Biomedical subjects

A D Moore

Publications and source records attributed to A D Moore.

At least 19 recordsLinked to original sources

PubMed2004

Factors associated with abnormal Pap results in systemic lupus erythematosus.

OBJECTIVE: Previous studies have suggested that women with systemic lupus erythematosus (SLE) are at greater risk for cervical dysplasia than are women in the general population. However, the factors associated with abnormal Pap test results in SLE have not been well studied. We therefore aimed to determine the factors associated with lifetime occurrence of an abnormal Pap test in women with SLE, and the influence of immunosuppressive exposure on the odds of abnormal Pap test results occurring after diagnosis of SLE. METHODS: Data were pooled from SLE cohorts from three centres. Self-report data were available on smoking, reproductive history, use of oral contraceptives (OC), history of sexually transmitted diseases (STDs) and whether the subjects had had cervical dysplasia on Pap testing. Logistic regression was used to examine the effect of these variables on the lifetime odds of cervical dysplasia. We then generated the adjusted odds ratio (OR) for the effect of immunosuppressive exposure on cervical dysplasia occurring after diagnosis of SLE. RESULTS: History of STDs and use of OCs were positively associated with reports of cervical dysplasia in adjusted analyses. The ORs for the effect of immunosuppressives on abnormal Pap test occurrence (adjusted for race, age, smoking, nulliparity, OC use and history of STDs) after diagnosis of SLE was 1.6 (95% CI 1.0, 2.7). CONCLUSIONS: A history of STDs and use of OCs were associated with abnormal Pap reports in this SLE sample. Immunosuppressive exposure may confer further risk to women with SLE.

Adult↗

PubMed2004

Hormonal exposures and breast cancer in a sample of women with systemic lupus erythematosus.

OBJECTIVES: To determine if breast cancer risk in women with SLE is modified by a history of exposure to hormone replacement therapy (HRT) or oral contraceptives (OC), after adjusting for other risk factors. METHODS: Data were pooled from SLE cohorts at three centres. For each female cohort member (n = 871), the probability of developing breast cancer was estimated from factors (age, parity, age at first live birth, age of menarche, personal history of benign breast disease, family history) in the Gail model, an established tool for predicting breast cancer risk. From these probabilities, the expected number of breast cancers for the cohort was estimated. Actual occurrence of cases was determined by linkage with regional cancer registries. Standardized incidence ratios (SIRs; ratio of cancers observed to expected) were calculated, with subgroup analyses according to HRT and OC exposure. RESULTS: In the cohort, 15 breast cancers occurred vs 7.2 predicted [SIR 2.1, 95% confidence interval (CI) 1.1, 3.5]. When controlling for Gail model risk factors, estimates were similar for women never exposed to HRT vs those exposed to HRT. Adjusted SIR estimates appeared similar also for women exposed or not exposed to OC. CONCLUSIONS: Although not definitive, the data suggest that the breast cancer experience in this sample is not completely explained by factors such as reproductive and family history, or by exogenous hormonal exposures. Other determinants, including medication exposures or genetic factors (possibly related to oestrogen receptors or metabolism) may be important. Variations in these factors might explain why an elevated risk of breast cancer has not been apparent in all SLE populations.

Adult↗

PubMed2001

Maximal exercise as a countermeasure to orthostatic intolerance after spaceflight.

UNLABELLED: Previous investigators have suggested that maximal exercise performed 24 h before the end of bed rest, a spaceflight analog, restores prebed rest plasma volume, baroreflex responses, and orthostatic tolerance. PURPOSE: In this case report, we examined the effect of a similar exercise protocol 24 h before a Shuttle landing on the orthostatic responses of four crewmembers (EX) after spaceflights of 8-14 d. Four additional crewmembers (CON) served as controls and did not perform exercise during the final day of the flight. METHODS: Each crewmember performed a 10-min stand test approximately 10 d before launch (L-10) and within 1-2 h of landing (R+0). Cardiac stroke volume was measured (Doppler ultrasound) supine and during each min of standing for three EX and three CON subjects. RESULTS: Preflight, all crewmembers completed the stand test and each group had similar heart rate and blood pressure responses. Postflight, all subjects also completed the 10-min stand test. Each group had similarly elevated supine and standing heart rates, elevated diastolic and mean arterial blood pressures, and reduced pulse pressures compared to L-10. However, postflight cardiac output, mean +/- SEM, (EX: 4.5+/-0.6 L x min(-1); CON: 3.1+/-0.3 L x min(-1)) and stroke volume (EX: 43+/-7 mL x beat; CON: 30+/-6 mL x beat) were higher after 10 min standing in the EX subjects compared to CON subjects. CONCLUSIONS: For these four crewmembers, maximal exercise performed 24 h before landing may have helped maintain stroke volume but did not maintain heart rate and blood pressure responses during standing compared to preflight.

