El Complex sinaptinèmic com a indicador de les anomalies meiòtiques : noves aportacions a l'estudi de la infertilitat masculina /

Consultable des del TDXTítol obtingut de la portada digitalitzad

Diagnòstic genètic preimplantacional en estadis embrionaris tardans

La incorporació de la biòpsia de blastocist en la pràctica clínica pot ser considerada com una alternativa vàlida per als cicles de diagnòstic genètic preimplantacional (DGP). La disponibilitat d'un major nombre de cèl·lules obre la possibilitat de realitzar diagnòstics múltiples en paral·lel en el mateix embrió, i es poden detectar teòricament malalties multigèniques o bé combinar diversos tipus de diagnòstic mitjançant FISH i PCR. Els embrions transferits en estadi de blastocist estan subjectes a una doble selecció: genètica i mitjançant el cultiu, i això es veu reflectit en elevades taxes d'implantació, fet que permet reduir el nombre d'embrions a transferir per tal d'evitar gestacions múltiples. Tot i que l'aplicació clínica de la biòpsia de blastocist per al DGP és encara limitada i recent, els bons resultats obtinguts pel que fa a taxes d'implantació i d'embaràs, així com les possibilitats diagnòstiques que obre, suggereixen que es tracta d'una tècnica que esdevindrà més freqüent en el futur.The incorporation of blastocyst biopsy into clinical practice can be considered as a valid alternative when performing PGD. The fact that it makes more material available for analysis is of particular value in those cases where the aim is to diagnose monogenic diseases. The availability of a greater number of cells opens the possibility of performing multiple diagdiagnoses in parallel on the same embryo; these could be used to detect multigenic diseases or for the combined diagnosis of different disorders through diagnostic approaches based on both FISH and PCR. Embryos transferred at the blastocyst stage are subjected to a dual selection process (genetic and through culture) and this is reflected in their greater implantation potential, thus enabling a lower number of embryos to be transferred, which in turn reduces the risk of multiple pregnancy. Although the clinical application of blastocyst biopsy for PGD remains a limited and recent development, the good results in terms of implantation and pregnancy rates obtained so far, as well as the diagnostic possibilities it opens up, suggest that this technique can become more widely used in the early future

Anàlisi citogenètica d'espermatozoides humans

Les anomalies cromosòmiques són una de les principals causes d'esterilitat en l'espècie humana. A les anomalies del cariotip, molt més freqüents en individus que consulten per problemes reproductius que en la població general, s'afegeixen les anomalies meiòtiques, limitades a la línia germinal, observades en pacients que presenten un cariotip somàtic normal. En ambdues situacions, s'ha descrit que en poden resultar espermatozoides portadors d'anomalies cromosòmiques. La producció d'aquests espermatozoides pot ser avaluada mitjançant la utilització de metodologies basades en la hibridació in situ fluorescent (FISH), i els estudis de FISH en espermatozoides s'han incorporat ràpidament als protocols d'estudi dels pacients amb problemes de fertilitat. En aquest article es revisen els resultats obtinguts en individus portadors d'anomalies numèriques per als cromosomes sexuals, en portadors d'anomalies cromosòmiques estructurals i en individus amb cariotip somàtic normal que consulten per problemes d'infertilitat; es fa també esment a la significança clínica d'aquest tipus d'estudi.Chromosome abnormalities are one of the major causes of human infertility. In infertile males, abnormal somatic karyotypes are more frequent than in the general population. Furthermore, meiotic disorders affecting the germ-cell line have been observed in men with normal somatic karyotypes consulting for infertility. In both cases, the production of unbalanced spermatozoa has been described. Basically addressed to establish reproductive risks, fluorescence in situ hybridization (FISH) on decondensed sperm nuclei has become the most frequently used method to study the chromosomal constitution of spermatozoa. This paper reviews the information obtained through sperm FISH studies in carriers of numerical sex chromosome anomalies, carriers of structural chromosome reorganizations and infertile males with normal karyotypes emphasizing on its clinical significance

High rates of de novo 15q11q13 inversions in human spermatozoa

Low-Copy Repeats predispose the 15q11-q13 region to non-allelic homologous recombination. We have already demonstrated that a significant percentage of Prader-Willi syndrome (PWS) fathers have an increased susceptibility to generate 15q11q13 deletions in spermatozoa, suggesting the participation of intrachromatid exchanges. This work has been focused on assessing the incidence of de novo 15q11q13 inversions in spermatozoa of control donors and PWS fathers in order to determine the basal rates of inversions and to confirm the intrachromatid mechanism as the main cause of 15q11q13 anomalies

