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In freshwater ecosystems in the northwest United States, the distribution and movements of fish between their essential habitats are particularly impacted by the presence of hydroelectric dams. Bull Trout Salvelinus confluentus and Westslope Cutthroat Trout Oncorhynchus clarkii var. lewisi are two fish species of concern inhabiting the Pend Oreille River between Idaho and Washington states. The purpose of this study was to identify the behavior and habitat use of Bull Trout and Westslope Cutthroat Trout in the restricted area of the Pend Oreille River, downstream of Albeni Falls Dam (AFD), using a long-term radio-telemetry dataset. Between 2015 and 2018, 24 Bull Trout and 24 Westslope Cutthroat Trout were captured, tagged, and released downstream AFD. Among the fish tagged, 79% (n = 19 of 24) of Bull Trout and 67% (n = 16 of 24) of Westslope Cutthroat Trout were detected during the study period. Our results revealed movements of fish towards tributary confluences mostly in May, June, and July for both species with Bull Trout traveling longer distances than Westslope Cutthroat Trout. Although the sample size was limited, Bull Trout individual movements towards the dam suggested attempts to re-ascend the river, indicating the importance of restoring upstream connectivity.

Current immunosuppressive strategies are aimed at abrogating the allospecific T-cell response against donor tissues or organs. However, little information is yet available on the potential influences of these drugs on innate immune responses. In order to address this, we have employed a whole blood model. Human whole blood was pretreated with sirolimus, cyclosporine A or tacrolimus in therapeutic as well as supra therapeutic doses, and subsequently stimulated with lipopolysaccharide (LPS), peptidoglycan (PepG) or lipoteichoic acid (LTA). Plasma cytokine analyses revealed a potent inhibitory effect of sirolimus on interleukin(IL)-10 production induced by all bacterial products tested. In contrast, cyclosporine A and tacrolimus inhibited the tumour necrosis factor (TNF)-α production in response to LPS, but not to PepG and LTA. Using a quantitative mRNA analyses, we also observed that sirolimus significantly decreased the IL-10 mRNA accumulation to sub-basal levels in peripheral blood mononuclear cells (PBMC). This suggests that the sirolimus inhibits IL-10 production by interfering with the IL-10 gene transcription. However, the molecular mechanism of this inhibition remains unclear. Based on the present study and observations by others, we postulate that the clinical use of the sirolimus may be associated with a dysregulated innate immune response to bacterial infection and thus an increased risk of hyperinflammation and sepsis.

Parasites, causing little apparent damage in feral fish populations, may become causative agents of diseases of great importance in farmed fish, leading to pathological changes, decrease of fitness or reduction of the market value of fish. Despite considerable progress in fish parasitology in the last decades, major gaps still exist in the knowledge of taxonomy, biology, epizootiology and control of fish parasites, including such ‘evergreens’ as the ciliate Ichthyophthirius multifiliis, a causative agent of white spot disease, or proliferative kidney disease (PKD), one of the most economically damaging diseases in the rainbow trout industry which causative agent remain enigmatic. Besides long-recognized parasites, other potentially severe pathogens have appeared quite recently such as amphizoic amoebae, causative agents of amoebic gill disease (AGD), the monogenean Gyrodactylus salaris which has destroyed salmon populations in Norway, or sea lice, in particular Lepeophtheirus salmonis that endanger marine salmonids in some areas. Recent spreading of some parasites throughout the world (e.g. the cestode Bothriocephalus acheilognathi) has been facilitated through insufficient veterinary control during import of fish. Control of many important parasitic diseases is still far from being satisfactory and further research is needed. Use of chemotherapy has limitations and new effective, but environmentally safe drugs should be developed. A very promising area of future research seems to be studies on immunity in parasitic infections, use of molecular technology in diagnostics and development of new vaccines against the most pathogenic parasites.

