Testing a short-term feeding trial to assess compositional and histopathological changes in hearts of rats fed vegetable oils

Male, female and castrated rats, three wk of age, were fed a low-fat diet for 14 wk followed by high-fat diets (20% by weight) for one wk containing graded levels of erucic acid from 1 to 50%, to evaluate the effect of short-term feeding and interaction of male sex hormones on formation of heart lesions. Some rats within each group were returned to the low-fat diet for one wk after the test period. For comparison, one group of three-wk-old male rats was fed the high fat 50% erucic acid diet for 15 wk. Erucic acid depressed growth rate and food consumption and increased cardiac lipidosis and triglycerides proportional to the erucic acid content of the diet. There were no sex differences, and the effects disappeared once rats were returned to the low-fat diet for one week. There was a significance (P<0.05) in the incidence of myocardial necrosis among male rats fed increased levels of erucic acid for one week, but the response was not linear to the increase in dietary erucic acid. Furthermore, the response was much less than in males fed the 50% erucic acid diet continually for 15 weeks. These results suggest that the short-term model is not a suitable substitute for the long-term feeding trial to test the cardiopathogenicity of a vegetable oil. The significantly lower incidence in myocardial lesions in female and castrated male rats compared with male rats suggests involvement of sex hormones. However, the process appears to be long term, since changes in cardiac lipids and their fatty acid pattern between sexes became evident after one wk on diet but was significant only after long-term feeding. Deceased.     

Quantitating heart lipids: Comparison of results obtained using the Iatroscan method with those from phosphorus and gas chromatographic techniques

The precision and accuracy of the Iatroscan method was evaluated by comparing the results obtained with established phosphorus and gas chromatographic techniques. A complete lipid class analysis of rat heart lipids was chosen in order to evaluate the performance of the Iatroscan method for biological samples which contained both neutral lipids and phospholipids. A partial scan and repeat development with chloroform/methanol/water (68.5∶29∶2.5) was introduced to achieve consistently good separations of the phospholipids on the Chromarods in the Iatroscan method. The results showed that the precision of the Iatroscan method for some lipid classes was comparable to that of phosphorus or gas chromatographic techniques, while for other lipid classes it was lower. Compared to the data obtained using the phosphorus method, the Iatroscan data were generally similar, while the gas chromatographic method generally gave lower values. These findings, together with the advantages of time required for analysis, size of sample, and universality of detection, suggest that the Iatroscan is a valuable complementary method for complex lipid analyses.     

Modeling Human Liver Biology Using Stem Cell-Derived Hepatocytes

Stem cell-derived hepatocytes represent promising models to study human liver biology and disease. This concise review discusses the recent progresses in the field, with a focus on human liver disease, drug metabolism and virus infection.     

Hematological and lipid changes in newborn piglets fed milk-replacer diets containing erucic acid

Canola oil is not presently permitted in infant formulations in the United States because of lack of information concenring the effects of feeding canola oil to the newborn. We have previously reported a transient decrease in platelet counts and an increase in platelet size in newborn piglets fed canola oil for 4 wk, and have confirmed this in the present study. In canola oil-fed piglets, changes in platelet size and number were overcome by adding either long-chain saturated fatty acids from cocoa butter (16:0 and 18:0), or shorter-chain saturates from coconut oil (12:0 and 14:0). Feeding a high erucic acid rapeseed (HEAR) oil, with 20% 22:1n−9, led to an even greater platelet reduction and increased platelet size throughout the 4-wk trial. Bleeding times were longer in piglets fed canola oil or HEAR oil compared to sow-reared and soybean oil-fed piglets. There were no other diet-related changes. Diet-induced platelet changes were not related to platelet lipid class composition, but there were fatty acid changes. The incorporation of 22:1n−9 into platelet phospholipids of piglets fed canola oil was low (0.2–1.2%), and even for the HEAR oil group ranged from only 0.2% in phosphatidylinositol to 2.4% in phosphatidylserine. A much greater change was observed in the concentration of 24:1n−9 and in the 24:1n−9/24:0 ratio in platelet sphingomyelin (SM). The 24:1n−9 increased to 49% in the HEAR oil group compared to about 12% in animals fed the control diets (sow-reared piglets and soybean oil-fed group), while the 24:1n−9/24:0 ratio increased from about 1 to 12. Even feeding canola oil, prepared to contain 2% 22:1n−9, led to a marked increase in 24:1n−9 to 29% and had a 24:1n−9/24:0 ratio of 5. The canola oil/cocoa butter group, which also contained 2% 22:1n−9, showed a lower level of 24:1n−9 (20%) and the 24:1n−9/24:0 ratio (3) compared to the canola oil group. The results suggest that the diet-related platelet changes in newborn piglets may be related to an increase in 24:1n−9 in platelet SM, resulting from chain elongation of 22:1n−9. The inclusion of canola oil as the sole source of fat in the milk-replacer diets of newborn piglets resulted in significant platelet and lipid changes.     

