Doxapram infusion during halothane anaesthesia in ponies

Doxapram, 0.05 mg/kg bodyweight/min, was infused during the second hour of 2 h halothane anaesthesia in six ponies. Two of the ponies were anaesthetised on a second occasion as controls and given 5 per cent dextrose in place of the doxapram. Respiratory depression typical of halothane anaesthesia in ponies developed in the first hour of anaesthesia and continued during the second hour in the control animals. During doxapram infusion arterial carbon dioxide tension decreased and pH increased. Arterial blood pressure increased but there was no change in pulse rate, the electrocardiogram or arterial oxygen tension. Anaesthesia lightened during doxapram infusion necessitating an increase in the vapouriser setting in order to prevent arousal. Recovery from anaesthesia appeared unaffected by the doxapram infusion.     

Autoimmune haemolytic anaemia in eight horses

Autoimmune haemolytic anaemia was diagnosed in eight horses on the basis of a positive Coomb's test. The disease was considered to be idiopathic in three cases and secondary to another condition in five. The clinical signs included dullness and depression, pyrexia, jaundice and haemoglobinuria. In addition to anaemia, haematological evaluation commonly revealed auto-agglutination of red cells and anisocytosis; reticulocytosis and an increased mean corpuscular volume were less commonly observed. Four horses were successfully treated with dexamethasone, but the other four were destroyed or died because of the underlying disease.     

Volatile release from an emulsion: headspace and in-mouth studies

The headspace concentrations of three esters above solutions containing emulsified lipids were more resistant to dilution by a stream of gas than those above water alone. The effect was greatest for ethyl octanoate, and least for ethyl butyrate, with ethyl hexanoate showing intermediate behavior. This correlated with their solubility in the lipid fraction of the emulsion. Headspace analysis (comparing the emulsion with water) underestimated the release of the esters during consumption. The ratios observed between water and emulsion systems were different for the maximum breath concentration compared with headspace analysis. The emulsion appears to have acted as a reservoir for volatile release, counteracting the effects of sample dilution by saliva.     

Effect of salivary components on volatile partitioning from solutions

Partition of fourteen volatile compounds, representing the diverse physicochemical properties of aroma compounds, was measured by static equilibrium headspace in solutions containing the components of artificial saliva, either singly or in mixtures. Comparison of a bovine salivary mucin and pig gastric mucin showed no significant difference in partition behavior of the volatiles, so gastric mucin was used. Mucin viscosity changed with pH, but binding of volatile compounds did not show a marked dependence on pH. All combinations of the salivary components were tested for their effect on partition. Three types of behavior were noted. Partition of some compounds was unaffected by mucin, and with other compounds mucin decreased partition, whereas another group showed a decrease with mucin that was affected by the presence of salivary salts and sugar. When volatiles or sugar were added to a mucin solution, the final headspace concentration depended on the order of addition, indicating some competition for binding. These solute-mucin effects are discussed in relation to mucin structure and behavior in solution.     

Fluorescent-antibody studies of haplosporidian parasites of oysters in Chesapeake and Delaware bays

A fluorescent antibody was produced against a plasmodial oyster parasite thought to be a haplosporidian, Minchinia nelsoni, which was termed MSX. The antibody reacted with this type of plasmodia from oysters, Crassostrea virginica ( Gmelin), from all sources, and it also reacted with its sporulating and spore stages. This reaction indicates cospecificity of the stages. No reaction occurred with any stage of another oyster haplosporidian, Minchinia costalis, indi- cating that the M. nelsoni and the M. costalis are antigenically distinct species.