PubMed Health⌕ Search

Biomedical subjects

C Hicks

Publications and source records attributed to C Hicks.

At least 37 records · Page 2Linked to original sources
PubMed1997

Identification of PDGF receptors on human megakaryocytes and megakaryocytic cell lines.

Platelet-derived growth factor (PDGF) is a potent chemotactic and mitogenic factor implicated to play important roles in a variety of normal and pathophysiologic settings. We investigated PDGF receptor expression on human megakaryocytes and several megakaryocytic cell lines (CHRF, DAMI, Meg-01, M-07e) using enzyme-linked immunosorbent assay (ELISA), flow cytometry and immunocytochemical staining. Both PDGF receptor subtypes were identified on CHRF, DAMI, and Meg-01 cells by ELISA; PDGF beta-receptor levels exceeded alpha-receptor levels. Flow cytometry revealed that beta-receptor levels on CHRF and DAMI cells exceeded those on Meg-01 cells, and that M-07e expressed neither receptor. Immunocytochemical staining confirmed these findings and determined that bone marrow megakaryocytes also expressed PDGF receptors. Exposure of megakaryocytes to PDGF-BB dramatically induced the expression of the immediate-early gene, c-fos, within 30 min. Moreover, PDGF-BB significantly stimulated CHRF proliferation and colony formation. The present study demonstrates the presence of functional PDGF receptors on human megakaryocytes and their ability to mediate a mitogenic response.

Cell Line↗
PubMed1996

Neuroprotective effects of 7-nitroindazole in the gerbil model of global cerebral ischaemia.

To evaluate the role played by nitric oxide in global cerebral ischaemia we examined the effects of 7-nitroindazole and a sodium salt of 7-nitroindazole (inhibitors of neuronal nitric oxide (NO) synthase) and NG-nitro-L-arginine methyl ester (a more general inhibitor of NO synthase) in the gerbil model of cerebral ischaemia. Four experiments were carried out. In the first experiment, animals were either sham-operated, subjected to 5 min bilateral carotid occlusion (BCAO) or administered 7-nitroindazole or NG-nitro-L-arginine methyl ester immediately after occlusion followed by three further doses at 3, 6 and 24 h post-occlusion. In the second experiment, we examined the effects of a sodium salt of 7-nitroindazole, which is more soluble than 7-nitroindazole, using the same protocol. In the third experiment, the effects of the sodium salt of 7-nitroindazole administered at 10 mg/kg at 0, 3, 6, 24, 27, 30, 33, 52, 55, 72, 75 and 78 h post-occlusion or at 0.05 mg/h for 72 h via mini-pumps were evaluated. In separate experiments, we examined the effects of three reference compounds dizocilpine (MK-801), 2, 3-dihydroxy-6-nitro-7-sulphamoyl-benz(F)-quinoxaline (NBQX) and eliprodil using the same model. Extensive neuronal death was observed in the CA1 layer of the hippocampus in 5 min bilateral carotid occluded animals 5 days after surgery. Both 7-nitroindazole and NG-nitro-L-arginine methyl ester provided significant neuroprotection (P < 0.01) against this neuronal death. The sodium salt of 7-nitroindazole showed no protection when administered up to 12 times post-occlusion, but did provide significant (P < 0.01) neuroprotection when administered via mini-pump. The neuroprotection was similar to that provided by MK-801 and eliprodil, but not as good as that observed with NBQX. These results indicate that nitric oxide plays a role in ischaemic cell death and that selective neuronal nitric oxide synthase inhibitors can protect against ischaemic brain damage.

Animals↗
PubMed1996

Nurse researcher: a study of a contradiction in terms?

