The influence of solution environment on the nucleation kinetics and crystallisability of para-aminobenzoic acid.

The influence of solvent type on the solution thermodynamics, nucleation-kinetics and crystal growth of alpha para-aminobenzoic acid (PABA) crystallising from supersaturated ethanol, acetonitrile and water solutions, is examined using poly-thermal analysis of the metastable zone width. Application of a recently proposed model for analysis of crystallisation kinetics (J. Cryst. Growth, 2010, 312, 698-704) indicates a solvent and concentration dependence of the nucleation mechanism and key nucleation parameters for the alpha form of PABA. The mechanism of nucleation is found to change from instantaneous to progressive with decreasing concentration and also when changing the solvent from ethanol to acetonitrile to water. The dependence of the nucleation mechanism is correlated to the kinetic component of the nucleation rate through calculated values of instantaneously nucleated crystallites, which increase from 1.40 × 109 m-3 in ethanol to 1.08 × 1010 m-3 in acetonitrile to 2.58 × 1010 m-3 in water. This in combination with low calculated number concentrations of interfacial tension between 1.13 and 2.71 mJ m-2, supports the conclusion that the kinetic component of the nucleation rate is more limiting when crystallising PABA from ethanol solutions in comparison to water solutions. This finding is further supported by molecular dynamics simulations of the solvation free energy of PABA, which is found to be greatest in water, -42.4 kJ mol-1 and lowest in ethanol, -58.5 kJ mol-1.

Towards an understanding of the nucleation of alpha-para amino benzoic acid from ethanolic solutions: a multi-scale approach.

The molecular assembly and subsequent nucleation of para-amino benzoic acid (PABA) from ethanolic solutions is probed using a multi-scale and multi-technique approach. This is applied by examining and interrelating information regarding the molecular, solution-state, cluster, solid-state and surface structures to understand why the alpha form of PABA is crystallised in preference to its low temperature beta form. Calculations suggest that conformational changes within the solute molecule play little or no role in directing the nucleation of either the alpha or beta crystal forms. Combined ab initio and molecular dynamics calculations of the stability of small clusters in solution suggests that the hydrogen-bonded carboxylic acid dimers, present in the alpha structure, are the most stable in solution and play a major role in the self-assembly and polymorphic expression of the alpha form in ethanol in preference to the beta form. These calculations are in good agreement with X-ray small-angle scattering analysis which reveals the presence of PABA clusters in ethanol which are consistent with the size and shape of a carboxylic acid dimer. SAXS studies also reveal the presence of larger cluster structures in a size range 10-40 nm which appear to grow, perhaps reflecting a change in the balance between monomers and dimers within the solution during the nucleation process. The results of crystallisation-kinetics experiments indicate an instantaneous nucleation mechanism where the number of instantaneously nucleated crystallites is calculated to be 1360-660 nuclei per ml and the subsequent growth is found to be only rate limited by diffusion of the growth unit to the crystallite surface. A linear dependence of growth rate with respect to supersaturation is observed for the (0 1 -1) capping face, which is associated with strong π-π stacking interactions. This is consistent with a solid-on-solid mechanism associated with surface roughened growth and concomitant poor lattice-perfection. Conversely, the side (1 0 -1) surface has a growth mechanism consistent with a 2D nucleation birth and spread mechanism. Hence, these mechanisms result in very fast growth along the b-axis and the needle-like morphology that is observed for alpha-PABA.

Isolation of α-linolenic acid biohydrogenation products by combined silver ion solid phase extraction and semi-preparative high performance liquid chromatography.

