Nylon textiles grafted with chitosan by open air plasma and their antimicrobial effect

Chitosan is a natural non-toxic biopolymer and is widely used in various fields because of the antimicrobial activities. In this study, the properties of nylon textiles grafted with chitosan oligomer or chitosan polymer after being activated by open air plasma were evaluated. Results showed that nylon textiles grafted with chitosan polymer had better antibacterial performances than those grafted with chitosan oligomer. Air plasma activation at a higher speed (26 m/min) for a few times facilitated the grafting of chitosan and critically determined the antibacterial activities. Further treatment with air plasma after grafting improved the antibacterial effect. Overall, chitosan-grafted nylon textiles showed good antibacterial potential as well as biocompatibility.     

Diagnosis of feline polycystic kidney disease by a combination of ultrasonographic examination and PKD1 gene analysis

Persian-related and non-Persian-related cats were examined by ultrasonography and/or molecular testing to determine the prevalence of feline polycystic kidney disease (PKD) and the presence of a PKD1 gene mutation. PCR was used to amplify exon 29 of the PKD1 gene using genomic DNA extracted from blood samples, and the PCR products were analysed by direct DNA sequencing. Among the 111 cats included in the study, 54 were examined by both ultrasonography and gene testing for a point mutation in exon 29 of the PKD1 gene. The prevalence of PKD diagnosed by ultrasonography was 25.9 per cent in all the cats and 24.2 per cent in Persian-related cats. The prevalence of the transversion mutation in exon 29 of the PKD1 gene was 13.5 per cent in all cats and 15.7 per cent in Persian-related cats. Three cats that were diagnosed with PKD by ultrasonography did not have the mutation within exon 29. Nucleotide analysis of exon 29 indicated that male cats had a higher point mutation rate than female cats.     

Manipulation of nitrogen digestion by sheep using defaunation and various nitrogen supplementation regimens

Five ruminally, duodenally, and ileally cannulated sheep (average BW 62 kg) were fed 65% roughage: 35% concentrate diets (CP = 15%) in a 5 x 5 Latin square design to study the applicability of using a combination of defaunation with N supplements (soybean meal [SBM], corn gluten meal [CGM], blood meal [BM], urea, and casein) with different extents of ruminal degradation to manipulate microbial protein synthesis and amount of ruminal escape protein. Diets were fed twice daily (1,759 g DM/d). Defaunation was accomplished with 30-ml doses of alkanate 3SL3 (active ingredient: sodium lauryl diethoxy sulfate)/sheep daily for 3 d with 2 d of fasting. Treatment 1 (control) involved feeding faunated sheep a diet in which the supplemental N (45% of total dietary N) was 67% SBM N and 33% urea N. Treatment 2 involved feeding defaunated sheep the same diet as the control. Treatments 3, 4, and 5 involved feeding defaunated sheep diets in which the supplemental N source was either 67% CGM-BM (1:1 N ratio) N:33% urea N, or 33% CGM-BM N:67% urea N or 33% CGM-BM N:33% urea N:33% casein N, respectively. Compared with the faunated control, defaunation decreased (P less than .05) ruminal ammonia concentration (19 vs 26 mg/dl) and increased (P less than .05) CP flow to the duodenum (253 vs 214 g/d) due to a trend for increases in both bacterial (BCP) and nonbacterial (NBCP) CP flows.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effects of defaunation and various nitrogen supplementation regimens on microbial numbers and activity in the rumen of sheep

Five sheep (average BW 62 kg) were fed 65% roughage: 35% concentrate diets (CP = 15%) in a 5 x 5 Latin square design to study the effects of combinations of defaunation and N supplements (soybean meal [SBM], corn gluten meal [CGM], blood meal [BM], urea, and casein) differing in ruminal degradation on ruminal microbial numbers and activity. Diets were fed twice daily (DM intake 1,759 g/d). Defaunation was accomplished with doses of 30 ml of alkanate 3SL3.sheep-1.d-1 for 3 d with 2 d of fasting. Treatment 1 (control) involved feeding faunated sheep a diet in which the supplemental N was 67% SBM N and 33% urea N. Treatment 2 involved feeding defaunated sheep the same diet as the control. Treatments 3, 4, and 5 involved feeding defaunated sheep diets in which the supplemental N source was either 67% CGM-BM N (CGM and BM combined on a 1:1 N ratio): 33% urea N, or 33% CGM-BM N:67% urea N or 33% CGM-BM N:33% urea N:33% casein N, respectively. Compared with the faunated control, defaunation (Treatments 2, 3, 4, and 5) increased (P less than .05) total direct counts of ruminal bacteria (2.7 vs 1.3 x 10(11)/ml), fungal zoospores (2.8 vs 1.4 x 10(5)/ml), and ruminal microbial protease activity (1.4 vs 1.0 mg azocasein/[ml ruminal fluid.h]). Defaunation did not have a consistent effect on ruminal microbial deaminase activity. Compared with the control, defaunation resulted in lower (P less than .05) total perchloric acid-soluble amino N in ruminal fluid at 4 and 10 h after the morning feeding. Defaunation did not decrease (P greater than .05) total free amino acid concentrations in ruminal fluid, but it altered the profile of free amino acids. Although defaunation increased (P less than .05) ruminal bacterial numbers, no increases in total microbial CP or OM concentrations in ruminal contents were observed.     

