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Biomedical subjects

K Wilson

Publications and source records attributed to K Wilson.

At least 127 records · Page 7Linked to original sources

Major histocompatibility complex variation associated with juvenile survival and parasite resistance in a large unmanaged ungulate population.

Antagonistic coevolution between hosts and parasites has been proposed as a mechanism maintaining genetic diversity in both host and parasite populations. In particular, the high levels of genetic diversity widely observed at the major histocompatibility complex (MHC) of vertebrate hosts are consistent with the hypothesis of parasite-driven balancing selection acting to maintain MHC genetic diversity. To date, however, empirical evidence in support of this hypothesis, especially from natural populations, has been lacking. A large unmanaged population of Soay sheep (Ovis aries L.) is used to investigate associations between MHC variation, juvenile survival, and parasite resistance. We show in an unmanaged, nonhuman population that allelic variation within the MHC is significantly associated with differences in both juvenile survival and resistance to intestinal nematodes. Certain MHC alleles are associated with low survivorship probabilities and high levels of parasitism or vice versa. We conclude that parasites are likely to play a major role in the maintenance of MHC diversity in this population.

Alleles↗

Telephone or face-to-face interviews?: a decision made on the basis of a pilot study.

De Vaus (1991) highlights five main considerations that may be key factors in decisions about whether to use telephone or face-to-face interviews for survey work: response rates, ability to produce representative samples, effects on interview schedule design, quality of responses and implementation problems. De Vaus' discussion of these five issues is outlined at the start of this article. The five issues are then applied to the experiences of researchers conducting a study on continence care. Description and discussion of pilot interviews, which explored both interview modes, are followed by a similar examination of the main study which employed telephone interviews. Ideas in this discussion are supported and challenged by reference to other publications on the subject of telephone and face-to-face interviews. The success of the decision to use telephone interviews in the main study is evaluated and recommendations are made.

Humans↗

Relationship between abdominal aortic aneurysm wall compliance and clinical outcome: a preliminary analysis.

BACKGROUND: Aortic compliance, as measured by the pressure-strain elastic modulus (Ep) and stiffness (B), may allow a more precise estimate of abdominal aortic aneurysm rupture risk than size alone. AIM: To determine the relationships between AAA compliance, size, growth, and clinical outcome. METHODS: One-hundred and twelve patients with initially non-operated AAA (86 men, 26 women, mean age 73 years), recruited from five centres, underwent baseline compliance measurements and were then followed for a median of 7 (range 2-18) months; 85 patients underwent repeated measurements (median 3, range 2-5) 3-6-monthly over a median of 12 (range 3-18 months). RESULTS: Seven patients have ruptured and 16 have undergone repair of non-ruptured AAA. AAA that ruptured had significantly lower Ep and B (more compliant). In AAA that ruptured or required repair there was an inverse relationship between diameter and Ep and B. In those undergoing repeated measurements AAA expansion was only associated with a significant increase in Ep and B in non-operated patients. CONCLUSIONS: Baseline AAA compliance was significantly related to rupture and the future requirement for operative repair. Failure of compliance to increase with size may be a marker for rapid growth, developmental symptoms and rupture.

Aged↗

Familial acute myeloid leukaemia: four male members of a single family over three consecutive generations exhibiting anticipation.

A kindred with familial acute myeloid leukaemia (AML) is described displaying the concept of anticipation which refers to increased disease severity and/or earlier age at onset with succeeding generations. The affected individual in the first generation was the father (aged 34 years at diagnosis) of two affected members of a single sibship (aged 24 and 25 years). The fourth patient is the son (aged 4 years) of one of these brothers in the second generation. The AML was of different subtypes and a karyotypic abnormality (del[6q]) was detected in one of three patients. The first-generation patient died during chemotherapy; the remaining three patients are in complete remission after chemotherapy and autologous bone marrow transplantation.

Acute Disease↗

Interviewing older people by telephone following initial contact by postal survey.

