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Biomedical subjects

A Walker

Publications and source records attributed to A Walker.

At least 379 records · Page 21Linked to original sources
PubMedDate not supplied

BRCA1 screening in a woman with breast cancer: a patient's perspective with commentary.

Genetic screening for breast cancer and other diseases poses major personal and psychological challenges for persons facing the prospect of testing. The personal report of those dilemmas by a woman considering BRCA1 screening who had had a lumpectomy for breast cancer and whose mother had died from that disease is presented here. Commentaries by a bioethicist and a genetics counselor show further complexities in the testing experience which persons considering testing and those providing them will need to confront.

Bioethics↗
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Early Homo erectus skeleton from west Lake Turkana, Kenya.

The most complete early hominid skeleton ever found was discovered at Nariokotome III, west Lake Turkana, Kenya, and excavated in situ in sediments dated close to 1.6 Myr. The specimen, KNM-WT 15000, is a male Homo erectus that died at 12 +/- 1 years of age, as judged by human standards, but was already 1.68 m tall. Although human-like in many respects, this specimen documents important anatomical differences between H. erectus and modern humans for the first time.

Animals↗
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Analysis of deletions in DNA from patients with Becker and Duchenne muscular dystrophy.

Duchenne muscular dystrophy (DMD) is an X-linked recessive genetic disorder for which the biochemical defect is as yet unknown. Recently, two cloned segments of human X-chromosome DNA have been described which detect structural alterations within or near the genetic locus responsible for the disorder. Both of these cloned segments were described as tightly linked to the locus and were capable of detecting deletions in the DNA of boys affected with DMD. In an attempt to determine more precisely the occurrence of these deletions within a large population of DMD patients and the accuracy of one of the segments, DXS164 (pERT87), in determining the inheritance of the DMD X chromosome, the subclones 1, 8 and 15 were made available to many investigators throughout the world. Here we describe the combined results of more than 20 research laboratories with respect to the occurrence of deletions at the DXS164 locus in DNA samples isolated from patients with DMD and Becker muscular dystrophy (BMD). The results indicate that the DXS164 locus apparently recombines with DMD 5% of the time, but is probably located between independent sites of mutation which yield DMD. The breakpoints of some deletions are delineated within the DXS164 locus, and it is evident that the deletions at the DMD locus are frequent and extremely large.

Chromosome Deletion↗
PubMedDate not supplied

Combating age discrimination at the workplace.

The article consists of four main parts. To begin, it examines the changing context within which organizations are operating their human resource policies and practices, especially the aging of the work force and changing public policies, and summarizes the main forms of age discrimination. Secondly it outlines the "Age Barriers" project and how good practice was defined. The third and main part of the article uses the results of the project to distil some key lessons for labor market participation about the factors which lead organizations to try to counteract age discrimination and the essential ingredients of successful policies. The fourth part emphasizes the importance of moving beyond specific and sometimes tokenistic examples of good practice towards an integrated age management strategy which focuses on the prevention of workforce aging. The conclusion will highlight some key action points for all participants in the labor market. The focus of the article is on policies and human resource practices (the demand side of the labor market), not the abilities of older workers. Discrimination can operate independently of work ability.

Aging↗
PubMedDate not supplied

Human and ape molecular clocks and constraints on paleontological hypotheses.

Although the relationships of the living hominoid primates (humans and apes) are well known, the relationships of the fossil species, times of divergence of both living and fossil species, and the biogeographic history of hominoids are not well established. Divergence times of living species, estimated from molecular clocks, have the potential to constrain hypotheses of the relationships of fossil species. In this study, new DNA sequences from nine protein-coding nuclear genes in great apes are added to existing datasets to increase the precision of molecular time estimates bearing on the evolutionary history of apes and humans. The divergence of Old World monkeys and hominoids at the Oligocene-Miocene boundary (approximately 23 million years ago) provides the best primate calibration point and yields a time and 95% confidence interval of 5.4 +/- 1.1 million years ago (36 nuclear genes) for the human-chimpanzee divergence. Older splitting events are estimated as 6.4 +/- 1.5 million years ago (gorilla, 31 genes), 11.3 +/- 1.3 million years ago (orangutan, 33 genes), and 14.9 +/- 2.0 million years ago (gibbon, 27 genes). Based on these molecular constraints, we find that several proposed phylogenies of fossil hominoid taxa are unlikely to be correct.

Animals↗
PubMedDate not supplied

Relationship between premenstrual symptoms and oral contraceptive use: a controlled study.

Patterns of menstrual cycle-related change were compared in three groups of women differing in their use of oral contraceptives and being matched for age, occupation, and parity. These groups were: a "monophasic group" (n = 35) established on low dose "combined" pills with stable levels of estrogen and progestagen. a "triphasic group" (n = 30) on low dose pills with escalating progestagen dosage, and a "non-pill control group" (n = 57) using nonsteroidal contraceptives. Each woman kept visual analogue ratings of mood, irritability, energy, tension, breast tenderness, bloating, and sexual interest for two or three cycles. Cyclicity was evident in all variables assessed, but the only variable to show a clear difference between groups was breast tenderness; the "monophasic group" showed less premenstrual breast tenderness than the other two groups. The monophasic group also showed a tendency to menstrual rather than premenstrual symptoms. In view of the similarity of timing of most cyclical symptoms in the three groups, it is difficult to attribute such cyclical phenomena to the effects of either ovulation or variation in corpus luteum function. For most subjects, the cyclical changes were relatively mild, and these findings need to be replicated in women suffering from severe premenstrual syndrome. However, alternative explanations need to account for changes in women both taking and not taking oral contraceptives.

Adolescent↗
PubMedDate not supplied

Filtering strategies in mass population screening for colorectal cancer: an economic evaluation.

On the basis of clinical trial data, 13 strategies for initial screening (filtering) for colorectal cancer are modeled for the purpose of economic evaluation. A wide range of detection cost estimates are generated, although ranking options by detection cost ignores the important consideration of undetected cancers. Formulating the problem as one of cost-effectiveness, however, allows the authors to demonstrate that members of a subset of strategies uniquely outperform all others and that the optimum strategy can be identified by the ex ante specification of the valuation of cancers missed on screening.

Colorectal Neoplasms↗
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Establishing electronic patient record standards using paper-based record functions and standards.

The South Australian Health Commission has embarked on a long term project to establish an Electronic Patient Record (EPR) for South Australia. The process requires extensive evaluation at the conclusion of each phase of development using a range of existing and purpose-developed evaluation tools. This paper describes a purpose-developed evaluation tool that uses the functional aspects of, and existing standards for, paper-based medical records in hospitals as its basis. The resulting EPR Standards are a tool which can be used to establish a benchmark against which to evaluate the efficiency and effectiveness of an electronic patient record.

Benchmarking↗
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Research for an ageing society.

This article outlines the research agenda of the Economic and Social Research Council's Growing Older Programme. The Programme focuses on extending quality life and is composed of six sub-themes: defining and measuring quality of life; inequalities in quality of life; technology and the built environment; healthy and productive ageing; family and support networks; and participation and activity in later life. The Programme aims not only to produce high quality research on the factors determining quality in old age and how it can be extended but, also, to contribute constructively to policy and practice. The article also introduces the new UK National Collaboration in Ageing Research which brings together four of the research councils to raise the profile of research on ageing and to develop a multidisciplinary approach.

Aged↗