Biomedical subjects

F A Neelon

Publications and source records attributed to F A Neelon.

70 records · Page 4Linked to original sources

PubMed1976

Chiasmal syndrome due to intrasellar abscess.

A 43-year-old woman had diabetes insipidus and amenorrhea. There was panhypopituitarism on endocrine testing and visual field examination showed inexorably progressive loss to bitemporal hemianopsia. All radiographic findings were normal, but craniotomy disclosed the cause of this chiasmal syndrome to be an intrasellar abscess which, on culture, grew a Gram-positive anaerobe, Peptococcus. Intrasellar or pituitary abscess is rare, but it must always be considered in the differential diagnosis of the chiasmal syndrome, since loss of pituitary and visual function may occur much more rapidly than with the tumors most often responsible for this syndrome and since surgical cure is possible.

Adult↗

PubMed1975

A comparison of the structure of hamster pancreatic insulin and insulin extracted from a transplantable hamster islet-cell carcinoma.

Insulin has been isolated from pancreases of the Syrian hamster and from a transplantable islet-cell tumor of the hamster. Acid/ethanol extraction, ether precipitation, ion exchange and gel filtration chromatography gave preparations of suitable purity for structural studies. Using trypsin cleavage, automatic Edman degradation and manual Edman degradation, a complete sequence of the pancreatic insulin B chain was determined. By automatic Edman degradation, the amino-terminal 10 residues of the pancreatic A chain were assigned and the sequence of carboxy-terminal eleven residues could be deduced by homology to other mammalian and avian insulins. The sequence assigned to hamster insulin A chain is identical to that of the rat, mouse and spiny mouse. The sequence of hamster insulin B chain is identical to rabbit and spiny mouse B chain. In terms of protein evolution, hamster insulin thus appears to occupy an intermediate position between rabbit and rat insulins. Amino acid composition, tryptic peptide composition and partial sequence analysis of the hamster tumor insulin showed no differences from hamster pancreatic insulin.

Adenoma, Islet Cell↗

PubMed1975

Stimulation of cartilage amino acid uptake by growth hormone-dependent factors in serum. Mediation by adenosine 3':5'-monophosphate.

The effects of growth hormone-dependent serum factors on amino acid transport and on cartilage cyclic AMP levels in embryonic chicken cartilage were studied in vitro. Cartilages incubated in medium containing rat serum showed a significantly greater uptake of alpha-amino [1-14C] isobutyrate or [1-14C] cycloleucine than control cartilages incubated in medium alone. Normal rat serum (5%) added to the incubation medium also caused an increase in cartilage cyclic AMP content (from as little as 23% to as much as 109%). The factors in serum which increase cartilage cyclic AMP and amino acid uptake are growth hormone dependent, since neither growth hormone itself nor serum from hypophysectomized rats restores these serum factors. Studies comparing the ability of sera with varying amounts of growth hormone-dependent factors to stimulate amino-aminoisobutyrate transport and to increase cartilage cyclic AMP show a striking linear correlation between the two effects (r=0.977). Theophylline and prostaglandin E1, WHICH RAISE CARTILAGE CYCLIC AMP also increase amino-aminoisobutyrate transport. Exogenous cyclic AMP, N6-monobutyryl cyclic AMP and n6, 02'-dibutyryl cyclic AMP increase cartilage amino-aminoisobutyrate transport. The data are compatible with the thesis that growth hormone-dependent serum factors increase cartilage amino acid transport by elevating cartilage cyclic AMP.

Amino Acids↗

PubMed1974