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Title
Black tea' green tea' and tea polyphenols. Effects on trace element
status in weanling rats.
Author
Record IR; McInerney JK; Dreosti IE
Address
CSIRO Division of Human Nutrition' Adelaide' S Australia.
Source
Biol Trace Elem Res, 53(1-3):27-43 1996 Summer
Abstract
Previous studies have shown that tea consumption can impair trace
element metabolism' particularly iron status' and increase the
risk of
anemia in humans and animals. More recently' however' evidence
has been
accumulating to show that' in animals' consumption of green tea
or its
polyphenols is associated with a reduction of the incidence and
severity of a variety of experimentally induced cancers. In this
study
we have monitored the growth' trace element status' including
hematological parameters of weanling rats given either (1) water'
(2)
1% black tea' (3) 1% green tea' or (4) 0.2% crude green tea extract
as
their sole drinking fluid while consuming diets containing either
adequate or low amounts of iron. With the exception of manganese'
none
of the trace elements studied (iron' copper' zinc' and manganese)
or
the hematological indices measured were affected by the type
of
beverage supplied' even though the polyphenol extract was shown
to
chelate metals in vitro and all the animals fed the low iron
diet were
shown to be anemic. There appeared to be an effect of black and
green
teas on manganese balance in both the first and last weeks of
the
study. A lower level of brain manganese was associated with green
tea
consumption' and a higher level of this element in the kidneys
of
animals fed black tea. The results demonstrate that both black
and
green teas and a green tea polyphenol extract do not represent
a risk
to animals consuming the beverages as their sole fluid intake
with
respect to iron availability' although the interactions with
manganese
deserve further study.
Title
Essential trace element alterations in amyotrophic lateral sclerosis.
Author
Kapaki E; Zournas C; Kanias G; Zambelis T; Kakami A; Papageorgiou
C
Address
Department of Neurology (Research Laboratory)' Athens National
University' Eginition Hospital' Greece.
Source
J Neurol Sci, 147(2):171-5 1997 Apr 15
Abstract
Although trace elements have been implicated in the pathogenesis
of
amyotrophic lateral sclerosis (ALS) for a long time' new evidence
has
connected familial ALS with the metalloenzyme copper-zinc superoxide
dismutase' thus reinforcing the study of their metabolism. This
work
presents the results of serum and cerebrospinal fluid levels
of copper'
zinc' manganese and magnesium' by atomic absorption spectrophotometry.
Statistically significant decreased cerebrospinal fluid and serum
copper levels were found in patients compared to the control
group
(20.25 +/- 7.09 vs. 30.86 +/- 16.02 SD micrograms/l and 913.21
+/-
165.55 vs. 1020.17 +/- 197.76 SD micrograms/l) while serum manganese
levels were found to be increased in patients (3.59 +/- 0.89
SD
micrograms/l) compared to controls (3.03 +/- 1.23 SD micrograms/l).
Zinc and magnesium levels were unchanged. Our findings indicate
an
essential trace element imbalance in the disease.
Title
Effects of orthodontic treatment on nutrient intake.
Author
Riordan DJ
Source
Am J Orthod Dentofacial Orthop, 111(5):554-61 1997 May
Abstract
Orthodontists often advise their patients to eat soft foods after
treatment to avoid pressure sensitivity. Yet there is little
research
as to how this affects nutrient intake. This study compared nutrient
intake before and after orthodontic adJustment to see whether
any
changes occurred. Ten patients between the ages of 12 and 16
years were
selected from the University of Buffalo School of Orthodontics.
These
patients recorded the foods they ate for 3 days before and 3
days after
treatment. Treatment types studied were those that cause a significant
level of pressure sensitivity such as an arch wire change. The
recorded
diets were analyzed with a paired two sample t test' with alpha
= 0.05
as the significance level. The results of this study show a decrease
in
intake of copper and manganese after orthodontic adJustment.
Also
trends toward a greater percentage of calories from total and
saturated
fat at the expense of carbohydrates' a decrease in fiber intake'
and an
improvement in the calcium to phosphorus ratio were seen. Bone
metabolism' and therefore tooth movement may be affected by copper
and
manganese levels. Thus' to optimize patient physiologic response
to
orthodontic treatment' it may be beneficial to provide nutritional
guidance to patients in choosing soft food diets.
Title
Role of manganese superoxide dismutase in a mucoid isolate of
Pseudomonas aeruginosa: adaptation to oxidative stress.
Author
Polack B; Dacheux D; Delic-Attree I; Toussaint B; Vignais PM
Address
Laboratoire de Biochimie Microbienne (Centre National de la Recherche
Scientifique Unite 1130 alli]ee a l`Institut National de la Sant]e
et
de la Recherche M]edicale)' Grenoble' France.
