Effects of MTHFR gene polymorphism on the adverse reactions in osteosarcoma patients after the first high-dose methotrexate treatment / 中国药房

OBJECTIVE To explore the effects of 5，10-methylenetetetrahydrofolate reductase （MTHFR） gene polymorphism on the adverse reactions in patients with osteosarcoma after the first high-dose methotrexate （HD-MTX） treatment. METHODS A prospective study was conducted to include 53 patients with osteosarcoma treated with HD-MTX at the first admission in General Hospital of Eastern Theater Command. The dose of MTX was evaluated according to the polymorphism of rs1801133 in the METHFR gene and demographic factors， then whole pharmaceutical monitoring was conducted. The data on liver toxicity， renal toxicity， hematological toxicity， and gastrointestinal reaction were collected after the first chemotherapy cycle. Single factor analysis and binary Logistic regression analysis were used to analyze the correlation between MTX dose， 24 h blood drug concentration， and rs1801133 locus genotype with four adverse reactions. RESULTS The MTX dosage in patients with CC wild type was significantly higher than that in TT mutant type （7.97 g/m2 vs. 6.98 g/m2， P＝0.030）， but this difference did not affect the 0 h and 24 h blood drug concentrations of MTX. The above four adverse reactions were not related to the dose of MTX. The results of binary Logistic regression analysis showed that carrying one T allele increased the risk of developing hematological toxicity by 4.13 times（95% confidence interval：1.35-12.62，P＝0.013）. When 24 h plasma concentration threshold of MTX was set to 2.65 µmol/L， the sensitivity and specificity of predicting liver function damage were 53.33% and 86.96%， respectively； when the threshold was set to 7.28 μmol/L， the sensitivity and specificity of predicting renal damage were 100% and 81.63%. CONCLUSIONS The polymorphism of the rs1801133 in the MTHFR gene is associated with hematological toxicity of MTX. Patients who take HD-MTX for the first time and carry the T allele have a high risk of hematological toxicity. The 24 h plasma concentration of MTX is related to liver toxicity and renal toxicity. In addition， monitoring the 24 h blood drug concentration can predict liver and renal toxicity， and take early intervention.

Characterization and function of short-chain dehydrogenases/reductases in hydroxysafflower yellow A biosynthesis pathway / 药学实践杂志

Objective To explore the function of short-chain dehydrogenases/reductases (SDRs) in safflower flavonoid, especially hydroxysafflower yellow A (HSYA) biosynthesis. Methods SDRs involved in HSYA biosynthesis pathway were screened based on safflower transcriptome database and metabolome database. The expression pattern was analyzed by qRT-PCR. The overexpression vector was constructed by seamless cloning technology, then genetically transformed to the Yunnan Weishan safflower strain by Agrobacterium gv3101. The transgenic T2 generation plants were positively verified, and the gene expression of corolla SDRs was analyzed. The content of secondary metabolites was assayed by UPLC-Q-TOF/MS. Results Three SDRs genes named CtSDR1, CtSDR2 and CtSDR3 involved in HSYA biosynthesis pathway were screened. Their expression in safflower from high to low was corolla > leaf > stem > root. The expression level in corolla increased gradually with corolla development. qRT-PCR analysis of corolla with positive verification of genome insertion sequence showed that the transcription level of CtSDR3 in corolla of T2 positive plants increased by 2~3 times compared with the blank control group, and the content of secondary metabolite HSYA increased by 7.1%~16.6% (P< 0.05). Conclusion CtSDR3 may be involved in the biosynthesis of flavonoids, especially HSYA, in safflower. It provides the support data for explaining the function of CtSDR3 in HSYA biosynthesis pathway.