Species of Ascocotyle Looss, 1899 (subgenus Phagicola Faust, 1920) (Digenea: Heterophyidae) related to A. (P.) longa Ransom, 1920, i.e. those with a bipartite gonotyl and a single crown of 16 circumoral spines, were revised on the basis of examination of type and voucher specimens. The species A. (P.) arnaldoi Travassos, 1929, A. (P.) byrdi (Robinson, 1956) and A. (P.) longicollis (KuntzChandler, 1956), all possessing 16 circumoral spines, are synonymised with A. (P.) longa. A. (P.) ascolonga Witenberg, 1929, the types of which were not available, is provisionally retained as a valid species despite its close similarity to A. (P.) longa (identical number of circumoral spines and morphology of the ventrogenital sac). It differs from A. (P.) longa in the presence of uterine loops posterior to the testes and intestinal caeca ending anterior to the ovary (versus the pretesticular uterus and intestinal caeca reaching to the posterior margin of the ovary in A. (P.) longa). A. (P.) inglei (HuttonSogandares-Bernal, 1959), found only once in a single specimen, is also tentatively considered a valid species because it differs in number of circumoral spines (19), slightly larger eggs (23-26 x 13-16 microns) and the distribution of refractile bodies of the gonotyl arranged in four separate groups from A. (P.) longa and A. (P.) ascolonga (16 circumoral spines; eggs 15-20 x 8-12 microns; refractile bodies in two groups).

The life cycles of species of Proteocephalus Weinland, 1858 (Cestoda: Proteocephalidea) parasitizing fishes in the Palearctic Region are reviewed on the basis of literary data and personal experimental observations, with special attention being paid to the development within the intermediate and definitive hosts. Planktonic crustaceans, diaptomid or cyclopid copepods (Copepoda), serve as the only intermediate hosts of all Proteocephalus species considered. A metacestode, or procercoid, develops in the body cavity of these planktonic crustaceans and the definitive host, a fish, becomes infected directly after consuming them. No previous reports of the parenteral location of metacestodes within the second intermediate host as it is in the Nearctic species P. ambloplitis have been recorded. Thus, the life cycles of Proteocephalus tapeworms resemble in their general patterns those of some pseudophyllidean cestodes such as Eubothrium or Bothriocephalus, differing from the latter in the presence of a floating eggs instead of possessing an operculate egg from which a ciliated, freely swimming larva, a coracidium, is liberated. The scolex of Proteocephalus is already formed at the stage of the procercoid within the copepod intermediate host; in this feature, proteocephalideans resemble caryophyllidean rather than pseudophyllidean cestodes. The morphology of procercoids of individual species is described with respect to the possibility of their differentiation and data on the spectrum of intermediate hosts are summarized. Procercoids of most taxa have a cercomer, which does not contain embryonic hooks in contrast to most pseudophyllidean cestodes. The role of invertebrates (alder-fly larvae — Megaloptera) and small prey fishes feeding upon plankton in the transmission of Proteocephalus tapeworms still remains unclear but these hosts are likely to occur in the life cycle. Data on the establishment of procercoids in definitive hosts, morphogenesis of tapeworms within fish hosts, and the length of the prepatent period are still scarce and new observations are needed. Whereas extensive information exists on the development of P. longicollis (syns. P. exiguus and P. neglectus), almost no data are available on the ontogeny of other taxa, in particular those occurring in brackish waters (P. gobiorum, P. tetrastomus). The morphology of P. cernuae and P. osculatus procercoids from experimentally infected intermediate hosts is described for the first time.

The morphology of the scolex of the tapeworm Silurotaenica siluri (Batsch, 1786) (Proteocephalidae: Gangesiinae), a specific parasite of European wels (Silurus glanis L.), was studied using light, scanning (SEM), and transmission electron (TEM) microscopy. The scolex of S. siluri is rather uniform in shape and size; it is globular, and has four prominent, anteriorly directed suckers and a spherical, muscular apical organ corresponding to the rostellum of cyclophyllidean cestodes. The rostellum-like apical organ is armed with five to six irregular rows of small hooklets with a wide, oval basal plate and a short, posteriorly curved blade. The excretory system of the scolex is formed by sinuous secondary canals ending blindly beneath the distal layer of the tegument, not opening outside. The surface of the scolex is covered with filiform microtriches; giant spine-like and blade-like microtriches, incorrectly interpreted as spines or hooklets in previous descriptions of S. siluri, are present on the neck region and posterior margins and internal cavities of the suckers. It is assumed that tegumental spines reported in the scolices of other proteocephalideans (subfamilies Acanthotaeniinae and Gangesiinae, genera Spasskyellina and Nomimoscolex) could indeed be spiniform microtriches.

