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M C Thomas

Publications and source records attributed to M C Thomas.

At least 127 records · Page 7Linked to original sources
PubMed1987

The total assessment of rheumatoid polyarthritis--evaluation of a training program for physiotherapists and occupational therapists.

We evaluated a training program for physiotherapists and occupational therapists in the total assessment of patients with rheumatoid polyarthritis. Close agreement was seen between the active joint counts of the rheumatologists and 36 therapists (p2 = 0.23). In the 7 quality variables for bedside case workups, a statistically significant learning effect was seen over the 6 week period (p2 = less than 0.005). In the 10 quality variables for the case presentations at Week 6, judged at the graduate medical trainee level, mean global scores achieved were 72.5%. Therapists reported a high level of satisfaction with all components of the program.

Arthritis, Rheumatoid↗
PubMed1980

Biosynthesis of daunorubicin glycosides: role of epsilon-rhodomycinone.

Daunorubicin (daunomycin; NSC 82151) is a fermentation-derived anthracycline antibiotic that is clinically useful in the treatment of human leukemias. Daunorubicin itself is found rarely in microbial fermentations, but is present normally in the form of glycoside derivatives that yield the free drug on simple acid hydrolysis. A major by-product of daunorubicin fermentations is usually the structurally related anthracyclinone epsilon-rhodomycinone. We have used mutants of a daunorubicin-producing Streptomyces species to study the biosynthetic relationship between epsilon-rhodomycinone and daunorubicin. We found that exogenously added epsilon-rhodomycinone can be converted to daunorubicin glycosides by a nonproducing mutant and by a mutant that produces daunorubicin glycosides but not epsilon-rhoeomycinone. Molar conversion efficiences were in the 15 to 30% range. The latter mutant was also shown to convert exogenous 14C-labeled epsilon-rhodomycinone to 14C-labeled daunorubicin glycosides, again at conversion efficiencies of about 25%. The same biotransformation was observed with daunorubicin production strain C5, which normally accumulates both epsilon-rhodomycinone and daunorubicin glycosides. A significant percentage (16 to 37%) of exogenously added epsilon-[14C]rhodomycinone was metabolized by strain C5, and 22 to 32% of the metabolized radioactivity could be recovered as daunorubicin glycosides. A mathematical model of epsilon-rhodomycinone metabolism was constructed based on plausible assumptions concerning the kinetics of epsilon-rhodomycinone accumulation and catabolsim. When analyzed according to this model, our data indicate that most (63 to 73%), but not all, of the daunorubicin glycosides accumulated in the experiments with production strain C5 derived from epsilon-rhodomycinone. A pathway network for the biosynthesis of daunorubicin glycosides is proposed that is in agreement with these data. In this proposed pathway network, epsilon-rhodomycinone is an intermediate in one of at least two pathways which yield daunorubicin glycosides.

Anthracyclines↗
PubMed1977

Microbial reduction of the side-chain carbonyl of daunorubicin and N-acetyldaunorubicin.

Microorganisms reduced the side-chain carbonyl of daunorubicin to yield 13-dihydrodaunorubicin (daunorubicinol; daunomycinol). This microbial transformation occurred under aerobic conditions in agitated baffled shake flasks incubated at 37 degrees C. The microorganisms were first grown in a medium which supported dense growth. Daunorubicin-HCl was then added. Following a period of incubation, broths were adjusted to pH 10.0 and extracted with chloroform. Daunorubicinol was recovered and purified from the chloroform extracts by preparative TLC. Identity of the daunorubicinol was established by TLC and spectroscopy (UV-vis, IR, NMR, MS, CD and ORD). N-Acetyldaunorubicin was likewise reduced microbially to N-acetyldaunorubicinol. N-Acetyldaunorubicinol appears to be a new compound which is yet to be tested for antitumor activity.

Bacteria↗
PubMedDate not supplied

Towards the physical map of the Trypanosoma cruzi nuclear genome: construction of YAC and BAC libraries of the reference clone T. cruzi CL-Brener.

Strategies to construct the physical map of the Trypanosoma cruzi nuclear genome have to capitalize on three main advantages of the parasite genome, namely (a) its small size, (b) the fact that all chromosomes can be defined, and many of them can be isolated by pulse field gel electrophoresis, and (c) the fact that simple Southern blots of electrophoretic karyotypes can be used to map sequence tagged sites and expressed sequence tags to chromosomal bands. A major drawback to cope with is the complexity of T. cruzi genetics, that hinders the construction of a comprehensive genetic map. As a first step towards physical mapping, we report the construction and partial characterization of a T. cruzi CL-Brener genomic library in yeast artificial chromosomes (YACs) that consists of 2,770 individual YACs with a mean insert size of 365 kb encompassing around 10 genomic equivalents. Two libraries in bacterial artificial chromosomes (BACs) have been constructed, BACI and BACII. Both libraries represent about three genome equivalents. A third BAC library (BAC III) is being constructed. YACs and BACs are invaluable tools for physical mapping. More generally, they have to be considered as a common resource for research in Chagas disease.

Animals↗