5-氨基水杨酸灌肠对大鼠免疫性结肠炎的影响

目的 探讨5-氨基水杨酸(5-ASA)灌肠对大鼠三硝基苯磺酸(TNBS)诱导的结肠炎的作用.方法用TNBS诱发大鼠结肠炎.造模7天后,用不同剂量的5-ASA(25、50、100mg·kg-1·d-1)开始灌肠.观察大鼠粪隐血(OB)反应强度、结肠大体形态和组织学改变,并检测肠黏膜髓过氧化物酶(MPO)活性.结果 5-ASA灌肠可明显降低结肠黏膜损伤指数(CMDI)、OB反应强度、MPO活性及组织学评分(HS),各剂量组间有一定的量效关系.结论 5-ASA灌肠对TNBS诱导的大鼠结肠炎有保护作用,且与剂量有一定关系.     

游离脂肪酸对大鼠骨骼肌细胞瘦素受体基因、蛋白表达及酪氨酸磷酸化的影响

目的　探讨游离脂肪酸是否会对大鼠骨骼肌细胞L eptin受体的基因、蛋白表达及酪氨酸磷酸化产生一定的影响 ,进而导致胰岛素抵抗及葡萄糖代谢的异常 .方法　分离、培养新生 Sprague- Dawley大鼠骨骼肌细胞 ,分别与软脂酸(0 .2 5 m mol· L- 1 )或油酸 (0 .12 5 mmol· L- 1 )孵育 12 ,2 4和36 h,提取蛋白后用 Western印迹法检测 L eptin受体的蛋白水平 .用 RT- PCR检测胰岛细胞内 L eptin受体 RNA含量的变化 .应用免疫沉淀法检测 L eptin受体的酪氨酸磷酸化程度 .结果　软脂酸和油酸孵育后大鼠骨骼肌细胞 L eptin受体的蛋白表达水平在孵育 12和 2 4h后同对照组相比无显著变化 ,在孵育 36 h后同对照组相比显著下调 [软脂酸 (0 .36±0 .0 3)和油酸 (0 .35± 0 .0 4) vs对照 (0 . 39± 0 .0 5 ) ,P<0 .0 5 ];L eptin受体的 RNA水平在孵育 12 h后同对照组相比无显著变化 ,孵育 2 4和 36 h 后显著下调 [2 4h:软脂酸(0 .2 6± 0 .0 3)和油酸 (0 .2 6± 0 .0 4) vs对照 (0 .31± 0 .0 3) ,P<0 .0 5 ;36 h:软脂酸 (0 .2 5± 0 .0 4)和油酸 (0 .2 3± 0 .0 3) vs对照 (0 .2 9± 0 .0 1) ,P<0 .0 5 ];L eptin受体的酪氨酸磷酸化程度在在孵育 12 h后同对照组相比无显著变化 ,孵育 2 4和36 h后显著下调 [2 4h:软脂酸     

冬凌草水溶性成分及氨基酸、无机元素的测定

目的 :分离冬凌草中的水溶性成分和测定某些无机元素和氨基酸的含量。方法 :对冬凌草进行柱层析分离水溶性成分 ;用原子吸收分光光度法测定无机元素含量 ;用氨基酸自动分析法测定氨基酸含量。结果 :冬凌草中的水溶性成分确定为葡萄糖 ;无机元素锌、铜、钙、镁质量分数分别为 0 0 32 ,0 0 0 2 ,16 43和 12 0 3mg·g-1;含 18种氨基酸 ,其总质量分数为 7 45 %。结论 :冬凌草含有水溶性成分单糖 ,含有多种氨基酸 ,而所含无机元素中以钙含量较高。     

5-氨基水杨酸片剂的抗炎镇痛作用

目的　研究 5 -氨基水杨酸 (5 ASA)的主要药效学。方法　镇痛试验采用小鼠热板法及扭体法 ;抗炎试验采用小鼠耳片法、蛋清诱导大鼠足肿胀模型。结果　 5 ASA片剂 3种剂量 (75、15 0及 30 0mg·kg-1,ig× 3d)对二甲苯诱导的小鼠耳肿胀度及蛋清诱导的大鼠踝关节肿胀度均有明显抑制作用 ;以上剂量还可明显抑制小鼠扭体反应 ,大剂量还可延长小鼠热板的舔足反应潜伏期。结论　 5 ASA片剂有明显的抗炎镇痛作用。     

