Ulex europaeus agglutinin 1 lectin histochemical staining of dog hepatocellular and bile duct carcinomas

Ulex europaeus agglutinin 1 (UEA-1) lectin-binding is a feature of canine intrahepatic bile duct epithelial cells but not of canine hepatocytes. In tumours diagnosed histologically as cholangiocarcinomas or hepatocellular carcinomas, UEA-1 staining occurred in tumour cells regardless of histological appearance. The division of primary liver carcinomas into different presumed cell types of origin is not reflected by equivalent differentiation of the tumour cells and is not of diagnostic value.     

The effect of CDAA (N,N,-diallyl-2-chloroacetamide) pretreatments on subsequent CDAA injury to corn (Zea mays L.)

The effects of CDAA (N,N-diallyl-2-chloroacetamide) pretreatment on subsequent CDAA injury to corn were examined and compared with the effects of the herbicide protectant R-25788 (N,N,-diallyl-2,2-dichloroacetamide). In addition, the effects of CDAA pretreatment on subsequent CDAA metabolism were determined. It was found that 5μM CDAA protected corn from injury by 200 μM CDAA when given as a 2.5- or 1-day pretreatment. R-25788 at similar concentrations did not protect corn from subsequent R-25788 injury. Pretreatment with CDAA increased GSH levels of corn roots by 61% within 1 day, and these levels did not increase with a longer 2.5-day pretreatment with CDAA. GSH-S-transferase activity was assayed spectrophotometrically using CDNB (1-chloro-2,4-dinitrobenzene). A 1-day pretreatment with CDAA increased the root GSH-S-transferase activity by 35%, but did not affect shoot GSH-S-transferase activity. A 2.5-day pretreatment resulted in a 50% increase in root GSH-S-transferase activity but no response of the shoot enzyme was observed. Even longer pretreatments with CDAA did not result in any further increases in enzyme activity. When corn roots pretreated with CDAA for 2.5 days were excised and incubated with radiolabeled CDAA, they exhibited greater rates of uptake and metabolism than did nonpretreated roots. With in vitro studies, a fairly high rate of nonenzymatic degradation of CDAA was observed. However, the enzymatic rate was always double that of the nonenzymatic rate under the experimental conditions used. It is concluded that elevations in the GSH levels and GSH-S-transferase activities of corn roots following CDAA pretreatments may be involved in the protection of corn from subsequent CDAA injury.     

The effect of tricaine on use of the fluorescein test for detecting skin and corneal ulcers in fish

Fluorescein has been used for rapid and sensitive detection of fish skin and corneal ulceration. Effective use of the fluorescein test requires knowledge of conditions that might cause misleading interpretations or otherwise interfere with test reliability. Examination of fish health and the clinical workup often require tricaine as one of the most commonly used anesthetics. However, tricaine may interfere with correct interpretation of the fluorescein test and might also cause significant fish injury. The effects of tricaine exposure sequence on the fidelity of the fluorescein test was studied in Pacific halibut Hippoglossus stenolepis, walleye pollock Theragra chalcogramma, and northern rock soles Lepidopsetta polyxystra by examining the fluorescence of experimentally induced epidermal wounding. Tricaine can quench fluorescence that is emitted by fluorescein retained in skin ulcers, causing a false-negative reaction. Thus, for the fluorescein test to work properly, it is important to avoid the exposure of fluorescein-treated and rinsed ulcers to tricaine. The effects of exposure to buffered versus unbuffered tricaine on epidermal and corneal integrity were studied in Nile tilapia Oreochromis niloticus and channel catfish Ictalurus punctatus subjected to the fluorescein test and histological examination. Fluorescein could detect not only ulcers but also areas with only a partial loss of epithelium (i.e., erosion). The use of unbuffered tricaine to anesthetize these fish caused serious epidermal and corneal damage. If fish are euthanized with unbuffered tricaine for clinical workup, this severe epidermal or corneal damage could be misinterpreted as an antemortem lesion, leading to misdiagnosis. Even in water with alkalinity exceeding 50 mg/L as CaCO3, it would seem prudent to always buffer tricaine with sodium bicarbonate to prevent a pH change that might lead to iatrogenic effects from unbuffered tricaine. Thus, current general recommendations suggesting that tricaine does not need to be buffered in waters with alkalinity greater than 50 mg/L might need to be modified.     

In this issue – March 2010

Topical anaesthesia for castration and tail docking in lambs · Disease surveillance activities for saleyard pigs · Reproductive effects of time on prepartum transition diets in dairy cows · Bovine herpesvirus type 5 in bull semen · Rib osteomyelitis in three foals · Mycobacterium ulcerans in two horses · Nasal vascular hamartoma in a cat     

In this issue – November 2010

Management and preventive health care in aged horses · Echocardiographs in healthy Thoroughbred foals · Surgical stapling technique for caecal impaction in horses · MRI of the second phalanx in horses · Radiotransmitters in snakes · Nasotracheal intubation of a kangaroo · Avian tracheal resection and anastomosis · Nasal bot fly in a cat · First report of Cryptosporidium andersoni in Australian cattle     

IN THIS ISSUE – July 2010

Presence of Mycobacterium avium subsp. paratuberculosis in raw milk · Profiling of Haemophilus parasuis in live pigs · Cysticercus bovis in Australian cattle · Thoracoscopy for lung lobectomy in the dog · Common bile duct cyst in a cat · Caecal intussusceptions in horses in New Zealand · Improving access to the oral cavity of the wombat · Mycobacterium in a Tasmanian devil · Surgical treatment of osteomyelitis in an alpaca cria     

Retrospective risk factor assessment for complication following tibial tuberosity transposition in 137 canine stifles with medial patellar luxation

This study identified risk factors for complication following tibial tuberosity transposition by retrospective examination of cases that used various surgical techniques. Records and radiographs of 113 dogs with 137 stifles undergoing tibial tuberosity transposition for medial patellar luxation were reviewed. Patient-specific factors, surgical factors, and complication information were recorded. Owners were contacted as necessary to attain a minimum of 30 days follow-up. Of 137 stifles, 59 (43%) had complications, with 24 (18%) identified as major complications. Factors significantly associated with reduced risk of complication included increased age [odds ratio (OR) 0.8] and concurrent cranial cruciate ligament rupture (OR 0.3). Factors significantly associated with increased risk of complication included large breed compared to toy breed (OR 5.5), increased weight (OR 1.3), and use of a screw for tibial tuberosity fixation (OR infinity). While significant, these associations do not imply causality and prospective study is necessary to determine the ideal fixation method for individual patients.     

Basis for antagonism by sodium bentazon of tritosulfuron toxicity to white bean (Phaseolus vulgaris L.)

White bean (Phaseolus vulgaris L.) was used to study the antagonism caused by Na-bentazon on the phytotoxic action of the sulfonylurea (SU) herbicide tritosulfuron. After 168 h, uptake and translocation of [14C]tritosulfuron were reduced by 60 and 89%, respectively, when Na-bentazon was added to the mixture. Addition of (NH4)2SO4 or replacement of Na-bentazon with NH4-bentazon completely eliminated the negative effects on [14C]tritosulfuron uptake but not on its translocation. Scanning electron microscopy revealed that a mixture of Na-bentazon plus tritosulfuron plus DASH HC (0.156%) formed a rough layer of grain-like crystals on the leaf surface, whereas the addition of (NH4)2SO4 or replacement of Na-bentazon with NH4-bentazon resulted in amorphous deposits that may be more easily absorbed. The antagonism of tritosulfuron's phytotoxicity by Na-bentazon involves two separate processes, chemical (uptake effect) and biochemical (translocation effect).