Severity of oEsophageal Anastomotic Leak in patients after oesophagectomy: the SEAL score

Background

Anastomotic leak (AL) is a common but severe complication after oesophagectomy. It is unknown how to determine the severity of AL objectively at diagnosis. Determining leak severity may guide treatment decisions and improve future research. This study aimed to identify leak-related prognostic factors for mortality, and to develop a Severity of oEsophageal Anastomotic Leak (SEAL) score.

Methods

This international, retrospective cohort study in 71 centres worldwide included patients with AL after oesophagectomy between 2011 and 2019. The primary endpoint was 90-day mortality. Leak-related prognostic factors were identified after adjusting for confounders and were included in multivariable logistic regression to develop the SEAL score. Four classes of leak severity (mild, moderate, severe, and critical) were defined based on the risk of 90-day mortality, and the score was validated internally.

Results

Some 1509 patients with AL were included and the 90-day mortality rate was 11.7 per cent. Twelve leak-related prognostic factors were included in the SEAL score. The score showed good calibration and discrimination (c-index 0.77, 95 per cent c.i. 0.73 to 0.81). Higher classes of leak severity graded by the SEAL score were associated with a significant increase in duration of ICU stay, healing time, Comprehensive Complication Index score, and Esophagectomy Complications Consensus Group classification.

Conclusion

The SEAL score grades leak severity into four classes by combining 12 leak-related predictors and can be used to the assess severity of AL after oesophagectomy.

AB0498 CONCENTRATIONS OF ADVANCED GLYCATION END PRODUCTS (AGEs) CORRELATE WITH INDEXES OF ACTIVITY AND DAMAGE ACCRUAL IN PATIENTS WITH SYSTEMIC LUPUS ERYTHEMATOSUS (SLE)

Background

It has been postulated that AGES could have a relevant role as inducers in the chronic inflammatory pathway present in various diseases1; among them, in immune-mediated diseases such as SLE, as well as that its concentration could be related to some parameters of the disease such as activity 2 or accumulated damage 3, showing studies discrepant results to date.

Objectives

To describe correlations between the concentrations of AGEs measured by cutaneous autofluorescence and various parameters related to the disease in a population of SLE patients.

Methods

AGE concentrations were measured by skin autofluorescence (Age Reader Mu Connect from Diagnoptics Technologies BV) in 66 SLE Caucasian patients and correlations with demographic and clinical data were analyzed, after adjusting for age, smoking and corticosteroids as possible confounding factors, according to previous data. Previous validation studies have shown that skin autofluorescence is strongly related to AGE levels in skin biopsies4. The indices were analyzed both as quantitative and categorized variables according to previously established categories or to medians/tertiles/quartiles depending on the distribution of the variable in our population.

Results

Table 1 shows some descriptive characteristics of our cohort. There were clinically and statistically significant differences in the values of AGEs according to the patient’s SLEDAI and SLICC. Specifically, it was observed that AGEs’ values in the population with severe activity according to SLEDAI was 0.61 (95% CI 0.85-2.046; p=0.045) points > than in those in remission (p=0.045); as well as AGEs‘ values in patients with SLICC ≥1 was 1.23 (95% CI 0.49-1.98; p=0.030) points > than in the group without cumulative damage. In all the models, the values of AGEs increased significantly with age, smoking and current treatment with corticosteroids, except for the model including the SLICC variable. Interactions in said model were explored, and it was observed that the concentration of AGES depended on the interaction between the value of SLICC and the intake of corticosteroids, so that differences were only observed between SLICC groups in those who took corticosteroids.

Table 1.

Descriptive characteristics of the cohort. c: categorized.

AverageSD%Age5415BMI25.364.68SmokerNo68.2Yes31.8AGEs2.60.7Disease duration (years)1611DAS282.221.16cDAS28remission71.2low9.1moderate15.2high4.5SLEDAI54cSLEDAIremission21.2low16.7moderate51.5high10.6SLICC11cSLICC00.0148.5>130.3321.2FACIT Fatigue Scale1810Patient global assessment (PGA)3.02.4cPGA0-131.82-328.8>339.4Physician global assessment1.71.3cPhysician global assessment0-147.0>153.0Visual Analogue Scale (VAS)3.13.1cVAS034.81-430.3>434.8Health Assessment Questionnaire (HAQ)0.5270.551cHAQ033.30-0.7536.4>0.7530.3CorticoidsYes27.3No72.7

Conclusion

A correlation with elevated values of AGEs was observed in those SLE patients with higher scores in the indexes of activity (SLEDAI) and damage accrual (SLICC). The fact that the differences in SLICC are only observed in those patients treated with corticosteroids suggests that, maybe, only the accumulated damage related to taking corticosteroids could be mediated by AGEs.

References

[1]Medzhitov R. Origin and physiological roles of inflammation. Nature 2008;454:428–435.

[2]Vytášek R, Šedová L, Vilím V. Increased concentration of two different advanced glycation end-products detected by enzyme immunoassays with new monoclonal antibodies in sera of patients with rheumatoid arthritis. BMC Musculoskelet Disord 2010;11:83.

[3]leeuw K de, Graaff R, Vries R de, Dullaart RP, Smit AJ, Kallenberg CG, Bijl M. Accumulation of advanced glycation endproducts in patients with systemic lupus erythematosus. Rheumatology 2007;46:1551–1556.

[4]Meerwaldt R, Links T, Graaff R, Thorpe SR, Baynes JW, Hartog J, Gans R, Smit A. Simple noninvasive measurement of skin autofluorescence. Ann N Y Acad Sci 2005;1043:290-298.

Disclosure of Interests

None declared

AB1460 ACCUMULATED ADVANCED GLYCATION ENDPRODUCTS ARE SIGNIFICANTLY HIGHER IN PATIENTS WITH IMMUNE-MEDIATED INFLAMMATORY DISEASES THAN IN HEALTHY POPULATION

Background

Advanced glycation endproducts (AGEs) are the result of non-enzymatic glycation of proteins, lipids or nucleic acids. In circumstances characterized by increased oxidative and carbonyl stress, such as chronic inflammation, AGEs can be formed more rapidly1, generating reactive oxygen species and activating inflammatory signaling cascades through their chief signaling receptor (commonly abbreviated as RAGE)2. This positive feedback of inflammation can play a role in the etiology of immune-mediated inflammatory diseases, more specifically in rheumatoid arthritis (RA), ankylosing spondylitis (AS) and systemic lupus erythematosus (SLE).

Objectives

To investigate whether the accumulated concentrations of AGEs in patients with SLE, RA or AS are significantly higher than in healthy patients.

