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ABSTRACT ARCHIVE |
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CryoLetters is a bimonthly, international journal for low temperature science and technology |
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CryoLetters 41 (3), 115-127 (2020) PERSPECTIVE: Naiana Barbosa Dinato1*, Izulmé Rita Imaculada Santos2, 1 Center for Biological and Health Sciences, Federal University of São Carlos, Brazil. Abstract Pollen conservation is an important tool for the maintenance of plant genetic resources and can promote improved efficiency in breeding programs and germplasm conservation and exchange. This review aims to understand the importance of pollen cryopreservation and how to use it for distinct species in order to encourage the use of this methodology in germplasm banks and plant breeding programs. Pollen from many plant species have already been successfully cryopreserved in liquid nitrogen. Analogous with other plant structures, to maintain pollen viability after storage at ultra-low temperatures it is necessary to adjust the water content so that at least the freezable is removed. Optimum pollen moisture levels for cryopreservation varies among species and different methods have been applied to control moisture content. Common methods to decrease pollen moisture content include exposure to saturated solutions of various salts (which have a well-defined relative humidity), silica gel, dry air or treatment with vitrification solutions. It is our understanding that pollen cryopreservation is a safe and practical alternative for conserving genetic material that is often neglected by potential users. The technique has the potential to overcome challenges of breeding programs, such as flowering asynchrony between different parent genotypes, and the production of insufficient pollen in nature. Generally, pollen cryopreservation techniques tend to be simple enough to be used routinely in research, plant breeding and germplasm conservation programs. Keywords: germplasm conservation, hybridization, liquid nitrogen, plant cryopreservation, pollen grain. Download the paper: POLLEN CRYOPRESERVATION FOR PLANT BREEDING AND GENETIC RESOURCES CONSERVATION (PDF)
CryoLetters 41 (3), 128-134 (2020) PARADOXICAL EFFECT OF QUERCETIN ANTIOXIDANT ON GOAT SPERM PARAMETERS AFTER CRYOPRESERVATION Marcelo Sant’Ana Borges1, Joana Larissa Barbosa Born1, 1 Santo Amaro University, UNISA, São Paulo, SP, Brazil. Abstract BACKGROUND: Some antioxidants have been used in semen extenders to reduce adverse effects caused by excessive reactive oxygen species (ROS) production. The study was carried out to assess the effect of quercetin (QC) antioxidant therapy on goat semen submitted to cryopreservation. OBJECTIVE: To evaluate the effect of quercetin incorporation in different phases of the cryopreservation process of goat spermatozoa. MATERIALS AND METHODS: Five ejaculates from each of four goats (n= 20) were collected and split into four groups: Control (G1), without QC; G2, 15 μM of QC added to semen before centrifugation; G3, 15 μM QC added to semen after centrifugation; G4, 15 μM QC added to semen before centrifugation and 15 μM of QC added to semen after centrifugation (total of 30 μM of QC); and cryopreserved. All semen samples were evaluated after thawing for sperm kinetics, plasma membrane integrity, and ROS levels. RESULTS: Although lower concentrations of ROS were associated with groups that received antioxidant supplementation (P=0.0213), linear and dose dependent (P<0.05) reductions of the total and progressive sperm motility, velocity and percentage of fast cells were related to the QC groups. Likewise, plasma membrane integrity was better preserved (P=0.0154) in the control group (35.5%) than in groups that received QC (G2=32.6%, G3=32.4% and G4=26.7%). CONCLUSION: Although quercetin was efficient at reducing the oxidative stress related to sperm cryopreservation, it exerted a deleterious dose-dependent effect on the kinetics and integrity of the frozen goat semen, contradicating its use in the tested concentrations. Keywords: antioxidant, cryopreservation, goat, quercetin, sperm quality.
