bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synergism between penicillin G and the antimicrobial ether lipid,rac‐1‐dodecylglycerol, acting below its critical micelle concentration
Authors: Ved H. S. , Gustow Evan , Pieringer Ronald A. 
Published: February 2007

Abstractrac‐1‐Dodecylglycerol (DDG) and penicillin G (Pen G) act synergistically to dramatically lower the minimum inhibitory concentration (MIC) of each other in four Gram‐positive bacteria studied. At one‐half its MIC, DDG ether lowered the MIC of Pen G 10‐ to 80‐fold. Under the same conditions, Pen G lowered the MIC of DDG 4‐ to 7.5‐fold.The critical micelle concentration of DDG was determined to be 7.93 mg/ml (0.0305 mM), which is approximately two‐fold greater than the minimum inhibitory concentration of DDG determined in the presence of a protein‐free chemically defined medium. This finding suggests that DDG is not killing bacteria through its detergent action. Pen G also did not alter the critical micelle concentration of DDG, which indicates that the synergism between these two agents is not related to micelle formation.
Sphingolipid metabolism in the regulation of bioactive molecules
Authors: Luberto Chiara , Hannun Yusuf A. 
Published: February 2007

ConclusionsIn conclusion, the study of signaling and cell regulation through ceramide has now evolved to the biochemical level by focusing on specific enzymes of ceramide metabolism. A general hypothesis can be presented whereby individual enzymes of ceramide metabolism serve as input points in the regulation of ceramide levels (Scheme 1). For example, activation of SMases or ceramide synthase would elevate ceramide levels and activate ceramide‐induced responses. On the other hand, activation of enzymes of ceramide degradation or incorporation such as ceramidases or SM synthase decreases and attenuates ceramide levels. Also, as an important corollary, some of these enzymes may play an additional fundamental role in interconverting lipid signals. For example, SM synthase has the capacity of interconverting a ceramide signal into a DAG signal, whereas ceramidases can transform a ceramide signal into a sphingosine or sphingosine‐phosphate signal. This area of research promises great future insight into important areas of cell studies.
Fatty acids, antioxidants, and coronary heart disease from an epidemiological perspective
Authors: Kromhout D. 
Published: February 2007

AbstractOxidized low density lipoproteins (LDL) play a major role in the development of atherosclerosis. Saturated fatty acids, especially fatty acids with 12–16 carbon atoms, are the most important determinants of the LDL cholesterol level. The LDL lipoprotein fraction can be oxidized by, e.g., smoking. Oxidative damage of LDL lipoproteins can be prevented by nutritive, e.g., vitamin E, and nonnutritive antioxidants, e.g., flavonoids. It can therefore be hypothesized that fatty acids and antioxidants are important determinants of coronary heart disease (CHD). There is a large body of evidence from prospective studies that LDL cholesterol‐lowering is associated with a lower CHD risk. The evidence for a protective effect of antioxidants on CHD risk is much weaker and is most promising for vitamin E and flavonoids. The Seven Countries Study showed that at the population level saturated fat, cigarette smoking, and flavonoids are important determinants of long‐term CHD mortality. These results suggest that a diet low in saturated fat and rich in antioxidants in combination with no smoking is associated with low CHD risk.
The effect of palmitic acid on lipoprotein cholesterol levels and endogenous cholesterol synthesis in hyperlipidemic subjects
Authors: Clandinin M. T. , Cook S. L. , Konrad S. D. , Goh Y. K. , French M. A. 
Published: February 2007