Polyunsaturated fatty acids typically found in cattle feed include linoleic (LA) and α-linolenic acid (ALA). In the rumen, microbes metabolize these resulting in the formation of biohydrogenation products (BHP), which can be incorporated into meat and milk. Bioactivities of LA-BHP, including conjugated linoleic acid (cis (c) 9,trans (t) 11-18:2 and t10,c12-18:2) and trans fatty acid isomers (t9-, t10- and t11-18:1) have been investigated, but effects of several BHP unique to ALA have not been extensively studied, and most ALA-BHP are not commercially available. The objective of the present research was to develop methods to purify and collect ALA-BHP using silver ion (Ag(+)) chromatography in sufficient quantities to allow for convenient bioactivity testing in cell culture. Fatty acid methyl esters (FAME) were prepared from perirenal adipose tissue from a cow enriched with ALA-BHP by feeding flaxseed. These were applied to Ag(+)-solid phase extraction, and eluted with hexane with increasing quantities of acetone (1, 2, 10, 20%) or acetonitrile (2%) to pre-fractionate FAME based on degree of unsaturation and double bond configuration. Fractions were collected, concentrated and applied to semi-preparative Ag(+)-high performance liquid chromatography (HPLC) for the isolation and collection of purified isomers, which was accomplished using isocratic elutions with hexane containing differing amounts of acetonitrile (from 0.015 to 0.075%). Purified trans-18:1 isomers collected ranged in purity from 88 to 99%. Purity of the ALA-BHP dienes collected, including c9,t13-18:2, t11,c15-18:2 and t10,c15-18:2, exceeded 90%, while purification of other dienes may require the use of other complementary procedures (e.g. reverse phase HPLC).

Effects of diets supplemented with sunflower or flax seeds on quality and fatty acid profile of hamburgers made with perirenal or subcutaneous fat.

Steers were fed grass hay or red clover silage based diets containing flaxseed or sunflower seed as sources of 18:3n-3 and 18:2n-6 respectively. Hamburgers were made from triceps brachii and perirenal or subcutaneous fat. Perirenal-hamburgers contained more polyunsaturated fatty acids (PUFA), several PUFA biohydrogenation intermediates (BHI), and 18:0 (P<0.05). Oxidative stability was similar across hamburgers (P>0.05). Sensory differences were found due to hamburger fat source, but were < one panel unit. Within perirenal-hamburgers, feeding flaxseed increased 18:3n-3 and its BHI (P<0.05), and feeding sunflower seed increased 18:2n-6 and its BHI (P<0.05). Feeding flaxseed increased off-flavour intensity and oxidation in perirenal-hamburgers (P<0.05). Feeding oilseeds in forage based diets while using perirenal fat to make hamburgers provides opportunities to increase PUFA and BHI with potential to impact human health, but control measures need to be explored to limit oxidation and off-flavours when feeding flaxseed.

Individual trans 18:1 isomers are metabolised differently and have distinct effects on lipogenesis in 3T3-L1 adipocytes.

The objective of this research was to study the metabolism of individual trans fatty acids (FAs) that can be found in ruminant fat or partially hydrogenated vegetable oils (PHVO) and determine their effects on FA composition and lipogenic gene expression in adipocytes. Differentiated 3T3-L1 adipocytes were treated with 200 µM of either trans-9-18:1, trans-11-18:1, trans-13-18:1, cis-9-18:1 or BSA vehicle control for 120 h. Trans-9-18:1 increased total cell FA content (µmole/well) compared to other FA treatments, which was mainly related to the accumulation of trans-9-18:1 in the cells. Adipocytes were able to desaturate a significant proportion of absorbed trans-11-18:1 and trans-13-18:1 (~20 and 30% respectively) to cis-9,trans-11-18:2 and cis-9,trans-13-18:2, whereas trans-9-18:1 was mostly incorporated intact resulting in a greater lipophilic index (i.e. decreased mean FA fluidity) of adipocytes. Trans-9-18:1 up-regulated (P < 0.05) the expression of lipogenic genes including acetyl-CoA carboxylase (1.65 fold), FA synthase (1.45 fold), FA elongase-5 (1.52 fold) and stearoyl-CoA desaturase-1 (1.49 fold), compared to the control, whereas trans-11-18:1 and trans-13-18:1 did not affect the expression of these genes compared to control. Our results suggest that the metabolism and lipogenic properties of trans-11-18:1 and trans-13-18:1, typically the most abundant trans FA in beef from cattle fed forage-based diets, are similar and are different from those of trans-9-18:1, the predominant trans FA in PHVO.

