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508 records – page 1 of 51.

5-oxo-6,8,11,14-eicosatetraenoic acid induces the infiltration of granulocytes into human skin.

https://arctichealth.org/en/permalink/ahliterature15223
Source
J Allergy Clin Immunol. 2003 Oct;112(4):768-74
Publication Type
Article
Date
Oct-2003
Author
Shigeo Muro
Qutayba Hamid
Ronald Olivenstein
Rame Taha
Joshua Rokach
William S Powell
Author Affiliation
Department of Medicine, McGill University, Montreal, Quebec, Canada.
Source
J Allergy Clin Immunol. 2003 Oct;112(4):768-74
Date
Oct-2003
Language
English
Publication Type
Article
Keywords
Arachidonic Acids - pharmacology
Asthma - physiopathology
Case-Control Studies
Cell Movement - drug effects
Chemotactic Factors - pharmacology
Granulocytes - drug effects - pathology
Humans
Macrophages - pathology
Mast Cells - pathology
Neutrophils - pathology
Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.
Research Support, U.S. Gov't, P.H.S.
Skin - pathology
Time Factors
Abstract
BACKGROUND: 5-Oxo-6,8,11,14-eicosatetraenoic acid (5-oxo-ETE) is an arachidonic acid metabolite with potent in vitro chemoattractant effects on eosinophils and neutrophils. It has also been shown to induce pulmonary eosinophilia in Brown Norway rats, but it is not known whether it is active in human beings in vivo. OBJECTIVE: To determine whether 5-oxo-ETE can induce cellular infiltration in patients with atopic asthma and nonatopic control subjects after intradermal administration. METHODS: 5-Oxo-ETE was administered intradermally to 11 patients with atopic asthma and 10 nonatopic control subjects. Skin biopsy specimens were taken 6 or 24 hours later and examined by immunocytochemistry for cells expressing specific markers for eosinophils (major basic protein), neutrophils (elastase), macrophages (CD68), lymphocytes (CD3), and mast cells (tryptase). RESULTS: 5-Oxo-ETE (1.5 and 5 microg) elicited the infiltration of both eosinophils and neutrophils into the skin in both control and atopic asthmatic subjects. Increased numbers of eosinophils were observed at 6 and 24 hours after injection, whereas significantly elevated neutrophil numbers were present only after 24 hours. Eosinophils were >3 times higher in patients with atopic asthma compared with control subjects after injection of the highest dose of 5-oxo-ETE. Macrophage numbers were also elevated, but only at the highest dose of 5-oxo-ETE. No effects were observed on the numbers of either lymphocytes or mast cells. CONCLUSIONS: 5-Oxo-ETE elicits the infiltration of eosinophils and neutrophils into the skin of human beings in vivo after intradermal administration. Asthmatic subjects are more responsive to this substance than nonallergic control subjects. These results suggest that 5-oxo-ETE may be an important mediator of inflammation.
PubMed ID
14564360 View in PubMed
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5-oxo-ETE induces pulmonary eosinophilia in an integrin-dependent manner in Brown Norway rats.

https://arctichealth.org/en/permalink/ahliterature10761
Source
J Clin Invest. 1998 Dec 15;102(12):2165-72
Publication Type
Article
Date
Dec-15-1998
Author
P. Stamatiou
Q. Hamid
R. Taha
W. Yu
T B Issekutz
J. Rokach
S P Khanapure
W S Powell
Author Affiliation
Meakins-Christie Laboratories, Department of Medicine, McGill University, Montreal, Quebec, Canada, H2X 2P2.
Source
J Clin Invest. 1998 Dec 15;102(12):2165-72
Date
Dec-15-1998
Language
English
Publication Type
Article
Keywords
Animals
Antibodies, Monoclonal - pharmacology
Antigens, CD - metabolism
Arachidonic Acids - administration & dosage - pharmacology
Chemotactic Factors - pharmacology
Immunohistochemistry
Integrin alpha4
Integrins - metabolism
Intubation, Intratracheal - methods
Leukotrienes - pharmacology
Lung - cytology - drug effects
Macrophage-1 Antigen - metabolism
Male
Platelet Activating Factor - pharmacology
Pulmonary Eosinophilia - chemically induced
Rats
Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.
Research Support, U.S. Gov't, P.H.S.
Time Factors
Abstract
We have shown previously that the 5-lipoxygenase product 5-oxo-6,8, 11,14-eicosatetraenoic acid (5-oxo-ETE) is a highly potent eosinophil chemoattractant in vitro. To determine whether this substance can induce pulmonary eosinophil infiltration in vivo, it was administered to Brown Norway rats by tracheal insufflation. Eosinophils were then counted in lung sections that had been immunostained with an antibody to eosinophil major basic protein. 5-Oxo-ETE induced a dramatic increase in the numbers of eosinophils (ED50, 2.5 microg) around the walls of the airways, which reached maximal levels (five times control levels) between 15 and 24 h after administration, and then declined. LTB4 also induced pulmonary eosinophil infiltration with a similar ED50 but appeared to be somewhat less effective. In contrast, LTD4 and LTE4 were inactive. 5-Oxo-ETE-induced eosinophilia was unaffected by the LTB4 and PAF antagonists LY255283 and WEB 2170, respectively. However, it was inhibited by approximately 75% by monoclonal antibodies to CD49d (VLA-4) or CD11a (LFA-1) but was not significantly affected by an antibody to CD11b (Mac-1). In conclusion, 5-oxo-ETE induces pulmonary eosinophilia in Brown Norway rats, raising the possibility that it may be a physiological mediator of inflammation in asthma.
PubMed ID
9854052 View in PubMed
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Accumulation of 137Cesium and 90Strontium from abiotic and biotic sources in rodents at Chornobyl, Ukraine.

