不同机种军事飞行员运动心肺功能研究

目的了解不同机种军事飞行员运动心肺功能有无差异。方法飞行员分为高性能战斗机和普通战斗机两组,采用意大利COSMED运动心肺功能测试仪,选择自行车功率计运动方式,以25 W/min功率递增速率极量运动方案,进行运动心肺功能测试,比较两组运动心肺功能数据的主要指标。结果两组飞行员各207例完成运动心肺功能测试,两组的年龄、身高、体质量和体质量指数差异均无统计学意义(P均>0.05)。两组数据的主要指标中,除了峰值氧脉搏[高性能战斗机组(15.36±2.43)mL/bpm,普通战斗机组(14.95±2.13)mL/bpm]差异有统计学意义(P=0.038),其他差异均无统计学意义,而且各指标差异幅度均较小,高性能战斗机飞行员组的峰值氧脉搏高于普通战斗机组2.74%。结论综合比较,高性能战斗机和普通战斗机飞行员的运动心肺功能无明显差异,提示两组飞行员日常有氧运动训练效果一致,在转换飞行机种时,可以不受运动心肺功能的限制。     

Associations between serum amino acids and incident type 2 diabetes in Chinese rural adults

Background and aimsSome amino acids (AAs) may be associated with type 2 diabetes (T2DM). This study aimed to determine the associations of individual AAs with the development of T2DM in rural Chinese adults.Methods and resultsA cohort study of 1199 individuals aged 18 years or older was conducted from 2006 to 2008 in a rural community of Deqing, China, a repeated survey was done in 2015 and data linkage with the electronic health records system was performed each year for identifying new T2DM cases. A high-performance liquid chromatography approach was used to measure the baseline serum concentrations of 15 AAs. Cox proportional hazards models were used to examine the associations between AAs and the risk of incident T2DM. A total of 98 new T2DM cases were identified during the follow-up of 12 years on average. Among 15 AAs, proline was associated with an increased risk of incident T2DM after adjusted for age, sex, body mass index, fasting plasma glucose, family history of T2DM, smoking status, alcohol use, and history of hypertension, the adjusted hazard ratio for 1-standard deviation increment was 1.20 (95% confidence interval: 1.00, 1.43). The association tended to be more marked in subjects younger than 60 years and overweight/obese subjects. Among participants without hypertension, proline and phenylalanine were associated with an increased risk of incident T2DM, while aspartic acid was associated with a decreased risk.ConclusionSerum proline was associated with the risk of incident T2DM in rural Chinese adults and might be a potential predictor.     

Levels of gingival tissue platelet activating factor after conventional and regenerative periodontal surgery

The hypothesis, a relationship between gingival tissue platelet activating factor (PAF) levels and healing after periodontal surgery, was tested by measuring PAF levels in gingival tissues collected from sites that had undergone flap surgery and guided tissue regeneration (GTR) or flap surgery alone. Using a split-mouth design, 20 intrabony defects were randomly assigned to treatment with flap surgery and GTR (group 1) or with flap surgery alone (group 2). Gingival tissue samples were obtained at surgery (baseline) and at 6-month follow-up evaluation visit. One half of each sample was used for analysis of PAF levels by high-performance liquid chromatography, and the other half of the sample was used for histomorphometric analysis that included measurements of number and diameter of blood vessels. PAF levels and diameter of blood vessels were significantly decreased (p < 0.01), and the number of blood vessels was significantly increased (p < 0.05) in both groups after 6 months compared to the baseline values. Postoperative number of blood vessels were significantly higher in group 1 (p < 0.05), whereas there was no significant difference in postoperative PAF levels between the two groups (p > 0.05). Based on the reported results, it is suggested that a decrease in gingival PAF levels might be found after conventional and regenerative periodontal surgery.     

