Cell-specific localisation of apoptosis in the bovine ovary at different stages of the oestrous cycle.

Apoptosis was localized in all ovarian cell types of 23 cows in various stages of the oestrous cycle, using the detection of active caspase-3, in situ end labelling (TUNEL) and DNA fluorescent staining (DAPI). Very few apoptotic cells were found in primordial, primary, secondary and vital tertiary follicles. In contrast, apoptosis in atretic tertiary follicles was much more frequent, and high apoptotic scores were recorded when using the TUNEL technique and lower scores with the caspase-3 assay. Cystic atretic follicles showed in general a higher apoptotic score than obliterative atretic follicles, with intermediate to high scores in granulosa cells and lower scores in theca cells. In corpora lutea, large and small lutein cells had intermediate to high scores using the caspase-3 assay, and intermediate to low scores using the TUNEL assay. Irrespective of the detection method, the scores were higher in lutein cells than in the capsular stroma cells. In all ovarian structures examined, variations in apoptotic scores were seen in the different cycle stages, suggesting a cycle-dependent influence on apoptosis, although correlations with plasma progesterone concentrations were low.

Variability in the eruption of the permanent incisor teeth in sheep.

The incisor teeth of 176 sheep of six breeds were inspected every two to three months for a year to record the shedding of the deciduous teeth and the eruption of the permanent teeth. In all the breeds the permanent central incisors erupted at between 12 and 18 months of age. In 96 per cent of the sheep the permanent middle incisors erupted at between 18 and 26 months; and in 92 per cent the permanent lateral incisors erupted at between 24 and 36 months of age. The permanent corner teeth erupted at between 32 and 44 months in 96 per cent of the sheep. The gingival redness and swelling accompanying the eruption of a permanent tooth disappeared within two months. In 14 cases two pairs of incisors erupted during the year, in 18 cases the incisors erupted asymmetrically, and in 22 cases no incisors erupted. Rotation of one incisor was observed in five sheep and was combined with dental deviation in one.

Anatomical localisation and histology of the ovine tonsils.

The topography and histologic structure of the various tonsils were studied anatomically and microscopically in 15 sheep aged between 9 and 15 months. The palatine, pharyngeal and paraepiglottic tonsils were readily visible macroscopically. They consisted mainly of secondary lymph nodules and were encapsulated in dense connective tissues. The epithelium covering the tonsils and their crypts was frequently infiltrated heavily by lymphocytes. The tubal tonsil and the tonsil of the soft palate were macroscopically visible after fixation in 2% acetic acid. These tonsils consisted of scattered lymph nodules, aggregations of lymphocytes and diffuse lymphoid tissue. They were not encapsulated, and therefore the borders of these tonsils could not be clearly delineated. The lingual tonsil was not macroscopically visible in sheep and consisted of scattered small aggregations of lymphocytes.

Measurement of very long-chain fatty acids, phytanic and pristanic acid in plasma and cultured fibroblasts by gas chromatography.

Two methods are described, both currently used in our laboratory, for the quantitative analysis of very long-chain fatty acids, phytanic acid and pristanic acid in plasma and cultured fibroblasts by gas-liquid chromatography. The first method is based on the procedure developed by Moser and Moser (1991) and the second is based on the method of Onkenhout and colleagues (1989), which is an application of the original method of Lepage and Roy for plasma and fibroblasts. A survey is given of the concentrations of very long-chain fatty acids, pristanic and phytanic acid in plasma and fibroblasts from control subjects and all patients investigated so far in our laboratory.

Incorporation of DL-[2-14C]ornithine and DL-[5-14C]arginine in milk constituents by the isolated lactating sheep udder.

1. Lactating mammary glands of sheep were perfused for several hours in the presence of dl-[2-(14)C]ornithine or dl-[5-(14)C]arginine and received adequate quantities of acetate, glucose and amino acids. 2. In the [(14)C]ornithine experiment 1.4% of the casein and 1% of the expired carbon dioxide came from added ornithine; 96% of the total radioactivity in casein was recovered in proline; 13% of the proline of casein originated from plasma ornithine. 3. In this experiment the results of chemical degradation of proline of casein as well as relative specific activities in the isolated products are consistent with the view that ornithine is metabolized, by way of glutamic gamma-semialdehyde, to proline or glutamic acid. 4. In the [(14)C]arginine experiments 3% of the casein and 1% of the expired carbon dioxide came from arginine; 84% of the arginine and 9% of the proline of casein originated from plasma arginine. 5. In these experiments the relative specific activities of arginine, ornithine and proline in plasma are in agreement with the view that arginine is metabolized by way of ornithine to proline. The conversion of arginine into ornithine is probably catalysed by arginase, so that arginase in mammary tissue may be involved in the process of milk synthesis.