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Iron (Fe) is the fourth most abundant element on the planet, and iron-oxidising bacteria (FeOB) play an important role in the biogeochemical cycle of this metal in nature. FeOB stands out as Fe oxidisers in microaerophilic environments, and new members of this group have been increasingly discussed in the literature, even though their isolation can still be challenging. Among these bacteria is the Gallionellaceae family, mainly composed of neutrophilic FeOB, highlighting Gallionella ferruginea, and nitrite-oxidiser genera. In the previous metagenomic study of the biofilm and sediments of the cooling system from the Irapé hydroelectric power plant (HPP-Irapé), 5% of the total bacteria sequences were related to Gallionellaceae, being 99% unclassified at genus level. Thus, in the present study, a phylogenetic tree based on this family was constructed, in order to search for shared and unique Gallionellaceae signatures in a deep phylogenetic level affiliation and correlated them with geomorphologic characteristics. The results revealed that Gallionella and Ferrigenium were ubiquitous reflecting their ability to adapt to various locations in the power plant. The cave was considered a hotspot for neutrophilic FeOB since it harboured most of the Gallionellaceae diversity. Microscopic biosignatures were detected only in the CS1 sample, which presented abundance of the stalk-forming Ferriphaselus and of the sheath-forming Crenothrix. Further studies are required to provide more detailed insights on Gallionellaceae distribution and diversity patterns in hydroelectric power plants, particularly its biotechnological potential in this industry., (© 2024. The Author(s) under exclusive licence to Sociedade Brasileira de Microbiologia.)

Limnoperna fortunei , the golden mussel, is a bivalve mollusk considered an invader in South America. This species is responsible for ecological and economic damages due to its voluminous fouling capability. Chemical biocides such as MXD-100™ and sodium dichloroisocyanurate (NaDCC) are often used to control L. fortunei infestations in hydraulic systems. Thus, we proposed to investigate the effects of different periods (24, 48 and 72 h) of exposure to MXD-100™ (0.56 mg L -1 ) and NaDCC (1.5 mg L -1 ) on the gills of L. fortunei through morphological and molecular analyses. NaDCC promoted progressive morphological changes during the analyzed periods and only an upregulation of SOD and HSP70 expression during the first 24 h of exposure. MXD-100™ led to severe morphological changes from the first period of exposure, in addition to an upregulation of SOD, CAT, HSP70 and CYP expression during the first 24 h. In contrast, MXD-100™ led to a downregulation of CAT transcription between 24 and 48 h. In static conditions, NaDCC causes lethal damage after 72 h of exposure, and that exposure needs to be continuous to achieve the control of the species. Meanwhile, the MXD-100™ treatment presented several effects during the first 24 h, showing acute toxicity in a shorter period of time.

Microfouling can have significant economic impacts for hydroelectric power plants. However, knowledge concerning the composition and metabolism of microbial biofilm in cooling systems remains scarce. We examined the metagenome present in a cooling system, comprising a filter (F) and heat exchanger (HE), in the Nova Ponte hydroelectric power plant in Brazil, to identify bacteria and pathways that could be targeted to monitor and control biofilm formation. Our data revealed that the microfouling sample from heat exchanger 1 (HEM1), with porous consistency, presented enriched bacterial members not frequently described as biofilm formers in cooling systems, besides it has been shown to be an autoinducer repression pathway. Furthermore, the microfouling sample from heat exchanger 2 (HEM2), with gelatinous consistency, seemed to be an established biofilm, containing enriched bacterial groups such as Desulfotomaculum and Crenothrix and autoinducers, with biotechnological relevance in industrial biofilms. The results demonstrate that biofilm composition will vary depending on different abiotic conditions and the antifouling strategy used, including type of compound, concentration, and frequency of use. Therefore, all these variables must be evaluated when a power plant is affected by microbial slime in the cooling system. Our findings could help to define strategies for efficient and ecofriendly measures to contain microfouling in power plants., (© 2023. The Author(s) under exclusive licence to Sociedade Brasileira de Microbiologia.)

