114 research outputs found

    Baseline and Stress-Induced Plasma Corticosterone during Long-Distance Migration in the Bar-Tailed Godwit, Limosa lapponica

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    The specific roles of corticosterone in promotion of avian migration remain unclear even though this glucocorticosteroid is elevated in many migrating bird species. In general, glucocorticosteroids promote metabolic homeostasis and may elicit effects on feeding and locomotion. Because the migratory stages of refueling and flight are characterized by distinct behaviors and physiology, the determination of corticosterone levels during each stage should help identify potential processes in which corticosterone is involved. We measured baseline levels of corticosterone in bar-tailed godwits (Limosa lapponica) during two distinct stages of migration: (1) immediately after arrival at a false stopover site just short of theWadden Sea and (2) throughout the subsequent 4-wk refueling period on the Wadden Sea. Plasma corticosterone was higher in arriving than in refueling birds. In addition, corticosterone increased with size-corrected body mass during the refueling phase, suggesting that corticosterone rises as birds prepare to reinitiate flight. Therefore, elevated corticosterone appears associated with migratory flight and may participate in processes characterizing this stage. We also performed a capture stress protocol in all birds and found that corticosterone increased in both arriving and refueling godwits. Therefore, the normal course of migration may be typified by corticosterone concentrations that are lower than those associated with stressful and life-threatening episodes.

    Blood parameter changes during stopover in a long-distance migratory shorebird, the bar-tailed godwit Limosa lapponica taymyrensis

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    Bar-tailed godwits migrate from West African wintering sites to breeding areas in northern Russia with only one stopover. We compared hematocrit (Hct), blood hemoglobin concentration (Hb), and mean cell hemoglobin concentration (MCHb; a measure of the relative proportion of Hb in the cellular blood fraction) between arriving godwits lured to land 60 km short of the stopover site and godwits during subsequent refueling. The Hct and Hb of arriving godwits was low when compared to that of refueling birds. On the stopover site, Hct and Hb correlated positively with size-corrected body mass. In addition, Hb and MCHb reached peak levels in the last days of stopover. We explored the possibility of regenerative anemia in arriving godwits by comparing the fraction of reticulocytes (young red blood cells) between arriving and refueling birds. No differences were found. Therefore, we suggest that the increase in Hct, Hb, and MCHb during refueling is not in response to a severe anemic state at arrival. Rather, we suggest that the increase in blood parameters may anticipate the increased aerobic requirements of impending migratory flight and possibly satisfy heightened oxygen demands of the larger body mass of fattened birds. The Hct increase on the stopover site may also serve to buffer the red blood cell population against possible red blood cell breakdown during long-distance flight.

    Current trends in research, development and production of prophylactic vaccines : Report of Vaccipharma 2015 Congress

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    On June 14-19, 2015, the IUPHAR Section of Immunopharmacology and the Cuban Society of Pharmacology, together with the Latin- American Association of Pharmacology (ALF), Finlay Vaccine Institute and other prestigious Cuban scientific institutions, organized the Congress VACCIPHARMA 2015 (3rd International Congress on Pharmacology of Vaccines), held as part of the First International Convention IMMUNOPHARMACOLOGY–VACCIPHARMA 2015 (Meliá Marina Varadero Hotel, in Varadero beach, Cuba) VACCIPHARMA 2015 was organised into two large Workshops, addressing topics related to the research, development, clinical evaluation, production and quality control of Therapeutic and Prophylactic Vaccines, respectively. At the same time the Workshop on Prophylactic Vaccines was integrated by several Symposiums, focused on meningococcal, pneumococcal, enteric, tuberculosis and pertussis vaccines. About 250 delegates, including 100 international researchers from 15 countries, attended this meeting. The Congress had a remarkable Opening Session, with a Key Lecture given by the outstanding scientist Professor Dr. Shiv Pillai (United States of America), who talked about the changing views in the field of the immunology of vaccination and the challenges ahead. The aim of this review is to give an overview of the main topics discussed in the Prophylactic Vaccines Workshop, not as a complete narration of the events, but to provide an update of the latest state of the art and methodologies being applied to prophylactic vaccines with an expert commentary on the invited speakers

    Metabolic profile of long-distance migratory flight and stopover in a shorebird

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    Migrating birds often complete long non-stop flights during which body energy stores exclusively support energetic demands. The metabolic correlates of such long-distance travel in free-living migrants are as yet poorly studied. Bar-tailed godwits, Limosa lapponica taymyrensis, undertake a 4500 km flight to their single spring stopover site and thus provide an excellent model in which to determine the energy fuels associated with endurance travel. To this end, we evaluated plasma concentrations of six key metabolites in arriving godwits caught immediately upon landing near their stopover site. Initial metabolite levels were compared with levels after 5 h of inactive rest to determine how flight per se affects energy metabolism. Birds refuelling on the stopover site were also examined. Arriving godwits displayed elevated plasma free fatty acids, glycerol and butyrate, confirming the importance of lipid fuel in the support of extended migratory activity. Furthermore, elevated plasma triglycerides in these birds suggest that fatty acid provisioning is facilitated through hepatic synthesis and release of neutral lipids, as previously hypothesized for small migrants with high mass-specific metabolic rates. Finally, elevations in plasma uric acid suggest that protein breakdown contributes to the support of long-distance movement, to possibly maintain citric acid cycle intermediates, gluconeogenesis and/or water balance