Adult↗

PubMed2000

The use of alternative medical therapies in patients with systemic lupus erythematosus. Trination Study Group.

OBJECTIVE: As part of an ongoing study of health resource utilization and diminished productivity in patients with systemic lupus erythematosus (SLE), the use of alternative medical therapies was assessed. METHODS: A cohort of 707 patients with SLE from 3 countries completed questionnaires on demographics, social support, health status (using the Short Form 36 health survey), satisfaction with health care, health resource utilization (conventional resources and alternative therapies), and time losses in labor market and non-labor market activities. Annual direct and indirect costs (1997 Canadian dollars) were calculated and compared for users and nonusers of alternative medical therapies. RESULTS: Among the 707 patients, 352 (49.8%) were found to use alternative therapies and at similar rates across Canada, the United States, and the United Kingdom. Users were younger and better educated than nonusers, exhibited poorer levels of self-rated health status and satisfaction with medical care, and had minimal to no objective evidence of worse disease (according to the revised Systemic Lupus Activity Measure instrument). The mean of log direct medical costs for conventional resources was higher for users of select alternative therapies compared with nonusers. In a logistic regression, neither the number of alternative therapies used nor the individual therapy increased the probability of incurring indirect costs. CONCLUSION: The use of alternative medical therapies is common in patients with SLE. Users of many alternative medical therapies accrue greater conventional medical costs compared with nonusers. The use of alternative medical therapy may be a marker for care-seeking behavior associated with higher consumption of conventional medical resources in the absence of demonstrable additional morbidity and should be considered in future cost analyses of patients with SLE.

Adult↗

PubMed2000

Owning genetic information and gene enhancement techniques: why privacy and property rights may undermine social control of the human genome.

In this article I argue that the proper subjects of intangible property claims include medical records, genetic profiles, and gene enhancement techniques. Coupled with a right to privacy these intangible property rights allow individuals a zone of control that will, in most cases, justifiably exclude governmental or societal invasions into private domains. I argue that the threshold for overriding privacy rights and intangible property rights is higher, in relation to genetic enhancement techniques and sensitive personal information, than is commonly suggested. Once the bar is raised, so-to-speak, the burden of overriding it is formidable. Thus many policy decisions that have been recently proposed or enacted--citywide audio and video surveillance, law enforcement DNA sweeps, genetic profiling, national bans on genetic testing and enhancement of humans, to name a few--will have to be backed by very strong arguments.

Commerce↗

PubMed1999

Survival of women with surgical stage II endometrial cancer.

OBJECTIVE: The aim of this study was to report survival and determine prognostic factors and results of therapy in women with surgical stage II endometrial cancer. METHODS: Forty-eight consecutive women with surgical stage II endometrial cancer treated at the University of Vermont between March 1984 and March 1998 were reviewed. Patients' characteristics, surgical procedure, postoperative treatment and its complications, and tumor recurrence and its treatment were recorded. In addition, a formal review of their pathological material for confirmation of the diagnosis was performed. RESULTS: The median duration of follow-up was 6.2 years. Three patients (6.3%) had tumor recurrence and two (4.2%) died of their disease. The estimated 5-year overall survival and disease-free survivals were 92.1% (SE = 5.5%, 95% confidence interval: 81.3, 100%) and 89.9% (SE = 5.8%, 95% confidence interval: 78.5%, 100%), respectively. None of the patients treated by total abdominal hysterectomy followed by both whole pelvic and vaginal cuff radiation therapy (the main line of treatment for patients in whom cervical involvement was diagnosed following hysterectomy, n = 20) or by radical hysterectomy (the main line of treatment for patients in whom cervical involvement was known before hysterectomy, n = 11) had tumor recurrence. Three of 17 (17.6%) patients treated with total abdominal hysterectomy followed by either whole pelvic (n = 13) or vaginal cuff (n = 4) radiation therapy had tumor recurrence. The difference between those two groups was statistically significant (0/31 versus 3/17, P = 0.02). There was no difference in survival among women with stage IIA and IIB or women who underwent radical abdominal hysterectomy and those who underwent total abdominal hysterectomy with postoperative pelvic and vaginal cuff radiation. Morbidity secondary to therapy was mild. Age, depth of myometrial invasion, tumor histology, and grade were not significantly related to recurrence. CONCLUSIONS: Survival of women with surgical stage II endometrial cancer is excellent especially among those treated with total abdominal hysterectomy followed by both pelvic and vaginal cuff radiotherapy or by radical abdominal hysterectomy.

