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Biomedical subjects

C P Lucas

Publications and source records attributed to C P Lucas.

At least 19 recordsLinked to original sources
PubMed2001

The DISC Predictive Scales (DPS): efficiently screening for diagnoses.

OBJECTIVE: To derive and test a series of brief diagnosis-specific scales to identify subjects who are at high probability of meeting diagnostic criteria and those who may safely be spared more extensive diagnostic inquiry. METHOD: Secondary data analysis of a large epidemiological data set (n = 1,286) produced a series of gate and contingent items for each diagnosis. Findings were replicated in a second retrospective analysis from a residential care sample (n = 884). The DISC Predictive Scales (DPS) were then used prospectively as a self-report questionnaire in two studies, in which parents (n = 128) and/or adolescents (n = 208) had subsequent diagnostic interviewing with the Diagnostic Interview Schedule for Children or the Schedule for Affective Disorders and Schizophrenia for School-Age Children. RESULTS: All analyses showed that gate item selection was valid and that any missed cases were due solely to inconsistent reports on the same questions. Screening performance of the full scales was shown to be good, and substantial reductions in scale length were not associated with significant changes in discriminatory power. CONCLUSIONS: The DPS can accurately determine subjects who can safely be spared further diagnostic inquiry in any diagnostic area. This has the potential to speed up structured diagnostic interviewing considerably. The full DPS can be used to screen accurately for cases of specific DSM-III-R disorders.

Adolescent↗
PubMed2000

Effects of weight loss with orlistat on glucose tolerance and progression to type 2 diabetes in obese adults.

BACKGROUND: Orlistat is a gastrointestinal lipase inhibitor that reduces dietary fat absorption by approximately 30%, promotes weight loss, and may reduce the risk of developing impaired glucose tolerance and type 2 diabetes in obese subjects. OBJECTIVE: To test the hypothesis that orlistat combined with dietary intervention improves glucose tolerance status and prevents worsening of diabetes status more effectively than placebo. METHODS: We pooled data from 675 obese (body mass index, 30-43 kg/m2) adults at 39 US and European research centers in 3 randomized, double-blind, placebo-controlled multicenter clinical trials. Subjects received placebo plus a low-energy diet during a 4-week lead-in period. On study day 1, the diet was continued, and subjects were randomized to receive placebo 3 times a day (n=316) or treatment with orlistat, 120 mg 3 times a day (n=359), for 104 weeks. A standard 3-hour oral glucose tolerance test was performed on day 1 and at the end of treatment. MAIN OUTCOME MEASURES: The categorical assessment of glucose tolerance status (normal, impaired, diabetic) and changes in status from randomization to end of treatment were the primary efficacy measures. The secondary measures were fasting and postchallenge glucose and insulin levels. RESULTS: The mean length of follow-up was 582 days. Subjects who were treated with orlistat lost more weight (mean +/- SEM, 6.72 +/- 0.41 kg from initial weight) than subjects who received placebo (3.79+/-0.38 kg; P<.001). A smaller percentage of subjects with impaired glucose tolerance at baseline progressed to diabetic status in the orlistat (3.0%) vs placebo (7.6%) group. Conversely, among subjects with impaired glucose tolerance at baseline, glucose levels normalized in more subjects after orlistat treatment (71.6%) vs placebo (49.1%; P=.04). CONCLUSIONS: The addition of orlistat to a conventional weight loss regimen significantly improved oral glucose tolerance and diminished the rate of progression to the development of impaired glucose tolerance and type 2 diabetes.

Adult↗
PubMed2000

External validity of conduct and oppositional defiant disorders determined by the NIMH Diagnostic Interview Schedule for children.

