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The miniature swine is steadily gaining prominence as a laboratory animal. This paper attempts to survey the existing literature concerning the Göttinger Minipig and to give some information about breeding, growth-rate and handling. Further studies dealing with the circulation (ECG, blood pressure and heart-rate) of conscious minipigs are reported. In this regard, the Göttinger Minipig is shown, to display a more favorable ratio between diastole and systole than normal swine.

The influence of fixation methods, buffers and ions on the ultrastructure of parathyroid cells was studied in dogs, cats, rats and mice. Parathyroids fixed by immersion showed 3 chief cell variants referred to as cells in active, intermediate and resting stages, multinucleated syncytial cells, atrophic cells and, only in 1 feline parathyroid, a few oxyphil cells. Parathyroid glands fixed by perfusion, however, consisted only of 1 cell type. Satisfactory preservation was achieved by perfusion with 2.5% glutaraldehyde in 0.1M Na cacodylate containing 0.25 mM CaCl₂ and 0.5 mMMgCl₂, and postfixation with 1% Os0₄ in 0.1M s-collidine containing 0.5 mMCaCl₂ and 1.0 mMMgCl₂. Good preservation was also obtained using Na phosphate during prefixation and postfixation. Other combinations of buffers led to shrinkage, dilation of rough endoplasmic reticulum cisternae, disruption of membranes or loss of matrix and secretory granules. The results demonstrate that the variants of parathyroid chief cells, multinucleated syncytial cells and atrophic cells arise during fixation.

The cockroaches Blatella germanica and Supella longipalpa can act as intermediate hosts of Trichospirura leptostoma as demonstrated by experimental infestation. The parasite developed from the embryonated egg into the infective larval stage (L3) in cockroaches within 5-6 weeks. After experimental infection of marmosets (Callithrix jacchus), eggs were first found in faecal samples (prepatency) at 8-9 weeks post-infection. Patency lasts about 2 years. Despite the presence of living adult worms in the marmosets' pancreas, no additional eggs were observed in their faeces after the patent period.