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Biomedical subjects

M Wilkes

Publications and source records attributed to M Wilkes.

16 recordsLinked to original sources
PubMed1999

Learning to value ethnic diversity--what, why and how?

INTRODUCTION: Learning to value ethnic diversity is the appreciation of how variations in culture and background may affect health care. It involves acknowledging and responding to an individual's culture in its broadest sense. This requires learning the skills to negotiate effective communication, a heightened awareness of one's own attitudes, and sensitivity, to issues of stereotyping, prejudice and racism. This paper aims to contribute to debate about some of the key issues that learning to value ethnic diversity creates. CONTEXT: Although some medical training is beginning to prepare doctors to work in an ethnically diverse society, there is a long way to go. Promoting 'valuing ethnic diversity' in curricula raises challenges and the need to manage change, but there are increasing opportunities within the changing context of medical education. Appropriate training can inform attitudes and yield refinement of learners' core skills that are generic and transferable to most health encounters. CURRICULUM DEVELOPMENT: Care must be taken to avoid a narrow focus upon cultural differences alone. Learning should also promote examination of learners' own attitudes and their appreciation of structural influences upon health and health care, such as racism and socio-economic disadvantage. Appropriate training and support for teachers are required and learning must be explicitly linked to assessment and professional accreditation. CONCLUSION: Greater debate about theoretical approaches, and much further experience of developing, implementing and evaluating effective training in this area are needed. Medical educators may need to overcome discomfort in developing such approaches and learn from experience.

Culture↗
PubMed1998

Cellular localization of AT1 receptor mRNA and protein in normal placenta and its reduced expression in intrauterine growth restriction. Angiotensin II stimulates the release of vasorelaxants.

Angiotensin II (ANG II) is a potent vasoconstrictor and growth promoter. Quantitative receptor autoradiography using the nonselective radioligand [125I]ANG II and subtype-selective competing compounds demonstrated the presence of both ANG II receptor (AT)1 and AT2 receptor recognition sites. In addition, a relatively small population of apparently non-AT1/non-AT2 sites was identified that may represent a novel high affinity ANG II recognition site in human placenta. Using placental membrane preparations, the AT2 receptor antagonist PD123177 failed to compete for [3H]ANG II binding at relevant concentrations, whereas the AT1 receptor antagonist losartan competed in a monophasic manner for all the specific binding, suggesting that the non-AT1/non-AT2 recognition site identified using autoradiography may be a cytosolic binding site. AT1 receptor binding was significantly reduced (P < 0. 02) in intraeuterine growth restriction (IUGR) pregnancies. Western blot analysis confirmed this showing a reduction in AT1 receptor protein. In situ hybridization and immunocytochemistry revealed that AT1 receptor mRNA and protein were localized throughout pregnancy in the cytotrophoblast, syncytiotrophoblast, and extravillous trophoblast, as well as in or around the blood vessels of placental villi. The intensity of the hybridization signal for AT1 receptor mRNA over the syncytium was reduced in IUGR. ANG II evoked a rapid and concentration-dependent release of NO in first trimester cytotrophoblast-like cells that was abolished by the inclusion of the competitive NOS inhibitor NG-monomethyl-L-arginine. Neither losartan nor PD123177 alone significantly inhibited ANG II-evoked NO release, and when cells were stimulated with ANG II in the presence of losartan (10 microM) and PD123177 (10 microM) in combination, NO release was significantly inhibited (P < 0.05). These observations also suggest, for the first time, the existence of a cross-talk between AT1 or AT2 receptors in trophoblast and that the reduction in placental AT1 receptors in IUGR may, in part, account for poor placental function in this disorder.

Angiotensin II↗
PubMed1998

Medical, law, and business students' perceptions of the changing health care system.

