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1.
Sci Rep ; 7(1): 17102, 2017 12 06.
Article in English | MEDLINE | ID: mdl-29213103

ABSTRACT

The pervasive and unabated nature of global amphibian declines suggests common demographic responses to a given driver, and quantification of major drivers and responses could inform broad-scale conservation actions. We explored the influence of climate on demographic parameters (i.e., changes in the probabilities of survival and recruitment) using 31 datasets from temperate zone amphibian populations (North America and Europe) with more than a decade of observations each. There was evidence for an influence of climate on population demographic rates, but the direction and magnitude of responses to climate drivers was highly variable among taxa and among populations within taxa. These results reveal that climate drivers interact with variation in life-history traits and population-specific attributes resulting in a diversity of responses. This heterogeneity complicates the identification of conservation 'rules of thumb' for these taxa, and supports the notion of local focus as the most effective approach to overcome global-scale conservation challenges.


Subject(s)
Amphibians/physiology , Conservation of Natural Resources , Animals , Climate Change , Europe , North America , Population Dynamics , Seasons , Urodela/physiology
2.
Vet Pathol ; 54(4): 686-694, 2017 07.
Article in English | MEDLINE | ID: mdl-28494706

ABSTRACT

Amphibian pathogens are of current interest as contributors to the global decline of amphibians. However, compared with chytrid fungi and ranaviruses, herpesviruses have received relatively little attention. Two ranid herpesviruses have been described: namely, Ranid herpesvirus 1 (RHV1) and Ranid herpesvirus 2 (RHV2). This article describes the discovery and partial characterization of a novel virus tentatively named Ranid herpesvirus 3 (RHV3), a candidate member of the genus Batrachovirus in the family Alloherpesviridae. RHV3 infection in wild common frogs (Rana temporaria) was associated with severe multifocal epidermal hyperplasia, dermal edema, a minor inflammatory response, and variable mucous gland degeneration. Intranuclear inclusions were numerous in the affected epidermis together with unique extracellular aggregates of herpesvirus-like particles. The RHV3-associated skin disease has features similar to those of a condition recognized in European frogs for the last 20 years and whose cause has remained elusive. The genome of RHV3 shares most of the features of the Alloherpesviruses. The characterization of this presumptive pathogen may be of value for amphibian conservation and for a better understanding of the biology of Alloherpesviruses.


Subject(s)
Dermatitis/veterinary , Herpesviridae Infections/veterinary , Herpesviridae , Rana temporaria/virology , Animals , Animals, Wild/virology , Dermatitis/pathology , Herpesviridae/genetics , Herpesviridae/isolation & purification , Herpesviridae Infections/pathology , Herpesviridae Infections/virology , Phylogeny , Polymerase Chain Reaction/veterinary , Sequence Analysis, DNA/veterinary , Skin/pathology , Skin/virology , Switzerland
3.
Science ; 346(6209): 630-1, 2014 Oct 31.
Article in English | MEDLINE | ID: mdl-25359973

ABSTRACT

Emerging infectious diseases are reducing biodiversity on a global scale. Recently, the emergence of the chytrid fungus Batrachochytrium salamandrivorans resulted in rapid declines in populations of European fire salamanders. Here, we screened more than 5000 amphibians from across four continents and combined experimental assessment of pathogenicity with phylogenetic methods to estimate the threat that this infection poses to amphibian diversity. Results show that B. salamandrivorans is restricted to, but highly pathogenic for, salamanders and newts (Urodela). The pathogen likely originated and remained in coexistence with a clade of salamander hosts for millions of years in Asia. As a result of globalization and lack of biosecurity, it has recently been introduced into naïve European amphibian populations, where it is currently causing biodiversity loss.


