Disposition kinetics and dosage of cephaloridine in calves

The disposition kinetics and dosage regimen of cephaloridine were investigated in calves following a single intravenous dose of 10 mg.kg-1. The distribution half-life and elimination half-life were 0.16 +/- 0.02 and 1.96 +/- 0.16 h, respectively. The apparent volume of distribution was 0.64 +/- 0.06 l.kg-1 and total body clearance which represents the sum of all clearance processes, was 225.2 +/- 15.1 ml.kg-1.h-1. Based on kinetic parameters, a satisfactory intravenous dosage regimen of cephaloridine in calves would be 11.0 mg.kg-1 repeated every 8 h.     

The disposition kinetics,urinary excretion and dosage regimen of amikacin in cross-bred bovine calves

The disposition kinetics, urinary excretion and dosage regimen of amikacin after a single intravenous administration of 10 mg/kg was investigated in six cross-bred bovine calves. At 1 min, the concentration of amikacin in the plasma was 116.9±3.16 µg/ml and the minimum therapeutic concentration was maintained for 8 h. The elimination half-life and volume of distribution were 3.09±0.27 h and 0.4±0.03 L/kg, respectively. The total body clearance (Cl_B) and T/P ratio were 0.09±0.002 L/kg/h and 4.98±0.41, respectively. Approximately 50% of the total dose of amikacin was recovered in the urine within 24 h after administration. Amikacin in concentrations ranging from 5 to 150 µg/ml bound to plasma proteins to the extent of 6.32%±0.42%. A satisfactory intravenous dosage regimen of amikacin in bovine calves would be 13 mg/kg followed by 12 mg/kg at 12 h intervals.     

Effect of a paired mixture of aldrin and formothion on carbohydrate metabolism in a fish, Heteropneustes fossilis

Exposure of the Indian catfish (Heteropneustes fossilis) to a high sublethal concentration, 0.114 ppm (0.8 of the 96-hr LC₅₀) of a mixture of aldrin and formothion, added in a one-to-one ratio, for 3, 6, 12, 48, and 96 hr affected carbohydrate metabolism. Muscle glycogen decreased significantly at 6 and 48 hr; hepatic glycogen content declined at 3, 6, 12, and 48 hr in exposed fish. Blood glucose levels in fish were significantly decreased at 3, 12, 48, and 96 hr. Mean value of blood pyruvate was significantly depressed at 3 hr. Blood lactate levels were elevated at 3, 6, 12, and 96 hr in pesticide-treated fish. The observed effects of the mixture of aldrin and formothion on carbohydrate metabolism in fish could prove useful as a rapid method for evaluating toxicity of pesticides and other toxicants.     

High-throughput approach to detection of knockdown resistance (kdr) mutation in mosquitoes, Culex quinquefasciatus, based on real-time PCR using single-labelled hybridisation probe/melting curve analysis

BACKGROUND: Knockdown resistance (kdr) mutation (L1014F) is a well‐defined mechanism of resistance to pyrethroids and DDT in many insect species. Sensitive detection of the mutations associated with resistance is a prerequisite for resistance management strategies. The authors have developed a new real‐time molecular diagnostic assay based on SimpleProbe^®/melting curve analysis for large‐scale kdr genotyping in the wild population of Culex quinquefasciatus Say, the principal vector of bancroftian filariasis. Melting curve analysis is based on the thermal stability difference between matched and mismatched DNA duplexes. The application of SimpleProbe^® chemistry in insects described here is novel in entomology research. RESULTS: The mosquitoes homozygous for knockdown‐resistant and knockdown‐susceptible allele showed melting peaks at 60.45 °C ( ± 0.25) and 64.09 °C ( ± 0.24) respectively. The heterozygous mosquitoes yielded both peaks at approximately 60.5 °C ( ± 0.2) and 64.20 °C ( ± 0.23). Among the 92 samples genotyped, 16 were found to be homozygous resistant, 44 homozygous susceptible and 32 heterozygous. Comparative assessments were made of all the reported methods for kdr genotyping. CONCLUSION: The present method is cheaper, faster, more reliable and versatile than other alternatives proposed in detecting correct kdr genotypes in mosquitoes. This is the first report using a single‐labelled hybridisation probe to detect point mutations in insect populations. Copyright © 2010 Society of Chemical Industry     

Studies on the immunogenicity of Streptococcus equi vaccines in foals.

The ability of either formalin-treated or heat-inactivated whole Streptococcus equi cell vaccines or partially purified M-protein of S. equi to give rise to protective antibody levels was studied in Standardbred foals by serological means. Two commercial preparations, i.e. a beta-propiolactone killed whole S. equi cell bacterin and a cell-free extract of S. equi cells were included in the study. The mean passive hemagglutination antibody titers (10 X log2) in sera of foals given either four doses of formalin-treated whole cell vaccine or an initial dose of formalin-treated followed by three doses of heat-inactivated vaccine with or without levamisole were significantly higher two weeks after the final dose. These passive hemagglutination antibody titers were higher in foals given formalin-treated whole cell vaccine (6.7 +/- 1.5) than given commercial bacterin (4.5 +/- 2.1). The passive hemagglutination antibody titers in all the groups decreased at 12 to 16 weeks after fourth dose of the vaccine. Foals given a commercial cell-free extract did not show a significant increase in passive hemagglutination antibody titers even up to four weeks after third dose. A group of six pony foals immunized with partially-purified M protein showed mean passive hemagglutination antibody titers lower than those observed in foals given whole cell vaccines. In a challenge experiment with S. equi, two of six foals vaccinated with partially-purified M-protein and all three controls developed clinical disease. The passive hemagglutination antibody of vaccinated foals increased after challenge, while at 28 days postchallenge the passive hemagglutination antibody titers of vaccinates and recovered controls were similar.     

Heavy sarcocystosis in the ocular musculature of cattle and buffaloes

A high prevalence of 71.5 per cent and 69.7 per cent of sarcocystosis was observed in the ocular musculature of cattle and buffaloes respectively, in Bihar, India. The concentration of cysts in the eye muscle was also usually heavy. Ocular musculature appears to be a preferred site for the development ofSarcocystis in these intermediate hosts, second only to the heart muscle. The species ofSarcocystis involved in the present study were morphologically indistinguishable fromS. cruzi in cattle andS. levinei in buffaloes. This appears to be the first report on the occurrence ofS. cruzi andS. levinei in ocular musculature.     

Isolation and characterisation of an Indian strain of Mycoplasma mycoides subsp. mycoides type LC from a case of caprine arthritis

Isolation and characterisation of an Indian strain of Mycoplasma mycoides subsp. mycoides LC from a case of caprine arthritis is reported in the study. The isolate was identified based on biochemical, digitonin sensitivity and growth inhibition tests. The virulence of the organism was studied by pathogenicity test in mice and goat. The antigenic and genomic profile of the isolate was compared with that of the standard strain (Y-Goat). Using different sets of primers, polymerase chain reaction was employed for rapid detection of the strain.