Ex vivo influence of carbetocin on equine myometrial muscles and comparison with oxytocin.

To determine the intercyclic effect of oxytocin and carbetocin on equine myometrial tissue, the effect of the drugs was evaluated through pharmacokinetic and pharmacodynamic studies. The complete pharmacokinetic profile for oxytocin was unknown and had to be established. To do so, 25 IU of oxytocin were administered intravenously to six cycling mares and blood samples were collected before and 2, 4, 8, and 15 min after administration. The half-life of oxytocin was determined to be 5.89 min, the clearance rate 11.67 L/min, mean residence time (MRT) 7.78 min. The effective plasma concentration was estimated to be 0.25 ng/mL. This was similar to the concentration achieved for the organ bath study where the concentration that produced 50% of the maximum effect (EC(50)) was calculated at 0.45 ng/mL. To determine the intercyclic effect of oxytocin and carbetocin uterine myometrial samples were collected from slaughtered mares in estrus, diestrus, and anestrus. The samples were mounted in organ baths and exposed to four ascending, cumulative doses of oxytocin and carbetocin. Area under the curve and amplitude, maximum response (E(max)), and concentration that produced 50% of the maximum effect were studied for each agonist and statistically evaluated. The effect of oxytocin on equine myometrial tissue was higher during diestrus, and surprisingly anestrus, than during estrus, whereas the effect of carbetocin was the same independent of the stage of estrous cycle. A significant difference was found for estrous and anestrous samples when oxytocin was used but not when carbetocin was used.

[The use of a GnRH vaccine in mares and stallions to influence undesirable behavior: a retrospective study of 31 cases]. / Einsatz einer GnRH-Vakzine bei Stute und Hengst zur Beeinflussung von unerwünschtem Verhalten: Eine retrospektive Studie von 31 Fällen.

The aim of this study was to investigate the effect of a GnRH vaccine (Equity) on behavior and gonadal function in horses with unwanted behavior. The reason for the treatment was asked using a questionnaire and the findings of physical examination, rectal palpation as well as rectal ultrasonography, were recorded. The results of these examinations and the behavior of 21 mares and 10 stallions before the first and after the second administration of the GnRH vaccine were compared. In 84 % of all cases a decrease of the unwanted behavior could be observed. In the mares the ovaries were significantly (p

Influence of seminal plasma on fertility of fresh and frozen-thawed stallion epididymal spermatozoa.

The use of epididymal stallion spermatozoa for routine artificial insemination can secure easy future use of valuable genetics after unforeseen death or injury of a valuable stallion. The aims of this study were to (1) directly compare pregnancy rates for fresh and frozen-thawed stallion epididymal and ejaculated spermatozoa after conventional artificial insemination and (2) to investigate the effect of seminal plasma on the fertility of epididymal spermatozoa after insemination. Twenty-one mares were randomly assigned to three stallions. Mares were inseminated at five consecutive oestrous periods using fresh ejaculated spermatozoa (Fr-E, n=18), fresh epididymal spermatozoa that had been exposed to seminal plasma (Fr-SP+, n=12) or fresh epididymal spermatozoa that had never been exposed to seminal plasma (Fr-SP-, n=9), frozen-thawed ejaculated spermatozoa (Cr-E, n=18), frozen-thawed epididymal spermatozoa that had been exposed to seminal plasma prior to freezing (Cr-SP+, n=18) and frozen-thawed epididymal spermatozoa that had never been exposed to seminal plasma (Cr-SP-, n=15). Pregnancy examinations were performed 14 days after each ovulation. Pregnancy rates were 55.6% (Fr-E, 10/18), 75% (Fr-SP+, 9/12), 22.2% (Fr-SP-, 2/9), 38.9% (Cr-E, 7/18), 27.8% (Cr-SP+, 5/18) and 6.7% (Cr-SP-, 1/15). Overall pregnancy rates for fresh and frozen-thawed epididymal spermatozoa that had been exposed to seminal plasma were significantly better than for epididymal spermatozoa that had never been exposed to seminal plasma (P<0.05). We conclude that the exposure of stallion epididymal spermatozoa to seminal plasma improves pregnancy rates.

Fixed-time AI pregnancy rate following insemination with frozen-thawed or fresh-extended semen in progesterone supplemented CO-Synch protocol in beef cows.

