Background: The naturally occurring α-tocopherol (α-T) stereoisomer, -α-tocopherol (-α-T), is known to be more bioactive than -α-tocopherol (-α-T), a synthetic racemic mixture of 8 stereoisomers. There is widespread use of -α-T in maternal supplements.
Objective: The aim of the study was to thoroughly describe the α-T stereoisomer profile of human milk.
Objective: Macular pigment optical density (MPOD) - a non-invasive indicator of retinal xanthophylls and correlate of brain lutein - has been associated with superior cognitive function among adult populations. Given that lutein accumulation in the brain occurs in early life, it is possible that the cognitive implications of greater MPOD may be evident in childhood.
Methods: Participants aged 8-9 years (n = 56) completed MPOD measurements via heterochromatic flicker photometry.
Lutein and zeaxanthin are plant pigments known to preferentially accumulate in neural tissue. Macular Pigment Optical Density (MPOD), a non-invasive measure of retinal carotenoids and surrogate measure of brain carotenoid concentration, has been associated with disease prevention and cognitive health. Superior MPOD status in later adulthood has been shown to provide neuroprotective effects on cognition.
View Article and Find Full Text PDFBackground: Protein quantity and quality at a meal affect muscle protein synthesis (MPS); however, long-term effects of protein distribution at individual meals on adult muscle mass remain unknown.
Objective: We used a precise feeding protocol in adult rats to determine if optimizing postmeal MPS response by modifying the meal distribution of protein, and the amino acid leucine (Leu), would affect muscle mass.
Methods: Two studies were conducted with the use of male Sprague-Dawley rats (∼300 g) trained to consume 3 meals/d, then assigned to diet treatments with identical macronutrient contents (16% of energy from protein, 54% from carbohydrates, and 30% from fat) but differing in protein quality or meal distribution.
Magnetic resonance spectroscopy (MRS) is an important tool for studying the effects of nutrition on brain health. MRS can be used to measure the concentrations of metabolites which are related to cognitive performance and sensitive to diet. These measurements can provide information about metabolic efficiency, plasma membrane stability, antioxidant status, and neurotransmitter availability.
View Article and Find Full Text PDFAnimal experiments and cross-sectional or prospective longitudinal research in human subjects suggest a role for nutrition in cognitive ageing. However, data from randomised controlled trials (RCT) that seek causal evidence for the impact of nutrients on cognitive ageing in humans often produce null results. Given that RCT test hypotheses in a rigorous fashion, one conclusion could be that the positive effects of nutrition on the aged brain observed in other study designs are spurious.
View Article and Find Full Text PDFPrevious research demonstrates that the anabolic response of muscle protein synthesis (MPS) to a meal is regulated at the level of translation initiation with signals derived from leucine (Leu) and insulin to activate mTORC1 signaling. Recent evidence suggests that the duration of the meal response is limited by energy status of the cell and inhibition of translation elongation factor 2 (eEF2). This study evaluates the potential to extend the anabolic meal response with post-meal supplements of Leu or carbohydrates.
View Article and Find Full Text PDFBackground: Leucine (Leu) regulates muscle protein synthesis (MPS) producing dose-dependent plasma Leu and MPS responses from free amino acid solutions. This study examined the role of Leu content from dietary proteins in regulation of MPS after complete meals.
Methods: Experiment 1 examined 4 protein sources (wheat, soy, egg, and whey) with different Leu concentrations (6.
Muscle protein synthesis (MPS) increases after consumption of a protein-containing meal but returns to baseline values within 3 h despite continued elevations of plasma amino acids and mammalian target of rapamycin (mTORC1) signaling. This study evaluated the potential for supplemental leucine (Leu), carbohydrates (CHO), or both to prolong elevated MPS after a meal. Male Sprague-Dawley rats (∼270 g) trained to consume three meals daily were food deprived for 12 h, and then blood and gastrocnemius muscle were collected 0, 90, or 180 min after a standard 4-g test meal (20% whey protein).
View Article and Find Full Text PDFCurrent theory on the influence of breast cancer on bone describes metastasis of tumor cells to bone tissue, followed by induction of osteoclasts and bone degradation. Tumor influences on bone health in pre- or nonmetastatic models are unknown. Female rats (n = 48, 52 days old) were injected with N-methyl-N-nitrosourea (MNU) to induce breast cancer.
View Article and Find Full Text PDFBreast cancer is the most prevalent cancer in American women. Dietary factors are thought to have a strong influence on breast cancer incidence. This study utilized a meal-feeding protocol with female Sprague-Dawley rats to evaluate effects of two ratios of carbohydrate:protein on promotion and early progression of breast tissue carcinomas.
View Article and Find Full Text PDFApoptosis, or programmed cell death, plays an important role in many physiological and diseased conditions. Induction of apoptosis in cancer cells has been monitored during the cells' progression to apoptosis by anti-cancer drugs and inhibitors of the cell surface glycolipids, gangliosides and SA-Le(x) biosyntheses [Basu, S (1991) Glycobiology, 1, 469-475; and ibid, 427-435] in animal tissues and human carcinoma cells, respectively. Induction of apoptosis in cancer cells by cell surface glycolipids in the human breast cancer (SKBR3) cells is the aim in this study.
View Article and Find Full Text PDFApoptosis, or programmed cell death, plays an important role in many physiological and diseased conditions. Induction of apoptosis in cancer cells by anti-cancer drugs and biosynthetic inhibitors of cells surface glycolipids in the human colon carcinoma cells (Colo-205) are of interest in recent years. In our present studies, we have employed different stereoisomers of PPMP and PDMP (inhibit GlcT-glycosyltransferase (GlcT-GLT)) to initiate apoptosis in Colo-205 cells grown in culture in the presence of (3)H-TdR and (3)H/or (14)C-L-Serine.
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