The template matching technique is one of the most applied methods to find patterns in images, in which a reduced-size image, called a target, is searched within another image that represents the overall environment. In this work, template matching is used via a co-design system. A hardware coprocessor is designed for the computationally demanding step of template matching, which is the calculation of the normalized cross-correlation coefficient. This computation allows invariance in the global brightness changes in the images, but it is computationally more expensive when using images of larger dimensions, or even sets of images. Furthermore, we investigate the performance of six different swarm intelligence techniques aiming to accelerate the target search process. To evaluate the proposed design, the processing time, the number of iterations, and the success rate were compared. The results show that it is possible to obtain approaches capable of processing video images at 30 frames per second with an acceptable average success rate for detecting the tracked target. The search strategies based on PSO, ABC, FFA, and CS are able to meet the processing time of 30 frame/s, yielding average accuracy rates above 80% for the pipelined co-design implementation. However, FWA, EHO, and BFOA could not achieve the required timing restriction, and they achieved an acceptance rate around 60%. Among all the investigated search strategies, the PSO provides the best performance, yielding an average processing time of 16.22 ms coupled with a 95% success rate.

Background: Limnoperna fortunei is a freshwater bivalve mollusc originally from southern Asia that invaded South America in the 1990's. Due to its highly efficient water pumping and filtering, and its capacity to form strong adhesions to a variety of substrates by byssus thread, this invasive species has been able to adapt to several environments across South America, causing significant ecological and economic damages. By gaining a deeper understanding of the biological and ecological aspects of L. fortunei we will be able to establish more effective strategies to manage its invasion. The gills of the mollusc are key structures responsible for several biological functions, including respiration and feeding. In this work, we characterized the ultrastructure of L. fortunei gills and its ciliary epithelium using light microscopy, transmission and scanning electron microscopies. This is the first report of the morphology of the epithelial cells and cilia of the gill of L. fortunei visualized in high resolution., Results: The analysis showed highly organized and abundant ciliary structures (lateral cilia, laterofrontal cirri and frontal cilia) on the entire length of the branchial epithelium. Mitochondria, smooth endoplasmic reticulum and glycogen granules were abundantly found in the epithelial cells of the gills, demonstrating the energy-demanding function of these structures. Neutral mucopolysaccharides (low viscosity mucus) were observed on the frontal surface of the gill filaments and acid mucopolysaccharides (high viscosity mucus) were observed to be spread out, mainly on the lateral tract. Spherical vesicles, possibly containing mucus, could also be observed in these cells. These findings demonstrate the importance of the mucociliary processes in particle capture and selection., Conclusions: Our data suggest that the mechanism used by this mollusc for particle capture and selection could contribute to a better understanding of key aspects of invasion and also in the establishment of more efficient and economically viable strategies of population control., (© 2022. The Author(s).)

Microfouling, ie biofilm formation on surfaces, can have an economic impact and requires costly maintenance in water-powered energy generation systems. In this study, the microbiota of a cooling system (filter and heat exchanger) in the Irapé hydroelectric power plant in Brazil was examined. The goal was to identify bacteria that could be targeted to more efficiently reduce biofilm formation. Two sampling campaigns were made corresponding to two well-defined seasons of the Brazilian Cerrado biome: the dry (campaign 1) and the wet (campaign 2). Microfouling communities varied considerably over time in samples obtained at different times after the last clearance of the heat exchanger. The thermophilic bacteria Meiothermus , Thermomonas and Symbiobacterium were exclusive and abundant in the microfouling of the heat exchanger in campaign 2, while methanotrophs and iron-reducing bacteria were abundant only in filter sediments. These findings could help to guide strategies for ecofriendly measures to reduce biofilm fouling in hydroelectric power plants, minimizing environmental and economic losses.