The objective of this study was to compare fixed-time AI pregnancy rate in Angus crossbred beef cows inseminated with frozen-thawed or fresh-extended semen. Two ejaculates from each of two Angus bulls were collected by artificial vagina and pooled for each bull. The pooled semen from each bull was divided into two aliquots; Aliquot 1 was extended using Caprogen (LIC, Hamilton, New Zealand) to a concentration of 3 x 10(6)sperm/straw and Aliquot 2 was extended using egg-yolk-glycerol extender to a concentration of 20 x 10(6)sperm/straw. Semen extended with Caprogen was maintained at ambient temperature and semen extended with egg-yolk-glycerol extender was frozen and maintained at -196 degrees C until insemination. In each of two breeding seasons (Fall 2007 and Spring 2008), Angus-crossbeef cows (N=1455) at 12 locations were randomly assigned within location to semen type [Fresh (N=736) vs. Frozen (N=719)] and sire [1 (N=731) vs. 2 (N=724)]. All cows were synchronized with 100 microg of GnRH im and a progesterone Controlled Internal Drug Release insert (CIDR) on Day 0, and on Day 7, 25mg of PGF2(alpha) im and CIDR removal. All cows received 100 microg of GnRH im and were inseminated at a fixed-time on Day 10, 66 h after CIDR removal. Timed-AI pregnancy rates were influenced by season (P<0.05), cows detected in estrus prior to and at AI (P<0.001), and dam age (P<0.01). Pregnancy rates were not affected by semen type (Fresh=51.5% vs. Frozen=50.4%; P=0.66) and there were no significant interactions of semen type by estrus expression, semen type by sire, or semen type by season (P>0.1). In conclusion, commercial beef cows inseminated with fresh-extended semen (3 x 10(6)sperm/straw) yielded comparable pregnancy rates to conventional frozen-thawed semen in a progesterone supplemented, CO-Synch fixed-time AI synchronization protocol and may provide an alternate to frozen semen for more efficient utilization of superior genetics.

Influence of long-term treatment with equine somatotropin (EquiGen) on gonadal function in stallions with poor semen quality.

The aim of the present study was to investigate the spermatogenic and Leydig cell activity in stallions with impaired semen quality after treatment with equine somatotropin. Experiments were performed using 18 adult clinically healthy stallions with poor semen quality which did not pass breeding soundness evaluation. The animals were randomly divided into a treatment (n = 9) and a control (n = 9) group. Over a period of 90 days, nine stallions received a daily intramuscular injection of 10 mg recombinant equine somatotropin (EquiGen, BresaGen Limited, Adelaide, Australia) and 9 control animals were injected with the same amount of physiological saline solution. During and until 2 months after treatment, semen characteristics and daily sperm output as well as plasma testosterone concentrations were determined monthly in all stallions. In addition, testosterone concentration measurement after stimulation with hCG was performed in all animals immediately before and at the end of the treatment period as well as 2 months later. Our results demonstrate that equine somatotropin (EquiGen) given daily in a dose of 10 mg per animal during 90 days had no significant effect neither on plasma testosterone concentrations and hCG-induced testosterone release nor on semen quality parameters in adult stallions with poor semen characteristics.

Monitoring the bovine fetus during stage II of parturition using pulse oximetry.

Measurement of oxygen saturation using pulse oximetry is an established method of continuous monitoring of the well-being of the human fetus during parturition. In veterinary medicine, pulse oximetry has been used almost exclusively in intensive care and anesthesiology. The goal of the present study was to investigate the physiological changes in oxygen saturation of the bovine fetus during stage II of parturition and to determine whether the findings can be used to predict postnatal acidosis. The correlation between the oxygen saturation (SpO(2)) measured via pulse oximetry and the oxygen saturation (SaO(2)) of arterial blood measured via blood gas analysis was determined in 23 newborn calves. In addition, the oxygen saturation was monitored continuously via pulse oximetry (FSpO(2)) in 33 bovine fetuses during stage II of parturition. Correlations between the FSpO(2) values during the last 30 and 5min of stage II of parturition and the postpartum values for pH, partial pressures of oxygen and carbon dioxide, bicarbonate concentration, BE, SaO(2) and lactate concentration in arterial blood were determined. There was a high correlation between SpO(2) and SaO(2) postpartum (r=0.923). The FSpO(2) values correlated moderately with the pH and BE and weakly with the lactate concentration postpartum; calves with a pH<7.2, a BE<-3mM/L or a lactate concentration of >5.4mM/L had significantly lower FSpO(2) values than non-acidotic calves. FSpO(2) values <30% for a period of at least 2min had the highest predictive value for a calf born with a pH<7.2. Pulse oximetry is a novel method of monitoring the bovine fetus during parturition; however, technical modifications are required to improve its usefulness.

