Yazar "Ozdas, Ozen Banu" seçeneğine göre listele

Listeleniyor 1 - 6 / 6
  • [ X ]
    Öğe
    Effect of different transport temperatures on in vitro maturation of oocytes collected from frozen-thawed sheep ovaries
    (Tubitak Scientific & Technological Research Council Turkey, 2013) Ozdas, Ozen Banu; Baran, Alper; Tas, Muzaffer; Cirit, Umut; Demir, Kamber; Bacinoglu, Suleyman; Pabuccuoglu, Serhat
    The aim of this study was to determine the effects of 2 different transport temperatures on the in vitro maturation of oocytes collected from frozen-thawed sheep ovaries. Sheep ovaries were transferred into saline at temperatures of 4 degrees C and 32 degrees C. After the 2 experimental groups (A: fresh cortex, B: frozen-thawed cortex) were formed, each group was divided into 2 subgroups (group A1: 4 degrees C, group A2: 32 degrees C [control]; group B1: 4 degrees C, group B2: 32 degrees C). The cortexes were dissected into slices 1-3 mm thick and pieces of 0.5 cm(2). For groups B1 and B2, 1-2 cortex pieces were placed in cryogenic vials containing 1 mL of freezing medium modified with Earle's salts (TCM-199) and supplemented with 10% fetal calf serum (FCS) (FCS + 2.5 M ethylene glycol + 0.1 M sucrose). The vials were then cooled to 7 degrees C at 2 degrees C/min and held at 7 degrees C for 10 min for manual seeding. The temperature was then lowered by 0.3 degrees C/min to -35 degrees C and thereafter by -10 degrees C/min to -75 degrees C. Vials were plunged into -196 degrees C liquid nitrogen and stored. Cortexes were thawed at 37 degrees C. Collected oocytes were matured in their own groups in 700 mu L of TCM-199 (supplemented with luteinizing hormone, follicle-stimulating hormone, pyruvate, and FCS) for 23 h in a gas mixture of 5% CO2, 5% O-2, and 90% N-2 at 38.8 degrees C. After maturation, oocytes were fixed in acetic acid and ethyl alcohol (1: 3) for 48 h. Oocytes were stained with aceto-orcein and then examined. At the end of the study, maturation rates for reaching metaphase I (MI) were similar in all groups (group A1: 30.76%, group A2: 38.09%, group B1: 30.65%, and group B2: 33.33%). The rates at which metaphase II (MII) was reached were 18.58%, 34.69%, 7.25%, and 6.48%, respectively. The best development was seen in group A2 (P < 0.001). Sheep oocytes obtained from fresh and frozen-thawed cortexes reached the MII stage if transported at 4 degrees C.
  • [ X ]
    Öğe
    Effect of transport and storage temperature of ovaries on in vitro maturation of bitch oocytes
    (Elsevier Science Bv, 2006) Tas, Muzaffer; Evecen, Mithat; Ozdas, Ozen Banu; Cirit, Umut; Demir, Kamber; Birler, Sema; Pabuccuoglu, Serhat
    In this study, the effects of ovary transport and storage temperature on in vitro maturation of bitch oocytes were investigated. Ovaries were collected from 23 mature bitches and one randomly selected ovary of each pair (n = 23 pairs) was transported in physiologic saline at 4 degrees C, while the other one at 35-38 degrees C for 2-4 h. A total of 316 cumulus oocyte complexes (COCs) were obtained from the 4 degrees C group and 301 COCs from the 35-38 degrees C group. All COCs were matured in modified synthetic oviduct fluid (mSOF) supplemented with follicle stimulating hormone (FSH), essential and non-essential amino acids at 38 degrees C in ahumidified 5% CO2, 5% O-2, and 90% N-2 atmosphere for 72 h. At the end of the in vitro maturation period, nuclear maturation of oocytes was classified as germinal vesicle (GV), germinal vesicle breakdown (GVBD), metaphase I (MI), metaphase II (MII), undetermined nuclear maturation (UDNM), and MI + MII. The nuclear maturation rates to MI, MII, and MI + MII stages were 60.44%, 10.75%, and 71.20% in the 4 degrees C group and 37.20%, 7.64%, and 45.85% in the 35-38 degrees C group, respectively. The data demonstrated that oocytes obtained from ovaries transported at 4 degrees C had higher maturation rates than from the ones transported at 35-38 degrees C (p < 0.001). (c) 2005 Published by Elsevier B.V.