Despite considerable top-down pressure and numerous professional body initiatives, a persistent shortfall in published nursing research has been noted. Numerous explanations have been put forward to account for this which implicate issues at both the individual/psychological and the structural/ organizational levels. However, one area which has not yet been properly addressed is that of role appropriateness, in that research skills and activities may be construed as being incompatible with the traditional role expectations and values of nursing. To test this proposition, two groups of qualifed nurses were each required to consider six descriptors of an imaginary nurse following the paradigm of Asch's (1946) seminal Central Trait Theory study. Of these, five adjectives were identical for both groups, but the sixth descriptor was manipulated, such that one group received "good clinician' and the other "good researcher'. The subjects then had to rate this imaginary nurse along each of 15 bipolar traits. The groups' ratings were compared using a series of unrelated t-tests. The results indicated that if a nurse was described as a good researcher she or he was also assumed to be more ambitious, a poorer communicator, less kind, stronger, more logical, more controlled, more confident, less popular, more ruthless, more rational and more analytical than if she or he was described as a good clinician. These findings suggest that the qualities attributed to a good nurse are dissonant with those attributed to a good researcher and, in this way, the mutual incompatibility of each role's requirements may serve as an obstacle to the development of research with nursing.

Clinical Competence↗
PubMed1996

A study of nurses' attitudes towards research: a factor analytic approach.

Despite considerable top-down pressure on nurses to undertake research, the available evidence suggests that relatively few nursing studies are submitted for publication. Given the need to increase the degree to which research informs practice, this shortfall in output must of necessity constitute a cause for concern. Therefore, it seems timely that a full-scale investigation into the possible reasons for non-submission is conducted. This study, therefore, in an attempt to meet this aim, used factor analysis on the scores from an attitude-to-research scale completed by 230 nurses. The results suggested that five coherent factors underpinned the sample's general attitudes to research. These were labelled 'nurses' subjective barriers to research', 'organizational/structural barriers to research', 'doctors' reactions to nursing research', 'health care professionals' reactions to research' and 'impact of nursing research'. The variables clustering on two of these factors suggested a predictive relationship with two relevant outcome behaviours relating to research. When this was tested, the predictions were supported, indicating that these factors could be used as a quick and simple screening tool to highlight individuals or groups of nurses who might benefit maximally from specific attitude change programmes. In this way, it might be possible to increase nursing research activities and output.

Attitude of Health Personnel↗
PubMed1996

The potential impact of gender stereotypes for nursing research.

The move towards evidence-based health care has meant an increasing pressure on paramedical professionals to become more research aware and research active. However, despite various initiatives designed to encourage research, there remains within nursing a notable paucity of relevant published research. While numerous explanations have been put forward in an attempt to account for this shortfall, they have tended to focus on structural/organizational barriers rather than difficulties located at the individual level. However, Hicks, in studies of midwives and nurse managers suggests that one critical perspective may be the stereotypes and assumptions associated with the nursing profession, these being so diametrically opposed to the core skills required of researchers that they operate as a natural deterrent to research activities of any sort. Embedded within this theory is the notion of gender roles, which are archetypally feminine for nursing yet archetypally masculine for research. However, Hicks' studies, which were both variants of Asch's Central Trait Theory, focused on women both as the hypothetical subject of the exercise involved and as participants. If research is bound up with gender attributions in the way she suggests, it would be necessary to ask if this is still relevant when the gender of the hypothetical figure at the centre of the study is changed. To this end, the present study was conducted which, apart from the modification just highlighted, was a replication of Hicks' earlier studies. In brief, two groups of participants rated a hypothetical male candidate for a nursing post along 15 bipolar dimensions. The candidate had been described by his referee using six adjectives, of which five were identical for each group. However, the final phrase used to describe the first group's candidate was "good clinician' while for the second group it was "good researcher'. The ratings given by the two groups along the 15 dimensions were then compared. It was found that the male applicant described as a good researcher was assumed to be more successful, more ambitious, more confident and more ruthless than one described as a good clinician. The implications of these results are discussed in relation to gender theories and nursing research.

Adult↗
PubMed1996

Investigating attitudes to research in primary health care teams.

Despite top-down professional body and government agency pressure to increase the research base of clinical practice, there remains a considerable body of evidence which suggests that many ineffective, and even dangerous, health care interventions continue to be practised in areas where there are significant contradictory findings. While numerous explanations have been put forward which implicate the role of structural, organizational and informational barriers to integrating research with practice, less attention has been focused on the individual and psychological contributions. The study reported here forms part of a larger scale project aimed at developing a diagnostic instrument for identifying research training needs, in the widest sense, within primary health care groups. To provide the instrument with content validity, following formal psychometric guidelines, opaque and transparent techniques of data collection were employed at the development stage. This yielded some interesting and unexpected results from the respondents, which suggested that despite overt statements to the contrary, the majority of the primary health care professionals studied perceived research as being unimportant and peripheral to their jobs, and the responsibility of other health care professionals. Moreover, the subjects' understanding of research and its methodologies was discordant both within and across professional groups. The implications of these results from this pilot phase suggest that fundamental and deep-seated attitudes which are resistant to research may be a contributory factor to the persistence of ritualistic, non-evidence-based care.

