bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ultrastructural Characteristics of Non‐matured and In Vitro Matured Oocytes Collected from Pre‐pubertal and Adult Domestic Cat Ovaries
Authors: Martins LR , Fernandes CB , Minto BW , Landim‐Alvarenga FC , Lopes MD 
Published: July 2009

ContentsThe present study describes the ultrastructural characteristics of cat oocytes before maturation and after 12‐ and 24‐h in vitro maturation (IVM). Oocytes were recovered from pre‐pubertal and adult queen ovaries after ovariohysterectomy and a proportion were stored in glutaraldehyde at 4°C until examination by transmission electronic microscopy (TEM). Those selected for maturation were cultured before TEM in DMEM for 12 and 24 h at 38°C in a humidified environment of 5% O2, 5% CO2 and 90% N2. Specimens were divided into six groups: non‐matured oocytes from pre‐pubertal queens (PP0), non‐matured oocytes from adult queens (A0), 12‐h in vitro matured oocytes from pre‐pubertal queens (PP12), 12‐h in vitro matured oocytes from adult queens (A12), 24‐h in vitro matured oocytes from pre‐pubertal queens (PP24) and 24‐h in vitro matured oocytes from adult queens (A24). Across the treatment groups, it was possible to observe differences in the thickness of the perivitelline space, the penetration of cumulus cell projections forming a junctional complex, distribution and density of small vesicles, lipid droplets, microvilli, mitochondria and cortical granules and variable degrees of development of Golgi complexes. These findings demonstrated that ultrastructural analysis of oocytes matured in vitro is a valuable tool to evaluate oocyte cytoplasmic maturation and that this IVM protocol was efficient in inducing gradual morphological changes necessary for cytoplasmic maturation of pre‐pubertal and adult cat oocytes.
Uterine Progesterone Receptor and Leukaemia Inhibitory Factor mRNA Expression in Canine Pregnancy
Authors: Schäfer‐Somi S , Klein D , Beceriklisoy HB , Sabitzer S , Ay SS , Agaoglu AR , Kücükaslan I , Kaya D , Aksoy OA , Aslan S 
Published: July 2009

ContentsThe study investigated the expression of genes for progesterone receptor (PR) and for the cytokine leukaemia inhibitory factor (LIF) in the uterine tube and uterine horn tissues from pregnant and non‐pregnant bitches. The aim was to study whether a relation existed between the likely biological effectiveness of progesterone (P4) and the change in the uterine expression of LIF mRNA during pregnancy, as has been described in primates. For this purpose, 20 pregnant bitches were ovariohysterectomized after being allotted to three groups according to gestational age (pre‐implantation: days 10 to 12, n = 7; peri‐implantation: days 18 to 25, n = 7; post‐placentation: days 28 to 45, n = 7). Tissue samples were obtained from the uterine tubes, one uterine horn (including placentation sites and interplacental sites in bitches that had already implanted) and the corpus uteri, stored at −80°C, and then analysed by qualitative and quantitative PCR for PR and LIF mRNA expression. From the pre‐implantation to the placentation stage, a decrease in the relative expression of PR mRNA in uterine tissue was obvious and significant when expressed relative to β‐actin (11.2 ± 6.8 vs 2.7 ± 1.9; p < 0.05). However, over the same period, the relative expression of LIF mRNA increased (10.1 ± 16.1 vs 50.0 ± 32.3; p < 0.05). In addition, PR mRNA went from being detectable to no longer detectable in the uterine tube, and no longer detectable in interplacental‐site uterine tissue. We conclude that LIF is important for the establishment of canine pregnancy; that decreased uterine PR mRNA expression may contribute to the increase in uterine LIF mRNA; and, that the ability of the embryo to preserve PR mRNA expression at implantation and placentation sites while expression is lost in the remainder of the uterus represent an effect important to the establishment and maintenance of pregnancy. We additionally propose that canine embryo secretory proteins have a regulatory effect on both PR and LIF before as well as at and after implantation.
The Influence of Oxygen Tension on Cumulus Cell Viability of Canine COCs Matured in High‐Glucose Medium
Authors: Silva AEF , Rodriguez P , Cavalcante LF , Rodrigues BA , Rodrigues JL 
Published: July 2009