Methods

One hundred thirteen consecutive patients fulfilling ACR/EULAR criteria for RA, 60 patients fulfilling ASAS/OMERACT MRI criteria for AS, 97 patients fulfilling ACR/SLICC criteria for SLE and 527 sex-matched healthy controls were recruited.in cross-sectional study. Exclusion criteria were pregnancy, diabetes mellitus, corticosteroid treatment ≥ 20mg/day and malignant neoplasm. Accumulated AGEs were non-invasively measured by skin autofluorescence (Age Reader Mu Connect, Diagnostics Technologies B.V) and demographic and clinical data were collected. AGEs comparisons between patients and controls were performed by multiple linear regression analysis adjusted by confunders, previously described in literature (age, smoking habit and cardiovascular risk-factors). Age was centered at 55 years.

Results

Table 1 shows some descriptive characteristics of our cohorts. AGEs adjusted mean was significantly increased in SLE patients compared with matched controls (95% CI [2.27, 2.76] vs [1.66, 1.89], p<0.0001), RA patients and controls (95% CI [2.41, 2.61] vs [1.68, 1.88], p<0.0001) and AS patients and controls (95% CI [2.03, 2.6] vs [1.66, 1.93], p<0.0001). In all 3 models, AGEs were also significantly positive correlated with smoking habit measured by packs per year (p<0.001) and age (p<0.0001).

Table 1.

Descriptive characteristics of the cohorts

SLERAASPatientsControlsPatientsControlsPatientsControlsN=96N=189N=113N=240N=60N=99AGEs2.57 (0.65)1.98 (0.45)2.59 (0.58)2.00 (0.42)2.26 (0.46)1.90 (0.46)Age51.0 [43.0;61.0]56.0 [52.0;62.0]58.0 [54.0;65.0]61.0 [56.0;66.0]47.5 [41.0;55.0]53.0 [49.0;57.0]SmokerNo76 (79.2%)133 (70.4%)86 (76.1%)196 (81.7%)42 (70.0%)58 (58.6%)Yes20 (20.8%)56 (29.6%)27 (23.9%)44 (18.3%)18 (30.0%)41 (41.4%)Packs/year0.00 [0.00;10.8]2.50 [0.00;18.8]2.50 [0.00;18.0]0.00 [0.00;12.6]0.00 [0.00;7.88]14.9 [2.00;30.6]HypertensionNo74 (77.1%)116 (61.4%)77 (68.1%)146 (60.8%)53 (88.3%)75 (75.8%)Yes22 (22.9%)73 (38.6%)36 (31.9%)94 (39.2%)7 (11.7%)24 (24.2%)ObesityNo80 (83.3%)128 (67.7%)86 (76.1%)163 (67.9%)51 (85.0%)81 (81.8%)Yes16 (16.7%)61 (32.3%)27 (23.9%)77 (32.1%)9 (15.0%)18 (18.2%)DyslipidemiaNo85 (88.5%)104 (55.0%)79 (69.9%)108 (45.0%)51 (85.0%)55 (55.6%)Yes11 (11.5%)85 (45.0%)34 (30.1%)132 (55.0%)9 (15.0%)44 (44.4%)

Continuous normal: mean (SD); Continuous non-normal: median [IQR]; Categorical: absolute (relative frequency)

Conclusion

Accumulated AGEs in all 3 pathologies are significantly higher than in the healthy controls. The different means of AGEs in each of the diseases, being higher in SLE and lower in AS, may suggest a different participation of AGEs in the immune-mediated mechanisms of each pathology.

References

[1]K. de Leeuw, R. Graaff et al., Accumulation of advanced glycation endproducts in patients with systemic lupus erythematosus, Rheumatology, Volume 46, Issue 10, October 2007, Pg 1551–1556.

[2]Yan S., Ramasamy R. & Schmidt A. Mechanisms of Disease: advanced glycation end-products and their receptor in inflammation and diabetes complications. Nat Rev Endocrinol4, 285–293 (2008).

Disclosure of Interests

None declared

An exploratory analysis of seasonal and intraseasonal variations of the main airborne pollen types in Sunchales city, Argentina

Background and aims: The study of the seasonal and intra-seasonal variability of the airborne pollen concentration is of paramount importance to understand the relationships with the emitting vegetation and the atmospheric parameters that modulate pollen transport. This research aims to study these variabilities in Sunchales, a city located in the center-east of Argentina. M&M: Atmospheric monitoring was carried out with a Burkard trap during two seasons in 2012 and 2013 on the outskirts of the city. Results & Conclusions: The pollination periods of the studied pollen types show a delay in 2013 compared to the previous year, presumably related to a greater amount of cumulative heat units in 2012. However, the integral pollen for the period 2013 was 1.4 times higher than 2012, a fact that is not explained by accumulated precipitation but by the time of day when the hydrometeors occur. Binned pollen concentrations show that the highest concentrations coincide with the urban location of the tree sources while the herbaceous ones show an association with a rural origin. Regarding the intra-seasonal variability, the highest proportion of the airborne pollen variance accumulates on the synoptic-scale (80 - 60%) with periods between 3 and 10 days. During 2012 long waves predominated (> 5.5 days) while in 2013 medium waves prevailed (3.9 - 5.5 days).

AB0212 NON-ADHERENCE IN RHEUMATOLOGIC IMMUNE-MEDIATED DISEASES

Background:

Patient adherence is a key determinant of treatment success in rheumatologic immune-mediated diseases. Available data about adherence to biological treatments and factors associated to non-adherence is limited in Spain. Moreover, no studies compare adherence between subcutaneous and oral drugs.

Objectives:

To evaluate non-adherence to prescribed subcutaneous biologicals and oral drugs in patients with rheumatologic immune-mediated diseases and to assess possible predictor factors associated to treatment non-adherence.

Methods:

Retrospective observational study including all patients with oral and subcutaneous treatment for rheumatologic immune-mediated diseases from 2017 to 2019 in the outpatient pharmaceutical care area from a tertiary university hospital. Non-adherence was evaluated by reviewing all scheduled drug-dispensing visits in the computerized application. We considered non-adherent every time that a patient missed at least one drug administration.

Data collected: demographic, total patients and patient-treatments, total dispensing visits and route of administration for drug dispensed in every visit.

We classified patients in adherent and non-adherent considering dispensing visits. Non-adherent group: number of dispensing visits, reasons for non-adherence, number of missed administrations per patient and drug and predictor factors for non-adherence.

Results:

783 patients included: 52.4(13.7) years; 427(54.5%) female; 164 (20.9%) smoker; 697 (89%) Caucasian.

