Comprehensive profiling of α-glucosidase inhibitors from the leaves of Rubus suavissimus using an off-line hyphenation of HSCCC,ultrafiltration HPLC-UV-MS and prep-HPLC

The leaves of Rubus suavissimus (also called “Chinese sweet tea”) is used not only as a beverage tea and food additive but also as a folk herbal medicine for the treatment of diabetes mellitus. To systematically investigate its material foundation of efficacy for treating diabetes, herein, a hyphenated strategy by off-line coupling high-speed countercurrent chromatography, ultrafiltration HPLC-UV-MS and prep-HPLC was developed. And thus, α-glucosidase inhibitors from Rubus suavissimus leaves was comprehensively profiled, purified and characterized. As a result, twenty-six compounds were identified as potential α-glucosidase inhibitors and favorably isolated by prep-HPLC. Their structures were identified via UV, MS, and ¹H-NMR. Notably, fourteen compounds, including protocatechuic acid (1), myketin (3), epicatechin (4), vanillic acid (6), apigenin (11), catechin (12), ferulic acid (15), luteolin (16), 3, 3′-di-O-methylellagic acid (17), chlorogenic acid (19), 3, 3′-di-O-methylellagic acid-4′-O-β-D-glucoside (20), cinnamic acid (21), syringate (24) and ethylbrevifolin-carboxylate (25), were reported in leaves of Rubus suavissimus for the first time. In addition, α-glucosidase inhibitory activities of compounds 1–26 were evaluated, and eighteen compounds exhibited stronger α-glucosidase inhibitory activities than acarbose (IC₅₀ value at 214.24 ± 3.48 μg/mL, positive control). The results indicated that the proposed method is a highly efficient strategy for comprehensive profiling and purification of bioactive target compounds, including both major and minor components, from natural products.     

Comparison of complications according to incision types in nipple-sparing mastectomy and immediate reconstruction

BackgroundNipple-sparing mastectomy (NSM), followed by immediate reconstruction (IR) of the breast, has become a preferred surgical procedure with good cosmesis results and patient satisfaction. However, nipple-areolar complex (NAC) ischemia and necrosis remain major problems after NSM and IR.MethodsWe retrospectively analyzed patients who underwent NSM and IR at Gangnam Severance Hospital from January 2009 to June 2018. We compared the patient characteristics and complication rate among three different incisions (inframammary fold [IMF], radial, periareolar). Additionally, we identified the risk factors of NAC necrosis.ResultsData from 290 eligible breasts in 275 patients were analyzed. Patients with IMF incision had relatively lower breast weights. The overall complication rate was the highest with periareolar incision and the lowest with IMF incision (42.6% vs. 18.8%, p < 0.001). The rate of NAC ischemia or necrosis was significantly different among the three incisions (9.7%, 17.0%, and 31.1% in IMF, radial, and periareolar, respectively; p < 0.001). Moreover, surgical treatments were more frequently needed in patients with periareolar incision. Periareolar incision, short distance from the tumor to the nipple base, and large breast weight were independent risk factors of NAC ischemia or necrosis in multivariable analysis.ConclusionsCompared with IMF incision, periareolar incision was associated with higher incidences of surgical complications and NAC necrosis. Careful consideration is needed when planning NSM in patients with a large breast volume or a tumor close to the nipple.     

Impact of sleeve gastrectomy on hip structural analysis in adolescents and young adults with obesity

BackgroundSleeve gastrectomy (SG), the most commonly performed metabolic and bariatric surgery, is associated with reductions in areal bone mineral density at multiple sites, and changes in bone structure at the distal radius and tibia without reductions in strength estimates at these peripheral sites. Data are lacking regarding effects on hip strength estimates.ObjectiveTo evaluate effects of SG on measures of hip structural analysis in adolescents and young adults over 12 months using dual-energy x-ray absorptiometry.SettingsTranslational and Clinical Research Center.MethodsWe enrolled 48 youth 14- to 22-years old with moderate-to-severe obesity; 24 underwent SG and 24 controls were followed without surgery (18 females, 6 males in each group). Hip structure was assessed using dual-energy x-ray absorptiometry at baseline and 12 months. Analyses are adjusted for age, sex, race, and the baseline bone measure.ResultsThe SG group lost 25.9% weight versus .3% in controls. Compared with controls, SG had reductions in narrow neck, intertrochanteric and femoral shaft bone mineral density Z-scores (P ≤ .012). Furthermore, SG had greater reductions in narrow neck and intertrochanteric region (but not femoral shaft) cross-sectional area, cortical thickness, cross-sectional moment of inertia and section modulus, and increases in buckling ratio (P ≤ .039). Differences were attenuated after adjusting for 12-month body mass index change. At 12 months, differences were minimal after adjusting for age, sex, race, and weight.ConclusionsOver 12 months, SG had negative effects at the narrow neck and intertrochanteric regions of the hip, but not the femoral shaft. Reduced body mass index may compensate for these deleterious effects on bone.     

