Cancer incidence estimation at a district level without a national registry: A validation study for 24 cancer sites using French health insurance and registry data

Background: District-level cancer incidence estimation is an important issue in countries without a national cancer registry. This study aims to both evaluate the validity of district-level estimations in France for 24 cancer sites, using health insurance data (ALD demands – Affection de Longue Durée) and to provide estimations when considered valid. Incidence is estimated at a district-level by applying the ratio between the number of first ALD demands and incident cases (ALD/I ratio), observed in those districts with cancer registries, to the number of first ALD demands available in all districts. These district-level estimations are valid if the ratio does not vary greatly across the districts or if variations remain moderate compared with variations in incidence rates. Methods: Validation was performed in the districts covered by cancer registries over the period 2000–2005. The district variability of the ALD/I ratio was studied, adjusted for age (mixed-effects Poisson model), and compared with the district variability in incidence rate. The epidemiological context is also considered in addition to statistical analyses. Results: District-level estimation using the ALD/I ratio was considered valid for eight cancer sites out of the 24 studied (lip–oral cavity–pharynx, oesophagus, stomach, colon–rectum, lung, breast, ovary and testis) and incidence maps were provided for these cancer sites. Conclusion: Estimating cancer incidence at a sub-national level remains a difficult task without a national registry and there are few studies on this topic. Our validation approach may be applied in other countries, using health insurance or hospital discharge data as correlate of incidence.     

Magnetic resonance distinction between site bound and atmospherically bound paramagnetic counterions in polyelectrolyte solutions.

A combination of the water protons NMR chemical shifts, longitudinal and transversal relaxation rates and of the paramagnetic counterion EPR signal is shown to provide a clear distinction between site binding, atmospheric trapping and free counterions in solutions of polyelectrolyte TMA salts with increasing concentrations of the divalent counterions Co++ and Mn++. Site binding is defined by the loss of water in the counterion first hydration shell while atmospheric binding results in a change in the counterion correlation time as compared to a free ion.     

Collagenase in mineralized tissues of human teeth

A collagenase cleaving native type I [14C]collagen but inactive against the synthetic substrate Pz-Pro-Leu-Gly-Pro-D-Arg was extracted from mineralized human dental tissue. The enzyme specifically degrades native collagen into characteristic products (3/4) and (1/4). Its apparent molecular mass of 68 kDa is relatively high in comparison with collagenases from other oral tissues. The enzyme is a metalloproteinase inhibited by low concentrations of the chelating agents EDTA, 1, 10-phenanthroline, alpha alpha'-dipyridyl, and not affected by diisopropylfluorophosphate, soybean trypsin inhibitor, and p-chloromercuribenzoate. It is stable to lyophilization and can be stored at-20 degrees C for at least 6 months.     

Ant genomics sheds light on the molecular regulation of social organization

Ants are powerful model systems for the study of cooperation and sociality. In this review, we discuss how recent advances in ant genomics have contributed to our understanding of the evolution and organization of insect societies at the molecular level.     

Variation in Wolbachia cidB gene,but not cidA,is associated with cytoplasmic incompatibility mod phenotype diversity in Culex pipiens

Endosymbiotic Wolbachia bacteria are, to date, considered the most widespread symbionts in arthropods and are the cornerstone of major biological control strategies. Such a high prevalence is based on the ability of Wolbachia to manipulate their hosts' reproduction. One manipulation called cytoplasmic incompatibility (CI) is based on the death of the embryos generated by crosses between infected males and uninfected females or between individuals infected with incompatible Wolbachia strains. CI can be seen as a modification‐rescue system (or mod‐resc) in which paternal Wolbachia produce mod factors, inducing embryonic defects, unless the maternal Wolbachia produce compatible resc factors. Transgenic experiments in Drosophila melanogaster and Saccharomyces cerevisiae converged towards a model where the cidB Wolbachia gene is involved in the mod function while cidA is involved in the resc function. However, as cidA expression in Drosophila males was required to observe CI, it has been proposed that cidA could be involved in both resc and mod functions. A recent correlative study in natural Culex pipiens mosquito populations has revealed an association between specific cidA and cidB variations and changes in mod phenotype, also suggesting a role for both these genes in mod diversity. Here, by studying cidA and cidB genomic repertoires of individuals from newly sampled natural C. pipiens populations harbouring wPipIV strains from North Italy, we reinforce the link between cidB variation and mod phenotype variation fostering the involvement of cidB in the mod phenotype diversity. However, no association between any cidA variants or combination of cidA variants and mod phenotype variation was observed. Taken together our results in natural C. pipiens populations do not support the involvement of cidA in mod phenotype variation.     

Phylogenetic analysis of the tenascin gene family: evidence of origin early in the chordate lineage

Background  

Tenascins are a family of glycoproteins found primarily in the extracellular matrix of embryos where they help to regulate cell proliferation, adhesion and migration. In order to learn more about their origins and relationships to each other, as well as to clarify the nomenclature used to describe them, the tenascin genes of the urochordate Ciona intestinalis, the pufferfish Tetraodon nigroviridis and Takifugu rubripes and the frog Xenopus tropicalis were identified and their gene organization and predicted protein products compared with the previously characterized tenascins of amniotes.