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Biomedical subjects

A B Robinson

Publications and source records attributed to A B Robinson.

50 records · Page 3Linked to original sources
PubMed1973

Acceleration of the rate of deamidation of GlyArgAsnArgGly and of human transferrin by addition of L-ascorbic acid.

Experiments on the model peptide, GlyArgAsnArgGly, and the protein, human transferrin, have shown that hydrolytic deamidation of these molecules is markedly accelerated by addition of physiologically significant concentrations of l-ascorbic acid. Since hydrolytic demidation has been suggested as an important timer of biological events, the effects on hydrolytic deamidation of substances that are normally present in living organisms and are subject to nutritional control are of special relevance.

Amides↗
PubMed1971

Quantitative analysis of urine vapor and breath by gas-liquid partition chromatography.

When a human being is placed for several days on a completely defined diet, consisting almost entirely of small molecules that are absorbed from the stomach into the blood, intestinal flora disappear because of lack of nutrition. By this technique, the composition of body fluids can be made constant (standard deviation about 10%) after a few days, permitting significant quantitative analyses to be performed. A method of temperature-programmed gas-liquid partition chromatography has been developed for this purpose. It permits the quantitative determination of about 250 substances in a sample of breath, and of about 280 substances in a sample of urine vapor. The technique should be useful in the application of the principles of orthomolecular medicine.

Air↗
PubMed1970

Experimental allergic encephalomyelitis: synthesis of disease-inducing site of the basic protein.

A highly encephalitogenic peptide whose structure resembles the sequence of amino acids surrounding the single tryptophan residue in the encephalitogenic A1 protein from bovine myelin was synthesized. This peptide is similar in the sequence to peptic peptide E and tryptic T27, derived directly from the A1 protein, and is as active on a molar basis as the A1 protein. The major disease-inducing site of the A1 protein resides in a linear sequence of nine amino acids: H-Phe-Ser-Trp-Gly-Ala-Glu-Gly-Gln-Lys-OH. This region of the A1 protein is apparently the major encephalitogenic determinant since specific modification of the tryptophan residue in the A1 protein with 2-hydroxy-5-nitrobenzyl bromide destroyed its encephalitogenic activity.

Amino Acid Sequence↗
PubMed1970

Controlled deamidation of peptides and proteins: an experimental hazard and a possible biological timer.

Experiments on model peptides show that the rate of deamidation of asparaginyl residues depends strongly on the nature of neighboring residues. The natural distribution of glutaminyl and asparaginyl residues is ordered with respect to the biological lifetime of the peptides and the functional groups of the residues neighboring to glutaminyl and asparaginyl residues. The rates of deamidation of such amide peptides under physiological conditions could serve as useful timers of development and aging.

Amides↗
PubMed1965

Anesthesia of Artemia larvae: method for quantitative study.

Potency of anesthetics is quantitatively measured with laboratory-hatched larvae of the brine shrimp Artemia salina. Statistical fluctuations are minimized in that 100,000 animals are used to determine a single median anesthetic dose value. The technique was developed to study molecular mechanisms of general anesthesia.

Anesthesia, General↗
PubMedDate not supplied

A prospective evaluation of successful terminal ileum intubation during routine colonoscopy.

This study prospectively evaluated a dedicated effort to intubate the terminal ileum in an unselected population of patients undergoing colonoscopy in conjunction with our training program. The influence of the visual appearance of the terminal ileal mucosa on patient management was assessed subjectively. The cecum was reached in 270/295 (91%) patients, with successful terminal ileal intubation being accomplished in 213/270 (79%) examinations. The time required to intubate the terminal ileum (x = 3.4 minutes; range, 30 seconds to 10 minutes) was not significantly different (p < 0.05) between the several levels of training in our fellowship program. The terminal ileum was considered to be visually abnormal in 4 cases, but only 1 of these was abnormal on histologic examination. In this unselected population, routine ileoscopy was unrewarding for finding an incidental positive diagnosis; however, brief attempts at terminal ileal intubation may be useful to improve or maintain endoscopic skills, especially in a training setting.

Adult↗