Wojciech Niżański

Wojciech Niżański
Wrocław University of Environmental and Life Sciences · Department of Reproductive and Clinic of Farm Animals

Full Professor

About

214
Publications
48,047
Reads
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1,650
Citations
Introduction
I am interested in Assisted Reproduction Technologies in animals as Artificial Insemination, Gamete Cryopreservation, general aspects of Andrology and Embryology. I studied for years methods of semen preservation, semen assessment by CASA and Flow Cytometry, as well as methods of monitoring of estrous cycle and evaluation of reproductive potential. Apart from this I am interested in diagnosis and treatment of fertility disorders.
Additional affiliations
July 2014 - present
Wrocław University of Environmental and Life Sciences
Position
  • Professor
Education
September 1986 - April 1992

Publications

Publications (214)
Article
Benign prostatic hyperplasia (BPH) is one of the most common problems in older male dogs that often has a huge impact on their health and welfare. This article presents a comparison between osaterone acetate (Ypozane®; Virbac®)(OA) and deslorelin acetate (Suprelorin®; Virbac®)(DA), medications that are the main therapeutic alternative to castration...
Article
Cell cycle synchronization of donor cells is an important step in mammalian somatic cell nuclear transfer (SCNT). This study was designed to compare the efficiency of serum starvation (Ss) and contact inhibition (cI) on cell cycle synchronization of jaguarundi, manul, and domestic cat skin fibroblasts, in the production of G0/G1 cells suitable for...
Article
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The perinatal period has a critical impact on viability of the newborns. The variety of factors that can potentially affect the health of a litter during pregnancy, birth, and the first weeks of life requires proper attention from both the breeder and the veterinarian. The health status of puppies can be influenced by various maternal factors, incl...
Article
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The wisent, or European bison (Bison bonasus), belongs to the same family (Bovidae) as the American bison and domestic cattle. The wisent is the largest mammal in Europe, and is called the “Forest Emperor”. The wisent is listed as “Vulnerable” on the IUCN Red List, and is protected by international law. Achievements in reproductive biotechnology ha...
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Disorders of sex development (DSDs) are congenital malformations defined as discrepancies between sex chromosomes and phenotypical sex. Testicular or ovotesticular XX DSDs are frequently observed in female dogs, while monogenic XY DSDs are less frequent. Here, we applied whole genome sequencing (WGS) to search for causative mutations in XX DSD fema...
Article
This study describes, for the first time, the relationship between morphology and ploidy in domestic cat embryos. Blastocyst morphology and quality were assessed using time-lapse recordings, while ploidy was analyzed using fluorescence in situ hybridization. Out of 54 blastocysts, clear fluorescence signals for all the molecular probes used were ob...
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Hypo-osmotic swelling test (HOST) is used to assess the functional integrity of sperm plasma membranes in many species. The primary aim of this study was to test a simplified HOST procedure for the evaluation of feline semen. The second objective was to check if sperm abnormalities can influence the results of this test. Urethral semen was collecte...
Article
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Although artificial reproductive techniques (ART) are considered to be a valuable tool for species conservation, information about their introduction into clinical practice for wild felids is limited. The aim of this paper was to jointly describe cases of non-experimental sperm collection from males of various species of wild felids, performed by t...
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This case report presents an observation of the influence of meloxicam administration, during the periovulatory phase, on corpora lutea function in the domestic dog (Canis familiaris). A 2 year old female German Shepherd dog, with a level of progesterone suggestive of the periovulatory period (5.97 ng/mL), received a single subcutaneous injection o...
Article
Active link before February 24, 2022 https://authors.elsevier.com/a/1eMoW1M2wIBlXu Semen cryopreservation is a key biotechnological strategy used to preserve and protect genetic resources, which are subject to increasingly serious reductions in some species, and to protect animal biodiversity. Assisted reproductive techniques, however, are still n...
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Oxidative stress in sperm is a phenomenon related to the increasing rate of oxidation of cellular components and the excessive production of reactive oxygen species (ROS). The high content of polyunsaturated fatty acids in bird sperm cell membranes renders these cells particularly susceptible to lipid peroxidation (LPO). Therefore, to ensure the pr...
