Complete mitochondrial DNA profile in stroke: A geographical matched case-control study in Spanish population

INTRODUCTION

Stroke, the second leading cause of death worldwide, is a complex disease influenced by many risk factors among which we can find reactive oxygen species (ROS). Since mitochondria are the main producers of cellular ROS, nowadays studies are trying to elucidate the role of these organelles and its DNA (mtDNA) variation in stroke risk. The aim of the present study was to perform a comprehensive evaluation of the association between mtDNA mutations and mtDNA content and stroke risk.

MATERIAL AND METHODS

Homoplasmic and heteroplasmic mutations of the mtDNA were analysed in a case-controls study using 110 S cases and their corresponding control individuals. Mitochondrial DNA copy number (mtDNA-CN) was analysed in 73 of those case-control pairs.

RESULTS

Our results suggest that haplogroup V, specifically variants m.72C > T, m.4580G > A, m.15904C > T and m.16298 T > C have a protective role in relation to stroke risk. On the contrary, variants m.73A > G, m.11719G > A and m.14766C > T appear to be genetic risk factors for stroke. In this study, we found no statistically significant association between stroke risk and mitochondrial DNA copy number.

CONCLUSIONS

These results demonstrate the possible role of mtDNA genetics on the pathogenesis of stroke, probably through alterations in mitochondrial ROS production.

Genetic, environmental and life-style factors associated with longevity. Protocol and response of the LONGECYL Study

OBJECTIVE

To describe the objectives, the methodological approach, the response rate of the Genetic, Environmental and Life-style Factors Study in Castilla y León (Spain).

METHOD

The Health Sentinel Network studied a sample of long-lived individuals aged 95 or more (LLI). The study included biological samples processed with the Global Screening Array v3.0 that contains a total of 730,059 markers. Written consent was obtained before the examination.

CONCLUSIONS

The LLI contacted were 944, and 760 were completed studied. The 87.4% of LLI were born in Castile and Leon and only 1% were non-native of Spain. Severe cognitive impairment was declared in 8.1% of men and 19.2% of women. Genotyping was performed in 739 LLI, the 78.3% of the contacted sample. Family doctors and nurses achieve high participation in population-based studies. DNA samples were taken from 94% of fully studied LLI, and 100% of these samples where successfully genotyped.

Exercise interventions in Alzheimer's disease: A systematic review and meta-analysis of randomized controlled trials

AIMS

To assess the potential multi-domain benefits of exercise interventions on patients with Alzheimer's disease (AD), as well as to determine the specific effects of different exercise modalities (aerobic, strength, or combined training).

METHODS

A systematic search was conducted in PubMed and Web of Science until March 2021 for randomized controlled trials assessing the effect of exercise interventions (compared with no exercise) on patients with AD. Outcomes included cognitive function (mini-mental state examination [MMSE] test), physical function (e.g., 6-minute walking test [6MWT]), functional independence (Barthel index), and neuropsychiatric symptoms (Neuropsychiatric Inventory [NPI]). A random-effects meta-analysis was conducted.

RESULTS

28 studies (total n = 1337 participants, average age 79-90 years) were included in the systematic review, of which 21 could be meta-analyzed. Although considerable heterogeneity was found, exercise interventions induced several significant benefits, including in Barthel index (n = 147 patients, mean difference [MD]=8.36 points, 95% confidence interval [CI]=0.63-16.09), 6MWT (n = 369, MD=84 m, 95% CI=44-133)), and NPI (n = 263, MD=-4.4 points, 95% CI=-8.42 to -0.38). Benefits were also found in the MMSE test, albeit significance was only reached for aerobic exercise (n = 187, MD=2.31 points, 95% CI 0.45-4.27).

CONCLUSIONS

Exercise interventions appear to exert multi-domain benefits in patients with AD.

POS0749 ASSOCIATION BETWEEN IMMUNE-SEROLOGICAL PROFILE AND PULMONARY MANIFESTATIONS IN COLOMBIAN PATIENTS WITH SYSTEMIC LUPUS ERYTHEMATOSUS (LES)

Background:

Pulmonary involvement is common in Systemic Lupus Erythematosus (SLE) patients with varying degrees of parenchymal, vascular, and pleural compromise. In GLADEL, pulmonary involvement was reported in 28.4% of the cohort, but its occurrence ranges between 30-90% due to diversity in populations and the methods used to define it.

Objectives:

To describe the immune-serological profile of a Colombian cohort of SLE patients and to establish its association with pulmonary manifestations.

Methods:

Retrospective analysis of observational data from the follow-up of a cohort of adult patients with SLE. We included 559 patients that fulfilled the SLICC 2012 classification criteria with at least 6 months of disease history and being treated in a rheumatology specialized medical center between 2015 and 2018. The immuno-serological profile was characterized, and pulmonary involvement was monitored for 1 year. Diagnosis of pulmonary involvement was performed with the rheumatologist report in the clinical chart. Prevalence of pulmonary manifestations and immune-serological profile was determined, and logistic regression was performed afterward adjusted by age, sex, and level of education to establish the association between pulmonary manifestations and a positive auto-antibodies profile.

Results:

The median age of the cohort was 45 years, 96.5% were female. Pulmonary involvement was documented in 113 patients (20.5%) at the beginning of the study. Their frequency was: pleuritis (14.3%), lupus pneumonitis (3.6%), pulmonary hypertension (3.2%), interstitial lung disease (ILD) (2.3%), pulmonary embolism (2.3%), lung fibrosis (2.14%), alveolar hemorrhage (1.4%), shrinking lung (0.2%). At 1 year of follow up. there were no statistically significant differences in the frequency of pulmonary manifestations. As for the immune-serological profile, there were positive ANA in 92%, anti-dsDNA in 53.1%, anti-B2GP IgM 15.2%, anti- B2GP IgG in 17.2%, and ENA in 97.2%; as for the ENA 41.7% had positive anti-RNP, 40.2% anti-Ro, 36.4% anti-SM and 16.5% anti-La. Low complement levels was characterized as follows: C3 53.1% and C4 29.2%. In the logistic regression adjusted by age, sex and level of education, there was an association between anti-SM and pulmonary manifestations with an adjusted OR of 1.85; 95% CI 1.13-3.01.

