Northeast Portugal Research Articles

Antioxidant and antimicrobial effects of phenolic compounds extracts of Northeast Portugal honey

Phenolic compounds of dark and clear honeys from Trás-os-Montes of Portugal were extracted with Amberlite XAD-2 and evaluated for their antioxidant and antimicrobial activities. The antioxidant effect was studied using the in vitro test capacity of scavenge the 2,2-diphenyl-1-picryhydrazyl (DPPH) free radical and of reducing power of iron (III)/ferricyanide complex. The antimicrobial activity was screened using three Gram-positive bacteria ( Bacillus subtilis, Staphylococcus aureus, Staphylococcus lentus) and three Gram-negative bacteria ( Pseudomonas aeruginosa, Klebsiella pneumoniae and Escherichia coli). The results obtained from the partial identification of honey phenolic compounds by high-performance liquid chromatography with a diode array detector showed that p-hydroxibenzoic acid, cinnamic acid, naringenin, pinocembrin and chrysin are the phenolic compounds present in most of the samples analyzed. Antioxidant potential was dependent of honey extract concentration and the results showed that dark honey phenolic compounds had higher activity than the obtained from clear honey. In the biological assays, results showed that S. aureus were the most sensitive microrganisms and B. subtilis, S. lentus, K. pneumoniae and E. coli were each moderately sensitive to the antimicrobial activity of honey extracts. Nevertheless, no antimicrobial activity was observed in the test with P. aeruginosa.

Photochemical pollution in a rural mountainous area in the northeast of Portugal

During a two-week-long campaign in June/July 2006, samples of volatile organic compounds (VOCs) in ambient air were simultaneously collected at two sites located at different altitudes (500 and 950 masl) in the northern mountainous region of Portugal (Alvao Natural Park), where spring and summer ozone exceedences have been registered over the last years. High ozone concentrations (ca. 150–220 μg m− 3) have been detected in both locations. The calculation of propylene equivalent concentrations showed an important contribution of biogenic VOCs (e.g. 3-carene, isoprene and β-pinene) to the photochemical production of ozone, especially at the low-altitude mountain area. The importance of atmospheric transport on a synoptic scale to the VOC levels in rural mountain areas and the contribution of these precursors to the ozone formation were highlighted.

Rumex induratus leaves: phytochemical profiling and antioxidant activity

Several species of the Rumex (Polygonaceae) genus have been used in traditional medicine, although their high oxalic acid content has been implicated in oxalic intoxication, mainly in children. Rumex induratus Boiss. & Reuter is an endemic Iberian herb that prefers rocky habitats of the thermo Mediterranean region. It grows spontaneously in Northeast Portugal, where its leaves are highly consumed in salads. Phenolic compounds and organic acids, known to influence the organoleptic properties of plant foods, have been successfully used in their quality control. On the other hand, antioxidants present in fruits and vegetables, including those belonging to these two phtyochemical classes, are associated with oxidative damage prevention.

Multifactorial correspondence analysis of risk factors for sheep and goat brucellosis seroprevalence

This paper reports the investigation of herd characteristics as potential risk factors for sheep and goat brucellosis seroprevalence, based on multifactorial correspondence analysis. The survey was carried out on 4123 herds in Trás-os-Montes e Alto Douro, in the north-east of Portugal. Brucellosis in small ruminants is a disease with Obligatory Notification status in Portugal and is the subject of an Official Eradication Campaign. Multifactorial correspondence analysis identified an association between herds with high seroprevalence (≥5%), intermediate seroprevalence (>0% and <5%), 3 or more positive animals, 2 positive animals, 1 positive animal, and larger herds (150 or more analyzed animals), and this group supplied contrasting results to the group of no positive animals and small herds. Within this study, larger herds were associated with milk production and intermediate seroprevalence values (of >0% and <5%), and contrast with those herds with 3 or more positive animals and high seroprevalence. The significant contribution made by the principal and secondary axes consolidates this explanation. The results of this study suggest that herd size and production type might have an impact on brucellosis seroprevalence.

