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1.
Oncology (Williston Park) ; 34(6): 196-201, 2020 Jun 10.
Article in English | MEDLINE | ID: mdl-32609864

ABSTRACT

Pancreatic ductal adenocarcinoma (PDAC) is a disease marked by high rates of mortality; it is mostly incurable at the time of diagnosis. Only about 7% of patients survive 5 years after diagnosis. Diagnosis at a late stage and rapid progression with minimal response to available treatments are the main reasons for this poor outcome. It is crucial to identify individuals at high risk of developing PDAC so preventive and early detection measures can be employed. Approximately 10% to 15% of PDAC cases have a hereditary or familial basis. In the majority of PDAC cases, no main causative gene has been identified, but several known germline pathogenic mutations have been shown to be related to an increased risk of this cancer. The presence of 2 or more patients with pancreatic cancer within the circle of first-degree relatives, without the presence of a causative germline mutation, is defined as familial pancreatic cancer; this accounts for 4% to 10% of PDAC. Based on the growing evidence supporting the benefit of germline genetic testing in patients with PDAC, both the American Society of Clinical Oncology and the National Comprehensive Cancer Network recently updated their guidelines to include recommendations around genetic testing for patients with pancreatic cancer. However, there is no general consensus on the group of patients and individuals who should be studied and screened. We present a demonstrative case and review the available data on hereditary and familial PDAC.


Subject(s)
Carcinoma, Pancreatic Ductal/genetics , Carcinoma/genetics , Germ-Line Mutation , Pancreatic Neoplasms/genetics , Aged , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Carcinoma/diagnostic imaging , Carcinoma/therapy , Carcinoma, Pancreatic Ductal/diagnostic imaging , Carcinoma, Pancreatic Ductal/therapy , Genetic Testing/methods , Humans , Male , Neoplastic Syndromes, Hereditary/diagnostic imaging , Neoplastic Syndromes, Hereditary/genetics , Neoplastic Syndromes, Hereditary/pathology , Pancreatectomy/methods , Pancreatic Neoplasms/diagnostic imaging , Pancreatic Neoplasms/therapy , Risk Factors
2.
Clin Pediatr (Phila) ; 59(8): 787-800, 2020 07.
Article in English | MEDLINE | ID: mdl-32503395

ABSTRACT

This study evaluates the impact of a 6-month care management intervention for 206 children diagnosed with comorbid attention deficit hyperactivity disorder (ADHD) from a sample of 321 five- to 12-year-old children recruited for treatment of behavior problems in 8 pediatric primary care offices. Practices were cluster-randomized to Doctor Office Collaboration Care (DOCC) or Enhanced Usual Care (EUC). Chart reviews documented higher rates of service delivery, prescription of medication for ADHD, and titration in DOCC (vs EUC). Based on complex conditional models, DOCC showed greater acute improvement in individualized ADHD treatment goals and follow-up improvements in quality of life and ADHD and oppositional defiant disorder goals. Medication use had a significant effect on acute and follow-up ADHD symptom reduction and quality of life. Medication continuity was associated with some long-term gains. A collaborative care intervention for behavior problems that incorporated treatment guidelines for ADHD in primary care was more effective than psychoeducation and facilitated referral to community treatment.


Subject(s)
Attention Deficit Disorder with Hyperactivity/complications , Attention Deficit Disorder with Hyperactivity/therapy , Delivery of Health Care, Integrated/organization & administration , Problem Behavior , Child , Child, Preschool , Female , Humans , Male , Pennsylvania , Primary Health Care
3.
J Agric Food Chem ; 68(3): 769-778, 2020 Jan 22.
Article in English | MEDLINE | ID: mdl-31826608

ABSTRACT

Previous work with Caco-2 cell cultures has shown that individual polyphenols can either promote or inhibit iron uptake. This investigation was designed to characterize the relationship between iron bioavailability and seed coat polyphenol composition in a panel of 14 yellow beans representing five market classes with the potential for fast cooking time and high iron content. The study included two white and two red mottled bean lines, which represent high and low iron bioavailability capacity in dry beans, respectively. Polyphenols were measured quantitatively by high-performance liquid chromatography-mass spectrometry (HPLC-MS)/UV and iron bioavailability of seed coat extracts was measured in Caco-2 assays. Thirteen of the yellow bean seed types contained high concentrations (up to 35.3 ± 2.7 µmol/g) of kaempferol 3-glucoside (k 3-g), a known promoter of iron uptake. A general association between the ratio of promoting to inhibiting polyphenols (P/I) and iron uptake was observed. The presence of iron uptake inhibiting condensed tannins proportionately countered the promotional effects of kaempferol compounds. Unidentified factors present in seed coats other than polyphenols also appeared to affect iron uptake.


