Differentially methylated genes involved in reproduction and ploidy levels in recent diploidized and tetraploidized Eragrostis curvula genotypes

Epigenetics studies changes in gene activity without changes in the DNA sequence. Methylation is an epigenetic mechanism important in many pathways, such as biotic and abiotic stresses, cell division, and reproduction. Eragrostis curvula is a grass species reproducing by apomixis, a clonal reproduction by seeds. This work employed the MCSeEd technique to identify deferentially methylated positions, regions, and genes in the CG, CHG, and CHH contexts in E. curvula genotypes with similar genomic backgrounds but with different reproductive modes and ploidy levels. In this way, we focused the analysis on the cvs. Tanganyika INTA (4x, apomictic), Victoria (2x, sexual), and Bahiense (4x, apomictic). Victoria was obtained from the diploidization of Tanganyika INTA, while Bahiense was produced from the tetraploidization of Victoria. This study showed that polyploid/apomictic genotypes had more differentially methylated positions and regions than the diploid sexual ones. Interestingly, it was possible to observe fewer differentially methylated positions and regions in CG than in the other contexts, meaning CG methylation is conserved across the genotypes regardless of the ploidy level and reproductive mode. In the comparisons between sexual and apomictic genotypes, we identified differentially methylated genes involved in the reproductive pathways, specifically in meiosis, cell division, and fertilization. Another interesting observation was that several differentially methylated genes between the diploid and the original tetraploid genotype recovered their methylation status after tetraploidization, suggesting that methylation is an important mechanism involved in reproduction and ploidy changes.

Personalized atrial fibrillation ablation by tailoring ablation index to the left atrial wall thickness. the ablate by-law single center study

Funding Acknowledgements

Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): Dr Teres is funded by the research fellowship grant from the Swiss Heart Rhythm Foundation, Dr Carreno was funded was funded by a Scholarship from Sociedad Española de Cardiología (SEC).

Introduction

Left atrial wall thickness (LAWT) is a determinant of transmural lesion formation during atrial fibrillation (AF) ablation. The utility of ablation index (AI) to dose radiofrequency (RF) delivery for the reduction of AF recurrences has already been proven with a target AI ≥ 400 at the posterior wall and ≥550 at the anterior wall.

Objective

To determine if adapting AI to atrial wall thickness (AWT) is feasible, effective and safe during AF ablation.

Methods

Consecutive patients referred for a first PAF ablation. LAWT 3D-maps were obtained from multidetector computed tomography (MDCT) and integrated into the CARTO navigation system. LAWT maps were semi-automatically computed from the MDCT as the local distance between the LA endo and epicardium and categorized into 1mm-layers and AI was titrated to the LAWT, as follows: Thickness < 1 mm (red): 300; 1-2 mm (yellow): 350; 2-3 mm (green): 400; 3-4 mm (blue): 450; > 4 mm (purple): 450 (Figure). The ablation line was designed in a personalized fashion to avoid thicker regions. All ablation procedures were performed under general anesthesia with a high frequency low-volume ventilation. Primary endpoints were acute efficacy and safety, and freedom from AF recurrences. Follow-up (FU) was scheduled at 1, 3, 6, and every 6 months thereafter.

Results

90 patients [60 (67 %) male, age 58 ± 13 years] were included. Mean LAWT was 1.25 ± 0.62 mm. Mean AI was 366 ± 26 on the right pulmonary veins (RPVs) with a first-pass isolation in 84 (93%) patients and 380 ± 42 on the left pulmonary veins (LPVs) with first-pass in 87 (97%). Procedure time was 59 min [49-66]; RF time 14 min [12,5-16]; fluoroscopy time 0.7 min [0.5-1.4]. No major complication occurred. Eighty-six out of 90 (95.5%) patients were free of recurrence after a mean FU of 11 ± 4 months.

Conclusions

 Personalized AF ablation, adapting the AI to LAWT allowed decreasing RF delivery, fluoroscopy and procedure time while obtaining a high rate of first-pass isolation. Lesion durability as estimated by freedom from AF recurrences was as high as in more demanding ablation protocols. Abstract Figure. Personalized protocol and results

Esophagus-to-posterior Atrial wall relationship: pre- and Intra-procedural three-dimensional multimodality imaging for esophageal position

Funding Acknowledgements

Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): Dr Teres was funded by the research fellowship grant of the Swiss Heart Rhythm Foundation. Dr Carreno-Lineros was funded by a Scholarship from Sociedad Española de Cardiología (SEC).

Introduction

  pulmonary vein isolation (PVI) approach implies unavoidable ablation  on the posterior atrial wall which is closely related to the esophagus. PVI may result in several complications.

