44 EFFECT OF CRYOPROTECTANT AGENTS IN EQUINE OVARIAN BIOPSY FRAGMENTS

2016 ◽  
Vol 28 (2) ◽  
pp. 152
Author(s):  
G. D. A. Gastal ◽  
B. G. Alves ◽  
S. O. Paiva ◽  
K. A. Alves ◽  
S. G. S. de Tarso ◽  
...  
Keyword(s):  
Ethylene Glycol ◽  
Dimethyl Sulfoxide ◽  
Propylene Glycol ◽  
Cell Density ◽  
Stromal Cell ◽  
Ovarian Tissue ◽  
Rank Correlation ◽  
Analysis Data ◽  
Exact Test ◽  
Spearman’S Rank Correlation

Studies on ovarian tissue preservation in horses are scarce, and only one research group (Devireddy et al. 2006 Mol. Reprod. Develop. 73, 330–341) has tested the effect of the cryoprotectant agents in equine ovarian tissue. The purpose of this study was to evaluate (1) the effect of cryoprotectant agents in the morphology of equine preantral follicles (PAF) and structure of the ovarian tissue, (2) the relationship between ovarian stromal cell density and PAF density, and (3) the association of ovarian stromal cell density with PAF morphology after exposure to cryoprotectant agents. Three independent experiments with identical methodologies were performed in this study. Each experiment was composed by one cryoprotectant agent (dimethyl sulfoxide, ethylene glycol, propylene glycol) performed in 3 replicates. Ovarian biopsy fragments (1.5 × 1.5 × 10 mm) were harvested from 6 mares and submitted to 4 times of exposure (0, 10, 15, 20 min) at room temperature in a solution of α-minimal essential medium (MEM)+ and one cryoprotectant (dimethyl sulfoxide, ethylene glycol, or propylene glycol) at a concentration of 1.5 M. The cryoprotectant removal was performed by a 3-step (5 min each) equilibration process using (1) α-MEM + 0.5 M sucrose, (2) α-MEM + 0.25 M sucrose, and (3) α-MEM alone after each time of exposure. All fragments were fixed in Bouin’s solution for histological analysis. Data were analysed by ANOVA, Fisher’s exact test, Spearman’s rank correlation, and power test. The PAF density, stromal cell density, and area of the fragments were not affected (P > 0.05) by any of the cryoprotectant agents throughout the time of exposure. However, the morphology of the PAF was affected (P < 0.05) by the cryoprotectant agents. In the propylene glycol and dimethyl sulfoxide, higher (P < 0.05) percentages of abnormal PAF were observed at 10 and 20 min of exposure, respectively. However, the PAF morphology in the ethylene glycol treatments was not affected (P > 0.05) throughout the times of exposure. Strong correlations (range, 0.57 to 0.77; power, 96 to 99%) were identified between PAF density and stromal cell density in all experiments. When stromal cells were classified into groups of density (i.e. low, 25.67–34.66; medium, 34.67–43.66; and high, 43.67–52.67 cells/2500 μm2), only the high stromal cell density was positively correlated (P < 0.001) with the PAF density; however, no correlation between stromal cell density and PAF morphology was observed. In conclusion, (1) ethylene glycol seems to be a less harmful cryoprotectant agent to equine PAF, (2) exposure to cryoprotectant agents did not affect the cell density and area of ovarian fragments, (3) PAF density was positively correlated with stromal cell density, and (4) stromal cell density did not affect the morphology of PAF.

