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Species-specific microenvironmental preferences and interactions between parasite species have been the focus of many ecological studies. Here, we studied the distribution of ectoparasite species within the gill apparatus of bream (Abramis brama) from Lake Lubāns (Latvia) to establish whether digenean metacercariae: (1) prefer specific patches within the gill apparatus; (2) co-occur in the same patches with monogeneans and copepods within a host individual; and (3) interact with monogeneans and copepods. We recorded all parasites on gill arches of the same host species and used null models to analyse co-occurrences of digenean metacercariae, monogeneans and copepods. Zero-inflated mixture models were used to define the preferred patches of parasites. We found that digenean metacercariae (Bucephalus polymorphus) prefer specific patches of the gill apparatus to encyst, and shared these preferences with monogeneans and copepods, but did not interact with them. We concluded that digenean metacercariae have a species-specific microenvironmental preference to encyst in the gill apparatus and their occurrence (even in high numbers) does not reduce the success of attachment of monogeneans and copepods in the same gill patches. [ABSTRACT FROM AUTHOR]

In August of 2003 and August of 2004, blooms of potentially toxic cyanobacteria Microcystis spp. persisted in western Lake Erie. Samples collected from the bloom were analyzed for the cyanobacterial toxin microcystin and the presence of Microcystis spp. cells. Estimates of microcystin toxicity exceeding 1 μg L-1 (microcystin-LR activity equivalents), the safety limit set by the World Health Organization, were found from the samples in both 2003 and 2004. The presence of Microcystis spp. in water samples was confirmed through standard polymerase chain reaction (PCR) using a combination of four primer sets. Quantification of Microcystis was accomplished by a real- time PCR assay utilizing specific primer-Taq-man probe sets targeted on a conserved, Microcystis-specific 16S rDNA fragment and a microcystin toxin synthetase gene mcyD. This approach allowed us to specifically study the distribution and abundance of toxic Microcystis in the lake in contrast to previous studies that have assessed Microcystis populations with less refined methods. On the basis of quantification by quantitative real-time PCR analysis, the total abundance of Microcystis cells in the bloom area varied from 4 × 108 to 2 × 10³ cells L-1. The results of this study provide novel insight regarding the distribution and abundance of Microcystis spp. in the western basin of Lake Erie, a region plagued in recent years by large-scale (>20 km²) blooms. Our results suggest that the Maumee River and Bay may serve as a source for Microcystis to western and central Lake Erie. [ABSTRACT FROM AUTHOR]

We have tested the usefulness of the critical flicker fusion threshold-test (CFF), Maddox wing readings (MW), and visual analoque scale scores (VAS) in a double-blind, random-order study designed to evaluate the clinical effects of two different kinds of opiates, buprenorphine and fentanyl in comparison with those of placebo. The results were compared with the so-called postanaesthetic recovery score (PARS). In 7 healthy volunteers MW and VAS differentiated the effects of buprenorphine 7.5 µg/kg i.v. from those of fentanyl 2.5 µg/kg i.v. and placebo. CFF was very insensitive in this respect and PARS completely useless. Our results show that, in addition to the known usefulness of VAS, MW is also able to differentiate the effects of these opiates. [ABSTRACT FROM AUTHOR]

A sensitive radioreceptor assay for the determination of glycopyrrolate concentrations in human plasma, urine and cerebrospinal fluid (CSF) is described. The applicability of the assay for kinetic studies in humans was studied by determining the plasma concentrations and the renal excretion in three gynaecological surgical patients, who received 8 μg/kg of glycopyrrolate as a premedication intramuscularly. Tritiated N-methyl scopolamine was used to label the muscarinic cholinergic receptors in the membrane preparation obtained from the rat brain. The limit of detection of the assay was 70 ng/1 in plasma, 2 μg/1 in urine and 140 ng/1 in CSF. There was no evidence of cross-reactivity of glycopyrrolate derivatives in clinical concentrations. A very rapid absorption was found with a mean maximum plasma concentration (Cmax) of 14.26 (range 12.02-16.97) μg/1 and mean Tmax (time to Cmax) of 13.3 (range 10-15) min. and almost 50% of the dose administered was excreted into the urine within 3 hr. The CSF levels of glycopyrrolate were under detection limit. It is concluded that the sensitivity of the method is sufficient for pharmacokinetic studies of glycopyrrolate after therapeutic dosing. [ABSTRACT FROM AUTHOR]

The effects of two partial agonist opioid analgesics, meptazinol (at doses 0.7 and 1.4 mg/kg intravenously) and pentazocine (at doses 0.3 and 0.6 mg/kg), on anterior and posterior pituitary hormone secretion were studied in six normal human volunteers. Both drugs stimulated the secretion of prolactin dose-dependently, as expected. This effect was seen in all subjects, although two of the six subjects reacted more sensitively to both drugs. Plasma growth hormone concentrations were increased only after the higher dose of meptazinol. This was also seen in all subjects suggesting a spesific pharmacological effect. Vasopression (AVP) in plasma was greatly increased (up to 76 pg/ml) in three of the six subjects after the higher dose of meptazinol, but remained on a low level in the other three and after all other drug doses. The increase in AVP occurred only in those individuals who reported nausea after meptazinol. It was concluded that the augmented AVP release following meptazinol administration was likely to be a non-specific response induced by nausea and not an effect mediated by opiate receptors. [ABSTRACT FROM AUTHOR]

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