Source
Infect Immun, 64(6):2216-9 1996 Jun
Abstract
Chronic infection by alginate-producing (mucoid) Pseudomonas
aeruginosa
is a leading cause of morbidity among cystic fibrosis (CF) patients.
In
the lungs of CF patients' the bacteria are exposed to activated
oxygen
species produced by the phagocytes of the host or resulting from
the
metabolism of oxygen. Two isoforms of superoxide dismutase are
synthesized by P. aeruginosa; they differ by the metal present
at their
active site' which is either iron or manganese. To evaluate the
role of
manganese-containing superoxide dismutase (MnSOD)' encoded by
sodA' we
have isolated a sodA mutant of the mucoid P. aeruginosa strain
CHA
isolated from the bronchopulmonary tract of a CF patient. The
sodA
mutant exhibited an increased sensitivity to oxidative stress
generated
by paraquat and was less resistant to oxidative stress in the
stationary phase of growth compared with its parental strain.
It was
observed that MnSOD was expressed in the parental strain solely
during
the stationary phase of growth and that cells of the sodA mutant
taken
at the stationary phase resumed growth with a longer delay than
the
sodA+ cells when reinoculated in a new medium' especially in
the
presence of paraquat. These results suggest that MnSOD may participate
in the adaptation of mucoid strains of P. aeruginosa to the stationary
phase of growth in the lungs of CF patients.
Title
A pilot study of antioxidant intake in patients with cholesterol
gallstones.
Author
Worthington HV; Hunt LP; McCloy RF; Maclennan I; Braganza JM
Address
Department of Nutrition' Royal Infirmary' Manchester' UK.
Source
Nutrition, 13(2):118-27 1997 Feb
Abstract
Whereas macronutrient intake has been extensively investigated
in an
attempt to unravel the pathogenesis of human cholesterol gallstones'
theoretical considerations and animal models suggest that deficits
in
micronutrient antioxidants may be more relevant. We report a
pilot
study of this aspect. The plan was to obtain 7-d weighed food
inventories over a 6-mo period from equal numbers of patients
who had
not consciously changed their diets' patients who were on low-fat
diets
and age- and gender-matched controls. Food tables would be used
to
derive daily intakes of 16 known antioxidants' essential amino
acids'
and essential fatty acids. Under-reporting of food intake' a
recognized
drawback of this dietary method' would be sought retrospectively
by
reference to a key publication giving minimum cut-off limits
for ratios
of energy intakes to basal metabolic rates. There were 18 pairs
for
study. Analysis of data for the 9 pairs involving patients on
their
normal diets showed no differences in the intakes of energy
macronutrients' and cholesterol' but the patients ingested lower
amounts of 10 among 16 antioxidants (P < 0.05 for methionine'
alpha-tocopherol' manganese' and vitamin D; 0.05 < P <
0.10 for
cysteine' beta-carotene' vitamin C' selenium' zinc' and phosphorus).
Both subsets of patients ingested lower amounts of linoleic acid
(diet
unchanged P = 0.009' changed P = 0.026) and several essential
amino
acids than did matched controls. Institution of a low-fat diet
caused
the expected fall in intakes of energy and saturated fatty acids
such
that the deficit in alpha-tocopherol was amplified' but substitution
of
fruit and vegetables by the patients resulted in a fortuitous
increase
in vitamin C' beta-carotene' and manganese intake. Retrospective
analysis confirmed under-reporting of food intake by all four
subsets
of subjects but there was no significant difference in the mean
ratio
of energy intake to estimated basal metabolic rate in the subset
of
patients who had not consciously altered their diets and the
subset of
matched controls. Furthermore' the lower daily intake of
alpha-tocopherol and linoleic acid by these patients persisted
when
results were expressed relative to total fat consumption. The
results
support the hypothesis that insufficiency of dietary antioxidants'
particularly alpha-tocopherol' may be germane to human gallstone
disease; they also suggest that low intakes of linoleic acid
and
essential amino acids may be relevant. Because of the small sample
sizes' however' these deductions should be regarded as tentative'
pending confirmation by biochemical analysis of blood and especially
of
hepatic bile.
Title
High- versus low-meat diets: effects on zinc absorption' iron
status'
and calcium' copper' iron' magnesium' manganese' nitrogen' phosphorus'
and zinc balance in postmenopausal women.
Author
Hunt JR; Gallagher SK; Johnson LK; Lykken GI
Address
United States Department of Agriculture' Grand Forks Human Nutrition
Research Center' ND 58202-9034' USA.