An unanswered question in previous research on attitudes to health care systems is whether the values held by medical students are unique to them or simply a cohort phenomenon. This study addresses this by measuring values and attitudes on entry to medical school, and comparing them with two other groups whose academic standing at entry and social status are likely to be comparable business and law students. In this paper four substantive areas are dealt with: managed care, cost controls such as rationing, access to care. and the role of the federal government in regulating health care. There was a high level of agreement between the three groups that society should provide health care to all citizens, and that individuals should have appropriate access. There was also a general preference for being treated in a fee-for-service setting. Some differences were that medical students held more negative views about managed care than some of the others. The students tended to disagree on cost controls, particularly on issues that might impact on their own professions. Medical students were more restrictive than others on concepts of rationing health care and with regard to high tech procedures. Thus the results reflect areas of extensive agreement, but also the fact that even at entry students may differ on issues that are likely to have an economic impact on their careers. The relationship of these attitudes to the changing health care system and to theories about professionalism and the state is discussed.

Adult↗
PubMed1998

A comparative study of chiropractic and medical education.

BACKGROUND: Chiropractic is the largest of the alternative/complementary health professions in North America. However, little attention has been given in the health sciences literature to the formal curriculum of chiropractic education or to its similarities to and differences from the curriculum of allopathic medical education. This lack of information precludes extensive referrals and interaction between the 2 professions, even when historical and political barriers can be overcome. METHOD: This is a descriptive, comparative study of the curriculum content of North American chiropractic and medical colleges, supplemented by in-depth data obtained through site visits with 6 institutions (3 chiropractic and 3 medical). DISCUSSION: Considerable commonality exists between chiropractic and medical programs. Regarding the basic sciences, these programs are more similar than dissimilar, both in the types of subjects offered and in the time allotted to each subject. The programs also share some common areas in the clinical sciences. Chiropractic and allopathic medicine differ the greatest in clinical practice, which in medical school far exceeds that in chiropractic school. The therapies that chiropractic and medical students learn are distinct from one another, and the settings in which students receive clinical training are different and isolated from one another. With these similarities and differences established, future studies should examine the quality of the 2 educational programs in detail.

Chiropractic↗
PubMed1997

Role of VEGF receptor-1 (Flt-1) in mediating calcium-dependent nitric oxide release and limiting DNA synthesis in human trophoblast cells.

Vascular endothelial growth factor (VEGF) receptor KDR (kinase-insert-domain-containing receptor) is linked to endothelial cell proliferation, and VEGF receptor Flt-1 (fms-like tyrosine kinase) is essential for the organization of embryonic vasculature. Flt-1 is also known to be expressed on adult endothelial and trophoblast cells, although its function has not yet been established. Herein we report that human trophoblast and endothelial cells contain functional Flt-1 receptors for VEGF that trigger the synthesis and release of nitric oxide (NO) by the activation of constitutive NO synthase (cNOS). In first-trimester human trophoblast cells isolated by chorionic villous sampling, VEGF165 stimulated NO release in a concentration- and time-dependent manner, with a maximal increase of 60% (in comparison to basal release levels) occurring within 30 minutes (basal: 1342 pmol/ml; VEGF (10 ng/ml): 2162 pmol/ml; p < 0.001), as measured by an NO chemiluminescence analyzer. VEGF20, a peptide fragment that is composed of the first 20 amino acids at N-terminus, displayed properties of a partial agonist. VEGF165- and VEGF20-mediated NO biosynthesis was attenuated by NG-nitro-L-arginine in a concentration-dependent fashion, indicating NOS activation. VEGF-neutralizing anti-VEGF monoclonal antibody significantly inhibited VEGF-mediated NO release (p < 0.001), and the addition of a neutralizing anti-Flt-1 antibody inhibited the response by 79.6% +/- 7.59%, an effect found to be reversible with higher concentrations of VEGF. In contrast, anti-KDR antibody had no significant inhibitory effect. RT-PCR confirmed the presence of mRNA encoding the Flt-1 and KDR receptors as well as the endothelial form of cNOS in trophoblast cells. VEGF165-stimulated NO release was inhibited by genistein (5 microM; p < 0.001) as well as by the removal of calcium from the extracellular environment (p < 0.001), which suggests the contingency of this process on tyrosine phosphorylation and extracellular calcium, respectively. Addition of sodium nitroprusside, an NO donor, inhibited trophoblast DNA synthesis in a concentration-dependent manner, as measured by [3H]thymidine incorporation, without affecting cell viability. VEGF under maximal NO production had no mitogenic activity, suggesting that trophoblast-derived NO may limit trophoblast proliferation. Endogenous trophoblast DNA synthesis increased 3-fold in the presence of anti-Flt-1 antibody but not in the presence of anti-KDR antibody, suggesting that Flt-1 functions as a growth suppressive receptor to counteract the proliferative actions of KDR. Levels of immunoreactive endothelial cNOS were markedly increased in growth-restricted placentae (n = 4) in comparison to those of normal (n = 5) placentae, which may account for the relatively small-sized placentae associated with intrauterine growth restriction. VEGF165 stimulated NO release via phosphorylation of the Flt-1 receptor, indicating that VEGF may be an autocrine regulator of NO biosynthesis by aiding trophoblast penetration into spinal arterioles during the first trimester and preventing platelet aggregation within the placenta. Finally, the activation of Flt-1 receptor suppressed trophoblast DNA synthesis within the placenta via NO.

