Characterization of three novel desaturases involved in the delta-6 desaturation pathways for polyunsaturated fatty acid biosynthesis from Phytophthora infestans.

Phytophthora infestans is the causative agent of potato blight that resulted in the great famine in Ireland in the nineteenth century. This microbe can release large amounts of the C20 very long-chain polyunsaturated fatty acids arachidonic acid (ARA; 20:4Δ(5, 8, 11, 14)) and eicosapentaenoic acid (EPA; 20:5Δ(5, 8, 11, 14, 17)) upon invasion that is known to elicit a hypersensitive response to their host plant. In order to identify enzymes responsible for the biosynthesis of these fatty acids, we blasted the recently fully sequenced P. infestans genome and identified three novel putatively encoding desaturase sequences. These were subsequently functionally characterized by expression in Saccharomyces cerevisiae and confirmed that they encode desaturases with Δ12, Δ6 and Δ5 activity, designated here as PinDes12, PinDes6 and PinDes5, respectively. This, together with the combined fatty acid profiles and a previously identified Δ6 elongase activity, implies that the ARA and EPA are biosynthesized predominantly via the Δ6 desaturation pathways in P. infestans. Elucidation of ARA and EPA biosynthetic mechanism may provide new routes to combating this potato blight microbe directly or by means of conferring resistance to important crops.

Proximal aortic compliance and diastolic function assessed by speckle tracking imaging.

PURPOSE: Speckle tracking imaging (STI) is a recent technique that evaluates an echocardiographic image throughout the cardiac cycle and provides dynamic variables such as tissue velocities and strain rates. The objective of our study was to determine 1) if STI can be used to quantify proximal aortic compliance and 2) if decreased aortic compliance determined by STI will reproduce the previously reported correlation with diastolic function. METHODS: This was a retrospective observational case series using previously obtained intraoperative transesophageal images. Diastolic performance was quantified by STI-based longitudinal velocities of the basal-septal and basal-lateral walls of the left ventricle in early diastole (LV E'). Change in proximal aortic volume was calculated using STI to measure peak longitudinal and radial velocities in early diastole. After normalizing for mean arterial pressure, compliance was calculated and then compared with basal-septal and basal-lateral LV E' using single regression analysis. RESULTS: Twenty patients were included in our analysis. Linear regression of basal-septal LV E' and basal-lateral LV E' vs proximal aortic compliance during diastole each resulted in an R(2) value of 0.26 (P < 0.05). CONCLUSION: Speckle tracking can be used to describe the physical motion of the aortic wall and to calculate its compliance. We confirm that variation in diastolic function can be attributed, in part, to aortic compliance. Our novel approach of measuring compliance throughout the cardiac cycle, isolating radial and longitudinal contributions, and evaluating previously obtained images retrospectively provides advantages over previously reported measures of aortic compliance. Speckle tracking promises new insights into ventricular function, aortic mechanics, and the interaction between these structures.

The viscous behaviour of HES 130/0.4 (Voluven®) and HES 260/0.45 (Pentaspan®).

PURPOSE: Several fluids are available for volume therapy to address hypovolemia. We focus on two hydroxyethyl starches (HES) available for volume expansion in Canada, HES 130/0.4 (Voluven®) and HES 260/0.45 (Pentaspan®). Although information is available regarding their pharmacokinetic and risk/benefit profiles, this paper examines their viscous properties. METHODS: Dynamic viscosities of HES 130/0.4 and HES 260/0.45 were measured through capillary viscometry at 21°C and 37°C. The viscosities of the solutions were then measured through a closed flow loop at room temperature across physiologically relevant flow rates that maintained a laminar flow regime. RESULTS: Measured dynamic viscosity through capillary viscometry for HES 130/0.4 and HES 260/0.45 was 2.76 centipoises (cP) and 7.62 cP, respectively, at 21°C decreasing to 1.74 cP and 4.25 cP, respectively, at 37°C. Pipe flow analysis found that HES 130/0.4 (expiry 02/13) and HES 260/0.45 (expiry 10/10) displayed marginal variation in viscosity suggesting Newtonian behaviour. However, a sample of HES 130/0.4 (expiry 10/10) displayed an appreciable increase in viscosity (13%) at higher flow rates suggesting shear thickening behaviour. CONCLUSION: This study represents an innovative characterization of not only the viscosity of two commonly utilized HES solutions but also their viscous behaviour across physiologically relevant flow rates. The shear thickening behaviour of a sample of HES 130/0.40 (expiry 10/10) at high flow rates was not expected, and the effect this result may have on endothelial cell function is unknown.