Attitude of Health Personnel↗
PubMed1996

Development of a psychometrically valid training needs analysis instrument for use with primary health care teams.

The growing demand for professional updating and training within the health service has created a proliferation of post-registration courses, many of which fail to reach the appropriate personnel or the real training objectives of the participants and their managers. One reason behind this problem relates to the fact that many such courses are constructed and delivered in a haphazard way, without systematic reference to the direct and indirect consumers of the educational programmes. A more rational approach to post-experience provision of this sort might involve the methodical collection of information regarding the training needs of target health professional populations. Such a data base would afford a global overview of competencies and deficiencies, both within and between individuals. From this the content, level and focus of training could be customized to meet the reported needs, thereby streamlining the commissioning process to enhance efficiency and effectiveness. Previous attempts to rationalize provision through the prior use of training needs analysis instruments have been compromised by the shortcomings of the analysis tool. This study, then, was an attempt to redress this problem, using a training needs analysis instrument developed along traditional psychometric principles. The tool was intended to be used with primary health care teams because of the increasing role this sector of the health service will play in the future delivery of care, although this would not preclude its use with other health care professionals (following appropriate modification), since the principles behind its construction and format are transferable. The instrument has demonstrable construct, content and face validity and significant reliability. Moreover, preliminary investigations suggest that it also has criterion validity in the areas tested. These findings suggest that the instrument is unique of its kind. Early use of the tool has demonstrated its value in a variety of ways, such as in team building exercises and skill mix reviews as well as in precise and effective commissioning of training and education in a range of areas.

Community Health Nursing↗
PubMed1996

The relationship of behavioral cues to assaultive behavior.

The purpose of this 2-year, case control study was to determine whether differentiation between assaultive and nonassaultive patients can be made based on behavioral assessments and/or sociodemographic variables. For each assault incident, the chart of the patient who assaulted and a randomly chosen patient who did not assault on that day were reviewed (N = 72 subjects or 26 pairs). Various scales were used to evaluate the subjects retrospectively (the day prior to the assault), and patients who assaulted staff were interviewed when possible. An analysis found no differences between patients who assaulted and controls on sociodemographic variables. Those who assaulted had significantly more prior assaults (p = .04) and more difficulty verbalizing angry feelings appropriately on their units (p < .01). Prior to the assault, assaultive patients were more verbally hostile (p = .037) and showed more increased motor activity (p = .001) than controls.

Cues↗
PubMed1996

Effects of gentle human touch on preterm infants: pilot study results.

A pilot study was conducted to evaluate the effects of gentle human touch (GHT) provided for 15 minutes a day to preterm infants from day 7 to day 12 of life. The study suggested that GHT has no adverse effects on the oxygen saturation or heart rate levels of small preterm infants and that GHT has a soothing effect as evidenced by decreased levels of active sleep, motor activity, and behavioral distress. These results can provide NICU nurses with a basis for guiding parents in their early interactions with preterm infants in the NICU.

Female↗
PubMed1995

A factor analytic study of midwives' attitudes to research.

Midwives are increasingly being encouraged to undertake research activities at various levels, as a routine part of their job. However, despite topdown directives to this end, there is some evidence that relatively little research is published and reasons, such as lack of time, confidence and skill have been put forward to explain the short-fall. While these reasons may be valid obstacles, it is also conceivable that they are manifestations of a set of underlying attitudes to research in midwifery. If attitudes are assumed to be predictors of behaviour, then it may be relevant to study midwives' attitudes to research more closely in order to identify whether these are responsible in some measure for the short-fall in research output. To this end, a national survey of 397 midwives was undertaken to establish their attitudes to research. The results were subjected to factor analysis, using an orthogonal solution, in order to establish whether any coherent source components existed in the sample's attitude responses. The factor analysis yielded four coherent factors, which were (i) other health care professionals' views of the value of midwifery research; (ii) the value of research for midwifery practice; (iii) the research role of the midwife; (iv) midwives' competence to carry out research. On further analysis the first two factors were also found to be significantly related to midwives' likelihood of undertaking research and publishing research findings. These factors could form the basis for future attitude change and staff development and training programmes as a means by which midwifery research output could be increased.

