Comparative efficacy, persistent effect, and treatment intervals of anthelmintic pastes in naturally infected horses.

Eighty horses were involved in a comparative, controlled, and randomised field study conducted in Australia and Brazil. This study was undertaken to address the duration of efficacy (by faecal egg count reduction) of four anthelmintic pastes and to measure the time required between treatments on horses naturally infected by gastrointestinal nematodes. The treatment interval was based on the egg reappearance period (ERP), defined as "the period after treatment when horses have reached a positive egg count equal or superior to 200 eggs per gram (epg) of faeces". Horses were ranked according to pre-treatment faecal egg counts and randomly allocated on Day 0 to one of the four treatment groups (n=16). Group A received a combination of ivermectin at 200 microg/kg and praziquantel at 1.5mg/kg, Group B received an ivermectin paste at 200 microg/kg, Group C received a reference product containing ivermectin at 200 microg/kg, Group D received a moxidectin paste at 400 microg/kg, and Group E received a placebo. Horses were individually faecal sampled at weekly interval from Days 0 to 70 after treatment and coprocultures were made on pooled samples at the pre-treatment time on D-7 in Brazil and D-6 in Australia. The nematode population was mainly composed of small strongyles (Cyathostominae, Gyalocephalus spp., Triodontophorus spp.). All products were efficient (>90% efficacy) until Day 42 with no statistical difference between groups. From Day 49 onwards, Group C reached the threshold, while Group B exceeded this threshold on Day 56. Groups A and D remained below 200 epg for the entire study period (70 days). The interval between two anthelmintic treatments can vary according to the threshold. The ERP was defined as the period after treatment while the output of eggs is negligible or considered as acceptable. The mean number of days calculated to recurrence of 200 epg and more was, respectively, 60 days for product A, 56 days for products B and C, and 64 days for product D. If treatments are combined with other methods of limiting exposure to infective larvae on pasture, the number of treatments required will be reduced even further.

[A case of intramedullary primary melanocytic tumor: meningeal melanocytoma or malignant melanoma?]. / Un cas de tumeur mélanocytaire primitive intramédullaire: mélanocytome méningé ou mélanome malin?

We report a case of an intramedullary thoracic primary melanocytic tumor of the leptomeninges in a 38-year-old woman. According to the WHO classification, the lesion showed the histological features of a meningeal melanocytoma. Two local recurrences were successively operated on, two and three years after the first surgery respectively. The patient died of a subarachnoidian dissemination after a four year course. This case emphasized the therapeutic problems we have to deal with when facing an isolated black tumor of the central nervous system. The features and the differential diagnosis of the meningeal melanocytoma are detailed.

[Platelet group polymorphism in Provence. Comparison with the frequencies of platelet-specific allo-antigens observed in other populations]. / Polymorphisme des groupes plaquettaires en Provence. Comparaison avec les fréquences des allo-antigènes spécifiques plaquettaires observées dans les autres populations.

Systems HPA-1 (Pla); HPA-3 (Bak) HPA-5 (Br) are involved in neonatal alloimmune thrombocytopenia and post-transfusion purpura. The frequencies of platelet-specific antigens in these three systems have been studied among one hundred one unrelated blood donors from Provence (South of France) for three generations. Typing was performed by the MAIPA test (monoclonal antibody-specific immobilization platelet antigen). The phenotypes frequencies found were: HPA-1a (PlA1): 97%; HPA-3a (Baka): 88.1%. These frequencies are quite similar to those reported in Europe and North America, but are different compared to Oriental and South American populations. Our Provence population has the highest frequency of HPA-5b (Bra) yet reported: 23.8%. These results define the polymorphism of platelet-specific antigens in the Provence population. Similar studies, among other populations, would provide new data for geographical haematology, which has so far been based on erythrocyte, leucocyte and serum polymorphisms. The variations between populations in these platelet-specific polymorphisms would be so many useful descriptive elements for the epidemiological study of associated diseases.