Lipoprotein lipase in relation to inflammatory activity in rheumatoid arthritis

Objective. To evaluate the impact of chronic inflammation on lipoprotein lipase (LPL) levels and triglyceride metabolism in patients with rheumatoid arthritis (RA). Design. Plasma levels of LPL activity and mass before and after heparin were determined in post-menopausal women with active RA and in controls. The results were related to lipid levels and inflammatory variables. The LPL activity and mass together with triglyceride levels were also measured before and 6 h after an oral fat load. Setting. The study was performed on in- and out-patients at a University Rheumatology clinic. The controls came from the same reference area. Subjects. Altogether 17 consecutive post-menopausal female patients with RA and 16 age and sex matched controls were enrolled for the initial determination of LPL. Fifteen of the patients and 15 of the controls agreed to take part in the fat load. Of these, one patient and one control were excluded. Main outcome measures. LPL determination: basal levels and post-heparin levels of LPL activity and mass. Correlations between LPL and blood lipids (cholesterol, triglycerides), lipoprotein levels (high density lipoprotein, HDL; low density lipoprotein, LDL), erythrocyte sedimentation rate (ESR) acute phase proteins (orosomucoid, haptoglobin, fibrinogen mass) and cytokines (tumour necrosis factor α, TNF-α; interleukin 1β, IL-1β; and interleukin-6, IL-6). Fat tolerance test: LPL activity, mass and triglyceride levels before and 6 h after a per oral fat load. Results. Pre-heparin LPL mass (P<0.01) and activity (P<0.01) were significantly lower in the rheumatoid patients. Pre-heparin LPL mass showed no correlation to the lipid levels, but an inverse correlation to several inflammatory parameters; it was significant for orosomucoid (r_s=?0.63, P<0.05) and C-reactive protein (CRP) (r_s=?0.54, P<0.05) and close to significant for haptoglobin (r_s=?0.48, P=0.087) and IL-6 (r_s=?0.52, P=0.061). Six hours after a lipid load the LPL activity and mass were significantly lower in RA (P<0.05 and P<0.01, respectively) but the triglyceride level was not significantly different compared to controls. Conclusion. An inverse relationship exists between inflammatory status and pre-heparin LPL mass. Pre-heparin LPL mass reflects mainly the inactive monomeric fraction of LPL. This has been shown to hinder the uptake of remnant lipoprotein particles through competition with lipoprotein bound dimeric LPL for the LDL receptor-related protein (LRP receptor) on hepatocytes and macrophages in culture. A decrease of the level of monomeric LPL in plasma may thus be beneficial for remnant catabolism. The same mechanism may on the other hand increase macrophage uptake of lipids. This may not affect global lipid metabolism but may be important in driving the atherosclerotic process in the vessel wall.     

ΔNp63蛋白在膀胱移行上皮癌中的表达及其临床意义

目的 :探讨 p5 3基因家族新成员截短型p6 3(△Np6 3)在膀胱癌组织中的表达及其意义。 方法 :采用免疫组织化学SP法检测 4 0例膀胱移行上皮癌 (TCC)、6例膀胱内翻性乳头状瘤和 8例正常膀胱移行上皮中△Np6 3的表达 ,并分析△Np6 3表达与膀胱癌病理类型、临床分期的关系。 结果 :正常膀胱移行上皮、膀胱内翻性乳头状瘤、TCC中△Np6 3的阳性表达率分别为 37.5 % (3/ 8)、6 6 .7% (4/ 6 )、10 0 % (40 / 4 0 ) ,组间差异有统计学意义 (P <0 .0 1)。TCCG3 级与G2 级△Np6 3的强阳性、中度阳性表达率显著高于G1级 (P <0 .0 1)。Ta～T1期以△Np6 3弱阳性为主 (6 6 .7% ) ,随TCC浸润程度的增加 ,△Np6 3染色强度逐渐增强。T2 期△Np6 3强阳性表达率为 35 .3% ,T3 ～T4期增至 6 3.6 %。结论 :△Np6 3在TCC中高表达 ,与TCC病理分级、临床分期密切相关 ;△Np6 3可能参与TCC的发生、发展 ,是评估TCC预后的潜在因素之一。     

