Acute outbreak of gnathostomiasis in a fishing community in Sinaloa, Mexico

An increasing number of human cases of gnathostomiasis have been reported in Sinaloa, Mexico, most of whom have a custom of eating of raw fish dishes such as 'cebiche'. Here we report five adult patients, three women and two men, having an acute episode of vomiting and abdominal pain a few minutes after eating a dish of cebiche prepared from a spotted sleeper perch (Eleotris picta) fished from a nearby lake in southern Sinaloa. All five patients experienced acute throat pain, chest and joint pains, headache and fever. One patient, a 55-year-old male, was hospitalized with suspected pancreatitis and pneumonia. By 8-9 days later, all five patients developed between three and 12 edematous, migrating skin lesions on the back, abdomen, upper and lower extremities, face, eye and scalp. By ELISA, all of them were sero-positive to Gnathostoma doloresi antigen and had elevated IgE levels. Eosinophilia was found in two patients. These patients lived in an agricultural and fishing community. In this community we carried out a sero-epidemiological survey and study of living conditions in a random sample of 309 individuals distributed in 74 households. Frequent consumption of raw fish was reported in 36% of households, and 12 individuals had a clinical history of migrating skin lesions. The sero-prevalence to Gnathostoma antigens was 34.95%. Five fish species and four species of ichthyophagous birds collected from three lakes in the village and a nearby estuary were infected with the advanced third-stage larvae of G. binucleatum, a species found in Ecuador and Mexico. The results describe the first known outbreak of acute gnathostomiasis on the American continent.     

Regulated mRNA stability of the Cdk inhibitor Rum1 links nutrient status to cell cycle progression

BACKGROUND: The survival of a cell depends on continuous sensing of the nutritional environment and appropriate coordination of the cell cycle. The fission yeast Schizosaccharomyces pombe is an excellent model system in which to study these processes. In the presence of nutrients, fission yeast cells grow and divide, spending most of their time in G2; when nutrients are limiting, they are promoted into mitosis and arrest the cell cycle in G1. The molecular mechanisms underlying this response are currently unknown.RESULTS: Here, we show that expression of the fission yeast Cdk inhibitor Rum1, a key regulator of Cdc2/cyclin B in G1, is subject to regulated mRNA stability in response to nutrient deprivation. In complete minimal medium, rum1 mRNAs are very unstable. Following nitrogen starvation, rum1 mRNAs are rapidly stabilized, allowing the accumulation of Rum1 protein to delay the G1 phase of the subsequent cell cycle. Instability of rum1 mRNAs in complete minimal medium depends on the presence of AU-rich elements in the 3'UTR. We also show that lack of this mechanism has consequences in the mitotic cell cycle, in meiosis, and in the control of ploidy.CONCLUSION: We propose that mRNA stability is an important mechanism to fine tune the expression of the rum1 gene, in order to allow the production of appropriate levels of Rum1 protein in response to changes in the nutritional environment.     

LIG4 and RAD52 DNA repair genes polymorphisms and systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is a complex autoimmune disorder with a strong genetic background. Nevertheless, SLE might also be triggered due to environmental factors, such as UV light exposure. DNA double strand breaks (DSBs) may be induced secondarily by UV radiation, increasing DNA immunogenicity and in SLE patients DNA repair is diminished, allowing the accumulation of DSBs and genomic instability. LIG4 and RAD52 genes play important roles in DNA repair mechanisms and a recent microarray analysis showed their differential expression in active SLE patients. In this study we investigated a potential association between LIG4 and RAD52 single nucleotide polymorphisms (SNPs) and SLE predisposition in a Southeast Brazilian population. We assessed four Tag SNPs in LIG4 and three in RAD52 gene region, encompassing most of the gene sequence, in 158 SLE patients and 212 healthy controls. We also performed SNPs analysis considering clinical manifestation, gender and ethnicity in SLE patients. Our data did not show association between LIG4 and RAD52 SNPs and SLE, its clinical manifestations or ethnicity in the tested population. The analysis regarding ethnicity and SLE clinical manifestations indicated Caucasian-derived patients as more susceptible to cutaneous and hematological alterations than the African-derived. To our knowledge, this is the first association study involving LIG4 and RAD52 genes and SLE predisposition.     

