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Biomedical subjects

W Insull

Publications and source records attributed to W Insull.

At least 73 records · Page 4Linked to original sources

Development of standardized simulated patients for quality control of the clinical interview.

The evaluation and training of clinical trial staff who counsel patients in lifestyle changes for disease prevention is aided by a review of videorecorded interviews conducted with a simulated patient. This report describes the Inventory of Simulated Patient Characteristics, a listing of 34 generic parameters for developing a simulated patient for use in staff training and evaluation in counseling. The Inventory creates a complete person in all critical aspects of counseling for lifestyle change (e.g., daily routines, family, job). The Inventory was used in the Lipid Research Clinics' Coronary Primary Prevention Trial (CPPT) to examine the trial staff's skills in counseling for regimen adherence. In 1979 and 1980, 85 and 52 clinic staff, respectively, conducted a total of 548 interviews with four different simulated patients developed using the Inventory, and rated the portrayals as highly realistic. The Inventory also was used to verify that the simulated patient portrayals were greater than 90% faithful to their characterizations. While simulated patients limited to specific clinical syndromes have been used widely in medical education, no guidelines exist for their use in training trial staff in regimen counseling. The Inventory provides a simple template for creating simulated patients with broad characterizations that closely mimic actual trial participants.

Clinical Trials as Topic↗

Assessing methods for measuring compliance with a fat-controlled diet.

This study assessed the relative validity of the following non-laboratory measures of compliance with a fat-controlled diet by hypercholesterolemic males: quantitative and qualitative measures of compliance derived from three-day food records and structured interviews, and summary ratings by nutritionists and interviewers. The quantitative measures of consumption referred to: saturated fat, linoleic acid, polyunsaturated fat, P/S ratio and cholesterol. The non-laboratory measures were assessed using the following two laboratory measures as criteria of validity: serum cholesterol concentration and the proportion of linoleic acid among the fatty acids of the serum cholesteryl esters. The results showed that, with respect to quantitative measures, the food record and interview manifested approximately equal validity, with the former marginally more valid. However, under certain conditions qualitative measures, such as patients' self-ratings, were about as valid as the more rigorous and expensive quantitative measures. Characteristics of the patient influenced the validity of the various measures. Validity was enhanced by the simultaneous use of certain combinations of measures.

Adult↗

Occupational screenings: recruitment from private industry.

Occupational screening involving private sector employees represents a source with relatively high volumes of initial contacts and entries, a low ratio of entries to initial contacts, and a relatively high effort level requirement for the recruitment team. In the CPPT, all centers used this strategy, to provide, overall, 26% of initial contacts, 20% of first protocol visits and 17% of entries. Occupational screening is costly and involves careful planning and implementation of complex arrangements. Procedures for contacting industries and conducting screenings are described. Screening yield was inversely related to company size.

Adult↗

Evaluation and training of medication adherence counselors in a clinical trial: application of a skill inventory to video-recorded interviews.

This report describes the procedures and feasibility of an integrated evaluation and training program developed at the Baylor-Methodist Lipid Research Clinic to examine the skills used by the clinic's professional staff in conducting medication adherence interviews with participants in the Coronary Primary Prevention Trial (CPPT). The specific aims of this project were to evaluate the staff's interviewing and counseling skills, identify strengths and deficits, provide needed training, and reexamine the staff's skills following this training. Each of five staff members conducted two 20-minute video-recorded interviews with two different simulated CPPT participants. A trained observer reviewed the video-recordings and evaluated, by an Inventory for Interviewing and Counseling Skills for Adherence to Medication (IICS-AM), each staff member's possession and frequency of use of 17 interviewing skills and 10 counseling skills. The 27 skills on the IICS-AM were selected from the literature as being most frequently recommended for effective interviewing and counseling for medication adherence. These rating data were used to design a 14-week training program to acquire and promote the use of these skills. Following training, the video-recorded interview procedure was repeated and the data analyzed to identify the effects of the training program. The integrated evaluation and training procedures used in this project offer a practical, objective method for examining, improving, and monitoring the skills of the adherence counseling staff in a clinic participating in a multicenter clinical trial.

Audiovisual Aids↗

Cholesteryl ester-rich lipid inclusions from human aortic fatty streak and fibrous lesions of atherosclerosis. II. Physical properties of swelling, resiliency and lyotropy as liquid crystal.

The physical properties of the lipids accumulating as spherical inclusions in human atherosclerotic lesions were explored both in vivo and in vitro conditions. They were mostly anisotropic within the cytoplasma of cells and in an average diameter of 1.96 mu. When suspended in hydrophilic media, say of physiological saline solution, in 4 hours they swelled 2.4 times in volume and changed into isotropic form. They were resilient and deformable in three dimensional configuration, and lyotropic in polar media. When dried they underwent a phase shifting from liquid crystal to true solid crystal. These physical properties of lipid inclusions gained in a new significance for their role in metabolic deterioration of intima cells, rupture and necrosis of foam cells, and destruction of the intimal and medial architectures, which set on mesenchymal reactions leading eventually to thickening and hardening of the arteries.

Adult↗

Plasma high-density lipoprotein cholesterol in children and young adults. The Lipid Research Clinics Program Prevalence Study.

