Biomedical subjects
B D Davis
Publications and source records attributed to B D Davis.
Germ-line therapy: evolutionary and moral considerations.
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Academic levels in nursing.
With the developments of new academic courses in nursing comes the need for a debate about educational levels. This paper offers a discussion of some of the issues involved in such a debate and draws upon data collected from professors of nursing in the United Kingdom, masters students in a Dutch college and from the American literature on the topic. The need to be able to distinguish between diploma, bachelors, masters and doctoral degrees is highlighted and various suggestions about how such distinctions may be made are offered.
Science and politics: tensions between the head and the heart.
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The human genome initiative. Some problems with a crash program.
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Two perspectives: on René Dubos, and on antibiotic actions.
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The human genome and other initiatives.
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Nurse Education Tomorrow Conference 1990. How nurses learn and how to improve the learning environment.
This paper considers some of the evidence that can help nurse teachers more effectively prepare nurses for practice. In particular it is concerned with how students learn and how teachers can improve the learning environment. There are four main sections to the paper. The first looks at learning styles and considers the importance of matching teaching style to the learning style of the student. The second section considers the research into the process of integrating theory and practice in nursing education and the relationship between theory, the classroom and the clinical area. The next section of the paper looks at factors influencing the process of becoming a nurse. Socialising agents such as people and techniques are reviewed in the light of research evidence from nursing and similar professions. Finally the paper represents a series of ways in which it is possible to assess and improve the learning environment for the student nurse, including human aspects, equipment and information.
The nursing management of elderly patients with pain in the community: study and recommendations.
This study is designed to identify factors which influence quality of life for elderly people suffering from painful conditions. It is based upon a theoretical model of control in which mood state is used as the indicator of coping. One hundred and ninety elderly patients took part in semi-structured interviews about their pain and coping experiences, and data were also collected from their nurses in the community. Multivariate statistical analysis revealed that the key determinants of mood were having regrets about the past, being occupied, perceived level of pain control, additional personal problems (notably bereavement) and feeling informed about the painful condition. Active personal coping strategies were identified as more therapeutic than passive strategies. Nurses' data revealed that pain complaints were associated with perceived exaggeration. Few nurses used formal pain assessment. Recommendations for the management of persistent pain in the community are given.
Loneliness in children and adolescents.
Feeling lonely is a sad but relatively common experience for children, adolescents, and adults. When loneliness becomes a frequently occurring phenomenon, there are serious implications for emotional and physical well-being. The concept of loneliness can be described in relation to psychosocial development. Loneliness in children and adolescents is a relatively new research topic. In this paper the author reviews research for both age groups. Pediatric nurses should recognize the importance of identifying children and adolescents at high risk for the development of chronic loneliness. Nursing interventions for assisting the lonely child or adolescent are described briefly.
Transitioning the child fed by gastrostomy into school.
Young children dependent on gastrostomy feeding are examples of special-needs children now eligible for expanded nutrition services in schools through Public Law 99-457. With the implementation of this law, nutritionists have an opportunity to expand their roles as consultants to special education teachers. A team approach involving nutrition, nursing, and special education was used to prepare a gastrostomy-fed preschool child and his family for school. The family of the multihandicapped child had been isolated by the child's feeding problems and viewed the problems as barriers to his entering school. Components of a nutrition care plan for an interdisciplinary team included oral feeding readiness, nutritional adequacy and timing of meals, and mechanical aspects of gastrostomy feeding in the classroom. Nutrition interventions were adjusted for the classroom from those used in the home or clinical setting. The major activity in the transition program was behavioral management of the child's rumination, which affected nutritional status and feeding. The major outcome of the transition program was enrollment of the child in school, with gastrostomy feeding as a routine activity. A transition program for a gastrostomy-fed child is an appropriate mechanism for expanding the role of the nutritionist into the classroom.
Limits to genetic intervention in humans: somatic and germline.
The promise of somatic cell gene therapy is likely to be limited to a narrow range of monogenic hereditary defects. This therapy raises few moral issues. However, extension to the 'improvement' of a normal trait might raise problems, similar to the use of hormones in sports. Another danger is uses that result, like heroic measures to save the premature newborn, in the prolongation of misery and in intolerable expense. The genetic alteration of germline cells, which can already be accomplished in animals, is in principle applicable to all monogenic diseases. Its use in humans is much less acceptable than somatic cell therapy. The objection that it tampers with human evolution is widely cited. However, more important may be the risk of producing a new defect, for risk is much less acceptable in a yet unborn person than in an already ill individual. In addition, the goal of germline therapy could almost always be accomplished more simply and safely by prenatal diagnosis and selective abortion. The highly polygenic nature of the most interesting traits, both behavioural and physical, makes it unlikely that we shall be able to modify them usefully in the foreseeable future by either somatic or germline intervention. Despite this delivery from temptation, public fear of future 'blueprinting' of humans no doubt contributes to a multi-faceted antiscience movement.
