Biomedical subjects

S L Norris

Publications and source records attributed to S L Norris.

At least 19 recordsLinked to original sources

PubMed2001

Effectiveness of self-management training in type 2 diabetes: a systematic review of randomized controlled trials.

OBJECTIVE: To systematically review the effectiveness of self-management training in type 2 diabetes. RESEARCH DESIGN AND METHODS: MEDLINE, Educational Resources Information Center (ERIC), and Nursing and Allied Health databases were searched for English-language articles published between 1980 and 1999. Studies were original articles reporting the results of randomized controlled trials of the effectiveness of self-management training in people with type 2 diabetes. Relevant data on study design, population demographics, interventions, outcomes, methodological quality, and external validity were tabulated. Interventions were categorized based on educational focus (information, lifestyle behaviors, mechanical skills, and coping skills), and outcomes were classified as knowledge, attitudes, and self-care skills; lifestyle behaviors, psychological outcomes, and quality of life; glycemic control; cardiovascular disease risk factors; and economic measures and health service utilization. RESULTS: A total of 72 studies described in 84 articles were identified for this review. Positive effects of self-management training on knowledge, frequency and accuracy of self-monitoring of blood glucose, self-reported dietary habits, and glycemic control were demonstrated in studies with short follow-up (<6 months). Effects of interventions on lipids, physical activity, weight, and blood pressure were variable. With longer follow-up, interventions that used regular reinforcement throughout follow-up were sometimes effective in improving glycemic control. Educational interventions that involved patient collaboration may be more effective than didactic interventions in improving glycemic control, weight, and lipid profiles. No studies demonstrated the effectiveness of self-management training on cardiovascular disease-related events or mortality; no economic analyses included indirect costs; few studies examined health-care utilization. Performance, selection, attrition, and detection bias were common in studies reviewed, and external generalizability was often limited. CONCLUSIONS: Evidence supports the effectiveness of self-management training in type 2 diabetes, particularly in the short term. Further research is needed to assess the effectiveness of self-management interventions on sustained glycemic control, cardiovascular disease risk factors, and ultimately, microvascular and cardiovascular disease and quality of life.

Adaptation, Psychological↗

PubMed2000

Effectiveness of physician-based assessment and counseling for exercise in a staff model HMO.

BACKGROUND: Few primary care physicians routinely counsel for exercise, despite the benefits of physical activity and the high prevalence of inactivity. The objective of this study is to assess the effectiveness of Physician-Based Assessment and Counseling for Exercise (PACE), a brief, behavior-based tool for primary care providers counseling healthy adults. METHODS: This study is a randomized controlled trial of 812 patients age 30 years or older registered for well visits at 32 primary care physician offices at a staff model health maintenance organization. Intervention physicians were trained to deliver PACE exercise counseling protocols at the index visit, and one reminder telephone call occurred at 1 month. An enhanced intervention group received additional activity reminders. RESULTS: At the 6-month follow-up, the control group did not differ significantly from the intervention group for energy expended (2,048 kcal/week versus 2,108 kcal/ week, P = 0.77), time spent in walking or other moderate to vigorous activities (202 min/week versus 187 min/ week, P = 0.99), mental health, physical function, or behaviors previously shown to predict activity change. Among the intervention patients, the stages-of-change score for Contemplators increased significantly compared with controls (P = 0.03), but without a significant change in energy expended. Baseline levels of physical activity counseling were high (50%), as were baseline patient physical activity levels (61% exercised at least three times a week). CONCLUSIONS: These results suggest that a one-time PACE counseling session with minimal reinforcement, in a setting with high baseline levels of activity, does not further increase activity. The finding that Contemplators advanced in stage of behavior change suggests that further studies are needed to examine long-term, repeated counseling interventions.

Adult↗

PubMed1998

Women in medicine: shaping the future.

The dramatic increase in the number of women in medicine presents some new challenges to an old institution. This article provides an overview of current trends and future directions as greater numbers of women are entering medicine. The first section describes women's particular approach to medicine, including their motivations for pursuing medicine as a career, their specialty choices and practice patterns, their attitudes about patient care and doctor-patient relationships, and their advocacy for women's health issues. The second section documents women's negative experiences in medicine, such as higher stress levels than men, gender discrimination, sexual harassment, role strain, and a paucity of mentors and role models. In the final section, the authors suggest how medicine as an institution can change to better accommodate women.