We administered the Diagnostic Interview Schedule for Children (DISC) two times to a group of youth (222 boys, 147 girls) entering residential care, once at their time of entry and once 1 year later. We then compared their DISC outcomes on Conduct Disorder (CD) and Oppositional Defiant Disorder (ODD) against changes in independent direct observations of diagnostically relevant behavior obtained over the course of that year. Results from hierarchical linear modeling analyses showed significant discriminative relationships between results from the DISC and the independent observations. Specifically, observations of symptomatic behaviors (CD or ODD) decreased for youth who met diagnostic criteria at the first administration of the DISC but not at the second, increased for youth who did not meet criteria at the first administration but did at the second, and did not change for youth who met criteria at both administrations. These results extend the data on the validity of the DISC and support continued research efforts to determine its clinical utility.

Adolescent↗
PubMed2000

NIMH Diagnostic Interview Schedule for Children Version IV (NIMH DISC-IV): description, differences from previous versions, and reliability of some common diagnoses.

OBJECTIVE: To describe the National Institute of Mental Health Diagnostic Interview Schedule for Children Version IV (NIMH DISC-IV) and how it differs from earlier versions of the interview. The NIMH DISC-IV is a highly structured diagnostic interview, designed to assess more than 30 psychiatric disorders occurring in children and adolescents, and can be administered by "lay" interviewers after a minimal training period. The interview is available in both English and Spanish versions. METHOD: An editorial board was established in 1992 to guide DISC development and ensure that a standard version of the instrument is maintained. Preliminary reliability and acceptability results of the NIMH DISC-IV in a clinical sample of 84 parents and 82 children (aged 9-17 years) drawn from outpatient child and adolescent psychiatric clinics at 3 sites are presented. Results of the previous version in a community sample are reviewed. RESULTS: Despite its greater length and complexity, the NIMH DISC-IV compares favorably with earlier versions. Alternative versions of the interview are in development (the Present State DISC, the Teacher DISC, the Quick DISC, the Voice DISC). CONCLUSIONS: The NIMH DISC is an acceptable, inexpensive, and convenient instrument for ascertaining a comprehensive range of child and adolescent diagnoses.

Child↗
PubMed1999

Weight control and risk factor reduction in obese subjects treated for 2 years with orlistat: a randomized controlled trial.

CONTEXT: Orlistat, a gastrointestinal lipase inhibitor that reduces dietary fat absorption by approximately 30%, may promote weight loss and reduce cardiovascular risk factors. OBJECTIVE: To test the hypothesis that orlistat combined with dietary intervention is more effective than placebo plus diet for weight loss and maintenance over 2 years. DESIGN: Randomized, double-blind, placebo-controlled study conducted from October 1992 to October 1995. SETTING AND PARTICIPANTS: Obese adults (body mass index [weight in kilograms divided by the square of height in meters], 30-43 kg/m2) evaluated at 18 US research centers. INTERVENTION: Subjects received placebo plus a controlled-energy diet during a 4-week lead-in. On study day 1, the diet was continued and subjects were randomized to receive placebo 3 times a day or orlistat, 120 mg 3 times a day, for 52 weeks. After 52 weeks, subjects began a weight-maintenance diet, and the placebo group (n = 133) continued to receive placebo and orlistat-treated subjects were rerandomized to receive placebo 3 times a day (n = 138), orlistat, 60 mg (n = 152) or 120 mg (n = 153) 3 times a day, for an additional 52 weeks. MAIN OUTCOME MEASURES: Body weight change and changes in blood pressure and serum lipid, glucose, and insulin levels. RESULTS: A total of 1187 subjects entered the protocol, and 892 were randomly assigned on day 1 to double-blind treatment. For intent-to-treat analysis, 223 placebo-treated subjects and 657 orlistat-treated subjects were evaluated. During the first year orlistat-treated subjects lost more weight (mean +/- SEM, 8.76+/-0.37 kg) than placebo-treated subjects (5.81+/-0.67 kg) (P<.001). Subjects treated with orlistat, 120 mg 3 times a day, during year 1 and year 2 regained less weight during year 2 (3.2+/-0.45 kg; 35.2% regain) than those who received orlistat, 60 mg (4.26+/-0.57 kg; 51.3% regain), or placebo (5.63+/-0.42 kg; 63.4% regain) in year 2 (P<.001). Treatment with orlistat, 120 mg 3 times a day, was associated with improvements in fasting low-density lipoprotein cholesterol and insulin levels. CONCLUSIONS: Two-year treatment with orlistat plus diet significantly promotes weight loss, lessens weight regain, and improves some obesity-related disease risk factors.