AbstractThe present study assesses the effect of high vs. low palmitic acid intakes on plasma lipoprotein cholesterol levels and on rates for endogenous synthesis of cholesterol in healthy and hyperlipidemic subjects. Four diets were formulated to provide combinations of 16:0 at two levels of 18:2n‐6. Subjects received each diet treatment for 21 d, followed by washout periods of 21 d. On day 21 of each diet treatment, a fasting blood sample was drawn for lipoprotein determination and to provide a measure of the background level of deuterium. A priming dose of deuterium was consumed and a second blood sample obtained 24 h after the first sample. Isotope ratio mass spectrometry was used to determine the incorporation of deuterium into the newly synthesized cholesterol molecule, and fractional synthetic rates were calculated. Serum total cholesterol and low density lipoprotein‐cholesterol was not significantly affected by the high level of 16:0 when diets also contained a high level of 18:2n‐6. There was no effect of dietary 16:0 on high density liproprotein‐cholesterol at either the high or low levels of intake. The results indicate that 16:0 has no effect on serum lipoprotein profiles in the presence of recommended intakes for 18:2n‐6.
Regulation of the biosynthesis of 22:5n‐6 and 22:6n‐3: A complex intracellular process
Authors: Sprecher Howard , Chen Qi , Yin Feng Qin 
Published: February 2007

AbstractBoth 22:4n‐6 and 22:5n‐3 are synthesized from n‐6 and n‐3 fatty acid precursors in the endoplasmic reticulum. The synthesis of both 22:5n‐6 and 22:6n‐3 requires that 22:4n‐6 and 22:5n‐3 are metabolized, respectively, to 24:5n‐6 and 24:6n‐3 in the endoplasmic reticulum. These two 24‐carbon acids must then move to peroxisomes for partial degradation followed by the movement of 22:5n‐6 and 22:6n‐3 back to the endoplasmic reticulum for use as substrates in membrane lipid biosynthesis. Clearly an understanding of the control of intracellular fatty acid movement as well as of the reactions carried out by microsomes, peroxisomes, and mitochondria are all required in order to understand not only what regulates the biosynthesis of 22:5n‐6 and 22:6n‐3 but also why most tissue lipids selectively accumulate 22:6n‐3.
Cellular fatty acid transport in heart and skeletal muscle as facilitated by proteins
Authors: Luiken J. J. F. P. , Schaap F. G. , van Nieuwenhoven F. A. , van der Vusse G. J. , Bonen A. , Glatz J. F. C. 
Published: February 2007

AbstractDespite the importance of long‐chain fatty acids (FA) as fuels for heart and skeletal muscles, the mechanism of their cellular uptake has not yet been clarified. There is dispute as to whether FA are taken up by the muscle cellsvia passive diffusion and/or carrier‐mediated transport. Kinetic studies of FA uptake by cardiac myocytes and the use of membrane protein‐modifying agents have suggested the bulk of FA uptake is due to a protein component. Three membrane‐associated FA‐binding proteins were proposed to play a role in FA uptake, a 40‐kDa plasma membrane FA‐binding protein (FABPpm), an 88‐kDa FA translocase (FAT/CD36), and a 60‐kDa FA transport protein (FATP). In cardiac and skeletal myocytes the intracellular carrier for FA is cytoplasmic heart‐type FA‐binding protein (H‐FABP), which likely transports FA from the sarcolemma to their intracellular sites of metabolism. A scenario is discussed in which FABPpm, FAT/CD36, and H‐FABP, probably assisted by an albumin‐binding protein, cooperate in the translocation of FA across the sarcolemma.
A hypothesis to explain the reduced blood levels of docosahexaenoic acid in inherited retinal degenerations caused by mutations in genes encoding retina‐specific proteins
Authors: Anderson Robert E. , Maude Maureen B. , Alvarez Richard A. , Acland Gregory , Aguirre Gustavo D. 
Published: February 2007

