A simple and reliable electroanalytical method for the fast determination of aluminum in natural and drinking waters by a. c. oscillopolarography using solochrome violet RS(SVRS) is described. The alkaline buffer solution used was 0.85 mol/L NH3·H2O- NH4 Cl(pH 8.8) containing 5 × 10-5 mol/L SVRS. A sensitive incision due to the redox reaction of Al-SVRS complex adsorption wave on the Hg-film electrode was observed on the dE/dtE oscillogram at - 1.05 V. The incision depth was linearly proportional to the A1 concentration in the range of 1 ×10-7 ～6 × 10-6 mol/L. No serious interference was found. The detection limit of this method was 5 × 10-8 mol/L,and the relative standard deviation was 5.5% for 2 × 10-7 mol/L Al ( n = 10). This method was successfully applied to the determination Al in 22 real samples. The results were found to be in good agreement with those obtained by inductively coupled plasma-atomic emission spectrometry.

Objective To compare the infectivity of several transformed Chlamydia trachomatis (Ct) mouse pneumonitis (Mopn) strains to host cells, and to identify cell invasion-related virulence genes in Chlamydial plasmids. Methods Several Ct strains, including wild-type Ct Mopn strain(WT strain), plasmid-free Ct strain(CMUT3 strain), Ct Mopn strain transformed with the shuttle vector carrying pGFP and the complete C. muridarum (CM) plasmid (pGFP::CM strain)and Ct Mopn strains transformed with shuttle vectors carrying pGFP and mutant CM plasmids with in-frame deletions of Pgp3, 4, 5 or 7 (pGFP::CM△Pgp3, 4, 5, 7 strains), were cultured, amplified and collected. After the concentrations of Ct were determined, each of these strains was divided into four groups to be inoculated at a same amount(1.5 × 104 inclusion forming units(IFU)) followed by four different treatments respectively: centrifugalization +DEAE group treated with centrifugalization followed by ion-exchange chromatography on diethylaminoethyl(DEAE)-cellulose columns, centrifugalization group treated with centrifugalization only, DEAE group treated with chromatography on DEAE-cellulose columns only, control group receiving no treatment. After additional culture for 20 - 24 hours, indirect immunofluorescence assay was performed to count the number of chlamydial inclusions. At 20, 40 and 60 hours after infection, the growth rate and area of chlamydial plaques were assessed after three continuous passages. Lugol′s iodine staining was conducted to observe glycogen synthesis in bacterial inclusions. Results The inclusion number in the centrifugalization + DEAE group, centrifugalization group, DEAE group and control group was 10.20 ± 1.30, 6.80 ± 0.44, 3.00 ± 1.22 and 0.80 ± 0.45 respectively for the pGFP::CM△Pgp4 strain, 6.40 ± 0.89, 3.80 ± 0.83, 1.60 ± 0.89 and 0.60 ± 0.54 respectively for the CMUT3 strain. Under same experiment conditions, the pGFP::CM△Pgp4 strain and CMUT3 strain showed similar infectivity, and formed less inclusions compared with the other Ct strains (all P < 0.01). The number of inclusions formed by the same Ct strains were significantly different among the 4 groups(F = 845.310, P <0.01), and were highest in the centrifugalization + DEAE group for all the strains. The pGFP::CM△Pgp4 strain showed significantly lower growth rate and area of plaques with an abnormality in glycogen accumulation compared with the other strains at 20, 40 and 60 hours after infection. Conclusion The plasmid-encoding gene Pgp4 may be a cell invasion-associated virulence gene in chlamydial plasmids.

OBJECTIVETo get the genotype and allele frequency distribution of 6 short tandem repeat (STR) loci VWA, FGA, PENTAE, D6S1043, D2S1772, D7S3048 in NongQu Mongolia of China.

METHODSTwo hundred and ninety-three unrelated individuals from Nongqu Mongolian were investigated. Polymerase chain reaction and polyacrylamide gel electrophoresis were used.

RESULTSEighty alleles and 335 genotypes were detected, with frequencies ranging from 0.0017 to 0.2828. All the 6 loci met Hardy-Weinberg equilibrium. The statistical analysis of 6 STR loci showed the heterozygosity (H) >/= 0.7945, the discrimination power (DP) >/= 0.9160, the probability of paternity exclusion (PPE) >/= 0.5919, and the polymorphic information content (PIC) >/= 0.7617.

CONCLUSIONThese results could serve as valuable data to enrich the Chinese genetic database and play an important role in Chinese population genetic forensic medical application.

Alleles ; China ; Electrophoresis, Polyacrylamide Gel ; Gene Frequency ; Genotype ; Humans ; Linkage Disequilibrium ; Microsatellite Repeats ; genetics ; Polymerase Chain Reaction ; Polymorphism, Genetic ; genetics

Adult ; China ; Contraceptive Agents, Female ; therapeutic use ; Data Collection ; Female ; Humans ; Intrauterine Devices ; Levonorgestrel ; therapeutic use ; Patient Education as Topic ; statistics & numerical data