Monitoring of a Southern Giant Petrel Macronectes giganteus population on the Frazier Islands, Wilkes Land, Antarctica

Abstract Since 1956, Southern Giant Petrels on the Frazier Islands, East Antarctica, have been counted with different census techniques, sometimes varying within seasons and among islands, which hindered analysis of the data. Protective measures for the islands from 1986 onwards have increased the need for reliable long-term census data, but reduced the ways to collect these data. Published and unpublished data were re-examined, and population trends were reconstructed based on two relatively standardised techniques: the number of active chicks (AC) and the number of apparently occupied nests (AON) around hatching. AC-values from Nelly Island from 1959 to 1998 indicate substantial periodic fluctuations, but no consistent long-term change. Since the late 1970s, AC-values on the other two islands and AON-values suggest that the breeding population may have grown by 35%. This recent growth, however, is within the extent of periodic fluctuations observed in Southern Giant Petrel population that is stable over the long term

Generation of lung epithelial-like tissue from human embryonic stem cells

<p>Abstract</p> <p>Background</p> <p>Human embryonic stem cells (hESC) have the capacity to differentiate <it>in vivo </it>and <it>in vitro </it>into cells from all three germ lineages. The aim of the present study was to investigate the effect of specific culture conditions on the differentiation of hESC into lung epithelial cells.</p> <p>Methods</p> <p>Undifferentiated hESC, grown on a porous membrane in hESC medium for four days, were switched to a differentiation medium for four days; this was followed by culture in air-liquid interface conditions during another 20 days. Expression of several lung markers was measured by immunohistochemistry and by quantitative real-time RT-PCR at four different time points throughout the differentiation and compared to appropriate controls.</p> <p>Results</p> <p>Expression of <it>CC16 </it>and <it>NKX2.1 </it>showed a 1,000- and 10,000- fold increase at day 10 of differentiation. Other lung markers such as <it>SP-C </it>and <it>Aquaporin 5 </it>had the highest expression after twenty days of culture, as well as two markers for ciliated cells, <it>FOXJ1 </it>and <it>β-tubulin IV</it>. The results from qRT-PCR were confirmed by immunohistochemistry on paraffin-embedded samples. Antibodies against CC16, SP-A and SP-C were chosen as specific markers for Clara Cells and alveolar type II cells. The functionality was tested by measuring the secretion of CC16 in the medium using an enzyme immunoassay.</p> <p>Conclusion</p> <p>These results suggest that by using our novel culture protocol hESC can be differentiated into the major cell types of lung epithelial tissue.</p

SP-A binds alpha(1)-antitrypsin in vitro and reduces the association rate constant for neutrophil elastase

BACKGROUND: α1-antitrypsin and surfactant protein-A (SP-A) are major lung defense proteins. With the hypothesis that SP-A could bind α1-antitrypsin, we designed a series of in vitro experiments aimed at investigating the nature and consequences of such an interaction. METHODS AND RESULTS: At an α1-antitrypsin:SP-A molar ratio of 1:1, the interaction resulted in a calcium-dependent decrease of 84.6% in the association rate constant of α1-antitrypsin for neutrophil elastase. The findings were similar when SP-A was coupled with the Z variant of α1-antitrypsin. The carbohydrate recognition domain of SP-A appeared to be a major determinant of the interaction, by recognizing α1-antitrypsin carbohydrate chains. However, binding of SP-A carbohydrate chains to the α1-antitrypsin amino acid backbone and interaction between carbohydrates of both proteins are also possible. Gel filtration chromatography and turnover per inactivation experiments indicated that one part of SP-A binds several molar parts of α1-antitrypsin. CONCLUSION: We conclude that the binding of SP-A to α1-antitrypsin results in a decrease of the inhibition of neutrophil elastase. This interaction could have potential implications in the physiologic regulation of α1-antitrypsin activity, in the pathogenesis of pulmonary emphysema, and in the defense against infectious agents

The surfactant protein C mutation A116D alters cellular processing, stress tolerance, surfactant lipid composition, and immune cell activation