AbstractSome humans and animals with inherited retinal degenerations (RD) have lower blood levels of docosahexaenoic acid (22:6n‐3) than controls. As a result of recent studies, clearly the low blood 22:6n‐3 phenotype is found in multiple RD phenotypes and no mutation thus far identified in humans or animals is involved in lipid metabolism. Therefore, it seems reasonable to suggest that the primary defect is not in 22:6n‐3 metabolism, but rather in some common convergent pathway that ultimately leads to the reduction of blood and tissue 22:6n‐3 levels. One possibility is that the different mutations produce a metabolic stress that provokes structural and biochemical adaptive changes in photoreceptor cells and their rod outer segments. If the stress is oxidant, the retina could downregulate 22:6n‐3 and upregulate antioxidant defenses. How such a stress could lead to changes in blood levels of 22:6n‐3 is not obvious. However, the consistent finding of the 22:6n‐3 phenotype in many different retinal degeneration genotypes suggests that some form of communication exists between the retina and other tissues that serves to reduce blood levels of 22:6n‐3.
Dietary 18:3n‐3 and 22:6n‐3 as sources of 22:6n‐3 accretion in neonatal baboon brain and associated organs
Authors: Su H. ‐M. , Bernardo L. , Mirmiran M. , Ma X. ‐H. , Nathanielsz P. W. , Brenna J. T. 
Published: February 2007

AbstractThe bioequivalence of dietary linolenic acid (LNA) and docosahexaenoic acid (DHA) for brain DHA accretion was measured in neonatal baboons at 4–6 wk of age using stable isotope tracers. Neonates consumed a conventional U.S. term‐infant formula devoid of long chain polyunsaturates and with an n‐6/n‐3 ratio of about 10:1. At 4 wk of age, neonates were dosed with either13C LNA or13C DHA. At 6 wk of age, neonate brain, retina, and other organs were harvested for fatty acid and isotopic analyses. The relative accretion of labeled DHA was 7‐fold greater as a percentage of dose for the DHA‐dosed animals compared to the LNA‐dosed animals. The baboon is an omnivore that regularly consumes meat and insects; its plasma lipid profile responds similarly to humans in response to changes in feeding and living habits. These observations suggest that the baboon is a suitable model for human unsaturated fatty acid studies.
A study of the structures and reactions of some methyl substituted unsaturated C18 ester intermediates in the synthesis of a racemic mixture of 10‐methyloctadecanoic acid
Authors: Lie Marcel S. F. , Jie Ken , Leung David W. Y. 
Published: February 2007

AbstractMethyl 10‐undecenoate was hydrated to methyl 10‐hydroxyundecanoate using mercury (II) acetate in aqueous tetrahydrofuran (THF). Chromic acid oxidation of methyl 10‐hydroxyundecanoate gave methyl 10‐oxoundecanoate, which was hydrolyzed to 10‐oxoundecanoic acid. Reaction of n‐octyl magnesium bromide complex in THF with 10‐oxoundecanoic acid furnished 10‐hydroxy‐10‐methyloctadecanoic acid after hydrolysis. The latter compound was esterified, and dehydration of methyl 10‐hydroxy‐10‐methyloctadecanoate withp‐toluenesulfonic acid in benzene gave a mixture of unsaturated branched fatty ester intermediates:viz. methyl 10‐methyl‐9‐octadecenoate, 10‐methyl‐10‐octadecenoate and 10‐octyl‐10‐undecenoate. Treatment of the mixture of unsaturated branched fatty ester intermediates with mercury (II) acetate in methanol gave exclusively methyl 10‐methoxy‐10‐methyloctadecanoate. Epoxidation of the same mixture of unsaturated fatty esters withm‐chloroperbenzoic acid provided a mixture of epoxy derivatives: methyl 9,10‐epoxy‐10‐methyloctadecanoate, 10,11‐epoxy‐10‐methyloctadecanoate and 2‐octyl‐oxirane‐nonanoate. Catalytic hydrogenation of the mixture of unsaturated fatty esters gave a racemic mixture of methyl 10‐methyloctadecanoate, which was hydrolyzed to 10‐methyloctadecanoic acid. The structures of the mixture of unsaturated branched fatty ester intermediates and their derivatives were characterized by chemical and spectroscopic analyses.
Autoxidation of polyunsaturated triacylglycerols. II. Trilinolenoylglycerol
Authors: Frankel E. N. , Neff W. E. , Miyashita K. 
Published: February 2007