Objective

the present study aims to analyze the stability of the esophageal position inside the mediastinum at the level of the posterior atrial wall from one procedure to another (Redo group) and during a single procedure (multi-image group).

Methods

the esophageal position was compared in two groups. First, pre-procedural multidetector computerized tomography (MDCTs) of the first PVI and the redo intervention (Redo group) were segmented with ADAS 3D™ software to compare the esophageal position and the atrio-esophageal distance prints (Figure A). Second, three imaging modalities were compared for the same procedure (multi-image group): i) preprocedural MDCT; ii) intraprocedural fluoroscopy obtained with the TEE probe in place in three projections with CARTOUNIVU™ (Biosense Webster); and iii) esophageal fast-anatomical map (FAM) obtained at the end of the procedure (Figure D). Ablation procedures were performed under general anesthesia. Exclusion criteria were unavailability or contraindication to obtain any of the techniques. The 3D correlation of the esophageal position acquired with different techniques, was computed in Matlab using semiautomatic segmentation analysis.

Results

35 patients were analyzed for the Redo group. Mean age 61 ± 10 years, 17 (65%) male, mean LVEF 57 ± 7%, mean LA diameter 43 ± 5 mm, median time since previous ablation (and therefore between MDCT acquisitions) was 6 months (IQR 3-9). Mean atrio-esophageal distance for both MDCTs was 1.2 ± 0.6 mm . The esophageal trajectory as related to the atrial posterior wall was left for 20 (57%) patients, central for 6 (18%) patients, and right for 3 (9%) patients, left-central for 4 (11%) patients, and right-central for 2 (5%) patients. There was a 91 ± 5% correlation on the esophageal position between the first procedure and the redo procedure MDCT. In 3 cases the position was clearly different with a correlation of only 40 ± 22%. The multi-imaging group was composed of 100 patients, mean age 61 ± 10 years, 17 (65%) male, mean LVEF 56 ± 7%, mean LA diameter 39 ± 6 mm. The esophageal trajectory as related to the atrial posterior wall was left for 55 (55%) patients, central for 23 (23%) patients, and right for 9 (9%) patients, left-central for 8 (8%) patients, and right-central for 5 (5%) patients. The correlation between MDCT and CARTOUNIVU™ was 82 ± 10% (Figure B); between MDCT and ESOFAM 80 ± 12% (Figure B); and between ESOFAM and CARTOUNIVU™ 83 ± 15% (Figure C).

Conclusions

There is a high stability of the esophageal position between procedures and from the beginning to the end of procedure. This observation needs to be tested for its clinical utility by designing studies that take into account the esophagus distance print to modulate RF delivery Abstract Figure. Multimodal Esophageal imaging

1244Feasibility, safety and efficacy of tailoring ablation index to left atrial wall thickness (lawt) during atrial fibrillation ablation. The Ablate By-LAW Study

Funding Acknowledgements

Dr Teres was funded by Swiss Heartrhythm Foundation

Introduction

Circumferential pulmonary vein isolation (PVI) has become a mainstay in the treatment of atrial fibrillation (AF). The utility of ablation index (AI) to dose radiofrequency delivery for the reduction of AF recurrences has already been proven with a target AI ≥ 400 at the posterior wall and ≥550 at the anterior Wall. Nevertheless, the left atrial wall is a thin, heterogeneous structure with an important inter and intra-patient variability of LAWT.

Objective

To determine if adapting AI to atrial wall thickness (AWT) is feasible, effective and safe during AF ablation.

Methods

Single-Center study that included 80 consecutive patients referred for a first paroxysmal AF ablation that was performed with a single catheter approach with the intention to reduce vascular access complication rate. All patients had a MDCT prior to the ablation procedure. LAWT maps were semi-automatically computed from the MDCT as the local distance between the LA endo and epicardium. All procedures were performed under general anesthesia with a high-rate low-volume ventilation protocol for obtaining higher catheter stability. The transeptal puncture was TEE-guided. During the procedure, the WT map was fused with the LA anatomy using CARTO-merge. LAWT was categorized into 1mm-layers and the AI was titrated to the local atrial WT as follows: Thickness < 1 mm (red): 300; 1-2 mm (yellow): 350; 2-3 mm (green): 400; 3-4 mm (blue): 450; > 4 mm (purple): 450 (Figure). Maximal inter-lesion distance was set at 6 mm. VisiTag settings were: catheter position stability: minimum time 3 s, maximum range 4 mm; force over time: 25%, minimum force 3 g; lesion tag size: 3 mm. Respiration training was not possible due to the high catheter stability.  The circumferential ablation line was designed in a personalized fashion to avoid thicker regions.