Use of Social Media for Knowledge Sharing Among Students

2018 ◽  
Vol 8 (2) ◽  
pp. 65-75
Author(s):  
Funmilola O. Omotayo ◽  
Olugboyega M. Salami
Keyword(s):  
Social Media ◽  
Knowledge Sharing ◽  
Significant Relationship ◽  
Rank Correlation ◽  
Sampling Technique ◽  
Analysis Data ◽  
Chi Square ◽  
Spearman’S Rank Correlation ◽  
Use Of Social Media ◽  
Set Up

The world of research requires researchers, students to share knowledge. With the invention of social media, knowledge sharing process has been more effective and easier. This study examined the usage of social media for knowledge sharing among students of the Polytechnic Ibadan, Nigeria. Descriptive survey research design was adopted, while stratified random sampling technique was adopted to select the students. Four hundred and thirty four copies of questionnaire were administered, while 301 were retrieved and 271 copies found useful for data analysis. Data was analysed using frequencies and percentage distribution, Spearman’s rank correlation, Kruskal Wallis test, and Chi-Square. Findings reveal that Facebook and Whatsapp are the widely used social media tools for knowledge sharing by the students. The study found significant relationship between social influence and attitude towards using social media for knowledge sharing, as well as significant relationship between attitude and use of social media for knowledge sharing.The study recommends that institutions should exploit the proliferation of social media and its use to set up off-class student-student and student-lecturer discussion groups, which could help encourage and promote knowledge sharing, and thereby help students in achieving good academic outcomes.

64 CRYOPRESERVATION OF CAT OVARIAN TISSUE BY VITRIFICATION

2013 ◽  
Vol 25 (1) ◽  
pp. 179 ◽  
Author(s):  
J. Galiguis ◽  
C. E. Pope ◽  
M. C. Gómez ◽  
C. Dumas ◽  
S. P. Leibo
Keyword(s):  
Ethylene Glycol ◽  
Dimethyl Sulfoxide ◽  
Ovarian Tissue ◽  
Genetic Material ◽  
Cortical Tissue ◽  
Rock Inhibitor ◽  
Tissue Samples ◽  
Preantral Follicles ◽  
Wide Range ◽  
Chi Square Analysis

The cryopreservation of ovarian tissue is linked to a wide range of possible applications, from oocyte harvesting to allo- and xenotransplantation. These procedures have significant potential for the preservation of valuable genetic material and endangered-species conservation. The objectives of the present study were to (1) compare viability of preantral follicles obtained from fresh v. vitrified feline ovarian cortex, (2) evaluate the effect of apoptotic inhibitors (ROCK inhibitor v. glutathione) on viability of follicles from vitrified samples, and (3) determine the optimal inhibitor concentration for follicle viability. In Experiment 1, 5 × 5 × 1 mm cortical tissue samples were obtained from excised cat ovaries and assigned to either the fresh control or vitrification group. Fresh samples were processed through a 230-micron-pore dissection strainer to collect preantral follicles. Follicles were then stained in Trypan blue to determine membrane integrity and survival rates. Vitrification samples were first equilibrated in 7.5% dimethyl sulfoxide and 7.5% ethylene glycol at ~22°C and then in vitrification solution consisting of 20% dimethyl sulfoxide, 20% ethylene glycol, and 0.5 M sucrose. They were then vitrified on a thin, perforated, metal strip (Cryotissue, Kitazato Biopharma, Fujinomiya, Japan). Samples were later warmed in 1.0 M sucrose at 38°C. Follicles were then collected and assessed for survival. In Experiment 2, follicles were collected from samples vitrified/warmed in cryo-media supplemented with either 3 × 104 nM ROCK inhibitor or 6 nM glutathione. Follicles from samples vitrified/warmed without inhibitor treatment were used as controls. In Experiment 3, tissue samples were vitrified/warmed in cryo-media supplemented with 0, 2, 6, or 10 nM glutathione before follicle viability was determined. Data were evaluated by chi square analysis. In Experiment 1, 637 and 340 follicles were collected from fresh and vitrified samples, respectively. Overall, survival was higher in freshly collected follicles when compared to those from the vitrified group (67 v. 18%, respectively; P < 0.05). Evaluation of apoptotic inhibitors was determined through collection of 314, 354, and 506 follicles from inhibitor-free, ROCK inhibitor, and glutathione-treated media, respectively. Follicles from samples vitrified in inhibitor-free media and in ROCK inhibitor survived at a lower rate than those from glutathione-treated samples (10 and 13% v. 18%, respectively; P < 0.05). In Experiment 3, a total of 539, 641, 625, and 632 follicles were collected from samples treated in 0, 2, 6, and 10 nM glutathione, respectively. There were no statistical differences in follicle survival among the 0, 2, and 6 nM groups. However, follicles treated in 10 nM glutathione survived at a higher rate than those vitrified/warmed in the absence of glutathione (20 v. 14%; P < 0.05). In summary, viability of preantral follicles from ovarian cortical tissue was significantly reduced by vitrification. Despite this, tolerance of such follicles to cryopreservation was improved by vitrifying and warming in cryo-media containing 10 nM glutathione. Partially funded by the LSU/ACRES Collaborative Project.

