Extended abstract of a paper presented at Microscopy and Microanalysis 2007 in Ft. Lauderdale, Florida, USA, August 5 – August 9, 2007

Grazing experiments have shown that using a ryegrass (Lolium perenne L.) variety bred by conventional techniques for high water-soluble carbohydrate (WSC) concentrations can improve liveweight gain in pre-weaned lambs (Lee et al., 2001) and increase milk yields and reduce N excretion in dairy cows (Miller et al., 2001) compared to conventional ryegrass. The aim of this study was to determine the effects of using reseeded upland pastures, sown with either a ryegrass variety bred for elevated levels of WSC or a control ryegrass on the production performance of grazing steers when compared to steers grazing permanent ryegrass/white clover pastures.

Dangerous and even fatal interactions can occur in man following combinations of antidepressants which include non-selective MAO inhibitors. To ascertain the causation, interactions reproducing the clinical phenomena have been elicited in animals with these combinations, and the mechanisms involved have been explored by various pharmacological strategies; 5-HT re-uptake inhibitors proved especially hazardous in combination. Interactions could, however, be avoided even with the 5-HT re-uptake inhibitors, by combination with relatively selective MAO A or B inhibitors, an approach with potential clinical value.

Interest has recently focused on the possibility that the efficacy of drugs used in schizophrenia depends on their ability to alter disposition of cerebral dopamine. Thus, Phenothiazines and butyrophenones elevate dopamine turnover in the brain. (Andén, Roos, and Werdinius, 1964; Laverty and sharman, 1965; Sharman, 1966; Andén, Butcher, Corrodi, Fuxe, and Ungerstedt, 1970); Compounds which are clinically the most potent are those with greatest effect on dopamine turnover (Laverty and Sharman, 1965; O'Keeffe, Sharman, and Vogt, 1970). Augmented turnover is thought to be a consequence of the blockade of central dopamine receptors by these drugs. X-ray crystallography has revealed a similarity of the dopamine conformation to part of the chlorpromazine structure, suggesting that of the chlorpromazine structure, suggesting that phenothiazines can occupy dopamine receptors (Horn and snyder, 1971). More conclusively, in cats, dogs, and rabbits, chlorpromazine antagonized vascular effects of dopamine (Rossum, 1966; Yeh, McNay, and Goldberg, 1969; Brotzu, 1970); and haloperidol considerably diminished motor effects evoked by dopamine infused into the brain of cats and fowls (Cools and Rossum, 1970; Marley and Nistico, 1972).

Hypertensive attacks during treatment with amine oxidase inhibitors were first described in tuberculous patients, and were “rediscovered'’ when these drugs were introduced into psychiatry. In an assessment of iproniazid for tuberculosis (Ogilvie, 1955), 4 out of 42 patients experienced “attacks of a most distressing nature”, with severe throbbing occipital headache and high blood pressure. Six years later, similar attacks were observed in 5 out of 212 patients treated for depression with nialamide (Davies, 1959), but it was not until the introduction of tranylcypromine that reports again appeared (Lurie and Salzer, 1961; Clark, 1961). By the beginning of 1963, over 40 such cases had been reported, including several complicated by intracerebral haemorrhage or cardiac failure due to the rise in blood pressure (Songco, 1961; McClure, 1962; Dorrell, 1963).