Although the use of the telephone for interviewing has become a commonly used and largely accepted research method, the literature on this subject makes it clear that certain reservations remain. Some of these relate to problems encountered when interviewing older adults by telephone and others concern the use of the telephone in interviews where there has been no prior face-to-face contact. The conclusions of others who have studied these two sets of problems in combination are that special difficulties exist. These conclusions are examined with reference to researchers' experiences of conducting a study on continence care, in which a postal survey (as opposed to face-to-face contact) preceded telephone interviews. Interviews were conducted with adults of all ages, including a high proportion of older people. Researchers encountered few major difficulties and were satisfied with both response rate and response quality. Research to compare the effects of a variety of initial contact modes on telephone interviews with both younger and older adults is recommended.

Aged↗

Comparison of rehabilitation outcomes in violent versus non-violent traumatic SCI.

This paper represents the results of a cohort study comparing functional outcomes of individuals with violent and non-violent traumatic spinal cord injury (SCI) following inpatient rehabilitation. Twenty-seven consecutive patients with a diagnosis of traumatic SCI of violent etiology (gunshot wound, stabbing or assault) and 27 patients with non-violent etiology (motor vehicle accident and falls) were matched for neurological level of injury and classification. Demographic comparison of violent versus non-violent groups revealed mean age 30 versus 39, gender 93 percent versus 78 percent male, race 89 percent versus 59 percent non-white, 74 percent versus 41 percent unmarried and 56 percent versus 22 percent unemployed, respectively. Violent and non-violent traumatic SCI groups had similar lengths of stay, admission and discharge functional independent measures (FIM), FIM improvement, payor sources, hospital charges and discharge to home rates. Despite the differences noted in the demographics of violent and non-violent traumatic SCI, these two matched groups achieved similar functional outcomes and discharge disposition following inpatient rehabilitation.

Accidental Falls↗

Changes in field potentials and membrane currents in rat sensorimotor cortex following repeated tetanization of the corpus callosum in vivo.

Repeated, daily tetanization of the corpus callosum induces lasting changes in sensorimotor cortex field potential responses, but the synaptic populations that mediate these responses and support long-term potentiation (LTP) have not been characterized. Current source density analyses of field responses were compared between control animals and those in which LTP was induced by 10 daily series of tetanizations. Tetanization and paired-pulse stimulation (100 ms interval) enhanced the duration of initial (approximately 3 ms onset) deep-negative population spike activity generated by a current sink in layer V that peaked repeatedly at a frequency of approximately 400 Hz. The early (approximately 10 ms to peak) surface-negative component of field responses was generated by a current sink in upper layer V and a source in layer VI. This monosynaptic component followed high stimulation frequencies, recovered quickly from the effects of anaesthesia, and was enhanced by both tetanization and paired-pulse stimulation. The late (approximately 20 ms to peak) surface-negative component was generated by a sink in upper layer V and a source deep in layer V, and was greatly enhanced by tetanization and paired-pulse stimulation. The late component did not follow high-frequency stimulation and recovered slowly from anaesthesia, suggesting that it is driven polysynaptically. Potentiation of monosynaptic thalamic and cortico-cortical afferents probably mediates enhancements of the early component and population spikes, while potentiation of polysynaptic afferents to layer V may contribute to growth in the late component.

Animals↗

Perfusion technique determines alveolar fluid resorption rate in the isolated perfused rat lung.

The isolated perfused lung (IPL) preparation is a well-established model for the study of alveolar epithelial sodium transport. We noted that preparations of normal fluid-filled rat lungs with recirculated perfusate reproducibly lost weight, whereas preparations in which the perfusate was discarded after a single pass through the lungs had a variable and lesser weight change. To confirm this, we performed IPL experiments by using male Sprague-Dawley specific-pathogen-free rats (175-225 g). In 10 IPLs, perfusate initially was discarded after passing through the lungs and then was recirculated continuously. During the single-pass period, the rate of weight change was +0.7 +/- 2.0 mg/min compared with -9.0 +/- 1.3 mg/min for the recirculating period. Adenosine 3',5'-cyclic monophosphate (cAMP) accumulated during recirculation. The weight loss induced by recirculation was reproduced by perfusion with 8-bromoadenosine 3',5'-cyclic monophosphate or terbutaline in single-pass fashion and blocked when the kinase inhibitor H-8 or phosphodiesterase was present in the recirculating perfusate. In summary, perfusate recirculation in the IPL stimulates fluid resorption at least partially via cAMP. This should be factored into the design and interpretation of IPL experiments.

