BKCa-Cav channel complexes mediate rapid and localized Ca2+-activated K+ signaling     

Berkefeld H  Sailer CA  Bildl W  Rohde V  Thumfart JO  Eble S  Klugbauer N  Reisinger E  Bischofberger J  Oliver D  Knaus HG  Schulte U  Fakler B 《Science (New York, N.Y.)》2006,314(5799):615-620

Large-conductance calcium- and voltage-activated potassium channels (BKCa) are dually activated by membrane depolarization and elevation of cytosolic calcium ions (Ca2+). Under normal cellular conditions, BKCa channel activation requires Ca2+ concentrations that typically occur in close proximity to Ca2+ sources. We show that BKCa channels affinity-purified from rat brain are assembled into macromolecular complexes with the voltage-gated calcium channels Cav1.2 (L-type), Cav2.1 (P/Q-type), and Cav2.2 (N-type). Heterologously expressed BKCa-Cav complexes reconstitute a functional "Ca2+ nanodomain" where Ca2+ influx through the Cav channel activates BKCa in the physiological voltage range with submillisecond kinetics. Complex formation with distinct Cav channels enables BKCa-mediated membrane hyperpolarization that controls neuronal firing pattern and release of hormones and transmitters in the central nervous system.  相似文献   

Early reactivation of European rivers during the last deglaciation   总被引：1，自引：0，他引：1  

Ménot G  Bard E  Rostek F  Weijers JW  Hopmans EC  Schouten S  Sinninghe Damsté JS 《Science (New York, N.Y.)》2006,313(5793):1623-1625

During the Last Glacial Maximum, the sea-level lowstand combined with the large extent of the Fennoscandian and British ice sheets led to the funneling of European continental runoff, resulting in the largest river system that ever drained the European continent. Here, we show an abrupt and early reactivation of the European hydrological cycle at the onset of the last deglaciation, leading to intense discharge of the Channel River into the Bay of Biscay. This freshwater influx, probably combined with inputs from proglacial or ice-dammed lakes, dramatically affected the hydrology of the region, both on land and in the ocean.  相似文献   

Effects of oral administration of controlled-ileal-release budesonide and assessment of pituitary-adrenocortical axis suppression in clinically normal dogs     

Stroup ST  Behrend EN  Kemppainen RJ  Smith-Carr S 《American journal of veterinary research》2006,67(7):1173-1178

OBJECTIVE: To evaluate the effects of oral administration of controlled-ileal-release (CIR) budesonide on the pituitary-adrenal axis in dogs with a normal gastrointestinal mucosal barrier. ANIMALS: 10 healthy dogs. PROCEDURES: 5 dogs received CIR budesonide orally once daily for days 1 through 28, and 5 dogs received placebo. Treatment group dogs that weighed < 18 kg received 2 mg of CIR budesonide; treatment group dogs that weighed > or = 18 kg received 3 mg of CIR budesonide. In the treatment and placebo groups, there were 3 and 2 dogs, respectively, that weighed > 18 kg. Plasma cortisol concentration before and after ACTH stimulation, basal plasma endogenous ACTH concentration, and body weight were measured on days 0, 7, 14, 21, 28, and 35. Serum biochemical analysis, CBC determination, and urinalysis were performed on days 0, 28, and 35. On days 7, 14, and 21, serum ALP and ALT activities, serum glucose concentration, and urine specific gravity were obtained in lieu of a full hematologic evaluation and urinalysis. RESULTS: Basal and post-ACTH stimulation plasma cortisol concentrations and plasma endogenous ACTH concentration were significantly suppressed by treatment. No other variables were altered over the course of the study. CONCLUSIONS AND CLINICAL RELEVANCE: Budesonide suppresses pituitary-adrenal function in dogs with normal gastrointestinal integrity, whereas other variables often affected by glucocorticoids were not altered by a 4-week treatment course. Budesonide may be a good alternative to traditional cortico-steroids if used short-term for acute exacerbations of inflammatory bowel disease.  相似文献   

What is your diagnosis? Mass of hair on left side of the nasal choanae     

Siedlecki ED  Gamblin RM  Fagin B 《Journal of the American Veterinary Medical Association》2006,228(8):1195-1196

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Comparing apparent electrical conductivity measurements on a paddy field under flooded and drained conditions     

Mohammad Monirul Islam  Eef Meerschman  Timothy Saey  Philippe De Smedt  Ellen Van De Vijver  Marc Van Meirvenne 《Precision Agriculture》2012,13(3):384-392