ContentsHigh in vitro oxygen (O2) tensions are associated with enhanced levels of reactive oxygen species and cumulus oocyte complex (COC) apoptosis. The objective of this study was to determine the influence of O2 tension on cumulus cell (CC) viability from canine oocytes. Cumulus oocyte complexes were distributed into three groups (CG, T20 and T5) and two O2 tension levels (20% and 5%). The control group (CG) was matured in vitro in a humidified atmosphere with 5% CO2 in air in TCM199 with 26.19 mm sodium bicarbonate, 10% (v/v) foetal calf serum (FCS), 0.10 mm gentamicin, 0.20 mm pyruvic acid, 20 μg/ml oestradiol, 0.5 μg/ml follicle‐stimulating hormone, 0.03 IU/ml human chorionic gonadotropin, and 1.0 μg/ml human somatotropin. Groups T20 and T5 were matured under 20% or 5% O2 tensions respectively in a high‐glucose medium, without FCS. T20 and T5 were as CG, and supplemented with 0.1% Polyvinyl Alcohol, and 5.5 mm glucose. After 48 h of IVM, CCs from COCs were stained with propidium iodide (1.50 mm). The results showed that viability of CCs (cytoplasmic features and nuclear morphological integrity) was different for the three groups. Rates of apoptosis were at 57.9% (521/900) for CG, 54.4% (490/900) for T20 and 38.9% (350/900) for T5 (p < 0.001). Predominant features in apoptotic cells (n = 1361) were DNA nuclear fragments (94.0%). It was concluded that CCs of canine COCs cultured in high‐glucose medium showed significantly less apoptosis than those cultured in medium with FCS. Low O2 tension was efficient in reducing apoptosis in canine CCs.
Tris‐Lecithin Extender Supplemented With Antioxidant Catalase for Chilling of Canine Semen
Authors: Beccaglia M , Anastasi P , Chigioni S , Luvoni GC 
Published: July 2009

ContentsThe aims were to evaluate the suitability of a non‐commercial TRIS‐lecithin (LC) extender and the effect of different concentrations of catalase (CAT) on motility, capacitation status (Chlortetracycline‐assay) and zona pellucida (ZP) binding capacity of canine spermatozoa stored at +5°C for 4 days. The sperm‐rich fractions of the ejaculates of four stud dogs were divided into four aliquots. After centrifugation, sperm pellets were diluted (200 × 106 sperm/ml) in TRIS buffer, citric acid, fructose, antibiotics, supplemented with 20% egg yolk (TRIS‐EY) or 0.04% soybean lecithin (TRIS‐LC) with CAT (150 or 450 UI/ml) or without CAT, and then preserved at 5°C for 4 days. The results showed that LC is a valid alternative to EY for chilling canine semen, as similar rates of motility, number of uncapacitated spermatozoa and of spermatozoa binding the oocyte ZP were obtained in semen chilled in TRIS‐LC or TRIS‐EY. Different concentrations of CAT in a TRIS‐LC based extender did not improve the quality of semen after chilling. However, a concentration of 150 UI/ml CAT resulted in an increased number of spermatozoa bound to the oocyte ZP, after 4 days of chilling when compared to semen chilled with TRIS‐EY and TRIS‐LC. In conclusion, an animal protein‐free extender with soybean LC, as a replacement of EY, is suitable for 4 days chilling of canine spermatozoa, but the addition of CAT does not improve general semen quality except for a slight effect on sperm‐ZP binding.
Follicular Dynamics, Ovulation and Conception Rates in Bitches
Authors: England GCW , Russo M , Freeman SL 
Published: July 2009