CryoLetters 41 (3), 135-139 (2020) VITRIFICATION OF MOUSE BLASTOCYSTS BY OPEN OR CLOSED SYSTEM AND WARMING IN SUCROSE-CONTAINING OR SUCROSE-FREE DILUENT D. Garza1,3, M. Camacho1, M. Gauly2 and W. Holtz1* 1 Department of Animal Science, Georg-August-University Goettingen, Albrecht-Thaer-Weg 3, 37075 Goettingen, Germany. Abstract BACKGROUND: Cryopreservation of embryos is of considerable relevance for the implementation of embryo transfer programs and the establishment of embryo banks in several mammalian species. OBJECTIVE: The present investigation compares two different vitrification systems and two different warming solutions. MATERIALS AND METHODS: Vitrification was performed using Open Pulled Straw (OPS) or CVM RingFibre plug™ (CVM) devices. Warming was carried out either in a warming solution containing 0.33 M sucrose or in a solution devoid of sucrose. RESULTS: Differences between vitrification systems were not significant. Warming in sucrose-containing diluent resulted in an expansion rate of 64%, as compared to 86% in a solution devoid of sucrose; reported hatching rates were 45% vs. 9%, respectively (p<0.05). Upon transfer, implantation rates for OPS- and CVM were 50% and 27%, respectively, compared with 55% for freshly collected embryos. The implantation rate after warming was 43% for sucrose-containing and 33% for sucrose-free medium. CONCLUSION: a) both vitrification systems are suitable for vitrifying mouse blastocysts; b) warming in sucrose-free diluent yields better embryo survival rates than in diluent containing 0.33 M sucrose. Keywords: vitrification; mouse embryos; Open Pulled Straw vitrification; CVM RingFibre plug vitrification; sucrose-free reconstitution diluent.
CryoLetters 41 (3), 140-144 (2020) STUDY FREQUENCY SHIFT EVALUATION OF ULTRASOUND IN FRESH AND FROZEN-THAWED TISSUES OF CRYOSURGERY BY AR MODEL Fuliang Luo1, Yue Tang1, Hansong Sun2*, Jing Liu3 and Lei Sheng3* 1 Beijing Key Laboratory of Pre-clinical Research and Evaluation for Cardiovascular Implant Materials, State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Centre
for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China. Abstract BACKGROUND: Noninvasive monitoring of cryosurgery is important for performing precise monitoring of the freezing process in situ and evaluating postoperative effects after therapy. One potential approach is to monitor the normal and freeze-thawed tissues through ultrasonic backscattered signal processing. OBJECTIVE: A noninvasive method for cryosurgery monitoring based on the analysis of microstructural characteristics of in vitro porcine liver tissues at different state including normal and freeze-thawed tissues by estimating the center frequency of scatterers (CFS) using the autoregressive (AR) cepstrum of ultrasonic backscattered signals. MATERIALS AND METHODS: The method is based on the discrete scattering model described in the tissue characterization literature and the observation that most biological tissues are semi-regular scattering lattices. A total of ten in vitro porcine liver samples were used and freeze by water bath in the experiments. RESULTS: Experimental results show that the CFS in porcine liver tissues decreases after pre-frozen and then thawed. CONCLUSION: The CFS obtained using this method may be used as a characteristic parameter for tissue characterization in noninvasive monitoring the transition zone between frozen and unfrozen tissues during the surgical therapy, and evaluating postoperative effects. Keywords: cryosurgery monitoring, freeze-thawed tissue, autoregressive cepstrum, ultrasound tissue characterization.
