Capillary transport of adenosine

We tested the hypothesis that capillary exchange of adenosine is influenced by the ability of endothelial cells (ECs) to take up adenosine. Triple-indicator diffusion experiments were performed by injecting [14C]adenosine, [3H]9-beta-D-arabinofuranosylhypoxanthine ( [3H]araH), and radioiodinated serum albumin (RISA) into the arterial perfusate of isolated nonworking guinea pig hearts. Tracer appearance in venous effluent was observed over time. The early extraction of [14C]adenosine was much higher than that of [3H]araH. Extracted [3H]araH returned to the vascular space, but [14C]adenosine did not. Quantitative analysis of the curves by using a mathematical model indicates that approximately half of the extracted adenosine enters ECs and is metabolized. The remainder enters the interstitium and is taken up by myocytes, ECs, or other cells and is metabolized. We conclude that uptake of adenosine by ECs represents a significant influence on the capillary exchange of adenosine.     

Factors affecting radioactive microsphere measurement of blood flow in pregnant guinea pigs

Comparative blood flow studies were performed in pregnant guinea pigs using radioactive microspheres to test the effects of different sphere sizes on blood flow measurements and the relationship between flows obtained intraoperatively and those performed after 5 days of recovery from anesthesia and surgery. We observed that 1.5% of the cardiac output was shunted through the microcirculation of the carcass, gut, skin and endomyometrium when 15 mu microspheres were used. Intraoperative measurements of heart rate, cardiac output and placental blood flow are significantly lower than measurements made after 5 days recovery. These reductions were ameliorated with the addition of a continuous infusion of isoproterenol and the deletion of atropine from the anesthetic.     

Treatment of Used Diesel Invert Drilling Mud to Remove Hydrocarbons,Fix Lead,and Leach Brine

A sample of used, highly saline diesel invert drilling mud (DIDM), artificially contaminated with lead, was tested for remediation using ICPET/ NRC's Solvent Extraction Soil Remediation (SESR) process. The work comprised investigation of the concurrent solvent extraction of diesel oil and fixation of lead by co-agglomeration of metal binding agents. Peat, soluble and insoluble phosphates, coal combustion fly ashes, and flue gas desulfurization scrubber sludge were tested as lead fixation agents. Virtually complete extraction of diesel oil was achieved in a five-step extraction process using toluene, trichloroethylene, or hexane as solvents. The effect of the metal fixation agents on solvent extraction efficiency was also investigated. After remediation to remove hydrocarbons and fix heavy metals, the DIDM sample remained saline. Successful leaching of brine from the dried agglomerates was accomplished by water percolation through a fixed bed of the dried, agglomerated soil. The cleaned DIDM was evaluated for resistance to acid leaching of lead using the U.S.-EPA's toxicity test method 1310A and Toxicity Characteristics Leaching Procedure method 1311. Long-term stability of the treated solids to acid leaching was tested using the U.S.EPA's multiple extraction procedure method 1320. Bioavailability of fixed lead to barley plants grown on synthetic soils prepared from remediated DIDM was determined by analyzing the roots and shoots for lead content. Acid phosphatase, peroxidase, and protein levels were determined in plant roots and soil leachates by biochemical analysis methods. These results were used to assess the effect of enzymes produced by plant root systems, or soil associated microorganisms, on the stability of fixed lead. The presence of fixation agents reduced the bioavailability of lead to the plants.     

Bidirectional replication of the mini-ColE1 plasmid pVH51.

Replicating molecules of the min-ColE1 plasmid pVH51 have been examined by electron microscopy after cleavage with the restriction endonuclease EcoRI. Replication apparently starts at a unique site indistinguishable from the origin of replication used by the parental plasmid ColE1. In contrast to ColE1, the structure of the majority of the replication intermediates was consistent with a bidirectional mode of replication. A minor portion of the molecules appeared to replicate unidirectionally in either direction from the same origin.     

A coccidian infection of the kidney of the native littleneck clam, Protothaca staminea

During the summer of 1980, numerous exposed native littleneck clams (Protothaca staminea) were observed in Sequim Bay, Washington. The kidneys of these clams were found to be parasitized by a coccidian. Heavily parasitized kidney was characterized by massive epithelial destruction and an intense inflammatory response. In addition, large numbers of “brown cells” were present throughout the tissues of infected clams.Infected kidneys harbored several stages of the life history of the parasite. The present coccidian differs markedly in several respects from other coccidians in bivalves. First, the entire life history apparently occurs in the kidney of the clam, in contrast to the presumed involvement of an alternative host in other known coccidian parasites of bivalves. Second, a thick-walled spore is produced in addition to a thin-walled oocyst. The apparent presence of two types of dissemination stages is unknown in the Coccidia. Finally, the sporocysts are tetrazoic as opposed to dizoic or multiple sporocysts in previously described species. This parasite, therefore, appears to represent an undescribed genus and species of Coccidia.     

Effects of aspirin on renal sodium excretion,blood pressure,and plasma and extracellular fluid volume in salt-loaded rats

The effect of aspirin administration and presumed blockade of prostaglandin synthesis on renal sodium excretion, plasma and extracellular fluid volumes, and blood pressure were examined in rats on a high sodium intake. After acute salt loading aspirin treated rats showed an impaired sodium excretion, while no changes in glomerular filtration rate were observed. In chronically loaded rats (7 weeks) administration of aspirin induced significant increases in both plasma and extracellular fluid volume, but no significant changes in blood pressure were found. The results are consistent with the hypothesis that prostaglandins mediate renal sodium excretion and therefore participate in extracellular fluid volume regulation.     