Results

80 patients [41 (51,2 %) male, age 60± 11 years] were included. Mean LVEF was 59 ± 5 %, Mean LA diameter 39,1 ± 5,8 mm, Mean LAWT was 1.36 ± 0.63 mm. Mean AI was 352 ± 36 on the RPVs and 356 ± 36 on the LPVs. Procedure time was 60,0 min (IQR 51-70). Fluoroscopy time was 58,5 s (35-97,5). First pass isolation was obtained in 72 (90%) of the RPVs and 75 (93,8%) of the LPVs.

Conclusions

the present study, assessing a novel, personalized protocol for radiofrequency titration during atrial fibrillation ablation, shows a high rate of first pass isolation with a lower need for RF energy delivery and lower procedure requirements, as compared to previous PV ablation protocols. Further studies are needed to evaluate the long-term results of this approach.

Abstract Figure. LAWT-map Visitag points with tailored AI

659Left atrial wall thickness evaluation during atrial fibrillation redo procedures

Funding Acknowledgements

Dr Teres was funded by Swiss Heartrhythm Foundation

Introduction

pulmonary vein (PV) reconnections due to gaps on circumferential ablation lines are responsible for atrial fibrillation recurrences after catheter ablation. We sought to analyze the local left atrial wall thickness (LAWT) of PV line gaps at AF redo ablation during real-time catheter positioning. LAWT was measured on the MDCT 3D reconstruction and fused with the LA anatomy using CARTO-merge.

Objective

To analyze the relationship between local reconnection gaps and the LAWT during AF redo procedures.

Methods

Single-Center cohort study that included 41 consecutive patients referred for AF redo procedure. All patients had a MDCT prior to the ablation procedure. LAWT maps were semi-automatically computed from the MDCT as the local distance between the LA endo and epicardium. Each PV line was subdivided into 8 segments and mean LAWT was computed. During the procedure, the local gap was defined as the earliest activation site at the reconnected segment of the circumferential PV line (Figure 1A & 1B).

Results

41 patients [31 (75.6%) male, age 60 ± 10 years] were included. Mean LAWT was 1.36 ± 0.20 mm. Mean PV circumferential line WT was higher in left PVs than in the right PVs 1.68 ± 0.57 vs. 1.31 ± 0.39 mm p < 0.001 respectively. Mean WT of the reconnected points was 44% higher than the mean WT of the segment where the reconnection was located. Mean reconnection point WT was at the 87th percentile of the circumferential line in the LPVs and at the 76th percentile in the RPVs. The reconnected point WT was higher in the LPVs than RPVs 2.13 ± 1.14 vs. 1.47 ± 0.48 mm p < 0.001 respectively.  The most frequent location for reconnections was the left anterior carina (71%), with a mean WT of 2.24 ± 0.91mm; and the right anterior carina (56%) with a mean WT of 1.57 ± 0.62mm (Figure 2A & 2B).

Conclusions

Reconnection points were more frequently present in the thicker segments of the PV circumferential line. The most frequently reconnected segment was the anterior carina in both right and left PVs. Atrial wall thickness maps derived from MDCT are useful to guide AF redo procedures.

Abstract Figure. 1) Activation & WT map; 2) Segment WT

P917 Additional value of atrial parameters evaluated by echocardiography on the scales of cardioembolic risk in atrial fibrillation

Background

Atrial morphological parameters may influence the presence of atrial thrombus, a factor strongly associated with cardiac thromboembolism, independently of those included in the CHA2DS2-VASc risk estimation scale in patients with a history of atrial fibrillation (AF). The aim of our study was to evaluate this possible association by transthoracic echocardiography (TTE).

Methods

Prospective multicenter study including 401 patients with a history of AF, in which a TTE and a transesophageal echocardiogram (TEE) were performed for evaluation of atrial thrombus between 2016-2019. The parameters included in the CHA2DS2-VASc scale, the heart rhythm at the time of the study and the anticoagulant treatment performed, as well as the atrial morphological parameters were collected.

