|
|
Giangaspero, A., Traversa, D., & Otranto, D. (2004). [Ecology of Thelazia spp. in cattle and their vectors in Italy]. Parassitologia, 46(1-2), 257–259.
Abstract: The genus Thelazia (Spirurida, Thelaziidae) includes a cosmopolitan group of eyeworm spirurids responsible for ocular infections in domestic and wild animals and transmitted by different species of muscids. Bovine thelaziosis is caused by Thelazia rhodesi Desmarest 1828, Thelazia gulosa Railliet & Henry 1910, and Thelazia skrjabini Erschow 1928, which occur in many countries; T. gulosa and T. skrjabini have been reported mainly in the New World, while T. rhodesi is particularly common in the Old World. In Italy, T. rhodesi was reported in southern regions a long time ago and, recently, T. gulosa and T. skrjabini have been identified in autochthonous cattle first in Apulia and then in Sardinia. Thirteen species of Musca are listed as intermediate hosts of eyeworms, but only Musca autumnalis and Musca larvipara have been demonstrated to act as vectors of Thelazia in the ex-URSS, North America, ex-Czechoslovakia and more recently in Sweden. In Italy, after the reports of T. gulosa and T. skrjabini in southern regions, the intermediate hosts of bovine eyeworms were initially only suspected as the predominant secretophagous Muscidae collected from the periocular region of cattle with thelaziosis were the face flies, M. autumnalis and M. larvipara, followed by Musca osiris, Musca tempestiva and Musca domestica. The well-known constraints in the identification of immature eyeworms to species by fly dissection and also the time-consuming techniques used constitute important obstacles to epidemiological field studies (i.e. vector identification and/or role, prevalence and pattern of infection in flies, etc.). Molecular studies have recently permitted to further investigations into this area. A PCR-RFLP analysis of the ribosomal ITS-1 sequence was developed to differentiate the 3 species of Thelazia (i.e. T. gulosa, T. rhodesi and T. skrjabini) found in Italy, then a molecular epidemiological survey has recently been carried out in field conditions throughout five seasons of fly activity and has identified the role of M. autumnalis, M. larvipara, M. osiris and M. domestica as vectors of T. gulosa and of M. autumnalis and M. larvipara of T. rhodesi. Moreover, M. osiris was described, for the first time, to act as a vector of T. gulosa and M. larvipara of T. gulosa and T. rhodesi. The mean prevalence in the fly population examined was found to be 2.86%. The molecular techniques have opened new perspectives for further research on the ecology and epidemiology not only of Thelazia in cattle but also of other autochthonous species of Thelazia which have been also recorded in Italy, such as Thelazia callipaeda, which is responsible for human and canid ocular infection and Thelazia lacrymalis, the horse eyeworm whose epidemiological molecular studies are in progress.
|
|
|
|
Huebener, E. (2004). Die Bewegungen von Pferderumpf und -rücken aus der Sicht des Reiters. Tierärztl. Umschau, 6, 327–334.
Abstract: Die Bewegungen von Rumpf und Rücken des Pferdes in der Fortbewegung bestimmen Sitz und Schenkelhilfen – Grundlagen pferdgerechten und kultivierten, feinfühligen Reitens. In ihrer Tendenz ließen sich diese Bewegungen jetzt aus den Fußfolgen der Grundgangarten ableiten. Die Erkenntnisse sind per Video verifiziert. Mit ihrer Übersetzung in Diagramme wurde versucht, den gegenwärtigen Wissensstand für nicht-reitende Wissenschaftler und denkende Reiter gleichermaßen verständlich darzustellen. Die Akzeptanz des aufbereiteten Wissens in der Reiterei würde verbessert, wenn man zu gemessenen Werten für die Bewegungen des Pferderückens und des Pferderumpfes käme. Plädoyer eines “Nur-Reiters” für einschlägige, universitäre Forschung.
|
|
|
|
Huebener, E. (2004). Movements of Trunk and Back of the Horse from a Rider's View. Tierärztl. Umschau, 6, 327.
