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Biomedical subjects

F A Kummerow

Publications and source records attributed to F A Kummerow.

At least 127 records · Page 7Linked to original sources
PubMed1979

Nutrition imbalance and angiotoxins as dietary risk factors in coronary heart disease.

Imbalancing nutritionally adequate diets with an excessive amount of fat calories and cholesterol has obscured the fact that intimal thickening occurs spontaneously in time on low-fat cholesterol-free diets during the aging process, and that intimal thickening can be accelerated by dietary angiotoxic "risk factors." Electron microscopy of arterial tissue from animal models identified degenerated smooth muscle cells in the fetus from sows kept on low-fat cholesterol-free diets. After birth, the degenerated smooth muscle cells increased in number with age. The presence of angiotoxic "risk factors" such as oxidized cholesterol and vitamin D3 (cholecalciferol) in the diet of such animal models increased the frequency of smooth muscle cell death in their arteries. Two types of pathology could be developed in the thoracic aorta by continuous or short term feeding of 12.5 times more vitamin D than normally present in commercial rations: 1) a diffuse fibroelastic intimal thickening in the thoracic aorta (arteriosclerosis) with no evidence of lipid deposition by continuous feeding of vitamin D or 2) an initimal thickening in the thoracic aorta and intimal thickening with foam cells and extracellular lipid deposits (atherosclerosis) in the coronary arteries after a short period of supplemental vitamin D followed by 3 to 4 months of supplement-free diets. These two types of arterial damage were identical to that in the plugs of thoracic aorta obtained as a by-product of elective coronary bypass surgery. Although all of the possible sources of oxidized cholesterol in the diet have as yet not been identified, laboratory studies have identified oxidized cholesterol as an angiotoxic factor. Since population groups that consume less vitamin D-supplemented foods, less deep fat fried cholesterol-containing foods, and less hydrogenated fats have a lower incidence of coronary heart disease than Americans, it seems judicious for food processors to reduce these previously unconsidered risk factors to a minimum. This could be done by eliminating vitamin D2 and D3 from all vitamin supplements, from all food and cereal products and from the diet of livestock 1 month before they were killed so that the intake of vitamin D is no larger than the 400 IU/quart in milk which is necessary to prevent rickets in children. Deep fat fryers, which are kept at almost 200 C for 24 hr/day, could perhaps be replaced with microwave ovens in fast food chain outlets. Processors could hydrogenate vegetable oils to a minimum trans fatty acid content and rearrange this fat with polyunsaturated fats to produce high polyunsaturated fats trans-free margarines and shortenings.

Aging↗
PubMed1979

Morphological alteration of aortic wall and mitotic cells after complete endothelial loss induced by repeated balloon denudation of swine aorta.

The aortic endothelium in weanling swine was rubbed ten times with an inflated balloon catheter in a repeated balloon denudation. This procedure produced more drastic, extensive and uniform changes in the aortic wall than the commonly used balloon denudation. Sequential alternations of regenerating endothelium, intimal thickening and medial reaction, and the incidence of mitotic cells were studied by scanning and transmission electron microscopy. Complete endothelial loss was confirmed from the descending thoracic aorta to the right femoral artery within 24 hr. By the third day, regenerated endothelium began to cover over the endothelial defect area from the uninjured areas such as the aortic arch and the orifices of branching arteries. Thrombus formation and fibromuscular intimal thickening were observed in the endothelial defect areas by the fifth and seventh days. Three types of mitotic cells, such as endothelial, intimal and medial cells were noted in the aortic wall. Mitotic endothelial and mitotic medial cells were most frequent at Day 3; the latter were closely associated with dead medial cells. Mitotic intimal cells initially appeared at Day 3 and were most frequent at Day 7. Mitotic intimal and mitotic medial cells were frequently present in the aortic wall subjacent to the endothelial defect areas containing interstitial blood components. The large numbers of mitotic aortic cells indicated that endothelial cells give rise to new endothelial cells, intimal cells to new intimal cells, and medial cells to new medial cells.

Animals↗
PubMed1979

Vitamin D-induced coronary atherosclerosis in normolipemic swine: comparison with human disease.

Coronary atherosclerosis developed in normolipemic swine fed a basal ration supplemented with 125,000 IU, 62,500 IU and 31,250 IU of vitamin D3/kg of diet for 3 months and subsequently only the basal ration for the following 3 months. Lesions consisted of intimal atheromata and calcified internal elastica and caused luminal narrowing. The incidence of atherosclerotic lesions was proportional to the vitamin D3 doses. The present experimentally induced lesions had many morphological features resembling those in coronary arteries from human subjects.

