Boar semen can tolerate rapid cooling rates prior to freezing

2011 ◽  
Vol 23 (5) ◽  
pp. 681 ◽  
Author(s):  
Jorge D. Juarez ◽  
Inma Parrilla ◽  
Juan M. Vazquez ◽  
Emilio A. Martinez ◽  
Jordi Roca
Keyword(s):  
Cooling Rate ◽  
Flow Cytometric Analysis ◽  
Membrane Integrity ◽  
Annexin V ◽  
Objective Evaluation ◽  
Membrane Lipid ◽  
Cooling Rates ◽  
Rapid Cooling ◽  
Motile Cells ◽  
Boar Spermatozoa

Two experiments were performed in the present study that demonstrated that boar spermatozoa are capable of surviving rapid cooling rates within a range of 15–5°C before freezing. Boar ejaculates diluted in Beltsville thawing solution (BTS) (1 : 1, v/v) were held at 17–20°C and shipped over a 24-h time period from two AI centres to a cryobiology laboratory, where they were pooled (Experiment 1) or cryopreserved individually (Experiment 2) using a standard 0.5-mL straw freezing protocol. The effects of cooling before freezing were assessed after thawing through the objective evaluation of sperm motility and flow cytometric analysis of membrane integrity, acrosomal status, changes in membrane lipid architecture monitored by merocyanine and annexin V binding and intracellular production of reactive oxygen species. In Experiment 1 (six replicates), two semen pools (five ejaculates per pool) were cooled from 15 to 5°C at rates of 0.08, 0.13, 0.40 and 1.50°C min–1. These cooling rates did not result in any significant differences (P > 0.05) in any of the post-thaw sperm assessments, even in thawed samples incubated under capacitation conditions. In Experiment 2, three individual ejaculates from 16 boars were slowly (0.08°C min–1) or rapidly (1.5°C min–1) cooled before freezing. A consistent interboar variability (P < 0.01) was detected, which was independent of the cooling rate used. Cooling rate only significantly influenced (P < 0.05) sperm assessments in four of 16 boars, which exhibited slightly higher percentages of motile cells and intact plasma and acrosomal membranes in the samples that had been cooled slowly. These findings demonstrate that boar spermatozoa undergoing cryopreservation can withstand rapid cooling rates before freezing.

scholarly journals Cryopreservation of boar semen in 0.5mL straws at low spermatozoa concentration is better than high concentration to maintain sperm viability

2018 ◽  
Vol 38 (9) ◽  
pp. 1726-1730 ◽  
Author(s):  
Gisele M. Ravagnani ◽  
Mariana A. Torres ◽  
Diego F. Leal ◽  
Simone M.M.K. Martins ◽  
Frederico O. Papa ◽  
...  
Keyword(s):  
Lipid Peroxidation ◽  
Membrane Potential ◽  
Mitochondrial Membrane Potential ◽  
Mitochondrial Membrane ◽  
Membrane Integrity ◽  
Membrane Lipid ◽  
Membrane Lipid Peroxidation ◽  
Progressive Motility ◽  
Acrosomal Membrane ◽  
Boar Spermatozoa

ABSTRACT: To date, no studies have been performed evaluating the effect of boar spermatozoa concentration in 0.5mL freezing straws, leading us to examine this question. Each sperm-rich fraction of the ejaculate (n=25) was diluted at five different sperm concentrations (100, 200, 300, 600 and 800 x 106 spermatozoa/mL), packaged in 0.5mL straws, and subsequently frozen. After thawing, the sperm from all of treatment groups were analyzed to determine motility characteristics using a sperm class analyzer (SCA-CASA), and their plasma and acrosomal membrane integrity, mitochondrial membrane potential, sperm membrane lipid peroxidation and fluidity were analyzed by flow cytometry. An increase in spermatozoa concentration above 300x106 spermatozoa/mL in a 0.5mL straw impaired (p<0.05) the total and progressive motility, curvilinear velocity, straight-line velocity, linearity and beat cross frequency. However, the plasma and acrosomal membrane integrity, mitochondrial membrane potential, membrane lipid peroxidation and fluidity were not influenced (p>0.05) by high spermatozoa concentrations at freezing. Therefore, to increase spermatozoa survival and total and progressive motility after thawing, boar spermatozoa should be frozen at concentrations up to 300x106 spermatozoa/mL.

