Background: Dietetic students often show limited counseling skills when they enter internship pro... more Background: Dietetic students often show limited counseling skills when they enter internship programs. Research has shown that dietetic students need more training in counseling skills. This study was developed to assess students’ learning needs in counseling skills through peer-evaluations and self-reflection. Methods: Students who registered in the senior Nutrition Assessment and Counseling course from a mid-sized university in southeast Texas, United States, performed a counseling practicum at the end of the semester. Students role-playing as clients were given scenarios of common disease conditions (e.g., hyperlipidemia, hypertension, diabetes, and obesity), and students playing as counselors would interview and counsel the client with the specific condition. Each counselor rotated to four different clients, with each session lasting about 20 minutes. Each client filled out an evaluation and noted the strengths and weaknesses of each counselor they met. Each student also evalua...
Background: Dietetic students often show limited counseling skills when they enter internship pro... more Background: Dietetic students often show limited counseling skills when they enter internship programs. Research has shown that dietetic students need more training in counseling skills. This study was developed to assess students' learning needs in counseling skills through peer-evaluations and self-reflection. Methods: Students who registered in the senior Nutrition Assessment and Counseling course from a mid-sized university in southeast Texas, United States, performed a counseling practicum at the end of the semester. Students role-playing as clients were given scenarios of common disease conditions (e.g., hyperlipidemia, hypertension, diabetes, and obesity), and students playing as counselors would interview and counsel the client with the specific condition. Each counselor rotated to four different clients, with each session lasting about 20 minutes. Each client filled out an evaluation and noted the strengths and weaknesses of each counselor they met. Each student also ev...
Genetic markers of two general types have been used to assess the number of simultaneously produc... more Genetic markers of two general types have been used to assess the number of simultaneously productive stem cells in vivo, retrovirus markers and enzyme or hemoglobin variants. Use of the two techniques has led to different conclusions regarding stem-cell population organization, kinetics, and usage. To better understand this discrepancy, we have combined the two methods by retrovirally marking and transplanting stem cell populations of allophenic mice in which all tissues, including the hematopoietic system, are chimeric. Hematopoietic and lymphoid tissues of engrafted recipients were analyzed by Southern blotting to determine the number and extent of participation of individually marked stem cells. Genotypic chimerism of the same tissues was determined by quantitating electrophoretic variants of glu-
Genetic markers of two general types have been used to assess the number of simultaneously produc... more Genetic markers of two general types have been used to assess the number of simultaneously productive stem cells in vivo, retrovirus markers and enzyme or hemoglobin variants. Use of the two techniques has led to different conclusions regarding stem-cell population organization, kinetics, and usage. To better understand this discrepancy, we have combined the two methods by retrovirally marking and transplanting stem cell populations of allophenic mice in which all tissues, including the hematopoietic system, are chimeric. Hematopoietic and lymphoid tissues of engrafted recipients were analyzed by Southern blotting to determine the number and extent of participation of individually marked stem cells. Genotypic chimerism of the same tissues was determined by quantitating electrophoretic variants of glucose phosphate isomerase. This procedure permitted the genotypic identification of individual stem-cell clones. The results demonstrate the participation of few pluripotent stem cells in...
We have studied contributions to hematopoiesis of genetically distinct stem cell populations in a... more We have studied contributions to hematopoiesis of genetically distinct stem cell populations in allophenic mice. Chimeras were made by aggregating embryos of inbred strains known to differ with respect to stem cell population kinetics. One partner strain (DBA/2) has previously been shown to normally have a stem cell (CFU-S) population of which 24% are in S-phase of the cell cycle, whereas the homologous population of the other partner strain (C57BL/6) was characterized by having only 2.6% in cycle (7). Contributions of the chimeric stem cell population to mature blood cell pools were studied throughout the life of the mice and intrinsic differences in stem cell function and aging were reflected in dynamic patterns of blood cell composition. The DBA/2 stem cell population was eclipsed by stem cells of the C57BL/6 genotype and, after 1.5-3 yr, the hemato-lymphoid composition of 22 of 27 mice studied for this long had shifted by at least 25 percentage points toward the C57BL/6 genotype...