Background and Aim: Several studies reported a high prevalence of Obstructive Sleep Apnoea (OSA) in patients with Idiopathic Pulmonary Fibrosis (IPF) or restrictive end-stage lung disease (ESLD). Besides the known risk factors for OSA like high Body Mass Index (BMI), reduced static and dynamic volumes for IPF patients and reduced DLCO and low minimal O 2 saturation during sleep for ESLD patients were associated with higher Apnoea-Hypopnoea Index (AHI). The aim of our study was to determine potential predictive factors of OSA in patients with Fibrotic Lung Diseases (FLD)., Materials and Methods: In this study, 49 patients with FLD and BMI ≤30 kg/m 2 were included. All patients underwent portable cardiorespiratory polysomnography (PSG) and were asked to fill in Epworth Sleepiness Scale (ESS). Their epidemiological, medication and subsidiary exams data were retrieved from their hospital records. Univariate and multivariate correlation models were obtained., Results: Approximately 70% of patients had an AHI ≥5 events/h. In an univariate correlation model, AHI showed a statistically significant correlation with age, BMI, the duration of immunosuppressant treatment, and Forced Expiratory Volume in the first second (FEV1). Only BMI remained an independent predictor of OSA in a multivariate correlation model adjusted for the other statistically meaningful variables., Conclusions: FLD patients, in general, show a prevalence of OSA superior to that of the general population. Excess of weight might predict a higher risk for OSA in FLD patients. Larger and more homogenous studies are warranted to clarify the associations between OSA severity and lung function impairment and the duration of immunosuppressant treatment., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Introduction: Recent studies have reported a high prevalence of obstructive sleep apnoea (OSA) among patients with diffuse parenchymal lung disease (DPLD), mainly idiopathic pulmonary fibrosis (IPF). Effective OSA treatment appears to have a positive impact on morbidity and mortality in these patients. However, poor compliance to positive airway pressure (PAP) treatment in fibrotic DPLD patients has been reported. The aims of our study were to characterize patients with fibrotic DPLD and OSA and to assess their compliance to PAP treatment., Methods: Forty-nine patients with fibrotic DPLD underwent level III polysomnography. Auto-adjusting PAP (APAP) treatment was proposed for those patients with moderate-to-severe OSA and those with mild OSA with daytime sleepiness and/or cardiovascular disease. The APAP treatment compliance was assessed after 1 month of therapy., Results: The distribution of the 49 fibrotic DPLD patients included was as follows: 21 with chronic hypersensitivity pneumonitis, 12 with IPF, 10 with connective-tissue associated DPLD, 4 with stage IV sarcoidosis, 1 with idiopathic pleuropulmonary fibroelastosis, and 1 with DPLD-associated vasculitis. Thirty-four (69.4%) of the patients presented with OSA; 22 had mild OSA, and 12 had moderate-to-severe OSA. APAP treatment was prescribed in 17 of the patients. After 1 month of therapy, all patients used APAP more than 70% of the nights for more than 4 h per night., Conclusion: We found a high prevalence of OSA among all of the patients with fibrotic DPLD (not only IPF). Despite certain difficulties, it was possible to achieve good APAP compliance in these patients.

Background: Sarcoidosis is a systemic granulomatous disease of unknown etiology. Epidemiological studies of different populations are essential because clinical presentation, organ involvement, disease severity, and prognosis vary significantly according to region and population. The aim of this study was to assess epidemiological and clinical characteristics, staging factors, and clinical course in patients with sarcoidosis from a tertiary hospital in Oporto, Portugal., Methods: A retrospective analysis of patients with sarcoidosis and at least 2 years of follow-up evaluated at the Centro Hospitalar de São João between 2000 and 2014., Results: We identified 409 patients with sarcoidosis (females, 58.9%; mean age at diagnosis, 38.9±13.4 years; smokers, 14.4%]. All the patients were diagnosed according to the ERS/ATS/WASOG consensus statement and 64.1% had evidence of noncaseating epithelioid cell granulomas in biopsy specimens. Bronchoalveolar lavage was performed as part of the diagnostic work-up in 289 patients and 90.2% had lymphocytosis (CD4/CD8 ratio ≥3.5 in 60.9% of cases). Exertion dyspnea, cough, and constitutional symptoms were the most common presenting symptoms; 10.1% of patients were asymptomatic, 22.8% had Löfgren syndrome, and 50.5% had extrathoracic involvement. Radiographic stages of disease according to the Scadding criteria were as follows: stage 0 (5.2%), stage I (33.7%), stage II (47.0%), stage III (8.4%), and stage IV (5.7%). Impaired respiratory function was observed in 45.6% patients and was mostly mild. Systemic treatment was administered in 58.6% of cases. Overall, 45.3% of patients experienced disease resolution., Conclusion: The epidemiological and clinical characteristics of this cohort of patients with sarcoidosis from the Oporto region in northern Portugal revealed epidemiological and clinical characteristics that were generally similar to those described in other Western Europe populations and in the US ACCESS study. However, we found a higher proportion of patients who progressed to chronic forms., (Copyright © 2017 Sociedade Portuguesa de Pneumologia. Published by Elsevier España, S.L.U. All rights reserved.)

