ApoE基因多态性对毛南族人群血清apoA1、apoB水平的影响

目的 探讨载脂蛋白（apo）E基因多态性对毛南族人群血清apoA1、apoB水平的影响。 方法 收集221名贵州省黔南州毛南族人群血样品,采用免疫透射比浊法测定血清apoA1、apoB浓度;应用聚合酶链反应-限制性片段长度多态性方法（PCR-RFLP）检测apoE2、E3、E4基因多态性。 结果 与apoE2/2+E2/3+E2/4基因型亚组（ n =37）比较,apoE3/4+E4/4基因型亚组（ n =41）和apoE3/3基因型亚组（ n =143）血清apoB水平升高（ P ＜0.05）,apoA1/B比值降低（P ＜0.05）;apoE3/4+E4/4基因型亚组apoB水平高于apoE3/3亚组（ P ＜0.05）。未发现不同apoE基因型亚组间血清apoA1水平差异存在统计学意义（ P ＞0.05）。结论 毛南族人群apoE基因多态性明显影响血清apoB水平和apoA1/B比值,但未见该基因多态性与血清apoA1水平相关联。     

Effect of pravastatin on metabolic parameters of apolipoprotein B in patients with mixed hyperlipoproteinemia

Summary 3-Hydroxy-3-methylgluratyl coenzyme A reductase inhibitors reduce plasma cholesterol in different forms of hyperlipoproteinemia. Although an increase in low-density lipoprotein (LDL) receptor activity is the proven mechanism of this therapy in familial hypercholesterolemia, the mechanism remains controversial in mixed hyperlipoproteinemia. A decreased production of apolipoprotein B (apoB) and/or an increased removal of lipoproteins could mediate the hypocholesterolemic effect of these drugs. The effect of pravastatin on the metabolism of apoB was evaluated in a randomized, double blind, placebo controlled, cross-over study in five men with mixed hyperlipoproteinemia. Metabolic parameters for apoB were determined using endogenous labeling with [1^t3C]leucine and [¹⁵N]glycine and multicompartmental modeling. During pravastatin therapy cholesterol, LDL cholesterol, apoB, and LDL apoB levels were significantly reduced (P < 0.01) by 18%, 20%, 27%, and 29%, respectively, while triglyceride and high-density lipoprotein cholesterol levels remained unchanged. Pravastatin therapy increased the fractional catabolic rate of very low density lipoprotein apoB from 3.9±0.6 to 5.1±1.7 per day (P = 0.08) and that of LDL apoB from 0.37±0.09 to 0.46±0.10 per day (P<0.01). The apoB production (placebo 35.2±11.9 mg/kg per day; pravastatin 25.8±8.7 mg/kg per day) and conversion of very low density lipoprotein apoB to LDL apoB (placebo 65%, pravastatin 57%) remained stable. Thus, also in mixed hyperlipoproteinemia 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors increase the catabolism of apoB-containing lipoproteins without significantly affecting the production of apoB.Abbreviations apoB apolipoprotein B - FCR fractional catabolic rate - HMG hydroxy-methylglutaryl - CoA coenzyme A - FH familial hypercholesterolemia - HDL high-density lipoprotein - IDL intermediate-density lipoprotein - LDL low-density lipoprotein - VLDL very low density lipoprotein Dedicated to Prof. Dr. G. Paumgartner on the occasion of his 60th birthday     

Do age and baseline LDL cholesterol levels determine the effect of regular exercise on plasma lipoprotein cholesterol and apolipoprotein B levels?