Attitude of Health Personnel↗

PubMed1997

Early radionuclide scans for risk assessment in suspected acute myocardial infarction.

First-day thallium-201 myocardial perfusion scans and technetium-99m RBC gated scintiangiography were performed during the initial clinical and prognostic evaluation of 69 patients with suspected acute myocardial infarction. Patients were monitored for clinical course, diagnosis confirmation, and use of specialty services (cardiac catheterization, percutaneous balloon angioplasty, and cardiac surgery) during hospitalization. Myocardial infarction, confirmed in 20 patients, was associated with significantly more left ventricular dilatation, lower ejection fractions, lower peak left ventricular filling rates, wall motion abnormalities, and thallium-201 perfusion defects than nonmyocardial infarction patients. Among all patients, left ventricular dilatation carried a relative risk of myocardial infarction of 5.8; low ejection fraction and right ventricular dilatation were strongly associated with myocardial infarction. A logistic model for congestive heart failure included: left ventricular dilation, lower mean left ventricular filling rates and time to peak filling rates, and abnormal thallium-201 lung:heart uptakes. Among nonmyocardial infarction patients, subsequent cardiac catheterization was predicted by the presence of anterior thallium-201 perfusion defects, Killip functional class II-III, and ischemia on ECG. These findings suggest that early detection of myocardial perfusion defects and cardiac dysfunction by radionuclide scans enhances initial evaluation of suspected acute myocardial infarction patients. Additional studies are needed to confirm these findings.

Analysis of Variance↗

PubMed1994

MRI-derived ventricular volume curves for the assessment of left ventricular function.

To assess the utility of double oblique, ECG-gated 1H magnetic resonance (MR) derived volume curves for assessing LV function, cardiac short axis images were acquired with a fast field echo technique. We applied this methodology to assess left ventricular function in three groups: normals, patients with left ventricular hypertrophy, and dilated cardiomyopathy. Six slices with 16-20 phases per RR interval were analyzed, representing the initial 75-80% of the cardiac cycle. For each slice, the endocardial border of the left ventricular (LV) chamber was manually traced. Using Simpson's rule, the total LV volume at a given phase was determined considering the traced area, thickness and position in three-dimensional space of each of the six constituent slices. The calculated volumes were plotted against time and the stroke volume, ejection fraction and cardiac output were determined. The volume vs time plots for the systolic and diastolic portions of the curve were individually fit to third degree polynomials using a least squares approximation. From the fit curves, the following data were extracted: the mean slope (dV/dT) during filling and emptying, and the time to 1/4, 1/3 and 1/2 filling and emptying. These parameters are valuable indices of the functional status of the myocardium; thus, accurate and useful estimates of LV function can be obtained using MRI derived volume curves in normal and abnormal states.

Cardiac Volume↗

PubMed1994

One-year prospective replication study of an untreated sample of community dysthymia subjects.

This study replicates an earlier naturalistic-prospective investigation of nontreatment, community DSM-III-R dysthymia subjects. Major goals were to determine spontaneous remission rates and monitor the stability of psychosocial functioning levels over time. Twenty-four dysthymia subjects were followed for 1 year. Three remissions (13%) were diagnosed at the final interview. At a 4-year diagnostic follow-up contact with the remitters only, one remitter had relapsed and two remained in remission. Subjects were monitored for depressive symptom intensity, personality functioning, general medical distress, cognitive functioning, coping stylistics, interpersonal functioning, quality of their social support resources, and general family functioning. Stable levels of psychosocial functioning were maintained across all measures over the 1-year period. Current psychometric findings confirm the conclusions of the earlier nontreatment prospective study that dysthymia is a chronic mood disorder with stable psychosocial features and is unlikely to remit spontaneously over time.

Adaptation, Psychological↗

PubMed1994

Comparison of a community dysthymia sample at screening with a matched group of nondepressed community controls.

The primary goal of the study was to compare the psychosocial functioning of an untreated, community sample of DSM-III-R dysthymia subjects (N = 24) at screening to that of a matched sample of community nondepressed volunteers (N = 18) with no lifetime or current history of axis I disorders. Subjects were compared across a number of psychosocial indices. The dysthymics were found to be less sociable (introversion) and clinically high on neuroticism-instability, external in regard to their causal attributions, less stable for positive uncontrollable events and more stable and global for negative uncontrollable events, relying more on coping strategies such as wishful thinking and self-blame, more interpersonally submissive and hostile, and to have a poorer social support-resource network. In addition, the dysthymics reported more family dysfunction and a higher rate of negative major life events.

