Cryo letters最新文献

Background: Some antimicrobials could adversely affect sperm quality during sperm cryopreservation and antibiotic treatment with subsequent effects on fertility outputs. To our knowledge, no similar studies have been conducted on breeding roosters, especially for oxytetracycline (OTC).

Objective: To investigate both in vitro and in vivo impact of oxytetracycline on sperm parameters in breeding roosters.

Methods: Sperm motility parameters were objectively analyzed using the CASA system including total motility (TM %), progressive motility (PM %), all sperm velocities, the sperm count, and cell viability during 9 days of in vivo treatment. In the in vitro investigation, the pooled sperm was diluted and divided into a control aliquot (diluted in 0.9% NaCl) and treated samples. Motility parameters were assessed after 0, 1, 2, 3, 4, 5, and 6 hours of storage at 37ºC. In the in vivo study, 1 g per L of OTC was administrated to five individuals for nine consecutive days. Fresh semen samples were analyzed at T0 (before treatment) and after 6 (T6) and 9 days (T9) of treatment.

Results: OTC caused significant impairment of sperm quality in vivo. A drastic reduction in sperm concentration, viability, TM, PM, and all kinematic parameters was observed after 6 days of treatment. However, at day 9 sperm quality had improved to be nearly similar to T0. In vitro, OTC induced similar sperm impairment on all sperm motility parameters.

Conclusion: Oxytetracycline exhibited negative effects on rooster sperm both in vivo and in vitro and appears consequently not suitable in cryopreservation extenders. Doi.org/10.54680/fr23510110412.

Background: Cryopreservation of porcine oocytes is difficult compared with other species and immature oocytes particularly so compared to the meiotic stage.

Objective: To evaluate the efficacy of a pretreatment with 1 micromole per L paclitaxel (PTX, 30 min exposure) before vitrification to promote the maturation of porcine immature oocytes.

Materials and methods: Cumulus cell-enclosed oocytes (COs) aspirated from porcine ovaries were divided into three groups: i) non-pretreated with PTX and non-vitrified group (control group); ii) pretreated with PTX and vitrified group (PTX-V group); and iii) non-pretreated with PTX and vitrified group (nPTX-V group).

Results: The nuclear maturation rate up to the preovulatory stage was significantly lower (P < 0.05) in the nPTX-V group than in the control group, but was similar in the PTX-V and control groups. No significant differences were observed in viability assessed by a normal CO morphology and the embryonic development of oocytes activated by the parthenogenetic stimulation between the PTX-V and control groups, but not the non-PTX-V group.

Conclusion: PTX may promote the maturation of vitrified porcine immature oocytes. Doi.org/10.54680/fr23510110812.

Background: Film boiling occurs in the cooling process of samples with liquid nitrogen, which limits heat transfer and decreases the cooling rate.

Objective and methods: The study developed a method to enhance convective heat transfer by wrapping the French straw (FS) with a layer of medical gauze upon cooling to eliminate film boiling. A numerical model was used to study the thermodynamic mechanism in the method.

Results: Numerical simulation based on heat transfer and crystallization equations indicated that wrapping the FS with medical gauze could suppress film boiling. Experimental verification showed the increased cooling rate and better cell survival when wrapped FS was used.

Conclusion: Numerical simulation and experimental verification demonstrated the efficacy of wrapping FS with medical gauze for better cell cryopreservation. Doi.org/10.54680/fr23510110312.

The loss of biodiversity caused by anthropogenic actions is also a reality for the members of the Felidae family. Except for the domestic cat, all felid species have some degree of threat of extinction in their natural habitat. For this reason, felids have been included in conservation-related studies. This scenario has aroused increasing interest in the formation of somatic cell banks, which when efficiently implemented can be used in preservation strategies for the species. Nevertheless, one of the important steps in the formation of these banks is the understanding of the technical principles and variations involved in cryopreservation techniques, especially because cryopreservation increases the possibilities for Assisted Reproduction Technologies (ARTs) by making the use of biological materials independent of time and space. In wild felids, several species already have promising results in the formation of somatic cell banks, and studies aimed at better viability rates have been constantly proposed, as well as new species have been studied. In some species, aspects involved in successful cryopreservation are already well defined, and slow freezing associated with cryoprotectant solutions composed of intra- and extracellular substances is the most useful approach. The aim of this review was to present the main parameters involved in the elaboration of a somatic cell cryopreservation protocol and their effects, as well as to address the main results achieved for different wild felids. Doi.org/10.54680/fr23510110112.