1,534 research outputs found
Migraine in postmenopausal women and the risk of invasive breast cancer.
BACKGROUND: The frequency of migraine headache changes at various times of a woman's reproductive cycle. Menarche, menses, pregnancy, and perimenopause may carry a different migraine risk conceivably because of fluctuating estrogen levels, and in general, migraine frequency is associated with falling estrogen levels. Given the strong relationship between endogenous estrogen levels and breast cancer risk, migraine sufferers may experience a reduced risk of breast cancer. METHODS: We combined data from two population-based case-control studies to examine the relationship between migraine and risk of postmenopausal invasive breast cancer among 1,199 ductal carcinoma cases, 739 lobular carcinoma cases, and 1,474 controls 55 to 79 years of age. Polytomous logistic regression was used to estimate odds ratios (OR) and 95% confidence intervals (95% CI). RESULTS: Women who reported a clinical diagnosis of migraine had reduced risks of ductal carcinoma (OR, 0.67; 95% CI, 0.54-0.82) and lobular carcinoma (OR, 0.68; 95% CI, 0.52-0.90). These associations were primarily limited to hormone receptor-positive tumors as migraine was associated with a 0.65-fold (95% CI, 0.51-0.83) reduced risk of estrogen receptor-positive (ER+)/progesterone receptor-positive (PR+) ductal carcinoma. The reductions in risk observed were seen among migraine sufferers who did and did not use prescription medications for their migraines. CONCLUSIONS: These data suggest that a history of migraine is associated with a decreased risk of breast cancer, particularly among ER+/PR+ ductal and lobular carcinomas. Because this is the first study to address an association between migraine history and breast cancer risk, additional studies are needed to confirm this finding
3D human skin bioprinting: a view from the bio side
Based on the 3D printing technologies and the concepts developed in tissue engineering during the last decades, 3D bioprinting is emerging as the most innovative and promising technology for the generation of human tissues and organs. In the case of skin bioprinting, thanks to the research process carried out during the last years, interfollicular skin has been printed with a structural and functional quality that paves the way for clinical and industrial applications. This review analyzes the present achievements and the future improvements that this area must bring about if bioprinted skin is to become widely used. We have made an effort to integrate the technological and the biological/biomedical sides of the subject.We thank the Spanish Fundación Ramón Areces for its continuous support.
This work was partially supported by grant DPI2014-61887-EXP from the Spanish Ministerio de Economía y Competitividad
BLUF Domain Function Does Not Require a Metastable Radical Intermediate State
BLUF
(blue light using flavin) domain proteins are an important
family of blue light-sensing proteins which control a wide variety
of functions in cells. The primary light-activated step in the BLUF
domain is not yet established. A number of experimental and theoretical
studies points to a role for photoinduced electron transfer (PET)
between a highly conserved tyrosine and the flavin chromophore to
form a radical intermediate state. Here we investigate the role of
PET in three different BLUF proteins, using ultrafast broadband transient
infrared spectroscopy. We characterize and identify infrared active
marker modes for excited and ground state species and use them to
record photochemical dynamics in the proteins. We also generate mutants
which unambiguously show PET and, through isotope labeling of the
protein and the chromophore, are able to assign modes characteristic
of both flavin and protein radical states. We find that these radical
intermediates are not observed in two of the three BLUF domains studied,
casting doubt on the importance of the formation of a population of
radical intermediates in the BLUF photocycle. Further, unnatural amino
acid mutagenesis is used to replace the conserved tyrosine with fluorotyrosines,
thus modifying the driving force for the proposed electron transfer
reaction; the rate changes observed are also not consistent with a
PET mechanism. Thus, while intermediates of PET reactions can be observed
in BLUF proteins they are not correlated with photoactivity, suggesting
that radical intermediates are not central to their operation. Alternative
nonradical pathways including a keto–enol tautomerization induced
by electronic excitation of the flavin ring are considered
A comparison of the cosmic-ray energy scales of Tunka-133 and KASCADE-Grande via their radio extensions Tunka-Rex and LOPES
The radio technique is a promising method for detection of cosmic-ray air
showers of energies around PeV and higher with an array of radio
antennas. Since the amplitude of the radio signal can be measured absolutely
and increases with the shower energy, radio measurements can be used to
determine the air-shower energy on an absolute scale. We show that calibrated
measurements of radio detectors operated in coincidence with host experiments
measuring air showers based on other techniques can be used for comparing the
energy scales of these host experiments. Using two approaches, first via direct
amplitude measurements, and second via comparison of measurements with air
shower simulations, we compare the energy scales of the air-shower experiments
Tunka-133 and KASCADE-Grande, using their radio extensions, Tunka-Rex and
LOPES, respectively. Due to the consistent amplitude calibration for Tunka-Rex
and LOPES achieved by using the same reference source, this comparison reaches
an accuracy of approximately - limited by some shortcomings of LOPES,
which was a prototype experiment for the digital radio technique for air
showers. In particular we show that the energy scales of cosmic-ray
measurements by the independently calibrated experiments KASCADE-Grande and
Tunka-133 are consistent with each other on this level
Behavioral and cognitive interventions to improve treatment adherence and access to HIV care among older adults in sub-Saharan Africa: an updated systematic review
BACKGROUND: Approximately 14% of Africans infected with HIV are over the age of 50, yet few intervention studies
focus on improving access to care, retention in care, and adherence to antiretroviral therapy (ART) in this
population. A review of the published literature until 2012, found no relevant ART management and care interventions
for older people living with HIV (OPLHIV) in sub-Saharan Africa. The aim of this systematic review is to update the
original systematic review of intervention studies on OPLHIV, with a focus on evidence from sub-Saharan Africa.
