New perspectives on the renal slit diaphragm protein podocin

Podocin is a critical component of the glomerular filtration barrier, its mutations causing recessive steroid-resistant nephrotic syndrome. A GenBank analysis of the human podocin (NPHS2) gene resulted in the possible existence of a new splice variant of podocin in the kidney, missing the in-frame of exon 5, encoding the prohibitin homology domain. Using RT–polymerase chain reaction and immunoblotting followed by sequence analysis, we are for the first time able to prove the expression of a novel podocin isoform (isoform 2), exclusively and constitutively expressed in human podocytes. Furthermore, we reveal singular extrarenal podocin expression in human and murine testis. Our data show the Sertoli cells of the seminiferous tubules to be the origin of testicular podocin. Confocal laser microscopy illustrates the co-localization of podocin with filamentous actin within Sertoli cells, suggesting a role of podocin in the blood/testis barrier. These results led to the rationale to examine podocin expression in testes of men with Sertoli cell-only syndrome, a disorder characterized by azoospermia. Interestingly, we observed a complete down-regulation of podocin mRNA in Sertoli cell-only syndrome, indicating a possible role of podocin in the pathogenesis of this germinal aplasia. Men with Sertoli cell-only syndrome show normal renal podocin expression, suggesting an alternate regulation of the testicular promoter. Our findings may change the perception of podocin and give new insights into the ultrastructure of glomerular slit diaphragm and the blood/testis barrier

Predicting Adult Perfusion Practice Trends and the Adoption of Evidence-Based Practice

In an effort to provide optimal patient care, perfusionists should rely on information provided by current research. Present statistics, however, document a substantial underuse of evidence-based clinical practice and therapies not only in perfusion, but throughout the entire medical field. This investigation applied a statistical method—binomial proportion analysis—to aid in uncovering the trends in perfusion practice from 2004 to 2011. Through the analysis of national adult perfusion practice surveys, the feasibility of using binomial proportion statistical analysis is assessed in its ability to track adult perfusion practice proportional differentials over time and evaluate the adoption and attitudes toward the compliance of evidence-based practice within the field of perfusion. Surveys conducted in 2004 and 2006 on adult perfusion practice in the United States—although not published—are compared with data obtained by a similar survey distributed in 2011 through an international perfusion network system and perfusion mailing system, Perflist and Perfmail. The increase of perfusionists who practice retrograde and antegrade autologous priming (R/A AP) seen from 2004 to 2006 (35–50%) was statistically significant (Zcalc = −2.30, p < .05) and from 2006 to 2011 (Zcalc = −5.23; p < .05). Although the increase in biocompatible circuit (BC) use by perfusionists from 2004–2006 (53–64%) was not statistically significant (Zcalc = −1.69, p < .05), the use of BCs did continue to increase (86%) significantly from 2006 to 2011 (Zcalc = −9.15, p < .05). Other trends were observed; however, statistical significance was variable. This investigation demonstrates that binomial proportion statistical analysis is an effective method of evaluating perfusion practice trends and adoptions based on increasing or decreasing perfusion population proportion compliance over time

Ar/Ar ages from transitionally magnetized lavas on La Palma, Canary Islands, and the geomagnetic instability timescale

International audienc