Biomechanics in ascending aortic aneurysms correlate with tissue composition and strength.

Objective: This study correlates low strain tangential modulus (LTM) and transition zone onset (TZo) stress, biomechanical parameters that occur within the physiological range of stress seen in vivo, with tissue strength and histopathologic changes in aneurysmal ascending aortic tissue. Method: Ascending aortic aneurysm tissue samples were collected from 41 patients undergoing elective resection. Samples were subjected to planar biaxial testing to quantify LTM and TZo. These were then correlated with strength assessed from uniaxial testing and with histopathologic quantification of pathologic derangements in elastin, collagen, and proteoglycan (PG). Results: Decreased LTM and TZo were correlated with reduced strength (P < .05), PG content (P < .05), and elastin content (P < .05). Reduced TZo also was correlated with increased elastin fragmentation (P < .05). Conclusions: LTM and TZo are correlated with common biomechanical and histopathologic alterations in ascending aortic aneurysm tissue that are thought to relate to the risk of acute aortic syndromes. LTM and TZo are measured under conditions approximating in vivo physiology and have the potential to be obtained noninvasively using medical imaging techniques. Therefore, they represent parameters that warrant future study as potential contributors to our growing knowledge of pathophysiology, disease progression, and risk stratification of aortic disease.

Polyphenol and vitamin C contents in European commercial blackcurrant juice products.

Vitamin C and polyphenol contents (anthocyanins, proanthocyanidins, phenolic acids and flavonols) were analysed in commercial blackcurrant juice products purchased from various European countries (Finland, Poland, Germany, United Kingdom) using HPLC methods. The aim was to study variation between countries, as well as evaluate the intake of polyphenols from commercial juices. There was significant variation in the contents of polyphenols and vitamin C between countries. Expressed as the ready-to-drink beverages, German, Polish, Finnish and British products averaged anthocyanin contents of 38, 32, 12 and 7.5mg/2.5dl, proanthocyanidin contents of 27, 24, 10 and 1.2mg/2.5dl, flavonol contents of 16, 15, 5.2 & 1.9mg/2.5dl and phenolic acid contents of 12, 8.9, 3.7 and 1.5mg/2.5dl, respectively. The mean vitamin C content was highest in British (70mg/2.5dl) and lowest in Finnish products (15mg/2.5dl). The intake of polyphenols from German and Polish ready-to-drink beverages was clearly higher than that from Finnish, and especially, British beverages.

Bioaccessible Raspberry Extracts Enriched in Ellagitannins and Ellagic Acid Derivatives Have Anti-Neuroinflammatory Properties.

Chronic neuroinflammation associated with neurodegenerative disorders has been reported to be prevented by dietary components. Particularly, dietary (poly)phenols have been identified as having anti-inflammatory and neuroprotective actions, and their ingestion is considered a major preventive factor for such disorders. To assess the relation between (poly)phenol classes and their bioactivity, we used five different raspberry genotypes, which were markedly different in their (poly)phenol profiles within a similar matrix. In addition, gastro-intestinal bio-accessible fractions were produced, which simulate the (poly)phenol metabolites that may be absorbed after digestion, and evaluated for anti-inflammatory potential using LPS-stimulated microglia. Interestingly, the fraction from genotype 2J19 enriched in ellagitannins, their degradation products and ellagic acid, attenuated pro-inflammatory markers and mediators CD40, NO, TNF-α, and intracellular superoxide via NF-κB, MAPK and NFAT pathways. Importantly, it also increased the release of the anti-inflammatory cytokine IL-10. These effects contrasted with fractions richer in anthocyanins, suggesting that ellagitannins and its derivatives are major anti-inflammatory (poly)phenols and promising compounds to alleviate neuroinflammation.

Glutathionyl-S-chlorogenic acid is present in fruit of Vaccinium species, potato tubers and apple juice.

