Variation in blood mercury concentrations in brown skuas (Stercorarius antarcticus) is related to trophic ecology but not breeding success or adult body condition.

Mercury is a pervasive environmental contaminant that can negatively impact seabirds. Here, we measure total mercury (THg) concentrations in red blood cells (RBCs) from breeding brown skuas (Stercorarius antarcticus) (n = 49) at Esperanza/Hope Bay, Antarctic Peninsula. The aims of this study were to: (i) analyse RBCs THg concentrations in relation to sex, year and stable isotope values of carbon (δ13C) and nitrogen (δ15N); and (ii) examine correlations between THg, body condition and breeding success. RBC THg concentrations were positively correlated with δ15N, which is a proxy of trophic position, and hence likely reflects the biomagnification process. Levels of Hg contamination differed between our study years, which is likely related to changes in diet and distribution. RBC THg concentrations were not related to body condition or breeding success, suggesting that Hg contamination is currently not a major conservation concern for this population.

Plastic ingestion risk is related to the anthropogenic activity and breeding stage in an Antarctic top predator seabird species.

During the last decades plastic pollution has become a common issue in marine environments. Studies on seabirds have focused on species that ingest plastics mistaken for prey or indirectly through their preferred prey or, on how foraging strategy influences this behaviour. We evaluated plastic ingestion in relation to the proximity of nests to areas with different anthropogenic pressure, breeding status and breeding stage. We analyzed regurgitated pellets (n = 1001) from a seabird, the Brown Skua (Stercorarius antarcticus lonnbergi) at Esperanza/Hope Bay, Antarctic Peninsula. Plastics were found in 9% of pellets, only in breeders from an area with high antropogenic activity. The prevalence of plastic increased during the brooding of chicks stage, when skuas expand their feeding niche. Our results support previous work which demonstrated that seabirds with wider feeding niche show higher loads of plastics. Altogether, this provides insights into the dynamics of plastic transfer within the environment.

Importancia del déficit selectivo de inmunoglobulina A / Importance of selective immunoglobulin A deficiency

La deficiencia selectiva de inmunoglobulina A (IgA) es la inmunodeficiencia primaria más común. Se conoce muy poco sobre los mecanismos etiopatogénicos que conducen a esta enfermedad. Se estima que la incidencia de la enfermedad en España es de 1:163. Presentamos 3 casos diagnosticados en atención primaria. La mayoría de las personas con déficit selectivo de IgA suelen estar asintomáticas y se diagnostican por casualidad; sin embargo, deberíamos tener presentes a los pacientes con infecciones de vías respiratorias recurrentes, gastrointestinales, alérgicas y enfermedades autoinmunes que pueden estar asociadas a esta afección. A pesar de que no existe tratamiento en el momento actual, su importancia radica en las asociaciones con diferentes enfermedades como la enfermedad celíaca o púrpura trombocitopénica idiopática. Por otra parte, es importante conocer el riesgo de anafilaxia tras realizar transfusiones y su posible progresión a una inmunodeficiencia común variable. Es importante conocer la correcta vacunación en esta enfermedad (AU)

Selective IgA deficiency is the most common primary immunodeficiency. Little is known about the pathogenetic mechanisms leading to this disease. It is estimated that the incidence of this disease in Spain is 1:163. We report 3 cases diagnosed in Primary Care. Most people with selective IgA deficiency are usually asymptomatic and are diagnosed by chance, but patients with recurrent respiratory infections; gastrointestinal, allergic and autoimmune diseases can be associated with this disease. Although there is no treatment at present, its importance lies in the association with different diseases, such as coeliac disease or idiopathic thrombocytopenic purpura. Another important feature is the risk of anaphylaxis after transfusion, and the possible progression to Common Variable Immunodeficiency. It is important to know the vaccines that we can use due to the risk of disease (AU)

[Importance of selective immunoglobulin A deficiency]. / Importancia del déficit selectivo de inmunoglobulina A.

Selective IgA deficiency is the most common primary immunodeficiency. Little is known about the pathogenetic mechanisms leading to this disease. It is estimated that the incidence of this disease in Spain is 1:163. We report 3 cases diagnosed in Primary Care. Most people with selective IgA deficiency are usually asymptomatic and are diagnosed by chance, but patients with recurrent respiratory infections; gastrointestinal, allergic and autoimmune diseases can be associated with this disease. Although there is no treatment at present, its importance lies in the association with different diseases, such as coeliac disease or idiopathic thrombocytopenic purpura. Another important feature is the risk of anaphylaxis after transfusion, and the possible progression to Common Variable Immunodeficiency. It is important to know the vaccines that we can use due to the risk of disease.