Results

Twenty-three patients (6%) presented with atrial thrombus in TEE. The left atrial area (28 ± 6cm2 vs 33 ± 6cm2; p < 0.001), the presence of AF during the study (83% vs 17%; p = 0.002) and CHA2DS2-VASc (1.7 ± 1.5cm2 vs 3.0 ± 1.3cm2; p < 0.001) were associated with the presence of atrial thrombus. The left atrial area was a diagnostic predictor of atrial thrombus (area under the curve = 73%; p = 0.001): a value >30cm2 presented a sensitivity of 79% and a specificity of 70% to detect its presence. Logistic regression analysis, including heart rhythm during the study and anticoagulant treatment, showed that CHA2DS2-VASc (OR = 1.5; CI95%=1.1-1.9; p = 0.003) and left atrial area >30cm2 (OR = 5.2;CI 95% =1.7-16.0; p = 0.004) were independent predictors of atrial thrombus presence.

Conclusions

The left atrial area is associated with the presence of atrial thrombus in patients with a history of AF independently of the CHA2DS2-VASc scale, heart rhythm during the study, and anticoagulant treatment. This parameter should be evaluated to be included in the cardioembolic risk scales.

A high-quality genome of Eragrostis curvula grass provides insights into Poaceae evolution and supports new strategies to enhance forage quality

The Poaceae constitute a taxon of flowering plants (grasses) that cover almost all Earth’s inhabitable range and comprises some of the genera most commonly used for human and animal nutrition. Many of these crops have been sequenced, like rice, Brachypodium, maize and, more recently, wheat. Some important members are still considered orphan crops, lacking a sequenced genome, but having important traits that make them attractive for sequencing. Among these traits is apomixis, clonal reproduction by seeds, present in some members of the Poaceae like Eragrostis curvula. A de novo, high-quality genome assembly and annotation for E. curvula have been obtained by sequencing 602 Mb of a diploid genotype using a strategy that combined long-read length sequencing with chromosome conformation capture. The scaffold N50 for this assembly was 43.41 Mb and the annotation yielded 56,469 genes. The availability of this genome assembly has allowed us to identify regions associated with forage quality and to develop strategies to sequence and assemble the complex tetraploid genotypes which harbor the apomixis control region(s). Understanding and subsequently manipulating the genetic drivers underlying apomixis could revolutionize agriculture.

Proteomic footprint of ultrasound intensification on sliced dry-cured ham subjected to mild thermal conditions

Ultrasound can intensify the heating process used to correct texture defects in dry-cured hams. The effect of ultrasound-assisted heating on the proteome of sliced dry-cured ham was evaluated. Dry-cured hams with high proteolysis index (PI > 36) were sliced, vacuum packed and subjected to conventional (CV) and ultrasound-assisted (US) thermal treatments. Comparative proteome profiling between sample groups was assessed by two-dimensional electrophoresis (2-DE) coupled to tandem mass spectrometry. It was found that protein fragmentation increased markedly after US thermal treatment. Specifically, fragments of the major myofibrillar protein, actin, were abundantly over-represented following US heating. In addition, five unfragmented sarcoplasmic proteins (i.e. fatty acid-binding protein, peroxiredoxin-6, superoxide dismutase, carbonyl reductase and aminoacylase) showed increased abundance in the US sample group. These results suggest candidate biomarkers to monitor proteolysis intensity and proteolysis-independent effects linked to cured ham quality by ultrasound application. SIGNIFICANCE: The present proteome profiling study of treated dry-cured ham demonstrates the impact of ultrasound action on proteins. Moreover, negative organoleptic effects can be appearing with ultrasound treatment due to proteolysis increase. Therefore, the proteolysis monitoring could help to control these effects. In this regards, our results suggest that actin can be a candidate biomarker to monitor proteolysis intensity.

Application of temperature and ultrasound as corrective measures to decrease the adhesiveness in dry-cured ham. Influence on free amino acid and volatile compound profile

The impact of low temperature treatment and its combination with ultrasound has been evaluated in order to correct texture defects in dry-cured hams. A total of 26 dry-cured hams, classified as high proteolysis index (PI>36%), were used. From these hams, ten slices from each ham sample were cut, vacuum packed and submitted to three different treatments: control (without treatment), conventional thermal treatments (CV) and thermal treatment assisted by power ultrasound (US). The impact of these treatments on instrumental adhesiveness, free amino acid and volatile compounds profile were assessed. Statistical analysis showed that both US and CV treatments, significantly (P < .001) decreased the instrumental adhesiveness of dry-cured hams from 85.27 g for CO to 40.59 and 38.68 g for US and CV groups, respectively. The total free amino acid content was significantly (P < .001) affected by both treatments, presenting higher values the samples from the US group (6691.5 vs. 6067.5 vs. 5278.2 mg/100 g dry matter for US, CV and CO groups, respectively). No significant differences were observed between US and CV treatments. All the individual free amino acids were influenced by ultrasound and temperature treatments, showing the highest content in sliced dry-cured ham submitted to ultrasounds at 50 °C, except for isoleucine which presented the highest level in samples from CV group. Similarly, significant differences (P < .05) were also detected in the total volatile compound content between CO and US groups, with a higher concentration in the CO batch (56,662.84 AU × 10³/g of dry-cured ham) than in the US treatment (45,848.47 AU × 10³/g of dry-cured ham), being the values in the CV treatment intermediate (48,497.25 AU × 10³/g of dry-cured ham). Aldehydes, ethers and esters, carboxylic acids and sulphur compounds were more abundant in the CO group, while CV group showed higher concentrations of ketones, alcohols and nitrogen compounds.