Article
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During the ovarian cycle in domestic dogs, females do not accept males during the first days of estrus but become attractive to males from the beginning of proestrus, with this attractiveness persisting until the end of the estrus phase. It is believed that increased estradiol is responsible for the female attractiveness to the males. In this paper...
Article
The aim of this study was to compare several culture systems for cat embryos. Domestic cat oocytes were matured in vitro (IVM), fertilized (IVF), and cultured individually or in groups in drops under oil (20 μL or 50 μL) and in 16 microwell dishes (Primo Vision®). Moreover, the effects of co-culture with a) uncleaved oocytes, b) homospecific and c)...
Conference Paper
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Most reports on the effect of freezing-thawing procedure on the sperm of red deer concern the Iberian deer. This study investigated the effect of cryopreservation on motility, membrane and DNA in- tegrity of epididymal sperm of European red deer. Samples of sperm were obtained post mortem from cauda epididymis (from 10 bucks). Samples were froz...
Article
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Highly active antiretroviral therapy (HAART) is used in HIV-infected patients. Alongside the prolongation of patients’ life, adverse side effects associated with long-term therapy are becoming an increasing problem. Therefore, optimizing of HAART is extremely important. The study is aimed at evaluating the toxicity of abacavir and etravirine in mon...
Article
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Fluorescence in situ hybridization is a molecular cytogenetics technique that enables the visualization of chromosomes in cells via fluorescently labeled molecular probes specific to selected chromosomes. Despite difficulties in carrying out the FISH technique on sperm, related to the need for proper nuclear chromatin decondensation, this technique...
Article
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Disorders of sex development (DSD) caused by chromosome abnormalities are rarely diagnosed in dogs. In this report, there is a focus on five DSD cases in which the dogs had abnormal karyotypes. All animals were recognized by owners as females, however, these dogs had a large number of reproductive defects. Among these were abnormal external genital...
Article
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Adrenoceptors mediate the action of the sympathetic nervous system, including the contraction of the epididymis and vas deferens. The aim of this study was to immunolocalize the adrenergic receptors in the reproductive tract of the male cat, as this information is not yet available. The epididymis and vas deferens of domestic cats and rats (the bio...
Article
In this study, we investigated the influence of long‐term administration of stiripentol on sex hormones and semen quality in young Wistar rats. Investigated animals received for 6 months either stiripentol or saline solution. After one month, stiripentol increased temporarily serum level of testosterone (p < 0.05) and FSH (p < 0.01). However, after...
Article
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The aim of this study was to analyze the morphokinetic parameters of feline embryos using a time lapse system. Oocytes matured in vitro were fertilized (IVF) and in vitro cultured in a time lapse-system (Primo Vision®, Gothenburg, Sweden). The first cell division of embryos occurred between 17 h post insemination (hpi) and 38 hpi, with the highest...
Article
Urethral catheterisation after medetomidine administration is the method of choice for semen collection in cats, but it yields variable results. This study tested whether scrotal manual stimulation can improve urethral sperm collection in domestic cats. The study was performed on 20 male cats, from which two urethral semen samples were collected, o...
Article
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The article presents the results of the clinical evaluation (Apgar scores, AS) and umbilical cord blood gas analysis (UCBGA) obtained from clamped umbilical cords of newborn pups delivered by the elective Caesarean section. The study was planned as a controlled clinical study, the newborns were allocated into one of the groups, I—critical neonates...
Article
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Shear wave elastography (SWE) can be useful to discriminate between malignant and benign mammary tumors. In dogs with elevated progesterone levels compared to the baseline and fast-growing tumors, treatment with the use of aglepristone allows for tumor size reduction, which facilitates surgery. This study aimed to evaluate the influence of the preo...
Article
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Apoptosis is a crucial process in spermatogenesis, responsible for the elimination of abnormal sperm cells and testicular regression out of breeding season. The aim of this study was to assess if the expression of apoptosis-related genes in testicular tissue of domestic cats differed: (1) between normozoospermic and teratozoospermic donors, and (2)...
