Lingual vein injection in the rat

The difficulties encountered with repeated intravenous injections in rodents limit many experiments. A method is described which employs the lingual veins of anesthetized rats and which allows for repeated intravenous administration of fluids and cells in young rats and hamsters.     

Molecular diagnosis of Marteilia sydneyi (Paramyxea) in Sydney rock oysters, Saccostrea commercialis (Angas)

Abstract. To prepare a diagnostic test, the polymerase chain reaction (PCR) with universal primers was used to amplify the internal transcribed spacer 1 (ITS1) of Marteilia sydneyi rDNA. A radiolabelled probe for M. sydneyi comprising putative ITS1 rDNA gave a strong signal for genomic DNA from M. sydneyi and no signal for host genomic DNA in Southern blots. A PCR to detect M. sydneyi used a forward primer designed from an internal site within the sequenced region and a reverse universal primer. It amplified a 650-bp fragment of M. sydneyi DNA when a combination of host and parasite DNA, extracted from an infected oyster, was used as the template.     

Studies into immunisation of cattle against interdigital necrobacillosis

Calves were immunised with fractions of Fusobacterium necrophorum incorporated in mineral oil adjuvant and then each foot was experimentally exposed to interdigital necrobacillosis (foot abscess) by subcutaneous injection of homologous organisms through the interdigital skin. The number of cells from an 18 h liquid culture that might be expected to cause 50% of the feet of control calves to develop marked swellings following subcutaneous injection was shown to be approximately 2.2 X 10(8) cells. Immunity was shown to be associated with antigens that were located in the supernatant of the culture, and which may be identical with or closely associated with the exotoxins.     

Resistance to benzimidazole anthelmintics in field strains of Ostertagia and Nematodirus in sheep

SUMMARY: Resistance to a range of benzimidazole anthelmintics was investigated in 2 strains of Ostertagia spp. One strain (SRBO) had been exposed to fenbendazole, oxfendazole and thiabendazole, the other strain (KR79) only to thiabendazole. Both strains showed a high degree of resistance to albendazole, fenbendazole, oxfendazole and thiabendazole, which had efficiencies of 11–38% and 0–60% against all developmental stages of SR80 and KR79, respectively. There was no significant reduction in the KR79 worm count by thiabendazole at 132 mg kg-1 given either as a single dose or divided into 12 equal portions, one administered every 6h. Nematodirus spp were also found to be resistant to all benzimidazoles tested. Levamisole at 7 mg kg^-1 and naphthalophos at 30 mg kg-1 had efficiences of 89 and 66%, respectively, against SR80 Ostertagia and 99 and 19% against Nematodirus, all but the last of these being significant reductions in worm burdens. The resistant SR80 Ostertagia occurred on a research station, but possibly originated from a property which 3 years earlier had supplied ewes to the station. The use of benzimidazole anthelmintics and subsequent grazing on worm-free pasture may have enhanced the level of resistance. A relationship was established between egg counts and adult worm counts 10 days post-treatment, which suggested that for Ostertagia the worm count could be predicted from the geometric mean egg count from about 10 animals. Thus, where an Ostertagia population is suspected of being resistant, an anthelmintic efficiency assay using pre-and post-treatment faecal egg counts should provide a satisfactory diagnostic procedure.     

The efficacy of mixtures of albendazole sulphoxide and levamisole against sheep nematodes resistant to benzimidazole and levamisole

Faecal egg count reduction tests and an anthelmintic efficiency assay were used to assess the efficacy of combinations of albendazole sulphoxide and levamisole against populations of Ostertagia and Trichostrongylus sp. which contained different proportions of worms resistant to both benzimidazole and levamisole anthelmintics. Compared to the effects of either drug alone, significantly greater efficacy was obtained using combinations which included dose rates similar to those recommended for the separate components. At these dose rates, the mixtures reduced mean faecal egg counts by 95% or more, and caused a reduction of 68% in adult Ostertagia sp. and more than 95% for 4th stage Ostertagia and T colubriformis. The increased efficacy of the mixtures could be accounted for by actions of the drugs acting independently.     

Reversal of Oxymorphone Sedation by Naloxone, Nalmefene, and Butorphanol

The effects of naloxone (0.4 mg and 1.2 mg intravenously [IV]), nalmefene (0.03 mg/kg IV) and butorphanol (0.2 mg/kg IV and 0.4 mg/kg IV) on oxymorphone-induced sedation were studied in six dogs over a 4-hour observation period. The same dogs were observed for 4 hours untreated (unsedated control) and with oxymorphone sedation followed by saline solution (sedated control). The reversal drug or saline placebo was administered IV 20 minutes after oxymorphone (4.5 mg IV). Blinded observers evaluated the dogs for positional and attitudinal responses, heart rate, and respiratory rate. Sedated dogs treated with nalmefene most closely resembled unsedated dogs in all observed variables. Naloxone was most effective when administered at the higher dose. Mild renarcotization occurred in two dogs at hour 2, even after the higher naloxone dose. Residual sedation was observed in all dogs treated with 0.4 mg naloxone. Butorphanol resulted in partial reversal of sedation at both dosage levels. However, the degree of sedation was significantly less than that observed in the saline-treated controls, and it appeared that 0.4 mg/kg butorphanol may be clinically useful for opiate reversal in some situations.