AbstractThe hydroperoxides and secondary products formed from trilinolenoylglycerol autoxidized at 40°C were isolated and characterized to clarify the mechanism of oxidative deterioration of polyunsaturated vegetable oils. The products were purified by high performance liquid chromatography (HPLC) and identified either as intact triacylglycerols spectrophotometrically, or after lipolysis (pancreatic lipase) and capillary gas chromatography and gas chromatography‐mass spectrometry. The products included 9‐, 12‐, 13‐, and 16‐mono‐,bis‐, tris‐hydroperoxy, 9‐ and 16‐hydroperoxy epidioxy, 9‐ and 16‐hydroperoxy bicycloendoperoxy and 9,12‐, 13,16‐, and 9,16‐dihydroperoxy linolenoylglycerols. The mono‐hydroperoxides and sydroperoxy epidioxides were the only main products initially formed at peroxide values (PV) below 30.Bis‐ and tris‐hydroperoxides were formed consecutively as minor products from the mono‐hydroperoxides at PV's between 31 and 47. Hydroperoxy bicycloendoperoxides and monodihydroperoxides were also formed as minor secondary products at PV's above 75. HPLC analyses show a small preference for the formation of 16‐hydroperoxides on the 1(3)‐position over the 2‐position of trilinolenoylglycerol. However, there was no selectivity for the formation of the 9‐, 12‐ and 13‐hydroperoxides and for the hydroperoxy epidioxides between the 1(3)‐ and the 2‐positions in trilinolenoylglycerol. Mono‐hydroperoxides and hydroperoxy epidioxides of linolenate triacylglycerols may be important precursors of volatile compounds contributing to oxidative deterioration of vegetable oils.
Employing community data to investigate social and structural dimensions of urban neighborhoods: An early childhood education example
Authors: McWayne Christine M. , McDermott Paul A. , Fantuzzo John W. , Culhane Dennis P. 
Published: February 2007

AbstractThe present study sought to define neighborhood context by examining relationships among data from city‐level administrative databases at the level of the census block group. The present neighborhood investigation included 1,801 block groups comprising a large, northeastern metropolitan area. Common factor analyses and multistage, hierarchical cluster analyses yielded two dimensions (i.e., Social Stress, Structural Danger) and two typologies (i.e., Racial Composition, Property Structure Composition) of neighborhood context. Simultaneous multiple regression analyses revealed small but statistically significant associations between neighborhood variables and academic outcomes for public school kindergarten children.
Altered Lipid Parameters in Hepatic Subcellular Membrane Fractions Induced by Fumonisin B1
Authors: Burger H.‐M. , Abel S. , Snijman P. W. , Swanevelder S. , Gelderblom W. C. A. 
Published: February 2007

