Contribution of water chemistry and fish condition to otolith chemistry: comparisons across salinity environments.

This study quantified the per cent contribution of water chemistry to otolith chemistry using enriched stable isotopes of strontium ((86) Sr) and barium ((137) Ba). Euryhaline barramundi Lates calcarifer, were reared in marine (salinity 40), estuarine (salinity 20) and freshwater (salinity 0) under different temperature treatments. To calculate the contribution of water to Sr and Ba in otoliths, enriched isotopes in the tank water and otoliths were quantified and fitted to isotope mixing models. Fulton's K and RNA:DNA were also measured to explore the influence of fish condition on sources of element uptake. Water was the predominant source of otolith Sr (between 65 and 99%) and Ba (between 64 and 89%) in all treatments, but contributions varied with temperature (for Ba), or interactively with temperature and salinity (for Sr). Fish condition indices were affected independently by the experimental rearing conditions, as RNA:DNA differed significantly among salinity treatments and Fulton's K was significantly different between temperature treatments. Regression analyses did not detect relations between fish condition and per cent contribution values. General linear models indicated that contributions from water chemistry to otolith chemistry were primarily influenced by temperature and secondly by fish condition, with a relatively minor influence of salinity. These results further the understanding of factors that affect otolith element uptake, highlighting the necessity to consider the influence of environment and fish condition when interpreting otolith element data to reconstruct the environmental histories of fish.

Rodlet cells in Murray cod, Maccullochella peelii peelii (Mitchell), affected with chronic ulcerative dermatopathy.

We have previously identified an unknown cell type in the gills of Murray cod affected with chronic ulcerative dermatopathy (CUD), a condition that causes severe erosion of epidermis surrounding cephalic and lateral line sensory canals. The condition arises in aquaculture facilities that utilize groundwater, with the cause of the condition suggested to be an unknown contaminant(s). Light and transmission electron microscopy were used to characterize and quantify the unknown cells in CUD-affected Murray cod. The cells were identified as rodlet cells and were characterized by their oval or round shape, basally located nucleus, thick fibrillar capsule surrounding the cell, and multiple rodlet sacs containing a central electron-dense core within the cell. Rodlet cells were present in the gills, kidney and intestine of non-CUD-affected and CUD-affected Murray cod; however, differences in the numbers were observed between the groups of fish. A significantly greater number of rodlet cells were observed in the gills and collecting ducts of CUD-affected fish. This is the first report of rodlet cells in Murray cod, and we suggest that the increased rodlet cell numbers in CUD-affected Murray cod may be in response to unknown water contaminant(s) present in the groundwater that give rise to CUD.

Ultrasound-guided biopsy of the equine forelimb proximal suspensory ligament by longitudinal access / [Biópsia guiada por ultrassom da origem do ligamento suspensor do boleto de equinos por acesso longitudinal]

A literatura atual discute múltiplas modalidades de imagem para acompanhar o processo de cicatrização da origem do ligamento suspensor do boleto (LSB) em equinos, mas nenhuma pode garantir que eles possuam fibras colágenas com calibre suficiente para suportar o retorno ao exercício. Já as técnicas morfológicas e bioquímicas, bem como a análise de birrefringência, podem ser mais apropriadas para caracterizar o processo de cicatrização e avaliar a eficiência do tratamento. O objetivo deste artigo é descrever procedimento simples que possibilita a coleta de amostras teciduais de boa qualidade e em sentido longitudinal, por biópsia em equinos em estação. Após antissepsia local, sedação e bloqueio do nervo palmar lateral no aspecto medial do osso acessório do carpo (OAC), o membro foi colocado em suspensão com o carpo flexionado em 90º; a agulha de biópsia guiada por ultrassom foi introduzida em sentido distoproximal, 11 a 13cm distal ao OAC, ângulo de 20º em relação ao LSB, até a região de sua origem. O equipamento foi disparado e coletou-se a amostra tecidual. Essa técnica possibilitou a coleta de fragmentos de boa qualidade para análise histológica e de birrefringência, sem reações adversas, podendo ser usada em modelos experimentais ou na prática clínica.(AU)

Asymmetric syntheses, opioid receptor affinities, and antinociceptive effects of 8-amino-5,9-methanobenzocyclooctenes, a new class of structural analogues of the morphine alkaloids.