Sequence and phylogenetic analysis of P10- and P17-encoding genes of avian reovirus

Avian reovirus (ARV) causes viral arthritis, chronic respiratory diseases, and malabsorption syndrome. The P10 protein is a viroporin and induces cell fusion, whereas the biological function of P17 protein is completely unknown. In this study, the nucleotide sequences of the P10- and P17-encoding genes from 17 field isolates and vaccine strains of ARV isolated over a 23-year period from distinct geographic locations were analyzed to define phylogenetic profiles and to study sequence variability and genetic evolution. These genes displayed the signs of a high level of sequence divergence and have evolved into five distinct lineages, respectively. The P17-encoding gene showed higher sequence divergence than that of P10-encoding gene. Our results indicated that synonymous substitutions predominate over nonsynonymous substitutions in both genes. Comparison of P10 and P17 gene phylograms with those of S-class genes revealed distinct evolutionary patterns, indicating that P10 and P17 evolve in an independent manner. Comparative sequence analysis also showed extensive sequence divergence between ARV and other orthoreoviruses. The phylogenetic analysis of P10- and P17-encoding genes revealed that diversity within both genes is neither dependent of viral serotypes nor correlated with the disease states caused by avian reovirus.     

Effect of yohimbine on xylazine-ketamine anesthesia in cats

Xylazine and ketamine are an anesthetic combination used in feline practice for routine surgical procedures. In a controlled study, we evaluated the effects of yohimbine, an antagonist of xylazine, on the anesthesia induced by this anesthetic combination in cats. Two intramuscular doses of xylazine and ketamine (2.2 mg of xylazine/kg plus 6.6 mg of ketamine/kg and 4.4 mg of xylazine/kg plus 6.6 mg of ketamine/kg) caused approximately 60 and 100 minutes of anesthesia, respectively, in control cats. When yohimbine (0.1 mg/kg) was given intravenously 45 minutes after ketamine administration, the cats regained consciousness within 3 minutes. They were ambulatory 1 to 2 minutes after regaining consciousness. Yohimbine also reversed the bradycardia and respiratory depression elicited by xylazine-ketamine. The results indicated that yohimbine may be useful for controlling the duration of xylazine-ketamine anesthesia in cats.     

Effect of yohimbine on xylazine-induced immobilization in white-tailed deer

Two groups of white-tailed deer were given IM injections of xylazine with a projectile syringe. Deer in one of the groups served as controls and did not receive any treatments other than xylazine. Deer in the other group were given yohimbine IV at various times (15 to 171 minutes) to evaluate its effect on xylazine-induced immobilization. In 5 control deer given 3.7 +/- 1.2 mg of xylazine/kg (mean +/- SD), onset of recumbency was 13 +/- 2 minutes and time to standing was 268 +/- 76 minutes. In 20 principal deer given 2.8 +/- 1.0 mg of xylazine/kg, onset of recumbency was 8 +/- 7 minutes, time to sitting after giving yohimbine was 3 +/- 4 minutes in 18 of the deer, and time to standing after giving yohimbine was 4 +/- 5 minutes in 19 of the deer. Most of these deer were still moderately sedated 30 minutes after injection of yohimbine, but none of them became reimmobilized or as deeply sedated as before the injection of yohimbine. Yohimbine also reversed the bradycardia and respiratory depression induced by xylazine.     

Retrograde flow of spermatozoa into the urinary bladder of rams

Retrograde flow of spermatozoa into the urinary bladder of rams during electroejaculation (EE) was examined. In experiment 1, semen and 4 consecutive samples of the urine released during the first post-EE micturition were collected once a week from 6 rams for 5 weeks during the nonbreeding season. The overall mean concentration per milliliter and the mean total number of spermatozoa in the urine ranged from 3.06 to 4.32 X 10(6) and from 80 to 2,865 X 10(6), respectively. The spermatozoal concentration in sequential urine samples was not different between samples, indicating that these spermatozoa had mixed with the urine before micturition. The percentage of the total number of spermatozoa displaced during EE, which flowed into the urinary bladder (retrograde flow), varied among rams (range 3.9% to 80%). The overall mean percentage of retrograde flow during the nonbreeding season was 28.3%. In experiment 2, a catheter was implanted into the urinary bladder of 6 rams (4 rams were from experiment 1), and semen was collected over 4 weeks during the subsequent breeding season. A urine sample was collected from the implanted catheter before EE. Immediately after semen collection, urine was collected by evacuating the bladder. The spermatozoal concentration in the pre-EE urine ranged from 0 to 1.3 X 10(6) (mean +/- SD, 0.17 +/- 0.38 X 10(6)) and was significantly (P less than 0.0001) lower than the spermatozoal concentration in the post-EE urine, which ranged from 1.10 to 22.55 X 10(6) (mean +/- SD, 9.46 +/- 11.30 X 10(6)).(ABSTRACT TRUNCATED AT 250 WORDS)     

Winter Field Trials of Enrofloxacin for the Control of Aeromonas salmonicida Infection in Salmonids

The antimicrobial enrofloxacin (Baytril®, Bayer) was evaluated under field conditions in the winter months for treatment of clinical Aeromonas salmonicida infections in salmonids by feeding medicated diets. Two trials in which lake trout Salvelinus namaycush were treated with enrofloxacin at 10mg/kg per d for 10d resulted in reduced mortalities when compared to non-medicated controls. A third trial in which Atlantic salmon Salmo salar were treated required 20d for the fish to consume the 10d medicated ration, due to poor feeding. This resulted in an effective dose of 5mg/kg per d for 20d. In spite of the lower feeding activity, a reduction in mortalities in medicated fish was observed. Tissue concentrations of drug were in excess of minimum inhibitory concentrations of the drug for the A. salmonicida isolates tested.