Testis transcriptome analysis in male infertility: new insight on the pathogenesis of oligo-azoospermia in cases with and without AZFc microdeletion

<p>Abstract</p> <p>Background</p> <p>About 10% of cases of male infertility are due to the presence of microdeletions within the long arm of the Y chromosome (Yq). Despite the large literature covering this critical issue, very little is known about the pathogenic mechanism leading to spermatogenesis disruption in patients carrying these microdeletions. In order to identify the presence of specific molecular pathways leading to spermatogenic damage, testicular gene expression profiling was carried out by employing a microarray assay in 16 patients carrying an AZFc microdeletion or affected by idiopathic infertility. Hierarchical clustering was performed pooling the data set from 26 experiments (16 patients, 10 replicates).</p> <p>Results</p> <p>An intriguing and unexpected finding is that all the samples showing the AZFc deletion cluster together irrespectively of their testicular phenotypes. This cluster, including also four patients affected by idiopathic infertility, showed a downregulation of several genes related to spermatogenesis that are mainly involved in testicular mRNA storage. Interestingly, the four idiopathic patients present in the cluster showed no testicular expression of <it>DAZ </it>despite the absence of AZFc deletion in the peripheral blood.</p> <p>Conclusions</p> <p>Our expression profiles analysis indicates that several forms of infertility can be triggered by a common pathogenic mechanism that is likely related to alterations in testicular mRNA storage. Our data suggest that a lack of testicular DAZ gene expression may be the trigger of such mechanism. Furthermore, the presence of AZFc deletions in mosaic or the loss of function of AZFc genes in absence of Yq deletion can perhaps explain these findings. Finally, based on our data, it is intriguing to hypothesize that <it>DAZ </it>gene dysfunctions can account for a larger number of previously thought "idiopathic" infertility cases and investigation of such testicular gene dysfunction can be important to reveal the molecular determinant of infertility than are undetected when only testing Yq deletions in peripheral blood.</p

Bryostatin enhancement of memory in Hermissenda

Author Posting. © Marine Biological Laboratory, 2006. This article is posted here by permission of Marine Biological Laboratory for personal use, not for redistribution. The definitive version was published in Biological Bulletin 210 (2006): 201-214.Bryostatin, a potent agonist of protein kinase C (PKC), when administered to Hermissenda was found to affect acquisition of an associative learning paradigm. Low bryostatin concentrations (0.1 to 0.5 ng/ml) enhanced memory acquisition, while concentrations higher than 1.0 ng/ml down-regulated the pathway and no recall of the associative training was exhibited. The extent of enhancement depended upon the conditioning regime used and the memory stage normally fostered by that regime. The effects of two training events (TEs) with paired conditioned and unconditioned stimuli, which standardly evoked only short-term memory (STM) lasting 7 min, were—when bryostatin was added concurrently—enhanced to a long-term memory (LTM) that lasted about 20 h. The effects of both 4- and 6-paired TEs (which by themselves did not generate LTM), were also enhanced by bryostatin to induce a consolidated memory (CM) that lasted at least 5 days. The standard positive 9-TE regime typically produced a CM lasting at least 6 days. Low concentrations of bryostatin (<0.5 ng/ml) elicited no demonstrable enhancement of CM from 9-TEs. However, animals exposed to bryostatin concentrations higher than 1.0 ng/ml exhibited no behavioral learning. Sharp-electrode intracellular recordings of type-B photoreceptors in the eyes from animals conditioned in vivo with bryostatin revealed changes in input resistance and an enhanced long-lasting depolarization (LLD) in response to light. Likewise, quantitative immunocytochemical measurements using an antibody specific for the PKC-activated Ca2+/GTP-binding protein calexcitin showed enhanced antibody labeling with bryostatin. Animals exposed to the PKC inhibitor bisindolylmaleimide-XI (Ro-32-0432) administered by immersion prior to 9-TE conditioning showed no training-induced changes with or without bryostatin exposure. However, if animals received bryostatin before Ro-32, the enhanced acquisition and demonstrated recall still occurred. Therefore, pathways responsible for the enhancement effects induced by bryostatin were putatively mediated by PKC. Overall, the data indicated that PKC activation occurred and calexcitin levels were raised during the acquisition phases of associative conditioning and memory initiation, and subsequently returned to baseline levels within 24 and 48 h, respectively. Therefore, the protracted recall measured by the testing regime used was probably due to bryostatin-induced changes during the acquisition and facilitated storage of memory, and not necessarily to enhanced recall of the stored memory when tested many days after training.AMK and HTE acknowledge the support of the Marine Biological Laboratory and Blanchette Rockefeller Neurosciences Institutes for these initial studies

High prevalence of BRCA1 deletions in BRCAPRO-positive patients with high carrier probability.