Adult↗
PubMed1999

Features of interviews questions associated with attenuation of symptom reports.

Previous studies have suggested that discrepant reporting in a test-retest reliability paradigm is not purely random measurement error, but partly a function of a systematic tendency to say "no" during retest to questions answered positively at initial testing ("attenuation"). To examine features of interview questions that may be associated with attenuation, three raters independently assessed the structural and content features of questions from the Diagnostic Interview Schedule for Children (version 2.3) and linked these to data from a test-retest reliability study of 223 community respondents (parent and child reports). Results indicated that for both parent and youth reports, item features most strongly associated with attenuation were (a) being a "stem" question (asked of all respondents, regardless of any skip structure); (b) question placement in the first half of the interview; (c) question length; (d) question complexity; or (e) requiring assessment of the timing, duration, or frequency of a symptom. Findings may be explained by participants' conscious efforts to avoid further questions or by their learning more about the nature and purpose of the interview as they gain more experience; alternatively, findings may represent a methodological artifact of structured interview design.

Adolescent↗
PubMed1998

A randomized placebo-controlled trial of repaglinide in the treatment of type 2 diabetes.

OBJECTIVE: The objective of the study was to assess the efficacy and safety of repaglinide compared with placebo in the treatment of patients with type 2 diabetes. RESEARCH DESIGN AND METHODS: This was a phase II multicenter, double-blind, placebo-controlled, randomized, dose-adjustment and maintenance trial. After screening and a 2-week washout period, 99 patients were randomized to receive either repaglinide (n = 66) or placebo (n = 33). Patients underwent 6 weeks of dose adjustment followed by 12 weeks of dose maintenance. Fasting and stimulated glycosylated hemoglobin (HbA1c), plasma glucose, insulin, and C-peptide were measured at predetermined intervals. Adverse events and hypoglycemic episodes were recorded. RESULTS: From baseline to last visit, mean HbA1c decreased from 8.5 to 7.8% in patients treated with repaglinide and increased from 8.1 to 9.3% in patients receiving placebo, with a statistically significant difference of - 1.7% (P < 0.0001) between treatment groups at the last visit. Mean fasting plasma glucose and postprandial glucose increased in patients receiving placebo and decreased in patients treated with repaglinide, with statistically significant (P < 0.01) differences between groups at the last visit. Concentrations of fasting and postprandial insulin and C-peptide were lower at the last visit compared with baseline for patients treated with placebo and higher for patients treated with repaglinide, and the differences between groups were statistically significant (P < 0.05). Overall, repaglinide was well tolerated. CONCLUSIONS: This study demonstrated that repaglinide was safe and efficacious in lowering blood glucose concentrations. In addition to overall improvement in glycemic control noted with repaglinide in both sulfonylurea-treated patients and oral hypoglycemic agent-naive patients, repaglinide had a potent glucose-lowering effect in the postprandial period.

Adult↗
PubMed1998

Role of orlistat in the treatment of obese patients with type 2 diabetes. A 1-year randomized double-blind study.

