Biomedical subjects

L McKenna

Publications and source records attributed to L McKenna.

14 recordsLinked to original sources

PubMed2004

Tinnitus impairs cognitive efficiency.

Many people who complain of tinnitus say that the noises impair their mental concentration. This complaint was investigated by self-report (primarily the Cognitive Failures Questionnaire) and by means of five cognitive tasks, four presented via laptop computer and one given manually. The tasks measured performance under single- and dual-task conditions and included tests of sustained attention, reaction time, verbal fluency and immediate and delayed memory. Two groups of outpatients attending audiological clinics (tinnitus, n = 43; hearing impairment, n = 17) were compared with non-clinical volunteers (n = 32). The results replicated earlier findings that tinnitus outpatients report significantly more everyday cognitive failures than do controls. The tinnitus group responded significantly more slowly than the two control groups on the variable fore-period reaction time task under dual-task conditions. In general, comparisons between the groups on other tasks showed equivalent performance, but both clinical groups performed more poorly than non-clinical controls on verbal fluency. We conclude that cognitive inefficiency in tinnitus participants is related to the control of attentional processes, consistent with our earlier theoretical speculation about the nature of tinnitus complaint and with published findings on the effects of chronic pain on cognitive processes.

Adult↗

PubMed2002

Molecular pathology and pathobiology of osteoarthritic cartilage.

The biochemical properties of articular cartilage rely on the biochemical composition and integrity of its extracellular matrix. This matrix consists mainly of a collagen network and the proteoglycan-rich ground substance. In osteoarthritis, ongoing cartilage matrix destruction takes place, leading to a progressive loss in joint function. Beside the degradation of molecular matrix components, destabilization of supramolecular structures such as the collagen network and changes in the expression profile of matrix molecules also take place. These processes, as well as the pattern of cellular reaction, explain the pathology of osteoarthritic cartilage degeneration. The loss of histochemical proteoglycan staining reflects the damage at the molecular level, whereas the supramolecular matrix destruction leads to fissuring and finally to the loss of the cartilage. Chondrocytes react by increasing matrix synthesis, proliferating, and changing their cellular phenotype. Gene expression mapping in situ and gene expression profiling allows characterization of the osteoarthritic cellular phenotype, a key determinant for understanding and manipulating the osteoarthritic disease process.

Animals↗

PubMed2001

Apoptotic cell death is not a widespread phenomenon in normal aging and osteoarthritis human articular knee cartilage: a study of proliferation, programmed cell death (apoptosis), and viability of chondrocytes in normal and osteoarthritic human knee cartilage.

OBJECTIVE: Chondrocytes are crucial for adequate matrix balance and function. Cell proliferation and, recently, extensive apoptotic cell death have been reported in osteoarthritic (OA) cartilage. Apoptotic cell death would be an obvious central factor in the initiation and progression of OA, since there is no potential for replacing articular chondrocytes in the adult. Therefore, we studied the occurrence of apoptotic cell disintegration and cell proliferation in OA and normal articular cartilage obtained from the knees of adult donors of all ages. METHODS: Following immunostaining for cellular proteins as well as staining for nuclear DNA, we performed triple-channel confocal laser scanning microscopy on thick cartilage slices to evaluate lacunar emptying and cell viability. Cell proliferation and apoptotic cell death were evaluated morphologically, by immunodetection of the proliferation-associated Ki-67 antigen, and by the TUNEL reaction. RESULTS: With the exception of the calcified layer, we were not able to detect any major (apoptotic or nonapoptotic) cell disintegration in normal young or aged articular knee cartilage. Single apoptotic cells were detected in OA articular knee cartilage. A significant increase in lacunar emptying was observed in late-stage specimens with higher Mankin scores compared with age-matched normal control cartilage specimens, but not in low-grade lesions. A significant (but lesser) increase in empty lacunae was also observed with age in normal cartilage. Cell proliferation was rarely detected in OA cartilage samples and was not detected at all in normal cartilage samples. CONCLUSION: Our results confirm the findings of previous studies showing that cell proliferation occurs in OA cartilage. They also show that, contrary to previous suggestions, apoptotic cell death is not a widespread phenomenon in aging or OA cartilage.

Adult↗

PubMed2001

Anabolic and catabolic gene expression pattern analysis in normal versus osteoarthritic cartilage using complementary DNA-array technology.

