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Biomedical subjects

J D Barth

Publications and source records attributed to J D Barth.

28 records · Page 2Linked to original sources

Progression and regression of human coronary atherosclerosis. The role of lipoproteins, lipases and thyroid hormones in coronary lesion growth.

Relations between lipoprotein fractions, lipoprotein lipase activities, thyroid hormones and coronary lesion growth were studied among 35 male patients with severe coronary atherosclerosis, who had participated in the lipid lowering, dietary Leiden Intervention Trial. Coronary arteriographies were performed at the beginning of the study and 2 years later at termination. The coronary anatomy was quantitated with a computer-based analysis system to assess the progression rate of coronary atherosclerosis on the basis of the absolute arterial dimensions in a patient's coronary tree; for these purposes an absolute coronary score was computed. On the basis of the absolute coronary scores, the entire group of patients could be divided into a no lesion growth group (14 patients) and a progression group (21 patients). Lipoprotein fractions, lipoprotein lipases and thyroid hormones were determined at the end of the trial. No significant difference was found between the no lesion growth and progression groups of patients for total cholesterol (TC) and LDL-cholesterol (LDL-C). The VLDL-cholesterol (VLDL-C) and triglycerides (TG) were significantly higher (P less than 0.05) and HDL-C was almost significantly lower (P less than 0.10) in the progression group. Hepatic lipase (HL) values were significantly higher in the no lesion growth group, as compared to the progression group, whereas lipoprotein lipase (LPL) values were not significantly different. Triiodothyronine (T3) was significantly lower (P less than 0.01) in the progression group. Multivariate regression analysis showed HL to be the most important determinant of changes in coronary atherosclerotic lesions. T3 and HDL were also independently inversely related to coronary atherosclerotic lesion growth.(ABSTRACT TRUNCATED AT 250 WORDS)

Angiocardiography↗

Long-term effects of a linoleic acid-enriched diet, changes in body weight and alcohol consumption on serum total and HDL-cholesterol.

Investigations on diet, body weight, and lipoproteins were carried out in 28 patients with stable angina pectoris. They consumed a linoleic acid-enriched diet (P/S ratio = 2) for a period of 2 years. The total fat content remained constant before and during intervention, contributing 34% to energy intake. During intervention serum total cholesterol and the total/HDL cholesterol ratio decreased significantly, but HDL cholesterol did not change. Changes in body weight were significantly inversely related to changes in HDL cholesterol and positively to the total/HDL cholesterol ratio. Changes in alcohol intake were significantly positively related to both total and HDL cholesterol but unrelated to the total/HDL cholesterol ratio. From the results of this long-term study it can be concluded that a moderate fat diet with a P/S ratio of 2 can lower total cholesterol effectively without affecting HDL cholesterol.

Adult↗

Diet and the role of lipoproteins, lipases, and thyroid hormones in coronary lesion growth.

Relationships between lipoprotein fractions, lipoprotein lipase activities, thyroid hormones, and coronary lesion growth were studied among 35 male patients with severe coronary atherosclerosis, who had participated in the Leiden Intervention Trial, a lipid-lowering dietary intervention program. Coronary arteriography was performed at the beginning of the study and again 2 years later at its termination. The lesions were quantified using a computer-based analysis system to assess the progression rate of coronary lesions based on absolute arterial dimensions in a patient's coronary tree. For this reason an absolute coronary score was computed. Based on absolute coronary scores, patients could be divided into a no-lesion growth group (14 patients) and a progression group (21 patients). Lipoprotein fractions, lipoprotein lipases, and thyroid hormones were determined at the end of the trial. No significant differences were found between the no-lesion growth and progression groups for total cholesterol and low-density lipoprotein (LDL) cholesterol. In the progression group very-low-density lipoprotein (VLDL) cholesterol and triglycerides were significantly higher (p less than 0.05) and high-density lipoprotein (HDL) cholesterol was almost significantly lower (p = 0.058). Hepatic lipase (HL) values were significantly higher in the no-lesion growth group, when compared with the progression group, whereas lipoprotein lipase (LPL) values were not significantly different. Triiodothyronine (T3) was significantly lower (p less than 0.01) in the progression group. Multivariate regression analysis showed HL to be the most important determinant of changes in coronary atherosclerotic lesions. T3 and HDL cholesterol were also independently inversely related to coronary lesion growth.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Diet, lipoproteins, and the progression of coronary atherosclerosis. The Leiden Intervention Trial.

