Fluctuations and symmetry energy in nuclear fragmentation dynamics

Within a dynamical description of nuclear fragmentation, based on the liquid-gas phase transition scenario, we explore the relation between neutron-proton density fluctuations and nuclear symmetry energy. We show that, along the fragmentation path, isovector fluctuations follow the evolution of the local density and approach an equilibrium value connected to the local symmetry energy. Higher-density regions are characterized by smaller average asymmetry and narrower isotopic distributions. This dynamical analysis points out that fragment final state isospin fluctuations can probe the symmetry energy of the density domains from which fragments originate.

National cancer incidence is estimated using the incidence/mortality ratio in countries with local incidence data: is this estimation correct?

BACKGROUND

In countries with local cancer registration, the national cancer incidence is usually estimated by multiplying the national mortality by the incidence/mortality (I/M) ratio from pooled registries. This study aims at validating this I/M estimation in France, by a comparison with estimation obtained using the ratio of incidence over hospital discharge (I/HD) or the ratio of incidence over health insurance data (long-duration diseases, I/LDD).

METHODS

This comparison was performed for 22 cancer sites over the period 2004-2006. In France, a longitudinal I/M approach was developed relying on incidence and mortality trend analyses; here, the corresponding estimations of national incidence were extracted for 2004-2006. The I/HD and I/LDD estimations were performed using a common cross-sectional methodology.

RESULTS

The three estimations were found similar for most cancers. The relative differences in incidence rates (vs. I/M) were below 5% for numerous cancers and below 10% for all cancers but three. The highest differences were observed for thyroid cancer (up to +21% in women and +8% in men), skin melanoma (up to +13% in women and +8% in men), and Hodgkin disease in men (up to +15%). Differences were also observed in women aged over 60 for cervical cancer. Except for thyroid cancer, differences were mainly due to the smoothing performed in the I/M approach.

CONCLUSION

Our results support the validity of I/M approaches for national estimations, except for thyroid cancer. The longitudinal version of this approach has, furthermore, the advantage of providing smoothed estimations and trend analyses, including useful birth-cohort indicators, and should thus be preferred.

Natural killer (NK) and NK-like cells at mucosal epithelia: Mediators of anti-microbial defense and maintenance of tissue integrity

Natural killer (NK) cells are innate lymphocytes that play important roles in the defense against microbial pathogens through secretion of IFN-γ and recognition and lysis of virally or bacterially infected host cells. A recently identified population of NK-like cells that shares characteristics of both NK cells and lymphoid tissue inducer (LTi) cells promotes innate immune responses in epithelial tissue through the secretion of IL-22. In contrast to classical NK cells, NK-like cells are localized preferentially at mucosal sites, such as the intestinal mucosa. In this review, we consider the function of NK and NK-like cells in anti-microbial defense as well as the maintenance of tissue integrity in the mucosal epithelium of the intestine, lung, and female reproductive tract. Current experimental evidence supports an important protective role for IL-22-producing NK-like cells during intestinal infections, whereas classical NK cells are crucial in the early defense against many pathogens in the respiratory tract. NK cells isolated from the pregnant uterus differ significantly in phenotype and function from those at other tissue locations. Uterine NK cells clearly contribute to the tissue remodeling that takes place during placentation, but their role in anti-microbial defense remains largely undefined.

Primary lung adenocarcinoma: characteristics by smoking habit and sex

The incidence of adenocarcinoma is increasing, particularly among females. We sought to assess the role of tobacco consumption in clinical presentation according to sex. In this retrospective study, 848 patients diagnosed between 1997 and 2006 at Grenoble University Hospital (Grenoble, France) were stratified into four groups according to smoking habits. Differences between sexes and two contrasting female profiles emerged. Female current smokers were younger than female never-smokers (median 51 versus 69 yrs; p < 0.001), more often had surgery (62.7% versus 39%; p = 0.01) and had a median (95% CI) estimated survival of 26.2 (18.1-49.2) versus 15.1 (12.8-22.2) months (p = 0.002). Both groups had similar survival when taking treatment into account. Among males, smoking did not influence presentation. Male current smokers were older than female current smokers (median 59 yrs; p < 0.001) and fewer had surgery (48.8%; p = 0.015), although the percentage of stage IIIb-IV disease was similar (53% and 46%; nonsignificant) and they had a poorer estimated survival of 14.3 (13.0-18.5) months (p = 0.0024). Males smoked more than females (median 41 versus 30 pack-yrs; p < 0.001). Quitting smoking delayed age at diagnosis by 11 yrs for females (p = 0.0035) and 8 yrs for males (p < 0.001). Our results support the hypothesis that carcinogenesis differs between males and females, and between female smokers and never-smokers.