A hydroxycinnamate-like component was identified in highbush blueberry (Vaccinium corymbosum) fruit, which had identical UV and mass spectrometric properties to an S-linked glutathionyl conjugate of chlorogenic acid synthesized using a peroxidase-catalyzed reaction. The conjugate was present in fruits from all highbush blueberry genotypes grown in one season, reaching 7-20% of the relative abundance of 5-caffeoylquininc acid. It was enriched, along with anthocyanins, by fractionation on solid phase cation-exchange units. Mining of pre-existing LC-MS data confirmed that this conjugate was ubiquitous in highbush blueberries, but also present in other Vaccinium species. Similar data mining identified this conjugate in potato tubers with enrichment in peel tissues. In addition, the conjugate was also present in commercial apple juice and was stable to pasteurization and storage. Although glutathionyl conjugates of hydroxycinnamic acids have been noted previously, this is the first report of glutathionyl conjugates of chlorogenic acids in commonly-eaten fruits and vegetables.

Production of very long chain polyunsaturated omega-3 and omega-6 fatty acids in plants.

We report the production of two very long chain polyunsaturated fatty acids, arachidonic acid (AA) and eicosapentaenoic acid (EPA), in substantial quantities in a higher plant. This was achieved using genes encoding enzymes participating in the omega3/6 Delta8 -desaturation biosynthetic pathways for the formation of C20 polyunsaturated fatty acids. Arabidopsis thaliana was transformed sequentially with genes encoding a Delta9 -specific elongating activity from Isochrysis galbana, a Delta8 -desaturase from Euglena gracilis and a Delta5 -desaturase from Mortierella alpina. Instrumental in the successful reconstitution of these C20 polyunsaturated fatty acid biosynthetic pathways was the I. galbana C18-Delta9 -elongating activity, which may bypass rate-limiting steps present in the conventional Delta6 -desaturase/elongase pathways. The accumulation of EPA and AA in transgenic plants is a breakthrough in the search for alternative sustainable sources of fish oils.

A practical guide to the isolation, analysis and identification of conjugated linoleic acid.

Natural and synthetic conjugated linoleic acids (CLA) are reputed to have therapeutic properties that are specific to particular geometrical and positional isomers. Analysis of these has presented unique problems that have brought forward distinctive solutions, especially the use of gas chromatography-mass spectrometry and silver-ion high-performance liquid chromatography. In the analysis of CLA present at low levels in tissue samples, it is sometimes necessary to use concentration methods. In this review, the most useful and practical methods for the isolation and analysis of CLA isomers in tissues and in commercial CLA preparations are described.

Effects of Juice Matrix and Pasteurization on Stability of Black Currant Anthocyanins during Storage.

The effects of juice matrix and pasteurization on the stability of total phenols and especially total and individual anthocyanins were examined in black currant (BC) juice and mixtures with apple, persimmon, and peach juices at 4 °C and 20 °C. Total phenol content decreased in all juices at both temperatures but there was a trend to lower levels in unpasteurized over pasteurized juices. Differences in the decline of total anthocyanins between pasteurized and unpasteurized juices varied according to the juice type and the storage temperature. At 4 °C storage, anthocyanins declined in all juices according to pseudo 1st-order kinetics and there were only small differences in the rates between pasteurized and unpasteurized juices. However, at 20 °C, although pasteurized and unpasteurized BC juices and pasteurized mixed juices followed pseudo 1st-order kinetics, there was a different pattern in unpasteurized mixed juices; a rapid initial decline was followed by a slowing down. The effect of the added juice on anthocyanin decline was also different at either temperature. At 4 °C, the anthocyanins decreased faster in mixed juices than BC juice alone, but at 20 °C, at least in pasteurized mixed juices, the decline was similar or even slower than in BC juice; there were only small differences among the 3 mixed juices. At 20 °C, in pasteurized and unpasteurized BC juices, the rate of decrease was essentially the same for all 4 individual anthocyanins but in the mixed juices the 2 glucosides decreased significantly faster than the 2 rutinosides.

The composition of potentially bioactive triterpenoid glycosides in red raspberry is influenced by tissue, extraction procedure and genotype.