Subject(s)
Iron/metabolism , Phaseolus/chemistry , Plant Extracts/chemistry , Polyphenols/chemistry , Biological Availability , Biological Transport , Caco-2 Cells , Humans , Iron/chemistry , Phaseolus/classification , Phaseolus/metabolism , Plant Extracts/metabolism , Polyphenols/metabolism , Seeds/chemistry , Seeds/metabolism
4.
Nutrients ; 11(10)2019 Oct 14.
Article in English | MEDLINE | ID: mdl-31615146

ABSTRACT

This study assessed and compared the effects of the intra-amniotic administration of various concentrations of soluble extracts from chia seed (Salvia hispanica L.) on the Fe and Zn status, brush border membrane functionality, intestinal morphology, and intestinal bacterial populations, in vivo. The hypothesis was that chia seed soluble extracts will affect the intestinal morphology, functionality and intestinal bacterial populations. By using the Gallus gallus model and the intra-amniotic administration approach, seven treatment groups (non-injected, 18 Ω H2O, 40 mg/mL inulin, non-injected, 5 mg/mL, 10 mg/mL, 25 mg/mL and 50 mg/mL of chia seed soluble extracts) were utilized. At hatch, the cecum, duodenum, liver, pectoral muscle and blood samples were collected for assessment of the relative abundance of the gut microflora, relative expression of Fe- and Zn-related genes and brush border membrane functionality and morphology, relative expression of lipids-related genes, glycogen, and hemoglobin levels, respectively. This study demonstrated that the intra-amniotic administration of chia seed soluble extracts increased (p < 0.05) the villus surface area, villus length, villus width and the number of goblet cells. Further, we observed an increase (p < 0.05) in zinc transporter 1 (ZnT1) and duodenal cytochrome b (Dcytb) proteins gene expression. Our results suggest that the dietary consumption of chia seeds may improve intestinal health and functionality and may indirectly improve iron and zinc intestinal absorption.


Subject(s)
Chickens , Plant Extracts/pharmacology , Salvia/chemistry , Seeds/chemistry , Animals , Chick Embryo , Dietary Fiber/analysis , Gene Expression Regulation , Hemoglobins , Injections , Iron/blood , Iron/chemistry , Liver/chemistry , Ovum , Phytic Acid , Plant Extracts/chemistry , Zinc/blood , Zinc/chemistry
5.
J Dev Behav Pediatr ; 40(9): 686-695, 2019 12.
Article in English | MEDLINE | ID: mdl-31393319

ABSTRACT

OBJECTIVE: Pediatric primary care providers (PCPs) work in challenging environments and are increasingly called to implement complex interventions, such as behavioral health (BH) service integration. We explore how perceived stressful practice climates (1) change over time in and (2) influence provider perceptions of collaborative care versus usual care, 2 models of integrated BH care. METHODS: Secondary exploratory analysis using hierarchical linear modeling was performed on an 18-month cluster-randomized trial of 8 pediatric primary care practices to Doctor-Office Collaborative Care (DOCC), where an on-site care manager delivered BH services in coordination with PCPs, or Enhanced Usual Care (EUC), where a care manager facilitated referrals to local BH providers. Various indicators of PCP perceptions of BH services, including satisfaction with practice, burdens and beliefs regarding psychosocial problems, and effectiveness in treating behavioral problems, were assessed as outcomes. Moderators were 2 domains of stressful climates, role conflict and role overload. RESULTS: Role conflict and role overload stayed stable in both conditions. Role conflict strengthened the positive effect of DOCC on PCP perceived effectiveness in treating behavioral problems (ß [SE], 0.04 [0.02]; p = 0.04) and improvement in managing oppositional/aggressive behavior (0.02 [0.01]; p = 0.02). Role overload strengthened the positive effect of DOCC on PCP-perceived improvement in managing attention-deficit hyperactivity disorder (0.03 [0.01]; p = 0.01). Stressful climates did not influence perceptions for EUC providers. CONCLUSIONS: Providers experiencing more stressful practice climates developed more positive perceptions of collaborative care. This may encourage stressed providers to make effective practice changes and promote practice integration of BH services.


