WHEY PROTEIN RESEARCH
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Med Sci Sports Exerc. 2004
Dec;36(12):2073-81. |
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Ingestion of casein and
whey proteins result in muscle anabolism after resistance exercise.
Tipton KD, Elliott TA, Cree MG, Wolf SE,
Metabolism Unit, Shriners Hospitals for Children and Department of Surgery, The
University of Texas Medical Branch, Galveston, TX 77550, USA. ktipton@utmb.edu
PURPOSE: Determination of the anabolic response to exercise and nutrition is
important for individuals who may benefit from increased muscle mass. Intake of
free amino acids after resistance exercise stimulates net muscle protein
synthesis. The response of muscle protein balance to intact protein ingestion
after exercise has not been studied. This study was designed to examine the
acute response of muscle protein balance to ingestion of two different intact
proteins after resistance exercise. METHODS: Healthy volunteers were randomly
assigned to one of three groups. Each group consumed one of three drinks:
placebo (PL; N = 7), 20 g of casein (CS; N = 7), or whey proteins (WH; N = 9).
Volunteers consumed the drink 1 h after the conclusion of a leg extension
exercise bout. Leucine and phenylalanine concentrations were measured in
femoral arteriovenous samples to determine balance across the leg. RESULTS:
Arterial amino acid concentrations were elevated by protein ingestion, but the
pattern of appearance was different for CS and WH. Net amino acid balance
switched from negative to positive after ingestion of both proteins. Peak
leucine net balance over time was greater for WH (347 +/- 50 nmol.min(-1).100
mL(-1) leg) than CS (133 +/- 45 nmol.min(-1).100 mL(-1) leg), but peak
phenylalanine balance was similar for CS and WH. Ingestion of both CS and WH
stimulated a significantly larger net phenylalanine uptake after resistance
exercise, compared with the PL (PL -5 +/- 15 mg, CS 84 +/- 10 mg, WH 62 +/- 18
mg). Amino acid uptake relative to amount ingested was similar for both CS and
WH (approximately 10-15%). CONCLUSIONS: Acute ingestion of both WH and CS after
exercise resulted in similar increases in muscle protein net balance, resulting
in net muscle protein synthesis despite different patterns of blood amino acid
responses.
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Nutr. 2004 Nov;134(11):3011-5. |
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Protein source, quantity,
and time of consumption determine the effect of proteins on short-term food
intake in young men.
Department of Nutritional Sciences, Faculty of Medicine,
The objective of these 4 studies was to describe the effects of protein source,
time of consumption, quantity, and composition of protein preloads on food
intake in young men. Young men were fed isolates of whey, soy protein, or egg
albumen in sweet and flavored beverages (400 mL) and provided a pizza meal 1-2
h later. Compared with the water control, preloads (45-50 g) of whey and soy
protein, but not egg albumen, suppressed food intake at a pizza meal consumed 1
h later. Meal energy intake after egg albumen and soy, but not after control or
whey treatments, was greater when the treatments were given in the late morning
(1100 h) compared with earlier (0830-0910 h). Suppression of food intake after
whey protein, consumed as either the intact protein or as peptides, extended to
2 h. Altering the composition of the soy preload (50 g) by reducing the soy
protein content to 25 g and by adding 25 g of either glucose or amylose led to
a loss in suppression of food intake by the preload. Egg albumen, in contrast
to whey and soy preloads, increased cumulative energy intake (sum of the energy
content of the preload plus that in the test meal) relative to the control. We
conclude that protein source, time of consumption, quantity, and composition
are all factors determining the effect of protein preloads on short-term food
intake in young men.
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Altern Med Rev. 2004
Jun;9(2):136-56. |
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Therapeutic applications
of whey protein.
Marshall K.