We used an in vitro model for venovenous bypass in a prospective, randomized study to analyze the effect on leukocytes cell activation after coating the total blood contact surface with covalently bound heparin. In ten experiments heparin-coated circuits were used, and in ten other experiments noncoated circuits were used. Monocyte cytokine production and neutrophil myeloperoxidase release were analyzed. Monocytes were isolated using anti-CD14 paramagnetic beads, and oligo (dT)25 beads were used to isolate mRNA before subsequent reverse transcription and semiquantitative amplification of various cytokines in order to determine time-related changes in expression during bypass. After 2 h, mRNAs for IL-1 beta and IL-6 were highly upregulated in noncoated compared to heparin-coated circuits. Little or no change was seen in the expression of other cytokines. IL-1 beta and IL-6 were measured in plasma after 12 h and reflected the upregulated mRNAs in noncoated circuits. A significantly reduced release of myeloperoxidase was observed in coated versus noncoated circuits. This indicates that heparin-coated surfaces reduce cellular activation and the release of inflammatory mediators.

In a porcine model of endotoxemia we have studied the effects of nitric oxide (NO) on hepatic oxygen delivery and consumption. After 3 h of endotoxemia, NO biosynthesis was modulated by a bolus dose of the NO synthase inhibitor NG-nitro-L-arginine methyl ester (L-NAME). Fifteen minutes thereafter a continuous infusion of the NO donor sodium nitroprusside (SNP) was started. Endotoxin significantly reduced hepatic oxygen delivery from 3.4 +/- 0.6 to 2.2 +/- 0.3 ml/kg/min at 3 h. Due to an increased extraction ratio (ER), oxygen consumption was nearly unaffected. L-NAME further diminished oxygen delivery to 1.0 +/- 0.2 ml/kg/min within 15 min (p0.05), but despite an increase in ER from 47 to 68% (p0.05), oxygen consumption tended to decrease (from 1.0 to 0.7 ml/ kg/min, nonsignificant). A similar tendency was observed in a control group of 9 pigs which was treated in the same way as the study group, except for the SNP infusion. SNP induced an almost selective increase in hepatic arterial flow, with a corresponding increase in oxygen delivery to 1.8 +/- 0.3 ml/kg/min (p0.05). At the same time ER was reduced from 68 to 42% (p0.05). Oxygen consumption remained unaltered. The control group exhibited no change in either oxygen delivery or consumption. The study shows that nonselective inhibition of NO synthesis is detrimental to hepatic perfusion and oxygen transport. The NO donor SNP increased oxygen delivery via a selective increase in hepatic arterial flow, but failed to influence oxygen consumption. This was probably mainly due to a massive shutdown of sinusoids, which did not reopen when flow was increased. A functioning microcirculation thus seems to be a prerequisite for the stimulation of organ blood flow to be effective.

Mechanisms of circulatory effects induced by nitric oxide synthase inhibition in endotoxemia were investigated in 36 pigs randomized to 1) endotoxin infusion (1.7 micrograms.kg-1.h-1 iv) for 7 h and bolus NG-nitro-L-arginine methyl ester (L-NAME; 25 mg/kg iv) after 3 h; 2) endotoxin infusion for 7 h; 3) saline infusion for 7 h and L-NAME after 3 h; and 4) saline infusion for 7 h. Fifteen minutes after L-NAME injection during endotoxemia, reductions in cardiac output (41%, P < 0.05), portal venous flow (51%, P < 0.05), and hepatic artery flow (50%, P < 0.05) were observed. Systemic vascular resistance increased by 82% (P < 0.05), and the portocaval vascular resistance increased by 101% (P < 0.05). Despite marked vasoconstriction after L-NAME, left ventricular intracavitary filling pressure, central venous pressure, and arterial pressure remained unchanged. During endotoxemia, hematocrit increased from 38.4 +/- 1.4 to 41.9 +/- 1.2 after L-NAME, and blood volume (n = 3) was reduced by an average of 8.3 ml/kg body wt. These changes probably reflect transcapillary fluid loss as urine output was unchanged. In conclusion, L-NAME decreased intravascular blood volume and increased splanchnic venous resistance. These effects will tend to reduce venous return. Combined with a marked increase in left ventricular after-load, L-NAME may thus compromise cardiovascular function in endotoxemia.