Conclusion:

An association between anti-SM positivity and pleuro-pulmonary manifestations was found. In other cohorts with a greater size, anti-La and anti-RNP have been associated with pulmonary involvement (OR 2.51; 95% CI 1.39-4.57 and OR 1.32; 95% CI 1-1.75 respectively). Anti-RNP positivity has been associated in particular with ILD, pulmonary hypertension and shrinking lung. Although these manifestations prevalence was similar in our cohort, an association with this antibody was not found (OR 1.01, 95% CI: 0.2-4.9). This could be explained by the smaller sample size. As for anti-La positivity, its prevalence in our cohort was less than what was found in the GLADEL cohort (16.5% vs 24.3% respectively). It is possible that this could explain the poor association between anti-La positivity with the presence of pulmonary manifestations in our study compared with those of the GLADEL cohort. There are data that indicates that anti-SM and anti-RNP simultaneous positivity is related mainly to pleuritis OR 1.98 (95% CI: 1.31-3); and this kind of involvement was found to be more frequent in our study. Our results suggest an association between positive anti-SM and pulmonary manifestations in Colombian patients with SLE, pleuritis in particular.

References:

[1]Haye Salinas MJ, Caeiro F, Saurit V et al. Pleuropulmonary involvement in patients with systemic lupus erythematosus from a Latin American inception cohort (GLADEL). Lupus. 2017;26(13):1368–77.

[2]Emad Y, Gheita T, Darweesh H, Klooster P, et al. Antibodies to extractable nuclear antigens (ENAS) in systemic lupus erythematosus patients: Correlations with clinical manifestations and disease activity. Reumatismo. 2018;70(2):85–91.

Disclosure of Interests:

None declared

AB0336 PULMONARY MANIFESTATIONS IN A COLOMBIAN COHORT OF PATIENTS WITH SYSTEMIC LUPUS ERYTHEMATOSUS

Background:

Pulmonary manifestations are frequent in systemic lupus erythematosus (SLE) with a frequency of 30-90% that depends on the cohort and the methods used for their identification. The association of this compromise with mortality highlights its importance and the need for biomarkers to adequately predict this complication. We describe the prevalence of pulmonary manifestations, and the clinic and immunoserological characteristics of 551 Colombian patients with SLE

Objectives:

We performed an observational and analytic study of a retrospective cohort with adult SLE patients who fulfilled the 2012 SLICC classification criteria and that had a history of at least 6 months of the disease. These patients were treated in a specialized center of rheumatology with presence in six cities of Colombia between 2015 and 2018. We excluded pregnant patients and those with incomplete data for our survey. The first clinic consult occurred between 2015 and 2018, being defined as moment one. The follow up one year later was defined as moment two. We obtained 710 registries that were potentially eligible and analyzed 465 patients at moment two after applying the exclusion criteria

Methods:

In 465 eligible patients, 20,5% had pulmonary compromise (93.8% female) with a median age of 42,4 years. The average SLICC Damage Index of 551 patients with SLE was 0,9 in women and 1.05 in men, while the average SDI of patients with pulmonary compromise was 1. The most frequent manifestation was pleural (14.3%), followed by Lupus pneumonitis (3.6%) and pulmonary hypertension (3.2%). Other manifestations and serological characteristics are recorded in Table 1. Of note, ANA homogeneous pattern was the most common (34.5%), anti-RNP positivity was 41.7%, anti-dsDNA positivity was 53.1% and 53.1% had hypocomplementemia.

Results:

The prevalence of pulmonary manifestations in our cohort was 20,5%, which is lower that in the previous described GLADEL cohort (28,4%). This could be explained by the regional differences of ethnicities in Latin America and in immune-serological profiles. Anti-RNP positivity was frequent (41.7%) and new pulmonary compromise for one year follow-up was rare. Of not, the mean damage index for our patients with pulmonary manifestations was 1, this could highlight the importance of this organ as a causa of higher damage accrual and mortality, which we will explore in the future

Conclusion:

The prevalence of pulmonary manifestations in our cohort was 20,5%, which is lower that in the previous described GLADEL cohort (28,4%). This could be explained by the regional differences of ethnicities in Latin America and in immune-serological profiles. Anti-RNP positivity was frequent (41.7%) and new pulmonary compromise for one year follow-up was rare. Of not, the mean damage index for our patients with pulmonary manifestations was 1, this could highlight the importance of this organ as a causa of higher damage accrual and mortality, which we will explore in the future

References:

[1]G. Aguilera-Pickens, C. Abud-Mendoza. Pulmonary Manifestations in Systemic Lupus Erythematosus: Pleural Involvement, Acute Pneumonitis, Chronic Interstitial Lung Disease and Diffuse Alveolar Hemorrhage. Reumatol Clin. 2018;14(5):294–300.

[2]Haye Salinas MJ, Caeiro F, Saurit V. Pleuropulmonary involvement in patients with systemic lupus erythematosus from a Latin American inception cohort (GLADEL). Lupus (2017) 0, 1–10.

[3]Santamaria-Alza Y, Sanchez-Bautista J, Fajardo-Rivero J. Acute respiratory involvement in Colombian patients with systemic lupus erythematosus undergoing chest computed tomography. Int J Rheum Dis. 2019;00:1–7.

Table 1.

clinical and immunoserological characteristics

n%Women10693,8Global mortality468,3Pulmonary compromise mortality87,1ANA10492Anti-DNA6053,1ENAS97,2Ro35/8740,2La14/8516,5SM32/8836,4RNP35/8441,7Follow up 1 %Follow up 2 %P Value *Pulmonary hypertension3,22,80,28Pulmonary fibrosis2,142,61Shrunken lung0,20,21Pleuritis14,315,050,42Lupus pneumonitis3,63,010,85Alveolar hemorrhage1,41,30,76Pulmonary embolism2,31,930,72

Disclosure of Interests:

None declared

AB0335 SURVIVAL ASSESSMENT IN PATIENTS WITH SLE AND PULMONARY MANIFESTATIONS IN A COLOMBIAN COHORT WITH 2-YEAR FOLLOW-UP

Background:

Systemic lupus erythematosus (SLE) is a multisystemic autoimmune disease with heterogenous and variable behavior. The frequency of pulmonary involvement ranges from 10-90%, with this variability in occurrence attributed to differences in populations and heterogeneity in detection methods and study designs.

