Association of Candidate Gene Polymorphisms With Chronic Kidney Disease: Results of a Case-Control Analysis in the Nefrona Cohort

Chronic kidney disease (CKD) is a major risk factor for end-stage renal disease, cardiovascular disease and premature death. Despite classical clinical risk factors for CKD and some genetic risk factors have been identified, the residual risk observed in prediction models is still high. Therefore, new risk factors need to be identified in order to better predict the risk of CKD in the population. Here, we analyzed the genetic association of 79 SNPs of proteins associated with mineral metabolism disturbances with CKD in a cohort that includes 2, 445 CKD cases and 559 controls. Genotyping was performed with matrix assisted laser desorption ionizationtime of flight mass spectrometry. We used logistic regression models considering different genetic inheritance models to assess the association of the SNPs with the prevalence of CKD, adjusting for known risk factors. Eight SNPs (rs1126616, rs35068180, rs2238135, rs1800247, rs385564, rs4236, rs2248359, and rs1564858) were associated with CKD even after adjusting by sex, age and race. A model containing five of these SNPs (rs1126616, rs35068180, rs1800247, rs4236, and rs2248359), diabetes and hypertension showed better performance than models considering only clinical risk factors, significantly increasing the area under the curve of the model without polymorphisms. Furthermore, one of the SNPs (the rs2248359) showed an interaction with hypertension, being the risk genotype affecting only hypertensive patients. We conclude that 5 SNPs related to proteins implicated in mineral metabolism disturbances (Osteopontin, osteocalcin, matrix gla protein, matrix metalloprotease 3 and 24 hydroxylase) are associated to an increased risk of suffering CKD

Palaeonitella trifurcata n. sp., a cortoid building charophyte from the Lower Cretaceous of Catalonia

Palaeonitella trifurcata n. sp. is a minute ecorticate thallus of a charophyte from a non-marine upper Barremian-Lower Aptian section of the Garraf Massif, near Barcelona (Catalonia, Spain). Whorls of trifurcated branchlets built glomerules about 1 mm across. Small radial branchlets were trifurcated once in three terminal acuminate dactyls. Longer and more robust branches, two per whorl emerge from a basal trifurcation, bore opposite secondary branchlets and ended in three terminal branchlets bearing one oospore. The whole set of characters suggests affinity with Nitella, making of this fossil one of the oldest and unique possible records of thalli of this extant genus. The thallus of P. trifurcata n. sp. was encrusted by a thin micrite film, and additionally, the whorls were coated by a thicker crust while the plant was still alive. It is suggested that this crust was formed upon the periphyton which grew perhaps upon a mucilage covering the whorls and apical heads, as it happens in extant Nitella. After encrustation, a small (ca. 5 mm across) constructive micrite envelope, called a cortoid, was formed attached to the plant, preserving in the inside the thallus articulated and slightly encrusted. Once the plant died, such cortoids accumulated on the lake bottom and were buried and lithified, forming a 'cortolite.' This is the first report of constructive micrite envelopes protecting delicate and poorly calcified charophyte thalli from being destroyed