Subject(s)
Attitude of Health Personnel , Child Health Services , Delivery of Health Care, Integrated , Mental Health Services , Occupational Stress , Organizational Culture , Primary Health Care , Adult , Child , Child Health Services/organization & administration , Delivery of Health Care, Integrated/organization & administration , Humans , Mental Health Services/organization & administration , Primary Health Care/organization & administration
6.
Nutrients ; 9(7)2017 Jul 21.
Article in English | MEDLINE | ID: mdl-28754026

ABSTRACT

This paper represents a series of in vitro iron (Fe) bioavailability experiments, Fe content analysis and polyphenolic profile of the first generation of Fe biofortified beans (Phaseolus vulgaris) selected for human trials in Rwanda and released to farmers of that region. The objective of the present study was to demonstrate how the Caco-2 cell bioassay for Fe bioavailability can be utilized to assess the nutritional quality of Fe in such varieties and how they may interact with diets and meal plans of experimental studies. Furthermore, experiments were also conducted to directly compare this in vitro approach with specific human absorption studies of these Fe biofortified beans. The results show that other foods consumed with beans, such as rice, can negatively affect Fe bioavailability whereas potato may enhance the Fe absorption when consumed with beans. The results also suggest that the extrinsic labelling approach to measuring human Fe absorption can be flawed and thus provide misleading information. Overall, the results provide evidence that the Caco-2 cell bioassay represents an effective approach to evaluate the nutritional quality of Fe-biofortified beans, both separate from and within a targeted diet or meal plan.


Subject(s)
Food, Fortified , Iron/analysis , Iron/pharmacokinetics , Phaseolus/chemistry , Biological Assay , Biological Availability , Caco-2 Cells , Food Analysis , Humans , Oryza/chemistry , Phytic Acid/analysis , Polyphenols/analysis , Rwanda , Solanum tuberosum/chemistry
7.
J Agric Food Chem ; 65(16): 3285-3294, 2017 Apr 26.
Article in English | MEDLINE | ID: mdl-28361541

ABSTRACT

Polyphenolic compounds present in the seed coat of common bean (Phaseolus vulgaris L.) are known to act collectively as inhibitors of iron bioavailability. Recent research identified specific polyphenols as being potent Fe uptake inhibitors. That research also identified other polyphenols as being promoters of Fe uptake. The present study extends that work using a Caco-2 cell model to characterize the effects of 43 additional polyphenols on Fe uptake. In addition, this study indicates that the inhibitory compounds have a more potent effect that outweighs the ability of promoting compounds to increase Fe uptake. For example, a ratio of 100:0 epicatechin (a promoter)/myricetin (an inhibitor) produced 78.5 ± 6.7 ng ferritin/mg protein, 90:10 yielded 27.4 ± 3.0, 50:50 yielded 3.42 ± 0.54, and 0:100 yielded 2.26 ± 0.25 ng ferritin/mg protein. A simulation of the relative concentrations of eight major polyphenols (four inhibitors, four promoters) present in a sample of black bean seed coats demonstrated that most of the inhibitory compounds would need to be removed to reduce the negative effect on Fe uptake. In vivo studies are now warranted to confirm the above in vitro effects. Such work would be significant as other bean color classes exist that are likely to have polyphenolic profiles that are more favorable to Fe bioavailability.