scholarly journals Vitrifying multiple embryos in different arrangements does not alter the cooling rate

2021 ◽  
Author(s):  
Timothy Ostler ◽  
Thomas E Woolley ◽  
Karl Swann ◽  
Andrew Thomson ◽  
Giles Palmer ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Cooling Rate ◽  
Survival Rates ◽  
Spatial Arrangement ◽  
Common Method ◽  
Slow Freezing ◽  
Cooling Rates ◽  
Rapid Cooling ◽  
Rate Of Cooling ◽  
Over Time

Vitrification is the most common method of cryopreservation of gametes in fertility clinics due to its improved survival rates compared to slow freezing techniques. For the Open Cryotop® vitrification device, the number of oocytes, or embryos, mounted onto a single device can vary. In this work, a mathematical model is developed for the cooling of oocytes, or embryos, that is solved computationally, to investigate whether varying the number of samples mounted onto the Open Cryotop® affects the cooling rates, and therefore survival rates, of vitrified samples. Several realistic spatial arrangements of oocytes/embryos are examined, determining the temperature of the system over time, which highlights the effect of spatial arrangement on the rate of cooling. Results indicate that neither spatial arrangement nor the number of mounted oocytes, or embryos, has a large effect on cooling rates, so long as the volume of the cryoprotectant remains minimal. Under the manufacturer's guidelines, clinical decisions regarding the number and arrangement of oocytes or embryos placed on a device can be varied, whilst maintaining rapid cooling.

scholarly journals Importance of cooling rate and animal variability for boar sperm cryopreservation: insights from the cryomicroscope

Reproduction ◽  
2002 ◽  
pp. 315-322 ◽  
Author(s):  
A Medrano ◽  
PF Watson ◽  
WV Holt
Keyword(s):  
Plasma Membrane ◽  
Cooling Rate ◽  
Propidium Iodide ◽  
Membrane Integrity ◽  
Cooling Rates ◽  
Boar Sperm ◽  
Sperm Plasma Membrane ◽  
Thawing Process ◽  
Set Up ◽  
Two Stages

A series of experiments was set up to investigate the effect of different cooling rates on boar sperm cryosurvival using cryomicroscopy. The cooling protocols were split into two stages: (i) from +5 degrees C to -5 degrees C and (ii) from -5 degrees C to -50 degrees C. Fluorescent probes (SYBR14 and propidium iodide) were used to monitor plasma membrane integrity during the entire process. Cooling rates in the range 3 degrees C min(-1) to 12 degrees C min(-1) did not cause significant damage to the sperm plasma membrane between +5 degrees C and -5 degrees C; however, spermatozoa cooled at 24 degrees C min(-1) to -5 degrees C were slightly damaged. Motility was not particularly sensitive to variations in cooling rate. Cooling rates in the range 15 degrees C min(-1) to 60 degrees C min(-1) did not produce differences in sperm cryosurvival during freezing between -5 degrees C and -50 degrees C, or after thawing. In addition, cooling rates in the range 3 degrees C min(-1) to 80 degrees C min(-1) did not produce significant differences in sperm cryosurvival. However, slow freezing (3 degrees C min(-1)) induced a slight increase in the percentage of plasma membrane-damaged spermatozoa (propidium iodide-positive) at -50 degrees C. Inter-ejaculate and inter-boar differences in sperm cryosurvival were manifested independently of cooling rate. The sperm plasma membrane remained intact (SYBR14-positive) during cooling and freezing, but upon rewarming, the plasma membrane of a high proportion of spermatozoa was damaged (propidium iodide-positive), indicating that rewarming is a critical step of the freezing-thawing process.

Design, Synthesis, Anti-Proliferative Evaluation and Cell Cycle Analysis of Hybrid 2-Quinolones

2019 ◽  
Vol 19 (9) ◽  
pp. 1132-1140
Author(s):  
Heba A.E. Mohamed ◽  
Hossa F. Al-Shareef
Keyword(s):  
Cell Cycle ◽  
Anticancer Agents ◽  
Biological Activities ◽  
Flow Cytometric Analysis ◽  
Annexin V ◽  
Cytotoxic Activities ◽  
Significant Group ◽  
Design Synthesis ◽  
Standard Drug ◽  
Wide Range