OBJECTIVE: To understand changes in gene expression levels that occur during osteoarthritic (OA) cartilage degeneration, using complementary DNA (cDNA)-array technology. METHODS: Nine normal, 6 early degenerated, and 6 late-stage OA cartilage samples of human knee joints were analyzed using the Human Cancer 1.2 cDNA array and TaqMan analysis. RESULTS: In addition to a large variability of expression levels between different patients, significant expression patterns were detectable for many genes. Cartilage types II and VI collagen were strongly expressed in late-stage specimens, reflecting the high matrix-remodeling activity of advanced OA cartilage. The increase in fibronectin expression in early degeneration suggests that fibronectin is a crucial regulator of matrix turnover activity of chondrocytes during early disease development. Of the matrix metalloproteinases (MMPs), MMP-3 appeared to be strongly expressed in normal and early degenerative cartilage and down-regulated in the late stages of disease. This indicates that other degradation pathways might be more important in late stages of cartilage degeneration, involving other enzymes, such as MMP-2 and MMP-11, both of which were up-regulated in late-stage disease. MMP-11 was up-regulated in OA chondrocytes and, interestingly, also in the early-stage samples. Neither MMP-1 nor MMP-8 was detectable, and MMP-13 and MMP-2 were significantly detectable only in late-stage specimens, suggesting that early stages are characterized more by degradation of other matrix components, such as aggrecan and other noncollagenous molecules, than by degradation of type II collagen fibers. CONCLUSION: This investigation allowed us to identify gene expression profiles of the disease process and to get new insights into disease mechanisms, for example, to develop a picture of matrix proteinases that are differentially involved in different phases of the disease process.

Adult↗

PubMed2001

Guidelines for the grading of tinnitus severity: the results of a working group commissioned by the British Association of Otolaryngologists, Head and Neck Surgeons, 1999.

Tinnitus is a common experience with up to one third of the adult population experiencing it at some time in their life. Less than 1% of the adult population have tinnitus of sufficient severity to affect their quality of life seriously (although up to 8% may seek medical advice about it). Much of the severity of tinnitus relates to the individuals' psychological response to the abnormal tinnitus signal. The prevalence of tinnitus increases in association with high frequency hearing loss. There is, unfortunately, no diagnostic test that either confirms the presence of tinnitus or its severity. Currently there is no satisfactory severity grading system. A five-point severity grading scheme is therefore proposed and the entry criteria detailed. The five severity points are: slight, mild, moderate, severe and catastrophic. Categorization as 'severe' or 'catastrophic' should be, by epidemiological definition, very rare. General guidance, theory and evidential support are contained within.

Adult↗

PubMed2001

Turning tapes into text: issues surrounding the transcription of interviews.

Transcription of interview data is a common practice in qualitative health research. However, there has been little discussion of the techniques of transcription and the issues inherent in the use of transcription as a strategy for managing qualitative data in nursing publications. The process of transcription may disclose or obscure certain information. Researchers need to question practices of transcription that have been taken for granted and make transparent the processes used to preserve the integrity of data. This paperfirst examines research reported in nursing and allied health journals employing interviews for data collection and the attention given to the transcription phase. It then deals with issues of concern regarding the transcription of interviews, and offers suggestions for promoting validity.

Ethics↗

PubMed2000

Children's experience of tinnitus: a preliminary survey of children presenting to a psychology department.

Tinnitus has been much researched within adult populations with consideration of prevalence as well as the impact of tinnitus on individual's lives. Although the literature highlights the prevalence of tinnitus in children, there is little information on its effects from a psychological perspective. This small-scale preliminary study looked at 24 children (50% with normal hearing and 50% with a hearing loss) who presented to the Psychology Department with troublesome tinnitus. In line with adult studies, preliminary results suggested that tinnitus can have as marked an effect on children's lives as it is reported to have on adults. Insomnia, emotional distress, listening and attention difficulties are the main psychological factors associated with tinnitus in children. These, in turn, may have an effect upon their school performance. Differences were found between children with normal hearing and those with some degree of hearing loss. Overall, children with normal hearing found tinnitus more troublesome and presented with higher levels of anxiety than those with some level of hearing impairment. The present study suggests that children who complain of tinnitus should be taken seriously. In terms of management, individual intervention packages were found to be useful in alleviating anxiety and other associated factors. Recommendations are made on areas for future research.

Acoustic Stimulation↗

PubMed1997

Support group membership and perceptions of control over health in HIV+ men.

We compared health-related control perceptions in 115 HIV+ gay/ bisexual British men who were or were not members of an AIDS support group. Participants completed the Multidimensional Health Locus of Control Scale (MHLC). Compared to those who were not members of a support group, HIV+ men who belonged to a support group reported higher frequencies of perceptions that both oneself and powerful others (health professionals) are major determinants of one's health. Support group members also reported a lower frequency of perceptions that chance factors greatly influence one's health.

Adolescent↗

PubMed1997

Changing handover practices: one private hospital's experiences.