AbstractAlteration of lipid constituents of cellular membranes has been proposed as a possible mechanism for cancer promotion by fumonisin B1 (FB1). To further investigate this hypothesis a dietary dosage which initiates and promotes liver cancer (250 mg FB1/kg) was fed to male Fischer rats for 21 days and the lipid composition of plasma, microsomal, mitochondrial and nuclear subcellular fractions determined. The effect of FB1 on the cholesterol, phosphatidylcholine (PC) and phosphatidylethanolamine (PE), as well as sphingomyelin (SM) and the phospholipids‐associated fatty acid (FA) profiles, were unique for each subcellular membrane fraction. PE was significantly increased in the microsomal, mitochondrial and plasma membrane fractions, whereas cholesterol was increased in both the microsomal and nuclear fraction. In addition SM was decreased and increased in the mitochondrial and nuclear fractions, respectively. The decreased PC/PE and polyunsaturated/saturated (P/S) FA ratio in the different membrane fractions suggest a more rigid membrane structure. The decreased levels in polyunsaturated fatty acids in PC together with a pronounced increase in C18:1ω9 and C18:2ω6 were indicative of an impaired delta‐6 desaturase. The increased ω6/ω3 ratio and decreased C20:4ω6 PC/PE ratio due to an increase in C20:4ω6 in PE relatively to PC in the different subcellular fractions suggests a shift towards prostanoid synthesis of the E2 series. Changes in the PE and C20:4ω6 parameters in the plasma membrane could alter key growth regulatory and/or other cell receptors in lipid rafts known to be altered by FB1. An interactive role between C20:4ω6 and ceramide in the mitochondria, is suggested to regulate the balance between proliferation and apoptosis in altered initiated hepatocytes resulting in their selective outgrowth during cancer promotion effected by FB1.
Evidence for the silicate source of relict soils on the Edwards Plateau, central Texas
Authors: Cooke M. Jennifer , Stern Libby A. , Banner Jay L. , Mack Lawrence E. 
Published: February 2007

AbstractRelict soils provide insights into Quaternary soil formation and erosion on the Edwards Plateau of central Texas and into soil-forming processes in karst terranes. Late Quaternary climate-driven soil erosion produced a mosaic of thick and thin soils on the Edwards Plateau landscape. Thick soils on uplands of the Edwards Plateau are interpreted to be relicts of a formerly more extensive soil cover that was eroded during the late Pleistocene to middle Holocene. The relict, thick soils are silicate-rich and most commonly overlie the relatively silicate-poor Cretaceous Edwards Limestone, which supports the idea that the thick soils did not form from weathering of the underlying limestone. Other potential sources of silicates for the relict soils include dust, alluvial sediments, and the Del Rio Clay, a stratigraphically higher but locally eroded clay-rich unit. Here we investigate the geographic distribution, texture, clay-sized mineralogy, rare earth element geochemistry, and neodymium isotope composition of the relict soils. We have found that the relict, thick soils are deeply weathered soils that occur dominantly over the Edwards Limestone and have a high clay content and a neodymium isotope composition that is similar to that of the Del Rio Clay. Thus, we propose that in situ weathering of the Del Rio Clay, along with partial weathering of the upper portion of the underlying Edwards Limestone produced thick chert- and clay-rich soils over resistant limestone. In areas like the Edwards Plateau, where pure limestones are interbedded with clay-rich strata, the overlying clay-rich strata must be considered as a possible silicate source to soils on pure limestone bedrock.
Lipid, protein and carbohydrate intake in relation to body mass index: an Italian study
Authors: Randi Giorgia , Pelucchi Claudio , Gallus Silvano , Parpinel Maria , Dal Maso Luigino , Talamini Renato , Augustin Livia SA , Giacosa Attilio , Montella Maurizio , Franceschi Silvia , La Vecchia Carlo 
Published: February 2007

AbstractObjectiveTo analyse the association between macronutrient intake and body mass index (BMI).DesignA series of hospital-based case–control studies.SettingsSelected teaching and general hospitals in several Italian regions.SubjectsA total of 6619 subjects from the comparison groups of the case–control studies were included in the analysis.MethodsWe obtained data from a validated 78-item food-frequency questionnaire submitted between 1991 and 2002. For various macronutrients, the partial regression coefficient (variation of BMI (kg m− 2) per 100 kcal increment of energy intake) was derived from multiple linear regression models, after allowance for age, study centre, education, smoking habits, number of eating episodes and mutual adjustment for macronutrients.ResultsBMI was directly associated with protein intake among women only (β = 0.68) and with unsaturated fats in both genders (for monounsaturated fats β = 0.27 for men and 0.26 for women; for polyunsaturated fats β = 0.27 for men and 0.54 for women), and inversely related to carbohydrates (β = − 0.05 for men and − 0.21 for women) and number of eating episodes in both genders (β = − 0.42 for men and − 0.61 for women) and to saturated fats among women only (β = − 0.57).ConclusionsThese results confirm and provide convincing evidence that, after allowance for selected covariates including total energy intake, a protein-rich diet is not inversely related to BMI, and a carbohydrate-rich diet is not directly related to BMI.
The influence of fruit and vegetable intake on the nutritional status and plasma homocysteine levels of institutionalised elderly people
Authors: Bermejo LM , Aparicio A , Andrés P , López-Sobaler AM , Ortega RM 
Published: February 2007