OBJECTIVE: Obesity is an important risk factor for type 2 diabetes. Weight loss in patients with type 2 diabetes is associated with improved glycemic control and reduced cardiovascular disease risk factors, but weight loss is notably difficult to achieve and sustain with caloric restriction and exercise. The purpose of this study was to assess the impact of treatment with orlistat, a pancreatic lipase inhibitor, on weight loss, glycemic control, and serum lipid levels in obese patients with type 2 diabetes on sulfonylurea medications. RESEARCH DESIGN AND METHODS: In a multicenter 57-week randomized double-blind placebo-controlled study, 120 mg orlistat or placebo was administered orally three times a day with a mildly hypocaloric diet to 391 obese men and women with type 2 diabetes who were aged > 18 years, had a BMI of 28-40 kg/m2, and were clinically stable on oral sulfonylureas. Changes in body weight, glycemic control, lipid levels, and drug tolerability were measured. RESULTS: After 1 year of treatment, the orlistat group lost 6.2 +/- 0.45% (mean +/- SEM) of initial body weight vs. 4.3 +/- 0.49% in the placebo group (P < 0.001). Twice as many patients receiving orlistat (49 vs. 23%) lost > or = 5% of initial body weight (P < 0.001). Orlistat treatment plus diet compared with placebo plus diet was associated with significant improvement in glycemic control, as reflected in decreases in HbA1c (P < 0.001) and fasting plasma glucose (P < 0.001) and in dosage reductions of oral sulfonylurea medication (P < 0.01). Orlistat therapy also resulted in significantly greater improvements than placebo in several lipid parameters, namely, greater reductions in total cholesterol, (P < 0.001), LDL cholesterol (P < 0.001), triglycerides (P < 0.05), apolipoprotein B (P < 0.001), and the LDL-to-HDL cholesterol ratio (P < 0.001). Mild to moderate and transient gastrointestinal events were reported with orlistat therapy, although their association with study withdrawal was low. Fat-soluble vitamin levels generally remained within the reference range, and vitamin supplementation was required in only a few patients. CONCLUSIONS: Orlistat is an effective treatment modality in obese patients with type 2 diabetes with respect to clinically meaningful weight loss and maintenance of weight loss, improved glycemic control, and improved lipid profile.

Adult↗
PubMed1998

What's in a case formulation? Development and use of a content coding manual.

A case formulation content coding method is described and applied to the formulation section of 56 intake evaluations randomly selected from an outpatient psychiatric clinic. The coding manual showed good reliability (mean kappa = 0.86) across content and quality categories. Although 95% of the formulations included descriptive information, only 37% addressed hypothesized predisposing life events accounting for the individual's presenting problems, and 16% included a precipitating stressor. Only 43% inferred a psychological mechanism, 2% inferred a biological mechanism, and 2% mentioned sociocultural factors. Formulations were more descriptive than inferential, more simple than complex, and moderately precise in use of language. In sum, clinicians used the formulation primarily to summarize descriptive information rather than to integrate it into a hypothesis about the causes, precipitants, and maintaining influences of an individual's problems.

Adult↗
PubMed1998

Evolution of artificial neural network architecture: prediction of depression after mania.

Artificial neural networks (ANNs) are compared to standard statistical methods for outcome prediction in biomedical problems. A general method for using genetic algorithms to "evolve" ANN architecture (EANN) is presented. Accuracy of logistic regression, a fully interconnected ANN, and an EANN for predicting depression after mania are examined. All methods showed very good agreement (training set accuracy, chi-square all p < 0.01). However, significant differences were found for stability (test set accuracy); logistic regression being the most unstable and EANN being significantly more stable than a fully interconnected ANN (McNemar p < 0.01). We conclude that the EANN method enhances ANN stability. This approach may have particular relevance for biomedical prediction problems, such as predicting depression after mania.

Algorithms↗
PubMed1997

Treatment for intracranial dural arteriovenous malformations: a meta-analysis from the English language literature.

OBJECTIVE: The treatment of intracranial dural arteriovenous malformations (DAVMs) remains problematic. Options include ligature of feeding vessels, endovascular procedures, surgical obliteration, or a combination of the latter two. We conducted a meta-analysis of the English language literature on DAVMs to determine the most effective treatment option related to location and angiographic characteristics. METHODS: The criteria for inclusion were pre- and post-treatment angiography, a description of the type of treatment, and clinical outcome. The analysis included a total of 258 patients, 248 from a review of 223 published articles and 10 from the authors' series. DAVMs were divided into six categories by location, and the results of treatment were compared based on obliteration rates using chi 2 analysis. RESULTS: In transverse-sigmoid sinus DAVMs (n = 64), combined therapy (endovascular plus surgical treatment) proved significantly more effective than either therapy alone (P < 0.01). For lesions of the tentorial incisura (n = 66), combined therapy and surgical obliteration alone proved superior to embolization (P < 0.001). For lesions of the cavernous sinus (n = 67), treatment was primarily endovascular, with success rates of 62 to 78% for transarterial and transvenous approaches, respectively. In the anterior fossa (n = 23), surgical obliteration was highly effective, with a success rate of 95%. The small number of cases in both the superior sagittal sinus (n = 28) and middle fossa (n = 10) regions, precluded any statistical analysis. Finally, simple ligature of feeding vessels produced success rates of only 0 to 8% and can no longer be recommended. CONCLUSION: There is no single ideal treatment for the obliteration of DAVMs. The management of each case is best considered individually. The results of this review serve as a rational starting point for the selection of treatment options.

