A case-control study on the duration of sleeping and cerebral infarction / 中华流行病学杂志

Objective To explore the relationship between duration of sleeping and cerebral infarction.Methods A case-control study involved 1037 cerebral infarction patients admitted by the Second Affiliated Hospital of Harbin Medical University,December 2011-December 2012 as cases.Another 1205 adults free from cerebro-vascular diseases who had undergone physical examination in the hospital at the same period,were served as controls.All the subjects were interviewed with unified questionnaire.Chi-square test,u-test and multivariate logistic regression analysis were performed.Results After adjustment for potential confounding factors including age,sex,body mass index,wrist-hip ratio,smoking,alcohol intake,hypertension,diabetes mellitus,coronary artery disease and lipid parameters,data from the multivariate logistic regression analysis showed that the risk of cerebral infarction was greater in people who slept less than 6 hours per night than those who slept between 6 hours and 8 hours per night,with an odds ratio (95％ CI) as 2.81 (95％ CI:1.68-4.70).There was no significant association between factor as ‘sleeping longer than 8 hours/pre day' and cerebral infarction.Through the subgroup analysis,data showed that the association between ‘ shorter than 6 hour sleep/night' and cerebral infarction consistently exsited,across the categories of sex,and the degree of association was greater in women than in men,with the odds ratio as 5.58 (95％CI:1.78-17.52) and 2.00(95％CI:1.10-3.64) respectively.Conclusion Short sleeping duration might increase the risk of developing cerebral infarction.

Analysis on variation of hemagglutinin genes of sixteen H9N2 subtype avian influenza viruses isolated in Shandong area / 病毒学报

In order to explore the genetic mutations of the H9N2 subtype avian influenza viruses isolated in Shandong, sixteen avian influenza virus subtype H9N2 were isolated from different areas of Shandong Province. The complete HA fragments of the viruses were amplified by RT-PCR and the sequences were analyzed on homology and heredity evolution after the cloning and sequencing of the products. The results showed that the amino acid motif of cleavage sites for all the sixteen virus in the HA gene were RSSR decrease GLF, which was consistent with the characterization of the LPAIV. Seven to nine potential glycosylation sites were found during the analysis and the receptor binding sites were relatively conservative except the 198 site. The Leucine(L) at the amino acid position 234 in the HA genes of all isolates indicated the potential of binding with SAalpha,2-6 receptor of mammals. Homology analysis showed that the homology of HA nucleotide and amino acid sequences was 96.3%-99.9% and 97.1%-99.6% for different strains. They belonged to a branch of the A/Duck/Hong Kong/Y280/97 in the phylogenetic tree.

Expression of annexin A7 in spermatogonial stem cells / 中华男科学杂志

<p><b>OBJECTIVE</b>To study the expression of Annexin A7 in the mouse testis, especially in different types of spermatogonia.</p><p><b>METHODS</b>We prepared Annexin A7 recombinant protein using prokaryotic expression, adsorbed the Annexin A7 antibody with it after identified by mass spectrometry, and detected the expression of Annexin A7 by Western-blot and immunohistochemistry.</p><p><b>RESULTS</b>Annexin A7 was expressed in a development-dependent manner in the spermatogonia of the prepubertal mice and in the type-A single (As) and type-A paired (Apr) spermatogonia of adult mice. These results were confirmed by the co-localization of Annexin A7 and Stra8, a known determinant of differentiated spermatogonial stem cells (SSCs).</p><p><b>CONCLUSION</b>Annexin A7 is the internal factor of As and Apr spermatogonia, which might be involved in the biological functions of SSCs.</p>

Analysis of viral etiology of severe pneumonia in infants and young children in Chongqing area / 中华儿科杂志