Abstract: The trunk and back movements of the horse during locomotion determine seat position and leg aids of the rider, this is the basis for horse-oriented and cultivated, sensitive riding. In their tendency these movements could now be derived from the foot sequences of the basic paces. The realizations are verified by video. By translating these movements into diagrams, the author is making an attempt to present the current state of knowledge for non-riding scholars and academically oriented riders alike. The acceptance of the prepared riding knowledge would be improved if one could produce measured values of the horse's back and trunk movements. An appeal of a rider for relevant, scholarly research.
|
|
|
|
Zeitler-Feicht, M. H. (2004). [Critical consideration of the “Guideline for the Evaluation of Raising Horses” and keeping horses outside in the winter]. Dtsch Tierarztl Wochenschr, 111(3), 120–123.
Abstract: The guidelines of the Federal Ministry of User Protection, Nutrition and Agriculture (BMVEL) regarding “horse keeping with respect to animal welfare” are from 1995 (BMELF, 1995). Therefore, they are not suitable for modern horse keeping. The Veterinary Association for Animal Welfare (TVT) held it to be necessary to rework the guide-lines in light of 1) many subsequent investigations concerning horse keeping, and 2) the species-specific needs of horses in practice. Each chapter of the BMELF (1995) guide-lines was revised such that the literature and practical experiences were updated. Several chapters (recumbency resting behaviour, fences, underground outdoor and in stables, litter) were added in the position paper of the TVT to reflect the increasing use of boxes with paddocks, loose housing systems with open yards, pasture and winter yards as housing conditions. Keeping horses outdoors permanently during winter is possible because horses have very good thermoregulatory capabilities so that they are able to adapt themselves to cold conditions. However, in light of animal welfare, the holding system must include adequate shelter (natural or artificial). Shelters should protect against wetness, heat, cold and wind, and must be sufficiently large and high, with a dry and clean underground. In keeping horses outdoors permanently, the paths to the feeding and watering areas and to the shelter must be dry. The food must also be protected against mould and soiling. Keeping horses permanently without adequate shelter or in deep marsh without any dry places is against the Animal Protection Act.
|
|
|
|
Bloom, P. (2004). Behavior. Can a dog learn a word? Science, 304(5677), 1605–1606.
|
|
|
|
Wilkins, L. J., Brown, S. N., Zimmerman, P. H., Leeb, C., & Nicol, C. J. (2004). Investigation of palpation as a method for determining the prevalence of keel and furculum damage in laying hens. Vet. Rec., 155(18), 547–549.
Abstract: Old breaks of the keel and furculum were identified by palpation in 500 end-of-lay hens from 10 flocks housed in free-range and barn systems, and the results were compared with the results obtained by a full dissection and inspection. The method was considered to be sufficiently precise to be used as a diagnostic tool although people using it would need to be trained. The results obtained by dissection indicated that 50 to 78 per cent of the birds in the flocks had breaks of the furculum and keel, but no other breaks of bones were detected.
|
|
|
|
Guo, G. L., Moffit, J. S., Nicol, C. J., Ward, J. M., Aleksunes, L. A., Slitt, A. L., et al. (2004). Enhanced acetaminophen toxicity by activation of the pregnane X receptor. Toxicol Sci, 82(2), 374–380.
Abstract: The pregnane X receptor (PXR) is a ligand-activated transcription factor and member of the nuclear receptor superfamily. Activation of PXR represents an important mechanism for the induction of cytochrome P450 3A (CYP3A) enzymes that can convert acetaminophen (APAP) to its toxic intermediate metabolite, N-acetyl-p-benzoquinone imine (NAPQI). Therefore, it was hypothesized that activation of PXR plays a major role in APAP-induced hepatotoxicity. Pretreatment with the PXR activator, pregnenolone 16alpha-carbonitrile (PCN), markedly enhanced APAP-induced hepatic injury, as revealed by increased serum ALT levels and hepatic centrilobular necrosis, in wild-type but not in PXR-null mice. Further analysis showed that following PCN treatment, PXR-null mice had lower CYP3A11 expression, decreased NAPQI formation, and increased maintenance of hepatic glutathione content compared to wild-type mice. Thus, these results suggest that PXR plays a critical role in APAP-induced hepatic toxicity, probably by inducing CYP3A11 expression and hence increasing bioactivation.
|
|
|
|
Jeong, S., Han, M., Lee, H., Kim, M., Kim, J., Nicol, C. J., et al. (2004). Effects of fenofibrate on high-fat diet-induced body weight gain and adiposity in female C57BL/6J mice. Metabolism, 53(10), 1284–1289.
