287 research outputs found
Pregnancy outcomes in female childhood and adolescent cancer survivors: a linked cancer-birth registry analysis
Objective: To compare birth outcomes among childhood and adolescent female cancer survivors who subsequently bear children, relative to those of women without cancer history.
Design: Retrospective cohort study.
Setting: 4 U.S. regions.
Participants: Cancer registries identified girls <20 years, diagnosed with cancer 1973-2000. Linked birth records identified first live births after diagnosis (n=1898). Comparison subjects were selected from birth records (n=14278). Cervical/genital tract cancer cases were analyzed separately.
Main Exposure: Cancer diagnosis <20 years.
Outcome Measures: Infant low birth weight, preterm delivery, sex ratio, malformations, mortality, delivery method; maternal diabetes, anemia, preeclampsia.
Results: Childhood cancer survivors’ infants were more likely to be preterm (relative risk [RR] 1.54, 95% CI 1.30-1.83) and weigh <2500 g (RR 1.31, 95% CI 1.10-1.57). For cervical/genital cancer patients’ offspring, estimates were 1.33 (95% CI 1.13, 1.56), and 1.29 (95% CI 1.10-1.53), respectively. There were no increased risks of malformations, infant death, or altered sex ratio, suggesting no increased germ cell mutagenicity. In exploratory analysis, bone cancer survivors had an increased risk of diabetes (RR 4.92, 95% CI 1.60-15.13), and anemia was more common among brain tumor survivors (RR 3.05, 95% CI 1.16-7.98) and childhood cancer survivors with initial treatment of chemotherapy only (RR 2.45, 95% CI 1.16-5.17).
Conclusions: Infants of female childhood and adolescent cancer patients were not at increased risk of malformations or death. Increased occurrence of preterm delivery and low birth weight suggest close monitoring is warranted. Increased diabetes and anemia among sub-groups have not been reported, suggesting areas for study
Reproductive outcomes in male childhood cancer survivors: a linked cancer-birth registry analysis
OBJECTIVE: Compare the risk of reproductive and infant outcomes between male childhood cancer survivors and a population-based comparison group.
DESIGN: Retrospective cohort study.
SETTING: 4 U.S. regions.
PARTICIPANTS: Cancer registries identified males <20 years old diagnosed with cancer 1973-2000. Linked birth certificates identified first subsequent live offspring (n=470). Comparison subjects were identified from remaining birth certificates, frequency-matched on year and age at fatherhood, and race/ethnicity (n=4150).
MAIN EXPOSURE: Cancer diagnosis prior to age 20.
OUTCOME MEASURES: Pregnancy and infant outcomes identified from birth certificates.
RESULTS: Compared with infants born to unaffected males, offspring of cancer survivors had a borderline risk of birth weight <2500 g (RR 1.43, 95% CI 0.99-2.05), with risk associated most strongly with younger age of cancer diagnosis and exposure to any chemotherapy (RR 1.96, 95% CI 1.22-3.17) or radiotherapy (RR 1.95, 95% CI 1.14-3.35). However, they were not at risk of being born prematurely, small for gestational age, having malformations or an altered male:female sex ratio. Overall, female partners of male survivors were not more likely to have maternal complications recorded on birth records versus the comparison group. However, preeclampsia was associated with some cancers, especially central nervous system tumors (RR 3.36, 95% CI 1.63-6.90). CONCLUSIONS: Most pregnancies resulting in live births among partners of male childhood cancer survivors were not at significantly greater risk of complications versus comparison subjects. The possibility of a paternal component affected by prior cancer history influencing predisposition towards some adverse perinatal outcomes merits further investigation
Looking For Disoriented Chiral Condensates From Pion Distributions
We suggest two methods for the detection of the formation of disoriented
chiral condensates in heavy ion collisions. We show that the variance in the
number of charged pions (in a suitable range of momentum space) provides a
signature for the observation of a disoriented chiral condensate. The signal
should be observable even if multiple domains of DC form provided the
average number of pions per domain is significantly larger than unity. The
variance of the number charged pions alone provides a signal which can be used
even if the number of neutral pions cannot be measured in a given detector. On
the other hand, the probability distribution in , the proportion of neutral
pions to all pions emitted in heavy ion collisions in certain kinematic
regions, has been suggested as a signal of a disoriented chiral condensate.