Whey, a protein complex derived from milk, is being touted as a functional food
with a number of health benefits. The biological components of whey, including
lactoferrin, beta-lactoglobulin, alpha-lactalbumin, glycomacropeptide, and
immunoglobulins, demonstrate a range of immune-enhancing properties. In
addition, whey has the ability to act as an antioxidant, antihypertensive,
antitumor, hypolipidemic, antiviral, antibacterial, and chelating agent. The primary
mechanism by which whey is thought to exert its effects is by intracellular
conversion of the amino acid cysteine to glutathione, a potent intracellular
antioxidant. A number of clinical trials have successfully been performed using
whey in the treatment of cancer, HIV, hepatitis B, cardiovascular disease,
osteoporosis, and as an antimicrobial agent. Whey protein has also exhibited
benefit in the arena of exercise performance and enhancement.
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Int J Sport Nutr Exerc Metab.
2004 Feb;14(1):104-20. |
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Erratum in:
·
Int J Sport Nutr Exerc
Metab. 2004 Oct;14(5):following 606.
Nutritional supplement use
among college athletes and their sources of information.
Froiland K, Koszewski W, Hingst J, Kopecky L.
Department of Nutritional Science and Dietetics,
A survey was conducted to examine the source of information and usage of
nutritional supplements in 115 male and 88 female varsity athletes at a
Division I university. The survey asked each athlete to define supplement, and
report supplement use and type, source of information, and reasons for use.
Supplement use frequencies were determined, and comparisons were made between
gender and sport. Eighty-nine percent of the subjects had or were currently
using nutritional supplements. Many athletes did not consider sports drinks and
calorie replacement products as supplements. Females were more likely to take
calcium and multivitamins, and males had significant intake for ginseng, amino
acids, glutamine, hydroxy-methyl-buterate (HMB), weight gainers, whey protein,
and Juven. The most frequently used supplements overall were energy drinks
(73%), calorie replacement products of all types (61.4%), multivitamin (47.3%),
creatine (37.2%), and vitamin C (32.4%). There was also significant supplement
use noted per sport. Females were more likely to obtain information from family
members regarding supplementation, and males from a store nutritionist, fellow
athletes, friends, or a coach. Female athletes were more likely to take
supplements for their health or because of an inadequate diet, while men
reported taking supplements to improve speed and agility, strength and power,
or for weight/muscle gain.
PMID: 15129934 [PubMed - indexed for MEDLINE]
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Int J Food Sci Nutr. 2004
Mar;55(2):131-41. |
Whole blood and
mononuclear cell glutathione response to dietary whey protein supplementation
in sedentary and trained male human subjects.
Middleton N, Jelen P,
Faculty of Agriculture, Food and Nutritional Sciences,
Sedentary male subjects (n=9) on a controlled diet were fed two doses (0.8 or
1.6 g/kg body mass) of a whey protein isolate (WPI), in addition to an
isocaloric placebo; blood samples were drawn over a 4-h period and glutathione
concentration determined. There was no effect of the supplementation at either
level over the 4-h sampling period. The effects of a WPI supplemented diet on
glutathione concentrations in whole blood as well as peripheral mononuclear
cell populations were also investigated over a 6-week period in male subjects
(n=18) involved in arduous aerobic training; blood was collected prior to and
following a 40 km simulated cycling trial. The aerobic training period resulted
in significantly lower glutathione concentrations in whole blood, an effect
that was mitigated by WPI supplementation. A significant increase in
mononuclear cell glutathione was also observed in subjects receiving the WPI
supplement following the 40 km simulated cycling trial.
Publication Types:
- Clinical Trial
- Randomized Controlled
Trial
PMID: 14985185 [PubMed - indexed for MEDLINE]
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J Nutr Biochem. 2003
May;14(5):251-8. |
Functional properties of
whey, whey components, and essential amino acids: mechanisms underlying health
benefits for active people (review).
