Nitrosothiol esters of diclofenac: synthesis and pharmacological characterization as gastrointestinal-sparing prodrugs.

Despite its widespread use, diclofenac has gastrointestinal liabilities common to nonsteroidal antiinflammatory drugs (NSAIDs) that might be reduced by concomitant administration of a gastrointestinal cytoprotectant such as nitric oxide (NO). A series of novel diclofenac esters containing a nitrosothiol (-S-NO) moiety as a NO donor functionality has been synthesized and evaluated in vivo for bioavailability, pharmacological activity, and gastric irritation. All S-NO-diclofenac derivatives acted as orally bioavailable prodrugs, producing significant levels of diclofenac in plasma within 15 min after oral administration to mice. At equimolar oral doses, S-NO-diclofenac derivatives (20a-21b) displayed rat antiinflammatory and analgesic activities comparable to those of diclofenac in the carrageenan-induced paw edema test and the mouse phenylbenzoquinone-induced writhing test, respectively. All tested S-NO-diclofenac derivatives (20a-21b) were gastric-sparing in that they elicited markedly fewer stomach lesions as compared to the stomach lesions caused by a high equimolar dose of diclofenac in the rat. Nitrosothiol esters of diclofenac comprise a novel class of NO-donating compounds having therapeutic potential as nonsteroidal antiinflammatory agents with an enhanced gastric safety profile.

Use of electronic probes for classifying lamb carcasses.

Three commercially available electronic lamb carcass grading probes (Hennessy Grading Probe, AUS-Meat Sheep Probe, Swedish FTC Lamb Probe) and one developmental probe (Ruakura GR lamb probe) were assessed for accuracy and suitability for use on-line on the lamb dressing chain for objectively classifying lamb carcasses. GR is the total tissue thickness over the 12th rib taken at a distance 11 cm from the mid-line, used to define fatness in lamb carcass grading in New Zealand. Probe measurements were compared with manually measured GR (sometimes used at present) and Toland probe measurements (total tissue depth between the ribs) for accuracy of predicting both GR on the right side of the carcass and also carcass water (indicating muscle) and fat content. Probes were tested on six occasions, each having approximately 50 lambs. All probes combined with carcass weight accounted for over 70% of the variation (R(2)) of GR right, with GR left accounting for 92% of the variation of GR right. Inclusion of a quadratic probe term was not quite as useful as inclusion of carcass weight for predicting GR right. The three commercial electronic probes individually when combined with carcass weight could account for 36-49% of the variation in the percentage of water and fat in the carcass, with the manual GR probe (right) on the chilled carcass accounting for 55% of the variation in water and 58% of the variation in fat percentages. Chilled carcass measurements are expected to give better results than readings on hot carcasses. The use of a quadratic probe coefficient instead of carcass weight with the probe readings gave similar accuracy of prediction of carcass composition. There was little difference between the two sides in the accuracy of prediction. Small differences were found between regressions relating probe readings to GR and composition for the different probing occasions. The electronic probe results from this trial are consistent with overseas results where probes are in use for objectively grading the carcasses of meat animals.

Carcass composition and meat quality of brush-tail possums (Trichosurus vulpecula).

One-hundred-and-thirty-nine possums, balanced as far as possible for sex (68 male, 71 female) and age (1 year, 42; 2-4 years, 61; 5+ years, 36), were slaughtered and the dissected carcass composition, muscle, and cooked meat composition measured. Possums were slaughtered at time in captivity TIC 0 (n = 58), TIC 14 days (n = 20) and TIC 28 days (n = 61). Compared with the 5+ years (mature) age group the 1 year olds (juveniles) were 67% and the 2-4 year olds (immature) 96% of the live weight of the mature possums. Carcass composition was characterised by high lean (78-80%) and low fat (around 1-2%). The cooked meat from possums is very high in protein (∼ 25%) and low in fat, suggesting it should be a valuable source of animal protein with a low total fat, high unsaturated fat content. In all cases cooked meat was rated as tender, based on shear force values, despite having a pH of around 6·3.