Apolipoprotein B (apoB) concentration and age are independently associated with an increased risk for cardiovascular disease. Age is also associated with increased apoB concentration. The purpose of this study was to determine the effects of exercise on apoB and examine the association between age and lipoproteins. Forty-one sedentary individuals exercised for 6 months, four times/week for 40 min between 60 and 85% of their maximal heart rate. Lipids were determined three times: before training, 24 and 72 h after the last training session. Exercise did not alter apoB (1.2 ± 0.05 g/l vs. 1.2 ± 0.05 g/l; P > 0.05), or other lipids or lipoproteins. When participants were sequestered by baseline low density lipoprotein cholesterol (LDLc), total cholesterol (TC) was decreased at 24 h post (6.3 ± 0.2 mmol/l vs. 6.0 ± 0.2 mmol/l, P < 0.05) and LDLc after 24 and 48 h post (4.3 ± 0.1 mg/dl vs. 3.9 ± 0.1 and 4.1 ± 0.2 mg/dl, P < 0.05) in the high LDLc group. In the low LDLc group both TC (4.4 ± 0.2 mmol/l vs. 4.6 ± 0.2 and 4.6 ± 0.2 mmol/l, P > 0.05) and LDLc (2.6 ± 0.1 mmol/l vs. 2.8 ± 0.1 and 2.8 ± 0.2 mmol/l, P < 0.05) were elevated at 24 h and remained elevated at 72 h post compared to baseline. Age does not affect apoB or lipoproteins in response to exercise. Individuals with high baseline LDLc experienced acute reduction in TC and LDLc produced by each exercise session.     

Lp（a）、apoB/apoA1及HOMA-IR在2型糖尿病与糖耐量受损患者中的变化及意义

目的探讨2型糖尿病（T2DM）、糖耐量受损（IGT）患者脂蛋白（a）[Lp（a）]、载脂蛋白A1（apoA1）、载脂蛋白B（apoB）和稳态模型的胰岛素抵抗指数（HOMA-IR）的变化及其相互间的关系和意义。方法测定24例2型糖尿病患者（T2DM组）、22例糖耐量受损患者（IGT组）和36例健康成人（正常对照组）的Lp（a）、apoA1、apoB等血脂指标,同时检测T2DM组和IGT组的空腹血糖、空腹胰岛素并计算HOMA-IR,分析T2DM及IGT患者血脂指标的变化及其与HOMA-IR的关系。结果 T2DM组、IGT组与正常对照组比较Lp（a）、apoB、apoB/apoA1显著升高（P〈0.01）,apoA1显著降低（P〈0.05）;T2DM组与IGT组之间的差异有统计学意义,且两组间apoB、apoB/apoA1与HOMA-IR有显著的相关性（P〈0.05）。结论 Lp（a）、apoB、apoB/apoA1等血脂指标与T2DM的发生发展有关,且apoB、apoB/apoA1与胰岛素抵抗显著相关,在CV危险评估、病情与治疗监测等方面有重要的应用价值。     

血清瘦素水平变化对围绝经期妇女脂类代谢的影响

探讨瘦素与围绝经期妇女肥胖及脂类代谢的关系.本文分别测量了110例围绝经期妇女(疾病组)血清瘦素(Leptin)、胰岛素(INS)、低密度脂蛋白胆固醇(LDL-C)、甘油三酯(TG)、高密度脂蛋白胆固醇(HDL-C)、载脂蛋白A1(apoA1)、载脂蛋白B(apoB)、垂体促性腺激素(LH、FSH)、雌二醇(E2)、睾酮(T)、孕酮(P)及体重和身高.与60名正常育龄妇女(对照组)进行比较分析.结果表明围绝经期肥胖组、非肥胖组血清Leptin、INS水平增高与对照组比较其差异有显著意义(P＜0.01).肥胖组LDL-C 5.01mmol/L、TG 2.21mmol/L、apoB 0.89g/L与非肥胖组及对照组相比,其差异有显著意义(P＜0.01).研究组内LH、FSH、E2和T值,差异无显著意义(P＞0.05),但与对照组比较,差异有显著意义(P＜0.01).相关分析显示:围绝经期妇女Leptin与BMI、INS、LDL-C、apoB高度相关(r=0.762,P=0.002;r=0.382,P=0.01,r=0.430,P=0.002;r=0.545,P=0.001; r=0.454,P=0.001),且LDL-C与apoB同步升高在明显相关(r=0.796,P=0.001).围绝经期瘦素水平与HDL-C、apoA1分析未见相关(r=-0.222～-0.190,P＞0.05).围绝经期Leptin水平与脂类代谢异常相关,肥胖、Leptin增高围绝经期妇女更应重视脂类代谢异常.     

Effects of terlipressin and naloxone compared with epinephrine in a rat model of asphyxia-induced cardiac arrest

OBJECTIVE:

To evaluate the hemodynamic and metabolic effects of terlipressin and naloxone in cardiac arrest.