Predicting fat quality from pigs fed reduced-oil corn dried distillers grains with solubles by near infrared reflectance spectroscopy: fatty acid composition and iodine value.

This study tested the ability of near infrared reflectance spectroscopy (NIRS) to estimate the fatty acid (FA) composition and iodine value (IV) of backfat from carcasses of pigs fed reduced-oil corn dried distillers grains with solubles. NIRS was suitable for screening purposes for the proportions of total saturated, monounsaturated, polyunsaturated, n-3 and n-6 FAs and some individual FAs such as C16:0, C18:1, C18:2n-6 and C18:3n-3 (R(2)=0.80-0.89; RMSECVs, root mean square errors of cross-validation=0.21-1.37% total FA) in both cold and warm intact backfat samples. This technology also met the requirements for a quick screening for the backfat IV in both cold and warm intact samples (R(2)=0.90 and 0.87; RMSECVs=1.66 and 1.80% total FA, respectively), which would help provide differential feed-back to pig producers and the feed industry and may provide the opportunity for breeding pigs for a desirable fat quality.

Inclusion of sunflower seed and wheat dried distillers' grains with solubles in a red clover silage-based diet enhances steers performance, meat quality and fatty acid profiles.

The current study compared beef production, quality and fatty acid (FA) profiles of yearling steers fed a control diet containing 70 : 30 red clover silage (RCS) : barley-based concentrate, a diet containing 11% sunflower seed (SS) substituted for barley, and diets containing SS with 15% or 30% wheat dried distillers' grain with solubles (DDGS). Additions of DDGS were balanced by reductions in RCS and SS to maintain crude fat levels in diets. A total of two pens of eight animals were fed per diet for an average period of 208 days. Relative to the control diet, feeding the SS diet increased (P<0.05) average daily gain, final live weight and proportions of total n-6 FA, non-conjugated 18:2 biohydrogenation products (i.e. atypical dienes) with the first double bond at carbon 8 or 9 from the carboxyl end, conjugated linoleic acid isomers with the first double bond from carbon 7 to 10 from the carboxyl end, t-18:1 isomers, and reduced (P<0.05) the proportions of total n-3 FA, conjugated linolenic acids, branched-chain FA, odd-chain FA and 16:0. Feeding DDGS-15 and DDGS-30 diets v. the SS diet further increased (P<0.05) average daily gains, final live weight, carcass weight, hot dressing percentage, fat thickness, rib-eye muscle area, and improved instrumental and sensory panel meat tenderness. However, in general feeding DGGS-15 or DDGS-30 diets did not change FA proportions relative to feeding the SS diet. Overall, adding SS to a RCS-based diet enhanced muscle proportions of 18:2n-6 biohydrogenation products, and further substitutions of DDGS in the diet improved beef production, and quality while maintaining proportions of potentially functional bioactive FA including vaccenic and rumenic acids.

Types of oilseed and adipose tissue influence the composition and relationships of polyunsaturated fatty acid biohydrogenation products in steers fed a grass hay diet.

The current study evaluated the composition and relationships of polyunsaturated fatty acid biohydrogenation products (PUFA-BHP) from the perirenal (PRF) and subcutaneous fat (SCF) of yearling steers fed a 70 % grass hay diet with concentrates containing either sunflower-seed (SS) or flaxseed (FS). Analysis of variance indicated several groups or families of structurally related FA, and individual FA within these were affected by a number of novel oilseed by fat depot interactions (P < 0.05). Feeding diets containing SS increased the proportions of non-conjugated 18:2 BHP (i.e., atypical dienes, AD) and conjugated linoleic acids (CLA) with the first double bond from carbon 7 to 9, trans-18:1 isomers with double bonds from carbon 6 to 12, and these PUFA-BHP had greater proportions in SCF compared to PRF (P < 0.05). Enrichment of conjugated linolenic acids, AD and CLA isomers with the first double bond in position 11 or 12, and t-18:1 isomers with double bonds from carbon 13 to 16 were achieved by feeding diets containing FS, with PRF having greater proportions than SCF (P < 0.05). Principal component analysis visually confirmed interaction effects on these groups/families of FA, and further confirmed or suggested a number of relationships between PUFA-BHP. Feeding SS or FS in a grass hay diet and exploiting adipose tissue differences, therefore, present unique opportunities to differentially enrich a number of PUFA-BHP which seem to have positive health potential in humans (i.e., t11-18:1, c9,t11-18:2 and c9,t11,c15-18:3).