51 Effect of Cryoprotectant Exposure Time on Development of Vitrified-Warmed Immature Equine Oocytes

2018 ◽  
Vol 30 (1) ◽  
pp. 164
Author(s):  
H. S. Canesin ◽  
J. G. Brom-de-Luna ◽  
Y.-H. Choi ◽  
A. M. Pereira ◽  
G. G. Macedo ◽  
...  
Keyword(s):  
Ethylene Glycol ◽  
Propylene Glycol ◽  
Exposure Time ◽  
In Vitro Maturation ◽  
Initial Exposure ◽  
Exact Test ◽  
Fetal Bovine ◽  
Follicle Aspiration ◽  
Meiotic Competence

Effective methods for cryopreservation of equine oocytes have not yet been established. Vitrification involves use of high cryoprotectant (CPA) concentrations, which can be cytotoxic. Thus, it is critical to determine a CPA concentration and exposure time able to protect the cell during cooling but with a minimal toxicity. Using a rapid non-equilibrating system, we fixed the time in the first, lower CPA concentration solution (V1) at 40 s, based on the time to maximal shrinkage. We then evaluated different exposure times in the final vitrification solution (V2). Cumulus-oocyte complexes (COC) were collected from slaughterhouse-derived ovaries and held overnight in commercial embryo holding medium. Fetal bovine serum was used as the base medium (BM). In experiment 1, COC were held in BM, incubated in V1 (2% propylene glycol + 2% ethylene glycol) for 40 s followed by incubation in V2 (17.5% propylene glycol + 17.5% ethylene glycol + 0.3 M trehalose) for 0, 45, 75, or 110 s, and then loaded in groups of 6 to 10 oocytes on a 75-µm steel mesh and plunged into liquid nitrogen. Warming was performed in decreasing trehalose concentrations in BM: 0.4 M (60-70 s), 0.2 M (5 min), 0.1 M (5 min), 0.05 M (5 min), and 0 M. After warming, oocytes were cultured for in vitro maturation (IVM) and evaluated after staining with Hoechst 33258. Differences between treatments were analysed by Fisher’s exact test. The maturation (metaphase II, MII) rate of the Control (non-vitrified oocytes; 38.8%, 31/80) was similar to that of the 75-s treatment (34.8%, 16/46; P = 0.71), and higher (P < 0.05) than those of the 0, 45, and 110 s treatments (0.0%, 0/10; 11.4%, 4/35; and 3.6%, 1/28; respectively). In experiment 2, timings in V2 focusing around 75 s were evaluated. The COC were collected and vitrified as for experiment 1, except that time in V2 was 50, 60, 70, 80, 90, or 100 s. The vitrified COC were then shipped to the intracytoplasmic sperm injection (ICSI) laboratory. After warming and IVM, oocytes were subjected to ICSI and embryo culture. Control oocytes were recovered by transvaginal follicle aspiration. The MII rate of the Control (60%, 33/55) was similar (P > 0.05) to that of the 60- and 70-s treatments (38.9%, 7/18, and 35.3%, 6/17, respectively), and higher (P < 0.05) than those of the 50-, 80-, 90-, and 100-s treatments (5.6 to 31.6%). The cleavage rates were 94% (31/33) for the Control and 71 to 100% for vitrified oocytes (P > 0.05). No blastocyst was produced from vitrified oocytes compared with 8/33 (24.2%) for Control. This work demonstrates that a rapid, non-equilibrating vitrification technique using a 40-s initial exposure and 70- to 80-s final exposure to CPA is associated with maintenance of meiotic competence of immature equine oocytes; however, further work is required to optimize embryonic development with this method. Research supported by the Clinical Equine ICSI Program and the Link Equine Research Fund, Texas A&M University.