METHODS:

Cardiac arrest in rats was induced by asphyxia and maintained for 3.5 minutes. Animals were then resuscitated and randomized into one of six groups: placebo (n = 7), epinephrine (0.02 mg/kg; n = 7), naloxone (1 mg/kg; n = 7) or terlipressin, of which three different doses were tested: 50 µg/kg (TP50; n = 7), 100 µg/kg (TP100; n = 7) and 150 µg/kg (TP150; n = 7). Hemodynamic variables were measured at baseline and at 10 (T10), 20 (T20), 30 (T30), 45 (T45) and 60 (T60) minutes after cardiac arrest. Arterial blood samples were collected at T10, T30 and T60.

RESULTS:

The mean arterial pressure values in the TP50 group were higher than those in the epinephrine group at T10 (165 vs. 112 mmHg), T20 (160 vs. 82 mmHg), T30 (143 vs. 66 mmHg), T45 (119 vs. 67 mmHg) and T60 (96 vs. 66.8 mmHg). The blood lactate level was lower in the naloxone group than in the epinephrine group at T10 (5.15 vs. 10.5 mmol/L), T30 (2.57 vs. 5.24 mmol/L) and T60 (2.1 vs. 4.1 mmol/L).

CONCLUSIONS:

In this rat model of asphyxia-induced cardiac arrest, terlipressin and naloxone were effective vasopressors in cardiopulmonary resuscitation and presented better metabolic profiles than epinephrine. Terlipressin provided better hemodynamic stability than epinephrine.     

Different Seasonal Variations of Potassium in Hemodialysis Patients with High Longitudinal Potassium Levels: A Multicenter Cohort Study Using DialysisNet

PurposeTo determine seasonal variations in serum potassium levels among hemodialysis patients.Materials and MethodsThis was a multicenter cohort study of patients whounderwent hemodialysis and were registered in DialysisNet at our four associated general hospitals between January and December 2016. Month-to-month potassium variability was quantified as SD/√ {n/(n−1)}, and a non-hierarchical method was used to cluster groups according to potassium trajectories. Seasonal variations in potassium levels were analyzed using a cosinor analysis.ResultsThe analysis was performed on 279 patients with a mean potassium level of 5.08±0.58 mmol/L. After clustering, 52.3% (n=146) of patients were included in the moderate group (K⁺, 4.6±0.4 mmol/L) and 47.7% (n=133) in the high group (K⁺, 5.6±0.4 mmol/L). The mean potassium level peaked in January in the moderate group (4.83±0.74 mmol/L) and in August in the high group (5.51±0.70 mmol/L). In the high potassium group, potassium levels were significantly higher in summer than in autumn (p<0.001) and spring (p=0.007). Month-to-month potassium variability was greater in the high group than in the moderate group (0.59±0.19 mmol/L vs. 0.52±0.21 mmol/L, respectively, p=0.012). Compared to patients in the first quartile of potassium variability (≤0.395 mmol/L), those with higher variability (2nd–4th quartiles) were 2.8–4.2 fold more likely to be in the high potassium group.ConclusionDifferent seasonal patterns of serum potassium were identified in the moderate and high potassium groups, with potassium levels being significantly higher in the summer season in the high potassium group and in winter for the moderate potassium group.     

血糖控制对2型糖尿病患者载脂蛋白A水平的影响

目的 观察分析2型糖尿病患者载脂蛋白A（apoA）水平变化与血糖控制状态关系及其可能的影响机制。方法 采用自动生化仪检测213名2型糖尿病患者血浆总胆固醇（TC）、甘油三酯（TG）、高密度脂蛋白（HDL）、极低密度脂蛋白（VLDL）、低密度脂蛋白（LDL）、载脂蛋白A（apoA）、载脂蛋白B（apoB），用离子交换高效液相色谱分析法测定糖化血红蛋白（HbAlc），比较其与血脂指标的相关性。结果 两组HDL-C水平差异无统计学意义[（1．26±0．45）mmol／L vs （1．13±0．35）mmol／L，P〉0．05]；控制满意组apoA水平显著高于非满意组[（1．16±0．31）g／L vs （0．98±0．32）g／L，P〈0．01]，apoB／apoA显著低于非满意组（P〈0．05）。TC、TG、LDL、VLDL水平两组差异无统计学意义（P〉0．05）。直线相关分析显示apoA与HbAlc、FBG呈显著负相关（r=-0．30，P〈0．01；r=-0．24，P〈0．01）：apoA与HDL、TC呈显著正相关（r=0．74，P〈0．01；r=0．39，P〈0．01）。结论 2型糖尿病患者血糖控制状态显著影响apoA水平，这可能是HDL功能紊乱的重要原因。     