Objectives:

To analyze survival in patients with SLE and the presence of pulmonary manifestations according to clinical and demographic characteristics in a cohort of patients in Colombia

Methods:

Observational-analytical, retrospective, follow-up study of a cohort of adult patients with SLE. We included 559 adult patients who fulfilled the 2012 SLICC SLE classification criteria and with at least 6 months of disease evolution, treated in a medical center specialized in rheumatology with locations in 6 cities in Colombia between 2015 and 2018. Pregnant patients and those who had incomplete data or visits were excluded. Immunoserological profile was characterized and pulmonary involvement was followed for 1 year. The diagnosis of pulmonary involvement was obtained from the rheumatology report in the clinical chart. The prevalence of pulmonary manifestations and the immunoserological profile were determined and subsequently a logistic regression adjusted for age, sex and level of education was performed to establish the association between pulmonary manifestations and a positive autoantibody profile

Results:

Median age was 44.5 ± 14 years, 96.6% were women. In patients with pulmonary compromise 9.7% were smokers, 12.4% had an active alcohol intake, 58.4% had a low socioeconomic status, 38.1% medium and 4.7% high. Pulmonary involvement was present in 20% of patients, the most common manifestations were pleuritis (14.3%), lupus pneumonitis (3.6%), pulmonary hypertension (3.2%), interstitial lung disease (2.3%), pulmonary embolism (2.3%), pulmonary fibrosis (2.14%), alveolar hemorrhage (1.4%), shrinking lung (0.2%). there was no significant difference in the follow up at one year. Immunoserological characteristics shows ANA positivity in 92%, anti-DNA in 53%, ENAS in 97%, with anti-RNP being the most common (41.7%), and low complement levels in 53%. Mortality for pulmonary compromise was 1.4%, and survival at 2 years did not have a statistically significant difference (p=0.155)

Conclusion:

Survival was not found to be lower in patients with SLE and pulmonary involvement (p=0.155) when compared to SLE patients without pulmonary involvement after 2-year follow-up. This finding was independent of age, gender, and educational level. Previous large cohorts like GLADEL and RELESSER describe an association between pulmonary involvement and lower survival HR 2,79 (95% CI: 1,80-4,31), p <0,001 and HR 3.13, (95% IC: 1.56– 6.28, P = 0.00 respectively. In the RELESSER cohort pleural involvement and pulmonary embolism was found to have low to minimal impact on survival.

In our cohort pleuritis was the most common finding whereas the other pulmonary manifestations were reported in less than 4% of patients. This difference could explain our differences with other cohorts. Other causes for this difference are a smaller sample size and a short follow-up.

The results of our study do not suggest that there is an association between pulmonary involvement and mortality in Colombian patients with SLE during a 2-year follow-up. We will continue to monitor and report in this regard

References:

[1]Narváez J, Borrell H, Sánchez-Alonso F, Rúa-Figueroa I, López-Longo FJ, Galindo-Izquierdo M, et al. Primary respiratory disease in patients with systemic lupus erythematosus. (RELESSER) cohort. Arthritis Res Ther. 2018;20(1):1–10.

[2]Keane MP, Lynch JP. Pleuropulmonary manifestations of systemic lupus erythematosus. Vol. 55, Thorax. Thorax; 2000. p. 159–66.

[3]Haye Salinas MJ, Caeiro F, Saurit V, Alvarellos A, Wojdyla D, Scherbarth HR, et al. Pleuropulmonary involvement in patients with systemic lupus erythematosus from a Latin American inception cohort (GLADEL). Lupus. 2017;26(13):1368–77

Disclosure of Interests:

None declared

Transmissibility of influenza during the 21st-century epidemics, Spain, influenza seasons 2001/02 to 2017/18

BackgroundUnderstanding influenza seasonality is necessary for determining policies for influenza control.AimWe characterised transmissibility during seasonal influenza epidemics, including one influenza pandemic, in Spain during the 21th century by using the moving epidemic method (MEM) to calculate intensity levels and estimate differences across seasons and age groups.MethodsWe applied the MEM to Spanish Influenza Sentinel Surveillance System data from influenza seasons 2001/02 to 2017/18. A modified version of Goldstein's proxy was used as an epidemiological-virological parameter. We calculated the average starting week and peak, the length of the epidemic period and the length from the starting week to the peak of the epidemic, by age group and according to seasonal virus circulation.ResultsIndividuals under 15 years of age presented higher transmissibility, especially in the 2009 influenza A(H1N1) pandemic. Seasons with dominance/co-dominance of influenza A(H3N2) virus presented high intensities in older adults. The 2004/05 influenza season showed the highest influenza-intensity level for all age groups. In 12 seasons, the epidemic started between week 50 and week 3. Epidemics started earlier in individuals under 15 years of age (-1.8 weeks; 95% confidence interval (CI):-2.8 to -0.7) than in those over 64 years when influenza B virus circulated as dominant/co-dominant. The average time from start to peak was 4.3 weeks (95% CI: 3.6-5.0) and the average epidemic length was 8.7 weeks (95% CI: 7.9-9.6).ConclusionsThese findings provide evidence for intensity differences across seasons and age groups, and can be used guide public health actions to diminish influenza-related morbidity and mortality.

Use of the moving epidemic method (MEM) to assess national surveillance data for respiratory syncytial virus (RSV) in the Netherlands, 2005 to 2017

Background

To control respiratory syncytial virus (RSV), which causes acute respiratory infections, data and methods to assess its epidemiology are important.

Aim

We sought to describe RSV seasonality, affected age groups and RSV-type distribution over 12 consecutive seasons in the Netherlands, as well as to validate the moving epidemic method (MEM) for monitoring RSV epidemics.

Methods

We used 2005−17 laboratory surveillance data and sentinel data. For RSV seasonality evaluation, epidemic thresholds (i) at 1.2% of the cumulative number of RSV-positive patients per season and (ii) at 20 detections per week (for laboratory data) were employed. We also assessed MEM thresholds.

Results

In laboratory data RSV was reported 25,491 times (no denominator). In sentinel data 5.6% (767/13,577) of specimens tested RSV positive. Over 12 seasons, sentinel data showed percentage increases of RSV positive samples. The average epidemic length was 18.0 weeks (95% confidence intervals (CI):  16.3–19.7) and 16.5 weeks (95% CI: 14.0–18.0) for laboratory and sentinel data, respectively. Epidemics started on average in week 46 (95% CI: 45–48) and 47 (95% CI:  46–49), respectively. The peak was on average in the first week of January in both datasets. MEM showed similar results to the other methods. RSV incidence was highest in youngest (0–1 and >1–2 years) and oldest (>65–75 and > 75 years) age groups, with age distribution remaining stable over time. RSV-type dominance alternated every one or two seasons.

Conclusions

Our findings provide baseline information for immunisation advisory groups. The possibility of employing MEM to monitor RSV epidemics allows prospective, nearly real-time use of surveillance data.

