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Biomedical subjects

M Boyle

Publications and source records attributed to M Boyle.

At least 55 records · Page 3Linked to original sources
PubMed1996

The arteriovenous fistula for hemodialysis access: gold standard or archaic relic?

A five year retrospective review was undertaken to evaluate the patency rates of arteriovenous fistulae (AVF) in patients with end stage renal disease. From July 1989 through June 1994, 150 fistulae were created in the wrists of 144 patients. Thirty-four percent of the patients had diabetes mellitus. Patient death or irreparable fistulae were considered end points in the study. Patency rates were calculated by the Kaplan-Meier Actuarial Analysis. An analysis to assess the impact of the demographic characteristics, underlying renal disease, and effect of revisions on patency rates was calculated. The results demonstrate a high initial failure rate (less than 1 month) of 13 per cent in the entire cohort undergoing fistulae replacement. The 1 and 5-year patency rates were 56 per cent and 30 per cent, respectively. Diabetics had a significantly lower patency rate at 1 and 5 years (42% and 18%) respectively. Others, who had poor patency rates, include patients 70 years old or greater (40% patency at one year). The results suggest that the AVF should not be the first choice of access in elderly diabetics and that these patients would be better served with other modes of access, such as synthetic conduits or permanent indwelling venous catheters.

Adult↗
PubMed1996

Reproducibility of Bayesian belief network assessment of breast fine needle aspirates.

OBJECTIVE: To assess the consistency of diagnosis of fine needle aspiration biopsies of breast lesions by three experienced and five less experienced pathologists using conventional means and applying a Bayesian belief network (BBN) to 10 diagnostic features to support diagnostic decision making. STUDY DESIGN: Forty fine needle aspiration biopsies, previously assessed by one of the experienced pathologists both conventionally and using a BBN, were assessed by two further experienced pathologists and five less experienced pathologists. RESULTS: Using the BBN, the experienced pathologists arrived at diagnoses in agreement with an established consensus at a slightly lower rate than by conventional means. The less experienced pathologists arrived at the correct diagnoses no more frequently with the help of the BBN than conventionally. CONCLUSION: As used in this study, the BBN did not help less experienced pathologists to interpret their observations but did not enable less experienced pathologists to identify how their observations differed and affected their diagnoses. The prototype system used in this study has since been upgraded by providing computer graphic displays of the features to be observed so that a more uniform mental image can be held by the participating pathologists. This will be tested with the same study design.

Biopsy, Needle↗
PubMed1995

Nitric oxide: a positive poison.

In 1987 the demonstration that nitric oxide (NO) was formed in vascular endothelial cells opened up a vast area of research. Ten years ago NO was viewed primarily as a toxic gas related to air pollution. Today NO is recognised as a major endogenous mediator of multiple physiological processes. NO's vasodilatory properties and short half life has led to the use of inhaled NO as a selective pulmonary vasodilator. NO was first used in neonates with acute pulmonary hypertension. It is now being used in the treatment of critically ill adults with severe respiratory compromise. It is very likely that intensive care nursing staff will increasingly be asked to contribute to the maintenance and management of NO inhalation therapy.

Aged↗
PubMed1995

Comparative clearance performance of two dialyser units used in the CVVHD mode.

Continuous renal replacement therapies are now commonly used modes of support in acute renal failure (ARF). This study compared the clearance performance and it's degradation over time of two dialysers, one of flat plate configuration, and one of hollow fibre configuration (Asahi PAN 06 hollow fibre dialyser, Domedica, Sydney, and Hospal AN69HF flat plate dialyser, Gambro, Sydney) used in the CVVHD mode. Data were obtained from seven patients. Urea clearance was determined at commencement of dialysis and then at 12 hour intervals up to 48 hours post commencement. At each study time, urea clearance was determined at dialysis fluid (DF) flows of 500, 1000, 1500 and 2000 ml/hr. The procedure was repeated for each patient using the alternate dialyser. Comparisons of the two dialyser's urea clearance did not demonstrate any significant difference at any of the time periods studied. Overall, clearance was dependent upon (DF) flow with the diffusive clearance initially equal to DF flow but falling to 0.7 and 0.85 times increase in DF flow at 48 hours.

Acute Kidney Injury↗
PubMed1995

The development of the Australian Basic Intensive Care Knowledge Test.