Serum biochemistry of Iranian Turkmen (Akhal-Teke) horses

In order to study the serum biochemistry of Iranian Turkmen horses, we conducted sampling from 48 clinically normal horses aged between 1.5 and 12 years, and the following results were obtained: albumin (Alb) 43.95±4.48 g/l; total protein (Tp) 73.58±6.1 g/l; globulin (Glo) 2.81±0.65 g/l; A:G 1.66±0.46; glucose (Glu) 4.92±0.63 mmol/l; triglyceride (Tri) 0.26±0.1 mmol/l; cholesterol (Cho) 2.44±0.43 mmol/l; urea (Ure) 6.2±0.98 mmol/l; creatinine (Cre) 119.34±19.45 mol/l; bilirubin (Bili) 16.07±7.01 mol/l; aspartate aminotransferase (AST) 269.81±74.40 IU/l; alanine aminotransferase (ALT) 9.92±2.9 IU/l; alkaline phosphatase (AP) 422.7±110.37 IU/l; sodium (Na) 143.75±7.26 mmol/l; potassium (K) 3.84±0.46 mmol/l; chloride (Cl) 89.55±4.17 mmol/l; calcium (Ca) 2.85±0.15 mmol/l; phosphorus (P) 1.16±0.16 mmol/l; magnesium (Mg) 0.81±0.11 mmol/l; iron (Fe) 23.97±7.48 mol/l. Between age groups, ALT, bilirubin, phosphorus and iron levels showed significant differences, with higher levels in horses aged 3–5 years, >5 years, <3 years and >5 years, respectively (P<0.05). Creatinine was the only parameter that showed significant difference between the genders, with male horses having higher values than female (P<0.05). Marginal difference was also seen between genders for bilirubin levels (P=0.052). Correlations between measured parameters were also determined.     

The impact of obesity on cardiac troponin levels after prolonged exercise in humans

Elevated cardiac troponin I (cTnI), a marker for cardiac damage, has been reported after high-intensity exercise in healthy subjects. Currently, little is known about the impact of prolonged moderate-intensity exercise on cTnI release, but also the impact of obesity on this response. 97 volunteers (55 men and 42 women), stratified for BMI, performed a single bout of walking exercise (30–50 km). We examined cTnI-levels before and immediately after the exercise bout in lean (BMI < 25 kg/m², n = 30, 57 ± 19 years), overweight (25 ≤ BMI < 30 kg/m², n = 29, 56 ± 11 years), and obese subjects (BMI ≥ 30 kg/m², n = 28, 53 ± 9 years). Walking was performed at a self-selected pace. cTnI was assessed using a high-sensitive cTnI-assay (Centaur; clinical cut-off value ≥0.04 μg/L). We recorded subject characteristics (body weight, blood pressure, presence of cardiovascular risk) and examined exercise intensity by recording heart rate. Mean cTnI-levels increased significantly from 0.010 ± 0.006 to 0.024 ± 0.046 μg/L (P < 0.001). The exercise-induced increase in cTnI was not different between lean, overweight and obese subjects (two-way ANOVA interaction; P = 0.27). In 11 participants, cTnI was elevated above the clinical cut-off value for myocardial infarction. Logistic regression analysis identified exercise intensity (P < 0.001), but not BMI, body fat percentage or waist circumference to significantly relate to positive troponin tests. In conclusion, prolonged, moderate-intensity exercise results in a comparable increase in cTnI-levels in lean, overweight and obese subjects. Therefore, measures of obesity unlikely relate to the magnitude of the post-exercise elevation in cTnI.     

