Predictores de hipocalcemia postquirúrgica tras tiroidectomía total / Predictors of post-surgical hypocalcaemia following total thyroidectomy

Introducción y objetivo: Dado el número creciente de cirugía de tiroides, la incidencia de hipoparatiroidismo postquirúrgico está en aumento. La frecuencia de la hipocalcemia por hipoparatiroidismo tras tiroidectomía total es muy variable según la literatura (0,3-68%). El objetivo principal del presente estudio es analizar los factores bioquímicos, quirúrgicos y demográficos relacionados con un mayor riesgo de hipocalcemia.Metodología: Se trata de un estudio retrospectivo, sobre un total de 297 pacientes intervenidos de tiroidectomía total en un periodo de 8 años en un hospital terciario. Se analizan datos demográficos, clínicos y bioquímicos, tanto preoperatorios, intraoperatorios como postoperatorios y su relación con la hipocalcemia postquirúrgica.Resultados: La tasa de hipocalcemia total fue de 40,2%, siendo transitoria en el 26,1%.Fueron variables estadísticamente significativas la edad (p=0,04), la enfermedad de Graves (p=0,04), el carcinoma confirmado por anatomía patológica (p=0,04), la tiroidectomía en dos tiempos (p=0,00), el número de paratiroides trasplantadas (p=0,00) y la PTH pre y post –operatorias (p=0,03 y p=0,00) y el gradiente de PTH (p=0,00).Conclusiones: Este estudio demuestra que hay una serie de factores de riesgo intrínsecos al paciente y al acto quirúrgico capaces de predecir el riesgo de hipocalcemia tras la tiroidectomía total. Posiblemente, la optimización de la técnica quirúrgica podría evitar la aparición de hipocalcemia tras la tiroidectomía total en algunos casos, mientras que en otros, la identificación de dichos factores en el postoperatorio podría permitir la detección temprana y el tratamiento eficaz de estos pacientes. En el presente estudio, la edad, la enfermedad de Graves y el autotrasplante de paratiroides se asociaron con hipocalcemia postquirúrgica; mientras que el carcinoma de tiroides y la tiroidectomía en dos tiempos fueron factores protectores. (AU)

Mental Health Signs Relevant for an Assessment Tool Suitable for Student and Novice Nurses: A Document Analysis.

Novice nurses' mental health assessment practice is characterised by lack of consistency, despite mental health assessment being a core issue in professional nursing and patient safety across health services. This study aimed to identify mental health signs relevant for an assessment tool suitable for student and novice nurses. A document analysis approach was applied, and content analysis was used to analyse data extracted from carefully selected documents. Four main categories of mental health issues were identified: risk issues, symptom issues, psychological issues and self-care issues. Mental health signs were thereafter grouped in ten sub-categories characterising mental health concerns. These were: risk concerns, psychotic concerns, mood, affect and energy concerns, substance use concerns, somatic concerns, perception concerns, communication concerns, cognitive concerns, anxiety concerns and self-care concerns. The identified signs are considered relevant for student and novice nurses to learn and can be further developed into a clinical assessment tool for use in nursing education to strengthen mental health assessment competence in nursing education.

Efficacy and Safety of Up-dosing Antihistamines in Chronic Spontaneous Urticaria: A Systematic Review of the Literature.

BACKGROUND AND OBJECTIVES: According to current guidelines, oral antihistamines are the first-line treatment for chronic spontaneous urticaria (CSU). Up-dosing antihistamines to 4-fold the licensed dose is recommended if control is not achieved. Such indications are based mainly on expert opinion. Objectives: To critically review and analyze clinical evidence on the efficacy and safety of higher-than-licensed dosage of second-generation oral antihistamines in the treatment of CSU. MATERIAL AND METHODS: A systematic literature review was performed following a sensitive search strategy. All articles published in PubMed, EMBASE, and the Cochrane Library between 1961 and October 2018 were examined. Publications with CSU patients prescribed secondgeneration antihistamines in monotherapy compared with placebo, licensed dosages, and/or higher dosages were included. Articles were evaluated by peer reviewers. Quality was evaluated using the Jadad and Oxford scores. RESULTS: We identified 337 articles, of which 14 were included in the final evaluation (fexofenadine, 6; cetirizine, 2; levocetirizine and desloratadine, 1; levocetirizine, 1; rupatadine, 2; ebastine, 1; and bilastine, 1). Only 5 studies were placebo-controlled. The number of patients included ranged from 20 to 439. The observation lapse was ≤16 weeks. High fexofenadine doses produced a significant dosedependent response and controlled urticaria in most patients. Cetirizine, levocetirizine, rupatadine, and bilastine were more effective in up-dosing. The most frequent adverse events were headache and drowsiness. CONCLUSION: The low quality and heterogeneity of the articles reviewed made it impossible to reach robust conclusions and reveal the need for large-scale randomized clinical trials.

