Physicochemical Processes of Biofilm Formation on The Surface of Structures in Water / 生物化学与生物物理进展

Microorganisms can form biofilms, complex, heterogeneous, multicellular communities that adhere to surfaces. Biofilm formation on the surface of structures in water will accelerate structures’ corrosion, seriously affect their service efficiency and life, and significantly impact the growth of animals, plants, and human life. Hence, clarifying the mechanism of biofilm formation contributes to developing new strategies to control biofilm formation on surface and then reduce infections, biofouling, and contaminations. Biofilm-targeting strategies include the regulation of established biofilms or the modulation of single-cell attachment. In most studies, physicochemical mechanism is frequently applied to explain the initial bacterial adhesion phenomena but rarely to explain other stages of biofilm formation. This review presents a five-step comprehensive description of the physicochemical process from film formation to biofilm maturation: (1) period of film formation; (2) period of bacterial adhesion; (3) period of extracellular-polymeric-substances (EPSs) membrane formation; (4) period of regulating biofilm by quorum sensing (QS); (5) period of biofilm maturation. We first clarify how the film formed by compound molecules affects the surface’s physicochemical properties and initial adhesion, summarizing many factors that affect bacterial adhesion. We then review the types of EPSs and signal molecules secreted by bacteria after irreversible adhesion, as well as their role and QS mechanism in biofilm maturation. Finally, we discuss how bacteria or microcolonies separate from the mature biofilm by physicochemical action and summarize the morphology and adhesion characterization methods after the biofilm matures. This review redefines the role of physicochemical in the whole process of biofilm formation and provides a theoretical basis for the prevention, removal, and utilization of biofilm and other related research fields.

Proteomics of epilepsy induced by focal disorder of cortical development / 中华神经医学杂志

Objective To explore the proteomics of epilepsy induced by focal disorder of cortical development (DCD) in revealing the molecular mechanisms of epilepsy caused by DCD and looking for the candidate targets and new therapeutic approaches in clinical practice. Methods Animal models of DCD were established and induced by liquid nitrogen in healthy Wistar newborn rats. Animal model of DCD were divided into epilepsy group and control group according to Racine classification. The proteomics maps of the frontal cortex were obtained in the epilepsy group and the control group by two-dimensional electrophoresis and both Coomassie brilliant blue G250 and silver dying. The proteomics profiles of frontal cortex were preliminary analyzed with PD Quest 7.3 analysis package. The differentially expressed protein spots were excised from gel and digested with trypsin under optimal conditions. The masses of tryptic-digested peptides were acquired with a Voyager DA-STR matrix assisted laser desorption ionization time of flight (MALDI-TOF) mass spectrometer. The acquired monoisotopic masses of analyzed proteins were matched in silico with theoretical peptide masses of human protein in the swiss-prot database with a mass tolerance of less than 50 ppm. Results One hundred and three proteins of differential expression were observed in the frontal cortex tissues of epilepsy associated with disorder of cortical development in rats, in which 64 were detected to be up-regulated and 39 were down-regulated. Finally, 12 proteins were identified as Lissencephaly-1 protein, synaptotagmin Ⅳ, Glial fibrillary acidic protein, HSP70, growth associated protein 43, neuronal enolase, tubulin beta chain, glutamine synthetase, neuron cytoplasmic protein, voltage-dependent anion channel proteins 1, pyruvate kinase and neurofilament light polypeptide. Conclusion These proteins may play pivotal roles in the pathogenic mechanisms of epilepsy caused by disorder of cortical development and may provide new therapeutic targets for refractory epilepsy in the future.