Hypertriglyceridemia as an indicator of the severity of<Emphasis Type="Italic"> falciparum</Emphasis> malaria in returned travelers: a clinical retrospective study

To test the hypothesis that the magnitude of plasma triglyceride changes could be related to the severity of falciparum malaria, we performed a retrospective case-control study from January 1999 to December 2000 among hospitalized patients with fever who were returning to France from the tropics. Plasma triglycerides were measured in patients with severe falciparum malaria (n=13), mild falciparum malaria (n=169), non-falciparum malaria (n=20) and controls (n=55). Triglyceride level was significantly higher in the malaria group than in controls [mean values were 2.17±1.43 mmol/l versus 1.30±0.70 mmol/l, respectively (P<0.0001)]. Triglyceride level was also significantly higher in severe than in mild malaria [4.78±1.93 mmol/l versus 1.94±1.11, respectively (P<0.00001)]. Hypertriglyceridemia (>1.80 mmol/l) was noted in all the patients with severe malaria, compared to 37% of patients with mild disease (P<0.001). Although further studies are needed, these results define the relevance of hypertriglyceridemia as an indicator of the severity of falciparum malaria.     

Ba2+ and amiloride uncover or induce a pH-sensitive and a Na+ or non-selective cation conductance in transitional cells of the inner ear

The membrane potential V _m the cytosolic pH (pH_i), the transference numbers (t) for K⁺, Cl^– and Na⁺/ non-selective cation (NSC) and the pH-sensitivity of V _m were investigated in transitional cells from the vestibular labyrinth of the gerbil. V _m, pH_i, , and the pH_i sensitivity of V _m were under control conditions were –92±1 mV (n=89 cells), pH_i 7.13±0.07 (n=11 epithelia), 0.87±0.02 (n=22), 0.02±0.01 (n=19), 0.01±0.01 (n=24) and –5 mV/pH unit (n=13 cells/n=11 epithelia), respectively. In the presence of 100 mol/l Ba²⁺ the corresponding values were: –70±1 mV (n=32), pH_i 7.16±0.08 (n=6), 0.31±0.05 (n=4), 0.06±0.01 (n=6), 0.20±0.03 (n=10) and -16 mV/pH-unit (n=15/n=6). In the presence of 500 mol/l amiloride the corresponding values were: –72±2mV (n=34), pH_i 7.00±0.07 (n=5), 0.50±0.04 (n=6), 0.04±0.01 (n=11), 0.28±0.04 (n=9) and –26 mV/pH-unit (n=20/n=5). In the presence of 20 mmol/l propionate plus amiloride the corresponding values were: –61±2 mV (n=27), pH_i 6.72±0.06 (n=5), 0.30±0.02 (n=6), 0.06±0.01 (n=5) and 0.40±0.02 (n=8), respectively. V _m was depolarized and and pH_i decreased due to (a) addition of 1 mmol/l amiloride in 150 mmol/l Na⁺ by 38±1 mV (n=8), from 0.82±0.02 to 0.17±0.02 (n=8) and by 0.13±0.01 pH unit (n=6), respectively; (b) reduction of [Na⁺] from 150 to 1.5 mmol/l by 3.3±0.5 mV (n=30), from 0.83±0.02 to 0.75±0.04 (n=9) and by 0.33±0.07 pH unit (n=4), respectively and (c) addition of 1 mmol/l amiloride in 1.5 mmol/l Na⁺ by 20±1 mV (n=11) and from 0.83±0.03 to 0.53±0.02 (n=5), respectively. These data suggest that the K⁺ conductance is directly inhibited by amiloride and Ba²⁺ and that Ba²⁺ and amiloride uncover or induce a pH-sensitive and a Na⁺/NSC conductance which may or may not be the same entity.Some of the data have been presented at various meetings and appear in abstract form in [31, 35, 37]     

Fuel utilisation during prolonged low-to-moderate intensity exercise when ingesting water or carbohydrate