The Basic knowledge Assessment Tool (BKAT), a test developed in the United States, has been presented as a valid and reliable test of basic knowledge for critical care nursing. However, it was necessary to determine the BKAT's validity and reliability in the Australian intensive care (IC) context. The Delphi technique, utilising a panel of eleven experts, was used to determine the content validity of the BKAT. The Delphi process resulted in the development of a test with 105 questions. These questions consist of 49 original BKAT questions, 25 original BKAT questions slightly modified, 3 original BKAT questions with major modifications and 28 new questions. A criterion group design was used to establish the modified test's reliability and decision validity. Item analysis was undertaken using item difficulty and item discrimination indexes. The modified test was completed by 14 registered nurses with no IC experience, 18 registered nurses with intermediate IC experience and 25 registered nurses qualified as intensive care specialists. The mean score (and standard deviation) for the test for each of the respective groups was 41(9), 69(9) and 86(7). These results were significantly different (p < 0001). The reliability was established with a Cronbach Alpha coefficient of .96. The modified test is a reliable and valid measure of IC basic knowledge and can be used as a valuable adjunct in the assessment of IC orientation programs.

Australia↗
PubMed1995

Risky heterosexual practices amongst women over 30: gender, power and long term relationships.

Statistics suggest that older and younger people are about equally at risk for HIV infection, yet existing research on heterosexuality and safer sexual practices has tended to focus on people under the age of 25. The present qualitative study investigates risk behaviours and the practice of safer sex in older populations. Group discussions comprising women over the age of 30 (n = 23) targeted two issues: the gendered power dimension of heterosexuality and safer sex in long term relationships. Cohort issues were also discussed. The discussion groups revealed that the imbalance of power between men and women which has been shown by previous research to constrain younger women's choices with regard to safer sex, continues to affect older women's decisions. Many of the group participants still found it difficult to assert themselves in sexual relationships and even those who were able to challenge overt pressures to engage in unsafe sex were still susceptible to internalized social pressures. In addition, it seems that risks for older age groups are increased by difficulties in continuing to use condoms in long term relationships where monogamy cannot be taken for granted. It was also apparent that there are difficulties in changing sexual behaviours which were established before HIV became an issue.

Adult↗
PubMed1995

Large group community-based parenting programs for families of preschoolers at risk for disruptive behaviour disorders: utilization, cost effectiveness, and outcome.

A significant percentage of children with disruptive behavior disorders do not receive mental health assistance. Utilization is lowest among groups whose children are at greatest risk. To increase the availability, accessibility, and cost efficacy of parent training programs, this prospective randomized trial compared a large group community-based parent training program to a clinic-based individual parent training (PT) programs. All families of junior kindergartners in the Hamilton public and separate school boards were sent a checklist regarding problems at home. Those returning questionnaires above the 90th percentile were block randomly assigned to: (1) a 12-week clinic-based individual parent training (Clinic/Individual), (2) a 12-week community-based large group parent training (Community/Group), or (3) a waiting list control condition. Immigrant families, those using English as a second language, and parents of children with severe behaviour problems were significantly more likely to enroll in Community/Groups than Clinic/Individual PT. Parents in Community/Groups reported greater improvements in behaviour problems at home and better maintenance of these gains at 6-month follow-up. A cost analysis showed that, with groups of 18 families, Community/Groups are more than six times as cost effective as Clinic/Individual programs.

Child Behavior Disorders↗
PubMed1995

Specification, migration and assembly of the somatic cells of the Drosophila gonad.

The adult ovaries and testes contain several specialized somatic cell types that support the differentiation of germ cells into mature gametes. Each of these cell types arise from mesodermal cells that constitute the embryonic gonad. To explore the mechanisms governing the development and differentiation of these cells, we focus on the formation of the gonad during Drosophila development. Using markers for the precursors of the somatic cells of the gonad, we identify discrete steps in the development of the gonad. Our results suggest the existence of different populations of gonadal precursors at early stages in gonadogenesis that represent precursors of cell types found within the adult gonad. The functions of the homeotic genes abdominal A and Abdominal B are required for the development of gonadal precursors, however, here we provide evidence that each plays a distinct role. abd A activity alone specifies anterior gonadal precursor fates, whereas abd A and Abd B act together to specify a posterior subpopulation of gonadal precursors. Once specified, gonadal precursors born within posterior parasegments must move to the site of gonad formation. Here, we show that the proper regional identities, as established by homeotic gene function, are required for the arrest of migration at the correct position. Finally, our analysis of late stages of gonadogenesis suggests that abd A is required in a population of cells within parasegments 10 and 11 that partially ensheath the coalescing gonad. Mutations in iab-4 abolish expression of abd A within these cells, and as a result block the coalescence of the gonad.

Animals↗
PubMed1995

Multi-attribute health status classification systems. Health Utilities Index.