The bioavailability of selenium (Se) from veal, chicken, beef, pork, lamb, flounder, tuna, seleno... more The bioavailability of selenium (Se) from veal, chicken, beef, pork, lamb, flounder, tuna, selenomethionine (SeMet), and sodium selenite was assessed in Se-deficient Fischer-344 rats. Se as veal, chicken, beef, pork, lamb, flounder, tuna, SeMet, and sodium selenite was added to torula yeast (TY) basal diets to comprise Se-inadequate (0.05 mg Se/kg) diets. Se as sodium selenite was added to a TY basal diet to comprise a Se-adequate (0.10 mg Se/kg), Se-control diet. The experimental diets were fed to weanling Fischer-344 rats that had been subjected to dietary Se depletion for 6 wk. After 9 wk of the dietary Se repletion, relative activity of liver glutathione peroxidase (GSHPx) from the different dietary groups compared with control rats (100%) was: flounder 106%, tuna 101%, pork 86%, sodium selenite 81%, SeMet 80%, beef 80%, chicken 77%, veal 77%, and lamb 58%. Se from flounder was the most efficient at restoring Se concentrations in the liver and skeletal muscle. Se from sodium sel...
During the aging process of males, testosterone biosynthesis declines in testicular Leydig cells ... more During the aging process of males, testosterone biosynthesis declines in testicular Leydig cells resulting in decreases in various physiological functions. To explore the possibility of delaying the decline using food supplements, we have studied steroidogenic effects of a natural flavonoid, chrysin, in mouse Leydig cells. Chrysin dramatically increased cyclic AMP (cAMP)-induced steroidogenesis in MA-10 mouse Leydig tumor cells. This result was confirmed using Leydig cells isolated from mouse testes. The steroidogenic effect of chrysin is not associated with an increase in expression of the P450 side-chain cleavage enzyme, required for the conversion of cholesterol to pregnenolone. In addition, when 22(R)hydroxylcholesterol was used as a substrate, chrysin induced a non-significant increase in steroid hormone, suggesting that the majority of the observed increase in steroidogenesis was due to the increased supply of substrate cholesterol. These observations were corroborated by show...
Critical Reviews in Food Science and Nutrition, 2009
The science supporting the Dietary Reference Intakes (DRI) for phosphorus, magnesium, vitamin D, ... more The science supporting the Dietary Reference Intakes (DRI) for phosphorus, magnesium, vitamin D, and fluoride was examined in this review. Along with the previous article on calcium in this series both of these reviews represent all the DRI for nutrients considered essential for bone metabolism and health, as reported in the Dietary Reference Intakes for Calcium, Phosphorus, Magnesium, Vitamin D, and Fluoride (Institute of Medicine, Food and Nutrition Board (FNB), 1997). The Recomended Dietary Allowances (RDA) or adequate intake (AI), and the tolerable upper intake level (UL) were recommended for each of these essential nutrients. For adults and in the case of fluoride, for infants as well, UL were calculated since all of these nutrients have the potential for mild to detrimental side effects. Dietary intake data and controversies regarding the role these nutrients may play in other chronic diseases have also been discussed. Advances and controversies reported since the publication of the DRI for these nutrients were also addressed in this review. A recent Dietary Reference Intake Research Synthesis Workshop report identified an extensive range of suggested future research directions needed to improve our understanding of these bone-related nutrients and their contributions to human health.
Critical Reviews in Food Science and Nutrition, 2008
In this article the science relied on to establish the Dietary Reference Intakes (DRI) specifical... more In this article the science relied on to establish the Dietary Reference Intakes (DRI) specifically for calcium was examined. The latest dietary recommendations for the essential nutrients significant with respect to their roles in bone metabolism and health were reported in the Dietary Reference Intakes for Calcium, Phosphorus, Magnesium, Vitamin D, and Fluoride (1997) (NIM, 1997). For calcium an adequate intake was recommended because insufficient data were available at the time to determine specific Recommended Dietary Allowances. Dietary intake data and the controversies regarding the role calcium may play in other chronic diseases have also been discussed. Advances and continued dilemmas regarding these topics reported since the publication of the DRI were also addressed in this review. A recent Dietary Reference Intake Research Synthesis Workshop report identified an extensive range of suggested future research directions needed to improve our understanding of calcium and bone and health.