Efficacy and Safety of Up-dosing Antihistamines in Chronic Spontaneous Urticaria: A Systematic Review of the Literature

Background: According to current guidelines, oral antihistamines are the first-line treatment for chronic spontaneous urticaria (CSU). Up-dosing antihistamines to 4-fold the licensed dose is recommended if control is not achieved. Such indications are based mainly on expert opinion. Objectives: To critically review and analyze clinical evidence on the efficacy and safety of higher-than-licensed dosage of second-generation oral antihistamines in the treatment of CSU. Material and Methods: A systematic literature review was performed following a sensitive search strategy. All articles published in PubMed, EMBASE, and the Cochrane Library between 1961 and October 2018 were examined. Publications with CSU patients prescribed secondgeneration antihistamines in monotherapy compared with placebo, licensed dosages, and/or higher dosages were included. Articles were evaluated by peer reviewers. Quality was evaluated using the Jadad and Oxford scores. Results: We identified 337 articles, of which 14 were included in the final evaluation (fexofenadine, 6; cetirizine, 2; levocetirizine and desloratadine, 1; levocetirizine, 1; rupatadine, 2; ebastine, 1; and bilastine, 1). Only 5 studies were placebo-controlled. The number of patients included ranged from 20 to 439. The observation lapse was ≤16 weeks. High fexofenadine doses produced a significant dosedependent response and controlled urticaria in most patients. Cetirizine, levocetirizine, rupatadine, and bilastine were more effective in up-dosing. The most frequent adverse events were headache and drowsiness. Conclusion: The low quality and heterogeneity of the articles reviewed made it impossible to reach robust conclusions and reveal the need for large-scale randomized clinical trials (AU)

Geographic and ontogenetic variations in parasite communities of intertidal fish species from the south-eastern Pacific coast.

Parasite composition can be affected by physiological and ecological changes during host ontogeny. Intertidal fish do not travel long distances and live in the same area throughout their lifetimes, meaning that parasite communities can differ across geographic ranges. The objective of this study was to analyse the parasite communities of three fish species (Hypsoblennius sordidus, Helcogrammoides cunninghami and Scartichthys viridis) collected from the Chilean coast. The composition of parasite species was compared among host ontogenetic stages (larvae, juveniles and mature fish) and geographic areas. A total of 184 larval, 252 juveniles and 217 mature individuals were collected in the northern area (c. 24°S), and 186 larval, 192 juveniles and 112 mature individuals from the central area (c. 33°S). Ectoparasites were most prevalent in fish from the central area, whereas endoparasites were most prevalent in the northern area. The parasite species richness varied significantly between geographical areas for H. sordidus and H. cunninghami, but the parasite composition varied significantly between geographical areas for all fish species analysed. Therefore, the geographical area was the most important factor determining the parasite composition of intertidal fish species. The absence of endoparasites in fish larvae and the increased infestation in juvenile and mature fish may be explained by the shift in habitat from the water column to intertidal pools where prey abundance and availability are higher. On the other hand, hydrographic barriers affecting prey distributions may also offer an explanation as to the differences in parasite composition.

Galactose-α-1,3-galactose (alpha-gal) allergy: first pediatric case in a series of patients in Spain.