Dream engineering: Simulating worlds through sensory stimulation

We explore the application of a wide range of sensory stimulation technologies to the area of sleep and dream engineering. We begin by emphasizing the causal role of the body in dream generation, and describe a circuitry between the sleeping body and the dreaming mind. We suggest that nearly any sensory stimuli has potential for modulating experience in sleep. Considering other areas that might afford tools for engineering sensory content in simulated worlds, we turn to Virtual Reality (VR). We outline a collection of relevant VR technologies, including devices engineered to stimulate haptic, temperature, vestibular, olfactory, and auditory sensations. We believe these technologies, which have been developed for high mobility and low cost, can be translated to the field of dream engineering. We close by discussing possible future directions in this field and the ethics of a world in which targeted dream direction and sleep manipulation are feasible.

Evaluating tools to define influenza baseline and threshold values using surveillance data, Egypt, season 2016/17

BACKGROUND

Establishing influenza thresholds and transmission intensity can help evaluate seasonal changes in influenza severity and potential pandemics. We aimed to evaluate the moving epidemic method (MEM) for calculating influenza thresholds for season 2016/17 in Egypt using four parameters, to identify the most useful parameter. Also to measure the agreement between both the country-specific statistical empirical method and World Health Organization method to MEM for determining the length and intensity level of activity of the influenza season.

METHODS

Routinely epidemiological and laboratory data from sentinel surveillance sites for Severe Acute Respiratory Infection (SARI) and influenza-like illness (ILI) were used for calculating thresholds for seasons between 2010/11 and 2015/16 to test 2016/17 season. The parameters calculated were: screened ILI consultation rate × 1000, screened ILI composite parameter, influenza positivity percentage among sampled SARI cases, and influenza positivity percentage among sampled ILI and SARI cases. These parameters assess seasonality and intensity of influenza activity using the three proposed methods (mentioned above). Agreement between the three methods was done using several approaches.

RESULTS

The intensity of influenza activity by MEM was lower than the other two methods. Agreement between MEM and each of the other two techniques varied appreciably from good to very good for seasonal duration, and poor to fair for intensity level. In addition, parameters including laboratory data showed a pattern of bi-wave activity; the first wave occurred in winter mostly between epidemiological weeks 39 and 52 and the second occurred in spring mostly between weeks 12 and 17.

CONCLUSION

Parameters including laboratory data were more useful in defining seasonality of influenza. Further exploration of the MEM model in future seasons may help to provide a more comprehensive understanding of its use and application.

Toxicological assessment of Xanthigen® nutraceutical extract combination: Mutagenicity, genotoxicity and oral toxicity

Xanthigen® is a nutraceutical combination for weight management capable of increasing energy expenditure via uncoupling protein 1 (UCP-1) in white adipose tissue. It consists of brown seaweed Undaria pinnatifida extract, rich in the carotenoid fucoxanthin (FX) and pomegranate seed oil (PSO), rich in punicic acid. Xanthigen was screened to determine its genotoxicity and 90-days repeated oral toxicity. Genotoxicity was assessed with the Ames test (TA89, TA100, TA1535, TA1537, WP2), chromosomal aberration assay (Chinese hamster ovary cells) and mammalian micronucleus test (in mice). Xanthigen did not exhibit genotoxicity in any tested strain. Sub-chronic toxicity was evaluated with daily oral administration of 250, 500 and 1000 mg/kg/day doses of Xanthigen® to Sprague-Dawley rats over 90 days. No deaths and no deleterious effects were observed during the 90-day treatment, indicating an absence of sub-chronic toxicity and a no observed adverse effect level greater than 1000 mg/kg/day. A statistically significant decrease in bodyweight and food intake in Xanthigen® treated groups was attributed to the weight loss property of Xanthigen®. Overall, Xanthigen® shows no significant mutagenic or toxic effects.

Involvement of mitochondrial haplogroups in myocardial infarction and stroke: A case-control study in Castile and Leon (Spain) population

There are strong evidences that common mitochondrial DNA (mtDNA) haplogroups may influence the pathogenesis of cardiovascular diseases (CVDs). In this matched case-control study, we investigate the association between mtDNA haplogroups and two CVDs, myocardial infarction (MI) and stroke, and classical cardiovascular risk factors. Data obtained show that haplogroup H constitute a susceptibility risk factor for MI (p=0.001; OR=2.379, 95% CI [1.440-3.990]). Otherwise, our data also suggest a beneficial role of haplogroup J against hypertension (p=0.019; OR=0.348, 95% CI [0.144-0.840]). These results may provide some guidance for predicting the genetic risk of these diseases in different human populations through the differences in energy efficiency between haplogroups.

Influenza surveillance in Europe: comparing intensity levels calculated using the moving epidemic method

Objectives

Although influenza-like illnesses (ILI) and acute respiratory illnesses (ARI) surveillance are well established in Europe, the comparability of intensity among countries and seasons remains an unresolved challenge. The objective is to compare the intensity of ILI and ARI in some European countries.

Design and setting

Weekly ILI and ARI incidence rates and proportion of primary care consultations were modeled in 28 countries for the 1996/1997–2013/2014 seasons using the moving epidemic method (MEM). We calculated the epidemic threshold and three intensity thresholds, which delimit five intensity levels: baseline, low, medium, high, and very high. The intensity of 2013/2014 season is described and compared by country.

Results

The lowest ILI epidemic thresholds appeared in Sweden and Estonia (below 10 cases per 100 000) and the highest in Belgium, Denmark, Hungary, Poland, Serbia, and Slovakia (above 100 per 100 000). The 2009/2010 season was the most intense, with 35% of the countries showing high or very high intensity levels. The European epidemic period in season 2013/2014 started in January 2014 in Spain, Poland, and Greece. The intensity was between low and medium and only Greece reached the high intensity level, in weeks 7 to 9/2014. Some countries remained at the baseline level throughout the entire surveillance period.

Conclusions

Epidemic and intensity thresholds varied by country. Influenza-like illnesses and ARI levels normalized by MEM in 2013/2014 showed that the intensity of the season in Europe was between low and medium in most of the countries. Comparing intensity among seasons or countries is essential for understanding patterns in seasonal epidemics. An automated standardized model for comparison should be implemented at national and international levels.

