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Biomedical subjects

R Thun

Publications and source records attributed to R Thun.

At least 37 records · Page 2Linked to original sources
PubMed2001

[Hydrosalpinx in a goat].

A two year old Swiss Alpine goat was referred to our clinic because of sterility. Ultrasound examination revealed a nonechogenic area cranially to the urinary bladder. As hydrometra was suspected, the goat was treated repeatedly with PGF2 alpha. Success of this therapy, however, was unsatisfactory and estrus was therefore induced by progesterone in combination with eCG and the goat mated. As conception failed and ultrasonography remained unchanged, laparoscopy was performed and a fluid filled structure could be located in the region of the right oviduct. After ovariohysterectomy and histo-pathological examination of the genital organs hydrosalpinx was diagnosed on both sides.

Animals↗
PubMed2000

Characterisation of the enzymatic 4-O-acetylation of sialic acids in microsomes from equine submandibular glands.

Microsomes prepared from equine submandibular glands and incubated with tritium-labelled AcCoA incorporated acid-insoluble radioactivity in a manner dependent on time, protein, membrane integrity and AcCoA concentration, with incorporation being optimal at 37 degrees C and pH 6.6. Under the experimental conditions used a K(M) of 32.1 microM for AcCoA and a V(max) of 1.2 pmol/mg protein x min was obtained. The incorporation of acid-insoluble radioactivity was also inhibited by CoA in a competitive manner (K(i)=240 microM), as well as by para-chloromercuribenzoate, 3'-dephospho-CoA, 5'-IDP, 5'-ADP, beta-NAD and 4,4'-diisothiocyanatostilbene-2,2'-disulfonate. We demonstrate here that this incorporation of radioactivity into endogenous sialic acid is due to the action of an AcCoA:sialate-4-O-acetyltransferase [EC 2.3.1.44]. Radio thin-layer chromatography analyses of propionic acid-released sialic acids showed that the incorporation of radioactivity correlated with the formation of a radiolabelled species that co-migrated with authentic Neu4,5Ac2. Saponification experiments using NaOH, mouse hepatitis virus strain S and Influenza C/JJ/50 virus also showed that the transfer of [3H]acetyl groups from [3H]AcCoA to endogenous sialic acid acceptors was occurring exclusively at carbon 4 of the pyranose ring.

Acetyl Coenzyme A↗
PubMed2000

[Bovine herpes mammillitis: clinical symptoms and serologic course].

Bovine herpes mammillitis was diagnosed in a dairy herd with udder and teat skin lesions. Clinical symptoms seen in 6 cows consisted of round dry areas at the teats as well as large red and painful areas with crust formation at the teats, the teat basis and the udder. Diagnosis was verified by demonstrating numerous virus particles with the typical herpes structure and by BHV-2 serum neutralization test. Prevalence of BHV-2 in the herd was determined by using BHV-2 SNT at 7 occasions during a period of 15 months. The relatively low BHV-2 SNT-titres as well as the seasonal increase of BHV-2 titres and seroprevalence in the month of September were indicative of a chronic and latent BHV-2 infection in the herd.

Animals↗
PubMed1996

[Relationship between cortisol and testosterone during resting conditions, after acute stress and hormone stimulation in steers].

In this study the relationship between peripheral concentrations of cortisol and testosterone was investigated in 7 adult bulls under resting conditions as well as after sexual and hormonal stimulation. The animals were kept under natural photoperiods of 16L:8D and for hormone determinations blood was withdrawn from an indwelling jugular vein catheter every 30 minutes for 24 and 48 h, respectively. Evaluation of the hormonal profiles revealed that both steroids are secreted episodically characterized by irregular, short term fluctuations with high individual variability. A clear circadian rhythm with high levels in the morning and during the day and low concentrations in the evening and during night was observed for cortisol only. Concentrations of both steroidal hormones were not significantly correlated with each other. Intense sexual stimulation (mounting several times with ejaculation) during 30 minutes caused a rapid increase of cortisol without affecting testosterone secretion. After intravenous application of 1500 IU hCG and 0.5 mg GnRH a sharp rise of testosterone concentrations occurred with high values remaining for several hours but leaving the circadian cortisol pattern unchanged. The intravenous injection of 5 mg PGF2 alpha stimulated both the cortisol and testosterone secretion. Results from this investigation show that cortisol and testosterone are secreted episodically without any interrelationship under resting conditions. Sexual stress induced an increase of cortisol which did not inhibit testosterone secretion and high testosterone levels did neither influence the cortisol pattern. The concomitant increase of cortisol and testosterone after PGF2 alpha suggests a central (hypothalamus/hypophysis) action for prostaglandin.

Animals↗
PubMed1996

[Measurement of stress parameters in farm animals using active telemetry].

We investigated the effect of an acute stressor on body temperature and heart rate in cows. Both parameters were recorded by active telemetry. For the experiments, five cyclic Brown Swiss cows were used, each of them exposed to an acute stressor during estrus and the luteal phase of the cycle. The stressor consisted in restraining the cows in a crush for hoof treatments. During the 2-hour stress period and for additional 6 hours, body temperature and heart rate were measured every 10 minutes. Control animals remained in their accustomed environment during the whole experiment of 8 hours. The course of body temperature and heart rate was clearly influenced by the stressor. While heart rate was maximal already at the beginning of the stress period, the body temperature showed highest values only one hour after stress and then continuously decreased. Changes in body temperature and heart rate under stress differed significantly from the values of control animals. Both parameters are reliable indicators of stress in the bovine species. The transmitters used in this investigation allowed us to register exact data without manipulation of the animal, which could possibly falsify the results. This advantage as well as the functional longevity of the transmitters (ca. 6 months) make active telemetry a useful tool for stress research in farm animals.