In this article, multi-attribute approaches to the assessment of health status are reviewed with a special focus on 2 recently developed systems, the Health Utilities Index (HUI) Mark II and Mark III systems. The Mark II system consists of 7 attributes: sensation, mobility, emotion, cognition, self-care, pain and fertility. The Mark III system contains 8 attributes: vision, hearing, speech, ambulation, dexterity, emotion, cognition and pain. Each attribute consists of multiple levels of functioning. A combination of levels across the attributes constitutes a health state. The HUI systems are deliberately focused on the fundamental core attributes of health status, and on the capacity of individuals to function with respect to these attributes. Thus, the measure obtained constitutes a pure description of health status, uncontaminated by differential opportunity or preference. Multi-attribute systems provide a compact but comprehensive framework for describing health status for use in population health and programme evaluation studies. An important advantage of such systems is their ability to simultaneously provide detail on an attribute-by-attribute basis and to capture combinations of deficits among attributes. An additional advantage is their compatibility with multi-attribute preference functions, which provide a method for computing a summary health-related quality-of-life score for each health state.

Canada↗
PubMed1995

Multi-attribute preference functions. Health Utilities Index.

Multi-attribute utility theory, an extension of conventional utility theory, can be applied to model preference scores for health states defined by multi-attribute health status classification systems. The type of preference independence among the attributes determines the type of preference function required: additive, multiplicative or multilinear. In addition, the type of measurement instrument used determines the type of preference score obtained: value or utility. Multi-attribute utility theory has been applied to 2 recently developed multi-attribute health status classification systems, the Health Utilities Index (HUI) Mark II and Mark III systems. Results are presented for the Mark II system, and ongoing research is described for the Mark III system. The theory is also discussed in the context of other well known multi-attribute systems. The HUI system is an efficient method of determining a general public-based utility score for a specified health outcome or for the health status of an individual. In clinical populations, the scores can be used to provide a single summary measure of health-related quality of life. In cost-utility analyses, the scores can be used as quality weights for calculating quality-adjusted life years. In general populations, the measure can be used as quality weights for determining population health expectancy.

Health Services↗
PubMed1994

The usefulness of intensive care treatment: perspectives of medical and nursing staff.

Which patients' states or circumstances effect the judgement of Intensive Care specialist (IC) medical and nursing staff as to how useful intensive care treatment is? Do IC medical and nursing staff differ significantly in their attitudes regarding the usefulness of IC treatment? Or do they show similarity in their attitude but differ as a group from broader community views of the usefulness of IC treatment? To gain insight into these questions a group of IC staff (35 medical, 108 nursing) and pre-clinical students (110 medical, 136 nursing) responded to a questionnaire asking them to consider how 12 patient factors including age, functional state, socioeconomic factors, length and cost of the IC stay, culpability, disease state and length of survival after IC unit discharge effected their judgement of the usefulness of IC treatment for an individual patient. Results indicated that: (i) medical and nursing students felt IC treatment more useful than IC staff regardless of the patient characteristic; (ii) IC doctor and nurse responses were very similar; (iii) IC staff considered that IC treatment "tended to be useless" or was "useless" if the patient had required "institutional care", was in a "vegetative" state before or after IC treatment, belonged to the pathology groups of "malignancy" and "diseases of ageing", belonged to the diagnostic groups "AIDS" and "quadriplegia", or where survival post discharge from IC was expected to be "< 3 months"; and (iv) cost and length of stay in IC were not factors that negatively effected any groups perception of the usefulness of IC treatment.

Adult↗
PubMed1994

Myxoma of the larynx: a case report and a review of the literature.

Laryngeal myxomas are rare benign mesenchymal tumours in contrast to myxomatous degeneration in laryngeal polyps which occurs frequently. A correct diagnosis of myxoma is usually not difficult to reach if the possibility of myxomatous degeneration in laryngeal polyps is excluded and strict pathological criteria are adhered to. We report a myxoma arising from the left vocal fold in a 64-year-old male who presented with a four-year history of intermittent dysphonia. Although excision was microscopically incomplete, there is no evidence of recurrence macroscopically 18 months later and the patient remains asymptomatic.

Humans↗
PubMed1994

Conservative surgery in multimodal therapy for pelvic rhabdomyosarcoma in children.

Twenty-six previously untreated children, median age 3.4 years, with pelvic rhabdomyosarcoma (RMS) were seen between 1983 and 1988. Fourteen were girls. The planned strategy was to conserve pelvic organs, especially the bladder, by using primary chemotherapy, conservative surgery and, in most cases, radiotherapy. With a median follow-up of 71 months (range 34-103 months) overall survival was 73%, with no treatment-related death. The bladder salvage rate of 88% in survivors with bladder base/prostate primaries was much higher than that reported by the United States Intergroup Rhabdomyosarcoma Studies (IRS), though many of the preserved bladders did not function normally. We identified problems with both radiological and histological off-treatment monitoring. The overall accuracy of computerised tomographic (CT) scanning for prediction of tumour recurrence was only 81%, and endoscopic biopsies proved misleading in four of the ten bladder base/prostate patients monitored by serial cystoscopy. We conclude that a higher cure rate can be achieved by using intensive chemotherapy/radiotherapy and conservative surgery to treat children with pelvic RMS. Factors that might contribute to our favourable bladder salvage results, compared with those of the IRS, include (a) the fact that one of two specialist surgeons monitored and operated on all these patients and (b) our increasing awareness, during the study, that post-chemotherapy/radiotherapy histopathology and pelvic CT scan appearances may be misleading. Referral to paediatric centres with special experience of pelvic RMS may help raise the rate of bladder salvage in these children.

