Toxicity of cryoprotectants agents in freshwater prawn embryos of Macrobrachium amazonicum

Zygote ◽  
2014 ◽  
Vol 23 (6) ◽  
pp. 813-820 ◽  
Author(s):  
Arthur Vinícius Lourenço Ferreira ◽  
Elias José Teles Castro ◽  
Mariana Silva Alves Barbosa ◽  
Míriam Luzia Nogueira Martins de Sousa ◽  
Manoel Paiva de Araújo Neto ◽  
...  

SummaryThe process of cooling and cryopreservation of prawn embryos is a viable alternative for a continuous supply of larvae for freshwater prawn farming ponds. However, studies involving the application of those techniques as well as on toxicity of cryoprotectants in freshwater prawn embryos are scarce. Thus, this study aims to test the toxicity of methylic alcohol (MET), dimethyl sulfoxide (DMSO) and ethylene glycol (EG) on Macrobrachium amazonicum embryos. For the present experiment, pools of embryos were taken from 15 M. amazonicum females and were divided into three groups and tested in duplicate at concentrations of 10, 5, 3; 1, 0.5 or 0.1%. Toxicity tests were conducted for 24 h in Falcon® pipes to obtain the lethal concentration for 50% of the larvae (LC50). After the set period for testing, random samples of embryos were removed for morphological analysis under stereoscopic microscopes. Results were analysed using analysis of variance (ANOVA) and Tukey's test at a 5% significance level and Trimmed Spearman-Karber Analysis to determine LC50-24 h. DMSO toxicity tests revealed that 5% and 10% concentrations showed the highest toxicity and differed from the control (P ≤ 0.05), 24h-LC50 was 437.4 ± 14.4 µL. MET was less toxic among the tested cryoprotectants and concentrations did not allow the determination of its LC50-24h. For tests with EG, concentrations of 3, 5 or 10% solutions resulted in a 100% mortality to tested embryos; EG was the tested cryoprotectant with the highest toxicity, with an LC50-24h average of 81.91 ± 35.3 µl.

Zygote ◽  
2018 ◽  
Vol 26 (2) ◽  
pp. 111-118
Author(s):  
Caroline Costa Lucas ◽  
Luana Rolim Melo ◽  
Míriam Luzia Nogueira Martins de Sousa ◽  
Glayciane Bezerra de Morais ◽  
Moisés Fernandes Martins ◽  
...  

SummaryThere are few reports of cryopreservation and injuries in Macrobrachium amazonicum embryos. Thus, the aim of this study was to analyze the effects of cryoprotectants agents and cooling on stage VIII of this species. Fertilized eggs from ovigerous females were removed from the incubation chamber, then placed in 10 ml Falcon tubes with a cryoprotectant solution and saline-free calcium solution. Thus, the embryos underwent a cooling curve of 1°C per min until reaching 5°C, and then were stored for 2 h. The tubes containing the embryos were washed to remove the cryoprotectant, acclimated for 5 min and then transferred to 50 ml incubators. At the end of the 24-h period, living embryos from each tube were counted and tabulated. A pool of embryos was fixed with 4% formaldehyde and then subjected to histology using 3-mm thick sections and stained with haematoxylin/eosin. Another pool was used for biometric analysis in which length, width and volume were analyzed. The cryoprotectants agents used were: dimethylsulfoxide (DMSO), methyl alcohol, ethylene glycol at 1, 5 and 10% and sucrose (0.5 M). Variance analysis was performed followed by Tukey's honest significant difference (HSD) test at 5% significance level. DMSO cryoprotectant affected embryo survival the least with rates of 71.8, 36.2 and 0% for concentrations of 1, 5 and 10%, respectively. Ethylene glycol caused 100% mortality at all the concentrations used. It was not possible to observe the interference of cooling and cryoprotectants on embryonic structures in this study.


2019 ◽  
Vol 37 (1) ◽  
pp. 116
Author(s):  
Chenliang FAN ◽  
Yuhong ZHANG ◽  
Chuan WANG ◽  
Zhenlei PENG ◽  
Zhirong GAO

2020 ◽  

The banana agro-export sector in Ecuador provides millions of dollars in income for this concept, but with this development, a series of quality standards have been established that must be met to enter the export system. This has contributed to establishing good post-harvest production and management practices that guarantee the optimal production of bananas and plantains. The objective of this study was to determine the factors involved in the rejection of bananas (Musa acuminata) destined for international commercialization. The methodology considered the design modality of non-experimental transactional research, with a quantitative approach. The methodological design was developed in three phases at Finca 6 Hermanas located in the Barraganete sector of the San Juan parish in the Puebloviejo canton of the Los Ríos Province, Ecuador. The results highlight that the main causes for which banana rejection is generated are due to abiotic factors (damage, dry latex, scar, insect damage, broken neck, overgrowth) in a higher percentage of 79.55 % and biotic factors ( twins, diseases, short finger) by 20.45 %. The average rejection was 6 361 fingers and1 269 Kilograms (K) over the 6-week study duration. The analysis of variance turned out to be significant for variable 1 (biotic and abiotic). Ho is rejected; with the criterion of p-value < 0.0001 and F (9; 45) = 2.10., F = 13.17> F critic. In the case of variable (2) “work weeks”, Ho is accepted with the criteria obtained of p-value of 0.7694 and F (5; 45) = 2.4., As F = 0.51 < F critic, it is concludes, that with a significance level of 5% the null hypothesis is accepted. It is concluded that these figures lead to the elaboration of strategies that systemically mitigate the damages, by correcting each one of the causes that cause the deterioration of the banana and increasing the economic gains of the commercialization process.


