Bronchial stent placement in a dog with bronchomalacia and left atrial enlargement.

A 13-year-old neutered male Maltese was referred for paroxysms of coughing and cyanosis, with radiographic evidence of bronchial disease and cardiomegaly. Investigation with echocardiography, bronchoscopy, fluoroscopy and bronchoalveolar lavage led to a diagnosis of myxomatous mitral valve degeneration with insufficiency, ISACHC class II heart failure and bronchomalacia with severe left mainstem bronchial collapse. Persistence of intractable cough despite medical therapy prompted placement of a stent in the left mainstem bronchus. Immediately after stent placement, severe pulmonary oedema developed, thought to be due to compression of the left atrium by the stent or acute lung injury related to stent placement. The dog recovered over a 3-day period with diuretic therapy and positive end expiratory pressure ventilation. Subsequently, the dog died from congestive heart failure 102 days after stent placement, during which time occasional, self limiting coughing episodes occurred.

Diagnosis of feline haemoplasma infection in Australian cats using a real-time PCR assay.

A total of 147 cats from the Sydney area of Australia that had blood samples submitted to veterinary laboratories were tested using a real-time polymerase chain reaction (PCR) assay able to detect and distinguish the two feline haemoplasma species. This sample number included two cats diagnosed with feline haemoplasma infection by routine blood smear examination. Statistical analysis was performed to evaluate associations between haemoplasma infection, age, sex, breed, haematocrit (HCT) values and anaemia status. One hundred and six cats (72.1%) were negative. Thirty-four cats (23.1%) were positive for 'Candidatus M. haemominutum', six cats (4.1%) were positive for M. haemofelis and one cat (0.7%) was positive for both species. Older, male, non-pedigree cats, with lower HCT values were more likely to be infected with 'Candidatus M. haemominutum'. Significant inverse correlation was found between the amount of M. haemofelis DNA present in the blood and the HCT value. This report documents the existence of, and prevalence of, both haemoplasma species in a sample of cats in Australia and is the first to use quantitative real-time PCR in a prevalence study for haemoplasma infection.

Inefficacy of selegiline in treatment of canine pituitary-dependent hyperadrenocorticism.

OBJECTIVE: To evaluate selegiline, a monoamine oxidase-B inhibitor, for treating dogs with pituitary-dependent hyperadrenocorticism. DESIGN: Prospective clinical trial using client-owned dogs with pituitary-dependent hyperadrenocorticism treated at The University Veterinary Centre, Sydney, from September 1999 to July 2001. PROCEDURE: Eleven dogs with pituitary-dependent hyperadrenocorticism treated with selegiline were monitored at days 10, 30 and 90 by clinical examination, tetracosactrin stimulation testing, urinary corticoid:creatinine ratio measurement and client questionnaire. Endogenous adrenocorticotropic hormone measurements were also performed on most dogs on days 0 and 90. No dog treated with selegiline had satisfactory control of disease. CONCLUSION: Selegiline administration was safe and free of side-effects at the doses used, but did not satisfactorily control disease in pituitary-dependent hyperadrenocorticism affected dogs.

The use of real-time PCR in the diagnosis and monitoring of Mycoplasma haemofelis copy number in a naturally infected cat.

A 5-year-old male neutered cat was diagnosed with severe anaemia due to acute Mycoplasma haemofelis infection. Inflammatory respiratory disease was present concurrently. The cat was treated successfully using a fresh transfusion of whole blood and a 6 week course of doxycycline. The patient made a rapid recovery although the allergic airway disease subsequently required specific therapy consisting of inhaled fluticasone and salbutamol. Real-time quantitative PCR assays confirmed the presence of M. haemofelis DNA copies in the blood at presentation. Repeat PCR assays showed a reduction in copy number during treatment and negative PCR results were obtained both 91 and 425 days after presentation. The report describes, for the first time, the use of real-time PCR in the diagnosis and monitoring of natural M. haemofelis copy number, as well as the induction of long-term negative PCR status.

A retrospective analysis of feline bronchoalveolar lavage cytology and microbiology (1995-2000).

A retrospective study of 88 bronchoalveolar lavage specimens from 80 cats presenting to the University of Sydney Veterinary Centre between 1995 and 2000 was performed. Bronchoalveolar lavage cytology and microbiology in conjunction with other diagnostic aids and patient records were used to classify cases as lower respiratory tract infections (LTRIs), LRTI revisits, feline bronchial disease, cardiac disease, neoplastic disease and multisystemic disease. Cases for which a definitive diagnosis could not be made were classified as inconclusive. Infectious agents identified were Mycoplasma spp., Pasteurella spp., Bordetella bronchiseptica, Salmonella typhimurium, Pseudomonas sp., Cryptococcus neoformans, Aelurostrongylus abstrusus and Eucoleus aerophilus. The study highlights the importance of bronchoalveolar lavage cytology and microbiology in the evaluation of feline lower respiratory tract disease.

