Detection of testosterone, nandrolone and precursors in horse hair.

Growing interest among several horse-breeder associations has initiated the development of a screening procedure to test for anabolic agents in hair, which has the advantage over blood and urine specimens of allowing long-term detection. An analytical method was established to monitor in tails or manes several anabolic substances available as veterinary medicines or as so-called nutritional supplements (clenbuterol, different esters or prohormones of nandrolone and testosterone). The analytical procedure to detect steroids in hair samples consists of the following steps: decontamination of the hair strand or segment with methanol/water (1:1), milling, extraction of the hair material in an ultrasonic bath using methanol, purification by liquid-liquid extraction (n-pentane/methanol, 25:1) and HPLC cleanup, derivatisation of the relevant LC fractions with MSTFA, and measurement using GC-MS/MS technique.

A new tool to monitor training and performance of sport horses using global positioning system (GPS) with integrated GSM capabilities.

Global Positioning Systems (GPS) are considered suitable to monitor the position and velocity of horses during cross-country competition or in training. Furthermore, simultaneous recording of life data such as heart rate could be useful to assess the horse's condition during exercise. To test the suitability and reliability of a commercially available GPS system with integrated heart rate recording system and with built in GSM for data transmission, the Fidelak Equipilot Type EP-2003-15/G-2.

The beta-agonist clenbuterol in mane and tail hair of horses.

Reasons For Performing Study: The beta2-agonist clenbuterol is commonly administered for therapeutic purposes in the horse, but its use an an anabolic agent is illegal. Clenbuterol can be detected in blood and urine for a relatively short period after administration and detection in hair could enhance the analytical range and be used to determine the history of clenbuterol application.

Hypothesis: That detection in mane or tail hair is possible over an extended period.

Localization of the fertilized germinal disc in the chicken egg before incubation.

At the time of oviposition, the embryo in the fertilized chicken egg has developed the germinal disc on top of the yolk and contains thousands of blastodermal cells. The germinal disc escapes exact localization because it is surrounded by albumen and shell membranes under a calcified shell. This study investigated whether or not ultrasonography or nuclear magnetic resonance imaging (MRI) are suited to localize the germinal disc and, if so, to estimate the accuracy of localization.

Neuroendocrine regulation of growth hormone and luteinizing hormone in fetal and neonatal pig.

Ontogeny of the production and the regulation of growth hormone and Luteinizing hormone is studied in a series of experiments utilizing male and female pigs at different fetal and neonatal stages. Growth hormone mRNA is detectable in both sexes as early as d. 50 p.

[ACTH stimulation test for the determination of salivary cortisol and of cortisol responses as markers of the training status/fitness of warm-blooded sports horses].

Previous work (Marc et al., 2000) suggested that plasma cortisol responses to treadmill exercise or ACTH injection are a reliable marker for performance evaluation in warmblood horses. For practical purposes blood sample collections and treadmill exercise tests are somewhat troublesome and time consuming.

Plasma cortisol and ACTH concentrations in the warmblood horse in response to a standardized treadmill exercise test as physiological markers for evaluation of training status.

Reliable physiological markers for performance evaluation in sport horses are missing. To determine the diagnostic value of plasma ACTH and cortisol measurements in the warmblood horse, 10 initially 3-yr-old geldings of the Hannovarian breed were either exposed to a training schedule or served as controls. During experimental Phase 1, horses were group-housed, and half of the horses were trained for 20 wk on a high-speed treadmill.

Localization of Xho1 repetitive sequences on autosomes in addition to the W chromosome in chickens and its relevance for sex diagnosis.

Repetitive sequences of the Xho1 family comprise about 70% of the W chromosome in chickens, are considered to be restricted to this sex chromosome and are used in sex diagnosis. This study investigated the reliability of sex diagnosis on small cell numbers. Fluorescent in situ hybridizations (FISH) with the Xho1 repeat sequence were performed on metaphases and signals were detected on the W chromosome and on some autosomes.

Concentrations of free steroids in the jugular and hepatic portal veins of pigs after ingestion of testosterone, estrogen, or progesterone or transplantation of ovaries to the intestine.

Estrogen, progesterone or testosterone were administered orally to ovariectomized gilts fitted with indwelling catheters. Blood samples were taken from the jugular and hepatic portal veins at intervals varying from a few minutes to daily over periods that varied from 1 d to several months. Concentrations of free steroids rose dramatically in the hepatic portal vein within a few min of feeding steroids and remained high for 3-8 hr before declining to base levels.

Analysis of chicken embryonic development after removal of blastodermal cells for sexing.

1. The present study evaluated developmental characteristics in the chick embryo throughout incubation following cell removal from the freshly laid egg. 2.

Ontogeny of growth hormone and LH beta-, FSH beta- and alpha-subunit mRNA levels in the porcine fetal and neonatal anterior pituitary.

The mechanism underlying the ontogenetic increase in plasma growth hormone (GH), luteinizing hormone (LH) and follicle stimulating hormone (FSH) concentration during fetal life in mammalian species and the prenatal sex difference in these hormones in some species is not fully understood. To this end anterior pituitaries were collected from German Landrace fetuses and piglets at day (d) 50, 65, 80, 95, 110 pc and d 6 pp and pituitary GH, LH beta, FSH beta and alpha-subunit mRNA levels were determined by measuring Northern blot hybridization signals. GH mRNA was detected in both sexes as early as d 50 pc.

Expression of GH, TSH beta, LH beta and FSH beta genes during fetal pituitary development in the pig.

The development of the anterior pituitary gland involves the proliferation and differentiation of ectodermal cells in Rathke's pouch to generate distinct cell types, each of which produces its corresponding trophic hormone. Studying pituitary development will therefore reveal novel aspects of organogenesis. In the present study, we examined by in situ hybridization the expression of genes for anterior pituitary hormones during development of the fetal pig pituitary.