Effect of gender on breast and thigh turkey meat quality

1. The influence of gender on chemical composition, physicochemical parameters, fatty acid profile, amino acid and mineral composition of turkey breast and thigh meat was studied in order to assess nutrient requirements. 2. Chemical composition showed that only intramuscular fat in breast meat was significantly affected by gender (p < 0.05). The results showed a higher percentage of intramuscular fat in male samples, almost double the amount found in females (0.73% vs. 0.38%). 3.For meat colour parameters, only a* showed different results between sexes, with male samples (breast: p < 0.01; thigh: p < 0.001) having the highest values. 4. Fatty acid profiles showed that medium chain unsaturated fatty acids were the most abundant. The significant differences (p < 0.05) found in both breast and thigh muscle could be linked to a difference in metabolism between males and females. 5.There were higher levels of C16:1n-7 in females (breast: p < 0.001; thigh: p < 0.01) compared with male muscle sample (5.05 vs. 2.67 g/100 g in breast and 4.95 vs. 3.27 g/100 g in thigh). Nutritional indices (n-6/n-3 and thrombogenic index) were more favourable in female samples demonstrating that female turkeys had better fatty acid profile than the others. 6. Turkey meat is an important source of dietary amino acids, and female samples had the highest contents both of essential and non-essential amino acids. Furthermore, gender had a numeric effect (p > 0.05) on amino acid composition. 7. Mineral composition showed that Na, Zn and Fe were the minerals most affected by turkey gender.

Influencia del sexo sobre la calidad de la carne de cerdo de la raza Celta

El objetivo de este trabajo fue estudiar el efecto del sexo sobre la composición química, parámetros de color y análisis de textura de la carne en cerdos de la raza Celta. Para ello se utilizaron 27 cerdos (16 machos castrados y 11 hembras). Los animales fueron alimentados ad libitum con un pienso comercial adecuado a sus necesidades nutricionales y se sacrificaron cuando alcanzaron un peso vivo de 102,49±8,23 y 100,72±9,74 kg (P>0.05) en machos y hembras, respectivamente. En cada canal se tomaron muestras del músculo longissimus dorsi (LD) entre las vértebras 4ª y 10ª. Para estudiar el efecto del sexo sobre los distintos parámetros analizados se realizó un análisis de varianza (ANOVA) usando el programa SPSS versión 21.0. Los parámetros de color no se vieron afectados de un modo significativo por el sexo, aunque la carne procedente de los machos fue más oscura que la de las hembras. Por otro lado, los valores de pH no mostraron diferencias significativas (P>0,05) entre sexos, con valores medios de 5,94. Con respecto a la composición química, los machos presentaron los mayores contenidos de humedad y proteína, mientras que las hembras mostraron los mayores porcentajes de grasa intramuscular. No hubo diferencias significativas en las pérdidas por cocción entre sexos, con valores medios de 15,7%. Finalmente, no se encontraron diferencias significativas entre géneros (P>0,05) en los parámetros de textura medidos por los test WB y TPA.

Influence of the Ripening Time on the Viscoelastic Behaviour of Tetilla Cheese

Controlled shear stress tests were used to monitor the changes of viscoelastic properties in industrial samples of Tetilla cheese with the ripening time. The linear viscoelastic range was determined from both stress sweep and creep-and-recovery tests conducted at 20ºC. One-week-old samples were found to be more rigid and elastic, and to exhibit broader linear ranges, than older samples. Mechanical spectra recorded at the same temperature confirmed this trend since viscoelastic moduli G’ and G" decreased markedly during the first week of ripening, indicating a loss of structure during this period. Besides, physico-chemical information (pH, water content, protein content, nitrogen fractions, and s1 and β casein fractions) was obtained by analytical methods. Quite good correlation between rheological and chemical results was found. For each ripening time, an additional study of mechanical spectra as a function of temperature was performed. A marked increase of the power law exponents as temperature is raised is observed after the second week. Crosslink breakdown and the resulting structural weakening of the micellar network through casein hydrolysis during ripening can explain this result. The whole study provided similar results to those found for other type of cheeses and, also, allowed the classification of samples into two groups of markedly different behaviour, namely, one-week-old samples and older samples. In conclusion more than one week of ripening is needed to reach the adequate texture standardisation of Tetilla cheese.

