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Biomedical subjects

L J Cook

Publications and source records attributed to L J Cook.

At least 37 records · Page 2Linked to original sources
PubMed1983

Assessment of transportability of a perinatal education program.

We evaluated a perinatal outreach education program to determine its "transportability" (usefulness to other regional centers). Three kinds of data were available from seven regional centers: (1) participation in the program by health care providers, (2) changes in cognitive knowledge, and (3) changes in neonatal care practices. Data were obtained from 2,735 program participants and from retrospective chart review of 2,781 at-risk babies born in participating hospitals. Analysis showed that results were comparable when the program was used by six regional centers from two states and when it was used by the regional center that originally developed the program. We therefore concluded that the Perinatal Continuing Education Program is transportable.

Education, Continuing↗
PubMed1983

Lack of effect of cimetidine in chronic-idiopathic urticaria.

The effect of an H1 and an H2 receptor blocker singly and in combination was studied in 20 patients with chronic idiopathic urticaria. Both H1 receptor blockade alone and in combination with H2 receptor blockade produced a significant reduction in wealing and itch; there was no significant difference between these treatments. H2 blockade alone produced no significant reduction in wealing; there was a slight increase in itch, though not statistically significant.

Adolescent↗
PubMed1982

Iatrogenic hyperadrenocorticism during topical steroid therapy: assessment of systemic effects by metabolic criteria.

Systemic absorption of topically applied glucocorticoids in quantities sufficient to replace endogenous production is not uncommon. However, iatrogenic Cushing's syndrome resulting from the use of topical corticosteroids is very rare. Thus the possibility that systemic absorption may cause hyperglucocorticism has been deemphasized and examined only sporadically. We have studied changes in carbohydrate metabolism induced by topical glucocorticoids in a psoriatic patient who had developed Cushing's syndrome from topical desoximetasone (Topicort). The results indicated that (1) fasting hyperglycemia and increased insulin-glucose ratios could be induced within 24 hours of administration of topical glucocorticoids, (2) insulin resistance accompanied abnormal carbohydrate tolerance, and (3) fluctuations in circulating leukocytes paralleled the changes in carbohydrate metabolism. The findings suggest that metabolic indexes of glucocorticoid action action may provide useful parameters for assessing systemic absorption of topical glucocorticoids. glucose relationship as one such index to assess the risk of treatment of extensive chronic skin disease with potent topical glucocorticoids.

Administration, Topical↗
PubMed1980

Effect of feeding protected lipids on fatty acid synthesis in ovine tissues.

The effects of including protected lipid supplements in the sheep diet have been studied by measuring the incorporation of [1-14C]acetate into tissue fatty acids in vivo and in vitro. Supplementing the diet with protected lipid significantly (P > 0.05) depressed lipogenesis in adipose tissue both in vovo and in vitro. However, when protected lipids of different fatty acid composition were given to lambs, the protected safflower oil supplement containing high levels of linoleic acid was the only treatment to cause a significant (P > 0.05) depression in fatty acid synthesis in adipose tissue, the major site of lipogenesis in the sheep. Larger adipose cells in the lipid-supplemented sheep indicate that these sheep were fatter than those receiving the basal diet. Therefore, supplemented wethers deposited more fat than sheep receiving the basal diet and this fat was derived from the supplement rather than from de novo synthesis.

Acetates↗
PubMed1979

Lesions induced by trauma in pemphigoid.

Three patients are described with pemphigoid (two with typical adult type and one with juvenile pemphigoid) in whom bullous lesions had clearly been induced by the trauma of scratching. In two patients this phenomenon occurred during the first few weeks of systemic corticosteroid treatment at a time when other lesions were resolving or had completely healed. Although lesions induced by trauma are not usually of great clinical importance, epidermolysis bullosa acquisita may represent a variant of pemphigoid in which trauma-induced lesions predominate. Induction of pemphigoid lesions by trauma may prove a useful method of studying early immunopathological events.

Aged↗
PubMed1978

Effect of feeding protected cholesterol on ruminant milk fat secretion.