Calcium↗
PubMed1995

A Windows-based tool for the study of clinical decision-making.

Studies of health-provider decision-making, and of their practice patterns, play a central role in efforts to improve the quality and effectiveness of care and in decreasing costs of healthcare delivery systems. Researchers from a variety of disciplines have studied a broad range of clinical conditions, using a number of methodological approaches and measurement tools, including self-report, written clinical vignettes, simulated clinical encounters using actors as patients and analysis of medical records and administrative data. Although these provide information about the outcomes of clinical decisions, they provide little or no information about the process of the decision. Most clinicians agree that the decision process is as important as the outcome, and indeed it is not unusual to have an exemplary process but a poor outcome. Process information is therefore a crucial dimension of care evaluation. In this paper, we describe a new software product that was originally used to measure diagnostic reasoning in the basic medical science of immunology; subsequently adapted to measure key steps in the clinical decision-making process. This Windows-based software is user-friendly, inexpensive, and requires only commonly available hardware for its operation. It is very flexible, permitting the creation of unlimited numbers and types of clinical scenarios, with diagnostic and/or management approaches. Being clinically "real-world," the scenarios are familiar to the user, who is therefore likely to respond in a "real-world" fashion, with the consequent improved accuracy of data. In addition, a wide range of users may be accommodated. The clinical activities of physicians, nurses, pharmacists, and any other clinical providers may be measured and analyzed by the system. Non-clinical providers, such as managers and administrators, could also be assessed. The system has three major modes. In the Authoring Mode, the author creates a menu, which is common to a number of linked scenarios. For example, the menu for physicians might include the History, Physical examination, Laboratory tests, Radiology, Consultations, etc. The actual details of each related clinical case may then be varied. There is virtually unlimited flexibility in the design of the menu and the clinical details, depending on the needs of the author, and the type of information desired. Both diagnostic and management scenarios are easily constructed. The cost for each individual step may be assigned, using any scoring scale desired. Actual dollar costs, or a suitable point score, are equally possible. Once the menu and associated scenarios are generated, the candidate is asked to solve the clinical problem in the User Mode. The candidate obtains information by "mouse-clicking," so it is not necessary to be a computer expert to use the system. Eventually, the candidate is presented with a short vignette outlining the desired solution, which may include the authors comments, sources for further information, etc. In the Data Collection and Analysis Mode, the candidate proceeds to solve the scenario, the software captures and stores each individual information request i.e., each step in the candidates reasoning process. Thus, the reasoning process can be examined, including timing and order and types of information used; this may be done both for individual candidates, and also for groups. A "gold standard" reasoning may be predetermined by the author for comparison purposes. The software has already been used to teach immunology to medical students, and is currently being expanded to train gynecology surgeons in the use of Clinical Practice Guidelines. The software has potential applications in many aspects of the healthcare field. For educators, it could serve in traditional exit examinations for the clinical disciplines, both undergraduate and postgraduate. (abstract truncated)

Computer-Assisted Instruction↗
PubMed1990

Attributional style and perceived stress in endogenous and reactive depression.

