New strategies are needed for prevention of Pseudomonas aeruginosa (P. aeruginosa) infections, a widespread disease caused by P. aeruginosa with strong drug resistance. The immunoprotective capacity of the receptor of autoinducers protein LasR/RhlR was examined in the BALB/c mice. At first, specialized expression plasmids were developed to facilitate expression of LasR/RhlR proteins in Escherichia coli (E. coli). Then, biofilms were grown from clinical isolated P. aeruginosa PA0305 to investigate the relative contributions of cell signaling for biofilm formation. Morphological characters of biofilm were quantified using Image-Pro Plus software. Fluorescence analysis demonstrated that cell signal molecule LasR/RhlR significantly (P ＜ 0.05) influenced development of P. aeruginosa biofilm. Active immunization of mice with LasR/RhlR was found to provide significant protection against homologous challenge with P. aeruginosa in mice lungs. In 10 days after lungs inoculation, the bacterial clearance rate of the immunized mice was clearly higher than that of non-immunized groups on the basis of microbiological and histological assays. The protective effects of immunization with LasR and Rh1R together were the same as the result of LasR or Rh1R immunized mice alone. These data indicate that the manner ofLasR, Rh1R or both is an important determinant of immunoprotection in mice lungs infection.

OBJECTIVETo evaluate the role of p53 gene mutation in colorectal carcinoma and assess the value of peripheral blood p53 single nucleotide polymorphism (SNP) in early diagnosis of colorectal carcinoma.

METHODSNSP in axons 5-8 of p53 gene was detected using ligase detection reaction-polymerase chain reaction (LDR-PCR) in the peripheral blood of 100 patients with colorectal cancer and 100 healthy subjects.

RESULTSThe mutation rate of p53 gene was 24% (24/120) in colorectal carcinoma patients and 0% (0/120) in the healthy subjects (P<0.05).

CONCLUSIONp53 plays an important role in the carcinogenesis of colorectal carcinoma, and SNP analysis for p53 gene can be helpful in early diagnosis of colorectal carcinoma.

Adult ; Case-Control Studies ; Colorectal Neoplasms ; diagnosis ; genetics ; DNA Mutational Analysis ; DNA, Neoplasm ; genetics ; Early Detection of Cancer ; Female ; Humans ; Male ; Mutation ; Polymorphism, Single Nucleotide ; Tumor Suppressor Protein p53 ; genetics

Objective To investigate the change of expression pattern of microRNA in the lung with acute lung injury (ALI)/acute respiratory distress syndrome(ARDS) induced by lipopolysaccharide (LPS),and to provide an evidence that microRNAs are involved in the pathogenesis of ALI/ARDS.Methods Twenty-four C57BL mice were randomly divided into control group and LPS treated group,12 mice in each group.The rats in LPS treated group were treated with intratracheal injection of LPS at a dose of 10 mg/kg body weight into the lung.The rats in control group were treated with the same dose of saline instead.All mice were sacrificed 24 hours after operation,the left lung was excised to measure the wet-to-dry weight (W/D) ratio,and the right upper lobe was stained with hematoxylin and eosin (HE).A microRNA microarray chip was used to profile miRNA expressions in the lung of rats in both LPS treated group and control group.Online software packages were used to predict the gene targeted by microRNAs.Results Compared with the control group,the LPS treated mice had obvious respiratory symptoms,the W/D ratio was significantly increased (P ＜ 0.01),and the pathology was characterized with ALI/ARDS.The microarray chip results demonstrated that the expressions of 48 microRNAs were significantly changed in the ALI/ARDS mice.Among these miRNA,27 cases were up-regulated,21 cases were down-regulated.The target genes of these microRNAs might be involved in regulating the signal pathway of inflammation.Conclusions Some miRNAs express differently in the model of ALI/ARDS,and they may play an important role in pathophysiological process of ALI/ARDS.

OBJECTIVETo investigate the incidence, pathogens, and clinical features of infection in consecutive cases from 2010 to 2012 in Peking Union Medical College Hospital.

METHODThe incidence, pathogen, treatment, and outcomes of patients with hematological diseases who had positive findings of bacterium in their samples from 2010 to 2012 were retrospectively analyzed.

RESULTSThere were 449 positive samples (5.8%) from 4 890 patients during this period, among which 388 were proved to be with pathogenic bacteria. Samples separated from patients with community-aquired infections accounted for 8.4% of all positive samples. Most community-aquired infections were caused by Gram-negative bacteria (75%), although no multidrug-resistant bacteria was observed. Samples separated from patients with nosocomial infections accounted for 91.6% of all positive samples. Respiratory tract (49.4%) and peripheral blood (32.6%) were the most common samples with positive results. Skin soft tissues (10.4%), and urine (3.7%) were less common samples. Most of the pathogenic bacteria of the nosocomial infections were Gram-negative (66.9%). The most common Gram-negative bacteria included Escherichia coli (13.8%), Pseudomonas aeruginosa (12.1%), and Klebsiella pneumonia (12.1%), while Staphylococcus aureus (10.4%), Enterococcus faecium (7.0%), and Staphylococcus epidermidis (5.1%) were the most common Gram-positive bacteria. Gram-negative bacteria consisted of most of sputum samples and peripheral blood samples. Samples from the surface of skin wound and anal swab were composed largely by Gram-positive bacteria (63.8%). The detection rates of extended-spectrum beta-lactamase-producing Klebsiella pneumonia/Klebsiella oxytoca, Escherichia coli, and Proteus mirabilis were 24.0%, 87.9% and 38.4%, respectively. The resistance to Acinetobacter baumannii was serious. Multidrug-resistant, extensive drug resistant and pan drug resistant A. baumannii acountted for 74% of all A. Baumannii infections. Stenotrophomonas maltophilia showed low resistance to sulfamethoxazole/trimethoprim, levofloxacin and minocycline. Also, 22 methicillin-resistant Staphylococcus aureus and 9 methicillin-resistant Staphylococcus Epidermidis were detected, which were only sensitive to vancomycin, teicoplanin, and linezolid. All patients were treated in the haematology wards and most of them were under agranulocytosis or immunosuppression. Finally, 22 patients reached clinical recovery through anti-infective therapy, whereas 49 patients died. Among those deaths, 42 patients attributed to severe infections and infection-associated complications. Fourteen of all the deaths might be infected with drug-resistance bacteria. There were 61 samples proved to be bacteria colonization. Nonfermenters such as Acinetobacter baumannii and Stenotrophomonas maltophilia made up for a large amount of bacteria colonization.

CONCLUSIONSThe pathogens of nosocomial infections in the hematology ward are mainly Gram-negative bacteria. The incidences and pathogens vary from different infection sites. Nosocomial infection still has a higher mortality rate. Once nonfermenters are detected positive, the pathogenic or colonial bacteria should be distinguished.

Adolescent ; Adult ; Aged ; Aged, 80 and over ; Bacteria ; isolation & purification ; Bone Marrow Transplantation ; Cross Infection ; microbiology ; Female ; Hematologic Diseases ; complications ; microbiology ; Hematology ; Hospital Departments ; statistics & numerical data ; Humans ; Male ; Middle Aged ; Retrospective Studies ; Young Adult