Estimating influenza vaccine effectiveness in Spain using sentinel surveillance data

We aimed to estimate influenza vaccine effectiveness (VE) against laboratory-confirmed influenza during three influenza seasons (2010/11 to 2012/2013) in Spain using surveillance data and to compare the results with data obtained by the cycEVA study, the Spanish component of the Influenza Monitoring Vaccine Effectiveness (I-MOVE) network. We used the test-negative case–control design, with data from the Spanish Influenza Sentinel Surveillance System (SISS) or from the cycEVA study. Cases were laboratory-confirmed influenza patients with the predominant influenza virus of each season, and controls were those testing negative for any influenza virus. We calculated the overall and age-specific adjusted VE. Although the number of patients recorded in the SISS was three times higher than that in the cycEVA study, the quality of information for important variables, i.e. vaccination status and laboratory results, was high in both studies. Overall, the SISS and cycEVA influenza VE estimates were largely similar during the study period. For elderly patients (> 59 years), the SISS estimates were slightly lower than those of cycEVA, and estimates for children (0–14 years) were higher using SISS in two of the three seasons studied. Enhancing the SISS by collecting the date of influenza vaccination and reducing the percentage of patients with incomplete information would optimise the system to provide reliable annual influenza VE estimates to guide influenza vaccination policies.

Age and sex differences in the incidence of diabetes mellitus in a population-based Spanish cohort

BACKGROUND

The prevalence of diabetes mellitus (DM) in Spain ranges between 10% and 20%. However, very little is known about the incidence of DM because of difficulties involved in estimating it and its apparent lack of usefulness in practice. The aim of the present study was to describe the incidence of type 1 and type 2 DM (T1DM and T2DM, respectively) in the Castilla y León diabetes cohort (CODICyL).

METHODS

New diabetes cases, were registered on a standard form that included diagnostic criteria, background, symptoms, results of clinical examination, complications, other cardiovascular risk factors, and treatment. There were 1 354 619 person-years monitored between 2000 and 2013. We estimated the incidence of DM and calculated the relative risks adjusted for age, gender, and year of diagnosis with Poisson regression models.

RESULTS

The incidence of DM in individuals aged ≥15 years was 196.9 per 100 000 person-years (95% confidence interval [CI] 188.4-205.7), whereas in those aged <15 years the incidence was 10.8 per 100 000 person-years (95% CI 7.8-14.8). Men had a 36% higher risk than women of developing T2DM (95% CI 25%-49%). The greatest incidence of T2DM was found in 55-64-year-old men and 65-69-year-old women.

CONCLUSIONS

The annual incidence of T2DM is approximately 2 per 1000 person-years, higher in men, and peaks in middle age. Although specific tests to differentiate between the two types of DM are not available in this study, the estimation of incidence in those <15 years of age (10.8 per 100 000 person-years) represents a close approximation of the incidence of T1DM.

Metabolic and inflammatory profiles of biomarkers in obesity, metabolic syndrome, and diabetes in a Mediterranean population. DARIOS Inflammatory study

INTRODUCTION AND OBJECTIVES

There is a paucity of data regarding the differences in the biomarker profiles of patients with obesity, metabolic syndrome, and diabetes mellitus as compared to a healthy, normal weight population. We aimed to study the biomarker profile of the metabolic risk continuum defined by the transition from normal weight to obesity, metabolic syndrome, and diabetes mellitus.

METHODS

We performed a pooled analysis of data from 7 cross-sectional Spanish population-based surveys. An extensive panel comprising 20 biomarkers related to carbohydrate metabolism, lipids, inflammation, coagulation, oxidation, hemodynamics, and myocardial damage was analyzed. We employed age- and sex-adjusted multinomial logistic regression models for the identification of those biomarkers associated with the metabolic risk continuum phenotypes: obesity, metabolic syndrome, and diabetes mellitus.

RESULTS

A total of 2851 subjects were included for analyses. The mean age was 57.4 (8.8) years, 1269 were men (44.5%), and 464 participants were obese, 443 had metabolic syndrome, 473 had diabetes mellitus, and 1471 had a normal weight (healthy individuals). High-sensitivity C-reactive protein, apolipoprotein B100, leptin, and insulin were positively associated with at least one of the phenotypes of interest. Apolipoprotein A1 and adiponectin were negatively associated.

CONCLUSIONS

There are differences between the population with normal weight and that having metabolic syndrome or diabetes with respect to certain biomarkers related to the metabolic, inflammatory, and lipid profiles. The results of this study support the relevance of these mechanisms in the metabolic risk continuum. When metabolic syndrome and diabetes mellitus are compared, these differences are less marked.

Influenza vaccine effectiveness in Spain 2013/14: subtype-specific early estimates using the cycEVA study

Adjusted early estimates of the 2013/14 influenza vaccine effectiveness (VE) in Spain for all age groups was 35% (95% CI: -9 to 62), 33% (95% CI: -33 to 67) and 28% (95% CI: -33 to 61) against any influenza virus type, A(H1N1)pdm09 and A(H3N2) viruses, respectively. For the population targeted for vaccination, the adjusted VE was 44% (95% CI: -11 to 72), 36% (95% CI: -64 to 75) and 42% (95% CI: -29 to 74), respectively. These preliminary results in Spain suggest a suboptimal protective effect of the vaccine against circulating influenza viruses.

Effectiveness of influenza vaccine against laboratory-confirmed influenza, in the late 2011-2012 season in Spain, among population targeted for vaccination

BACKGROUND

In Spain, the influenza vaccine effectiveness (VE) was estimated in the last three seasons using the observational study cycEVA conducted in the frame of the existing Spanish Influenza Sentinel Surveillance System. The objective of the study was to estimate influenza vaccine effectiveness (VE) against medically attended, laboratory-confirmed influenza-like illness (ILI) among the target groups for vaccination in Spain in the 2011-2012 season. We also studied influenza VE in the early (weeks 52/2011-7/2012) and late (weeks 8-14/2012) phases of the epidemic and according to time since vaccination.

METHODS

Medically attended patients with ILI were systematically swabbed to collect information on exposure, laboratory outcome and confounding factors. Patients belonging to target groups for vaccination and who were swabbed <8 days after symptom onset were included. Cases tested positive for influenza and controls tested negative for any influenza virus. To examine the effect of a late season, analyses were performed according to the phase of the season and according to the time between vaccination and symptoms onset.

RESULTS

The overall adjusted influenza VE against A(H3N2) was 45% (95% CI, 0-69). The estimated influenza VE was 52% (95% CI, -3 to 78), 40% (95% CI, -40 to 74) and 22% (95% CI, -135 to 74) at 3.5 months, 3.5-4 months, and >4 months, respectively, since vaccination. A decrease in VE with time since vaccination was only observed in individuals aged ≥ 65 years. Regarding the phase of the season, decreasing point estimates were only observed in the early phase, whereas very low or null estimates were obtained in the late phase for the shortest time interval.