Physicochemical and sensory characteristics of restructured beef steak with added walnuts

The effects of different proportions (0, 5, 10, 15%) of added walnuts on the physicochemical and sensory characteristics of restructured beef steak were evaluated. The addition of 10 and 15% walnut reduced (P<0.05) cooking loss. Increasing proportions of walnut in the beef steak increased (P<0.05) water binding and reduced (P<0.05) fat binding properties. The addition of walnut did not affect (P>0.05) textural properties in uncooked restructured beef steak, but in cooked products Kramer shear force and bind strength were reduced (P<0.05) when 10% or more of walnut was added. Product morphology characteristics suggest that walnut interferes with the formation of protein network structures. Restructured steaks made with added walnut presented acceptable sensory properties. Incorporation of nuts in meat products can be use to confer potential heart-healthy benefits (Spanish Patent Application 200300367).

ErbB receptors and PKC regulate PC12 neuronal-like differentiation and sodium current elicitation

Excitability, neurite outgrowth and their specification are very important features in the establishment of neuronal differentiation. We have studied a conditioned medium (CM) from sciatic nerve which is able to induce a neuronal-like differentiation of PC12 cells. Previously, we have demonstrated that supplementing this CM with a generic inhibitor (k252a), which mainly inhibits tropomyosin-related kinase receptors (Trk receptors) and protein kinase C (PKC), caused neurite elongation, sodium current induction and axon development. In the present work, we are showing that the enhancement of neurite length and induction of sodium currents induced by CM+k252a were prevented by ErbB receptor inhibition. Additionally, we demonstrated that specific inhibition of PKC produced a similar effect to that exerted by k252a in CM-treated cells, specifically by increasing the percentage of differentiated cells with long neurites and inducing sodium currents. Moreover, CM changed the mRNA levels for ErbB2 and ErbB3 increasing them 6- and 36-folds respectively compared to their control. The inclusion of k252a with CM changed the ErbB1, ErbB2 and ErbB3 mRNA proportions increasing those eight-, seven- and fivefolds respectively. From this point, it is clear that appropriate ErbB receptor levels and PKC inhibition are necessary to enhance the effect of the CM in inducing the neuronal-like differentiation of PC12 cells. In summary, we demonstrated the involvement of ErbB receptors in the regulation of neurite elongation and sodium current induction in PC12 cells and propose that these processes could be initiated by ErbB receptors followed by a fine regulation of PKC signaling. These findings might implicate a novel interplay between ErbB receptors and PKC in the regulation of these molecular mechanisms.

Healthier meat and meat products: their role as functional foods

This review deals with the implications of meat and meat products for human health. It analyses the effect of the presence or absence of various factors: fat, fatty acid composition, cholesterol, calorific value, salt, nitrite or lipid oxidation products that can cause health problems. Bearing in mind these considerations, it then describes the strategies used in animal production, treatment of meat raw material and reformulation of meat products to obtain healthier meat and meat products. Functional ingredients are responsible for making functional foods work, and this review therefore discusses the scope of current meat technology to favour the presence of various active-food components, and provide an additional physiological benefit beyond that of meeting basic nutritional needs.

Effect of total replacement of pork backfat with walnut on the nutritional profile of frankfurters

The nutritional profile of a frankfurter with walnut (25%) (WF) was compared with that of low fat (6%) (LF) and normal fat (16%) (NF) sausages. LF frankfurters did not improve the fatty acid profile as compared with NF (p>0.05), or the indices of atherogenicity (IA) (0.50) or thrombogenicity (IT) (1.12), indicating that the reduction of animal fat produced no cardioprotective effect. However, frankfurter with walnut had a healthy polyunsaturated fatty acid profile, a lower ω-6/ω-3 ratio and lower IA (0.10) and IT (0.15). In addition, WF could be a good source of manganese, iron, copper, potassium and magnesium, supplying 39%, 35%, 34%, 16% and 15% of the respective daily recommended intakes, respectively. Also, there were significant amounts of other bioactive components such as α-,γ- and δ-tocopherol, total dietary fibre, polyphenols and tannins. The amino acid composition of WF indicated a healthier lysine/arginine ratio (0.83) than in LF (1.23) and NF (1.19).

