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Biomedical subjects

M M Campbell

Publications and source records attributed to M M Campbell.

At least 37 records · Page 2Linked to original sources
PubMed1989

A novel beta-turn location in an LHRH antagonist: a combined conformational search and molecular dynamics study.

A 50 pico-second molecular dynamics simulation on a cyclic LHRH antagonist analogue Ac-D-Phe1-D-Phe2-D-Trp3-Ser4-Glu5-D-Arg6-Leu7-Lys8+ ++-Pro9-D-Ala10-NH2 (where the cyclisation is via an amide linkage between the Glu5 and Lys8 side chains), reveals some hitherto unseen conformational features. The LHRH analogue is found to adopt a near beta-sheet type of conformation with the reversal in the chain being brought about by a D-Trp3-Ser4-Glu5-D-Arg6 beta turn. The N- and C-terminal ends of the peptide come close together and interact through a network of hydrogen bonds. Additional hydrogen bonds expected of a sheet type of conformation stabilise the lowest energy minima. A conformational search of all possible cyclic structures of a model system c(Glu-D-Ala-Ala-Lys) which was used to determine the starting structure for the simulation studies of the cyclic LHRH antagonist analogue is also highlighted. The influence of the cyclic part on the conformation of this LHRH analogue is discussed.

Amino Acid Sequence↗
PubMed1981

Citrinin toxicity in growing chicks.

Male broiler chicks, from day-old to 3 weeks of age, were fed diets containing 0, 100, 220, 330, and 440 ppm citrinin produced by Penicillium lanosum grown on whole corn. Body weight decreased (P less than .05) when chicks were fed the diets containing 330 and 440 ppm citrinin. Average body weight of chicks fed the diet containing 220 ppm citrinin was 8% less than that of chicks fed no toxin. Feed utilization decreased (P less than .05) with chicks fed the diet containing 440 ppm citrinin. Analysis of thigh muscle, kidney, liver, and blood for citrinin revealed detectable amounts in the liver and blood of chicks fed 440 ppm.

Animals↗
PubMed1979

Adolescents with myelodysplasia: impact of physical disability on emotional maturation.

Certain physical, psychological and social characteristics of 20 adolescents with myelodysplasia are compared to those of age and gender-matched controls. In addition to the obvious physical differences the areas of greatest concern are self-esteem and social-sexual adjustment. Family relations, feelings, and modes of expression were not different in the two groups. Lack of appropriate chores, decreased opportunities to interact and compete with peers, plus uncertainties to interact and compete with peers, plus uncertainties about bowel and bladder continence appear to be the greatest impediments to emotional growth in this physically handicapped group of teenagers. Early recognition of such problems and finding strategies to overcome them are important aspects of the comprehensive care of any person with a chronic disability.

Adolescent↗
PubMed1974

Calcification of selected strains of Streptococcus mutans and Streptococcus sanguis.

Nine strains of cariogenic Streptococcus mutans and two strains of Streptococcus sanguis were tested for their ability to form hydroxyapatite. The cells were examined by X-ray diffraction and electron microscopy for apatite crystals after growth in a synthetic calcification medium. Each of the test isolates, except for one strain of S. sanguis, produced intracellular mineral. Two strains of S. mutans formed both intra- and extracellular crystals. There was no apparent relationship between calcifiability and serotype.

Apatites↗