IOHEXOL AND IOPAMIDOL MYELOGRAPHY IN THE DOG: A CLINICAL TRIAL COMPARING ADVERSE EFFECTS AND MYELOGRAPHIC QUALITY

In a blind clinical trial, adverse effects after iohexol and iopamidol myelography were evaluated in 151 dogs. Eighty-one dogs were given iohexol (240 mgI/ml) and 70 dogs were given iopamidol (200 mgI/ml) by pre-determined assignment. Each dog was evaluated postmyelographically for seizures, hyperthermia, prolonged recovery from anesthesia and intensification of pre-existing neural signs. Myelographic quality was evaluated with a subjective scoring method. In comparing iohexol and iopamidol groups, there was not a statistically significant difference in the incidence of adverse effects or in myelographic quality. Iopamidol and iohexol appeared to be equally efficacious for routine canine myelography.     

Molecular Identification of a New Member of the Clover Proliferation Phytoplasma Group (16SrVI) Associated with Centaurea Solstitialis Virescence in Italy

In the United States, yellow starthistle (Centaurea solstitialis) is an annual invasive weed with Mediterranean origins. Malformed plants displaying witches' broom, fasciations, abortion of buds and flower virescence symptoms were observed in central Italy. Attempts to transmit the causal agent from the natural yellow starthistle host to periwinkle by grafting, resulted in typical symptoms of a phytoplasma, i.e. yellowing and shortening of internodes. The detection of phytoplasmas was obtained from both symptomatic yellow starthistle and periwinkle by the specific amplification of their 16S-23S rRNA genes. PCR amplification of extracted DNA from symptomatic plant samples gave a product of expected size. Asymptomatic plants did not give positive results. An amplicon obtained by direct PCR with universal primers P1/P7 was cloned and sequenced. The homology search using CLUSTALW program showed more than 99% similarity with Illinois elm yellows (ILEY) phytoplasma from Illinois (United States) and 97% with Brinjal little leaf (BLL) phytoplasma from India. Digestion of the nested-PCR products with restriction enzymes led to restriction fragment length polymorphism patterns referable to those described for phytoplasmas belonging to the clover proliferation (16S-VI) group. Since this is a previously undescribed disease, the name Centaurea solstitialis virescence has been tentatively assigned to it. This is a new phytoplasma with closest relationships to ILEY and BLL, but distinguishable from them on the basis of 16S rDNA homology, the different associated plant hosts and their geographical origin.     

LOW-FIELD MAGNETIC RESONANCE IMAGING OF EARLY SUBCHONDRAL CYST-LIKE LESIONS IN INDUCED CRANIAL CRUCIATE LIGAMENT DEFICIENT DOGS

Six healthy adult male mongrel dogs underwent cranial cruciate ligament transection in the left stifle. Survey radiography of both stifles and low-field (0.064 T) MRI of the left stifle were performed preoperatively and at 2, 6, and 12 weeks postoperatively. Focal changes in signal intensity were seen with MRI in the subchondral bone of the medial tibial condyle at 2 and 6 weeks postoperatively. At 12 weeks postoperative, a cyst-like lesion was detected using MRI in the subchondral bone of the medial tibial condyle in 4 of 6 dogs and a less defined lesion at this site in the remaining 2 dogs. The cyst-like lesion was spherical in shape and showed typical characteristics of fluid with low signal intensity on T1-weighted images, high signal intensity on T2-weighted images and high signal intensity on inversion recovery images. The lesion was seen in the subchondral bone of the caudal medial and/or middle region of the tibial plateau slightly cranial to the insertion of the caudal cruciate ligament. No subchondral cysts were seen in the tibia on radiographs. Histopathologically, the tibia was characterized by a loose myxomatous phase of early subchondral cyst formation.     