Population dynamics and spatial distribution of Griffon Vultures (Gyps fulvus) in Portugal

AbstractThe global decrease of vulture populations has been attributed to several factors, such as food availability, poisoning, human disturbance, or habitat suitability. We studied the effect of factors that vary both spatially and temporally on the nest site distribution of the Griffon Vulture Gyps fulvus in northeast Portugal, and influence the population dynamics of these cliff-dwelling birds. Several demographic parameters were studied in the field, and the age structure of the population was determined. Additionally we investigated how food availability affected population fluctuations. The vulture population was most sensitive to juvenile mortality according to our model results. Our models showed that a decrease in the present food supply resulted in a decrease in vulture abundance and, moreover, negatively affected the spatial distribution of the species by decreasing the number of breeding pairs per colony. The total quantity of sheep and goat biomass, a greater distance to the nearest unpaved road, and the presence of Egyptian Vultures Neophron percnopterus at the breeding colonies showed a significant positive relationship to the numbers of Griffon Vulture breeding pairs. It is recommended that the available food supply in the most important foraging areas should be monitored and protected. Furthermore, to manage the community of cliff breeding raptors adequately, future research should identify and protect the most suitable breeding areas for each species. Human disturbance should be kept to a minimum by protecting breeding areas, especially in an area like Riba-Côa where species such as the Egyptian Vulture, Bonelli's Eagle Hieraaetus fasciatus and Griffon Vulture breed so close to each other.

Promoting the educative use of the internet in Portuguese primary schools: a case study

PurposeThe purpose of this paper is to summarise the authors' experience in furthering the educative use of Information Technology and the internet in the primary schools of northeast Portugal. The main goal of the Programme “Internet in Schools” is the development of Information Technology in Portuguese schools. It focuses on the use of the technology, rather than on its immediate pedagogical use. The characteristics of the target regions help in understanding this aim: teachers and students, as well as the population in general, were largely unaware of the potential of IT in general.Design/methodology/approachThe project, the first and still the largest of its kind in Portugal, ultimately involved 1,137 schools, more than 1,700 teachers, and roughly 13,000 pupils. It was decided to centre the training process in the schools and communities themselves. The methodology implemented is distributed rather than centralised, and involves a series of school visits interspersed with training sessions.FindingsThe transfer of the training process from the university campus to the schools and communities themselves allowed for a very high degree of teacher participation. The first school visit was vital, allowing for the creation of a strong feeling of empathy between the trainer and the teachers and pupils. This was undoubtedly one of the main factors that lead to an easier and more enthusiastic participation from the teachers. The efforts to put theory into practice in the classrooms were rewarded by a quicker rate of acceptance of IT in the classroom. The use of the internet, namely of web services and e‐mail, was stimulated through the various training and awareness raising sessions (supported by Netmobiles) directed at the community in general. Such sessions enabled many individuals in the region to have their first contact with and experience of IT. This constitutes a sound and valuable contribution in terms of awareness raising, training and development towards IT in the region. The following factors played a very important role in the achievement of the goals: the training team was always present or could be easily contacted; both teachers and pupils contributed with material and resources; there was a continuous exchange of experiences; a vast number of individuals and entities participated in the project.Originality/valueThis was the first and still the largest approach of its kind in Portugal, and this is the only paper purposing and describing the used methodology in detail and the main conclusions reached.

Kinetics and Mechanism of Ni(II) Chelation in Model and Real Solutions of Xylem Sap of Quercus ilex

AbstractThe kinetics of formation and dissociation of Ni(II) complexes with oxalic and citric acids was studied by cyclic voltammetry in model solutions of xylem sap of Q. ilex (the dominant tree growing on serpentine soils of Northeast Portugal) using representative concentrations, pH and ionic strength. The role of magnesium on complex formation was analyzed from solutions where Mg is present at concentration levels found in the xylem sap of Q. ilex growing on both nonserpentine and serpentine soils. Kinetics studies were also done in diluted solutions of real xylem sap samples, spiked with increasing amounts of magnesium. The values obtained for the apparent rate constants were those anticipated by the proposed model. To test the validity of the methodology and mechanisms, formation rate constants, kf (M−1 s−1) of Ni(II) complexes with citrate and oxalate were evaluated that compare with the values from Eigen mechanism.