Source
Am J Clin Nutr, 62(3):621-32 1995 Sep
Abstract
The effects of three diets--high meat (HM)' low meat (LM)' or
low meat
with mineral supplements (LS)--on zinc absorption' elemental
balance'
and related clinical indexes were investigated in a metabolic
study of
14 women aged 51-70 y. The women ate each of the three diets
for 7 wk
in random order. Lean beef' chicken' ham' and tuna in the HM
diet
replaced foods with a low mineral content in the LM diet. The
LS diet
was similar to the HM diet in K' P' Fe' Mg' and Zn contents.
Compared
with the other diets' the HM diet increased zinc absorption and
retention' and slightly increased urinary zinc. Nitrogen and
calcium
balances and urinary calcium were not different for the HM and
LM
diets. Iron balance was not different for the HM and LS diets
with
similar iron content' but the HM diet was unexpectedly associated
with
lower iron status (higher iron-binding capacity and lower ferritin
than
LM and LS diets). These results indicate that 0.8 g protein/kg
body wt
meets protein requirements in older women' and that high meat
consumption increases zinc retention without compromising calcium
status and may reduce indexes of iron status' in contrast with
iron
absorption results from studies with radiolabeled test meals.
Title
Expression of manganese superoxide dismutase mRNA in reproductive
organs during the ovulatory process and the estrous cycle of
the rat.
Author
Nomura T; Sasaki J; Mori H; Sato EF; Watanabe S; Kanda S; Matsuura
J;
Watanabe H; Inoue M
Address
Department of Anatomy' Okayama University Medical School' Japan.
Source
Histochem Cell Biol, 105(1):1-6 1996 Jan
Abstract
Expression of manganese superoxide dismutase (Mn-SOD) mRNA during
the
pregnant mare serum gonadotrophin (PMSG)/human chorionic gonadotrophin
(HCG)-induced ovulatory process' and during the estrous cycle
was
examined in rat female reproductive organs. Mn-SOD mRNA levels
in theca
interna cells markedly increased in PMSG-primed rats and high
levels of
the transcripts were maintained after HCG inJection. The PMSG-enhanced
expression of Mn-SOD mRNA in follicular epithelial cells increased
concomitantly with luteinization of these cells. The levels of
Mn-SOD
mRNA remained high and became equivalent in both granulosa and
theca
lutein cells 24 h after HCG inJection. Neither luteinization
nor the
expression of Mn-SOD mRNA was observed in the epithelial cells
of
unovulated follicles. Luteal bodies had formed 3 days after HCG
inJection' and the same level of Mn-SOD mRNA expression continued
in
lutein cells' but not in stromal cells. During the estrous cycle'
Mn-SOD mRNA was localized to theca interna cells on proestrus'
to the
epithelial cells of luteinizing follicles on estrus' and to newly
formed luteal bodies on diestrus. The epithelial cells in the
oviduct
did not express Mn-SOD mRNA throughout the ovulatory process
or the
estrous cycle. Expression of Mn-SOD mRNA in the luminal epithelial
cells of the uterus increased after PMSG inJection' reaching
a maximum
after 24 h' and became relatively negative 3 days after HCG inJection
when corpora lutea had formed in the ovary. During the estrous
cycle'
uterine epithelial cells and leukocytes showed marked increases
in
Mn-SOD mRNA expression on estrus and on proestrus' respectively.
Expression in the vaginal epithelium became apparent 3 days after
HCG
inJection and continued for at least 12 days after HCG inJection.
The
expression was localized to the superficial layer of the epithelium.
During the estrous cycle' expression occurs in the basal layer
on
proestrus and estrus' transferring to the superficial layer on
diestrus
day 1' and expression stops on diestrus day 2. The relationship
between
the expression of Mn-SOD mRNA and hormone-induced metabolic changes'
including steroidogenesis' is discussed.
Title
Immunohistochemical localization of manganese superoxide dismutase
in
the rat cochlea.
Author
Lai MT; Ohmichi T; Egusa K; Okada S; Masuda Y
Address
Department of Otolaryngology' Okayama University Medical School'
Japan.
Source
Eur Arch Otorhinolaryngol, 253(4-5):273-7 1996
Abstract
There has been recent increasing interest in the involvement
of
superoxide radicals (O2-) and their scavenging enzymes' the superoxide
dismutases' in the patho-physiology of certain diseases. Since
mitochondria are significant intracellular sources of O2- and
important
targets of oxidant inJury' determining the intracochlear localization
of mitochondrial O2- scavenging enzyme may provide important
insight
into the pathogenesis of inJury due to cochlear oxidants. In
order to
locate the mitochondrial O2- scavenging enzyme' manganese superoxide
dismutase (MnSOD)' the authors used a modified immunoglobulin
peroxidase bridge sequence method to detect MnSOD in paraffin-embedded'
formalin-fixed rat cochleas. Site-specific immunolocalization
of MnSOD
could be demonstrated in the cochlear labyrinth' suggesting that
the
generation of intracochlear O2- was possibly implicated in the
metabolically active sites and sites rich in vascularity. This
study
also provided a useful probe for detecting MnSOD immunohistochemically
from ethylenediamine tetra-acetic acid-treated materials without
requiring an antigen retrieval procedure.