Congenital portosystemic shunts in dogs and cats.

Congenital portosystemic shunts (PPS) are abnormal vascular communications that allow blood from the intestine to bypass the liver, and are classified as intrahepatic or extrahepatic. Clinical signs are generally related to the nervous, gastrointestinal or urinary systems, and are often vague. In addition, changes present on routine blood analysis are often mild and non-specific. For this reason, alternative tests are required for a diagnosis. Diagnostic tests include serum bile-acid concentrations, ammonia tolerance test, portography, ultrasonography and/or scintigraphy. Medical therapy involves reducing absorption of encephalopathic toxins from the gastrointestinal tract and may prolong survival. Surgical therapy is aimed at attenuation of the shunting vessel and provides improved survival rates. The traditional approach has been complete or partial ligation of the shunt. More recent approaches have involved slow, progressive attenuation with ameroid constrictors or cellophane banding. Overall, prognosis following surgical therapy is good in dogs and fair in cats.

Isolation and identification of Photobacterium phosphoreum from an unexpected niche: migrating salmon.

Six luminous bacteria were isolated from migrating salmon in the Yukon River, Alaska. All isolates were identified as Photobacterium phosphoreum. Previous studies suggest that P. phosphoreum is an exclusively marine bacterium, while our Alaskan isolates are from salmon which migrated up to 1,228 km from the marine environment.

Trilostane treatment in dogs with pituitary-dependent hyperadrenocorticism.

OBJECTIVE: To evaluate the efficacy of trilostane in treating dogs with pituitary-dependent hyperadrenocorticism. DESIGN: Prospective clinical trial using client-owned dogs with pituitary-dependent hyperadrenocorticism treated at University Veterinary Centre, Sydney from September 1999 to July 2001. PROCEDURE: Thirty dogs with pituitary-dependent hyperadrenocorticism treated with trilostane, a competitive inhibitor of 3beta-HSD, were monitored at days 10, 30 and 90 then 3-monthly by clinical examination, tetracosactrin stimulation testing, urinary corticoid:creatinine ratio measurement and by client questionnaire. RESULTS: Twenty-nine of 30 dogs were successfully treated with trilostane (median dose 16.7 mg/kg; range 5.3 to 50 mg/kg, administered once daily); one responded favourably but died of unrelated disease before full control was achieved. CONCLUSION: Trilostane administration controlled pituitary-dependent hyperadrenocorticism in these dogs. It was safe, effective and free of side-effects at the doses used. Most dogs were initially quite sensitive to the drug for 10 to 30 days, then required higher doses until a prolonged phase of stable dose requirements occurred. Urinary corticoid:creatinine ratio was useful in assessing duration of drug effect. Some dogs treated for more than 2 years required reduction or temporary cessation of drug because of iatrogenic hypoadrenocorticism.

Assessment of natural attenuation of chlorinated aliphatics and BTEX in subarctic groundwater.

We examined biogeochemistry and microbiology associated with natural attenuation of trichloroethene (TCE), trichloroethane (TCA), and benzene in a subarctic aquifer. Identification of a predominant terminal electron-accepting process (TEAP) and characterization of typical natural attenuation footprints was difficult. Hydrogen and ferrous iron concentrations suggested that iron reduction was the predominant TEAP; calculated in situ Gibbs free energies for iron reduction were energetically feasible at all wells although a source of ferric iron has not been conclusively determined. The presence of dissolved sulfide and favorable free energies for sulfate reduction provided support of concurrent iron and sulfate reduction. Methanogenesis from H2/CO2 was generally not energetically favorable. The presence of TCE and TCA degradation intermediates suggested that biological reductive dechlorination occurred, although proportions of intermediates relative to parent compounds remained stable. By September 2000, contaminant concentrations were within regulatory standards at most sampling points. However, low rates of microbial activity and incomplete degradation imply that intrinsic bioremediation did not likely represent an important contribution to contaminant removal atthis site, where dilution appeared to be the primary attenuation mechanism.

Effects of chitin on microbial emulsification, mineralization potential, and toxicity of bunker C fuel oil.

Bunker C, one of the most frequently spilled petroleum products in the US, is difficult to remove from oiled surfaces and is relatively recalcitrant to biodegradation; therefore, emulsification and biodegradability must be optimized before bioremediation can be considered a viable treatment option. Sand from a freshly oiled beach near Dutch Harbor, Alaska, was incubated at 10 degrees C with nutrients (Bushnell-Haas (BH)) or nutrients with crab shell chitin (BH-C). BH-C amendment resulted in greater numbers of bunker C emulsifiers and greater mineralization potentials for hexadecane, phenanthrene, and fluorene than with BH only. Compared to BH alone, mineralization potentials for bunker C also were higher in BH-C, with an estimated 8% of fuel oil mineralized after 6 weeks. Microbially emulsified oil was more toxic than in uninoculated controls (p < 0.05) as measured by Microtox assays. However, toxicity was significantly lower in BH-C than BH after 4 and 6 weeks incubation (p < 0.05).

