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Biomedical subjects

J Coyle

Publications and source records attributed to J Coyle.

At least 19 recordsLinked to original sources
PubMed2000

An exploration of the epistemological intricacies of using qualitative data to develop a quantitative measure of user views of health care.

Nurse researchers are increasingly combining qualitative and quantitative methods in order to understand more fully the world of research subjects. Qualitative data are often used to explore the subjective meanings behind survey responses and to develop quantitative measures and scales. Insights from qualitative data help researchers to design instruments which are more sensitive to respondents' meanings and interpretations. The aim of this paper is to highlight the epistemological and methodological complexities involved in this enterprise through drawing on our own experience of developing an instrument to examine person-centredness in health care from a qualitative study of dissatisfaction. The intricacies of this project relate to: epistemological continuity and inconsistency; research roles; reflexivity; confirmation; and completeness. Through discussing the literature around integrating methods, we suggest that researchers could be assisted in their attempts to develop conceptually sound quantitative measures by extending the concept of reflexivity (used in qualitative research) to the quantitative components of mixed method studies. This would aid conceptual clarity by making explicit the social, cultural, and political construction of knowledge, and would also encourage researchers to reflect upon the ethical and political consequences of their research.

Adolescent↗
PubMed2000

DX-8951f, a hexacyclic camptothecin analog, on a daily-times-five schedule: a phase I and pharmacokinetic study in patients with advanced solid malignancies.

PURPOSE: To assess the feasibility of administering DX-8951f (exatecan mesylate), a water-soluble, camptothecin analog, as a 30-minute intravenous infusion daily for 5 days every 3 weeks, determine the maximum-tolerated dose (MTD) and pharmacokinetic (PK) behavior of DX-8951f, and seek preliminary evidence of anticancer activity. PATIENTS AND METHODS: Patients with advanced solid malignancies were treated with escalating doses of DX-8951f. After three patients were treated at the first dose level, doses were to be escalated in increments of 100%, using a single patient at each dose level unless moderate toxicity was observed. The MTD, defined as the highest dose level at which the incidence of dose-limiting toxicity did not exceed 20%, was calculated separately for minimally pretreated (MP) and heavily pretreated (HP) patients. The PK and excretory profiles of DX-8951, the anhydrous form of DX-8951f, were also characterized. RESULTS: Thirty-six patients were treated with 130 courses of DX-8951f at six dose levels ranging from 0.1 to 0.6 mg/m(2)/d. Brief, noncumulative neutropenia was the most common toxicity observed. Severe myelosuppression (neutropenia that was protracted and/or associated with fever and/or severe thrombocytopenia) was consistently experienced by HP and MP patients at doses exceeding 0.3 and 0.5 mg/m(2)/d, respectively. Nonhematologic toxicities (nausea, vomiting, and diarrhea) were also observed, but these effects were rarely severe. Objective antitumor activity included partial responses in one patient each with platinum-resistant extrapulmonary small-cell and fluoropyrimidine- and irinotecan-resistant colorectal carcinoma, and minor responses in patients with prostate, hepatocellular, thymic, primary peritoneal, and irinotecan-resistant colorectal carcinomas. The PKs of total DX-8951 were linear and well fit by a three-compartment model. CONCLUSION: The recommended doses for phase II studies of DX-8951f as a 30-minute infusion daily for 5 days every 3 weeks are 0.5 and 0.3 mg/m(2)/d for MP and HP patients, respectively. The characteristics of the myelosuppressive effects of DX-8951f, paucity of severe nonhematologic toxicities, and antitumor activity against a wide range of malignancies warrant broad disease-directed evaluations of DX-8951f on this schedule.

Adult↗
PubMed1999

Differentiation of normal and abnormal airway protection during swallowing using the penetration-aspiration scale.

