Tailored Synthesis of Catalytically Active Cerium Oxide for N, N-Dimethylformamide Oxidation.

Cerium oxide nanopowder (CeOx) was prepared using the sol-gel method for the catalytic oxidation of N, N-dimethylformamide (DMF). The phase, specific surface area, morphology, ionic states, and redox properties of the obtained nanocatalyst were systematically characterized using XRD, BET, TEM, EDS, XPS, H2-TPR, and O2-TPO techniques. The results showed that the catalyst had a good crystal structure and spherelike morphology with the aggregation of uniform small grain size. The catalyst showed the presence of more adsorbed oxygen on the catalyst surface. XPS and H2-TPR have confirmed the reduction of Ce4+ species to Ce3+ species. O2-TPR proved the reoxidability of CeOx, playing a key role during DMF oxidation. The catalyst had a reaction rate of 1.44 mol g-1cat s-1 and apparent activation energy of 33.30 ± 3 kJ mol-1. The catalytic performance showed ~82 ± 2% DMF oxidation at 400 °C. This work's overall results demonstrated that reducing Ce4+ to Ce3+ and increasing the amount of adsorbed oxygen provided more suitable active sites for DMF oxidation. Additionally, the catalyst was thermally stable (~86%) after 100 h time-on-stream DMF conversion, which could be a potential catalyst for industrial applications.

[Comparison of the proteome of Mycobacterium tuberculosis with Bovine mycobacterium by immuno-proteomic technology].

OBJECTIVE: To compare the proteome of Mycobacterium tuberculosis (MTB) H(37)Rv strain with Bovine mycobacterium (Bacillus Calmette-Guerin, BCG) strain at the sub-cellular level. METHODS: Proteins of the cell wall, membrane and cytolymph of H(37)Rv and BCG were extracted by density gradient centrifugation. Sub-cellular proteome of H(37)Rv and BCG were analyzed using 2-dimensional liquid chromatography. The immunity reactions of H(37)Rv fractions with sera from patients (n = 5) and healthy controls (n = 5), as well as BCG fractions with sera from healthy controls (n = 5) were analyzed by ELISA. Data was analyzed by t test. RESULTS: Twenty-six fractions of H(37)Rv were found to elicit specific antibody response. Fraction M3Fr18 of H(37)Rv reacted with sera from patients. The A(450) [(721 ± 3) × 10(-3)] was higher than that with sera from healthy controls [(356 ± 6) × 10(-3)], as well as the A(450) of the corresponding fractions of BCG with sera from healthy controls [(414 ± 7) × 10(-3)]. The differences between the patient group and the 2 healthy control groups were significant (t = 1.852 and 1.037, all P < 0.01). Moreover, fraction M10Fr21 of H(37)Rv reacted with sera from the patients. The A(450) [(954 ± 6) × 10(-3)] was higher than that with sera from the healthy controls [(415 ± 6) × 10(-3)], as well as the A(450) of the corresponding fractions of BCG with sera from the healthy controls [(315 ± 4) × 10(-3)]. The differences between the patient group and the 2 healthy control groups were significant (t = 2.113 and 2.550, all P < 0.01). CONCLUSIONS: The combination of 2-dimensional liquid chromatography and immunology technology is useful in finding antigens associated with MTB infection. Fractions M3Fr18 and M10Fr21 can elicit specific immune reaction among MTB patients, suggesting that they may be specific antigens of MTB infection.

[Evaluation of the GenoType MTBDRplus assay for rifampin and isoniazid susceptibility testing of Mycobacterium tuberculosis].

OBJECTIVE: to evaluate the ability of GenoType MTBDRplus Assay for detection of rifampin (RFP) and isoniazid (INH) resistance in Mycobacterium tuberculosis. METHODS: seventy-five clinical isolates were tested for traditional drug susceptibility testing and GenoType MTBDRplus assay. The results were compared to assess the sensitivity and specificity of GenoType MTBDRplus assay. RESULTS: the sensitivity of GenoType MTBDRplus assays for detection of RFP and INH resistance were 98.0% and 86.5%, respectively. In pan-susceptible isolates of Mycobacterium tuberculosis, the specificity was 100% for both RFP resistance and INH resistance. CONCLUSION: with its high sensitivity and specificity, GenoType MTBDRplus assay is a promising rapid method to detect INH and RFP resistant Mycobacterium tuberculosis strains in Shanghai.

[Multiple infections of Mycobacterium tuberculosis in treated patients].

