Faculty Research Interests
Steven A. Abrams, M.D.
research focuses on the mineral nutritional needs of
infants, children and adolescents. His first major
area of interest is in calcium and bone mineral requirements
of children. The goal of this work is to evaluate methods
for optimizing bone mass in childhood, using stable
isotopes to measure calcium absorption and bone kinetics.
His second area of interest is in identifying the optimal
forms and amount of iron and zinc to provide to small
children, especially those who live in developing countries.
In these countries, iron deficiency anemia and zinc
deficiency are extremely common and strategies must
be developed for fortifying food sources and providing
complementary foods with adequate amounts of bioavailable
minerals. His team frequently travels to other countries
to assess these issues and assist in developing research
programs using iron and zinc stable isotopes.
Cheryl B. Anderson,
Dr. Anderson's research is aimed at
promoting regular physical activity through understanding
its determinants, including self-identity as a motivational
factor in health behavior. A primary focus is the description
and measurement of athletic identity and its relation
to physical activity in children, adolescents, and
parents, as well as factors that contribute to identity
formation, stability, and change. Another focus of
her research is the development of psychometrically
valid and reliable measurement instruments of attitudes
and behaviors, as well as the statistical evaluation
of existing measurement instruments that are used in
Janice Baranowski, M.P.H.,
Ms. Baranowski is interested in
dietary and physical activity health promotion, and
obesity and chronic disease prevention among children
and their families. She designs, implements and evaluates
programs to help children and their families change
dietary and physical activity behaviors. Ms. Baranowski
currently is co-principal investigator on a diet and
physical activity badge program for Boy Scouts, and
an investigation of influences on availability of fruit,
juice and vegetables in the home, and a diabetes prevention
trial among middle-school students.
Dr. Baranowski is interested in obesity
and chronic disease prevention among children and their
families. Toward this end, he develops and tests new
measures of diet and physical activity; assesses correlates
of diet and physical activity; and designs, implements
and evaluates programs to help children and their families
change dietary and physical activity behaviors. He
currently is principal investigator on an obesity prevention
project among African-American girls, a diet and physical
activity badge program for Boy Scouts, a diabetes prevention
trial among middle-school students, and an investigation
of influences on availability of fruit, juice and vegetables
in the home.
Dennis M. Bier, M.D.
primary research interest is the integrated regulation
of interorgan transport of metabolic fuels; specifically,
substrate and hormonal regulation of the macronutrient
fuels, glucose, fatty acids, ketones, and proteins/amino
acids. This work has contributed broadly to the endocrine,
nutritional and physiological regulation of endogenous
fuel availability for biochemical and nutritional functions
in otherwise healthy infants born very prematurely,
normal newborn infants born at term, growing children,
maturing adolescents, and healthy young and elderly
adults. Further, his laboratory has helped both define
and refine assessment of the altered metabolic fates
of ingested, exogenous fuels under various pathophysiological
circumstances that detrimentally change nutritional
homeostasis, for example the metabolic fuel derangements
accompanying diabetes and renal failure. In these endeavors,
his laboratory has developed and employed a wide variety
of stable isotope tracer kinetic methods that have
now become the standards in the field for quantifying
substrate flux, metabolism, precursor-product relationships,
and irreversible oxidation to exhaled or excreted end
Douglas G. Burrin, Ph.D.
major research goal is to elucidate the critical cellular
and hormonal signals mediating the stimulatory effects
of enteral nutrition on the growth and function of
the neonatal intestine. Current studies examine the
physiological and clinical significance of GLP-2 and
enteral nutrition, and how they impact intestinal nutrient
metabolism in his neonatal pig model. Current studies
are designed to quantify the intestinal metabolism
of sulfur amino acids, methionine and cysteine, and
their impact on epithelial cell function. Isotope tracers
coupled with arteriovenous organ balance and blood
flow measurements are used to quantify the intestinal
absorption and metabolism of amino acids provided either
enterally or parenterally. Several studies are also
aimed at establishing the neuroendocrine cellular signals
that mediate the stimulation of intestinal blood flow
and enhanced epithelial cell survival in response to
enteral nutrition and GLP-2 treatment. The cellular
localization of the GLP-2 receptor and intercellular
signaling networks involved in receptor function are
being characterized using in situ hybridization
and confocal microscopy. In addition the intracellular
signaling pathways that mediate the effect of GLP-2
on mucosal epithelial cell protein turnover, proliferation
and programmed cell death rates.
Nancy F. Butte, Ph.D.
environmental causes of childhood obesity are the current
focus of Dr. Butte's research. A genomic scan for loci
associated with the development of obesity is being
performed in 1,600 Hispanic individuals from 300 nuclear
families. Extensive phenotyping of the children includes
measurements of body composition, food intake, eating
behavior, energy partitioning during growth, energy
expenditure, physical fitness and activity, and serum
hormones and metabolites. Extensive research on the
food intake, energy expenditure and body composition
of infants and children preceded this work on childhood
obesity. Other major interests include the functional
consequences of variations in energy balance on pregnancy
outcome, postpartum weight retention, lactation performance,
and infant growth and development.