<p><b>OBJECTIVE</b>To investigate the prevalence of viral infections and putative association of viral infection with illness severity in young children with severe lower respiratory tract infection (LRTI) in Chongqing.</p><p><b>METHOD</b>Respiratory secretion specimens were collected from 119 hospitalized patients with severe pneumonia from December 2006 to March 2008.After being processed, the samples were detected for respiratory viruses including respiratory syncytial virus (RSV), adenovirus (ADV), human metapneumovirus (hMPV), human bocavirus (HBoV), parainfluenza virus 1, 2, 3 (PIV 1, 2, 3), influenza virus A and B (IVA and IVB) either by PCR or RT-PCR. Clinical data were analyzed along with virological data by using appropriate statistical methods.</p><p><b>RESULT</b>Viral pathogens were identified in specimens of 86 (72.3%) cases, among which RSV was detected in 49 (41.2%) patients. More than one virus was detected in 23 individual (26.7%) samples, of which 19 were dual positive for RSV and another virus. Bacterial cultures were performed for 69 patients. Both bacterial and viral pathogens were identified in 53 (76.8%) patients. Bacterial and viral coinfection was demonstrated in samples from 41 (59.4%) cases.</p><p><b>CONCLUSION</b>Viral pathogens are the main etiology of severe pneumonia in young children in Chongqing area during the study period. RSV was the most frequent viral pathogens, followed by ADV and hMPV. Coinfection with respiratory common viruses was relatively common, though co-infection with viruses did not appear to aggravate the patients' condition.</p>

Clinical evaluation of Nickel-Titanium rotary instruments in preparation of root canals / 中国基层医药

Objective To study and assess clinical application of two Nickel-Titanium(NiTi)rotary instru- ments,namely ProTaper and Hero 642,in preparation of root canals.Methods 125 teeth were divided into three groups and respectively instrumented by stainless K-files,ProTaper or Hero 642 rotary instruments.All teeth were obturated with lateral condensation method.The efficiency of preparation and obturation was analyzed with radio- graphs.Results NiTi rotary instruments were better in keeping the curvature and flow of curved canals than stain- less K files.There was no transportation,apical blockage and ledge in NiTi groups.The operative time was shorter and endodontic flare-up seldom occurred in NiTi groups.Conclusion The NiTi rotary instrumentation technique could be used to prepare curved root canals effectively and quickly.The future use of NiTi engine-driven rotary in- strument appeared to be promising.

Construction of TK Gene-deleted PRV SH StrainContaining a Single LoxP Site / 中国生物工程杂志

Pseudorabies virus (PRV) is a swine herpesvirus of the Alphaherpesvirinae subfamily and a pathogen of swine resulting in devastating disease and economic losses worldwide. Cre/loxP site-specific system has the character of site specific, time specific, tissue specific and high efficiency in recombination, which makes this system universal in vivo and in vitro recombination of bacteria, fungus, plants, insects and mammals. A recombinant PRV which contain a loxP site in TK locus by using Cre/LoxP recombinant system was construsted. A pair of primers were synthesized according to the pEGFP-C1 sequence published on GenBank, and were used to amplify the EGFP gene expression cassette with two loxP sites flanking each side. This target gene was cloned into pSKLR, the resulting transfer vector pSKLR-GFP-loxP was then cotransfected into 293T cells with PRV SH strain genomic DNA. The recombinant virus rPRV1 was selected and purified in TK-143 cells by choosing fluorescent expressing plaques. Cre expression vector pOG231 was cotransfected into 293T cells with rPRV1 genomic DNA. The second recombinant virus rPRV2 was obtained, which contains only one loxP site in TK locus. Sequencing results of rPRV2 TK gene indicated that 34bp loxP site was inserted into rPRV2 genome and there were 270bp deletion in TK gene. PCR amplifying different generations of rPRV2 TK gene showed that the mutant was stable when passages in RK-13 cells. TCID_ 50 assay indicated that rPRV2 grows well on RK-13 cells. The LD_ 50 test results on BALB/C mice suggested that the virulence of rPRV2 was reduced. As a conclusion, the report gene GFP expression cassette was removed successfully from rPRV1 genome and only one LoxP site was leaved in rPRV2 genome by using Cre/LoxP recombinant system.