Exploration and practice of integrated governance system in hospital with multi-branches / 中华医院管理杂志

Aiming at the problems of resource allocation, cost control, homogenization management of medical and nursing quality and so on in a hospital with multi-campuses, People′s Hospital of Ningxia Hui Autonomous Region explored an integrated governance system. It incorporated a series of aspects, such as the establishment of Internet hospital platform using payment and settlement as the link, the construction of operation and management mode for integrating information of multiple branches, the completion of " one hospital, multiple branches" organizational structure and integrated operation system, the innovation of personnel and post compensation system in line with features of medical industry, the implementation of new service mode of diagnosis teams and inpatient wards, the execution of budget management and cost accounting control, and the establishment of integrated online and offline epidemic prevention and control system for the joint prevention and control. These practices achieved good effects that quality and efficiency of medical services were greatly improved, cost of medical services was effectively controlled, and the efficiency of hospital operation and management were enhanced. It provided valuable experience for the integrated management of public hospitals with multi-campuses.

Pharmaceutical Care for a Case of Osteosarcoma Patient with Periprosthetic Joint Infection Provided by Clinical Pharmacist / 中国药房

OBJECTIVE： To explore the role of clinical pharmacist in individualized treatment for osteosarcoma patients with periprosthetic joint infection （PJI）. METHODS： An osteosarcoma patient was admitted to our hospital and then suffered from PJI after operation. Clinical pharmacist adjusted the initial anti-infection plan and carried out pharmaceutical care according to the results of patients’ etiology and drug sensitivity. According to the PK-PD principle， combined with the therapeutic drug monitoring （TDM）， the dose of antibiotics was adjusted. With the occurrence of ADR， the antibiotic therapeutic regimen was adjusted again. RESULTS： The patient was administrated cefotiam for empiric therapy initially after the diagnosis of PJI. After obtaining the results of etiology and drug sensitivity， the clinical pharmacist suggested that vancomycin sensitive to penicillin-resistant Staphylococcus epidermidis should be used for targeted anti-infection treatment. After adjusting the dosage according to the steady-state valley concentration， the patient had slight liver function damage， accompanied with chest tightness and shortness of breath. After analysis， the clinical pharmacist considered the adverse drug reactions related to vancomycin， and again suggested that the patient should be treated with teicoplanin. After the doctor adopted the treatment plan recommended by the clinical pharmacist， PJI of the patient was effectively controlled， and the adverse reaction symptoms disappeared. The patient was effectively cured for PJI and discharged eventually. During the treatment period， the clinical pharmacist also carried out medication education for the drugs used by the patient. CONCLUSIONS： Clinical pharmacist should master the principle of antibiotic drug PK-PD theory and evaluate the clinical efficacy and safety of anti-infective drugs dynamically based on the guidance of TDM， so as to develop individualized anti-infection therapeutic regimen for osteosarcoma patient with PJI， improve the effect of clinical treatment and guarantee the safety of drug use.

Teaching practice and effect evaluation in medical genetics based on PAD Class / 中华医学教育探索杂志

Objective This study aimed to explore the practice and effect of PAD Class (presentationassimilation-discussion Class) in the teaching of Medical Genetics.Methods We randomly selected a teaching class (117) for PAD Class and the other class (115) for lecture-style teaching.The two classes took the same exam in the end,with the PAD class taking an extra questionnaire on teaching conditions at the same time.The average scores of the two classes were tested by SPSS 19.0.Results The scores of the final exams for PAD and control classes were (72.21 ± 7.42) and (69.77 ± 8.89),differences were statistically significant (t=2.27,P=0.02).Questionnaire results showed that in PAD Class,68.81％ (75/109) of the students could complete homework,93.58％ (102/109) thought that PAD class had (obviously) increased their initiative and enthusiasm for learning,and 53.21％ (58/109) were very satisfied with their learning results.Conclusion PAD Class is suitable for the teaching of Medical Genetics and improves the teaching efficiency.