Effect of pulse consumption on perceived flatulence and gastrointestinal function in healthy males

Despite their demonstrated health benefits, consumption of pulses in Western societies has traditionally been low. This is, in part, due to the perception that pulses cause flatulence and gastrointestinal upset. This randomized, double-blind placebo-controlled, cross-over study assessed the impact of 28 consecutive days consumption of 100 g dry weight Kabuli chickpeas, green Laird lentils, and green peas, in comparison to a potato control, on perceived flatulence, abdominal comfort, bowel movements and overall gastrointestinal function using a questionnaire with yes/no and visual analog rankings, in 21 healthy males between the ages of 19–40. Questionnaires were completed during three phases (PRE, EARLY, LATE) of each treatment period. Chi-square (occurrence) and Wilcoxon test (severity rank) analyses revealed minor changes in occurrence and/or severity of flatulence and abdominal comfort, but no changes in overall gastrointestinal function. These results demonstrate that pulses containing oligosaccharides are well tolerated with negligible perceived changes in flatulence and overall gastrointestinal function when incorporated into the diet of healthy adult males.     

Survey of vomitoxin contamination of the 1980 white winter wheat crop in ontario,canada

During the summer of 1980, there was a great deal of rainfall and high humidity in southwestern Ontario. Sprouting of the kernels on plants in the field and pink discoloration down-graded the white winter wheat crop. Samples were submitted to Agriculture Canada from elevators and boats loading wheat for export. Chemical analyses indicated low levels of vomitoxin, with some analytical results as high as 8.5 ppm. A series of feeding trials was initiated with contaminated wheat (1.0 ppm vomitoxin) to determine effects on swine and poultry. Swine diets containing 0.3 and 0.7 ppm vomitoxin resulted in decreased feed consumption and weight gains. Poultry were fed similar levels of vomitoxin without any serious effects. Gross examination of internal organs at the termination of the subacute studies revealed no apparent toxic effects. Several farmers reported feed refusal, vomiting and death in their livestock. Chemical analyses, in general, revealed relatively low levels of vomitoxin. In one case, the level of vomitoxin (0.95 ppm) in the feed was high enough to be a possible contributing factor in the observed ill effects.     

Self‐Compensation in Transparent Conducting F‐Doped SnO2

The factors limiting the conductivity of fluorine‐doped tin dioxide (FTO) produced via atmospheric pressure chemical vapor deposition are investigated. Modeling of the transport properties indicates that the measured Hall effect mobilities are far below the theoretical ionized impurity scattering limit. Significant compensation of donors by acceptors is present with a compensation ratio of 0.5, indicating that for every two donors there is approximately one acceptor. Hybrid density functional theory calculations of defect and impurity formation energies indicate the most probable acceptor‐type defects. The fluorine interstitial defect has the lowest formation energy in the degenerate regime of FTO. Fluorine interstitials act as singly charged acceptors at the high Fermi levels corresponding to degenerately n‐type films. X‐ray photoemission spectroscopy of the fluorine impurities is consistent with the presence of substitutional F_O donors and interstitial F_i in a roughly 2:1 ratio in agreement with the compensation ratio indicated by the transport modeling. Quantitative analysis through Hall effect, X‐ray photoemission spectroscopy, and calibrated secondary ion mass spectrometry further supports the presence of compensating fluorine‐related defects.     

