Objective To construct a new intubation method with an otoscope and establish a murine model of Acinetobacter baumannii pneumonia with this method.Methods Part I:The Hallowell Intubation Pack for mice (Braintree Scientific Inc., USA)was used to construct a new intubation method with an otoscope.Part II:Twenty-four female ICR mice were randomized into 3 groups including control (group 1),immunosuppression (group 2)and infection after immunosuppression groups (group 3),with 8 mice in each group.The mice were treated with cyclophosphamide (CTX)by peritoneal injection to posterior orbital venous plexus.The total number of white blood cells,the number of neutrophils and the percentage of neutrophils were determined.Four mice were sacrificed at 0 h and 48 h after inoculation in each group.Then the lungs from each mouse were aseptically collected for quantitative culture and histopathology.Results Part I:Ten mice were successfully intubated using the new method and none of the mice was dead.Pulmonary bacterial culture at baseline (0 h)was (2.91×107-5.32×107 )CFU/g tissue,while the mean± standard deviation was (4.05 × 107 ± 0.82 × 107 )CFU/g tissue.The results showed that this new method had a perfect repeatability.Part II:Over 48 h,2 mice were dead in group 3,while no mouse was dead in other 2 groups.For group 3,the average pulmonary bacterial culture was 4.13×107 CFU/g tissue at 0 h and reached 3.62×1010 CFU/g tissue at 48 h (increased appropriate 1 000 times,P <0.01).The histopathologic changes in lung showed local granulomas and abscess in the alveolar space.Conclusions Intubation under the guidance of otoscope had the advantages of high repeatability and easy to operate.Additionally,the method provided stable and consistent bacterial inocula into lungs.The murine model of Acinetobacter baumannii pneumonia was successfully established with a new intubation method under the guidance of otoscope.

Objective To establish and validate an ultra performance liquid chromatography-tandem mass spectrometric (UPLC-MS/MS)method for quantification of MRX-I,a new oxazolidinone antibacterial agent,in human plasma and urine.Methods Chromatographic separation was performed on a Waters ACQUITY UPLC BEH C8 column using an isocratic elution.The mo-bile phase consisted of acetonitrile and water (40∶60,v/v).Quantitative analysis was conducted in the multiple reaction moni-toring mode.Linezolid was used as an internal standard.Liquid-liquid extraction with ethyl acetate was used to remove impuri-ties in the plasma and urine samples.The method was validated in terms of matrix effect,recovery,precision,accuracy and stability.Results The calibration curves were linear within the range of 0.005 00-1 .00 mg/L.The lower limit of quantification was 0.005 00 mg/L for both plasma and urine samples.Retention time was less than 1 .5 min for both MRX-I and internal standard in plasma and urine.The ma-trix effect factors of plasma and urine for MRX-I was 90.4%±8.2% and 82.7%±7.9%,respectively.The recovery of MRX-I was 112.8% ± 13.4% from plasma and 105.6% ± 13.4% from urine samples,respectively.The inter- and intra-day accuracy of MRX-I was 98.9%-105.0% and 96.5%-102.6% in plasma samples,and 92.7%-98.6% and 95.1 %-105.7% in urine samples.MRX-I was stable for 24 h at room tem-perature,48 h in automatic sampler after pretreatment,and stable after 3 freeze-thaw cycles in plasma and urine.MRX-I was also stable at-40℃for eight months in plasma and six months in urine,respectively.Conclusions The UPLC-MS/MS method established in this study shows high sensitivity and specificity for determination of MRX-I in human plasma and urine.The re-sults of validation are consistent with the requirement of bioanalytical method validation.

OBJECTIVETo analyze the correlation between content of glycyrrhizic acid and the single nucleotide polymorphism of beta-amyrin synthase (bAS) in Glycyrrhiza uralensis.

METHODglycyrrhizic acid content in 80 samples of the cultivated G. uralensis were determined by HPLC; According to the very significant level (P < 0.000 1), 80 samples in accordance with glycyrrhizic acid will be grouped by SAS 9.0; Using RT-PCR strategy to amplification the Open Reading Frame of beta-amyrin synthase with the template of total RNA extracted from roots of G. uralensis and then using DNAman to analyze the relationship between glycyrrhizic acid content and the single nucleotide polymorphism of beta-amyrin synthase (bAS).

RESULTThere exited two mutation sites 94 bp and 254 bp, G/A conversion occurred at 94 bp site, which belonged to a missense mutation. G/A conversion led to the corresponding amino acid conversion (Gly --> Asp); C/T conversion occurred at 254 bp site, which belonged to a synonymous mutation. According to sequence variation, the samples were divided into four genotypes: G-T genotype, A-T genotype, G/A-C genotype and G-T genotype.