CONCLUSIONS

The 2011-2012 influenza vaccine showed a low-to-moderate protective effect against medically attended, laboratory-confirmed influenza in the target groups for vaccination, in a late season and with a limited match between the vaccine and circulating strains. The suggested decrease in influenza VE with time since vaccination was mostly observed in the elderly population. The decreasing protective effect of the vaccine in the late part of the season could be related to waning vaccine protection because no viral changes were identified throughout the season.

Influenza surveillance in Europe: establishing epidemic thresholds by the moving epidemic method

BACKGROUND

Timely influenza surveillance is important to monitor influenza epidemics.

OBJECTIVES

(i) To calculate the epidemic threshold for influenza-like illness (ILI) and acute respiratory infections (ARI) in 19 countries, as well as the thresholds for different levels of intensity. (ii) To evaluate the performance of these thresholds.

METHODS

The moving epidemic method (MEM) has been developed to determine the baseline influenza activity and an epidemic threshold. False alerts, detection lags and timeliness of the detection of epidemics were calculated. The performance was evaluated using a cross-validation procedure.

RESULTS

The overall sensitivity of the MEM threshold was 71·8% and the specificity was 95·5%. The median of the timeliness was 1 week (range: 0-4·5).

CONCLUSIONS

The method produced a robust and specific signal to detect influenza epidemics. The good balance between the sensitivity and specificity of the epidemic threshold to detect seasonal epidemics and avoid false alerts has advantages for public health purposes. This method may serve as standard to define the start of the annual influenza epidemic in countries in Europe.

Acetohydroxyacid synthase (AHAS) in vivo assay for screening imidazolinone-resistance in sunflower (Helianthus annuus L.)

The objective of this work was to evaluate the in vivo acetohydroxyacid synthase (AHAS) activity response to imidazolinones and its possible use as a selection method for evaluating AHAS inhibitor resistance. In vivo AHAS assay and the comparison of parameters from dose-response curves have been used as a valid tool for comparing sunflower lines and hybrids differing in imidazolinone resistance. The sunflower resistant genotypes evaluated here were 100-fold and 20-fold more resistant compared with the susceptible line for imazethapyr and imazapyr, respectively. This assay also allowed discrimination of homozygous from heterozygous genotypes for I(mr1) locus that codify for the catalytic subunit of AHAS. The in vivo AHAS assay described in this study was useful for the selection of sunflower genotypes differing in herbicide resistance and could be a useful tool when breeding for imidazolinone resistance in sunflower.

Early estimates of the effectiveness of the 2011/12 influenza vaccine in the population targeted for vaccination in Spain, 25 December 2011 to 19 February 2012

We present early estimates of influenza vaccine effectiveness (VE) in the population targeted for vaccination, during 25 December 2011 to 19 February 2012. The adjusted VE was 55% (95% CI: 3 to 79) against any type of influenza virus and 54% (95% CI: 1 to 79) against influenza A(H3N2) virus. This suggests a moderate protective effect of the vaccine in the targeted population in a late influenza epidemic with limited match between vaccine and circulating strains.

Early estimates of the effectiveness of the 2011/12 influenza vaccine in the population targeted for vaccination in Spain, 25 December 2011 to 19 February 2012

We present early estimates of influenza vaccine effectiveness (VE) in the population targeted for vaccination, during 25 December 2011 to 19 February 2012. The adjusted VE was 55% (95% CI: 3 to 79) against any type of influenza virus and 54% (95% CI: 1 to 79) against influenza A(H3N2) virus. This suggests a moderate protective effect of the vaccine in the targeted population in a late influenza epidemic with limited match between vaccine and circulating strains.

[Palliative and support care at home in primary care]

OBJECTIVES

To estimate the proportion of people requiring palliative and support care at home in primary care and to describe their characteristics.

METHODS

A descriptive study was carried out by five Spanish sentinel networks between October 2007 and March 2008 in 282,216 people attended by 218 general practitioners and nurses. Patients receiving comprehensive, active and continued care at home were included if the aim was not to prolong life but to achieve the best quality of life for the patient, the family and the carers. A standard form was used to collect data on age, sex, type of patient, underlying diseases and other variables related to the process. Crude and age-adjusted rates were estimated.

RESULTS

Of the 400 men and 792 women registered, 12% were strictly terminal. The mean age was 82.4 years and was higher in patients with functional disability (82.9 years) than in terminally-ill patients (78.9 years) (p<0.01). The estimated prevalence was 422.3 per 100,000 inhabitants aged 14 years or more (95% CI: 398.7-447.0) and was much higher in women than in men (553.9 versus 287.3, p<0.01). The estimate for the entire Spanish population was 309.0 per 100,000 inhabitants (95% CI: 286.0-332.0).

CONCLUSIONS

The prevalence of palliative and support care in Spain is around three cases per 1,000 inhabitants and is higher in elderly populations. More than 85% of patients needing palliative or support care have a life expectancy of over 6 months and thus represent the majority of persons using this type of medical and social support. The most susceptible groups are women and the oldest-old.

Sunflower propagation

Sunflower (Helianthus annuus L.) has been cultivated both as an oilseed and as an ornamental plant. Several protocols have been described for the micropropagation, direct plant regeneration by organogenesis being acceptable for this plant species. Besides a strong genotype dependency, the type and ontogenic stage of explants, environmental conditions of the culture, and media composition affect sunflower organogenesis. Several problems have hindered the ability to regenerate normal shoots; the most common being hyperhydricity and precocious flowering. This chapter describes a protocol for direct shoot regeneration from cotyledons developed and established in our laboratory, as well as the improvement regenerated shoot quality.

Determinants of health system delay among confirmed tuberculosis cases in Spain

BACKGROUND

Health system delay (HSD) is an important issue in tuberculosis (TB) control. This report investigates HSD and associated factors in a cohort of Spanish culture-confirmed TB patients.

METHODS

Data were collected from clinical records. Using logistic regression with two different cut-off points to define HSD (median and 75th percentile), adjusted odds ratios were used to estimate the association between HSD and different variables.

RESULTS

A total of 5184 culture-confirmed TB cases were included. Median and 75th percentile HSD were 6 and 25 days respectively. HSD significantly greater than the median was associated with: age >44 years, past or present intravenous drug use, diagnosis at a primary-care centre, prior preventive therapy, positive histology, request for drug-sensitivity testing, presence of silicosis or neoplasia in addition to TB, presence of non-TB related symptoms, and gastrointestinal site. HSD greater than the 75th percentile was related to the same variables, with the exception of diagnosis at a primary-care centre, positive histology, silicosis, non-TB-related symptoms and gastrointestinal site, for which the association disappeared; in contrast, an association with female gender emerged.