Effect of hyperbaric oxygen on delayed neuropsychiatric sequelae followed carbon monoxide poisoning / 中华急诊医学杂志

Objective To explore the effect of different hyperbaric oxygen treatment (HBOT) on delayed neuropsychiatric sequelae followed carbon monoxide (CO) poisoning (DNS).Methods Patients diagnosed acute carbon monoxide poisoning (ACOP) or DNS due to CO poisoning in the hospital from October 2015 to October 2016 were included.Patients who died of ACOP or in persisting unconsciousness condition were excluded.Information of the patients were retrospectively collected including personal data,clinical features and treatment course of hyperbaric oxygen (HBO).All subjects were divided into two groups,consisting of cases who developed into DNS and who fully recovered,according toclinical symptoms.The differences of personal data,clinical features and treatment course of HBO were compared between the two groups.After adjusting the confounding factors,hyperbaric oxygen treatment program of the two groups were analyzed.Results DNS occurred in 39 patients with acute CO poisoning,while 130 patients were fully recovery.The ratio of patients over 55 years old or with smoking history in the DNS group were higher than that in the good outcome group (82.1％ vs.60.8％,23.1％ vs.10.8％).Patients who awoke from unconsciousness but left cognitive impairment were more likely to develop into DNS (P=0.017).Patients who treated with HBO within the first 24 hours,risk of developing into DNS were decreased(OR=0.14,P＜0.01).At the same time,2 times per day and within the first 24 hours worked also as well.(OR=0.29,P=0.011).Even if patients who were given 2 times a day of HBO but not in the first 24 hours after poisoning,could not reduce the risk of evolving to DNS(OR=0.06,P＞0.05);The proportion of patients in the good outcome group accepted HBO for more than six days after poisoning was higher than that in the DNS group (68.5％ vs.48.7％).After adjusting confounding factors,patients who treated with HBO within the first 24 hours (OR=0.22,95％CI:0.09-0.52),2 times per day(OR=0.30,95％CI:0.10-0.87)and lasted for more than 6 days(OR=0.30,95％CI:0.10-0.87)were in a lower risk of involving to DNS.Conclusions For patients diagnosed ACOP,HBOT began in the first 24 hours,1 or 2 times per day or early sustaining to give HBO for more than 6 days could reduce the risk of DNS.

The status of thyroid volume of children aged 8-10 years and influencing factors in Hefei City / 中华地方病学杂志

Objective To investigate the status and the influencing factors of thyroid volume of children aged 8-10 years in Hefei City.Methods In 2016,according to the requirements of "National Iodine Deficiency Disorders Surveillance Plan (the 2016 Edition)",the method of multistage stratified sampling was used in 9 counties (cities,districts) of Hefei.Five primary schools were randomly selected from each county (city,district),with one in each direction (the east,west,south,north and center),then 40 children aged 8-10 years (male ∶ female =1 ∶ 1,with similar age distribution) were randomly chosen in each primary school.The thyroid volume,height and weight were measured.In addition,a questionnaire with the items including personality,learning pressure,dietary habits,related disease history and contact history was designed and used to collect the data of the subjects.Results Totally 1 800 children aged 8-10 years were selected from 45 primary schools in 9 counties (cities,districts).The mean thyroid volume was (3.009 ± 1.197) ml.Totally 71 people were found with thyroid enlargement and the goiter rate was 3.9％,which was in the range described in the elimination iodine deficiency disorders (IDD) standard (＜ 5％).Univariate analysis showed that for children in different age groups,seafood consumption frequency,radiological examination,height,and body mass,the thyroid volumes were significantly different (P＜ 0.05);Multivariate linear regression showed that body weight and height were main factors affecting the thyroid volume of children aged 8-10 years in Hefei City,the standard partial regression coefficient are 0.288 and 0.140,respectively.Conclusions The thyroid volume of the 8-10 years old children is generally in the normal range in Hefei.Goiter rate is lower than the standard for elimination of iodine deficiency The findings have showed that not only age,but also height,body mass and other factors should be considered while evaluating the influencing factors of the thyroid volume of school-aged children.