AbstractObjectiveTo determine the difference in the nutritional status of elderly people depending on their consumption of fruits and vegetables, and to study the possible association between the consumption of these foods and different cardiovascular risk factors, especially total plasma homocysteine (t-Hcys) levels.Design, setting and subjectsA cross-sectional study in 152 institutionalised older people from Madrid aged ≥ 65 years. Food and nutrient intakes were recorded over 7 days using the ‘precise individual weighing’ method. The weight, height, and waist and hip circumferences of all subjects were recorded, as were their α-erythrocyte glutathione reductase, serum B6, B12and folate levels, erythrocyte folate levels, t-Hcys levels, serum lipids and blood pressure. The experimental population was then divided into tertiles depending on the serving intake of fruit and vegetables (T1, < 2.29 servings day− 1; T2, 2.29–2.79 servings day− 1; and T3, >2.79 servings day− 1).ResultsCompared with T1 subjects, T3 subjects showed consumptions of cereals, pulses, meat, fish and eggs closer to those recommended (P < 0.05). In addition, the contribution of their diet towards covering the recommended daily intake of vitamin B1, niacin, vitamin B6, folic acid, vitamin C, B12, vitamin A, and P, Mg, Zn and Fe was higher. The intake of fibre increased with consumption of fruit and vegetables (r = 0.6839,P < 0.001). T3 subjects also had better serum and erythrocyte folate levels than T1 and T2 subjects (P < 0.05). A positive correlation was found between the consumption of fruit and vegetables and serum folate (r = 0.2665,P < 0.01) and with erythrocyte folate levels (r = 0.2034,P < 0.05), and a negative correlation with t-Hcys (r = − 0.2493,P < 0.01).ConclusionsGreater consumption of fruit and vegetables is associated with better food habits, increased vitamin and mineral intakes and lower t-Hcys levels. Considering that the fruit and vegetable intake in Spanish elderly people is very low, it is recommended that the consumption of fruits and vegetables by elderly people be increased.
Comparison of buffet and à la carte serving at worksite canteens on nutrient intake and fruit and vegetable consumption
Authors: Lassen A , Hansen KS , Trolle E 
Published: February 2007

AbstractObjectiveTo evaluate the nutritional composition of worksite canteen lunches and to examine the impact of two meal serving systems on employee intake, i.e. buffet style with a fixed price for a varied number of dishes and à la carte style with a separate price for each item on the menu.DesignLaboratory technicians observed employees' food selection and collected identical dishes. Food items were weighed separately to calculate the content of fruit and vegetables. The content of protein, fat and ash of each dish was chemically analysed and the carbohydrate and energy content calculated.SettingFifteen randomly chosen worksite canteens in Denmark: eight canteens serving buffet style and seven canteens with an à la carte line.Subjectsone hundred and eighty randomly chosen employees having lunch at the worksite canteens.ResultsThe average percentage energy from fat was 37 ± 12 among men and 33 ± 12 among women. No association was found between the meal serving system and energy intake or macronutrient composition. Eating at canteens serving buffet style, on the other hand, was associated with an increased intake of fruit and vegetables, on average 76 g, and a lower energy density of the food for both genders.ConclusionThe results highlight the possibilities of promoting healthy food choices in the catering sector and the need to identify models of healthy catering practice. Serving buffet style appears to be a promising strategy in order to increase fruit and vegetable consumption in food served away from home.