Accidental loss of food or liquids into the airway while eating or drinking is perhaps the most clinically significant consequence of dysphagia. Although videofluoroscopic recording of swallowing is the current gold standard for identifying and determining remediation for aspiration, results are generally described in descriptive terms, thus limiting information and lending to errors of interpretation. We previously published an 8-point scale to quantitate selected aspects of penetration and aspiration conveying depth of airway invasion and whether or not material entering the airway is expelled (Rosenbek et al., 1996, Dysphagia 11:93-98). The present study defines the distribution of the Penetration-Aspiration Scale scores in healthy normal subjects of different genders and ages. The scale was also used with two groups of patients known to have significant dysphagia relative to stroke or head and neck cancer. Significant differences found among groups are discussed.

Adult↗
PubMed1999

Understanding dissatisfied users: developing a framework for comprehending criticisms of health care work.

Recent government proposals have underlined the importance of ascertaining users' views of health care. Traditionally these have been obtained through satisfaction surveys. However, researchers argue that the focus of attention should now shift to exploring dissatisfaction because it highlights more clearly any problems in lay-practitioner relationships. Research has shown that dissatisfaction is a complex social construct which is underpinned by a range of values, beliefs, attitudes and experiences. The aim of this paper is to provide insights into the meaning of dissatisfaction by exploring how dissatisfied users attribute cause, responsibility and blame for their untoward experiences. Forty-one people were identified from a household survey of user views as experiencing problems with their health care. They were interviewed in depth, and a grounded theory approach was used to construct a framework inductively from their accounts. This identified a number of normative expectations through which health work was routinely criticized; these included respondents casting aspersions on the professional integrity of health care practitioners and preserving their own moral identity through demonstrating competence, knowledge, rationality, reasonableness and concern for others. Moreover, it is argued that these patterns help practitioners to understand how dissatisfied users' perceive subsequent health care encounters.

Adolescent↗
PubMed1999

Seeing the wood for the trees: defining the forgotten concept of patient dissatisfaction in the light of patient satisfaction research.

Studies of patient satisfaction are regarded by many as the most important way to obtain patients' views. To date, relatively few studies have focussed specifically on dissatisfaction. Concerns have been expressed about the validity of the concept of satisfaction. Dissatisfaction, however, has received little attention since it has been assumed to be the opposite of satisfaction and thus already defined. Therefore a series of assumptions have also been made about dissatisfaction, which may or may not compromise its validity or usefulness. The aim of this review is to clarify the concept of dissatisfaction by examining what studies of patient satisfaction can and cannot tell us about dissatisfaction; identifying assumptions; and finally by suggesting how research might best be oriented to accommodate the complexity of patient experiences.

Attitude to Health↗
PubMed1998

The meaning of patient satisfaction: an explanation of high reported levels.

The social policy background to the proliferation of patient satisfaction surveys is a desire for increased patient representation and participation. Within this context, it is assumed that satisfaction surveys embody patients' evaluations of services. However, as most surveys report high satisfaction levels, the interpretation of satisfaction as the outcome of an active evaluation has been called into question. The aim of this study is to identify whether and how service users evaluate services. This was made possible through unstructured in-depth interviews with users of mental health services and through more structured discussion around their responses on a patient satisfaction questionnaire (CSQ 18B) whose psychometric properties has been well documented. Twenty-nine people with current or recent contact with mental health services within the British National Health Service were interviewed. The data revealed that service users frequently described their experiences in positive or negative terms. However, the process by which these experiences were transformed into "evaluations" of the service was complex. Consequently, many expressions of "satisfaction" on the CSQ 18B hid a variety of reported negative experiences. An explanation for this lack of correspondence is outlined.

Bias↗
PubMed1998

Frequency-range discriminations: special and general abilities in zebra finches (Taeniopygia guttata) and humans (Homo sapiens).

The acoustic frequency ranges in birdsongs and human speech can provide important pitch cues for recognition. Zebra finches and humans were trained to sort contiguous frequencies into 3 or 8 ranges, based on associations between the ranges and reward. The 3-range task was conducted separately in 3 spectral regions. Zebra finches discriminated 3 ranges in the medium and high spectral regions faster than in the low region and discriminated 8 ranges with precision. Humans discriminated 3 ranges in all 3 spectral regions to the same modest standard and acquired only a crude discrimination of the lowest and highest of 8 ranges. The results indicate that songbirds have a special sensitivity to the pitches in conspecific songs and, relative to humans, have a remarkable general ability to sort pitches into ranges.