Modifying current thin-film microextraction (TFME) solutions for analyzing prohibited substances: Evaluating new coatings using liquid chromatography

For identifying and quantifying prohibited substances, solid-phase microextraction (SPME) continues to arouse interest as a sample preparation method. However, the practical implementation of this method in routine laboratory testing is currently hindered by the limited number of coatings compatible with the ubiquitous high-performance liquid chromatography (HPLC) systems. Only octadecyl (C₁₈) and polydimethylsiloxane/divinylbenzene ligands are currently marketed for this purpose. To address this situation, the present study evaluated 12 HPLC-compatible coatings, including several chemistries not currently used in this application. The stationary phases of SPME devices in the geometry of thin film-coated blades were prepared by applying silica particles bonded with various functional ligands (C₁₈, octyl, phenyl-hexyl, 3-cyanopropyl, benzenesulfonic acid, and selected combinations of these), as well as unbonded silica, to a metal support. Most of these chemistries have not been previously used as microextraction coatings. The 48 most commonly misused substances were selected to assess the extraction efficacy of each coating, and eight desorption solvent compositions were used to optimize the desorption conditions. All samples were analyzed using an HPLC system coupled with triple quadrupole tandem mass spectrometry. This evaluation enables selection of the best-performing coatings for quantifying prohibited substances and investigates the relationship between extraction efficacy and the physicochemical characteristics of the analytes. Ultimately, using the most suitable coatings is essential for trace-level analysis of chemically diverse prohibited substances.     

刺五加叶中金丝桃苷的薄层鉴别和含量测定

目的：以金丝桃苷为指标成分,建立刺五加叶的薄层定性和含量测定的方法。方法：采用薄层色谱法对刺五加叶中金丝桃苷进行定性鉴别,并用高效液相色谱法进行含量测定,色谱柱：Kromasil 100-5C18色谱柱（4.6mm×250mm）;流动相：甲醇-0.1％冰醋酸水溶液(35：65);流速：0.8mL/min;检测波长：360nm;柱温：30℃;进样量：10μL。结果：刺五加叶金丝桃苷的薄层鉴别特征明显,金丝桃苷在0.13～0.78μg范围内具有良好线性关系,r=0.9994,平均回收率为98.17％,RSD为1.02％（n=5）。结论：此方法简便、快速、准确,可用于刺五加叶的质量控制。     

Novel colloidal associations of soyasaponins and lipid components (DPPC,cholesterol) as potential adjuvants for vaccines

Soyasaponins from soybean (Glycine max) represent promising new potent adjuvants for vaccine research because of their immunostimulating properties and weak hemolytic activity. In the present study, saponin microstructures of soyasaponins (soyasaponin Bb, soyasaponin Ab) with lipid components (cholesterol, DPPC (dipalmitoylphosphatidylcholine)) were designed by the lipid film method. In interaction studies between soyasaponins (soyasaponin Ab/Bb) and Langmuir monolayers (model membranes), composed of cholesterol and DPPC, marked interactions between soyasaponins and a pure cholesterol monolayer were observed. No interaction was detected for soyasaponins with a pure DPPC monolayer. The intercalation of soyasaponins in a mixed DPPC/cholesterol (3:1, w/w) monolayer was only observed for the monodesmosidic soyasaponin Bb whereas the second sugar chain of the bidesmosidic soyasaponin Ab impaired the access to the monolayer. Transmission electron microscopy was used for visualizing particle formation of soyasaponins and lipid components. Pseudo-binary systems (soyasaponin Ab/Bb, cholesterol) formed colloidal associations built up from ring-like subunits in the nanometer size range. In pseudo-ternary systems (soyasaponin, cholesterol, DPPC) soyasaponin Bb attacked the liposomal membrane by forming colloidal associations. Colloidal associations in pseudo-ternary systems with soyasaponin Ab, cholesterol and a phospholipid were only observed in the presence of PE (phosphatidylethanolamine) instead of DPPC. In an MTT assay with a HaCaT cell line (keratinocyte cell line) the cell viability was neither affected by the soyasaponins nor by the corresponding formulations. Both the pure soyasaponin solution and the saponin formulations may be promising adjuvant systems for the intradermal vaccine application. Furthermore, interaction studies between the model antigen ovalbumin and colloidal associations of saponins and cholesterol using MST (Microscale Thermophoresis) gave first indications of an antigen binding to colloidal associations. Ex vivo T-cell proliferation in the presence of soyasaponin Ab was confirmed.     