血清总胆汁酸测定在胆石症诊治中的应用

目的：探讨胆汁酸（ＴＢＡ）测定在胆石症诊治中的应用价值。方法：酶法测定１０７例胆石症病人和３９例正常人血甭ＴＢＡ,并与ＡＬＴ和ＡＬＰ进行比较分析。结果：与对照组比较,胆石症病人血清ＴＢＡ升高,伴发炎症或胆汁淤积时差异显著：ＴＢＡ在反映胆道炎症和胆汁淤积症方面分别与ＡＬＴ、ＡＬＰ有正相关关系。结论：血清ＴＢＡＩ 胆石症诊治中有一定参考价值。     

Effect of binding protein surface charge on palmitate uptake by hepatocyte suspensions

1. Studies were directed at determining whether hepatocytes, isolated from female Sprague-Dawley rats, facilitate the uptake of protein-bound long-chain fatty acids. We postulated one form of facilitated uptake may occur through an ionic interaction between the protein-ligand complex and the cell surface. These interactions are expected to supply additional ligand to the cell for uptake.
2. The clearance rate of [³H]-palmitate in the presence of α₁-acid-glycoprotein (pI=2.7), albumin (pI=4.9) and lysozyme (pI=11.0) was investigated. Palmitate uptake was determined in the presence of protein concentrations that resulted in similar unbound ligand fractions (=0.03). The experimental clearance rates were compared to the theoretical predictions based upon the diffusion-reaction model.
3. By use of our experimentally determined equilibrium binding and dissociation rate constants for the various protein-palmitate complexes, the diffusion-reaction model predicted clearance rates were 4.9 μl s⁻¹/10⁶ cells, 4.8 μl s⁻¹/10⁶ cells and 5.5 μl s⁻¹/10⁶ cells for α₁-acid-glycoprotein, albumin and lysozyme, respectively; whereas the measured hepatocyte palmitate clearance rates were 1.2±0.1 μl s⁻¹/10⁶ cells, 2.3±0.3 μl s⁻¹/10⁶ cells and 7.1±0.7 μl s⁻¹/10⁶, respectively.
4. Hepatocyte palmitate clearance was significantly faster (P<0.01) in the presence of lysozyme than albumin which was significantly faster than α₁-acid-glycoprotein (P<0.01). The marked difference in clearance rates could not be explained by considering differences in solution viscosity.
5. Our results are consistent with the notion that ionic interactions between protein-ligand complexes and the cell surface facilitate the ligand uptake by decreasing the diffusional distance of the unbound ligand and/or by facilitating the protein-ligand dissociation rate.

     

Lipoteichoic acid fractions from pathogenic and apathogenic Listeria species and Staphylococcus aureus induce similar amounts of macrophage-derived cytokines

Lipoteichoic acids (LTAs) of pathogenic and apathogenic Listeria species and of Staphylococcus aureus were fractionated and tested for their ability to stimulate production of cytokines (IL-1α, IL-6, TNF-α) in resident peritoneal macrophages (Mϕ) of endotoxin-resistant C3H/HeJ mice using a serum-free medium. For IL-1α and IL-6 there were no detectable differences in the ability of LTA fractions of pathogenic and apathogenic Listeria species and of Staphylococcus aureus. However, LTA-2 fractions of Staphylococcus aureus, which might be less hydrophobic than the LTA-2 fractions of the listeriae-induced lower amounts of TNF-α. Furthermore, the more lipophilic LTA-2 fractions of all LTAs employed were more potent inducers of cytokines than the less lipophilic LTA-1 fractions. The biologic effect of LTAs appears, therefore, to depend mainly on their hydrophobicity.     

Inhomogeneous exercise uptake and accelerated washout of a radioiodinated fatty acid analogue in syndromeX A SPECT study of the left ventricle

Myocardial metabolism in exercise was determined by studying 21 syndromeX patients and 14 healthy volunteers with an aromatic fatty acid analogue IPPA and a gamma camera. We developed criteria for visual semiquantitative assessment of relative segmental radiotracer uptake and washout, and tested a new computer program for quantitative evaluation. One volunteer (7%) and 12 patients (57%) showed visually inhomogeneous uptake (p=0.006, ²-test) in SPECT polar tomograms after a maximal ergometry test. Images in none of the volunteers and seven patients (33%) gave the impression of a slowed regional washout (p=0.057). Only six patients (29%) had a normal radial polarogram. Patients with irregular coronary angiograms (showing slow flow or minor sclerosis) and those with chest pain during the IPPA exercise test had a very low frequency of normalcy, but this was not significant.Total washout was higher in patients than in the reference population, as the exercise to rest activity ratio was 1.36 SD 0.13 versus 1.25 SD 0.11 in computerized quantitation (p=0.015, t-test). Washout did not correlate with age, sex or exercise heart rate. Regarding computerized analysis of uptake and slow washout, the number of deviant segments was not significantly higher in patients than in reference population. Semiquantitative and quantitative analysis correlated in the assessment of uptake, but not in the assessment of washout. Possible reasons for the discrepancy are discussed.Conclusions of this study are not straightforward. SyndromeX was associated with inhomogeneous IPPA uptake, which is not at variance with the theory of microvascular dysfunction. On the other hand, the analysis of washout presumably implies higher fatty acid utilization in patients than in normal controls, which is not a characteristic phenomenon in myocardial ischemia.     