Acoustic Stimulation↗
PubMed1995

Pfcrk-1, a developmentally regulated cdc2-related protein kinase of Plasmodium falciparum.

A gene encoding a novel cdc2-related protein kinase has been identified in Plasmodium falciparum, using degenerate oligonucleotides designed to hybridise to regions that are conserved in members of the cdc2 gene family. This gene, called Pfcrk-1, is located on chromosome 4. It is most closely related to the p58GTA gene family, members of which are negative regulators of cell growth in vertebrates. Pfcrk-1 is developmentally regulated, as indicated by stage-specific accumulation of mRNA in gametocytes.

Amino Acid Sequence↗
PubMed1990

Detection and measurement of simulated early rheumatoid lesions of the hand using digital subtraction radiography.

The ability of digital subtraction radiography, a new technique to detect and quantify small bone lesions, is demonstrated. Discrete lesions in the metacarpals of cadaver hands simulated erosive bone loss. Radiographs made before and after removal of bone were digitized and subtracted. Density changes on subtraction images were determined, and bone loss was estimated by an automatic procedure that compared changes in radiographic density with a calibration wedge included in the radiographs. Comparison of estimated bone loss with the weight of bone removed showed reproducible detection and measurement of bone lesions as small as 4.6 mg, a size undetectable using current radiographic methods. Subtraction radiographs of bone chips overlaid on the hand of a volunteer indicated detection limits were similar in vivo. This technique enhanced the radiographic visibility of erosive lesions and thus has the potential to improve the detection of subtle bone changes in clinical settings.

Arthritis, Rheumatoid↗
PubMed1989

Effect of local or systemic treatment prior to primary tumor removal on the production and response to a serum growth-stimulating factor in mice.

This report indicates that not only does the preoperative administration of cyclophosphamide or radiation prevent the kinetic changes observed in a distant tumor focus following tumor removal but that the preoperative administration of the antiestrogen tamoxifen and the luteinizing hormone-releasing hormone analogue Zoladex are equally effective in that regard. It also provides evidence indicating that serum obtained from mice treated with those therapies when transferred to a recipient bearing a tumor of a similar type to that in the donor fails to stimulate DNA synthesis in the tumor of the recipient. In contrast, an increase in labeling index occurs following transfer of serum obtained following tumor removal from untreated mice. Moreover, when tumor-bearing mice were treated by each of the four modalities prior to receiving serum obtained from untreated donors following removal of a tumor, no kinetic changes were observed in the tumor of the serum recipient.

Animals↗
PubMed1989

Presence of a growth-stimulating factor in serum following primary tumor removal in mice.

The effect of removal of a primary tumor on the kinetics of cells in a metastasis was evaluated using six different tumors (C3H, MXTa, MXTb, MC54, CD8, and 3LL) which varied relative to their origin, histology, and the strain of mice in which they were carried. There was an increase in the labeling index (LI) of distant tumor focus ("metastasis") associated with the removal of each of the tumor types and unrelated to operative and anesthetic trauma. Information presented supports the presence of a serum growth factor as being responsible for the phenomenon. Serum obtained from mice following removal of a tumor, when transferred to a recipient with the same type of tumor as in the donor, resulted in an increase in the LI of the tumor. Multiple injections of serum failed to add to the increase but did prolong its presence, suggesting that there is a finite population of cells, most likely in the G1-G0 phase, which are capable of responding to the stimulating factor. The transfer of serum obtained following removal of a tumor type different from that in recipients resulted in findings which indicate that tumors producing a stimulating growth factor are those capable of responding to it. Serum obtained from animals with unremoved tumors or less than 18 h after removal failed to substantially augment the LI of tumors in recipients. It is postulated that the growth factor released by a tumor is in an inactive form which becomes activated over time. Observations indicate that medium conditioned by the growth of C3H tumor contains a growth-stimulating factor which is capable of increasing the LI of a C3H tumor in a recipient in a fashion similar to that obtained following tumor removal. That finding indicates the capability of the tumor to elaborate growth-stimulating material which may be similar to that found in serum. The findings presented refute the premise that removal of a primary tumor is a local phenomenon with no other biological consequences. They indicate that, following primary tumor removal, metastatic behavior may be affected by an interplay of growth factor(s) which can influence the outcome of a host to its tumor.