Previously, we examined the effects of carbohydrate (CHO) ingestion on glucose kinetics during exercise at 70% of maximum O₂ uptake ( O_2,max). Here we repeat those studies in heavier cyclists (n=6 per group) cycling for 3 h at a similar absolute O₂ uptake but at a lower (55% of O_2,max) relative exercise intensity. During exercise, the cyclists were infused with a 2-³H-glucose tracer and ingested U-¹⁴C glucoselabelled solutions of either flavoured water (H₂O) or 10 g/100 ml glucose polymer, at a rate of 600 ml/h. Two subjects in the H₂O trial fatigued after 2.5 h of exercise. Their rates of glucose appearance (R _a) declined from 2.9±0.6 to 2.0±0.1 mmol/min (mean ± SEM) and, as their plasma glucose concentration [Glu] declined from 4.7±0.2 to below 3.5±0.2 mM, their rates of glucose oxidation (R _ox) and fat oxidation plateaued at 2.7±0.4 and 1.7±0.1 mmol/min respectively. In contrast, all subjects completed the CHO trial. Although CHO ingestion during exercise reduced the final endogenousR _a from 3.4±0.6 to 0.9±0.3 mmol/min at the end of exercise, it increased totalR _a to 5.5±0.5 mmol/min (P<0.05). A higher totalR _a with CHO ingestion raised [Glu] from 4.3±0.3 to 5.3±0.1 mM and acceleratedR _ox from 3.5±0.2 to 5.9±0.2 mmol/min after 180 min of exercise (P<0.05). The increased contribution to total energy production from glucose oxidation (34±1 vs. 20±1 %) decreased energy production from fat oxidation from 51±2 to 40±5% (P=0.08) and produced patterns of glucose, muscle glycogen (plus lactate) and fat utilisation similar to those during exercise at 70% of ( O_2,max). Thus, CHO ingestion is necessary to sustain even prolonged, low to moderate intensity exercise and when ingested, it suppresses the higher relative rates of fat oxidation usually observed at exercise intensities less than 60% of O_2,max.     

Effect of sprint interval training on circulatory function during exercise in sedentary, overweight/obese women

Very high-intensity, low-volume, sprint interval training (SIT) increases muscle oxidative capacity and may increase maximal oxygen uptake ( [(V)\dot]\textO _{2 \textmax} {\dot{V}\text{O}}_{{ 2 {\text{max}}}} ), but whether circulatory function is improved, and whether SIT is feasible in overweight/obese women is unknown. To examine the effects of SIT on [(V)\dot]\textO _{2 \textmax} {\dot{V}\text{O}}_{{ 2 {\text{max}}}} and circulatory function in sedentary, overweight/obese women. Twenty-eight women with BMI > 25 were randomly assigned to SIT or control (CON) groups. One week before pre-testing, subjects were familarized to [(V)\dot]\textO _{2 \textmax} {\dot{V}\text{O}}_{{ 2 {\text{max}}}} testing and the workload that elicited 50% [(V)\dot]\textO _{2 \textmax} {\dot{V}\text{O}}_{{ 2 {\text{max}}}} was calculated. Pre- and post-intervention, circulatory function was measured at 50% of the pre-intervention [(V)\dot]\textO _{2 \textmax} {\dot{V}\text{O}}_{{ 2 {\text{max}}}} , and a GXT was performed to determine [(V)\dot]\textO _{2 \textmax} {\dot{V}\text{O}}_{{ 2 {\text{max}}}} . During the intervention, SIT training was given for 3 days/week for 4 weeks. Training consisted of 4–7, 30-s sprints on a stationary cycle (5% body mass as resistance) with 4 min active recovery between sprints. CON maintained baseline physical activity. Post-intervention, heart rate (HR) was significantly lower and stroke volume (SV) significantly higher in SIT (−8.1 and 11.4%, respectively; P < 0.05) during cycling at 50% [(V)\dot]\textO _{2 \textmax} {\dot{V}\text{O}}_{{ 2 {\text{max}}}} ; changes in CON were not significant (3 and −4%, respectively). Changes in cardiac output ( [(\textQ)\dot] {\dot{\text{Q}}} ) and arteriovenous oxygen content difference [(a − v)O₂ diff] were not significantly different for SIT or CON. The increase in [(V)\dot]\textO _{2 \textmax} {\dot{V}\text{O}}_{{ 2 {\text{max}}}} by SIT was significantly greater than by CON (12 vs. −1%). Changes by SIT and CON in HR_max (−1 vs. −1%) were not significantly different. Four weeks of SIT improve circulatory function during submaximal exercise and increases [(V)\dot]\textO _{2 \textmax} {\dot{V}\text{O}}_{{ 2 {\text{max}}}} in sedentary, overweight/obese women.     