    Breeding on the extreme edge: Modulation of the adrenocortical response to acute stress in two High Arctic passerines

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    Arctic weather in spring is unpredictable and can also be extreme, so Arctic-breeding birds must be flexible in their breeding to deal with such variability. Unpredictability in weather conditions will only intensify with climate change and this in turn could affect reproductive capability of migratory birds. Adjustments to coping strategies are therefore crucial, so here we examined the plasticity of the adrenocorticotropic stress response in two Arctic songbird species—the snow bunting (Plectrophenax nivalis) and Lapland longspur (Calcarius lapponicus)—breeding in northwest Greenland. Across the breeding season, the stress response was strongest at arrival and least robust during molt in male snow buntings. Snow bunting females had higher baseline but similar stressinduced corticosterone levels compared to males. Modification of the stress response was not due to adrenal insensitivity, but likely regulated at the anterior pituitary gland. Compared to independent nestlings and adult snow buntings, parental-dependent chicks had a more robust stress response. For Lapland longspurs, baseline corticosterone was highest at arrival in both male and females, and arriving males displayed a higher stress response compared to arriving females. Comparison of male corticosterone profiles collected at arrival in Greenland (76°N) and Alaska (67–71°N;) reveal that both species have higher stress responses at the more northern location. Flexibility in the stress response may be typical for birds nesting at the leading edges of their range and this ability will become more relevant as global climate change results in major shifts of breeding habitat and phenology for migratory birds

    Second international congress on immunopharmacology : delivery systems and current strategies for drug design

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    The 2nd International Congress on Immunopharmacology was held in June of 2011 at the Conference Center of Plaza America in Varadero, Cuba. The main goal of this meeting was to provide state-of-the-art communications for scientists, manufacturers, regulators and healthcare workers, to accelerate progress in the development of biological and biotechnological products and to promote exchange/scientific cooperation between researchers. 300 delegates from 22 countries attended the conference. The wide-ranging programme commenced with a plenary session and then split into a series of parallel workshops and symposia, covering “Advances in Immunopharmacology”, “Neuroimmunology”, “Therapeutic Biological Products”, “Prophylaxis and Treatment of Helicobacter pylori”, “Pharmacology of Cytochrome P450”, “Hereditary Ataxias” and “Delivery Systems and Current Strategies for Drug Design”. In this last Symposium, a substantial body of data was presented relating to the development of delivery systems with adjuvant and vaccine potential and also to strategies focused in therapeutic and prophylactic approaches against tuberculosis. This issue is dedicated to some of the results presented in this area

    Prognostic value of hematogenous dissemination and biological profile of the tumor in early breast cancer patients: A prospective observational study

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    <p>Abstract</p> <p>Background</p> <p>The aim of this study was to investigate the incidence and prognostic value of disseminated tumor cells in bone marrow of breast carcinoma patients with early disease, and to analyze this finding in relation to lymph node involvement, determined by sentinel lymph node (SLN) biopsy analysis, and to prognostic factors of interest.</p> <p>Methods</p> <p>104 patients with operable (T < 3 cm) breast cancer and clinically- and sonographically-negative axillary lymph nodes were scheduled for SLN biopsy. Bone marrow aspirates were collected before the start of surgery from both iliac crests, and mononuclear cell layers were separated by density centrifugation (Lymphoprep). Slide preparations were then examined for the presence of disseminated tumor cells by immunocytochemistry with anti-cytokeratin antibodies (A45-B/B3). Lymphoscintigraphy was performed 2 hours after intratumor administration of 2 mCi (74 MBq) of 99mTc colloidal albumin. The SLN was evaluated for the presence of tumor cells by hematoxylin-eosin staining and, when negative, by immunocytochemistry using anti-cytokeratin antibody (CAM 5.2). Survival analyses and comparative analyses were performed on the results of bone marrow determinations, SLN biopsy, and known prognostic factors, including breast cancer subtypes according to the simplified classification based on ER, PR and HER2.</p> <p>Results</p> <p>Lymph node and hematogenous dissemination occur in one-third of patients with early-stage breast cancer, although not necessarily simultaneously. In our study, disseminated tumor cells were identified in 22% of bone marrow aspirates, whereas 28% of patients had axillary lymph node involvement. Simultaneous lymph node and bone marrow involvement was found in only 5 patients (nonsignificant). In the survival study (60 months), a higher, although nonsignificant rate of disease-related events (13%) was seen in patients with disseminated tumor cells in bone marrow, and a significant association of events was documented with the known, more aggressive tumor subtypes: triple negative receptor status (21%) and positive ERBB2 status (29%).</p> <p>Conclusions</p> <p>Tumor cell detection in bone marrow can be considered a valid prognostic parameter in patients with early disease. However, the classic prognostic factors remain highly relevant, and the newer breast cancer subtypes are also useful for this purpose.</p
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