Ha E,
Functional Ingredients Research, Inc,
Whey proteins and amino acid supplements have a strong position in the sports
nutrition market based on the purported quality of proteins and amino acids
they provide. Recent studies employing stable isotope methodology demonstrate
the ability of whey proteins or amino acid mixtures of similar composition to
promote whole body and muscle protein synthesis. Other developing avenues of
research explore health benefits of whey that extend beyond protein and basic
nutrition. Many bioactive components derived from whey are under study for
their ability to offer specific health benefits. These functions are being
investigated predominantly in tissue culture systems and animal models. The
capacity of these compounds to modulate adiposity, and to enhance immune
function and anti-oxidant activity presents new applications potentially suited
to the needs of those individuals with active lifestyles. This paper will
review the recent literature that describes functional properties of essential
amino acids, whey proteins, whey-derived minerals and other compounds and the
mechanisms by which they may confer benefits to active people in the context
that exercise is a form of metabolic stress. The response to this stress can be
positive, as with the accretion of more muscle and improved functionality or
greater strength. However, overall benefits may be compromised if immune
function or general health is challenged in response to the stress. From a
mechanistic standpoint, whey proteins, their composite amino acids, and/or
associated compounds may be able to provide substrate and bioactive components
to extend the overall benefits of physical activity.
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J Mammary Gland Biol Neoplasia.
2002 Jul;7(3):313-26. |
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The comparative biology of
whey proteins.
Simpson KJ, Nicholas KR.
Department of Biochemistry and Molecular Biology, The
Lactational strategies and associated development of the young have been
studied in a diverse range of species, and comparative analysis allows common
trends and differences to be revealed. The whey fraction contains a vast number
of proteins, many of which have not been assigned a function. However, it is
expected that an understanding of the comparative biology of these proteins may
provide some promise in assigning a function to the major whey proteins. Whey
acidic protein is a major component of the whey fraction that has been studied
across a range of species, revealing conservation of gene structure, whereas
regulation and temporal expression patterns vary. This review focuses primarily
on comparative analysis of whey acidic protein, highlighting gene structure,
developmental and hormonal regulation, and potential functional roles for this
protein. In addition, the contrasting regulation and secretion profiles of
several other major whey proteins are discussed.
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Crit Rev Food Sci Nutr. 2002
Jul;42(4):353-75. |
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Whey components: millennia of evolution create functionalities for mammalian
nutrition: what we know and what we may be overlooking.
Walzem RL, Dillard CJ, German JB.
Faculty of Nutrition,
Nutrition is undergoing a revolution owing to the recognition that some foods
contain trophic, health-promoting factors distinct from essential nutrients. In
this revolution, whey is increasingly being viewed as more than a source of
proteins with a particularly nutritious composition of essential amino acids.
Milk evolved under continuous Darwinian selection pressure to nourish mammalian
neonates. Evolutionary pressure appears to have led to the elaboration of a
complex food that contains proteins, peptides, complex lipids, and
oligosaccharides that act as growth factors, toxin-binding factors,
antimicrobial peptides, prebiotics, and immune regulatory factors within the
mammalian intestine. Importantly, these trophic macromolecules are not
essential, although the health benefits that their biological activities within
the intestine provide likely contributed to neonatal survival. Human and bovine
milks contain many homologous components, and bovine whey may prove to be a source
for molecules capable of providing biological activities to humans when
consumed as food ingredients. To approach this potential, food and nutrition
research must move beyond the description of food ingredients as delivering
only essential nutrients and develop a mechanistic understanding of the
interactions between dietary components and the metabolic and physiological
properties of the intestine.
EGG PROTEIN RESEARCH
Biochem Soc Symp. 2003;(70):179-99.
Cystatins.
Abrahamson M, Alvarez-Fernandez M, Nathanson CM.
Department of Clinical Chemistry, Institute of Laboratory Medicine, University
of Lund, University Hospital, S-221 85 Lund, Sweden.