Abstract: Our previous study suggested that fenofibrate affects obesity and lipid metabolism in a sexually dimorphic manner in part through the differential activation of hepatic peroxisome proliferator-activated receptor alpha (PPARalpha) in male and female C57BL/6J mice. To determine whether fenofibrate reduces body weight gain and adiposity in female sham-operated (Sham) and ovariectomized (OVX) C57BL/6J mice, the effects of fenofibrate on not only body weight, white adipose tissue (WAT) mass, and food intake, but also the expression of both leptin and PPARalpha target genes were measured. Compared to their respective low-fat diet-fed controls, both Sham and OVX mice exhibited increases in body weight and WAT mass when fed a high-fat diet. Fenofibrate treatment decreased body weight gain and WAT mass in OVX, but not in Sham mice. Furthermore, fenofibrate increased the mRNA levels of PPARalpha target genes encoding peroxisomal enzymes involved in fatty acid beta-oxidation, and reduced apolipoprotein C-III (apo C-III) mRNA, all of which were expressed at higher levels in OVX compared to Sham mice. However, leptin mRNA levels were found to positively correlate with WAT mass, and food intake was not changed in either OVX or Sham mice following fenofibrate treatment. These results suggest that fenofibrate differentially regulates body weight and adiposity due in part to differences in PPARalpha activation, but not to differences in leptin production, between female OVX and Sham mice.
|
|
|
|
Cheung, C., Akiyama, T. E., Ward, J. M., Nicol, C. J., Feigenbaum, L., Vinson, C., et al. (2004). Diminished hepatocellular proliferation in mice humanized for the nuclear receptor peroxisome proliferator-activated receptor alpha. Cancer Res, 64(11), 3849–3854.
Abstract: Lipid-lowering fibrate drugs function as agonists for the nuclear receptor peroxisome proliferator-activated receptor alpha (PPARalpha). Sustained activation of PPARalpha leads to the development of liver tumors in rats and mice. However, humans appear to be resistant to the induction of peroxisome proliferation and the development of liver cancer by fibrate drugs. The molecular basis of this species difference is not known. To examine the mechanism determining species differences in peroxisome proliferator response between mice and humans, a PPARalpha-humanized mouse line was generated in which the human PPARalpha was expressed in liver under control of the tetracycline responsive regulatory system. The PPARalpha-humanized and wild-type mice responded to treatment with the potent PPARalpha ligand Wy-14643 as revealed by induction of genes encoding peroxisomal and mitochondrial fatty acid metabolizing enzymes and resultant decrease of serum triglycerides. However, surprisingly, only the wild-type mice and not the PPARalpha-humanized mice exhibited hepatocellular proliferation as revealed by elevation of cell cycle control genes, increased incorporation of 5-bromo-2'-deoxyuridine into hepatocyte nuclei, and hepatomegaly. These studies establish that following ligand activation, the PPARalpha-mediated pathways controlling lipid metabolism are independent from those controlling the cell proliferation pathways. These findings also suggest that structural differences between human and mouse PPARalpha are responsible for the differential susceptibility to the development of hepatocarcinomas observed after treatment with fibrates. The PPARalpha-humanized mice should serve as models for use in drug development and human risk assessment and to determine the mechanism of hepatocarcinogenesis of peroxisome proliferators.
|
|
|
|
Nicol, C. J. (2004). Development, direction, and damage limitation: social learning in domestic fowl. Learn Behav, 32(1), 72–81.
Abstract: This review highlights two areas of particular interest in the study of social learning in fowl. First, the role of social learning in the development of feeding and foraging behavior in young chicks and older birds is described. The role of the hen as a demonstrator and possible teacher is considered, and the subsequent social influence of brood mates and other companions on food avoidance and food preference learning is discussed. Second, the way in which work on domestic fowl has contributed to an understanding of the importance of directed social learning is examined. The well-characterized hierarchical social organization of small chicken flocks has been used to design studies which demonstrate that the probability of social transmission is strongly influenced by social relationships between birds. The practical implications of understanding the role of social learning in the spread of injurious behaviors in this economically important species are briefly considered.
|
|
