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M Demay

Publications and source records attributed to M Demay.

9 recordsLinked to original sources

Nucleotide sequence of cloned cDNAs encoding chicken preproparathyroid hormone.

In order to characterize an avian parathyroid hormone gene, a lambda gt10 cDNA library constructed from chicken parathyroid gland mRNA was screened with a human preproparathyroid hormone (preproPTH) cDNA probe. Nucleotide sequence analysis of three independent clones confirmed that they encoded chicken preproPTH. This analysis, complemented by primer extension and Northern blot analysis of mRNA, demonstrated a 5'-untranslated region for chicken preproPTH of 127 nucleotides, a coding region of 357 nucleotides, and a 3'-untranslated region of approximately 2500 nucleotides. The coding sequence predicts a mature chicken PTH of 88 amino acids in contrast to the 84 amino acids of the mammalian hormones. Comparison of the avian and the mammalian hormones shows striking homology in the region of amino acids 1-32. The middle and carboxyl-terminal portions of chicken PTH, however, differ considerably from the mammalian hormones and include deletions of sequences conserved in mammalian PTH and insertions of novel peptide sequences. Comparison of the avian and mammalian structures suggests potential alterations of the mammalian sequences that may lead to altered bioactivity and/or hormone metabolism.

Amino Acid Sequence

Comparison of renal and osseous binding of parathyroid hormone and hormonal fragments.

We compared receptor binding and adenylate cyclase stimulation of intact bovine parathyroid hormone (bPTH)-(1-84) and the synthetic amino-terminal fragments, bPTH-(1-34) and rat PTH (rPTH)-(1-34). Radioligands for binding studies were prepared by the lactoperoxidase technique and purified by high-pressure liquid chromatography. In both canine renal membranes and cloned rat osteosarcoma cells the amino-terminal fragments bound to a single order of sites; the affinity of rPTH-(1-34) exceeded that of bPTH-(1-34), correlating with its higher potency in stimulating adenylate cyclase. In studies with oxidized bPTH-(1--84), the middle and carboxyl regions of intact PTH were found to bind to both tissues but with higher affinity to osteosarcoma cells than to renal membranes. Our results demonstrate that rPTH-(1--34) is the most favorable probe of amino-terminal PTH binding and the most potent of the PTH peptides in stimulating renal and osseous adenylate cyclase. The results also show that midregion and carboxyl determinants within intact PTH contribute to hormone binding, which does not correlate with adenylate cyclase activation and appears more significant for skeletal than for renal binding.

Adenylyl Cyclases

Admissions to a provincial psychiatric hospital: the effects of opening a second in-patient facility.

Until 1955, the Saskatchewan Hospital, North Battleford, was the only facility designated for in-patient psychiatric treatment of the northern half of Saskatchewan's population. In that year the University Hospital's 39-bed psychiatric unit was opened in Saskatoon, but the number of Saskatoon patients referred to North Battleford have continued to increase.A statistical study of changes in the annual admission rates (patients/1000 population) to the Saskatchewan Hospital shows that the opening of the University Hospital unit has reduced the rate of intake of Saskatoon residents to the Saskatchewan Hospital. This decrease is related to specific diagnostic groups. There have also been changes in methods of referral.

Adolescent