Microvascular endothelial cells play an important part in inflammation as well as in organ specific leucocyte traffic, and may be functionally different from large vessel endothelium in this respect. This study therefore established a method for isolation and longterm culture of human intestinal microvascular endothelial cells (HIMEC). After dissociation by collagenase/dispase/DNase of mucosal and submucosal tissue obtained from normal adult jejunum, cells were plated and cultured to subconfluence in endothelial serum free medium containing 2.5% fetal calf serum, hydrocortisone, and N6, O2-dibutyryladenosine cyclic monophosphate. Primary cultures were trypsinised and endothelial cells were isolated by paramagnetic beads armed with monoclonal antibody to CD31. Optimal growth conditions for HIMEC cultures were established, allowing up to nine passages (three months in vitro). The cells contained Weibel-Palade bodies, expressed von Willebrand factor, CD31, and VE-cadherin; and bound Ulex Europaeus lectin I. A method to establish longterm cell cultures of HIMEC will facilitate further investigation of the function of intestinal endothelial cells and their participation in physiological and pathological events in the gut.

Type-specimens (syntypes) and comparative material of twoProteocephalus species,P. exiguus La Rue, 1911 andP. fallax La Rue, 1911, parasitic in coregonid fishes from the Holarctic Region, were evaluated taxonomically. Morphological and biometrical study revealed conspecificity of the taxa.P. fallax is therefore, considered to be a synonym ofP. exiguus. Supplementary information is added to the species diagnosis ofP. exiguus and a lectotype is designated herein.

Fisheries and limnological investigations in post-restoration Medical Lake, Washington, suggest that establishing a successful rainbow trout Oncorhynchus mykiss fishery depends on the maintenance of a healthy Daphnia pulex population and that phytoplankton volume is related to interactions between rainbow trout and D. puluex. As rainbow trout abundance increases, D. pulex standing crop decreases. This change results in an increase in phytoplankton standing crop. Multiple regression analyses on eight years of data was used to determine the statistical relationship between rainbow trout—D. pulex interactions, total phosphorus levels, and phytoplankton volume. Seasonal variation in phytoplankton volume correlated more closely to rainbow trout—D. pulex interactions than did monthly variations in algal biomass. Accounting for the lag in response time between the independent variables and phytoplankton volume improved the percentage of explained variance. The results indicate that the variance in seaso...

The introduction of lahontan cutthroat trout (Oncorhynchus clarki henshawi Richardson) into previously fishless, Granite lake, Washington in 1987, drastically reduced the density of larval Chaoborus trivittatus in 1988. Chaoborus trivittatus was reduced from a mean summer density of 650/m2 in 1987 to a mean summer density of 10/m2 in 1988. Chaoborus trivittatus and Daphnia pulicaria were the most important prey items of the trout. Although D. pulicaria was equally important in the trout diet, its density following trout introduction did not change. Two factors may explain the lack of D. pulicaria decline. First, size-selective predation from trout was not intense enough to remove the largest D. pulicaria, which likely had the highest fecundity. Secondly, any predation effect the trout had upon D. pulicaria was offset by the lack of C. trivittatus predation on D. pulicaria, due to the precipitous decline of C. trivittatus. During the decline of C. trivittatus, no significant changes in the density...

The external morphology of some developmental stages of the fluke Opisthorchis viverrini (Trematoda: Opisthorchiidae), parasitizing humans in Southeast Asia was studied for the first time using electron microscopy. The surface structure of the egg, as well as the rediae, cercaria, metacercaria, and adult found in naturally infected hosts from Laos are described herein and their morphological characteristics discussed.