scholarly journals Ovarian fragment sizes affect viability and morphology of preantral follicles during storage at 4°C

Reproduction ◽  
2017 ◽  
Vol 153 (5) ◽  
pp. 577-587 ◽  
Author(s):  
G D A Gastal ◽  
B G Alves ◽  
K A Alves ◽  
M E M Souza ◽  
A D Vieira ◽  
...  
Keyword(s):  
Membrane Potential ◽  
Dna Fragmentation ◽  
Cell Density ◽  
Mitochondrial Membrane Potential ◽  
Mitochondrial Membrane ◽  
Stromal Cell ◽  
Ovarian Tissue ◽  
Ovarian Tissue Cryopreservation ◽  
Preantral Follicles ◽  
Whole Ovary

The method of transportation and the conditions imposed on the ovarian tissue are pivotal aspects for the success of ovarian tissue cryopreservation (OTC). The aim of this study was to evaluate the effect of the size of the ovarian tissue (e.g. whole ovary, biopsy size and transplant size) during different times of storage (0, 6, 12 and 24 h) on the structural integrity of equine ovarian tissue transported at 4°C. Eighteen pairs of ovaries from young mares (<10 years old) were harvested in a slaughterhouse and processed to simulate the fragment sizes (biopsy and transplant size groups) or kept intact (whole ovary group) and stored at 4°C for up to 24 h in α-MEM-enriched solution. The effect of the size of the ovarian tissue was observed on the morphology of preantral follicles, stromal cell density, DNA fragmentation and mitochondrial membrane potential. The results showed that (i) biopsy size fragments had more morphologically normal preantral follicles after 24 h of storage at 4°C; (ii) mitochondrial membrane potential was the lowest during each storage time when the whole ovary was used; (iii) DNA fragmentation rate in the ovarian cells of all sizes of fragments increased as storage was prolonged and (iv) transplant size fragments had increased stromal cell density during storage at cool temperature. In conclusion, the biopsy size fragment was the best to preserve follicle morphology for long storage (24 h); however, transportation/storage should be prior determined according to the distance (time of transportation) between patient and reproduction centers/clinics.

scholarly journals Dorsopathies: routine checkups as a procedure necessary for early diagnostics, risk factors and comorbidities identification

2018 ◽  
pp. 12-17
Author(s):  
IN Denisov ◽  
TV Zaugolnikova ◽  
TS Popova ◽  
TE Morozova
Keyword(s):  
Risk Factors ◽  
Primary Care Physicians ◽  
Rank Correlation ◽  
Statistical Processing ◽  
Noncommunicable Diseases ◽  
Exact Test ◽  
Spearman’S Rank Correlation ◽  
Spearman’S Rank Correlation Coefficient ◽  
Urgent Task ◽  
Working People

Early detection of dorsopathies is an urgent task for primary care physicians, since such conditions can combine with other chronic noncommunicable diseases (NСD) and adversely affect the course all comorbidities, consequently disimproving the quality of life of patients and increasing the frequency of their requests for medical assistance. This study aimed to determine the value of routine checkups in the context of detection of dorsopathies, NCD, and identification of risk factors (RF). We have retrospectively analyzed the patient records database of a rural outpatient clinic in the Tver region (years 2015 to 2017). The prevalence of dorsopathies and NCD RF were the subjects investigated. Fisher's exact test and Spearman's rank correlation coefficient (SRCC) were applied for the purposes of statistical processing of the results. We discovered that dorsopathy most often was a comorbidity to arterial hypertension and gastrointestinal tract diseases; it was strongly related to the NCD (SRCC = 0.506), age (SRCC = 0.383), slightly less so — to hypodynamia (SRCC = 0.146), type of the patient's occupation (intellectual or physical labor) (SRCC = 0.07). Routine checkups improve the rate of detection of dorsopathy: the more patients undergo such examinations, the more cases of dorsopathy are diagnosed. Thus, it is necessary to increase the number of working people attending the checkups in order to detect dorsopathies early and prevent them effectively.