OBJECTIVE: To identify multiple infections of Mycobacterium tuberculosis in tuberculosis patients. METHODS: From the clinical isolates of M. tuberculosis during 1999 to 2004 stored at Shanghai Municipal Center for Disease Control and Prevention, cases who had two isolates with different drug resistance patterns in the same treatment episode were selected. The first isolate from the selected patients was inoculated onto Middlebrook 7H11 agar plates, and 30 single colonies from each isolate were picked and genotyped by the 7 loci Variable Number Tandem Repeat (VNTR) method. RESULTS: Two out of 22 isolates had two different genotypes among their 30 single colonies, and the proportions of the two genotype colonies were 24:6 and 29:1. The other 20 isolates showed identical genotype pattern among their 30 single colonies. CONCLUSION: Multiple infections of M. tuberculosis occurred in tuberculosis patients in Shanghai.

[The prevalence and risk factors of drug-resistant tuberculosis among migratory population in Shanghai, China].

OBJECTIVE: To determine the prevalence of and risk factors for drug-resistant tuberculosis among migratory population in Shanghai. METHODS: All sputum culture positive patients among migratory population, confirmed at any district (county) tuberculosis dispensary in Shanghai from February 2004 to January 2005, were enrolled. The drug susceptibility test was performed by the proportion method. Univariate and multivariate analysis were performed to determine the risk factors associated with drug resistance. RESULTS: 493 patients were enrolled during the study period, among whom 431 patients had bacterial identification and drug susceptibility results. Of the 431 strains, 427 (99.1%) strains were Mycobacterium tuberculosis and 4 (0.9%) strains were Mycobacterium non-tuberculosis. The prevalence of drug-resistant tuberculosis among new cases and re-treatment cases was 16.0% (62/387) and 40.0% (16/40), respectively. The prevalence of MDR-tuberculosis among new cases and re-treatment cases was 4.1% (16/387) and 22.5% (9/40), respectively. A history of previous treatment for tuberculosis and age group of 45 - 60 years were significantly associated with drug resistance. CONCLUSION: The prevalence of drug-resistant tuberculosis among migratory population was relatively high in Shanghai, suggesting the necessity to strengthen the tuberculosis control program for migratory population.

[Primary drug-resistance is the main cause of drug-resistant tuberculosis].

OBJECTIVE: To investigate the main cause of drug-resistant tuberculosis. METHODS: Clinic isolates of Mycobacterium tuberculosis from 1996 to 2004 in Shanghai were analyzed and the proportion of isolates from new cases (the proxy of primary drug-resistance) and retreatment cases (the proxy of acquired drug-resistance) were calculated. Mycobacterial interspersed repetitive units (MIRU) genotyping was performed and analyzed on pairs of isolates of Mycobacterium tuberculosis from 16 recurrent patients with drug-resistant tuberculosis. RESULTS: Of all 8 120 isolates of Mycobacterium tuberculosis from new cases, 707 isolates (8.7%) were drug resistant. Of all 610 isolates from retreatment cases, 150 isolates (24.6%) were drug resistant. Primary drug resistance accounted for 82.5% (707/857) of all drug resistant isolates. Based on the MIRU genotypes, 13 of all 16 recurrent drug-resistant patients were reinfected with new drug-resistant strain of Mycobacterium tuberculosis. CONCLUSION: Primary drug-resistance is the main cause of drug-resistant tuberculosis.

[Study on the cause of tuberculosis recurrence by Mycobacterium tuberculosis genotyping method].

OBJECTIVE: To study the contribution of exogenous reinfection to tuberculosis recurrence. METHODS: Mycobacterium tuberculosis isolates from patients who had experienced 2 successive tuberculosis episodes during the years from January 1999 to March 2004 were genotyped by mycobacterial interspersed repetitive units (MIRU) method. The cause of tuberculosis recurrence was determined by comparing the MIRU pattern of Mycobacterium tuberculosis isolates responsible for different tuberculosis episodes from patients. RESULTS: Of 37 qualified patients with recurrent tuberculosis, the isolates from 25 patients in their two tuberculosis episodes showed different MIRU patterns, indicating that 68% recurrent patients were due to exogenous reinfection. The exogenous reinfection rate decreased with the age from 3/3 (under 30 years) to 73% (11/15, 30 to 60 years) and 58% (11/19, over 60 years). The frequency of exogenous reinfection increased with the tuberculosis recurrent interval. Within 6 months, the exogenous reinfection accounted for 58% (7/12) of all the recurrence, while for the time more than one year, the percentage increased to 79% (11/14). CONCLUSIONS: Exogenous reinfection was a major cause of tuberculosis recurrence in Shanghai. MIRU genotyping method is useful to study the cause of tuberculosis recurrence.

[Evaluation of the mycobacterial interspersed repetitive units typing as a practical approach in molecular epidemiology of Mycobacterium tuberculosis].