Magnus.Abrahamson@klinkem.lu.se
Chicken egg white cystatin was first described in the late 1960s. Since then,
our knowledge about a superfamily of similar proteins present in mammals,
birds, fish, insects, plants and some protozoa has expanded, and their
properties as potent peptidase inhibitors have been firmly established. Today,
12 functional chicken cystatin relatives are known in humans, but a few
evolutionarily related gene products still remain to be characterized. The type
1 cystatins (A and B) are mainly intracellular, the type 2 cystatins (C, D,
E/M, F, G, S, SN and SA) are extracellular, and the type 3 cystatins (L- and
H-kininogens) are intravascular proteins. All true cystatins inhibit cysteine
peptidases of the papain (C1) family, and some also inhibit legumain (C13)
family enzymes. These peptidases play key roles in physiological processes,
such as intracellular protein degradation (cathepsins B, H and L), are pivotal
in the remodelling of bone (cathepsin K), and may be important in the control
of antigen presentation (cathepsin S, mammalian legumain). Moreover, the
activities of such peptidases are increased in pathophysiological conditions,
such as cancer metastasis and inflammation. Additionally, such peptidases are
essential for several pathogenic parasites and bacteria. Thus cystatins not
only have capacity to regulate normal body processes and perhaps cause disease
when down-regulated, but may also participate in the defence against microbial
infections. In this chapter, we have aimed to summarize our present knowledge
about the human cystatins.
Biologically active human
interferon alpha-2b produced in the egg white of transgenic hens.
Rapp JC, Harvey AJ, Speksnijder GL, Hu W, Ivarie R.
AviGenics, Inc.,
We have previously described the expression of a bacterial protein in the egg
white of transgenic chickens using a replication-deficient retroviral vector.
Here we report the expression of a glycosylated human protein, interferon
alpha-2b (hIFN), in the egg white of transgenic hens. The hIFN secreted into the
egg white was biologically active as determined by a viral inhibition assay.
Purification and carbohydrate analysis of the hIFN expressed in egg white
revealed that two of the six major glycosylated hIFN species match the
naturally occurring human hIFN glycovariants. These results support the
potential of the hen as a bioreactor for the production of commercially
valuable, biologically active, and glycosylated proteins in egg white.
Bone. 2004 Sep;35(3):689-96.
Family 2 cystatins inhibit
osteoclast-mediated bone resorption in calvarial bone explants.
Brand HS, Lerner UH, Grubb A, Beertsen W, Nieuw Amerongen AV, Everts V.
Department of Oral Biochemistry, Academic Centre for Dentistry Amsterdam,
Universiteit van Amsterdam and Vrije Universiteit,
Osteoclastic bone resorption depends on the activity of various proteolytic
enzymes, in particular those belonging to the group of cysteine proteinases.
Biochemical studies have shown that cystatins, naturally occurring inhibitors
of these enzymes, inhibit bone matrix degradation. Since the mechanism by which
cystatins exert this inhibitory effect is not completely resolved yet, we
studied the effect of cystatins on bone resorption microscopically and by
Ca-release measurements. Calvarial bone explants were cultured in the presence
or absence of family 2 cystatins and processed for light and electron
microscopic analysis, and the culture media were analyzed for calcium release.
Both egg white cystatin and human cystatin C decreased calcium release into the
medium significantly. Microscopic analyses of the bone explants demonstrated
that in the presence of either inhibitor, a high percentage of osteoclasts was
associated with demineralized non-degraded bone matrix. Following a 24-h
incubation in the presence of cystatin C, 41% of the cells were adjacent to
areas of demineralized non-degraded bone matrix, whereas in controls, this was
only 6%. If bone explants were cultured with both PTH and cystatin C, 60% of
the osteoclasts were associated with demineralized non-degraded bone matrix,
compared to 27% for bones treated with PTH only (P < 0.01). Our study
provides evidence that cystatins, the naturally occurring inhibitors of
cysteine proteinases, reversibly inhibit bone matrix degradation in the
resorption lacunae adjacent to osteoclasts. These findings suggest the
involvement of cystatins in the modulation of osteoclastic bone degradation.
Biophys J. 2004 Feb;86(2):1118-23.
Dielectric behavior of
lysozyme and ferricytochrome-c in water/ethylene-glycol solutions.
Bonincontro A, Cinelli S, Onori G, Stravato A.