Adolescent↗
PubMed1996

Sinus skeletonization: a treatment for dural arteriovenous malformations of the tentorial apex. Report of two cases.

Two cases of dural arteriovenous malformation of the tentorial apex are presented. Both were treated surgically by means of a sinus skeletonization technique. The operative technique included a combined bioccipital and median suboccipital craniotomy in which the posterior third of the superior sagittal and the straight and bilateral transverse sinuses were skeletonized by incising the falx and the tentorium along the sinuses. Endovascular embolization was used prior to the surgical approach in one case. Clinical and angiographic cure was achieved in both patients, with a follow up of 4 years in the first case and 1 year in the second one. The surgical technique is described in detail.

Combined Modality Therapy↗
PubMed1995

Physical activity as a predictor of weight maintenance in previously obese subjects.

We examined the association between exercise and weight loss maintenance in a group of 45 previously obese subjects 2 years post very-low-calorie diet (VLCD) to suggest exercise goals for this population. At baseline, subjects weighed a mean 100 kg and had a mean total cholesterol (TC) of 5.8 mmol/L. With VLCD they lost an average 28 kg and decreased their TC by 1.6 mmol/L. Two years post-VLCD their weight and lipids were measured and they completed a physical activity survey (Paffenbarger). Subjects were grouped into tertiles by reported exercise levels: low active (< 850 kcals per week), moderate active (850-1575 kcals per week) and high active (> 1575 kcals per week). Walking accounted for the greatest calorie expenditure (65%). Analysis of variance showed that baseline characteristics and weight and blood lipid changes during the VLCD did not differ (P > 0.05) among groups. At follow-up, high active patients maintained significantly greater weight loss, had a lower percent regain and a significantly greater decrease in total cholesterol (P < 0.05) than less active patients. Multiple regression analysis indicated that total exercise calories independently predicted overall weight loss and percent regain (r = 0.66 and r = 0.62, respectively). Exercise calories also predicted total cholesterol change (r = -0.37). The high active group walked more miles (16.2 per week) than the low and moderate active groups (4.8 and 9.1 per week, respectively) and exercised more days per week (5.3 vs. 1.9 and 3.7).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Comparison of cardiovascular risk factors in obese blacks and whites.

Blacks are known to have higher blood pressure levels, a higher prevalence of hypertension, and higher body weights than whites. However, the interrelationships of these and other cardiac risk factors have not been analyzed in an obese population. We compared blood pressure (BP) and lipid levels in 174 obese blacks and 939 obese white patients who were entering a weight loss program; we also assessed the effects of weight loss on these factors. Prevalence of treated hypertension was similar in blacks and whites (28% vs. 25%, respectively). In patients not taking BP medication, black women weighed more (108 kg) than white women (102 kg) and black and white males' weights were similar (135 kg vs. 131 kg). Systolic and diastolic BP were similar in black and white women; black males had similar SBP but a significantly lower DBP than white males (83 mmHg vs. 89 mmHg, respectively). Lipid levels were similar in black and white women except black women had lower triglycerides (1.30 mmol/L) than white women (1.58 mmol/L, p < 0.05); and black males compared to white males had significantly lower total cholesterol (4.76 mmol/L vs. 5.56 mmol/L), LDL-cholesterol (3.15 mmol/L vs. 3.52 mmol/L) and triglycerides (1.31 mmol/L vs. 2.17 mmol/L, p < 0.05). Adult-onset obesity adversely affected a number of cardiovascular risk factors in whites, but not in blacks. Blacks lost significantly less weight (-13 kg) than whites (-19 kg). However, controlling for the difference in weight loss, blacks sustained comparable improvement in lipids and blood pressure, except for TC/HDL-C (whites improved significantly more, -0.36 kg/m2, than blacks, 0.03 kg/m2). Thus, the impact of obesity on cardiovascular risk factors seems ameliorated in blacks compared to whites.