Tissue distribution and residues of clenbuterol, salbutamol, and terbutaline in tissues of treated broiler chickens.

To examine the tissue distribution and residues after withdrawal of various beta-agonists (i.e., clenbuterol, salbutamol, and terbutaline) 160 1-d-old broiler chickens were assigned to four groups.

Proopiomelanocortin gene expression during pig pituitary and brain development.

The expression of proopiomelanocortin (POMC) mRNA, which plays an important role in neural, endocrine, neuroendocrine and immune systems, was studied by in situ hybridization during the development of pituitary in the domestic pig. The POMC gene was activated as early as fetal day 30 (E30). The signal for POMC mRNA in the anterior lobe progressively increased from E30 to E80 and then remained at relatively constant level.

[Plasmid profiles of different Salmonella serovars from poultry flocks in Germany].

151 salmonella isolates belonging to 6 serotypes and originating from diverse material collected in broiler chicken farms, hatcheries and poultry slaughteries in Northern Germany during 1984 and 1990 were investigated for their plasmid DNA content. This is the first report describing plasmids of S. saint-paul, isolated from poultry lines.

Arginine vasotocin gene expression and hormone synthesis during ontogeny of the chicken embryo and the newborn chick.

Chicken embryos at different developmental stages (embryonal day (E) 6 to 21) and chicks at posthatch day 1 (D1) were monitored for the development of their hypothalamo-neurohypophysial system as indicated by the kinetics of arginine vasotocin (AVT) gene expression via mRNA concentration and brain AVT content. Our data concerning the onset of gene expression support previous results from our laboratory and others about an early activation of the AVT gene transcriptional and translational activity around E6. We could detect measurable amounts of AVT in chicken embryo brains at E6 and an exponential increase during further development until D1.

Arginine vasotocin gene expression during osmotic challenge in the chicken.

The avian hypothalamic nonapeptide arginine vasotocin (AVT) is released from axon terminals in the neural lobe upon the application of osmotic stimuli. We have investigated whether, and to what extent, hormone secretion from the neurohypophysis is related to gene expression in the hypothalamus. Results from hybridization experiments with an AVT-specific cDNA probe indicate that in adult chickens stimulated by water deprivation or by hypertonic saline (2% w/v) drinking water, an upregulation of the AVT mRNA pool takes place, since consistently higher AVT mRNA levels compared to controls were monitored in osmotically challenged birds.

Functional maturation of arginine vasotocin secretory responses to osmotic stimulation in the chick embryo and the newborn chicken.

The time-course of appearance of plasma vasotocin and the ontogeny of the vasotocin response to osmotic stimulation during embryonic development was examined in the chicken. In the first experiment, blood was obtained by heart puncture of chicken embryos on embryonic days (E) 15-20, and by decapitation of chickens on the day of hatching (D1 = E21). Plasma was separated for measurement of osmolality and vasotocin.

Comparative studies on in vitro reactivity of fresh and cryopreserved pig lymphocytes.

The effect of cryopreservation on in vitro reactivity of pig lymphocytes was studied. Peripheral blood mononuclear cells (PBMC) were frozen by controlled-rate freezing and stored in liquid nitrogen (LN2) between 4 and 36 days. Following thawing 74.

Opioid action on luteinizing hormone secretion in newborn pigs: paradoxical effect of naloxone.

German Landrace piglets, 6-7 days of age, received either saline (9 males, 8 females), 0.5 mg naloxone/kg body weight (7 males, 7 females), 2.0 mg naloxone/kg (7 males, 8 females) or 0.

Embryonal development of arginine vasotocin/mesotocin gene expression in the chicken brain.

Abstract An ontogenic series of chick embryo brains (4, 6, 9,12,14,16 and 18 days of incubation, hatching day: 21) was coronally or saggitally sectioned and investigated for expression of the arginine vasotocin (AVT)/mesotocin (MT) gene. To this end a 39mer oligonucleotide recognizing the AVT/MT encoding sequence of their respective mRNAs was constructed employing optimized codon usage and was used for in situ hybridization. AVT/MT mRNA-expressing neurons were first detected on embryonal day (E) 6 adjacent to the third ventricle.

Spontaneous electromyographic activity throughout the cycle in the sow and its change by intrauterine oestrogen infusion during oestrus.

Two experiments were carried out to monitor influences on the uterine electromyographic activity (EMG) in cyclic gilts with chronic uterine EMG electrodes. In Exp. 1 the EMG was recorded continuously from Day -1 for 24 days and was evaluated for frequency, duration and amplitude.

[Halothane anesthesia of several hours' duration in swine of the German Landrace breed, selected for resistance to malignant hyperthermia].

The malignant hyperthermia syndrome is widely spread in pigs of the German Landrace. This has precluded the use of halothane anesthesia. The advent of homozygous halothane-negative strains stimulated us to test whether such animals were suitable for longduration halothane anesthesia.

In vitro characterization of secretion rates from silastic micropellets containing estradiol.

For local, controlled steroid hormone administration into tissues, such as the brain, we have prepared cylindric micropellets of 1 mm in length and 1 mm diameter. The micropellets are a mixture of silicone glue (silastic) and 0.1%, 1.

Characteristics of milk ejection, associated intramammary pressure changes and oxytocin release in the mare.

The neuroendocrine reflex theory of milk ejection was investigated in the horse under natural suckling conditions. To this end 12 lactating mares were provided with acute jugular catheters and with intramammary pressure (IMP) recording catheters. The foal had free access to the contralateral mammary complex.