Kamber Demir

Kamber Demir
İstanbul University-Cerrahpaşa · Faculty of Veterinary Medicine

PhD, DVM

About

72
Publications
10,684
Reads
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386
Citations
Additional affiliations
January 2002 - September 2015
Istanbul University
Position
  • Research Assistant
January 2002 - present
Istanbul University
Position
  • Research Assistant

Publications

Publications (72)
Conference Paper
Full-text available
BACKGROUND-AIM Transgenesis in livestock allows improvement of desired traits besides being used as animal models for biomedical research. Intracytoplasmic microinjection (ICI) appears to be a favorable alternative for gene delivery to embryos. In this study, effects of different pEGFP-N1 concentrations on fluorescing embryo rate and embryonic deve...
Article
Gene transfer studies, preferred in many biotechnology studies such as in vitro transgenic cell modeling systems, gene therapy, transgenic animal production by cloning, etc., are quite limited due to transfection difficulties on primary cell lines. The main purpose of this study is on the production of biocompatible gene carrier systems with high t...
Article
Full-text available
Usage of oocytes obtained from ovaries after long-term cold storage for in vitro embryo production is a promising tool for the protection of wildlife and endangered animal species. Mammalian oocytes are susceptible to oxidative stress with regard to the high lipid content of plasma membranes. Melatonin is known as a powerful antioxidant and anti-ap...
Article
In this study, it was aimed to determine the effect of destruction of lyophilized and frozen-thawed ram sperm plasma and acrosomal membrane on development of embryos produced by intracytoplasmic sperm injection (ICSI). Semen samples were divided into two groups for lyophilization (L) and freezing (F). For the removal of the plasma membrane, L and F...
Article
The aim of this study is both to design the chitosan (Chi) nanoparticles with different Mw containing the phosphoester bonds and increase their amino function for the transfection. The phosphorylamine-modification of Chi and depolymerized Chi (DChi) was realized using o-phosphorylethanolamine (o-PEA) and characterized, for the first time. The nanop...
Article
The determination of the maximum slaughter weight which will not cause a decrease in carcass quality is a very important issue to ensure optimal utilization of the meat production potential of lambs. To determine that, the slaughtering and carcass characteristics of thin-tailed Kivircik (n = 60) and fat-tailed Kangal Akkaraman (n = 59) lambs slaugh...
Article
The primary aim of the study was to investigate whether iodixanol and trehalose would have a synergic effect on the cryosurvival of electroejaculated ram semen. Tris‐based diluter was used to prepare 9 different extenders by the addition of iodixanol or trehalose alone or varying combinations of these substances. Diluters were prepared as follows:...
Article
Full-text available
The reproductive biology of the domestic dog is unique among mammalian species; because of this, in vitro maturation (IVM) rate is still very low compared with other domestic animals in spite of attempts at improvement. The aim of this study was to consider the use of recombinant human gonadotropins as a replacement for pituitary gonadotropins for...
Article
Full-text available
Percoll gradient and swim-up are the most common methods used to obtain high quality intact sperm to be used for the in vitro fertilization procedures. In this study, we evaluated the effects of swim-up and percoll gradient methods on DNA integrity and other spermatological parameters. To determine DNA breakdown, toluidine blue staining was used. M...
Article
Full-text available
The motility, sperm membrane and acrosome integrity during post-thawing incubation is an indication of the usability of the semen. The maintenance of higher motility of sperm during post-thawing incubation simultaneously with the maintenance of intact cell membrane and acrosome integrity reflects a greater likelihood of their survival in the female...
Article
Full-text available
Summary: Synchronization of donor cells and activation of the reconstructed oocytes are important factors affecting the success rate in somatic cell cloning. In this study, it was aimed to investigate the effects of serum starvation in donor cell synchronization and ionomycin treatment in the activation of reconstructed oocytes after somatic cell n...
Article
Full-text available
Synchronization of donor cells and activation of the reconstructed oocytes are important factors affecting the success rate in somatic cell cloning. In this study, it was aimed to investigate the effects of serum starvation in donor cell synchronization and ionomycin treatment in the activation of reconstructed oocytes after somatic cell nuclear tr...
