Concentration of trace metals in excrements of two species of penguins from different locations of the Antarctic Peninsula

The presence of metals in Antarctica is becoming an issue that needs to be more investigated as human presence is increasing in the region, especially in the Antarctic Peninsula, where most of the polar animals, scientific bases and tourists are concentrated. Penguins are endemic species of Antarctica situated at the top of food web and are useful sentinels of pollution. To improve data of trace metal contamination in the Antarctic Peninsula region, concentrations of Cd, Pb, As, Cu and Zn in fresh excrement of penguins were determined by atomic absorption. Samples were collected in several locations during the 2011/2012 austral summer: eight sites (O’Higgins Station, Yankee Harbour, Mikkelsen Harbor, Danco Island, Gonzalez Videla Base, Yelcho Station and Brown Station) from gentoo penguin (Pygoscelis papua) colonies and four locations (Hydrurga Rocks, Cape Shirreff, Narebski Point and Kopaitic Island) from chinstrap penguin (Pygoscelis antarctica) colonies. Data showed that gentoo penguin colonies had higher levels of metals (μg g^?1 dw) like Pb, Cu and Zn at locations such as O’Higgins (2.89 for Pb, 199.95 for Cu and 379.99 for Zn) and Gonzalez Videla (2.74 for Pb and 222.51 for Cu). Levels of Cd in excreta of chinstrap penguins were higher at Narebski Point (3.13 μg g^?1). The levels of Pb, As, Cd, Cu and Zn were similar or even higher to those reported in excreta of the same species by previous studies at Antarctica. Data suggest that metals ingested by these two penguin species feeding in the sea end up in terrestrial ecosystems.     

Expanded Regulatory T Cells in Chronically Friend Retrovirus-Infected Mice Suppress Immunity to a Murine Cytomegalovirus Superinfection

It is still unclear whether expanded and activated regulatory T cells (Tregs) in chronic viral infections can influence primary immune responses against superinfections with unrelated viruses. Expanded Tregs found in the spleens of chronically Friend virus (FV)-infected mice decreased murine cytomegalovirus (mCMV)-specific CD8⁺ T cell responses during acute mCMV superinfection. This suppression of mCMV-specific T cell immunity was found only in organs with FV-induced Treg expansion. Surprisingly, acute mCMV infection itself did not expand or activate Tregs.     

Estimation of capture probabilities using generalized estimating equations and mixed effects approaches

Modeling individual heterogeneity in capture probabilities has been one of the most challenging tasks in capture–recapture studies. Heterogeneity in capture probabilities can be modeled as a function of individual covariates, but correlation structure among capture occasions should be taking into account. A proposed generalized estimating equations (GEE) and generalized linear mixed modeling (GLMM) approaches can be used to estimate capture probabilities and population size for capture–recapture closed population models. An example is used for an illustrative application and for comparison with currently used methodology. A simulation study is also conducted to show the performance of the estimation procedures. Our simulation results show that the proposed quasi‐likelihood based on GEE approach provides lower SE than partial likelihood based on either generalized linear models (GLM) or GLMM approaches for estimating population size in a closed capture–recapture experiment. Estimator performance is good if a large proportion of individuals are captured. For cases where only a small proportion of individuals are captured, the estimates become unstable, but the GEE approach outperforms the other methods.     

Evolución del microprolactinoma a largo plazo con tratamiento médico

IntroductionProlactinoma is the most frequent functioning pituitary adenoma. Most commonly occurs as microprolactinoma (less than 1 cm in size), which may be cured with medical therapy, but few long-term studies are available about optimal duration of treatment with dopamine agonists to ensure cure after drug discontinuation and its withdrawal without recurrence are do not report consistent results.ObjectiveTo establish criteria for cure of microprolactinoma with medical treatment and to analyze the potential predictors involved.PatientsA retrospective study was conducted on 47 adult women with microprolactinoma followed up between 1975 and 2010; none of them had undergone prior surgery or radiotherapy, and all of them received treatment with a dopamine agonist for at least 4 years. They were divided into two groups for analysis: cured patients with at least 4 years with normal prolactin levels after drug discontinuation, and not cured patients.ResultsCure was achieved in 57.4% of patients. Only age at diagnosis was a significant predictor: there were more young patients in the cured group and youngest patients needed less time to cure. Development of empty sella turcica or normal MRI were similar regarding time to cure.ConclusionsMicroprolactinoma may be cured with dopamine agonists, and life-long treatment is not required, although more than 10 years may be required to achieve cure, 11,6 ± 5,3 years in our experience.     