This study was designed to monitor movements of bull trout that were provided passage above Albeni Falls Dam, Pend Oreille River. Electrofishing and angling were used to collect bull trout below the dam. Tissue samples were collected from each bull trout and sent to the U. S. Fish and Wildlife Service Abernathy Fish Technology Center Conservation Genetics Lab, Washington. The DNA extracted from tissue samples were compared to a catalog of bull trout population DNA from the Priest River drainage, Lake Pend Oreille tributaries, and the Clark Fork drainage to determine the most probable tributary of origin. A combined acoustic radio or radio tag was implanted in each fish prior to being transported and released above the dam. Bull trout relocated above the dam were able to volitionally migrate into their natal tributary, drop back downstream, or migrate upstream to the next dam. A combination of stationary radio receiving stations and tracking via aircraft, boat, and vehicle were used to monitor the movement of tagged fish to determine if the spawning tributary it selected matched the tributary assigned from the genetic analysis. Seven bull trout were captured during electrofishing surveys in 2008. Of these seven, four were tagged and relocatedmore » above the dam. Two were tagged and left below the dam as part of a study monitoring movements below the dam. One was immature and too small at the time of capture to implant a tracking tag. All four fish released above the dam passed by stationary receivers stations leading into Lake Pend Oreille and no fish dropped back below the dam. One of the radio tags was recovered in the tributary corresponding with the results of the genetic test. Another fish was located in the vicinity of its assigned tributary, which was impassable due to low water discharge at its mouth. Two fish have not been located since entering the lake. Of these fish, one was immature and not expected to enter its natal tributary in the fall of 2008. The other fish was large enough to be mature, but at the time of capture its sex was unable to be determined, indicating it may not have been mature at the time of capture. These fish are expected to enter their natal tributaries in early summer or fall of 2009.« less

Milanella familiaris n. gen. and n. sp. (Bothriocephalidea: Triaenophoridae) is proposed to accommodate a new cestode from blackfish Centrolophus niger (Gmelin) (Perciformes: Centrolophidae). Milanella is characterized as follows: trapeziform, i.e., markedly craspedote proglottids with a velum-like posterior margin and horn like lateral projections; pyriform uterine sac in the first gravid proglottids; arrow-shaped scolex with well-developed apical disc and prominent posterior margins; strobila with intensively stained corpuscles, most numerous in the anterior part; deeply lobated ovary; absence of a neck; a large, pyriform, thin-walled cirrus-sac with the proximal part bent anteromedially; vagina posterior to the cirrus-sac; and cortical vitelline follicles. Milanella most closely resembles Bathycestus Kuchta and Scholz, 2004, Pistana Campbell and Gartner, 1982, and Probothriocephalus Campbell, 1979, differing mainly in the shape of proglottids and uterine sac.

Development of therapies to treat visual system dystrophies resulting from the degeneration of rod and cone photoreceptors may directly benefit from studies of animal models, such as the zebrafish, that display continuous retinal neurogenesis and the capacity for injury-induced regeneration. Previous studies of retinal regeneration in fish have been conducted on adult animals and have relied on methods that cause acute damage to both rods and cones, as well as other retinal cell types. We report here the use of a genetic approach to study progenitor cell responses to photoreceptor degeneration in the larval and adult zebrafish retina. We have compared the responses to selective rod or cone degeneration using, respectively, the XOPS-mCFP transgenic line and zebrafish with a null mutation in the pde6c gene. Notably, rod degeneration induces increased proliferation of progenitors in the outer nuclear layer (ONL) and is not associated with proliferation or reactive gliosis in the inner nuclear layer (INL). Molecular characterization of the rod progenitor cells demonstrated that they are committed to the rod photoreceptor fate while they are still mitotic. In contrast, cone degeneration induces both Muller cell proliferation and reactive gliosis, with little change in proliferation in the ONL. We found that in both lines, proliferative responses to photoreceptor degeneration can be observed as 7 days post fertilization (dpf). These two genetic models therefore offer new opportunities for investigating the molecular mechanisms of selective degeneration and regeneration of rods and cones.

A new proteocephalidean cestode is described from 2 catfishes, Clarias gariepinus (type host) and C. cf. anguillaris (Siluriformes: Clariidae), from Ethiopia (type locality), Sudan, Tanzania, and Zimbabwe, and a new genus, Barsonella, is proposed to accommodate it. The genus belongs to the Proteocephalinae because its genital organs (testes, ovary, vitellarium, and uterus) are situated in the medulla. Barsonella lafoni, the type and only species of the new genus, is characterized mainly by the possession of an additional opening of each sucker; circular musculature on the anterior margin of suckers, serving as a sphincter; a small thin-walled glandular apical organ; absence of well-developed osmoregulatory canals in mature, pregravid, and gravid proglottids; and a large strobila, up to 173 mm long and 3.2 mm wide. Species of Marsypocephalus Wedl, 1861 (Marsypocephalinae), other large-sized proteocephalidean tapeworms occurring sympatrically in African catfishes (Clarias and Heterobranchus) and also possessing a sphincter-like, circular musculature on the anterior part of suckers, differ from B. lafoni in the absence of an additional sucker opening and glandular apical organ, the cortical position of the testes, well-developed osmoregulatory canals throughout the strobila, and a large cirrus sac. Proteocephalus glanduligerus (Janicki, 1928), another cestode parasitic in Clarias spp. in Africa, is much smaller than B. lafoni (maximum length 15 mm), has suckers without additional opening and circular musculature on the suckers, a large-sized glandular organ, much larger than suckers, and well-developed osmoregulatory canals. Comparison of partial sequences of the 28S rRNA gene for 7 samples of B. lafoni from 2 different hosts and 4 localities in Ethiopia, Sudan, and Tanzania has shown a very low genetic variability. In a limited phylogenetic analysis, B. lafoni formed a clade with Corallobothrium solidum Fritsch, 1886 (Proteocephalidae: Corallobothriinae), an African electric catfish parasite. This clade was the sister group of almost all Neotropical taxa from pimelodid and other catfishes.