Joan Carter, R.D., M.B.A.
focus is the dissemination of information about the
research activities of the USDA/ARS Children's Nutrition
Research Center through print and electronic materials
describing the center's mission, organization, and
research efforts. She is editor of the CNRC's award-winning
consumer-oriented newsletter, Nutrition & Your
Child, and webmaster for the center's web site, www.kidsnutrition.org,
as well as for related faculty and research project
web sites. She also serves as the center's liaison
to the public, the media, and Baylor College of Medicine
Ning-Hui Cheng, Ph.D.
of calcium transporters is essential for modulating
Ca 2+ signaling and/or Ca 2+ homeostasis that are involved
in the growth and adaptation of all organisms. Dr.
Cheng's research focus is to study the molecular mechanism
underlying the regulation of plant ion transporters,
such as particular calcium transporters ( Ca lcium
e x changer, CAX). He recently identified and isolated
multiple regulatory proteins that can post-translationally
modulate CAX-mediated Ca 2+ transport and may play
a vital role in integrating Ca 2+ signaling with other
cellular processes. He is also investigating the regulation
of those ion transporter genes under normal and stress
condition. Using a genetic tool, he is performing a
genome-wide screening for the genes that can transcriptionally
regulate CAX expression. These studies will elucidate
how the regulatory networks modulate Ca 2+ signaling
and homeostasis and also provide insights in developing
new strategies to manipulate the nutritional quality
of plant foods.
Brian S. Conklin, Ph.D.
is a bioengineer currently studying the effects of
shear stress on the permeability of endothelium, specifically
the permeability of endothelium in arteries to the
passage of LDL. These studies involve the development
of in vitro and ex vivo models
that establish authentic arterial pulse waves with
physiologically relevant wall shear stresses for the
study of functional and gene expression effects on
Orla M. Conneely, Ph.D.
research concerns the role of the iron-binding protein,
lactoferrin (LF), in the regulation of homeostasis,
growth and development of the gastrointestinal tract
and in protection against bacterial infection and inflammation.
Lactoferrin is a multifunctional protein found at very
high levels in milk and in the body secretions that
interface with the external environment. The second
most abundant protein in human breast milk, LF is inactivated
in infant formulae. Studies in LF-deficient mice generated
by Dr. Conneely indicate that LF is not required for
intestinal iron uptake, but plays a critical role in
preventing excessive iron absorption during the neonatal
period of development. She plans to continue her studies
on the neonatal iron sequestration role of LF, and
to examine its role in prevention against bacterial
infections. She will also examine the consequences
of LF ablation on intestinal inflammation, using mouse
models of Crohn's disease and ulcerative colitis.
Austin J. Cooney, Ph.D.
research goal is to understand the mechanism by which
the transcription factor GCNF regulates embryonic gene
expression, and the influence of the maternal diet
on its activity. His research focuses on identifying
GCNF- responsive target genes expressed during embryogenesis
and studying the GCNF mode of regulation of these genes.
To date, he has been able to identify HNF4 as a GCNF-
responsive gene that is silenced in somatic cells after
gastrulation by GCNF. Using a yeast two-hybrid screen,
he has identified DNA methyl transferases as interacting
partners of GCNF. Methylation of DNA around genes has
been implicated in the silencing of genes, so this
would be the first example of regulated and targeted
DNA methylation by specific recruitment of a DNA methyltransferase.
His laboratory is using knockout mouse models and the
multipotent embryonic carcinoma cell P19 to study GCNF's
regulation of HNF4 expression via DNA methylation.
Karen Weber Cullen, Dr. P.H.
Cullen's research focuses on two main areas: promoting
healthy school food environments, and enabling families
to provide healthy food environments and appropriate
parenting about food. Current projects include developing
and implementing a school-based program for the prevention
of Type 2 diabetes among youth, conducting a feasibility
study on an Internet-based dietary behavior change
program for families, and developing and implementing
a family based intervention in conjunction with the
Texas Cooperative Extension program.
A. Cunningham, Ph.D.
Dr. Cunningham is studying
the contributions of adhesion molecules to the migration
of leukocytes from blood into tissue, a potentially
important step in the accumulation of macrophages in
adipose tissue. These studies deal with the molecular
interactions of adhesion molecules in a newly discovered
family referred to as junctional adhesion molecules
(JAMs). She has discovered two new members of this
family and has developed mice that are selectively
deficient in the expression of these two new JAM family
members. These mice are currently being evaluated for
phenotypic characteristics associated with the deletion
of these genes.
Teresa A. Davis,
Dr. Davis' research goal is to identify
the mechanisms by which hormones and nutrients interact
to regulate the high rate of skeletal muscle protein
deposition in the neonate. To achieve this objective,
her research focuses on five main areas: the role of
insulin, amino acids, and glucose in the regulation
of protein synthesis in the neonate; the role of insulin,
amino acids, and glucose in the regulation of the insulin
and nutrient signaling pathways that lead to translation
initiation in the neonate; the role of hormones, cytokines,
and nutrients in the regulation of muscle protein synthesis
during sepsis in the neonate; the role of development
in the regulation of the protein synthetic response
to dietary protein, and the role of nutrient intake
and insulin in the anabolic response to growth hormone.
Debby Demory-Luce, Ph.D.
points of interest of Dr. Demory-Luce are the eating
habits of preschool children and pediatric nutrition
education for primary care providers. A current research
area involves the examination of how preschool children's
eating habits are affected by environmental factors
and their parents' personal characteristics, such as
weight and health-related beliefs.
J. Ellis, Ph.D.
A primary goal of Dr. Ellis'
research is to establish reference standards for body
elemental composition in infancy, childhood and adolescence.
This research focuses on the development and application
techniques for in vivo studies of human body composition.