Flaxseed fed pork: n-3 fatty acid enrichment and contribution to dietary recommendations.

The potential to increase n-3 fatty acid (FA) intake via flaxseed fed pork is underestimated when restricted to pure longissimus muscle, whereas a combination of muscle and adipose tissue is typically consumed. Presently, the FA content of pigs fed 0%, 5% and 10% dietary flaxseed for 11 weeks was measured in loin, picnic and butt primals (lean muscle with epimysium (L), L plus seam fat (LS), and LS plus 5 mm backfat (LSS)). The n-3 FA content necessary for an enrichment claim in Canada (300 mg/100 g serving) was exceeded in L from all primals when feeding 5% flaxseed, being 4 fold that of controls (P<0.001), with further enrichment from inclusion of associated adipose tissues (P<0.001). Increasing flaxseed feeding levels in combination with adipose tissue inclusion amplified total long chain n-3 FA (P<0.05), particularly 20:5n-3 and 22:5n-3. Flaxseed-fed n-3 FA enriched pork can contribute substantially to daily long chain n-3 FA intakes, particularly for societies with typically low seafood consumption.

Effects of feeding flaxseed or sunflower-seed in high-forage diets on beef production, quality and fatty acid composition.

Yearling steers were fed 70:30 forage:concentrate diets for 205 d, with either grass hay (GH) or red clover silage (RC) as the forage source, and concentrates containing either sunflower-seed (SS) or flaxseed (FS), each providing 5.4% oil to diets. Feeding diets containing SS versus FS significantly improved growth and carcass attributes (P<0.05), significantly reduced meat off-flavor intensity (P<0.05), and significantly increased intramuscular proportions of vaccenic (t11-18:1), rumenic (c9,t11-CLA) and n-6 fatty acids (FA, P<0.05). Feeding diets containing FS versus SS produced significantly darker and redder meat with greater proportions of atypical dienes (P<0.05). A significant forage × oilseed type interaction (P<0.05) was found for n-3 FA, α-linolenic acid, and conjugated linolenic acid, with their greatest intramuscular proportions found when feeding the RC-FS diet. Feeding GH versus RC also significantly improved growth and carcass attributes, sensory tenderness (P<0.05) and significantly influenced intramuscular FA composition (P<0.05), but overall, forage effects on FA profiles were limited compared to effects of oilseed.

Influence of oilseed supplement ranging in n-6/n-3 ratio on fatty acid composition and Δ5-, Δ6-desaturase protein expression in steer muscles.

