Characteristics and measurement principles of reference methods in clinical biochemistry were described.Implementation of reference systems is one of the most effective approaches to improve the accuracy and comparability of clinical laboratory test results.Reference methods are the key components of reference systems.Reference methods should have measurement uncertainties that meet the requirements of the intended use,and thus should be based on reliable measurement principles.For the well-defined biochemistry analytes,reference methods have been almost all based on instrumental analysis.Isotope dilution mass spectrometry (ID/MS) is considered most reliable and has been the major analytical principle of the reference methods.ID/MS analysis is accurate but expensive.Use of other validated instrumental analyses as reference measurement principles would be justified.

(3S)-Linalool synthase (LIS) is a key enzyme involved in the monoterpene biosynthetic pathway. Based on our previous transcriptome study, the expression level of LIS gene was exceedingly related to glycyrrhizic acid (GA) biosynthesis. Therefore, we used hairy root culturing to further investigate the effect of LIS on the GA biosynthesis. A LIS gene (GenBank accession number: MZ169552) was cloned from Glycyrrhiza uralensis. The plant binary overexpression vector pCA-LIS was constructed by gene fusion. G. uralensis hairy roots overexpressing LIS were induced by the Agrobacterium rhizogenes ATCC15834. The expression levels of LIS were analyzed by real-time quantitative PCR (RT-qPCR) and the contents of GA in hairy root lines were determined by UPLC. It was found that in the hairy root lines overexpressing LIS, the expression levels of LIS were significantly higher than that in the wild type, while the contents of GA were remarkably lower than those in the wild type and negative control. These findings indicate that the expression level of LIS is negatively correlated with the accumulation of GA. In this study, LIS was cloned from G. uralensis for the first time and the negative regulatory effect of LIS on GA biosynthesis was confirmed by reverse genetics. This work provides support for further improvement of the molecular regulatory network of GA biosynthesis in G. uralensis.

Isoliquiritigenin (ISL) is a flavonoid compound isolated from licorice. It possesses excellent antioxidant and anti-diabetic activities. This study aims to investigate the molecular mechanism underlying the alleviatory effect of ISL on energy metabolism imbalance caused by type 2 diabetes mellitus (T2DM). 8-week-old male C57BL/6J mice were used in in vivo experiments. The high-fat-high-glucose diet combined with intraperitoneal injection of streptozotocin was applied to establish T2DM animal model. All animal experiments were performed in accordance with the Institutional Guidelines of Laboratory Animal Administration issued by the Committee of Ethics at Beijing University of Chinese Medicine. HepG2 cells were used in in vitro experiments. Enzyme-linked immunosorbent assay (ELISA) and real-time quantitative polymerase chain reaction (RT-qPCR) were used to examine the protein and mRNA levels of mitochondrial function-related targets. The levels of reactive oxygen species (ROS) and mitochondrial membrane potential (MMP) in HepG2 cells were measured by the flow cytometry. Additionally, the molecular docking of ISL and key target proteins was analyzed. It was found that ISL significantly inhibited the activity of mitochondrial respiratory chain complex I and increased the protein levels of uncoupling protein 2 (UCP2) in the livers of mice and HepG2 cells. It also obviously decreased the ROS levels and increased the MMP levels in cultured HepG2 cells. In addition, ISL promoted mitochondrial biogenesis by activating proliferator-activated receptor gamma co-activator 1α (PGC-1α) and enhanced mitophagy by upregulating Parkin. It also improved mitochondrial fusion by increasing the mRNA and protein levels of mitofusin 2 (MFN2). In conclusion, ISL alleviates energy metabolism imbalance caused by T2DM through suppression of excessive mitochondrial oxidative phosphorylation and promotion of mitochondrial biogenesis, mitophagy, and fusion.