CONCLUSION

Despite free health care being universally available in Spain, there are some groups of TB patients whose treatment is unduly delayed.

Determinants of patient delay among tuberculosis cases in Spain

BACKGROUND

Patient delay was investigated in a cohort of TB patients identified from May 1996 until April 1997 in 13 Autonomous Regions in Spain. The study covered almost 67% of the total Spanish population.

METHODS

Data were collected from clinical records. Using unconditional logistic regression with two different cut-off points to define 'patient delay' (the median and 75th percentile), the association between patient delay and different factors was estimated.

RESULTS

A total of 7,037 cases were included. Median and 75th percentile delays were 22 and 57 days respectively. Factors associated with patient delay greater than the median (p<0.05) were: non-respiratory symptoms of TB and age over 14 years, although the effect of age was not linear. Furthermore, an interaction was observed between intravenous drug user (IDU) and HIV status, in that, whereas patient delay was greater in IDUs than in non-IDUs among cases whose HIV status was either negative or unknown, among HIV-positive patients no such IDU-related differences were in evidence. Factors associated with extreme patient delay (greater than the 75th percentile) were essentially the same, but the above-described interaction disappeared, with IDU status showing no direct effect. In addition, likelihood of extreme patient delay increased in the case of alcoholism and female gender and decreased in the case of chronic renal failure, corticoid treatment, prison inmates and residents of old age homes.

CONCLUSION

Although there is a universally enjoyed right to health care in Spain, some groups of TB patients could nevertheless be experiencing problems in seeking medical attention.

Heterogeneous case definitions used for the surveillance of influenza in Europe

We reviewed the case definitions used by 21 influenza sentinel-based surveillance networks in Western Europe. Two clinical syndromes were used with a wide range of case definitions that nevertheless shared common criteria. Although there is currently no international consensus, efforts are being undertaken to standardise influenza case definitions in Europe.

Tuberculosis in Spain: epidemiological pattern and clinical practice

SETTING

Thirteen Autonomous Regions in Spain.

OBJECTIVE

To study the incidence of all forms of tuberculosis (TB) and investigate clinical practice in TB.

DESIGN

Cases of all forms of tuberculosis diagnosed in the study setting from May 1986 to April 1997 were identified though active search of different databases. Clinical and epidemiological information on cases was collected from clinical records or by interview with physicians.

RESULTS

The overall incidence of all forms of tuberculosis was 38.5/100,000 and the incidence of smear-positive disease was 13.83/100,000. Most cases (97.1%) were Spanish nationals, with rates higher in men than in women (52.7/100,000 vs. 24.87/100,000) and in groups aged 25-34 and 75 years and over (61.35/100,000 and 59.35/100,000, respectively). Disseminated forms were frequent (6.6%), and the most common risk factor was human immunodeficiency virus (HIV) infection (17.7% of cases). Hospitalisation was common (71.6%). Microbiological confirmation of diagnosis was sought for 87.7% of the cases (91.8% of pulmonary vs. 75.5% of extra-pulmonary cases), and 65.2% were culture-positive (73.8% of pulmonary vs. 39.7% of extra-pulmonary cases). HIV-infected patients were treated in almost equal proportions with three or four drugs (49.7% and 48.2%, respectively), while HIV-negative cases or those whose HIV status was unknown were usually treated with three drugs.

CONCLUSION

The epidemiological pattern of TB in Spain is different to other industrialised countries in the age distribution of cases and the proportions of foreigners and cases with HIV infection. Microbiological confirmation of diagnosis is more common in pulmonary than in extra-pulmonary disease, and treatment with four drugs more frequent in HIV-positive cases.

Safety and efficacy of Omniscan (gadodiamide injection) at 0.1 mmol/kg for MRI in infants younger than 6 months of age: phase III open multicenter study

RATIONALE AND OBJECTIVES

To demonstrate that gadodiamide injection is a safe and efficient contrast agent for MRI in infants younger than 6 months of age.

METHODS

The authors designed a phase III multicenter nonrandomized study using a control group. Gadodiamide injection at a dosage of 0.1 mmol/kg body weight was administered to 39 children; 20 received no contrast. The mean age was 10.6 weeks in the contrast group and 9.3 weeks in the control group. MR examinations, blood (serum creatinine, S-ASAT, S-ALAT, S-bilirubin, alkaline phosphatase) and urine (proteins, blood, others) sampling before sedation and after examination, heart rate (electrocardiography) and oxygen saturation (pulse oximetry) during examination, adverse events, and efficacy parameters were analyzed.

RESULTS

In the contrast group, 18 (51.4%) children had 31 abnormal changes in one or more of the safety parameters and vital signs. In the control group there were 16 (80.0%) children with 19 abnormal changes. Gadodiamide injection had no negative influence on the safety parameters. No serious adverse events occurred, and only three clinically relevant adverse events (elevation of S-ALAT and S-ASAT, elevation of bilirubin) in two patients in the contrast group and one event (vomiting) in one patient in the control group were documented. The benefit of the contrast medium was clearly shown for all evaluated parameters.

CONCLUSIONS

Gadodiamide injection is safe, well tolerated, and effective in infants younger than 6 months of age.

Under-reporting of adverse drug reactions. Estimate based on a spontaneous reporting scheme and a sentinel system

OBJECTIVE

Spontaneous reporting is the most common method used in pharmacovigilance and the best one to generate signals on new or rare adverse drug reactions (ADRs). Under-reporting is a major drawback of this system. The objective of this study was to quantify the extent of under-reporting in general practice and to assess the factors which influence it.

METHODS

Details of ADRs collected through a short intensive survey were compared with primary care spontaneous reports received by the Castilla y Leon Regional Pharmacovigilance Centre during a 12-month reference period. The survey was undertaken by a random sample of 146 general practitioners (GPs), providing care to 149,487 people. The pharmacovigilance centre received reports concerning the whole regional population (2.5 million) covered by primary health care. The under-reporting coefficient (U) was estimated as the ratio between the number of effects observed by physicians in the survey and those spontaneously reported to the pharmacovigilance centre.

RESULTS

The overall under-reporting rate was 1144 [95% confidence interval (CI): 928-1409]. Under-reporting was greater for psychiatric (2119; 945-4752) and gastrointestinal (1946; 1424-2659) disorders. Severe effects were more reported (U = 605; 151-2431) than moderate (863; 473-1575) and mild (1209; 973-1503) ones. The under-reporting rate was lower for drugs recently marketed (706; 406-1230) and slightly lower for unlabelled effects (1031; 641-1657).

