The functions of wildlife and their possible use for deriving site selection components

The beneficial uses or functions of wildlife are numerous. In agriculture these include not only the cropping of species growing in the wild but also their potential for future cultivation and role in such processes as crop pollination and biological control of pests. Wild animals are used in medicine for essential research; wild plants provide a source of drugs, and wild places can help to relieve the tension and stress associated with modern living. Wildlife is also a sensitive indicator of environmental change. Furthermore, research and education in the environmental sciences rely on the conservation of natural and semi-natural areas. These areas and the species which inhabit them have considerable aesthetic value and have inspired many great works of art. Finally, there is a moral argument that all species have the right to exist, and that the options made possible by the presence of wildlife should be left for future generations to use. Each of these functions is discussed in detail.Sixteen components should be taken into consideration when evaluating an area for wildlife conservation. A possible approach to weighting these components is outlined.     

Amputation and Cisplatin for Treatment of Canine Osteosarcoma

Seventy-one dogs with histologically confirmed appendicular osteosarcoma were evaluated. Seventeen dogs were treated with amputation and two postoperative [corrected] doses of IV cisplatin given 21 days apart (group 1). Nineteen dogs were treated with IV cisplatin 21 days before amputation, with a second dose given immediately after amputation (group 2). Thirty-five dogs were treated by amputation of the affected limb with no chemotherapy (group 3). The median disease-free interval for group 1 was 226 days, and 177 days for group 2. This was not significantly different. The median survival time was 262 days for group 1, 282 days for group 2 and 119 days for group 3. Group 1 and 2 dogs had survival times that were significantly longer than for dogs in group 3. Two IV courses of cisplatin given before or after amputation appears to improve the survival of dogs with osteosarcoma.     

Cystic Meningiomas in 2 Dogs

Two dogs with signs of forebrain disease had hypodense lesions on computed tomography evaluation. Magnetic resonance imaging of the first dog showed a hypointense lesion on the T1-weighted scan and a hyperintense lesion on T2-weighted scanning. At surgery, both dogs had a primary cystic intracranial lesion, and the abnormal tissue adjacent to the cyst had histological features of meningiorna. Each dog underwent whole brain irradiation after surgery, and 1 dog lived for 3 years after treatment. While uncommon, meningioma should be considered as a differential diagnosis in dogs with cystic intracranial lesions. J Vet Intern Med 1996;10:72–75. Copyright © 1996 by the American College of Veterinary Internal Medicine .     

RADIOTHERAPY OF CANINE NON-TONSILLAR SQUAMOUS CELL CARCINOMA

The records of 14 dogs treated with megavoltage radiation for non-tonsillar oral squamous cell carcinoma were reviewed to determine the efficacy of this treatment modality. Total radiation dose was either 48 or 57 Gray (Gy), while dose per fraction was either 3.0 or 4.0 Gy. Median disease free interval and survival were 365 and 450 days, respectively. Median disease free interval was shorter in dogs older than nine years (210 days) as compared with dogs less than or equal to nine years old (470 days), (p < .005). Median survival was shorter in dogs older than nine years (315 days) as compared with dogs less than or equal to nine years old (1080 days), (p < 0.02). Weight, stage, anatomic subsite, intraoral location, duration of disease, prior surgery, and number of radiation fractions did not appear to influence disease free interval or survival. Data presented herein suggest that survival in dogs with non-tonsillar squamous cell carcinoma receiving megavoltage radiation may be longer than that achieved with orthovoltage radiation or surgery. Megavoltage radiation appears to be an effective treatment for non-tonsillar oral squamous cell carcinoma in dogs. Further study is needed to determine the optimal time-dose sched-ule.     

A Promising New Chemotherapeutant for Use in Treatment of Fusarium solani Infections in Penaeid Shrimp

A commercially available microbicide, composed of 5-Chloro-2-methyl-4-isothiPzolin-3-one and 2-methyl-4-isothiazolin-3-one, was tested for its in vivo effectiveness in controlling pathogenicity and mortalities in the marine shrimp Penaeus stylirostris , caused by the fungus Fusurium solani . Sub-adult shrimp (100% with Fusurium lesions) were treated with the microbicide at levels of 5.0 and 7.5 ppm (Trial 1) and with 1.0, 2.5 and 5.0 ppm (Trial 2), and each compared to a non-treated control. In Trial 1, treatments were administered during the first 9 days of the 22 day experiment, approximately every other day as 8 h static baths. The mean levels of Fusarium lesions on Day 22 for the 0, 5.0 and 7.5 ppm treatments were 87%, 25% and 13%, respectively. Statistically both levels of treatment (5.0 and 7.5 ppm) had significantly lower levels of Fusurium lesions when compared to the controls. In Trial 2, treatments of the microbicide were administered (8 h static bath) every seventh day over the course of the 64 day experiment. The Day 64 mean Fusarium lesion levels for the 0, 1.0, 2.5 and 5.0 ppm treatments were 54%, 59%, 10% and 7%, respectively. Treatment with 2.5 and 5.0 ppm reduced the prevalence of Fusarium lesions to statistically lower levels when compared to the 0 and 1.0 ppm treatments. The microbicide had earlier been reported to be highly toxic to fish. The use of activated charcoal filters on the microbicide-treated effluent appeared to remove any residual compound from the water. The data in the present study indicate a possible inverse relationship between the level of "BG 101" and growth rate. The data from both trials suggest that periodic treatment over a longer test period could limit or eliminate Fusurium lesions, which are known to be the potential cause of substantial mortalities, particularly in captive broodstock populations.     

