A proposal of clinical breakpoints for amoxicillin applicable to porcine respiratory tract pathogens

In the present position paper, an attempt was made to establish clinical breakpoints of amoxicillin to classify porcine respiratory tract pathogens as susceptible, intermediate or resistant based on their minimum inhibitory concentrations of amoxicillin. For this, a thorough review of the published literature with regard to swine-specific pharmacological data (including dosages of amoxicillin applied and routes of administration used), clinical efficacy, and in vitro susceptibility of the target pathogens was performed. Based on the comparative analysis of the results, the working group "Antibiotic Resistance" of the German Veterinary Medical Society (DVG) proposed to classify porcine respiratory tract pathogens that show MIC values of amoxicillin of < or =0.5microg/ml as "susceptible", those with MICs of 1microg/ml as "intermediate", and those with MICs of > or =2microg/ml as "resistant".     

An approximately 15,000-year record of El Nino-driven alluviation in southwestern ecuador

Debris flows have deposited inorganic laminae in an alpine lake that is 75 kilometers east of the Pacific Ocean, in Ecuador. These storm-induced events were dated by radiocarbon, and the age of laminae that are less than 200 years old matches the historic record of El Nino events. From about 15,000 to about 7000 calendar years before the present, the periodicity of clastic deposition is greater than or equal to 15 years; thereafter, there is a progressive increase in frequency to periodicities of 2 to 8.5 years. This is the modern El Nino periodicity, which was established about 5000 calendar years before the present. This may reflect the onset of a steeper zonal sea surface temperature gradient, which was driven by enhanced trade winds.     

Evolution and functional impact of rare coding variation from deep sequencing of human exomes

As a first step toward understanding how rare variants contribute to risk for complex diseases, we sequenced 15,585 human protein-coding genes to an average median depth of 111× in 2440 individuals of European (n = 1351) and African (n = 1088) ancestry. We identified over 500,000 single-nucleotide variants (SNVs), the majority of which were rare (86% with a minor allele frequency less than 0.5%), previously unknown (82%), and population-specific (82%). On average, 2.3% of the 13,595 SNVs each person carried were predicted to affect protein function of ~313 genes per genome, and ~95.7% of SNVs predicted to be functionally important were rare. This excess of rare functional variants is due to the combined effects of explosive, recent accelerated population growth and weak purifying selection. Furthermore, we show that large sample sizes will be required to associate rare variants with complex traits.     

Proposals of the working group "Antibiotic resistance" for the configuration of microtitre plates to be used in routine antimicrobial susceptibility testing of bacterial pathogens from infections of large food-producing animals and mastitis cases

Two layouts for microtitre plates, which should serve for in-vitro susceptibility testing in routine diagnostics, have been set up by the working group "Antibiotic resistance" of the German Society for Veterinary Medicine. One of these layouts was designed for the testing of bacteria from cases of mastitis and the other for bacteria from infections in large food-producing animals. The choice of the antimicrobial agents and their concentrations to be included in these layouts were based on (1) the bacteria frequently associated with the respective diseases/animals, (2) the antimicrobial agents licensed for therapeutic use in these diseases/animals, (3) the currently available breakpoints, and (4) cross-resistances between the antimicrobial agerts so far known to occur in the respective bacteria.     

Amplification of mesenchymal stem cells from human bone marrow and orientation to induce MSCs differentiating into endothelial cells in vitro

AIM: Our purpose was to induce MSCs differentiating into endothelial cells (EC) in vitro and to provide the seed cells for study of cardiovascular tissue-engineering. METHODS: MSCs were separated by gradient centrifugation on Percoll (density 1 073 g/L) from human bone marrow (HBM), and incubated for purification and amplification in DMEM (low glucose) with 10% fetal bovine serum (FBS). Then, the MSCs were incubated for orientation differentiated into EC in DMEM (high glucose) with 20% FBS, VEGF (10 μg/L), bFGF (5 μg/L), L-glutamine (2 mmol/L), penicillin (1×105U/L) and streptomycin (100 mg/L) for about 14-21 days and their phenotypic characteristics were analyzed by flow cytometry. Afterwards, the differentiating cells were evaluated by histology and immunohistochemistry. RESULTS: The quantity of MSCs was increased from 5.0×105 in the primary culture to 8.0×1012, or to increase to 1.6×107 times after 15 generations of incubation. The purity of MSCs was above 95% and 98% homogeneous at passages 2 and 3, respectively. About 80%-90% of the differentiating cells from MSCs after 14-21 days were positively stained for Ⅷ factor (vWF) related antigen by immunohistochemistry assay, and Weible-palade corpuscle was also observed by transmission electron microscopy in the cytoplasm. CONCLUSION: MSCs from HBM have the capability of differentiation into ECs in vitro, which may be a potential source of seed cells for fabrication of tissue-engineering heart valve, particularly in children with congenital heart disease.     

Layout proposal for a microtitre plate to be used in routine antimicrobial susceptibility testing of bacteria from infections of dogs and cats

The determination of minimum inhibitory concentrations by broth microdilution is recommended as method of choice for susceptibility testing of veterinary bacterial pathogens. Accordingly, broth microdilution is used in veterinary routine diagnostic laboratories at a progressive rate. To reduce the costs of susceptibility testing, it is reasonable to develop widely accepted uniform microtitre plate layouts that are produced in large quantities. Such microtitre plate layouts have already been developed and published for the susceptibility testing of pathogens from food-producing animals. However, a microtitre plate layout, especially designed for the testing of bacteria from dogs and cats, should be available, too. The choice of the antimicrobial agents or combinations of antimicrobial agents to be included in a suitable layout should be based on the following criteria: (1) the approval and availability of an antimicrobial agent or combination of agents, (2) known cross-resistances, and (3) availability of approved clinical breakpoints. The latter point is of particular importance for the choice of the numbers of concentrations per antimicrobial agent tested and the range of test concentrations. Taking into account these aspects, a science-based layout proposal for microtitre plates, which are suitable for routine testing of bacteria from dogs and cats, is presented and discussed.     

加工类型黄瓜品质性状的主成分及聚类分析

对19个加工类型黄瓜品种的7个品质性状进行了主成分和聚类分析.结果表明19个品种分为产量、形态和品质3个主成分因子,其主成分的累计贡献率达89.81%,而且基本上可描述7个品质性状的遗传变异.当类平均距离为1.035时,19个品种被聚为短果和长果2种类型,而当类平均距离为0.942时,19个品种被聚为短果中等品质、短果优质和长果高产3种类型.