稳定性核素测定大鼠小肠蛋白质合成

目的：建立稳定性核素（[L-^15N]亮氨酸）测定大鼠小肠蛋白质合成率的方法。方法：分别测定静脉注射相同剂量[L-^15N]亮氨酸不同时相的大鼠小肠^15N丰度及不同剂量[L-^15N]亮氨酸同一时相的大鼠小肠^15N丰度。结果：大鼠小肠游离氨基酸池中^15N核素丰度在注射后0．5h内呈线性上升并达高峰，维持4h后缓慢下降，小肠蛋白质中的^15N丰度0．5h至12h基本维持不变；随着注射剂量的增加，大鼠小肠蛋白质分数合成率（FSR）亦增加，当[L-^15N]亮氨酸剂量在1．0mmol／kg以上，FSR并不随施加[L15N]亮氨酸剂量的加大而增加。结论：在进行大鼠小肠蛋白质合成率测定时，一次性静脉注射的测量最佳时限为0．5h，剂量为1．0mmol／kg。     

Stable Transfection of Nonosteogenic Cell Lines with Tissue Nonspecific Alkaline Phosphatase Enhances Mineral Deposition Both in the Presence and Absence of β-Glycerophosphate: Possible Role for Alkaline Phosphatase in Pathological Mineralization

It is documented that alkaline phosphatase (AP) plays an important role in bone mineralization. Considering that TN-AP is expressed in periodontal ligament fibroblasts, renal epithelial cells, and vascular endothelial cells, and that TN-AP is both a calcium-/phosphate-binding protein and a phosphohydrolytic enzyme, we hypothesize that membrane-bound AP also plays an important role in the initiation of physiological and pathological mineralizations in tissues other than bone and cartilage. To test this hypothesis, nonosteoblast cell lines, including a fibroblast line, a renal epithelial line, and a capillary endothelial line, were stably transfected to express high levels of rat bone AP on their cell surfaces. These rat bone AP-expressing cells were then cultured on filter membranes in the presence or absence of β-glycerol phosphate. von Kossa staining for calcium phosphate and transmission electron microscopy with electron diffraction analysis for minerals were employed to investigate the effect of membrane AP on extracellular calcium phosphate mineralization. Our results indicated that AP expression on these nonosteoblast-like cell surfaces have induced extracellular hydroxyapatite (HAP) mineralization. Our findings support the concept that membrane-bound AP contributes to extracellular apatitic mineralization by mechanisms that do not necessarily involve its hydrolase activity. They also suggest that AP might be important for the initiation of pathological mineralization in nonosteogenic tissues. Received: 11 January 1996 / Accepted: 31 October 1996     

舒利迭加无创通气治疗稳定期慢性阻塞性肺疾病的临床研究

目的探讨舒利迭(吸入型肾上腺皮质激素与长效β2-受体激动剂的预混制剂)联合双水平气道正压通气(B iPAP)对稳定期慢性阻塞性肺疾病(COPD)的治疗作用。方法稳定期COPD病人52例,舒利迭TM50/250,1吸/次,2次/d;B iPAP,吸气压力(IPAP)10~20cm H2O,呼气压力(EPAP,也称PEEP)3~6cm H2O,吸氧浓度(FiO2)3L/m in,每天夜间通气6~8h。观察治疗前、治疗后12周病人临床症状、生活质量、健康状态和肺功能。结果治疗前、治疗后12周病人的临床症状、急性加重次数及严重程度、健康状态和生活质量、肺功能等指标比较差异有统计学意义(P<0.05)。结论舒利迭联合B iPAP治疗稳定期COPD病人能够明显改善其症状,提高生活质量,有一定的临床应用价值,对减缓COPD病人肺功能下降有积极意义。     

明天的医学向何处去——平衡医学方法论略谈

《明天的医学向何处去》一文是王佑三同志应中国中医研究院、中西医结合研究会1990～2010年中医药研究的重大进展与突破预测研究课题组和中国人体科学学会之约所撰。本报征得作者同意稍加删节后发表,期望引起对“明天的医学”的关注。     

Perceiving a stable world during active rotational and translational head movements