A total of 79 (10.1%) of 783 patients received more than one treatment.

869 patient-treatments: 294 adalimumab (33.8%), 236 etanercept (27.2%), 78 golimumab (8.9%), 47 apremilast (5.4%), 39 certolizumab (4.5%), 34 secukinumab (3.9%), 30 tocilizumab (3.5%).

9,197 dispensing visits. Route of administration: 6,406 subcutaneous (93.2%), 374 oral (6.8%).

Non-adherence analysis: 2417 (26.3%) dispensing visits, reasons for non-adherence/ dispensing visits: 92 unjustified (97.5%), 33 infection (1.4%), 18 (surgery) 0.7%, 3 pregnancy (0.1%), 6 others (0.3%).

Number of missed administrations/patient treatment: 675 patients missed at least one administration (77.7%).Mean 2.5 (±12.9) missed administrations.

Number of missed administrations/drug: 9.9 baricitinib (±20.8), 15.8 tofacitinib (±31.2), 25.4 apremilast (±53.2).

Predictor factors for non-adherence: ethnicity (p=0.015), treatment with golimumab (p=0.006), and tocilizumab (p=0.036). Age (p=0.072).

Conclusion:

- Non-adherence to the prescribed drug occurred in 77.7% of patients with rheumatologic immune-mediated diseases

- Demographic factors such as ethnicity as well as golimumab and tocilizumab treatment, despite their different frequency of administration, were predictors for non-adherence

- Route of administration did not influence non-adherence.

Disclosure of Interests:

None declared

The impact of livestock grazing on the evapotranspiration-vegetation biomass relationship in a Southern Hemisphere salt marsh, Buenos Aires (Argentina)

Among the ecosystem services provided by salt marshes is the use of their natural vegetation as pastures for livestock production. As a result, the prediction of biomass productivity can be of great interest for the sustainable management of these environments. Evapotranspiration is one of the variables most used to estimate the yield of green biomass in pastures and crops, which to date has not been examined for natural environments such as salt marshes. We studied the aboveground biomass and species cover variability for two categories (erect and sward plants) in three plots affected by low, moderate, and high cattle grazing. Erect biomass was associated only with Spartina densiflora while for sward plants it gathered a diverse set of prostrate and stoloniferous species with high seasonal turnover. The evapotranspiration was estimated with a coupled surface resistance-Penman-Monteith model developed for these environments. The biomass of the plant categories shows different growth response according to livestock impact. S. densiflora has a slow-growing response after cattle consumption, even with high evapotranspiration. On the other hand, sward plants respond with biomass overproduction to livestock consumption, and a significantly positive relationship to evapotranspiration rate.

AB1167 PREGNANCY AND INFLAMMATORY ARTHROPATIES: EXPERIENCE IN A MULTIDISCIPLINARY UNIT

Background:

Systemic inflammatory diseases are common in women at the reproductive age. These women may have fertility problems and complications during pregnancy.

Objectives:

To describe the experience in a multidisciplinary unit (composed of Rheumatologists and Obstetricians) and asses the complications and treatments used in patients with inflammatory diseases in a tertiary hospital compared to those registered in healthy women from the same center (preterm births 6.59%, Caesarean section (C-section) 14.4%, maternal average age 33.33 years).

Methods:

Retrospective and descriptive study of the evolution of pregnancy in patients with inflammatory diseases and follow-up in a multidisciplinary unit for more than 15 years (until December 2019). Demographics, maternal disease, time until conception, births, abortions, C-sections, treatments and complications were collected. Data was analyzed using IBM SPSS v23.

Results:

We registered 29 pregnancies (25 patients): 20 Rheumatoid Arthritis (RA), 5 Psoriatic Arthritis (PsA), and 4 Spondylarthritis (SpA). Maternal average age at diagnosis was 27.6±6.36 years and average age at childbirth/abortion 35±5.6 years.

It took an average time of 8 months to conceive. 11.5% received fertility treatment using in vitro fertilization techniques.

5 abortions were registered prior to follow-up in this unit (0.2 abortions/mother). During follow-up 1 abortion (0.04 abortions/mother) was recorded in a RA patient. C-section was performed in 11 cases (39.2%): 6 RA (31.6%), 3 SpA (75%) and 2 PsA (40%).

17.2% of pregnancies were preterm (<37 weeks).

Intrauterine growth restriction (IUGR) was observed in a woman (3.4%) with RA and preeclampsia was observed in 2 cases (6.9%) (RA 1, SpA 1).

Disease activity (DAS28 and BASDAI) is shown in Table 1.

Table 1.DAS28 (median)PreviousFirstTrimesterSecondTrimesterThirdTrimesterPosteriorRheumatoid Arthritis2.692.593.093.333.11Psoriatic Arthritis2.582.53.323.082.89RA with biological agents (n: 6)2.372.942.712.42.52BASDAI (median)Spondylarthritis2.82.41.7511.9

Treatments used prior to and during pregnancy are listed in Table 2.

Table 2.TREATMENT BEFORE PREGNANCYn (%)TREATMENT DURINGPREGNANCYn (%)Hydroxychloroquine13 (44.8%)Prednisone17 (58.6%)Prednisone12 (41.4%)Acetylsalicylic acid16 (55.2%)Methotrexate9 (31%)Hydroxychloroquine15 (51.7%)TNF inhibitors7 (24.1%)Sulfasalazine2 (6.9%)Sulfasalazine2 (6.9%)TNF inhibitors2 (6.9%)

8 patients had received biological treatment prior to pregnancy (2 SpA, 6 RA)(3 Etanercept, 3 Adalimumab, 2 Certolizumab). 2 of them (RA) continued treatment during pregnancy. 1 of them discontinued it at week 17 on her own (Adalimumab) while the other continued with Certolizumab throughout pregnancy and presented IUGR. No other complications, such as infections or malformation, were observed in newborns. DAS28 data of these women can be found in Table 1.

Conclusion:

In our series, as described in the literature, women with inflammatory arthropaties are older, need longer time to achieve pregnancy and have increased use of fertility techniques and increased likelihood of preterm and instrumental delivery compared to general population. Given the low number of patients receiving biological treatment no conclusions about complications and evolution of the disease can be drawn, so further investigation are needed in this group of patients.

Monitoring inflammatory arthropathies in a multidisciplinary unit increases the chances of successful pregnancies.