Several 8-amino-5,9-methanobenzocyclooctenes have been prepared by asymmetric organic synthesis techniques. Opioid receptor affinity studies have revealed the virtual absence of enantioselectivity for receptor binding, particularly at the mu-receptor, for the (+)-3a-f and the (-)-3a-f series. It is noteworthy that inversion of configuration at the nitrogen-bearing carbon atom [5S,8S,9S)-8-amino-3-hydroxy-5, 9-methano-9-(methoxymethyl)-5-methylbenzocyclooctene, (+)-3a vs (5S,8S,9R)-8-amino-3-hydroxy-5, 9-methano-9-(methoxymethyl)-5-methylbenzocyclooctene, (dl)-22] resulted in a > 10-fold increase in kappa-receptor affinity. Antinociceptive studies demonstrated that (dl)-22 was a full kappa-agonist while (+)-3a and (-)-3a did not possess kappa-activity. Although both (dl)-22 and (+)-3a/(-)-3a had high affinity for the mu-receptor, these compounds did not act as high-affinity agonists or antagonists at this receptor.

Preparation and photochemical rearrangements of 2-phenyl-2,5-cyclohexadien-1-ones. an efficient route to highly substituted phenols.

[reaction: see text]. The synthesis of 2-phenyl-2,5-cyclohexadien-1-ones 1a-c and 2a-b from methyl 3-phenylbenzoate 4 and methyl 2-methoxy-5-phenylbenzoate 8 by the Birch reduction alkylation methodology is described. 1a-c and 2a-b undergo regiospecific photorearrangements at 300 nm to give tetrasubstituted phenols 14a-c and pentasubstituted phenols 18a-b, respectively. The type A photoproducts 17a-b resulting from irradiation of 2a-b at 366 nm have been isolated as approximately 1:1 diastereomer mixtures. When an optimized condition is applied, a single diastereomer of 17a is obtained.

Metopon and two unique derivatives: affinity and selectivity for the multiple opioid receptors.

5 beta-Methyl-7,8-dihydromorphinone (metopon), an isomer [6aS-(6a alpha,9a alpha, 10 beta)13aS]-1,10-methano-4-hydroxy-11-methyl- 6,6a,8,9,10,11,12,13-octahydro-[1]-benzopyrano[4,3,e]isoquinoline- 7-(9aH)-one (compound 1) derived from a photochemical rearrangement of 5 beta-methylmorphinone, and [6aS-(6a alpha,9a alpha,10 beta)13aS]-1,10-methano-4-hydroxy-11-methyl- 6,6a,8,9, 10,11,12,13-octahydro-[1]-benzopyrano[4,3,e]-14 beta- (p-nitrocinnamoylamino) isoquinoline-7-(9aH)-one (compound 2) were characterized for opioid receptor affinity, selectivity and analgesic properties. In competition binding assays using bovine striatal membranes, the three compounds inhibited the binding of 0.25 nM [3H][D-Ala2,(Me)-Phe4,Gly(ol)5]enkephalin (DAMGO), a mu-selective peptide, with IC50 values less than 5 nM. All three compounds exhibited lower affinity for delta- and kappa-opioid receptors. In the mouse 55 degrees C warm-water tail-flick assay, both metopon and compound 1 displayed antinociception that lasted for 60 min after i.c.v. injection. Morphine sulfate, metopon and compound 1 produced 50% antinociception with i.c.v. doses of 0.83, 2.0 and 4.0 nmol, respectively. The mu-selective, irreversible opioid receptor antagonist beta-funaltrexamine blocked antinociception induced by metopon and compound 1, while delta- and kappa-opioid receptor selective antagonists did not effect antinociception. These findings demonstrate metopon and its isomer bound with high affinity to the mu-opioid receptor and produced antinociception through this receptor.