A case–control study of risk factors for brucellosis seropositivity in Portuguese small ruminants herds

A case–control study involving 255 small ruminants herds randomly selected was carried out in Portugal between January and December 2004, to identify risk factors associated with brucellosis seropositivity. To achieve this objective, two groups of herds selected according their prevalence status were compared: “cases” (farms with seroprevalence higher than 5%, n = 123) and “controls” (farms seronegatives, n = 132). A carefully structured questionnaire was used to collect data from each herd. A statistical analysis to compare “case” versus “control” herds was performed with the variables obtained from the questionnaire and the seroprevalence results. The effects on seroprevalence of several variables such as: individual characteristics; farm management practices; farm characteristics; animal health; knowledge and characteristics of farmers were evaluated. Data were analysed using logistic regression. Univariable analysis was used to screen the variables used in the logistic regression model. Nine variables were associated with brucellosis seropositivity in univariable analysis p < 0.10. These variables were retained for multivariable logistic regression model. Regression model identified five variables as risk factors for seropositivity. The odds of brucellosis were increased: herds with more than 116 animals (OR = 2.99); in herds with no cleaned-watering places (OR = 3.05); in herds with insufficient manure removal and insufficient cleaning of premises (OR = 2.87); in introduction of animals from non-free brucellosis herds or from herds of unknown status (OR = 12.11). In the other hand, farmers’ age (the eldest) was related to decreased odds (OR = 0.4). Potential risk factors identified in this study were consistent factors associated with brucellosis seropositivity and support current recommendations for the control of brucellosis. Considering the paucity of epidemiological reports on brucellosis in the Northeast of Portugal and the absence of any data concerning factors related to either the prevention or the spread of the disease, our results could make a useful contribution towards the prevention of small ruminants brucellosis in the area.

Applying a stochastic-dynamic methodology (StDM) to facilitate ecological monitoring of running waters, using selected trophic and taxonomic metrics as state variables

As an improvement of a previous work [Cabecinha, E., Cortes, R., Cabral, J.A., 2004. Performance of a stochastic-dynamic modelling methodology for running waters ecological assessment. Ecol. Modell. 175, 303–317], the present paper examined the applicability of a holistic stochastic-dynamic methodology (StDM) in predicting the tendencies of benthic macroinvertebrate metrics from mountain streams facing expected scenarios either: (1) of pollution increase due to the agricultural intensification; or (2) of farming activity abandonment becoming less pollutant as a non-point source. The StDM is a sequential modelling process developed in order to predict the ecological status of changed ecosystems, from which management strategies can be designed. These procedures focus on the interactions between conceptually isolated key-components, such as some relevant trophic and taxonomic metrics and changes in local environmental conditions. The dataset recorded from the field included true gradients of environmental changes. The samples of aquatic macroinvertebrate, environmental and physical–chemical data were collected from four watersheds of mountain rivers in Northeast Portugal, between 1983 and 1985. The dynamic model developed was preceded by a conventional multivariate statistical procedure performed to discriminate the significant relationships between the selected components of the studied watersheds. The model validation was based on independent data from a watershed not included in the model construction. Overall, the simulation results are encouraging since they seem to demonstrate the StDM reliability in capturing the stochastic environmental dynamics of the studied aquatic ecosystems facing agricultural scenarios that will characterize the region, namely by predicting credible behavioural patterns for the selected metrics.

Effect of solvent and extraction temperatures on the antioxidant potential of traditional stoned table olives “ alcaparras”

This paper reports the first approach to the antioxidant potential evaluation of traditional stoned table olives “ alcaparras”. This kind of olives are largely produced and consumed in Trás-os-Montes region (Northeast of Portugal). Different solvents and temperature extraction conditions were employed in order to achieve the best method to obtain phenolic compounds and a higher antioxidant activity. The optimum method (water at boiling temperature) was applied on 10 samples from the traditional market. The total phenol content ranged between 5.58 mg gallic acid equivalents (GAE)/g and 29.88 mg GAE/g and effective concentration (EC 50) values were in the range 0.36–1.64 and 0.34–1.72 mg/mL for reducing power and radical scavenging effect, respectively. A significantly negative linear regression was observed between the total phenol content found in the samples and its antioxidant activity.