Adaptation, Psychological↗

PubMed1993

Risk factors and mortality among black, Caucasian, and Latina women with acute myocardial infarction.

The purpose of this study was to examine the clinical outcome of acute myocardial infarction among women of three ethnic/racial groups and to determine whether observed differences in outcome are explained by differences in associated risk factors. Nine hundred seventeen (917) consecutive admissions occurred among 810 women, of whom 347 (42.8%) were Caucasian, 258 (31.9%) were black, and 205 (25.3%) were Latina. The overall mortality rate was 13%; the Caucasian rate was significantly higher than the Latina rate (16.9% vs 7%, p < 0.01), as was the black rate (13.8% vs 7%, p < 0.05). Comparing survivors with nonsurvivors among the three groups, hypertension was more common for survivors among blacks, as was a history of angina; in-hospital congestive failure was associated with a higher mortality for blacks and Caucasians, as was in-hospital angina for Caucasians. Univariate and multivariate logistic regression for the outcome variables of congestive failure, in-hospital angina, and mortality, showed race to be a significant factor in the lower mortality rate for Latinas in the univariate analysis. In the multivariate analysis, only in-hospital angina and congestive failure significantly influenced mortality. In this study of myocardial infarction among women of lower socioeconomic status, factors other than race were the primary influences on outcome.

Aged↗

PubMed1993

Altered muscle metabolism shown by magnetic resonance spectroscopy in sickle cell disease with leg ulcers.

We performed 31P magnetic resonance spectroscopy of gastrocnemius muscle at rest in 7 normal volunteers and 12 patients with sickle cell disease (7 with leg ulcers and 5 without leg ulcers but with painful crises). We measured intracellular pH and ratios of Pi to ATP, PCr to ATP and PCr to Pi (Pi = inorganic phosphate, ATP = adenosine triphosphate, and PCr = phosphocreatine). Magnetic resonance arteriograms were also performed. Significant differences were found for PCr/Pi ratios between normals and sickle cell disease patients with leg ulcers (p < 0.008). Magnetic resonance arteriograms were normal in volunteers and patients with sickle cell disease. The altered high energy phosphate metabolism in sickle cell disease with leg ulcers is consistent with muscle ischemia or hypoxia.

Adult↗

PubMed1992

Left ventricular filling pressure in sickle cell anemia.

Indirect left ventricular filling pressures were measured via balloon-tipped catheters in 11 studies of 10 patients with sickle cell anemia and cardiorespiratory symptomatology. Pulmonary capillary wedge pressures exceeded 12 mm Hg in 8 of 11 studies (8 of 10 patients). Mean pressures in mm Hg were: pulmonary capillary wedge, 16.5 +/- 4.2 (SEM); pulmonary artery, 38 +/- 16; brachial artery, 104 +/- 128; and right atrium, 11 +/- 4. The mean cardiac output was 8.8 +/- 3.1 L/min. The mean pulmonary vascular resistance was 237 +/- 122 dynes sec cm-5 and was significantly increased in 4 patients. In addition to further documentation of significantly elevated pulmonary artery pressures in sickle cell anemia patients with cardiopulmonary symptomatology, these data indicate that a contributory role for elevated left ventricular filling pressures must be considered in the pathogenesis of pulmonary hypertension in sickle cell anemia. Elevation of the pulmonary artery pressure was usually associated with elevation of the pulmonary capillary wedge pressure.

Adult↗

PubMed1991

Cardiac calcifications: difficult MRI diagnosis.

Magnetic resonance imaging (MRI) and computed tomography (CT) were performed in 40 patients with a variety of cardiovascular diseases. These imaging modalities were compared to investigate their relative value in the assessment of cardiovascular diseases. Of these 40 patients, 7 were found by CT to have detectable cardiovascular calcifications. These patients included one calcified mitral stenosis, one calcified coronary artery, one calcified type B aortic dissection, two calcified myocardial infarctions, and two patients with calcific pericarditis. In several cases, MRI was misleading because of difficulty in detecting calcifications. We present a series of cases illustrating a limitation of MRI in identifying diagnostically and clinically important cardiovascular calcifications.

Adolescent↗

PubMed1989

An unusual scintigraphic pattern in sickle cell patients.

