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Biomedical subjects

W Phillips

Publications and source records attributed to W Phillips.

At least 19 recordsLinked to original sources
PubMed1995

Frequent use of medical services. Patient reports of intentions to seek care.

OBJECTIVE: To examine differences between frequent and infrequent users in decisions to seek medical care based on symptom type and duration of experience of the symptom. DESIGN: Retrospective study. SETTING: University family practice clinic. PATIENTS: Fifty-eight of 130 patients returned the completed instruments, a response rate of 45%. MAIN OUTCOME MEASURES: The following two instruments were used: the Intentions to Seek Care questionnaire, which measures intention to see a physician, self-treat, or use medications for 11 different symptoms after three time periods--1 day, 3 days, and 1 week of symptom duration--and the SF-36 Health Survey measure. RESULTS: Initial analyses suggested that patients perceive three clusters of symptoms, which we have labeled as serious, mild, and psychological. Scale scores for these groups of symptoms yielded significant reliability and were used in subsequent analyses. Multivariate analysis of variance comparing source of care, symptom duration, and frequent vs infrequent user groups indicated that both user groups are more likely to seek care from physicians for symptoms that are serious. Analysis of mild and psychological symptoms yielded significant three-way interactions, with frequent users more likely than infrequent users to seek care from physicians at a 1-day duration. Such differences disappear by 7 days. Significantly lower scores were obtained on five of the eight SF-36 Health Survey dimensions for the infrequent users. CONCLUSIONS: Frequent users are more likely than infrequent users to report that they would seek care for minor symptoms. Infrequent users tend to self-treat for 3 to 7 days, after which time physician advice is sought. Efforts to teach patients optimal timing of use for different symptoms may be an effective intervention.

Family Practice↗
PubMed1995

The association of assimilation and an increase in visibility in perceptual grouping.

Subjects performed a series of forced-choice discriminations to determine whether both group-assimilation and group-visibility associations could be obtained from nearly identical strong and weak group patterns. The discrimination between the context+target square and the context [symbol: see text] was better than between the target- and background, as was the case for --, whose context and target components were its left and right halves, but not for [symbol: see text]. Square and -- produced a better performance when their lines (halves) were the same in color, and a poorer performance when their lines were different in color, but [symbol: see text] produced the reverse. Likewise, only square and -- produced a better performance when closed, and a poorer performance when open. These context+target etc., same-different, and closure results argue that square and -- produced a greater increase in visibility of their component --, more assimilation among their parts, and a stronger group than did [symbol: see text]. This evidence of a group-assimilation-visibility association cannot be attributed to the fortuitous occurrence of an increase in visibility with one object, assimilation with a second, and closure with a third, unlike previous evidence. This association cannot be explained by feature-based theories. Therefore, a superordinate unit is the cause of this association.

Choice Behavior↗
PubMed1994

Psychometric properties of the children's atypical development scale.

The Children's Atypical Development Scale (CADS) is a 53-item rating scale designed to measure unusual behaviors in children. Principal-factor analysis on a clinic-referred and pediatric sample of 474 children resulted in a four-factor solution: Communication Deficits, Lability, Social Relatedness Deficits, and Preoccupation. The CADS is internally consistent and has adequate temporal stability. CADS factor scores were differentially associated with parent and teacher rating scales, IQ, and Continuous Performance Test errors. The scale shows promise as a clinical and research tool for assessing atypical behaviors associated with pervasive developmental disorder and other neurobehavioral disorders.

Adolescent↗
PubMed1988

Reproducibility of the measurement of plasma noradrenergic and dopaminergic metabolites in normal subjects.

The object of this study was to determine the reproducibility of the measurement of plasma catecholamine metabolites in normal control subjects and to assess the influence of factors such as time of day, diet, activity, blood pressure, and mood on the variance of these measures. Plasma free homovanillic acid (HVA), 3-methoxy-4-hydroxyphenylglycol (MHPG), and vanillylmandelic acid (VMA) were simultaneously measured by high performance liquid chromatography with electrochemical detection. Samples were collected from 15 doctors and nurses at 8 a.m. and at noon on 2 separate days. After the fasting 8 a.m. sample, the subjects ate a regular hospital breakfast. Activity in their usual tasks on an inpatient psychiatric unit was monitored electronically by an activity meter. Levels of each metabolite were not significantly different between days at the respective assay times and were highly correlated for individuals. MHPG showed a significant increase from morning to noon, while HVA showed a significant decrease. Activity, dietary intake of tyrosine and tyramine, blood pressure, pulse, scores on the Profile of Mood States, age, and sex were not related to plasma levels. The results demonstrate that measures of dopamine and norepinephrine metabolites have significant reliability in normal subjects in a setting used for research studies with psychiatric patients.

Adult↗
PubMed1986

The epidemiology of childhood scalds in Brisbane.

