Neonatal hemodynamic response to visual cortex activity: high-density near-infrared spectroscopy study

The neurodevelopmental outcome of neonatal intensive care unit (NICU) infants is a major clinical concern with many infants displaying neurobehavioral deficits in childhood. Functional neuroimaging may provide early recognition of neural deficits in high-risk infants. Near-infrared spectroscopy (NIRS) has the advantage of providing functional neuroimaging in infants at the bedside. However, limitations in traditional NIRS have included contamination from superficial vascular dynamics in the scalp. Furthermore, controversy exists over the nature of normal vascular, responses in infants. To address these issues, we extend the use of novel high-density NIRS arrays with multiple source-detector distances and a superficial signal regression technique to infants. Evaluations of healthy term-born infants within the first three days of life are performed without sedation using a visual stimulus. We find that the regression technique significantly improves brain activation signal quality. Furthermore, in six out of eight infants, both oxy- and total hemoglobin increases while deoxyhemoglobin decreases, suggesting that, at term, the neurovascular coupling in the visual cortex is similar to that found in healthy adults. These results demonstrate the feasibility of using high-density NIRS arrays in infants to improve signal quality through superficial signal regression, and provide a foundation for further development of high-density NIRS as a clinical tool

The fraction of breast cancer attributable to smoking: The Norwegian women and cancer study 1991–2012

Background: Results from several recent cohort studies on smoking and breast cancer incidence and mortality suggest that the burden of smoking on society is underestimated. We estimated the fraction of breast cancer attributable to smoking in the Norwegian Women and Cancer Study, a nationally representative prospective cohort study. Methods: We followed 130 053 women, aged 34–70 years, who completed a baseline questionnaire between 1991 and 2007, through linkages to national registries through December 2012. We used Cox proportional hazards models to estimate hazard ratios (HRs) with 95% confidence intervals (CIs), while adjusting for confounders. Never smokers, excluding passive smokers, were used as the reference group in all main analyses. We estimated attributable fractions (AFs) % in smokers and in the population (PAFs) % with 95% CIs. Results: Altogether, 4132 women developed invasive breast cancer, confirmed by histology. Compared with never active, never passive smokers, ever (former and current) smokers had an overall risk of breast cancer that was 21% higher (HR¼1.21; 95% CI¼1.08–1.34). For ever smokers, the AF was 17.3% (95% CI ¼7.4–25.4) and for the population the PAF of breast cancer was 11.9% (95% CI¼5.3–18.1). For passive smokers, the PAF of breast cancer was 3.2% (95% CI¼1.0–5.4). When we applied PAF estimates for ever smoking on the 2907 new breast cancer cases among Norwegian women aged 35þ at diagnosis in 2012, this yielded 345 (95% CI¼154–526) breast cancer cases that could have been avoided in the absence of active smoking that year. Conclusions: In smokers, one in six and in the population, one in nine breast cancer cases could have been avoided in the absence of active smoking. Our findings support the notion that the global cancer burden due to smoking is substantially underestimated

Smoking and risk of ovarian cancer by histological subtypes: an analysis among 300 000 Norwegian women.

Background: We prospectively investigated the association between different measures of smoking exposure and the risk of serous, mucinous, and endometrioid ovarian cancers (OC) in a cohort of more than 300 000 Norwegian women. Methods: We followed 300 398 women aged 19–67 years at enrolment until 31 December 2013 for OC incidence through linkage to national registries. We used Cox proportional hazards models with attained age as the underlying time scale to estimate multivariable-adjusted hazard ratios (HRs) with 95% confidence intervals (CIs) adjusted for relevant confounders. Results: During more than 5.9 million person-years and a median follow-up time of 19 years, 2336 primary invasive (1647, 71%) and borderline (689, 29%) OC were identified (53% serous, 19% mucinous). Compared with never smokers, current smokers who had smoked for X10 years had a higher risk of mucinous OC (HR10–19 years vs never¼1.73, 95% CI 1.24–2.42; HRX20 vs never¼2.26, 95% CI 1.77–2.89, Ptrend o0.001). When stratified by invasiveness, current smokers had a higher risk of invasive mucinous OC (HR¼1.78, 95% CI 1.20–2.64) and borderline mucinous OC (HR¼2.26 95% CI, 1.71–2.97) (Pheterogeneity¼0.34) than never smokers. Smoking was not associated with serous or endometrioid OC. Conclusions: Using a very large cohort of women, the current analysis provides an important replication for a similar risk of invasive and borderline mucinous OC related to smoking