Disclosure of Interests:

None declared

Electronic nicotine delivery systems (ECs) and COVID-19: the perfect storm for young consumers

The COVID-19 pandemic caused a change in our society and put health systems in crisis worldwide. Different risk factors and comorbidities have been found that increase the risk of mortality when acquiring this infection. The use of alternative devices to the cigarette like the electronic cigarettes, the vapers have been studied widely and generators of great controversy since it has been discovered that they also produce different pulmonary affections. When developing the SARS-CoV2 infection, different theories have been generated about the greater predisposition to a worse prognosis of people who use electronic cigarettes; however, the information on this continues in discovery. A group of experts made up of oncologists, infectologists, pulmonologists, and epidemiologists met to review the literature and then generate theories about the impact of electronic cigarettes on SARS-CoV2 infection.

Characteristic limits of 230Th in alpha spectrometry with 229Th as tracer, calculated by simulating interfering tails and overlapping peaks

This study explores the effect of ²²⁹Th tracer tail interference on the determination of the sensitivity of ²³⁰Th alpha spectrometry of samples with environmental levels of radioactivity. Tracer peak tail interference was calculated with Suma-Alpha, whilst Visual Basic for Applications (VBA in Excel©) software was used to study the variation in sensitivity in terms of the amount of tracer added. Unnecessary increases in the amount of tracer or extended sample measuring times were observed to have adverse effects on method sensitivity (Detection Limit- L_d).

Irrigation implementation promotes increases in salinity and nitrate concentration in the lower reaches of the Cidacos River (Navarre, Spain)

The shift from rainfed to irrigated agriculture is associated with a change in the fertilization rates due to increases in expected production and the fact of growing more N demanding crops. In addition, the circulation of irrigation return flows (IRF) mobilizes soluble salts stored in soils or geological materials. As a consequence, it implies severe modifications in the dynamics and total amount of soluble salts and nitrogen exported, especially in semi-arid watersheds. In this study, long-term data collected by the regional authorities was used to assess the effects of irrigation implementation on salinity (using electrical conductivity, EC, as a proxy) and nitrate concentration (NO₃^-) after the transformation of ca. 77 km² from rainfed to irrigated agriculture in the Cidacos River (CR) watershed. The results indicate that water quality in the lower reaches of the CR was significantly modified after the diffuse incorporation of IRF. In contrast, neither EC nor NO₃^- were different in those monitoring stations whose contributing watersheds did not include transformed area. In addition, the temporal dynamics in the analysed variables shifted from a rainfed land signal typical in the region to an irrigated land signal, and the hydrochemical type of the CR shifted from mixed-to-Na⁺-mixed-to-HCO₃^- to mostly Na⁺-mixed type, typical of waters affected by IRF in the region. Groundwater EC and NO₃^- also increased in those wells located within the irrigated area. Although there are great uncertainties in the actual amount of salt and N reaching the CR via IRF, the expected contribution of waste water spilled into the CR is minor in comparison to other sources, mostly agricultural sources in the case of N. The observed changes have promoted the designation of the lower reaches of the CR as "affected" by NO₃^- pollution, and the whole CR watershed as a Nitrate Vulnerable Zone, with the emergent question about whether irrigation implementation as carried out currently in Spain is against the environmental objectives of the Water Framework Directive.

Norovirus detection in environmental samples in norovirus outbreaks in closed and semi-closed settings

BACKGROUND

Environmental surfaces are a potential vehicle for the transmission of norovirus outbreaks in closed and semi-closed settings. Testing of environmental samples may help control outbreaks.

AIM

To assess the level of environmental contamination by norovirus in acute gastroenteritis outbreaks in closed or semi-closed settings (nursing homes, schools, kindergartens, youth accommodations, hospitals and social health centres) in the Barcelona region between January 2017 and March 2019.

METHODS

A prospective surveillance study was carried out. Environmental samples (529) were collected in 46 of the 50 outbreaks of acute norovirus gastroenteritis from environmental surfaces of common areas, bathrooms and kitchens in closed and semi-closed settings when the outbreak was notified and 10 days later. Instructions for taking environmental samples were distributed to public health inspectors. Norovirus was detected by reverse transcription polymerase chain reaction.

FINDINGS

Environmental samples were positive for norovirus in 31 (67.4%) outbreaks. Norovirus was most frequently detected on elevator buttons (4/17, 24%), toilet handles (16/66, 24%) and handrail bars (7/34, 21%). Positive samples from the first sampling were mainly found in bathrooms and greater viral persistence in the second sampling was found on elevator buttons and TV remote controls. Nursing homes were the setting with the most types of environmental surfaces contaminated (82% in first samples and 55% in second samples).

CONCLUSION

The probability of virus detection is independent of the time between notification of the outbreak or symptom onset and sample collection. Our results suggest possible defects in cleaning protocols and disinfection in closed and semi-closed settings.

Structures and internal dynamics of diphenylether and its aggregates with water

We report on a detailed multi-spectroscopic analysis of the structures and internal dynamics of diphenylether and its aggregates with up to three water molecules by employing molecular beam experiments.

Comparison between single and multi-locus approaches for specimen identification in Mytilus mussels

Mytilus mussels have been the object of much research given their sentinel role in coastal ecosystems and significant value as an aquaculture resource appreciated for both, its flavour and nutritional content. Some of the most-studied Mytilus species are M. edulis, M. galloprovincialis, M. chilensis and M. trossulus. As species identification based on morphological characteristics of Mytilus specimens is difficult, molecular markers are often used. Single-locus markers can give conflicting results when used independently; not all markers differentiate among all species, and the markers target genomic regions with different evolutionary histories. We evaluated the concordance between the PCR-RFLP markers most commonly-used for species identification in mussels within the Mytilus genus (Me15-16, ITS, mac-1, 16S rRNA and COI) when used alone (mono-locus approach) or together (multi-locus approach). In this study, multi-locus strategy outperformed the mono-locus methods, clearly identifying all four species and also showed similar specimen identification performance than a 49 SNPs panel. We hope that these findings will contribute to a better understanding of DNA marker-based analysis of Mytilus taxa. These results support the use of a multi-locus approach when studying this important marine resource, including research on food quality and safety, sustainable production and conservation.

Post-mortem toxicology in the diagnosis of sudden death in young and middle-aged victims

OBJECTIVE

We aimed to investigate the impact of the toxicological results found in cases of sudden death (SD) and to correlate the clinical, autopsy and genetic findings with the toxicology results.

MATERIALS AND METHODS

Consecutive SD in people aged between 16 and 50 years with medico-legal autopsies and toxicology studies were included over a 3-year period. The comparison between the toxicological data and demographic characteristics, clinical circumstances, autopsy, and genetic results were taken into account.