Hospitalization Expenses of Patients with Type 2 Diabetes and their Influencing Factors / 现代医院

Objective To conduct an empirical analysis of constitutes and changes of type 2 diabetes patients′ hospitalization expenses and find out the differences and influencing factors so as to provide hospitals and related departments with the decision basis of controlling medical costs, arranging medical resources and optimizing systems.Methods Information of type 2 diabetes patients who had been admitted to a certain first-class grade one hospital in Ningxia from 2013 to 2016 were collected and categorized.Hospitalization costs and influencing factors of the patients were comprehensively analyzed through descriptive statistics, variance analysis and regression analysis.Results The medicine and examination costs as the constitutes of hospitalization expenses were too high.Gender, length of stay, age and diabetic complications were main contributory factors of type 2 diabetes patients′ hospitalization expenses.Conclusion The costs of hospitalization of patients with type 2 diabetes are unreasonable and need to optimize.Type 2 diabetes patients′ hospitalization expenses should be effectively controlled and medical resources should be reasonably used through standardizing treatment behavior, shortening length of stay, intensifying publicity and education, enhancing prevention and reinforcing follow-ups, expanding health insurance coverage and upgrading its level.

Interpretation of tacrolimus guidelines for individualized medication / 医学研究生学报

Tacrolimus exhibits varied individual pharmacokinetic and a narrow therapeutic window, resulting in difficulties in personalized medication.In order to improve the safety of tacrolimus in clinical application and its efficiency and rationality in clinical practice, many countries and regions in the world have issued a number of guidelines for tacrolimus application.However, these guidelines generally aim at particular disease and race, and have certain limitation.In this article, the guidelines were explicated and analyzed in detail.Moreover, an individual tacrolimus medication recommendation for Chinese population was summarized based on the latest research of tacrolimus pharmacogenomics and therapeutic drug monitoring so as to provide assistance for the rational use of tacrolimus.

Practice and Investigation of Strengthening Outpatient Clinic Service for Multiple Branches of the Large Scale Hospital / 中国医院管理

According to the reality of outpatient clinic service,expanding the service items,laying off solid foundation,making the working procedures more concrete in details and establishing suitable polices,the professionalization of specialists and special diseases in outpatient clinic of multiple branches hospital,even resources of outpatient clinic of multiple branches hospital,diversified service pattern of outpatient clinic,refined outpatient clinic service procedure,informationization of treatment procedure of outpatient service,and different requirements of people of different levels are realized.

Expression of matrix metalloproteinases-9 in the brain tissue of experimental hepatic encephalopathy rats / 中国基层医药

Objective To investigate the significance of MMP-9 expression in the pathogenesis of hepatic encephalopathy.Methods 180 rats were randomly divided into the control group,hepatic encephalopathy 4,8 and 12h groups,45 rats in each group.In hepatic encephalopathy group,rats were intraperitoneally injected D-galactosamine (400mg/kg) with lipopolysaccharide (100μg/kg),and then the symptom was observed.Ammonia,the evans blue(EB) content,the brain water content and the MMP-9 mRNA in the brain tissue were assessed by real-time Q-PCR after 4,8 and 12h.Results 2h later the rats in hepatic encephalopathy groups began to appear the symptom.4 hours later,ammonia,the EB content,the brain water content and MMP-9 mRNA content of the hepatic encephalopathy groups began to increase [(74.27 ± 1.77) μ mol/L vs (33.85 ± 1.50) μ mol/L,F =5 983.36 ;(4.84 ±0.43)μg/g vs (3.96 ±0.48)μg/g,F =111.54; (78.63 ± 0.46)％ vs (76.07 ±0.39)％,F =737.25,and (1.037 ± 0.071) vs (0.829 ± 0.053),F =132.10,P ＜ 0.01],and with the extension of time increased obviously [(136.32 ± 3.88) μmol/L and (279.53 ± 9.78) μmol/L,F =5 983.36 ; (5.94 ± 0.35) μg/g and (6.71 ±0.50)μg/g,F=111.54;(80.50±0.32)％ and (82.14±0.30)％,F=737.25;(1.235 ±0.095) and (1.425± 0.113),F =132.10,P ＜ 0.01].Conclusion Blood brain barrier permeability enhancement and brain edema in hepatic encephalopathy rats may be related with MMP-9 mRNA increasing.