A psbA mutation in Kochia scoparia (L) Schrad from railroad rights-of-way with resistance to diuron, tebuthiuron and metribuzin

Kochia [Kochia scoparia (L) Schrad] has become resistant to many herbicides used in cropland and railroad rights-of-way in North Dakota and Minnesota. Kochia scoparia plants that had survived annual treatments with diuron and tebuthiuron were sampled along railroad rights-of-way in North Dakota and Minnesota. The samples were screened in the greenhouse for resistance to diuron, tebuthiuron, metribuzin and bromoxynil from 0.5x to 32x the recommended use rates. A resistant K scoparia accession (MN-3R) was confirmed with resistance up to 16-fold higher than recommended use rates for tebuthiuron and diuron and up to 4-fold higher for metribuzin. However, the resistant K scoparia accession was susceptible to bromoxynil even at 50% of the recommended use rate. The herbicide binding region of the psbA gene fragment of eight resistant (R) and seven susceptible (S) K scoparia accessions was PCR-amplified and sequenced for detection of mutations. The psbA gene of four R K scoparia accessions was mutated at residue 219 with substitution of isoleucine for valine (GenBank accession number AY251265). The seven S K scoparia accession sequences were wild-type at this residue (GenBank accession number AY251266). The other four R accessions sequences showed a previously known triazine R mutation with substitution of glycine for serine at residue 264. All 15 K scoparia accessions were wild-type at all other psbA residues within the region analyzed. Resistance to diuron, tebuthiuron and metribuzin among the railroad rights-of-way K scoparia is probably due to the mutation at residue 219 of the psbA gene in some plants, but due to the previously reported Ser(264)Gly substitution in other plants. Target-site resistance associated with a change of valine to isoleucine at residue 219 of the psbA target-site in weeds has previously been reported for Poa annua L selected in diuron-treated grass seed fields, and for Amaranthus powelli S Wats selected in linuron-treated carrot fields. This is the first report of the mutation in herbicide-resistant K scoparia.     

Escherichia coli 0157:H7: an update on intestinal colonization and virulence mechanisms

Cattle are a major reservoir of Escherichia coli 0157:H7, an important zoonotic pathogen that causes hemorrhagic colitis and hemolytic uremic syndrome (HUS). Colonization of cattle occurs predominantly in the large intestine, and may especially target follicle-associated epithelium (FAE) in the terminal rectum. Bacterial colonization involves induction of attaching-effacing (A/E) lesions, mediated by type III secreted proteins and an outer membrane protein called intimin. ToxB, encoded on plasmid pO157, contributes to adherence of E. coli O157:H7 through promotion of the production and/or secretion of type III secreted proteins. Production of type III secreted proteins and intestinal colonization appear to involve quorum-sensing mechanisms. In the human host, E. coli O157:H7 may have a preference for FAE in the distal small intestine. The H7 flagellum induces production of chemokines such as interleukin 8, and neutrophilic infiltration of the intestinal mucosa, which in turn may enhance Shiga toxin (Stx) uptake across the intestinal epithelium. Both Stx and cytokine responses play critical roles in the induction of the vascular lesions that underlie hemorrhagic colitis and HUS. In cattle, Stx binds to intestinal crypt cells and submucosal lymphocytes but not vascular endothelium. The role played by Stx in cattle may be to suppress mucosal immunity, yet enhance other effects that promote intestinal colonization.     

Larvae of gryporhynchid cestodes (Cyclophyllidea) from fish: a review

Larvae (metacestodes) of tapeworms of the cyclophyllidean family Gryporhynchidae (previously included in the Dilepididae) occur in different internal organs of fresh- and brackish water fish (110 fish species of 27 families in 12 orders reported), which serve as the second intermediate hosts. The species composition, spectrum of fish hosts, sites of infection, and geographical distribution of gryporhynchids recorded from fish are reviewed here on the basis of literary data and examination of extensive material from helminthological collections. Metacestodes of the following genera have been found in fish: Amirthalingamia Bray, 1974 (1 species), Ascodilepis Guildal, 1960 (1), Cyclustera Fuhrmann, 1901 (4), Dendrouterina Fuhrmann, 1912 (1), Glossocercus Chandler, 1935 (3), Neogryporhynchus Baer et Bona, 1960 (1), Paradilepis Hsü, 1935 (5), Parvitaenia Burt, 1940 (2), and Valipora Linton, 1927 (3). However, most published records concern only three species, namely Neogryporhynchus cheilancristrotus (Wedl, 1855) from the intestinal lumen, Paradilepis scolecina (Rudolphi, 1819) from the liver and mesenteries, and Valipora campylancristrota (Wedl, 1855) from the gall bladder of cyprinids and other fish in the Palaearctic Region. Data on other species as well as reports from other regions are very scarce and almost no information is available from Australia, tropical Asia and South America. A recent study of gryporhynchid metacestodes from Mexico (Scholz and Salgado-Maldonado 2001), which reported 13 species, suggested that they may be more common than indicated by records in the literature. Although only a few cases of pathogenic influence of larvae on fish hosts have been reported, the veterinary importance of gryporhynchids remains to be assessed on the basis of more detailed studies. The data available indicate a strict host and site specificity of some species whereas others occur in a wide spectrum of fish hosts and are not strictly site-specific. Evaluation of Paradilepis larvae from the liver of salmonid fish from British Columbia, Canada, identified as P. simoni Rausch, 1949 by Ching (1982), has shown that they probably belong to two species, P. simoni and P. rugovaginosus Freeman, 1954. Metacestodes of the latter species and those of Cyclustera magna (Baer, 1959) from the intestinal wall of Tilapia zillii (Gervais) from Kenya are reported from fish for the first time.