Subject(s)
Chytridiomycota , Communicable Diseases, Emerging/veterinary , Endangered Species , Mycoses/veterinary , Urodela/microbiology , Animals , Biodiversity , Communicable Diseases, Emerging/microbiology , Mycoses/microbiology , Phylogeny , Urodela/classification
4.
J Evol Biol ; 18(2): 415-25, 2005 Mar.
Article in English | MEDLINE | ID: mdl-15715847

ABSTRACT

Species that occupy similar habitats are expected to show convergent phenotypes. If habitats are defined by the presence of predators, then traits that modify vulnerability to predation, including predator-induced phenotypic plasticity, should be similar within habitats. We tested this idea using larvae of six syntopic newt species belonging to the two Triturus clades. Behavioural plasticity induced by odonate predators was strongly dissimilar between the two main clades but similar within them. Morphological plasticity was variable among species, even between one pair of closely related species. A predation experiment tested whether differences between clades could be caused by differences in body size. Size-specific vulnerability differed between newts in the small-bodied and large-bodied clades, indicating that similar predators may affect the two clades differently. The results showed both similarity and dissimilarity in predator-induced phenotypic plasticity in syntopic larval newts although theory suggests that divergence is unlikely in such ecologically similar species.


Subject(s)
Behavior, Animal/physiology , Environment , Phenotype , Phylogeny , Salamandridae/physiology , Animals , Body Weights and Measures , Insecta/physiology , Larva/physiology , Predatory Behavior/physiology , Salamandridae/genetics , Species Specificity
5.
Vet Comp Oncol ; 3(2): 73-80, 2005 Jun.
Article in English | MEDLINE | ID: mdl-19379215

ABSTRACT

Invasive transitional cell carcinoma (TCC) of the urinary bladder responds poorly to medical therapy. Combining platinum chemotherapy with a cyclooxygenase (cox) inhibitor has shown promise against canine TCC, where the disease closely mimics the human condition. A phase II clinical trial of carboplatin combined with the cox inhibitor, piroxicam, was performed in 31 dogs with naturally occurring, histopathologically confirmed, measurable TCC. Complete tumour staging was performed before and at 6-week intervals during therapy. Tumour responses in 29 dogs included 11 partial remissions, 13 stable disease and five progressive disease. Two of the 31 dogs were withdrawn prior to the re-staging of the tumour. Gastrointestinal toxicity was observed in 23 dogs. Hematologic toxicity was noted in 11 dogs. The median survival was 161 days from first carboplatin treatment to death. In conclusion, carboplatin/piroxicam induced remission in 40% of dogs providing evidence that a cox inhibitor enhances the antitumour activity of carboplatin. The frequent toxicity and limited survival, however, do not support the use of this specific protocol against TCC.

6.
J Am Vet Med Assoc ; 218(11): 1783-6, 2001 Jun 01.
Article in English | MEDLINE | ID: mdl-11394830

ABSTRACT

OBJECTIVE: To evaluate the use of piroxicam for the treatment of oral squamous cell carcinoma in dogs. DESIGN: Prospective case series. ANIMALS: 17 dogs with measurable oral squamous cell carcinoma. PROCEDURE: Dogs were treated with piroxicam at a dosage of 0.3 mg/kg (0.14 mg/lb) of body weight, PO, every 24 hours until progressive disease or unacceptable signs of toxicosis developed or the dog died. RESULTS: One dog had a complete remission (maxillary tumor), and 2 dogs had partial remissions (lingual tumor and tonsillar tumor). An additional 5 dogs had stable disease, including 1 with a maxillary tumor, 2 with mandibular tumors, and 2 with tonsillar tumors. Variables associated with tumor response were not identified. Median and mean times to failure for the 3 dogs that had a remission were 180 and 223 days, respectively. Median and mean times to failure for the 5 dogs with stable disease were 102 and 223 days, respectively. Time to failure was positively associated with tumor response and negatively associated with tumor size. One dog had mild adverse gastrointestinal tract effects that resolved with the addition of misoprostol to the treatment regimen. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that piroxicam may be useful in the treatment of dogs with oral squamous cell carcinoma; response rate was similar to that reported for other cytotoxic treatments. Larger-scale studies are warranted to determine what role piroxicam may have, alone or in combination with other treatments, for the treatment of dogs with oral squamous cell carcinoma.