Physiological behaviour, oxidative damage and antioxidative protection of olive trees grown under different irrigation regimes

Irrigation effects were investigated on an 8-year-old olive (Olea europaea L., cv. Cobrancosa) commercial orchard located in northeast Portugal. Trees were subjected to a rainfed control (T0) and three treatments (T1, T2, T3) that received a seasonal water amount equivalent to 30%, 60% and 100% of the estimated local evaporative demand by a drip irrigation system. Irrigation increases the photosynthetic activity of olive trees, in association with increases in water status, and reduces the midday and afternoon depression in gas exchange. The closely association between photosynthetic rate (A) and stomatal conductance (gs) revealed that the decline in net photosynthesis over the course of the day was largely a consequence of stomatal limitation. However, the ratio of intercellular to atmospheric CO2 concentration increased markedly from morning to midday in non-irrigated plants, in spite of lower gs, suggesting that non-stomatal limitations of photosynthesis also occur when environmental conditions become more stressful. The occurrence of perturbations at chloroplastic level in rainfed plants was demonstrated by a lower maximum photochemical efficiency of photosystem II during the afternoon. Chlorophyll fluorescence measurements also revealed the occurrence of a dynamic photoinhibition in irrigated trees, mainly in T2 and T3, which seemed to be effective in protecting the photosynthetic apparatus from photodamage. Irrigation enhances antioxidant protection and decreases the oxidative damage at leaf level. Leaves grown under rainfed conditions revealed symptoms of oxidative stress, like the reduction (14%) in chlorophyll concentration and the increased levels (57%) of lipid peroxidation. We also found that the scavenging function of superoxide dismutase was impaired in rainfed plants. In contrast, the low thiobarbituric acid reactive substances concentration in T3 indicates that irrigation enhances the repairing mechanisms and decreases the oxidative damage by lipid peroxidation. Accordingly, leaves in T3 treatment had high levels of –SH compounds and the highest antioxidant potential. Meanwhile, the finding that guaiacol peroxidase activity increased in rainfed plants, associated with the appearance of oxidative damage, suggests that this enzyme has no major antioxidative function in olive.

Bioactive properties of the medicinal mushroom Leucopaxillus giganteus mycelium obtained in the presence of different nitrogen sources

Leucopaxillus mushroom species are used in the chemical industry for extraction of clitocybin antibiotic and particularly the edible mushroom Leucopaxillus giganteus can be found in Northeast Portugal. Nevertheless, the production of its mycelium for pharmacological applications has not been explored. Herein, the mycelium obtained in the presence of four different nitrogen sources was investigated with regard to phenol production and antimicrobial and antioxidant properties. Phenol concentration increased along the growth time as a response to the oxidative stress and therefore free radical production. Although significant differences for mycelium growth between the nitrogen sources had not been observed, (NH 4) 2HPO 4 proved to be the most appropriate to increase bioactive properties, leading to the highest phenol content and lowest EC 50 and MIC values. The antimicrobial capacity was screened against Gram positive and Gram negative bacteria, and fungi. The samples selectively inhibited the growth of Gram positive bacteria, Staphylococcus aureus being the most susceptible one. Gram negative bacteria and fungi were resistant to the extracts. Antioxidant activity was calculated by the reducing power assay, the scavenging effect on DPPH radicals, and hemolysis and lipid peroxidation inhibition. Significantly negative linear regressions were established between phenols/flavonoids contents, which increased along the mycelia growth time and antioxidant activity.

