scholarly journals Review of Laboraotory and Clinical Studies of Olestra, a Nonabsorbable Lipid

1991 ◽  
Vol 5 (4) ◽  
pp. 137-146 ◽  
Author(s):  
Carolyn M Bergholz ◽  
Ronald J Jandacek ◽  
Alan BR Thomson

The classical understanding of fat digestion and absorption is provided as background for a review of research on olestra, a triglyceride-derived lipid that is not digested or absorbed from the intestinal lumen. Olestra (formerly ‘sucrose polyester’) is the generic name proposed for the mixture of the hexa, hepta and octa long chain fatty acid esters of sucrose. Olestra has the physical properties of fat and can therefore function as a zero calorie fat replacement in foods. The fate and effects of olestra in the gastrointestinal tract have been extensively investigated in animals and humans. Evidence from a variety of studies shows that olestra is not digested or absorbed and is not metabolized by colonic microflora. Feeding studies in five different species of animals show that olestra is nontoxic and noncarcinogenic, and causes no morphological changes in any tissues of the gastrointestinal tract. Consumption of olestra foods does not alter gastric emptying, transit through the small and large bowel, bile acid physiology, bowel function, or fecal pH, water and electrolytes. Nutritional research shows no effect on absorption of macronutrients. Highly lipophilic materials such as cholesterol and vitamin E have the potential to partition into olestra, thereby decreasing their solubilization in intestinal micelles and subsequent absorption. Clinical research shows a modest reduction in serum cholesterol and vitamin E levels. The effect on vitamin E absorption can be offset by supplementation of olestra with vitamin E. The status of vitamins D and K and absorption of lipophilic drugs are not altered by daily consumption of 18 g olestra. Although serum retinol levels are not reduced, additional research is focusing on effects of olestra on hepatic stores of vitamin A to assess the appropriateness of supplementation. Using olestra to reduce the amount of fat in high fat foods, without affecting other nutrient, should contribute to a diet lower in energy from fat and higher in energy from carbohydrate.

Author(s):  
Zhongqi Wan ◽  
Li Wang ◽  
Yinyang Xu ◽  
Yuanyuan Wang ◽  
Tianyou Zhang ◽  
...  

Background: College students may have risk of fat-soluble vitamins deficiencies due to unhealthy dietary habits, especially for vitamin A and E. They are important members in the human antioxidant network, deficiencies of these vitamins may increase risk of many critical diseases. Objective: The current study was undertaken to determine the status of vitamin A and E in college students. Methods: Healthy college students were recruited, and fasting blood samples of them were collected and used for determining serum levels of retinol and α-tocopherol by the HPLC method. Results: We found that there was no vitamin A deficiency in college students. However, vitamin E deficiency existed in 34.5% of college students, especially in males. All the students had no vitamin E adequacy. In addition, our findings showed that BMI was inversely associated with serum α-tocopherol, but not serum retinol. Conclusion: These results suggest that vitamin E deficiency in college students should be given more attention, and it is necessary to consider using vitamin E supplements.


Author(s):  
Frank J. Longo

Measurement of the egg's electrical activity, the fertilization potential or the activation current (in voltage clamped eggs), provides a means of detecting the earliest perceivable response of the egg to the fertilizing sperm. By using the electrical physiological record as a “real time” indicator of the instant of electrical continuity between the gametes, eggs can be inseminated with sperm at lower, more physiological densities, thereby assuring that only one sperm interacts with the egg. Integrating techniques of intracellular electrophysiological recording, video-imaging, and electron microscopy, we are able to identify the fertilizing sperm precisely and correlate the status of gamete organelles with the first indication (fertilization potential/activation current) of the egg's response to the attached sperm. Hence, this integrated system provides improved temporal and spatial resolution of morphological changes at the site of gamete interaction, under a variety of experimental conditions. Using these integrated techniques, we have investigated when sperm-egg plasma membrane fusion occurs in sea urchins with respect to the onset of the egg's change in electrical activity.


