Search PubMed⌕ Search

Biomedical subjects

J M Wilkinson

Publications and source records attributed to J M Wilkinson.

156 records · Page 9Linked to original sources
PubMed1969

Variation in the N-terminal sequence of heavy chains of immunoglobulin G from rabbits of different allotype.

The sequences of the N-terminal peptides prepared by Pronase digestion of the heavy chain of rabbit immunoglobulin G of allotype Aa1, Aa2 and Aa3 were determined and were shown to be related to the allotype. An N-terminal fragment of about 34 residues was also prepared from the allotype heavy chains, by cleavage with cyanogen bromide; the yield varied with the allotype. The sequences of the cyanogen bromide fragments from the Aa1 and Aa3 heavy chains contain allotype-related variations similar to those found in the N-terminal Pronase peptides, and these sequences are thought to be representative of the whole heavy-chain populations. There is about 60% homology between the two sequences, and superimposed on the differences between them there are a number of positions within each sequence at which at least two amino acids are present.

Amino Acid Sequence↗
PubMed1966

The N-terminal sequence of the heavy chain of rabbit immunoglobulin IgG.

The absence of an N-terminal amino acid with a free alpha-amino group from the heavy chain of rabbit immunoglobulin IgG has been confirmed and no evidence could be found of a blocking formyl, acetyl or propionyl group. The N-terminal amino acid appears to be pyrrolid-2-one-5-carboxylic acid (PCA) in all molecules. A mixed amino acid sequence follows in the approximate proportions: PCA-Ser-Val-Glu-Glu-Ser-Gly-Gly-Arg, 50%; PCA-Ser-Leu-Glu, 20%; PCA-Glu(NH(2)), 20%. The heavy chains of a purified antibody, namely anti-(human serum albumin), and of immunoglobulin IgG from a rabbit homozygous at the allotypic loci both showed a similar mixed N-terminal sequence.

Amino Acids↗
PubMed1965

The immunological activity of some of the chymotryptic peptides of sperm-whale myoglobin.

1. Sperm-whale apomyoglobin was digested with chymotrypsin in a dialysis sac. The ultrafiltrate contained incompletely hydrolysed fragments which partially inhibited the precipitation of metmyoglobin and apomyoglobin by some antisera produced against metmyoglobin. The inhibitory activity was stable to heating at 100 degrees and depended on the peptide structure. 2. The fragments were fractionated according to molecular size and were purified by ion-exchange chromatography. Six pure peptides and two peptides which contained a minor impurity were isolated. Their amino acid compositions and N-terminal amino acid sequences were determined and their entire amino acid sequences deduced from the known amino acid sequence of sperm-whale myoglobin. 3. The peptides formed no detectable precipitates with the antisera. Five of the eight peptides partially inhibited the precipitation of apomyoglobin and/or metmyoglobin by one antiserum. Six of the peptides inhibited the precipitation of apomyoglobin by one or other of two antisera; at least two of these peptides inhibited both antisera. One peptide failed to inhibit the precipitation of either antigen by either antiserum. Two of the peptides possessed the same serological specificity. 4. The molar ratios of inhibitors to antigen for 50% of the maximum inhibition decreased as the molecular size of the inhibitor increased. With one antiserum and with apomyoglobin as the antigen, molar ratios 12 and 80 were obtained for peptides with molecular weights 2051 and 793 respectively. 5. The size and structure of an antigenic site is discussed in relation to the known steric configuration of myoglobin.

Journal Article↗
PubMedDate not supplied

Effect of ginger tea on the fetal development of Sprague-Dawley rats.

This study investigated the effect of ginger, a common morning sickness remedy, on fetal development. Pregnant Sprague-Dawley rats were administered, from gestation day 6 to 15, 20 g/liter or 50 g/liter ginger tea via their drinking water and then sacrificed at day 20. No maternal toxicity was observed, however embryonic loss in the treatment groups was double that of the controls (P<0.05). No gross morphologic malformations were seen in the treated fetuses. Fetuses exposed to ginger tea were found to be significantly heavier than controls, an effect that was greater in female fetuses and was not correlated with increased placental size. Treated fetuses also had more advanced skeletal development as determined by measurement of sternal and metacarpal ossification centers. The results of this study suggest that in utero exposure to ginger tea results in increased early embryo loss with increased growth in surviving fetuses.

Abnormalities, Drug-Induced↗
PubMedDate not supplied

Posterior surgical approaches to the elbow: a comparative anatomic study.

Triceps splitting, triceps reflecting, and olecranon osteotomy are the most common posterior surgical approaches to the adult elbow, but no comparative data exist as to the exposure provided by each approach. The aim of this study was to determine which of these approaches provides the greatest exposure of the distal humeral articular surface. Each approach was performed on 4 adult cadaveric elbows. After the completion of each approach, the visible articular surface was painted with methylene blue. The elbow was then disarticulated, and the percentage of articular surface visible was measured. The median exposed articular surface for the triceps splitting, triceps reflecting, and olecranon osteotomy approaches was 35%, 46%, and 57%, respectively. Olecranon osteotomy exposed more articular surface than the triceps splitting approach (Mann-Whitney test, P =.03) but was not significantly greater than the triceps reflecting approach. However, even the olecranon osteotomy approach failed to provide visualization of more than 40% of the distal humeral articular surface.

Adult↗
PubMedDate not supplied

Moral distress: a labor and delivery nurse's experience.

Moral distress occurs when nurses make moral decisions they cannot implement. This article contains a true account of such a case. A nurse was present at the delivery of a premature infant who was allowed to expire without intervention. A moral distress equation is used as a framework for describing the nurse's experience and its effects on her and her patient care.

Adaptation, Psychological↗
PubMedDate not supplied

After-hours telephone triage. Recruitment, training and retention of personnel.

Harvard Community Health Plan's nighttime telephone triage program, currently known as Telecommunications, has evolved through several stages, corresponding to HCHP membership growth, technological enhancements, and changes in the medicolegal environment. Recruiting, training, and retaining staff for nighttime telephone triage are discussed.

Boston↗
PubMedDate not supplied

Medical applications of microsystems technology: news update.

Medical product companies showed an increasing level of interest in microsystems technology (MST) during 2000. Access to MST has improved with the emergence of new suppliers and existing technology providers becoming more market oriented. Some of the highlights and details of forthcoming events are reported here.

Biomedical Engineering↗