Tomoko Minagawa | PubMed Health

PubMed2002

Continuous-flow chemical processing on a microchip by combining microunit operations and a multiphase flow network.

A new design and construction methodology for integration of complicated chemical processing on a microchip was proposed. This methodology, continuous-flow chemical processing (CFCP), is based on a combination of microunit operations (MUOs) and a multiphase flow network. Chemical operations in microchannels, such as mixing, reaction, and extraction, were classified into several MUOs. The complete procedure for Co(II) wet analysis, including a chelating reaction, solvent extraction, and purification was decomposed into MUOs and reconstructed as CFCP on a microchip. Chemical reaction and molecular transport were realized in and between continuous liquid flows in a multiphase flow network, such as aqueous/aqueous, aqueous/organic, and aqueous/organic/aqueous flows. When the determination of Co(II) in an admixture of Cu(II) was carried out using this methodology, the determination limit (2sigma) was obtained as 18 nM, and the absolute amount of Co chelates detected was 0.13 zmol, that is, 78 chelates. The sample analysis time was faster than that of a conventional processing system. Moreover, troublesome operations such as phase separation and acid and alkali washing, all necessary for the conventional system, were simplified. The CFCP methodology proposed here can be applied to various on-chip applications.

Journal Article↗

PubMed2002

[Mycobacterium abscessus infection complicated with diabetes mellitus].

We report a case of Mycobacterium abscessus infection complicated with diabetes mellitus. A 38-year-old man with diabetes mellitus as an underlying disease, was admitted to our hospital because of a productive cough. He had had pulmonary tuberculosis two years before. Chest radiography revealed infiltration in both lung apices and chest CT showed a cavitary lesion in the left upper lobe. Gaffky 2 was found on a sputum smear. However, in the examination of PCR on sputum, not only M. tuberculosis but M. avium complex was negative, and repeated cultures of sputum were positive for M. abscessus. On the basis of the diagnosis of an M. abscessus infection, the patient was initially treated with amikacin, imipenem/cilastatin and levofloxacin during hospitalization while receiving insulin for diabetes mellitus. The smear and culture of sputum became negative for Mycobacterium, and the findings of chest radiography and chest CT improved. After discharge, treatment was continued with clarithromycin and levofloxacin. It is considered that the choice of effective drugs and the additional treatment of an underlying disease are very important for the treatment of a Mycobacterium abscessus infection.

Adult↗