Here we note that the signature can be greatly enhanced by making suitable cuts
in the data. In particular, we consider reducing the data set such that the
pions with lowest are all neutral. We find that, given such cuts,
can be substantially different from 1/3. For example, for a single D$\chi$C
domain without contamination due to incoherently emitted pions, is 3/5
given the pion with lowest is neutral, and 5/7 given the two pions with
lowest are both neutral, {\it etc.}. The effects of multi-domain DC
formation and noise due to incoherent pion emission can be systematically
incorporated. Potential applications to experiments and their limitations are
briefly discussed.Comment: 16 pages in REVTeX, 7 figures. Combined and updated version of
nucl-th/9903029 and nucl-th/9904074. Accepted by Phys. Rev.
Tobacco smoking, body mass index, hypertension, and kidney cancer risk in central and eastern Europe
In a case–control study of kidney cancer in four central European countries, with 1097 incident cases and 1476 controls, we found an increased risk for self-reported hypertension and for obesity. Additional unknown risk factors are likely to be responsible for the high rates of kidney cancer in this region
Parkour as a donor sport for athletic development in youth team sports: insights through an ecological dynamics lens
Analyses of talent development in sport have identified that skill can be enhanced through early and continued involvement in donor sports which share affordances (opportunities for action) with a performer's main target sport. Aligning key ideas of the Athletic Skills Model and ecological dynamics theory, we propose how the sport of parkour could provide a representative and adaptive platform for developing athletic skill (e.g. coordination, timing, balance, agility, spatial awareness and muscular strength). We discuss how youth sport development programmes could be (re) designed to include parkour-style activities, in order to develop general athletic skills in affordance-rich environments. It is proposed that team sports development programmes could particularly benefit from parkour-style training since it is exploratory and adaptive nature shapes utilisation of affordances for innovative and autonomous performance by athletes. Early introduction to varied, relevant activities for development of athleticism and skill, in a diversified training programme, would provide impetus for a fundamental shift away from the early specialisation approach favoured by traditional theories of skill acquisition and expertise in sport
Conformation Regulation of the X Chromosome Inactivation Center: A Model
X-Chromosome Inactivation (XCI) is the process whereby one, randomly chosen X becomes transcriptionally silenced in female cells. XCI is governed by the Xic, a locus on the X encompassing an array of genes which interact with each other and with key molecular factors. The mechanism, though, establishing the fate of the X's, and the corresponding alternative modifications of the Xic architecture, is still mysterious. In this study, by use of computer simulations, we explore the scenario where chromatin conformations emerge from its interaction with diffusing molecular factors. Our aim is to understand the physical mechanisms whereby stable, non-random conformations are established on the Xic's, how complex architectural changes are reliably regulated, and how they lead to opposite structures on the two alleles. In particular, comparison against current experimental data indicates that a few key cis-regulatory regions orchestrate the organization of the Xic, and that two major molecular regulators are involved
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Electrophysiological Assessment in Birdshot Chorioretinopathy: Flicker Electroretinograms Recorded With a Handheld Device
Purpose: The flicker electroretinogram (ERG) is a sensitive indicator of retinal dysfunction in birdshot chorioretinopathy (BCR). We explored recordings from a handheld device in BCR, comparing these with conventional recordings in the same patients and with handheld ERGs from healthy individuals.
Methods: Non-mydriatic flicker ERGs, using the handheld RETeval system (LKC Technologies), were recorded with skin electrodes at two centers. At one center (group 1), the stimuli (85 Td·s, 850 Td background) delivered retinal illuminance equivalent to international standards; at the other center (group 2), a different protocol was used (32 Td·s, no background). Patients also underwent international standard flicker ERG recordings with conventional electrodes following mydriasis. Portable ERGs from patients were also compared with those from healthy individuals.
