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Biomedical subjects

B Cardinaud

Publications and source records attributed to B Cardinaud.

16 recordsLinked to original sources
PubMed1998

Activity of moxidectin 1% injectable solution against first instar Hypoderma spp. in cattle and effects on antibody kinetics.

The activity of the moxidectin as an 1% w/v injectable solution on first instar Hypoderma spp. has been evaluated in sixteen naturally infested young cattle. The animals were selected on the basis of their serological status and allocated to two groups of eight animals. At the end of November, one group was treated with moxidectin at a dose rate of 0.2 mg/kg via the subcutaneous route and the non treated control calves injected with the vehicle. The serological status was assessed 1, 2, 4, 8 and 12 weeks post treatment and the presence of Hypoderma lumps determined every two weeks from February to June. A 100% efficacy of the injectable formulation was demonstrated. A progressive fall of the antibody levels was observed in the treated calves for one month following treatment, suggesting a progressive action of the test compound and a limited risk of hypersensitivity.

Animals↗
PubMed1998

[Evolution of monoamine receptors and the origin of motivational and emotional systems in vertebrates].

The evolving vertebrate nervous system was accompanied by major gene duplication events generating novel organs and a sympathetic system. Vertebrate neural pathways synthesizing catecholamine neurotransmitters (dopamine and noradrenaline), were subsequently recruited to process increased information demands by mediating psychomotor functions such as selective attention/predictive reward and emotional drive via the activation of multiple G-protein linked catecholamine receptor subtypes. Here we show that the evolution of these receptor-mediated events were similarly driven by forces of gene duplication, at the cephalochordate/vertebrate transition. In the cephalochordate Amphioxus, a sister group to vertebrates, a single catecholamine receptor gene was found, which based on molecular phylogeny and functional analysis formed a monophyletic group with both vertebrate dopamine D1 and beta adrenergic receptor classes. In addition, the presence of dopamine but not of noradrenaline was assayed in Amphioxus. In contrast, two distinct genes homologous to jawed vertebrate dopamine D1 and beta adrenergic receptor genes were extant in representatives of the earliest craniates, lamprey and hagfish, paralleling high dopamine and noradrenaline content throughout the brain. These data suggest that a D1/beta receptor gene duplication was required to elaborate novel catecholamine psychomotor adaptive responses and that a noradrenergic system specifically emerged at the origin of vertebrate evolution.

Animals↗
PubMed1997

Early emergence of three dopamine D1 receptor subtypes in vertebrates. Molecular phylogenetic, pharmacological, and functional criteria defining D1A, D1B, and D1C receptors in European eel Anguilla anguilla.

The existence of dopamine D1C and D1D receptors in Xenopus and chicken, respectively, challenged the established duality (D1A and D1B) of the dopamine D1 receptor class in vertebrates. To ascertain the molecular diversity of this gene family in early diverging vertebrates, we isolated four receptor-encoding sequences from the European eel Anguilla anguilla. Molecular phylogeny assigned two receptor sequences (D1A1 and D1A2) to the D1A subtype, and a third receptor to the D1B subtype. Additional sequence was orthologous to the Xenopus D1C receptor and to several other previously unclassified fish D1-like receptors. When expressed in COS-7 cells, eel D1A and D1B receptors display affinity profiles for dopaminergic ligands similar to those of other known vertebrate homologues. The D1C receptor exhibits pharmacological characteristics virtually identical to its Xenopus homologue. Functionally, while all eel D1 receptors stimulate adenylate cyclase, the eel D1B receptor exhibits greater constitutive activity than either D1A or D1C receptors. Semiquantitative reverse transcription-polymerase chain reaction reveals the differential distribution of D1A1, D1A2, D1B, and D1C receptor mRNA within the hypothalamic-pituitary axis of the eel brain. Taken together, these data suggest that the D1A, D1B, and D1C receptors arose prior to the evolutionary divergence of fish and tetrapods and exhibit molecular, pharmacological, and functional attributes that unambiguously allow for their classification as distinct D1 receptor subtypes in the vertebrate phylum.

Adenylyl Cyclases↗
PubMed1997

Persistent efficacy of topical moxidectin against Dictyocaulus viviparus and Ostertagia ostertagi.

The persistent activity of moxidectin topically administered at the dose rate of 0.5 mg kg-1 bodyweight was evaluated against experimental nematode infection in 30 calves randomly allocated to six groups. Five groups were treated on days -42, -35, -28, -21 and -14. The 6th group remained untreated as a control. On Day 0, the calves were infected experimentally with 1000 Dictyocaulus viviparus and 50,000 Ostertagia ostertagi larvae and killed 3 weeks later. The formulation of moxidectin showed excellent activity against both parasites for up to 5 weeks (> 99%). Six weeks after treatment the reduction in the number of D. viviparus was still high (> 90%). No adverse reactions to moxidectin were observed in any of the animals.

Administration, Topical↗
PubMed1996

Efficacy of moxidectin as a 1% injectable solution and a 0.1% oral drench against nasal bots, pulmonary and gastrointestinal nematodes in sheep.

Thirty ewes, 3-10 years old, known to be naturally infected with internal parasites, were allocated to three homogeneous groups of ten ewes each based on faecal nematode egg counts. The following experimental treatments were administered on Day 0: (A) moxidectin 1% injectable solution at 0.2 mg kg-1 body weight; (B) moxidectin 0.1% oral drench solution at 0.2 mg kg-1 liveweight; (C) untreated control. Faecal samples were taken on Days -7, 0, 1, 2, 3, 7, 14, 21, 28 and 35 to obtain counts of nematode eggs. One-half of the ewes in each treatment group were slaughtered 14 days after dosing, while the remainder were slaughtered 35 days after treatment to count the numbers of nasal bots, pulmonary nematodes and gastrointestinal nematodes. Moxidectin 1% injectable solution and moxidectin 0.1% oral drench solution were highly effective against gastrointestinal nematodes and against a variable infection of Dictyocaulus filiaria. Moxidectin 1% injectable solution was effective against first stage larvae of Oestrus ovis, whereas moxidectin 0.1% oral drench was ineffective.