When a person moves through the world, the associated visual displacement of the environment in the opposite direction is not usually seen as external movement but rather as a changing view of a stable world. We measured the amount of visual motion that can be tolerated as compatible with the perception of moving within a stable world during active, sinusoidal, translational and rotational head movement. Head movements were monitored by means of a low-latency, mechanical head tracker and the information was used to update a helmet-mounted visual display. A variable gain was introduced between the head tracker and the display. Ten subjects adjusted this gain until the visual display appeared stable during sinusoidal yaw, pitch and roll head rotations and naso-occipital, inter-aural and dorso-ventral translations at 0.5 Hz. Each head movement was tested with movement either orthogonal to or parallel with gravity. A wide spread of gains was accepted as stable (0.8 to 1.4 for rotation and 1.1 to 1.8 for translation). The gain most likely to be perceived as stable was greater than that required by the geometry (1.2 for rotation; 1.4 for translation). For rotational motion, the mean gains were the same for all axes. For translation there was no effect of whether the movement was inter-aural (mean gain 1.6) or dorso-ventral (mean gain 1.5) and no effect of the relative orientation of the translation direction relative to gravity. However translation in the naso-occipital direction was associated with more closely veridical settings (mean gain 1.1) and narrower standard deviations than in other directions. These findings are discussed in terms of visual and non-visual contributions to the perception of an earth-stable environment during active head movement.     

Availability of glucose ingested during muscle exercise performed under acipimox-induced lipolysis blockade

This study investigated the percentage of carbohydrate utilization than can be accounted for by glucose ingested during exercise performed after the ingestion of the potent lipolysis inhibitor Acipimox. Six healthy male volunteers exercised for 3 h on a treadmill at about 45% of their maximal oxygen uptake, 75 min after having ingested 250 mg of Acipimox. After 15-min adaptation to exercise, they ingested either glucose dissolved in water, 50 g at time 0 min and 25 g at time 60 and 120 min (glucose, G) or sweetened water (control, C). Naturally labelled [¹³C]glucose was used to follow the conversion of the ingested glucose to expired-air CO₂. Acipimox inhibited lipolysis in a similar manner in both experimental conditions. This was reflected by an almost complete suppression of the exercise-induced increase in plasma free fatty acid and glycerol and by an almost constant rate of lipid oxidation. Total carbohydrate oxidation evaluated by indirect calorimetry, was similar in both experimental conditions [C, 182, (SEM 21); G, 194 (SEM 16) g · 3 h^–1], as was lipid oxidation [C, 57 (SEM 6); G, 61 (SEM 3) g · 3 h^–1]. Exogenous glucose oxidation during exercise G, calculated by the changes in¹³C:¹²C ratio of expired air CO₂, averaged 66 (SEM 5) g · 3 h^–1 (19% of the total energy requirement). Consequently, endogenous carbohydrate utilization was significantly smaller after glucose than after placebo ingestion: 128 (SEM 18) versus 182 (SEM 21) g · 3 h^–1, respectively (P < 0.05). Symptoms of intense fatigue and leg cramps observed with intake of sweet placebo were absent with glucose ingestion.In conclusion, we found glucose ingestion during 3-h exercise with lipolysis blockade could provide metabolic substrate permitting a significant sparing of endogenous carbohydrate and consequently an improvement in performance.     

孕血清中早孕因子（EPF）的活性及其对T淋巴细胞亚群影响的研究

本文分别用抗人E受体、抗T_H、Ts细胞单抗的Ea花结抑制试验检测孕血清中EPF活性并对其进行了动态观察,同时检测了EPF活性与HCG-β、AFP、孕酮的关系以及对T淋巴细胞亚群的影响。结果说明:孕血清中EPF活性明显高于对照组(P<0.001)。孕血清中EPF活性主要通过对T_H细胞的作用实现。在孕早期EPF活性较高,随孕期延长活性逐渐下降,至孕6个月活性渐趋消失,分娩前10周基本消失。EPF活性与血中HCG-β、AFP浓度无关,与孕酮呈负相关。EPF不能直接抑制淋巴细胞的花结形成,但能显著地增强ATS、anti-CCT_3、anti-CD_4的花结抑制效应。     