We studied the relation between diet, serum lipoproteins, and the progression of coronary lesions in 39 patients with stable angina pectoris in whom coronary arteriography had shown at least one vessel with 50 per cent obstruction before intervention. Intervention consisted of a two-year vegetarian diet that had a ratio of polyunsaturated to saturated fatty acids of at least 2 and that contained less than 100 mg of cholesterol per day. Dietary changes were associated with a significant increase in linoleic acid content of cholesteryl esters and a significant lowering of body weight, systolic blood pressure, serum total cholesterol, and the ratio of total to high-density lipoprotein (total/HDL) cholesterol. Angiographic examination was performed after 24 months; angiograms were assessed visually (with blinding) and by computer-assisted image analysis. Both types of assessment indicated progression of disease in 21 of 39 patients but no lesion growth in 18. Coronary lesion growth correlated with total/HDL cholesterol (r = 0.50, P = 0.001) but not with blood pressure, smoking status, alcohol intake, weight, or drug treatment. Disease progression was significant in patients who had values for total/HDL cholesterol that were higher than the median (greater than 6.9) throughout the trial period. No coronary-lesion growth was observed in patients who had lower values for total/HDL cholesterol (less than 6.9) throughout the trial or who initially had higher values (greater than 6.9) that were significantly lowered by dietary intervention.

Adult↗

Post-heparin lipases, lipids and related hormones in men undergoing coronary arteriography to assess atherosclerosis.

Post-heparin lipase activities were measured in normolipemic men with complaints suggestive of symptomatic coronary artery disease. A study group, who showed diffuse atherosclerotic narrowing of the coronary vessels, assessed by a quantitative computer-assisted analysis method, had a lowered hepatic lipase in comparison with a group with normal angiograms. Lipoprotein lipase was lower in the study group but well within the normal range and not statistically different. Some related hormones (cortisol, estradiol, testosterone and glucagon) were different in the two groups while others (insulin, human growth hormone, prolactin, thyroid hormones) were not. The results are discussed in view of the proposed role of hepatic lipase in the uptake of HDL-cholesterol by the liver.

Adult↗

Reproducibility of mean transit time for maximal myocardial flow assessment by videodensitometry.

In the assessment of myocardial perfusion by ECG-triggered digital radiography, time parameters are calculated from the time density curve (TDC) and related to blood flow. Recently we developed a method which uses mean transit time (Tmn) as time parameter, and which is in accordance with the original principles of indicator dilution theory. In this approach, variability in vascular volume is excluded and Tmn-1, determined at maximal hyperemia, showed an excellent correlation with maximal flow in animal validation studies. For calculation of Tmn, however, a large part of the descending limb of the TDC has to be known for reliable extrapolation, and especially this part of the curve is subject to variability in image quality in man. Therefore we tested reproducibility of Tmn in 30 arteries in 20 patients. Tmn was derived from the TDCs, obtained from paired studies under identical circumstances with an interval of 10 minutes. Satisfactory images could be obtained in all but one patient. Image processing was performed in an identical way in the paired studies. Reproducibility proved to be excellent for all three coronary arteries. The absolute value of the relative differences between the first and second determination was 7 +/- 7% for the LAD, 6 +/- 3% for LCx and 4 +/- 2% for the RCA (mean +/- SD). Correlation coefficients between both measurements were 0.97, 0.95 and 0.95 for the respective arteries. Therefore, it is concluded that, using this approach, Tmn at maximal hyperemia can be determined reproducibly in man and used for maximal myocardial flow assessment.

Absorptiometry, Photon↗

Quantitative ultrasound pulsation study in human carotid artery disease.

Pulsation in the human carotid artery during two complete cardiac cycles was studied by using computer digitized video-frames from B-mode ultrasound images. Eight patients with identifiable atherosclerotic lesions in the common carotid immediately proximal to the bulb area were studied. Diameter, strain, and elastic modulus were compared between lesion site and an adjacent reference segment 1 or 2 cm proximal to the bulb. As controls, nine patients without identifiable lesions were analyzed. The results indicate a significantly wider diameter (p less than 0.01) at the proximal reference site in patients with lesions as compared to comparable segments in control patients. The strain was significantly lower (p less than 0.05), whereas the elastic modulus was significantly higher (p less than 0.05), at the lesion site as compared to the proximal reference sites in patients with lesions. These results may indicate that an initial dilation of the carotid artery followed by loss of wall flexibility may be associated with atherosclerotic lesion formation.

Blood Flow Velocity↗