In vitro activity of dicationic compounds against a North American foxhound isolate of Leishmania infantum

Canine leishmaniasis caused by Leishmania infantum is enzootic in the North American foxhound population. Currently available chemotherapy for canine leishmaniasis is not completely effective and relapses are common in treated dogs. Pentamidine and related aromatic diamidines possess broad spectrum antiprotozoal activity. The in vitro antileishmanial activities of 35 aromatic cationic molecules were determined, using pentamidine as the reference drug. The compounds were examined for activity against promastigotes of L. infantum isolated from a foxhound from Virginia. The compounds most active against Leishmania parasites were reversed amidines. Compound 9, a reversed amidine, exhibited the highest activity against L. infantum, with a 50% inhibitory concentration (IC(50)) of 0.0042 microM compared with 14.2 microM for pentamidine. Antileishmanial activities of nine compounds were at least 1000-fold higher relative to the reference drug. Results from this study indicate that several pentamidine-related compounds warrant further investigation as possible new agents for the treatment of canine leishmaniasis.     

Surgical correction of brachycephalic syndrome in dogs: 62 cases (1991-2004)

OBJECTIVE: To assess results of surgical correction of brachycephalic syndrome (including stenotic nares, elongated soft palate, and everted laryngeal saccules) in dogs and determine whether dogs with hypoplastic trachea have a less favorable long-term outcome. DESIGN: Retrospective case series. ANIMALS: 62 dogs with brachycephalic syndrome. PROCEDURES: Medical records from 1991 to 2004 were reviewed for information regarding signalment, clinical signs, diagnosis, surgery, and long-term outcome. Surgical outcome was rated by owners as excellent, good, fair, or poor. Common abnormalities, treatments, and long-term outcomes among the 62 dogs were assessed. RESULTS: Predominantly affected breeds included English Bulldog, Pug, and Boston Terrier. Elongated soft palate was the most common abnormality (54/62 [87.1%] dogs); the most common combination of abnormalities was elongated soft palate, stenotic nares, and everted saccules (16/62 [25.8%] dogs). The English Bulldog was the most common breed for all abnormalities, including elongated soft palate (27/54 [50%] dogs), stenotic nares (14/36 [38.9%] dogs), everted saccules (20/36 [55.6%] dogs), hypoplastic trachea (7/13 [53.9%] dogs), and laryngeal collapse (2/5 [40%]). No dogs had everted saccules alone. Outcome did not differ between dogs under-going staphylectomy by use of laser or scissor resection. Follow-up information was obtained for 34 dogs; 16 (47.1%) had an excellent outcome, and 16 (47.1%) had a good outcome. Overall treatment success rate was 94.2%, and overall mortality rate was 3.2%. CONCLUSIONS AND CLINICAL RELEVANCE: Surgical treatment of brachycephalic syndrome in dogs appeared to be associated with a favorable long-term outcome, regardless of age, breed, specific diagnoses, or number and combinations of diagnoses.     

Cotton remains from archeological sites in central coastal peru

Cotton remains from four archeological sites in central coastal Peru, representing a time sequence from about 2500 to 1000 B.C., were compared with similar materials obtained from living wild and cultivated forms of Gossypium barbadense L. The comparison revealed that the archeological cotton samples were primitive forms of Gossypium barbadense, differing little from present-day wild forms of the same species. Although not the earliest cottons recorded for the New World, they appear to represent the earliest stages of cotton domestication yet recorded.     

Impact of livestock and settlement on the large mammalian wildlife of Bale Mountains National Park, southern Ethiopia

Large mammals, both wild and domestic, were censused in four study areas in Bale Mountains National Park (BMNP), southern Ethiopia, from April until August 1997, using established road counts, horse-back counts and systematic transects, a new approach to censusing large mammals in BMNP. Data collected since 1983 were also examined to indicate trends in mammalian abundance. Civil unrest following the government changeover in 1991 disrupted management of BMNP, leading to an increase in human settlement and livestock densities. The effect of these factors on BMNP's wildlife is assessed and discussed. Most large mammalian wildlife has declined since 1983 but signs of recovery for some species in recent years are positive. The fates of two charismatic endemics are emphasised. BMNP's current population of mountain nyala (Tragelaphus buxtoni, an endangered antelope) was estimated to be between 1100 and 1300. This is lower than estimates for the late 1980s, but shows an increase from very low levels recorded following social turmoil during the government changeover in 1991. Data on the Ethiopian wolf (Canis simensis, a critically endangered canid) also indicate positive trends in abundance, following severe declines between 1989 and 1992 due to rabies epizootics. Action to reduce human utilisation of parts of BMNP is urgently required to prevent further degradation of the environment and to safeguard the future of both the mountain nyala and Ethiopian wolf.     

Where nothing stands still: quantifying nomadism in Australian arid-zone birds

Landscape Ecology - Nomadism is a movement strategy in response to non-seasonal environmental variability. Knowledge of nomadic species movements is poor but is necessary to understand life...     

Identification of a tractable model system and oxalic acid-dependent symptom development of the dollar spot pathogen Clarireedia jacksonii

Clarireedia jacksonii causes dollar spot disease of cool-season turfgrasses in the United States and produces the phytotoxin oxalic acid. The role of oxalic acid in host–pathogen interactions of C. jacksonii is unknown and there are multiple challenges to studying these interactions in natural turfgrass hosts. Consequently, identification of model plants to study C. jacksonii–host interactions and the role of oxalic acid in pathogenesis is necessary. Controlled environment inoculation assays were used to evaluate pathogenesis of C. jacksonii in various model plants and investigate the role of oxalic acid in symptom development. Observations at microscopic and macroscopic levels demonstrated that infection progressed similarly in all monocots tested (creeping bentgrass, wheat, barley, rice, Brachypodium distachyon) but not in the dicot Arabidopsis thaliana. Plant oxalic acid content increased from near zero to around 0.2–0.4 mM following inoculation with C. jacksonii in creeping bentgrass, barley, and wheat. Conversely, oxalic acid content remained near zero in A. thaliana and was not well correlated with inoculation in rice and B. distachyon, both of which had higher endogenous oxalic acid levels than other monocots. Time-course oxalic acid quantification experiments with creeping bentgrass and B. distachyon further supported a link between symptom development and in planta oxalic acid content and identified 48 hr postinoculation as a critical time-point for investigating the role of oxalic acid in C. jacksonii pathogenesis. These studies demonstrate that various monocots can serve as tractable model systems for studying C. jacksonii–host interactions and that increases in oxalic acid content are associated with C. jacksonii symptom development.