Published studies that deal with the question of how the temperature of chair seats influences human activities are few, but the studies considering such a factor, a function of the type of material, could contribute to improvements in the design of chairs. This study evaluates seat temperatures of 8 types of chairs made of different materials. The parts of the furniture that people come into contact with, and the thermal response of the material to heating and cooling have been evaluated. Infrared thermography was used for this, as it is a non-contact technique that does not present any type of risk in the measurement of temperatures. Seats made of synthetic leather (leatherette), wood and polyester fabric were found to have the highest temperatures, and the plywood seat showed the lowest. The study has also revealed that thermography can contribute to studies of thermal comfort of chair seats in addition to determining the most suitable material., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Cystic fibrosis (CF) is the most common autosomal recessive disease in Caucasians. Although most cases are diagnosed in childhood, diagnosis in adults is apparently increasing., Objective: Evaluate the adult population with CF, comparing patients who were diagnosed before and after 18 years of age., Methods: Retrospective analysis of patients followed in three main medical centres in Portugal in 2012. Comparison of two groups: G1 - patients diagnosed at <18 years and G2 - patients diagnosed at ≥18 years., Results: 89 adults were identified: 61.8% in G1, 38.2% in G2. Gender distribution was similar in both groups. Average age in G2 was higher (38.3±8.4 vs. 26.8±6.1 years, p<0.001). Respiratory symptoms most frequently led to CF diagnosis in all patients, mainly in adulthood. There was a greater percentage of patients homozygous for the mutation delF508 in G1 (43.6 vs. 8.8%, p=0.02). Respiratory and pancreatic function, and body mass index (BMI) showed a higher severity in G1 (G1 vs. G2: FEV1: 54.6±27.3 vs. 29.9±64.6%, p=0.177; pancreatic insufficiency 72.7 vs. 26.5%, p<0.001; BMI 20.2±3.4 vs. 22.2±4.8, p=0.018). Pseudomonas aeruginosa and methicillin-sensitive Staphylococcus aureus were the most frequently isolated microorganisms. Lung transplantation rate was higher in G2 (20.6 vs. 10.9%, p=0.231) while mortality rate was higher in G1 (0 vs. 3.6%, p=0.261). Hospital admission rate was higher in G1 as well as mortality rate., Conclusion: The results suggest that patients with CF diagnosed in childhood have characteristics that distinguish them from those diagnosed in adulthood, and these differences may have implications for diagnosis, prognosis and life expectancy., (Copyright © 2016 Sociedade Portuguesa de Pneumologia. Published by Elsevier España, S.L.U. All rights reserved.)

Chagas disease is a neglected chronic condition with a high burden of morbidity and mortality. It has considerable psychological, social, and economic impacts. The disease represents a significant public health issue in Brazil, with different regional patterns. This document presents the evidence that resulted in the Brazilian Consensus on Chagas Disease. The objective was to review and standardize strategies for diagnosis, treatment, prevention, and control of Chagas disease in the country, based on the available scientific evidence. The consensus is based on the articulation and strategic contribution of renowned Brazilian experts with knowledge and experience on various aspects of the disease. It is the result of a close collaboration between the Brazilian Society of Tropical Medicine and the Ministry of Health. It is hoped that this document will strengthen the development of integrated actions against Chagas disease in the country, focusing on epidemiology, management, comprehensive care (including families and communities), communication, information, education, and research .

Chagas disease is a neglected chronic condition that presents high morbidity and mortality burden, with considerable psychological, social, and economic impact. The disease represents a significant public health issue in Brazil, with different regional patterns. This document presents the evidence that resulted in the Brazilian Consensus on Chagas Disease. The objective was to review and standardize strategies for diagnosis, treatment, prevention, and control of Chagas disease in the country, based on the available scientific evidence. The consensus is based on collaboration and contribution of renowned Brazilian experts with vast knowledge and experience on various aspects of the disease. It is the result of close collaboration between the Brazilian Society of Tropical Medicine and the Ministry of Health. This document shall strengthen the development of integrated control measures against Chagas disease in the country, focusing on epidemiology, management, comprehensive care (including families and communities), communication, information, education, and research.