Subject(s)
Anti-Inflammatory Agents, Non-Steroidal/therapeutic use , Carcinoma, Squamous Cell/veterinary , Dog Diseases/drug therapy , Mouth Neoplasms/veterinary , Piroxicam/therapeutic use , Animals , Anti-Inflammatory Agents, Non-Steroidal/adverse effects , Carcinoma, Squamous Cell/drug therapy , Dogs , Drug Evaluation/veterinary , Female , Male , Mouth Neoplasms/drug therapy , Piroxicam/adverse effects , Time Factors , Treatment Failure , Treatment Outcome
7.
Nature ; 404(6779): 752-5, 2000 Apr 13.
Article in English | MEDLINE | ID: mdl-10783886

ABSTRACT

Although there is growing concern that amphibian populations are declining globally, much of the supporting evidence is either anecdotal or derived from short-term studies at small geographical scales. This raises questions not only about the difficulty of detecting temporal trends in populations which are notoriously variable, but also about the validity of inferring global trends from local or regional studies. Here we use data from 936 populations to assess large-scale temporal and spatial variations in amphibian population trends. On a global scale, our results indicate relatively rapid declines from the late 1950s/early 1960s to the late 1960s, followed by a reduced rate of decline to the present. Amphibian population trends during the 1960s were negative in western Europe (including the United Kingdom) and North America, but only the latter populations showed declines from the 1970s to the late 1990s. These results suggest that while large-scale trends show considerable geographical and temporal variability, amphibian populations are in fact declining--and that this decline has been happening for several decades.


Subject(s)
Amphibians/physiology , Animals , Population Dynamics
8.
J Am Anim Hosp Assoc ; 35(4): 311-8, 1999.
Article in English | MEDLINE | ID: mdl-10416776

ABSTRACT

In this report, the authors describe four dogs referred for diagnosis and treatment of unusual and aggressive testicular tumors. For the vast majority of dogs with testicular tumors, orchiectomy is curative. All dogs in this report had surgical resection, and three of four dogs were treated with cisplatin chemotherapy. Cisplatin is widely recognized as the most active agent in testicular cancer in human medicine.


Subject(s)
Dog Diseases/diagnosis , Dog Diseases/therapy , Seminoma/veterinary , Sertoli Cell Tumor/veterinary , Testicular Neoplasms/veterinary , Animals , Dogs , Male , Seminoma/diagnosis , Seminoma/therapy , Sertoli Cell Tumor/diagnosis , Sertoli Cell Tumor/therapy , Testicular Neoplasms/diagnosis , Testicular Neoplasms/therapy
9.
Trends Ecol Evol ; 11(6): 253-4, 1996 Jun.
Article in English | MEDLINE | ID: mdl-21237833
10.
Trends Ecol Evol ; 9(2): 62, 1994 Feb.
Article in English | MEDLINE | ID: mdl-21236768
11.
J Vet Intern Med ; 7(2): 65-7, 1993.
Article in English | MEDLINE | ID: mdl-7684785

ABSTRACT

Recombinant canine granulocyte colony-stimulating factor (rcG-CSF) was administered subcutaneously at a dosage of 5 micrograms/kg/day to five healthy, young adult cats for 42 days. Mean neutrophil counts +/- standard deviation increased significantly (P < 0.001) from 10,966/microL +/- 2324 to 30,688/microL +/- 5296 within 24 hours after administration of the first dosage of rcG-CSF. Mean neutrophil counts reached 52,978/microL +/- 11,207 on day 6, representing a second significant increase (P < 0.01) over the previous 5 days. Mean neutrophil counts continued to increase, reaching 66,994/microL +/- 12,419 on day 14, then remaining within a range of 66,994 to 87,839/microL throughout the remainder of the study. The maximum mean neutrophil count was 87,839/microL +/- 8,695 on day 42. Neutrophil counts remained high until the administration of recombinant canine granulocyte colony-stimulating factor was discontinued 42 days after initiation of therapy. Once the rcG-CSF administration was discontinued, neutrophil counts returned to pretreatment values within 5 days. There were no significant changes in numbers of any of the other cell lines. There was no clinically significant toxicosis associated with the administration of rcG-CSF.


Subject(s)
Cats/blood , Granulocyte Colony-Stimulating Factor/pharmacology , Neutrophils/drug effects , Animals , Dogs , Female , Leukocyte Count/veterinary , Male , Recombinant Proteins/pharmacology
12.
Trends Ecol Evol ; 8(8): 271-3, 1993 Aug.
Article in English | MEDLINE | ID: mdl-21236166
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