In mammals, neuronal cell death during retinal degenerative diseases or following acute retinal injury often leads to irreversible visual impairment because, as is true for most regions of the adult central nervous system, the mammalian retina harbors little capacity for regeneration. In contrast, the neural retinas of urodele amphibians and teleost fishes show remarkable regenerative ability in response to many types of experimental damage. In teleost fishes, retinal regeneration is mediated in part by the proliferation of a specialized population of cells called the rod progenitor cells. These cells possess some of the properties characteristic of transit amplifying cells, such as steady-state proliferation and a commitment to the rod photoreceptor cell fate. However, these cells are also able to respond to rod photoreceptor damage by increasing their rate of proliferation. Therefore, an understanding of the signals that induce rod progenitor cells to proliferate and differentiate following retinal damage may help us to understand the barriers to photoreceptor regeneration in higher vertebrate organisms. Although it has been many years since the discovery that rod progenitor cells are a source for new neurons in the regenerating fish retina, the in vivo factors that regulate rod progenitor proliferation and differentiation, as well as the source of the proliferative cues, remain poorly defined. This chapter will review the phenomena of persistent and injury-induced neurogenesis in the zebrafish retina, with particular emphasis on the role of rod progenitor cells, and will describe a new genetic model that should further our understanding of the regulation of rod progenitor proliferation.

A significant logistic factor as to the successful clinical application of the autologous tissue engineering concept is efficient transportation: the donor cells need to be delivered to tissue processing facilities which in most cases requires air transportation. This study was designed to evaluate how human chondrocytes react to X-ray exposure. Primary cell cultures were established, cultured, incubated and exposed to different doses and time periods of radiation. Subsequently, quantitative cell proliferation assays were done and qualitative evaluation of cellular protein production were performed. Our results show that after irradiation of chondrocytes with different doses, no significant differences in terms of cellular viability occurred compared with the control group. These results were obtained when chondrocytes were exposed to luggage transillumination doses as well as exposure to clinically used radiation doses. Any damage affecting cell growth or quality was not observed in our study. However, information about damage of cellular DNA remains incomplete.

Glucocorticoid (GC) and mineralocorticoid (MC) action in target tissues is determined by prereceptor metabolism by 11beta-hydroxysteroid-dehydrogenases (HSDs) and receptor transactivation. We characterized these parameters for steroids often used in clinical practice. HSD activity was examined in human liver (HSD1) and kidney microsomes (HSD2) and in CHO cells stably transfected with both enzymes. GC and MC transcriptional activity was tested by luciferase assay in CV-1 cells transfected with human GC or MC receptor expression vectors. The 11-hydroxy-group is necessary for GC and MC receptor transactivation. As HSD2 oxidizes 11-hydroxysteroids to inactive 11-dehydrosteroids, GC and MC activity in HSD2-expressing tissues (kidney, colon) is regulated by this enzyme. As 9alpha-fluorination (such as in 9alpha-fluorocortisol) decreases oxidation by HSD2 and increases both GC and MC receptor transactivation, this modification leads to optimal, but non-selective transactivation of both receptors. Increased GC receptor and decreased MC receptor transactivation leading to more selective GC activity is reached using the following substituents: 16beta-methyl (in betamethasone), 16alpha-methyl (in dexamethasone) and triangle up 1-dehydro-configuration (in prednisolone). Whereas the modifications in position 16 decrease oxidation by HSD2, the triangle up 1-dehydro-configuration increases HSD2-activity leading to an enhanced inactivation of prednisolone compared to all other steroids. 9alpha-fluorocortisol, the most frequently used substance for MC-substitution, seems to be the best choice of available steroids for this purpose. Whereas GC selectivity can be improved by hydrophobic substituents in position 16 and the triangle up 1-dehydro-configuration, maximal GC activity needs additional fluorination in position 9alpha (such as in dexamethasone). For GC therapy directed to HSD2-expressing organs, widely used prednisolone does not seem to be the optimal recommendation.