AUSWIRKUNGEN VON INSEKTIZIDBEHANDLUNGEN AUF DIE EPIGÄISCHEN RAUBARTHROPODEN IN GETREIDEFELDERN,INSBESONDERE DIE LAUFKÄFER (COLEOPTERA,CARABIDAE)

Zusammenfassung Die Ergebnisse wurden mit Bodenfallen in Getreidefeldern erarbeitet. Fenitrothion beeinflußte bei Flugzeugausbringung in normaler Dosierung (600 g/ha in 40 1 Wasser) nur die Populationsdichte von Pterostichus vulgaris und P. niger vorübergehend. Eine Spritzung mit erhöhter Dosierung (900 g/ha in 350 1 Wasser) wirkte sehr stark auf die fünf häufigsten Carabidenarten ein. Parathion-äthyl beeinflußte in normaler Dosierung (125 g/ha in 300 1 Wasser) bei einer Behandlung Anfang Juni besonders einschneidend die Frühlingstiere, Ende Juni stark die Frühlings- und die Herbsttiere. In doppelter Dosierung reduzierte es alle wichtigen Prädatorengruppen sehr deutlich. Parathion-methyl (Staub) wirkte bei Ausbringung auf feuchte Pflanzen (200 g/ha) nicht stark auf die epigäischen Räuber. Nur kletternde Arten (Staphyliniden und Agonum dorsale) wurden geschädigt. Methoxychlor wirkte als Spritzmittel (600 g/ha in 300 1 Wasser) stark auf die großen Carabiden, während die kleinen Laufkäferarten, die Staphyliniden und Spinnen nicht beeinflußt wurden. Methoxychlor-Staub, auf die feuchten Pflanzen ausgebracht (1000 g/ha), beeinflußte die epigäischen Räuber nicht. Eine Randbehandlung eines Winterrapsfeldes mit Methoxychlor-Staub störte die Besiedlung des Feldes durch Carabiden und Staphyliniden nicht.

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Summary The influence of some insecticides often used in agriculture upon the terrestrial predaceous arthropods was investigated by pitfall trapping on cereal fields of about 10 hectares each, half the area of which was treated.Fenitrothion, sprayed by aeroplane at the normal dosage (600 g/ha in 40 1 water) influenced the abundance of Pterostichus vulgaris and P. niger only, for a short period. Spraying fenitrothion at a higher dosage (900 g/ha in 350 1 water) killed a high percentage of the five most common carabid species.Parathion-ethyl at the normal dosage (125 g/ha in 300 1 water), sprayed at the beginning of June reduced numbers of spring breeders especially (e.g. Pterostichus cupreus). Sprayed at the end of June, it influenced both spring and autumn breeders (e.g. P. vulgaris). Rain, falling one day after the insecticide treatment, did not alter its effect upon the terrestrial predators. At a higher dosage (250 g/ha) parathion-ethyl reduced numbers of all predators to a large extent, but not very much more than at the normal dosage.Parathion-methyl dust, applied to moist plants (200 g a.i./ha), did not influence all terrestrial predators, but only those species which also climb up the plants (some staphylinids and Agonum dorsale).Methoxychlor emulsion, sprayed at a dosage of 600 g/ha in 300 1 water, killed the bigger ground beetles only (Carabus spp. and P. vulgaris), but not the smaller ones (Agonum dorsale and Bembidion lampros), the staphylinids and the spiders. Methoxychlor, dust, applied to moist plants (1000 g a.i./ha) did not influence the terrestrial predators. Treating the edge only (ca. 20 m) of a winter-rape field with methoxychlor dust did not prevent the colonization of the field by carabids and staphylinids. It is recommended, therefore, to treat the field edges only, which should control most cereal pests.

     

The hyperaccumulator Alyssum murale uses complexation with nitrogen and oxygen donor ligands for Ni transport and storage

The Kotodesh genotype of the nickel (Ni) hyperaccumulator Alyssum murale was examined to determine the compartmentalization and internal speciation of Ni, and other elements, in an effort to ascertain the mechanism used by this plant to tolerate extremely high shoot (stem and leaf) Ni concentrations. Plants were grown either hydroponically or in Ni enriched soils from an area surrounding an historic Ni refinery in Port Colborne, Ontario, Canada. Electron probe micro-analysis (EPMA) and synchrotron based micro X-ray fluorescence (μ-SXRF) spectroscopy were used to determine the metal distribution and co-localization and synchrotron X-ray and attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopies were used to determine the Ni speciation in plant parts and extracted sap. Nickel is concentrated in the dermal leaf and stem tissues of A. murale bound primarily to malate along with other low molecular weight organic ligands and possibly counter anions (e.g., sulfate). Ni is present in the plant sap and vasculature bound to histidine, malate and other low molecular weight compounds. The data presented herein supports a model in which Ni is transported from the roots to the shoots complexed with histidine and stored within the plant leaf dermal tissues complexed with malate, and other low molecular weight organic acids or counter-ions.     

Examining the total arrival distribution of migratory birds

This paper reports on the total distribution of spring migration timing of willow warbler, chiffchaff and pied flycatcher at locations in the UK, Germany, Russia and Finland. This is the first time that high‐quality data based on known‐effort monitoring has been examined on a continental scale. First arrival dates, commonly reported in the literature, were positively correlated with mean arrival dates although they would not make good predictors of the latter. At all locations, at least one aspect of the arrival distribution of each species had got significantly earlier in recent years. The trend towards earliness was associated with warmer local temperatures and more positive winter North Atlantic Oscillation index. In years that were early, the arrival distribution became more elongated and skewed. Researchers should now investigate the consequences of earlier arrival on current and future bird populations.