CONCLUSION

The under-reporting rate of ADRs is considerable, though not homogeneous for the different cases. This should be taken into account when comparing adverse effects (AEs) for different drugs. Under-reporting seems to be positively selective, as it involves mainly the less severe and better-known effects, preserving the value of spontaneous reporting for signal detection.

Drastic facilitation by alpha-latrotoxin of bovine chromaffin cell exocytosis without measurable enhancement of Ca2+ entry or [Ca2+]i

1. Latrotoxin (LTX, 1-3 nM) caused a gradual increase of the spontaneous catecholamine release rate in bovine adrenal chromaffin cells superfused with normal Krebs-Hepes solution containing 2.5 mM Ca2+. Ca2+ removal abolished this effect. LTX enhanced also the secretory responses to high K+ (35 or 70 mM) and to acetylcholine (ACh, 30 microM). 2. The application of Ca2+ pulses to cells previously superfused with a 0 Ca2+ solution (Krebs-Hepes deprived of CaCl2) induced secretory responses that gradually reached 400-800 nA of catecholamines, provided that LTX was present. The responses to ACh or 35 mM K+ pulses (in the presence of Ca2+) were also enhanced by LTX, from around 100-200 nA to over 1000 nA. Though such enhancement remained in the presence of Ca2+ channel blockers, it disappeared upon the lowering of [Na+]o or in electroporated cells. 3. Using protocols similar to those of secretion, LTX did not enhance basal 45Ca2+ uptake, whole-cell Ca2+ currents or basal [Ca2+]i. In fact, LTX attenuated the K(+)- or ACh-evoked increases in 45Ca2+ uptake and [Ca2+]i. 4. It is proposed that the secretory response to brief periods of Ca2+ reintroductions is triggered by local subplasmalemmal Ca2+i transients, produced by the Na(+)-Ca2+ exchanger of the plasma membrane working in the reverse mode. This situation might be physiologically reproduced during ACh stimulation of chromaffin cells, which is followed by the firing of Na(+)-dependent action potentials.

Effects of tyramine and calcium on the kinetics of secretion in intact and electroporated chromaffin cells superfused at high speed

Fast superfusion of electroporated bovine adrenal chromaffin cells with a K+ glutamate-based solution containing 50 nM free Ca2+ and 2 mM adenosine 5'-triphosphate, dipotassium salt (K2ATP), produced a steady-state low catecholamine secretion, measured on-line with an electrochemical detector (about 20 nA). Rapid switching to electroporation solutions containing increasing Ca2+ concentrations ([Ca2+]) produced a rapid increase in the rate and peak secretion, followed by a decline. At intermediate [Ca2+] (3-100 microM), a fast peak and a slow secretory plateau were distinguished. The fast secretory peak identifies a readily releasable catecholamine pool consisting of about 200-400 vesicles per cell. Pretreatment of cells with tyramine (10 microM for 4 min before electroporation) supressed the initial fast secretory peak, leaving intact the slower phase of secretion. With [Ca2+] in the range of 0.1-3 microM, the activation rate of secretion increased from 2.3 to 35.3 nA.s-1, reached a plateau between 3-30 microM and rose again from 100 to 1000 microM [Ca2+] to a maximum of 91.9 nA.s-1. In contrast, total secretion first increased (0.1-1 microM Ca2+), then plateaud (1-100 microM Ca2+) and subsequently decreased (100-1000 microM Ca2+). At 30 and 1000 microM extracellular [Ca2+] or [Ca2+]o, the activation rates of secretion from intact cells depolarised with 70 mM K+ were close to those obtained in electroporated cells. However, secretion peaks were much lower in intact (93 nA at 30 microM Ca2+) than in electroporated cells (385 nA). On the other hand, inactivation of secretion was much faster in intact than in electroporated cells; as a consequence, total secretion in a 5-min period was considerably smaller in intact (10.6 microA.s at 1000 microM Ca2+) than in electroporated cells (42.4 microA.s at 1 microM Ca2+). Separation of the time-courses of changes in intracellular [Ca2+] or [Ca2+]i and secretion in intact chromaffin cells depolarised with 70 mM K+ was demonstrated at different [Ca2+]o. The increase in the rate of catecholamine release was substantially higher than the increase of the average [Ca2+]i. In contrast, the decline of secretion was faster than the decline of the peak [Ca2+]i. The results are compatible with the idea that the peak and the amount of catecholamine released from depolarised intact cells is determined essentially by plasmalemmal factors, rather than by vesicle supply from reserve pools. These plasmalemmal factors limit the supply of Ca2+ by the rates of opening and closing of voltage-dependent Ca2+ channels of the L- and Q-subtypes, which control the local [Ca2+]i near to exocytotic sites.

Effects of omega-toxins on noradrenergic neurotransmission in beating guinea pig atria

The effects of four omega-toxins, known to block various subtypes of neuronal voltage-activated Ca2+ channels, on the beating guinea pig left atrium have been analyzed. Atria were suspended in oxygenated Krebs-bicarbonate solution at 32 degrees C and driven with electrical pulses delivered by a stimulator at 1 Hz, 1 ms, 4 V. A 10-fold increase of voltage caused a potent and rapid enhancement of the size of contractions (about 3- to 4-fold above basal), which reflects the release of endogenous noradrenaline from sympathetic nerve terminals. omega-Conotoxin MVIIC, omega-conotoxin MVIIA and omega-conotoxin GVIA inhibited the inotropic responses to 10 x V stimulation with IC50 values of 191, 44 and 20.4 nM, respectively. omega-Agatoxin IVA did not affect the contractile responses. The inotropic responses to exogenous noradrenaline were unaffected by the toxins. The potent blocking effects of omega-conotoxin GVIA were present even in conditions in which the release of noradrenaline was strongly facilitated by presynaptic alpha 2-adrenoceptor blockade by phenoxybenzamine. These effects were not reversed upon repeated washing of the tissue with toxin-free medium. In contrast, the blockade induced by omega-conotoxin MVIIC and omega-conotoxin MVIIA were fully reversed, with t1/2 of 13.5 and 31.2 min, respectively. omega-Conotoxin MVIIC (1 microM) protected against the irreversibility of the blockade induced by omega-conotoxin GVIA (100 nM).(ABSTRACT TRUNCATED AT 250 WORDS)