Background: Dietetic students often show limited counseling skills when they enter internship pro... more Background: Dietetic students often show limited counseling skills when they enter internship programs. Research has shown that dietetic students need more training in counseling skills. This study was developed to assess students’ learning needs in counseling skills through peer-evaluations and self-reflection. Methods: Students who registered in the senior Nutrition Assessment and Counseling course from a mid-sized university in southeast Texas, United States, performed a counseling practicum at the end of the semester. Students role-playing as clients were given scenarios of common disease conditions (e.g., hyperlipidemia, hypertension, diabetes, and obesity), and students playing as counselors would interview and counsel the client with the specific condition. Each counselor rotated to four different clients, with each session lasting about 20 minutes. Each client filled out an evaluation and noted the strengths and weaknesses of each counselor they met. Each student also evalua...
Background: Dietetic students often show limited counseling skills when they enter internship pro... more Background: Dietetic students often show limited counseling skills when they enter internship programs. Research has shown that dietetic students need more training in counseling skills. This study was developed to assess students' learning needs in counseling skills through peer-evaluations and self-reflection. Methods: Students who registered in the senior Nutrition Assessment and Counseling course from a mid-sized university in southeast Texas, United States, performed a counseling practicum at the end of the semester. Students role-playing as clients were given scenarios of common disease conditions (e.g., hyperlipidemia, hypertension, diabetes, and obesity), and students playing as counselors would interview and counsel the client with the specific condition. Each counselor rotated to four different clients, with each session lasting about 20 minutes. Each client filled out an evaluation and noted the strengths and weaknesses of each counselor they met. Each student also ev...
Genetic markers of two general types have been used to assess the number of simultaneously produc... more Genetic markers of two general types have been used to assess the number of simultaneously productive stem cells in vivo, retrovirus markers and enzyme or hemoglobin variants. Use of the two techniques has led to different conclusions regarding stem-cell population organization, kinetics, and usage. To better understand this discrepancy, we have combined the two methods by retrovirally marking and transplanting stem cell populations of allophenic mice in which all tissues, including the hematopoietic system, are chimeric. Hematopoietic and lymphoid tissues of engrafted recipients were analyzed by Southern blotting to determine the number and extent of participation of individually marked stem cells. Genotypic chimerism of the same tissues was determined by quantitating electrophoretic variants of glu-
Genetic markers of two general types have been used to assess the number of simultaneously produc... more Genetic markers of two general types have been used to assess the number of simultaneously productive stem cells in vivo, retrovirus markers and enzyme or hemoglobin variants. Use of the two techniques has led to different conclusions regarding stem-cell population organization, kinetics, and usage. To better understand this discrepancy, we have combined the two methods by retrovirally marking and transplanting stem cell populations of allophenic mice in which all tissues, including the hematopoietic system, are chimeric. Hematopoietic and lymphoid tissues of engrafted recipients were analyzed by Southern blotting to determine the number and extent of participation of individually marked stem cells. Genotypic chimerism of the same tissues was determined by quantitating electrophoretic variants of glucose phosphate isomerase. This procedure permitted the genotypic identification of individual stem-cell clones. The results demonstrate the participation of few pluripotent stem cells in...
We have studied contributions to hematopoiesis of genetically distinct stem cell populations in a... more We have studied contributions to hematopoiesis of genetically distinct stem cell populations in allophenic mice. Chimeras were made by aggregating embryos of inbred strains known to differ with respect to stem cell population kinetics. One partner strain (DBA/2) has previously been shown to normally have a stem cell (CFU-S) population of which 24% are in S-phase of the cell cycle, whereas the homologous population of the other partner strain (C57BL/6) was characterized by having only 2.6% in cycle (7). Contributions of the chimeric stem cell population to mature blood cell pools were studied throughout the life of the mice and intrinsic differences in stem cell function and aging were reflected in dynamic patterns of blood cell composition. The DBA/2 stem cell population was eclipsed by stem cells of the C57BL/6 genotype and, after 1.5-3 yr, the hemato-lymphoid composition of 22 of 27 mice studied for this long had shifted by at least 25 percentage points toward the C57BL/6 genotype...
