Joint effect of school and family on domestic second-hand smoke exposure in middle school students / 中国学校卫生

Objective@#To observe the joint effect of school and family tobacco control on middle school students, and to explore its effectiveness in reducing second-hand smoke exposure in middle school students’ families, as so asto provide a new way of thinking for controlling smoking among middle school sudents.@*Methods@#A questionnaire survey was conducted on the study of 2 125 primary and high school students in four middle schools in the Dongcheng District of Beijing by means of a stratified group sampling method. Personal information of students, tobacco control environment around the family, school and surrounding ares, as well as the knowledge, attitude and behavior of students related to tobacco control was collected.@*Results@#The exposure rate of second-hand smoke in the families of middle and high school students in Dongcheng District of Beijing was 33.41%. Smoking by at least one parent was positively correlated with second-hand smoke exposure in the student’s home (OR=22.88, P<0.05). Among the students who saw the "clear no-smoking label" on campus, the exposure rate (4.92%) when the smoking restriction was set on the home was lower than that of those who did not have a regulation in the home (58.94%) (χ2=452.57, P<0.01). The results of Logistic regression showed that there was a combination of family smoking restrictions and second-hand smoke exposure in middle and high school students who had seen the smoking ban on campus (OR=0.08) and had the school’s tobacco control education (OR=0.08).@*Conclusion@#The joint tobacco control measures between school and family can effectively reduce the exposure rate of second-hand smoke in middle school students’ families, which is better than the effect of tobacco control alone.

A novel numerical model for protein sequences analysis based on spherical coordinates and multiple physicochemical properties of amino acids.

How to characterize short protein sequences to make an effective connection to their functions is an unsolved problem. Here we propose to map the physicochemical properties of each amino acid onto unit spheres so that each protein sequence can be represented quantitatively. We demonstrate the usefulness of this representation by applying it to the prediction of cell penetrating peptides. We show that its combination with traditional composition features yields the best performance across different datasets, among several methods compared. For the convenience of users, a web server has been established for automatic calculations of the proposed features at http://biophy.dzu.edu.cn/SNumD/.

Active-State Structures of a Small Heat-Shock Protein Revealed a Molecular Switch for Chaperone Function.

Small heat-shock proteins (sHsps) maintain cellular homeostasis by binding to denatured client proteins to prevent aggregation. Numerous studies indicate that the N-terminal domain (NTD) of sHsps is responsible for binding to client proteins, but the binding mechanism and chaperone activity regulation remain elusive. Here, we report the crystal structures of the wild-type and mutants of an sHsp from Sulfolobus solfataricus representing the inactive and active state of this protein, respectively. All three structures reveal well-defined NTD, but their conformations are remarkably different. The mutant NTDs show disrupted helices presenting a reformed hydrophobic surface compatible with recognizing client proteins. Our functional data show that mutating key hydrophobic residues in this region drastically altered the chaperone activity of this sHsp. These data suggest a new model in which a molecular switch located in NTD facilitates conformational changes for client protein binding.

A novel protein isolated from the serum of rabbitfish (Siganus oramin) is lethal to Cryptocaryon irritans.

The susceptibility of eight marine fish species cultured in South China were tested for infection by the parasitic ciliate, Cryptocaryon irritans, via a challenge examination and an immobilization assay. All species of fish (representing six different families) that we investigated were infected by C. irritans except the rabbitfish (Siganus oramin), which displayed resistance to C. irritans infection. The infection intensity of rabbitfish (0.92+/-0.97, p<0.05) was significantly lower while the immobilization titres of rabbitfish serum were significantly higher (44.51+/-22.98, p<0.05) than the other seven species of fish. Additionally, the serum of the rabbitfish presented a strong killing effect to C. irritans in vitro. Light microscopy, scanning electron microscopy and fluorescence microscopy confirmed that rabbitfish serum could induce the theront cilia fall off, rupture of the cell membrane because of the swell and rupture of the macronucleus. Rabbitfish serum could also induce the rupture of the trophont membrane and content efflux. Herein a novel antiparasitic protein (APP) was isolated and purified from the serum of rabbitfish (S. oramin) by using a series of salting-out, cation exchange chromatography and two step of reversed phase high performance liquid chromatography (RP-HPLC). Analysis of sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) showed that APP was a homogenous polymeric protein with an N-terminal amino acid sequence of SSVEKNLAACLRDND. Its monomeric molecular mass, determined by matrix-assisted laser desorption ionization tandem time-of-flight mass spectrometer (MALDI-TOF-TOF-MS), was found to be 61,739.87 Da. Results of homology analyses indicated that this protein was a newly discovered functional protein in the rabbitfish serum. Laser confocal fluorescence microscopy conformed that the action site of the APP was mainly on the cell membrane and nucleus of theront, which agreed with the results of light microscopy, fluorescence microscopy and scanning electron microscopy. These findings suggest that this protein may contribute considerably to the innate host defence mechanism to combat microbes of the rabbitfish.

[Six novel mutations in PAH gene detected by sequencing].

OBJECTIVE: To explore new mutation in phenylalanine hydroxylase (PAH) gene. METHODS: The PAH genes from 40 phenylketonuria (PKU) patients and 30 normal controls were screened by PCR-single strand conformation polymorphism (SSCP) and further sequencing. RESULTS: Eleven mutations and 3 polymorphisms in PAH gene were found. No abnormalities in the PAH gene from 30 controls were detected. CONCLUSION: M276K, M276R, 280insT, IVS10nt+32T-->A, IVS4nt+47C-->T were demonstrated as novel mutations in comparison with the PAH mutation database. One mission mutation (H290R) was first documented in Chinese PKU gene.