[Structure and function of class 1 integron in clinical isolates of Klebsiella pneumoniae].

To investigate molecular mechanism of multi-resistance of Klebsiella pneumoniae and its spreading, 179 strains isolated from different clinical samples in the period of 2002-2007 with serious resistance to 14 anti-bacterial agents were examined. Among them, 118 (65.9%) were resistant to at least two anti-bacterial agents; 36.3% (65/179) were found to contain class 1 integrons. There was a significant difference for resistance rate between the integron positive and the negative groups, especially for antimicrobial agents of aminoglycosides, quinolones and sulfonamides (P<0.01). Gene cassette structures of the class 1 integrons in these bacteria were analyzed and their resistance genes were further cloned and tested for antibiotic resistance activities. Fifteen gene cassettes were identified with dfrA17-aadA5 being the most popular form. Three recombinant plasmids pET28a-dhfr17, pET28a-dhfr17-orfF and pET28a-dhfr17-orfF-aadA2 were cloned from a gene cassette of dhfr17-orfF-aadA2. When introduced into a recipient E. coli strain BL21, all of them rendered resistance to co-trimoxazole, with minimum inhibitory concentration (MIC) value up to 256 µg/µL. The E. coli BL21 carrying pET28a- dhfr17 or pET28a-dhfr17-orfF had the same MIC value of 8 µg/µL to streptomycin as the recipient strain without plasmid. However, the E. coli carrying pET28a-dhfr17-orfF-aadA2 was resistant to streptomycin with MIC level up to 256 µg/µL. In conclusion, class 1 integrons were regularly identified in Klebsiella pneumoniae. They mainly carry resistance genes against antimicrobial agents of aminoglycosides and sulfonamide. Transferable plasmid carrying integrons with resistance genes may play an important role in resistance spreading among bacterial species.

Clinical and genetic analysis of 8 Chinese pedigrees with inherited dysfibrinogenemia / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To analyze clinical manifestation and genetic mutations in 8 Chinese pedigrees featuring hereditary dysfibrinogenemia.</p><p><b>METHODS</b>Prothrombin time(PT), activated partial thromboplastin time(APTT), thrombin time(TT), calibration of plasma protamine sulfate against TT, fibrinogen (Fg) activity, coagulation factors II, V, VII, VIII, IX, X, XI and XII of all probands and their family members were detected with an automatic blood coagulation analyzer; D-dimer(D-D) and fibrin(ogen) degradation products(FDPs) were also dtected by automatic blood coagulation analyzer, Fg antigen were detected with an immunoturbidimetry method. Exons of fibrinogen genes FGA, FGB and FGG and flanking sequences were amplified by polymerase chain reaction(PCR) and sequenced.</p><p><b>RESULTS</b>All of the probands showed normal levels of FDPs, D-dimer(D-D) and activity of coagulation factor II,V,VII, VIII, IX,X,XI, XII. Plasma PT and APTT were normal or slightly prolonged. Prolonged TT was found in all of the probands, whilst TT was not significantly shortened by protamine sulfate. Fg antigen was within the normal range, but Fg activity was significantly decreased. The Fg antigen/activity ratio was greater than 2. One proband has carried a heterozygous variant of the FGA gene g.1233G>A(p.A α Arg35His). Four have carried a heterozygous mutation of the FGB gene g.9692A>G(p.Bβ Asn190Ser). The remaining 3 had heterozygous substitution of FGG gene g.10819G>A(p.γ Arg301His). In addition, 2 polymorphisms (p.A α Thr331Ala) and p.B β Arg478Lys) were identified in FGA and FGB genes.</p><p><b>CONCLUSION</b>p.A α Arg35His, p.B β Asn190Ser and p. γ Arg301His are responsible for the inherited dysfibrinogenemia in the 8 Chinese pedigrees. p.B β Asn190Ser is firstly reported in China. p.B β Asn190Ser and p. γ Arg301His may be mutation hot spot in the Chinese population.</p>

