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Record
1 from database: MEDLINE
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- Title
- Antipain-mediated suppression of X-ray-induced
chromosomal aberrations in human lymphocytes.
- Author
- Afzal V; Wiencke JK; Wolff S
- Address
- Laboratory of Radiobiology and Environmental
Health, University of California, San Francisco
94143.
- Source
- Carcinogenesis, 1989 Jul, 10:7, 1193-6
- Abstract
- The protease inhibitor antipain is known to
modulate the number of chromosomal aberrations
induced by the S-phase-dependent alkylating
agent N-methyl-N'-nitro-N-nitrosoguanidine.
Experiments have now been carried out to see if
antipain might also effect the yield of
aberrations induced by X-rays, which are
S-independent and thus produce chromosomal
aberrations by a different mechanism. The
results show that human lymphocytes exposed to
0.4 or 1.5 Gy of X-rays at 48 h of culture and
fixed at 3, 6, 8, 10 or 12 h thereafter contain
27-52% fewer chromatid breaks if the cells are
also treated with antipain before irradiation.
Because previous studies postulated that
antipain could affect the induction of
chromosomal aberrations by suppressing free
radical reactions within cells, we also tested
whether antipain affects X-ray-induced
aberrations when present only during the time of
irradiation, as is the case for free radical
scavengers, such as L-cysteine. The results
indicate that, in contrast to L-cysteine,
antipain can suppress the induction of
X-ray-induced aberrations even when administered
as late as 2 h after irradiation, suggesting
that the effects of antipain on aberrations are
not attributable to its interference with
short-lived radicals within the cells. Although
the exact mechanism whereby antipain decreases
the yield of chromosome aberrations induced by
the S-independent agent X-rays is unknown, these
data indicate that the formation of chromosome
aberrations by S-independent agents too can
involve an antipain-sensitive process.
- Language of Publication
- English
- Unique Identifier
- 89288525
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- MeSH Heading (Major)
- Antipain|*PD; Chromosome Aberrations|*;
Chromosomes, Human|DE/*RE; Lymphocytes|DE/*RE;
Oligopeptides|*PD
- MeSH Heading
- Cells, Cultured; Chromatids|DE/RE; Chromosome
Deletion; Cysteine|PD; Human; Kinetics; Support,
U.S. Gov't, Non-P.H.S.
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0143-3334
- Country of Publication
- UNITED STATES
Record 2 from
database: MEDLINE
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- Title
- Increased frequency of spontaneous and
X-ray-induced chromosomal aberrations in
lymphocytes from neonates and the influence of
caffeine--an in vitro study.
- Author
- Karsdon J; van Rijn J; Berger H; Natarajan AT
- Address
- Department of Pediatrics, University Hospital
of Leiden, The Netherlands.
- Source
- Mutat Res, 1989 May, 226:1, 13-9
- Abstract
- We have examined lymphocytes from human
preterm (PT) and fullterm (FT) babies for an
effect of gestational age (GA) on chromosomal
aberrations either occurring spontaneously or
induced by treatment with X-rays (1 Gy) alone;
or with caffeine (1,3,7-trimethylxanthine)
supplementation (5 X 10(-4) M), in comparison to
the lymphocytes of healthy adults (AD). Percent
of abnormal cells (%Abn) was used as an
indicator of chromosome sensitivity to the
different treatments. PT babies had
significantly higher spontaneous and
X-ray-induced %Abn values than AD, but were
comparable to FT. After X-irradiation + caffeine
the yield of aberrations in any 2 groups was not
significantly different. Chromosomal sensitivity
may result from factors other than GA. This in
vitro model may permit study of the mechanisms
of chromosomal damage repair and prevention of
free radical damage of DNA during the perinatal
period.
- Language of Publication
- English
- Unique Identifier
- 89238431
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- MeSH Heading (Major)
- Caffeine|*TO; Chromosome Aberrations|*;
Lymphocytes|*/DE/RE/UL; Mutagens|*
- MeSH Heading
- Adult; Aging; Cells, Cultured; Gestational
Age; Human; Infant, Newborn; Interphase; Middle
Age
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0027-5107
- Country of Publication
- NETHERLANDS
Record 3 from
database: MEDLINE
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- Title
- Concentration-dependent protection against
X-ray-induced chromosome aberrations in human
lymphocytes by the aminothiol WR-1065.