Adult↗
PubMed1992

The order effect: reflections on the validity of multiple test presentations.

The effect of order has been previously addressed in test-retest studies but its effect on the presentation of more than one test, in the same time, is often underestimated. This study has shown that when two rating scales were given sequentially, each scored lower if received second in the pair, and that this particular form of order effect (occasion effect) was enough to affect markedly agreement on caseness when utilizing standard cut-off scores. It is therefore important that research workers not only adopt design strategies such as counterbalanced presentation, but also analyse their data for the effects of test order and position within such designs.

Bias↗
PubMed1992

Long-term follow-up of patients attending a combination very-low calorie diet and behaviour therapy weight loss programme.

We examined the effects of treatment with a very-low calorie diet (VLCD) combined with behaviour modification on weight loss and long-term maintenance of weight loss in 118 of 199 patients who completed eight weeks of VLCD. Those who began therapy in 1984 were surveyed by telephone an average of 3.3 years after ending the VLCD. Questionnaire data included reported weight, exercise, eating, work and sleep habits, emotional factors, and current use of behavioural techniques taught in the programme. Results showed that mean maximum weight loss during the time they attended the programme (average 51.6 weeks) was 31.3 kg, corresponding to a decrease in body mass index of 10.7 kg/m2. At follow-up a regain of 60.9% was reported yielding a net overall weight loss of 13.6 kg and decrease in body mass index of 4.4 kg/m2. Seventy-five per cent of subjects showed only a 37.5% regain of the weight they had lost. Those whose weight loss was better maintained at the time of follow-up reported exercising more, eating fewer high fat foods, and using more of the behavioural techniques taught in the programme. This study provides support for the conclusion that some patients treated with VLCD and behaviour modification can maintain significant weight losses over a relatively long period of time and that specific behaviours relate to this success.

Adult↗
PubMed1991

Comparison of the effects of guanadrel sulfate and propranolol on blood pressure, functional capacity, serum lipoproteins and glucose in systemic hypertension.

In a controlled, double-blind, crossover study, the effects of guanadrel sulfate and propranolol on blood pressure (BP) and selected cardiopulmonary and metabolic variables were compared in 15 physically active and moderately hypertensive subjects. Guanadrel sulfate reduced systolic and diastolic BP at rest by -16 and -15 mm Hg, and at maximal exercise by -33 and -13 mm Hg, respectively (p less than 0.005), without affecting submaximal oxygen consumption (VO2), maximal VO2, ventilatory threshold, forced vital capacity, forced expiratory volume in 1 second, or fatigue, as assessed by perceived exertion. In contrast, propranolol significantly decreased diastolic BP at rest (-16 mm Hg) and systolic BP at maximal exercise (-44 mm Hg); however, it significantly decreased submaximal VO2 (-3.9 ml.kg-1.min-1), maximal VO2 (-3.9 ml.kg-1.min-1), ventilatory threshold (-0.3 liters.min-1), minute ventilation at submaximal exercise (-7.3 liters.min-1), forced expiratory volume in 1 second (-0.27 liters), and concomitantly increased the rating of perceived exertion at maximal exercise (1.9 U). Guanadrel sulfate was also associated with significant decreases in mean fasting plasma glucose and total serum cholesterol, whereas propranolol resulted in an increase in serum triglycerides (p less than 0.05). In contrast to propranolol, guanadrel sulfate appears to decrease BP without evoking negative metabolic consequences or impairing exercise tolerance.

Antihypertensive Agents↗