Scald injuries in Brisbane have shown a stable pattern over the past 5 years which is similar to that of other Australian cities. The great majority of scald accidents occur to children between 1 and 2 years of age, between the hours of 1600 and 1900, in the home of the average Australian family while both parents are in attendance. The kitchen and bathroom are the sites of most scalds, with the hot cup of tea the greatest offender.

Accidents, Home↗
PubMed1984

Turner's syndrome: assessment and treatment for adult psychiatric patients.

Turner's Syndrome and its associated problems are discussed. The developmental/adaptational difficulties surrounding Turner's Syndrome necessitate a comprehensive treatment approach, with a special emphasis on psychological assessment of "space-form blindness." A case history of assessment and treatment is presented to illustrate this approach.

Adult↗
PubMed1980

Effects of metabolic inhibitors on spontaneous and interferon-boosted human natural killer cell activity.

Human natural killer (NK) cell activity can be augmented by pretreatment with partially purified preparations of human interferon (IF). Studies have now been performed to determine the metabolic processes required for and involved in spontaneous NK activity and augmentation of cytotoxicity. A 4-hr 51Cr release cellular cytotoxicity assay was used to measure the NK activity, and peripheral blood leukocyte cells (PBL) were treated with: a) x-ray or mitomycin C; b) actinomycin D; or c) emetine, cycloheximide, pactamyhcin, or puromycin to assess the roles of DNA, RNA, and protein synthesis, respectively, in spontaneous NK activity and in boosting by IF. Prolonged incubation (18 hr) of PBL after blockage of synthesis of DNA almost completely abrogated NK activity; however, NK activity could be partially or totally restored to these populations by incubation of the effector cells for 1 hr at 37 degrees C with IF. Blockage of DNA synthesis for 1 hr had no effect on spontaneous NK activity or on boosting by IF. Inhibition of RNA synthesis also had no effect on spontaneous NK activity. Treatment of PBL with actinomycin before exposure to IF prevented boosting, but treatment with the RNA synthesis inhibitor after boosting with IF for 5 to 6 hr no longer had an appreciable effect on cytotoxicity. The effect of protein synthesis inhibitors on spontaneous NK activity was dependent on the inhibitor selected. Emetine and puromycin totally abrogated spontaneous NK activity at concentrations of inhibitor that blocked 3H-leucine incorporation 90% or more. In contrast, cycloheximide and pactamycin had only minimal effects on spontaneous NK activity but totally abrogated the boosting of IF.

Cycloheximide↗
PubMed1979

Development of a ceramic surface replacement for the hip. An experimental Sialon model.

The objective of this study was to investigate the design and fixation advantages of Sialon ceramic surface replacements implanted without acrylic bone cement. The biocompatibility and friction and wear properties of Sialon ceramic were compared with more conventional prosthetic materials such as stainless steel and alumina. A functional load-bearing canine hip surface replacement model was established to test Sialon femoral cups designed for fixation by bone ingrowth. The results of the polyethylene wear tests on highly polished ceramic and stainless steel counterfaces were essentially similar. These laboratory data indicated that the in-vivo polyethylene wear performance on metal or ceramic prosthetic surfaces could be expected to be indistinguishable, i.e. the ceramic/polyethylene combination would not offer any improved wear resistance in-vivo. It was found possible to get bone ingrowth into the macrokeying areas of the ceramic femoral cups but not into the microporous surfaces due to the presence of a fibrous membrane lining their internal surfaces. The biocompatability specimens also appeared to be invested with a fibrous membrane. Further studies are under way to determine the relationship between reaming procedures, micro motion at the interfaces and Sialon biocompatibility.

Aluminum↗
PubMed1976

Automatic control of the artificial heart.

An automatic control system has been developed to balance and control the output of an artificial heart. The system consisted of 2 linked negative feedback loops. The left ventricle was controlled by a Servo-Stroke Optimizer, which insured complete filling and full stroke operation of the left pump with each beat and changed the beat rate in accord with changes in aortic pressure. The right ventricle was controlled by a Servo-Variable Systolic Duration unit, which changed the stroke of the right ventricle to maintain the left atrial pressure within a preset band. In the initial animal studies, control pressures (aortic and left atrial pressure) were obtained from implanted transducers. More recently, a method has been devised whereby the control pressures were obtained from specific points on the left air line pressure wave, obviating the need for implanted transducers. The control system has been evaluated in a mock circulatory loop and in 9 calves with implanted artificial hearts. The system has provided balance of the 2 implanted ventricles and changes in flow rate in response to changes in peripheral resistance. The need for an operator to make manual adjustment to the power units has been considerably reduced. Further studies are indicated to evaluate the function of the control system in animals performing moderate-to-maximal exercise. Furthermore, the ultimate benefits of full stroke operation vs fill limited mode operation remain to be delineated.

Animals↗