Assessing the neurotoxicity of the carbamate methomyl in Caenorhabditis elegans with a multi-level approach

The neurotoxicity and developmental effects of a widely applied insecticide (methomyl) was investigated by a multi-level approach (behavior and biometry, biochemical alterations and neurodegeneration) in Caenorhabditis elegans upon a short-term exposure (1 h) and a post-exposure period (48 h). The 1-h exposure to sub-lethal concentrations of methomyl (lower than 0.320 g L^-1; i.e. below the estimated LC₁₀) triggered significant changes on motor behavior and development impairment. The type of movement was significantly altered in methomyl-exposed worms, as well as biometric parameters (worms frequently idle and moving more backwards than controls; small body area, length and wavelength). These effects were followed by an increase of acetylcholine levels. Interestingly, after the 48-h recovery period, movement of previously exposed worms was similar to controls, and a concentration-dependent reversion of biometric endpoints was recorded, pointing out the transient action of the carbamate in line with an apparent absence of cholinergic neurons damage. This study provided new insight on the neurotoxicity of methomyl by showing that effects on movement and development were transient, and apparently did not result in neurodegeneration in cholinergic neurons. Moreover, these findings reinforced the advantages of using C. elegans in a multi-level approach for pesticide effects assessment.

Environmental benchmarks based on ecotoxicological assessment with planktonic species might not adequately protect benthic assemblages in lotic systems

Freshwater ecosystems face widespread diffuse and point-source contamination. Species Sensitivity Distributions (SSDs) have been used as a tool to determine chemical concentration benchmarks that represent protective levels for most species in the environment. Here we used a SSD approach to assess on the adequacy of standard planktonic organisms to reflect the response of benthic communities, critically supporting the structure and function of lotic ecosystems. For the purpose, SSDs reflecting non-lethal responses of standard planktonic and selected benthic organisms were built based on EC50 values (collected in the literature or estimated following testing herein) regarding three model contaminants: potassium dichromate (PD), 3,5-dichlorophenol (DCP) and lead chloride (LC). The derived HC5 estimates were discriminatory between chemicals and the uncertainty associated with the estimate was remarkably low. The HC5 estimates with corresponding uncertainty were generally within the same order of magnitude for the three chemicals tested, with better discrimination between chemicals regarding their hazardous potential being achieved for benthic organisms: DCP was clearly less hazardous than PD, but LC tends to be as hazardous as PD and DCP (assuming the confidence interval ranges). Moreover, benthic communities were more sensitive to both DCP and PD, in this later case the HC5 being lower by more than one order of magnitude than that found for planktonic communities; for LC, confidence intervals overlapped, preventing a feasible assumption regarding differential sensitivity of the compared communities. Microphytobenthos was highlighted as the most sensitive group to the three tested chemicals in SSDs covering the benthic compartment, while SSDs with planktonic organisms did not consistently show trends in sensitivity ordering. Overall, our results suggest that protective benchmarks retrieved from SSDs built with the responses of standard planktonic organisms (which are the most commonly used for regulation purposes) do not adequately protect benthic communities.

Caenorhabditis elegans as a tool for environmental risk assessment: emerging and promising applications for a "nobelized worm"

Caenorhabditis elegans has been an invaluable model organism in research fields such as developmental biology and neurobiology. Neurotoxicity is one of the subfields greatly profiting from the C. elegans model within biomedical context, while the corresponding potential of the organism applied to environmental studies is relevant but has been largely underexplored. Within the biomedical scope, the implication of metals and organic chemicals with pesticide activity (hereinafter designated as pesticides) in the etiology of several neurodegenerative diseases has been extensively investigated using this nematode as a primary model organism. Additionally, as a well-known experimental model bearing high sensitivity to different contaminants and representing important functional levels in soil and aquatic ecosystems, C. elegans has high potential to be extensively integrated within Environmental Risk Assessment (ERA) routines. In spite of the recognition of some regulatory agencies, this actual step has yet to be made. The purpose of this review is to discuss the major advantages supporting the inclusion of C. elegans in lower tiers of ERA. Special emphasis was given to its sensitivity to metals and pesticides, which is similar to that of other model organisms commonly used in ERA (e.g. Daphnia magna and Eisenia sp.), and to the large array of endpoints that can be tested with the species, both concerning the aquatic and the soil compartments. The inclusion of C. elegans testing may hence represent a relevant advance in ERA, providing ecologically relevant insights toward improvement of the regulatory capacity for establishing appropriate environmental protection benchmarks.

