Quorum sensing is defined as the cell density-dependent regulation of gene expression, and the involved system is the quorum sensing system, in which N-acyl homoserine lactone is known as the signal molecules of most gram-negative organisms. It can regulate diverse physiological functions. This paper reviewed the quorum sensing systems and the recent advances which play a major role in the formation of the symbiosis between the rhizobia and their host plants.

The Baculoviridae are a large family of enveloped DNA viruses exclusively pathogenic to arthropods. Baculoviruses have been extensively used in insect cell-based recombinant protein expression system and as biological pesticides. They have been deomostrated to be safe to mammals, birds and fish. Recently, baculoviruses has been shown to transduce different mammalian cells in spite of the fact that they cannot replicate in mammalian cells (11, 73, 76). This has resulted in the development of baculoviruses as mammalian expression systems and even as vestors for gene therapy.

Child, Preschool ; Histoplasmosis ; complications ; pathology ; Humans ; Lymph Nodes ; pathology ; Male ; Mycobacterium Infections ; etiology

strains of fast-growing rhizobia isolated from Chinas western (mainly from Qinghai province),and 4 representative strains were compared by performing numerical taxonomy. 132 phenotypic characteristics were analyzed. The results of numerical taxonomy constructed a dendrogram. It shows that all the strains examined clustered into five phena at a similarity level of 79%. 16S rDNA PCR-RFLP were applied to 57 rhizobial strains (among the 61 strains) and 10 reference strains. The 16S rDNA-RFLP analysis described 20 different genotypic characteristics and form one dendrogram. For some large groups, the results of 16S rDNA-RFLP were agreement with that of numerical analysis of phenotypic characteristics.

Eustachian Tube ; abnormalities ; surgery ; Humans ; Laser Therapy ; Male ; Middle Aged ; Prosthesis Implantation ; Stents ; Tympanoplasty

Objective To investigate the correlation between the degree of pathogenetic condition and cogni-tive impairment in young OSAHS patients. Methods Sixty-three patients (18～44 years old) were divided into 3 groups according to the assessment criteria regarding the degrees of pathogenetic conditions of hypoxemia and its persistence time: mild group(the lowest SaO2 ≥ 85 %, n = 20 ), moderate group (the lowest SaO2 : 65 ～ 84 %, n =24), and severe group (the lowest SAO2<65%, n= 19). Twenty-five healthy young adults were selected as the control group. All the subjects were tested with event-related potential, namely P300, the polysomnogram and the mini-mental state examination scale(MMSE). Results P300 latency in patients of three OSAHS groups was sig-nificantly prolonged as 326.1±12.7, 346.9±19.1, and 34.9±18.3 ms, as compared with those of control group: 311.9±18.3 ms (P< 0.05, respectively). In severe group, P300 latency was markedly increased compared with mild and moderate groups(P<0.01, P<0.05, respectively). No obvious differences were observed between mild and moderate groups(P=0. 095). The difference of hypoxemia lasting time could influence the P300 latency, such as when the hypoxemia lasting time was 4～60 seconds, the latency was 338. 12±13.7 ms, and when the hypoxemia lasting time increased to 60 ～ 140 s, the latency was prolonged to 354.74±16.7 ms(P = 0. 031 ). There was no difference among all groups in the P300 amplitudes. The MMSE scores for all patients were within normal limits andthere were differences between serve and control group(RA -RB=9. 91, P= 0. 003). Conclusion Among patients with OS-AHS, the impairment of cognitive function is con'anon. The degrees of pathogenetic conditions of hypoxemia and its lasting time may be used to evaluate the impairment degree of cognitive function in patients with OSAHS.

Objective To observe the effects of repeated +10 Gz stress on cerebral lipid peroxidation,liver and renal function in rats and the prophylactic effects of antioxidant tea polyphenols(TP).Method Twenty-four male Wistar rats were randomly divided into three groups(n=8 each):group A(control),group B(+10 Gz),and group C(TP).Group B and C were exposed to repeated +10 Gz stress(each for 30s,onset rate about 0.5 G/s,3 times/d with +1 Gz 1 min intervals,3 d/wk,4 weeks in total),but group A was only submitted to +1 Gz.TP(200 mg/kg) was given orally in group C about 1 h prior to the +Gz experiment,while distilled water was given in group A and B.Lipid peroxidation in the brain,liver and renal functions and serum lipids were determined.Results As compared with the control,lipid peroxidation in rat cerebral homogenate,mitochondria and cytoplasm was significantly increased( P<0.05),and serum creatinine concentration was markedly elevated after repeated +10 Gz stress(P<0.01).But,TP had significant inhibitory effect on +10 Gz stress induced peroxidative injury in rat brain and reduced the serum creatinine level.There were no differences of serum triglyceride and total cholesterol concentrations and glutamic-pyruvic transaminase activity among the three groups.Conclusion These results indicated that repeated high +Gz stress could bring about peroxidative injury in brain and harmful effect on renal function,and natural antioxidant TP had signficant protective effects.

We aimed to make comprehensive cancer care guidelines of China according to American guidelines of National Comprehensive Cancer Network,Ametican Society of Clinical Oncology and Oncology Nursing Society,and to guide clinical nurses to study and draw lessons from foreign latest guidelines,and combined with the actual situation in our country.The results of study and application were advantageous to the nursing profession,the security and interests of the patients.We should develop comprehensive cancer care guidelines of our country,eventually make nursing practice guide system of China constantly improve and perfect.

Baculovirus has many advantages as vectors for gene transfer. We demonstrated that recombinant baculovirus vectors expressing p35 (Ac-CMV-p35) and eGFP (Ac-CMV-GFP) could be transduced into human kidney 293 cells efficiently. The level of transgene expression was viral dose dependent and high-level expression of the target gene could be achieved under the heterogonous promoter. MTT assay suggested that both Ac-CMV-p35 and Ac-CMV-GFP did not have cytotoxic effect on human embryo kidney 293 cells. Cell growth curve showed the Ac-CMV-p35 and Ac- CMV-GFP transduced and non-transduced cells had similar proliferation rate, so baculovirus-mediated p35expression had no adverse effect on cell proliferation. In addition, baculovirus-mediated p35 gene expression protected human embryo kidney 293 cells against apoptosis induced by various apoptosis inducers such as Actinomycin D, UV or serum-free media. These results suggested that the baculovirus vector mediated p35 gene expression was functional and it could be widely used in molecular research and even gene therapy.

Adolescent ; Child ; Child, Preschool ; CpG Islands ; Cyclin-Dependent Kinase Inhibitor p15 ; genetics ; DNA Methylation ; Female ; Humans ; Leukemia, Myeloid, Acute ; genetics ; Male ; Promoter Regions, Genetic