Feeding 1-2 g/day of cholesterol protected against ruminal hydrogenation caused a 20-30% drop in the secretion of milk fat by goats and cows. The effect was observed with goats fed conventional rations or with goats and cows fed rations supplemented with protected lipids, but was not observed with cows fed conventional rations, or when unprotected cholesterol and protected beta-sitosterol was fed to these animals. The results suggest that this depression in milk fat is due to a decreased uptake of plasma triacylglycerol fatty acids by the mammary gland, induced by dietary cholesterol.

Animals↗
PubMed1978

Ruminal hydrogenation of cholesterol.

Cholesterol was hydrogenated by anaerobic incubation with sheep rumen fluid for periods up to 20 hr. The principal product of cholesterol hydrogenation was identified as coprostanol. Cholesterol could be protected against in vitro ruminal hydrogenation by encapsulation in a matrix of formaldehyde-treated casein. Formaldehyde-treated casein-cholesterol preparations were also shown to be protected against hydrogenation in vivo and, when supplements containing 1 g per day of protected or unprotected cholesterol were fed to sheep over a period of 8-9 weeks, there were marked differences in the plasma cholesterol response. The plasma cholesterol of the sheep fed protected cholesterol increased by at least 60%. The plasma cholesterol of the sheep fed unprotected cholesterol also tended to increase during the first 5 weeks of supplementation but thereafter declined to almost control levels at 8 weeks.

Animals↗
PubMed1978

The effect of dietary fat supplements on cholesterol metabolism in ruminants.

The serum cholesterol on ruminant animals rises when supplemental fat is fed in a form that ensures the absorption of long-chain fatty acids. The effects of these fat supplements on cholesterol metabolism have been studied in sheep and goats. The proximal part of the small intestine was the major site of sterol synthesis in sheep. Supplementing the diet with fat significantly enhanced sterolgenesis in the small intestine both in vivo and in vitro, whereas in vitro sterolgenesis appeared to be suppressed in the liver. Increased intestinal sterolgenesis was seen with several varieties of fat, but was greatest when palm oil was fed. The reciprocal findings in the intestine and liver may reflect the increased requirement for cholesterol for the transport of triglyceride in chylomicrons and the secondary inhibiting effect of this cholesterol on sterol synthesis in the liver. Dietary fat supplementation did not alter the excretion of neutral steroids in the feces of goats but did not cause a marked reduction in the excretion of acidic steroids which may have been due to the decreased formation of sterols in the liver. In two lactating goats in which an injection of [14C] cholesterol was followed by daily intraruminal administration of labeled cholesterol, fat supplementation lowered the specific radioactivity of cholesterol in alimentary particles and in milk, being consistent with an increase in intestinally synthesized cholesterol. The hypercholesterolemia that develops in fat-fed ruminants appears to be primarily due to an increased intestinal biosynthesis of cholesterol but may also be partly due to a decreased fecal excretion of bile acids.

Acetates↗
PubMed1976

Effect of dietary fat supplementation on the composition and positional distribution of fatty acids in ruminant and porcine glycerides.

Dietary fats which were protected from ruminal metabolism were fed to ruminants, and the constituent fatty acids subsequently appeared in the glycerides of tissues and secretory products. These dietary fat induced alterations in tissue lipid composition were particularly apparent when the fat source was enriched with linoleic acid. Similarly, when pigs were fed linoleic-enriched fats, the linoleic acid was incorporated into the adipose tissue triglycerides. Stereospecific analyses were carried out on triglycerides from various tissues and secretory products obtained from animals fed control or linoleate-enriched diets. The analysis of adipose tissue triglycerides showed that linoleate and oleate were preferentially esterified to positions 2 and 3 (cattle and sheep), and positions 1 and 3 (pigs). Of the other major adipose tissue fatty acids, palmitate was preferentially esterified at position 1 (ruminants) and position 2 (pigs), and stearate was preferentially esterified at positions 1 and 3 (ruminants), and position 1 (pigs). Stereospecific analysis of high mol wt milk triglycerides showed that linoleate was either evenly distributed on all three positions (goats), or predominantly on position 3 (cows). Furthermore, the incorporation of this linoleate did not markedly alter the positional specificity of the other major milk triglyceride fatty acids. Of these fatty acids, the short and medium chain length acids (butyratelaurate) were mainly on position 3, myristate and palmitate on positions 1 and 2, and stearate and oleate evenly distributed. Thoracic duct lymph triglycerides from sheep tended to show preferential incorporation of linoleate at position 3, palmitate at position 2, and stearate at position 1 and 3; oleate, on the other hand, tended to be evenly distributed on all three positions of the lymph triglyceride. The stereospecific arrangement of fatty acids in sheep liver triglycerides was similar to that of lymph triglycerides, and this may reflect the uptake of intact or partially hydrolysed chylomicron and/or very low density lipoprotein triglycerides by the liver. There were also some analogies in the stereospecific arrangement of fatty acids on ruminant lymph and milk triglycerides and this may reflect an incomplete hydrolysis of chylomicron and/or very low density lipoprotein triglycerides prior to uptake by the mammary gland. An unusual feature of lymph from sheep fed linoleate was the presence of phospholipids which contained large amounts of linoleate in ca. equal proportion at both positions 1 and 2 of the phospholipid molecule.

