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Biomedical subjects

W E Wilkinson

Publications and source records attributed to W E Wilkinson.

At least 55 records · Page 3Linked to original sources
PubMed1990

MR imaging in patients with temporal lobe seizures: correlation of results with pathologic findings.

Thirty-nine consecutive patients with medically intractable complex partial seizures were studied with electroencephalography and MR imaging to localize an epileptogenic focus for temporal lobectomy. The patients were divided into three groups on the basis of pathologic findings after lobectomy: Group 1 comprised 13 patients with neoplasms, hamartomas, or cysts; group 2 comprised 13 patients with moderate and severe mesial temporal sclerosis (one patient was included in both groups 1 and 2); and group 3 comprised 14 patients who underwent aspiration lobectomy, which yielded limited tissue for pathologic study so no pathologic diagnosis was made. The majority of the patients in group 3 were assumed to have mesial temporal sclerosis. Abnormal MR signal in the temporal lobe on T2-weighted images was graded as minimal increase (1+), intermediate or moderate increase (2+), and very significant increase (3+). An abnormal signal was demonstrated in 26 (67%) of the 39 patients. In group 1, the tumor/cyst subgroup, an abnormal signal was seen in all 13 patients. Most had 3+ signal. There was increased signal in eight (62%) of 13 patients in group 2 and in six (43%) of 14 patients in group 3. This study suggests that MR can detect almost all tumors and a significant number of mesial temporal sclerosis lesions in individuals with complex partial seizures. On the basis of this small series, individuals who exhibit significant signal (3+) can be expected to have neoplasms, hamartomas, or cysts, and patients who exhibit minimal signal (1+) will usually have mesial temporal sclerosis.

Adult↗
PubMed1990

Regional cerebral blood flow measurement in humans by xenon-133 clearance.

Almost 30 years have passed since the first measurement of regional cerebral blood flow in humans by 133Xe clearance. A review of the methodology is presented for the two-dimensional intracarotid method and the related inhalation and IV injection techniques. Emphasis is placed on the mathematical models employed and the blood flow indices derived from them. Similarities and differences between methods are described, and the contribution of each to clinical research is summarized.

Brain↗
PubMed1990

A conceptual model of occupational health nursing.

Occupational health nurses can practice and research in their profession better if they approach occupational health nursing with a well developed conceptual model. The Wilkinson Windmill Model is one conceptualization of occupational health nursing an occupational health nurse may use for guidance in practice, research, and education. The model consists of five primary components. This conceptual model may be a useful framework for understanding the role of the occupational health nurse in many different environments and may prove valuable as a tool for conducting research.

Humans↗
PubMed1990

Oral contraceptives and breast cancer: a case-control study with hospital and community controls.

Several recent reports have noted an increase risk of breast cancer associated with the use of oral contraceptives (OCs) among various subgroups of young women. These reports spurred us to analyze data from a case-control study in North Carolina of 158 breast cancer patients, 326 hospital controls, and 1140 community controls less than 60 years of age. A logistic regression model was used to calculate odds ratios and 95% confidence intervals and to control for potential confounders. No association between ever-use of OCs and the risk of breast cancer was found for cases compared with either control group. No increased risk was observed for OC use before age 25 or before first full-term pregnancy, or in relation to duration of use, recency of use, or time since first use. Analysis of the subgroup of women less than 45 years of age also showed no relationship between OC use and breast cancer risk. However, an elevated risk of breast cancer was observed among nulliparous women with 5 or more years of OC use in comparisons with hospital controls (odds ratio 7.8) and community controls (odds ratio 2.3). This analysis was based on small numbers of subjects and the 95% confidence intervals touched or overlapped with 1. An unexpected association between duration of OC use and breast cancer risk was found among older premenopausal women in comparisons of cases with both control groups. For these women, a trend was evident in the odds ratio by duration of OC use, and the comparison between cases and community controls was statistically significant.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

Random and nonrandom behavior of symptomatic paroxysmal atrial fibrillation.