Attitude of Health Personnel↗
PubMed1995

Good researcher, poor midwife: an investigation into the impact of central trait descriptions on assumptions of professional competencies.

OBJECTIVE: in an attempt to explain the serious shortfall in published midwifery research an attempt was made to assess whether the way in which midwives construe their professional role acts as a deterrent to undertaking research. DESIGN: different subject experimental. SETTING: a college of nursing and midwifery in central England. PARTICIPANTS: 30 midwives attending postregistration continuing education courses. INTERVENTIONS: the midwives were divided into two groups and were asked to imagine that they were interviewing a candidate for a midwifery post following Asch's (1946) paradigm. The candidate had been described by her referee using six adjectives. Five of these were common to both groups of subjects, but the sixth descriptor for one group was 'good clinician', while for the other group it was 'good researcher'. MEASUREMENTS AND FINDINGS: the groups were asked to assess how much of each of 16 dimensional traits their candidate possessed. Analysis of the findings, using unrelated t-tests, suggested that if the candidate had been described as a poor researcher, it was also assumed that the candidate was more ambitious, a poorer communicator, less kind, stronger, more logical, less emotional, more confident, less popular, less compassionate, more rational, more organised and more analytical than the candidate described as a good clinician. IMPLICATIONS FOR PRACTICE: these findings suggest that if midwives are to become more research active they can only do so if they sacrifice their constructs of themselves as good midwives. If midwifery is to accept research as part of its responsibility it appears that there has to be a radical shift in predispositional assumptions to integrate the traits required for good clinical practice, sound research and femaleness?

Adult↗
PubMed1995

The shortfall in published research: a study of nurses' research and publication activities.

Although in recent years there has been increasing pressure on nurses to become more research minded, available evidence still suggests that there is a significant shortfall in published nursing research. To date, it has not been clear whether this lack of output is a function of nurses' failure either to conduct research in the first place or to get it published. It is self-evident that if patient care is to be enhanced through research, then the reasons for the low output must be investigated systematically in order to understand the precise nature of the problem. Therefore, a national survey of 230 nurses was undertaken in order to ascertain the reasons underpinning the low publication rate. A questionnaire, comprising sections on biographical information, research activities and attitudes to research was distributed to a random sample of nurses and the results were analysed using techniques of descriptive and inferential statistics. The results suggest that the observed shortfall in published research is not a product of nurses' failure to conduct research projects but rather of their reluctance to submit their findings for publication. This reluctance seemed for the majority of respondents to be the result of a pronounced lack of confidence. The findings from this survey are discussed with reference to future professional development programmes.

Adult↗
PubMed1995

A study of nurse managers' constructs of nurse researchers.

Recent fundamental changes in health care policy and provision have emphasized the need for a research culture within the National Health Service (NHS). The argument underpinning this revolves around the assumption that increasing the evidence-base of practice may have a significant impact on the quality of patient care. In consequence, members of the paramedical professions have been urged to become more research aware and research active. Despite these exhortations, however, there is mounting concern generally within the professions allied to medicine and, within nursing in particular, that the corpus of essential research evidence is not sufficient and that which exists is only partially effective in informing practice. While numerous explanations have been put forward to account for this, it is conceivable that the way in which the nurse's role is construed both by the nurse and by associated personnel is dysfunctional to the development of the nurse as researcher. To test this hypothesis, two groups of nurse managers were asked to consider how much of each of 15 bipolar dimensions was possessed by a nurse described either as 'a good clinician' or as 'a good researcher'. The results suggested that a nurse described as a good researcher was attributed with fewer of the characteristics assumed to be inherent to a good nurse. In this way, to be a good researcher appears to be fundamentally incompatible with being a good nurse. Moreover, a good researcher was also less likely to be employed. These results implicate the role of traditional attributions of nursing and are discussed in the context of the development of nursing research.

