram/ml) for 48 hr caused a dose-related increase in 125I-labeled LDL binding to a maximum of approximately 300%. In the presence of added LDL, this increase in LDL binding was not seen. Cholesterol esterifiction was also stimulated following a 48-hr exposure to PDGF. Following a conditioning period in LDL- and PDGF-depleted medium, cholesterol esterification was greatly increased during a 48-hr exposure to LDL alone; a smaller but significant increase occurred with PDGF alone. However, both PDGF and LDL were required to return the level of esterification to that observed with whole human serum. Fibroblasts from a patient with homozygous familial hypercholesterolemia, which lack the LDL receptor, also showed a significant increase in cholesteol esterification with PDGF alone, whereas LDL had no effect. These studies demonstrate that PDGF can stimulate the LDL receptor activity in cultured human fibroblasts. The effect on other related activities of the LDL receptor system and the mechanism involved remain to be defined.     

Platelet-derived growth factor (PDGF) binding promotes physical association of PDGF receptor with phospholipase C.

Phospholipase C (PLC)-mediated production of inositol trisphosphate and diacylglycerol is stimulated by binding of platelet-derived growth factor (PDGF) to cell-surface receptors. Antibodies recognizing native PDGF receptors through peptide-domain epitopes coprecipitated 4-fold more PLC activity with receptors from PDGF-stimulated than from unstimulated BALB/c 3T3 cells, despite equivalent PDGF receptor recovery. Activity coprecipitated from unstimulated cells was comparable to nonspecific activity recovered with preimmune sera or in the presence of competing peptide immunogen. PLC activity coprecipitating with PDGF receptors represented 60% of anti-phosphotyrosine antibody-recovered activity from PDGF-stimulated cells. Coprecipitation was rapidly induced in cells treated with PDGF at 4 degrees C, reversibly lost with acid dissociation of PDGF from receptors, and recovered with PDGF readdition. PDGF concentrations effecting coprecipitation correlated with stimulation of intact-cell inositol phosphate production. Monoclonal antibodies to PLC gamma (145 kDa) coprecipitated from PDGF-stimulated cell lysates (but not from unstimulated cell lysates) tyrosine kinase activity that phosphorylated PDGF receptor and PLC gamma. Stable physical association of PDGF receptors with PLC may participate in coupling ligand binding to increased PLC activity.     

抗纤维化短肽N-乙酰基-丝氨酰-天门冬酰-赖氨酰-脯氨酸对大鼠心脏成纤维细胞胶原合成与降解的调节作用

目的探讨N-乙酰基-丝氨酰-天门冬酰-赖氨酰-脯氨酸（AcSDKP）对血小板源性生长因子（PDGF）诱导的大鼠心脏成纤维细胞增殖、胶原合成和降解代谢的调节作用。方法分离培养新生大鼠心脏成纤维细胞。采用^3H-TdR和。H-脯氨酸掺入法分别检测心脏成纤维细胞增殖与胶原蛋白合成。Western blot法检测心脏成纤维细胞Ⅰ、Ⅲ型胶原蛋白表达和基质金属蛋白酶（MMP）-1蛋白的表达。明胶酶谱法检测心脏成纤维细胞MMP-2和MMP-9活性的表达。结果PDGF促进心脏成纤维细胞增殖、胶原合成,Ⅰ、Ⅲ型胶原表达,以及MMP-2、MMP-9活性和MMP-1表达。AcSDKP对PDGF介导的心脏成纤维细胞增殖、胶原合成均有抑制作用。AcSDKP上调由PDGF介导的心脏成纤维细胞MMP-2、MMP-9活性和MMP-1的表达。结论AcSDKP抑制PDGF介导的心脏成纤维细胞增殖和胶原的合成,上调MMPs活性或表达,促进胶原的降解,这些可能与AcSDKP抗心脏纤维化作用相关。     

A glioma-derived analog to platelet-derived growth factor: demonstration of receptor competing activity and immunological crossreactivity.

A human clonal glioma cell line, U-343 MGa Cl 2, cultured under serum-free conditions, was found to release a factor that competed with 125I-labeled platelet-derived growth factor (125I-PDGF) for binding to human foreskin fibroblasts. The concentration of competing activity in conditioned medium was equal to 20-30 ng of PDGF per ml. The PDGF receptor competing activity had an elution position on Sephadex G-200 close to that of tracer PDGF. The same fractions in the chromatogram also contained growth-promoting activity and material active in a PDGF radioimmunoassay. Incubation of partially purified, 125I-labeled glioma factor with fibroblasts, or rabbit anti-PDGF serum, led to the selective binding of a component with an estimated Mr of 31,000, as shown by NaDodSO4/gel electrophoresis under nonreducing conditions. After reduction this component migrated as a Mr 18,000 protein. Thus, the behavior in NaDodSO4/gel electrophoresis was similar to that of PDGF. Furthermore, incubation of partially purified glioma factor with immobilized PDGF antibodies markedly decreased the amount of PDGF receptor competing activity remaining in the supernatant. These results suggest that the factor produced by glioma cells has structural, immunological, and functional resemblance to PDGF. We previously reported that a human osteosarcoma cell line produces a PDGF-like molecule with growth-promoting activity. Taken together with the recent finding that PDGF is homologous to the transforming gene product of simian sarcoma virus, our present data give additional support for the idea that an autocrine activation of the PDGF receptor may be operational in the growth of human tumors of mesenchymal or glial origin.     