Results: Thirty-two patients with BCR (mean age ± SD, 56.4 ± 11.3 years) underwent recordings. Portable and standard ERG parameters correlated strongly (r > 0.75, P < 0.01) in both groups. Limits of agreement for peak times were tighter in group 1 (n = 21; −4.3 to+2.0ms [right eyes], −3.9to1.5ms [left eyes]) than in group 2(n=11;−3.4 to +6.9 ms [right eyes], −4.8 to +9.0 ms [left eyes]). Compared with healthy controls (n =66 and n =90 for groups 1 and 2, respectively), patients with BCR showed smaller mean amplitudes and longer peak times.
Conclusions: Portable ERGs correlated strongly with conventional recordings, suggesting potential in rapid assessment of cone system function in office settings.
Translational Relevance: Flicker ERGs, known to be useful in BCR, can be obtained rapidly with a portable device with skin electrodes and natural pupils
Essential versus accessory aspects of cell death: recommendations of the NCCD 2015
Cells exposed to extreme physicochemical or mechanical stimuli die in an uncontrollable manner, as a result of their immediate structural breakdown. Such an unavoidable variant of cellular demise is generally referred to as ‘accidental cell death’ (ACD). In most settings, however, cell death is initiated by a genetically encoded apparatus, correlating with the fact that its course can be altered by pharmacologic or genetic interventions. ‘Regulated cell death’ (RCD) can occur as part of physiologic programs or can be activated once adaptive responses to perturbations of the extracellular or intracellular microenvironment fail. The biochemical phenomena that accompany RCD may be harnessed to classify it into a few subtypes, which often (but not always) exhibit stereotyped morphologic features. Nonetheless, efficiently inhibiting the processes that are commonly thought to cause RCD, such as the activation of executioner caspases in the course of apoptosis, does not exert true cytoprotective effects in the mammalian system, but simply alters the kinetics of cellular demise as it shifts its morphologic and biochemical correlates. Conversely, bona fide cytoprotection can be achieved by inhibiting the transduction of lethal signals in the early phases of the process, when adaptive responses are still operational. Thus, the mechanisms that truly execute RCD may be less understood, less inhibitable and perhaps more homogeneous than previously thought. Here, the Nomenclature Committee on Cell Death formulates a set of recommendations to help scientists and researchers to discriminate between essential and accessory aspects of cell death
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Electrophysiological Assessment in Birdshot Chorioretinopathy: Use of a Portable Device in the Clinic
Road avoidance and its energetic consequences for reptiles
Roads are one of the most widespread human-caused habitat modifications that can increase wildlife mortality rates and alter behavior. Roads can act as barriers with variable permeability to movement and can increase distances wildlife travel to access habitats. Movement is energetically costly, and avoidance of roads could therefore impact an animal's energy budget. We tested whether reptiles avoid roads or road crossings and explored whether the energetic consequences of road avoidance decreased individual fitness. Using telemetry data from Blanding's turtles (Emydoidea blandingii; 11,658 locations of 286 turtles from 15 sites) and eastern massasaugas (Sistrurus catenatus; 1,868 locations of 49 snakes from 3 sites), we compared frequency of observed road crossings and use of road-adjacent habitat by reptiles to expected frequencies based on simulated correlated random walks. Turtles and snakes did not avoid habitats near roads, but both species avoided road crossings. Compared with simulations, turtles made fewer crossings of paved roads with low speed limits and more crossings of paved roads with high speed limits. Snakes made fewer crossings of all road types than expected based on simulated paths. Turtles traveled longer daily distances when their home range contained roads, but the predicted energetic cost was negligible: substantially less than the cost of producing one egg. Snakes with roads in their home range did not travel further per day than snakes without roads in their home range. We found that turtles and snakes avoided crossing roads, but road avoidance is unlikely to impact fitness through energetic expenditures. Therefore, mortality from vehicle strikes remains the most significant impact of roads on reptile populations
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