Abomasum↗
PubMed1995

The persistence of the efficacy of injectable or oral moxidectin against Teladorsagia, Haemonchus and Trichostrongylus species in experimentally infected sheep.

The persistence of the efficacy of moxidectin was evaluated against experimental gastrointestinal nematode infections in 55 lambs randomly allocated to 11 equal groups and infected on day 0. Moxidectin 1 per cent injectable solution was administered at a dose rate of 0.2 mg moxidectin/kg bodyweight to five of the groups on days -42, -35, -28, -21 and -14; five other groups were treated with moxidectin 0.1 per cent oral drench at the same dose rate on days -35, -28, -21, -14 and -7, and the 11th group remained untreated as a control. The lambs were infected experimentally with 8000 Teladorsagia circumcincta, 2000 Haemonchus contortus and 10,000 Trichostrongylus colubriformis infective larvae and killed three weeks later. Both formulations of moxidectin showed excellent activity against T circumcincta and H contortus with almost 100 per cent efficacy against the abomasal parasites for up to 35 days after treatment. The efficacy of moxidectin 1 per cent injectable against T colubriformis was much higher (> 99 per cent) than that of the oral drench and it was highly effective up to 21 days after treatment, and gave a moderate reduction in worm burden for up to 35 days after treatment. No adverse reactions to moxidectin were observed in any of the animals.

Administration, Oral↗
PubMed1995

Efficacy of moxidectin pour-on against nematode infections in cattle.

Three groups of eight calves, naturally infected with gastrointestinal nematodes and artificially infected with Dictyocaulus viviparus were used to evaluate the efficacy of moxidectin pour-on at dose rates of 0.35 mg/kg and 0.5 mg/kg bodyweight. With both doses the efficacy was 100 per cent against adult D viviparus, Trichostrongylus axei, Ostertagia species and Nematodirus helvetianus. It was more than 99 per cent against Ostertagia and Nematodirus species fourth stage larvae. A small number of Cooperia species were found after treatment, and for this parasite, the efficacy of moxidectin ranged from 97.6 per cent against the larval stages to 98.8 per cent against the adults. No adverse reactions to the moxidectin treatment were observed.

Abomasum↗
PubMed1995

Efficacy of oral moxidectin against benzimidazole-resistant isolates of gastrointestinal nematodes in sheep.

The efficacy of orally administered moxidectin was determined against four benzimidazole-resistant nematode isolates. At the start of the trial, 30 lambs were each infected experimentally with 20,000 third stage larvae (5000 Haemonchus contortus, 7000 Teladorsagia circumcincta, 3000 Trichostrongylus colubriformis and 5000 Cooperia curticei); 28 days later they were allocated randomly to three groups of 10: one untreated group, one group treated orally with fenbendazole (5 mg/kg bodyweight) and one group treated orally with moxidectin (0.2 mg/kg). Samples of faeces were taken five and 10 days after treatment and the lambs were killed 10 days after treatment. Fenbendazole reduced the average number of nematode eggs in faeces by 95 per cent and the average number of worms by 25 to 45 per cent according to the species. The efficacy of moxidectin against these benzimidazole-resistant isolates was 100 per cent. No adverse reactions to either of the drugs were observed.

Animals↗
PubMed1995

An evolutionary view of drug-receptor interaction: the bioamine receptor family.

The large molecular diversity of receptors and their subtypes means that the pharmacologist is faced with many puzzling characterization questions. First, the molecular diversity of the receptors is deciphered only in part by a pharmacological approach, which precludes a satisfactory receptor classification based solely on pharmacological characteristics. Second, the physiological counterpart of the numerous subtypes of receptors specifically activated by single endogenous ligands remains unclear. Here, Philippe Vernier and colleagues use the example of the bioamine G protein-coupled receptors to show that many of the apparent inconsistencies that emerge from pharmacological and molecular characterizations of receptors can be better understood if the evolutionary history of the receptors is taken into account.

Amines↗
PubMed1994

Sequence and regulation of European eel prolactin mRNA.

cDNA clones encoding the European eel (Anguilla anguilla L.) prolactin were isolated from a pituitary cDNA library constructed in gamma gt10, using a rainbow trout Prl cDNA fragment as a probe. Four different inserts were subcloned into the pGEM 3Z plasmid after PCR amplification. The 1082 bp-long nucleotide sequence revealed an open reading frame of 627 bp encoding a 24 amino acid-long signal peptide followed by a 185 amino acid-long mature protein. Comparison studies showed 60-70% homology with other known teleost fish prolactins and 30-45% with non-teleost fish, amphibian, reptilian, avian and mammalian prolactins. In situ hybridization studies using labelled prolactin RNA probe showed a strong signal in the rostral pars distalis of the pituitary gland. We next examined the physiological regulation of this prolactin synthesis in vivo using Northern blot analysis and prolactin cDNA probe labelled by random priming. The pituitary prolactin mRNA level was markedly decreased 3 weeks after transfer of eels from freshwater to sea water. Implants of thyroid hormones left for up to three weeks were ineffective on prolactin mRNA. Estradiol administered as implant, alone or in combination with 500 micrograms testosterone, was also unable to significantly alter the pituitary mRNA level for prolactin in the freshwater silver eels whatever the dose used (20-500 micrograms) and whatever the duration of treatment (from 4 days to 10 weeks).

Amino Acid Sequence↗