Author(s):  
Peter H. Wiebe ◽  
Ann Bucklin ◽  
Mark Benfield

This chapter reviews traditional and new zooplankton sampling techniques, sample preservation, and sample analysis, and provides the sources where in-depth discussion of these topics is addressed. The net systems that have been developed over the past 100+ years, many of which are still in use today, can be categorized into eight groups: non-opening/closing nets, simple opening/closing nets, high-speed samplers, neuston samplers, planktobenthos plankton nets, closing cod-end samplers, multiple net systems, and moored plankton collection systems. Methods of sample preservation include preservation for sample enumeration and taxonomic morphological analysis, and preservation of samples for genetic analysis. Methods of analysis of zooplankton samples include determination of biomass, taxonomic composition, and size by traditional methods; and genetic analysis of zooplankton samples.


1992 ◽  
Vol 20 (2) ◽  
pp. 266-270
Author(s):  
Jens-Uwe Voss ◽  
Hasso Seibert

The toxicity of allyl alcohol and several glycols (ethylene glycol, 1,2-propanediol, 1,3-propanediol, methoxyethanol, and the glycol ether dioxane) was studied in cultures of 3T3 cells and in co-cultures of 3T3 cells with microcarrier-attached hepatocytes. Metabolism-mediated effects on the cytotoxicity to 3T3 cells were recorded by differences in the growth of the cultures exposed in the presence or absence of hepatocytes. Hepatocyte viability was determined by depletion of intracellular lactate dehydrogenase and effects on the biotransformation ability of hepatocytes were assessed by determination of O-deethylation of 7-ethoxycoumarin (EOD activity). Allyl alcohol was the only substance more toxic to the hepatocytes than to 3T3 cells cultured in the absence of hepatocytes. Toxicity to 3T3 cells of allyl alcohol, ethylene glycol, and 1,3-propanediol, but not of 1,2-propanediol, methoxyethanol and dioxane, was markedly enhanced when the cells were co-cultured with hepatocytes. The results indicate that the toxicity of allyl alcohol, ethylene glycol, and 1,3-propanediol, to 3T3 cells depends on the formation of active metabolites. For ethylene glycol and 1,3-propanediol, growth of 3T3 cells in co-cultures was reduced at concentrations without effects on hepatocyte viability. Co-culture of 3T3 cells with microcarrier-attached rat hepatocytes represents a suitable approach for the in vitro evaluation of metabolism-mediated cytotoxicity.


Healthcare ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 936
Author(s):  
Milan Kojić ◽  
Branka Protić Gava ◽  
Milan Bajin ◽  
Marko Vasiljević ◽  
Jasmina Bašić ◽  
...  

Background: The research objective of the study is to determine the differences in the manifestation of the motor status of normally fed preschool test subjects, classified into groups according to foot status. Methods: This is a simple, comparative observational study. Preschool children included in this study have been subjected to anthropometric measurements in order to determine BMI, tests for motor skills assessment (running at 20 m from a high start, standing broad jump, backwards polygon, rectangular seated forward bend, plate tapping, sit-ups for 60 s, and bent arm hang), and a determination of foot status. The total sample was comprised of 202 test subjects who attended a regular sports program, aged 3.9 to 6.5 years of decimal age (M = 141; Age = 5.3 ± 0.74; Height = 117.3 ± 7.1; Weight = 22 ± 3.7; F = 61; Age = 5.1 ± 0.73; Height = 114.9 ± 7.4; Weight = 21.2 ± 3.8), of which 153 (75.7%) were normally fed, 6 (3%) were undernourished, 30 were overweight (14.9%), and 13 were obese (6.4%). Results: In the total sample, 30 (14.9%) subjects had normal arch feet, 90 (44.6%) high arched feet, and 41 (20.3%) flat feet. We found 41 (20.3%) subjects who had different left and right foot statuses within this sample. The data were processed by means of nonparametric tests (the Kruskal–Wallis and Mann–Whitney U tests) at a significance level p ≤ 0.05. Conclusion: The results show that there is a statistically significant difference between groups of subjects with different foot statuses in the manifestation of motor status in most tests, with a significance level of p ≤ 0.01, and in tests of sit-ups for 60 s and the bent arm hang, there is a statistically significant difference, the level of which is p ≤ 0.05. It is only in the inclination test of rectangular seated forward bend that no statistically significant difference was displayed.


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