32 research outputs found
SNPs in DNA repair or oxidative stress genes and late subcutaneous fibrosis in patients following single shot partial breast irradiation
<p>Abstract</p> <p>Background</p> <p>The aim of this study was to evaluate the potential association between single nucleotide polymorphisms related response to radiotherapy injury, such as genes related to DNA repair or enzymes involved in anti-oxidative activities. The paper aims to identify marker genes able to predict an increased risk of late toxicity studying our group of patients who underwent a Single Shot 3D-CRT PBI (SSPBI) after BCS (breast conserving surgery).</p> <p>Methods</p> <p>A total of 57 breast cancer patients who underwent SSPBI were genotyped for SNPs (single nucleotide polymorphisms) in XRCC1, XRCC3, GST and RAD51 by Pyrosequencing technology. Univariate analysis (ORs and 95% CI) was performed to correlate SNPs with the risk of developing ≥ G2 fibrosis or fat necrosis.</p> <p>Results</p> <p>A higher significant risk of developing ≥ G2 fibrosis or fat necrosis in patients with: polymorphic variant <it>GSTP1 </it>(Ile105Val) (OR = 2.9; 95%CI, 0.88-10.14, <it>p </it>= 0.047).</p> <p>Conclusions</p> <p>The presence of some SNPs involved in DNA repair or response to oxidative stress seem to be able to predict late toxicity.</p> <p>Trial Registration</p> <p>ClinicalTrials.gov: <a href="http://www.clinicaltrials.gov/ct2/show/NCT01316328">NCT01316328</a></p
Cytochrome P450 1A2 (CYP1A2) activity, mammographic density, and oxidative stress: a cross-sectional study
INTRODUCTION: Mammographically dense breast tissue is a strong predictor of breast cancer risk, and is influenced by both mitogens and mutagens. One enzyme that is able to affect both the mitogenic and mutagenic characteristics of estrogens is cytochrome P450 1A2 (CYP1A2), which is principally responsible for the metabolism of 17β-estradiol. METHODS: In a cross-sectional study of 146 premenopausal and 149 postmenopausal women, we examined the relationships between CYP1A2 activity, malondialdehyde (MDA) levels, and mammographic density. In vivo CYP1A2 activity was assessed by measuring caffeine metabolites in urine. Levels of serum and urinary MDA, and MDA–deoxyguanosine adducts in DNA were measured. Mammograms were digitized and measured using a computer-assisted method. RESULTS: CYP1A2 activity in postmenopausal women, but not in premenopausal women, was positively associated with mammographic density, suggesting that increased CYP1A2 activity after the menopause is a risk factor for breast cancer. In premenopausal women, but not in postmenopausal women, CYP1A2 activity was positively associated with serum and urinary MDA levels; there was also some evidence that CYP1A2 activity was more positively associated with percentage breast density when MDA levels were high, and more negatively associated with percentage breast density when MDA levels were low. CONCLUSION: These findings provide further evidence that variation in the activity level of enzymes involved in estrogen metabolism is related to levels of mammographic density and potentially to breast cancer risk
Effects Of June Winds On Rainfall In The Coastal Region Of Kenya
Although the equatorial Eastern region of Africa is adjacent to the
Indian Ocean, it tends to exhibit a drier climate rather than one
characterized by abundant tropical rains. A number of studies on
rainfall variability in the East African region have tended to suggest
a stronger influence of local factors in controlling rainfall amounts
and their characteristics rather than the global wind circulation
system. A climatic phenomenon that is locally termed "June winds" is
unique to East Africa's coastal region. The study mainly involved
analysing rainfall anomalies and means of 39- year meteorological data
from the region and data from earlier studies about the region. The
results indicate that June winds occur annually after the onset of long
rains between the months of May and June. They impart subsidence,
drying and cloud free conditions, altering the climatological
properties in the areas they traverse. The attainment of peak June wind
velocities causes a characteristic depression in rainfall probability
and amounts on their course, similar to the ‘Ganges depression'
of temperatures in the Indian subcontinent, which in turn affects
available soil moisture for crop growth. The results also reveal
existence of years of "above-normal rains" (herein referred to as El
Niño years) and years of "below-normal rains" (herein referred to
as La Niña years) which are associated and modulated by El
Niño southern oscillation. They also reveal that drought years
tend to occur in succession and that the June winds tend to be
suppressed or absent during El Niño years, but strongly associate
with La Niña years. The study suggests that the frequency and
therefore the ratio of La Niña years to El Niño years have
been increasing. The study also suggests possibility of developing a
decision support system for farmers in resource use and allocation
based predicted time of occurrence of the June winds
The Effects Of East African Low Level Jet On Food Security In Horn Of Africa: A Case Study Of Coastal Region Of Kenya
Literature on rainfall variability in Eastern Africa has suggested a
significant influence from local factors that control rainfall amounts
and distribution in contrast to the global wind circulation systems in
oceanic atmospheres. All oceans are associated with unique wind systems
that reflect temperature and other physical attributes of the water
masses. However, the influence of such systems on Eastern Africa has
not been investigated in conjunction with unique climatic phenomena,
including the June winds in the coastal region of Kenya. This study
involved a review of literature and the analyses of secondary data from
studies conducted in the region, including 39 years of meteorological
data. The results indicated that only two months in a year, namely
April and May, experience a positive net moisture regime. In all other
months, predicted evaporation exceeds received precipitation. The
results also suggest that the annual June winds create a cyclic
depression in rainfall amounts during the long rains season, resulting
in decreased soil moisture and therefore adverse effects on annual
field crops. The June winds, at critical stages of maize growth,
results in depressed crop yields that threaten food supply and food
security. Maize yields in the region are associated over time with
amounts of rain received during the long rains season. Cyclic patterns
indicated that a year of higher rainfall alternates with a year of
lower rainfall amounts. The study reveals that June winds causes over
95% in yield loses and suggests that the region can feed itself and
export excess grains if only appropriate technologies to counter June
winds effects are adopted. Since the occurrence of June winds is
strongly linked to the La Niña climatic phenomenon the study
suggests development of a maize yield prediction model for seasonal
forecasting based on the onset of June winds during the long rains
season
The effects of East African low level jet on food security in horn of Africa: A case study of coastal region of Kenya
Literature on rainfall variability in Eastern Africa has suggested a significant influence from local factors that control rainfall amounts and distribution in contrast to the global wind circulation systems in oceanic atmospheres. All oceans are associated with unique wind systems that reflect temperature and other physical attributes of the water masses. However, the influence of such systems on Eastern Africa has not been investigated in conjunction with unique climatic phenomena, including the June winds in the coastal region of Kenya. This study involved a review of literature and the analyses of secondary data from studies conducted in the region, including 39 years of meteorological data. The results indicated that only two months in a year, namely April and May, experience a positive net moisture regime. In all other months, predicted evaporation exceeds received precipitation. The results also suggest that the annual June winds create a cyclic depression in rainfall amounts during the long rains season, resulting in decreased soil moisture and therefore adverse effects on annual field crops. The June winds, at critical stages of maize growth, results in depressed crop yields that threaten food supply and food security. Maize yields in the region are associated over time with amounts of rain received during the long rains season. Cyclic patterns indicated that a year of higher rainfall alternates with a year of lower rainfall amounts. The study reveals that June winds causes over 95% in yield loses and suggests that the region can feed itself and export excess grains if only appropriate technologies to counter June winds effects are adopted. Since the occurrence of June winds is strongly linked to the La Niña climaticphenomenon the study suggests development of a maize yield prediction model for seasonal forecasting based on the onset of June winds during the long rains season