Transcriptional bias: a non-Lamarckian mechanism for substrate-induced mutations.
In bacterial cultures in the stationary phase, substrates can selectively stimulate mutations that lead to their own utilization, but because of apparent conflict with the neo-Darwinian view of evolution the phenomenon has encountered widespread resistance. Building on further evidence for this process, Cairns et al. [Cairns, J., Overbaugh, J. & Miller, S. (1988) Nature (London) 335, 142-145] have suggested a Lamarckian mechanism of directed mutation. This paper proposes an alternative mechanism: transcription induced by the substrate introduces a bias in the random process of mutation, because the resulting single-stranded regions of DNA are more mutable. This stimulation of adaptive mutations by the environment has implications for evolution similar to those of directed mutation, but without contradicting the central "dogma" of molecular genetics. In addition, in eukaryotic cells a mutagenic effect of induction on protooncogenes could contribute to the stimulatory effect of proliferation on carcinogenesis.
Non-specific membrane permeability and aminoglycoside action.
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The nursing management of pain in the community: a theoretical framework.
This paper is based upon a research project designed to investigate the nursing management of pain in the community. A theoretical framework is described which has been designed to encompass the complexities of different types of pain, individual differences in reaction to pain, and to identify key differences between patients who cope with pain and those who do not. The framework is based on a model of stress, the concept of controllability, and contemporary learning theory. It identifies a unique role for the nurse in pain management and will be used to direct a study into strategies which nurses can use to enhance the coping abilities and resources of elderly patients in the community with pain.
Evolutionary principles and the regulation of engineered bacteria.
The introduction of engineered bacteria to the environment is being overregulated, on the basis of several assumptions: (i) the danger from deliberate introduction on a large scale is much greater than that from accidental release; (ii) the more distant the source of the DNA the greater the risk; (iii) novel organisms are likely to cause unexpected ecological damage, like that seen with native organisms transplanted to a novel location; (iv) even if the probability of harm is very small, great care must be taken because the harm might be large; (v) products of recombinant DNA must be treated differently from products of classical genetic manipulation; and (vi) our unlimited power to manipulate DNA implies an unlimited power to refashion organisms. Evolutionary principles contradict all these assumptions. Moreover, our increased power of genetic manipulation must be recognized as an expansion of the biotechnology of domestication; and unlike the physical technologies, the long history of domestication has not adventitiously created harmful by-products. I propose that in dealing with such novel and unpredictable developments it would be better to respond with speed and resilience to problems as they arise, rather than to hamper advances by clumsy regulations based on unsubstantiated guesses.
Metabolism, toxicity, and carcinogenicity of trichloroethylene.
Lifetime cancer or unit risk estimates for TRI have been calculated by the EPA on the basis of metabolized dose-tumor incidence relationships. Previously, it was common practice to directly extrapolate exposure dose-tumor incidence data from laboratory animal studies to predict cancer risks in humans. Such direct species-to-species extrapolations, however, do not take into account potentially important species differences in systemic uptake, tissue distribution, metabolism, deposition at the site(s) of action, and elimination. The consideration and use of pharmacokinetic and metabolic data can significantly reduce, though not eliminate, uncertainties inherent in species-to-species, route-to-route, and high- to low-dose extrapolations. The total amount of TRI metabolized was considered in the most recent EPA Health Assessment Document for Trichloroethylene to be the effective dose (EFD) producing tumors. Exposure dose-metabolism relationships were determined from direct measurement data in inhalation and oral dosing studies in mice and rats. The magnitude of TRI metabolism in these two species closely approximated body surface area. Thus, it was assumed that the amount of TRI metabolized per square meter of surface area was equivalent among species when calculating human equivalent doses from the animal data. Direct measurement data from an inhalation study in humans were used to calculate the amount of TRI metabolized and the unit risk estimate when a person inhales 1 microgram TRI per cubic meter continuously for 24 h. The EPA Cancer Assessment Group (CAG) elected to use this risk estimate for TRI in air, since it was calculated on the basis of a human metabolized dose rather than unit risk estimates based on animal studies. The current survey of literature and ongoing research uncovered no new animal or human studies in which TRI metabolites were directly measured, which would be any more suitable for use in estimating the total metabolized dose of TRI. On the basis of information now available, it is appropriate to continue to use the total amount of TRI metabolized as the EFD producing tumors in the liver. Use of the total amount metabolized represents an important "step in the right direction" in reducing uncertainties in interspecies extrapolations of data on a chemical such as TRI. TRI is believed to be metabolically activated to a reactive intermediate(s), although the identity of the intermediate(s) is unclear. There is evidence that formation of reactive intermediate(s) and TRI hepatotoxicity are directly proportional to the overall extent of TRI metabolism.(ABSTRACT TRUNCATED AT 400 WORDS)