Iron absorption in young Indian women: the interaction of iron status with the influence of tea and ascorbic acid

BACKGROUND: Ascorbic acid (AA) enhances and tea inhibits iron absorption. It is unclear whether iron status influences the magnitude of this effect. OBJECTIVE: We evaluated the influence of the iron status of young women on iron absorption from a rice meal with or without added tea or AA. DESIGN: Two stable-isotope iron absorption studies were made in 2 groups of 10 subjects with iron deficiency anemia (IDA) and 10 subjects who were iron replete (control subjects). In study 1, the reference rice meal was fed alone or with 1 or 2 cups of black tea. In study 2, the reference meal was fed alone or with AA (molar ratio to iron, 2:1 or 4:1). Iron absorption was measured by the erythrocyte incorporation of (57)Fe and (58)Fe labels at 14 d. RESULTS: Mean fractional iron absorption from the reference rice meal was approximately 2.5 times as great in the IDA group as in the control group (P < 0.05). The consumption of 1 or 2 cups of tea decreased iron absorption in the control subjects by 49% (P < 0.05) or 66% (P < 0.01), respectively, and in the IDA group by 59% or 67% (P < 0.001 for both), respectively. AA (molar ratio to iron, 2:1 or 4:1) increased iron absorption by 270% or 343%, respectively, in control subjects and by 291% or 350%, respectively, in subjects with IDA (P < 0.001). CONCLUSIONS: The inhibitory effect of tea and the enhancing effect of AA on iron absorption were similar in the 2 groups. Overall differences in iron absorption in the 2 groups, however, continued to be dictated by iron status.     

Intestinal microbial contribution to metabolic leucine input in adult men

New estimates of the indispensable amino acid requirements of adult humans are much higher than previously thought and questions the adequacy of cereal-based diets of low protein quality. However, dietary amino acid requirements may be supplemented by contributions from the intestinal microbiota. This study measured the contribution of intestinal microbes to leucine input in healthy adult men. Fourteen adult men were studied during each of 2 11-d periods (before and after intestinal antimicrobial treatment), in which leucine was supplied at 1.25 times the estimated average requirement (EAR) (d 1-7) and at 2.5 times the EAR (d 8-11) providing an l-amino acid diet. We estimated fasting- and fed-state leucine oxidation on d 7 and d 11 using a (13)C-leucine tracer infusion. The microbial contribution to body leucine input was calculated from the relationship of leucine oxidation to leucine intake and the reduction in leucine oxidation after antimicrobial treatment. Antimicrobial treatment did not affect the slope of the relationship of leucine oxidation to leucine intake. Mean and fed-state leucine oxidation declined by approximately 13 and 20%, respectively (both P < 0.05) after antimicrobial treatment with the 1.25 EAR diet, but not with the 2.5 EAR diet. The contribution of the intestinal microbiota to body leucine input was estimated to be between 19 and 22% at the 1.25 EAR diet. The contribution of the intestinal microbiota to body amino acid homeostasis may be significant at maintenance intakes, but its long-term nutritional importance remains to be determined.     

In vitro and in vivo characterization of neurally modified mesenchymal stem cells induced by epigenetic modifiers and neural stem cell environment

Mesenchymal stem cell (MSC)-mediated tissue regeneration is a promising strategy to treat several neurodegenerative diseases and traumatic injuries of the central nervous system. Bone marrow MSCs have great potential as therapeutic agents, since they are easy to isolate and expand and are capable of producing various cell types, including neural cells. Recently we developed a highly efficient methodology to produce neural stem-like and neural precursor-like cells from mice bone marrow-derived MSCs that eventually differentiate into neuronal- and glial-like cells in vitro. The aim of this study is to further elucidate neural expression profile of neurally induced mesenchymal stem cells (NI-MSCs) and their ability to retain neural differentiation potential when grafted into the intact spinal cord of rats. To this end, we further characterized in vitro and in vivo properties of NI-MSCs by immunocytochemistry, Western blot, ELISA, and immunohistochemistry. Immunocytochemical data demonstrated that NI-MSCs express several mature neural markers such as B3T, GFAP MAP-2, NF-200, and NeuN, which were confirmed through Western blot. ELISA data showed that NI-MSCs release nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF). In vivo studies demonstrated that grafted NI-MSCs survived after transplantation into intact spinal cord and produced cells that expressed neural markers. All these data suggest that neurally modified MSCs, induced by recently developed methodology, could be a potential source of cells to replace damaged neurons and glia in injured spinal cord, and/or to promote cell survival and axonal growth of host tissue.     