Subject(s)
Iron/metabolism , Phaseolus/chemistry , Plant Extracts/pharmacology , Polyphenols/pharmacology , Biological Transport/drug effects , Caco-2 Cells , Humans , Plant Extracts/chemistry , Polyphenols/chemistry
8.
Plant Physiol Biochem ; 111: 193-202, 2017 Feb.
Article in English | MEDLINE | ID: mdl-27940270

ABSTRACT

Common beans (Phaseolus vulgaris) are the most important legume crops. They represent a major source of micronutrients and a target for essential trace mineral enhancement (i.e. biofortification). To investigate mineral accumulation during seed maturation and to examine whether it is possible to biofortify seeds with multi-micronutrients without affecting mineral bioavailability, three common bean cultivars were treated independently with zinc (Zn) and selenium (Se), the two critical micronutrients that can be effectively enhanced via fertilization. The seed mineral concentrations during seed maturation and the seed Fe bioavailability were analyzed. Common bean seeds were found to respond positively to Zn and Se treatments in accumulating these micronutrients. While the seed pods showed a decrease in Zn and Se along with Fe content during pod development, the seeds maintained relatively constant mineral concentrations during seed maturation. Selenium treatment had minimal effect on the seed accumulation of phytic acid and polyphenols, the compounds affecting Fe bioavailability. Zinc treatment reduced phytic acid level, but did not dramatically affect the concentrations of total polyphenols. Iron bioavailability was found not to be greatly affected in seeds biofortified with Se and Zn. In contrast, the inhibitory polyphenol compounds in the black bean profoundly reduced Fe bioavailability. These results provide valuable information for Se and Zn enhancement in common bean seeds and suggest the possibility to biofortify with these essential nutrients without greatly affecting mineral bioavailability to increase the food quality of common bean seeds.


Subject(s)
Iron/metabolism , Phaseolus/metabolism , Seeds/metabolism , Selenium/metabolism , Zinc/metabolism , Biofortification , Biological Availability , Biomass , Caco-2 Cells , Humans , Minerals/metabolism , Phytic Acid/metabolism , Polyphenols/metabolism , Seeds/growth & development
9.
Physiol Plant ; 158(1): 80-91, 2016 Sep.
Article in English | MEDLINE | ID: mdl-27152969

ABSTRACT

Selenium (Se) is an essential micronutrient for animals and humans and a target for biofortification in crops. Sulfur (S) is a crucial nutrient for plant growth. To gain better understanding of Se and S nutrition and interaction in plants, the effects of Se dosages and forms on plant growth as well as on S level in seven wheat lines were examined. Low dosages of both selenate and selenite supplements were found to enhance wheat shoot biomass and show no inhibitory effect on grain production. The stimulation on plant growth was correlated with increased APX antioxidant enzyme activity. Se forms were found to exert different effects on S metabolism in wheat plants. Selenate treatment promoted S accumulation, which was not observed with selenite supplement. An over threefold increase of S levels following selenate treatment at low dosages was observed in shoots of all wheat lines. Analysis of the sulfate transporter gene expression revealed an increased transcription of SULTR1;1, SULTR1;3 and SULTR4;1 in roots following 10 µM Na2 SeO4 treatment. Mass spectrometry-based targeted protein quantification confirmed the gene expression results and showed enhanced protein levels. The results suggest that Se treatment mimics S deficiency to activate specific sulfate transporter expression to stimulate S uptake, resulting in the selenate-induced S accumulation. This study supports that plant growth and nutrition benefit from low dosages of Se fertilization and provides information on the basis underlying Se-induced S accumulation in plants.


Subject(s)
Micronutrients/metabolism , Selenium/pharmacology , Sulfur/metabolism , Triticum/drug effects , Antioxidants/metabolism , Biomass , Plant Roots/drug effects , Plant Roots/growth & development , Plant Roots/metabolism , Triticum/growth & development , Triticum/metabolism
10.
PLoS One ; 10(9): e0138479, 2015.
Article in English | MEDLINE | ID: mdl-26381264