RESULTS

101 cases were finally included. They were predominately males (84%) and the mean age was 39.8 years. 52 (51.5%) cases had positive toxicological findings and in 25 cases (24.8%), toxic compounds were considered the first cause of death. Ethanol was the most frequently identified agent (69%), following by licit drugs (56%) and drugs of abuse (39%). Cases with positive toxicology were younger than those with negative results (37.9±9.1 vs. 41.9±7.8; p=0.02). Patients with more than 3 comorbidities showed an association with positive toxicological results (n=14 vs. n=3; p=0.017). The genetic study was performed in 70 (69.3%) SD cases. We identified pathogenic or likely pathogenic variants in 17.1% cases and uncertain significance variants in 42.8% cases. 58% of these variants were probably related to the cause of death.

CONCLUSIONS

A large fraction of SD victims had positive toxicological findings and a quarter of deaths were directly caused by toxic substances. The identification of the factors that trigger SD provides a good approach to contribute in avoiding future episodes.

Cerebrospinal fluid and blood lactate concentrations as prognostic biomarkers in dogs with meningoencephalitis of unknown origin

Meningoencephalitis of unknown origin (MUO) is a common inflammatory disease of the central nervous system. Several studies investigated finding prognostic factors, but results are contradictory. The aim of this study was to determine the concentrations of blood lactate (Blood-L) and cerebrospinal fluid lactate (CSF-L) in dogs with MUO for prognostic purposes. A total of 45 dogs with MUO (MUO group) and 11 with idiopathic epilepsy (IE group) were included. In the MUO group, 22 dogs were treated with prednisolone + cytosine arabinoside, 17 with prednisolone ± cyclosporine, and six received no treatment. In the MUO group, there was a strong-moderate positive correlation between Blood-L and CSF-L (ρ = 0.63557; P < 0.0001), a strong-moderate negative correlation between survival and CSF-L (ρ= -0.50210; P < 0.0004), and a weak negative correlation between survival and Blood-L (ρ= -0.35685; P < 0.0220). Dogs with a favourable response to treatment at 1 month had lower initial concentrations of Blood-L and CSF-L (P < 0.0010; P < 0.0037), and those with a worse response had higher values (P < 0.0497; P < 0.0004). Dogs that remained stable with treatment showed lower CSF-L concentrations (P < 0.0013). Dogs with Blood-L>4 mmol/L (P < 0.03) and/or CSF-L> 4 mmol/L (P < 0.009) had lower survival rates with the latter also showing more severe signs, probably indicating severe neuronal damage. These findings suggest that concentrations of CSF-L and Blood-L in dogs with MUO could be used as prognostic indicators.

Spatial and temporal variation of the vegetation of the semiarid Puna in a pastoral system in the Pozuelos Biosphere Reserve

This study aimed to analyze the spatial and temporal variation of the vegetation in the northern Argentine Puna, utilizing both field sampling and remote-sensing tools. The study was performed within the Pozuelos Biosphere Reserve (Jujuy province, Argentina), which aims to generate socio-economic development compatible with biodiversity conservation. Our study was designed to analyze the dynamics of the Puna vegetation at local scale and assess and monitor the seasonal (dry and wet seasons), interannual, and spatial variation of the vegetation cover, biomass, dominant species, and vegetation indices. Ten vegetation units (with differences in composition, cover, and high and low stratum biomass) were identified at our study site. The diversity of these vegetation units correlated with geomorphology and soil type. In the dry season, the vegetation unit with greatest vegetation cover and biomass was the Festuca chrysophylla grassland, whereas in the wet season, the units with greatest cover and biomass were vegas (peatlands) and short grasslands. The Festuca chrysophylla grasslands and short grasslands were located in areas with clay soils, except peatlands, associated with valleys and coarse-texture soils. The vegetation indices used (NDVI, SAVI, and MSAVI2) were able to differentiate functional types of vegetation and showed a good statistical fit with cover values. Our results suggest that the integrated utilization of remote-sensing tools and field surveys improves the assessment of the Puna vegetation and would allow a periodic monitoring at production unit scale taking into account its spatial and temporal variation.

Advanced-stage mycosis fungoides: role of the signal transducer and activator of transcription 3, nuclear factor-κB and nuclear factor of activated T cells pathways

BACKGROUND

The malignant mechanisms that control the development of cutaneous T-cell lymphoma (CTCL) are beginning to be identified. Recent evidence suggests that disturbances in specific intracellular signalling pathways, such as RAS-mitogen-activated protein kinase, T-cell receptor (TCR)-phospholipase C gamma 1 (PLCG1)-nuclear factor of activated T cells (NFAT) and Janus kinase (JAK)-signal transducer and activator of transcription (STAT), may play an essential role in the pathogenesis of CTCL.

OBJECTIVES

To investigate the mechanisms controlling disease development and progression in mycosis fungoides (MF), the most common form of CTCL.

METHODS

We collected 100 samples that were submitted for diagnosis of, or a second opinion regarding, MF between 2001 and 2018, 80% of which were in the early clinical stages of the disease. Formalin-fixed paraffin-embedded tissues were used for histological review and to measure the expression by immunohistochemistry of surrogate markers of activation of the TCR-PLCG1-NFAT, JAK-STAT and NF-κB pathways. Folliculotropism and large-cell transformation were also examined.

RESULTS

NFAT and nuclear factor kappa B (NF-κB) markers showed a comparable activation status in early and advanced stages, while STAT3 activation was more frequent in advanced stages and was associated with large-cell transformation. Consistently with this observation, STAT3 activation occurred in parallel with MF progression in two initially MF-negative cases. A significant association of NFAT with NF-κB markers was also found, reflecting a common mechanism of activation in the two pathways. Genomic studies identified nine mutations in seven genes known to play a potential role in tumorigenesis in T-cell leukaemia/lymphoma, including PLCG1, JAK3 and STAT3, which underlies the activation of these key cell-survival pathways. A higher mutational allele frequency was detected in advanced stages.

CONCLUSIONS

Our results show that STAT3 is activated in advanced cases and is associated with large-cell transformation, while the activation of NFAT and NF-κB is maintained throughout the disease. These findings could have important diagnostic and therapeutic implications. What's already known about this topic? Mycosis fungoides is characterized by a clonal expansion of T cells in the skin. The mechanisms controlling disease development and progression are not fully understood. What does this study add? An association of the nuclear factor of activated T cells and nuclear factor kappa B pathways was found, which could reflect a common mechanism of activation. These pathways were activated in early and advanced stages at the same level. Signal transducer and activator of transcription 3 activation was associated with large-cell transformation and was more frequent in advanced stages. A genomic analysis of cutaneous T-cell lymphoma-associated genes was performed. Nine mutations were detected. What is the translational message? These results could have important implications for the treatment of MF in the near future.