INTRODUCTION AND OBJECTIVES: Allergy to galactose-α-1,3-galactose (alpha-gal) is a peculiar form of food allergy generally manifesting as an anaphylactic reaction hours after mammalian meat consumption, due to the presence of specific IgE against this oligosaccharide. In addition, immediate anaphylaxis may develop after exposure to other sources of alpha-gal, such as monoclonal antibody cetuximab, vaccines, plasma expanders or anti-snake venoms. Sensitization to alpha-gal has also been implicated in the rapid degeneration of biological valve implants, and recognized as a cause of occupational disease in cattle raisers. The implication of tick bites in this type of sensitization has been accepted by all the research groups dedicated to this disease. PATIENTS AND METHOD: The present study describes the clinical and sensitization characteristics of 39 patients diagnosed with alpha-gal allergy in the hospitals of our province (Lugo, Monforte de Lemos and Burela, Spain). RESULTS: Most patients were middle-age males. Of note, is the fact that the series includes the first pediatric patient reported in Spain to date. The predominant clinical manifestations were urticaria or delayed anaphylaxis after consumption of mammalian meat. Seventy-four percent of the patients reported having suffered a previous tick bite, and the clinical presentation of anaphylaxis was significantly more prevalent in those with a persistent local reaction following the bite than in those with no such reaction (p = 0.032). CONCLUSIONS: A review is also made of the disorder which, due to its variable clinical expression, is referred to as alpha-gal syndrome. The study concludes that a diagnosis of alpha-gal allergy should be considered in patients with urticaria-anaphylaxis of uncertain origin or manifesting after the administration of vaccines or products of bovine/porcine origin.

Estradiol impairs epithelial CXCL1 gradient in the cervix to delay neutrophil transepithelial migration during insemination.

Female reproductive mucosa must allow allogenic sperm survival whereas at the same time, avoid pathogen infection. To preserve sperm from neutrophil attack, neutrophils disappear from the vagina during the ovulatory phase (high estradiol); although the mechanisms that regulate neutrophil influx to the vagina during insemination remain controversial. We investigated the sex hormone regulation of the neutrophil migration through the cervix during insemination and revealed that ovulatory estradiol dose fades the CXCL1 epithelial expression in the ectocervix and fornix; hence, retarding neutrophil migration and retaining them in the epithelium. These mechanisms spare sperm from neutrophil attack to preserve reproduction, but might compromise immunity. However, luteal progesterone dose promotes the CXCL1 gradient expression to restore neutrophil migration, to eliminate sperm and prevent sperm associated pathogen dissemination. Surprisingly, these mechanisms are hormone dependent and independent of the insemination. Thus, sex hormones orchestrate tolerance and immunity in the vaginal lumen by regulating neutrophil transepithelial migration in the fornix and ectocervix.

Characterization of EHG Contractions at Pregnancy and Term Labor by Multiscale Entropy Analysis.

Monitoring uterine activity by electrohysterogram (EHG), associated with contractions both in pregnancy and labor, may contribute to the knowledge for evaluating possible risks to the binomial mother-fetus. In this context, the aim of the present study was to explore the complexity of EHG generated by women during the third trimester of pregnancy (group P) and at term labor (group L). The EHG was obtained by band-pass filtering in the range from 0.1 to 3 Hz the monopolar raw signal of the electrode number 1, of a 4-by-4 sensor array, which was located near to the tocodynamometer transducer. Multiscale entropy (MSE) analysis measures the entropy over multiple time scales to provide the complexity of the EHG time series. The results pointed out that such nonlinear technique has the potential to discriminate contractions from both groups using the area under the MSE curve (AUC) as index. The highest complexity was obtained for group P (N= 8) as AUC was 13.9233 ± 0.2015 while the lowest complexity was for group L, with N=8 and AUC of 5.1675 ± 0.0783 (p<; 0.0001). Consequently, the complexity of EHG by MSE could provide an index to discriminate between the electrical uterine activity generated during pregnancy or at labor.

Morphometrical and molecular evidence suggests cryptic diversity among hookworms (Nematoda: Uncinaria) that parasitize pinnipeds from the south-eastern Pacific coasts.

