Pathogens and drug-resistance of hospital-acquired pneumonia in an EICU in Tianjin,China

Objective: Observing the pathogens and drug-resistance within hospital-acquired pneumonia (HAP) in an emergency intensive care unit (EICU) to provide a reference for clinically reasonable use of antibiotics. Methods: Sixty-two patients with HAP in Tianjin Medical University General Hospital from January 2017 to May 2019 were analyzed retrospectively. Bacterial identification and susceptibility were reviewed. Results: One hundred and thirty-seven strains of pathogenic bacteria were isolated from 62 patients, with 97.1% Gram-negative and only 2.9% Gram-positive. There were also six fungal isolates. The most common pathogens were Acinetobacter baumannii, accounting for 30.8% of all isolates, followed by Klebisella spp, Pseudomonas aeruginosa, Stenotrophomonas maltophilia, and Escherichia coli. Acinetobacter baumannii was poorly susceptible to piperacillin-tazobactam, cefepime, Amoxicillin+clavulonic acid, ciprofloxacin. However, the isolates were sensitive to Tigecycline, so as the isolates of Klebisella spp. Pseudomonas aeruginosa was mostly sensitive to Amikacin, followed by Tobramycin. All of the isolates of Staphylococcus aureus were susceptible to Linezolid, Tigecycline and Vancomycin. Conclusions: Gram-negative bacteria especially Acinetobacter baumannii, are the main pathogens for HAP in the observed EICU. The variety of pathogens should be monitored at regular intervals to improve resistance issues and therapeutic effect.     

The Distribution of Extracellular Cellulase Activity in Marine Eukaryotes,Thraustochytrids

Cellulolytic ability was evaluated in 19 strains of thraustochytrids, representing nine genera, using carboxymethylcellulose (CMC) as a substrate. Extracellular cellulolytic enzyme activity was determined in the culture supernatants during cell growth. CMC hydrolysis was observed in 14 out of the 19 strains examined. These belonged to the genera Aplanochytrium, Botryochytrium, Oblongichytrium, Parietichytrium, Schizochytrium, Sicyoidochytrium, Thraustochytrium and Ulkenia. On the other hand, cellulolytic enzyme activity was not detected in any strains belonging to the genus Aurantiochytrium.     

Identification of blood biomarkers of rheumatoid arthritis by transcript profiling of peripheral blood mononuclear cells from the rat collagen-induced arthritis model

Rheumatoid arthritis (RA) is a chronic debilitating autoimmune disease that results in joint destruction and subsequent loss of function. To better understand its pathogenesis and to facilitate the search for novel RA therapeutics, we profiled the rat model of collagen-induced arthritis (CIA) to discover and characterize blood biomarkers for RA. Peripheral blood mononuclear cells (PBMCs) were purified using a Ficoll gradient at various time points after type II collagen immunization for RNA preparation. Total RNA was processed for a microarray analysis using Affymetrix GeneChip technology. Statistical comparison analyses identified differentially expressed genes that distinguished CIA from control rats. Clustering analyses indicated that gene expression patterns correlated with laboratory indices of disease progression. A set of 28 probe sets showed significant differences in expression between blood from arthritic rats and that from controls at the earliest time after induction, and the difference persisted for the entire time course. Gene Ontology comparison of the present study with previous published murine microarray studies showed conserved Biological Processes during disease induction between the local joint and PBMC responses. Genes known to be involved in autoimmune response and arthritis, such as those encoding Galectin-3, Versican, and Socs3, were identified and validated by quantitative TaqMan RT-PCR analysis using independent blood samples. Finally, immunoblot analysis confirmed that Galectin-3 was secreted over time in plasma as well as in supernatant of cultured tissue synoviocytes of the arthritic rats, which is consistent with disease progression. Our data indicate that gene expression in PBMCs from the CIA model can be utilized to identify candidate blood biomarkers for RA.     

Migration timing influences the responses of birds to food shortage at their refuelling site

Because migration is highly time‐constrained and migration timing varies among individuals, the responses of migrants to food shortage at a refuelling site could differ between individuals that arrive early and late at the site. To test this hypothesis, we compared the stopover decision, in terms of occurrence and length of stay (LOS), of radiotagged Great Knots Calidris tenuirostris before (2012) and after (2015) a dramatic decline in food supply at a critical spring final pre‐breeding refuelling site in the northern Yellow Sea. The probability of occurrence at the refuelling site was consistent between the two years, whereas the average LOS significantly shortened in the year of food shortage in late‐arriving individuals. This suggests migration timing intensifies the influence of food shortage in late‐arriving individuals, which might be more sensitive and vulnerable to food shortage at refuelling sites compared with early‐arriving individuals.     

Maikottia属骨骼微细构造及其分类

Ｍａｉｋｏｔｔｉａ Ｌａｕｒｕｓｅｖｉｃｈ,１９６７属是泡沫珊瑚目中较特殊的类型,呈多角块状复体。经电镜研究表明,其骨骼微细构造以晶片型层状骨骼为主,隔壁刺由复式杆晶榍组成,层状骨骼包绕隔壁刺,在隔壁刺内包绕和联结单杆晶榍。体壁和横板均由层状骨骼组成。本属的纤状骨骼属较原始简单类型－晶粒和短轴晶柱,它组成复式杆晶榍内单杆晶榍的轴带,并呈分散状排列。根据该属为泡沫珊瑚类型隔壁及复式杆晶榍,将其归入泡     

Loss of p53 in mesenchymal stem cells promotes alteration of bone remodeling through negative regulation of osteoprotegerin

p53 plays a pivotal role in controlling the differentiation of mesenchymal stem cells (MSCs) by regulating genes involved in cell cycle and early steps of differentiation process. In the context of osteogenic differentiation of MSCs and bone homeostasis, the osteoprotegerin/receptor activator of NF-κB ligand/receptor activator of NF-κB (OPG/RANKL/RANK) axis is a critical signaling pathway. The absence or loss of function of p53 has been implicated in aberrant osteogenic differentiation of MSCs that results in higher bone formation versus erosion, leading to an unbalanced bone remodeling. Here, we show by microCT that mice with p53 deletion systemically or specifically in mesenchymal cells possess significantly higher bone density than their respective littermate controls. There is a negative correlation between p53 and OPG both in vivo by analysis of serum from p53^+/+, p53^+/−, and p53^−/− mice and in vitro by p53 knockdown and ChIP assay in MSCs. Notably, high expression of Opg or its combination with low level of p53 are prominent features in clinical cancer lesion of osteosarcoma and prostate cancer respectively, which correlate with poor survival. Intra-bone marrow injection of prostate cancer cells, together with androgen can suppress p53 expression and enhance local Opg expression, leading to an enhancement of bone density. Our results support the notion that MSCs, as osteoblast progenitor cells and one major component of bone microenvironment, represent a cellular source of OPG, whose amount is regulated by the p53 status. It also highlights a key role for the p53-OPG axis in regulating the cancer associated bone remodeling.Subject terms: Cell biology, Pathogenesis