The beneficial effects of consumption of berry fruits on a range of chronic diseases has been attributed (at least in part) to the presence of unique phytochemicals. Recently, we identified novel ursolic acid-based triterpenoid glycosides (TTPNs) in raspberry fruit and demonstrated their survival in human ileal fluids after feeding which confirmed their colon-availability in vivo. In this paper, in vitro digestion studies demonstrated that certain TTPNs were stable under gastrointestinal conditions and confirmed that these components may have been responsible for bioactivity noted in previous studies. Sequential extractions of raspberry puree, isolated seeds and unseeded puree showed that certain TTPN components (e.g. peak T1 m/z 679, and T2 m/z 1358) had different extractabilities in water/solvent mixes and were differentially associated with the seeds. Purified seed TTPNs (mainly T1 and T2) were shown to be anti-genotoxic in HT29 and CCD841 cell based in vitro colonocyte models. Further work confirmed that the seeds contained a wider range of TTPN-like components which were also differentially extractable in water/solvent mixes. This differential extractability could influence the TTPN composition and potential bioactivity of the extracts. There was considerable variation in total content of TTPNs (∼3-fold) and TTPN composition across 13 Rubus genotypes. Thus, TTPNs are likely to be present in raspberry juices and common extracts used for bioactivity studies and substantial variation exists in both content and composition due to genetics, tissue source or extraction conditions, which may all affect observed bioactivity.

Improving the productivity and efficiency of vascular surgery and radiology multidisciplinary meetings.

Multidisciplinary team meetings are recognized as an important factor in driving quality of care. The Vascular Society of Great Britain and Northern Ireland recommend that all aspects of vascular surgery are suitable for discussion at multidisciplinary team (MDT) meetings, including carotid, peripheral, and aortic disease. The juniors doctors were tasked with preparing the patient list in our unit. This had become time consuming and somewhat unrewarding. The methods of preparation and information required on the patient list were reviewed. It was felt that typing a clinical summary for each patient on the list was the most time consuming factor. This was removed and patients were instead simply categorized into subgroups such as aneurysms, critical limb ischemia, and others. The information removed was substituted with the use on an electronic care record during the meeting to answer questions regarding comorbidities and previous interventions. Time spent preparing the meeting by the junior doctors was recorded before and after cycles of intervention. Prior to intervention this was found be a mean of 140 minutes (2.3 hours), and improved to a mean of 45 minutes (0.45 hours) with consequent cycles. The overall proportion of patients receiving definitive outcomes in each meeting after changes were implemented increased from 35 to 55%. This was not a primary outcome, but an unintended consequence of careful consideration of each cycle. In conclusion, the changes implemented have allowed junior doctors to spend more of their time with other activities such as the outpatient department (OPD) and theatre during their vascular surgery rotation. The proportion of cases discussed has increased due to more focused discussions during the MDT meeting, resulting in improved patient care. All stakeholders gave a largely positive reaction to the changes implemented.

Lipid metabolism in cultured lichen photobionts with different phosphorus status.

Lipid metabolism was studied in different photobiont species from lichens by following incorporation of radiolabel from [1-14C]acetate. In four algal photobionts, Coccomyxa mucigena, C. peltigera variolosae, Trebouxia aggregata, T. erici, polar lipids were mainly (73-90%) labelled while triacylglycerols were the most highly labelled non-polar lipid class. A rhamnose-containing lipid was found in two Coccomyxa species, representing about 11% of the polar lipids of C. mucigena. All the major algal glycosyl- and phospho-glycerides were labelled with monogalactosyldiacylglycerol and phosphatidylglycerol, respectively, being the main labelled lipids in the polar lipid classes. The photobionts were grown in media differing in their phosphate content by one hundred-fold. Low phosphate levels caused only a small decrease in the proportion of phosphoglyceride labelling--mainly in phosphatidylglycerol. However, total lipid labelling was reduced (by 83.3 and 76.6% in two Coccomyxa spp. and 62.1 and 27% in two Trebouxia spp.) for the green algae. By comparison, variations in phosphate availability had no significant effect on a Nostoc sp. Examination of the algal species by electron microscopy revealed phosphorus-containing granules. This reserve of phosphorus explains why the algal photobionts were able to maintain the proportion of phosphoglyceride labelling well and may be an important adaptive mechanism for lichens.

Comparison of fatty acid and polar lipid contents of tubers from two potato species, Solanum tuberosum and Solanum phureja.