Mutation screening of the BRCA1 and BRCA2 genes in probands with familial breast/ovarian cancer has been greatly improved by the multiplex ligation-dependent probe amplification (MLPA) assay able to evidence gene rearrangements not detectable by standard screening methods. However, no criteria for selection of cases to be submitted to the MLPA test have been reported yet. We used the BRCAPro software for the selection of familial breast/ovarian cancer probands investigated with the MLPA approach after negative BRCA1/2 conventional mutation screening. One hundred and seventy-seven probands were investigated for germline BRCA1/2 mutations after assessment of genetic risk using BRCAPro. Probands were classified as BRCAPro positive (n = 67) when the carrier probability (CP) was >10% and as BRCAPro negative (n = 110), when the CP was <10%. Conventional mutational analyses of the BRCA1/2 genes and, in one case, of p53 identified 22 pathogenetic germline mutations, 12 in BRCA1, 9 in BRCA2 and 1 in p53, in 22/177 (12.4%) probands. All the mutations except one were detected in BRCAPro-positive patients. In the 46 BRCAPro-positive cases that resulted negative by BRCA1/2 mutation, screening analysis of rearrangements within BRCA1/2 by MLPA was carried out. Three patients with a very high CP showed BRCA1 deletions, consisting of deletions of exons 1–2 in two probands and of exon 24 in the third proband. In one case, the exons 1–2 deletion was shown to cosegregate with disease in the family. No BRCA2 rearrangements were detected, but one patient showed the 1100delC of the CHEK2 gene, whose probe is present in the BRCA2 kit. In our series, the highest carrier detection rate of mutation screening plus MLPA analysis (52.3%) was in patients with a BRCAPro CP >50%

Il problema di Dirichlet

Il risultato principale di questa tesi è un risultato di esistenza e unicità della soluzione debole per il problema di Dirichlet associato ad un operatore ellittico in forma di divergenza. Seguendo la presentazione di Gilbarg-Trudinger, la prova utilizza in un primo tempo il Teorema di Lax-Milgram, e successivamente il principio del massimo debole. La prima parte della tesi è dedicata alla presentazione dei risultati di Analisi Funzionale che vengono utilizzati: teoria degli operatori lineari, proprietà degli operatori lineari compatti, teoremi dell'indice, spazi di Sobolev e teoremi di immersione

A physics-based integer-linear battery modeling paradigm

Optimal steady-state dispatch of a stand-alone hybrid power system determines a fuel-minimizing distribution strategy while meeting a forecasted demand over six months to a year. Corresponding optimization models that integrate hybrid technologies such as batteries, diesel generators, and photovoltaics with system interoperability requirements are often large, nonconvex, nonlinear, mixed-integer programming problems that are difficult to solve even using the most state-of-the-art algorithms. The rate-capacity effect of a battery causes capacity to vary nonlinearly with discharge current; omitting this effect simplifies the model, but leads to over-estimation of discharge capabilities. We present a physics-based set of integer-linear constraints to model batteries in a hybrid system for a steady-state dispatch optimization problem that minimizes fuel use. Starting with a nonlinear set of constraints, we empirically derive linearizations and then compare them to a commonly used set of constraints that assumes a constant voltage and neglects rate-capacity. Numerical results demonstrate that assuming a fixed voltage and capacity may lead to over-estimating discharge quantities by up to 16% compared to our overestimations of less than 1%

Optimal design and dispatch of a system of diesel generators, photovoltaics and batteries for remote locations

Renewable energy technologies, specifically, solar photovoltaic cells, combined with battery storage and diesel generators, form a hybrid system capable of independently powering remote locations, i.e., those isolated from larger grids. If sized correctly, hybrid systems reduce fuel consumption compared to diesel generator-only alternatives. We present an optimization model for establishing a hybrid power design and dispatch strategy for remote locations, such as a military forward operating base, that models the acquisition of different power technologies as integer variables and their operation using nonlinear expressions. Our cost-minimizing, nonconvex, mixed-integer, nonlinear program contains a detailed battery model. Due to its complexities, we present linearizations, which include exact and convex under-estimation techniques, and a heuristic, which determines an initial feasible solution to serve as a “warm start” for the solver. We determine, in a few hours at most, solutions within 5% of optimality for a candidate set of technologies; these solutions closely resemble those from the nonlinear model. Our instances contain real data spanning a yearly horizon at hour fidelity and demonstrate that a hybrid system could reduce fuel consumption by as much as 50% compared to a generator-only solution