Synthesis and inhibitory activity on platelet aggregation of 13'-aza and other omega-chain modified BW245C analogues

BW245C analogues which have 15'-keto, -oximino, -sulphinyl, -sulphonyl, -methyl, -1-adamantyl, 14'-hydroxy, 16'-hydroxy, 13'-14'-NH=CH, -NH-CH2, or -NH-CO groups have been synthesized and evaluated for their activity in inhibiting platelet aggregation and for their cardiovascular actions: the 13'-aza analogues 13 and 14 are more potent inhibitors of human platelet aggregation than BW245C (0.3, 0.6 and 0.2 x PGI2, respectively) and these inhibitory activities on platelet aggregation increase on incubation in vitro. The prostaglandin mimetic properties of 13 (BW68C) and 14 (BW361C) were studied in more detail and their platelet inhibitory and vasodilatory effects found to be of longer duration than those of BW245C. All other modifications to the omega-chain of BW245C led to less potent or inactive compounds.

Cardiotonic 'C' ring modified isomazole analogues

Isomazole analogues which have achiral electron withdrawing substituents at the 4'-position and analogues with heterocyclic 'C' rings have been synthesized and evaluated as inotropic agents. It was found that pyridyl could replace phenyl in the 'C' ring without loss of activity. The 4'-methylsulphonyl, -cyano, -carboxamido, and acetyl analogues had similar inotropic potencies to Isomazole whilst displaying superior cardiovascular profiles in in vivo studies.

Inotropic activities of imidazopyridines

A series of 2-substituted 1H-imidazo[4,5-b]pyridines and the isomeric 1H-imidazo[4,5-c]pyridine derivatives has been prepared and evaluated as inotropic agents. The 1H-imidazo-[4,5-b] derivatives were found to be consistently more potent than their isomers in the [4,5-c] series in isolated guinea pig papillary muscle preparations. Structure-activity relationships and the species-dependence of inotropic potencies are discussed.

Lupins and energy-yielding nutrients in ewes. II. Responses in ovulation rate in ewes to increased availability of glucose, acetate and amino acids

An experiment, using a total of 320 Merino ewes, over two successive breeding seasons was conducted to investigate the separate effects of energy-yielding and protein-yielding nutrients on ovulation rate in sheep. The available energy-yielding or protein-yielding nutrients in the blood of sheep fed a maintenance pelleted ration were increased by either intravenous infusions of metabolites (acetate, glucose or acetate + glucose), feeding lupin grain, modification of the pattern of rumen fermentation to increase propionate production using the ionophore, lasalocid, or by feeding of ruminally undegradable protein (formaldehyde-treated casein). All treatments were given for 9 days prior to and including expected time of ovulation. Ovulation rates were measured by laparoscopy. In the first season (the 1984 experiment) when the effects of lupin grain, glucose + acetate and formaldehyde-treated casein were compared, ovulation rates were increased significantly in the group fed lupin (29%, P less than 0.001) and the group infused with glucose + acetate (24%, P less than 0.01). There was an apparent (17%) but statistically non-significant increase in the group fed casein. In comparisons between lupin grain, glucose, acetate, glucose + acetate, formaldehyde-treated casein and lasalocid in the 1985 experiment there were similar significant increases in ovulation rates in the groups fed lupin, and those infused with glucose or glucose + acetate (approximately 25%, P less than 0.001). The increase in the group infused with acetate was lower at 14% (P less than 0.05) and the increases of 7% in the groups fed casein or lasalocid were not significant.(ABSTRACT TRUNCATED AT 250 WORDS)

Lupins and energy-yielding nutrients in ewes. 1. Glucose and acetate biokinetics and metabolic hormones in sheep fed a supplement of lupin grain

Measurements were made of metabolism of glucose and acetate and changes in plasma hormones in sheep fed a basal ration to meet maintenance requirements for metabolizable energy (ME) or fed the same level of basal ration and given either a supplement of 750 g day-1 lupin grain (Experiment I) or intravenous glucose infusions over periods of 17 h (Experiment 2).In ewes given supplementary lupins, concentrations of volatile fatty acids (VFAs) in rumen liquor increased but molar proportions of VFAs were unchanged. Plasma concentrations of glucose, acetate and propionate increased; entry rates of glucose, acetate and CO2 increased and glucose oxidation (but not acetate oxidation) increased during supplementation with lupins. Other changes measured during lupin supplementation included increased plasma urea, a transient and marked increase in plasma insulin and a concomitant decrease in plasma growth hormone during the first three days, and an increase in plasma tri-iodothyronine (T3) with no changes in plasma thyroxine (T4).When glucose was infused intravenously at rates ranging from 0 to 46.8 mmoles h-1 (cf. 31 mmoles h-1 due to lupins) endogenous entry rate of glucose only increased at the highest infusion rate. There was a negative linear relationship between infusion rate of glucosc and plasma urea, whereas positive linear relationships were found between glucose infusion rate and both plasma insulin and T3.It was concluded that ewes on a maintenance basal diet and fed a supplement of 750 g day-1 lupin grain would rapidly switch to the anabolic mode concomitant with increases in glucose entry rate by more than 100% and acetate entry rate by more than 50%. Long-term intravenous infusion of the amount of glucose equivalent to that promoted by the lupin grain supplement would probably not suppress endogenous glucose production.

Modification of the haemoglobin oxygen dissociation curve in whole blood by a compound with dual action

2-Ethoxy-6-(5-tetrazolyl)xanthone reduces the oxygen affinity of blood by two mechanisms; firstly, by a direct effect on the haemoglobin molecule and secondly by maintaining levels of 2,3-diphosphoglycerate (DPG) in stored blood. This compound thus has potential as a blood storage additive which will improve the oxygen delivery of stored blood.

Achieving the potential of decision support systems

The notion of “decision support systems” (DSS) has entered the lexicon of strategic management in recent years. Practitioner‐oriented planning journals now carry numerous advertisements for commercially available “decision support systems.” The research literature has also begun to address the topic of strategic DSS (e.g.,[15, 24]).