Blood gas analysis of bovine fetal capillary blood during stage II labor.

The aim of this study was to determine whether blood gas variables in fetal capillary blood during the last 30 min of stage II labor can be used to diagnose fetal asphyxia. Twenty-five newborn calves were used to investigate the correlation between capillary blood gas values obtained from the dorsolateral aspect of the distal pastern and those in arterial and venous blood. The pH, partial pressure of oxygen, partial pressure of carbon dioxide, concentration of bicarbonate, base excess and oxygen saturation were determined. The bicarbonate concentration (arterial, r=0.759; venous, r=0.766; both P<0.0001) and base excess (arterial, r=0.730; venous, r=0.807; both P<0.0001) had the highest correlations. Fetal capillary blood was collected during the last 30 min of stage II labor and the results of blood gas analysis were compared with those of arterial and venous blood collected immediately after birth in 38 calves. The pH (arterial, r=0.806; venous, r=0.885; both P<0.0001) and base excess (arterial, r=0.822; venous, r=0.871; both P<0.0001) had the highest correlations. The pH and base excess were significantly lower after birth than during the last 30 min of stage II labor. The severity of fetal acidosis during stage II labor can be easily and reliably determined using the pH or base excess of fetal capillary blood.

Blood gas and acid-base analysis of arterial blood in 57 newborn calves.

The pH, partial pressure of oxygen (pO(2)), partial pressure of carbon dioxide (pCO(2)), concentration of bicarbonate (HCO(3)(-)), base excess and oxygen saturation (SO(2)) were measured in venous and arterial blood from 57 newborn calves from 55 dams. Blood samples were collected immediately after birth and 30 minutes, four, 12 and 24 hours later from a jugular vein and a caudal auricular artery. The mean (sd) pO(2) and SO(2) of arterial blood increased from 45.31 (16.02) mmHg and 64.16 (20.82) per cent at birth to a maximum of 71.89 (8.32) mmHg and 92.81 (2.32) per cent 12 hours after birth, respectively. During the same period, the arterial pCO(2) decreased from 57.31 (4.98) mmHg to 43.74 (4.75) mmHg. The correlation coefficients for arterial and venous blood were r=0.86 for pH, r=0.85 for base excess and r=0.76 for HCO(3)(-). The calves with a venous blood pH of less than 7.2 immediately after birth had significantly lower base excess and HCO(3)(-) concentrations for 30 minutes after birth than the calves with a venous blood pH of 7.2 or higher. In contrast, the arterial pO(2) was higher in the calves with a blood pH of less than 7.2 than in those with a higher pH for 30 minutes after birth.

Ultrasonic transit-time measurement of blood flow in the umbilical arteries and veins in the bovine fetus during stage II of labor.

The vitality of the bovine fetus during parturition depends on an intact umbilical circulation to supply adequate amounts of oxygen and nutrients to the fetus. The goal of the present study was to measure the blood flow in the umbilical vessels during stage II of labor and to determine when blood flow ceases in the umbilical cord. In 20 cows, ultrasonographic transducers were placed on one umbilical vein and one umbilical artery after rupture of the allantochorionic sac, and the blood flow volume per unit time was measured. At the same time, a pressure transducer was placed into the uterus to measure uterine pressure. Parturition was spontaneous in all 20 cows. In 20 live calves born, pH, base excess and lactate concentration were measured in the blood immediately after birth. During the last 90 min before birth the mean total umbilical blood flow (artery and vein combined) was 1.186+/-0.028 L/min. Calves with a blood pH> or =7.2 (n=13) had a higher mean total blood flow than calves with a pH<7.2 (n=7; 1.243+/-0.038 versus 1.095+/-0.038 L/min). In calves with a blood pH<7.2, the mean total blood flow decreased from 1.178+/-0.134 at 20 min before birth to 0.959+/-0.126 L/min at the end of stage II of labor. During this time period, the arterial blood flow did not differ between calves with a blood pH> or =7.2 and<7.2, but venous blood flow decreased significantly in calves with a blood pH<7.2. During uterine contractions, the total umbilical blood flow decreased significantly by 0.22 L/min. The blood flow in the umbilical artery and vein ceased before the calves were completely born.