This approach provides knowledge of changes in growth
and body composition that reflect the body's cumulative
response to basic physiologic and metabolic processes.
Detection of these changes often requires unique instrumentation
like the CNRC's whole body counter, which monitors
40 K, a naturally occurring isotope in the human. Dr.
Ellis has continued to develop in vivo neutron
activation techniques for clinical research and postmortem
examinations, and he has extended the use of dual-energy
X-ray absorptiometry to the examination of infants
Marta L. Fiorotto, Ph.D.
of Dr. Fiorotto's research is the regulation of muscle
growth rate during early postnatal life and its impact
on muscle function in adulthood. The major objective
is to identify how the developmental stage of muscle
tissue influences both the short- and the long-term
response of the muscle to two of the primary regulators
of muscle growth: nutrient availability and endocrine
factors (GHRH, growth hormone, and insulin-like growth
factors). In addition to overall growth and body composition
effects, Dr. Fiorotto is also examining the rate of
muscle protein turnover, the expression of muscle-specific
protein genes and transcription factors, satellite
cell replication and accretion. For these studies,
she uses animal models, such as transgenic mice with
altered muscle growth and growth factor expression,
as well as gene-transfer techniques in which an exogenous
gene for GHRH is administered postnatally, or prenatally
to the mother.
Jennifer Orlet Fisher, Ph.D.
Fisher's research investigates the development of food
preferences and the controls of food intake during
infancy and early childhood. The broad goal of her
research program is to understand how early eating
environments modify young children's eating behavior
and health outcomes. Of particular interest
is the role of parents in selecting foods of the family
diet, in serving as models of eating behavior, and
in making child-feeding decisions that affect child
food preferences, selection, and intake patterns. Currently
studies are being conducted to understand the influence
of maternal feeding practices on the development of
food intake regulation and growth during infancy. Another
line of research evaluates the role of maternal feeding
practices and family eating styles in problematic food
intake regulation and overweight among Hispanic children. Finally,
experimental research is being conducted to determine
the effects of large portions on daily intake in young
children and their mothers.
John P. Foreyt, Ph.D.
Lifestyle Overweight (FLOW) Prevention Program is designed
to determine the effectiveness of a self-help intervention
versus a community-based, instructor-led, multi-component
physical activity and nutrition intervention for 10-15
year-old children and adolescents who are at risk for
obesity. Both interventions involve a behavioral approach
to weight management and both stress the importance
of balancing exercise and healthy nutrition in a family-based
environment. The interventions consist of 12 weeks
of intensive training followed by 9 months of maintenance
sessions and measurement visits. Each child and adolescent
completes a baseline physical (i.e., height, weight,
triceps skinfold, pulse, blood pressure, and fasting
lipid profile) and psychosocial (i.e., eating disorder,
quality of life) measures and returns for these measurements
at 6-and 12-month follow-up visits.
Ian J. Griffin, M. B., Ch.
Dr. Griffin's work focuses on understanding
the mechanisms by which humans regulate zinc metabolism,
particularly the metabolic adaptations to low zinc
intakes, and the importance of marginal zinc status
in human disease. His research uses stable nonradioactive
isotopes and mathematical modeling techniques to describe
zinc metabolism in health and disease.
Michael A. Grusak, Ph.D.
laboratory is involved in both plant physiology and
human nutrition research. His plant physiology research
is focused on the mechanisms and regulation of nutrient
transport in plants. His long-term goals are to characterize
the dynamics of nutrient flow within plants in order
to determine the biophysical/molecular signals that
regulate source-to-sink nutrient partitioning, and
ultimately to use this information to enhance the nutritional
quality of plant foods for human consumption. With
regard to his human nutrition research, his laboratory
group has developed hydroponic growth facilities and
various protocols to intrinsically label plant foods
with stable isotopes of important nutrients; these
are then used to assess nutrient bioavailability and
metabolism in humans.
Darryl L. Hadsell, Ph.D.
growth factors (IGFs) are necessary for mammary gland
development and lactation. Despite this, the mechanisms
by which these peptides regulate mammary gland function
are poorly understood. The focus of Dr. Hadsell's research
is to understand the specific signaling mechanisms
through which the IGF-I receptor (IGF-IR) regulates
mammary gland development and lactation. Transgenic
and/or gene targeting strategies are used to modify
the activity of key IGF-IR signaling pathway intermediates
within the mammary gland. These strategies have demonstrated:
1) that IGF-IR regulates early mammary ductal development
through the ability to regulate cell cycle progression
within specialized structures called terminal endbuds;
2) that IGF-I also acts during lactation to maintain
mammary cell survival; 3) that specific intracellular
scaffolding proteins, termed insulin receptor substrates
(IRS), are important to both the cell survival actions
and to other potential actions of IGF-I on the regulation
of milk volume and composition during early lactation.
M. Haney, M.D., Ph.D.
Dr. Haney's research
goal is to understand the molecular cell biology of
lactation. Current work focuses on glucose transport
in the lactating mammary gland. Dr. Haney is studying
the regulation of GLUT1, the only glucose transporter
isoform identified in the mammary gland and in established
and primary mammary epithelial cell lines in humans
and rodents. He has shown that GLUT1, normally a plasma
membrane protein, is diverted to the intracellular
site of lactose synthesis in lactating mammary epithelial
cells, suggesting that these cells have a unique and
nutritionally important mechanism to alter GLUT1 targeting.