Economic valuation of kelp forests in northern Chile: values of goods and services of the ecosystem

Kelp beds, besides being one of the most important benthic resources in northern Chile, provide a variety of environmental goods and services. In order to evaluate economically the wild kelp populations in northern Chile (26° to 32° S) more than simply their commercial value as a source of raw materials for alginate extraction, we used several economic indicators to holistically assess the value of a group of brown seaweeds of economic importance, Lessonia spp. and Macrocystis pyrifera: (1) market value of biomass as a source of raw material for extraction of alginic acid, (2) market value of associated species of economic importance, (3) value as a source of scientific information, (4) value as a climate buffer (CO₂ capture and release of O₂), (5) value of associated biodiversity (non-commercial species), (6) value as cultural heritage and (7) value as a reservoir of biodiversity. Existence values of kelp beds which estimate the willingness of citizens to pay and work without payment to preserve the ecosystem were calculated using the contingent valuation technique. The results indicate that kelp beds in northern Chile have a total value of US $540 million. Of this total, kelp fishery accounts for 75 % and associated-species fisheries account for 15 %. In this context, the economic value of Chilean kelp beds is mainly associated with the industry of alginate extraction. By contrast, existence value as a source of scientific information or environmental buffer for CO₂ capture or O₂ production represents only 9 % of the total value, representing a very low relative importance to society. The economic valuation of coastal resources and marine ecosystems is a complementary tool for decision making and implementation of public policies related to the conservation and sustainable exploitation of renewable resources and their ecosystems.     

Variation in phenolic compounds,anthocyanins, and color in red wine treated with enzymatic extract of Kluyveromyces marxianus

The effect of the addition of enzymatic extract of Kluyveromyces marxianus NRRL-Y-7571 during the maceration and fermentation steps of Cabernet Sauvignon wine production was evaluated. The results obtained in the analytical determinations of the wines showed levels within the limits established by legislation and similar to values found in other studies. The results show that by adding the enzyme to the red wines these showed color characteristics considered to be superior to those of the control wine and accelerated the extraction of phenolic compounds and anthocyanins. It was observed that by using the commercial enzyme preparation there was an increase of 15 % in polyphenol content compared to the control wine and an increase of 28 % when the crude enzyme extract was used. Anthocyanin content in the wine increased after treatment with the commercial enzyme preparation (10 %) and with the use of the crude enzymatic extract (22 %). Considering all comparison criteria, the K. marxianus enzymatic extract showed results statistically similar or superior to those obtained with the commercial enzyme preparation.     

Structure–function relationships of the peptide Paulistine: A novel toxin from the venom of the social wasp Polybia paulista

Background

The peptide Paulistine was isolated from the venom of wasp Polybia paulista. This peptide exists under a natural equilibrium between the forms: oxidised — with an intra-molecular disulphide bridge; and reduced — in which the thiol groups of the cysteine residues do not form the disulphide bridge. The biological activities of both forms of the peptide are unknown up to now.

Methods

Both forms of Paulistine were synthesised and the thiol groups of the reduced form were protected with the acetamidemethyl group [Acm-Paulistine] to prevent re-oxidation. The structure/activity relationships of the two forms were investigated, taking into account the importance of the disulphide bridge.

Results

Paulistine has a more compact structure, while Acm-Paulistine has a more expanded conformation. Bioassays reported that Paulistine caused hyperalgesia by interacting with the receptors of lipid mediators involved in the cyclooxygenase type II pathway, while Acm-Paullistine also caused hyperalgesia, but mediated by receptors involved in the participation of prostanoids in the cyclooxygenase type II pathway.

Conclusion

The acetamidemethylation of the thiol groups of cysteine residues caused small structural changes, which in turn may have affected some physicochemical properties of the Paulistine. Thus, the dissociation of the hyperalgesy from the edematogenic effect when the actions of Paulistine and Acm-Paulistine are compared to each other may be resulting from the influence of the introduction of Acm-group in the structure of Paulistine.

General significance

The peptides Paulistine and Acm-Paulistine may be used as interesting tools to investigate the mechanisms of pain and inflammation in future studies.     

Diversity and colonization of arbuscular mycorrhizal fungi in the tree fern Alsophila firma in rainy and dry season

Alsophila firma is a deciduous tree fern considered as an emblematic species of Mexican tropical montane cloud forest (TMCF). We studied spores diversity, structure and colonization by arbuscular mycorrhizal fungi (AMF) within the roots of the Alsophila firma in rainy and dry season. Eighteen species of the genera Acaulospora (5), Gigaspora (4), Glomus (4), Funneliformis (2), Sclerocystis (2) and Scutellospora (1) were identified. The species F. constrictum, F. geosporum, Gigaspora albida, G. decipiens, Glomus microaggregatum and Sclerocystis coremioides are reported for the first time in TMCF. The dominant genera were Funneliformis and Acaulospora. In rainy season, a higher richness (H′ t_0.005(2)9?=?4.78) and evenness (E) of AMF spores was recorded, compared to the dry season. However, the degree of colonization was statistically significant higher in the dry season. This study is the first to estimate the species richness of AMF associated with the rhizosphere of a fern in Mexico as well as for A. firma.