应用蛋白质组学技术筛检肝癌血清差异蛋白质并分离鉴定阿朴脂蛋白AⅡ

Objective To screen differential proteins in serum from hepatocellular carcinoma (HCC) patients by Proteomic Technology and to purify and identify them. Methods Surface enhanced laser desorp-tion Ionization time of flight-mass spectrum (SELDI-TOF-MS) was employed to screen differential proteins in serum from 33 HCC patients and 33 control cases, and then to purify and identify them using isoelectric precipitation, Tricine sodium dodecyl sulphate ployacrylamide gel electrophoresis (Tricine-SDS-PAGE) and high performance liquid chromatography tandem Mass Spectrum (HPLC-MS). Result 65 protein peaks in the range of relative molecular weight from 2000 to 10 000 were found significant difference (P < 0.05) between the patient group and control group. Based on these differential protein peaks, diagnostic model for HCC detection was established and its sensitivity and specificity were 100% and 96.97 % respectively. Proteins with 8706.5 and 8579.2 relative molecular weights (the t value was 2.562 and 2.783 respectively, and P value was 0.013 and 0.015 respectively) out of the 65 differential proteins were purified and identified, and then recognized as Apolipoprotein A Ⅱ (Apo AⅡ). Conclusion Apo A II is probably a differential protein of HCC and maybe related to the pathogenesis of HCC.     

Serum adiponectin levels predict the effect of short-term dietary interventions on insulin sensitivity in humans

Aims/hypothesis Fat-rich diets can acutely induce insulin resistance. Data from adiponectin knock-out mice suggest that this effect might be increased in the absence of adiponectin. In the present study we tested whether plasma adiponectin concentrations influence changes in insulin sensitivity induced by a short-term dietary intervention in humans.Methods We analysed data from 27 healthy, non-obese men with normal glucose tolerance. These men ate a diet high in fat and a diet high in carbohydrates for three days each.Results The high-fat diet induced a significant drop in insulin sensitivity (determined by euglycaemic–hyperinsulinaemic clamp) compared to baseline (0.100±0.009 vs 0.083±0.007 µmol·kg^–1·min^–1·(pmol·l^–1), p=0.01). The drop in insulin sensitivity was more pronounced in subjects with low serum adiponectin (0.094±0.011 vs 0.077±0.010 µmol·kg^–1·min^–1·(pmol·l^–1), p=0.02) than in subjects with high serum adiponectin (0.103±0.011 vs 0.090±0.040 µmol·kg^–1·min^–1·(pmol·l^–1), p=0.16). In the whole group the high-carbohydrate, low-fat diet did not cause an increase in insulin sensitivity (0.095±0.007 vs 0.102±0.009 µmol·kg^–1·min^–1·(pmol·l^–1), p=0.06). However, insulin sensitivity was significantly increased in the subgroup with low serum adiponectin levels (0.084±0.013 vs 0.099±0.018 µmol·kg^–1·min^–1·(pmol·l^–1), p=0.01). In an additional multivariate analysis post-intervention insulin sensitivity was predicted by pre-intervention insulin sensitivity (p<0.001) and adiponectin concentrations (p=0.001).Conclusions/interpretation These data indicate that the reduction in insulin sensitivity achieved by a short-term high-fat diet is more pronounced in non-obese subjects with low serum adiponectin. Thus it is possible that the restriction of dietary fat and a diet high in carbohydrates might be particularly effective in subjects with low adiponectin such as obese or Type 2 diabetic individuals.     

Pravastatin restored the infarct size-limiting effect of ischemic preconditioning blunted by hypercholesterolemia in the rabbit model of myocardial infarction

OBJECTIVES

We tested to find out whether pravastatin restores the infarct size (IS)-limiting effect of ischemic preconditioning (IP) and if it has any effect on the IP-induced activation of adenosine producing enzyme ecto-5′-nucleotidase which plays a key role in the IP-induced cardioprotection.

BACKGROUND

The IS-limiting effect of IP is blunted by hypercholesterolemia. Recently, HMG-CoA reductase inhibitors are shown to have direct cytoprotective effects.

METHODS

Rabbits were fed with a normal or cholesterol (1%) added diet with or without pravastatin (5 mg/kg/day) treatment. Infarct size was measured after 30 min occlusion and 3 h reperfusion of circumflex coronary artery with or without the IP procedure (5 min occlusion and 10 min reperfusion). Additionally, ecto-5′-nucleotidase activities of ischemic and nonischemic myocardium were measured immediately after IP procedure.

RESULTS

This dose of pravastatin did not normalize the increased level of serum cholesterol. The IS-limiting effect of preceding IP (IS reduced from 36.7% to 9.6%, p < 0.001) was abolished by hypercholesterolemia (from 46.1% to 31.3%, p = NS) and restored by pravastatin treatment (from 35.2% to 9.4%, p < 0.001). Pravastatin treatment did not affect IS or the effect of IP under normocholesterolemia. The activation of ecto-5′-nucleotidase presented as the activity ratio of ischemic to nonischemic myocardium (3.1-fold in normocholesterolemia) was blunted by hypercholesterolemia (1.8-fold, p < 0.05) and restored by pravastatin treatment (2.9-fold).

CONCLUSIONS

Pravastatin, at the dose serum cholesterol was not normalized, restored the IS-limiting effect of IP and IP-induced ecto-5′-nucleotidase activation, which were both blunted by hypercholesterolemia. The activation of ecto-5′-nucleotidase may be worth further investigation as a possible mechanism for the hypercholesterolemia-induced retardation and pravastatin-mediated restoration of the cardioprotective effect of IP.     