Calcium Kinetics in Children with Osteogenesis Imperfecta Type III and IV: Pre- and Post-Growth Hormone Therapy

Children with osteogenesis imperfecta (OI) type III and type IV were studied using a ⁴²Ca stable isotope technique. Serum dilution kinetics of ⁴²Ca were studied pre- and post-growth hormone (GH) treatment in 9 OI III (age range 5–9 years) and 8 OI IV patients (age range 5–12 years). Each subject was studied twice: at baseline and following GH therapy (range 1–1.5 years). Isotopic enrichments of ⁴²Ca were followed over 7 days using thermal ionization mass spectrometry. A binding site model, which describes reversible and irreversible binding of calcium (Ca) ions to postulated short- and long-term binding sites in bone, was used to analyze the kinetic data. In type III patients, GH treatment (1) increased the fraction of short-term binding sites, θ (0.777 ± 0.112 versus 0.877 ± 0.05, respectively; P= 0.034); (2) increased the apparent half-life of a Ca ion attached to the long-term binding site by 76% (P= 0.009); (3) although not statistically significant (P= 0.098), a trend toward an increased growth rate was observed with increasing change in θ (Δθ); (4) patients experienced a 75% increase in growth rate during the first 6 months of treatment. In type IV patients, GH treatment increased the apparent half-life of a Ca ion attached to the long-term binding site by 83% (P= 0.048), however, no trend toward an increased growth rate was observed with increasing Δθ in these patients. These significant changes in Ca binding to bone may influence growth in type III patients. Received: 10 September 1999 / Accepted: 29 February 2000     

针刺治疗稳定性心绞痛30例体会

目的:比较针刺与药物治疗稳定性心绞痛的疗效差异。方法:随机选取稳定性心绞痛患者,分为针刺组30例、药物组2 2例,分别比较治疗后两组症状、心电图及硝酸甘油停减情况。结果:症状疗效方面:针刺组有效率为90 .0 0 %,药物组有效率为81 .82 %,两组比较有显著性差异(P <0 .0 5 )。心电图改善情况两组未见明显差异。硝酸甘油停减情况:针刺组停药率为2 3.3%,药物组停药率为1 8.2 %,两组比较无明显差异。结论:针刺具有明显改善稳定性心绞痛症状的功效。     

RNAi沉默整合素连接激酶基因表达对结肠癌细胞HT-29增殖的影响

目的:利用RNA干扰(RNA interference,RNAi)技术,阻断结肠癌细胞系HT-29中整合素连接激酶(integrin-linked kinase,ILK)基因的表达,研究ILK基因沉默后对HT-29细胞系增殖产生的影响。方法:构建针对ILK基因的真核表达质粒pSUPER-neo-EGFP-ILK(pSNE-ILK),在脂质体介导下稳定转染人结肠癌细胞系HT-29细胞(HT-29/pSNE-ILK组),同时以无关质粒pSUPER-neo-EGFP-C(pSNE-C)转染HT-29细胞(HT-29/pSNE-C组)和未转染细胞(HT-29组)作为对照,分别应用RT-PCR技术及蛋白印迹法检测ILK mRNA及蛋白表达水平,四甲基偶氮唑盐(MTT)比色法检测细胞增殖状况。结果:稳定转染后,HT-29/pSNE-ILK组ILK mRNA及蛋白表达水平分别为0.16±0.11和0.24±0.07,HT-29/pSNE-C组分别为0.53±0.10和0.56±0.08,HT-29组分别为0.64±0.11和0.77±0.02,前组ILK mRNA及蛋白表达水平分别与后两组比较,差异均有统计学意义(P<0.05);稳定转染pSNE-ILK质粒后HT-29细胞中ILK mRNA及蛋白表达抑制率分别为69.8%和57.1%。MTT比色法检测显示,HT-29/pSNE-ILK组细胞增殖率明显下降(P<0.05)。结论:RNA干扰技术能有效抑制靶基因ILK的表达,进而可抑制结肠癌细胞系HT-29的增殖。