The Effect of Inkjet Printing over Polymeric Films as Potential Buccal Biologics Delivery Systems

The buccal mucosa appears as a promissory route for biologic drug administration, and pharmaceutical films are flexible dosage forms that can be used in the buccal mucosa as drug delivery systems for either a local or systemic effect. Recently, thin films have been used as printing substrates to manufacture these dosage forms by inkjet printing. As such, it is necessary to investigate the effects of printing biologics on films as substrates in terms of their physical and mucoadhesive properties. Here, we explored solvent casting as a conventional method with two biocompatible polymers, hydroxypropyl methylcellulose, and chitosan, and we used electrospinning process as an electrospun film fabrication of polycaprolactone fibers due to its potential to elicit mucoadhesion. Lysozyme was used as biologic drug model and was formulated as a solution for printing by thermal inkjet printing. Films were characterized before and after printing by mechanical and mucoadhesive properties, surface, and ultrastructure morphology through scanning electron microscopy and solid state properties by thermal analysis. Although minor differences were detected in micrographs and thermograms in all polymeric films tested, neither mechanical nor mucoadhesive properties were affected by these differences. Thus, biologic drug printing on films was successful without affecting their mechanical or mucoadhesive properties. These results open way to explore biologics loading on buccal films by inkjet printing, and future efforts will include further in vitro and in vivo evaluations.     

Occurrence of melanin granules and melanosynthesis in the kidney of Sparus auratus

An optical, ultrastructural, and biochemical study of the melanin accumulation nodules found in the kidney of the teleost fish Sparus auratus is presented. These nodules are randomly distributed in the interstitium of the renal tissue. They are formed by large aggregates of cells replete with melanin granules. The melanin granules occur singly or also in aggregates inside the cells. Most of the granules are electron-dense, but sometimes small electron-lucent spaces within them can be seen. Some secondary lysosomes and dendritic processes can also be observed. Biochemical studies have proved for the first time the existence of measurable tyrosinase activity in those nodules. That activity was assayed using three methods: tyrosine hydroxylation, dopa oxidation, and melanin formation. Furthermore, inhibitors of well-characterized plant and animal skin tyrosinases were effective agents for inhibiting those activities in fish kidney preparations. This finding supports the notion of the existence of true tyrosinase in the melanin accumulation nodules of this tissue. Taking into account the results obtained, the origin and functions of the melanin-containing cells found in the teleost fish kidney are discussed.     

Ecological aspects of nematode parasites of introduced salmonids from Valdivia river basin, Chile.

Between 1986 and 1987, 666 fishes distributed among the following species introduced in Chile, and from different sectors of the Valdivia river basin (39 degrees 30'-40 degrees 00'S, 73 degrees 30'-71 degrees 45'W), were examined: 348 Salmo trutta, 242 Salmo gairdneri, 24 Cyprinus carpio and 52 Gambusia affinis holbrooki. The presence of Camallanus corderoi and Contracaecum sp. in S. gairdneri and of C. corderoi in S. trutta is recorded in Chile for the first time. Cyprinus carpio and G. a. holbrooki did not present infections by nematodes. The prevalence and mean intensity of the infections by nematodes presented significant differences among some sectors of the Valdivia river basin. In general, the prevalence and intensity of the infections by C. corderoi were greater than those by Contracaecum sp. The infections in S. gairdneri were higher than in S. trutta. The sex of the hosts had no influence on the prevalence and intensity of the infections by both nematodes. The length of the hosts did have an influence, except in the case of the infections by Contracaecum sp. in S. gairdneri. The infrapopulations of both nematode species showed over-dispersion in most cases. The diet of the examined salmonids suggests that they would become infected principally through the consumption of autochthonous fishes.