Purpose: Auto-titrating continuous positive airway pressure (APAP) devices were developed to improve treatment efficacy and compliance in patients with obstructive sleep apnoea syndrome (OSAS). Since there are insufficient data on the optimal pressure range setting, we aimed to compare the adherence, efficacy and tolerability of treatment with high-span versus low-span APAP., Methods: Seventy-six newly diagnosed OSAS patients fulfilling the treatment criteria were randomised to receive high-span (HS, range 4-15cmH2O, n = 38) or low-span (LS, range 8-12cmH2O, n = 38) APAP. Patients were assessed at 1 and 3 months., Results: Median Epworth sleepiness scale (ESS) was 13 (IQR, 6-16) and median apnoea-hypopnoea index (AHI) was 35.9 (IQR, 27.6-56.3). There were no significant differences in baseline demographic and clinical characteristics between groups. Overall, no significant differences were found at the first month assessment. After 3 months of therapy, we found again no differences in residual AHI or ESS. However, the group HS proved less adherent than group LS, respectively, with median 87 % (IQR, 60.5-97.5) versus 94 % (IQR, 80.0-98.3) of the nights using ≥4 h (P = 0.014) and mean (±SD) usage 5.7 ± 1.6 versus 6.4 ± 1.2 h/night (P = 0.049). The group HS reported more frequently nasal congestion, excessive oronasal dryness and nocturnal awakenings of at least moderate intensity, the latter with statistical significance (P = 0.005)., Conclusions: Both pressure ranges appear to be equally effective to correct AHI and to improve symptoms. Though, patients with high-span APAP were less compliant to treatment, raising issues about the tolerability of wide pressure range settings of these devices.

Background: Rapid on-site evaluation (ROSE) has the potential to increase endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) accuracy in the diagnosis of mediastinal lesions and lung cancer staging. However, studies have reported controversial results. The purpose of our study was to evaluate the influence of ROSE on sample adequacy and diagnostic accuracy of EBUS-TBNA., Methods: Prospective observational study that enrolled 81 patients who underwent EBUS-TBNA for investigation of hilo-mediastinal lesions or lung cancer staging. The first 41 patients underwent EBUS-TBNA with ROSE (ROSE group) and the last 40 patients without ROSE (non-ROSE group). Sample adequacy and diagnostic accuracy of EBUS-TBNA in both groups were compared., Results: Adequate samples were obtained in 93% of the patients in the ROSE group and 80% in non-ROSE group (p=0.10). The diagnostic accuracy of EBUS-TBNA was 91% in ROSE group and 83% in non-ROSE group (p=0.08). Analyzing the EBUS-TBNA purpose, in the subgroup of patients who underwent EBUS-TBNA for investigation of hilo-mediastinal lesions, these differences between ROSE and non-ROSE group were higher compared to lung cancer staging, 93% of patients with adequate samples in the ROSE group vs. 75% in the non-ROSE group (p=0.06) and 87% of diagnostic accuracy in ROSE group vs. 77% in non-ROSE group (p=0.10)., Conclusions: Despite the lack of statistical significance, ROSE appears to be particularly useful in the diagnostic work-up of hilo-mediastinal lesions, increasing the diagnostic yield of EBUS-TBNA., (Copyright © 2014 Sociedade Portuguesa de Pneumologia. Published by Elsevier España, S.L.U. All rights reserved.)

In this study we characterized the surface morphology and ultrastructure of the foot of the golden mussel, Limnoperna fortunei (Dunker, 1857), relating its characteristics to the attaching mechanisms of this mollusk. The observation of the foot of this bivalve reveals the presence of micro-scaled cilia with a unique shape, which has a narrowing at its end. This characteristic was associated to the capacity for underwater adhesion to substrates through the employment of van der Waals forces, resembling the adhesion phenomenon of the gecko foot. The temporary attachment during locomotion by means of the foot to substrates was observed to be strong even on smooth surfaces, like glass, or hydrophobic waxy surfaces. Comparing TEM and light microscopy results it was possible to associate the mucous secretions and secreting cells found along the tissues to the production of the byssus inside the groove on the ventral portion of the foot. Not only our experiments, but also the state of the art allowed us to discard the involvement of secretions produced in the foot of the mussel to the temporary adhesion. Through SEM images it was possible to build a virtual three-dimensional model where total foot surface was measured for the estimated calculation of van der Waals forces. Also, some theoretical analysis and considerations have been made concerning the characteristics of the functional surface of L. fortunei foot., (Copyright © 2015 Elsevier B.V. All rights reserved.)