Author(s):  
C.J. Seal ◽  
D.S. Parker ◽  
J.C. MacRae ◽  
G.E. Lobley

Amino acid requirements for energy metabolism and protein turnover within the gastrointestinal tract are substantial and may be met from luminal and arterial pools of amino acids. Several studies have demonstrated that the quantity of amino acids appearing in the portal blood does not balance apparent disappearance from the intestinal lumen and that changing diet or the availability of energy-yielding substrates to the gut tissues may influence the uptake of amino acids into the portal blood (Seal & Reynolds, 1993). For example, increased net absorption of amino acids was observed in animals receiving exogenous intraruminal propionate (Seal & Parker, 1991) and this was accompanied by changes in glucose utilisation by the gut tissues. In contrast, there was no apparent change in net uptake of [l-13C]-leucine into the portal vein of sheep receiving short term intraduodenal infusions of glucose (Piccioli Cappelli et al, 1993). This experiment was designed to further investigate the effects on amino acid absorption of changing glucose availability to the gut with short term (seven hours) or prolonged (three days) exposure to starch infused directly into the duodenum.


2020 ◽  
Vol 113 (1) ◽  
pp. 221-231
Author(s):  
Ibukun Afolami ◽  
Martin N Mwangi ◽  
Folake Samuel ◽  
Erick Boy ◽  
Paul Ilona ◽  
...  

ABSTRACT Background Vitamin A deficiency is a public health problem in sub-Saharan Africa. Pro-vitamin A biofortified (yellow) cassava has the potential to contribute significantly to improve vitamin A status, especially in populations that are difficult to reach with other strategies. Objectives The study aimed at determining the efficacy of biofortified cassava to improve vitamin A status of Nigerian preschool children. Methods An open-label randomized controlled trial was conducted in southwestern Nigeria. In total, 176 preschool children (aged 3–5 y) were randomized into 2 parallel arms comprising an experimental group (n = 88), fed foods prepared from biofortified (yellow) cassava, and a control group (n = 88), fed foods prepared from white cassava, twice a day, 6 d a week for 93 d. Results A total of 159 children completed the trial (yellow cassava group, n = 80; white cassava group, n = 79). Children consumed 221 and 74 µg/d retinol activity equivalents from intervention foods in the yellow and white cassava groups, respectively. The treatment effect on serum retinol concentrations at the end of the feeding trial was 0.06 µmol/L (95% CI: 0.004, 0.124 µmol/L), after adjustment for baseline retinol concentrations, inflammation, and asymptomatic malaria status. No significant treatment effects were detected for serum β-carotene (adjusted effect: 3.9%; 95% CI: −0.6%, 8.6%) and gut permeability (adjusted effect: 0.002; 95% CI: −0.089, 0.092), but a significant effect was detected for hemoglobin concentrations (adjusted effect: 3.08 g/L; 95% CI: 0.38, 5.78 g/L). Conclusions Daily consumption of β-carotene from biofortified cassava improved serum retinol and hemoglobin concentrations modestly in Nigerian preschool children. This study was registered with clinicaltrials.gov as NCT02627222.


2003 ◽  
Vol 285 (5) ◽  
pp. C1294-C1303 ◽  
Author(s):  
Ya-Qin Zhu ◽  
Yu Lu ◽  
Xiao-Di Tan

