Structure of the sheep epidermis.

The stratum corneum measured on fresh frozen sections was found to be considerably thicker than previously reported. It was uniformly permeated with sebum, which also formed an intact film over the skin surface and it could readily be divided into two zones. The living epidermis was approximately half as thick as the stratum corneum.     

Identification of feline blood B and T lymphocytes by cell electrophoresis.

The electrokinetic properties of feline blood lymphocytes isolated by centrifugation over Ficoll-Isopaque gradient were investigated. A biphasic electrophoretic mobility (EPM) distribution was regularly observed with a low-mobility (LM) population (mean EPM: 0.82) accounting for 32% of blood lymphocytes and a high-mobility (HM) population (mean EPM: 1.09) representing 68% of blood lymphocytes. Following fractionation on nylon-wool columns, lymphocytes with B-cell properties (64% sIg⁺; 9% guinea pig erythrocytes (GPE)-rosette⁺, PHA and Con A unresponsive) were enriched in the adherent fraction and belonged mainly (78%) to the LM population. In contrast, lymphocytes with T properties (5% sIg⁺, 42% GPE-rosette⁺, PHA and Con A responsive) were recovered in the effluent fraction and comprised 84% of HM elements.Thus, in cat blood, LM lymphocytes are likely to represent in majority B cells and HM lymphocytes T cells. This indicates that cell electrophoresis provides an interesting mean for differentiating B and T cells in the cat.     

The activity of albendazole against adult and larval gastrointestinal nematodes in naturally infected calves in the Netherlands

Summary The activity of albendazole against gastrointestinal helminths in naturally infected calves in the Netherlands was tested. The calves were in their fist grazing season and kept in two groups of ten. One of these groups was grazed alternately with sheep. Five out of each group were drenched with albendazole (7.5 mg/kg) on the day they were housed (November 1). Before and 2, 14, and 28 days after treatment individual faecal samples were taken from all calves and larval cultures were made. Ten calves, six treated and four untreated, were killed for post mortem studies 14 days after treatment The remaining calves were slaughtered 14 days later. The drug was highly effective in reducing the egg output, measured as the number of larvae cultured per gram of faeces. Compared with the untreated calves, the reduction was more than 99% two days after treatment, 100% at 14 days, and 99% after 28 days. It was shown that egg output 28 days after treatment came from worms which had developed from arrested larvae of Ostertagia ostertagi that had survived treatment. Post mortem results showed an efficacy of 100% against adult O. ostertagi, of almost 100% against Trichostrongylus axei, and 100% against adult and larval Cooperia oncophora. Twenty-eight days after treatment, the reduction of arrested early fourth stages of O. ostertagi was 85% in comparison with the untreated calves. Apparently less effect was found against Trichuris ovis at the given dose rate.     

Scanning electron microscopic studies on males of trichinella species

Ultrastructure of the cuticle and pseudobursa of adult males of four species of Trichinella has been studied by SEM. T. nativa differs markedly from T. spiralis, T. nelsoni and Trichinella sp. in the form of the pseudobursa. Trichinella sp. differs only slightly from T. spiralis and T. nelsoni. The ultrastructure of the cuticle revealed no characters suitable for the differentiation of the taxons under study.     

Prevalence of antibodies to equine viruses in the Netherlands

Summary The prevalence of antibodies to various viruses was investigated in a series of serum samples collected from horses in the Netherlands between 1963 and 1966 and from 1972 onwards. Neutralizing antibodies to equine rhinopneumonitis virus, equine arteritis virus and to equine rhinovirus types 1 and 2 were detected in respectively 76%, 14%, 66% and 59% of the equine serum samples tested. The observed incidence of serum samples positive to equine adenovirus in the complement fixation test was 39%. Precipitating antibodies to equine infectious anaemia virus were detected only in serum samples from two horses imported from abroad. Haemagglutination inhibiting antibodies to Myxovirus influenzae A / equi-1, M. Influenzae A / equi-2, and Reovirus types 1, 2, and 3 were present in respectively 82%, 50%, 10%, 33% and 3.6% of the serum samples tested. The most frequently observed incidence of antibodies to the various equine respiratory viruses occurred in the groups of horses having repeatedly contact with other horses.