Adult↗
PubMed1979

Mast cells in human aorta.

Aortic specimens from 111 autopsy and 23 surgical cases were examined by light and electron microscopy. Differential mast cell counts were made of three aortic segments (ascending, thoracic, and abdominal) and layers (intimal, medial, adventitial). The mast cell counts varied considerably from case to case and sector to sector and generally showed no correlation with age, sex, or atherosclerotic severity. However, intimal mast cells were fewer in number in areas of lipid accumulation than in areas of diffuse intimal thickening without lipid accumulation. The reduction in the number of intimal mast cells may play a part in the localization of atherosclerosis.

Adolescent↗
PubMed1978

Mitotic structure of aortic intimal cells induced by mechanical injury in swine.

Repair processes of the aortic wall have been studied electron microscopically after removal of the endothelium by an inflated balloon procedure in the thoracic aortae of swine. Initial responses after injury included a thrombotic reaction, the appearance of intimal cells over the denuded surface, and increased mitotic activity of medial cells adjacent to the dead cells by day 3. Cells which engaged in intimal thickening were classified as modified smooth muscle cells throughout the course of this investigation. Mitosis of intimal cells, which was initially observed at day 3, substantially increased at day 7 and decreased by day 14. Mitotic intimal cells contained the same cytoplasmic organelles as interphase modified smooth muscle cells. A detailed description of the paired cisternae as an ultrastructural feature of cell division of modified smooth muscle cells was provided. The paired cisternae were initially observed among the remnants of the nuclear envelope in late prophase; they remained at the periphery of the mitotic apparatus in meta- and anaphase, and finally attached themselves to the nuclear envelope of the daughter cells in late telophase.

Animals↗
PubMed1978

Ultrastructure of cardiovascular lesions induced by hypervitaminosis D and its withdrawal.

Aortic, coronary and cardiac lesions were induced in swine by a hypervitaminosis D3 diet Lipid-free intimal plaques overlying focally calcified medial or internal elastica occured in the thoracic aorta, pulmonary trunk and coronary artery of swine fed a basal ration supplemented with 250,000 IU of vitamin D3/kg of diet for an induction period of 4 months. Cartilage formation with minimal calcification was initiated in the aortic valve during this period. When such animals were subsequently fed only the basal ration free of excessive vitamin D3 for 3 months, intimal plaques regressed in the aorta and pulmonary trunk but progressed in the coronary artery. The calcific deposits in the medial elastica and internal elastica of all three arteries decreased in size. Atherosclerotic intimal thickening occurred in the main coronary arteries. The most severe lesion occupied 75 p.100 of the lumen area. Multiple intimal plaques were noted in the left atrium and aortic and mitral valves. The thickened intima at these coronary and cardiac sites contained calcified elastica and collagen fibers.

Animals↗
PubMed1977

An ultrastructural study of the Brunner's cyst.

A Brunner's cyst, removed from a 54-year-old woman, was studied by light and electron microscopy. The cyst was spherical, measured 1.5 cm in diameter and was located in the duodenal bulb. Histologically, the cyst, confined in the submucosa, consisted of a single layer of epithelial cells and connective tissue. The epithelial cells were composed of an orderly array of tall columnar cells containing basal round nuclei and fine granular cytoplasm. Ultrastructurally, the epithelial cells contained many secretory granules in the cytoplasm. Each secretory granule was membrane-bound and appeared electron-lucid with a dense core. They were small and sparse around the Golgi apparatus but large and numerous in the apical region. Multinucleated cells were intermingled with cells of the epithelial lining.

Brunner Glands↗
PubMed1977

The influence of egg consumption on the serum cholesterol level in human subjects.

The influence of whole fresh eggs on the serum cholesterol level in men and women was studied independently in hospitalized patients in Sofia, Prague and Urbana-Champaign. The patients were fed two eggs or the equivalent of two eggs in a custard base or milk shake in addition to the foods that were consumed in their diet pattern. The serum cholesterol level was determined before and at periods varying from 5 hr to 54 days after the consumption of the eggs. The mixed fatty acid composition of the total lipids in the serum and the erythrocytes was also determined. In the majority of patients, the serum cholesterol level did not change significantly 5 hr after the consumption of 465 mg of cholesterol in an egg custard base or milk shake or after up to 54 days of continued consumption of two whole eggs per day. The serum cholesterol level of some subjects increased and others decreased at all three experimental sites. A comparison of the mixed fatty acid composition of the total serum lipids obtained from men and women who had received treatment for other reasons than cardiovascular disease with those that had been treated for cardiovascular disease indicated that the serum from both groups contained a substantial amount of polyunsaturated fatty acids. The lipids extracted from the red blood cells obtained from patients in Urbana-Champaign and Sofia did not differ significantly in linoleic and arachidonic acid content.

