Biomedical subjects

M Tuomela

Publications and source records attributed to M Tuomela.

3 recordsLinked to original sources

PubMed2005

Validation overview of bio-analytical methods.

Several regulatory challenges are encountered when proceeding towards human clinical trials with gene therapy products, one of these relating to the validity of the analytical methods. Many of the analytical methods used in preclinical studies and/or for analysing the gene therapy products are not yet recognized as a standardized pharmacopoeial methods. Thus, their validity should be demonstrated for the regulatory authorities by thorough assay validations, the extent being dependent on the product developmental stage. We hereby provide an overview on the critical parameters that have to be taken into consideration during the optimization and validation of bio-analytical methods such as PCR, enzyme-linked immunospot assay, Microarray and Limulus Amebocyte Lysate analyses.

Biological Assay↗

PubMed2003

Lignin degradation in a compost environment by the deuteromycete Paecilomyces inflatus.

Two strains of the deuteromycete Paecilomyces inflatus were isolated from compost samples consisting of municipal wastes, paper and wood chips. Lignin degradation by P. inflatus was studied following the mineralization of a synthetic (14)C(beta)-labeled lignin (side-chain labeled dehydrogenation polymer, DHP). Approximately 6.5% of the synthetic lignin was mineralized during solid-state cultivation of the fungus in autoclaved compost; and 15.5% was converted into water-soluble fragments. Laccase was the only ligninolytic enzyme detectable when the isolates were grown in autoclaved compost. Production of the enzyme was growth-associated and dependent on the culture conditions. The optimal pH for laccase production was between 4.5 and 5.5 and the optimal temperature was around 30 degrees C. Activity levels of laccase increased in the presence of low-molecular-mass aromatic compounds, such as veratryl alcohol, veratric acid, vanillin and vanillic acid.

Benzaldehydes↗

PubMed2001

Biodegradation of radiolabelled synthetic lignin (14C-DHP) and mechanical pulp in a compost environment.

Mineralization of radioactive synthetic lignin (14C-DHP) was studied in a compost environment at 35, 50 and 58 degrees C. Compost samples were successively extracted with water, dioxane and alkali, and the molecular weight distribution of some extracts was determined by gel permeation chromatography (GPC). Biodegradation of lignin-containing spruce groundwood (SGW) and pine sawdust was concurrently determined in controlled composting tests by measuring evolved CO2. The temperatures were the same as in the 14C-DHP mineralization experiment and bleached kraft paper, with a lignin content of 0.2%, was used as a reference. The mineralization of 14C-DHP was relatively high (23-24%) at 35 degrees C and 50 degrees C, although the mixed population of compost obviously lacks the most effective lignin degraders. At 58 degrees C the mineralization of 14C-DHP, as well as the biodegradation of SGW and sawdust, was very low, indicating that the lignin-degrading organisms of compost were inactivated at this temperature. SGW was poorly biodegradable (<40%) in controlled composting tests compared with kraft paper (77-86%) at all temperatures, which means that lignin inhibits the degradation of carbohydrates. During the incubation, water-soluble degradation products, mainly monomers and dimers, and the original 14C-DHP were either mineralized or bound to humic substances. A substantial fraction of 14C-DHP was incorporated into humin or other insolubles.

Biodegradation, Environmental↗