PubMed Health⌕ Search

Biomedical subjects

I MacIntyre

Publications and source records attributed to I MacIntyre.

At least 217 records · Page 12Linked to original sources
PubMed1973

Regulation of vitamin D metabolism: factors influencing the rate of formation of 1,25-dihydroxycholecalciferol by kidney homogenates.

The formation of 1,25-dihydroxycholecalciferol from 25-hydroxycholecalciferol by chick kidney homogenates is inhibited by increasing concentrations of Ca(2+). The apparent K(m) for the hydroxylation reaction is 1x10(-7)m, significantly lower than that reported for isolated mitochondria. Separated cytoplasmic and particulate fractions are inactive, but on recombination activity is restored, possibly because of the presence in the soluble fraction of a factor with a high affinity for 25-hydroxycholecalciferol.

Animals↗
PubMed1972

Paget's disease in a 5-year-old: acute response to human calcitonin.

A five-year-old boy presented with a three-and-a-half-year history of repeated bone fractures and progressive bone deformity. The excretion of hydroxyproline in the urine was greatly increased, and serum alkaline phosphatase and acid phosphatase levels were very high. These abnormalities together with the findings on bone histology and radiology suggested a diagnosis of juvenile Paget's disease. Human calcitonin reduced the bone turnover as evidenced by an immediate and sustained fall in urine hydroxyproline excretion, while calcium and phosphate balance became more positive. This treatment is therefore being continued on an outpatient basis.

Acid Phosphatase↗
PubMed1972

Immunochemical studies on human calcitonin M leading to information on the shape of the molecule.

1. Two antisera were obtained from a single rabbit. Both are highly specific for human calcitonin M but react with different parts of the amino acid sequence. 2. The different sequences that react with the antibodies of the two antisera were located. The first antiserum reacts at two sites in the molecule, one in the sequence residues 11-18, probably with residue 17 as the immunodominant group, and another on either side of the 28-29 peptide bond. The second antiserum, harvested 9 months later, reacts principally at one site bridging the 28-29 peptide bond. 3. A consideration of the properties of the hormone's binding sites and of data relating biological activity to structure enables some conclusions to be drawn with regard to the shape of the molecule. It appears that the peptide chain is folded to bring N- and C-termini closer together and that there is non-covalent interaction between regions in the chain near both termini. One of these is located near residue 8.

Amino Acid Sequence↗