Article
Ultrasonographic fetal biometry is a technique used in both human and veterinary medicine to predict parturition time and evaluate fetal development. In domestic cats, the parameters that have been examined so far are the inner chorionic cavity diameter (ICC), biparietal diameter (BPD), deep portion of diencephalotelencephalic vesicle (DPTV), femur...
Article
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The current population of wisents (Bison bonasus, Linnaeus 1758) originates from only 12 individuals that survived World War II in zoos and private enclosures. For better preservation of genetic variability, research is being conducted to introduce assisted reproductive techniques in this species. In this article, we describe the current state of k...
Article
Full-text available
The aim of the study was to compare the morphology and developmental potential of oocytes obtained from adult and prepubertal domestic cats (Felis catus) and wild cats (Lynx lynx, Leptailurus serval, Felis manul, Panthera tigris altaica). The average number of oocytes obtained from an adult domestic cat was 23 ± 11, which was significantly lower th...
Article
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This article presents B-mode and color Doppler imaging of the prostate and testes in dogs suffering from benign prostate hyperplasia (BPH), and receiving deslorelin acetate (SuprelorinTM) or osaterone acetate (YpozaneTM). The study was planned as a controlled clinical trial, dogs were divided into negative control (healthy dogs, n = 10), positive c...
Article
Disorders of sex development (DSD) are important causes of infertility and sterility, and are risk factors for gonadal carcinogenesis. Many DSDs are caused by genetic factors, mainly sex chromosome abnormalities or mutations of genes involved in sexual development, as well as structural variants (SVs) - large deletions, duplications, and insertions...
Article
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Acute phase proteins are blood components synthesized by hepatocytes, basic function of which is to defend the organism as part of the immune response to infl ammation, trauma, infection, stress, neoplasia. They trigger a complex systemic reaction in order to restore homeostasis recovery of the organism. Proinfl ammatory cytokines increase their ac...
Article
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This study aimed to assess the mechanisms of semiochemical signal detection in dogs. In the first experiment, five males were exposed to volatile semiochemicals emitted by a live female in estrus and the female’s urine sample collected during estrus. The odor of canine food and clean air were used as controls. In the second experiment, 25 males cou...
Article
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This article presents the results of a randomized clinical trial, designed to compare the efficacy and therapeutic profiles of YpozaneTM (osaterone acetate—OA) or SuprelorinTM (deslorelin acetate—DA) in male dogs with clinical signs of benign prostate hyperplasia (BPH). Forty-five intact male dogs were used in the study. The Group I (negative contr...
Article
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This article presents a retrospective study on dystocia cases in bitches that were unintentionally mated and carried an unwanted pregnancy in the last 39 years. The evaluated medical records include 76 cases of difficult labour, which is 8.3% of 914 dystocia cases recorded during the period. Of these bitches, 38.2% (29/76) were 8 years, and 18.4% (...
Article
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Cryopreservation is important for animal fertility and biodiversity. Unfortunately, cryopreservation of feline oocytes is still an experimental technique. The aims of this study were to analyze the potential toxicity of the cryoprotectants in the vitrification solution (VS) on cat oocytes and to investigate whether the meiotic status of oocytes inf...
Article
Domestic cats are frequently used as a research model for felid species that are threatened with extinction. Until now, the development of feline embryos has been evaluated using both classical observation methods and time-lapse monitoring (TLM). Blastocyst collapse observed using time-lapse cinematography is used as a predictor of blastocyst quali...
Article
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The chemokine chemerin is a novel adipokine involved in the regulation of energy metabolism but also female reproductive functions in mammals. Its effects on male fertility are less studied. Here, we investigated the involvement of chemerin in chicken male reproduction. Indeed, the improvement of the sperm of roosters is a challenge for the breeder...