INFM-Dipartimento di Fisica, Universita La Sapienza, I-00185 Rome, Italy.
adalberto.bonincontro@uniroma1.it
This work deals with a dielectric study at radio frequencies of the influence
at room temperature of two organic molecules, known as cryo-protectants,
ethylene-glycol and glycerol, on conformational and dynamic properties of two
model proteins, lysozyme (lys) from chicken egg-white and ferricytochrome-c (cyt-c)
from horse heart. Cyt-c is a compact globular protein whereas lys is composed
of two structural domains, separated by the active site cleft. Measurements
were carried out at the fixed temperature of 20 degrees C varying the
concentration of the cosolvent up to 90% w/w. From the analysis of the
dielectric relaxation of the protein solution, the effective hydrodynamic
radius and the electric dipole moment of the protein were calculated as a
function of the cosolvent concentration. The data show that glycerol does not
modify significantly the conformation of both proteins and cyt-c is also stable
in the presence of ethylene-glycol. On the contrary ethylene-glycol strongly
affects the dielectric response of lysozyme denoting a specific effect on its
conformation and dynamics. The data are coherently interpreted hypothesizing
that glycol molecule wedges between and separates the two domains of lys making
them rotationally independent.
Biochemistry. 2003 Aug 19;42(32):9669-76
Highly nonexponential
kinetics in the early-phase refolding of proteins at low temperatures.
Saigo S, Shibayama N.
Division of Biophysics, Department of Physiology,
Theory and simulations predict that the folding kinetics of protein-like
heteropolymers become nonexponential and glassy (i.e., controlled by escape
from different low-energy misfolded states) at low temperatures, but there was
little experimental evidence for such behavior of proteins. We have developed a
stopped-flow instrument working reliably down to -40 degrees C with high mixing
capability and applied it to study the refolding kinetics of horse cytochrome c
(cyt c) and hen egg white lysozyme at temperatures below 0 degrees C in the
presence of antifreeze NaCl, LiCl, or ethylene glycol and above 0 degrees C in
the presence and absence of antifreeze. The refolding was initiated by rapid
dilution of the guanidine hydrochloride unfolded proteins, and the kinetics
were monitored by intrinsic tryptophan fluorescence. Highly nonexponential
kinetics extended over 3 decades in time (0.01-10 s) were observed in the early
phases of the refolding of cyt c and lysozyme in the temperature range of
J Chromatogr. 1993 Aug 27;646(1):107-20
High-performance liquid
chromatography of amino acids, peptides and proteins. CXXXI. O-phosphoserine as
a new chelating ligand for use with hard Lewis metal ions in the
immobilized-metal affinity chromatography of proteins.
Zachariou M, Traverso I,
Department of Biochemistry,
Conditions for the immobilization of O-phosphoserine (OPS) to epoxy-activated
Sepharose CL-4B are described. The binding behaviour of OPS and iminodiacetic
acid (IDA) immobilized onto Sepharose CL-4B, toward the hard Lewis metal ions
Al3+, Fe3+, Ca2+ and Yb3+, and Cu2+ ion as a borderline metal ion control, over
the pH range pH 4.0 to pH 8.0, was examined. Immobilized OPS shows a stronger
affinity for Fe3+ and Al3+ ions but a lower affinity for Cu2+ and Yb3+ ions,
compared to immobilized iminodiacetic acid (IDA), over the equilibrating range
examined. Immobilized OPS-Mn+ was screened for protein binding using as model
proteins tuna heart cytochrome c (THCC), horse myoglobin (HMYO) and hen egg
while lysozyme (HEWL) over the pH range 5.5 to 8.0. Immobilized OPS-Fe3+ bound
THCC under all the examined equilibrating conditions, bound HMYO between pH 5.5
and pH 7.0 and did not bind HEWL under any condition examined. Immobilized OPS
thus presents an additional mode of metal ion and protein selectivity in
immobilized-metal affinity chromatography
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Raman spectroscopic
studies of hen egg-white lysozyme at high temperatures and pressures.
Remmele RL Jr, McMillan P, Bieber A.