Clinical, cytogenetic and hormonal findings in a stallion with hypospadias--a case report.

This case report describes a three-year-old Friesian stallion with hypospadias. Physical examination revealed a ventrocaudal deviation of the shaft of the penis and an incomplete glans penis. The urethral opening was 4 cm in length, slit-like and had a mucous membrane covering. A short fold ran from the ventral aspect of the anus and ended with a non-pigmented hairless area of skin. A human choriongonadotropin (hCG)-stimulation test resulted in an increase in the plasma levels of estrogen sulfate and testosterone, indistinguishable from that of a normal stallion. The karyogram had a normal number of chromosomes at 2n=64. The stallion was castrated, and histological evaluation of the testicular tissue was unremarkable. In contrast to other animal species and human beings, hypospadias is a rare congenital abnormality in stallions, the cause of which could not be elucidated in our patient.

Electrolytes in bovine prepartum mammary secretions and their usefulness for predicting parturition.

Accurately predicting parturition in cows can be difficult because of the variability in gestation length and uncertainty of the time of parturition. The goal of the present study was to determine the electrolyte concentrations of prepartum mammary secretions of gravid cows and to investigate retrospectively the possible predictive relationships between these concentrations and the time of parturition. Twenty-three cows were sampled once daily for 3 to 12 d before they calved. The concentrations of calcium, inorganic phosphorus, chloride, magnesium, sodium, and potassium were determined by photometric methods. In addition, the concentrations of calcium, magnesium, and inorganic phosphorus were determined using rapid test kits. The correlation between the photometrically measured electrolyte concentrations and the time of parturition was highest for inorganic phosphorus (r = 0.74). The inorganic phosphorus concentration was 11.8 to 26.5 mmol/L in cows that calved within 24 h of sample collection. When 11.8 mmol/L was used as a cutoff concentration for inorganic phosphorus, 21.7, 47.8, and 87.0% of cows calved within 24, 48, and 72 h, respectively. Within 12 d prepartum, the time of parturition can be estimated, with an error of +/- 32.4 h, by using the results of simultaneous determination of inorganic phosphorus and sodium concentrations in mammary secretions and a formula derived from a multiple regression analysis. The results of a phosphate field test positively and significantly correlated with those of the photometric analysis (r = 0.69) and the time of parturition (r = 0.41).

Influence of estradiol on adrenal activity in ovariectomized cows during acute stress.

Stress-dependent activation of the hypothalamo-pituitary-adrenal axis (HPA) can compromise reproductive function in animals and humans. In addition, it has been shown that estrogens are also capable of influencing the activity of the adrenal cortex. The objective of this study was to evaluate the effect of estradiol (E2) on adrenocortical secretion of cortisol and progesterone as well as on pituitary LH-release in cows during stress. Five ovariectomized Brown Swiss cows were exposed to acute restraint stress (2-h immobilization in a trimming chute), either with or without E2 treatment. Blood samples were taken every 15 min during a 5-h period for determination of cortisol progesterone and LH. Our results demonstrate that during the 2-h stress period mean cortisol concentrations significantly (P < 0.05) increased in all cows independent of E2 treatment. Mean progesterone concentrations also increased during stress, but the effect was only significant in E2-untreated cows. In contrast to cortisol and progesterone, mean LH values decreased in all animals during stress, but the decline was not significant. However, significantly lower mean LH values were seen at the end of the stress period comparing to values before stress. In cows without stress, E2 treatment had no significant effect on mean values of all three hormones analyzed. From our results it can be concluded that in ovariectomized cows (a) acute stress increases cortisol and progesterone secretion but decreases LH release and (b) the stress induced adrenocortical and pituitary responses were clearly attenuated under the influence of estradiol.

Laparoscopic ovariectomy in standing cows.