Two polyisoprenylated benzophenones from the trunk latex of Clusia grandiflora (Clusiaceae).

The polyisoprenylated benzophenones, chamones I and II, were isolated from the trunk latex of Clusia grandiflora (Clusiaceae) growing in southeastern Venezuela. A third benzophenone, nemorosone II, was isolated from the pollinator reward resin of the female flowers of the same plant. Chamone I and nemorosone II are structurally similar, differing only in the degree of prenylation. Bioassays of chamone I and nemorosone II using the honeybee pathogens, Paenibacillus larvae and Paenibacillus alvei, demonstrate that both have potent antibacterial activity, and that their structural differences affect both their bactericidal efficacies and their aqueous mobilities.

Microbial populations and hydrocarbon biodegradation potentials in fertilized shoreline sediments affected by the T/V Exxon Valdez oil spill.

The effort of clean up the T/V Exxon Valdez oil spill in Prince William Sound, Alaska, included the use of fertilizers to accelerate natural microbial degradation of stranded oil. A program to monitor various environmental parameters associated with this technique took place during the summer of 1990. Microbiological assays for numbers of heterotrophic and oil-degrading microbes and their hydrocarbon mineralization potentials were performed in support of this program. Fertilizer addition resulted in higher hexadecane and phenanthrene mineralization potentials on treated plots than on untreated reference plots. Microbial numbers in treated and reference surface sediments were not significantly different immediately after the first nutrient application in May 1990. However, subsurface sediments from treated plots had higher numbers of hydrocarbon degraders than did reference sediments shortly after treatment. The second application of fertilizer, later in summer, resulted in surface and subsurface increases in numbers of hydrocarbon degraders with respect to reference sediments at two of the three study sites. Elevated mineralization potentials, coupled with increased numbers of hydrocarbon degraders, indicated that natural hydrocarbon biodegradation was enhanced. However, these microbiological measurements alone are not sufficient to determine in situ rates of crude oil biodegradation.

Sheen screen, a miniaturized most-probable-number method for enumeration of oil-degrading microorganisms.

Sheen Screen is a miniaturized method for enumerating oil-degrading microorganisms. The technique relies on the ability of oil-degrading microorganisms to emulsify oil when provided as a sole carbon source in 24-well tissue culture plates. Sediments that actively respire hydrocarbons have high numbers of Sheen Screen-positive microorganisms.

Growth Kinetics of Thiobacillus ferrooxidans Isolated from Arsenic Mine Drainage.

Thiobacillus ferrooxidans is found in many Alaskan and Canadian drainages contaminated by metals dissolved from placer and lode gold mines. We have examined the iron-limited growth and iron oxidation kinetics of a T. ferrooxidans isolate, AK1, by using batch and continuous cultures. Strain AK1 is an arsenic-tolerant isolate obtained from placer gold mine drainage containing large amounts of dissolved arsenic. The steady-state growth kinetics are described with equations modified for threshold ferrous iron concentrations. The maximal specific growth rate (mu(max)) for isolate AK1 at 22.5 degrees C was 0.070 h, and the ferrous iron concentration at which the half-maximal growth rate occurred (K(mu)) was 0.78 mM. Cell yields varied inversely with growth rate. The iron oxidation kinetics of this organism were dependent on biomass. We found no evidence of ferric inhibition of ferrous iron oxidation for ferrous iron concentrations between 9.0 and 23.3 mM. A supplement to the ferrous medium of 2.67 mM sodium arsenite did not result in an increased steady-state biomass, nor did it appear to affect the steady-state growth kinetics observed in continuous cultures.

Anticholinesterase activity of the unsymmetric bisquaternary 6-aminoquinoline salt NSC-176319.

The anticholinesterase activity of the unsymmetric bisquaternary 6-aminoquinoline salt NSC-176319 (QB) was studied in vitro. QB proved to be a noncompetitive inhibitor of both acetylcholinesterase (or true cholinesterase) and butyrylcholinesterase (or pseudocholinesterase) having a KI = 0.5 X 10(-6) M for acetylcholinesterase and 1.5 X 10(-6) M for butyrylcholinesterase. Further, QB inhibited esterase activity of murine plasma in a noncompetitive manner (KI = 4.2 X 10(-6) M). The inhibition was instantaneous in onset and did not diminish with prolonged incubation of the drug and enzyme. All mice treated intravenously with 2 mg QB/kg died within 5 min. Prior to death, mice developed severe parasympathomimetic effects and convulsions. Although the parasympathomimetic effects were diminished by atropine sulfate pretreatment, death could only be prevented by barbiturate anesthesia.