Background: Quinolones are a significant group of nitrogen heterocyclic compounds that exist in therapeutic agents, alkaloids, and synthetic small molecules that have important biological activities. A wide range of quinolones have been used as antituberculosis, antibacterial, anti-malarial, antifungal, anticonvulsant, anticancer agents and urease inhibitors. Methods: Ethyl 3,3-disubstituted-2-cyano propionates containing hybride quinolones derivatives were synthesized by the reaction of 1-amino-7-hydroxy-4-methylquinolin-2(1H)-one and its dibromo derivative with α, β-unsaturated carbonyl in ethanol. Results: A novel series of hybrid 2-quinolone derivatives was designed and synthesized. The compounds structures were confirmed using different spectroscopic methods and elemental analysis. The cytotoxic activities of all the compounds were assessed against HepG2 cell line in comparison with doxorubicin as a standard drug. Conclusion: Most compounds revealed superior anti-proliferative activity than the standard. Compound 4b, is the most active compound (IC50 = 0.39mM) compared with doxorubicin (IC50 = 9.23mM). DNA flow cytometric analysis of compound 4b showed cell cycle arrest at G2/M phase with a concomitant increase of cells in apoptotic phase. Dual annexin-V/ propidium iodide staining assay of compound 4b revealed that the selected candidate increased the apoptosis of HepG-2 cells more than control.

scholarly journals Evaluation of a panel of spermatological methods for assessing reprotoxic compounds in multilayer semen plastic bags

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
M. Schulze ◽  
F. Schröter ◽  
M. Jung ◽  
U. Jakop
Keyword(s):  
Membrane Integrity ◽  
Diglycidyl Ether ◽  
Mitochondrial Activity ◽  
Prolonged Storage ◽  
Prolonged Incubation ◽  
Plastic Bags ◽  
Plastic Materials ◽  
Bisphenol A Diglycidyl Ether ◽  
Semen Preservation ◽  
Boar Spermatozoa

AbstractThe increase of fertility performance in sows is one of the biggest achievements in pig production over the last 30 years. Nevertheless, pig farms using artificial insemination (AI) repeatedly experienced in recent year’s fertility problems with dramatic consequences due to toxic compounds from plastic semen bags. In particular, bisphenol A diglycidyl-ether (BADGE) present in multilayer plastic bags can leach into the semen and could affect the functionality of the spermatozoa. Former studies could not find any alterations in spermatozoa based on the exposure to BADGE. The aim of the study was to evaluate effects of BADGE on boar spermatozoa using an extended panel of spermatological methods. In spring 2019, a large drop in farrowing rates from 92.6 ± 2.3% to 63.7 ± 11.1% in four sow farms in Croatia was detected. In migration studies, BADGE could be identified as a causal toxic compound and leached into the extended semen in concentration of 0.37 ± 0.05 mg/L. Detailed spermatological studies showed that significant predictors for effects on spermatozoa were different levels of motility and kinematic data after a prolonged storage time, thermo-resistance test (prolonged incubation time), mitochondrial activity, membrane integrity and fluidity. No serious effects were observed for sperm morphology and DNA fragmentation. These results provide new insights into the development of a new quality assurance concept for a detailed spermatological examination during testing of plastic materials for boar semen preservation. It could be shown that boar spermatozoa are an excellent biosensor to detect potential toxicity and fertility-relevant compounds.

The effect of cooling rate on crystallization behavior and tensile properties of CF/PEEK composites

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Guangming Dai ◽  
Lihua Zhan ◽  
Chenglong Guan ◽  
Minghui Huang
Keyword(s):  
Cooling Rate ◽  
Crystallization Temperature ◽  
Crystallization Behavior ◽  
Crystalline Polymer ◽  
Scanning Calorimetry ◽  
Nonisothermal Crystallization ◽  
Cooling Rates ◽  
Control Range ◽  
Temperature Range ◽  
Transverse Tensile

Abstract In this study, the differential scanning calorimetry (DSC) tests were performed to measure the nonisothermal crystallization behavior of carbon fiber reinforced polyether ether ketone (CF/PEEK) composites under different cooling rates. The characteristic parameters of crystallization were obtained, and the nonisothermal crystallization model was established. The crystallization temperature range of the material at different cooling rates was predicted by the model. The unidirectional laminates were fabricated at different cooling rates in the crystallization temperature range. The results showed that the crystallization temperature range shifted to a lower temperature with the increase of cooling rate, the established nonisothermal crystallization model was consistent with the DSC test results. It is feasible to shorten the cooling control range from the whole process to the crystallization range. The crystallinity and transverse tensile strength declined significantly with the increase of the cooling rate in the crystallization temperature range. The research results provided theoretical support for the selection of cooling conditions and temperature control range, which could be applied to the thermoforming process of semi-crystalline polymer matrixed composites to improve the manufacturing efficiency.