https://arctichealth.org/en/permalink/ahliterature61733
Source
Environ Toxicol Chem. 2001 Sep;20(9):1927-35
Publication Type
Article
Date
Sep-2001
Author
R K Chesser
B E Rodgers
J K Wickliffe
S. Gaschak
I. Chizhevsky
C J Phillips
R J Baker
Author Affiliation
Department of Genetics, University of Georgia, Athens 30602, USA. rchesser@ttu.edu
Source
Environ Toxicol Chem. 2001 Sep;20(9):1927-35
Date
Sep-2001
Language
English
Publication Type
Article
Keywords
Accidents, Radiation
Animals
Animals, Wild
Arvicolinae
Cesium radioisotopes - pharmacokinetics
Diet
Environmental monitoring
Female
Male
Mice
Power Plants
Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.
Soil Pollutants, Radioactive - pharmacokinetics
Strontium Radioisotopes - pharmacokinetics
Tissue Distribution
Trees
Ukraine
Abstract
Bank voles (Clethrionomys glareolus) and laboratory strains of house mice (Mus musculus BALB and C57BL) were relocated into enclosures in a highly contaminated area of the Red Forest near the Chornobyl (Ukraine) Reactor 4 to evaluate the uptake rates of 137Cs and 90Sr from abiotic sources. Mice were provided with uncontaminated food supplies, ensuring that uptake of radionuclides was through soil ingestion, inhalation, or water. Mice were sampled before introduction and were reanalyzed every 10 d for 137Cs uptake. Levels of 90Sr were assessed in subsamples from the native populations and in experimental animals at the termination of the study. Uptake rates in house mice were greater than those in voles for both 137Cs and 90Sr. Daily uptake rates in house mice were estimated at 2.72 x 10(12) unstable atoms per gram (whole body) for 137Cs and 4.04 x 10(10) unstable atoms per gram for 90Sr. Comparable rates in voles were 2.26 x 10(11) unstable atoms per gram for 137Cs and 1.94 x 10(10) unstable atoms per gram for 90Sr. By comparing values from voles in the enclosures to those from wild voles caught within 50 m of the enclosures, it was estimated that only 8.5% of 137Cs was incorporated from abiotic sources, leaving 91.5% being incorporated by uptake from biotic materials. The fraction of 90Sr uptake from abiotic sources was at least 66.7% (and was probably much higher). Accumulated whole-body doses during the enclosure periods were estimated as 174 mGy from intramuscular 137Cs and 68 mGy by skeletal 90Sr in house mice over 40 d and 98 mGy from 137Cs and 19 mGy from 90Sr in voles over 30 d. Thus, uptake of radionuclides from abiotic materials in the Red Forest at Chornobyl is an important source of internal contamination.
PubMed ID
11521818 View in PubMed
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Acute gastric dilatation and volvulus in a free-living polar bear.