Adipose Tissue↗
PubMed1976

Effects of protected cyclopropene fatty acids on the composition of ruminant milk fat.

Unsaturated fatty acids can be protected from ruminal hydrogenation, and when fed to lactating ruminants, the constituent acids are incorporated into milk triacylglycerols. By this means, it has been possible to reduce the melting point of milk triglycerides and to make softer butter fat. This report shows that, by feeding small amounts of protected cyclopropene fatty acids, one is also able to make harder butter fat. Sterculia foetida seed oil, a rich source of cyclopropene fatty acids, was emulsified with casein and spray dried to yield a free flowing dry powder. When this material was treated with formaldehyde and fed to lactating goats(ca. 1 g cyclopropene fatty acids per day), there were substantial increases in the proportions of stearic acid and decreases in the proportions of oleic acid in milk fat. Similar results were obtained when the formaldehyde-treated supplements were fed to lactating cows (ca. 3 g cyclopropene fatty acids per day). The effect was considerably less apparent when the S. foetida seed oil-casein supplement was not treated with formaldehyde, suggesting that cyclopropene fatty acids are hydrogenated in the rumen as are other unsaturated fatty acids. The effect of feeding protected cyclopropene fatty acids on the stearic:oleic ratio in milk fat is probably due to cyclopropene-mediated inhibition of the mammary desaturase enzymes.

Animals↗
PubMed1975

Increased sterol excretion with polyunsaturated-fat high-cholesterol diets.

Previous studies have shown that polyunsaturated ruminant fats in the diets of human subjects cause an increase in cholesterol and bile acid excretion during the first 3 weeks of such diets. The present studies were designed to compare the effects of polyunsaturated (P) and conventional (S) ruminant fats at two levels of dietary cholesterol intake: a higher (HC) and lower (LC). Four study periods, each of about 3 weeks' duration, were conducted in 5 healthy subjects providing these dietary combinations: HCS, HCP, LCS, LCP. Neutral sterols and bile acids were measured in the feces, and sterol balances were calculated. Plasma cholesterol levels were significantly lower with P than with S diets at both HC and LC intakes. Changes attributable to differences in fatty acids and to differences in cholesterol intake appeared to exert independent effects. The major changes occurred in lipoproteins with density 1.019-1.045. Cholesterol absorption expressed as a percentage of the dietary intake was not significantly different with the four diets. Neutral sterol excretion of probable endogenous origin and bile acid excretion were significantly higher during the HCP than during the HCS periods, but the difference between LCP and LCS periods was less marked. Net sterol excretion was therefore significantly greater with HCP and LCP than with HCS and LCS diets, the differences being greater at HC than at LC intakes. Comparisons of diets with similar fatty acid but differing cholesterol intakes showed lower net sterol excretion with HCS than with LCS diets (presumably due to suppression by HC by cholesterol synthesis), but this difference was not seen between HCP and LCP diets. This finding, together with greater sterol excretion with HCP than with HCS diets, showed that enhanced sterol excretion with polyunsaturated fat was potentiated with higher cholesterol intake. This enhanced excretion was generally greater during the first than during the second 3-week period of polyunsaturated fat.

Adolescent↗