Article
The aim of this study is to prepare the long linear aliphatic amine pendant group-functionalized chitosan based nanoparticulate gene carrier system with improved properties for the efficient transfection. The amine functionalized chitosan (MChi) was synthesized by using N-(2-hydroxyethyl)ethylenediamine (HE-EDA) and characterized for the first time...
Article
Full-text available
This study was conducted to evaluate the protective effects of cholesterol pre-incubation on ovine oocytes exposed to cold stress and vitrification. In the first experiment, cumulus oocyte complexes harvested from ovaries of slaughtered ewes were exposed to 2 mg/ml cholesterol loaded methyl-ßcyclodextrin (CLC) in maturation medium for 2, 4 or 24 h....
Article
The aim of this study was to determine the effects of the administration time of misoprostol (11 h (Miso11) and 6 h (Miso6) before artificial insemination) on fertility rates in Kivircik ewes (control: n = 41, Miso11: n = 32 and Miso6: n = 33) during breeding season. Artificial insemination (AI) was performed 48 h after sponge removal using frozen-...
Article
Full-text available
The objective of the present study was to examine the effects of two different transport temperature (37°C vs 4°C) and cold storage of ovaries for 24 h on cumulus cell apoptosis and maturation rates of cat oocytes in vitro. Ovaries were collected from 15 ovariohysterectomized domestic cats and maintained and transported to the laboratory in phospha...
Conference Paper
Full-text available
Long term storage of ovaries can provide opportunity to rescue oocytes from ovaries of endangered or recently dead felids. The objective of the study was to examine the effect of two ovary transport temperature (4 vs 37oC) and time on cumulus cell apoptosis and maturation rates of cat oocytes in vitro. Ovaries were collected from 15 domestic cats a...
Conference Paper
The increase in the human population causes rapid depletion of natural resources and depletion or extinction of wild species. Today, thirty-six species of wild cats face this danger. Biotechnological methods such as Artificial Insemination (AI), In Vitro Fertilization (IVF), In Vitro Maturation (IVM), Embryo Transfer (ET) and Cloning are used in th...
Article
The aim of this study is to investigate the effects of the thiolation on the mucoadhesion characteristics of the gelatinized and crosslinked wheat starch-graft-poly(acrylic acid) [(WS-g-PAA)gc] for potential use in drug delivery via vaginal route. Thiolation of (WS-g-PAA)gc was first time realized using l-cysteine hydrochloride monohydrate (CyS) an...
Article
Full-text available
Animal production via SCNT provides a unique tool for protection of valuable individuals, conservation of vulnerable and endangered species and production of transgenic animals. A total of 167 MI and 219 MII stage oocytes were used as the material of the study. The oocytes were enucleated at 44 h after in vitro maturation by aspiration of the polar...
Article
Full-text available
Çalışmanın ilk bölümünde, mezbahadan sağlanan ovaryumlardan kazanılan oositler (n=2990) olgunlaştırma medyumu içerisinde 24 saat süreyle olgunlaştırıldı. Ardından, 20 saat süreyle İn Vitro Fertilizasyona (İVF) bırakıldılar. Yarıklanma gösteren embriyolar (n=1305), Sentetik Ovidukt Fluid (SOF) medyumu içerisine alınarak altı gün süresince İn Vitro K...
Article
The aim of this study was to prepare and evaluate the mucoadhesive, biocompatible and biodegradable progesterone containing vaginal tablets based on modified starch copolymers for the estrus synchronization of ewes. Starch-graft-poly(acrylic acid) copolymers (S-g-PAA) were synthesized and characterized. The vaginal tablets were fabricated with S-g-...
Conference Paper
Full-text available
Anatolian grey cattle (endangered native Anatolian cattle) as 1 male (clone 1) and 4 females (clones 2-5) were produced from cells of 1 male and 1 female cattle by somatic cell nuclear transfer (SCNT) in a previous study. In this study, we examined the reproductive potential of these cloned animals, which are now 4 and 5 years old. The parameters e...