https://arctichealth.org/en/permalink/ahliterature5326
Source
J Wildl Dis. 1989 Oct;25(4):601-4
Publication Type
Article
Date
Oct-1989
Author
S C Amstrup
C A Nielsen
Author Affiliation
Alaska Fish and Wildlife Research Center, U.S. Fish and Wildlife Service, Anchorage 99503.
Source
J Wildl Dis. 1989 Oct;25(4):601-4
Date
Oct-1989
Language
English
Publication Type
Article
Keywords
Animals
Carnivora
Gastric Dilatation - complications - pathology - veterinary
Male
Research Support, U.S. Gov't, Non-P.H.S.
Stomach Volvulus - complications - pathology - veterinary
Ursidae
Abstract
A large, adult male polar bear (Ursus maritimus) was found dead on a barrier island north of Prudhoe Bay, Alaska (USA), in June 1987. There were no external signs of trauma. A twisted distended stomach, distinctive parenchymal and fascial congestion, and significant difficulty in repositioning the anterior abdominal organs, indicated that gastric dilatation-volvulus (GDV) was the proximate cause of death. Polar bears frequently consume large quantities of food at one time and have large stomachs that are well adapted to periodic gorging. The scarcity of food in winter and early spring, combined with voluntary fasting and protracted vigorous activity during the breeding season in late spring may have predisposed this bear to GDV. The relationship between GDV and postprandial exercise emphasizes the need for a better understanding of how the present human invasion of arctic habitats may influence polar bear activities.
PubMed ID
2810562 View in PubMed
Less detail

The adrenocortical response of tufted puffin chicks to nutritional deficits.

https://arctichealth.org/en/permalink/ahliterature4742
Source
Horm Behav. 2005 May;47(5):606-19
Publication Type
Article
Date
May-2005
Author
Alexander S Kitaysky
Marc D Romano
John F Piatt
John C Wingfield
Motoshi Kikuchi
Author Affiliation
Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, AK 99775, USA. ffask@uaf.edu
Source
Horm Behav. 2005 May;47(5):606-19
Date
May-2005
Language
English
Publication Type
Article
Keywords
Adrenal Cortex - physiology
Analysis of Variance
Animal Nutrition
Animals
Body Weight
Charadriiformes - physiology
Comparative Study
Corticosterone - blood
Energy Metabolism - physiology
Food Deprivation - physiology
Hypothalamo-Hypophyseal System - physiology
Nesting Behavior - physiology
Pituitary-Adrenal System - physiology
Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.
Stress - metabolism
Thyroid Hormones - blood
Abstract
In several seabirds, nutritional state of a nest-bound chick is negatively correlated with the activity of its hypothalamus-pituitary-adrenal (HPA) axis. Increased corticosterone (cort) secretion has been shown to facilitate changes in behavior that allow hungry chicks to obtain more food from parents. However, if parents are not willing/able to buffer their young from temporary food shortages, increased cort secretion could be detrimental to undernourished chicks. In a system where parents are insensitive to chick demands, low benefits and high costs of activation of the HPA-axis in hungry chicks should lead to a disassociation of the nutritional state of the young and the activity of its HPA-axis. We tested this novel hypothesis for the tufted puffin (Fratercula cirrhata), a seabird with intermittent provisioning of a nest-bound semi-precocial chick. We examined the HPA-axis activity of captive chicks exposed to the following: (1) a short-term (24 h) food deprivation; and (2) an array of prolonged (3 weeks) restrictions in feeding regimens. We found that in response to a short-term food deprivation chicks decreased baseline levels of cort and thyroid hormones. In response to prolonged restrictions, food-limited chicks exhibited signs of nutritional deficit: they had lower body mass, endogenous lipid reserves, and thyroid hormone titers compared to chicks fed ad libitum. However, baseline and maximum acute stress-induced levels of cort were also lower in food-restricted chicks compared to those of chicks fed ad libitum. These results support a major prediction of the study hypothesis that puffin chicks suppress HPA-axis activity in response to short- and long-term nutritional deficits. This physiological adaptation may allow a chick to extend its development in the nest, while eluding detrimental effects of chronic cort elevation.
PubMed ID
15811363 View in PubMed
Less detail

Adsorption inhibition as a mechanism of freezing resistance in polar fishes.

