Facile Cleavage of Si-C Bonds during the Sol-Gel Hydrolysis of Aminomethyltrialkoxysilanes - A New Method for the Methylation of Primary Amines

International audienceThe reaction of chloromethyltriethoxysilane with (1R,2R)-bis(methylamino)cyclohexane (1) afforded the corresponding bis-silylated compound 2. The sol-gel hydrolysis of 2 did not give the expected bridged silsesquioxane owing to quantitative Si-C-bond cleavage. Instead, silica and (1R,2R)-bis(dimethylamino)cyclohexane (3) were obtained. This reaction was exploited to propose a new route for the methylation of amines. Such methylation reaction of amines could be extended to other amines and provides a new method for the selective monomethylation of primary amines

Drug adherence and efficacy of smear microscopy in the diagnosis of pulmonary tuberculosis after 2 months of medication in North-western Tanzania

Objectives: The study aimed at assessing the Tuberculosis (TB) medication adherence level and the efficacy of smear microscopy in the diagnosing pulmonary TB at month 2. Methods: A prospective study was conducted at the four sites located in the Northern-western Tanzania. New smear positive, pulmonary TB patients were followed up and their adherence to TB medication assessed after 2 months of the treatment. In addition, the acid fast bacilli (AFB) smear microscopy was performed after 2 and 5 months of the treatment. All smear positive samples were subjected to geneXpert (MTB/RIF) assay and culture on the Lowenstein Jensen (LJ) media. Results: A total of 331 smear positive, newly diagnosed patients with pulmonary TB were enrolled. The median age was 36 [Interquartile range (IQR): 28–45] years and males formed the slightly majority, 187 (56.5%) of the participants. A total of 105 (31.7%) patients were infected with HIV. Out of 331 patients, 36 (10.9%) were still AFB smear positive at the end of two month. Of these 19 (52.8%) were positive on GeneXpert MTB RIF and none was Rifampicin resistant. Of note, only 13 (31.1%) were culture positive (viable). None of the patients was positive at month 5. Poor adherence to TB medications in the first 2 months of treatment was observed in 56/331 (16.9%) [95% CI = 12.9–21.0] of the patients. Conclusion: Over two thirds of smear positive patients are wrongly put in one month extension of the intensive phase treatment; this may cause increased costs and drug toxicity. Culture should be advocated to confirm smear positivity after 2 months of medications. TB treatment drug adherence in our setting is good and is associated with successful cure. No multidrug resistant tuberculosis (MDR-TB) was observed. Continued surveillance and emphasizing of TB drug adherence should be kept upbeat in order to control tuberculosis in developing countries

Investigation of household contacts of pulmonary tuberculosis patients increases case detection in Mwanza City, Tanzania

CITATION: Beyanga, M. et al. 2018. Investigation of household contacts of pulmonary tuberculosis patients increases case detection in Mwanza City, Tanzania. BMC Infectious Diseases, 18:110, doi.org/10.1186/s12879-018-3036-6.The original publication is available at https://bmcinfectdis.biomedcentral.comBackground: Tuberculosis (TB) contact tracing is a key strategy for containing TB and provides addition to the passive case finding approach. However, this practice has not been implemented in Tanzania, where there is unacceptably high treatment gap of 62.1% between cases estimated and cases detected. Therefore calls for more aggressive case finding for TB to close this gap. We aimed to determine the magnitude and predictors of bacteriologically-confirmed pulmonary TB among household contacts of bacteriologically-confirmed pulmonary TB index cases in the city of Mwanza, Tanzania. Methods: This study was carried out from August to December 2016 in Mwanza city at the TB outpatient clinics of Tertiary Hospital of the Bugando Medical Centre, Sekou-Toure Regional Hospital, and Nyamagana District Hospital. Bacteriologically-confirmed TB index cases diagnosed between May and July 2016 were identified from the laboratory registers book. Contacts were traced by home visits by study TB nurses, and data were collected using a standardized TB screening questionnaire. To detect the bacterioriologically-confirmed pulmonary TB, two sputum samples per household contact were collected under supervision for all household contacts following standard operating procedures. Samples were transported to the Bugando Medical Centre TB laboratory for investigation for TB using fluorescent smear microscopy, GeneXpert MTB/RIF and Löwenstein–Jensen (LJ) culture. Logistic regression was used to determine predictors of bacteriologically-confirmed pulmonary TB among household contacts. Results: During the study period, 456 household contacts from 93 TB index cases were identified. Among these 456 household contacts, 13 (2.9%) were GeneXpert MTB/RIF positive, 18 (3.9%) were MTB-culture positive and four (0.9%) were AFB-smear positive. Overall, 29 (6.4%) of contacts had bacteriologically-confirmed pulmonary TB. Predictors of bacteriologically-confirmed pulmonary TB among household contacts were7being married (Odds ratio [OR], 3.3; 95% confidence interval [CI], 1.4–8.0; p = 0.012) and consuming less than three meals a day (OR, 3.7; 95% CI, 1.6–8.7; p = 0.009). Conclusions: Our data suggest that in Mwanza, Tanzania, seven in 100 contacts living in the same house with a TB patient develop bacteriologically-confirmed pulmonary TB. These results therefore underscore the need to implement routine TB contact tracing to control tuberculosis in high TB burden countries such as Tanzania.Medical Mission Institute, Wuerzburg, GermanyPublishers versio

Structural Evolution of Self-Assembling Nanohybrid Thin Films from Functionalized Urea Precursors**

Hybrid organic-inorganic thin films exhibiting patterned structuring on the nanometer scale have been prepared through the controlled hydrolysis-condensation of enantiomerically pure chiral urea-based silyl compounds. The thin films are obtained by spin-coating of sols obtained via acid- or base-catalyzed hydrolytic condensation of these molecular precursors. A self-templating process is demonstrated via atomic force and transmission electron microscopy, showing the formation of nanometer size aggregates consisting of interconnected spherulates under acidic condition and of assembled fibers under basic conditions