Efforts are under way to elucidate this mechanism by
identifying structural determinants of intracellular
GLUT1 targeting in mammary epithelial cells. Video
confocal microscopy demonstrates that intracellular
GLUT1 targeting is highly dynamic and can be altered
with certain drugs. Dr. Haney is also examining how
GLUT1 gene expression and subcellular targeting regulate
the synthesis of lactose.
Morey W. Haymond, M.D.
primary area of investigation has been the hormonal
regulation of nutrient oxidation and metabolic control
of glucose and protein metabolism. He has been instrumental
in the development of models to measure in vivo rates
of protein synthesis, proteolysis, glucose production
and gluconeogenesis using stable isotopic tracers.
Since the initial development of stable isotope dilution
method by Dr. Bier, Dr. Haymond has applied this method
and developed a number of other methods and models.
Since then, he has carried out a number of investigations
in a variety of conditions examining the mechanism
of glucose regulation in a variety of hypoglycemic
conditions in infants and children. In addition, he
has investigated the impact of a variety of glucoregulatory
hormones on amino acid and glucose homeostasis. In
utilizing these recently developed isotope dilution
methods to increase gluconeogenesis, Drs. Haymond and
Sunehag are exploring the regulation of glucose production
and gluconeogenesis in normal children and in children
with type 1 and type 2 diabetes, obesity, hyperinsulinemic
hypoglycemia and other conditions associated with hypoglycemia
in children. In addition, they are studying metabolic
adaptation to lactation. With a better understanding
of the factors that impact the regulation of glucose
homeostasis in the diabetic, the hypoglycemic, and
normal child, we will be able to develop better strategies
and new therapeutic interventions to normalize glucose
homeostasis in both the conditions of hyper- and hypoglycemia.
William C. Heird, M.D.
research interests focus on the nutrient needs of low-birth-weight
infants and other infants and children with special
needs, including the specific amino acid needs of those
who depend upon parenterally delivered nutrients, as
well as ways of meeting these needs. An additional
interest concerns the metabolism of essential fatty
acids during infancy and childhood and the role of
long-chain polyunsaturated fatty acids in infant development.
Karen Hirschi, Ph.D.
Hirschi's goal is to understand, at the cellular and
molecular level, the events leading to blood vessel
formation. She is interested in elucidating regulators
of vascular cell recruitment, proliferation and differentiation
needed for blood vessel assembly and maintenance. One
aim is to define mechanisms by which soluble effectors,
such as retinoids and TGF-beta, and cell-cell junctional
components such as gap junctions, modulate vascular
cell phenotype and cell cycle progression. Another
focus is to investigate the potential of adult stem
cells to contribute to neovascularization in response
to tissue injury and growth. The mechanisms by which
adult stem cells are recruited, induced to differentiate
into vascular cells, and are functionally integrated
into existing vascular networks, are of particular
interest. Insights gained from such studies are applied
to the optimization of clinically relevant treatments,
including autologous vascular cell and gene therapy,
assembly of blood vessels grafts, and vascularization
of engineered tissues.
Kendal D. Hirschi, Ph.D.
cannot run from environmental stresses; they must adapt.
Dr. Kendal Hirschi is studying the mechanisms by which
plants sequester nutrients and toxic metals into the
plant vacuole to cope with environmental challenges.
At the molecular level, his goal is to understand the
structure, biological function, and regulation of transporter
proteins that control trafficking into and out of the
plant vacuole. Another major goal is to learn how to
manipulate the expression and function of these transporters
to increase the nutritional content of crop plants,
improve plant productivity, and cleanse polluted soils.
He views these objectives as integral components of
the Green Revolution, the global agricultural movement
whose aim is to end world hunger by developing innovative
ways of increasing grain yields, particularly via the
use of genetically improved food plant varieties.
Judy A. Hopkinson, Ph.D.
research goal is to define physiological and behavioral
factors associated with optimal breastfeeding practices.
To achieve this goal, her research focuses on the following
areas: the impact of lactation on maternal and infant
physiology, with special emphasis on bone metabolism;
the identification of cultural factors that limit breastfeeding
duration and/or exclusivity; the characterization and
etiology of breast and nipple discomfort encountered
by breastfeeding women; and the evaluation of intervention
strategies and counseling techniques designed to increase
optimal breastfeeding behaviors.
Russell P. Jago, Ph.D.
Dr Jago's research focuses on the prevention of
obesity and associated chronic diseases among children
and adolescents through the promotion of physical activity.
Of particular interest are understanding the environmental
and personal factors that influence the physical activity
levels of children and adolescents and designing and
evaluating programs that are designed to increase the
physical activity levels of these groups. Current projects
include examining whether the environment affects the
physical activity levels of adolescent boys, examining
the relationship between the physical activity levels
and chronic diseases risks of young children and developing
a school-based program for the prevention of type 2
diabetes among middle school students.
Farook Jahoor, Ph.D.
research focuses on the metabolic alterations of specific
nutrient transport and acute-phase proteins, amino
acids, carbohydrate and lipids in response to different
pathologies, including undernutrition, diabetes mellitus,
sickle cell disease and chronic infections. He also
studies glutathione metabolism and its relationship
to oxidant damage of lipids and proteins in conditions
of oxidative stress.