Dexamethasone turns tumor antigen-presenting cells into tolerogenic dendritic cells with T cell inhibitory functions

BACKGROUND

Dendritic cells (DCs) are usually immunogenic, but they are also capable of inducing tolerance under anti-inflammatory conditions. Immunotherapy based on autologous DCs loaded with an allogeneic melanoma cell lysate (TRIMEL/DCs) induces immunological responses and increases melanoma patient survival. Glucocorticoids can suppress DC maturation and function, leading to a DC-mediated inhibition of T cell responses.

METHODS

The effect of dexamethasone, a glucocorticoid extensively used in cancer therapies, on TRIMEL/DCs phenotype and immunogenicity was examined.

RESULTS

Dexamethasone induced a semi-mature phenotype on TRIMEL/DC with low maturation surface marker expressions, decreased pro-inflammatory cytokine induction (IL-1β and IL-12) and increased release of regulatory cytokines (IL-10 and TGF-β). Dexamethasone-treated TRIMEL/DCs inhibited allogeneic CD4⁺ T cell proliferation and cytokine release (IFNγ, TNF-α and IL-17). Co-culturing melanoma-specific memory tumor-infiltrating lymphocytes with dexamethasone-treated TRIMEL/DC inhibited proliferation and effector T cell activities, including cytokine secretion and anti-melanoma cytotoxicity.

CONCLUSIONS

These findings suggest that dexamethasone repressed melanoma cell lysate-mediated DC maturation, generating a potent tolerogenic-like DC phenotype that inhibited melanoma-specific effector T cell activities. These results suggest that dexamethasone-induced immunosuppression may interfere with the clinical efficacy of DC-based melanoma vaccines, and must be taken into account for optimal design of cellular therapy against cancer.

[Survival of 1,103 Chilean patients with multiple myeloma receiving different therapeutic protocols from 2000 to 2016]

BACKGROUND

Multiple myeloma (MM) is one of the most common malignancies found in hematology.

AIM

To describe the features of patients with MM and perform a survival analysis according to the different treatment protocols used between 2000 and 2016.

MATERIAL AND METHODS

Analysis of the database of the Chilean national anti-neoplastic drug program. Information was obtained from 1,103 patients, with a median age of 64.5 years (range 27-95) and a male to female ratio of 1:1.2.

RESULTS

The mean overall survival (OS) of patients receiving or not receiving Thalidomide was 46 and 30 months, respectively (p < 0.01). The mean OS of patients treated before 2007 (treated with melphalan and prednisone) and between 2007 and 2012 (treated with thalidomide and dexamethasone) was 36 and 48 months respectively. In the group starting in 2013 (treated with cyclophosphamide, thalidomide and dexamethasone) the median survival had not been reached at 20 months of follow up (p = 0.01 for all comparisons). Autologous transplantation (AT) was carried out in only 18% of the eligible patients. The median OS of the patients who receive an AT had not been reached at 48 month compared with 36 month among those who did not received the procedure (p < 0.01).

CONCLUSIONS

Even though overall survival has improved with time, new drugs must be introduced in our protocols to obtain similar results to those obtained worldwide.

Dispersion-controlled docking preference: multi-spectroscopic study on complexes of dibenzofuran with alcohols and water

The planarity and rigidity of dibenzofuran inverts the docking preference for increasingly bulky R-OH solvent molecules, compared to the closely related diphenyl ether. Now, London dispersion favors OH⋯π hydrogen bonding.

Sex hormone-binding globulin b expression in the rainbow trout ovary prior to sex differentiation

Salmonids have two sex hormone-binding globulin (Shbg) paralogs. Shbga is mainly expressed in the liver, while Shbgb is secreted by the granulosa cells of the rainbow trout ovary. Coexpression of shbgb and the gonadal aromatase cyp19a1a mRNAs been observed in granulosa cells, suggesting a physiological coordination between Shbgb expression and estrogen synthesis. As estrogens are essential for female sex determination in the fish ovary, we propose that Shbgb participates in early ovarian differentiation, either by binding with estrogen or through another mechanism that remains to be discovered. To elucidate this potential role, monosex populations of female trout were studied during the molecular ovarian differentiation period (28-56 dpf). shbgb mRNA expression was measured using qPCR and compared with expression of genes for other ovarian markers (cyp19a1a, foxl2, follistatin, and estrogen receptors). shbgb transcript expression was detected during the final stages of embryonic development (21-26 dpf) and during molecular ovarian differentiation (32-52 dpf) after hatching (which occurred at 31 dpf). In situ hybridization localized shbgb transcription to the undifferentiated ovary at 42 dpf, and shbgb and cyp19a1a mRNA showed similar expression patterns. These results suggest that Shbgb is involved in early ovarian differentiation, supporting an important role for the salmonid shbgb gene in sex determination.

Microsolvated complexes of ibuprofen as revealed by high-resolution rotational spectroscopy

Four conformers of microsolvated ibuprofen have been characterized using high-resolution microwave spectroscopy.

Cochlear obliteration following a translabyrinthine approach and its implications in cochlear implantation

The most frequent sequelae following a translabyrinthine approach for vestibular schwannoma resection is complete hearing loss on the affected side. Such patients could benefit from a cochlear implant, provided that two essential requisites are met before surgery: a preserved cochlear nerve and a patent cochlea to accommodate the electrode array. The goal of our study is to determine the prevalence and extent of cochlear ossification following a translabyrinthine approach. Postoperative MRI of 41 patients were retrospectively reviewed. Patients were classified according to the degree of cochlear obliteration into three groups (patent cochlea, partially obliterated cochlea and totally obliterated cochlea). The interval between surgery and the first MRI was studied as well as its relationship with the rate of cochlear ossification. At first postoperative MRI (mean interval of 20 months), 78% of patients showed some degree of cochlear ossification. Differences were found in the time interval between surgery and first MRI for each group, showing a smaller interval of time the patent cochlea group (p > 0.05). When MRI was performed before the first year after surgery, a larger rate of patent cochlea was found (p > 0.05). The present study suggests that cochlear ossification is a time-depending process, whose grounds are still to be defined.