人乳头瘤病毒多肽与人免疫球蛋白G融合表达

目的 将人乳头瘤病毒16型(Human papillomavirus type 16，HPV-16)的晚期表达蛋白E7上的抗原24肽(从第38位氨基酸到第61位氨基6病毒感染防治酸)与人免疫球蛋白G的重链恒定区融合表达，并以此融合蛋白作为抗原，可能为HPV-1提供免疫治疗方法。方法 利用PCR方法分别扩增HPV-16 E7(38-61)24肽的DNA片段和人免疫球蛋白G的重链恒定区DNA片段，并构建到pEV21a表达载体上，转化入E．coli中表达，利用SDS-聚丙烯酰胺凝胶电泳(SDS-PAGE)和蛋白质免疫印迹(Western-blotting)的方法对表达结果进行鉴定。结果 构建的表达载体HPV16E7e／hIgGHCCR-pET21a经酶切鉴定和测序显示序列正确；通过SDS-PAGE和Western-blotting的鉴定，重组融合蛋白Mr约40000，表达量可占菌体蛋白的20％左右。结论 成功构建HPV16-E7的抗原多肽片段和人免疫球蛋白G的重链恒定区的融合蛋白，并可在E．coli中高效表达。     

IL-2对垂体瘤细胞系RC-4B/C细胞分泌ACTH的影响

目的 :探讨白细胞介素 2 (IL 2 )对垂体瘤细胞系RC 4B/C细胞ACTH分泌的调控作用及其影响因素 .方法 :以放射免疫方法测定培养的垂体瘤细胞系RC 4B/C细胞的培养液中的ACTH浓度 .结果 :IL 2 (1× 10 4～ 5× 10 5U·L-1)促进RC 4B/C细胞分泌ACTH ;蛋白激酶A的抑制剂H 9(1μmol·L-1)和酪氨酸蛋白激酶的抑制剂tyrphostin2 3 (1μmol·L-1)均可显著性抑制IL 2的促ACTH分泌作用 .结论 :IL 2可促进RC 4B/C细胞分泌ACTH ,该作用与蛋白激酶A和酪氨酸蛋白激酶信号转导途径紧密相关     

大豆蛋白影响肾损害模型钙摄入和钙排出的实验研究

[目的]研究大豆蛋白对肾损害大鼠钙平衡的影响。[方法]选择3月龄断乳雄性SD大鼠40只．按体质量从小到大排序，采用完全随机化原则分为4组。每组10只。标准饲料对照组：喂食含有14％酪蛋白饲料；大豆蛋白饲料组：喂食含有14％大豆分离蛋白饲料；混合饲料1组：喂食含有7％酪蛋白加7％大豆分离蛋白饲料；混合饲料2组：喂食含有7％酪蛋白加14％大豆分离蛋白饲料。实验期用腺嘌呤灌胃共21d，建立肾损害大鼠模型，各组大鼠喂养相应饲料6周，测饲料消耗量、24h尿蛋白、尿钙、钙表观吸收率、储留钙量。[结果]4组实验大鼠饲料摄入量1d～30d无统计学差异，大豆蛋白饲料组和混合饲料1组实验结束时与另外两组相比，尿钙排泄量低，钙表观吸收率和储留钙量高，差异有统计学意义（P〈0．05）。[结论]蛋白质含量水平在14％条件下，含大豆蛋白的两种饲料对肾损害大鼠钙吸收、钙排泄的影响无统计学差异，有利于促进钙吸收，减少钙排泄。     