Isoliquiritigenin (ISL) is an active chalcone compound isolated from licorice. It possesses anti-inflammatory and anti-oxidative activities. In our previous study, we uncovered a great potential of ISL in treatment of type 2 diabetes mellitus (T2DM). Therefore, this study aims to reveal the mechanism underlying the alleviatory effects of ISL on T2DM-induced glycolipid metabolism disorder. High-fat-high-sugar diet (HFD) combined with intraperitoneal injection of streptozotocin (STZ) were used to establish T2DM mice model. All animal experiments were carried out with approval of the Committee of Ethics at Beijing University of Chinese Medicine. HepG2 cells were used in in vitro experiments, and sodium palmitate (SP) was applied to establish insulin resistance (IR) model cells. The effects of ISL on body weight, fasting blood glucose levels, and pathological changes in the livers of mice were examined. Enzyme-linked immune sorbent assay (ELISA) and real-time quantitative PCR (RT-qPCR) were applied to detect the regulatory effects of ISL on key targets involved in glucolipid metabolism. Additionally, molecular docking and analytical dynamics simulation methods were used to analyze the interaction between ISL and key target protein. The results indicate that ISL significantly downregulates the transcriptional levels and inhibits the activities of key enzymes involved in gluconeogenesis, including pyruvate carboxylase (PC), phosphoenolpyruvate carboxykinase (PEPCK), and fructose-1, 6-bisphosphatase (FBP). It also downregulates the transcriptional and protein levels of hepatocyte nuclear factor 4α (HNF4α) and cAMP response element binding protein (CREB), the two transcriptional factors involved in gluconeogenesis. Thus, ISL inhibits hepatic gluconeogenesis in T2DM mice. In addition, ISL reduces total cholesterol (TC) and triglyceride (TG) levels in the livers of T2DM mice. Moreover, ISL downregulates the mRNA levels of lipogenesis genes and upregulates those of genes involved in fatty acid oxidation, lipid uptake, and lipid export. In conclusion, ISL suppresses hepatic gluconeogenesis, promotes lipolysis, and restrains lipogenesis in T2DM mice, thereby improving the abnormal glycolipid metabolism caused by T2DM.

The volatile components of roots and stems of Zanthoxylum nitidum were investigated by supercritical fluid carbon dioxide extraction (SFE-CO2) and gas chromatography-mass spectrometry(GC-MS). Thirty-one and fifty-one compounds were identified in the supercritical extracts from roots and stems of Z. nitidum, respectively, and total twenty-seven compounds were the common constituents. Among them, the major constituents in root and stem supercritical extracts were spathulenol (18.49 and 26.18%), n-hexadecanoic acid (14.24% and 12.79%), ar-tumerone (6.95% and 8.88%), oleic acid (8.39% and 5.71%) and hexanoic acid (4.39% and 7.78%). The in-vitro MTT assay showed that the volatile components of roots and stems of Z. nitidum did not exhibited any cytotoxic activity against human cancer Huh-7 and normal IEC-6 cells. These results indicated the same nature of the volatile constituents in the root and stem of Z. nitidum. This investigation may provide further evidence for expansion of medicinal parts of Z. nitidum.
Animals ; Cell Line, Tumor ; Cell Survival ; drug effects ; Chromatography, Supercritical Fluid ; Drugs, Chinese Herbal ; chemistry ; isolation & purification ; toxicity ; Gas Chromatography-Mass Spectrometry ; methods ; Humans ; Mice ; Plant Roots ; chemistry ; Plant Stems ; chemistry ; Zanthoxylum ; chemistry

Zwittermicin A was purified by ion exchange resin and HPLC from supernatants of Bacillus thuringiensis.subsp.kurstaki strain D1-23 cultivation.2.89mg pure Zwittermicin A was acquired,proved by HPLC-MS.Results show that the optimized wash concentration of NH_ 4 H_ 2 PO_ 4 is 5mmol/L at first step.Next step CH_ 3 COONH_ 4 concentration is 30 mmol/L,the gradient pH is 8.0～9.5.Totally 93% Zwittermicin A can be reserved with ion exchange resin.The temperature and pH stability experiments show the half life of Zwittermicin A is 48.22 minutes in 100℃,and it is more stable in lower pH in pH 2.0～12.0.

OBJECTIVETo explore the mechanism of Astragalus injection (AI) in repairing mucous membrane by observing its effects on the proliferation, differentiation, migration as well as on intracellular content of ornithine decarboxylase (ODC) and polyamine in rat's small intestinal crypt-like cell line (IEC-6) in vitro.

METHODSAI was added in the IEC-6 cells after they had been cultured for 24 hours. Twelve hours after adding AI, the cells were collected to test the ODC mRNA level, ODC protein, ODC activity and the intracellular content of putrescine. Twenty-four hours after adding AI, the condition of cell proliferation and differentiation was observed. Another group of IEC-6 cells were injured after being cultured for 72 hours, and AI was added, the cell migration was observed at 24 hours, 48 hours and 72 hours after medication.