CryoLetters 41 (3), 145-153 (2020) ALPHA–TOCOPHERYL SUCCINATE IN EXTENDER IMPROVES THE POST THAW QUALITY OF WATER BUFFALO SPERMATOZOA Lubna Kanwal1, 2, S. A. H. Shah1, H. Ahmed1, A. Hussain2 1Animal Reproduction Laboratory, Animal Sciences Institute, National Agricultural Research Center, Islamabad 45500, Pakistan. Abstract BACKGROUND: Alpha–tocopheryl succinate, a major chain-splitting antioxidant, is the most effective form of vitamin E and may be used in the semen extender for cryopreservation of buffalo spermatozoa. OBJECTIVE: To use different concentrations of alpha–tocopheryl succinate (T1, 0.3 mM, T2, 0.6 mM, and T3, 0.9 mM) and control (0.0 mM) in extender for dose optimization and hence improve the frozen–thawed quality of water buffalo spermatozoa. MATERIALS AND METHODS: Semen samples were collected from three mature buffalo bulls with artificial vagina (42°C) and this study was replicated for five times. Semen was cryopreserved by conventional method which included filling of semen per experimental treatment into 0.5 mL French straws, sealing with polyvinyl alcohol powder and keeping them 5 cm above the liquid nitrogen vapors for 12 min and storing in liquid nitrogen tank. Frozen-thawed semen was also processed for total antioxidant capacity content (TAC) and lipid peroxidation (LPO) level by thiobarbituric acid (TBA). Computer-assisted semen analysis (CASA) and other assays were also performed. RESULTS: TAC levels were higher (P<0.05) with T2 and T3 as compared to T1 and control. LPO levels were lower (P<0.05) with T2 and T3 as compared to T1 and control. Sperm progressive motility (%) and rapid velocity (%) were higher (P<0.05) with T2 and T3 as compared to control. The extender containing T3 had higher (P<0.05) sperm average path velocity (μm/s) and straight line velocity (μm/s) as compared to control. At 1 and 2 h incubation period (37 °C) T2 and T3 in extenders had higher (P<0.05) progressive motility and rapid velocity compared to control. Sperm supra vital plasma membrane integrity (%), mitochondrial transmembrane potential (%), viable and intact acrosome (%) and DNA integrity (%) were higher (P<0.05) with T2 and T3 as compared to T1 and control, respectively. CONCLUSION: The supplementation of alpha–tocopheryl succinate in extender, either at 0.6 (T2) or 0.9 (T3) mM concentrations improves the post thaw quality of water buffalo spermatozoa by sustaining the TAC levels and keeping the LPO levels lower as compared to the control. It is suggested that future study should be aimed to explore the influence of these optimal concentrations of alpha–tocopheryl succinate on in vivo fertility of buffalo bull spermatozoa. Keywords: buffalo spermatozoa; alpha–tocopheryl succinate; vitamin E; CASA; LPO levels; TAC levels.
CryoLetters 41 (3), 154-184 (2020) SUMMARY REVIEW AND ABSTRACTS OF SLTB 2019 MEETING AND JOINT WORKSHOP ORGANISED BY THE STEM CELLS USER GROUP, ANDALUSIAN INITIATIVE FOR ADVANCED THERAPIES AND THE SOCIETY FOR LOW TEMPERATURE BIOLOGY October 2nd - 4th, 2019, Universidad de Sevilla, Calle San Fernando, SUMMARY REVIEW The SLTB 2019 scientific meeting was held on 2nd-4th October, in the historic Antigua de Fabrica Tobacos building of the Universidad of Seville and was hosted by Professor Ramon Risco and Dr Ariadna Corral. The meeting included a workshop on cryopreservation of cell therapy products (2nd October 2019) run in collaboration with the UK’s Stem Cells User Group and the Andalusian Initiative for Advanced Therapies. This represented an ongoing SLTB strategic objective to engage with other scientific groups interested in low temperature biology. Overall, the conference attracted nine invited keynote speakers and 34 free communications representing a scientifically dense programme dealing with a diverse applications and cryobiological issues in cell preservation of a wide range of cells, tissues and organs. SLTB Meeting 2019 Abstracts (PDF) |
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For Abstracts published from meetings, such as SLTB meetings, go to the
relevant Volume Year of the journal (above). For Full text Free Access Content (from 2000 onwards) go to CryoLetters at Ingenta and look for the blue symbol. |
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