Relationship between blood flow and fatty acid metabolism in subacute myocardial infarction: a study by means of99mTc-Sestamibi and23I-β-methyl-iodo-phenyl pentadecanoic acid

Contradictory data have been published on the relative behaviour of fatty acids and flow tracers during the subacute stage of myocardial infarction. Therefore, the present study was set up (1) to investigate the potential occurrence of mismatches between -methyl-iodophenyl pentadecanoic acid (BMIPP), a fatty acid analogue, and Sestamibi, and to describe their nature, and (2) to relate these mismatches to clinical characteristics such as whether or not thrombolysis or percutaneous transluminal coronary angioplasty (PTCA) had been performed. Twenty-six patients were studied within 2 weeks after myocardial infarction. Sestamibi and BMIPP single-photon emission tomography (SPET) were performed within 4 days of one another. Activity of both tracers was scored in 16 basal, 16 midventricular and 8 apical segments, using a four-point grading system: 3 = normal (65% of maximum activity), 2 = mildly decreased (45%–64%), 1 = moderately decreased (25%–44%), 0 = severely decreased (0%–24%). Coronary arteriography was obtained during the same hospital stay. Four hundred and seventy-seven segments out of 1040 studied were abnormal for at least one tracer: 197 with higher Sestamibi activity (group I), 226 with equal scores for Sestamibi and BMIPP (group II) and 54 with higher BMIPP activity (group III). Seventy-five percent of group I segments and 84% of group III segments were found in infarct-related artery territories. Group I segments were associated with acute thrombolysis and/or PTCA (P < 0.01), and with the absence of prior infarction in the territory of the infarct-related artery (P < 0.001). Group III segments were associated with the absence of thrombolysis or PTCA (P < 0.001), with occlusion of the infarct-related artery (P < 0.001), with previous infarction in the same territory (P < 0.001) and with a- or dyskinesia in this territory (P < 0.001). These data could support the interpretation that areas in which the uptake of BMIPP is more decreased than that of Sestamibi (group I) are due to delayed recovery of fatty acid metabolism after reperfusion, whereas those with higher BMIPP than Sestamibi activity (group III) are accounted for by the enhanced metabolism induced by passive systolic wall stretch.     

Small supplements of N-3 fatty acids change serum low density lipoprotein composition by decreasing phospholipid and apolipoprotein B concentrations in young adult women

Summary In order to investigate the effect of a short-term application of marine n-3 polyunsaturated fatty acids on the composition of serum very low density lipoproteins (VLDL), low density lipoproteins (LDL), and high density lipoproteins (HDL), nine women aged 29±4.2 years, following a diet with a SFA/MUFA/PUFA profile of 2.4/3/1, received supplements of six capsules daily, each capsule containing 0.137 g of n-3 fatty acids (14.5% eicosapentaenoic acid (EPA) and 8.9% docosahexaenoic acid (DHA)) for 10 d. Food consumption, assessed during two 10-days periods indicates that percentage contribution of SFA, MUFA, and PUFA to the daily energy intake did not change through the fish-oil supplementation period, but the daily consumption of n-3 fatty acids increased 2.3 times. N-3 fatty supplementation increased EPA and DHA percentages in serum phospholipids, but failed to decrease (p>0.05) the cholesterol and triglyceride concentration in serum LDL and HDL, although it did so in VLDL. In contrast, the lipoprotein-phospholipid and lipoprotein-protein concentrations were markedly affected, mainly in LDL and HDL (at least p<0.01). HDL and VLDL compositions were not affected but the total mass (lipid+protein in mg/dl) concentration of these lipoproteins significantly decreased (p<0.05), suggesting a lower number of these particles in circulating blood after the n-3 treatment. The LDL-cholesterol/LDL-apolipoprotein B ratio increased (p<0.01) reflecting a probable increase in LDL size. Following fish oil supplementation, LDL particles contained a significantly lower amount of phospholipids, which also suggests changes in the surface/core ratio of the average LDL. Changes in serum lipoprotein lipids did not significantly correlate with any dietary change other than the n-3 fatty acid increase. The results indicate that a 10-day application of a small supplement of n-3 change the LDL composition leading to less atherogenic LDL particles with lower phospholipid and apolipoprotein (Apo) B concentrations. Received: 15 May 1998, Accepted: 28 August 1998