Liquid chromatography as candidate reference method for the determination of vitamins A and E in human serum

BackgroundOwing to the increasing interest in public health research of antioxidant micronutrients and the inaccuracy of routine serum concentrations of the fat‐soluble vitamins A (retinol) and E (DL‐α‐tocopherol) measurements, we developed a reliable, highly sensitive, robust and rapid method for the quantification of two clinically important lipophilic antioxidants in serum using a reverse‐phase HPLC/DAD method.MethodSample preparation and analytical conditions that would affect extraction efficiency and quantitative results of vitamins A and E were investigated and optimized. Vitamins A and E were extracted from serum via liquid‐liquid extraction (LLE). After adequate sample preparation, the samples were injected directly into the HPLC system with diode‐array detector (DAD). Chromatographic separation was completed in 7 minutes for vitamins A and E. With vitamin A acetate and vitamin E acetate as internal standards, the method was applied to the measurement of vitamins A and E in human serum.ResultsWe evaluated method linearity, accuracy (recovery rate and trueness), precision, carryover, limit of quantitation and limit of detection, and measurement uncertainty. The method was evaluated for trueness using NIST Standard Reference Material SRM 968f. The serum concentration of the studied compounds had a good linear relationship in the range of 0.05 ~ 3.0 μg/mL concentration (r ＝ 0.9998), with 0.0077 μg/mL detection limit and 0.025 μg/mL quantitative limit for vitamin A, respectively, and 1.0 ~ 60.0 μg/mL concentration (r ＝ 0.9999), with 0.40 μg/mL detection limit and 0.50 μg/mL quantitative limit for vitamin E, respectively. The intra‐ and inter‐assay coefficients of variation were calculated by using three concentrations (1, 2, and 3) of the studied compounds in human serum samples. Intra‐assay and inter‐assay precision were 1.23%‐4.97% and 0.97%‐3.79% for vitamin A, respectively, and 0.64%‐4.07% and 0.81%‐5.96% for vitamin E, respectively. The average recovery rates were 100.98% for vitamin A, and 99.21% for vitamin E, respectively. The carryover rate of vitamins A and E was below 1%. As for the evaluation of accuracy, the biases were <± 5% by comparing with NIST standard reference material SRM 968f.ConclusionThe method is a simple sample treatment procedure for the determination of fat‐soluble vitamins A and E in human serum with high sensitivity and specificity. The proposed method could be recommended as a candidate reference method for the determination of serum concentrations of the fat‐soluble vitamins A and E in human serum.     

坐骨重叠征与发育性髋关节脱位手术后再脱位的相关性分析

目的提出坐骨重叠征(ischium overlap sign,IOS)的概念,并分析其与发育性髋关节脱位(developmental dysplasia of the hip,DDH)手术后再脱位的关系。方法回顾性分析2013年9月至2017年5月山东大学附属省立医院治疗的88例(105髋)DDH患儿病例资料,其中男童16例、女童72例;平均年龄12(5~24)个月,平均随访时间34(15~59)个月;双侧17例,左侧63髋,右侧42髋;1髋为髋臼发育不良,11髋半脱位,93髋全脱位。术中行髋关节造影检查,按照Bowen标准选择闭合或切开复位石膏固定术。IOS是指在人类位髋关节造影平片上股骨头软骨内缘与坐骨外缘的重叠关系,二者重叠为Ⅰ度,相接为Ⅱ度,分离为Ⅲ度。将93髋全脱位按照IOS分度进行分组,比较组间再脱位发生率。结果 1髋髋臼发育不良和11髋半脱位者IOS均为Ⅰ度。93髋全脱位中IOSⅠ度14髋,Ⅱ度39髋,此两组均行闭合复位石膏固定,无再脱位病例;Ⅲ度40髋中,闭合复位石膏固定17髋,6髋再脱位;切开复位石膏固定23髋,1髋再脱位。本研究发现Ⅲ度组的再脱位发生率(7/40,17.5%)高于其他两组(P=0.006)。IOS为Ⅲ度的40髋中,闭合复位的再脱位发生率(6/17,35.3%)高于切开复位(1/23,4.4%),差异有统计学意义(X^2=4.518,P=0.034)。结论 IOS与DDH术后再脱位有一定的关系,IOS为Ⅲ度的髋关节如行闭合复位,再脱位的风险较高。     

Some Preformulation Studies of Pyruvic Acid and Other α-Keto Carboxylic Acids in Aqueous Solution: Pharmaceutical Formulation Implications for These Peroxide Scavengers

The purpose of this study is to assess some of the variables determining the aldol-like condensation of pyruvic acid (1), a peroxide scavenger, in aqueous solution to parapyruvic acid and higher oligomers. Its stability is compared to 3 other α-keto carboxylic acids, 2 with sterically hindered methylene groups alpha to the keto functionality (2-3) and phenylglyoxylic acid (4) with no methylene group. High-performance liquid chromatography, nuclear magnetic resonance, and liquid chromatography mass spectroscopy techniques are used in the kinetics and product analyses. 1 condensation is concentration dependent and base catalyzed above pH 7, consistent with the reaction mechanism proceeding through the attack of the fraction of the methylene group, alpha to the keto group, in its anionic form, at the keto group of a second molecule of 1. The major product is confirmed to be parapyruvic acid, but higher-order oligomers are also observed. All 3 of the other α-keto carboxylic acids 2-4 are considerably less reactive, with 4 being completely stable. Stable solutions of 1 can be prepared by the use of relatively dilute solutions maintained at slightly acidic pH values. 1 prevents the oxidation of methionine on addition of hydrogen peroxide.