Animals↗
PubMed1988

Cerebrospinal fluid correlates of depression in Huntington's disease.

Patients with Huntington's disease (HD) commonly have concomitant depressive disorders. Prompted by reports of elevated corticotropin releasing factor (CRF) and reduced 5-hydroxyindoleacetic acid (5-HIAA) concentrations in lumbar cerebrospinal fluid (CSF) of patients with major depression, these CSF constituents were examined in 56 nonmedicated patients who were in the early stages of HD. Elevated CRF concentrations were found in patients with HD in comparison with a control group of 21 subjects without neurologic illness. The CSF 5-HIAA concentrations in patients with HD did not differ from that in four normal volunteers. Patients with HD who had depressive disorders (major depression or dysthymia) did not differ from those without depression with respect to CSF 5-HIAA or CRF concentration. However, a positive correlation was observed between severity of major depression and CRF concentration. These findings suggest that the depression associated with HD may differ neurochemically from that seen in other major depressive disorders, and support the notion that clinically significant depressive symptoms reflect heterogeneous pathophysiologic conditions with different neurochemical correlates.

Adult↗
PubMed1988

Cerebrospinal fluid homovanillic acid and parkinsonism in Huntington's disease.

In Huntington's disease (HD), normal or decreased levels of homovanillic acid (HVA) in cerebrospinal fluid (CSF) have been reported but have not been analyzed with respect to severity of parkinsonism, which in certain cases may be a predominant feature of the illness. We obtained CSF by lumbar puncture from four groups of nonmedicated subjects: (1) those with HD in the earliest stages of illness (n = 51), (2) those with parkinsonism, including idiopathic (n = 10) and atypical forms (n = 4), (3) those with nonparkinsonian movement disorders (n = 19), and (4) normal volunteers (n = 4). HVA was determined by high-pressure liquid chromatography with electrochemical detection, and motor signs were assessed in standardized fashion. The parkinsonian group had reduced levels of CSF HVA, but the other groups showed no significant differences. For those with HD, no correlation was found between HVA level and severity of parkinsonism, and there were no differences in HVA level between those subjects with (n = 14) or without (n = 37) prominent parkinsonism or between subjects whose age at illness onset was 30 years or less (n = 16) and those whose age at onset was over 30 (n = 35). Our findings indicate that in early, untreated HD, CSF HVA is in the normal range and does not correlate with the severity of parkinsonism. This observation supports neuropathological findings suggesting that parkinsonian features in HD are largely related to the loss of postsynaptic striatal dopamine receptors rather than to presynaptic nigral degeneration.

Adult↗
PubMed1986

The effect of propranolol on catecholamine clearance.

Normal subjects given propranolol increased their plasma t1/2 for infused isoproterenol from 2.68 to 6.25 minutes. Propranolol increased plasma norepinephrine (NE) levels only slightly. Propranolol increased the t1/2 of isoproterenol but not that of NE in men with autonomic nervous system degeneration. This suggests that propranolol acts on nonneuronal uptake-2 processes, rather than on uptake-1 mechanisms. alpha-Blockers slow uptake-1 and beta-blockers slow uptake-2 processes. When 27 subjects exercised, those who attained the highest plasma levels of the alpha- and beta-receptor agonist NE also had the briefest apparent t1/2 for NE. Adrenergic receptor blocking drugs slow catecholamine clearance. NE may stimulate its own clearance.

Blood Pressure↗