Objective:To clone and characterize the 16S rRNA of six species in the bacteria infecting respiratory tract to make gene chip.Methods:The primers of the target gene were designed and synthesized,and then the aimed fragment of the 16s rRNA was amplified by PCR and cloned.Finally the recombinant plasmids were characterized.Results:(1)The 16s rRNA gene of six species of bacteria was amplified.It was found that the size of amplified product by PCR was 1 300 bp in E.coli,S.aureus,S.pneumoniae,K.pneumoniae and H.influenzae and that of 1 100 bp in P.aeruginosa.(2)The JM109 transferred by the recombinant plasmid pMD18-T grew in Ampr culture was white colonies.(3)The specific bands could be found by restriction endonuclease and PCR analysis. (4)The sequence of the six bacterial 16s rRNA showed the same as those in the GenBank.Conclusion:The 16s rRNA of six species of bacteria is successfully amplified and cloned into plasmid pMD18-T. It will provide the basis for making gene chip detecting the six species of bacteria infecting respiratory tract.

Purpose Brain complications severely threaten the treatment and survival of children with leukemia. This paper aims to investigate the MRI manifestations and differences of brain complications in leukemia before and after chemotherapy for a clinical guidance.Materials and Methods The clinical data and MRI findings of 37 children with leukemia and brain complications were retrospectively analyzed. Thirty-four of them underwent MRI scan twice or more, among whom 28 received contrast-enhanced MRI scan.Results Twenty-two patients were discovered with brain complications before chemotherapy, 2 of whom were with two kinds of complications. Meningopathy was found in 7 patients who showed widespread or localized meningeal thickening. Among them, 5 patients'' lesions reduced or disappeared after chemotherapy. Intracerebral multiple small and micro bleed was found in these 7 patients, 2 of them combined with hematoma. Three patients were found with intracranial tumor which all proved to be temporal bone tumor, 1 of whom combined with temporal lobe tumor and 1 had tumor disappeared after chemotherapy. The other complications before chemotherapy included leukoencephalopathy (n=2), subdural collection of fluid (n=2), meninges and parenchymal infiltration of leukemia (n=1), fungal infection (n=1) and cerebral infarction (n=1). On the contrary, 17 patients were discovered with brain complications after chemotherapy, 8 of whom were with two or more complications. Two patients had different kinds of complications before and after chemotherapy. Brain atrophy was observed in 13 patients. Leukoenphalopathy was found in 9 patients who presented high signal in white matter of double periventricular and/or semi-oval center on T2WI; the lesions of 4 patients were reduced or disappeared after withdrawal. Infectious diseases were diagnosed in 3 patients, including viral encephalitis in 2 cases, tuberculous meningitis combined with tuberculoma in 1 case. The other complications included intracranial tumor (n=2), sinus thrombosis (n=1), posterior reversible encephalopathy syndrome (n=1) after chemotherapy. Conclusion The MRI findings of brain complications in childhood leukemia are various and demonstrate significantly different features before and after chemotherapy. The major complications before treatment include meningopathy and intra-cerebral hemorrhage;while after chemotherapy the main complications are brain atrophy, leukoencephalopathy and infectious diseases. MRI proves to be a valuable method to detect, observe and follow up these complications.

Beijing has been one of the epicenters attacked most severely by the SARS-CoV (severe acute respiratory syndrome-associated coronavirus) since the first patient was diagnosed in one of the city's hospitals. We now report complete genome sequences of the BJ Group, including four isolates (Isolates BJ01, BJ02, BJ03, and BJ04) of the SARS-CoV. It is remarkable that all members of the BJ Group share a common haplotype, consisting of seven loci that differentiate the group from other isolates published to date. Among 42 substitutions uniquely identified from the BJ group, 32 are non-synonymous changes at the amino acid level. Rooted phylogenetic trees, proposed on the basis of haplotypes and other sequence variations of SARS-CoV isolates from Canada, USA, Singapore, and China, gave rise to different paradigms but positioned the BJ Group, together with the newly discovered GD01 (GD-Ins29) in the same clade, followed by the H-U Group (from Hong Kong to USA) and the H-T Group (from Hong Kong to Toronto), leaving the SP Group (Singapore) more distant. This result appears to suggest a possible transmission path from Guangdong to Beijing/Hong Kong, then to other countries and regions.
Genome, Viral ; Haplotypes ; Humans ; Mutation ; Open Reading Frames ; Phylogeny ; SARS Virus ; genetics