<p>Abstract</p> <p>Background</p> <p>Surfactant protein C (SP-C) is important for the function of pulmonary surfactant. Heterozygous mutations in <it>SFTPC</it>, the gene encoding SP-C, cause sporadic and familial interstitial lung disease (ILD) in children and adults. Mutations mapping to the BRICHOS domain located within the SP-C proprotein result in perinuclear aggregation of the proprotein. In this study, we investigated the effects of the mutation A116D in the BRICHOS domain of SP-C on cellular homeostasis. We also evaluated the ability of drugs currently used in ILD therapy to counteract these effects.</p> <p>Methods</p> <p>SP-C^A116Dwas expressed in MLE-12 alveolar epithelial cells. We assessed in vitro the consequences for cellular homeostasis, immune response and effects of azathioprine, hydroxychloroquine, methylprednisolone and cyclophosphamide.</p> <p>Results</p> <p>Stable expression of SP-C^A116Din MLE-12 alveolar epithelial cells resulted in increased intracellular accumulation of proSP-C processing intermediates. SP-C^A116Dexpression further led to reduced cell viability and increased levels of the chaperones Hsp90, Hsp70, calreticulin and calnexin. Lipid analysis revealed decreased intracellular levels of phosphatidylcholine (PC) and increased lyso-PC levels. Treatment with methylprednisolone or hydroxychloroquine partially restored these lipid alterations. Furthermore, SP-C^A116Dcells secreted soluble factors into the medium that modulated surface expression of CCR2 or CXCR1 receptors on CD4⁺lymphocytes and neutrophils, suggesting a direct paracrine effect of SP-C^A116Don neighboring cells in the alveolar space.</p> <p>Conclusions</p> <p>We show that the A116D mutation leads to impaired processing of proSP-C in alveolar epithelial cells, alters cell viability and lipid composition, and also activates cells of the immune system. In addition, we show that some of the effects of the mutation on cellular homeostasis can be antagonized by application of pharmaceuticals commonly applied in ILD therapy. Our findings shed new light on the pathomechanisms underlying SP-C deficiency associated ILD and provide insight into the mechanisms by which drugs currently used in ILD therapy act.</p

Serum biomarkers in Acute Respiratory Distress Syndrome an ailing prognosticator

The use of biomarkers in medicine lies in their ability to detect disease and support diagnostic and therapeutic decisions. New research and novel understanding of the molecular basis of the disease reveals an abundance of exciting new biomarkers who present a promise for use in the everyday clinical practice. The past fifteen years have seen the emergence of numerous clinical applications of several new molecules as biologic markers in the research field relevant to acute respiratory distress syndrome (translational research). The scope of this review is to summarize the current state of knowledge about serum biomarkers in acute lung injury and acute respiratory distress syndrome and their potential value as prognostic tools and present some of the future perspectives and challenges

The ultrastructure of prolactin cells in the annual cyprinodont Cynolebias whitei during its life cycle. A morphometric study in freshwater- and saltwater-reared fish

Prolactin (PRL) cells were studied electron-microscopically and morphometrically in the annual cyprinodont fish, Cynolebias whitei during its life cycle. In prehatching larvae, PRL cells possessed small secretory granules, giant mitochondria and a well-developed Golgi apparatus. During hatching, no changes were observed in the volume density of the secretory granules, indicating that no increased release of PRL occurs at hatching. A significant change in the composition of PRL cells, i.e., the volume densities per cytoplasm volume of the different organelles, occurred between one day and one week of age. Thereafter, only minor differences were observed between age groups, indicating that no major changes occur in PRL cell activity during the lifespan of C. whitei. However, the volume density per cell volume of the nucleus decreased steadily with age during the lifespan. A comparison of the PRL cells in young and adult fish reared in fresh water (FW) with siblings reared from hatching in diluted sea water (1/3 SW) did not reveal any differences with respect to the volume densities of the organelles, including the secretory granules. However, significant differences were observed with respect to the diameter, electron-dense content and affinity to anti-PRL serum of the secretory granules. These differences indicate that, despite the similar volumetric composition of the PRL cells, their secretory granules contain a substantially higher concentration of PRL in FW-reared fish than in 1/3 SW-reared fis

Distribution and abundance of the Southern Fulmar Fulmarus glacialoides

We reviewed published and unpublished literature to establish the status of the breeding distribution and abundance of Southern Fulmars Fulmarus glacialoides. The species breeds widely throughout the Antarctic and on peri-Antarctic islands. From breeding population data collated from 73 of these localities, we estimated the minimum global population to be about 400,000 breeding pairs. After adjusting for seasonal variation in numbers of breeding pairs based on studies at Ardery Island, East Antarctica, the total global population is estimated to be at least one million breeding pairs. Of this, 72% nest on islands of the Scotia Sea arc and the South Atlantic Ocean. The precision of the estimate on the total number of breeding pairs is low, as several colony estimates were only available as orders of magnitude. Furthermore, different timing of the surveys and the difficulties of censusing colonial cliff-nesting birds reduced the count accuracy. Currently, there are no known threats to the global population, although the effects of fishery activities are not fully known