Influence of fiber,xylitol and fructose in enteral formulas on glucose and lipid metabolism in normal subjects

Summary To verify the benofit of nonglucose carbohydrates and fiber in enteral formula diets we studied the postprandial metabolism of eight healthy subjects after the intake of two helpings (25 g carbohydrates each) of five commonly used enteral formulas over 4 h. There were no significant differences in postprandial concentrations of blood glucose among the formulas. The area under the curve of postprandial insulin values, however, was significantly smaller after consumption of the fructose-containing formula (1948±285 U min ml^–1, P<0.05) than after fiber-free (3222 ±678 U min ml^–1) or two fiber-containing products (2664±326 U min ml^–1, P<0.05; and 3040±708 U min ml^–1, P<0.05). The insulin area of the xylitol-containing formula (2307±364 U min ml^–1) was significantly smaller compared to the fiber-free product (P<0.05). In addition, we found the postprandial increase in triglycerides to be significantly higher after the xylitol-containing formula (from 0.93±0.14 to 1.25±0.22 mmol/1) than after the fiber-free product (from 0.82±0.13 to 0.97±0.16 mmol/1, P<0.05) or the two fiber-containing products (from 0.88±0.16 to 0.96±0.18 mmol/1, P<0.05; and from 0.80±0.08 to 0.95±0.10 mmol/l, P<0.05). We conclude that a patient with type 11 diabetes may benefit from replacing glucose and glucose-equivalent carbohydrates with fructose or xylitol.Abbreviation IAB area under curve of current insulin values minus baseline insulin values     

Effects of elevated plasma adrenaline levels on substrate metabolism, effort perception and muscle activation during low-to-moderate intensity exercise

The aim of this study was to differentiate the role of raised plasma adrenaline (Adr) concentrations from sympathoadrenal activation associated with moderate-intensity exercise, on muscle activation, cardiopulmonary responses, fuel metabolism, and ratings of perceived exertion (RPE) during low-intensity exercise. Two groups of subjects (MOD, n=6; LOW, n=7) cycled on two occasions for 90 min. MOD cycled at 68% VO_2max with saline infusion, and at 34% VO_2max with Adr infusion. LOW cycled twice at 34% VO_2max, with either Adr or saline infusion. Infusions (0.015 g Adr/kg/min) started at 15 min and increased plasma [Adr] somewhat higher than during exercise at 68% VO_2max (~1.9 vs. 1.4 nM, at 75 min). Mean plasma glucose and lactate concentrations during LOW were significantly higher with Adr than saline infusion (5.1±0.6 vs. 4.4±0.3 mmol/l, P<0.01 and 2.1±0.8 vs. 1.3±0.5 mmol/l, P<0.01, respectively). Elevated [Adr], without increased exercise intensity, did not alter glycogenolysis. There were also no effects of Adr infusion at 34% VO_2max on heart rate, oxygen consumption, [FFA], respiratory exchange ratio, intramuscular triglyceride utilization, muscle activation or RPE. In conclusion, elevated [Adr] similar to those found during moderate-intensity exercise increased plasma glucose and lactate availability, but did not alter intramuscular fuel utilization, effort perception or muscle activation.     

The effect of hypoosmolarity on the electrical properties of Madin Darby canine kidney cells

The present study has been performed to test for the effect of hypotonic extracellular fluid on the electrical properties of Madin Darby canine kidney (MDCK)-cells. The volume of suspended MDCK-cell is 1,892±16 fl (n=8) in isotonic (298.7 mosmol/l) extracellular fluid. Exposure of the cells to hypotonic (230.7 mosmol/l) extracellular fluid is followed by cellular swelling to 2,269±18 fl (n=4) and subsequent volume regulatory decrease to 2,052±22 fl (n=4) within 512 s. Volume regulatory decrease is abolished by quinidine (1 mmol/l) and by lipoxygenase inhibitor nordihydroguaiaretic acid (50 mol/l). The potential difference across the cell membrane averages –53.6±0.9 mV (n=49) in isotonic extracellular perfusates. Reduction of extracellular osmolarity depolarizes the cell membrane by +25.7±0.8 mV (n=67), reduces the apparent potassium selectivity of the cell membrane, from 0.55±0.07 (n=9) to 0.09±0.01 (n=26), and increases the apparent chloride selectivity from close to zero to 0.34±0.02 (n=21). Potassium channel blocker barium (1 mmol/l) depolarizes the cell membrane by +15.2±1.1 mV (n=13). In the presence of barium, reduction of extracellular osmolarity leads to a further depolarization by +14.0±1.4 mV (n=12). Addition of chloride channel blocker anthracene-9-COOH (1 mmol/l) leads to a hyperpolarization of the cell membrane by –6.7±2.2 mV (n=11). In the presence of anthracene-9-COOH, reduction of the extracellular osmolarity leads to a depolarization by +22.4±1.7 mV (n=11). Application of 1 mmol/l quinidine depolarizes the cell membrane to –6.6±0.5 mV (n=8) and virtually abolishes the effect of reduced extracellular osmolarity on cell membrane potential. Nordihydroguaiaretic acid (50 mol/l), a substance known to inhibit lipoxygenase, increases steady state cell membrane potential in isotonic extracellular fluid to –58.8±1.8 mV (n=10) and blunts the depolarizing effect of hypotonic extracellular fluid (+5.4±1.5 mV,n=10). In conclusion, exposure of MDCK-cells to hypotonic media depolarizes the cell membrane by activation of a conductive pathway, which is insensitive to both barium and anthracene-9-COOH. The conductive pathway is possibly activated by leucotrienes.Parts of this work were presented at the 8th International Symposium on Biochemical Aspects of Kidney Function, Dubrovnik, 1986.     