Construction of nsdAmgh gene disruption mutant in Strempomyces roseoflavus Men-myco-93-63 / 生物工程学报

Insertional mutagenesis is a widely used method to determine the function(s) of a gene. To study the function(s) of the gene nsdAmgh in Streptomyces roseoflavus, a homologous recombination vector pSRNA2500 was structured in this paper. The recombination donor vector was then transformed into Strempomyces roseoflavus strain Men-myco-93-63 by conjugative transfer. The transformants were subjected to selection under the pressure of high temperature and appropriate antibiotics. As a result, several disrupted mutants of nsdAmgh gene, with a phenotype of Am(s)Km(r), were isolated and verified using PCR and Dot-blotting and Southern blotting hybridization methods. Functional analysis showed that the disrupted mutants of nsdAmgh had a two-fold higher inhibition against Verticillium dahlia Kleb than that of the wild strain Men-myco-93-63, which all will provide a new study route for future research about positive and negative regulator in Men-myco-93-63.

Activation and its clinical significance of the mammalian target of rapamycin pathway and its downstream proteins in gastric cancer / 中华消化杂志

Objective To investigate the activation and clinical significance of the mammalian target of rapamycin (mTOR) pathway related protein and eukaryotic translation factor 4E-binding protein 1 (4E-BP1) in gastric cancer.Methods The activation of mTOR and 4E-BP1 in gastric cancer tissues of 38 surgical patients were detected by immunohistochemical method.The differences of phosphorylated mTOR and 4E-BP1 expression among cancerous tissues,para-cancerous tissues and normal gastric mucosa tissues and dinicopathological variables were analyzed by Chi square test and Kruskal-Wallis test.Results The positive expression rate of phosphorylated mTOR in the gastric cancerous tissues was significantly higher than that of para-cancerous tissues and normal tissues [71.1％ (27/38),50.0 ％ (19/38) and 44.7 ％ (17/38),x2 =11.031,P =0.026].The positive expression rate of downstream protein 4E-BP1 in the gastric cancer tissues was also significantly higher than that of paracancerous tissues and normal tissues [68.4％(26/38),57.9％(22/38) and 28.9％ (11/38),x2 =13.943,P=0.007].There was no correlation between phosphorylated mTOR and 4E-BP1 expression and tumor Lauren's sub-type,infiltration,differentiation degree,lymph node metastasis and patient's age.There was statistical significant difference between activated 4E-BP1 expression and tumor size in gastric cancer (H=3.86,P＜0.05).Conclsions mTOR pathway was over activated in gastric cancer.There was difference between phosphorylation degree of its downstream protein 4E-BP1 and the tumor size.

Gankyrin involved in nimesulide induced apoptosis of human gastric cancer cells / 中华消化杂志

Objective To elucidate the expression of gankyrin in human gastric cancer cells and it's role in nimesulide induced apoptosis. Methods Four human gastric cancer cell lines including MKN28 (well differentiated), AGS (poorly differentiated), MKN45 (poorly differentiated), and SGC7901(moderately differentiated) were cultured and treated with nimesulide. Nimesulide induced growth inhibition and apoptosis of the cells were detected by methyl thiazolyl tetrazolium assay, and confirmed by flow cytometry. The expressions of gankyrin gene and protein were further assessed by real-time PCR and Western blotting. Results Gankyrin mRNA and protein were detected in all four human gastric cancer cell lines. The proliferations of AGS and SGC7901 cell lines were significantly suppressed by nimesulide in a time-dose dependent manner. When treated with 400 μmol/L of nimesulide for 48 hours, the significant apoptosis was found in AGS cells (23.30%±2.50%) and SGC7901 cells (16.80%±1.55% ) in comparison with controls (0.57%±0.19% and 0.88%± 0.17%, respectively, all P values <0.01). Apoptosis of AGS cells induced by nimesulide was accompanied by a considerably decreased gankyrin expression that was more significant at 24 hours (0.0035±0.0014) and 36 hours (0.0980±0.0160) in comparison with controls (0.4690±0.1190, all P values<0.01). Conclusion Gankyrin expresses in human gastric cancer cell lines and may be involved in nimesulide induced apoptosis of AGS cells.

