3 research outputs found

    Ultrastructural features of human sperm cells cryopreserved by different methods

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    Cryopreservation of human spermatozoa has been recognized as a key strategy for management of male fertility. Nevertheless, current protocols of sperm freezing are neither optimal nor standardized between different labs (1). In this study we compare the ultrastructural features of human normospermic sperm samples (according to WHO parameters 2010) from 5 different freezing techniques in order to identify the best methods of cryopreservation. After informed con- sent, 21 normospermic patients (from the Medically Assisted Procreation PMA Center of the Fondazione IRCCS Policlinico San Matteo in Pavia) were recruited and both traditional and improved analysis of sperm quality were applied, in order to define critical steps of cryopreservation. Cryopreservation of human spermatozoa has been related to decreased motility associated with impaired velocity and viability of sperm pre-freeze and post-thaw. For all applied methods there was a significant reduction of progressive and total motility (P) as a result of freezing. To investigate ultrastructural details, 5 additional cryopreserved samples by the best two freezing methods were analyzed with elec- tron microscopy (TEM). Preliminary data showed the minimal differences between the protocols, with a large number of queues detached and large quantities of cyto- plasmic debris after of the first protocol. Spermatozoa appear to be better preserved in the second analyzed method, despite both procedures induced deteriorations at ultrastructural level (2). Other non-routine analysis will be performed to determine whether the cooling time to +4°C may affect the procedure; Comet Assay (to assess the degree of sperm DNA fragmentation) (3) and flow cytometry (to study light scat- ters patterns and membrane integrity) (4) will be applied

    Cultivar-Dependent Effects of Non-Saccharomyces Yeast Starter on the Oenological Properties of Wines Produced from Two Autochthonous Grape Cultivars in Southern Italy

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    Global warming poses a threat to winemaking worldwide, especially in dry–warm regions such as Southern Italy. Must fermentation with non-Saccharomyces yeast starter is a possible approach to limit the negative effects of climate change, leading to desirable effects such as an increase in total acidity and/or aroma improvement. The aim of this study was to evaluate the effects of the use of a non-Saccharomyces starter (Lachancea thermotolerans) on the chemical and sensory properties of wines obtained by the the fermentation of two autochthonous Apulian grape cultivars, namely Bombino nero and Minutolo, as compared to the traditional Saccharomyces cerevisiae-driven fermentation. Bombino and Minutolo wines fermented with either Lachancea thermotolerans or Saccharomyces cerevisiae were characterized for their oenological parameters, volatile profiles, and sensory properties. Both chemical and sensory properties were affected by the yeast starter. Inoculation of L. thermotolerans increased sensory complexity, with different floral and sweet-like attributes for both cultivars. Bombino nero, a neutral cultivar, showed a clear effect on wine composition, with both an increase in lactic acid and a change in the volatile profile. On the contrary, the impact of L. thermotolerans was partially masked in Minutolo due to the strong primary aroma background of this highly terpenic cultivar. In this work, we evidenced a notable cultivar × yeast interaction, showing how generalizations of the effects of non-Saccharomyces yeasts on vinification are difficult to achieve, as they show a cultivar-specific outcome
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