Hookworms of the genus Uncinaria parasitize pinniped pups in various locations worldwide. Four species have been described, two of which parasitize pinniped pups in the southern hemisphere: Uncinaria hamiltoni parasitizes Otaria flavescens and Arctocephalus australis from the South American coast, and Uncinaria sanguinis parasitizes Neophoca cinerea from the Australian coast. However, their geographical ranges and host specificity are unknown. Uncinaria spp. are morphologically similar, but molecular analyses have allowed the recognition of new species in the genus Uncinaria. We used nuclear genetic markers (internal transcribed spacer (ITS) and large subunit (LSU) rDNA) and a mitochondrial genetic marker (cytochrome c oxidase subunit I (COI)) to evaluate the phylogenetic relationships of Uncinaria spp. parasitizing A. australis and O. flavescens from South American coasts (Atlantic and Pacific coasts). We compared our sequences with published Uncinaria sequences. A Generalized Mixed Yule Coalescent (GMYC) analysis was also used to delimit species, and principal component analysis was used to compare morphometry among Uncinaria specimens. Parasites were sampled from A. australis from Peru (12°S), southern Chile (42°S), and the Uruguayan coast, and from O. flavescens from northern Chile (24°S) and the Uruguayan coast. Morphometric differences were observed between Uncinaria specimens from both South American coasts and between Uncinaria specimens from A. australis in Peru and southern Chile. Phylogenetic and GMYC analyses suggest that south-eastern Pacific otariid species harbour U. hamiltoni and an undescribed putative species of Uncinaria. However, more samples from A. australis and O. flavescens are necessary to understand the phylogenetic patterns of Uncinaria spp. across the South Pacific.

In vivo antimicrobial activity of silver nanoparticles produced via a green chemistry synthesis using Acacia rigidula as a reducing and capping agent.

INTRODUCTION: One of the main issues in the medical field and clinical practice is the development of novel and effective treatments against infections caused by antibiotic-resistant bacteria. One avenue that has been approached to develop effective antimicrobials is the use of silver nanoparticles (Ag-NPs), since they have been found to exhibit an efficient and wide spectrum of antimicrobial properties. Among the main drawbacks of using Ag-NPs are their potential cytotoxicity against eukaryotic cells and the latent environmental toxicity of their synthesis methods. Therefore, diverse green synthesis methods, which involve the use of environmentally friendly plant extracts as reductive and capping agents, have become attractive to synthesize Ag-NPs that exhibit antimicrobial effects against resistant bacteria at concentrations below toxicity thresholds for eukaryotic cells. PURPOSE: In this study, we report a green one-pot synthesis method that uses Acacia rigidula extract as a reducing and capping agent, to produce Ag-NPs with applications as therapeutic agents to treat infections in vivo. MATERIALS AND METHODS: The Ag-NPs were characterized using transmission electron microscopy (TEM), high-resolution TEM, selected area electron diffraction, energy-dispersive spectroscopy, ultraviolet-visible, and Fourier transform infrared. RESULTS: We show that Ag-NPs are spherical with a narrow size distribution. The Ag-NPs show antimicrobial activities in vitro against Gram-negative (Escherichia coli, Pseudomonas aeruginosa, and a clinical multidrug-resistant strain of P. aeruginosa) and Gram-positive (Bacillus subtilis) bacteria. Moreover, antimicrobial effects of the Ag-NPs, against a resistant P. aeruginosa clinical strain, were tested in a murine skin infection model. The results demonstrate that the Ag-NPs reported in this work are capable of eradicating pathogenic resistant bacteria in an infection in vivo. In addition, skin, liver, and kidney damage profiles were monitored in the murine infection model, and the results demonstrate that Ag-NPs can be used safely as therapeutic agents in animal models. CONCLUSION: Together, these results suggest the potential use of Ag-NPs, synthesized by green chemistry methods, as therapeutic agents against infections caused by resistant and nonresistant strains.

Complexes of lutein with bovine and caprine caseins and their impact on lutein chemical stability in emulsion systems: Effect of arabinogalactan.

