Experimental study on invigorating kidney and activating blood on preventing and curing SD rats with knee osteoarthritis / 中国骨伤

<p><b>OBJECTIVE</b>To explore the effects and mechanism of invigorating kidney and activating blood, invigorating kidney and expelling wind on hemorheology, IL-1β and TNF-α of SD rats with knee osteoarthritis, then definite the evolution of muscle certified turning into heumatism and compare the effect of Chinese herbal.</p><p><b>METHODS</b>One hundred and eighty SD rats with 3-month-old (each weight was 185 to 215 g) received intra-articular injection of papain solution for establishing knee OA models. All rats were randomly divided into activating blood group, preventing group, expelling wind group, invigorating kidney group, invigorating kidney and activating blood group and model group. Laboratory indexes were obtained at the 30th, 60th, 90th days after gastric perfusion, which including state of mind, activity, fur, weight, joint swelling, largely image, hemorheology, inflammation and HE pathological appearance.</p><p><b>RESULTS</b>After operation, rats appeared blood stasis and swelling and difficulty crawling. There was significant difference of hemorheology in invigorating kidney and activating blood group the content of IL-1β and TNF-α was obviously lower than model group (P < 0.05 ). While the content of IL-1β and TNF-α on the early stage was obviously higher than late stage (P < 0.05).</p><p><b>CONCLUSION</b>Knee osteoarthritis mainly show synovial inflammation at the early stage, inflammation at early stage is more severe than late; invigorating kidney and activating blood decoction can inhibit the knee cartilage injury, improve blood circulation and prevent local inflammatory reaction. Activating blood decoction and invigorating kidney and activating blood Decoction have certain curative effect in early time, but the effects of invigorating kidney and activating blood Decoction is more effective than other on the late stage.</p>

Transconjugation and genotyping of the plasmid-mediated AmpC beta-lactamase and extended-spectrum beta-lactamase genes in Klebsiella pneumoniae / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>AmpC beta-lactamases and extended-spectrum beta-lactamases (ESBLs) are becoming predominant causes of resistance to third and forth-generation cephalosporins in Klebsiella pneumoniae (K. pneumoniae). It is very difficult to treat infectious diseases caused by multidrug-resistant K. pneumoniae. The purpose of the present study was to investigate transconjugation and characteristics of beta-lactamase genes in K. pneumoniae producing AmpC beta-lactamases and ESBLs.</p><p><b>METHODS</b>AmpC beta-lactamases were detected by three-dimension test and ESBLs by disc confirmatory test. Minimum inhibitory concentrations (MICs) were determined by agar dilution. Transfer of resistance to EC600 (Rif(r)) was attempted by conjugation in broth and screened on agar containing cefotaxime (2 microg/ml) plus rifampin (1024 microg/ml). The genes encoding AmpC or ESBLs and their transconjugants were detected by PCR and verified by DNA sequencing.</p><p><b>RESULTS</b>The resistant rates to ampicillin and piperacillin were 100% in 18 isolates of K. pneumoniae. However, imipenem was still of great bactericidal activity on K. pneumoniae, and its MIC(50) was 0.5 microg/mL. Eleven beta-lactamase genes, including TEM-1, TEM-11, SHV-13, SHV-28, CTX-M-9, CTX-M-22, CTX-M-55, OXA-1, LEN, OKP-6 and DHA-1, were found from 18 isolates. And at least one beta-lactamase gene occurred in each isolate. To our surprise, there were six beta-lactamase genes in the CZ04 strain. Among 18 isolates of K. pneumoniae, the partial resistant genes in 8 isolates were conjugated successfully, which had 100% homological sequence with donors by sequence analysis. Compared with donors, 8 transconjugants had attained resistance to most beta-lactams, including ampicillin, piperacillin, cefoxitin, cefotaxime and aztreonam, or even amikacin and gentamicin.</p><p><b>CONCLUSIONS</b>R plasmids can be easily transferred between the resistant and sensitive negative bacilli. It is very difficult to block and prevent the spread of antimicrobial resistance. So more attention should be paid to reducing the frequency, times and dosage of antimicrobials, especially third or fourth cephalosporins.</p>

Proteotyping: A New Approach Studying Influenza Virus Evolution at the Protein Level / 中国病毒学

Phylogenetic methods have been widely used to detect the evolution of influenza viruses.However, previous phylogenetic studies of influenza viruses do not make full use of the genetic information at the protein level and therefore cannot distinguish the subtle differences among viral genes. Proteotyping is a new approach to study influenza virus evolution. It aimed at mining the potential genetic information of the viral gene at the protein level by visualizing unique amino acid signatures (proteotypes). Neuraminidase gene fragments of some H5N1 avian influenza viruses were used as an example to illustrate how the proteotyping method worked. Bayesian analysis confirmed that the NA gene tree was mainly divided into three lineages. The NA proteotype analysis further suggested there might be multiple proteotypes within these three lineages and even within single genotypes. At the same time, some proteotypes might even involve more than one genotype. In particular, it also discovered some amino acids of viruses of some genotypes might co-reassort. All these results proved this approach could provide additional information in contrast to results from standard phylogenetic tree analysis.

Relationship between antimicrobial resistance and aminoglycoside-modifying enzyme gene expressions in Acinetobacter baumannii / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Acinetobacter baumannii is one of the main gram-negative bacilli in clinical practice. Nosocomial infections caused by multi-drug resistance Acinetobacter baumannii is very difficult to treat. This study was designed to investigate the antimicrobial resistance characteristics and four resistant gene expressions of aminoglycoside-modifying enzymes including N-acetyltransferases and O-phosphotransferases in Acinetobacter baumannii.</p><p><b>METHODS</b>Bacterial identification and antimicrobial susceptibility test were performed by Phoenix system in 247 strains of Acinetobacter baumannii. Minimal inhibitory concentrations (MICs) of seven aminoglycosides including gentamicin, amikacin, kanamycin, tobramycin, netilmicin, neomycin and streptomycin in 15 strains of multi-drug resistant Acinetobacter baumannii were detected by agar dilution. Four aminoglycoside-modifying enzyme genes were amplified by polymerase chain reaction (PCR) and verified by DNA sequencer.</p><p><b>RESULTS</b>The resistance rates of 247 strains of Acinetobacter baumannii against cefotaxime, levofloxacin, piperacillin, aztreonam, tetracycline, ciprofloxacin and chloramphenicol were more than 50%. Imipenem and meropenem showed high antibacterial activities with resistance rates of 3.2% and 4.1%. MIC50 and MIC90 of gentamicin, amikacin, streptomycin and kanamycin in 15 strains of multi-drug resistant Acinetobacter baumanii were all more than 1024 mg/L, and the resistance rates were 100%, 100%, 100% and 93.3%, respectively. But their resistance rates to tobramycin, netilmicin and neomycin were 86.7%, 93.3% and 46.7%, respectively. Three modifying enzyme genes, including aacC1, aacC2 and aacA4 genes, were found in 15 strains, but aphA6 had not been detected. Their positive rates were 93.3%, 20.0% and 20.0%, respectively. These three genes existed simultaneously in No.19 strain. Nucleotide sequences of aacC1, aacC2 and aacA4 genes shared 100%, 97.9% and 99.7% identities with GenBank genes (AY307113, S68058 and AY307114).</p><p><b>CONCLUSION</b>Multi-drug resistant Acinetobacter baumannii strains are rapidly spreading in our hospital, and their resistance to aminoglycosides may be associated with aminoglycoside-modifying enzyme gene expressions.</p>