Article
Full-text available
In this study we aimed to determinate the effects of three different cooling rates from +26°C to +5°C at (0.3°C/min 0.6°C/min and 0.9°C/min) on spermatologic and ultrastructure properties of ram semen. For this purpose semen from 6 rams was collected by electroejaculator and was pooled in a +26°C waterbath. Pooled semen was diluated with tris based...
Article
Full-text available
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 °C and 32 °C. After the 2 experimental groups (A: fresh cortex, B: frozen-thawed cortex) were formed, each group wa...
Data
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 (proest...
Article
Full-text available
This study was conducted to improve cryosurvival of electroejaculated (EE) ram semen in the presence of iodixanol (OptiPrep™), trehalose or cysteamine. A tris-based extender was used to prepare 12 extenders containing OptiPrep™ (Op), trehalose (Tr) or cysteamine (Cy) alone, or different combinations of these compounds. Extenders were designated as...
Article
Full-text available
This study was conducted to determine the most successful techniques on inmature and in vitro-matured cat oocytes that were parhtenogenically activated using 6-dimethylaminopurine (6-DMAP) and cycloheximide (CHX), in combination with electrical stimulation and calcium ionophore. After 44 h of in vitro maturation, the oocytes with a polar body were...
Article
Full-text available
The most frequent problems in current embryo freezing are formation of harmful ice crystals and toxicity of cryoprotectants. In slow freezing techniques although, the cryoprotectants can be used in a low concentration, ice crystals are formed and in rapid freezing process where ice crystals are avoided, this time toxicity of cryoprotectants deterio...
Article
Full-text available
ZET Günümüzde dondurulmuş embriyoların transferi ile üstün verim özelliklerine sahip sürülerin oluşturulması, hastalıkların kontrolü ve genetik materyallerin uzun süre saklanması mümkün olabilmektedir. Ancak donmuş embriyolarda eritme sonrası tranfer edilebilir embriyo eldesi ve gebelik oranları istenilen düzeyde değildir. Özellikle embriyoların do...
Article
Full-text available
The aim of this study was to clone native Anatolian Grey cattle by using different donor cell types, such as fibroblast, cartilage and granulosa cells cryopreserved in a gene bank and oocytes aspirated from ovaries of Holstein cows as the recipient cytoplasm source. One male calf from fibroblast, three female calves from granulosa cells and one fem...
Article
There have not been successful and repeatable methods for in vitro embryo production in the dog. Up to date, only one blactocyst has been achieved on in vitro culture. Since reproductive physiology of the dog is different from that of other mammalian species, it seems that a suitable method for in vitro production of canine embryos is still far fro...
Article
Full-text available
The aim of this study was to investigate the post-thaw motility and morphological defect rates of cat semen frozen with various extenders, and pregnancy rates aft er intrauterine insemination (IUI). Cats, 2 males and 14 queens, 2 to 3 years of age, and under the same managemental conditions were used. Semen was collected by means of an electroejacu...
Conference Paper
Full-text available
Embryo production via in vitro fertilization and nuclear transfer has been accomplished in the dog, and the transfer of the cloned embryos has recently resulted in the birth of puppies. However, the efficiency of these technologies is still very limited. Until now, only two morulas and single blactocyst have been achieved in vitro. Therefore, the a...
Article
Full-text available
In vitro embryo production has not been confidently applied to the dog successfully. Up to date, only one blactocyst have been achieved by in vitro culture. Therefore, the aim of the present study was to examine the effects of different oocyte diameters (<= 100 mu m and >100 mu m) on in vitro maturation (IVM), in vitro fertilization (IVF) and in vi...
Article
Full-text available
Embryo production via in vitro fertilization and nuclear transfer has been accomplished in the dog, and the transfer of the cloned embryos has recently resulted in the birth of puppies. However, the efficiency of these technologies is still very limited. Until now, only two morulas and single blactocyst have been achieved in vitro. Therefore, the a...