Analysis of patch-test results of para eczema and dermatitis / 中国基层医药

Objective To investigate the characteristics of contact allergens in eczema and dermatitis for further diagnosis and treatment. Methods 340 cases with eczema and dermatitis were tested with a standardized screening antigen kit. Results (80. 88% ) of the 340 patients tested had at least one positive allergen among 18 of 20 standardized screening antigen. The first six allergens were nickel sulfate ( 29. 70% ), potassium dichroroate (27.64% ) ,fragrant mix(22.35% ) ,carba mix(20.29% ) ,thimerosal( 18. 82% ) ,benzocaine( 17.94% ). Conclusion Nickel sulfate,potassium dichromate,fragrance mix and carba mix were the main allergens causing dermatitis and eczema presently. Patch-testing was helpful in identifying the property of contact allergens in para eczema and dermatitis.

Effect of Omegaven on blood clotting system and inflammatory reaction in ICU patients with parenteral nutrition / 肠外与肠内营养

Objective: To observe the changes of blood coagulation factors and inflammatory factors and the regulatin effect of Omegaven.Methods: Thirty ICU patients were randomly allocated into two groups: Omegaven group and control group.Serum concentrations of NF-κB、PGF1α、Eselectin、sICAM-1、TAT、D-dimer、TMD、PF1+2 were measured before and after parenteral nutrition.Results: Patients in control group had significantly higher NF-κB、Eselectin、sICAM-1、TAT、D-dimer、TMD、PF1+2 concentration,lower PGF1α concentration.Patients treated with Omegaven had significantly lower NF-κB、Eselectin、sICAM-1、TAT、D-dimer、TMD、PF1+2 concentration,higher PGF1α concentration.Conclusion: Omegaven can suppress inflammatory reaction and improve coagulopathy.

Rapamycin and PD98059 collaborative inhibit mammalian target of rapamycin pathway in the prevention and treatment of mouse colorectal cancer / 中华消化杂志

Objective To investigate the combined inhibition effect and the potential mechanism of rapamycin (mammalian target of rapamycin inhibitor) and PD98059 (mitogen-activated protein kinase/extracellular signal-regulated kinase kinase (MEK) inhibitor) on mouse colorectal cancer (CRC). Methods S-ICR mice were subcutaneously injected with 20 mg/kg of 1,2-dimethylhydrazine dihydrochloride in the nape for 20 weeks to induce CRC. From the 16th week, the mice were treated with alone or combined injection with 0.25 mg/kg rapamycin and 2.5 mg/kg PD98059. The drugs were administered for 8 weeks. Subsequently, the animals were sacrificed and dissected, the tumor sizes were measured, and the tumors were harvested for pathological assay. Furthermore, the phosphorylation of mTOR, p70S6K, and 4E-BPl proteins was detected by using immunohistoehemistry. Results The mice treated with rapamycin (44. 44 %) or PD 98059 (either alone (38.89%) or combination treatment (6.67%) were significantly less likely to develop cancer compared with mice receiving none of them (77.78%, P<0. 05). The average size of tumors was (6.15±2. 192), (8.85±3. 983), (2.917±0. 191), (16.36±6.855) mm3 respectively (P<0.05).The anti-cancer effect of the combination treatment was substantially significant. The proteins of phospho-mTOR, phospho-p70s6K and phospho-4E-BPl were significantly down-regulated after treatments (all P values < ,0.05). Conclusions Combined treatment was more effective than single-drug treatments of rapamycin or PD98059 alone for the prevention and treatment of mouse CRC. The mTOR signal pathway might be involved in the inhibitory mechanism.