Biogenic amine formation and nitrite reactions in meat batter as affected by high-pressure processing and chilled storage

Changes in biogenic amine formation and nitrite depletion in meat batters as affected by pressure-temperature combinations (300 MPa/30 min/7, 20, and 40 degrees C), cooking process (70 degrees C/30 min), and storage (54 days/2 degrees C) were studied. Changes in residual nitrite concentration in raw meat batters were conditioned by the temperature and not by the pressure applied. Cooking process decreased (P < 0.05) the residual nitrite concentration in all samples. High-pressure processing and cooking treatment increased (P < 0.05) the nitrate content. Whereas protein-bound nitrite concentration decreased with pressure processing, no effect was observed with the heating process of meat batters. High-pressure processing conditions had no effect on the rate of residual nitrite loss throughout the storage. The application of high pressure decreased (P < 0.05) the concentration of some biogenic amines (tyramine, agmatine, and spermine). Irrespective of the high processing conditions, generally, throughout storage biogenic amine levels did not change or increased, although quantitatively this effect was not very important.

Identification of enterococci isolated from cow's milk cheese: comparison of the classical methods and the API 20 STREP system (technical note)

A comparison of the results obtained using the classical methods with those of the API 20 Strep system was carried out in identifying 24 enterococci strains isolated from San Simón cow's milk cheese, a traditional Spanish variety. The results of both identification systems coincided exactly in 9 strains (37.5% of the strains studied). In one strain the results obtained using the classical methods did not coincide with those using the API 20 Strep method. 3 strains (12.5%) could not be identified using the API 20 Strep system. However, 11 strains (45%), that remained doubtful between both species E. faecalis and E. faecium on the basis of the classical methods, were identified using the API 20 Strep system. The API 20 Strep system does not include some biochemical tests of importance in identifying of foodborne enterococci and could not identify the atypical strains of Enterococcus. Moreover, this system is adapted to the identification of enterococci of clinical origin and their database does not include some species common in foods. However, it could have an application in combination with the classical methods in order to carry out a reasonably rapid and reliable identification of enterococci related to cheese.

Comparison of the acidifying activity of Lactococcus lactis subsp. lactis strains isolated from goat's milk and Valdeteja cheese

AIMS

This work was carried out to study the acid production by Lactococcus lactis subsp. lactis strains isolated from goat's milk and goat cheese (Valdeteja variety) in order to select a suitable starter culture for industrial goat cheese manufacturing.

METHODS AND RESULTS

The titrable acidity of 45 Lactococcus lactis subsp. lactis strains isolated from a home-made batch of Valdeteja cheese with excellent sensory characteristics was measured over a period of 18 h. The strains were divided into two groups depending on the acid production rate: 20 fast acid producer (F) strains and 25 slow acid producer (S) strains. The kinetic parameters (lag phase, maximum acid production rate and value of upper asymptote curve) of the acid production curves for F and S strains were significantly (P < 0.001) different.

CONCLUSIONS

Significant (P < 0.001) differences between titrable acidity of F and S strains were observed after the second hour of incubation.

SIGNIFICANCE AND IMPACT OF THE STUDY

An F strain acetoin producer (Lactococcus lactis subsp. lactis 470Ch2) was selected as autochthonous starter culture for industrial Valdeteja goat cheese manufacturing.

A survey on the microbiological changes during the manufacture of dry-cured lacón, a Spanish traditional meat product

This article describes a microbiological study carried out on lacón, a dry-cured meat product made in the north-west of Spain from the fore extremity of pig. Using classical methods, aerobic mesophilic flora, salt-tolerant flora, lactic acid bacteria, Enterobacteriaceae, enterococci, moulds and yeasts were enumerated, some physicochemical parameters (pH, aw and moisture and NaCl contents) were determined and a representative number of isolates of the salt-tolerant flora (the main microbial group) were identified during the manufacture of five batches. All the microbial groups, with the exception of Enterobacteriaceae and enterococci, reached maximum counts both on the surface and in the interior of the pieces at the end of the post-salting stage and afterwards progressively dropped during the drying-ripening stage. Staphylococcus xylosus, Staph. saprophyticus, Staph. simulans, Staph. sciuri and Micrococcus luteus were the main species isolated throughout manufacturing. This study will significantly increase knowledge of the microbiology of cured meat products made from entire pieces.

[Pericardial effusion in the elderly: A different disease?]

INTRODUCTION AND OBJECTIVES

The aim of the present study was to assess possible differences in etiologic spectrum and clinical course of pericardial effusion in elderly patients, as has been previously suggested, and therefore determine whether clinical, management should be based on patient age.

