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Biomedical subjects

D Wilson

Publications and source records attributed to D Wilson.

At least 91 records · Page 5Linked to original sources
PubMed1999

A South Australian population survey of the ownership of asthma action plans.

OBJECTIVE: To examine the relationships between ownership of written asthma action plans, asthma morbidity, use of devices, and patients' perceptions of their asthma management. DESIGN AND SETTING: A random population survey (in 1996) of the South Australian population aged 15 years or over, using interviewers to administer a questionnaire. PARTICIPANTS: People who reported that they had current, doctor-diagnosed asthma. MAIN OUTCOME MEASURES: Prevalence of written asthma action plans; night-time awakenings from asthma; ownership of peak flow meters; and people's perceptions of their asthma management. RESULTS: The ownership of asthma action plans by people with self-reported asthma was 33% and has declined since 1995 (42%; P < 0.001). Fifteen per cent were awakened weekly or more frequently by asthma symptoms. These people were more likely to have a peak flow meter and a written action plan, but less likely to consider they had been provided with enough information about their asthma, to feel comfortable managing their asthma, or to find it easy to see their doctor. Having a written asthma action plan was associated with regular corticosteroid use, understanding asthma, having enough information and owning a peak flow meter. CONCLUSIONS: Ownership of asthma action plans in South Australia is suboptimal. Before we develop new strategies to improve asthma outcomes, we must determine whether there is a need to target people with less severe asthma and/or improve the use of guidelines by health professionals.

Asthma↗
PubMed1999

Renal function following combination chemotherapy with ifosfamide and cisplatin in patients with osteogenic sarcoma.

BACKGROUND: Ifosfamide and cisplatin are active agents that are currently used in the treatment of osteosarcoma. Nephrotoxicity has been reported following their use in combination and alone. This study evaluates renal function in children and adolescents (median age 16 years) at least 3 months following completion of a chemotherapy regimen which included 54 g/m2 ifosfamide, 360 mg/m2 cisplatin, doxorubicin, and high-dose methotrexate. PROCEDURE: Mean glomerular filtration rate (GFR) was determined by inulin or iothalamate clearance; proximal tubular function was evaluated by measuring fractional excretion of glucose (FEglu), tubular maximum phosphate reabsorption per GFR (TMP/GFR), FE of urate, and 24-hour amino acid excretion. Distal tubular function was evaluated by 24-hour urinary calcium, FE of magnesium, and urinary osmolality after water deprivation. Twenty-four-hour urinary protein excretion was measured. RESULTS: The mean GFR was 97 ml/min/1.73 m2. Although 10 of 24 patients had GFRs lower than normal, the lowest value was only 22% below the lower limit of normal and would not account for any clinical compromise. Proximal tubular function evaluation revealed normal FEglu, normal mean TMP/GFR values, and high FE of urate (1 5.7%). Two of twenty-four patients were shown to have mild generalized aminoaciduria. Distal tubular function evaluation showed normal 24-hour urinary calcium levels (mean 3.4 mg/kg) and FE of magnesium as well as normal urinary osmolality. Twenty-four-hour urinary protein excretion was normal in all patients. CONCLUSIONS: The lack of clinically significant renal abnormalities observed in patients who received combination chemotherapy with ifosfamide and cisplatin for osteosarcoma is encouraging for future osteosarcoma protocol development.

Adolescent↗
PubMed1999

The health-related quality-of-life of never smokers, ex-smokers, and light, moderate, and heavy smokers.

BACKGROUND: Health related quality-of-life is recognized as an important health outcome measure; how ever, it may also have a significant application in smoking reduction and cessation programs. METHODS: Representative population data (n = 3010) was used to compare the quality-of-life status of differ ent smoking categories with never smokers. RESULTS: Statistically significant differences in mean quality-of-life scores, as measured by the SF-36 health status questionnaire, were observed between never smokers, as the reference group, ex-smokers, all smokers, and light, moderate, and heavy smokers. Heavy smokers also scored significantly lower than both other groups of smokers, scoring as low as the 29th percentile of the population on the general health dimension and lower than the 36th percentile of the population on all the mental health dimensions. CONCLUSIONS: The design of public health smoking cessation programs should consider the varying characteristics of different segments of the smoking population. The advantages of improved quality-of-life may strengthen the argument for encouraging heavier smokers to become light smokers as a precursor to total cessation.

Adolescent↗
PubMed1999

Preoperative dextrose does not affect spinal-induced hypotension in elective Cesarean section.