https://arctichealth.org/en/permalink/ahliterature46812
Source
Proc Natl Acad Sci U S A. 1977 Jun;74(6):2589-93
Publication Type
Article
Date
Jun-1977
Author
J A Raymond
A L DeVries
Source
Proc Natl Acad Sci U S A. 1977 Jun;74(6):2589-93
Date
Jun-1977
Language
English
Publication Type
Article
Keywords
Acclimatization
Adsorption
Animals
Blood Proteins - physiology
Cold Climate
Fishes - physiology
Freezing
Glycoproteins - blood
Kinetics
Microscopy, Electron, Scanning
Molecular Weight
Protein Conformation
Research Support, U.S. Gov't, Non-P.H.S.
Research Support, U.S. Gov't, P.H.S.
Species Specificity
Abstract
Polar fishes are known to have serum proteins and glycoproteins that protect them from freezing, by a noncolligative process. Measurements of antifreeze concentrations in ice and scanning electron micrographs of freeze-dried antifreeze solutions indicate that the antifreezes are incorporated in ice during freezing. The antifreezes also have a pronounced effect on the crystal habit of ice grown in their presence. Each of four antifreezes investigated caused ice to grow in long needles whose axes were parallel to the ice c axis. Together these results indicate the antifreezes adsorb to ice surfaces and inhibit their growth. A model in which adsorbed antifreezes raise the curvature of growth steps on the ice surface is proposed to account for the observed depression of the temperature at which freezing occurs and agrees well with experimental observations. The model is similar to one previously proposed for other cases of crystal growth inhibition.
PubMed ID
267952 View in PubMed
Less detail

Adverse health events associated with antimicrobial drug resistance in Campylobacter species: a registry-based cohort study.

https://arctichealth.org/en/permalink/ahliterature58186
Source
J Infect Dis. 2005 Apr 1;191(7):1050-5
Publication Type
Article
Date
Apr-1-2005
Author
Morten Helms
Jacob Simonsen
Katharina E P Olsen
Kare Mølbak
Author Affiliation
Department of Epidemiology Research, Danish Epidemiology Science Centre, Copenhagen, Denmark.
Source
J Infect Dis. 2005 Apr 1;191(7):1050-5
Date
Apr-1-2005
Language
English
Publication Type
Article
Keywords
Adult
Aged
Anti-Bacterial Agents - pharmacology
Campylobacter - drug effects - isolation & purification - pathogenicity
Campylobacter Infections - complications - epidemiology - microbiology - mortality
Cohort Studies
Denmark
Drug Resistance, Bacterial
Erythromycin - pharmacology
Female
Humans
Infant
Male
Microbial Sensitivity Tests
Middle Aged
Quinolones - pharmacology
Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.
Risk factors
Virulence
Abstract
BACKGROUND: Resistance to clinically important antimicrobial agents, particularly fluoroquinolones and macrolides, is increasing among Campylobacter isolates, but few studies have explored the human health consequences of such resistance. METHODS: In a registry-based cohort study, we determined the risk of invasive illness and death associated with infection with quinolone- and erythromycin-resistant Campylobacter strains, while adjusting for comorbidity. We linked data from the Danish Surveillance Registry for Enteric Pathogens with data from the Civil Registration System and National Health Registries. RESULTS: Of 3471 patients with Campylobacter infection, 22 (0.63%) had an adverse event, defined as invasive illness or death, within 90 days of the date of receipt of samples. Patients infected with quinolone-resistant Campylobacter strains had a 6-fold increased risk of an adverse event within 30 days of the date of receipt of samples, compared with patients infected with quinolone- and erythromycin-susceptible Campylobacter strains (adjusted odds ratio [AOR], 6.17 [95% confidence interval {CI}, 1.62-23.47]). However, infection with erythromycin-resistant strains was associated with a >5-fold risk of an adverse event within 90 days of the date of receipt of samples (AOR, 5.51 [95% CI, 1.19-25.50]). CONCLUSIONS: The present study provides evidence of the human health consequences of resistance to clinically important agents among Campylobacter infections and the need for increased efforts to mitigate such resistance.
Notes
Comment In: J Infect Dis. 2005 Apr 1;191(7):1029-3115747234
Comment In: J Infect Dis. 2005 Dec 1;192(11):2027-8; author reply 2028-916267777
Erratum In: J Infect Dis. 2005 May 1;191(9):1570
PubMed ID
15747238 View in PubMed
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Affective responses to changes in day length in Siberian hamsters (Phodopus sungorus).