- Author
- Littlefield LG; Joiner EE; Colyer SP; Sallam
F; Frome EL
- Address
- Oak Ridge Institute of Science and Education,
Tennessee 37831-0117.
- Source
- Radiat Res, 1993 Jan, 133:1, 88-93
- Abstract
- WR-1065, the free-thiol form of WR-2721, has
radioprotective effects in various biological
systems. We measured the efficiency of WR-1065
in modifying the induction of chromosome
aberrations by X rays in human lymphocytes. G0
lymphocytes were incubated for 30 min in medium
containing 1-12 mM WR-1065, exposed to 0 or 3.1
Gy 220-kV X rays, washed, and cultured for
evaluations of chromosome aberrations and
micronuclei (MN). Neither proliferation kinetics
nor baseline frequencies of aberrations or MN
were affected in nonirradiated cultures
incubated in WR-1065 for up to 45 min.
Radiation-induced chromosome aberrations and MN
varied inversely as a logarithmic function of
thiol concentration. At extracellular
concentrations of 8-12 mM, WR-1065 protected
against > 85% of X-ray-induced chromosome
damage as measured by either cytogenetic end
point. WR-1065 is more efficient in modulating
X-ray-induced chromosome aberrations than
dimethyl sulfoxide, which provides protection by
scavenging OH radicals. Our data suggest that
mechanisms in addition to OH radical scavenging
are involved in radioprotection by WR-1065.
- Language of Publication
- English
- Unique Identifier
- 93165916
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- MeSH Heading (Major)
- Chromosome Aberrations|*; Lymphocytes|DE/*RE;
Mercaptoethylamines|*TU; Radiation-Protective
Agents|*TU
- MeSH Heading
- Human; Micronuclei; Support, Non-U.S. Gov't;
Support, U.S. Gov't, Non-P.H.S.; Support, U.S.
Gov't, P.H.S.
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0033-7587
- Country of Publication
- UNITED STATES
Record 4 from
database: MEDLINE
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- Title
- Retinoid protection against x-ray-induced
chromatid damage in human peripheral blood
lymphocytes.
- Author
- Sanford KK; Parshad R; Price FM; Tarone RE;
Kraemer KH
- Address
- Laboratory of Cellular and Molecular Biology,
National Cancer Institute, Bethesda, Maryland
20892.
- Source
- J Clin Invest, 1992 Nov, 90:5, 2069-74
- Abstract
- Oral administration of isotretinoin (13-cis
retinoic acid) was shown previously (Kraemer, K.
H., J. J. DiGiovanna, A. N. Moshell, R. E.
Tarone, and G. L. Peck. 1988. N. Engl. J. Med.
318:1633-1637) to reduce the frequency of skin
cancers in xeroderma pigmentosum (XP) patients.
The mechanism of protection was unclear. In the
present study, x-ray-induced chromatid damage in
PHA-stimulated blood lymphocytes from five XP
patients receiving isotretinoin was
approximately half that in blood samples from
the same patients before or subsequent to
treatment. The x-ray-induced chromatid damage in
blood lymphocytes from a normal control was
reduced significantly by cocultivation with
blood or plasma from an XP patient receiving
isotretinoin or by addition of 10(-6) M
isotretinoin to cultures 1 h before
x-irradiation. A similar reduction in
x-ray-induced chromatid damage was reported
previously by adding to the culture medium,
mannitol, a scavenger of the free hydroxyl
radical, or catalase, which decomposes hydrogen
peroxide; both of these products are generated
during ionizing radiation. The present
observations suggest that isotretinoin acts as a
scavenger of such radiation products, thereby
providing protection against x-ray-induced
chromatid damage.
- Language of Publication
- English
- Unique Identifier
- 93055449
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- MeSH Heading (Major)
- Chromatids|*DE/*RE; DNA Damage|*DE;
Isotretinoin|*PD; Lymphocytes|*DE/*RE/UL
- MeSH Heading
- Adult; Aged; Cells, Cultured; Female; Human;
Male; Middle Age; Skin Neoplasms|PC; X-Rays;
Xeroderma Pigmentosum|CO
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0021-9738
- Country of Publication
- UNITED STATES
Record 5 from
database: MEDLINE
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- Title
- Concentration-dependent protection against
X-ray-induced chromosome aberrations in human
lymphocytes by the aminothiol WR-1065.
- Author
- Littlefield LG; Joiner EE; Colyer SP; Sallam
F; Frome EL
- Address
- Oak Ridge Institute of Science and Education,
Tennessee 37831-0117.