Phase II Clinical Trial of Carboplatin in Canine Transitional Cell Carcinoma of the Urinary Bladder

Fourteen dogs with histologically-confirmed transitional cell carcinoma (TCC) of the urinary bladder were treated with 300 mg/m² carboplatin every 3 weeks. Response to therapy was assessed with abdominal radiography, double contrast cystography, urinary bladder ultrasonography and thoracic radiography before therapy and at 6–week intervals during therapy. Dogs were monitored for hematologic toxicity with a CBC and platelet count performed immediately before and 10 to 14 days after carboplatin treatment. Tumor responses included progressive disease in 11 dogs and stable disease in 1 dog. Two dogs were euthanized due to carboplatin toxicity before assessment of tumor response. Toxicity included thrombocytopenia with or without neutropenia in 7 dogs and gastrointestinal toxicity in 6 dogs. Carboplatin therapy was not beneficial in the treatment of TCC in the 14 dogs in this study.     

Persistent hematuria in a dog with renal hemangioma

Persistent hematuria in a neutered male Collie failed to resolve after treatment for adult Dirofilaria immitis. Excretory urography revealed normal opacification and an hourglass-shaped right kidney, with distortion of the renal pelvis and diverticula. After ureteronephrectomy, recovery was uncomplicated, and hematuria ceased 2 weeks after surgery. The middle of the excised kidney had been replaced with blood-filled spaces that were consistent with histopathologic diagnosis of hemangioma.     

ENLARGING BILATERAL FEMORAL CONDYLAR BONE CYSTS WITHOUT SCINTIGRAPHIC UPTAKE IN A YEARLING FOAL

Bilateral subchondral bone cysts of the femoral condyles were diagnosed by conventional radiography in a 14 month old Appaloosa colt. Surgical debridement was performed, and over the next 18 months the appearance of the cysts was evaluated with radiography and bone scintigraphy. On the preoperative scintigrams, increased radiopharmaceutical uptake was associated with the cysts. Despite continued radiographic enlargement, the cysts did not demonstrate increased radiopharmaceutical uptake post-operatively.     

Marker assisted polycross breeding to increase diversity and yield in perennial ryegrass (Lolium perenne L.)

Summary In this study, the application of molecular markers to optimise genetic diversity in a polycross breeding program of perennial ryegrass (Lolium perenne L.) was evaluated. The genetic diversity among 98 potential parental plants from three maturity groups (early, intermediate and late flowering) was investigated using amplified fragment length polymorphism (AFLP) markers. For each maturity group, two polycrosses of six parental plants with contrasting levels of genetic diversity were composed. Average genetic diversity among parents selected for narrow polycrosses was 36% lower than among parents selected for wide polycrosses. Diversity within first generation synthetic progenies (Syn1) was proportional to the diversity within the respective parental polycrosses. However, differences were less pronounced with Syn1 progenies from narrow polycrosses showing 16% reduced diversity when compared to Syn1 progenies from wide polycrosses. Multivariate analyses allowed for a clear separation of the six Syn1 progenies based on AFLP markers and demonstrated their genetic distinctness. Evaluation of dry matter yield, date of ear emergence and stem length of Syn1 and Syn2 progenies showed progenies from wide polycrosses to be constantly higher yielding when compared to progenies from narrow polycrosses. On the other hand, there was no significant difference in variability for the two morphological traits between progenies of narrow- and wide polycrosses. The results presented here provide evidence for an efficient application of molecular markers to select genetically diverse polycross parents which resulted in an average yield increase of 3.8%.     

Rapid method of determining pollen incompatibility in Chrysanthemum morifolium Ramat

Summary A classification system for predicting high, medium and low seed set from Chrysanthemum morifolium crosses was developed. Stigmas collected and preserved 8 days after pollination were examined with a binocular microscope for adhering pollen grains. Florets from compatible crosses had brown stigmas with pollen grains attached and embryo development while florets from incompatible crosses had white stigmas with no or rarely 1 or 2 pollen grains attached and no embryo development. Using this method the occurrence of seed set was predicted with 78.5% accuracy in one year and 89% in the following. This provides a method of determining the compatibility of a chrysanthemum cross without waiting the 1 to 2 months required for seed ripening.Scientific Journal Series Paper Number 7570 of the Minnesota Agricultural Experiment Station.