Involvement of Beet western yellows virus, Cauliflower mosaic virus, and Turnip mosaic virus in Internal Disorders of Stored White Cabbage

ABSTRACT Experiments over two growing seasons clearly showed that Turnip mosaic virus (TuMV) infection was associated with internal necrosis (sunken necrotic spots 5 to 10 mm in diameter) and Beet western yellows virus (BWYV) infection was associated with collapse of leaf tissue at the margins (tipburn) in heads of stored white cabbage (Brassica oleracea var. capitata). Virtually no tipburn was seen in cv. Polinius, whereas cv. Impala was affected severely. Internal necrotic spots were seen in both cultivars. BWYV appeared to interact with TuMV. Plants infected with both viruses showed a lower incidence of external symptoms and had less internal necrosis than plants infected with TuMV alone. Cauliflower mosaic virus (CaMV) did not induce significant amounts of internal necrosis or tipburn, but did, in most cases, exacerbate symptoms caused by TuMV and BWYV. BWYV-induced tipburn worsened significantly during storage. Post-transplanting inoculation with TuMV induced more internal necrosis than pre-transplant inoculation. There was a significant association between detection of TuMV just prior to harvest and subsequent development of internal necrotic spots. Individually, all three viruses significantly reduced the yield of cv. Polinius, whereas only BWYV and CaMV treatments reduced the yield of cv. Impala.     

Cardiac muscle mass distribution in the domestic turkey and relationship to electrocardiogram.

Ventricular weights were measured in 20-week-old male and female heavy turkeys, and electrocardiograms (ECGs) were recorded in 10- and 20-week-old male and female heavy turkeys. Twenty-week-old males had heavier relative left ventricular and total ventricular weights than females of the same age. Left-to-right ventricular weight ratios were 4.4:1 in males and 4.5:1 in females. Heart rate was faster in young birds and in females, and that influenced the duration of the intervals of the ECG. Wave amplitudes were smaller in 10-week-old turkeys than in 20-week-old turkeys. There was no correlation between electrocardiographic parameters and ventricular weights of male and female turkeys. Two-dimensional ECGs were therefore found to be of minimal value for detecting turkeys with heavier ventricles.     

Recent advances and current concepts in tropical veterinary medicine Eighth CTVM course to be held from 4–16 April 1993

Recent advances and current concepts in tropical veterinary medicine Eighth CTVM course to be held from 4–16 April 1993     

Plasma pharmacokinetics and synovial fluid concentrations after oral administration of single and multiple doses of celecoxib in greyhounds

OBJECTIVE: To determine the plasma pharmacokinetics and synovial fluid concentrations after oral administration of single and multiple doses of celecoxib in Greyhounds. ANIMALS: 7 adult Greyhounds. PROCEDURES: Dogs received celecoxib (median dose, 11.8 mg/kg [range, 11.5 to 13.6 mg/kg], PO, q 24 h) for 10 days. Blood samples were collected prior to administration of celecoxib and serially for 24 hours after the 1st and 10th doses were administered. A synovial joint catheter was placed into a stifle joint in each dog for collection of synovial fluid samples. Concentrations of celecoxib in plasma and synovial fluid were quantified by use of a validated liquid chromatography/mass spectrometry method. Identification of hydroxy- and carboxyl-celecoxib in plasma and synovial fluid was also performed. Pharmacokinetic parameters were determined by use of noncompartmental analysis. RESULTS: Administration of multiple doses of celecoxib resulted in a significant decrease (40%) in median area under the curve (AUC) values and a corresponding decrease in median maximum concentrations (Cmax; 2,620 to 2,032 ng/mL) between the 1st and 10th doses. Synovial fluid concentrations were less than the corresponding plasma concentrations at all times except 24 hours after administration of the 10th dose of celecoxib. CONCLUSIONS AND CLINICAL RELEVANCE: Celecoxib distributes into the synovial fluid of Greyhounds. Although the exact mechanism for the decreases in AUC and Cmax is not known, results suggested that the plasma pharmacokinetics of celecoxib are different after administration of multiple doses in Greyhounds. These findings warrant further investigation on the absorption, distribution, metabolism, and elimination of celecoxib in Greyhounds and other breeds of dogs.     

BMP-2 and -6 modulate porcine theca cell function alone and co-cultured with granulosa cells

Bone morphogenetic proteins (BMPs) are emerging as a family of proteins crucial in the regulation of fertility and ovulation rate. We have shown that porcine theca cells express BMP receptors, however, there is a paucity of information regarding the effect(s) of BMPs on theca cell function. The purpose of this study was to investigate the effects of BMP-2 and -6 on theca cells cultured under serum-free conditions in terms of steroidogenesis, cAMP release and proliferation. The study was further extended to determine whether BMP responses in theca cells are affected by the addition of granulosa cells to the culture system. Both BMPs suppressed progesterone and androstenedione synthesis by theca cells (P < 0.05) after 144 h in culture. Oestradiol synthesis was suppressed (P < 0.05) by BMP-2, but not BMP-6, and theca cell proliferation was stimulated (P < 0.05) by BMP-6, but not BMP-2, after 144 h in culture. Both BMP-2 and -6 inhibited cAMP release (P < 0.05) by theca cells. Furthermore, progesterone and androstenedione synthesis by co-cultured theca and granulosa cells were suppressed (P < 0.05) whereas cell proliferation was stimulated (P < 0.05). These results provide strong evidence for a functional BMP system in the porcine ovary and that theca cells are responsive to BMPs in terms of steroidogenesis and proliferation. BMP-2 and -6 may have a role as luteinisation inhibitors in this polyovular species.     

Azithromycin metabolite identification in plasma,bile, and tissues of the ball python (Python regius)

Azithromycin is the first of a class of antibiotics classified as azalides. Six ball pythons (Python regius) were given a single dose of azithromycin at 10 mg/kg p.o. and i.v. in a crossover design. Serial blood samples were collected for unchanged azithromycin and to determine, if possible, the structure and number of circulating azithromycin metabolites. After a 4-month wash-out period, the snakes were given azithromycin p.o. as a single dose of 10 mg/kg for the study of azithromycin metabolism and metabolite tissue distribution. Bile, liver, lung, kidney, and skin samples were analyzed for the metabolites identified from the first experiment. Unchanged azithromycin accounted for 80, 68, and 60% of the total material at 12, 24, and 48 h postadministration in plasma, independent of route of administration. At both 24 and 72 h postadministration, azithromycin accounted for 70% of total azithromycin- associated material in bile. In liver and kidney, unchanged azithromycin accounted for 40% of the total azithromycin-associated material; this doubled in lung and skin. Fifteen metabolites were positively or tentatively identified in plasma, bile, or tissues of all snakes. Four of these possible metabolites: 3'-desamine-3-ene-azithromycin, descladinose dehydroxy-2-ene-azithromycin, 3'-desamine-3-ene descladinose-azithromycin, and 3'-N-nitroso,9a-N-desmethyl-azithromycin are unique to this species. Descladinose-azithromycin, 3'-N-desmethyl,9a-N-desmethyl-azithromycin, and 3'-N-desmethyl, 3'-O-desmethyl-azithromycin were the only metabolites identified in skin. Kidney tissue contained a greater number of metabolites than liver tissue, with 3'-N-didesmethyl-azithromycin being identified only in the kidney. Compared with the dog and cat, a greater number of metabolites were identified in ball python plasma. The percentage of unchanged azithromycin in bile is not different between the three species.