Fatty acid and sugar compositions, and nutritional value of five wild edible mushrooms from Northeast Portugal

The chemical composition and nutritional value of five wild edible mushroom species ( Agaricus arvensis, Lactarius deliciosus, Leucopaxillus giganteus, Sarcodon imbricatus, Tricholoma portentosum) commonly consumed in the Trás-os-Montes region of Northeast Portugal was determined. Chemical composition evaluation included moisture, total oil content, crude protein, ash, carbohydrates, and nutritional value determination. The macronutrient profile in general revealed that the wild mushrooms were rich sources of protein and carbohydrates, and had low amounts of fat. On the basis of the proximate analysis, it can be calculated that an edible portion of 100 g of these mushrooms provides, on average, 28 kcal (118 kJ). The analysis of fatty acid composition, performed by gas–liquid chromatography coupled to a flame ionization detector, allowed the quantification of fifteen fatty acids. Unsaturated fatty acids and, in particular, oleic and linoleic acids, were predominant. The composition in individual sugars was also determined by high performance liquid chromatography coupled to a refraction index detector, mannitol and trehalose being the most abundant sugars.

Evaluation of the effects, on canopy arthropods, of two agricultural management systems to control pests in olive groves from north-east of Portugal

This study aims to investigate the effect of management regime on canopy arthropod community of the olive tree ( Olea europaea L.). Field studies were performed in two successive years, 2002 and 2003, in two olive groves, one under organic farming and the other under integrated protection. The integrated protection grove was sprayed once a year in June, with dimethoate, to control the anthophagous generation of the olive moth, Prays oleae (Bern.). From April to November of each year, the canopy arthropods were sampled weekly. PRC method was used to analyse the effect of management regime at the community level and results showed that taxa responded differently to insecticide application suggesting that the organic grove was a more suitable habitat for the arthropods than the integrated protection grove. Abundance of arthropods peaked in May and June for both years but, after spraying with dimethoate, decreased significantly in integrated protection grove, recovering very slowly thereafter. Psocoptera, Miridae, Formicidae and Coccinellidae were the most sensitive taxa to insecticide application. Their decreasing in abundance was more evident in the second year of the trial. On the other hand chrysopids showed some tolerance to insecticide applications. These results suggest that the timing of spray is of utmost importance in reducing the side effects of spraying on beneficial arthropods. Moreover, differences in population susceptibility as well as in life cycle patterns must be considered.

Cryptosporidium spp. in Freshwater Bivalves in Portugal

RYPTOSPORIDIUM spp. in water has been implicated inseveral human cryptosporidiosis outbreaks (Fayer 2004).Studies on Cryptosporidium oocysts in surface waters are madedifficult by the low concentrations of organisms present due todilution. Since bivalves are filter-feeders oocysts in suspended inwater can be removed by this filtration and the mollusc digestiveenzymes reduce oocyst viability (Freire-Santos et al. 2002). Ifoocysts survive the bivalve digestive tract and are excreted, thedense fecal material containing viable oocysts are expected tosedimenttothebottomoftheriverbed.However,bivalvefiltrationmechanisms can also concentrate Cryptosporidium oocysts pres-ent in the water. Hence it is possible to recover higher numbersof oocysts from the bivalves compared with that recoverable fromsurface waters (Graczyk et al. 2004).Human consumption of freshwater clams and mussels is com-mon in northeast Portugal and in the Tejo and Guadiana riverbasins. These bivalves might be a source of human Cryptospo-ridium infection therefore, it is important to assess the publichealth risks of eating contaminated bivalves. As bivalves can beuseful bioindicators of superficial water contamination (Graczyket al. 2004), we examined clams in Portugal for the presence ofCryptosporidum oocysts examined evaluated considering thatclams can be.MATERIALS AND METHODSThree freshwater bivalves, Anodonta anatina, Unio pictorum,and Corbicula fluminea, were analyzed. Sixteen sampling areas inthe Guadiana river hydrographic basin in southeast Portugal wereselected and the clams were randomly collected by searching andby kick sampling. A total of 55 samples were obtained betweenMay 2003 and June 2005: 69% (24/55) were ofU. pictorium,50%(19/55) were C. fluminea, and 31% (12/55) were A. anatine. Vari-ation in the water levels, turbidity, and unfavourable conditionsprecluded, being able to collect all three species at each samplingarea each time.Gills and the gastrointestinal tracts of each species were dis-sected from three to 15 bivalves (depending on their size) and thetissues were pooled to provide uniform sizes of preparations fromdifferent bivalves. The tissues were homogenized and oocystswere concentrated using a modification of the methods describedby Ritchie (Pereira da Fonseca 2000) and purified by discontinu-ous sucrose density centrifugation. The material collected at theinterface of the two layers with densities of 1,103 and 1,064 waswashed and concentrated into a pellet by centrifugation and thenresuspended in distilled water to a final volume of 1.5ml.Detection of oocysts was performed by direct immunofluores-cent assay(IFA)using themonoclonal antibody(Mab) kitCrypto/Giardia Cel (Cellabs, Brookvale, Australia). The isolated oocystpreparation was incubated with the Mab and observed by fluor-escence microscopy at 400 magnification. The size and shapeof Cryptosporidium oocysts enabled us to distinguish these fromGiardia cysts.Genotyping using 18S suRNA gene probes was performed on47 samples by nested PCR analysis (Xiao et al. 1999). Genom-ic DNA was extracted by the proteinase K method and the QiagenDNA extraction kit. Qiagen, Hilden, Germany. The primers usedwere 5