RESULTSAI could inhibit IEC-6 cell proliferation, promote the cell differentiation, but with no apparent effect on injured IEC-6 cell migratin. AI of 62.5-250 micrograms/ml concentration could increase the ODC mRNA level, as compared with control, the difference was significant (P < 0.05-0.01). ODC activity and intracellular content of putrescine could be gradually increased by AI in a dose-dependant manner. No effect of AI was shown on ODC protein in various dosage of AI groups.

CONCLUSIONAI could promote IEC-6 cell differentiation by means of inducing the ODC activity and biosynthesis of polyamine, but without significant effect on cell migration.

Animals ; Astragalus Plant ; Cell Differentiation ; drug effects ; Cell Division ; drug effects ; Cell Line ; Drugs, Chinese Herbal ; pharmacology ; Intestinal Mucosa ; cytology ; Intestine, Small ; cytology ; Ornithine Decarboxylase ; biosynthesis ; metabolism ; Putrescine ; metabolism ; RNA, Messenger ; biosynthesis ; Rats

Although there are many methods to estimate the early postmortal interval, more attention has been paid to the research on measuring the amount of DNA in cells. This paper introduce several different measuring ways, law of variation and application situation of DNA in cells. In addition, the result evaluation of measuring methods and application prospect is given.
DNA/analysis* ; Flow Cytometry ; Forensic Medicine ; Humans ; Kidney/chemistry* ; Liver/chemistry* ; Myocardium/chemistry* ; Postmortem Changes ; Time Factors

OBJECTIVE: To analyze the cases of anaphylactic death cases and explore the standards of judicial expertise of anaphylactic death for providing evidence for judicial expertise. METHODS: Fifty-nine cases death due to allergic reaction in Shanghai were collected. And details of medical history, clinical manifestation of anaphylactic reaction and postmortem examination findings were reviewed for all cases. RESULTS: In the 59 cases, there were 58 cases died from drug allergy, including 77.6% of them were antibiotics. The rates of treating in standard hospital and illegal clinic were 37.3% and 61.0%, respectively. The allergic symptoms were dyspnea and facial cyanosis. The time from contacting allergens to death ranged from 1 min to 3 d. The concentration of total serum IgE ranged from 50 to 576.92 IU/mL. The results of clinical manifestation and pathological anatomy had obviously changes. CONCLUSION Based on the exclusion of all other cause of death and synthetically analysis of details of cases, medical history, clinical manifestation and anatomy, the conclusion of anaphylactic death can reached. The details of cases including clinical history, exposure to allergens, and clinical manifestation play an important role in diagnosis of anaphylactic death.
Anaphylaxis/mortality* ; Anti-Bacterial Agents/adverse effects* ; Autopsy ; China ; Drug Hypersensitivity/mortality* ; Forensic Sciences ; Humans

BACKGROUND: At present, finite element analysis can be used to judge intertrochanteric fractures, but mostly limited in the distribution of stress. Finite element model of various intertrochanteric fractures has not been reported in detail.OBJECTIVE: To build various types of intertrochanteric fracture models with Hypermesh 14.0 and LS-DYNA software to simulate the falling-induced external force on proximal femur, and to evaluate the effect of models, and to analyze the biomechanical mechanism of intertrochanteric fractures. METHODS: Normal side CT image data of one case of elderly intertrochanteric fracture were collected and imported into Mimics software to establish the proximal femur geometric models, were then analyzed and operated by LZ-DYNA solver after imported into Geomagic studio 2013 and Hypermesh 14.0 for smoothing and meshing. Before analysis, the material parameters were set, the boundary conditions were confirmed, and given the loading parameters. The operating results were checked in Hyper View. RESULTS AND CONCLUSION: (1) The distribution of stress of proximal femur exactly matched to the previous study. EvansⅠtype intertrochanteric fracture model was obtained under continuous shear stresses, and six types of fractures were obtained by adjusting the load. (2) These results manifest that based on the Hypermesh 14.0 and LS-DYNA software, the finite element can well simulate the intertrochanteric fractures, and shear stress plays an important role in intertrochanteric fractures, which can provide experimental basis for the prevention and treatment of intertrochanteric fractures.