Stem cells are currently considered as alternative cell resources for restorative transplantation strategies in Parkinson's disease. However, the mechanisms that induce differentiation of a stem cell toward the dopaminergic phenotype are still partly unknown thus hampering the production of dopaminergic neurons from stem cells. In the past, FGF-20 has been found to promote the survival of ventral mesencephalic (VM) dopaminergic (DA) neurons in culture. We hereby provide evidence that FGF-20, a growth factor of the FGF family, is expressed in the adult and 6-OHDA-lesioned striatum and substantia nigra, but is not expressed by VM glia or DA neurons, suggesting that FGF-20 may work on DA neurons in a paracrine- or target-derived manner. We also found that co-culture of Nurr1-NSCs with Schwann cells overexpressing FGF-20 induced the acquisition of a neuronal morphology by the NSCs and the expression of tyrosine hydroxylase (TH) as assessed by immunocytochemistry, cell ELISA, and Western blot analysis. RT-PCR showed, that both, Schwann cells and Nurr1-NSCs (differentiated or not), expressed the FGF-1 receptor suggesting that both direct and indirect actions of FGF-20 are possible. We show that differentiated Nurr1 cells retained both neuronal morphology and TH expression after transplantation into the striatum of 6-OHDA-lesioned postnatal or adult rats, but that neuritogenesis was only observed after postnatal grafts. Thus, our results suggest that FGF-20 promotes the differentiation of Nurr1-NSCs into TH-positive neurons and that additional factors are required for the efficient differentiation of DA neurons in the adult brain.

Walleye (Stizostedion vitreum) have been marked with floy tags in Lake Roosevelt since 1997 to estimate abundance, distribution and movement trends. In 2000, walleye were collected and marked during the spawning run in the Spokane River through electrofishing and angling to supplement movement and growth data collected in previous years. Walleye were also collected and marked during the 2000 and 2001 Kettle Falls Governor's Cup Walleye Tournaments. Seventy-six tag returns were recovered in 2000 and twenty-three in 2001. Walleye migrated into the Spokane River to spawn in mid April and early May. The majority of marked walleye were recovered within 25 km of their original marking location, with a few traveling long distances between recovery locations. Data also verified earlier results that walleye establish summer home ranges. Some walleye remained in the Spokane River, while others moved downstream, or upstream after entering the mainstem of Lake Roosevelt. Those moving upstream moved as far north as Keenlyside Dam in British Columbia (245 km). Growth data indicated similar trends exhibited in the past. Walleye growth and mortality rates were consistent with other walleye producing waters. Walleye condition was slightly below average when compared to other systems.

The selective Kupffer cell inhibitor gadolinium chloride (GdCl3) has been demonstrated to protect animals from lethality in experimental endotoxemia and sepsis in rodent models. This study was designed to investigate the effect of Kupffer cell blockade on the early response to endotoxin in a large animal model. Using a porcine endotoxemia model, animals were randomized to receive either GdCl3 (10 mg/kg or 30 mg/kg; n = 8 in each group) or vehicle saline (n = 8) 24 h before exposure to endotoxin. Pretreatment with GdCl3 resulted in a dose dependent reduction in early hepatic oxygen consumption as well as oxygen extraction ratio in response to continuous infusion of endotoxin. At 5 h there was significant lower serum AST level in animals given 30 mg/kg of GdCl3 as compared to the two other groups. Pretreatment with GdCl3 induced a dose dependent reduction of Kupffer cells in the liver sinusoids. Despite this, all animals deteriorated with continuous infusion of endotoxin as evidenced by the progressive reduction in cardiac output, mean arterial pressure and total liver blood flow. Also, increases in pulmonary arterial pressure, portal venous pressure and systemic, pulmonary and hepatic vascular resistance were seen. This is consistent with activation of other cell populations and defense mechanisms by endotoxin, perpetuating the septic response. However, modulation of reticuloendothelial cell function seems feasible also in larger animals, and our results stimulate to further research on potential immunomodulatory tools in early sepsis.