Every growing season, paddy fields are kept both flooded and drained for a significant period of time. As a consequence, these soils develop distinct physico-chemical characteristics. For practical reasons, these soils are mostly sampled under dry conditions, but the question arises how representative the results are for the wet growing conditions. Therefore, the apparent electrical conductivity (EC_a) of a 1.4 ha alluvial paddy field located in the Brahmaputra floodplain of Bangladesh was measured in both dry and wet conditions by a sensing system using the electromagnetic induction sensor EM38, which does not require physical contact with the soil, and compared both surveys. Due to the smooth water surface under wet conditions which ensured increased stability of the sensing platform, the results of the survey showed considerably reduced micro-scale variability of EC_a. Furthermore, the wet survey results more reliably furnished soil-related information mainly due to the absence of soil moisture dynamics. The differences between EC_a under wet and dry conditions were attributed to differences in soil texture, mainly the sand content variation having considerable effect on soil moisture differences when flooded following drainage. Accordingly, the largest differences between EC_a under wet and dry conditions were found in those parts of the field with a large sand content. Hence, the conclusion was that an EC_a survey on flooded fields has an added value to precision soil management.  相似文献   

IBI* series winner. Discovering nanoscience     

AC Blair  ER Fisher  D Rickey 《Science (New York, N.Y.)》2012,337(6098):1056-1057

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Triterpene saponins of Quillaja saponaria show strong aphicidal and deterrent activity against the pea aphid Acyrthosiphon pisum     

De Geyter E  Smagghe G  Rahbé Y  Geelen D 《Pest management science》2012,68(2):164-169

BACKGROUND: Saponins are a class of secondary plant metabolites consisting of a sugar moiety glycosidically linked to a hydrophobic aglycone (sapogenin) that often possess insecticidal activities. Four saponins were selected: two triterpene saponins, Q. saponaria saponins and aescin, and two steroidal saponins, digitonin and diosgenin. Their effects were investigated on an important pest species and a model piercing‐sucking insect, the pea aphid Acyrthosiphon pisum. The triterpene Q. saponaria saponins bark saponin received special attention because of its high activity. Aphids were challenged by oral and contact exposure to demonstrate aphicidal activities, and in choice experiments to support use as a natural deterrent. RESULTS: When aphids were exposed to supplemented artificial diet for 3 days, a strong aphicidal activity was recorded for three of the four saponins, with an LC₅₀ of 0.55 mg mL^?1 for Q. saponaria saponins, 0.62 mg mL^?1 for aescin and 0.45 mg mL^?1 for digitonin. The LT₅₀ values ranged between 1 and 4 days, depending on the dose. For diosgenin, only low toxicity (14%) was scored for concentrations up to 5 mg mL^?1. In choice experiments with treated diet, a deterrence index of 0.97 was scored for Q. saponaria saponins at 1 mg mL^?1. In contrast, direct contact showed no repellent effect. Spraying of faba bean plants with Q. saponaria saponins resulted in an LC₅₀ of 8.2 mg mL^?1. Finally, histological analysis in aphids fed with Q. saponaria saponins demonstrated strong aberrations of the aphid gut epithelium, and exposure of midgut CF‐203 cell lines to Q. saponaria saponins in vitro confirmed the cytotoxic effect. CONCLUSIONS: The present insect experiments provide strong evidence that saponins, as tested here with triterpene Q. saponaria saponins, can be useful as natural aphicides and deterrents. Furthermore, the insect midgut epithelium is suggested to be a primary target of saponin activity.Copyright © 2011 Society of Chemical Industry  相似文献   

Seasonal variation in results of diagnostic tests for pituitary pars intermedia dysfunction in older, clinically normal geldings     

CM Schreiber  AJ Stewart  E Kwessi  EN Behrend  JC Wright  RJ Kemppainen  KA Busch 《Journal of the American Veterinary Medical Association》2012,241(2):241-248

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Identification of Arcanobacterium (Trueperella) abortisuis, a novel species of veterinary importance, by matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS)     

Hijazin M  Ulbegi-Mohyla H  Alber J  Lämmler C  Hassan AA  Timke M  Kostrzewa M  Prenger-Berninghoff E  Weiss R  Zschöck M 《Berliner und Münchener tier?rztliche Wochenschrift》2012,125(1-2):32-37

In the present study A. (T.) abortisuis isolated from pigs and bovines could be reliably identified by determination of phenotypic properties, genotypically by polymerase chain reaction with the help of A. (T.) abortisuis 16s-23S rDNA intergenic spacer region specific oligonucleotide primer and by Matrix-Assisted Laser Desorption Ionization-Time Of Flight mass spectrometry (MALDI-TOF MS). The latter appeared to be a promising tool for fast and cost effective identification of this species and might help to elucidate the role A. (T.) abortisuis plays in infections of pigs, bovines, possibly other animals or humans.  相似文献   

Adverse reactions to equine‐derived F(ab’)2‐antivenin in 54 dogs envenomated by Vipera berus berus     

Heidi S. Lund DVM  Veronica Kristiansen DVM  Anna V. Eggertsdóttir DVM  PhD  Ellen Skancke DVM  PhD  Birgit Ranheim DVM  PhD 《Journal of Veterinary Emergency and Critical Care》2013,23(5):532-537

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