Adult↗
PubMed1994

Quantitation of platelet derived growth factor receptors on cells from human arterial segments.

The study of receptor expression in tissue containing multiple cell types presents a two-fold problem. Firstly, in situ studies are difficult to perform quantitatively and secondly, enzymatic disruption of the primary tissue results in the loss of cell surface receptors which may or may not be resynthesised. In vitro culture of cells following isolation may also alter receptor expression. To circumvent these problems, we have devised a reproducible non-enzymatic method for releasing endothelial and smooth muscle cells from human arterial segments and separating the mixture into constituent cell populations, in order to facilitate semi-quantitative receptor investigation by ELISA. The method involves the mechanical disruption of small artery segments and passage through progressively smaller sieves, resulting in a mixed population of single cells. Magnetic beads covalently attached to identifying lectins or antibodies are then used in a multistep procedure to give highly enriched cell populations. The dissociation/enrichment steps can be modified to select other cell types which may be present in the primary tissue, such as macrophages. We have used these preparations for locating and semi-quantitating PDGF and EGF receptors on the constituent cells of human umbilical artery preparations by ELISA using monoclonal receptor antibodies.

Antibodies, Monoclonal↗
PubMed1994

Bridging the gap between research and practice: an assessment of the value of a study day in developing critical research reading skills in midwives.

Despite increasing professional pressure on midwives to make their clinical practice research based, their remains a considerable amount of clinical activity which relies only on historical ritual rather than on rational scientific evidence. This apparent failure to integrate research into practice has generated a lot of debate regarding its cause. One widely accepted reason for midwives' non-use of empirical findings is simply that a large proportion of the workforce does not have the knowledge and training in the necessary skills to enable them to assess the value of published articles. Clearly the cost in time and human resources involved in providing a thorough training for the entire midwifery workforce in research skills would probably be unnecessary for the majority of midwives who simply want to be able to translate published research into their clinical practice. Consequently, a more pragmatic approach might be to assess the value of brief training days in developing midwives' competencies in reading research articles critically as a precursor to facilitating the integration of theory and practice. If the value of such courses could be demonstrated, then it is conceivable that study days of this type might be made more widely available for all midwifery personnel. This study investigated the effectiveness of one such study day in (a) modifying the participating midwives' evaluations of a published research article in accord with those of expert judges and (b) influencing the longer term use by the participants of published research. The day provided a brief introduction to basic research techniques both in theory and in practice, as well as a set of structured guidelines for evaluating research articles.(ABSTRACT TRUNCATED AT 250 WORDS)

Clinical Competence↗
PubMed1994

Lacrimal surgery in patients with congenital cranial or facial anomalies.

A series of 26 patients with lacrimal dysfunction due to congenital cranial or facial anomalies are reviewed. The underlying anatomical abnormalities responsible for symptoms and their influence on surgical management and outcome are discussed and illustrated with representative cases. It is shown that by adaptation of standard surgical techniques a high success rate can be achieved.

Abnormalities, Multiple↗
PubMed1994

Determinants for intracellular sorting of cytoplasmic and nuclear intermediate filaments.

The mechanism by which nuclear and cytoplasmic filaments are sorted in vivo was studied by examining which lamin sequences are required to target an otherwise cytoplasmic IF protein, the small neurofilament subunit (NF-L), to the nuclear lamina. By swapping corresponding domains between NF-L and lamin A, nuclear envelope targeting of NF-L was shown to require the presence of the "head" domain, a 42-amino acid sequence unique to lamin rod domains, a nuclear localization signal and the CAAX motif. Replacement of the entire COOH-terminal tail of lamin A with that of NF-L had no discernible effect on nuclear localization of lamin A, provided the substituted NF-L tail contained a NLS and a CAAX motif. This chimeric protein exhibited characteristics more typical of lamin B than that of the parental lamin A. With regard to cytoplasmic assembly properties, substitution of the head domain of lamin A for that of NF-L did not substantially affect the ability of NF-L to coassemble with vimentin in the cytoplasm. In contrast, insertion of a 42-amino acid sequence unique to lamin rod domains into NF-L profoundly affected NF-L coassembly with vimentin indicating that the 42-amino acid insertion in lamins may be important for sorting lamins from cytoplasmic IF proteins.

Amino Acid Sequence↗