ContentsReal‐time ultrasound imaging was used in a clinical study to estimate the number of follicles of different sizes, ovulation and conception rates, and to study follicle dynamics following oestrus‐induction of bitches.Follicles were identified during late anoestrus (between 100 and 60 days prior to the pre‐ovulatory LH surge) and there appeared to be a shift in the population from small follicles (1–3 mm in diameter) to large follicles (>4 mm diameter) approximately 2 days prior to the LH surge. Corpora lutea could be reliably identified although the majority were cavitated. High ovulation rates (97–100%) and pregnant rates (86–100%) were detected, and although the conception rate was approximately 70% it varied between 8 and 92%. Within the narrow range of the clinical population studied there were trends relating age to reproduction performance. Oestrus induction with a gonadotrophin regime appeared to result in large numbers of small follicles that did not ovulate, whilst when using cabergoline the number of small and large follicels and the number of copora lutea were similar to those of control cycles.
Cryopreservation of Canine Semen – New Challenges
Authors: Farstad W 
Published: July 2009

ContentsEgg yolk (EY) protects cell membranes against cold shock, and it prevents or restores the loss of phospholipids from the membrane. EY has been widely used in semen extenders. It has been added to Tris–Glucose buffer and has been widely used for cooling and cryopreservation of canine semen. EY is not a defined entity, but a complex biological compound containing proteins, vitamins, phospholipids, glucose and antioxidants which are all potentially useful for cell membrane integrity. Unfortunately, it also is a biologically hazardous compound. Hence, whole EY needs to be replaced by other chemically defined components for semen processing in dogs. Freezing poor semen does not improve its quality, so attention must be focused on how to cope with dogs whose semen does not freeze well, and on designing individual freezing extenders for semen from such males. Furthermore, differences have been found among canid species in the ability of their spermatozoa to withstand freezing. There are differences in sperm membrane fatty acid composition among species, which may explain part of these differences. If the presence of long‐chained polyunsaturated fatty acids contributes to increased membrane fluidity, this relationship may be biphasic, i.e. either too much membrane fluidity, or too little, could compromise successful sperm cryopreservation. An increase in fluidity of the outer leaflet of the plasma membrane has been shown in frozen thawed dog spermatozoa. The protective effect of exogenous lipids may lie in close association with the membrane rather than in modification or rearrangement of the membrane. This also points at lipids as an important, if not entirely new group of substances, which may substitute standard EY‐based diluents in preserving sperm survival during freezing. EY‐derived phospholipids or lecithin could be used to replace whole EY. Vegetable lecithin is currently investigated to avoid using substances of animal origin. EY also contains antioxidants which prevent cells from oxidative damage due to the generation of reactive oxygen species. An increasing number of publications now recognize the significance of protecting sperm from this damage during processing by using dietary or diluent supplemented antioxidants. This paper aims at looking at some of the new challenges in freezing of dog semen.
Comparison of Selected Endocrine Parameters During Luteal Phase and Pregnancy in German Shepherd Dogs and Beagles
Authors: Günzel‐Apel AR , Beste N , Nottorf S , Eschricht F , Hoppen HO , Dieleman S , Einspanier A 
Published: July 2009

ContentsConcentrations of progesterone, prolactin and relaxin in serum at predetermined intervals after ovulation (day 0) in non‐pregnant and pregnant normocyclic Beagles were assayed and results compared with those observed in German Shepherd dogs (GSD) in a previous study. The goal was to determine possible reproductive hormone specificities related to the GSD breed. Furthermore, the effects of medroxyprogesterone acetate (MPA)‐treatment in non‐pregnant Beagles and of progesterone supplementation in pregnant Beagles on the hormone concentrations were examined. Mean concentrations of progesterone and prolactin were not different in the non‐pregnant Beagles compared with those seen in non‐pregnant GSD, except at days 50–60, when progesterone concentrations were found to be higher in Beagles (p < 0.05). Mean progesterone concentrations in pregnant Beagles at days 50–60 after ovulation (day 0) were higher (p < 0.05) than in GSD at that time, but not at earlier time periods. Prolactin concentrations were higher (p < 0.05) in Beagles throughout pregnancy compared with those in the GSD. Mean relaxin concentrations were numerically but not significantly lower in GSD than in Beagles throughout pregnancy. A 10‐day oral MPA treatment did not affect progesterone or prolactin secretion in normocyclic non‐pregnant Beagles. Medroxyprogesterone acetate serum concentrations were approximately 3.9 ng/ml during treatment and decreased to 0.42 and 0.021 ng/ml within 5 and 15 days after end of treatment, respectively. Intramuscular progesterone supplementation from days 30 to 40 in pregnant Beagles resulted in higher concentrations of progesterone in the 36‐ to 45‐day time periods; prolactin and relaxin concentrations were not significantly affected during or after treatment compared with administration of placebo. The results suggest a tendency towards deficient luteal function in the short‐cycle GSD bitches previously studied, which in pregnancy may reflect the observed decreased prolactin concentrations; the possibility that GSD relaxin secretion is deficiency required needs further study. As oral treatment with MPA did not affect progesterone and prolactin release, it may be useful for studying luteal function in pregnant bitches with suspected hypoluteoidism.
Follicular Morphology, Oocyte Diameter and Localisation of Fibroblast Growth Factors in the Domestic Dog Ovary
Authors: Songsasen N , Fickes A , Pukazhenthi BS , Wildt DE 
Published: July 2009