Intrathecal synthesis of anti-myelin basic protein IgG in HIV-1+ patients

Human immunodeficiency virus type 1 (HIV-1)-infected individuals frequently develop a broad spectrum of neurological syndromes, classified as HIV-1-associated cognitive/motor complex. Diffuse demyelination of hemispheric white matter is a commonly observed in HIV-1 infected brain, but the events leading to myelin destruction are still obscure. Since oligodendrocyte infection by HIV-1 is not proven as yet, myelin damage in HIV-1 infection may result from indirect mechanisms such as the excessive release of myelinotoxic substances or the triggering of autoimmune responses directed to myelin constituents. To verify the latter hypothesis, we searched for elevated anti-myelin basic protein (MBP) IgG levels in the cerebrospinal fluid (CSF) and serum of 25 patients with HIV-1 infection, 12 with multiple sclerosis (MS), and 9 with non-inflammatory neurological diseases (NIND). CSF, but not serum, anti-MBP IgG levels were more frequently elevated in HIV-1⁺ (16/25, 64%) than in MS (3/12, 25%) or NIND (0/9) patients. By using the anti-MBP IgG index, the anti-MBP IgG antibody specificity index (ASI), and the search for anti-MBP oligoclonal IgG, we ascertained that anti-MBP IgG were produced within the CNS in 13 of 25 (52%) HIV-1⁺, in 6 of 12 (50%) MS, and in none of NIND patients. The incidence of increased CSF anti-MBP IgG levels was higher among HIV-1⁺ patients at stage II–III (4/4, 100%) or at stage IV B (7/9, 78%) than among those at stage IV C–IV D (5/12, 42%). Although our data indicate that intrathecal anti-MBP IgG may occur early during HIV-1 infection and that they are more common in patients with HIV-1-associated cognitive/motor complex, the possible demyelinating role of these antibodies remains to be demonstrated.     

Astrocyte RNA in relation to neuronal RNA depletion in Alzheimer's disease

Summary A new double-staining procedure, in which the techniques of immunocytochemistry of glial fibrillary acidic protein (GFAP) and quantitative microdensitometry of azure B-RNA were combined, was used to study nucleic acid alterations in fibrous astrocytes in Alzheimer's disease (AD). RNA contents of GFAP-positive cells of the hippocampal endplate (Rose's H₃-H₅ fields) and the dentate gyrus molecular layer were determined in ten autopsy-proven AD patients (ages 51–88) and ten age-matched, non-demented control. In addition, RNA contents of pyramidal neurons of the endplate were examined. While there were no differences in RNA contents of astrocytes of either region between AD patients and controls, neuronal RNA was markedly depleted. These data suggest that astrocytes maintain protein synthetic capabilities in AD and that RNA loss is limited to the neuronal compartment.Supported by Grants 1P01-AG05119 and 1P50-AG05144 from the National Institutes of Health and by a Small Research Project Award from the University of Kentucky Medical Center     

Segmental fixation with U-shaped rod in the treatment of spondylolisthesis

Summary From 1987 to 1990 the authors treated 20 cases of spondylolisthesis by an improved operative procedure including excision of the medial part of the superior articular processes of the slipped vertebra, excision of the soft tissue between the ununited isthmi, and excision of the ligamentum flavum between the intervertebral space above the slipped segment. In some instances the lower portion of the lamina over the slipped vertebra should be resected. A U-shaped rod was used to hold sublaminar fixation of two segments above and below the slipped vertebra, with the slipped vertebra spared. Utilizing the U-shaped rod as support, bone strips were placed along the lateral and anterior sides of the rod to bridge the gap between the laminae of the displaced vertebra. Other bone grafts were focused on the facet joints. The patients were allowed ambulation early postoperatively. 19 cases could be evaluated at preliminary follow-up. All showed satisfactory results.     

Evidence for negative control in protein kinase C substrate specificity

The peptide Leu-Asp-Asp-Ser-Lys-Arg-Val-Ala-Lys-Arg-Lys-Leu-Ile-Glu, which corresponds to sequence 124 to 137 of c-erb-A protein, was synthesized and tested as substrate for protein kinase C (PKC). Although a typical recognition sequence for PKC, consisting of a cluster of basic residues, is found on the C-terminus side of serine, its phosphorylation was totally prevented by the presence of the two acidic residues on the amino-terminus side. Three analogs in which aspartyl residues were successively replaced with alanine were studied and the influence of the acidic side chain in modulating phosphorylation by PKC was thus possible to determine. The results show that the presence of a single aspartyl residue located in positions i-1 or i-2 with respect to the phosphorylable residue can almost totally abolish the positive effect of a highly favorable cluster of basic residues. These observations highlight the role of negative substrate specificity determinants in settling the protein substrate profile of protein kinase C.