The meiofauna of hydrothermal deep-sea sediments in the North Fiji Basin (NE Pacific) was investigated. Nematodes were the dominant taxon. The structure of the hydrothermal nematode communities from the Fiji Basin is compared with (1) the communities from adjacent oxic deep-sea sediments. ( 2 ) other hydrothermal vent areas and (3) shallow reduced environments such as cold seeps and subsurface anoxic sediments of eutrophic bottoms. Although the genus composition of the hydrothermal area and the biodiversity on a generic or functional-morphological level did not deviate greatly from the control areas, we found differences at the species level and in the size spectra and the species diversity. None of the species found in the hydrothermal sediments occurred in the surrounding areas. The size spectra of the vent communities was shifted towards larger nematodes, and species diversity was much lower in the hydrothermal area. The similarity in nematode genus composition between hydrothermal sites and control areas stands in contrast with the presence of a specialized endemic hydrothermal macrofauna. The absence of a planktonic life stage, in combination with small size, makes it more difficult for nematode species to migrate between isolated hydrothermal patches.

1 The in¯uence of the cannabinoids anandamide, methanandamide and WIN 55212-2 on the delayed recti®er K + current (I K(V) ) in rat arterial myocytes was investigated. 2 Anandamide caused a concentration-dependent reduction of total peak and late K + current (I K ). The maximal eect (about 50% inhibition of I K ) was reached with 3 mM, and half-maximal current block was observed at 0.6 mM. Blockade was voltage-independent. Inhibition of I K by the cannabinoid was associated with a characteristic increase in the rate of current relaxation. 3 Methanandamide (10 mM), a metabolically more stable analogue of anandamide, decreased I K with a similar time course. Current traces in the presence of the drug also showed an acceleration of inactivation. 4 The presence of TEA did not impair the inhibition by anandamide or methanandamide, but inhibition was prevented by pre-exposure to 4-AP, showing that both cannabinoids inhibited I K(V) while having no in¯uence on Ca 2+-dependent K + current (I K(Ca) ). 5 The CB 1 receptor antagonist SR141716A (10 mM) did not in¯uence the action of anandamide or methanandamide. 6 Arachidonic acid (1 mM) increased I K considerably. However, in the presence of TEA it caused a decrease of I K(V) with a characteristic increase in the rate of current relaxation. 7 WIN 55212-2 (20 mM) caused similar inhibition of I K . 8 Internally applied anandamide (10 mM) or methanandamide (10 mM) was ineective at in¯uencing I K . In the dialyzed cells, the additional external application of a cannabinoid promptly initiated inhibition. 9 The results show that anandamide, methanandamide and WIN 55212-2 aect I K(V) in a cannabinoid receptor-independent way similar to that of arachidonic acid, which, unlike the cannabinoids, additionally increases a Ca 2+ -activated K + current. It is suggested that cannabinoids might bind to an external site on or near the K v channel of the vascular smooth muscle cells.

The hyperpolarizing factor that is liberated by vascular endothelial cells in response to various agonists, and known to induce relaxation by opening of smooth muscle K+ channels, has been suggested to be a product of cytochrome P450 dependent arachidonic acid metabolism. In this study, the direct influence of two phospholipase A2 inhibitors and of five structurally and mechanistically different cytochrome P450 inhibitors on K+ currents in freshly isolated vascular smooth muscle cells from the rat aorta was investigated. On stepping the cell membrane potential from -70 mV to a series of depolarized test potentials, a noisy outward current developed at test potentials > +10 mV, which showed no appreciable inactivation during the voltage pulse. It was largely abolished by 3 mM external tetraethylammonium chloride (TEA), suggesting that it predominantly consisted of current through large-conductance Ca(2+)-activated K+ channels. The phospholipase A2 inhibitor quinacrine considerably inhibited this TEA-sensitive current, while 4-bromophenacylbromide exerted no effect. The cytochrome P450 inhibitors proadifen and miconazole reversibly decreased the amplitude of I(K), while clotrimazole and 1-aminobenzotriazole had no effect. Conversely, 17-octadecynoic acid increased whole-cell I(K). These results show that some phospholipase A2 and cytochrome P450 inhibitors may interfere with K+ channel activation in the rat arterial smooth muscle cell. The relevance of these findings to studies on the involvement of cytochrome P450 dependent metabolism in the generation of the endothelium-derived hyperpolarizing factor in intact arteries is discussed.

Acute pancreatitis is a (usually sterile) inflammation with acute onset and characterized by necrosis and edema; it does not permanently disrupt the pancreatic architecture and is completely reversible. It is thought that, despite the pancreatic defense mechanisms, premature activation of trypsin in the acinar cells starts a cascade of reactions that result in autodigestion. Most cases are idiopathic. Dogs are often presented with gastrointestinal signs, whereas lethargy and anorexia are the most commonly observed symptoms in cats. Diagnosing pancreatitis remains a challenge, but the recent development of the pancreatic lipase immunoreactivity test is promising. SAMENVATTINGAcute pancreatitis is een plotse (meestal steriele) ontsteking die de structuur van de pancreas niet definitief aantast en die compleet reversibel is. Deze ontsteking wordt gekarakteriseerd door necrose en oedeem. Er wordt verondersteld dat, ondanks verdedigingsmechanismen, een vroegtijdige activering van trypsin in de acinaire cellen een cascade van reacties veroorzaakt met autodigestie tot gevolg. De meeste gevallen zijn idiopathisch. Honden worden vaak aangeboden met gastro-intestinale klachten, terwijl lethargie en anorexie de meest voorkomende symptomen zijn bij katten. Het diagnosticeren van pancreatitis blijft een uitdaging maar de recente ontwikkeling van de "pancreatic lipase immunoreactivity" test is veelbelovend.

Diagnosing acute pancreatitis in dogs and cats is difficult. Abdominal ultrasonography provides specific information about the size, shape and homogeneity of the pancreas, but is very dependent on the experience of the operator and the quality of the echography machine. Abdominal radiography is less useful, while computed tomography is less practicable in veterinary patients because of the anesthesia risks, the need for experienced operators, and the high cost. Furthermore, computed tomography has low diagnostic value in cats. Biopsy of pancreatic tissue remains the gold standard. Treatment consists of fluid therapy and nutritional support, combined with pain medication, anti-emetics and antibiotics. The prognosis in dogs and cats is variable and largely depends on the clinical condition of the patient at admission. It is usually guarded, especially in cats. SAMENVATTINGHet diagnosticeren van acute pancreatitis bij honden en katten is moeilijk. Abdominale echografie verschaft specifieke informatie over de grootte, vorm en homogeniciteit van de pancreas maar is erg afhankelijk van de ervaring van de uitvoerder en de kwaliteit van het echografietoestel. Radiografieën van het abdomen zijn minder nuttig, terwijl computertomografie minder bruikbaar is bij diergeneeskundige patiënten omwille van het anesthesierisico, de nood aan ervaren uitvoerders en de hoge kostprijs. Bovendien heeft computertomografie een lage diagnostische waarde bij de kat. De biopsie van pancreasweefsel blijft de gouden standaard. De behandeling omvat vloeistoftherapie en nutritionele ondersteuning in combinatie met pijnmedicatie, anti-emetica en antibiotica. De prognose bij de hond en de kat is variabel en afhankelijk van de klinische toestand van de patiënt op het tijdstip dat hij aangeboden wordt, maar ze is meestal gereserveerd, vooral bij katten.