- Source
- Radiat Res, 1993 Jan, 133:1, 88-93
- Abstract
- WR-1065, the free-thiol form of WR-2721, has
radioprotective effects in various biological
systems. We measured the efficiency of WR-1065
in modifying the induction of chromosome
aberrations by X rays in human lymphocytes. G0
lymphocytes were incubated for 30 min in medium
containing 1-12 mM WR-1065, exposed to 0 or 3.1
Gy 220-kV X rays, washed, and cultured for
evaluations of chromosome aberrations and
micronuclei (MN). Neither proliferation kinetics
nor baseline frequencies of aberrations or MN
were affected in nonirradiated cultures
incubated in WR-1065 for up to 45 min.
Radiation-induced chromosome aberrations and MN
varied inversely as a logarithmic function of
thiol concentration. At extracellular
concentrations of 8-12 mM, WR-1065 protected
against > 85% of X-ray-induced chromosome
damage as measured by either cytogenetic end
point. WR-1065 is more efficient in modulating
X-ray-induced chromosome aberrations than
dimethyl sulfoxide, which provides protection by
scavenging OH radicals. Our data suggest that
mechanisms in addition to OH radical scavenging
are involved in radioprotection by WR-1065.
- Language of Publication
- English
- Unique Identifier
- 93165916
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- MeSH Heading (Major)
- Chromosome Aberrations|*; Lymphocytes|DE/*RE;
Mercaptoethylamines|*TU; Radiation-Protective
Agents|*TU
- MeSH Heading
- Human; Micronuclei; Support, Non-U.S. Gov't;
Support, U.S. Gov't, Non-P.H.S.; Support, U.S.
Gov't, P.H.S.
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0033-7587
- Country of Publication
- UNITED STATES
Record 6 from
database: MEDLINE
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- Title
- Iron in the basal ganglia in Parkinson's
disease. An in vitro study using extended X-ray
absorption fine structure and cryo-electron
microscopy.
- Author
- Griffiths PD; Dobson BR; Jones GR; Clarke DT
- Address
- Academic Department of Radiology, University
of Sheffield, UK.
- Source
- Brain, 1999 Apr, 122 ( Pt 4):, 667-73
- Abstract
- Iron is found in high concentration in some
areas of the brain, and increased iron in the
substantia nigra is a feature of Parkinson's
disease. The purpose of this study was to
investigate the physical environment of brain
iron in post-mortem tissue to provide
information on the possible role of iron in
neurodegeneration in Parkinson's disease. Iron
has also been implicated as the cause of signal
loss in areas of high brain iron on T2-weighted
MRI sequences. Knowledge of the physical
environment of the brain iron is essential in
interpreting the cause of signal change.
Post-mortem tissue was obtained from six cases
of Parkinson's disease and from six age-matched
controls. Iron levels were measured using
absorption spectrophotometry. Extended X-ray
absorption fine structure was used to evaluate
the atomic environment of iron within the
substantia nigra and both segments of the globus
pallidus. Cryo-electron transmission microscopy
was used to probe the iron storage proteins in
these areas. Iron levels were increased in the
parkinsonian nigra and lateral portion of the
globus pallidus. Spectra from the extended X-ray
absorption fine structure experiments showed
that ferritin was the only storage protein
detectable in both control and parkinsonian
tissue in all areas studied. Cryo-electron
transmission microscopy studies showed that
ferritin was more heavily loaded with iron in
Parkinson's disease when compared with
age-matched controls. In summary we have shown
that iron levels are increased in two areas of
the brain in Parkinson's disease including the
substantia nigra, the site of maximal
neurodegeneration. This produces increased
loading of ferritin, which is the normal brain
iron storage protein. It is possible that
increased loading of ferritin may increase the
risk of free radical-induced damage. Differences
in ferritin loading may explain regional
differences in iron's effect on the T2 signal.
- Language of Publication
- English
- Unique Identifier
- 99235186
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- MeSH Heading (Major)
- Basal Ganglia|*CH/*PA; Iron|*AN; Parkinson
Disease|*PA
- MeSH Heading
- Aged; Aged, 80 and over; Cryoelectron
Microscopy|MT; Crystallography|MT; Female;
Fourier Analysis; Human; Male; Microscopy,
Electron|MT; Neurons|CH/UL; Spectrum Analysis;
Synchrotrons; X-Rays
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0006-8950
- Country of Publication
- ENGLAND
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