Total and individual fatty acid contents were determined in raw tubers of four genotypes from each of the two species Solanum phureja and S. tuberosum. The four S. phureja genotypes contained statistically significantly higher concentrations of total fatty acids, with their average value being 37% greater than that for the mean of the four S. tuberosum cultivars. In both species, a total of 17 fatty acids were detected in quantifiable amounts, and in all genotypes the predominant fatty acid was linoleic followed by alpha-linolenic and palmitic acids. Unusually, 15-methyl hexadecanoate was present as a minor acid in both species. Although a number of statistically significant differences in the fatty acid percentage compositions were found between and within the two species, these were generally small. Averaged over all species and genotypes, tuber storage resulted in an initial small but statistically significant increase in total fatty acid content, but prolonged storage resulted in a fall to the initial values detected close to harvest. The same trend was evident for S. phureja alone (for mean values of all genotypes), but for S. tuberosum the total fatty acid content remained constant over the whole storage period. For both species, the contents (both as absolute levels and as percent compositions) of linoleic acid decreased and alpha-linolenic acid increased in tubers over the whole storage period, and possible mechanisms are discussed. Also, the absolute levels of these two acids were greater in S. phureja than in S. tuberosum, and this is discussed in relation to the development of flavor-related compounds during cooking. The polar lipids of one representative of S. tuberosum and of S. phureja were qualitatively similar. There were only minor differences in the polar lipid percentage compositions and in the corresponding fatty acid compositions of the individual polar lipids between the two species, although the absolute levels of the total, and of some individual, polar lipids were higher in S. phureja.

Fatty acid content and juice characteristics in black currant (Ribes nigrum L.) genotypes.

The fatty acid compositions of seeds from 29 black currant genotypes were determined using a rapid small-scale procedure. There was interest in alpha-linolenic, stearidonic, and, especially, gamma-linolenic acid (GLA) contents, and most samples showed values between 11.1 and 18.7%, between 2.5 and 4.5%, and between 11.6 and 17.4%, respectively. However, six genotypes exhibited gamma-linolenic contents >18%, and values >20% were recorded in four of these genotypes. The fatty acid contents of the six genotypes were also analyzed by using a conventional procedure, and only slight differences in fatty acid composition were found between the two methods. Although GLA content was not strongly correlated with juice parameters, some genotypes had both high GLA contents and desirable juice characteristics. The results obtained provide evidence that it is possible to select for GLA contents without negatively affecting juice quality, and both aspects can be combined in a single cultivar, thereby increasing the added value of the whole fruit.

Three-dimensional speckle tracking of the right ventricle: toward optimal quantification of right ventricular dysfunction in pulmonary hypertension.

BACKGROUND: Quantitative assessment of right ventricular (RV) systolic function largely depends on right ventricular ejection fraction (RVEF). Three-dimensional speckle tracking (3D-ST) has been used extensively to quantify left ventricular function, but its value for RV assessment has not been established. OBJECTIVES: This study sought to prospectively assess whether 3D-ST would be a reliable method for assessing RV systolic function and whether strain values were associated with survival. METHODS: Comprehensive 2-dimensional echocardiographic assessment, 3D-ST of the RV free wall, and measurement of RVEF was performed in 97 consecutive patients with established pulmonary hypertension (PHT) (RVEF 31.4 ± 9.6%, right ventricular systolic pressure [RVSP] 76.5 ± 26.2 mm Hg) and 60 healthy volunteers (RVEF 43.8 ± 9.4%, RVSP 25.9 ± 4.3 mm Hg). RESULTS: Area strain (AS) (-24.3 ± 7.3 vs. -30.8 ± 7.2; p < 0.001), radial strain (23.2 ± 14.4 vs. 34.9 ± 18.2; p < 0.001), longitudinal strain (LS) (-15.5 ± 3.8 vs. -17.9 ± 4.4; p = 0.001), and circumferential strain (CS) (-12.2 ± 4.5 vs. -15.7 ± 6.1; p < 0.001) were all reduced in patients with PHT, compared with normal individuals. AS and CS strongly correlated to RVEF (r = 0.851, r = -0.711; p < 0.001). Systolic dyssynchrony index was greater in PHT (0.14 ± 0.06 vs. 0.11 ± 0.07; p = 0.003) and correlated to RVEF (r = -0.563, p < 0.001). AS (hazard ratio [HR]: 3.49; 95% confidence interval [CI]: 1.21 to 7.07; p = 0.017), CS (HR: 4.17; 95% CI: 1.93 to 12.97; p < 0.001), LS (HR: 7.63; 95% CI: 1.76 to 10.27; p = 0.001), and RVEF (HR: 2.43; 95 CI: 1.00 to 5.92; p = 0.050) were significant determinants of all-cause mortality. Only AS (p = 0.029) and age (p = 0.087) were predictive of death after logistic regression analysis. CONCLUSIONS: PHT patients have reduced RV strain patterns and more dyssynchronous ventricles compared with controls, which was relatable to clinical outcomes. AS best correlated with RVEF and provides prognostic information independent of other variables.