Intestinal epithelial cells are constantly stimulated by reactive oxidant metabolites (ROMs) in inflamed mucosa. Monochloramine (NH2Cl), a cell-permeant ROM, is particularly relevant to the pathogenesis of inflammation in the gastrointestinal tract. Nuclear speckles, a unique nuclear subcompartment, accumulate a family of proteins, namely, serine- and arginine-rich (SR) proteins. They play important roles in regulation of pre-mRNA splicing. Currently, little is known about the link between inflammatory stimulation and the pre-mRNA splicing process, although gene expression is changed in inflamed tissues. The present study was designed to investigate whether stimulation of human colonic epithelial cells (HT-29 and Caco-2 cell lines) with NH2Cl affects nuclear speckles and their components. By indirect immunofluorescence, nuclear speckles have been shown to undergo rapid aggregation after NH2Cl stimulation. By utilizing Western blotting, SRp30 (a subset of SR proteins) in intestinal epithelial cells was found to be phosphorylated after NH2Cl treatment, whereas other SR proteins were not responsive to NH2Cl stimulation. The cytotoxic effect of NH2Cl was excluded by both negative lactate dehydrogenase assay and propidium iodide staining. Therefore, NH2Cl-induced morphological changes on nuclear speckles and phosphorylated SRp30 do not result from intestinal epithelial injury. Furthermore, the effect of NH2Cl on nuclear speckles and SRp30 was blocked by bisindolylmaleimide I, a selective PKC inhibitor. Together, the available data suggest that stimulation of intestinal epithelial cells with NH2Cl results in a consequent change on pre-mRNA splicing machinery via a distinctive signal pathway involving activation of PKC. This effect may contribute to oxidant-induced pathophysiological changes in the gastrointestinal tract.


2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Saptarshi Biswas ◽  
Catherine Price ◽  
Sunil Abrol

Bullet embolism within the gastrointestinal system is extremely rare. Such bullet injuries are infrequently covered in the general literature, but the surgeon should be aware of the phenomenon. Smaller caliber bullets are more common in civilian gunshot wound (GSW) events. These bullets are able to tumble through the gastrointestinal tract and cause perforation of the intestinal lumen which is small enough to be easily missed. Bullets retained in the abdominal cavity should not be dismissed as fixed and should be carefully monitored to ensure that they do not embolize within the bowel and cause occult lesions during their migration. We present a unique case wherein a bullet caused a minute perforation in the small bowel, before migrating to the distal colon, which resulted in late presentation of sepsis secondary to peritonitis.


1995 ◽  
Vol 3 (3-4) ◽  
pp. 117-122 ◽  
Author(s):  
Mahesh Chandra ◽  
Vivek Gupta ◽  
Anil Kumar Rath ◽  
Arvind Kumar Vaish ◽  
Rikhab Chand Srimal ◽  
...  

The present work was conducted to study the status of oxidative stress (oxy-free radicals) in 24 patients with acute myocardial infarction and 12 matched healthy control patients and furthermore evaluate the effect of oral vitamin E on altered oxyfree radicals in these patients. The parameters assessed for oxy-free radical status were superoxide anion and malonyldialdehyde. These were found to be increased during acute myocardial infarction and this increment had a normalizing trend with the passage of time. It was found that the administration of vitamin E accelerated the normalizing trend of both superoxide anion and malonyldialdehyde. Thus, vitamin E has an antioxidant effect in acute myocardial infarction.


Zygote ◽  
2004 ◽  
Vol 12 (2) ◽  
pp. 117-124 ◽  
Author(s):  
F.J. Peña ◽  
A. Johannisson ◽  
M. Wallgren ◽  
H. Rodriguez Martinez

Previous studies have shown sperm quality after cryopreservation differs depending on the fraction of seminal plasma the boar spermatozoa are contained in. Thus, spermatozoa contained in the first 10 ml of the sperm-rich fraction (portion I) withstand handling procedures (extension, handling and freezing/thawing) better than those contained in the latter part of a fractionated ejaculate (second portion of the sperm-rich fraction and the post-spermatic fraction; portion II). The present study evaluated whether an exogenous antioxidant, the water-soluble vitamin E analogue Trolox (6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid), could, when added to the freezing extender in a split-sample design trial, improve the post-thaw viability and membrane quality of this particular portion of the ejaculate, with particular attention to the status of the plasma membrane. Using a split-sample design, the initial changes in the fluidity status of the sperm plasmalemma after thawing were measured by flow cytometry (FC) after loading with Merocyanine-540 and YO-PRO-1. The FC-derived data revealed a clear ejaculate portion-dependent effect of the antioxidant supplementation. While no beneficial effect of the antioxidant supplementation was visible in spermatozoa from portion I, more spermatozoa with intact membranes were observed in the supplemented samples of portion II, suggesting the protective effect of vitamin E is dependent of the portion of the boar ejaculate considered.


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