Little is known about the behavior of symptomatic paroxysmal atrial fibrillation (AF). The nature of the process formed by the successive occurrences of this arrhythmia was studied in 8 patients with a history of symptomatic paroxysmal AF. Trans-telephonic monitoring of the electrocardiogram was used to document the cardiac rhythm during symptoms. Patients were followed while successive attacks of paroxysmal AF were documented. A minimum of 12 and a maximum of 26 consecutive episodes of symptomatic paroxysmal AF were recorded from the 8 patients during 66 to 332 days. Methods developed in industrial reliability theory were used to show that, for the overall group of 8 patients, the interevent times between successive occurrences of symptomatic AF were not independent. However, for a subgroup including 6 of the patients, the interevent times were independent and governed by an exponential probability distribution. Differences in observed behavior of symptomatic AF may relate to differences in underlying mechanism within patients.

Adult↗
PubMed1988

Changes in serum lipids in patients with condylomata acuminata treated with interferon alfa-n1 (Wellferon).

Nine men with refractory condylomata acuminata were treated with intramuscular interferon alfa-n1 and the effect on their serum lipid levels was noted. Comparison of lipid panels before and after interferon revealed that all nine patients had an increase (median 62 mg/dl, p = 0.004) in their triglyceride level and a decrease (median 21 mg/dl, p = 0.004) in high-density lipoprotein cholesterol levels. Total cholesterol levels tended to decrease but the change was not statistically significant. This effect on serum lipids should be considered when interferon alfa-n1 is used in the treatment of genital warts.

Cholesterol↗
PubMed1988

Effects of image processing on nodule detection rates in digitized chest radiographs: ROC study of observer performance.

To evaluate the effects of image processing in digitized chest radiographs when high-resolution images are used, an examination was done in which the detection of pulmonary nodules in unprocessed digitized chest radiographs was compared with that in images that had undergone processing with two methods, adaptive filtration and histogram equalization. The processing techniques have been optimized in previous work to selectively enhance the retrocardiac and subdiaphragmatic areas without significant alteration of detail in the lung. Eight observers were shown 150 test radiographs (50 unprocessed, 50 processed with adaptive filtration, 50 processed with histogram equalization) containing 150 nodules. The results indicate a statistically significant (P less than .03) difference, with highest observer performance in the chest radiographs processed with adaptive filtration (median area under ROC curve = 0.78), compared with unprocessed images (median = 0.68) and chest radiographs processed with histogram equalization (median = 0.62). Performance in the lung was not significantly different. Adaptive filtration applied to selectively enhance underexposed areas of film images may improve nodule detection. Histogram equalization provided no improvement in performance.

Filtration↗
PubMed1988

Circadian occurrence of symptomatic paroxysmal supraventricular tachycardia in untreated patients.

Fifty-two patients with paroxysmal supraventricular tachycardia were studied to determine whether there was a circadian pattern to the occurrence of this arrhythmia. Antiarrhythmic therapy was discontinued, and patients were followed until they had one recurrence of tachycardia documented by telephone transmission of the electrocardiogram. By least-squares analysis, the times of day that the 52 attacks (one from each patient) occurred were fit to a sinusoidal density function with a period of 24 hr. The highest relative incidence of tachycardia was at 4 P.M.; tachycardia was five times more likely to occur at 4 P.M. than at 4 A.M., the time of the lowest relative incidence. A second attack of tachycardia was recorded from 35 of the 52 patients. The times of the two attacks in individual patients were found to be independent; thus the times of day at which the second attacks occurred were used as a test set for the distribution estimated from the first. The empirical distribution for the times from the 35 second attacks was compared with the distribution function estimated from the 52 first attacks, and there was no significant departure; this finding confirmed the circadian pattern. Since the relative incidence of attacks of paroxysmal supraventricular tachycardia is higher in the afternoon, it may be helpful to target antiarrhythmic therapy to that time of day.

Adult↗
PubMed1988

Drug screening in the workplace--scientific and legal issues.

Urine drug testing is gaining acceptance with employers nationwide as a method of assuring a drug-free work environment. This article explains and discusses the currently used urine drug screening tests (EMIT, TLC, RIA and GCMS). Practical considerations involving specimen collection and proper chain of custody procedures are outlined. The legality of such tests and the legal and ethical issues of drug testing in the workplace are explored by reviewing precedent-setting court decisions. Labor's position on drug testing is summarized. The nurse practitioner responsible for establishing and/or administering company testing policy will benefit by a review of the scientific and legal issues involved in testing workers for drug use.