The handover practice has long been an important component of clinical nursing practice allowing nurses to exchange relevant client information from one shift to the next and ensure continuity of patient care. Traditional approaches have seen nursing handovers taking place in a room away from general ward activity. Oncoming nursing staff receive the information verbally from nurses on the previous shift about all patients within the ward or unit. This practice has been proven over time to present difficulties and consequently, many hospitals are choosing to adopt models that better address current needs. This analysis describes the creative approaches taken by one private hospital in modifying handover practices with the view to reduce time and increase overall efficiency and effectiveness, whilst ensuring that staff and ward requirements are considered. The study highlights how action research principles can be applied to introduce change into the clinical practice environment.

Communication↗

PubMed1994

Tinnitus and suicide.

A retrospective study of tinnitus sufferers who had committed suicide was undertaken. A questionnaire was compiled, and circulated world-wide. Adequate information was obtained on 28 suicides. An association between suicide and left-sided tinnitus reported previously, was not conclusively replicated. In fact, no particular tinnitus parameter, or associated audiological symptom was over-represented in the suicide series. Demographically, tinnitus suicide victims were characterized by being male, elderly, and socially isolated. There was a high prevalence of psychiatric morbidity, in particular depression (70%). A suicide attempt within the year preceding suicide occurred in five individuals.

Adolescent↗

PubMed1991

The prevalence of psychological disturbance in neurotology outpatients.

This study assesses the prevalence of psychological disturbance among a consecutive series of 120 neuro-otology outpatients, using a structured interview conducted by a clinical psychologist. 42% of all patients were found to be in need of, and were offered, psychological help (27% of those with hearing loss, 45% of those with tinnitus and 64% of those with dizziness). 86% of those offered psychological help accepted it. Current psychological distress was associated with the number of symptoms complained of and past psychiatric history. Patients completed the General Health Questionnaire which was found to have a sensitivity rate of 82% and a specificity rate of 87% in this setting. Physicians were also asked to rate patients' psychological state; close agreement was found between these ratings and those of a psychologist. The contribution of psychological assessment of neuro-otology patients is discussed.

Ambulatory Care↗

PubMed1987

Goal planning in audiological rehabilitation.

This paper describes the processes involved in goal planning, a means of structuring and evaluating a rehabilitation programme which is individually designed for a particular patient. The goal planning procedure involves a multi-disciplinary effort with the patient as an integral member of the team. Goals, which are identified from a strengths-needs list compiled by the team for a patient, are broken down into specific steps which should be easy to achieve by a given target date. The patient's strengths are used to help achieve the goals. Each step should be written in clear and objective terms and the use of vague goals such as 'the patient should make better use of a hearing aid', should be avoided. Goal planning does not dictate which therapy should be used but it does provide a framework for implementing any therapy that the team decide is appropriate. An example of a goal plan used in an audiological rehabilitation clinic is given.

Adult↗

PubMed1986

The psychological assessment of cochlear implant patients.

The use of a cochlear implant (CI) to restore some acoustical input to patients with complete acquired hearing loss may be expected to result in changes in their psychological functioning. CI programmes should therefore include a careful psychological screening of all candidates and subsequent psychological assessments of patients who receive implants. Procedures used in the psychological assessment of CI candidates and patients outlined in the literature, as well as those used in the Royal Ear Hospital (REH) programme, are discussed. It is concluded that standard psychological tests of personality and intellectual functioning are of limited value in the screening of CI candidates and the postoperative evaluation of patients. It is proposed that more useful information be obtained by an analysis of the possible functional value of the implant to each individual candidate and by assessment of actual postoperative changes in the patient's behaviour. Unless an implant leads to improvements in the patient's psychosocial functioning, the device is unlikely to be used. Examples of this approach in assessing the REH candidates and patients are given.

Cochlear Implants↗

PubMedDate not supplied

Tinnitus masking and depression.

In this pilot study 30 patients with annoying tinnitus completed tinnitus matching and the Beck Depression Inventory (BDI). A cluster analysis revealed three clusters of patients. Cluster one had relatively low depression and average results on tinnitus parameters. Cluster two displayed high depression scores and lower results on tinnitus parameters. The last small cluster had high depression scores and high results on tinnitus and hearing parameters. A curvilinear regression showed a U-shaped relation between the BDI and minimal masking level. The results are interpreted according to a diathesis stress model, in which a vulnerable person might develop tinnitus distress following a comparatively low degree of tinnitus and a more stress-tolerant person might bear higher degrees of tinnitus before seeking help. As a conclusion this may have implications for what treatment to recommend and most certainly should be accounted for in the assessment of patients.

Adult↗