PURPOSE: To determine if preoperative intravenous dextrose affects the incidence and ease of treatment of spinal-induced hypotension in parturients having elective Cesarean section under spinal anesthesia. METHODS: In this prospective, double-blind study, following informed consent, 119 ASA I, II parturients for elective Cesarean section were randomized to receive intravenously either dextrose 5% in normal saline (Group D) or normal saline (Group NS) at 125 ml x hr(-1) for two hours prior to delivery. Following a bolus of 15 ml x kg(-1) normal saline iv, spinal anesthesia was induced with hyperbaric bupivacaine 0.75%, fentanyl and morphine. Hypotension (systolic blood pressure <100 mm Hg or >20% decrease) was treated with fluids and/or vasopressor. DATA COLLECTED: demographics, blood glucose concentrations (fasting, time of spinal, delivery), blood pressure (baseline, one minute intervals from spinal to delivery), neonatal Apgar scores, umbilical blood gas analyses, glucose and lactate concentrations. RESULTS: There was no difference between the two groups in the rate of hypotension (P = 0.272). All parturients who experienced hypotension received fluids, and there was also no difference between the groups in vasopressor requirement [mean dose of ephedrine: Group D = 21.6 mg (95% CI 15.1-28.2), Group NS = 16 mg (95% CI 12.0-20.5)]. CONCLUSION: The routine administration of dextrose 5% at a rate of 5.22 g x hr(-1) preoperatively does not affect the hypotension rate, or make it easier to treat.

Adult↗
PubMed1999

Interaction Between Scientists and Nonscientists in Community-Based Watershed Management: Emergence of the Concept of Stream Naturalization.

/ Watershed management, although dependent on science and engineering, is first and foremost a social process. Given the current emphasis on community-based approaches to environmental decision making, scientists must, more than ever before, understand, appreciate, respect, and immerse themselves within local social contexts. Only by doing so will they be able to ensure that their opinions and information are fairly and meaningfully considered by nonscientists.The authors' personal experience in watershed planning and decision making in the agricultural Midwest is described to illustrate how: (1) formalization of the process of community-based management is not sufficient to guarantee that local people will meaningfully consider scientific information and opinion when making decisions about watersheds, and (2) genuine social interaction between scientists and nonscientists requires a considerable investment of time and energy on the part of the scientist to develop personal relationships with nonscientists based on trust and mutual exchange of information. This experience provides the basis for developing a general conceptual model of the interaction between scientists and nonscientists in community-based watershed management in the agricultural Midwest.An important aspect of integrating science effectively into community-based decision making is the need to revise existing concepts to accommodate place-based contexts. Stream naturalization is introduced as an alternative to stream restoration and rehabilitation, which are viewed as inappropriate management strategies in human-dominated environments. Stream naturalization seeks to establish sustainable, morphologically and hydraulically varied, yet dynamically stable fluvial systems that are capable of supporting healthy, biologically diverse aquatic ecosystems. This general goal is consistent with the types of stream-management practices emerging from community-based decision making in human-dominated, agricultural landscapes. Further research on the linkages between geomorphological and ecological dynamics of human-modified agricultural streams over multiple spatial and temporal scales is needed to provide a sound scientific framework for stream naturalization.KEY WORDS: Community-based decision making; Watershed management; Stream naturalizationhttp://link.springer-ny.com/link/service/journals/00267/bibs/24n3p297.html

Journal Article↗
PubMed1999

Elasticity of the red cell membrane and its relation to hemolytic disorders: an optical tweezers study.

We have used optical tweezers to study the elasticity of red cell membranes; force was applied to a bead attached to a permeabilized spherical ghost and the force-extension relation was obtained from the response of a second bead bound at a diametrically opposite position. Interruption of the skeletal network by dissociation of spectrin tetramers or extraction of the actin junctions engendered a fourfold reduction in stiffness at low applied force, but only a twofold change at larger extensions. Proteolytic scission of the ankyrin, which links the membrane skeleton to the integral membrane protein, band 3, induced a similar effect. The modified, unlike the native membranes, showed plastic relaxation under a prolonged stretch. Flaccid giant liposomes showed no measurable elasticity. Our observations indicate that the elastic character is at least as much a consequence of the attachment of spectrin as of a continuous membrane-bound network, and they offer a rationale for formation of elliptocytes in genetic conditions associated with membrane-skeletal perturbations. The theory of Parker and Winlove for elastic deformation of axisymmetric shells (accompanying paper) allows us to determine the function BH(2) for the spherical saponin-permeabilized ghost membranes (where B is the bending modulus and H the shear modulus); taking the literature value of 2 x 10(-19) Nm for B, H then emerges as 2 x 10(-6) Nm(-1). This is an order of magnitude higher than the value reported for intact cells from micropipette aspiration. Reasons for the difference are discussed.

Biophysical Phenomena↗
PubMed1999

Evaluation of a computerized contraceptive decision aid for adolescent patients.

