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Biomedical subjects

J C Fletcher

Publications and source records attributed to J C Fletcher.

142 records · Page 8Linked to original sources
PubMed1967

Amino acid sequences of peptides from a tryptic digest of a urea-soluble protein fraction (U.S.3) from oxidized wool.

1. A tryptic digest of the protein fraction U.S.3 from oxidized wool has been separated into 32 peptide fractions by cation-exchange resin chromatography. 2. Most of these fractions have been resolved into their component peptides by a combination of the techniques of cation-exchange resin chromatography, paper chromatography and paper electrophoresis. 3. The amino acid compositions of 58 of the peptides in the digest present in the largest amounts have been determined. 4. The amino acid sequences of 38 of these have been completely elucidated and those of six others partially derived. 5. These findings indicate that the parent protein in wool from which the protein fraction U.S.3 is derived has a minimum molecular weight of 74000. 6. The structures of wool proteins are discussed in the light of the peptide sequences determined, and, in particular, of those sequences in fraction U.S.3 that could not be elucidated.

Journal Article↗
PubMed1967

The reaction of iodobenzene-p-sulphonyl chloride (pipsyl chloride) with certain amino acids and peptides, and with insulin.

1. A system of separation using buffered Celite columns is described that enables the pipsyl derivatives of most of the common amino acids to be separated. 2. The reaction of pipsyl chloride with several amino acids not included in previous studies has been investigated. In particular, knowledge of the acid-soluble pipsyl derivatives of arginine, histidine, lysine, tyrosine and cysteic acid has been extended. 3. Reproducible factors have been obtained that enable corrections to be applied for the breakdown of pipsylamino acids on acid hydrolysis. 4. The reaction of pipsyl chloride with peptides has been studied under various conditions. 5. The extent of the reaction between pipsyl chloride and insulin depends on the nature of the solvent-buffer system, and under the best conditions so far found is about 75% complete. 6. In an Appendix, the separation of pipsylamino acids by thin-layer chromatography is described.

Journal Article↗
PubMedDate not supplied

Ethical issues of perinatal human gene therapy.

This paper examines some key ethical issues raised by trials of human gene therapy in the perinatal period--i.e., in infants, young children, and the human fetus. It describes five resources in ethics for researchers' considerations prior to such trials: (1) the history of ethical debate about gene therapy, (2) a literature on the relevance of major ethical principles for clinical research, (3) a body of widely accepted norms and practices, (4) knowledge of paradigm cases, and (5) researchers' own professional integrity. The paper also examines ethical concerns that must be met prior to any trial: benefits to and safety of subjects, informed assent of children and informed parental permission, informed consent of pregnant women in fetal gene therapy, protection of privacy, and concerns about fairness in the selection of subjects. The paper criticizes the position that cases of fetal gene therapy should be restricted only to those where the pregnant woman has explicitly refused abortion. Additional topics include concerns about genetic enhancement and germ-line gene therapy.

Adenosine Deaminase↗
PubMedDate not supplied

An international survey of attitudes of medical geneticists toward mass screening and access to results.

A survey on mass screening was sent to 1,053 medical geneticists in 18 nations, of whom 677 responded. Three theoretical screening situations were proposed, screening in the workplace for genetic susceptibility to work-related disease, carrier screening for cystic fibrosis, and presymptomatic testing for Huntington disease. Of the respondents, 72 percent thought screening in the workplace should be voluntary, and 81 percent said employers should have no access without the worker's consent, including 22 percent who believed that employers should have no access at all. There was strong consensus in all but one nation that insurance companies should have no access to test results without the worker's consent, and strong consensus in two countries that they should have no access at all. Most (82 percent) believed that screening for cystic fibrosis should be applied to the entire population, but 18 percent believed that it should be applied primarily to Caucasians. In all, 66 percent of respondents believed that individuals at risk for Huntington disease should be told their test results only if they say that they wish to know, recognizing a "right not to know" whether they will develop the disease in later life. Twelve percent thought that spouses should have access to test results if they asked, and 26 percent thought that spouses should be informed of results even if they did not ask. Geneticists in all nations were vividly aware of the potential damage from third party access to results, especially access by insurance companies. They had little sympathy with insurers' needs to assess actuarially accurate premiums.

Attitude of Health Personnel↗
PubMedDate not supplied

Fatal knowledge? Prenatal diagnosis and sex selection.

Moral and social arguments weigh heavily against performing medical procedures solely for purposes of sex selection. The medical profession has a responsibility to abandon its posture of ethical neutrality and take a firm stand now against sex selection.

Abortion, Legal↗
PubMedDate not supplied

Respect for autonomy.

Explore the source record for details and available documents.

Confidentiality↗