Animals↗
PubMed1996

[Gynecomastia in a goat buck].

A 3-year old horned buck of the Toggenburger breed was referred to our clinic with signs of gynecomastia. Cytogenetic abnormalities could not be detected in the karyogram and compared to control animals the buck had normal plasma concentrations of testosterone and estradiol but not prolactin. Hyperprolactinemia has been considered the cause of gynecomastia leaving the semen quality undisturbed.

Animals↗
PubMed1995

Influence of endometrial cysts on conception rate of mares.

A total of 259 normally fertile mares were examined gynecologically by means of rectal palpation and ultrasonography in order to record the presence of uterine cysts and pregnancy. The incidence of endometrial cysts was 22.4%. Of the 95 cysts observed during the trial, 87.4% were located in the middle and posterior segments of both uterine horns. The size of all endometrial cysts ranged between 3 and 48 mm. When all mares were assigned to three age groups, A < 7 years (n = 116), B 7-14 years (n = 117) and C > 14 years (n = 26), a significant (P < 0.01) increase in the number of endometrial cysts was observed with advancing age (4.3%, 29.1% and 73.1%, respectively). The pregnancy rates at Days 14 and 40 were significantly (P < 0.01) lower in mares with cysts (77.6% and 71.4%) compared to mares without cysts (91.5% and 88.0%). This suggests that the presence of uterine cysts plays an important role in the reduction of fertility of Thoroughbred mares.

Animals↗
PubMed1995

[Case report: varicocele in a ram].

In a 7 year old ram a partly fluctuating mass proximal to the left testicle was diagnosed as varicocele. On ultrasound examination non-echogenic tortuous areas were present. Spermatologic examination revealed an oligozoospermia and an oligokinespermia. Considering the poor prognosis, the ram was slaughtered and the diagnosis of varicocele could be verified on post mortem examination.

Animals↗
PubMed1993

Human PCK1 encoding phosphoenolpyruvate carboxykinase is located on chromosome 20q13.2.

Cytoplasmic liver phosphoenolpyruvate carboxykinase (GTP) (PEPCK) catalyzes a rate-limiting step in gluconeogenesis. Primers derived from the rat liver PEPCK sequence were used to amplify a portion of the human liver cDNA and to screen a YAC library of human genomic DNA. The sequences of human and rat PEPCK cDNA differed at 16% of the nucleotides compared (45/291). Analysis of a human/rodent hybrid mapping panel demonstrated concordant segregation of PCK1 with chromosome 20. Fluorescence in situ hybridization with YAC DNA further localized PCK1 to subband 20q13.2.

Animals↗
PubMed1993

[Uterine motility of cattle during late pregnancy, labor and puerperium. III. Use of flunixin meglumine and endocrine changes].

In the present study the effect of Flunixin meglumine (FM), a cyclooxygenase inhibitor, was investigated on postpartal prostaglandin production and uterine activity in the cow. For that purpose 8 cows were given FM in a dose of 2.2 mg/Kg b.w. twice daily (08.00 and 16.00 h) for the first 10 days p.p. Blood samples were collected at various times before, during and after parturition and the concentrations of 15-keto-13,14-dihydro-PGF2 alpha (PGFM), progesterone as well as adrenaline and noradrenaline determined. Eight cows served as controls. Uterine activity was measured by means of pressure microsensors and electrodes which were surgically implanted into the uterine wall before parturition. During the whole treatment period FM inhibited endogenous PG-production by more than 80% (p < 0.05). The suppressive effect of FM was maximal 4 h after the last injection and lasted no longer than 8 h. PGF2 alpha-suppression clearly decreased spontaneous uterine motility and reduced the myometrial response to ocytocin (5 IU i.v.) and PGF2 alpha (15 mg i.v.). Treatment with FM did not interfere with uterine involution, the return to cyclicity and the first postpartal cycle length. Also, no obvious effects were seen on catecholamine concentrations which fluctuated during parturition without regularly representing the actual stress situation. Our results demonstrate that FM is able to effectively inhibit PGF2 alpha-secretion as well as uterine activity in the cow. Further evaluation of FM as a tocolyticum or in the treatment of uterine infections is required.

Animals↗
PubMed1990

[The uterine motility in cattle during late pregnancy, labor and puerperium. II. Drug modification].

The uterine effects of oxytocin, the prostaglandins dinoprost and cloprostenol as well as clenbuterol, ergometrin, xylazine and Utrorale were investigated in 8 cows during late pregnancy, parturition and early puerperium (until 4th day p. p.). Uterine motility was measured by means of pressure microsensors and electrodes which were surgically implanted 3 to 4 weeks before parturition. Hysterograms were characterized by means of pressure amplitude, frequency and duration of uterine contractions and also by electromyography. Oxytocin (2-5 IE) given intravenously always provoked strong uterine contractions until the 4th day p.p. From the prostaglandins examined during early puerperium only dinoprost (15 mg i.v.) produced uterotonic effects, while the synthetic analogue cloprostenol (0.25 mg i.v.) had a weak stimulatory activity only on day 1 p.p. Both prostaglandins were ineffective when injected intramuscularly. Clenbuterol (0.3 mg i.v.) a beta 2-mimetic compound effectively induced long lasting tocolysis during parturition, which could be abolished by oxytocin. Xylazine (10 mg i.v.) was able to significantly increase uterine motility during late gestation. Following intravenous administration of ergometrin (1 and 10 mg), bunitrolol (1-16 mg) and Utrorale (0.1-4 ml) including its compounds oleum sabinae, oleum terebinthinae, balsamum copaivale and Styrax no uterokinetic activity was recorded at any time.

Animals↗