Lutein is an important xanthophyll carotenoid with many benefits to human health. Factors affecting the application of lutein as a functional ingredient in low-fat dairy-like beverages (pH 6.0-7.0) are not well understood. The interactions of bovine and caprine caseins with hydrophobic lutein were studied using UV/visible spectroscopy as well as fluorescence. Our studies confirmed that the aqueous solubility of lutein is improved after binding with bovine and caprine caseins. The rates of lutein solubilization by the binding to bovine and caprine caseins were as follows: caprine αS1-II-casein 34%, caprine αS1-I-casein 10%, and bovine casein 7% at 100 µM lutein. Fluorescence of the protein was quenched on binding supporting complex formation. The fluorescence experiments showed that the binding involves tryptophan residues and some nonspecific interactions. Scatchard plots of lutein binding to the caseins demonstrated competitive binding between the caseins and their sites of interaction with lutein. Competition experiments suggest that caprine αS1-II casein will bind a larger number of lutein molecules with higher affinity than other caseins. The chemical stability of lutein was largely dependent on casein type and significant increases occurred in the chemical stability of lutein with the following pattern: caprine αS1-II-casein > caprine αS1-I-casein > bovine casein. Addition of arabinogalactan to lutein-enriched emulsions increases the chemical stability of lutein-casein complexes during storage under accelerated photo-oxidation conditions at 25°C. Therefore, caprine αS1-II-casein alone and in combination with arabinogalactan can have important applications in the beverage industry as carrier of this xanthophyll carotenoid (lutein).

Spatio-temporal patterns of genetic variations in populations of yellowtail kingfish Seriola lalandi from the south-eastern Pacific Ocean and potential implications for its fishery management.

The genetic population structure and genetic diversity of yellowtail kingfish Seriola lalandi from the coastal south-eastern Pacific Ocean (SEP) were evaluated at spatiotemporal scale in order to understand the ecology of this species. Between 2012 and 2015, temporal and spatial population genetic structure and a low genetic diversity were detected in S. lalandi from SEP. These results suggest that S. lalandi specimens arriving annually from offshore to the SEP coast could come from at least two genetically distinct populations, revealing a particular life strategy (i.e. reproductive or habitat segregation) for this fish species. Therefore, the SEP coast might constitute a point of population mixing for this species. Additionally, the low genetic diversity of S. lalandi in the SEP could be a result of a founder effect or overfishing. Regardless of the process explaining the genetic diversity and structure of S. lalandi in this geographical area, this new information should be considered in order to implement successful fishery management of this resource in the South Pacific.

Decolorization and biogas production by an anaerobic consortium: effect of different azo dyes and quinoid redox mediators.

The inhibitory effect of azo dyes and quinoid compounds on an anaerobic consortium was evaluated during a decolorization process and biogas production. In addition, the impact of quinoid compounds such as lawsone (LAW) and anthraquinone-2,6-disulfonate (AQDS) on the rate of decolorization of Direct Blue 71 (DB71) was assessed. The anaerobic consortium was not completely inhibited under all tested dye concentrations (0.1-2 mmol l(-1)), evidenced by an active decolorization process and biogas production. The presence of quinoid compounds at different concentrations (4, 8, and 12 mmol l(-1)) also inhibited biogas production compared to the control incubated without the quinoid compounds. In summary, the anaerobic consortium was affected to a greater extent by increasing the quantity of azo dyes or quinoid compounds. Nevertheless, at a lower concentration (1 mmol l(-1)) of quinoid compounds, the anaerobic consortium effectively decolorized 2 mmol l(-1) of DB71, increasing up to 5.2- and 20.4-fold the rate of decolorization with AQDS and LAW, respectively, compared to the control lacking quinoid compounds.

Contrasting definitive hosts as determinants of the genetic structure in a parasite with complex life cycle along the south-eastern Pacific.