We reviewed the nuclear medicine files of all patients enrolled in the sickle cell disease clinic who had had scans performed within the previous 5 years. We specifically looked for patterns of tracer uptake in these scans that would correlate with the severe anemia and consequent bone marrow hyperactivity of sickle cell patients. Thirty-three patients were included (21 men and 12 women) with a mean age of 26.8 years (range 17-48 years). The appearance of each of these patients' most recent scans was examined in the areas of the distal femurs, the proximal tibias and the distal tibias; a distinct triangular shaped pattern of increased activity was identified in these areas in a majority of patients. Thirty-three patients without sickle cell disease served as age-matched controls. This pattern was seen in 65.1% (95 out of 146 images) of the sickle cell patients' delayed images and 80.4% (82 out of 102 images) of their blood pool images. In contrast, the control patients demonstrated the triangular pattern in none of their blood pool studies (0%) and only 10.9% of their delayed bone images (P less than 0.001). The mean age of sickle cell patients with this pattern is 25.6 years which was significantly lower than that of those without this pattern (mean = 37.5 years, P less than 0.05). Given the high prevalence of this unique scintigraphic pattern in a group of patients with known accelerated bone marrow function, these findings may be scintigraphic evidence of bone marrow expansion. The patient's age appears to be an important factor in visualization of this pattern.

Adult↗

PubMed1986

Thermodilution cardiac output--an in vitro model of low flow states.

The accuracy and reproducibility of thermodilution cardiac output measurements were examined in vitro at low flows, using the Edwards cardiac output computer. For each of 18 different volumetrically measured flows between 130 and 1035 ml/min, three cardiac outputs were determined for each of four different injectate volumes (1,2,3, and 5 ml) at two different temperatures (0 degrees C and room temperature). There was a significant (p less than .001) correlation between measured flow and cardiac output for all injectate volumes at both temperatures. The slopes of the regression lines ranged between 0.97 and 1.25, and the y-intercepts were all greater than 0. Although this thermodilution technique overestimated cardiac output, it was a reproducible means of measuring cardiac output in this low-flow in vitro model.

Cardiac Output↗

PubMed1986

Acute cardiopulmonary effects of subarachnoid hemorrhage in monkeys.

Twenty-eight cynomolgus monkeys had an autologous subarachnoid blood clot placed in the basal cisternae via craniectomy. Twenty-three monkeys survived clot placement and five animals died within 24 h. An additional eight monkeys underwent sham procedures and six acted as anesthetic controls. Cardiopulmonary indices were measured before clot placement and 30 to 60 min thereafter, to determine if certain changes had prognostic value for immediate outcome. In the 24-h survivors, heart rate and arteriovenous oxygen content difference increased significantly (p less than .05 and .01, respectively), while stroke index (SI) (p less than .01), mean pulmonary artery pressure (p less than .001), pulmonary artery wedge pressure (p less than .001), and central venous pressure (p less than .05) fell. In the 24-h nonsurvivors, cardiac index (CI) (p less than .05) and SI (p less than .01) fell to an even greater extent than in the survivors. There was a significant (p less than .05) difference between the two groups for CI and SI. There were no significant differences in the sham-operated animals. In six control monkeys, neither heart rate nor CI significantly increased throughout 5 h of anesthesia.

Animals↗

PubMed1986

Nimodipine and chronic vasospasm in monkeys: Part 3. Cardiopulmonary effects.

A subarachnoid hemorrhage was induced in 30 cynomolgus monkeys by the placement of a 6- to 7-ml blood clot through a frontotemporal craniectomy (Day 0). The monkeys underwent a 1-week-long, randomized, blind trial comparing various doses of nimodipine to placebo, sham, and no treatment. The treatment groups were: nimodipine, 3 mg/kg every 8 hours (n = 6), 6 mg/kg every 8 hours (n = 6), and 12 mg/kg every 8 hours (n = 6); placebo (polyethylene glycol 400), 0.33 ml/kg every 8 hours (n = 6); and no treatment (n = 6). An additional sham group underwent craniectomy without clot placement (n = 6) so that 36 animals in total were operated upon. Differences in cardiopulmonary indices between Day 0 and Day 7 were compared within and between groups. No significant differences were obtained in the sham and no treatment groups. The nimodipine 6- and 12-mg/kg groups showed significant decreases in blood pressure (P less than 0.04 and P less than 0.015). Systemic vascular resistance was increased in the placebo and 3-mg/kg groups (P less than 0.02) and decreased in the 12-mg/kg group (P less than 0.015). Stroke index was increased in the 12-mg/kg group (P less than 0.05). Cardiac index and stroke index correlated positively with nimodipine dosage (r = 0.99, P less than 0.05). There were no pronounced changes in pulmonary artery wedge pressure, central venous pressure, alveolar-arterial oxygen pressure difference, arteriovenous oxygen content difference, and percentage of shunting.