ContentsRemarkably little is known about folliculogenesis in the dog. Objectives were to characterise (1) changes in follicle/oocyte diameter and granulosa cell number and (2) localisation of fibroblast growth factor (FGF)‐2 and FGF‐7 during dog ovarian follicle development. Fourteen ovarian pairs were excised and processed for histological evaluation. Two to four serial sections/bitch were stained with hematoxylin, and follicle/oocyte diameters and granulosa cell number were determined at each developmental stage. Mean follicle and oocyte size were compared among stages by one‐way analysis of variance. Relationships between follicle and oocyte size and granulosa cell number were determined using correlation and regression analysis, respectively. Another eight serial sections/bitch were processed for immunostaining to determine FGF‐2 and FGF‐7 localisation. Primordial and primary follicles were similar in size, but smaller than the progressively increasing (p < 0.05) diameter of the later stages. Oocyte diameter gradually increased (p < 0.05) among oocytes derived from primordial, primary, secondary and early antral follicles with no difference (p > 0.05) thereafter. Oocyte size and granulosa cell number increased (p < 0.01) with follicular diameter. Except during anoestrus, FGF‐2 occurred in oocytes and granulosa cells of primordial to secondary follicles. In adult bitches, FGF‐7 was localised in granulosa cells of primary and secondary follicles and also occurred in the theca layer of antral follicles during prooestrus and oestrus. In summary, folliculogenesis in the domestic dog occurs in two phases: pre‐antral phase characterised by increasing follicle size in association with oocyte growth and granulosa cell proliferation and antral phase linked with marked granulosa cell proliferation and accumulation of antral cavity fluid. Finally, the temporal localisation pattern of FGF‐2 implies its role in follicular activation, whereas FGF‐7 activities appear related to later folliculogenesis.
Peripartum Haemodynamic Status of Bitches with Normal Birth or Dystocia
Authors: Lúcio CF , Silva LCG , Rodrigues JA , Veiga GAL , Vannucchi CI 
Published: July 2009

ContentsThere has been limited investigation of parturition in the bitch and there is little information published on clinical and obstetrical examination other than opinion and anecdote. While there are substantial data on haemodynamic and vascular changes during normal parturition in humans, little is known about the physiological events in the dog. This study was aimed at maternal haemodynamic changes occurring during normal parturition and to investigate how these were modified in bitches with dystocia (DYST) treated either medically or via assisted delivery and caesarean operation. Three groups of 10 bitches were investigated; those with normal parturition, those with DYST corrected by manipulative assistance or caesarean operation and those with uterine inertia treated by oxytocin administration. Heart rate, systolic and diastolic blood pressure, electrocardiogram and blood glucose concentration were measured pre‐partum, intra‐partum, immediately after parturition and 1 h later. Heart rate was high at all times throughout the study and the majority of bitches had normal sinus rhythm. Blood pressure was generally within the normal range, and although systolic and diastolic blood pressure was highest during the intra‐partum period and sometimes during the immediate post‐partum period, there were no significant differences between groups. All bitches had blood glucose concentrations within the normal range throughout the study although pre‐partum concentrations were statistically lower than many of the other time periods. The study provides useful physiological data that will facilitate monitoring and clinical management of bitches throughout normal parturition and DYST.
Acid–Base Changes in Canine Neonates Following Normal Birth or Dystocia
Authors: Lúcio CF , Silva LCG , Rodrigues JA , Veiga GAL , Vannucchi CI 
Published: July 2009