Tratamiento de la artrosis trapecio-metacarpiana mediante artroplastia total tipo ARPE. Modificación técnica

Se presenta un estudio prospectivo protocolizado de los resultados obtenidos tras el tratamiento quirúrgico de la artrosis trapecio-metacarpiana mediante la artroplastia total no cementada tipo ARPE®. Ciento cuarenta artroplastias tipo ARPE® fueron colocadas en 126 pacientes. Ciento treinta y dos muñecas corresponden a mujeres (94,3%) y 8 a hombres (5,7%) con una edad media de 58,1 años (rango: 39-79). Con seguimiento promedio de 53,8 meses (rango: 24-102), observamos una mejora importante del dolor según la escala analógica visual, 3 muñecas (2,1%) tiene una puntuación 4, 19 muñecas (13,6%) tiene una puntuación 3, 42 muñecas (30%) tiene una puntuación 2, 51 muñecas (36,4%) tiene una puntuación 1 y 25 muñecas (17,9%) tiene una puntuación 0. La movilidad promedio de la articulación trapecio-metacarpiana fue de 21,7º de antepulsión, 34,2º de retropulsión, abducción 31,9º y aducción 23,5º medida según los criterios de la Internacional Federation of Societies for Surgery of the Hand y una oposición según la escala de Tubiana de 7 en un 95,7% de las muñecas. El valorpromedio de la fuerza de puño fue de 26,5 kg, de la fuerza lateral de 9,2 kg y de la fuerza de pinza de 8,6 kg y conservaron la longitud normal del pulgar todas las muñecas intervenidas excepto una. La recuperación postoperatoria de los pacientes fue rápida y con mínimo dolor postoperatorio. Las complicaciones que se produjeron fueron 6 luxaciones (4,3%), una falsa vía del vástago (0,7%) y 2 fracturas del borde radial del trapecio intraoperatorias sin repercusión clínica (1,4%). Cinco de las 7 complicaciones graves, 4 luxaciones y la falsa vía del vástago metacarpiano se produjeron en los primeros 22 pacientes intervenidos (curva de aprendizaje). Las pequeñas desalineaciones de los componentes protésicos se toleran sin que exista una repercusión clínica en los pacientes, sobre todo las del vástago metacarpiano. Existe una supervivencia a medio plazo (5-8 años) del 100% de los implantes en nuestra serie. Un 92,9% expresaron estar satisfechos con la intervención y un 96,4% volvería a operarse con la misma técnica si fuera necesario. El valor medio obtenido tras la realización del cuestionario Disability of the Arm, Shoulder and Hand fue de 17,2. La evaluación a medio plazo de la artroplastia total no cementada tipo ballsocked de ARPE® confirma que puede ser una alternativa quirúrgica en la artrosis trapecio-metacarpiana tipo III de Eaton y Littler, teniendo en cuenta el período de aprendizaje.

Ultra-low background and environmental measurements at Laboratorio Subterráneo de Canfranc (LSC)

To support the construction of experiments at the Laboratorio Subterráneo de Canfranc (LSC) in Spain, an Ultra-Low Background Service (ULBS) and a Copper Electroforming Service (CES) were created. The measurement technique employed at the ULBS is gamma spectroscopy with high purity germanium (HPGe) detectors. A new anti-radon system is being implemented. The main goal of CES is to obtain high-purity copper pieces. A new electroforming set-up inside LSC underground clean room is planned. Radon and environmental measurements at the LSC are presented. The ULBS and CES are reviewed.

The Clinical Course of Venous Thromboembolism May Differ According to Cancer Site

BACKGROUND

We hypothesized that the clinical course of venous thromboembolism in patients with active cancer may differ according to the specificities of primary tumor site.

AIM AND METHODS

We used data from RIETE (international registry of patients with venous thromboembolism) to compare the clinical venous thromboembolism-related outcomes during the course of anticoagulation in patients with one of the 4 more frequent cancers (breast, prostate, colorectal, or lung cancer).

RESULTS

As of September 2014, 3947 cancer patients were recruited, of whom 938 had breast, 629 prostate, 1189 colorectal, and 1191 lung cancer. Overall, 55% had metastatic disease (42%, 36%, 53%, and 72%, respectively). During the course of anticoagulant therapy (mean duration, 139 days), the rate of thromboembolic recurrences was similar to the rate of major bleeding in patients with breast (5.6 [95% confidence interval (CI), 3.8-8.1] vs 4.1 [95% CI, 2.7-5.9] events per 100 patient-years) or colorectal cancer (10 [95% CI, 7.6-13] vs 12 [95% CI, 9.4-15] per 100 patient-years). In contrast, in patients with prostate cancer, the rate of venous thromboembolic recurrences was half the rate of major bleeding (6.9 [95% CI, 4.4-10] vs 13 [95% CI, 9.2-17] events per 100 patient-years), whereas in those with lung cancer, the rate of thromboembolic recurrences was twofold higher than the rate of major bleeding (27 [95% CI, 22-23] vs 11 [95% CI, 8.6-15] per 100 patient-years).

CONCLUSIONS

Significant differences in the clinical profile of venous thromboembolic-related outcomes were observed according to the site of cancer. These findings suggest the development of cancer-specific anticoagulant strategies as an area for further research.

Effects of a Dam Reservoir on the Distribution of Heavy Metals in Two Chilean Native Freshwater Fish Species

In order to determine the effect of a dam on metal concentrations in riverine fish species, we studied fish inhabiting the influent (Cachapoal River) and effluent (Rapel River) of the Rapel Reservoir in central Chile. Heavy metals were quantified in gills, liver and muscle of the catfish Trichomycterus areolatus and the silverside Basilichthys microlepidotus. Also, the bioaccumulation index (BAI) was estimated by considering heavy metal concentrations obtained from water and sediment. Results showed the presence of Al, Cu, Fe, Mn, Pb and Zn in the fish organs. The analysis showed high metal concentrations in catfish inhabiting the influent compared to those collected in the effluent. These results indicate a possible filter effect of the dam for most of the metals identified in the fish organs, because metal concentrations decreased in the effluent. Finally, catfish exhibited a larger BAI for most metals analyzed.

Progress in tear microdesiccate analysis by combining various transmitted-light microscope techniques

Background

Tear desiccation on a glass surface followed by transmitted-light microscopy has served as diagnostic test for dry eye. Four distinctive morphological domains (zones I, II, III and transition band) have been recently recognized in tear microdesiccates. Physicochemical dissimilarities among those domains hamper comprehensive microscopic examination of tear microdesiccates. Optimal observation conditions of entire tear microdesiccates are now investigated. One-μl aliquots of tear collected from individual healthy eyes were dried at ambient conditions on microscope slides. Tear microdesiccates were examined by combining low-magnification objective lenses with transmitted-light microscopy (brightfield, phase contrasts Ph1,2,3 and darkfield).