Association between CACNB2 gene polymorphisms and essential hypertension / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To assess the association between single nucleotide polymorphisms (SNPs) of calcium channel β 2 subunit (CACNB2) gene and essential hypertension (EH) in ethnic Han Chinese in Wenzhou area, and to study the influence of rs7069292 alleles on gene expression with luciferase reporter technique.</p><p><b>METHODS</b>Sixty hundred and thirty seven Han Chinese with EH and 600 normal controls were enrolled. Genotypes of 6 SNP within CACNB2 gene including rs2228645, rs2357928, rs7069292, rs7099380, rs10764319 and rs11014166 were determined with matrix assisted laser desorption ionization/time of flight mass spectrometer (MALDI-TOF MS). A luciferase reporter gene plasmid containing the fragment flanking rs7069292 (-2831 bp to -2460 bp) in the 5' regulatory region of CACNB2 was constructed.</p><p><b>RESULTS</b>Compared with the control, CT and TT genotypes for the rs7069292 locus were significantly more common in EH group (5.20% vs. 2.17%, 2.59% vs. 1.08%, P< 0.05). CC genotype was not found. Promoter activity for allele C of the rs7069292 locus was significantly increased compared with allele T (P< 0.05). No significant difference was detected for other 5 SNPs in terms of genotypes and allele frequency.</p><p><b>CONCLUSION</b>The rs7069292 CT polymorphism of the CACNB2 gene is associated with EH in ethnic Han Chinese from Wenzhou area. A T>C mutation may affect the expression of CACNB2.</p>

Changes of the peripheral Thelper cell cytokines of patients with chronic hepatitis B during antiviral treatment / 中华传染病杂志

Objective To determine the changes of peripheral levels of T helper cell cytokines of patients with chronic hepatitis B (CHB) during antiviral treatment,and to further explore its clinical significance.Methods The plasma levels of interleukin (IL)-2,IL-6,IL-10,interferon (IFN)-γ and tumor necrosis factor(TNF)-α of thirty-three CHB patients during antiviral treatment (entecavir) were measured using enzyme linked immunosorbont assay (ELISA).And their biochemical indicators of liver function were determined.The differences of cytokines levels before and after antiviral treatment were compared using ANOVA.The correlations between the changes of cytokines and alanine transaminase (ALT),hepatitis B virus (HBV) DNA levels were analyzed.Results Levels of IFNγ before and 12,24,48 weeks after treatment were (5.98±2.77),(5.95±3.37),(2.93±2.15) and (9.29±4.65) pg/mL,respectively (F=3.845,P＜0.05),which were positively correlated with ALT levels (r =0.396,P＜0.05).Both TNF-α and IL-10 levels declined after antiviral treatment,which were significantly different at different time points (F=20.156 and 16.695,respectively; both P＜0.05),and both levels of TNF-α and IL-10 were positively correlated with ALT levels (r=0.354and 0.316,respectively; both P＜0.05) and positively correlated with HBV DNA levels (r=0.382and 0.386,respectively; both P＜0.05).While both IL-2 and IL-6 levels were not significantly different between before and after antiviral treatment (F=0.010 and 0.932,respectively; both P＞0.05).The serum levels of ALT and HBV DNA before and after antiviral treatment were all significantly different (F=17.69 and 198.98,respectively; both P＜0.05),which declined gradually during treatment and were positively correlated (r =0.581,P＜0.05).Conclusions IL-10,IFNγand TNF-α may be involved in the pathologic process of CHB,and closely related to the deterioration of the disease.Monitoring plasma levels of these cytokines during antiviral treatment could be useful to understand the immune status and evaluate the efficacy of antiviral drugs.

The comparative study on three kinds of electrolytic analyzer / 中华检验医学杂志

0.975). The deviation of medical decision level was within 1.6. Conclusion Comparison among various analyzers were improved after the other analyzers corrected by the one comparable analyzer through the result of the fresh serums determined by it.