Craig L. Jensen, M.D.
research is directed toward determining the optimal
intakes of polyunsaturated fatty acids for term and
preterm infants. The ability of infants to synthesize
longer-chain n-3 and n-6 polyunsaturated fatty acids
from their precursors, alpha-linolenic and linoleic
acids, respectively, is being investigated using stable
isotope techniques. The effects of different dietary
intakes of essential fatty acids on biochemical and
functional outcomes in both term and preterm infants
are being assessed.
Heidi E. Karpen, M.D.
Dr. Karpen's research involves the study of Patched,
a tumor suppressor gene responsible for Gorlin Syndrome.
Patched is a member of the Sonic Hedgehog signaling
pathway, critical for early embryonic patterning and
development. Dr. Karpen is using mutations identified
in Gorlin patients and sporadic basal cell carcinomas
to define functional domains important for protein
trafficking and function. The goal of this research
is to better understand mechanisms of aberrant embryonic
development and cancer formation so that targets for
intervention may be identified.
Gerard Karsenty, M.D., Ph.D.
Dr. Karsenty's research focus is on the regulation
of bone remodeling by hormones that also affect body
weight and reproduction. To that end, Dr. Karsenty
is using mutant mouse strains in which either specific
hormones or their receptors are deleted. He currently
is studying how leptin controls bone mass. He hopes
to determine whether leptin acts through a different
set of secondary messengers to regulate body weight
and bone mass, using mouse models generated in the
laboratory. He also is exploring the concept that antagonizing
the leptin pathway may be a way to treat osteoporosis
without affecting body weight. Lastly, he is studying
other hormones that may regulate body weight and bone
Alexandre A. Lapillonne, M.D., Ph.D.
Lapillonne's research interest is to determine whether,
and how, early nutritional events affect long-term
growth, metabolic function and development. His work
has focused on the effect of intrauterine growth on
body composition and postnatal growth, the effects
of specific nutrients on gene transcription, and how
alterations in gene transcription affect growth and
body composition. Current research focuses specifically
on the effect of n-3 polyunsaturated fatty acids on
weight gain, body composition, fat oxidation, energy
expenditure and transcription of genes controlling
lipid oxidation and thermogenesis. He is also planning
to assess how and when in early life, optimization
of protein intake can maximize catch-up growth and
neurological development of very-low-birth-weight infants.
The overall goal of Dr. Lapillonne's research is to
optimize the nutritional management of extremely low-birth-weight
infants in order to overcome long- lasting effects
on growth and development.
Carlos H. Lifschitz, M.D.
Dr. Lifschitz's research relates to nutrient gut
interaction and intestinal adaptation. The current
project consists on the investigation of the effect
of glutamine supplementation in neonatal infection
of low birthweight infants.
Ronald L. McNeel, Dr. P.H.
Dr. McNeel's research interests include evaluation
of the role of dietary supplements and macronutrients
in disease prevention and in reduction of risk factors
associated with disease. Specific interests include
the effects of macronutrients and dietary supplements
(including herbals) on whole body lipid metabolism
and energy homeostasis with emphasis on lipid metabolism
of the adipocyte. The goal is to obtain a more complete
understanding of the molecular mechanisms of action
of macronutrients and dietary supplements as they relate
to fat mass accretion. Special emphasis is given to
the role of the peroxisome proliferator-activated receptor
family, including PPAR alpha, PPAR beta, and PPAR gamma
as well as their target genes in response to nutrient
signaling. This understanding is critical for the development
of new health promotion strategies and therapeutic
approaches (nutritional, alternative herbal, and pharmacological)
to the management and prevention of nutritional obesity.
Harry J. Mersmann, Ph.D.
Adipocyte growth and differentiation are regulated
by various hormones and growth factors and may be altered
by dietary components. Dr. Mersmann's laboratory has
studied the influence of the stage of development and
of dietary factors on adipocyte beta-adrenergic receptors.
Currently, the focus of his efforts is on adipocyte
development. Porcine adipocyte precursor cells may
be isolated from adipose tissue and when grown in culture
in vitro under the proper conditions, differentiate
to adipocytes. He has used this system to evaluate
factors regulating the differentiation process and
the influence of dietary components of differentiation.
In addition to mRNA for the beta-adrenergic receptors,
mRNA for various transcription factors that regulate
differentiation (e.g., C/EBP-alpha or PPAR-gamma) and
mRNA for key proteins that characterize the adipocyte
(e.g., lipoprotein lipase and aP2) are being measured.
He is particularly interested in the role of individual
fatty acids in the stimulation or inhibition of adipocyte
David D. Moore, Ph.D.
The receptors for retinoic acid, thyroid hormone,
steroids, and other potent biological regulators belong
to a nuclear hormone receptor superfamily. This family
also includes a number of additional proteins called
orphan receptors, which do not have known ligands.
The conventional receptors regulate a variety of processes
in developing and adult animals. The orphans are less
well characterized, but it is thought that they also
play important roles in diverse areas. The broad-ranging
effects of these proteins are a consequence of their
function as ligand-dependent, or in some cases, ligand-independent
transcription factors. The main goal of Dr. Moore's
laboratory is to understand the mechanisms of action
of the members of this superfamily. Toward this aim,
he has identified a number of proteins that interact
with both conventional and orphan receptors, and he
is characterizing their functions.
Kathleen J. Motil, M.D., Ph.D.
Motil's studies focus on estimating dietary protein
and amino acid needs of lactating women and adolescents
and elucidating the mechanisms that underlie increased
nutrient needs for milk production. She has found that
lean body mass of adult women is preserved during lactation,
suggesting that nutrient conservation occurs because
of the needs of milk production. In contrast, lean
body mass of adolescents increases during lactation
at the expense of a reduction in milk production. Dr.