Pandemic influenza A (H1N1) in the North of Portugal: how did the autumn-winter wave behave?

INTRODUCTION

In April 2009 the Centers for Disease Control and Prevention announced the identification of a novel influenza virus in two patients in California, called influenza A (H1N1) 2009. On 11 June 2009 the Director-General of the World Health Organization declared a pandemic of influenza A (H1N1). In Portugal the first case of pandemic influenza A (H1N1) was reported on 29th April and the Northern Region of the country registered the first cases soon after that.

AIM

This report pretends to give an overview of the characteristics of Autumn/Winter pandemic wave in the North of Portugal.

RESULTS

A total of 64 195 cases of influenza-like illness were registered in public health services in the region between week 40, 2009 and week 4, 2010. The cumulative attack rate of those cases was 17.1/1 000 inhabitants. Most of the cases occurred in females and in the under 20 years. The peak of the Autumn/Winter wave was attained in week 48, but geographic and time distribution of the pandemic was heterogeneous in the region. Hospitalization rate for influenza-like illness cases in the population was higher for the under 10 years and decreased with age. Forty four deaths in pandemic influenza A (H1N1) laboratory-confirmed cases occurred in the region (mortality rate - 1.2/100 000) and the risk of death was lower in younger age groups. The peak of deaths occurred two weeks later than the peak of cases.

CONCLUSION

We can assume that the Autumn/Winter pandemic wave impact was mild in the Northern Region of Portugal. We consider the importance of pursuing and reinforcing influenza surveillance in the region.

Infectious diseases surveillance activities in the north of Portugal, during the EURO 2004 football tournament

A European football tournament (EURO 2004) took place in Portugal, from the 12 June to the 4 July 2004. Portugal's Northern Regional Health Authority serves a population of 3.2 million people. This region hosted 12 matches, more than any other region. We describe the communicable disease surveillance activities in the region, during EURO 2004. Ten foodborne outbreaks, seven cases of meningococcal disease and one case of legionnaires disease, were detected. Visitors were not affected, furthermore, cases among residents seemed not to be influenced by the presence of thousands of visitors. A similar pattern has been observed at other mass gatherings where special surveillance activities were implemented. This does not reduce the importance of public health surveillance during such mass gatherings. Furthermore, evaluation of this special activities should be an opportunity to put, issues of communicable disease surveillance resources, priorities, organisation and training back on the agenda.

Philadelphia-positive T-cell acute lymphoblastic leukemia with polymyositis, migratory polyarthritis and hypercalcemia following a chronic myeloid leukemia

Transformation of chronic myeloid leukemia (CML) often results in acute myeloblastic or, less frequently, in precursor B-cell acute lymphoblastic leukemia (ALL). T-cell blast crisis is rare. Hypercalcemia has also been described as a rare complication of CML, but this usually occurs as a terminal event. Here we report a case of a 35-year-old woman who developed a CD4(+)/CD8(+) T-cell ALL 2 years after the diagnosis of a typical Ph(+) CML. Polymyositis and polyarthritis preceded by 4 months, and symptomatic hypercalcemia occurred just before blastic transformation, probably representing paraneoplastic manifestations of the disease.

[The seroprevalence for hepatitis E viral antibodies in the northern region of Portugal (among the donor population)]

The authors have undertaken a study in the north of Portugal in what concerns the prevalence of antibodies for HEV donors. This study was transverse through observation and survey. A sample of 1.473 donors was randomly selected from among the population of donors of the Oporto Regional Blood Centre. This sample was representative of the northern region and stratified by district. The usual EIA method has been used to search for HEV antibodies. The results, which were repeatedly reactive, have been confirmed by Western Blot. The prevalence of antibodies for Hepatitis E was 2.5%. The test identified a possible cohort effect and the sample showed that the average age of the donors with or without antibodies was identical. No difference was observed regarding sex, distribution by districts or the presence of antibodies for HB virus. Hepatitis E is benign, without chronic state carrier and almost every patient presents acute symptomatology. The value of prevalence found as well as the absence of clinical symptomatology in the observed donors and the normal state of the hepatic markers, indicate that the use of blood and components obtained from this population should not be a problem. The recommendation proposed by the European Council does not mention the systematic research of HEV. However the epidemiological HEV survey is considered important from the transfusional point of view and as an indicator of the sanitary development of the population. Bearing in mind the developing status of Portugal in this area, it is of utmost importance to create the means to reach European standards.