METHODS: We conducted a systematic review of the available published literature from 2012 to 2017 to explore
behavioral and cognitive interventions addressing access to ART, retention in HIV care and adherence to ART in
sub-Saharan Africa that include older adults (50+). We searched three databases (MEDLINE, EMBASE, and Education
Resources Information Center) using relevant Medical Subject Headings (MeSH) terms as well as a manual search of the
reference lists. No language restrictions were placed. We identified eight articles which were analyzed using content
analysis with additional information obtained directly from the corresponding authors.
RESULTS AND DISCUSSION: There were no studies that exclusively focused on OPLHIV. Three studies referred only to
participants being over 18 years and did not specify age categories. Therefore, it is unclear whether these studies
actively considered people living with HIV over the age of 50. Although the studies sampled older adults, they lacked
sufficient data to draw conclusions about the relevance of the outcomes of this group.
CONCLUSIONS: These findings underscore the need to increase the evidence-base of which interventions will work for
older Africans on ART
The Association of Tree Pollen Concentration Peaks and Allergy Medication Sales in New York City: 2003–2008
The impact of pollen exposure on population allergic illness is poorly characterized. We explore the association of tree pollen and over-the-counter daily allergy medication sales in the New York City metropolitan area. Dates of peak tree pollen (maple, oak, and birch) concentrations were identified from 2003 to 2008. Daily allergy medication sales reported to the city health department were analyzed as a function of the same-day and lagged tree pollen peak indicators, adjusting for season, year, temperature, and day of week. Significant associations were found between tree pollen peaks and allergy medication sales, with the strongest association at 2-day lag (excess sales of 28.7% (95% CI: 17.4–41.2) over the average sales during the study period). The cumulative effect over the 7-day period on and after the tree pollen peak dates was estimated to be 141.1% (95% CI: 79.4–224.1). In conclusion, tree pollen concentration peaks were followed by large increases in over-the-counter allergy medication sales
Relationship between migraine history and breast cancer risk among premenopausal and postmenopausal women.
Both migraine and breast cancer are hormonally mediated diseases, and it is biologically plausible that women with a history of migraine may have a reduced breast cancer risk. However, this relationship has only been assessed in a single relatively small study that was unable to assess the effect of migraine triggers, which are also well-established breast cancer risk factors (e.g., use of alcohol and exogenous hormones), on the inverse association observed. Utilizing data on 4,568 breast cancer cases and 4,678 controls who participated in a multicenter population-based case-control study in the United States, we evaluated the association between migraine history and breast cancer risk using unconditional logistic regression. Migraine history data were obtained from structured in-person interviews. Women with a history of migraine had a reduced risk of breast cancer [odds ratio, 0.74; 95% confidence interval (CI), 0.66-0.82]. This risk did not differ by menopausal status, age at migraine diagnosis, use of prescription migraine medications, or when analyses were restricted to women who avoided various migraine triggers (including alcohol, exogenous hormones, and smoking). These data support a previous finding that a history of migraine may be associated with a reduced risk of breast cancer. It extends the prior report in observing that this relationship holds for both premenopausal and postmenopausal women and is independent of exposure to common migraine triggers
The wavefront of the radio signal emitted by cosmic ray air showers
Analyzing measurements of the LOPES antenna array together with corresponding
CoREAS simulations for more than 300 measured events with energy above
eV and zenith angles smaller than , we find that the radio
wavefront of cosmic-ray air showers is of approximately hyperbolic shape. The
simulations predict a slightly steeper wavefront towards East than towards
West, but this asymmetry is negligible against the measurement uncertainties of
LOPES. At axis distances m, the wavefront can be approximated by
a simple cone. According to the simulations, the cone angle is clearly
correlated with the shower maximum. Thus, we confirm earlier predictions that
arrival time measurements can be used to study the longitudinal shower
development, but now using a realistic wavefront. Moreover, we show that the
hyperbolic wavefront is compatible with our measurement, and we present several
experimental indications that the cone angle is indeed sensitive to the shower
development. Consequently, the wavefront can be used to statistically study the
primary composition of ultra-high energy cosmic rays. At LOPES, the
experimentally achieved precision for the shower maximum is limited by
measurement uncertainties to approximately g/cm. But the simulations
indicate that under better conditions this method might yield an accuracy for
the atmospheric depth of the shower maximum, , better than
g/cm. This would be competitive with the established air-fluorescence
and air-Cherenkov techniques, where the radio technique offers the advantage of
a significantly higher duty-cycle. Finally, the hyperbolic wavefront can be
used to reconstruct the shower geometry more accurately, which potentially
allows a better reconstruction of all other shower parameters, too.Comment: accepted by JCA
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