Motil's studies also focus on estimating the dietary
protein and energy needs of girls with Rett syndrome
and elucidating the mechanisms that underlie the universal
finding of growth failure in this disorder. She has
found that involuntary motor movements associated with
Rett syndrome do not increase rates of energy expenditure,
and that poor growth results from reduced dietary energy
intakes associated with oropharyngeal and gastroesophageal
Paul A. Nakata, Ph.D.
plants is sequestered as a complex with other substances
such as oxalates, phytates, fiber, fatty acids, proteins
and other anions. Some of these substances (oxalates
and phytates) are considered antinutrients, and render
the calcium in plant foods unavailable for nutritional
absorption by the human. The purpose of Dr. Nakata's
research program is to elucidate the mechanism regulating
calcium partitioning and sequestration in plants. The
acquired information will be applied toward the rational
design of strategies to enhance calcium abundance and
bioavailability in plant food products.
Buford L. Nichols, M.D.
Dr. Nichols' research project focuses on the interactions
of nutrients and genes, especially the regulation of
genes as they contribute to the development of diet
associated with degenerative diseases, such as diabetes
and atherosclerosis. Our research objective is to determine
the mechanisms by which dietary starch interacts with
the gene expressing maltase-glucoamylase (MGAM). Maltase-glucoamylase
is the gate-keeping enzyme that determines small intestinal
starch digestion into glucose. The function and regulation
of maltase-glucoamylase is under investigation in knockout
mice and children with deficient starch digestion.
Epidemiological reports indicate that about 15-30%
of US children suffer from chronic abdominal pain.
Twenty-six percent of children with chronic abdominal
pain have deficiencies of maltase-glucoamylase enzyme
activity and poor small intestinal starch digestion.
Theresa A. Nicklas, Dr. P.H.
Nicklas' research focuses on nutritional epidemiology
and intervention aspects of chronic disease prevention
and health promotion: specifically, how eating behaviors
and other lifestyles influence the development of chronic
disease risk factors early in life and the behavioral
factors influencing the development of adverse lifestyles
in childhood. Current areas of research include a detailed
investigation of the relationship among eating patterns,
diet quality, and obesity in children and young adults;
an examination of environmental influences on fruit,
juice, and vegetable consumption and body mass index
of Head Start preschool children; development of a
valid and reliable computerized food preference measure
for use with preschool children; and examination of
predictors of children's serving seizes and mealtime
intake. Planned studies include a behavior-based intervention
aimed at favorably influencing food preferences and
consumption by African- and Hispanic-American preschool
children attending Head Start; and a behavioral-based
family intervention designed to increase fruit, fruit
juice, and vegetable consumption by preschool children.
Sharon I. O'Donnell, Ph.D.
O'Donnell's research interests focus on the role of
the market on food and physical activity choices. Spatial
disparities in the local market's availability of nutritious
foods can result in higher total food costs for some
households. Using data that describes the full Houston
market, her research has found that the locations of
grocery stores are not the outcome of a competitive
market and there is an association between the concentration
of specific ethnic groups and spatial concentration
of higher quality food stores. Planned studies includes
economic analysis to determine if there exists spatial
disparities in physical activity resources for children
and a study to determine if low income, economically "at
(households in markets with higher than average housing
and transportation costs)increase their nutrient intake
by participating in the Food Stamps Program.
Monique Rijnkels, Ph.D.
Dr. Rijnkels' primary research goal is to understand
the regulation of the casein genes, encoding major
nutritional proteins in milk, and the genomic domain
in which these genes reside. The Genomics approach
used to study the transcriptional regulation of the
casein gene cluster region combines three lines of
research: The study of the chromatin structure and
remodeling in the casein gene cluster region related
to tissue type and development, using e.g. Chromatin
Immuno-Precipitation (ChIP) assays; Computational approaches
to identify evolutionary conserved regions with potential
regulatory function and the transacting factors that
might bind them; The functional analysis of potential
regulatory regions in transgenic mice. In addition,
the non-casein genes in this genomic domain are studied
as they potentially share functional properties and
spatial expression patterns (expressed in mammary gland)
as well as evolutionary ancestry.
Jeffrey M. Rosen, Ph.D.
Dr. Rosen's research objectives are to elucidate
the mechanisms regulating the normal development of
the mammary gland and to determine how these regulatory
mechanisms deviate in breast cancer. Studies of the
role of systemic hormones and local growth factors
on critical periods of development in the mouse mammary
gland are under way. Transgenic and knockout mouse
models are being used to examine the roles of specific
transcription factors and their dominant-negative isoforms,
postnatal mammary gland development, and the changes
in normal signal transduction pathways that are involved
in the progression from the normal mammary gland to
preneoplasias, as well as the role of mutant p53 in
genomic instability and the development of aneuploidy.
In addition, methods that permit the analysis of both
gain and loss of specific gene function selectively
in the mammary gland have been developed.
Robert J. Schwartz, Ph.D.
Schwartz conducts research focused on defining the
molecular basis underlying the establishment and maintenance
of skeletal, cardiac and smooth muscle differentiation.
Of special interest is Nkx2-5, a transcription factor
instrumental in the patterning of the embryonic heart.