Use of bi-level biotinylation for concurrent measurement of in vivo recovery and survival in two rabbit platelet populations

BACKGROUND: The objectives of this research were 1) to determine whether two populations of platelets may be labeled with different levels of biotin and followed concurrently in vivo by flow cytometry and 2) to determine whether the level of biotinylation affects the in vivo platelet recovery and survival. STUDY DESIGN AND METHODS: Two platelet aliquots were biotinylated under conditions that resulted in either a lower or a higher number of biotin molecules per platelet. After transfusion, the two populations were distinguished and quantitated by flow cytometry. RESULTS: In five animals, recoveries were 69.8 +/− 27.0 percent for low-biotin platelets and 72.6 +/− 26.7 percent for high-biotin platelets. For each animal, the recoveries agreed closely. Life span, determined by the multiple-hit method, was 2.68 +/− 0.63 days for low-biotin platelets and 2.58 +/− 0.69 days for high-biotin platelets. These values for recovery and life span are consistent with those measured in rabbits by using radioisotope labels. CONCLUSION: Platelet biotinylation offers a nonisotopic method for direct comparison of alternative harvest and storage conditions. It also offers the potential for simultaneous evaluation of the in vivo characteristics of platelets from at least two donors.     

Recent advances in diagnosis of the childhood muscular dystrophies

Abstract: Recent advances in molecular genetics research have revolutionised our understanding of the childhood muscular dystrophies. The first breakthrough came in 1987 with the identification of the gene for dystrophin, the protein that is abnormal in X-linked Duchenne muscular dystrophy. Dystrophin is bound to a complex of proteins in the muscle membrane, and primary abnormalities of these protein have now been identified as the cause of some autosomally inherited forms of muscular dystrophy. A group of transmembrane proteins known as α- (adhalin) β-, γ- and δ-sarcoglycan are deficient in autosomal recessive limb-girdle muscular dystrophy, and the extracellular matrix protein merosin (α2-laminin), is deficient in a subset of patients with congenital muscular dystrophy. Identification of primary deficiencies in these 'dystrophin associated proteins' will result in improved diagnostic accuracy, more accurate genetic counselling and, in some cases, the availability of prenatal diagnosis.     

Body composition by a three compartment model in adult Indian male and female subjects

The body composition of 10 adult Indian male and female subjects was investigated by a three compartment model, using measurements of Total Body Water (TBW) by deuterium dilution, and of body density by hydrodensitometry. The three compartment model yielded significantly different (P < 0.005) estimates of percent body fat of 15.9+/-3.8 and 19.7+/-4.2% and of the Fat Free Mass (FFM) of 41+/-3.3 kg and 33.9+/-4.1 kg in the male and female subjects respectively. The hydration of the FFM was 0.704+/-0.032 in the males and 0.719+/-0.024 in the females; this difference was not signifcant between groups. The density of the FFM, measured from estimates of percent body fat by the 3 compartment approach and of body density by hydrodensitometry, was 1.107+/-0.014 in the males and 1.101+/-0.001 in the females with no significant differences between the groups. This study demonstrates differences in body composition between BMI matched healthy adult male and female subjects. Although there are significant differences for % Fat and FFM between the sexes, there are no significant differences in the hydration fraction and the density of the FFM.