8-Bromo Cyclic Adenosine Monophosphate↗

Clinicopathological analysis of follicular lymphoma with a polyploid karyotype.

The prognostic significance of specific cytogenetic abnormalities in follicular lymphoma (FL) is an area of ongoing research. A small percentage of FL are characterized by a polyploid karyotype. Several studies have analyzed ploidy level to determine its role as an independent prognostic factor in non-Hodgkins lymphoma, with equivocal results, mostly using DNA flow cytometry to ascertain ploidy status. We have performed cytogenetic analyses on 180 cases of FL with a t(14;18) diagnosed between 1980 and 1995. Cases were divided into a polyploid group (20 cases) and a non-polyploid group (160 cases), polyploidy defined as a modal chromosome number of 58 or greater. Each group included examples of the 3 subtypes of FL, [Working Formulation]: 1) follicular small cleaved cell (FSC), 2) follicular mixed, small and large cell (FM), and 3) follicular large cell (FLC). The median follow-up time was 38.5 months. The histological subclassification of the polyploid group revealed much less FSC (30% vs 66%, p < 0.004) and much more FLC (25% vs 4%, p < 0.003) than the non-polyploid group, implying histological progression may occur in parallel with the development of polyploidy. Recognized clinical prognostic factors were evenly distributed between the two groups and no survival difference was detected. We show that polyploidy as determined by classical cytogenetics is present in different frequencies across the subtypes of FL with a t(14;18), but is not an independent prognostic factor for survival in FL.

Cohort Studies↗

Origin of an insular population of the wood mouse based on parasitological evidence.

Parasitological data were used to test the hypothesis that the wood mouse (Apodemus sylvaticus) population of Fair Isle, Shetland, originated from the British Isles rather than Scandinavia, as is usually argued. This study was based on the assumption that the mice were likely to share most of their parasite fauna with conspecifics from their ancestral home. The ecto- and endo-parasites of wood mice on Fair Isle between 18 June to 10 July 1987 and 17 to 26 August 1991 were identified and compared with those reported from conspecifics in the two putative source areas. All eight species of metazoan parasites that infected A. sylvaticus on Fair Isle were common to mice of the British Isles, whereas just one parasite on Fair Isle, a mite, had been recorded from Scandinavia. This lends support to the hypothesis that the mice originated from Britain rather than Scandinavia.

Animals↗

Information system for clinical resource management in a regional setting.

The Hospital District of Varsinais-Suomi consists of five hospitals for non-psychiatric diseases to deliver specialised health care for the population of 440,000 inhabitants in South-western Finland. We have applied an open regional information system to aid clinical resource management in such a complex expert organisation. The main areas of application have been assessment of inpatient care usage in different communities and in different diagnosis-related-groups (DRG), measurement of length of hospital stay in different DRGs and comparison of DRG unit weight costs of different hospitals. The open structure of the data base and its distribution to all parties of health care professionals has resulted in mutual decisions on structural changes and increased cost containment activities.

Aged↗

Professional closure: constructing the image of New Zealand nursing 1880-1940.

The concept of professional closure is a sociological explanation for the way that professions limit their membership. From early in the nineteenth century the medical profession in New Zealand promoted exclusionary closure strategies which ensured their control over the other health-related occupational groups. This paper examines the way that professional closure has shaped the development of nursing in this country since Nightingale nurses arrived in New Zealand in the 1880s, and how professional closure effectively constructed the image of New Zealand nursing through the discourse of vocationism during the sixty year period 1880-1940.

Education, Nursing↗

Domains of distress: the experience of breast cancer in Australia.