Title
Antioxidant enzyme levels in cancer.
Author
Oberley TD; Oberley LW
Address
Pathology and Laboratory Medicine Service' William S. Middleton
Memorial Veterans Hospital' Madison' WI 53705' USA.
Source
Histol Histopathol, 12(2):525-35 1997 Apr
Abstract
Normal cells are protected by antioxidant enzymes from the toxic
effects of high concentrations of reactive oxygen species generated
during cellular metabolism. Even though cancer cells generate
reactive
oxygen species' it has been demonstrated biochemically that antioxidant
enzyme levels are low in most animal and human cancers. However'
a few
cancer types have been found to have elevated levels of antioxidant
enzymes' particularly manganese superoxide dismutase. Morphologic
studies of animal and human cancer have confirmed that although
the
maJority of tumor cell types from several organ systems have
low
antioxidant enzymes' adenocarcinomas may have elevated manganese
superoxide dismutase and catalase levels. However' all cancers
examined
to date have some imbalance in antioxidant enzyme levels compared
with
the cell of origin. Antioxidant enzyme importance in cancer genesis
has
been difficult to evaluate in early cancerous lesions using biochemical
techniques because such lesions are small and therefore below
the level
of detection. Using immunohistochemical techniques' early lesions
of
human and animal cancers were demonstrated to have low antioxidant
enzymes' thus suggesting a role for these enzymes both in the
genesis
of cancer and the malignant phenotype. All but one human cancer
cell
type (the granular cell variant of human renal adenocarcinoma)
examined
showed both low catalase and glutathione peroxidase levels' suggesting
that most cancer cell types cannot detoxify hydrogen peroxide.
Our
results to date are used to propose new cancer therapies based
on
modulation of cellular redox state.
Title
Trace elements and cardiovascular diseases.
Author
Houtman JP
Address
Interuniversity Reactor Institute' Delff' The Netherlands.
Source
J Cardiovasc Risk, 3(1):18-25 1996 Feb
Abstract
The relation between trace elements and human health has been
scarcely
studied. With respect to cardiovascular diseases and hypertension
attention has mostly focused on arsenic' cobalt' copper' chromium'
fluorine' manganese' vanadium' zinc' selenium' silicon' cadmium'
and
lead. Environmental contamination can influence organ concentrations
through long-term' low-level effects. This article reviews the
present
knowledge obtained by epidemiological' biochemical and cell biological
studies. Attention is paid to interpretation problems due to
the
complexity of biochemical interactions with proteins of various
sorts
which determine metabolic processes and to the occurrence of
detoxification mechanisms in which trace elements interact. This
can
also lead to strong variations in individual vulnerability. In
general'
the elements selenium' copper' zinc' chromium' and manganese
seem to
counteract the development of cardiovascular diseases' whereas
cadmium
and may be lead seem to stimulate it. Effects of arsenic' silicon
and
fluorine are unclear and for cobalt absent. The intensity of
these
effects on public health is difficult to measure' but is as yet
probably limited except in extra-ordinary situations.
Title
Effects of hypoxia on MnSOD expression in mouse lung.
Author
Russell WJ; Ho YS; Parish G; Jackson RM
Address
Birmingham Veterans Affairs Medical Center' Alabama' USA.
Source
Am J Physiol, 269(2 Pt 1):L221-6 1995 Aug
Abstract
Mitochondrial manganese-containing SOD (MnSOD) is located at
the
primary site of O2 metabolism' and its expression may be regulated
by
changes in O2 level. We hypothesized that lung MnSOD expression
and
promoter activity would decrease in response to hypoxia. We tested
effects of hypoxia (10% O2 at sea level for 7 days) on chloramphenicol
acetyltransferase (CAT) reporter and MnSOD gene expression in
transgenic mice. The transgene consisted of a 3.3-kb portion
of the rat
MnSOD gene 5` flanking region coupled to a CAT reporter gene.
Lung
MnSOD activity in male (but not female) mice decreased significantly
after hypoxia exposure. The decrease in MnSOD enzymatic activity
in
male mice was specific. Neither total SOD nor glucose-6-phosphate
dehydrogenase (G-6-PDH) activity decreased significantly in hypoxia.
CAT protein expression decreased in transgenic males exposed
to
hypoxia' while CAT protein expression in hypoxic transgenic females
remained comparable with controls. The mRNA for both the native
MnSOD
and the MnSOD-CAT reporter genes remained constant after hypoxia'
as
did CuZnSOD and G-6-PDH mRNAs. |
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