Adult↗

PubMed1999

Inflight exercise affects stand test responses after space flight.

PURPOSE: The purpose of this study was to determine whether exercise performed by Space Shuttle crew members during short-duration space flights (9-16 d) affects the heart rate (HR) and blood pressure (BP) responses to standing within 2-4 h of landing. METHODS: Thirty crew members performed self-selected inflight exercise and maintained exercise logs to monitor their exercise intensity and duration. Two subjects participated in this investigation during two different flights. A 10-min stand test, preceded by at least 6 min of quiet supine rest, was completed 10-15 d before launch (PRE) and within 4 h of landing (POST). Based upon their inflight exercise records, subjects were grouped as either high (HIex: > or = 3 times/week, HR > or = 70% HRmax, > or = 20 min/session, N = 11), medium (MEDex: > or = 3 times/week, HR < 70% HRmax, > or = 20 min/session, N = 10), or low (LOex: < or = 3 times/week, HR and duration variable, N = 11) exercisers. HR and BP responses to standing were compared between groups (ANOVA, P < or = 0.05). RESULTS: There were no PRE differences between the groups in supine or standing HR and BP. Although POST supine HR was similar to PRE, all groups had an increased standing HR compared with PRE. The increase in HR upon standing was significantly greater after flight in the LOex group (36 +/- 5 bpm) compared with HIex or MEDex groups (25 +/- 1 bpm; 22 +/- 2 bpm). Similarly, the decrease in pulse pressure (PP) from supine to standing was unchanged after space flight in the MEDex and HIex groups but was significantly greater in the LOex group (PRE: -9 +/- 3; POST: -19 +/- 4 mm Hg). CONCLUSIONS: Thus, moderate to high levels of inflight exercise attenuated HR and PP responses to standing after space flight.

Adult↗

PubMed1999

Sample size considerations for superiority trials in systemic lupus erythematosus (SLE).

For reasons of efficiency and ethics, sample size calculations are an important part of the design of all clinical trials. This paper highlights the statistical issues inherent to the estimation of sample size requirements in superiority trials particular to SLE. Calculations based on statistical power for testing hypotheses have historically been the method of choice for sample size determination in clinical trials. The advantages of using confidence intervals (CI's) rather than P-values in reporting results of clinical trials is now well established. Since the design of a trial should match the analysis that will eventually be performed, sample size methods based on ensuring accurate estimation of important parameters via sufficiently narrow CI widths should be preferred to methods based on hypothesis testing. Methods and examples are given for sample size calculations for continuous and dichotomous outcomes from both a power and confidence interval width viewpoint. An understanding of sample size calculations in association with expert statistical consultation will result in better designed clinical trials that accurately estimate clinically relevant differences between treatment outcomes, thereby furthering the treatment of patients with SLE.

Confidence Intervals↗

PubMed1999

Can health utility measures be used in lupus research? A comparative validation and reliability study of 4 utility indices.