METHODS

All echocardiograms performed in our hospital from 1990 to 1996 were screened for pericardial effusion, and those with moderate or large effusions were selected. Patients under 66 years of age were included in group I, and those above 65 years were assigned to group II.

RESULTS

We selected 322 patients with moderate (122) or with large (200) effusions. 221 patients being included in group I (aged 15-65, mean 47) and 101 in group II (aged 66-88, mean 72.5). Effusion was large in 60% of group I and in 66% of group II (p = NS), and tamponade occurred in 36% and 38.6%, respectively (p = NS). Specific pericardial infections (tuberculous and purulent pericarditis) were more frequent in group I (5.9 versus 0.9%; p < 0.05). No significant differences were found in incidence of idiopathic (33 vs 38%) or neoplastic (14.4 vs 10.8%) etiologies. During follow-up (96% of the patients, median time of 11 months, range 1-58 months) the mortality (24 vs 30%) and evolution to cardiac constriction (4 vs 2%) were similar in the two groups, but persistence of effusion was more common in group II (6.3 vs 14%; p < 0.05).

CONCLUSIONS

Our study suggests that etiology, clinical course and prognosis of moderate and large pericardial effusion are, in general, similar in elderly and younger patients. Thus, management should be similar in the different age groups, and no etiologic form of pericardial disease should be ruled out because of patient's age when considering the differential diagnosis.

[Diagnostic accuracy of tomographic myocardial imaging for evaluation of aortocoronary graft patency]

INTRODUCTION AND OBJECTIVES

Conventional ergometry has limitations in the evaluation of coronary artery bypass graft patency. The aim of the present study was to determine the efficacy of exercise single photon emission tomography with 99mTc-compounds for the diagnosis of coronary artery bypass grafts disease.

PATIENTS AND METHODS

The state of sixty-seven coronary artery bypass grafts (31 with mammary artery, 36 with safein vein; 35 to left descending anterior artery, 15 to circumflex and 17 to right coronary artery) were analyzed retrospectively in 38 patients (mean age 63+/-8.7; 35 men). The time that elapsed between the coronary surgery and the exercise tomography was 9,7 years. In 16 cases, exercise tomography was performed with 99mTc-MIBI and in the 22 remaining with 99mTc-tetrofosmin. In 6 cases, dipiridamol was administred simultaneously during an insufficient exercise test.

RESULTS

Sensitivity (73.1%), specificity (93%), positive predictive value (86.3%), negative predictive value (84.4%), global value (85%), positive likelihood ratio (10.4) and negative likelihood ratio (0.29) of exercise tomography were significantly (p<0.01) better than those obtained with the exercise test alone (53.8%, 43.6%, 38.9%, 58. 6%, 47.7%, 0.95 and 1.06, respectively).

CONCLUSIONS

Exercise tomography with 99mTc-compounds is a highly effective for the detection of coronary artery bypass grafts disease.

Microbiological changes in pressurized, prepackaged sliced cooked ham

This was a study of the influence of high-pressure conditions (200 and 400 MPa, 5 and 20 min, 7 degrees C) on microbiological quality and water-binding properties of vacuum-prepackaged sliced cooked ham and how this affects microbiological changes during chilled storage (2 degrees C). Pressurization caused a degree of microbiological inactivation, which increased with pressure level and processing time. Pressurization at 400 MPa significantly reduced the total viable count and lactic acid bacteria to the extent that after 20 min no Enterobacteriaceae, Baird Parker flora, or Brochothrix thermosphacta were detected throughout any of the chilled storage periods studied. In general, gram-positive flora was more resistant to pressure than gram-negative flora. The fact that high pressure (400 MPa) causes considerable inactivation of microorganisms could be used to prolong the shelf life of vacuum-prepackaged sliced cooked ham.

Retail Chilled Display Storage of High- and Reduced-Fat Sliced Bologna

This study examined the influence of light (1,900 lux) and dark display conditions on purge loss, color, residual nitrite, rancidity, texture, and microbiological changes of sliced vacuum packaged high-fat (24.7%) and reduced-fat (9.4%) bologna during chilled storage at 2 and 7°C. Color stability was more dependent upon photochemical action than upon temperature. The rate of color fading was greater at a lower fat content. Residual nitrite depletion varied according to fat content, chill temperature, and display conditions. High-fat sausages were harder and chewier (P < 0.05) than reduced-fat sausages. Texture parameters were not appreciably influenced by storage temperature or exposure to light. Microbiological counts were higher in reduced-fat samples than in high-fat samples. Temperature influenced the growth of microflora in sliced bologna sausage, but light had no important effect.