阿托伐他汀联合低分子肝素治疗短暂性脑缺血临床疗效

目的 探讨阿托伐他汀联合低分子肝素治疗短暂性脑缺血的临床疗效及对患者凝血功能的影响。方法 选取2013年6月~2018年5月我院收治的短暂性脑缺血患者110例,随机分为观察组和对照组,各55例,对照组使用阿托伐他汀治疗,观察组患者在此基础上使用低分子肝素联合治疗。比较两组临床疗效、治疗前后凝血功能、血脂水平和不良反应情况。结果 观察组总有效率为95.12%,高于对照组的75.61%,差异有统计学意义（P＜0.05）;治疗后观察组凝血功能改善优于对照组,差异有统计学意义（P＜0.05）;治疗后,观察组HDL-C水平高于对照组[（1.62±0.11）mmol/L vs（1.31±0.23）mmol/L],差异有统计学意义（P＜0.05）;TC[（5.09±0.43）mmol/L vs（5.92±0.61）mmol/L]、TG[（2.12±0.16）mmol/L vs（2.67±0.22）mmol/L]、LDL-C[（3.16±0.69）mmol/L vs（4.37±0.46）mmol/L]均低于对照组,差异有统计学意义（P＜0.05）;两组不良反应发生率比较,差异无统计学意义（P＞0.05）。结论 阿托伐他汀联合低分子肝素治疗短暂性脑缺血疗效显著,可明显改善患者凝血功能和血脂水平,且不增加不良反应,安全性较好。     

Effects of dinitrophenol on active-transport processes and cell membranes in the Malpighian tubule of Formica

In Formica Malpighian tubules KCl secretion is driven by a V-type H⁺ ATPase in the luminal membrane in parallel with a H⁺/K⁺ antiporter. The effect of the protonophore dinitrophenol (DNP) was investigated on the isolated, symmetrically perfused tubule. DNP was applied in two different concentrations: 0.2 mmol/l and 1 mmol/l. The effects were fast and rapidly reversible. The equivalent short-circuit current (I _sc) was reduced significantly to respectively 25±3% Cn=4) and –3±7% (n=11) of the control value when 0.2 mmol/ l or 1 mmol/l was added to the bath. When 1 mmol/l DNP was applied the transepithelial resistance (R _te) decreased significantly to 74±11% of the control value (n=11), and the luminal over basolateral voltage divider ratio (VDR), providing an estimate of luminal over basolateral membrane resistance, decreased to 37±12% of the control (n=6). A concentration of 1 mmol/l DNP was also applied from the lumen. The decrease in I _sc was significant, but much less pronounced (74±5% of control; n=6) and no significant changes in R _te and VDR were observed. It is argued that, when the concentration in the bath is high enough, DNP may cross the cell and have a protonophoric effect not only on the mitochondria but also across the luminal cell membrane explaining the drop in transepithelial and in relative luminal membrane resistance. The diminished effectiveness of DNP, when applied from the luminal side, suggests that the luminal membrane is somehow less permeable to toxic substances, but that DNP very rapidly enters the cell via the basolateral membrane and may bring about an initial protonophoric effect across this membrane.