Neonatal de-afferentation of capsaicin-sensitive sensory nerves increases in vivo insulin sensitivity in conscious adult rats

Summary Sensory neuropeptides, released from the peripheral nervous system, might modulate glucose homeostasis by antagonizing insulin action. The effects of de-afferentation of functional small diameter unmyelinated C-fibres (sensory nerves) on in vivo insulin-mediated intracellular glucose metabolism were investigated by using euglycaemic insulin (6 and 18 mU/kg.min) clamps with [3-³H]-glucose infusion in 24 adult rats, treated neonatally with either capsaicin (CAP) (50 mg/kg) or vehicle (CON). Following the clamp, skeletal muscle groups, liver and adipose tissue were freeze-clamped. At plasma insulin levels of approximately 90 mU/l, CAP-rats showed a 21 % increase in whole body glucose uptake compared with CON (24.4 ± 1.6 vs 20.1 ± 0.8 mg/kg · min, p < 0.02), which was paralleled by a 20 % increase in whole body glycolysis (12.6 ± 0.8 vs 10.5 ± 0.5 mg/kg.min p < 0.05) (concentration of ³H₂O in plasma). Whole body skeletal muscle glycogenesis was increased by 80 % in CAP-rats (5.7 ± 0.7 vs 3.1 ± 0.7 mg/kg · min, p < 0.05) with increased muscle glycogen synthase activity. Whole body (muscle, liver and adipose tissue combined) de novo lipogenesis also was increased in CAP-rats compared with CON (0.69 ± 0.10 vs 0.44 ± 0.06 mg/kg · min, p < 0.05) (incorporation of [3-³H]-glucose counts into glycogen or fat). Hepatic glucose production was lower in CAP-rats compared with CON (0.6 ± 0.6 vs 2.1 ± 0.7 mg/kg · min, p < 0.05). Plasma glucagon, corticosterone, epinephrine and norepinephrine levels were reduced in CAP-rats: 43 ± 2 compared with 70 ± 6 pg/ml, 855 ± 55 compared with 1131 ± 138 nmol/l, 513 ± 136 compared with 1048 ± 164 pmol/l and 928 ± 142 compared with 1472 ± 331 pmol/l, respectively, p < 0.05. At plasma insulin levels of approximately 400 mU/l, CAP-rats showed no differences in peripheral and hepatic insulin action compared with CON. We conclude that the removae of endogenous sensory neuropeptides, by de-afferentation of capsaicin-sensitive sensory nerves, increases in vivo insulin sensitivity, but not responsiveness: 1) primarily through an increased sensitivity of skeletal muscle glycogen synthesis to insulin; 2) through a reduction in the levels of counter-regulatory hormones, thereby creating a milieu which favours overall in vivo insulin sensitivity with respect to glucose uptake, glucose production, glycolysis, glycogenesis and lipogenesis. [Diabetologia (1998) 41: 813–820] Received: 10 November 1997 and in revised form 4 March 1998     

Absence of large bowel tumors in rats injected with 1,2-dimethylhydrazine and fed high dietary cellulose

The effect of very high concentrations of dietary cellulose against the development of colon tumors was investigated in 20 rats injected with conventional doses of 1,2-dimethylhydrazine. Ten of these rats were fed a regular (5%) concentration of cellulose and 10 were fed a very high (15%) concentration of cellulose. Rats fed regular cellulose developed a total of 16 tumors, nine in the small bowel and seven in the large bowel. In this group colonic tumors were large and invasive; 75% were carcinomas. Rats fed very high concentrations of cellulose had only four tumors, noninvasive and localized to the small intestine. Large bowels of rats fed high cellulose were completely devoid of neoplasms. This study suggests that very high concentrations of cellulose may suppress the development of large bowel tumors in rats. This could have significant implications concerning dietary protection against colon carcinogenesis.This study was supported by a research grant from the Veterans Administration.     

关于空腹血糖、空腹胰岛素乘积的倒数在流行病学研究中应用的补充说明

高胰岛素正糖钳夹技术可以测定活体的胰岛素敏感性,但它并不适用于大规模流行病学研究。流行病学研究需要简单的胰岛素抵抗测定法。本文补充报告在空腹血糖(FPG)(75～306mg/dl或4.2～17.1mmol/L)及空腹胰岛素(FIns)(9.7～120mU/L)范围很宽的Pima印第安人群中,正糖钳夹技术测定的胰岛素介导的葡萄糖代谢率(M)与涉及FPG、FIns的多种复合的胰岛素敏感指数的相关性:胰岛素作用指数(IAI)=1/(FPG×FIns)在非糖尿病人群及2型糖尿病人群都与M显著正相关(r>0.7,P=0.0001),而且这两者的相关性强于M与其他指数如FIns或FPG/FIns比值的相关性,也不弱于M与糖负荷后3～5个时间点的血糖、胰岛素曲线下面积乘积的相关性。IAI的五分变量分布情况表明有90.4%的IAI落在所预测的M值五分变量区域或与之相邻的一个五分变量区域之内。1/FPG×FIns虽相对简单但确实与机体的胰岛素敏感性密切相关,它可以做为胰岛素敏感指数在流行病学研究中应用。     

TURP治疗198例高危前列腺增生症患者围术期的护理体会

目的：讨论经尿道前列腺电切术( TURP )治疗高危前列腺增生症( BPH )围术期的护理方法。方法对行TURP术治疗的198例高危BPH患者,给予充分术前准备、手术耐受力评估、控制手术时间。术后严密观察生命体征变化,积极防御水中毒等并发症。膀胱冲洗,及时处理膀胱经痉挛,以及出院后健康指导。结果198例患者均接受TURP术,术后排尿通畅,无严重并发症发生,痊愈出院。结论对行TURP术高危患者施以精心围手术期护理,可使患者平稳安全地度过围手术期,减少术后并发症,缩短患者住院时间,加快患者康复。