Biomedical subjects

M E Colvin

Publications and source records attributed to M E Colvin.

21 records · Page 2Linked to original sources

PubMed1984

Eliminating barriers to the disabled.

Project Open House provides for the removal of architectural barriers in the homes of disabled low and moderate income New York City dwellers. This program was developed as a cooperative effort between United Cerebral Palsy of New York City, Inc., the New York City Mayor's Office for the Handicapped, and the Department of Housing Preservation and Development. Project Open House operates as follows. An occupational therapist evaluates both structure dwelling and client needs; this information is used as a basis for the prescription of structural modifications and equipment that will allow increased physical accessibility. On completion of the prescribed work, the therapist trains the individual and family in the use of the modifications. Project Open House and Family Support Services are community programs that provide a cost-effective method for improving the quality of life for disabled individuals and their families.

Activities of Daily Living↗

PubMedDate not supplied

Comparison of crystal structure and theory for 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine.

The crystal structure of the food mutagen 2-amino-1-methyl-6-phenylimidazo[4,5-b] pyridine (PhIP) has been determined by single-crystal X-ray crystallography. Crystals grown by evaporation of an aqueous solution form in the monoclinic space group P2(1)/n with two molecules of PhIP per asymmetric unit, along with six water molecules. The phenyl groups of these two PhIP molecules have torsion angles of different magnitude with respect to the plane of the imidazopyridine moiety. To maintain centrosymmetry, the crystal also contains an oppositely torsioned symmetry equivalent of each. The amino groups of both PhIP molecules take part in an extensive hydrogen bond network with the water of crystallization, forming long channels through the crystals parallel to the crystallographic b axis. The diffraction results are compared to theoretical calculations of the optimized geometry for a single PhIP molecule in vacuo as well as with water hydrogen-bonded to the exocyclic amine. In general, the agreement between the X-ray crystal structure of PhIP and its theory-derived counterpart in vacuo is within the combined experimental-theoretical uncertainty. The C-N bond to the exocyclic amine and the neighboring C=N imidazole bond are exceptions. This is attributed to the combined neglect of the crystal environment, waters of hydration, and the lack of coplanarity between the imidazole ring and the amine group in the calculations. To address the effect of waters of hydration, additional calculations were performed to optimize the geometry of a PhIP molecule with two water molecules hydrogen-bonded to the exocyclic amine. The resulting C-N exocyclic amine and C=N imidazole bond lengths were closer to those obtained by X-ray diffraction. The accord between theory and experiment demonstrates the utility of applying theory to (1) accurately predict structures of PhIP metabolites and intermediates that are too labile for study by conventional structural techniques such as X-ray crystallography and (2) assist in studying the mechanisms by which PhIP and its metabolites interact with proteins and DNA.

Crystallization↗

PubMedDate not supplied

Synthesis and analysis of glucuronides of N-hydroxyamides.

Reactions of five N-hydroxyacetylarylamines (N-hydroxyphenacetin, N-hydroxyacetanilide, N-hydroxy-p-chloroacetanilide, N-hydroxy-2-acetylaminonaphthalene, and N-hydroxy-2-acetylaminofluorene) with uridine 5'-diphosphoglucuronic acid catalyzed by immobilized glucuronyl transferase enzyme resulted in the formation of glucuronides conjugated at the N-hydroxyl group. Chromatographic properties of these compounds were examined by using thin layer, gas liquid, and high pressure liquid chromatography. A variety of mass spectrometric techniques were also evaluated for characterization of compounds of this class, including fast atom bombardment, chemical ionization, and electron impact. Electron impact spectra of the trimethylsilyl derivatives contain class characteristic ions and fragmentation pathways that would permit the special nature of the site of conjugation of this important class of compounds to be recognized in glucuronides of undetermined structure. Molecular ion species were not reliably detected in the electron impact spectra; however, these were readily distinguishable by the other two techniques.

Amides↗