Systems of Vegetal Façade and Green Roofs used as a Sustainable Option in Architecture

Green architecture contributes not only in reducing the building’s thermal loads but also in reducing the effects of the urban heat island in densely built-up areas in a hardly natural environment. The current green systems are built in situ/on site and are very expensive, hence the need to create industrialized prevegetated systems which improve the buildings’ energy savings and reduce the times of construction works. The present paper describes three green systems for façades (gabion façade, green sliding panel, green panel in plastic cell) and two prevegetated green tank roof systems (green roof in light concrete and pvc)

Unpaired sex chromosomes in metaphase I human spermatocytes locally modify autosomal bivalents positioning

Altres ajuts: Universitat Autònoma de Barcelona (CF-180034

Deletions and duplications of the 22q11.2 region in spermatozoa from DiGeorge/velocardiofacial fathers

Altres ajuts: Universitat Autònoma de Barcelona CF-180034 i PIF/2012Background: DiGeorge/velocardiofacial syndrome (DGS/VCFS) is the most common deletion syndrome in humans. Low copy repeats flanking the 22q11.2 region confer a substrate for non-allelic homologous recombination (NAHR) events leading to rearrangements. This study sought to identify DGS/VCFS fathers with increased susceptibility to deletions and duplications at the 22q11.2 region in spermatozoa and to assess the particular contribution of intra-chromatid and/or inter-chromatid NAHR. Semen samples from nine DGS/VCFS fathers were analyzed by triple-color FISH using a probe combination that discriminated between normal, deleted and duplicated genotypes. Microsatellite analysis were performed in the parents and the affected children to determine the parental origin of the deleted chromosome 22. - Results: A significant increase in 22q11.2 deletions was observed in the sperm of two out of nine DGS/VCFS fathers (odds ratio 2.03-fold, P < 0.01), and in both cases the deletion in the offspring was transmitted by the father. Patients with significant increases in sperm anomalies presented a disturbed deletion:duplication 1:1 ratio (P < 0.01). - Conclusions: Altogether, results support that intra-chromatid NAHR is the mechanism responsible for the higher rate of sperm deletions, which is directly related to the transmission of the deleted chromosome 22 to offspring. Accordingly, the screening of sperm anomalies in the 22q11.2 region should be taken into account in the genetic counseling of DGS/VCFS families

Green façades for urban comfort improvement. Implementation in a extreme Continental Mediterranean climate

Green façades constitute constructive technologies with a positive influence on sustainability in cities and several urban climate parameters such as thermal comfort, air quality and water management. According to the current research, the implementation of urban greenery contributes to increase the cooling effect and mitigate the urban heat island (UHI) phenomenon. This paper focuses on the role of vegetation in improving the urban environment of Madrid (Spain). The simulation results show that green walls could be more effective in urban morphologies with narrow streets. During overheated periods, the streets with green walls have a higher relative humidity in the surrounding areas than those with trees. The air temperature is found to be a little lower. The reduction of wind speed means a positive effect on urban hygrothermal comfort. Therefore, green walls could be taken into account as suitable tools to modify the outdoor thermal environment in cities with an extreme Continental Mediterranean climate

Meiotic abnormalities in metaphase I human spermatocytes from infertile males : frequencies, chromosomes involved, and relationship with polymorphic karyotype and seminal parameters

Altres ajuts: Universitat Autònoma de Barcelona CF-180034Resposta a un comentari sobre l'article: https://ddd.uab.cat/record/185096The aim of this study was to look in depth at the relationship between meiotic anomalies and male infertility, such as the determination of the chromosomes involved or the correlation with patient features. For this purpose, a total of 31 testicular tissue samples from individuals consulting for fertility problems were analyzed. Metaphase I cells were evaluated using a sequential methodology combining Leishman stained procedures and multiplex fluorescence in situ hybridization protocols. The number of chromosomal units and chiasmata count per bivalent were established and a hierarchical cluster analysis of the individuals was performed. The relationship of the seminogram and the karyotype over recombination were evaluated using Poisson regression models. Results obtained in this study show a significant percentage of infertile individuals with altered meiotic behavior, mostly specified as a reduction in chiasmata count in medium and large chromosomes, the presence of univalents, and the observation of tetraploid metaphases. Moreover, the number and the type of anomalies were found to be different between cells of the same individual, suggesting the coexistence of cell lines with normal meiotic behavior and cell lines with abnormalities. In addition, chromosomal abnormalities in metaphase I are significantly associated with oligozoospermia and/or polymorphic karyotype variants

Re : Is number of chiasmata an etiological factor of male infertility?

Article original: https://ddd.uab.cat/record/18507