  • [ X ]
    Öğe
    Effects of estrous cycle stage and transport temperature of ovaries on in vitro maturation of canine oocytes
    (Elsevier Science Bv, 2010) Evecen, Mithat; Cirit, Uemuet; Demir, Kamber; Ozdas, Ozen Banu; Tas, Muzaffer; Birler, Sema; Pabuccuoglu, Serhat
    Unlike other domestic animals, in vitro maturation (IVM) of canine oocytes still has limited success. The present study investigated the effects of estrous cycle stage and transport temperature of ovaries on in vitro maturation of canine oocytes. The donor bitches were categorized into three groups based on stage of estrus cycle: follicular (proestrus or estrous), luteal (diestrus) and anestrus. One ovary of each pair collected from 39 mature bitches was transported in Phosphate Buffer Saline (PBS) at 4 degrees C while the other was transported at 37 degrees C. A total of 1138 Grade I COCs obtained from all ovaries were grouped and matured in modified synthetic oviduct fluid (mSOF) supplemented with follicle stimulating hormone (FSH), luteinizing hormone (LH), essential and non-essential amino acids at 38.5 degrees C in a humidified 5% CO2, 5% O-2, and 90% N-2 atmosphere for 72 h. The nuclear maturation rates were evaluated by aceto-orcein staining. Oocytes harvested from follicular and luteal ovaries have a significantly higher maturation rates (MI+MII) than the oocytes from anestrual ovaries in the 37 degrees C group (p<0.05). However, oocytes harvested from anestrual ovaries transported at 4 degrees C had the highest maturation (MI + MII) rate, and the difference between anestrual and luteal ovary groups was significant (p < 0.05). The oocytes from anestrual ovaries transported at 4 degrees C have significantly higher maturation rates than those transported at 37 degrees C (p < 0.0001). However, the transport temperature (37 or 4 degrees C) did not significantly affect the maturation (MI + MII) rates of oocytes harvested from the luteal (p = 0.61) and follicular (p = 0.48) stage ovaries. It can be concluded from this study that (1) both transport temperature and transport temperature x estrus cycle stage interaction effected the maturation rates, while estrus cycle stage alone did not, and (2) transporting canine ovaries at 4 degrees C can improve in vitro maturation rates in oocytes harvested from anestrous ovaries. (C) 2009 Elsevier B.V. All rights reserved.
  • [ X ]
    Öğe
    The effects of oviductal cell co-culture and different gas mixtures on the development of bovine embryos in vitro
    (Tubitak Scientific & Technological Research Council Turkey, 2012) Ozdas, Ozen Banu; Cirit, Umut; Baran, Alper; Kasikci, Guven
    The objective of the current study was to investigate the effects of the addition of oviduct co-culture to synthetic oviduct fluid (SOF) and Menezo B2 media used in an in vitro study of cows, and the effects of different gas atmospheres (5% CO2 or 5% CO2, 5% O-2, and 90% N-2) on in vitro cultures. Oocytes obtained through aspiration from the ovaries of slaughtered Holstein cows were washed and cultured within a TCM-199 maturation medium at 38.8 degrees C for 23 h. Then the matured oocytes and thawed semen, prepared in accordance with the swim-up method, were incubated for fertilization within in vitro fertilization (IVF)-Tyrode's albumin lactate pyruvate (TALP) medium with an atmosphere including the combination of 5% CO2, 5% O-2, and 90% N-2 gas, at 38.8 degrees C for 18-24 h. Fertilized oocytes were distributed into 3 main groups: Group I: B2 (5% CO2), Group II: B2 medium (5% CO2, 5% O-2, and 90% N-2), and Group III: SOF (5% CO2, 5% O-2, and 90% N-2), and each group was divided into 2 subgroups, with and without oviduct co-culture cells, and were cultured for 9 days. The percentage of embryos that reached the blastocyst stage was 34.0%, 20.0%, and 32.3% in the co-culture group and 26.7% and 23.3% in the without co-culture group, respectively. Group III showed the highest development of expanded blastocyst stage (P < 0.01). In conclusion, the addition of co-culture to B2 (5% CO2 atmosphere) and SOF (5% CO2, 5% O-2, and 90% N-2 atmosphere) media increased the rate of transferable embryos.
