MicroRNA expression profile and lipid metabolism characteristics in liver of rat undergoing high-fat diet

This study aimed to investigate the microRNA expression profile and the characteristics of lipid metabolism in the livers of rats undergoing a high-fat diet. Fifty male Sprague-Dawley (SD) rats were divided into a standard chow group (C group, N = 10) and a high-fat diet group (H group, N = 40). After 12 weeks, the rat body weight, body length, fat mass, and serum lipid concentration were measured. The expression profile of microRNAs and the gene and protein expression levels involved in lipid metabolism in rat liver were detected. Body fat and serum lipid concentrations were all significantly higher in the H group than those in the C group (p < 0.05 or p < 0.01). The expression of 10 microRNAs showed significant differences in the liver (p < 0.05). In particular, the let-7 family expression levels significantly increased (p < 0.05) in the H group compared with those in the C group. Compared with the C group, the high-fat diet resulted in low FAS, CPT1A, and ApoAI mRNA expression levels (p < 0.05 or p < 0.01) and high PPARα and FAT/CD36 mRNA expression levels in the H group rat liver (p < 0.01). Meanwhile, the protein PPARα, FAS, CPT1A, FAT/CD36, and ApoAI expression levels were all significantly lower in the H group than those in the C group (p < 0.05 or p < 0.01). In conclusion, the high-fat diet increased the body fat and serum lipid levels and altered the 10 microRNA expression levels in the liver. The high-fat diet may affect hepatic carbohydrate metabolism and increase ectopic fat accumulation through let-7 family overexpression. The high-fat diet for 12 weeks decreased lipid metabolism level in the liver, thereby decreasing fatty acid synthesis, oxidation, and transport by down-regulating the PPARα, FAS, CPT1A, FAT/CD36, and ApoAI protein levels.     

Directly fast detection of digoxin in the serum sample by the synthetic receptor sensor

A novel biosensor (the synthetic receptor sensor) employing the molecular imprinted technology for the digoxin analysis is investigated. The molecularly imprinted polymer (MIP) modified electrode can specifically bind to the analyte in the sample without sample pretreatment. The digoxin analyzed by the MIP sensor was carried out in 1 mM K₃Fe(CN)₆ solution with the cyclic voltammetry. In the system, the K₃Fe(CN)₆³⁻/Fe₂(CN)₆⁴⁻ redox couple was taking place. When the solution contains the digoxin, the MIP on the electrode will bind the digoxin. Further the redox system is interrupted and the peak current is decreased according to the digoxin concentration increasing. Digoxin is a glycosylated steroid-like drug. It is important for the heart disease treatment. However, since the digoxin toxic level is low, the drug remains in the blood sample must be monitored frequently. The device possesses many advantages, such as high specific recognition properties, good chemical and mechanical stability, simplicity and low cost of preparation, sensitive and label free determination. The reproducibility is good (CV < 5). The linear relationship between the digoxin concentration and the current is 1.28–128 nM, and a detection limit of 1.28 nM is achieved. The detection time is less than 5 min.     

新生儿缺氧缺血性脑病与血清及脑脊液葡萄糖水平变化的研究

目的研究新生儿缺氧缺血性脑病(HIE)与血清及脑脊液葡萄糖水平的变化,为HIE临床分度与治疗提供参考依据。方法对HIE患儿于急性期及恢复期各测定1次血清及脑脊液葡萄糖的含量,并以正常新生儿作为对照组。结果轻、中、重度HIE组患儿急性期血清及脑脊液葡萄糖水平分别为:(1)血清葡萄糖:(4.50±0.20);(3.80±0.21);(3.20±0.22),低于对照组:(4.80±0.25)(P值分别<0.05、0.01、0.01);(2)脑脊液葡萄糖:(4.30±0.20);(4.00±0.21);(3.50±0.20),低于对照组(4.50±0.25)(P值分别<0.05、0.01、0.01)。且临床分度愈重,血清及脑脊液葡萄糖水平降低愈明显,HIE各组间差异显著(P<0.05)。HIE各组患儿恢复期血清及脑脊液葡萄糖水平上升。结论测定HIE患儿血清及脑脊液葡萄糖含量,有助于对HIE的分度,及指导临床治疗。     

荧光光谱法研究橙皮素与牛血清白蛋白的相互作用

采用荧光光谱技术研究了橙皮素与牛血清白蛋白(BSA)的相互作用.研究发现橙皮素对BSA的荧光猝灭属于静态猝灭过程,由热力学参数焓变△rHm=-60.543 kJ·mol<'-1>,熵变△rSm-114.121J-mol<'-1>均小于零,判断橙皮素与BSA之间主要靠氧键和范德华力相结合,生成自由能变(△rGm)为负值,...     

The Distribution of Fatty Acid Biomarkers of Dairy Intake across Serum Lipid Fractions: The Prospective Metabolism and Islet Cell Evaluation (PROMISE) Cohort

Circulating fatty acids (FA) derived largely from dairy consumption have most commonly been measured in total human serum or phospholipid (PL) fractions, and have been used as validated biomarkers of dairy intake in a growing number of epidemiological studies. Nevertheless, measurement and characterization of a wider spectrum of FA biomarkers of dairy across the four major serum lipid fractions is lacking. This study aimed to (1) quantify FA biomarkers of dairy in PL, triacylglycerol (TAG), cholesteryl ester (CE), and unesterified fatty acid (FFA) serum lipid fractions; and (2) identify potential demographic and metabolic factors that may modify the proportions of these FA across serum fractions. Baseline data from 444 adults in the PROMISE cohort were analyzed. FA biomarkers, 15:0, t16:1n-7, 18:2-c9,t11, and t18:1n-7 were quantified from serum. Dairy intake was estimated using the validated Canadian Diet History Questionnaire. Our results show that t18:1n-7 was the most abundant FA biomarker in all fractions except CE, where 18:2-c9,t11 was the most abundant. Positive correlations within fractions, and across FA in the PL, CE, and FFA fractions were found, however, TAG FA were negatively correlated with the other fractions. PL and CE FA were positively associated with dairy intake, and negatively associated with markers of dysmetabolism while, in contrast, these markers were predictors of higher TAG dairy FA. This study is the first to demonstrate distinct proportions of dairy FA in different serum lipid fractions. PL and CE FA marked dairy intake in this cohort, while TAG FA appeared to be markers of dysmetabolism.