ContentsThere are limited data concerning blood gas parameters in neonatal dogs. Knowledge of the normal physiology may facilitate effective therapeutic intervention and potentially reduce neonatal mortality. This study examined acid–base parameters in pups born at normal parturition (n = 27) compared with those born after obstetrical assistance or caesarean operation (n = 13) and those born following oxytocin (OXY) administration for treatment of uterine inertia (n = 11). Pups were subjected to an objective scoring method of neonatal health adapted from use in humans (the Apgar score) at birth and again at 5 and 60 min after birth. Venous blood samples were collected at 5 and 60 min after birth for evaluation of blood gas parameters. At birth, all pups had low Apgar scores and a mixed acidosis. The base excess was lowest for pups delivered after OXY administration. The Apgar score improved for all pups after 5 min of birth and there was an improvement in carbon dioxide tension, base excess and venous blood pH at 1 h, although in all pups a metabolic acidosis persisted. These data provide an important insight into neonatal physiology and the variability of blood gas parameters in pups born at normal and abnormal parturition and provide the basis for clinical decision making following dystocia.
Review and Update: Genomic and Molecular Advances in Sex Determination and Differentiation in Small Animals
Authors: Meyers‐Wallen VN 
Published: July 2009

ContentsInherited disorders of sexual development are important to identify as a cause of inherited infertility or sterility in humans and animals. Investigation of these disorders in dogs and cats can identify new mutations, allowing us to eliminate inherited disorders from breeding populations, while contributing to the understanding of mammalian sexual development and differentiation. This review updates an overview of normal mammalian sexual development while discussing disorders of sexual development at three consecutive levels, as errors in sex chromosome constitution, gonadal sex determination or phenotypic sexual development. The molecular mechanisms controlling sexual development and current molecular methods to identify causative mutations are illustrated in three specific examples of abnormal sexual development reported in small animals: XX sex reversal, Persistent Mullerian Duct Syndrome and cryptorchidism. Identification of causative mutations and development of practical tests to identify carrier and affected animals will provide effective mechanisms to reduce the prevalence of these disorders in small animals.
Gonadectomy in Cats and Dogs: A Review of Risks and Benefits
Authors: Reichler IM 
Published: July 2009

ContentsThe necessity, and in particular the timing, of gonadectomy in dogs and cats is still controversial. This is mainly because gonadectomy confers a mixture of benefits and adverse effects that depend upon the age at neutering, sex, species and breed. In this paper, the long‐term risks and benefits of gonadectomy, at various ages, in dogs and cats are reviewed using data describing the effects of desexing on the urogenital tract and on other medical conditions, such as orthopaedic diseases, immune‐mediated diseases, tumour development and behaviour.
Prostatic Perfusion in the Dog Using Contrast‐Enhanced Doppler Ultrasound
Authors: Russo M , Vignoli M , Catone G , Rossi F , Attanasi G , England GCW 
Published: July 2009

ContentsUltrasonography has become the imaging modality of choice for evaluation of the prostate gland in the dog. Unfortunately, despite providing excellent images, it may be difficult to differentiate the common canine prostatic diseases with ultrasound because many have a similar ultrasonographic appearance. Real‐time contrast‐enhanced ultrasound was used to monitor and characterise the normal perfusion pattern and perfusion dynamics of the canine prostate gland when using a micro bubble contrast agent. In all contrast studies, the prostatic artery, entered the prostate gland on the dorso‐lateral surface then tunnelled into the prostatic capsule and branched into many small parenchymal arteries which were directed medially towards the urethra to supply the body of the prostate gland. The flow of the contrast medium into the prostatic parenchyma was visible after 15 s. During the wash‐in phase, there was an homogenous enhancement of the prostatic parenchyma. During the wash‐out phase, an homogenous decrease of the echogenicity was visible in all cases.