Department of Biochemistry,
In situ high-temperature, high-pressure Raman experiments on 3 mM (pH 5)
aqueous solutions of hen egg-white (HEW) lysozyme show a decrease in the
relative height of the 505 cm-1 band associated with S-S stretching vibrations
at 72 degrees C (1 bar). The peak height changes are accompanied by significant
band broadening, and the integrated band intensity does not change within
experimental error. The effect of increased pressure at 72 degrees C was to
hinder broadening of the 505 cm-1 band. HEW lysozyme (2.4 mM, pH 5) was also heated
at 76 degrees C, 80 degrees C, and 95 degrees C for different periods of time,
and aliquots were quenched to room temperature for Raman and enzymatic activity
measurements. After 9 hr at 76 degrees C, the protein exhibits enzyme activity
less than 50% of the initial value, and approximately 50% reduction in activity
is achieved after 3 hr at 80 degrees C or 1 hr at 95 degrees C. The Raman
results suggest that different irreversibly denatured conformations are
attained during prolonged exposures at these different temperatures. It is
apparent from these studies that the S-S stretch intensity is decreased
irreversibly.
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Scand J Immunol. 1986
Oct;24(4):447-55. |
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Passage of undegraded dietary antigen into the blood of healthy
adults. Further characterization of the kinetics of uptake and the size
distribution of the antigen.
Husby S, Jensenius JC, Svehag SE.
The molecular weight distribution of ovalbumin (OA) absorbed into the blood in
eight healthy adults after a test meal was analysed by high pressure liquid gel
permeation chromatography (HPLC) followed by ELISA for OA. OA was found either
as free OA or as aggregates of a size mainly below 700 kD. The addition of OA
in vitro to an antibody-containing serum resulted in OA-containing immune
complexes (OA-IC) of similar size. The size distribution of serum OA-IC was
more heterogeneous late than early in the 7-h observation period. Free OA
disappeared at an equal or higher rate than OA-IC when both entities were
present in the same individual. The presence of OA-IC was related to the serum
IgG antibody levels. IgG, but not IgA or IgM, could be detected in OA-IC (in
three individuals) by ELISA. The kinetics of OA appearance was followed for 48
h after a test meal in three individuals. In one person, serum OA reached peak
values at 24 h and detectable amounts persisted for 48 h after the test meal.
In the other test persons the OA levels peaked earlier. The present study
indicates that in healthy adults dietary antigens are absorbed and circulate
regularly in minute amounts apparently as native protein and/or as small immune
complexes, mostly containing IgG antibodies.
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Pharm Res. 1995
Feb;12(2):209-14. |
Design for cell-specific targeting of proteins utilizing
sugar-recognition mechanism: effect of molecular weight of proteins on
targeting efficiency.
Nishikawa M, Hirabayashi H, Takakura Y, Hashida M.
Department of Drug Delivery Research, Faculty of Pharmaceutical Sciences,
Hepatic targeting of proteins utilizing the sugar-recognition mechanism was
investigated in mice after intravenous injection. Five proteins with different
molecular weights, i.e., bovine gamma-globulins (IgG), bovine serum albumin
(BSA), recombinant human superoxide dismutase (SOD), soybean trypsin inhibitor
(STI), and chicken egg white lysozyme (LZM), were modified with
2-imino-2-methoxyethyl 1-thiogalactoside to obtain galactosylated proteins
(Gal-IgG, Gal-BSA, Gal-SOD, Gal-STI, and Gal-LZM). The numbers of galactose
residues were 38, 20, 11, 6, and 5 for Gal-IgG, Gal-BSA, Gal-SOD, Gal-STI, and
Gal-LZM, respectively. All galactosylated proteins were dose-dependently taken
up by the liver and the relative amount accumulated in the liver was decreased
with an increase of the administered dose. At low doses (0.05 and 0.1 mg/kg),
Gal-IgG, Gal-BSA, and Gal-SOD could be taken up by the liver up to more than
70-80% of dose within 10 min after intravenous injection, but the maximum
amounts accumulated in the liver were approximately 40 and 30% of the dose for
Gal-STI and Gal-LZM, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)