This study investigated effects of roasted or extruded oilseed supplementation ranging in n-6/n-3 ratios from 0.3 to 5.0 on the fatty acid composition and expression of delta-5 desaturase (Δ5d) and Δ6-desaturase (Δ6d) protein in commercial steer cheek (m. masseter) and diaphragm (pars costalis diaphragmatis) muscles. In general, the n-6/n-3 ratio of the diet had a subsequent effect on the muscle n-6/n-3 ratio (P < 0.05), with muscle 18:2n-6 and 18:3n-3 content relating to proportion of dietary soya bean and linseed (P < 0.01). Compared with canola, pure linseed and soya bean diets reduced 14:1c-9 and 16:1c-9 (P < 0.05) but increased 18:1t-11 and c-9,t-11 conjugated linoleic acid (CLA) content (P < 0.01). Oilseed processing had a minor influence but extruded oilseeds increase 18:1t-11 and c-9,t-11 CLA compared with roasted (P < 0.05). Polar lipid 18:3n-3 and n-3 long-chain polyunsaturated fatty acid (LC, ⩾20 carbons PUFA) derivative content increased in relation to dietary linseed supplementation in the diaphragm (P < 0.01), whereas only 18:3n-3 was increased in the cheek (P < 0.01). Protein expression did not differ between diets; however, in each muscle the Δ5d protein expression had a stronger association with the desaturase products rather than the precursors. The relationship between Δ5d protein expression and the muscle LC n-6/n-3 ratio was negative in both muscles (P < 0.05). The relationship between Δ6d protein expression and the LC n-6/n-3 ratio was positive in the cheek (P < 0.001) and negative in the diaphragm (P < 0.05). In conclusion, diet n-6/n-3 ratio affected muscle 18:2n-6 and 18:3n-3 deposition, whereas the Δ5d and Δ6d protein expression had some influence on the polar lipid LC-PUFA profile. Results reaffirm that processed oilseeds can be used to increase the proportion of fatty acids potentially beneficial for human health, by influencing the formation of LC-PUFA and reducing the n-6/n-3 ratio.

The labile lipid fraction of meat: from perceived disease and waste to health and opportunity.

The fatty acid composition of beef and pork has been stigmatized due to their relationships with several diseases from cardiovascular disease to cancer. Meat lipids are, however, one of the few components of meat that can be modified in content and composition, and can present opportunities for value added production and health promotion. Until regulations and policies are in place to define requirements for fatty acid enrichment, however, the process remains relatively academic. Once practical goals are in place for fatty acid enrichment in meat, both theory and practice need to converge for successful production of fatty acid enriched meat. The present review covers aspects of policy in Canada, and requirements for research networks to respond to theoretical and practical challenges associated with production of fatty acid enriched meat. Finally, needs for education and marketing are outlined which must be in place to truly realize a transition of meat lipids from perceived disease and waste to health and opportunity.

Dietary influence on the m. longissimus dorsi fatty acid composition of lambs in relation to protein source.

Dietary lipid effect, as a consequence of protein supplement, on lamb m. longissimus dorsi fatty acid composition was investigated, with emphasis on biohydrogenation intermediates. Crossbred lambs (White Swedish Landrace × Texel) were fed a barley-based diet without (CON) or with protein supplements including peas (PEA), rapeseed cake (RC) or hempseed cake (HC). The HC diet resulted in the highest muscle 22:6n-3 proportion, with the RC diet being similar (P<0.05). Protein supplement did not affect the c9,t11 conjugated linoleic acid (CLA) proportion, however the HC diet increased some minor CLA isomers, including t10,c12 CLA (P<0.05). The t10-18:1 and total trans-18:1 were lowest for the RC diet (P<0.05), likely relating to rumen conditions and precursor availability. The saturated, monounsaturated and branched-chain fatty acids were largely unaffected by protein supplement. In conclusion, feeding the RC diet lowered the t10-18:1 and total trans-18:1 in meat, and modestly increased 22:6n-3 content. The direction of these changes would be beneficial, making the RC diet the preferred protein supplement; however the magnitude of the changes in the present experiment may not be sufficient to have an impact on human health.

Penetration of dynorphin 1-13 across the blood-brain barrier.

Previous studies have demonstrated neuroprotective effects of the opioid peptide dynorphin (dyn) 1-13 in focal cerebral ischemia. The passage of dyn 1-13 across the blood-brain barrier (BBB) was studied by a modification of the Oldendorf technique in the normal rat and cat, as well as in a feline model of experimentally induced focal cerebral ischemia. In the rat, dyn 1-13 penetration of the BBB could not be detected by this technique, even in the presence of peptidase inhibitors. In contrast, dyn 1-13 did cross the BBB into the normal cat hippocampus, cortex and cerebellum. The passage of dyn 1-13 across the BBB was greater in cats with experimentally induced focal cerebral ischemia. Some of the tritium-labeled material which crossed the BBB was confirmed by high performance liquid chromatography to be dyn 1-13. These studies support the hypothesis that the therapeutic effects observed after the peripheral administration of dyn 1-13 to cats with focal cerebral ischemia can be produced by a central mechanism of action.