Current situation and influential factors concerning the sexual transmission of HIV in Dehong prefecture, Yunnan province / 中华预防医学杂志

<p><b>OBJECTIVE</b>To investigate the current situation of the sexual transmission of HIV in Dehong prefecture, analyze the influential factors, and provide support for drafting pertinent preventive interventions in the future.</p><p><b>METHODS</b>We had analyzed the data of case report from 2005 to 2007, and the prostitutes surveillance data from 2003 to 2007. A special survey was conducted from October 26 to November 7, 2007. Totally 685 people including prostitutes, the clients of prostitutes, people who were HIV positive and their partners, key insiders were interviewed in order to better understand the influential factors related to sexual transmission of HIV.</p><p><b>RESULTS</b>Among 1636 cases reported from January 1 to September 20, 2007, 52% were infected through sexual transmission. Among 586 cases infected through sexual transmission, 40.6% had commercial sexual behavior and 28.6% had unmarried sexual behavior. And the average rate of condom use was below 30%. The prostitutes' surveillance data from 2003 to 2007 showed that the HIV positive rate in prostitutes was 3.3% - 5.5%. The rate of condom use in the last month was 29.4% - 84.4% during commercial sexual activity, but it was 9.5% - 34.8% with fixed sexual partners. Although the rate of HIV and AIDS-related knowledge among prostitutes was 95.0%, there were still many misunderstanding regarding certain aspects of HIV and AIDS awareness.</p><p><b>CONCLUSION</b>Sexual transmission has become one of the main transmission routes of HIV in Dehong prefecture. The main factors involved in the sexual transmission of HIV in Dehong prefecture might include the wide spreading of sexual services, cohabitation among unmarried couples, having multiple partners, casual sexual behavior, and the low rate of condom use.</p>

Changes of Aspartate and Glutamate in Hippocampus Formation and Cerebrospinal Fluid in Kainite Acid Induced Epilepsy Rat / 实用儿科临床杂志

Objective To explore the changes of contents of glutamate (Glu) and aspartate (Asp) in hippocampus formation and cerebrospinal fluid (CSF) in kainite acid(KA) induced epilepsy rats.Methods SD rats(n=40) were divided into 2 groups randomly:the KA group [intracerebroventricular injection(icv) of KA, 2 ?g/kg] and control group(icv of NS). KA group were divided into 4 groups at 6 h,1,3 and 7 d,each group 8 rats.High pressure liquid chromatgraphy(HPLC) was used to assess the concentrations of Glu and Asp in hippocampus formation and CSF.Results In the hippocampus, the contents of Glu and Asp increased continuously 1 d after seizure , but not different from those of control group.Three days later, only Glu became significantly different from control group. However, the contents of Glu and Asp in the CSF were significantly different from the control 6 h after seizure.Conclusion The contents of excite amino acid (especially Glu)in CSF increase immediately after KA injection, which are earlier than those in hippocampus formation.

Mechanism of Neuron Injury of Rats with Kainite Acid-Induced Epilepsy / 实用儿科临床杂志

Objective To investigate the dynamic changes of glutamic acid(Glu) levels,ATP levels,free calcium ion,mitochondrial membrane potential,apoptosis related to mitochondrial pathways of apoptosis and Na+-K+-ATPase activity,and explore the mechanism of mitochondrial pathways of apoptosis in neuron injury of rats with kainite acid(KA)-induced epilepsy.Methods KA-induced epilepsy model was induced by injection of KA into the hippocampus.Forty SD rats were randomly divided into 2 groups: control group(n=8)and KA group(6 h,1 d,3 d,7 d,n=8).The concentration of Glu in hippocampus CA3 area was detected by high performance liquid chromatography.The apoptosis of hippocampus neurons and the concentration of Ca2+ were assayed by flow cytometry.The mitochondrial membrane potential was detected by JC-1.The Na+-K+-ATPase activity was examined.Results 1.The concentration of Glu in hippocampus increased at 3 d after KA injection and reached the peak after 7 d injection.2.The concentration of Ca2+ level,mitochondrial membrane potential,and the number of apoptosis neurons were significantly increased,wherase the mitochondrial membrane potential decreased after 6 h of KA injection,7 d after KA injection,and the changes were more severe.3.In the hippocampus,the activities of the Na+-K+-ATPase significantly decreased at 1 d after KA injection,and they decreased more over at 7 d after KA injection.4.The levels of ATP,mitochondrial membrane potential,and the activity of the Na+-K+-ATPase were negatively correlated with the neuron apoptosis(Pa