OBJECTIVE: To assess validity and reliability of 4 utility indices in patients with systemic lupus erythematosus (SLE). METHODS: Twenty-five patients with stable SLE underwent assessment of disease activity [Systemic Lupus Disease Activity Measure (SLAM-R) and SLE Disease Activity Index (SLEDAI)] and damage [Systemic Lupus Collaborating Clinics/American College of Rheumatology Damage Index (SLICC/ACR DI)] and completed a health survey [Medical Outcome Survey Short Form-36 (SF-36)] and 4 utility measures: the visual analog scale (VAS), the time trade-off (TTO), the standard gamble (SG), and the McMaster Health Utilities Index Mark 2 (HUI2). To assess validity, Pearson's correlations were calculated between the SF-36 subscales and the utility measures. To assess reliability, intraclass correlations or kappa coefficients were calculated between first and second assessments, performed from 2 to 4 weeks apart, in patients without important clinical change in disease activity. RESULTS: Disease activity from a SLAM-R varied from 0 to 14 (median = 4) and SLEDAI from 0 to 18 (median = 0). All subscales of the SF-36 correlated well with the VAS [lowest r = 0.56, 95% confidence interval (CI) (0.17, 0.80)] and poorly with the SG [maximum r = 0.41, CI (-0.01, 0.70); minimum r = 0.10, CI (-0.32, 0.50)]. The subscales of bodily pain (r = 0.56), mental health (r = 0.45), physical functioning (r = 0.62), role-emotional (r = 0.47), social functioning (r = 0.49) and vitality (r = 0.44) correlated significantly with TTO. All subscales correlated significantly [lowest r = 0.48, CI (0.09, 0.75)] with the HUI2 index of pain. Intraclass correlations for the VAS (ICC = 0.67) and TTO (ICC = 0.60) were good. They were fair for the SG (ICC = 0.45). The kappa coefficient was poor (0.32) for the HUI attribute of pain, but varied from fair (0.46) to excellent (0.88) for the remaining attributes. Regression analysis showed that a model incorporating the SLAM-R value and SF-36 subset of mental health was a good predictor of VAS and TTO utility measures. CONCLUSION: The VAS, TTO, and to some extent, the HUI2, when compared with the SF-36 health survey, are valid and reliable measures to assess health related quality of life in a group of patients with SLE and may be useful for future research in this population. On the basis of these results the usefulness of the SG is questionable in these patients.

Adult↗

PubMed1999

Carbon dioxide accumulation, walking performance, and metabolic cost in the NASA launch and entry suit.

BACKGROUND: In the event of an emergency on landing, Space Shuttle crewmembers while wearing the Launch and Entry Suit (LES) must stand, move to the hatch, exit the spacecraft with the helmet visor closed breathing 100% O2, and walk or run unassisted to a distance of 380 m upwind from the vehicle. The purpose of this study was to characterize the inspired CO2 and metabolic requirements during a simulated unaided egress from the Space Shuttle in healthy subjects wearing the LES. METHODS: As a simulation of a Shuttle landing with an unaided egress, 12 male subjects completed a 6-min seated pre-breathe with 100% O2 followed by a 2-min stand and 5-min walking at 1.56 m x s(-1) (5.6 km x h(-1), 3.5 mph) with the helmet visor closed. During walks with four different G-suit pressures (0.0, 0.5, 1.0, 1.5 psi; 3.4, 6.9, 10.3 kPa), inspired CO2 and walking time were measured. After a 10-min seated recovery, subjects repeated the 5-min walk with the same G-suit pressure and the helmet visor open for the measurement of metabolic rate (VO2). RESULTS: When G-suit inflation levels were 1.0 or 1.5 psi, only one-third of our subjects were able to complete the 5-min visor-closed walk after a 6-min pre-breathe. Inspired CO2 levels measured at the mouth were routinely greater than 4% (30 mmHg) during walking. The metabolic cost at the 1.5 psi G-suit inflation was over 135% of the metabolic cost at 0.0 psi inflation. CONCLUSION: During unaided egress, G-suit inflation pressures of 1.0 and 1.5 psi resulted in elevated CO2 in the LES helmet and increased metabolic cost of walking, both of which may impact unaided egress performance. Neither the LES, the LES helmet, nor the G-suit were designed for ambulation. Data from this investigation suggests that adapting flight equipment for uses other than those for which it was originally designed can result in unforeseen problems.

Adult↗

PubMed1997

Validity of a heart rate monitor during work in the laboratory and on the Space Shuttle.