CONCLUSIONA-T genotype, G/A-C genotype and G-T genotype are correlated with the high content of glycyrrhizic acid.

Genotype ; Glycyrrhiza uralensis ; enzymology ; genetics ; metabolism ; Glycyrrhizic Acid ; metabolism ; Intramolecular Transferases ; genetics ; Polymorphism, Single Nucleotide ; Reproducibility of Results

Objective To establish an ultra-performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS)method for determination of tobramycin in human serum,and examine the utility of the method in a clinical pharmacokinetic study of tobramycin inhalation.Methods Serum samples were pretreated by solid phase extraction with tobramycin-D12 as internal standard.Chromatographic separation was performed on a TitankHilic(2.1 mm × 100 mm,3 μm)column.The mobile phase consisted of0.1％formic acid-acetonitrile and 0.1％formic acid aqueous solution at a flow rate of 0.4 mL/min.Electrospray ionization source and multiple reaction monitoring(MRM)scanning were used for monitoring the quantitative ion pairs with m/z 468.3→m/z 163.3(tobramycin)and m/z 480.6→m/z 166.2(tobramycin-D12).The established method was investigated in terms of selectivity,interaction,concomitant medication,standard curve and lower limit of quantitation,precision and accuracy,recovery,matrix effect,and stability of tobramycinin.Results The linear range of tobramycin was 0.050 0-10.0 mg/L(R2=0.999 5).The intra-and inter-batch precision was satisfactory(coefficient of variation[CV]≤3.6％).The accuracy ranged from-0.4％to 6.0％.The matrix effect factor(MF)in human serum samples(including hemolysis and lipemia)ranged from 92.2％to 94.9％(CV≤2.7％).The recovery of tobramycinin was 79.5％-81.9％in serum samples,while the recovery of internal standard was 78.9％.The analyte was stable in serum samples for 72 h at room temperature and for 274 days at-20℃/-70℃.The pharmacokinetic study of tobramycin inhalation in bronchiectasis patients showed that after continuous administration of tobramycin 300 mg twice a day to 3 patients,the mean Cmax of tobramycin was(0.72±0.61)mg/L on Day 1 and(0.76±0.73)mg/L on Day 28,respectively.The corresponding Tmax was(1.83±0.61)h and(1.50±0.50)h,respectively.Conclusions The UPLC-MS/MS method established in this study is sensitive,accurate and rapid.It is successfully applied to the clinical pharmacokinetic study of tobramycin inhalation.The method may be suitable for therapeutic drug monitoring of tobramycin in clinical practice.

Humans ; Severe Acute Respiratory Syndrome ; diagnosis ; therapy

Pyroptosis is a programmed death of inflammatory cells triggered by pathogen invasion,dependent on caspase activation,through both classical and non-classical pyroptosis pathways.Cell pyroptosis is related to the occurrence and development of a variety of animal infectious diseases caused by microbial infection.After microorganisms invading,cells are stimulated by pathology-re-lated molecular patterns,causing strong immune response,stimulating inflammatory signaling pathways,and then activating inflammasome,leading to pyroptosis.The immune system has e-volved multiple mechanisms to fight microbial infections and regulate inflammatory responses.The innate immune system,by recognizing microbial molecules in pathogens and responding quickly by producing inflammasome and activating pyroptosis,helps clear pathogens to prevent infection and maintain the normal functioning of the body.A thorough study of the pathogenesis and immune es-cape mechanism of cell pyroptosis in animal infectious diseases will provide a new direction for the treatment of animal infectious diseases.

Polymyxin B, which is a last-line antibiotic for extensively drug-resistant Gram-negative bacterial infections, became available in China in Dec. 2017. As dose adjustments are based solely on clinical experience of risk toxicity, treatment failure, and emergence of resistance, there is an urgent clinical need to perform therapeutic drug monitoring (TDM) to optimize the use of polymyxin B. It is thus necessary to standardize operating procedures to ensure the accuracy of TDM and provide evidence for their rational use. We report a consensus on TDM guidelines for polymyxin B, as endorsed by the Infection and Chemotherapy Committee of the Shanghai Medical Association and the Therapeutic Drug Monitoring Committee of the Chinese Pharmacological Society. The consensus panel was composed of clinicians, pharmacists, and microbiologists from different provinces in China and Australia who made recommendations regarding target concentrations, sample collection, reporting, and explanation of TDM results. The guidelines provide the first-ever consensus on conducting TDM of polymyxin B, and are intended to guide optimal clinical use.
Humans ; Anti-Bacterial Agents/therapeutic use* ; China ; Drug Monitoring/methods* ; Polymyxin B ; Practice Guidelines as Topic