Antioxidant activity and phenolic contents of Olea europaea L. leaves sprayed with different copper formulations

Olive trees ( Olea europaea L. Cv. Cobrançosa) from the northeast of Portugal were sprayed with three different copper formulations [bordeaux mixture (copper sulphate + calcium hydroxide − 20% Cu), copper hydroxide (40% Cu) and copper oxychloride (50% Cu)] to control olive fungal diseases. The residues of copper in olive leaves, harvested at different times, were evaluated by atomic absorption spectrometry. At all the collection times, treated olive leaves had significantly higher copper contents, compared to the control. The different copper amounts in pesticide formulations lowered the leaves contents in total phenols and hence their antioxidant properties. Olive leaves sprayed with copper oxychloride possessed the highest copper levels and the lowest content in phenols, which influenced its antioxidant activity (higher EC 50 values for reducing power, scavenging effect on DPPH radicals and inhibition of erythrocyte hemolysis). Leaves without copper residues proved to be a good natural source of antioxidants, giving values comparable to the reference compounds.

Effect of different hosts onThaumetopoea pityocampa populations in northeast Portugal

A study was carried out at the Natural Park of Montesinho, NE Portugal, in order to evaluate the effect of different pine species (Pinus pinaster Ait.,P. nigra Arn. andP. sylvestris L.) onThaumetopoea pityocampa populations. The structure of the egg batches, the impact of the egg parasitoids on natural mortality of the pest and the species of parasitoids present, as well as their emergence dynamics, were analyzed. The length of the egg batches varied among pine species with the longest ones onP. nigra. The mean number of eggs per batch differed betweenP. sylvestris and the two other hosts studied, with fewer eggs per batch on the first. No differences were found in the size of eggs among pine species. The egg mortality varied between 25.8% and 33.0%, with no differences among hosts. Parasitism was the main cause of death.Baryscapus servadeii (Mercet.) was the most abundant parasitoid species, followed byOoencyrtus pityocampae (Dom.) andTrichogramma embryophagum Htg.B. servadeii dominated in the egg batches collected fromP. pinaster andP. nigra, whereasO. pityocampae was most frequent onP. sylvestris. The emergence ofB. servadeii started in the middle of March and continued until August, with the emergence peak at the end of May. The emergence ofO. pityocampae started at the end of April and continued throughout September, with maximum values in June.