Platelet-derived growth factor is decreased in patients with myeloproliferative disorders

Platelet-derived growth factor (PDGF) has been suggested to play some role in the pathogenesis of myelofibrosis frequently encountered in patients with myeloproliferative disorders (MPD). In this study we measured PDGF activity and PF4 content in circulating platelets of patients with MPD. Both factors were lower than those of normal controls. PDGF activity in patients with myelofibrosis was slightly lower than in those without fibrosis. However, when adjusted to whole blood volume, there was a positive correlation between platelet count and PDGF activity per ml whole blood. Nevertheless, no correlation was found between activity and grade of bone marrow fibrosis. These results may support the idea that an abnormal release of PDGF occurs from platelets or megakaryocytes in the bone marrow environment, resulting in the stimulation of fibroblast proliferation, and hence, the occurrence of myelofibrosis in patients with MPD.     

Plasma binding proteins for platelet-derived growth factor that inhibit its binding to cell-surface receptors.

Evidence is presented that the binding of platelet-derived growth factor (PDGF) to plasma constituents inhibits the binding of PDGF to its cell-surface mitogen receptor. Approximately equivalent amounts of PDGF-binding activity were found in plasma from a number of different species known by radioreceptor assay to contain PDGF homologues in their clotted blood. Activation of the coagulation cascade did not significantly alter the PDGF-binding activity of the plasma components. Three molecular weight classes of plasma fractions that inhibit PDGF binding to its cell-surface receptor were defined by gel filtration: approximately equal to 40,000, 150,000, and greater than 500,000. Specific binding of 125I-labeled PDGF to the highest molecular weight plasma fraction could also be demonstrated by gel filtration. The binding of PDGF to these plasma components was reversible under conditions of low pH or with guanidine X HCl, and active PDGF could be recovered from the higher molecular weight fractions. Immunologic and functional evidence is presented that the highest molecular weight plasma fraction may be alpha 2-macroglobulin. A model is proposed in which the activity of PDGF released in vivo may be regulated by association with these plasma binding components and by high-affinity binding to cell-surface PDGF receptors.     

Activity of Platelet-Derived Growth Factor (PDGF) in Platelet Concentrates and Cryopreserved Platelets Determined by PDGF Bioassay

The bioassay of platelet-derived growth factor (PDGF) in platelets was established using the rat fibroblast cell line 3Y1. 3Y1 cells (5 X 10(3)/well) were cultured in 24-well microculture plates with RPMI 1640 medium using 1% of PDGF-free serum and 5% of platelet extracts for 4 days. Cell proliferation was measured by the increase of DNA content. This assay made it possible to measure the biological PDGF activity. PDGF activity of platelet concentrates kept the same level as that of fresh platelet samples during preservation for up to 120 h at 22 degrees C; cryopreserved platelets also retained PDGF activity well.     

A bone marrow stromal cell line is a source and target for platelet- derived growth factor

Platelet-derived growth factor (PDGF) stimulates multipotent and erythroid progenitors as well as stromal fibroblasts. Any of the three dimeric forms of PDGF (AA, AB, or BB) could potentially interact with these cells; however, the precise cellular origin of PDGF production in the bone marrow microenvironment is not known. In the present study, we found that medium conditioned by MBA-2, murine bone marrow-derived endothelial cells, contains PDGF activity that competes for [125I]PDGF binding to human foreskin fibroblasts and is mitogenic for these fibroblasts. Northern analysis of poly(A)+ RNA from MBA-2 shows the expression of both PDGF A-chain and B-chain mRNAs. Because cytokines such as transforming growth factor-beta (TGF-beta) regulate hematopoiesis and stimulate PDGF in certain mesenchymal cells, we determined whether TGF-beta influences PDGF secretion and gene expression in MBA-2. TGF-beta induced PDGF A-chain and B-chain mRNAs and the release of PDGF activity. Each of the three PDGF isoforms also stimulated DNA synthesis in MBA-2, but with different potency (BB > AB > AA). Ligand binding studies showed specific binding of labeled PDGF BB and, to a lesser extent, PDGF AA isoform, consistent with predominant expression of the PDGF-beta receptor in MBA-2. These data show that murine endothelial stromal cells release PDGF activity and respond to PDGF. Local production of PDGF in the marrow microenvironment may play an important role in regulating hematopoietic and stromal cell proliferation.