PURPOSE/OBJECTIVES: To describe difficulties experienced by women after treatment for primary breast cancer. DESIGN: Descriptive and exploratory. SETTING: Queensland, Australia. SAMPLE: 245 women (70% response rate) less than 16 weeks postsurgery for breast cancer completed a survey. The mean age for this sample was 55 years; 71% had undergone mastectomy, and 29% had undergone conservative breast surgery. METHODS: Focus groups were used to generate items for the survey, "Experience of Breast Cancer Questionnaire" (EBCQ). The EBCQ and the psychological subscale of the Rotterdam Symptom Checklist (RSCL) were administered by mail to the sample. MAIN RESEARCH VARIABLES: Psychological distress, fear of recurrence, decisional uncertainty, informational support, self-image and social relationships, sexual morbidity, and physical effects of treatments. FINDINGS: Factor analysis of the EBCQ identified five factors, accounting for 60% of the variance. These included psychological effects, treatment concerns, physical effects, self-image, and chemotherapy effects. Four of the five subscales had reliability coefficients of greater than 0.80. Psychological effects included cognitive and emotional effects. Treatment concerns included decisional uncertainty and poorly perceived informational support. Physical effects reflected the symptom pattern of axillary dissection. Self-image included breast loss and social isolation. CONCLUSIONS: Nurses who assist women in adjusting to breast cancer should consider the effect of fear of recurrence and perceptions of body image on the recovery process. Because participation in treatment decisions may increase the demands on women at diagnosis, informational support appropriate to each woman's needs is essential. How self-esteem can affect self-image and social relationships after breast cancer requires further investigation. IMPLICATIONS FOR NURSING PRACTICE: Understanding the experience of illness from the perspective of the patient assists nurses in validating their nursing practice and provides clinically relevant information to guide intervention. In particular, supportive psychological care should target both emotional and cognitive responses to breast cancer. Informational support is integral to a patient's satisfaction with treatment decisions and is likely to predict adjustment. When assisting women to adjust to self-image changes, nurses may need to target women's perceptions about their body image.

Body Image↗

Prevalence of hepatitis C infection in pregnant women in South Australia.

OBJECTIVES: To estimate the prevalence of hepatitis C virus (HCV) seropositivity and known risk factors for HCV infection in a group of pregnant women. DESIGN: Cross-sectional survey. SETTING: Lyell McEwin Health Service, Elizabeth, South Australia (a general public hospital with an annual average of about 2000 deliveries). SUBJECTS: 1537 consecutive women who delivered at the Lyell McEwin Health Service from February 1995 to December 1995. OUTCOME MEASURES: Presence of HCV antibodies; and associations between HCV-antibody status and known risk factors. RESULTS: 17 women (1.1%) were HCV-seropositive. Risk factors significantly more prevalent among HCV-seropositive patients were: a history of injecting drug use, a past or present sexual partner who had injected drugs, having a tattoo and having been incarcerated. The proportions who had received a blood transfusion, had acquired a sexually transmitted disease or were positive for hepatitis B virus surface antigen were not significantly different between seropositive and seronegative women. Multivariate analysis showed that only injecting drug use remained a strong independent predictor of HCV-seropositivity (odds ratio [OR], 50.1; P < 0.001), while having a tattoo approached significance (OR, 3.5; P = 0.07). CONCLUSION: As only 1.1% of this sample of women were HCV-seropositive, screening of all pregnant women does not seem warranted. Testing on the basis of a history of risk factors, such as injecting drug use and having a tattoo, would detect undiagnosed HCV infections more efficiently.

Adult↗

A cost effective, community based heart health promotion project in England: prospective comparative study.

OBJECTIVE: To determine whether a community based coronary heart disease health promotion project, undertaken over four years, was associated with changes in the prevalence in adults of lifestyle risk factors known to affect the development of coronary heart disease, and to estimate whether such an approach was cost effective. DESIGN: Prospective, comparative study of the effects of a health promotion intervention on coronary heart disease lifestyle risk factors, assessed by postal questionnaire sent to a randomly chosen sample, both at baseline and after four years. SUBJECTS: Intervention and control populations of adults aged 18-64 in Rotherham, both from areas with a high incidence of coronary heart disease and similar socioeconomic composition. MAIN OUTCOME MEASURES: Changes in prevalence of lifestyle risk factors between the control and intervention communities from 1991 to 1995. The effect of the intervention on certain lifestyle behaviours was evaluated using multiple logistic regression to model the proportion with a particular behaviour in the study communities as a function of age (18-40 or 41-64 years), sex, the year of observation (1991 or 1995), and area (intervention of control). RESULTS: 6.9% fewer people smoked and 8.7% more drank low fat milk in the intervention area, but no other statistically significant changes between the areas were detected. The estimated cost per life year gained was pounds 31. CONCLUSIONS: It is possible to have a cost effective impact on coronary heart disease lifestyle risk factors in a population of adults over four years using only modest resources.

Adolescent↗