The spatial genetic structure (and gene flow) of parasites with complex life cycles, such as digeneans, has been attributed mainly to the dispersion ability of the most mobile host, which most often corresponds to the definitive host (DH). In this study, we compared the genetic structure and diversity of adult Neolebouria georgenascimentoi in two fish species (DHs) that are extensively distributed along the south-eastern Pacific (SEP). The analysis was based on the cytochrome oxidase subunit I gene sequences of parasites collected between 23°S and 45°S. In total, 202 sequences of N. georgenascimentoi in Pinguipes chilensis isolated from nine sites and 136 sequences of Prolatilus jugularis from five sites were analysed. Our results showed that N. georgenascimentoi is a species complex that includes three different parasite species; however, in this study, only lineage 1 and 2 found in P. chilensis and P. jugularis, respectively, were studied because they are widely distributed along the coastline. Lineage 1 parasites had two common haplotypes with wide distribution and unique haplotypes in northern sites. Lineage 2 had only one common haplotype with wide distribution and a large number of unique haplotypes with greater genetic diversity. Both lineages have experienced recent population expansion. Only lineage 1 exhibited a genetic structure that was mainly associated with a biogeographical break at approximately 30°S along the SEP. Our finding suggests that host access to different prey (=intermediate hosts) could affect the genetic structure of the parasite complex discovered here. Consequently, difference between these patterns suggests that factors other than DH dispersal are involved in the genetic structure of autogenic parasites.

Perioperative anaphylactic reactions: Review and procedure protocol in paediatrics.

Perioperative anaphylactic reactions are immediate, hypersensitive reactions that are potentially life-threatening resulting from a sudden release of mediators from mast cells and basophiles, due to either immune (IgE or non-IgE mediated) or non-immune mechanisms. The most frequent causing agents are neuromuscular blocking agents (NMBAs), latex and antibiotics, with latex being the first cause in paediatrics. With regard to perioperative anaphylactic reactions, the usual early signs and symptoms of an anaphylactic reaction could be overlooked or erroneously interpreted and non-severe anaphylaxis could go undetected, with a risk of more severe reactions in the future. Using the data registered on the anaesthesia sheet, it is essential to establish a chronological relationship between drugs and/or substances administered and the reaction observed. An elevated level of tryptase confirms an anaphylactic reaction, but this does not usually increase in the absence of compromised circulation. An allergy study should be carried out preferably between 4 and 6 weeks after the reaction, using a combination of specific IgE, skin and controlled exposure tests (if indicated). Test sensitivity is good for NMBAs, latex, antibiotics, chlorhexidine, gelatine and povidone, and poor for barbiturates, opiates (these can give false positives since they are histamine releasers) and benzodiazepines. Special preventive measures should be taken, especially in the case of latex. We present the maximum concentrations recommended for skin tests, the recommended dosage to treat anaphylactic reactions in paediatrics and a procedure algorithm for the allergological study of these reactions.

Tadalafil for Endometrial Growth in Clomiphene Citrate stimulated cycles in an IUI programma: A pilot study.

AIM OF THE STUDY: The objective of this study was to assess the impact of tadalafil on endometrial growth, the uterine artery pulsatility index (PI) and the uterine artery resistance index (RI) in patients under clomiphene ovarian stimulation for intrauterine insemination (IUI). METHODS: This randomized crossover study included 30 patients with a normal endometrium over 53 cycles, and 46 of those cycles in 23 patients were included in the analysis. In group A the patients were under 100 mg clomiphene daily for five days (2-6) and 5 mg tadalafil daily for 7 days (4-10). For Group B (control) the patients only received clomiphene. Measurements of the endometrium, PI, RI and estradiol determinations were taken on cycle days 4, 8 and 10. RESULTS: We observed a better endometrial growth in Group A compared to Group B: 7.5 ± 2.1 mm vs 5.5 ± 1.2 mm, P < 0.0002 and 8.9 ± 1.8 mm vs 6.3 ± 1.8 mm, P < 0.0002 on days 8 and 10, respectively. Additionally, a progressive decrease in the RI was observed in Group A but not in Group B from day 8 (0.77 ± 0.15 vs 0.85 ± 0.18, P = 0.059) to day 10 (0.74 ± 0.20 vs 0.87 ± 0.14, P < 0.017). However, no differences were observed in PI or serum estradiol between Group A and Group B. CONCLUSION: The use of tadalafil improved endometrial growth in patients under clomiphene ovarian stimulation with no significant effect on the uterine artery Pulsatility Index and serum estradiol.

The first report of liver coccidian Goussia cruciata in jack mackerel, Trachurus murphyi, from the South Pacific and its relationship with host variables.