ABSTRACT

Iron (Fe) deficiency is a highly prevalent micronutrient insufficiency predominantly caused by a lack of bioavailable Fe from the diet. The consumption of beans as a major food crop in some populations suffering from Fe deficiency is relatively high. Therefore, our objective was to determine whether a biofortified variety of cream seeded carioca bean (Phaseolus vulgaris L.) could provide more bioavailable-Fe than a standard variety using in-vivo (broiler chicken, Gallus gallus) and in-vitro (Caco-2 cell) models. Studies were conducted under conditions designed to mimic the actual human feeding protocol. Two carioca-beans, a standard (G4825; 58 µg Fe/g) and a biofortified (SMC; 106 µg Fe/g), were utilized. Diets were formulated to meet the nutrient requirements of Gallus gallus except for Fe (33.7 and 48.7 µg Fe/g, standard and biofortified diets, respectively). In-vitro observations indicated that more bioavailable-Fe was present in the biofortified beans and diet (P<0.05). In-vivo, improvements in Fe-status were observed in the biofortified bean treatment, as indicated by the increased total-body-Hemoglobin-Fe, and hepatic Fe-concentration (P<0.05). Also, DMT-1 mRNA-expression was increased in the standard bean treatment (P<0.05), indicating an upregulation of absorption to compensate for less bioavailable-Fe. These results demonstrate that the biofortified beans provided more bioavailable Fe; however, the in vitro results revealed that ferritin formation values were relatively low. Such observations are indicative of the presence of high levels of polyphenols and phytate that inhibit Fe absorption. Indeed, we identified higher levels of phytate and quercetin 3-glucoside in the Fe biofortified bean variety. Our results indicate that the biofortified bean line was able to moderately improve Fe-status, and that concurrent increase in the concentration of phytate and polyphenols in beans may limit the benefit of increased Fe-concentration. Therefore, specific targeting of such compounds during the breeding process may yield improved dietary Fe-bioavailability. Our findings are in agreement with the human efficacy trial that demonstrated that the biofortified carioca beans improved the Fe-status of Rwandan women. We suggest the utilization of these in vitro and in vivo screening tools to guide studies aimed to develop and evaluate biofortified staple food crops. This approach has the potential to more effectively utilize research funds and provides a means to monitor the nutritional quality of the Fe-biofortified crops once released to farmers.


Subject(s)
Food, Fortified , Iron Deficiencies , Phaseolus/metabolism , Animals , Biological Availability , Caco-2 Cells , Cation Transport Proteins/genetics , Cation Transport Proteins/metabolism , Chickens , Cytochrome b Group/genetics , Cytochrome b Group/metabolism , Female , Ferritins/metabolism , Humans , Nutritional Requirements , Oxidoreductases/genetics , Oxidoreductases/metabolism , Phaseolus/genetics , Rwanda
11.
Nutr J ; 14: 11, 2015 Jan 23.
Article in English | MEDLINE | ID: mdl-25614193

ABSTRACT

BACKGROUND: Our objective was to compare the capacity of iron (Fe) biofortified and standard pearl millet (Pennisetum glaucum L.) to deliver Fe for hemoglobin (Hb)-synthesis. Pearl millet (PM) is common in West-Africa and India, and is well adapted to growing areas characterized by drought, low-soil fertility, and high-temperature. Because of its tolerance to difficult growing conditions, it can be grown in areas where other cereal crops, such as maize, would not survive. It accounts for approximately 50% of the total world-production of millet. Given the widespread use of PM in areas of the world affected by Fe-deficiency, it is important to establish whether biofortified-PM can improve Fe-nutriture. METHODS: Two isolines of PM, a low-Fe-control ("DG-9444", Low-Fe) and biofortified ("ICTP-8203 Fe",High-Fe) in Fe (26 µg and 85 µg-Fe/g, respectively) were used. PM-based diets were formulated to meet the nutrient requirements for the broiler (Gallus-gallus) except for Fe (Fe concentrations were 22.1±0.52 and 78.6±0.51 µg-Fe/g for the Low-Fe and High-Fe diets, respectively). For 6-weeks, Hb, feed-consumption and body-weight were measured (n = 12). RESULTS: Improved Fe-status was observed in the High-Fe group, as suggested by total-Hb-Fe values (15.5±0.8 and 26.7±1.4 mg, Low-Fe and High-Fe respectively, P<0.05). DMT-1, DcytB, and ferroportin mRNA-expression was higher (P<0.05) and liver-ferritin was lower (P>0.05) in the Low-Fe group versus High-Fe group. In-vitro comparisons indicated that the High-Fe PM should provide more absorbable-Fe; however, the cell-ferritin values of the in-vitro bioassay were very low. Such low in-vitro values, and as previously demonstrated, indicate the presence of high-levels of polyphenolic-compounds or/and phytic-acid that inhibit Fe-absorption. LC/MS-analysis yielded 15 unique parent aglycone polyphenolic-compounds elevated in the High-Fe line, corresponding to m/z = 431.09. CONCLUSIONS: The High-Fe diet appeared to deliver more absorbable-Fe as evidenced by the increased Hb and Hb-Fe status. Results suggest that some PM varieties with higher Fe contents also contain elevated polyphenolic concentrations, which inhibit Fe-bioavailability. Our observations are important as these polyphenols-compounds represent potential targets which can perhaps be manipulated during the breeding process to yield improved dietary Fe-bioavailability. Therefore, the polyphenolic and phytate profiles of PM must be carefully evaluated in order to further improve the nutritional benefit of this crop.