Biocompatibility of potential wound management products: hydrogen peroxide generation by fungal chitin/chitosans and their effects on the proliferation of murine L929 fibroblasts in culture.

Agaricus bisporus, Fusarium graminearum, Phycomyces blakesleeanus, unbleached and bleached, Rhizomucor miehei, and Rhizopus oryzae were examined as sources of fungal chitin/chitosan. The nitrogen content of the alkalitreated mycelia/sporangiophores obtained after optimization of culture conditions, and of similarly treated A. bisporus stipes, was 2.87, 1.29, 6.27, 6.50, 4.80, and 4.95% w/w, respectively, which relates to an estimated chitin content of 42, 19, 91, 94, 70, and 72%, respectively. The hydrogen peroxide (H2O2)-generating ability of the treated fungal materials after 8 h at pH 7.4 and 37 degrees C decreased in the order R. oryzae > P. blakesleeanus unbleached approximately R. miehi > F. graminearum > A. bisporus > P. blakesleeanus bleached. This did not correlate with estimated chitin content. The effect of these fungal materials on the rate of proliferation of murine L929 fibroblasts in culture also was examined. Both pro- and antiproliferant effects were observed. Significant (P < .05) proproliferant effects were observed on day 6 with R. miehei, R. oryzae, and P. blakesleeanus (unbleached and bleached) at 0.01% w/v. The greatest antiproliferant effect was observed with R. oryzae at 0.05% w/v on day 6 (-63% relative to the control, P < .05; cell viability, 95%). In contrast, A. bisporus failed to affect cell yield significantly at either 0.01 or 0.05% w/v. Addition of catalase to cultures containing R. oryzae or R. miehei at 0.05% w/v failed to abolish the antiproliferant effect on day 3, instead producing a small but significant (P < .05) increase in the effect. Catalase also failed to affect significantly the antiproliferant effect of F. graminearum at 0.05% w/v, but did abolish the proproliferant effect of P. blakesleeanus (unbleached and bleached) on day 3. Overall, our results suggest that the H2O2 being generated by the fungal materials modulates cell proliferation but that this effect is superimposed upon a H2O2-independent antiproliferant effect manifesting itself at the higher concentrations of fungal material. The antiproliferant effect was not attributable to Ca2+, Mg2+, or Fe2+ depletion although chelation of Fe2+ did correlate with H2O2-generating ability. Only P. blakesleeanus appears to lack this antiproliferant activity while retaining H2O2-generating activity. These results may aid the selection of fungal chitin/chitosan for further evaluation as a potential wound management material.

Prescribing in the community.

A White Paper issued in December 1996 (Primary Care: Delivering the future), stated that 'the current arrangements for the prescribing, supply and administration of medicines would be subject to review'. In mid-February, the Minister of Health, Gerald Malone, gave details of the team, chaired by Dr June Crown, to carry out this review over the next 12 months. The objectives will be to determine the circumstances in which health professionals may undertake new roles in the prescribing, administration and supply of medicines and the legal and training implications of these changes.

Interactive dressings used in the management of human soft tissue injuries and their potential in veterinary practice.