Cognitive assessment of patients with minimal hepatic encephalopathy in Brazil.

Minimal hepatic encephalopathy is a syndrome caused by liver cirrhosis and accompanied by a broad spectrum of cognitive symptoms. The objective of the present study was to describe the prevalence of minimal hepatic encephalopathy in cirrhotic patients and to compare their cognitive performance with controls using standardized tests. Patients receiving medication or experiencing comorbidities associated with cognitive disorders were excluded. The final cohort was compared with a control-matched group using the Mini-Mental State Examination (MMSE), as well as Simple Drawing, Clock Drawing, Rey Auditory-Verbal Learning Test (RAVLT), Random Letter, Stroop, Trail-Making Test (TMT) A and B, Boston Naming, Category Verbal Fluency, Digit Span, Constructional Praxis, Processing Speed, and Similarities Tests. The results indicated no differences in the prevalence of cognitive complaints spontaneously reported by 29 patients with cirrhosis versus 22 healthy controls. The most affected tests included: MMSE (26.3 ± 2 vs. 28.1 ± 1.8 points; p = 0.004), learning (35.4 ± 9 vs. 41 ± 9.1 points; p = 0.041), retroactive interference (0.67 ± 0.22 vs. 0.84 ± 0.16 points; p = 0.004), and recognition (8.7 ± 2.6 vs. 11.2 ± 4.1 points; p = 0.024) in RAVLT, TMT-A (63.2 ± 29.3 vs. 47.6 ± 16.5 s; p = 0.029) and TMT-B (197.9 ± 88.1 vs. 146.8 ± 76.5 s; p = 0.03). No differences were observed with respect to age, gender, and education. In conclusion, MMSE proved to be a useful tool for detecting global cognitive impairment experienced by cirrhosis patients. Moreover, the most impaired cognitive functions were verbal episodic memory and information processing speed. These findings suggest that minimal hepatic encephalopathy represents a disorder that affects the medial temporal system and, possibly, the prefrontal cortex, and this requires further study.

Tendon cell contraction of collagen-GAG matrices in vitro: effect of cross-linking.

The contraction of connective tissue cells can play important roles in wound healing and pathological contractures. The effects of this contractile behavior on cell-seeded constructs for tissue engineering have not yet been investigated. The goal of this work was to investigate in vitro tendon cell-mediated contraction of collagen-glycosaminoglycan (GAG) matrices cross-linked using selected methods. Highly porous collagen-GAG sponges were seeded with calf tendon cells and the projected area and DNA content of the sponges measured at 3, 7, 14, and 21 days post-seeding. Immunohistochemistry was performed to determine if alpha-smooth muscle actin (SMA) was associated with the cell contraction of the matrices. Dehydrothermal (DHT) treatment alone was not sufficient to resist contraction by the seeded tendon fibroblasts. Cross-linking of the collagen-GAG sponges to the extent that the modulus was three times that of sponges treated by DHT alone was necessary to resist contraction. SMA was seen in the cytoplasm of most cells in all sponges at all time periods. The results provide a rational basis for the determination of the mechanical properties of collagen matrices required for engineering certain connective tissues.

Application of X-ray micrography and imaging to study the effect of gentamicin on Pseudomonas aeruginosa.

Aminoglycosides disrupt the outer membrane of Pseudomonas aeruginosa to facilitate access to their intracellular target. High-resolution X-ray micrography of live specimens is a relatively new technique. We used laser (nanosecond) plasma to image live cells of P. aeruginosa ATCC 27853. After exposure to 25 mg/L gentamicin for 15 min. we observed perturbation of the cell surface, membrane blebbings (370 nm and 273 nm diameter) away from the cell, formation of distinct channels (241 nm long) resulting from indentation and induction of cell elongation from 3-3.6 microm (control) to 4.6-5.26 microm (gentamicin-treated cells). These data illustrate the potential of high-resolution X-ray micrography for studying effects of drugs on live microbiological specimens.