Subject(s)
Iron, Dietary/administration & dosage , Iron/analysis , Iron/pharmacokinetics , Pennisetum/chemistry , Polyphenols/analysis , Seeds/chemistry , Africa, Western , Animal Feed/analysis , Animals , Biological Availability , Caco-2 Cells , Chickens , Ferritins/analysis , Ferritins/biosynthesis , Food, Fortified , Hemoglobins/analysis , Hemoglobins/biosynthesis , Humans , India , Iron Deficiencies , Liver/chemistry , Models, Animal , Nutritional Requirements , Phytic Acid/analysis
12.
Proc Natl Acad Sci U S A ; 111(34): 12556-61, 2014 Aug 26.
Article in English | MEDLINE | ID: mdl-25114221

ABSTRACT

In a fluorescence polarization screen for the MYC-MAX interaction, we have identified a novel small-molecule inhibitor of MYC, KJ-Pyr-9, from a Kröhnke pyridine library. The Kd of KJ-Pyr-9 for MYC in vitro is 6.5 ± 1.0 nM, as determined by backscattering interferometry; KJ-Pyr-9 also interferes with MYC-MAX complex formation in the cell, as shown in a protein fragment complementation assay. KJ-Pyr-9 specifically inhibits MYC-induced oncogenic transformation in cell culture; it has no or only weak effects on the oncogenic activity of several unrelated oncoproteins. KJ-Pyr-9 preferentially interferes with the proliferation of MYC-overexpressing human and avian cells and specifically reduces the MYC-driven transcriptional signature. In vivo, KJ-Pyr-9 effectively blocks the growth of a xenotransplant of MYC-amplified human cancer cells.


Subject(s)
Antineoplastic Agents/pharmacology , Proto-Oncogene Proteins c-myc/antagonists & inhibitors , Pyridines/pharmacology , Pyrimidines/pharmacology , Animals , Antineoplastic Agents/chemistry , Basic Helix-Loop-Helix Leucine Zipper Transcription Factors/antagonists & inhibitors , Basic Helix-Loop-Helix Leucine Zipper Transcription Factors/chemistry , Cell Proliferation/drug effects , Cell Transformation, Neoplastic/drug effects , Cell Transformation, Neoplastic/genetics , Cells, Cultured , Chick Embryo , Drug Evaluation, Preclinical , Female , Fluorescence Polarization , Genes, myc , Humans , Interferometry , Mice , Mice, Nude , Multiprotein Complexes/antagonists & inhibitors , Multiprotein Complexes/chemistry , Protein Interaction Domains and Motifs/drug effects , Proto-Oncogene Proteins c-myc/chemistry , Pyridines/chemistry , Pyrimidines/chemistry , Xenograft Model Antitumor Assays
13.
Plant Sci ; 224: 27-35, 2014 Jul.
Article in English | MEDLINE | ID: mdl-24908503