A Validated High-performance Liquid Chromatograhy Method for Estimation of Ferulic Acid in Asafoetida and Polyherbal Preparation

A high-performance liquid chromatography method was developed for the estimation of ferulic acid from asafoetida and a polyherbal preparation. The separation was carried out on HiQSil ODS C-18 column with a mobile phase of acetonitrile: 10% acetic acid (20:80 v/v). The developed method was validated as per International Conference of Harmonization guidelines for various parameters such as accuracy, precision, linearity, limit of detection, limit of quantification and specificity; and found to be reliable. Linear regression analysis showed a good corelation between peak area and concentration with a corelation coefficient r²=0.996 in the range 200-7000 ng/ml. The developed method can be utilized for standardization of herbal formulation comprising asafoetida.     

Comparison of in-house and commercial 16S rRNA sequencing with high-performance liquid chromatography and genotype AS and CM for identification of nontuberculous mycobacteria

Sequencing of the 16S gene or other targets and line probe assay are in wide use for the identification of nontuberculous mycobacteria. We compared in-house and commercial sequencing with 3 sequence databases against high-performance liquid chromatography (HPLC) and line probe assay (HAIN Genotype AS and CM) for the identification of 84 reference, clinical, and unique strains representing 41 species. Consensus of methods was used as reference standard. Sequencing identification was more specific and flexible than HPLC, but it was limited by database content and quality as well as fragment length. No one database satisfied all requirements. In-house sequencing was lower in cost than commercial sequencing or line probe assay.     

HPLC-UV法测定环磷酰胺血药浓度及其临床应用

目的：建立测定环磷酰胺血药浓度的高效液相色谱法。方法：血浆样品经碱性乙腈沉淀蛋白后,以乙腈-水溶液（30∶70）为流动相,流速1.2 mL/min,采用XterraRP18色谱柱分离,在197 nm波长下进行检测,柱温30℃。结果：环磷酰胺在1.0～32.0 mg/L浓度范围内与峰面积呈良好的线性关系（r=0.9999,n=5）,提取回收率90.07%～91.44%,日内、日间精密度（RSD）均〈10%。血浆中环磷酰胺最低检测浓度为0.1 mg/L。结论：本文建立的方法灵敏度高,选择性好,简便、快速、准确,适用于临床样本环磷酰胺的血浆浓度测定和药代动力学研究,可为临床实施个体化给药提供参考。     

Decreased blood riboflavin levels are correlated with defective expression of RFT2 gene in gastric cancer

AIM: To investigate the relationship between blood riboflavin levels and riboflavin transporter 2 (RFT2) gene expression in gastric carcinoma (GC) development.METHODS: High-performance liquid chromatography was used to detect blood riboflavin levels in patients with GC. Real-time fluorogenic quantitative polymerase chain reaction and immunohistochemistry were used to analyze the expression of RFT2 mRNA and protein in samples from 60 GC patients consisting of both tumor and normal tissue.RESULTS: A significant decrease in the RFT2 mRNA levels was detected in GC samples compared with those in the normal mucous membrane (0.398 ± 0.149 vs 1.479 ± 0.587; P = 0.040). Tumors exhibited low RFT2 protein expression (75%, 16.7%, 8.3% and 0% for no RFT2 staining, weak staining, medium staining and strong staining, respectively), which was significantly lower than that in the normal mucous membrane (10%, 16.7%, 26.7% and 46.7% for no RFT2 staining, weak staining, medium staining and strong staining, respectively; P < 0.05). Tumors with low RFT2 expression were significantly associated with tumor stage and histological grade. Moreover, a significantly decrease in Uyghur patients was observed compared with Han patients. However, other parameters-gender, tumor location and lymph node metastasis-showed no significant relationship with RFT2 expression. Blood riboflavin levels were reverse correlated with development of GC (1.2000 ± 0.97 569 ng/mL in high tumor stage patients vs 2.5980 ± 1.31 129 ng/mL in low tumor stage patients; P < 0.05). A positive correlation of plasma riboflavin levels with defective expression of RFT2 protein was found in GC patients (χ² = 2.619; P = 0.019).CONCLUSION: Defective expression of RFT2 is associated with the development of GC and this may represent a mechanism underlying the decreased plasma riboflavin levels in GC.