https://arctichealth.org/en/permalink/ahliterature45723
Source
Psychoneuroendocrinology. 2005 Jun;30(5):438-52
Publication Type
Article
Date
Jun-2005
Author
Brian J Prendergast
Randy J Nelson
Author Affiliation
Department of Psychology, University of Chicago, Chicago, IL 60637, USA. prendergast@uchicago.edu
Source
Psychoneuroendocrinology. 2005 Jun;30(5):438-52
Date
Jun-2005
Language
English
Publication Type
Article
Keywords
Animals
Anxiety - psychology
Attention - physiology
Behavior, Animal - physiology
Body Weight - physiology
Conflict (Psychology)
Cricetinae
Depression - psychology
Emotions - physiology
Exploratory Behavior - physiology
Female
Light
Motor Activity - physiology
Muscle, Skeletal - physiology
Phodopus
Photoperiod
Research Support, U.S. Gov't, Non-P.H.S.
Research Support, U.S. Gov't, P.H.S.
Smell - physiology
Startle Reaction - physiology
Swimming - psychology
Abstract
The goal of these experiments was to test the hypothesis that day length influences anxious- and depressive-like behaviors in reproductively photoperiodic rodents. Male and female Siberian hamsters (Phodopus sungorus) were exposed to long (16 h light/day; LD) or short (8 h light/day; SD) photoperiods beginning at the time of weaning (day 18). Two weeks later hamsters were subjected to a series of behavioral tests to quantify anxiety-and depressive-like behaviors. In an elevated plus maze, SD males exhibited longer latencies to enter an open arm, entered fewer open arms, and spent less time exploring open arms relative to LD hamsters. SD males were likewise slower to enter either of the distal arms of a completely enclosed T-maze, and in a hunger-motivated exploratory paradigm SD males were slower to enter an open arena for food as compared to LD males. In a forced-swimming model of behavioral despair, SD males exhibited immobility sooner, more often, and for a greater total amount of time relative to LD males. Total activity levels, aversiveness to light, olfactory function, and limb strength were unaffected by SD, suggesting that the behavioral changes consequent to SD are not attributable to sensory or motor deficits, but rather may arise from changes in general affective state. The anxiogenic and depressive effects of SD were largely absent in female hamsters. Together the results indicate that adaptation to short photoperiods is associated with increased expression of anxiety- and depressive-like behaviors relative to those observed under LD photoperiod conditions.
PubMed ID
15721056 View in PubMed
Less detail

Age- and sex-related differences in opioid receptor densities in the songbird vocal control system.

https://arctichealth.org/en/permalink/ahliterature6796
Source
J Comp Neurol. 1999 Feb 22;404(4):505-14
Publication Type
Article
Date
Feb-22-1999
Author
C C Gulledge
P. Deviche
Author Affiliation
Institute of Arctic Biology, University of Alaska Fairbanks, 99775-7000, USA. cgulledg@emerald.tufts.edu
Source
J Comp Neurol. 1999 Feb 22;404(4):505-14
Date
Feb-22-1999
Language
English
Publication Type
Article
Keywords
Aging - physiology
Analgesics, Opioid - pharmacology
Animals
Autoradiography
Enkephalin, Ala(2)-MePhe(4)-Gly(5)-
Enkephalin, D-Penicillamine (2,5)-
Enkephalins - pharmacology
Female
Image Processing, Computer-Assisted
Male
Receptors, Opioid - physiology
Receptors, Opioid, delta - agonists - physiology
Receptors, Opioid, mu - agonists - physiology
Reproduction - physiology
Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.
Research Support, U.S. Gov't, P.H.S.
Sex Characteristics
Songbirds - physiology
Vocalization, Animal - physiology
Abstract
Avian vocal control regions of adult male songbirds contain opioid peptides and receptors, suggesting that opioids play a role in avian vocal behavior control. In a previous study, we found no difference in opioid receptor densities in singing versus nonsinging adult male dark-eyed juncos (Junco hyemalis), leading us to hypothesize that opioids are not involved in controlling song production. To assess whether opioids may be involved in other aspects of vocal behavior, we used quantitative in vitro autoradiography to compare mu and delta opioid receptor densities in vocal control regions of singing adult males with those of adult females and adolescent (about 3 months old) males and females. We found mu and delta receptors in all vocal control regions measured. Adolescents had significantly higher opioid receptor densities than did adults in area X (delta), robust n. of the archistriatum (delta and mu), and n. intercollicularis (mu), suggesting a developmental role for opioids in the vocal control system. Based on opioid roles in other animal models, we propose that opioids may be involved in song learning, auditory processing, and/or vocal control system development.
PubMed ID
9987994 View in PubMed
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508 records – page 1 of 51.