Photoaffinity ligands for the mu opioid receptor.

Two affinity ligands, 6 beta-(5-Azido-2-nitrophenacetamido) 14 beta-hydroxy-7,8-dihydromorphinone (4) and 6 beta-(5-azido-2-nitrophenacetamido) 14 beta-hydroxy-7,8-dihydro-N- cyclopropylmethylnormorphinone (5) bind reversibly to opioid receptors present in bovine caudate membranes and photolyse in a range of wavelengths centered about 366 nm to produce wash-resistant binding to the mu receptor. At these wavelengths very little if any photodestruction of the mu receptor occurs over the 20 minute period of irradiation at 0 degree C.

New substituent effects of the trimethylsilyl group: photochemistry of 3-trimethylsilyl-2,5-cyclohexadienones and preparation of 4-alkylidenecyclopentenones.

The 4-acetoxymethyl-4-alkyl-3-trimethylsilyl-2,5-cyclohexadien-1-ones 9a-g were prepared from methyl 2-trimethylsilylbenzoate by the Birch reduction-alkylation reaction. Type A photorearrangements of 9a-g were regiospecific to give mixtures of two diastereomers of the corresponding 5-trimethylsilylbicyclo[3.1.0]hex-3-en-2-ones 11a-g. These bicyclohexenones are uniquely photostable; the diastereomers do not photointerconvert nor do they undergo the type B photorearrangement. Bicyclohexenones 11a-g undergo acid-catalyzed protiodesilylative rearrangement to give the 4-alkylidene-2-cyclopenten-1-ones 25a-g. It was of interest to find that the 4-(3'-butenyl)-2,5-cyclohexadienone 9e photorearranged to the 5-trimethylsilylbicyclo[3.1.0]hex-3-en-2-one 11e rather than undergoing the intramolecular 2 + 2 photocycloaddition. Furthermore, the 4-acetoxymethyl-3-methoxy-4-methyl-5-trimethylsilyl-2,5-cyclohexadienone 30a did not show type A photobehavior at 366 and 300 nm, while the 4-(3'-butenyl) analogue 30b gave the intramolecular 2 + 2 cycloadduct 31b. The effects of the trimethylsilyl and methoxy substituents on the photochemical reactivity of 2,5-cyclohexadien-1-ones are discussed from the perspective of n --> p* vs pi --> p* character of the triplet states of the dienones.

Decahydroquinoline alkaloids: noncompetitive blockers for nicotinic acetylcholine receptor-channels in pheochromocytoma cells and Torpedo electroplax.

In pheochromocytoma PC12 cells, (+)-cis-decahydroquinoline 195A (5-methyl-2-propyl-cis-decahydroquinoline) and (+)-perhydro-cis-decahydroquinoline 219A (2,5-dipropyl-cis-decahydroquinoline) inhibit carbamylcholine-elicited sodium flux with IC50 values of 1.0 and 1.5 microM, respectively. Both of these decahydroquinolines appear to enhance desensitization, although apparent lack of complete removal of (+)-perhydro-cis-219A by washing complicates interpretation of the effects of that agent. A series of cis- and trans-decahydroquinolines with substituents in the 2- and 5-position also exhibit structure-dependent inhibition of carbamylcholine-elicited sodium flux in PC12 cells and all of the decahydroquinolines inhibit binding of the noncompetitive blocking agent [3H]perhydrohistrionicotoxin to muscle-type nicotinic acetylcholine receptor-channels in membranes from Torpedo electroplax. The Ki values in electroplax membranes range from 1.4 to 7.9 microM, making these alkaloids comparable in potencies to the histrionicotoxins. Potencies are increased 2- to 3-fold in the presence of an agonist, carbamylcholine. The profile of activities are similar in PC12 cells and electroplax membranes. The cis- and trans-decahydroquinolines represent another class of noncompetitive blockers for acetylcholine receptor-channels with similar activity for both muscle-type and ganglionic type nicotinic receptors.