The liver coccidian Goussia cruciata is considered as a specific parasite of the genus Trachurus, but to date, this parasite has only been reported for Atlantic species (Trachurus picturatus, Trachurus lathami, Trachurus trachurus and Trachurus mediterraneus). Therefore, this is the first report of this parasite in a species of Trachurus from the South Pacific. The prevalence and abundance of this coccidian in jack mackerel, T. murphyi, was determined, and its relationships with host variables such as total body length, condition factor and hepatosomatic index were evaluated. A total of 49 individuals were sampled from a commercial vessel of the central Chilean coast (36° 41' S, 73° 06' W) in November 2013 and February and May 2014. The parasite was identified by means of liver smears using light microscopy. The relationship between the abundance of the parasites and the host total length, condition factor and hepatosomatic index was analysed with Spearman's correlations. The sporogonic stages exhibited sporocysts that were morphologically concordant with coccidian G. cruciata. All hosts were parasitised with this coccidian, and the abundance varied between 2 and 224 oocytes per host. The parasite abundance was negatively correlated with the host total length. Infection levels of G. cruciata in T. murphyi apparently do not produce negative effects on fish condition.

Metazoan symbionts of the yellow clam, Mesodesma donacium (Bivalvia), in southern Chile: geographical variations.

Mesodesma donacium is a dominant species on sandy beaches along the Chilean coast. However, the only previous parasite records for this species were obtained for the northern Chilean coast (20° S-33° S), which dealt with cestodes, polychaetes, and copepods. In this study, the symbiotic fauna of M. donacium in its southern distributional range is reported, and the geographical variations in the occurrence of this fauna are evaluated. A total of 565 individuals of M. donacium were captured by local fishermen from 5 localities: Mehuín (MEH) (39° 26' S), Carelmapu (CAR) (41° 44' S), Ancud (ANC) (41° 53' S), Cucao (CUC) (42° 35' S), and Quellón (QUE) (43° 24' S), covering a total distance of 450 km. To collect metazoan symbionts, the valves, mantle, gills, gonad, and digestive gland of each specimen of yellow clam were examined, and symbiont identifications were made via morphological and genetic analyses. The prevalence and mean intensity of infestation were calculated for each symbiotic species. Univariate and multivariate analyses were performed to evaluate the differences in symbiotic load between localities. Seven metazoan symbiotic species were recorded. The most abundant species were Paranthessius mesodesmatis, Monorchiidae gen. sp., and Paravortex sp. The copepod P. mesodesmatis and metacercaria Monorchiidae gen. sp. showed a high prevalence in all localities, but their intensity of infection varied among localities. The turbellarian Paravortex sp. was most frequently associated with ANC and CUC. The digenean Sanguinicolidae gen. sp. was recorded only at CAR, and the polychaete Spionidae gen. sp. was recorded only at MEH. In its southern distributional range, M. donacium was characterized by an absence of cestodes. This absence can be explained by the absence of the definitive host. The local environmental conditions in the southern range of the host could explain the differences in symbiotic composition among localities.

Arsenic accumulation in maize crop (Zea mays): a review.

Arsenic (As) is a metalloid that may represent a serious environmental threat, due to its wide abundance and the high toxicity particularly of its inorganic forms. The use of arsenic-contaminated groundwater for irrigation purposes in crop fields elevates the arsenic concentration in topsoil and its phytoavailability for crops. The transfer of arsenic through the crops-soil-water system is one of the more important pathways of human exposure. According to the Food and Agriculture Organization of the United Nations, maize (Zea mays L.) is the most cultivated cereal in the world. This cereal constitutes a staple food for humans in the most of the developing countries in Latin America, Africa, and Asia. Thus, this review summarizes the existing literature concerning the conditions involved in agricultural soil that leads to As influx into maize crops and the uptake mechanisms, metabolism and phytotoxicity of As in corn plants. Additionally, the studies of the As accumulation in raw corn grain and corn food are summarized, and the As biotransfer into the human diet is highlighted. Due to high As levels found in editable plant part for livestock and humans, the As uptake by corn crop through water-soil-maize system may represent an important pathway of As exposure in countries with high maize consumption.