The self-assessment of the quality ofthe Family Health Strategy(FHS) was assessed in the context ofmanagement and its correlation with characteristics of FHS and of the municipality. Managers, coordinators and Family Health Unit managers of municipalities in the Northeast region of Minas Gerais replied with tools 1, 2 and 3 of the Assessment for Improving the Quality of Family Health Strategy (AIQ). Scores were defined for each subdimension, according to the number of features compliant with the standards of the AIQ. We tested the correlation of this score with coverage and the deployment time of the FHS, with the municipal population and the HDI (Human Development Index). The lowest scores were for Work Management, Permanent Education and Inputs, Immunobiologicals and Medicines. There was a positive correlation between the municipal population and Strengthening of Coordination, Support for Teams, Permanent Education Management and Standardization and a negative one with Infrastructure and Equipment. The use of the AIQ tools permitted the identification of subdimensions and municipalities which will require greater attention and intervention by the municipal management.

In the search for larvicidal compounds against Aedes aegypti L. (Diptera: Culicidae), a collection of monoterpenes were selected and evaluated. R- and S-limonene exhibited the highest larvicidal potency (LC(50)=27 and 30 ppm, respectively), followed by γ-terpinene (LC(50)=56 ppm) and RS-carvone (LC(50)=118 ppm). Structural characteristics which may contribute to the understanding of the larvicidal activity of monoterpenes were empirically identified. The presence of heteroatoms in the basic hydrocarbon structure decreases larvicidal potency. Conjugated and exo double bonds appear to increase larvicidal potency. Replacement of double bonds by more reactive epoxides decreases the larvicidal potency. The presence of hydroxyls in the cyclic structure resulted in decreased potency, probably due to increased polarity indicanting that lipophilicity seems to play an important role in increasing the larvicidal potency in this set of compounds., (Copyright © 2011 Elsevier Ltd. All rights reserved.)

Chagas disease can be transmitted to man by many different means, including contact with infected triatomine feces, blood transfusion, laboratory accidents, organ transplants, and congenital or oral routes. The latter mode has received considerable attention recently. In this assay, we evaluate the survival of Trypanosoma cruzi contaminating sugar cane used to prepare juice, as well as the viability and capacity for infection by the parasite after recovery. Thirty triatomines were contaminated with T. cruzi Y strain and 45 days later pieces of sugar cane were contaminated with the intestinal contents of the insects. The pieces were ground at different intervals after contamination (time=0, 1, 4, 6, 12 and 24 hours) and the juice extracted and analyzed. Different methods were used to show T. cruzi in the juice: direct analysis, hematocrit tube centrifugation and QBC, and experimental inoculation in 47 female BALB/c mice (five control mice and seven mice for each interval examined (five inoculated orally and two intraperitoneally). Positive results were found using the direct analysis and QBC methods for juice prepared up to 12 hours after initial contamination. However, by the centrifugation technique, positivity was found only up to four hours after contamination of the sugar cane. Inoculated animals showed parasitemia during a 14 day observation period, demonstrating the high survival rate of T. cruzi in sugar cane.

The investigation of the influence of sweetened food on feeding behavior targeted to non-sucrose nutrients as well as the sensitivity to painful stimuli in isolated and grouped animals is the aim of the present work. The tail withdrawal latencies in the tail-flick test (a spinal reflex) were measured before and immediately after the treatment with tap water or sucrose (62, 125 or 250 g/l). Our findings suggest that: (a) The analgesic effect of sucrose intake depends on the concentration of sucrose solution and on the time during which the solution is consumed; (b) the most effective concentration of sucrose followed by antinociceptive effect was the one of 250 g/l in both isolated and grouped animals; (c) considering the individually caged rats, the intake of sucrose in the highest concentration (250 g/l) was the smallest as compared with the consumption of sucrose in more diluted solutions (62.5 and 125 g/l), but this higher sweetened solution was followed by antinociception; (d) animals treated with concentrated sucrose solution ate smaller quantities of pellets than animals treated with tap water; (e) tonic intake of highly concentrated sweet substance seems to be crucial for the increase of the nociceptive threshold in our model of sweet substance-induced antinociception.