30 EFFECT OF THE REPEATED USE OF OPEN SYSTEM VITRIFICATION DEVICES ON MII STAGE AND CLEAVAGE RATES OF BOVINE CUMULUS-OOCYTE COMPLEXES

2016 ◽  
Vol 28 (2) ◽  
pp. 145
Author(s):  
F. A. Diaz ◽  
E. J. Gutierrez ◽  
B. A. Foster ◽  
P. T. Hardin ◽  
K. R. Bondioli
Keyword(s):  
Ethylene Glycol ◽  
Dimethyl Sulfoxide ◽  
Open System ◽  
High Efficiency ◽  
Beef Cows ◽  
Developmental Competence ◽  
Limiting Factor ◽  
Cleavage Rate ◽  
Exact Test ◽  
Repeated Use

Vitrification of mammalian gametes and embryos has become the cryopreservation tool of choice in research and commercial clinical programs because of its high efficiency. Vitrification relies upon high cooling rates. In this regard the use of open system vitrification devices (OSVD) provides the highest cooling-warming rates. A limiting factor of vitrification research in domestic animals is the high cost of OSVD. Reuse of these devices could be a viable alternative for cost reduction in vitrification research projects. The objective of this study was to evaluate the effect of the repeated use of OSVD on the developmental competence of bovine cumulus-oocyte complexes (COC). A 6-treatment factorial arrangement was evaluated, where factor A was number of uses of OSVD (new, one use, and two uses) and factor B was COC type (immature, mature). Cumulus-oocyte complexes were obtained by ovum pickup from crossbred nonlactating beef cows. The vitrification procedure consisted of exposure of COC to 7.5% ethylene glycol and 7.5% dimethyl sulfoxide for 9 min. Afterward, COC were exposed to 15% ethylene glycol, 15% dimethyl sulfoxide, and 0.5 M sucrose and loaded into the tip of the OSVD (Cryolock®) with minimal volume (<1 μL) to be immediately plunged into LN within 60 s. Three to four COC were loaded per OSVD. For warming, the COC were exposed to 0.5-M (37.5°C) and 0.25-M sucrose for 2.5 min each. The base medium for all solutions was D-PBS plus 20% fetal bovine serum. A total of 266 COC were used in the study collected during 6 days (repetitions). Cumulus-oocytes complexes obtained per day were divided for immediate vitrification or for a 22-h maturation period (84.5% MII stage rate) and then vitrified. In each case COC were randomly assigned to treatments (numbers of use of OSVD) before vitrification. From each treatment warmed oocytes were divided for assessment of maturation and cleavage rate evaluation. To assess MII stage rate, COC were exposed to Hoechst 33342 (3.5 μg mL–1) for 15 min at 37.5°C and then observed under an epifluorescence microscope. A standard bovine IVF protocol was used, and cleavage rate was evaluated at 42 h following fertilization. Results of the experiment were tested by chi-square test of independence or Fisher’s exact test when required (P < 0.05). The MII stage rates (mean ± standard error) for immature vitrified COC were 82 ± 2.3, 78.2 ± 5.8, and 75 ± 5.3, and for mature vitrified COC were 69.3 ± 4.3, 88.2 ± 4.1, 96 ± 2.1, for new, one-use, and two-uses OSVD, respectively. The cleavage rates for immature vitrified COC were 31.6 ± 4.8, 38.8 ± 3.4, and 37.7 ± 1.1, and for mature vitrified COC were 31.7 ± 4.8, 34.4 ± 4.7, and 33.3 ± 7.1, for new, one-use, and two-uses OSVD, respectively. No differences in cleavage rate were found when comparing immature vitrified COC with mature vitrified COC (36.1 ± 1.7 v. 33.1 ± 3.2; P > 0.05). Results of the experiment shown that no differences were detected, and similar results in terms of maturation and cleavage rate were obtained when reusing OSVD.

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