Accurate heart rate measurement during work is required for many industrial hygiene and ergonomics situations. The purpose of this investigation was to determine the validity of heart rate measurements obtained by a simple, lightweight, commercially available wrist-worn heart rate monitor (HRM) during work (cycle exercise) sessions conducted in the laboratory and also during the particularly challenging work environment of space flight. Three different comparisons were made. The first compared HRM data to simultaneous electrocardiogram (ECG) recordings of varying heart rates that were generated by an ECG simulator. The second compared HRM data to ECG recordings collected during work sessions of 14 subjects in the laboratory. Finally, ECG downlink and HRM data were compared in four astronauts who performed cycle exercise during space flight. The data were analyzed using regression techniques. The results were that the HRM recorded virtually identical heart rates compared with ECG recordings for the data set generated by an ECG simulator. The regression equation for the relationship between ECG versus HRM heart rate data during work in the laboratory was: ECG HR = 0.99 x (HRM) + 0.82 (r2 = 0.99). Finally, the agreement between ECG downlink data and HRM data during space flight was also very high, with the regression equation being: Downlink ECG HR = 1.05 x (HRM) -5.71 (r2 = 0.99). The results of this study indicate that the HRM provides accurate data and may be used to reliably obtain valid data regarding heart rate responses during work.

Adult↗

PubMed1996

Determining blood and plasma volumes using bioelectrical response spectroscopy.

We hypothesized that an electric field (inductance) produced by charged blood components passing through the many branches of arteries and veins could assess total blood volume (TBV) or plasma volume (PV). Individual (N = 29) electrical circuits (inductors, two resistors, and a capacitor) were determined from bioelectrical response spectroscopy (BERS) using a Hewlett Packard 4284A Precision LCR Meter. Inductance, capacitance, and resistance from the circuits of 19 subjects modeled TBV (sum of PV and computed red cell volume) and PV (based on 125I-albumin). Each model (N = 10, cross validation group) had good validity based on 1) mean differences (-2.3 to 1.5%) between the methods that were not significant and less than the propagated errors (+/- 5.2% for TBV and PV), 2) high correlations (r > 0.92) with low SEE (< 7.7%) between dilution and BERS assessments, and 3) Bland-Altman pairwise comparisons that indicated "clinical equivalency" between the methods. Given the limitation of this study (10 validity subjects), we concluded that BERS models accurately assessed TBV and PV. Further evaluations of the models' validities are needed before they are used in clinical or research settings.

Adult↗

PubMed1994

Comparing the effects of two in-flight aerobic exercise protocols on standing heart rates and VO(2peak) before and after space flight.

The effects of regular aerobic exercise on orthostatic tolerance have been the subject of a long-standing controversy that will influence the use of exercise during space flight. To examine these effects, astronauts performed continuous (CE) aerobic exercise (n = 8), interval (IE) aerobic exercise (n = 4), or no (NE) exercise (n = 5) during flights of 7 to 11 days. Heart rate (HR) responses to an orthostatic challenge (stand test) were measured 10 days before flight and on landing day. VO(2peak) (graded treadmill exercise) was measured 7 to 21 days before and 2 days after flight. No significant differences across the groups were observed in standing HRs before or after flight. However, the within-group mean HRs significantly increased in the NE (71-89 beats/min) and CE (60-85 beats/min) groups after space flight. The HRs for the IE group did not significantly increase (75-86 beats/min) after space flight. VO(2peak) decreased (P < .05) in the NE (-9.5%) group, but did not change in the CE (-2.4%) and IE (1%) groups. The relationship (r = 0.237) between the delta HR and delta VO(2peak) was not significant. These preliminary results indicate that: (1) continuous exercise does not affect the orthostatic HR response after space flight; (2) interval exercise may minimize an increase in the postflight orthostatic HR; and (3) both exercise protocols can maintain VO(2peak).

Adult↗

PubMed1994

Does bed rest produce changes in orthostatic function comparable to those induced by space flight?

Use of bed rest to simulate microgravity exposure is not well validated. We compared heart rate (HR) and blood pressure (BP) responses to standing in bed-rest (BR) subjects (n=11) to those of two astronaut groups. One astronaut group (n=28) fluid loaded (FL) before landing by consuming a water and salt tablet mixture, the second astronaut group (n=8) did not (NL). Bed-rest or microgravity exposure lasted approximately 7.0 days. Preexposure, the responses to standing did not differ between groups. Postexposure, all groups demonstrated an increased HR response (p<0.01), a decreased SBP response (p<0.05), no change in DBP response, and a reduced PP response (p<0.05) compared to preexposure. Change in HR response was lowest for the FL group, presumably due to increased plasma volume induced by fluid consumption. These findings generally support bed rest as a valid simulator of microgravity.