The heart appears to develop as a modular organ, such
that a distinct transcriptional regulatory program
controls each anatomical region. Consistent with this
notion, the heart tube can be divided into segments
that form the atria, left ventricle, right ventricle,
and ventricular outflow tract. Precursors of these
regions appear to originate from separate lineages,
which develop according to their positions along the
anteroposterior axis of the embryo. Recent studies
have revealed cis-regulatory elements that direct cardiac
transcription specifically in the left or right ventricular
chambers and atria, which could be important for the
physiologic and functional differences of the chambers
of the adult heart.
Partha Sen, Ph.D.
Dr. Partha Sen is the director of the Child Health
Research Center (CHRC) Molecular Core Laboratory. The
laboratory provides DNA sequencing and DNA synthesis
services to the CHRC awardees and their mentors and
Baylor faculty at large. Dr. Sen is also involved in
research related to alveolar capillary dysplasia (ACD).
This is a genetic disorder that causes misalignment
of lung blood vessels, and is also characterized by
a severe reduction of capillaries in the lungs of the
patient. The relentless course of the disease culminates
in the death of the neonate despite intensive therapy.
The inheritance of the disease is presumed to be autosomal
recessive. The primary goal of the research project
is to identify the causative gene for this human disorder.
Robert J. Shulman, M.D.
is investigating the factors regulating gastrointestinal
function. His studies include examination of the roles
of diet and feeding regimen on the developing gastrointestinal
tract of the preterm infant. In addition, Dr. Shulman
is researching the factors contributing to the expression
of recurrent abdominal pain in older children including
the role of diet and alterations in intestinal bacterial
Roman J. Shypailo, B.S.
growth of technology during the past decade has created
challenges for researchers. Powerful computers and
data acquisition equipment enable rapid accumulation
of information that requires processing. The CNRC Body
Composition Laboratory houses sophisticated instruments
designed to measure the elemental composition of the
human body using nuclear-based techniques. Each instrument
is in a dynamic state of evolution. New measurement
systems are being developed, including a multiparameter
whole-body counter capable of isolating and measuring
a signal coming from a specific site in the body, and
a portable 40 K counter for use in a hospital setting.
Coordinating these efforts and incorporating new technology
are the primary focus of Mr. Shypailo's work.
C. Wayne Smith, M.D.
research deals with the effects of dietary fat on the
inflammatory processes in adipose tissue, liver and
blood. There are two main goals of this work. The first
is to determine the role played by macrophages in adipose
tissue. Studies are underway to determine the kinetics
of macrophage accumulation in different fat pads in
animals on diets differing in lipid composition, the
origins of these macrophages and the consequences of
blocking their accumulation. These studies address
the hypothesis that macrophage/adipocyte interactions
play a role in the proinflammatory responses seen in
obesity. The second major goal is to determine the
role of the hepatic response to dietary lipids in the
systemic inflammatory response seen in obesity. A component
of these studies deals with the development of steatohepatitis
and a potential contribution of portal endotoxemia.
Animal models in rats and mice have been developed
for these studies.
E. O'Brian Smith, Ph.D.
O'Brian Smith provides statistical design, analysis,
and teaching support to the USDA/ARS Children's Nutrition
Research Center , the General Clinical Research Center
, the Pediatrics Department, and Baylor College of
Medicine investigators. This support includes teaching
statistical methods, developing grant applications,
the design of research protocols, statistical analysis,
interpretation, and manuscript preparation. His support
services range from basic consultation to extensive
involvement in a project.
Janice E. Stuff, Ph.D.
interest is nutritional epidemiology and the role of
nutrition in chronic diseases and public health problems.
One emphasis is to understand dietary carcinogen and
chemopreventive exposure, the genetic susceptibility
to dietary carcinogens, and their interaction as determinants
for cancer. Dr. Stuff is developing and validating
databases of N-nitroso compounds
and isothiocyanate compounds in foods in order to investigate
their role in the development and prevention of cancer.
Another interest is to investigate the role of diet,
body composition, and hormone levels in the development
of risk factors for breast cancer. Dr. Stuff also collaborates
with the USDA/ARS Delta NIRI (Nutrition Intervention
Research Initiative), an initiative designed to measure
the nutrition and health status of individuals and
communities in the Lower Mississippi Delta region,
and to develop interventions. This project also investigates
the impact of food insecurity on the health, nutritional
requirements and nutritional status of children.
Agneta L. Sunehag, M.D., Ph.D.
focus of Dr. Sunehag's research is carbohydrate metabolism
in infants and children. In particular, she is interested
in the metabolism of very premature infants during
their first days of life. The aim of her studies is
to determine how these infants utilize their gluconeogenic
pathway to produce glucose from parenterally administered
lipid and amino acid solutions. The ultimate goal of
these studies is to optimize the composition of neonatal
parenteral nutrition solutions to prevent both hypo-
and hyperglycemia, while providing a sufficient energy
intake for normal growth. She is also investigating
which factors regulates glucose metabolism, particularly
gluconeogenesis, in sick newborns (represented by Extremely
Low Birth Weight Infants, Infants with Respiratory
Distress Syndrome and Infants with Congenital Heart
Disease). Her other major research interest is to determine
the effects of dietary macronutrient intake, obesity,
exercise and ethnicity on parameters of glucose metabolism,
particularly insulin sensitivity in children and adolescents.
Dr Sunehag is also involved in studies of glucose metabolism
in lactating women and in children with diabetes.