OBJECTIVE: To introduce a new genotyping method, mycobacterial interspersed repetitive units (MIRU) typing, for Mycobacterium tuberculosis and to evaluate its feasibility. METHODS: Mycobacterium tuberculosis strains stored at Shanghai Municipal Center for Disease Control and Prevention during 2000 to 2002, were randomly selected by simple digital table and genotyped by MIRU and Spoligotyping. RESULTS: By Spoligotyping method, 91 strains were typed to 20 genotypes, of which 89% (81/91) strains belonged to Beijing genotype, while by MIRU method, these strains were divided into 46 genotypes. The MIRU typing showed high discriminatory power, especially for the Beijing genotype strains. The 81 Beijing genotype strains could be subdivided into 39 different MIRU genotypes. In this sample collection, 12 MIRU loci showed different discriminative according to their allelic diversity. Locus 26 showed highly discriminative, while locus 16, 31, and 40 showed moderately discriminative. CONCLUSIONS: MIRU genotyping is a simple and fast method. Its numerical result facilitates the comparison among strains of Mycobacterium tuberculosis from different labs.

[Prevalence and risk factors on the resistance related to second-line drugs among multi-drug resistant tuberculosis cases in Shanghai, China].

OBJECTIVE: To determine the prevalence and risk factors on second-line drug resistance in patients with multidrug resistant tuberculosis (MDR-TB) in Shanghai, China. METHODS: All pulmonary TB patients with sputum culture positivity detected in Shanghai during January to December, 2009, were enrolled. All of the pretreatment sputum-positive cultures samples were tested for routine specimen identification and routine drug susceptibility testing for first-line drugs (Isoniazid, Rifampin, Ethambutol and Streptomycin). Drug susceptibility testing on second-line anti-TB drugs (Ofloxacin, Amikacin, Kanamycin, Capreomycin, P-aminosalicylic acid and Prothionamide) was routinely performed on isolates of Mycobacterium (M.) TB with MDR. Logistic regression analysis was conducted to determine the risk factors regarding second-line drug resistance. RESULTS: A total of 1867 patients infected with M. TB isolates were diagnosed at the TB hospitals/clinics in Shanghai during the study period, of whom 112 (6.0%) were MDR-TB, in which 58 cases (51.8%) showed resistant to at least one of the second-line drugs tested and 10 cases belonged to extensively drug-resistant. In the multivariate analyses, MDR-TB patients who were aged 45 - 59 years (aOR = 4.76, P = 0.001), with sputum smear positivity (aOR = 6.51, P = 0.026) were significantly more likely to show resistance to second-line drugs. CONCLUSION: The prevalence of second-line drug resistance among MDR-TB patients was high in Shanghai. MDR-TB patients who were under age of 45 - 59 years and with sputum smear positivity would represent important common risk factors for the resistance to second-line drugs.

Validity and reliability testing of the Chinese (mainland) version of the 39-item Parkinson's Disease Questionnaire (PDQ-39).

The 39-item Parkinson's Disease Questionnaire (PDQ-39) has been tested in many languages, but not in Chinese mainland. We aimed to assess the Chinese (mainland) version of the PDQ-39. Seventy-one subjects with Parkinson's disease (PD) completed the PDQ-39 and the Medical Outcomes Study 36-item Short Form Health Survey (SF-36). All subjects were retested with the PDQ-39 a week later. The united Parkinson's disease rating scale (UPDRS) and the Hoehn and Yahr (H & Y) scale were also used to evaluate the subjects. Reliability was assessed by Cronbach's alpha and intra-class correlation coefficient (ICC). Validity was examined in terms of agreement with SF-36, UPDRS, and H & Y scales. The Chinese (mainland) version of the PDQ-39 demonstrated acceptable reliability (Cronbach's alpha: 0.84-0.88; ICC: 0.56-0.82). The item-total correlations (0.33-0.88) and scaling success rates (77.56%) indicated satisfactory convergent and discriminant validity of the PDQ-39 items. The correlations between related constructs of the PDQ-39 and UPDRS (r=0.44-0.68) and between those of the PDQ-39 and SF-36 (r=(-0.46)-(-0.69)) were all statistically significant (P<0.01). Except for stigma, cognitions, and bodily discomfort, all other dimensions of the PDQ-39 significantly discriminated patients at different H & Y stages indicated by the H & Y scale. Although our observations indicate that some problematic subscales of this version of the PDQ-39 could be improved upon, this study suggests acceptable reliability and validity of the Chinese (mainland) version of the PDQ-39.

Association between embB codon 306 mutations and drug resistance in Mycobacterium tuberculosis.

embB306 mutants were detected in both ethambutol (EMB)-resistant and EMB-susceptible strains of Mycobacterium tuberculosis. Multidrug-resistant (MDR) strains had a higher proportion of embB306 mutants than non-MDR strains (odds ratio, 6.78; P < 0.001). The embB306 locus is a candidate marker for rapid detection of MDR and extremely drug resistant tuberculosis.