Adult↗

PubMed1994

Coping and emotional attributions following spinal cord injury.

Ways of Coping Checklist-Revised protocols gathered from 35 persons with spinal cord injuries on admission to an in-patient rehabilitation unit were cluster analysed using Ward's method. A two-cluster solution was produced reflecting patterns of coping similar to Lazarus und Folkman's (1984) emotion- and problem-focused dichotomy. These patterns of coping were validated against sets of demographic/medical and emotional adjustment/attribution variables gathered on discharge. Results showed that a group of subjects using emotion-focused coping styles reported greater ratings of depression. These subjects focused less on physical and therapy progress to promote positive feelings and focused more on thoughts about the accident. There was also a trend for physical setbacks to contribute to negative mood in these patients. This pattern was associated with having been readmitted to hospital. The clinical and research implications of the study are discussed.

Activities of Daily Living↗

PubMed1994

Cognitive beliefs following severe traumatic brain injury: association with post-injury employment status.

In this exploratory study, the cognitive beliefs of 19 severely traumatically brain-injured (TBI) patients were assessed to determine their association with post-injury employment status (that is, full-time, part-time or unemployed). Cognitive measures included the Multidimensional Health Locus of Control (MHLC) scale, the Revised Internal-External Scale (RIES) and the Beck Hopelessness Scale (BHS). Patients who did not return to their pre-injury level of employment (n = 10) were found to have lower MHLC Internal, higher RIES Powerful Others locus of control beliefs, and higher BHS scores as compared with a group of patients who returned to their pre-injury employment status (n = 9). In addition, longer lengths of post-traumatic amnesia, longer hospital stays and lower-prestige occupations post-injury were associated with poorer employment status. No differences were present between the groups in age, years of education, Glasgow Coma Scale on admission, length of coma, months post-injury, or pre-injury occupation. These results suggest that cognitive beliefs are a potential target for further research in TBI outcome.

Adult↗

PubMed1993

Alternatives to the Glasgow Coma Scale as a quality of life predictor following traumatic brain injury.

Conventional "staging " of traumatic brain injury (TBI) typically uses depth of coma assessed by the Glasgow Coma Scale (GCS) score near admission as a severity marker. Frequently, early GCS scores are contaminated by alcohol or drug ingestion and other, nonneurological organ system trauma. As well, this measure's usefulness is limited due to its restricted range in survivors. Here we explore the utility of using length of posttraumatic amnesia, coma duration, and age as indirect markers of severity. Cluster analytic techniques were used to examine the relationship of severity so defined to long-term outcome in 106 mild, moderate, and severe TBI patients. Results indicate complex relationships between cluster groups with the influence of age of patient being highlighted as an important moderator in determining severity of injury and later psychosocial outcome.

Journal Article↗

PubMed1992

Swyer-James syndrome: CT findings in eight patients.

To determine the importance of chest CT findings in patients with Swyer-James syndrome (unilateral small lung with air trapping) and to compare these findings with those on chest radiographs and scintigrams, we reviewed the CT scans, chest radiographs, and scintigrams of eight patients with the syndrome. Radiographs showed unilateral hyperlucency in seven patients and bilateral asymmetric hyperlucency in one. CT showed that the hyperlucency was unilateral in only three and that hyperlucency in one. CT showed that the hyperlucency was unilateral in only three and that hyperlucent regions on radiographs contained patches of normal lung attenuation in five patients. Conversely, in four patients, CT also showed small hyperlucencies in regions considered normal on radiographs. These lucencies usually had poorly defined margins and irregular shapes (five patients), but sometimes were peripheral, wedge shaped, and sharply demarcated (two patients). CT also showed subtle abnormalities not visible on radionuclide scans in two patients. Air trapping in hyperlucent regions was confirmed by a lack of change in volume on expiratory CT scans in five cases. Bronchiectasis was found in only three patients. CT helps to exclude central bronchial obstruction, cysts, and vascular disease as causes of hyperlucency. By excluding central obstruction, CT may make bronchoscopy unnecessary in some patients. CT is more sensitive than radiographs and radionuclide scans in detecting hyperlucent regions and in showing their distribution. Our experience suggests that bronchiectasis is not a necessary component of the Swyer-James syndrome.

Adolescent↗