We examined the decline in high-density lipoprotein cholesterol in adolescent males and the postadolescent sex differences in HDL cholesterol levels. Prevalence data are presented for 1639 white males and females ages 6-25 years from six populations of the Lipid Research Clinics Program. The association of HDL cholesterol with age, smoking habits, and anthropometric, clinical chemistry and nutritional variables was examined by correlation and regression analyses. Although mean HDL cholesterol levels in children ages 6-10 years were lower in females than in males, HDL cholesterol levels gradually increased with age in females, while in males the mean HDL cholesterol levels declined form 55.9 mg/dl at ages 6-10 years to 45.5 mg/dl at ages 18-25 years. In young adults, HDL cholesterol levels were an average of 10.5 mg/dl higher in females than in males. In the 6-10-year-old age group, none of the study variables was significantly associated with HDL cholesterol. In the 11-17-year-old subjects, significant associations were noted with several variables, especially in the males. The strongest association was an inverse association with weight in males. In the young adults ages 18-25 years, significant inverse associations were found with weight and alkaline phosphatase in both sexes and with sucrose and smoking in females. The data suggested that the most important influence on HDL cholesterol levels in adolescent males are changes in gonadal hormone levels and that some of the factors known to influence HDL cholesterol levels in older adults are already associated with HDL cholesterol in adolescents and young adults.

Adolescent↗

A video-recording system for evaluating the clinical interview--a simple, inexpensive method.

A simple, inexpensive video-recording system was designed to provide raw data for the evaluation of therapist interview behaviors in the out-patient clinic. The system uses a combination of commercially available cameras, lenses, and recording equipment which do not require technical audio-video expertise to operate. Video-cassette recordings are produced that contain full-face, head-and-shoulders images of both the therapist and the patient. An automatic search control terminal rapidly locates any point on the video-cassette for review. Using normal clinic lighting and little space, the system is easily installed in any existing clinic examination room. A description of the system's use in examining the counseling and interviewing skills of a medical clinic staff is presented.

Clinical Competence↗

Role of endothelium and hypercholesterolemia in intimal thickening and lipid accumulation.

In experiments reported here we tested the hypothesis that persistent absence of endothelium favors intimal thickening, lipid accumulation, and atherosclerosis. Rabbit aortas were de-endothelialized with a balloon catheter at Day 0. Initially, all rabbits were fed a diet low in lipid. Some rabbits (Group I) were continued on a diet low in lipid for 8 to 20 weeks after de-endothelialization. Beginning 4 to 9 weeks after de-endothelialization, other rabbits were fed semisynthetic lipid-rich diets (Group II) or cholesterol-supplemented diets (Groups III) for 4 to 20 weeks. Lipid accumulation in all groups was significantly greater in the re-endothelialized intima than in adjacent intima lacking an endothelial lining. In aortas of Groups I, II, and III the degree of intimal thickening was significantly greater in re-endothelialized areas than in adjacent areas lacking endothelium. Intimal thickness was enhanced in re-endothelialized areas of hypercholesterolemic rabbits of Group III compared with normocholesterolemic rabbits of Group I but not in areas lacking endothelium. Thus, results of these experiments do not support the hypothesis that the absence of endothelium particularly favors intimal thickening and intimal lipid accumulation. Results indicate that intima covered by regenerated endothelium is significantly thicker and more likely to accumulate lipid.

Animals↗

Failure of regression of atherosclerosis in dogs with moderate cholesterolemia.

Controversy exists as to whether regression occurs in atherosclerotic plaques in response to serum cholesterol reduction. In the present study, using sequential observation of canine atherosclerosis, we attempted regression in hypothyroid dogs. Animals with established lesions prior to a regression attempt were placed on a 0.05% cholesterol diet and observed up to 60 months. Weighted average cholesterols ranged from 235 to 587 mg/100 ml during the regression attempt. A control fed for the entire period of the experiment, 75 months, had an average weighted cholesterol of 435 mg/100 ml. We failed to obtain regression of atherosclerotic plaques in spite of reduction of serum cholesterol from high to moderate levels. The lesions in the experimental animals contained less lipid and more collagen and calcium than occurred in the control. Complicated plaques with aneurysm formation, stenosis of the distal aorta, and gangrene of the tail were also noted.

Animals↗

Effect of regenerated endothelium on lipid accumulation in the arterial wall.

We tested the hypothesis that loss of endothelium results in increased transport of lipoprotein into the arterial wall, favors accumulation of lipid, and thus predisposes to atherosclerosis. In rabbits initially fed a diet low in lipid, the aortas were de-endothlialized with an intraarterial balloon catheter; 28 days later, the animals were divided into two groups. Group I animals were continued on a diet low in lipid and sacrificed at 8, 11, 13, and 15 weeks after de-endothelialization. Group II animals were fed the same diet supplemented with 0.5% cholesterol and sacrificed at comparable intervals. Aortas of group I animals revealed proliferative fibromuscular intimal thickening in both de-endothelialized and re-endothelialized areas, with little or no fatty change in the intima. In contrast, aortas of group II animals revealed slight to marked fatty change in the intima, characterized by accumulation of oil red O-positive material with anisotropic lipid inclusions. The greatest quantity of lipid was present in intimal thickening beneath regenerated endothelium, and not in adjacent intimal thickening lacking an endothelial lining. These results do not support the hypothesis that the absence of endothelium favors accumulation of lipid and predisposes to atherosclerosis. The experiments indicate that lipid accumulates preferentially in areas of intimal thickening covered by regenerated endothelium.

Animals↗