  • [ X ]
    Öğe
    The potential fertility estimation capacity of the hypoosmotic swelling test, the thermal stress test and a modified cervical mucus penetration test in the bovine
    (Elsevier Science Bv, 2008) Bacinoglu, Suleyman; Tas, Muzaffer; Cirit, Umut; Ozdas, Ozen Banu; Ak, Kemal
    In this study, hypoosmotic swelling (HOS), thermal stress (TS) and modified cervical mucus penetration (mCMP) tests have been used with routine tests for the assessment of semen quality. This is the first study in which the comparison of potential fertility estimation of fore-mention three tests was performed. Bull semen samples were divided into two fertility groups (high: n = 3, low: n = 3), according to their post-insemination NRR (non-return rate). Prior to the tests, post-thawed spermatological characteristics were assessed after which HOS, TS and mCMP tests were carried out. In the HOS test, the ratio of swollen cells, in the TS test the motility, and in the mCMP test the number of spermatozoa penetrating the cervical mucus, were examined. The relationship between the tests and fertility was also evaluated. HOS test was carried out according to different incubation times and temperatures (37 degrees C 60 min/41 degrees C 15 min/41 degrees C 30 min/46 degrees C 15 min/46 degrees C 30 min). For TS test, samples were subjected to various temperatures for different periods (no incubation (37 degrees C)/41 degrees C 15 min/41 degrees C 30 min/46 degrees C 15 min/46 degrees C 30 min). The mCMP test were subjected to various temperatures for the same period (37 degrees C 15 min/41 degrees C 15 min). In this study, post-thawed motility was found to be similar in high and low fertility groups. However, it has been determined that acrosomal (p < 0.01) and other morphological defects (p < 0.05) were low in the high fertility group. When HOS test was carried out at 37 degrees C, no difference was observed between the bulls with high and low fertility, but at 41 and 46 degrees C, results of high fertility group were significantly higher than those of low fertility group (p < 0.01). Similarly in TS test, the progressive motility rates of high fertility bulls was higher after thermal practices at 41 and 46 degrees C (p < 0.01). In mCMP test, at 37 degrees C, the number of cells that had penetrated was similar. However, significant differences were observed in the incubation at 41 degrees C (p < 0.01). It has been concluded that for the estimation of potential fertility of bulls, HOS, TS and mCMP tests, in combination with routine spermatological tests can be used and the use of further penetration distance range (PDR2) in mCMP test and higher temperatures such as 41 degrees C instead of 37 degrees C, during the incubations in the afore-mentioned performance tests, is more determinative. (C) 2007 Elsevier B.V. All rights reserved.
  • [ X ]
    Öğe
    Relationship between bovine fertility and the number of spermatozoa penetrating the cervical mucus within straws
    (Elsevier Science Bv, 2007) Tas, Muzaffer; Bacinoglu, Suleyman; Cirit, Umut; Ozdas, Ozen Banu; Ak, Kemal
    In this study, by using a recently developed test technique, the relationship between the total spermatozoa number penetrating determined sites of bovine cervical mucus in straws and potential fertility of bulls, and other spermatological characteristics were investigated. Furthermore, we aimed to determine the effect on the test results, of two different incubation temperatures (37 and 41 degrees C) and two sperm penetration distance ranges (PDRs). Frozen semen samples of six Holstein bulls were used in the study. The bulls were divided into two fertility groups (high and low fertility) according to the non-return rates (NRR). For the penetration test, cervical mucus was drawn into transparent plastic straws and incubated with semen at 37 and 41 degrees C for 15 min. After the incubation, straws were frozen in liquid nitrogen vapour and stored at -20 degrees C. On the evaluation day, concentrations of spermatozoa penetrated to the PDRs, each of which was 2.5 mm, between 32.5 and 35 mm (first penetration distance range, PDR1), and 50 and 52.5 mm (second penetration distance range, PDR2) distance in the straws from the open end, were measured. When compared with the low fertility group, bulls from the high fertility group showed a higher number of spermatozoa at the determined PDRs, and a significant positive correlation was found between the total number of spermatozoa at the penetration distances and the NRR scores of the bulls. (C) 2006 Elsevier B.V. All rights reserved.