EFFECTS OF ANESTHETIC PROTOCOL ON NORMAL CANINE BRAIN UPTAKE OF 18F‐FDG ASSESSED BY PET/CT

The purpose of this study was to assess the effects of four anesthetic protocols on normal canine brain uptake of 2‐deoxy‐2‐[¹⁸F]fluoro‐d ‐glucose (FDG) using positron emission tomography/computed tomography (PET/CT). Five clinically normal beagle dogs were anesthetized with (1) propofol/isoflurane, (2) medetomidine/pentobarbital, (3) xylazine/ketamine, and (4) medetomidine/tiletamine–zolazepam in a randomized cross‐over design. The standard uptake value (SUV) of FDG was obtained in the frontal, parietal, temporal and occipital lobes, cerebellum, brainstem and whole brain, and compared within and between anesthetic protocols using the Friedman test with significance set at P<0.05. Significant differences in SUVs were observed in various part of the brain associated with each anesthetic protocol. The SUV for the frontal and occipital lobes was significantly higher than in the brainstem in all dogs. Dogs receiving medetomidine/tiletamine–zolazepam also had significantly higher whole brain SUVs than the propofol/isoflurane group. We concluded that each anesthetic protocol exerted a different regional brain glucose uptake pattern. As a result, when comparing brain glucose uptake using PET/CT, one should consider the effects of anesthetic protocols on different regions of the glucose uptake in the dog's brain.     

Retrospective study of 60 cases of feline lymphosarcoma

Objective To characterise epidemiological and clinical findings, and diagnostic procedures undertaken, in cats with lymphosarcoma at a veterinary teaching hospital.
Design Retrospective case study.
Procedure Hospital records were reviewed for 7159 cats, sick or healthy, examined during a 10-year period (1984 to 1994). Sixty cats with lymphosarcoma were identified and classified by anatomical location of the tumour. Data on breed, age, sex, clinical signs and diagnostic procedures were collated.
Results The prevalence of feline lymphosarcoma in the hospital population was 0.84%. Siamese cats appeared predisposed to lymphosarcoma but other purebreds were not. Males were somewhat overrepresented amongst affected cats. Similar numbers of cases (12 to 18) were seen in each of the four anatomic categories (multicentric, mediastinal, alimentary and extranodal). Cats with mediastinal lymphosarcoma were mostly young and Siamese. Clinical signs in affected cats were varied, usually multiple and often nonspecific. Two of 22 cases tested positive for feline leukaemia virus antigen in blood and 6 of 13 were positive for feline immunodeficiency virus antibody.
Conclusions Extranodal lymphosarcoma seemed more prevalent in this study than reported elsewhere. Siamese cats in the study population may have had a genetic predisposition to lymphosarcoma. Limited evidence suggested feline leukaemia virus may be less important, and feline immunodeficiency virus more important, in the local population than indicated in overseas reports. Additional studies are needed to investigate breed predisposition and feline leukaemia virus and feline immunodeficiency virus status in Australian cats with lymphosarcoma.     

Sequential extraction methods for soil organic nitrogen

(pp. 825–831)
This study was carried out to clarify the effects of soil nitrate before cultivation and amounts of basal-dressed nitrogen on additional N application rate and yields of semi-forced tomato for three years from 1998 to 2000. The amounts and timing of additional N dressing were determined based on diagnosis of petiole sap nitrate. The top-dressing was carried out with a liquid fertilizer when the nitrate concentration of a leaflet's petiole sap of leaf beneath fruit which is 2–4 cm declined below 2000 mg L⁻¹.
For standard yield by the method of fertilizer application based on this condition, no basal-dressed nitrogen was required when soil nitrate before cultivation was 150 mg kg⁻¹ dry soil or higher in the 0–30 cm layer; 38 kg ha⁻¹ of basal-dressed nitrogen, which corresponds to 25% of the standard rate of fertilizer application of Chiba Prefecture, was optimum when soil nitrate before cultivation was 100150 mg kg⁻¹ dry soil; 75 kg ha⁻¹ of basal-dressed nitrogen, which corresponds to 50% of the standard, was optimum when soil nitrate before cultivation was under 100 mg kg⁻¹ dry soil. A standard yield was secured and the rate of nitrogen fertilizer application decreased by 49–76% of the standard by keeping the nitrate concentration of tomato petiole sap between 1000–2000 mg L⁻¹ from early harvest time to topping time under these conditions.     

In this issue – May 2010

Flea-associated infectious agents in cats in Eastern Australia · Complications of barium-impregnated polyethylene spheres · Reproductive efficiency of Thoroughbred and Standardbred horses · GPS tracking collars to monitor horses · Correction of vesicovaginal reflux in mares · Antibodies to Lawsonia intracellularis in Australian pig herds · Mucormycosis in the platypus · Panniculitis from Mycobacterium mageritense in a Tasmanian devil