The bioavailability of selenium (Se) from veal, chicken, beef, pork, lamb, flounder, tuna, seleno... more The bioavailability of selenium (Se) from veal, chicken, beef, pork, lamb, flounder, tuna, selenomethionine (SeMet), and sodium selenite was assessed in Se-deficient Fischer-344 rats. Se as veal, chicken, beef, pork, lamb, flounder, tuna, SeMet, and sodium selenite was added to torula yeast (TY) basal diets to comprise Se-inadequate (0.05 mg Se/kg) diets. Se as sodium selenite was added to a TY basal diet to comprise a Se-adequate (0.10 mg Se/kg), Se-control diet. The experimental diets were fed to weanling Fischer-344 rats that had been subjected to dietary Se depletion for 6 wk. After 9 wk of the dietary Se repletion, relative activity of liver glutathione peroxidase (GSHPx) from the different dietary groups compared with control rats (100%) was: flounder 106%, tuna 101%, pork 86%, sodium selenite 81%, SeMet 80%, beef 80%, chicken 77%, veal 77%, and lamb 58%. Se from flounder was the most efficient at restoring Se concentrations in the liver and skeletal muscle. Se from sodium sel...
During the aging process of males, testosterone biosynthesis declines in testicular Leydig cells ... more During the aging process of males, testosterone biosynthesis declines in testicular Leydig cells resulting in decreases in various physiological functions. To explore the possibility of delaying the decline using food supplements, we have studied steroidogenic effects of a natural flavonoid, chrysin, in mouse Leydig cells. Chrysin dramatically increased cyclic AMP (cAMP)-induced steroidogenesis in MA-10 mouse Leydig tumor cells. This result was confirmed using Leydig cells isolated from mouse testes. The steroidogenic effect of chrysin is not associated with an increase in expression of the P450 side-chain cleavage enzyme, required for the conversion of cholesterol to pregnenolone. In addition, when 22(R)hydroxylcholesterol was used as a substrate, chrysin induced a non-significant increase in steroid hormone, suggesting that the majority of the observed increase in steroidogenesis was due to the increased supply of substrate cholesterol. These observations were corroborated by show...
Critical Reviews in Food Science and Nutrition, 2009
The science supporting the Dietary Reference Intakes (DRI) for phosphorus, magnesium, vitamin D, ... more The science supporting the Dietary Reference Intakes (DRI) for phosphorus, magnesium, vitamin D, and fluoride was examined in this review. Along with the previous article on calcium in this series both of these reviews represent all the DRI for nutrients considered essential for bone metabolism and health, as reported in the Dietary Reference Intakes for Calcium, Phosphorus, Magnesium, Vitamin D, and Fluoride (Institute of Medicine, Food and Nutrition Board (FNB), 1997). The Recomended Dietary Allowances (RDA) or adequate intake (AI), and the tolerable upper intake level (UL) were recommended for each of these essential nutrients. For adults and in the case of fluoride, for infants as well, UL were calculated since all of these nutrients have the potential for mild to detrimental side effects. Dietary intake data and controversies regarding the role these nutrients may play in other chronic diseases have also been discussed. Advances and controversies reported since the publication of the DRI for these nutrients were also addressed in this review. A recent Dietary Reference Intake Research Synthesis Workshop report identified an extensive range of suggested future research directions needed to improve our understanding of these bone-related nutrients and their contributions to human health.
Critical Reviews in Food Science and Nutrition, 2008
In this article the science relied on to establish the Dietary Reference Intakes (DRI) specifical... more In this article the science relied on to establish the Dietary Reference Intakes (DRI) specifically for calcium was examined. The latest dietary recommendations for the essential nutrients significant with respect to their roles in bone metabolism and health were reported in the Dietary Reference Intakes for Calcium, Phosphorus, Magnesium, Vitamin D, and Fluoride (1997) (NIM, 1997). For calcium an adequate intake was recommended because insufficient data were available at the time to determine specific Recommended Dietary Allowances. Dietary intake data and the controversies regarding the role calcium may play in other chronic diseases have also been discussed. Advances and continued dilemmas regarding these topics reported since the publication of the DRI were also addressed in this review. A recent Dietary Reference Intake Research Synthesis Workshop report identified an extensive range of suggested future research directions needed to improve our understanding of calcium and bone and health.
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