Agus Suryawan, Ph.D.
period is characterized by rapid growth, particularly
in skeletal muscle. Our previous observations indicate
that higher rate of skeletal muscle protein synthesis
in neonates is partly due to increased activation of
insulin signaling components leading to translation
initiation. Despite tremendous efforts, the factors
that regulate high rate of skeletal muscle protein
synthesis are not completely understood. My research
focuses on understanding the role of TGFbeta family
and their binding proteins in the regulation of skeletal
muscle growth in neonate. Recent studies have focused
on the effect of follistatin (an activin binding protein)
on the regulation of skeletal muscle growth by determining
its effects on protein synthesis and the activation
of insulin signaling proteins and translation initiation
Deborah I. Thompson, Ph.D.
Thompson is interested in children's problem solving
to overcome barriers to physical activity and in the
design, development, and evaluation of interactive
multi media programs promoting healthy nutrition and
physical activity behaviors to youth. Dr. Thompson
is studying the use of Dual Code Theory and how to
best design interactive multi media programs to promote
health behavior change, as well as the impact of monetary
incentives on log-on rates to electronic media promoting
diet and physical activity change. She helped design
an interactive multi media program promoting healthy
nutrition behaviors to parents of minority youth and
is a member of the team developing an interactive multi
media game promoting healthy diet and physical activity
behaviors to youth. Dr. Thompson also coordinates qualitative
research for a large, multi-site study to prevent type
2 diabetes among middle school youth and provides mentorship
for the qualitative data coordinator for a Small Business
Industrial Grant to develop an interactive multi media
game promoting healthy nutrition and physical activity
behaviors to middle school youth.
Qiang Tong, Ph.D.
The study of
adipose tissue development may reveal clues about the
molecular mechanisms of metabolic diseases, such as
type 2 diabetes and cardiovascular disease. Dr. Tong
has established the mammalian GATA transcription factors
as molecular gatekeepers in the early stages of adipogenesis.
He demonstrated that both GATA-2 and GATA-3 transcription
factors are negative regulators of adipocyte differentiation.
This effect is mediated through direct suppression
of the promoters of adipogenic factors PPARg and C/EBPa
by GATA factors and protein-protein interactions between
GATA and C/EBPa or C/EBPb. Currently he is investigating
the regulation of GATA factors at the protein level,
with the goal of characterizing the identity and dynamics
of the GATA protein complexes during adipogenesis,
and the role of GATA in the lineage determination of
adipogenic progenitor cells. He also plans to identify
new regulators of adipogenesis and to develop mouse
models to study the roles of these genes in obesity.
Chermaine L. Tyler, Ph.D.
is interested in studying the effectiveness of community-based,
instructor-led, multi-component physical activity and
nutrition intervention for 10-15 year-old children
and adolescents who are at risk for obesity. Both interventions
involve a behavioral approach to weight management
and both stress the importance of balancing exercise
and healthy nutrition in a family-based environment.
Ignatia B. Van den Veyver, M.D.
The neurodevelopmental disorder Rett syndrome is
caused by mutations in a gene on the X chromosome, MECP2 .
This gene encodes methyl-CpG-binding protein 2, thought
to be a transcriptional repressor that binds to methylated
CpGs in DNA. Based on this, we propose the more general
hypothesis that DNA methylation is important for regulation
of gene expression during development, especially of
the brain. There is evidence that DNA methylation can
be influenced by methyl-donor enriched diets, containing
substances such as folic acid and betaine. We are investigating
in animal and cell culture models whether this treatment
can alter DNA methylation and gene expression in the
brain. This is not only important for conditions such
as Rett syndrome, but may also provide a better understanding
for the role of such agents in other prenatally-onset
disorders and birth defects, such as neural tube defects
or for the fetal origin of adult-onset disorders.
A. Waterland, Ph.D.
Research in the Waterland
laboratory aims to understand how nutrition during
prenatal and early postnatal development affects individual
susceptibility to various adult-onset chronic diseases.
We have focused on nutritional influences on developmental
epigenetics as a likely mediating mechanism. Epigenetic
gene regulatory mechanisms regulate tissue-specific
patterns of gene expression, and are established during
development. Cytosine methylation is an epigenetic
mechanism of particular interest to us because mammalian
one-carbon metabolism, which supplies the methyl groups
for DNA methylation, is intimately dependent on dietary
methyl donors and cofactors.
William W. Wong, Ph.D.
main research interests include strategies to prevent
childhood obesity and the use of dietary supplementation
to prevent chronic diseases. Based on the data he collected
in the Houston Independent School District to document
the prevalence and risk factors of childhood obesity,
a grant application designed to determine the appropriateness
and effectiveness of an after-school physical activity
program to prevent obesity among Hispanic children
is going to be submitted to the National Institutes
of Health. With respect to projects related to the
use of dietary supplements to prevent chronic diseases,
Dr. Wong is currently investigating the safety, efficacy,
and optimal dosage of soy isoflavones to prevent osteoporosis
in postmenopausal women and the effects of soy isoflavones
on nitric oxide production and blood pressure in postmenopausal
women with high-normal blood pressure.
Issa F. Zakeri, Ph.D.
Dr. Zakeri is interested in Nutrimetrics, the application
of statistical methods to problems in nutrition. His
goal is to advance, develop and apply more accurate
and computationally flexible statistical techniques
to analyze and better understand many complex problems
in nutrition, particularly behavioral nutrition. His
primary research interests in statistics are time series
analysis, multivariate analysis, sequential analysis,
and statistical pattern recognition.