Correlation of tumor growth and endothelial progenitor cells entering blood induced by surgical injury / 上海交通大学学报（医学版）

Objective To explore the correlation of tumor growth and endothelial progenitor cells (EPC) entering blood induced by surgical injury in tumor bearing nude mice. Methods Forty-two tumor bearing nude mice were randomly divided into seven groups (n=6): non-surgical injury groups (1 d and 30 d), anesthetic group, surgical injury groups (24 h, 48 h, 72 h and 30 d after surgery). Blood samples and xenograft tumor tissues were taken from anesthetic group 24 h after anaesthesia and surgical injury groups 24 h, 48 h, 72 h and 30 d after surgery. EPC levels in peripheral blood were measured by flow cytometry, serum VEGF levels were determined by ELISA, microvessel density (MVD) and expression of VEGF were detected by immunohistochemistry. Results The levels of EPC in 24 h post-surgery group, 48 h post-surgery group and 72 h post-surgery group were significantly higher than that in non-surgical injury 1 d group (P<0.05). The levels of VEGF in 24 h post-surgery group, 48 h post-surgery group, 72 h post-surgery group and anesthetic group were significantly higher than that in non-surgical injury 1 d group (P<0.05). There was no significant difference in MVD among groups (P>0.05). Pearson correlation analysis revealed that serum VEGF levels were related to EPC levels in peripheral blood (r=0.695 6, P<0.01), while EPC levels in peripheral blood were not related to MVD (r=0.221 4, P>0.05), and serum VEGF levels had no correlation with MVD (r=0.224 9, P>0.05). Conclusion Surgical injury has no obvious influence on xenograft tumor growth.

Rapid Determination of Four Kinds of Furocoumarin Compounds in Traditional Chinese Medicine by Dispersive Liquid-Liquid Microextraction / 分析化学

A method was developed for the determination of furocoumarin compounds(psoralen, oxypeucedanin, imperatorin, isoimperatorin) in traditional Chinese medicine samples by dispersive liquid-liquid microextraction(DLLME) coupled with high performance liquid chromatography and the relation of sample solution volume, sediment phase volume with enrichment factors was deducted. Some important parameters that influenced the extraction efficiency were optimized: 50 μL carbon tetrachloride and 300 μL acetonitrile were rapidly injected into 1.5 mL sample solution containing 2.5%(w/V) NaCl. After centrifugation at 3500 r/min for 3 min, the sedimented CCl_4 phase was pumped and recorded the volume, then dissolved with methanol and injected into the HPLC for analysis. Under the optimum conditions, a good linear relationship was obtained in the range of 0.006 6.00 mg/L of both psoralen and oxypeucedanin and 0.006-12.0 mg/L of both imperatorin and isoimperatorin. The limits of detection were 1.0-3.0 μg/L(S/N=3). The relative standard deviations were 2.3%-5.4%(n=5). The enrichment factors ranged from 12.6 to 38.5 folds. The average recoveries ranged from 97.5% to 114.8%. The four kinds of furocoumarin compounds in Radix Angelicae dahuricae and Yuanhu Zhitong tablet were determined by the proposed method with satisfactory results.

The effect of clavulanic acid in suporessing the antibiotic resistance of Helicobacter pylori to metronidazole / 中华消化杂志

Objective To elucidate the effect of clavulanic acid (CLA) in suppressing the antibiotic resistance of Helicobacter pylori (Hp) to metronidazole (MZ) and its mechanism. Methods All Hp strains were isolated from biopsy specimens taken endoscopically and random amplified polymorphic DNA assay (RAPD) was used to certificate the distinct origin of these strains. The minimum inhibitory concentration (MIC) of CLA and MZ aganst Hp were determined by using agar dilution procedure and Epailometer test (E-test). The effect of CLA on the morphology of Hp was examined by transmission electron microscopy. Fluorescein-C6-aminopenicillanic acid (FLU-C6-APA) competition assay was used to detect the binding between CLA and penicillin-binding proteins (PBPs). Results Eleven strains were isolated. In vitro CLA could decrease the MIC of MZ resistant(1.442±0.459 vs 0.376±0.288, P=0.0077), but not affect the MIC for MZ sensitive strains significantly (P>0.05). Exposure to CLA resulted in morphological changes of Hp, including cell wall disintegration and cell lysis. Furthermore, CLA inhibited the binding of FLU-C6-APA to PBPs(30.5-33.5×103). Conclusions CLA suppresses the antibiotic resistance of Hp to MZ through its binding with PBPs which results in the morphology changes of Hp.