Adult↗
PubMed1977

Influence of dietary trans-fatty acids on swine lipoprotein composition and structure.

Four groups of 20 weanling swine each were fed either (a) basal diet, (b) basal plus hydrogenated fat (13% trans), (c) basal plus hydrogenated fat (13% trans) and 0.4% cholesterol, or (d) basal plus beef tallow (all cis). After six months of feeding, the animals were killed and the blood and aortas were removed. Very low density, low density, and high density lipoproteins were then isolated from the plasma by ultracentrifugal flotation. Although the fatty acid composition of the basal diet was different from the diets supplemented with either hydrogenated fat containing trans-fatty acid or beef tallow containing all cis, the lipid and fatty acid compositions of each of the isolated lipoprotein classes for the four groups of animals were remarkably similar. Elaidate was clearly incorporated into the lipoproteins of animals fed hydrogenated fat, but the level of incorporation was generally less than 5%. In a direct comparison of the structure of the lipoproteins from the different groups, we did not find any significant differences in their physical properties as determined by pyrene fluorescence and electron paramagnetic resonance methods. Grossly visible fatty streaks and fibrous plaques were not found in any of the swine aorta. However, light and electron microscopy indicated the presence of atherosclerotic lesions in the distal abdominal aorta and bifurcation. These studies demonstrate that a diet containing a substantial amount of trans-fatty acid leads to a small but definite incorporation into the swine lipoproteins. However, such changes had relatively little effect on lipoprotein structure or the presence of atherosclerotic lesions in these 6-month-old swine.

Animals↗
PubMed1977

Degeneration of aortic smooth muscle cells in swine fed excess vitamin D3.

Twenty-eight weanling swine were divided into two groups and fed a basal ration of corn and soybean meal or one containing a high fat and cholesterol supplement. One subgroup of each received 220,000 IU of vitamin D3 per kilogram. Grossly normal areas of the distal abdominal aorta were used for quantitative comparison of degenerated smooth muscle cells by electron microscopical cell counts. Degeneration was classified into rarefaction, condensation, and frequency per 100 nucleated cells. The frequency of dead cells was demonstrable between the swine fed excess vitamin D3 with or without high fat and cholesterol and those fed the basal ration alone, or frequencies of 7.9, 7.4, and 5.6 at 3 months of age (P less than .05) and 7.3, 6.2, and 5.1 at 6 months (P less than .05), respectively. No significant difference was demonstrable between the swine fed high fat and cholesterol without excess vitamin D3 and those fed the basal ration alone, or frequencies of 5.7 and 5.6 at 3 months of age and 5.5 and 5.1 at 6 months.

Animals↗
PubMed1977

Aortic intimal changes in aging swine.

Aortic intimal lesions in aging swine contained smooth muscle, monocyte-like and unclassifiable cells. The most frequent cellular constituent was the smooth muscle cell that had slightly different features than those in the media. Monocyte-like and unclassified cells appeared largely in the innermost layer of the intima; both types of cells were ultrastructurally similar in appearance except the former had heterophagic vacuoles and overall resemblance to circulating monocytes in shape and size. These cells seemed to preexist in aortic lesions of untreated, aging swine. The intima-media strips of the grossly normal thoracic aortas in 3 1/2 year old swine showed significantly higher contents of cholesterol, triglycerides, phospholipids and total lipids than those of a 6 month old swine. Three to four month old cultured aortic cells accumulated extracellular components, such as fibriles, electron dense substances and cellular debris, which appeared similar to the extracellular matrix of aortic plaques in aged swine.

Aging↗
PubMed1976

Major lipid classes in plasma membrane isolated from liver of rats fed a hepatocarcinogen.

More phosphatidylethanolamine and less phosphatidylinositol were present in the lipid of plasma membrane isolated from the liver of rats fed a diet containing the hepatocarcinogen, N-2-fluorenylacetamide than were present in the lipid of plasma membrane isolated from the liver of rats fed the basal diet. Phosphatidylcholine, phosphatidylethanolamine, and sphingomyelin from the former membranes had relative amounts of 18 : 1 in their fatty acyl profiles that were 1.5--1.7 times the relative amount of 18 : 1 in the same phospholipid from the latter membranes. Furthermore, the former membranes contained 1.3 times more cholesterol and 1.35 times more sphingomyelin than the latter membrames.

2-Acetylaminofluorene↗