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Biomedical subjects

M L Chan

Publications and source records attributed to M L Chan.

6 recordsLinked to original sources
PubMed1981

Selective area tuberculosis surveys in Singapore 1978.

A random population sample survey in Singapore 1975 revealed that a relatively high proportion of active pulmonary tuberculosis patients remained undiagnosed, mainly in the older age groups. Previous studies disclosed the cause to the lack of symptoms of concern in these patients. A new programme was devised to discover hidden elderly patients by mass chest X-ray screening of population aged 45 years and older living in areas with known high incidence of tuberculosis. The yield of cases was less than expected mainly due to the dislocation and dispersion of population from recent extensive urban re-development in Singapore. Nevertheless the results were comparable to the most productive case finding programme carried out in this department.

Aged↗
PubMed1976

Further characterization of a lipopolysaccharide from Coxiella burneti.

The lipopolysaccharide previously isolated from the rickettsial agent of Q fever, Coxiella burneti, phase I, has been further characterized. The sugar residues ribose, mannose, gluclose, D-glycero-D-mannoheptose, and L-glycerto-D-mannoheptose are present. Two sugars remain unidentified, one of which is a minor and the other a major constituent. Isomyristic, palmitic, and beta-hydroxymyristic acids are the major fatty acid residues of the 15 identified. The nature and content of other lipopolysaccharide constituents are presented.

Coxiella↗
PubMedDate not supplied

Synthesis and characterization of singly modified (carboxyferrocenyl)cytochrome c derivatives.

Carbodiimide-activated coupling chemistry has been used to covalently attach 1,1'-dicarboxyferrocene (dcFc) to the epsilon-amine of surface lysine residues of horse heart cytochrome c. Conditions have been found that optimize the production of singly modified (dcFc)cytochrome c derivatives and the presence of one free carboxylate per modification site allows separation and purification of about 10 of these derivatives by cation-exchange chromatography. Reversed-phase HPLC tryptic peptide mapping techniques have been used to identify the attachment sites of eight pure (dcFc)cytochrome c derivatives (at lysines 7, 8, 13, 25, 60, 72, 73, and 100). Through-space distances from these lysines to the nearest heme edge span the 6-16 A range and these derivatives should prove useful in exploring the distance dependence of long-range intramolecular electron transfer in cytochrome c.

Animals↗