Article
Full-text available
The aim of this study was to obtain cloned lambs by somatic cell nuclear transfer. In vitro matured oocytes were enucleated and injected with serum-starved cumulus cells. After electrofusion and ionomycin treatments, reconstructed oocytes were activated by 10 ƒİg/ml cycloheximide (CHX) for 5 h or 2 mM 6-dimethylaminopurine (6-DMAP) for 3 h and cult...
Article
Full-text available
The aim of this study was to observe the effects of taurine containing and non-containing milk extenders on the spermatological characteristics of chilled stored male cat semen. Semen was collected from 4 cats of 2-3 ages under general anesthesia (xylazine-ketamine HC1) by an electro-ejaculator during the study. Total 5 ejaculates with a weekly bas...
Article
Full-text available
Two, 4-Dichlorophenol (2, 4-DCP), an environmental pollutant has been in agriculture and synthetic chemical industry. The aim of present study was to analyse the testicular toxicity of 2, 4-DCP, which caused biochemical, spermatological and histological changes in male mice and to evaluate the possible ameliorative effect of soybean extract and L-T...
Article
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 (proest...
Article
Temporal storage of ovaries can provide opportunity to rescue oocytes from ovaries of endangered felids. The objective of the study was to examine the effect of different storage periods (2, 24 and 48h) of ovaries at 4 degrees C for maturation of cat oocytes in vitro. Ovaries were collected from 25 domestic cats at various stages of the estrous cyc...
Conference Paper
Transfer of frozen embryos enables the establishment of elite herds, control of diseases and storage of genetic materials for longer periods. However, although intercontinental transfer of frozen embryos is possible, post-thaw degenerations are encountered and pregnancy rates are not at the expected level. Embryos especially degenerate during freez...
Article
Full-text available
In the present study, two new short estrus synchronization methods have been developed for lactating dairy cows. The study was completed in three consecutive phases. In experiment (Exp) 1, 32 cows, that were not detected in estrus since calving between the 50th and 84th post-partum days, were treated with PGF2alpha (PGF, d-cloprostenol, 0.150 mg),...
Article
Full-text available
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 2-4h. A total of 316...
Article
In this study Group I : contained the mineral substances TYH + KCl + CaCl2H2O (standard). Group II : TYH (no mineral substances). Group III : TYH + Co-culture (no mineral substances). Fertilization rate was the highest (75.6%; 102/135) in Group I (P<0.001) followed by Group III (63.5%; 101/159) and than Group II (46.3%; 63 / 136). It was concluded...
Article
Full-text available
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 • C, while the other one at 35–38 • C for 2–4 h. A total of 316 cumulus...
Article
Full-text available
The aim of study is to determine the effects of different transport temperatures (4°C, 32°C) of sheep and cattle ovaries on the in vitro maturation of oocytes. Two experimental groups were formed. Sheep and cattle ovaries were put into saline solution at 32°C. The ovaries were transported to the laboratory, at the same temperature (Group I) or at 4...
Article
Full-text available
Cat semen was extended with 3% and 4% glycerol containing Tris extender and frozen in (0.25 ml) straws. Spermatological characteristics were examined in post-thaw semen samples. Five tom cats aged 2-3 were used. Semen was collected by electro-ejaculator under general anesthesia (xylazine-ketamine HCl combination). On a weekly basis a total of 8 eja...
Article
Full-text available
Cat semen was extended with 3% and 4% glycerol containing Tris extender and frozen in (0.25 ml) straws. Spermatological characteristics were examined in post-thaw semen samples. Five tom cats aged 2-3 were used. Semen was collected by electro-ejaculator under general anesthesia (xylazine-ketamine HCl combination). On a weekly basis a total of 8 eja...
Article
Full-text available
The types and rates of acrosome and other (head, mid-piece and tail) abnormal spermatozoon types were determined by the Spermac¨ staining technique. Semen from 5 stray tom cats under the same management conditions was used. Semen collection was performed under general anesthesia by electro-ejaculator once a week for 5 weeks. After ejaculation the s...