Humans↗
PubMed1987

Comparison of two screening tests in Alzheimer's disease. The correlation and reliability of the Mini-Mental State Examination and the modified Blessed test.

The Mini-Mental State Examination (MMSE) and the Blessed Orientation-Memory-Concentration test (BOMC), a six-item derivative of the Blessed Information-Memory-Concentration Test, were each administered to 36 patients with a clinical diagnosis of Alzheimer's disease. In 24 patients, both tests were readministered a month later. The correlation between the MMSE and BOMC was -0.83 with a test-retest correlation of 0.89 (MMSE) and 0.77 (BOMC). Factor analysis indicated that the multiple MMSE cognitive components could be explained by two factors, which together accounted for 66% of the variance. These factors are conceptually similar to the components of the BOMC, and so may explain the substantial correlation between the two tests. Since these cognitive status tests seem to be equivalent for Alzheimer patients, the briefer measure (BOMC), which offers additional advantages, may be preferred.

Aged↗
PubMed1987

Early-onset Alzheimer's disease: clinical predictors of institutionalization and death.

Follow-up observations were made of 92 white patients with early-onset Alzheimer's disease to determine the demographic, clinical, and neuropsychological factors predictive of institutionalization or death. The cumulative mortality rate 5 years after entry into the study was 23.9%, compared with an expected rate of 9.5%. The 5-year cumulative rate of admission to nursing homes was 62.8%. The language ability of the patients on entry to the study, their scores on a brief screening test of cognitive function, and their overall ratings of clinical dementia were found to be predictors of subsequent institutional care and death. The age of the patients had a significant modifying effect on these predictive factors, resulting in a greater risk of institutionalization and death in younger patients with severe cognitive impairment as compared with older individuals with the same degree of dysfunction.

Aged↗
PubMed1987

Cigarette smoking, alcohol consumption, and breast cancer risk.

The effects of cigarette smoking and alcohol consumption on breast cancer risk were investigated in 276 primary, histologically confirmed breast cancer patients and 1,519 community-based comparison subjects identified in 1977 and 1978 in North Carolina. Data on both behaviors and other pertinent personal and medical characteristics were obtained by interview. Analytic methods included stratification and logistic regression. Among current cigarette smokers of 1-20 cigarettes per day and over 20 per day, the odds ratios (ORs) adjusted for age, race, alcohol consumption, estrogen use, and oral contraceptive use for breast cancer were 0.75 [95% confidence interval (CI) 0.52-1.09] and 0.57 (95% CI 0.30-1.08), respectively. A decrease in risk was not seen in former smokers. With respect to alcohol consumption, the adjusted OR for those having one drink or more per week compared to those having less than one was 1.45 (95% CI 0.99-2.12). If the comparison was ever versus never drinkers, the adjusted OR was 1.47 (95% CI 1.10-1.97); for current drinkers versus nondrinkers, the adjusted OR was 1.89 (95% CI 1.40-2.56). The ORs were adjusted for age, race, cigarette smoking, estrogen use, an oral contraceptive use. These data supports those reports showing an inverse association of cigarette smoking and a positive association of alcohol consumption with breast cancer risk.

Adult↗
PubMed1985

Comparison of amaurosis fugax and transient cerebral ischemia: a prospective clinical and arteriographic study.

We compared the clinical associations, arteriographic findings, and long-term outcome of 93 patients with amaurosis fugax and 212 patients with focal cerebral ischemia (transient ischemic attacks [TIAs]). The group of patients with cerebral TIAs included a significantly larger proportion of blacks and had a higher prevalence of hypertension than the group with amaurosis. Operable atherosclerotic lesions of the carotid arteries were more often associated with amaurosis (66%) than with cerebral TIAs (51%). The seven-year cumulative rate of cerebral infarction, however, was less in patients with amaurosis (14%) than in those with cerebral TIAs (27%; p less than 0.02). This difference in outcome persisted after adjustment for race, hypertension, and type of therapy. There were no significant differences, however, in the cumulative rates either of recurrent TIAs or of myocardial infarction or sudden death in the two groups of patients.

Blindness↗