Angiotensin I-Converting Enzyme Inhibitory Activity of Soy Protein Digests in a Dynamic Model System Simulating the Upper Gastrointestinal Tract

ABSTRACT: The objective of this study was to investigate whether peptides with inhibitory activity against angiotensin I-converting enzyme (ACE) would be produced by digestion of isolated soy protein (ISP) in a dynamic model system simulating gastrointestinal conditions. Using the model system, 5% ISP solution was pumped into the stomach reactor containing pepsin and HCl. The peptic digest was continuously pumped into the duodenum reactor containing pancreatin and Oxgall bile. The effects of blanching (100°C, 10 min) followed by pasteurization (75°C, 15 s) or sterilization (121°C, 20 min) of ISP before digestion on the inhibitory activity were also investigated. During the first 30 min of digestion, significantly higher ( P < 0.05) ACE-inhibitory activity was generated from unheated ISP after sequential digestion in both reactors compared with after peptic digestion only in the stomach reactor. However, at 90 min, subsequent digestion by pancreatin of unheated and blanched-sterilized ISP decreased ACE-inhibitory activity compared with peptic digestion alone. The IC₅₀ values at the end of 90 min digestion in both reactors were 0.38 ±0.01, 0.37 ± 0.02, and 0.44 ± 0.02 mg/mL for unheated, blanched-pasteurized, and blanched-sterilized ISP, respectively. The results suggest the potential production of peptides with ACE-inhibitory activity upon physiological digestion of soy protein, including products that have been subjected to heat processing. Although clinical trials would be required to provide final evidence of efficacy of the soy peptides, the present findings support the application of soy protein as an ingredient for functional foods.     

The effect of fatty acid chain length and unsaturation on the chromatographic behavior of triglycerides on latroscan chromarods

The chromatographic behavior of lipid classes on Chromarods with common developing solvents used for the Iatroscan system was influenced by the esterified fatty acids present in the lipid class. The R_f value of the lipid class increased with increasing chain length and increasing unsaturation of the fatty acids; the increase in R_f value per methylene carbon was about twice that per double bond. The effect was evident in both triglycerides and phosphatidylcholines. This partial separation of molecular species within a lipid class caused widening of the lipid class band on the Chromarods and can result in poorer resolution, particularly in biological samples.     

Myocardial changes in newborn piglets fed sow milk or milk replacer diets containing different levels of erucic acid

This study was undertaken to determine whether the neonate was more susceptible to the effects of dietary erucic acid (22∶1n−9) than the adult. Newborn piglets were used to assess the safety of different levels of 22∶1n−9 on lipid and histological changes in the heart. Newborn piglets showed no myocardial lipidosis as assessed by oil red 0 staining, but lipidosis appeared with consumption of sow milk and disappeared by seven days of age. Milk replacer diets containing soybean oil, or rapeseed oil mixtures with up to 5% 22∶1n−9 in the oil, or 1.25% in the diet, gave trace myocardial lipidosis. Rapeseed oil mixtures with 7 to 42.9% 22∶1n−9 showed definite myocardial lipidosis in newborn piglets, which correlated to dietary 22∶1n−9, showing a maximum after one week on diet. The severity of the lipidosis was greater than observed previously with weaned pigs. There were no significant differences among diets in cardiac lipid classes except for triacylglycerol (TAG), which increased in piglets fed a repeseed oil with 42.9% 22∶1n−9. TAG showed the highest incorporation of 22∶1n−9, the concentration of 22∶1n−9 in TAG was similar to that present in the dietary oil. Among the cardiac phospholipids, sphingomyelin and phosphatidylserine had the highest, and diphosphatidylglycerol (DPG) the lowest level of 22∶1n−9. The low content of 22∶1n−9 in DPG of newborn piglets is not observed in weaned pigs and rats fed high erucic acid rapeseed oil. The relative concentration of saturated fatty acids was lowered in all cardiac phospholipids of piglets fed rapeseed oils, possibly due to the low content of saturated fatty acids in rapeseed oils. The results suggest that piglets fed up to 750 mg 22∶1n−9/kg body weight/day showed no adverse nutritional or cardiac effects.