Abstract Interactive dressings have been successfully used in human wound management to modify the microenvironment at the wound interface to improve the conditions for tissue repair. Only minimal investigation has as yet been carried out to determine the comparative performance of these products in veterinary practice. Some confusion exists with reference to the performance profiles and composition of the product groups. This review will attempt to clarify these differences and indicate their potential for use in veterinary practice. Resumen En la especie humana, se han utilizado favorablemente vendajes interactivos en el manejo de heridas, para la modificación del microambiente a nivel de la interfase de la herida, mejorando las condiciones para la reparación del tejido. Solamente se ha llevado a cabo hasta el momento una investigación mínima para determinar el efecto comparativo de estos productos en veterinaria. Existe una cierta confusión por lo que refiere a los perfiles de rendimiento y composición de los distintos productos. Esta revisión intenta clarificar estas diferencias e indicar su potencial uso en veterinaria. [Turner, T.D. Interactive dressings used in the management of human soft tissue injuries and their potential in veterinary practice (Vendajes interactivos utilizados en el manejo de heridas en tejidos blandos humanos y su potencial en veterinaria). Veterinary Dermatology 1997; 8: 235-242] Zusammenfassung Interaktives Verbandsmaterial wird in der Humanmedizin zur Wundversorgung erfolgreich angewendet, um die Mikroumwelt an der Wundoberfläche zu beeinflussen und so die Bedingungen zur Wundheilung zu verbessern. Bis jetzt wurden nur wenige Untersuchungen durchgeführt, die die Leistungsfähigkeit dieser Produkte in der Veterinärmedizin vergleichen. Es bestehen Unklarheiten bezüglich der Leistungsprofile und Zusammensetzung der Produktgruppen. In dieser Übersicht wird der Verusch unternommen, die Unterschiede herauszuarbeiten und das Verwendungspotential dieser Produkte in der Veterinärmedizin darzustellen. [Turner, T.D. Interactive dressings used in the management of human soft tissue injuries and their potential in veterinary practice (In der Humanmedizin verwendetes interaktives Verbandsmaterial und dessen Potential in der Veterinärmedizin). Veterinary Dermatology 1997; 8: 235-242] Resumé Les pansements interactifs ont été utilises avec succès dans le traitement des plaies pour modifier le microenvironnement à l'interface des plaies afin d'améliorer les conditions de cicatrisation des tissus. Peu d'investigations ont été réalisées pour déterminer la performance comparative de ces produits en pratique vétérinaire. Des confusions existent concernant le profile de performance et la composition des groupes de produits. Cette revue essaye de clarifier ces différences et indique leur potentiel dans leur utilisation en pratique vétérinaire. [Turner, T.D. Interactive dressings used in the management of human soft tissue injuries and their potential in veterinary practice (Pansements interactifs utilisés dans le traitement des plaies des tissus mous chez l'humain et leur potentiel en pratique vétérinaire). Veterinary Dermatology 1997; 8: 235-242].

Management of veterinary wounds.

A comparison is made between the management of human and animal wounds. Wounds should be classified in order to aid the selection of the most appropriate form of treatment. The concept of the 'golden period' is now less accepted and effective early surgical treatment is advocated. The application of newer dressing materials is recommended together with the initial results of a pilot study based on the application of these materials to animal wounds. An enthusiasm was demonstrated in this study and the need for further research has been identified.

Moist wound healing: critique III.

Winter's paper can be identified as the key to many of the advances in wound management that have taken place over the past 25 years.

U50488 reduces the severity of tissue damage in a rabbit model of focal cerebral ischemia.

Many pharmacotherapies for stroke that have been successful in the laboratory have proven to be ineffective in the clinical setting, often because patients do not arrive for treatment until hours after the onset of the ischemic insult. Kappa opioid treatment of cerebral ischemia has been successful in the cat and mouse with treatment delays of up to 6 h. The purpose of the present study was to develop a model of delayed kappa opioid treatment of cerebral ischemia in the rabbit. Fourteen rabbits underwent permanent, unilateral occlusion of the internal carotid, middle cerebral, and anterior cerebral arteries via a transorbital, microsurgical approach. At 6 h postocclusion, animals received a blinded bolus injection and continuous infusion of either saline or the kappa agonist, U50488. Survival was not improved after U50488 treatment. U50488 treatment did, however, reduce areas of severe tissue damage and increase areas of modest tissue damage. This suggests U50488 arrested the progression of damage from noninfarcted to fully infarcted tissue. The present results show beneficial effects of delayed treatment with kappa agonists in a species similar in vasculature to humans, and much less costly than primates or cats.