The main objective of this study was to evaluate laparoscopic ovariectomy and to develop an optimal surgical technique for this procedure in standing cattle. Eight cows underwent laparoscopic ovariectomy. In two cows, a bilateral flank approach was used and in six cows, both ovaries were removed via a left flank approach. An important prerequisite for ensuring sufficient intrabdominal space for instrumentation, optimal endoscopic orientation and easy access to the ovaries and uterus was withholding feed for at least 36 h prior to surgery. The cows were sedated with xylazine and the portal sites infiltrated with lidocaine. The portal for the laparoscope was at the ventral angle of the left paralumbar fossa, approximately 10 cm cranioventral to the tuber coxae. The instruments were inserted through two portals approximately 20 cm and 30 cm ventral to the tuber coxae. After abdominal insufflation with carbon dioxide, the left ovary was grasped and local anesthetic was injected into the mesovarium and mesosalpinx. The mesovarium was transected using bipolar cauterization and the ovary removed through an extended instrument portal. The right ovary was removed in the same way. The incisions were closed with single interrupted absorbable sutures in the musculature and single interrupted non-absorbable sutures in the skin. The procedure lasted 120-150 min. Bilateral laparoscopic ovariectomy via left flank approach in standing cows is feasible. This procedure involves special instrumentation, but is minimally invasive and allows optimal visualization of the ovaries and uterus.

A host-specific bacteria-to-plant signal molecule (Nod factor) enhances germination and early growth of diverse crop plants.

Lipo-chitooligosaccharides (LCOs), or Nod factors, are host-specific bacteria-to-plant signal molecules essential for the establishment of a successful N(2)-fixing legume-rhizobia symbiosis. At submicromolar concentrations Nod factors induce physiological changes in host and non-host plants. Here we show that the Nod factor Nod Bj V(C18:1,MeFuc) of Bradyrhizobium japonicum 532C enhances germination of a variety of economically important plants belonging to diverse botanical families: Zea mays, Oryza sativa (Poaceae), Beta vulgaris (Chenopodaceae), Glycine max, Phaseolus vulgaris (Fabaceae), and Gossypium hirsutum (Malvaceae), under laboratory, greenhouse and field conditions. Similar increases in germination were observed for filtrates of genistein-induced cultures of B. japonicum 532C, while non-induced B. japonicum, induced Bj 168 (a nodC mutant of B. japonicum deficient in Nod factor synthesis) or the pentamer of chitin did not invoke such responses, demonstrating the role of Nod factor in the observed effects. In addition, three out of four synthetic LCOs evaluated also promoted germination of corn, soybean and Arabidopsis thaliana seeds. LCO also enhanced the early growth of corn seedlings under greenhouse conditions. These findings suggest the possible use of LCOs for improved crop production.

Repair of triplex-directed DNA alkylation by nucleotide excision repair.

Triplex-forming oligonucleotides (TFOs) are being investigated as highly specific DNA binding agents to inhibit the expression of clinically relevant genes. So far, they have been shown to inhibit transcription from the HER-2/neu gene in vitro, whereas their use in vivo has been studied to a limited extent. This study uses a TFO-chlorambucil (chl) conjugate capable of forming site-specific covalent guanine adducts within the HER-2/neu promoter. We demonstrate that nucleotide excision repair (NER) represents a mechanism of cellular resistance to TFO-directed DNA alkylation. In vitro repair assays demonstrate that triplex-directed chl-guanine adducts are substrates for repair by NER competent cell extracts but not XP12BE cell extracts deficient in NER. The degree of repair is estimated by a ligation-mediated polymerase chain reaction with a pre-formed triplex in a plasmid transfected into repair competent cells, indicating that approximately 25% of the guanine adducts are removed after 24 h. These data indicate that guanine adducts from TFO-directed alkylation are a substrate for NER and that DNA repair is a significant barrier to the intracellular persistence of target gene binding by TFOs.

Change in the therapist: the role of patient-induced inspiration.

Clinicians experience positive changes in emotion, cognition, and behavior that they attribute to their work with particular patients. This process of change is termed inspiration. The goals of this study are: (1) to demonstrate that clinicians report being inspired by certain patients; (2) to compare inspiring and noninspiring patients regarding the strength of the therapeutic alliance; (3) to explore how the therapist changes as a result of working with the inspiring patient, and (4) to investigate what patient factors are inspiring. Of 300 randomly selected NASW members in the New York metropolitan area working in mental health settings, 84 completed a survey about inspiring and noninspiring patients that included the Working Alliance Inventory. Of these participants, 59 provided narrative responses about ways in which they have changed as a result of their work with inspiring patients. Inspiring patient factors were described by 37. The therapeutic alliance with the inspiring patient was found to be stronger than that with the noninspiring patient. Clinicians described various changes in personal and professional realms. In addition, specific patient factors such as perseverance and the ability to overcome serious obstacles were described as inspiring. The process of inspiration and implication of the findings in this study are discussed.