scholarly journals Anthracycline-induced cytotoxicity in the GL261 glioma model system

2021 ◽  
Author(s):  
Amber M. Tavener ◽  
Megan C. Phelps ◽  
Richard L. Daniels
Keyword(s):  
Cell Viability ◽  
Tumor Cells ◽  
Flow Cytometric Analysis ◽  
Annexin V ◽  
Chemotherapeutic Agents ◽  
Cytotoxic Effects ◽  
High Concentrations ◽  
Induced Apoptosis ◽  
Dose Dependent ◽  
Gl261 Glioma

AbstractGlioblastoma (GBM) is a lethal astrocyte-derived tumor that is currently treated with a multi-modal approach of surgical resection, radiotherapy, and temozolomide-based chemotherapy. Alternatives to current therapies are urgently needed as its prognosis remains poor. Anthracyclines are a class of compounds that show great potential as GBM chemotherapeutic agents and are widely used to treat solid tumors outside the central nervous system. Here we investigate the cytotoxic effects of doxorubicin and other anthracyclines on GL261 glioma tumor cells in anticipation of novel anthracycline-based CNS therapies. Three methods were used to quantify dose-dependent effects of anthracyclines on adherent GL261 tumor cells, a murine cell-based model of GBM. MTT assays quantified anthracycline effects on cell viability, comet assays examined doxorubicin genotoxicity, and flow cytometry with Annexin V/PI staining characterized doxorubicin-induced apoptosis and necrosis. Dose-dependent reductions in GL261 cell viability were found in cells treated with doxorubicin (EC50 = 4.9 μM), epirubicin (EC50 = 5.9 μM), and idarubicin (EC50 = 4.4 μM). Comet assays showed DNA damage following doxorubicin treatments, peaking at concentrations of 1.0 μM and declining after 25 μM. Lastly, flow cytometric analysis of doxorubicin-treated cells showed dose-dependent induction of apoptosis (EC50 = 5.2 μM). Together, these results characterized the cytotoxic effects of anthracyclines on GL261 glioma cells. We found dose-dependent apoptotic induction; however at high concentrations we find that cell death is likely necrotic. Our results support the continued exploration of anthracyclines as compounds with significant potential for improved GBM treatments.

Effects of RE on Critical Cooling Rate of Bearing-B Steel

2012 ◽  
Vol 535-537 ◽  
pp. 761-763 ◽  
Author(s):  
Yi Sheng Zhao ◽  
Xin Ming Zhang ◽  
Zhi Guo Gao
Keyword(s):  
Phase Change ◽  
Cooling Rate ◽  
Experimental Results ◽  
Cooling Rates ◽  
Critical Cooling Rate ◽  
The Law

The law of phase change of bearing-B steel during continual cooling was studied by adopting dilatometer. The CCT curves of bearing-B steel were drawn, and the effects of RE on critical cooling rates were studied. The experimental results show that the start temperatures of martensite TM was decreased from 438 to 404°C. The critical cooling rate was simultaneously decreased from 33 to 15°C/s.

Effects of the Cooling Rate on the Acoustic Properties of Pb-10Sn Solder

2012 ◽  
Vol 729 ◽  
pp. 356-360
Author(s):  
Endre Harkai ◽  
Tamás Hurtony ◽  
Péter Gordon
Keyword(s):  
Sound Velocity ◽  
Cooling Rate ◽  
Acoustic Microscopy ◽  
Acoustic Properties ◽  
Scanning Acoustic Microscopy ◽  
Cooling Rates ◽  
Reliability Parameters ◽  
Microscopy Characterization ◽  
The Given

Microhardness and sound velocity were measured in case of differently prepared solder samples. The used Pb-10Sn solder samples were melted then cooled down applying different cooling rates. These procedures caused variant microstructure thus different microhardness and sound velocity values. The sound velocity was measured by means of scanning acoustic microscopy. Characterization of solder materials by acoustic microscopy gives the possibility to non-destructively estimate mechanical and reliability parameters of the given material.

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