Article
The aim of this study was to evaluate the applicability of the Cryotech technique for the vitrification of domestic cat (Felis catus) oocytes, as a model for other feline species threatened with extinction. This technique, in which oocytes are stored in a minimal volume of medium, is already widely used in human assisted reproductive technology. In...
Article
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During the early stages of pregnancy, the uterine endometrium undergoes dramatic morphologic and functional changes accompanied with dynamic variation in gene expression. Pregnancy-stage specific differentially expressed gene (DEG)-transcript-probes were investigated and identified by comparing endometrium transcriptome at 9th day (9D), 12th day (1...
Article
Disorders of sex development (DSD) are a well-known cause of sterility and reduced fertility in dogs. Here, we report on 6 new cases of DSD in French bulldogs diagnosed by us within the last year. The animals were phenotypical females who underwent detailed diagnosis due to the presence of an enlarged clitoris or a penis-like structure with atypica...
Article
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According to current knowledge, the vomeronasal organ (VNO, Jacobson's organ) is the structure responsible for semiochemical signal detection. In dogs and other mammals, it is located close to the vomer and palatine processes of the incisive and maxillary bones. Although there are reports describing the anatomy and histology of this structure, ther...
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The knowledge of the existing levels and the interrelationships between various blood and milk parameters is very useful for the analysis and monitoring of homeostasis high-yielding dairy cows. The aim of the study was to evaluate these values and correlations for selected blood markers of liver function aspartate aminotransferase (AST), alanine am...
Article
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Sperm cryopreservation is an assisted reproductive technique routinely used in canine species for genetic conservation. However, during cryopreservation, the DNA damages are still elevated, limiting the fertilization rate. The present study was conducted to evaluate whether supplementation of canine semen extender with a molecule limiting the metab...
Article
The binding of seminal plasma (SP) proteins by spermatozoa plays an important role in the regulation of sperm epididymal maturation, motility gaining in female reproductive tracts and sperm-egg interaction. The aim of the study was to analyze the SP and sperm extracts proteome of cat (Felis catus) semen. The seminal plasma and spermatozoa were obta...
Article
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Some human, bovine, and mouse in vitro fertilized (IVF) embryos with morphokinetic abnormalities such as fragmentation, direct cleavage, and cytoplasmic vacuoles have the potential to reach the blastocyst stage, which is related to a high potential for implantation. The latest techniques of embryo development observation to enable the evaluation an...
Article
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Reactive oxygen species (ROS) and free radicals are one of the major detrimental factors that can negatively affect the quality of sperm during cryopreservation. Melatonin is an effective antioxidant and free radical scavenger in various cells. In this study, therefore, the aim was to evaluate the post-thawed quality of spermatozoa after cryopreser...
Article
The genetic background of disorders of sex development (DSD) in dogs with a normal male sex chromosome set (78,XY) is poorly described. In this study, we present for the first time, an analysis of six genes of the testosterone pathway, encoding enzymes (CYP17A1, HSD3B2, HSD17B3, SRD5A2) and transcription factors (NR5A1, AR). The entire coding seque...
Article
Full-text available
With the exception of the domestic cat, all felid species ( Felidae ) are currently threatened with extinction in their natural habitat. To develop effective and optimal wild cat conservation programmes with assisted reproductive technology (ART) it is necessary to combine advances from different disciplines of science, starting from the biology of...
Article
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Background: Vitrification by Rapid-I method could be essential for felid rescue programs to protect wild felid in the future. Objective: This study was aimed at adapting the Rapid I method and evaluating the viability of serval and Pallas cat oocytes compared to oocytes of the domestic cat. Materials and methods: Oocytes after collection and i...
Article
Prostate cancer is the most common prostate disease diagnosed in castrated dogs. However, prostate cancer is considered to be quite rare in dog population. The presence of prostate tumours can lead to urethral obstruction. Other clinical signs include asymmetric, painful, hard growths on rectal examination, neurological deficit or lameness of the p...
Article
Full-text available
Testicular or ovotesticular disorders of sex development (DSD) in individuals with female karyotype (XX) lacking the SRY gene has been observed in several mammalian species, including dogs. A genetic background for this abnormality has been extensively sought, and the region harboring the SOX9 gene has often been considered key in canine DSD. Three...