Animals↗

PubMed1986

Quantitative analysis of stress thallium-201 myocardial scintigrams: a multicenter trial.

Previously we validated a method for quantification of 201TI myocardial stress distribution and washout in which the patient's stress and washout circumferential profiles are compared with observed normal limits. The present study reports the results of a multicenter trial in which this method, utilizing normal limits from our institution, was employed to evaluate the presence, location, and extent of coronary artery disease (CAD). The normal limits utilized were generated from 49 patients having a low likelihood of CAD. The study population included 157 patients from four centers in the United States and Canada as well as a comparative prospective population from Cedars-Sinai Medical Center (CSMC) of 51 patients with CAD, 30 patients with normal coronary arteriograms, and 30 additional low-likelihood normals. The results in the combined centers regarding overall detection of CAD revealed a sensitivity of 84% and a frequency of test normality in the patients with low likelihood of CAD of 88%, compared to a sensitivity of 82% and true normalcy rate of 83% obtained in the prospective CSMC population. The sensitivity for detecting disease increased according to the extent of angiographic CAD in both the multicenter sites and the prospective CSMC group. Regarding localization of disease, similar sensitivities and specificities for detecting disease in individual coronary arteries were found in the multicenter sites and the prospective CSMC population. The results indicate that our method for quantifying 201TI stress-redistribution scintigrams utilizing standard normal limits can be applied at other institutions using a variety of scintillation cameras with similar accuracy to that currently obtained at our institution.

Adult↗

PubMed1985

Gold-195m first-pass radionuclide ventriculography, thallium-201 single-photon emission CT, and 12-lead ECG stress testing as a combined procedure.

Graded, sequential, rest/exercise, gold-195m (Au-195m) (T1/2 = 30 seconds), first-pass ventriculography and thallium-201 (T1-201) single-photon emission computed tomography (SPECT) were performed simultaneously during a single, electrocardiograph-monitored, bicycle stress test in 24 individuals. The technical aspects and logistics involved in performing this combined radionuclide study are stressed in this preliminary report. Fourteen healthy volunteers each had a normal left ventricular ejection fraction and wall-motion response, along with normal Tl-201 perfusion and washout, as determined by both visual and quantitative analysis of the tomographic sections. Each of ten patients with coronary artery disease had at least one abnormality of these parameters. We suggest that it is technically feasible to evaluate both cardiac function and myocardial perfusion simultaneously by combining Au-195m ventriculography and T1-201 SPECT imaging into a single, noninvasive, diagnostic package.

Adult↗

PubMed1984

Sensitivity and specificity of nuclear phase analysis versus ejection fraction in coronary artery disease.

Phase standard deviation (SD) and skew characteristics of the first Fourier harmonic of equilibrium radionuclide volume curves were examined and compared during rest and during supine bicycle exercise with ejection fraction (EF) changes and the development of ischemia in 17 control subjects and in 2 groups of patients (n = 57) with coronary artery disease (CAD). Group I comprised 37 patients with CAD; IA was a subgroup of 20 patients with previous myocardial infarction (MI) and IB a subgroup of 17 patients with CAD without MI (all with coronary stenosis greater than 75% diameter narrowing). Group II comprised 20 patients with CAD who had undergone coronary bypass surgery. In the Group I subjects, phase SD was the most sensitive indicator of CAD at rest (Group I, 56%; Group IA, 70%, and Group IB, 29%), and the EF was the most sensitive indicator at submaximal (Group I, 78%; Group IA, 86%, and Group IB, 64%) and maximal exercise (Group I, 70%; Group IA, 93%, and Group IB, 53%). When phase SD and skewness were combined with EF changes, little increase in sensitivity occurred in Group I (rest 61%, submaximal exercise 88% and maximal exercise 76%). The results from Group II subgroups were qualitatively similar to those observed with Group I subgroups. These data reveal a marginally improved sensitivity for detection of CAD during supine bicycle radionuclide ventriculography when phase measurements were added to changes in global EF values.

Adult↗