Seroprevalence of ovine paratuberculosis infection in the Northeast of Portugal

A survey to estimate the prevalence of ovine paratuberculosis in sheep flocks was conducted in the Northeast of Portugal. In total, 3900 samples of sheep older than 2 years belonging to 150 sheep flocks from 12 different territorial Livestock Farmers Organizations (OPP) were investigated for the presence of antibodies against Mycobacterium avium subspecies paratuberculosis using a commercial enzyme-linked immunosorbent assay (ELISA) test. Seventy (46.7%) flocks had one or more serologically positive animals. The individual paratuberculosis prevalence was 3.7% (144/3900), with values ranging from 0.0 to 10.3% per flock. Statistically significant differences between OPP, herd size and the presence of clinical signs was observed. According to the test sensitivity and specificity claimed by the manufacturer, the true prevalence in the Northeast of Portugal was calculated as 6.4%. In summary, a small percentage of animals and a high percentage of flocks in the Northeast of Portugal were serologically positive.

Dynamic Modelling of Nickel Complexation in Xylem Sap of Quercus ilex: A Voltammetric Study

AbstractHolm oak (Quercus ilex) is the dominant tree growing on serpentine soils of northeast Portugal, characterized by elevated soil concentrations of Ni and Mg, combined with low Ca concentrations. Apparently Q. ilex does not suffer from excessive concentrations of Ni in the soil. In this work we report a complexation study of nickel by the relevant ligands present in xylem sap: histidine, aspartic acid, oxalic and citric acids, at 0.10 M ionic strength and pH 5.5. Single and mixed complexes were characterized. To validate the proposed complexation model, diluted solutions of Q. ilex xylem sap were titrated with nickel. All studies were done using square‐wave voltammetry (SWV) at a hanging mercury drop electrode. Due to the dynamic nature of SWV, it is possible to obtain the conditional stability constants of the complexes formed but also to have knowledge on the kinetics of the interconversion of the species present.

Paraquat intoxication and hemocarboperfusion

In the northeast of Portugal, paraquat intoxication is common. We report 31 patients, admitted at our institution from April 1997 to June 2004, with suspected paraquat intoxication. Thirty cases had suicidal intention and all have ingested the toxic by mouth. Treatment consisted of skin and digestive decontamination with gastric washing and activated charcoal or Fuller's Earth. The first medical care was performed after 1 h 14 min at median [9 min-11 h 26 min]. By laboratory measurement (n=13) and/or clinical observation (n=11) it was possible to confirm the gastrointestinal absorption of paraquat for 24 patients (17 male-7 female; 49 +/- 17 years). The estimated ingested volume was higher for 15 non-survivors relatively to nine survivors (170 +/- 60 mL vs 25 +/- 10 mL; P<0,001). Initial serum paraquat of seven non-survivors was also higher than the serum level of six survivors (8.3 +/- 6.9 mg/L vs 0.4 +/- 0.3 mg/L; P < 0.01). Remarkably, all patients with serum paraquat higher than 1.7 ml/l did not survived. The paraquat urine level, simultaneous to the first serum determination, was higher for six survivors (38 +/- 37 mg/L) comparing with four non-survivors patients (465 +/- 536 mg/L; P<0.04). Hemoperfusion with activated charcoal was performed after December 1997 until June 2004 for 25 patients. Twenty of the 24 patients confirmed for paraquat intoxication were treated with this technique (12/15 of the non-survivors and 8/9 of the survivors; p=NS). Total number of sessions was identical (2.0 +/- 1.0 vs 1.5 +/- 1.2; P=NS), total time of hemoperfusion was higher (7 h 58 min vs 5 h 37 min; P=0.07) but the beginning of the first session was later (7 h 44 min vs 4 h 18 min; P=0.04) for the survivors. Clinical signs and laboratory analysis were collected at admission trying to detect markers of prognostic survival value. Hypernatremia, hypokaliemia, hyperglycemia and acute renal failure were more frequent for non-survivors (P<0.05) but the variable timing of the first laboratorial determination jeopardize our analysis, perhaps excluding acute renal failure. Rapid evolution to shock, lead to death for seven patients at the first day of admission and to another four deaths at the next day. Median survival of non-survivors was 1.2 days [0.1-13.2]. Evolution to pulmonary fibrosis for the nine survivors was not investigated (median follow-up: 14 days [2-1053]). Paraquat intoxication was highly lethal, leading to a 63% mortality rate of our patients. Hemoperfusion did not reveal any survival advantage for our patients.