Results

Fern-like structures (zones II and III) were visible with all illumination methods excepting brightfield. Zone I was the microdesiccate domain displaying the most noticeable illumination-dependent variations, namely transparent band delimited by an outer rim (Ph1, Ph2), homogeneous compactly built structure (brightfield) or invisible domain (darkfield, Ph3). Intermediate positions of the condenser (BF/Ph1, Ph1/Ph2) showed a structured roughly cylindrical zone I. The transition band also varied from invisibility (brightfield) to a well-defined domain comprising interwoven filamentous elements (phase contrasts, darkfield).

Conclusions

Imaging of entire tear microdesiccates by transmitted-light microscopy depends upon illumination. A more comprehensive description of tear microdesiccates can be achieved by combining illumination methods.

Anti-inflammatory effect of dialysable leucocyte extract in a rat model of osteoarthritis: histopathological and molecular characterization

OBJECTIVES

To evaluate the effect of dialysable leucocyte extract (DLE) on pro- and anti-inflammatory profiles in a rat model of osteoarthritis (OA).

METHOD

Forty-eight male Wistar rats were divided into three groups: normal rats without treatment, OA rats treated with placebo, and OA rats treated with DLE. After treatment, the animals were killed to obtain cartilage for histological analysis and to determine the expression of pro- and anti-inflammatory cytokines by reverse transcription multiplex polymerase chain reaction (RT-MPCR) and immunohistofluorescence analyses.

RESULTS

Histological analysis revealed that OA cartilage from rats treated with DLE displayed similar characteristics to non-OA cartilage from the control group. The OA cartilage treated with placebo showed alterations in the cellular architecture and in chondrocyte cluster formation. Analysis of cytokine expression by RT-MPCR showed that OA cartilage from DLE-treated rats expressed platelet-derived growth factor (PDGF), interferon (IFN)-γ, and fibroblast growth factor (FGF)-2, similar to non-OA cartilage from the control group. However, OA cartilage from rats treated with placebo expressed interleukin (IL)-1, PDGF, and I kappa B (IκB). Confocal immunodetection of FGF-2, PDGF, and non-phosphorylated IκB showed that they were distributed in the cytoplasm of most chondrocytes in OA cartilage from DLE-treated rats whereas no nuclear factor kappa B (NF-κB) expression was observed in the nuclei. Instead, in OA cartilage from the placebo group, only weak FGF-2 staining was observed, PDGF and IκB were not detected, and NF-κB was strongly observed in both cytoplasm and nuclei.

CONCLUSIONS

Our findings suggest that DLE treatment modifies the OA process, promoting the expression of anti-inflammatory cytokines and diminishing the inflammatory effects, avoiding the nuclear translocation of NF-κB in chondrocytes.

Diagnosis and management of breakthrough cancer pain: Have all the questions been resolved? A Delphi-based consensus assessment (DOIRON)

OBJECTIVE

To ascertain the level of agreement and achieve a consensus among cancer pain specialists in Spain with regard to the optimal definition, diagnosis, and management of breakthrough cancer pain (BTcP).

DESIGN

Two-round Delphi methodology survey (February-May 2013) using seven-point Likert scales (ranging from 1 "strongly disagree" to 7 "strongly agree") was carried out. Mean scores >5 or <3 indicated, respectively, agreement or disagreement. Scores from 3 to 5 indicated no consensus.

RESULTS

A total of 126 experienced specialists were surveyed. Response rates were 68 % in round 1 and 90 % in round 2. Agreement (mean Likert score) was strongest for the proposed BTcP definition (6.6), the use of oral (6.1), and intranasal (6.0) transmucosal fentanyl, the need for early assessment after BTcP treatment initiation, and the need to improve staff knowledge of BTcP. Broad agreement was also reached regarding the need to systematically screen all cancer patients for BTcP (5.9). Most respondents (82 %) considered strong opioids to be appropriate treatment. In contrast, no consensus was reached regarding strong opioid treatment for baseline pain as a prerequisite for BTcP diagnosis.

CONCLUSIONS

Consensus was strong for most treatment, and diagnostic aspects were evaluated in the study. However, several important issues remain unresolved, particularly whether the diagnostic criteria must include strong opioids for background pain. Nurses' awareness and understanding of BTcP was considered insufficient, and more training is needed in this area. Overall, agreement among specialists was good, but more work is needed to better define the optimal diagnostic features and treatments for this condition.

Influence of Density Functionals and Basis Sets on One-Bond Carbon-Carbon NMR Spin-Spin Coupling Constants

The basis set and the functional dependence of one-bond carbon-carbon NMR spin-spin coupling constants (SSCC) have been analyzed using density functional theory. Four basis sets (6-311G**, TZVP, EPR-III, and aug-cc-pVTZ-J) and four functionals (PBE, PW91, B3LYP, and B3P86) are tested by comparison with 70 experimental values corresponding to 49 molecules that represent multiple types of hybridization of the carbon atoms. The two hybrid functionals B3P86 and B3LYP combined either EPR-III or aug-cc-pVTZ-J basis sets lead to the best accuracy of calculated SSCC. However, a simple linear regression allows for the obtaining of scaled coupling constants that fit much better with the experimental data and where the differences between the different basis sets and/or functional results are significantly reduced. For large molecules the TZVP basis set can be an appropriate election presenting a good compromise between quality of results and computational cost.

Carcass and meat quality of light lambs using principal component analysis

Eighty-six male light lambs of Manchego breed were used in this study. Principal component (PC) analysis was performed to study the relationship between carcass quality variables (n=22) and between meat quality measures (n=21). The carcass quality was assessed using objective and subjective measurements of conformation and fatness besides the joints proportion and tissues proportion of the leg. The measurements used to evaluate meat quality were pH in longissimus dorsi and semitendinosus muscles, the colour, moisture, water holding capacity, cooking losses, texture and sensorial analysis on longissimus dorsi. The five first PCs explained about 77% of the total variability for carcass measures whereas for meat quality the 74% of the total variability was explained for the eight first PCs. All the carcass measurements showed similar weight to define the first PC, whereas the muscle and bone proportion as well as muscle:bone ratio of the leg were useful to define the second PC. The meat quality measures that were more effective to define the first PC were the meat colour measurements, whereas the sensorial variables defined the second PC. The projection of the carcass quality data in the first two PCs allowed to distinguish clearly between heavier carcasses (higher than 6.5 kg) and lighter carcasses (lower than 5.5 kg). The carcasses with a weight higher than 6.5 kg were on the left side of the figure, where the variables of conformation and fatness lie. The group of medium carcass weight were placed between the two previous groups. The projection of the meat quality data in the first two PCs did not differ between hot carcass weights, although there was a trend, the lighter carcasses lay on the left side of the graph, which implies small differences between meat quality in this range of carcass weight.