Adolescent↗
PubMed1994

Pathways into the work force: antecedents of school and work force status.

OBJECTIVE: The study aim was to identify risk factors for specific pathways into the work force using data from the Ontario Child Health Study Follow-up. METHOD: Potential predictor variables were derived from data collected in 1983 on adolescents aged 13 to 16 years. The subjects were followed up 4 years later and the school/work force outcome was determined. Bivariate and multivariate statistical analyses were used to identify variables with a strong independent association with this outcome. RESULTS: Subjects in the work force were four times more likely than those attending school to have come from a low-income family and at least two times more likely to have a family background of low maternal education, to have failed a grade, or to have used substances heavily during early adolescence. Subjects with two or more of these risk factors were likely to be in part-time work or unemployed. CONCLUSIONS: Preventive interventions should be targeted at children from poor families, or who fail at school, or show early onset of substance abuse and other deviant behaviors. Studies are needed to further elucidate the relationship between these risk factors and pathways into the work force and beyond.

Adolescent↗
PubMed1994

Persistent generalized lymphadenopathy and non-Hodgkin's lymphoma in AIDS: association with Rochalimaea henselae infection.

Cat scratch disease, which is caused by infection with Rochalimaea henselae, is often manifested as lymphadenopathy. R. henselae has also been isolated from human immunodeficiency virus (HIV)-positive patients with bacillary angiomatosis. In order to determine the frequency of R. henselae-reactive antibodies in HIV-positive patients with persistent generalized lymphadenopathy (PGL) or non-Hodgkin's lymphoma (NHL), we tested a total of 124 HIV-positive patients for R. henselae-reactive immunoglobulin G (IgG), IgM, and IgA antibodies by an enzyme immunoassay procedure using whole R. henselae antigen. Of the patients, 7 had PGL, 17 had NHL, and 100 were HIV stage IV (Centers for Disease Control criteria). A total of 86% of PGL patients (6 of 7) were positive for R. henselae antibodies (three were positive for IgG, IgA, and IgM, one was positive for IgG and IgA only, and two were positive for IgG only). A total of 29% of NHL patients (5 of 17) were positive for R. henselae antibodies (two were positive for IgG, IgA, and IgM and three were positive for IgG only). Only 5% of HIV Stage IV patients without adenopathy (5 of 100) were positive for R. henselae-reactive IgG, IgA, and IgM. The high prevalence of R. henselae-reactive antibodies in HIV-positive PGL and NHL patients suggests that R. henselae is a potential etiologic agent or cofactor in these patients.

AIDS-Related Complex↗
PubMed1994

Piccadilly Circus legionnaires' disease outbreak.

BACKGROUND: An outbreak of legionnaires' disease occurred in central London in January and February 1989. An Infection Control Committee was established to investigate the outbreak and institute control measures. The objective of this paper is to describe the investigation and control of the outbreak. METHODS: An epidemiological survey and case-control study were carried out. The subjects were cases of community acquired pneumonia associated with central London with onset of illness in January and February 1989. RESULTS: Thirty-three confirmed cases, including five deaths, and ten suspected cases, including three deaths, were identified with dates of onset from 1 January to 11 February. A clustering of visits by cases to the vicinity of Piccadilly Circus was noted, and a case-control study demonstrated a strong association between illness and visits to this area in the two weeks before onset of symptoms. The causative organism, Legionella pneumophila serogroup 1, was isolated from six patients. Legionella pneumophila of the same serogroup was isolated from water samples from five wet cooling systems (cooling towers) in the area under investigation, but in only two systems was the organism indistinguishable by subtyping from the patients' strains. Many of the cooling towers examined were inadequately maintained, including one of the two above a building adjacent to Piccadilly Circus from which a strain indistinguishable from the outbreak strain was isolated. All cooling towers in the area were shut down until inspected, and only allowed to restart after appropriate maintenance had been instigated. CONCLUSIONS: This outbreak showed the continuing risk of legionnaires' disease posed by wet cooling systems, including cooling towers, and highlighted the need to assess this risk so that appropriate maintenance is carried out. Regulations have recently been introduced, under the Health and Safety at Work Act, requiring notification of all wet cooling systems to the local authority to facilitate the investigation of outbreaks of legionnaires' disease.

Adolescent↗