Recent efforts to involve patients more actively in therapeutic decisions have suggested the relevance of computer-based interventions at clinic visits. This paper presents a longitudinal, experimental study evaluating a computer-based contraceptive decision aid in Chicago and Madison family planning clinic visits. Patient interviews at three time points evaluated patient acceptance by and program impact on 949 young women. Both Chicago and Madison patients reported high acceptance. The program resulted in improved short-term knowledge and confidence in oral contraceptive (OC) efficacy for Chicago and Madison patients. In addition, compared to their control group, Madison experimental group patients had higher OC knowledge 1 year after the initial visit and a trend for fewer pregnancies (P < 0.074). Compared to their control group, a higher percent of the Chicago experimental group patients adopted OC's after stating their intention to do so at the initial visit. Exposure to the computer program had no observable impact on the number of months on the oral contraceptive for Chicago or Madison patients. Overall findings suggest the usefulness of informatics tools as a supplement to patient-provider interactions.

Adolescent↗
PubMed1999

Quantification of longitudinal tissue pO2 gradients in window chamber tumours: impact on tumour hypoxia.

We previously reported that the arteriolar input in window chamber tumours is limited in number and is constrained to enter the tumour from one surface, and that the pO2 of tumour arterioles is lower than in comparable arterioles of normal tissues. On average, the vascular pO2 in vessels of the upper surface of these tumours is lower than the pO2 of vessels on the fascial side, suggesting that there may be steep vascular longitudinal gradients (defined as the decline in vascular pO2 along the afferent path of blood flow) that contribute to vascular hypoxia on the upper surface of the tumours. However, we have not previously measured tissue pO2 on both surfaces of these chambers in the same tumour. In this report, we investigated the hypothesis that the anatomical constraint of arteriolar supply from one side of the tumour results in longitudinal gradients in pO2 sufficient in magnitude to create vascular hypoxia in tumours grown in dorsal flap window chambers. Fischer-344 rats had dorsal flap window chambers implanted in the skin fold with simultaneous transplantation of the R3230AC tumour. Tumours were studied at 9-11 days after transplantation, at a diameter of 3-4 mm; the tissue thickness was 200 microm. For magnetic resonance microscopic imaging, gadolinium DTPA bovine serum albumin (BSA-DTPA-Gd) complex was injected i.v., followed by fixation in 10% formalin and removal from the animal. The sample was imaged at 9.4 T, yielding voxel sizes of 40 microm. Intravital microscopy was used to visualize the position and number of arterioles entering window chamber tumour preparations. Phosphorescence life time imaging (PLI) was used to measure vascular pO2. Blue and green light excitations of the upper and lower surfaces of window chambers were made (penetration depth of light approximately 50 vs >200 microm respectively). Arteriolar input into window chamber tumours was limited to 1 or 2 vessels, and appeared to be constrained to the fascial surface upon which the tumour grows. PLI of the tumour surface indicated greater hypoxia with blue compared with green light excitation (P < 0.03 for 10th and 25th percentiles and for per cent pixels < 10 mmHg). In contrast, illumination of the fascial surface with blue light indicated less hypoxia compared with illumination of the tumour surface (P < 0.05 for 10th and 25th percentiles and for per cent pixels < 10 mmHg). There was no significant difference in pO2 distributions for blue and green light excitation from the fascial surface nor for green light excitation when viewed from either surface. The PLI data demonstrates that the upper surface of the tumour is more hypoxic because blue light excitation yields lower pO2 values than green light excitation. This is further verified in the subset of chambers in which blue light excitation of the fascial surface showed higher pO2 distributions compared with the tumour surface. These results suggest that there are steep longitudinal gradients in vascular pO2 in this tumour model that are created by the limited number and orientation of the arterioles. This contributes to tumour hypoxia. Arteriolar supply is often limited in other tumours as well, suggesting that this may represent another cause for tumour hypoxia. This report is the first direct demonstration that longitudinal oxygen gradients actually lead to hypoxia in tumours.

Animals↗
PubMed1999

Parents' experiences of general hospital admission for adults with learning disabilities.

General hospital care for people with learning disabilities is strongly emphasized in recent health policy. Ten sets of parents were interviewed about their experiences of general hospital inpatient care for their adult sons and daughters with learning disabilities. Findings in the areas of placement, occupation, basic nursing care, feeding, toileting, nursing attitudes, staffing and procedures are presented. Recommendations are made for changes to reported nursing practice to improve the quality of general hospital care for people with learning disabilities.

Adult↗
PubMed1999

The use of ECT in intellectual disability.

The present survey examines the use of electroconvulsive therapy (ECT) by consultant psychiatrists working with people with intellectual disability in Trent Region, UK, which has a population of 4.7 million people. In the first phase of the study, all consultants in the area were sent a questionnaire to find out how many patients had been given ECT during the previous 5 years. Some 92% of the consultant psychiatrists returned the questionnaires. Eight patients were given a total of 122 ECTs, which is low when compared with the use of ECT by general adult psychiatrists. The second phase of the research involved a study of the individual medical case notes to obtain information about individual indications for ECT, outcome and consent issues. The commonest indication for ECT was depression, and the best response was obtained when the clinical picture was dominated by biological and/or psychotic symptoms.

Adult↗