ABSTRACT

Exploration of genetic resources for micronutrient concentrations facilitates the breeding of nutrient-dense crops, which is increasingly seen as an additional, sustainable strategy to combat global micronutrient deficiency. In this work, we evaluated genotypic variation in grain nutrient concentrations of 20 Brazil wheat (Triticum aestivum L.) accessions in response to zinc (Zn) and Zn plus selenium (Se) treatment. Zn and Se concentrations in grains exhibited 2- and 1.5-fold difference, respectively, between these wheat accessions. A variation of up to 3-fold enhancement of grain Zn concentration was observed when additionally Zn was supplied, indicating a wide range capacity of the wheat lines in accumulating Zn in grains. Moreover, grain Zn concentration was further enhanced in some lines following supply of Zn plus Se, showing stimulative effect by Se and the feasibility of simultaneous biofortification of Zn and Se in grains of some wheat lines. In addition, Se supply with Zn improved the accumulation of another important micronutrient, iron (Fe), in grains of half of these wheat lines, suggesting a beneficial role of simultaneous biofortification of Zn with Se. The significant diversity in these wheat accessions offers genetic potential for developing cultivars with better ability to accumulate important micronutrients in grains.


Subject(s)
Genetic Variation , Genotype , Seeds/metabolism , Selenium/metabolism , Triticum/genetics , Zinc/metabolism , Brazil , Iron/metabolism , Species Specificity , Triticum/metabolism
14.
Methods Enzymol ; 438: 291-305, 2008.
Article in English | MEDLINE | ID: mdl-18413256

ABSTRACT

Signaling by class I phosphatidylinositol 3-kinase (PI3K) controls cell growth, replication, motility, and metabolism. The PI3K pathway commonly shows gain of function in cancer. Two small GTPases, Rheb (Ras homolog enriched in brain) and Ras (rat sarcoma viral oncogene), play important roles in PI3K signaling. Rheb activates the TOR (target of rapamycin) kinase in a GTP-dependent manner; it links TOR to upstream signaling components, including the tuberous sclerosis complex (TSC) and Akt (homolog of the Akt8 murine lymphoma viral oncoprotein). Constitutively active, GTP-bound Rheb is oncogenic in cell culture, and activity that requires farnesylation. Ras activates PI3K by recruitment to the plasma membrane and possibly by inducing a conformational change in the catalytic subunit p110 of PI3K. In return, Ras signaling through the MAP kinase (MAPK) pathway is activated by PIP(3), the product of PI3K. Loss of Ras function can interfere with PI3K signaling. Various lines of evidence suggest complementary roles for PI3K and MAPK signaling in oncogenesis.


Subject(s)
Neoplasms/physiopathology , Phosphatidylinositol 3-Kinases/genetics , Animals , Cell Transformation, Neoplastic , Class I Phosphatidylinositol 3-Kinases , Mice , Monomeric GTP-Binding Proteins/physiology , Neoplasms/genetics , Neuropeptides/physiology , Phosphatidylinositol 3-Kinases/physiology , Phosphatidylinositol Phosphates/physiology , Ras Homolog Enriched in Brain Protein , Signal Transduction
15.
New Phytol ; 167(2): 391-401, 2005 Aug.
Article in English | MEDLINE | ID: mdl-15998393

ABSTRACT

Here, we examined the effectiveness of two approaches for reducing cadmium (Cd) accumulation in durum wheat (Triticum turgidum L. var durum) grain: the application of supplemental zinc (Zn), and the use of cultivars exhibiting reduced grain Cd concentrations. Two durum wheat near-isogenic lines (NIL) that differ in grain Cd accumulation were grown to maturity in solution culture containing a chelating agent to buffer the free activities of Zn and Cd at levels approximating those of field conditions. The low Cd accumulating (L-Cd) isoline had Cd concentrations, in grains and shoot parts, which were 60-70% lower than those of the high Cd accumulating (H-Cd) isoline. Increasing the Zn activities in the nutrient solution from deficient to sufficient levels reduced the concentration of Cd in grains and vegetative shoot parts of both isolines. The results suggest that supplemental Zn reduces Cd tissue concentrations by inhibiting Cd uptake into roots. Cd partitioning patterns between roots and shoots and between spike components suggest that the physiological basis for the low Cd trait is related to the compartmentation or symplasmic translocation of Cd.


Subject(s)
Cadmium/pharmacokinetics , Triticum/drug effects , Triticum/metabolism , Zinc/pharmacology , Biological Transport, Active/drug effects , Biomass , Cadmium/toxicity , Food Contamination/prevention & control , Species Specificity , Tissue Distribution , Triticum/growth & development , Zinc/pharmacokinetics
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