The depressive Attributional Style Questionnaire (Peterson et al., 1982) and the Hassles and Uplifts Questionnaire (Kanner et al., 1981) were administered to melancholic and non-melancholic depressed patients (matched for severity according to a doctors/nurses rating scale), and to non-depressed volunteers. Compared to the other two groups, melancholic patients had higher internality and stability scores for negative attributions, and reported a greater intensity of 'hassles' and a lower frequency of 'uplifts'. The intensity of 'uplifts' was reduced in both depressed groups. On all other cognitive measures, the reactive patients were indistinguishable from non-depressed volunteers. The results suggest that the 'depressive attributional style' may be specific to melancholic patients, and underline the importance of studying well-defined diagnostic subgroups.

Adjustment Disorders↗
PubMed1988

The effects of ablation of visual cortex in neonatal rabbits on the organization of retinothalamic and retinopretectal projections.

Primary visual cortex was ablated unilaterally in neonatal rabbits. Following a survival of 2-4 months, retrograde degeneration of the dorsal lateral geniculate nucleus (LGd) was assessed, and reorganization of retinofugal pathways was studied using methods of anretrograde transport of [3H]proline or of horseradish peroxidase. A complete lesion of primary visual cortex resulted in complete retrograde degeneration of the LGd with no sparing of any class of neurons. The terminations of retinofugal axons in the pretectum and thalamus were compared with those observed in normal animals. No major reorganization of ipsilateral retinofugal projections was observed in either the thalamus and pretectum ipsilateral to the ablated cortex, or in the thalamus and pretectum contralateral to the ablated cortex. However, contralateral retinofugal projections to the thalamus and to the pretectum ipsilateral to the ablated cortex were significantly different from normal. In the thalamus, the projections to the lateral posterior nucleus were expanded in area and increased in density. In the pretectum, the projections to the rostral pretectal areas were greatly increased in area, especially in the region of the olivary pretectal nucleus and posterior pretectal nucleus. However, the density of these projections was not increased relative to normal. Consideration of these results in relation to other published data on the anatomical consequences of neonatal visual cortex lesions, both in mammals which show behavioral sparing following neonatal visual cortex lesions and in mammals which, like the rabbit, show no behavioral sparing, suggests that: (1) behavioral sparing may correlate with patterns of survival or death of neurons in the thalamus and retina; and (2) reorganization of retinofugal pathways is not necessarily associated with behavioral sparing.

Animals↗
PubMed1985

Survival of the ganglion cell population in the rabbit retina following neonatal visual cortex ablation.

Unilateral visual cortex ablations in neonatal rabbits produced no detectable loss of ganglion cells in the contralateral retina following a survival period of 3, 4 or 8 months. Analysis of neuron size distributions and neuron densities from whole-mounted retinas indicate that transneuronal retrograde degeneration does not occur in the rabbit following neonatal visual cortex removal. The results support the hypothesis that axon collaterals play a role in retinal ganglion cell survival in neonatally operated animals. The paradoxical relationship between functional sparing and ganglion cell survival is discussed.

Animals↗
PubMed1979

Catecholamine-mediated reduction in uterine blood flow after nicotine infusion in the pregnant ewe.

The effect of nicotine on uterine blood flow, uterine vascular resistance, and plasma catecholamine concentration was studied in chronically catheterized pregnant sheep equipped with electromagnetic flow probes. The systemic administration of nicotine (14--32 micrograms/kg body wt per min) resulted in a 44% reduction in uterine blood flow (P less than 0.001) and a 203% increase in uterine vascular resistance. Both responses were inhibited by pretreatment with the alpha blocker, phentolamine. Arterial plasma concentrations of norepinephrine and epinephrine, measured by a single isotopic radioenzymatic assay, rose (from 117.9 +/- 6.7 to 201.8 +/- 13.3 pg/ml, P less than 0.001; and from 71.6 +/- 4.5 to 124.1 +/- 8.4 pg/ml, P less than 0.001, respectively) during nicotine infusion. The findings suggest that nicotine exerts a deleterious effect on uterine blood flow mediated through the release of catecholamines.

Animals↗