Article
Aim: The aim of this study was to analyze the effect of bovine follicular fluid on the survival, morphology and kinetic parameters of bovine thawed spermatozoa under laboratory conditions. Materials and methods: The semen from 5 bulls of proven fertility was incubated in follicular and physiological fluid for 8 hours. During this time assessment...
Article
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Dermal fibroblasts are commonly used as donors of genetic material for somatic cell nuclear transfer in mammals. Basic fibroblast growth factor (bFGF) is a cytokine that regulates proliferation and differentiation of different cell types. The study was aimed at optimizing the cell culture protocol for cat dermal fibroblasts by assessing the influen...
Article
The aim of this study was to examine the suitability of commercial media designed for humans and cattle for oocyte maturation and embryo culture in the domestic cat. In Exp. I, feline oocytes collected ex vivo were subjected to in vitro maturation in a laboratory‐made culture medium (based on M199) or a commercial medium designed for cattle cells (...
Article
Full-text available
Clinical signs of prostatic diseases in dogs are often non‐specific. Appropriate treatment should be based on a detailed investigation using reliable diagnostic tools. The aim of our study was to evaluate the diagnostic value of ultrasonography (US) and fine‐needle aspiration (FNA) cytology in dogs' prostate diseases. The mean accuracy of FNA cytol...
Article
This study assessed the most suitable behavioral test for discrimination of the odor of female dog urine during estrus and anestrus, to identify chemical compounds acting as female pheromones. Twelve male dogs were used for testing. Urine samples were collected from 16 females in estrus, 5 females in anestrus, 5 spayed females, and 8 males. In test...
Article
The aim of this study was to analyze the influence of the type of spermatozoa and of different sperm abnormalities on fertilization and embryo development after ICSI in cats. In Exp I, ICSI was performed using urethral or epididymal spermatozoa collected from 7 tomcats. In Exp. II, epididymal spermatozoa from 16 cats were used for ICSI and an epidi...
Article
The genetic background of disorders of sex development (DSDs) in cats is poorly understood, due to a relatively low number of such studies in this species. Here we present three new DSD cases with different complements of sex chromosomes. The first, an Oriental Shorthair cat with a rudimentary penis, abdominal atrophic testicles and lack of uterus...
Article
Thermography is one of the most modern methods for non-invasive monitoring of animal behavior, health status and physiological state. The sparcity of scientific reports related to this subject in fur animals prompted the use of thermography in Chinchilla lanigera. The aim of the study was to evaluate the use of a thermal imaging camera to diagnose...
Article
More than hundred urine samples, vaginal secretions, vulval and anal imprints as well as anal sac secretions, collected during various phases of the ovarian cycle, were evaluated with the HS-SPME/GC-MS technique. The results indicate there were differences among samples of urine collected during particular phases of the ovarian cycle. Unequivocally...
Article
Hypospadias, the abnormal position of the urethral orifice, is considered a rare congenital malformation of the reproductive organs in male dogs. We present 5 new cases of hypospadias - 2 of the penile type in German Shepherd Dogs and 3 perineal types in a Bavarian Mountain Hound, a French Bulldog, and an American Staffordshire Terrier. Other abnor...
Article
This study was designed to test if treating chicken sperm with i) the cyclodextrins 2-hydroxypropyl-β-cyclodextrin (HBCD) and methyl-β-cyclodextrin (MBCD) alone improve fresh, liquid-stored and cryopreserved semen quality, or ii) cholesterol-loaded cyclodextrins (CLCs): 2-hydroxypropyl-β-cyclodextrin loaded with cholesterol (HCLC) and methyl-β-cycl...
Article
Full-text available
The aim of this study was to evaluate the influence of a vitrification-warming procedure on the viability of cat embryos and blastocysts and the incidence of apoptotic changes in blastocysts subjected to vitrification and blastocyst that developed from vitrified embryos. In the first part of the experiment, post-thaw embryo development and blastocy...