Lake Whatcom stock kokanee have been planted in Lake Roosevelt since 1988 with the primary goal of establishing a self-sustaining fishery. Returns of hatchery kokanee to egg collection facilities and recruitment to the creel have been minimal. Therefore, four experiments were conducted to determine the most appropriate release strategy that would increase kokanee returns. The first experiment compared morpholine and non-morpholine imprinted kokanee return rates, the second experiment compared early and middle run Whatcom kokanee, the third experiment compared early and late release dates, and the fourth experiment compared three net pen release strategies: Sherman Creek hatchery vs. Sherman Creek net pens, Colville River net pens vs. Sherman Creek net pens, and upper vs. lower reservoir net pen releases. Each experiment was tested in three ways: (1) returns to Sherman Creek, (2) returns to other tributaries throughout the reservoir, and (3) returns to the creel. Chi-square analysis of hatchery and tributary returns indicated no significant difference between morpholine imprinted and non-imprinted fish, early run fish outperformed middle run fish, early release date outperformed late release fish, and the hatchery outperformed all net pen releases. Hatchery kokanee harvest was estimated at 3,323 fish, which was 33% of the total harvest. Returnmore » rates (1998 = 0.52%) of Whatcom kokanee were low indicating an overall low performance that could be caused by high entrainment, predation, and precocity. A kokanee stock native to the upper Columbia, as opposed to the coastal Whatcom stock, may perform better in Lake Roosevelt.« less

Objective. To examine the effects of the inducible nitric oxide synthase inhibitor aminoethyl-isothiourea (AE-ITU) on haemodynamic measurements, and correlate these with hepatic morphology and function in a porcine model of endotoxaemia. Design. Experimental study. Animals: 15 juvenile pigs. Interventions: Flow probes were placed around the hepatic artery and portal vein. Catheters were introduced into the portal and hepatic veins, pulmonary artery, and aorta. Infusion of AE-ITU was started one hour before that of endotoxin (study group n = 6); thereafter both substances were infused simultaneously until the end of the study (6 hours). The controls (n = 9) had endotoxin alone. Main outcome measures: Hepatic morphology assessed by light and electron microscopy; and hepatic integrity and function by transaminase activities and oxygen consumption. Systemic, pulmonary, and hepatic blood flow and pressure. Results. AE-ITU maintained systemic blood pressure (p < 0.05 compared with controls) without causing pulmonary hypertension. Neither hepatic morphology nor function were adversely influenced. Conclusion: In endotoxaemia AE-ITU has a favourable haemodynamic profile which is achieved without impairment of hepatic function or morphology.

The diploid number 2n = 18 was revealed in Bathybothrium rectangulum, a specific parasite of barbels (Barbus spp.). All chromosome pairs were biarmed (pairs 1, 4, 7, 8, and 9 were metacentric; pairs 2, 3, and 6 were meta-submetacentric; and pair 5 was submetacentric) and small (from 1.49 to 2.95 microm). The C-banding method revealed pericentromeric heterochromatin in pairs 1, 3, 5, and 7; distinct C-bands in pairs 2, 4, 8, and 9; and a slight band in short arms of pairs 1 and 6. The karyotype of B. rectangulum is discussed with respect to the irresolute taxonomic position of B. rectangulum within the Pseudophyllidea.

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Background and aims—Cytokine production by endothelial cells has, for practical reasons, been chiefly studied in human umbilical vein endothelial cells (HUVEC) but, because tissue-specific differences apparently exist, the role of human intestinal microvascular endothelial cells (HIMEC) as a source of mucosal cytokines was also assessed.Methods—The expression of cytokine transcripts in HIMEC was screened by means of reverse transcription polymerase chain reaction (RT-PCR) and compared with cytokine profiles of HUVEC. Production of cytokines was investigated by bioassay and enzyme linked immunosorbent assay (ELISA).Results—In the basal unstimulated state, HIMEC and HUVEC cultures contained detectable mRNA for interleukin (IL)-3, IL-7, IL-8, IL-11, IL-14, IL-15, tumour necrosis factor (TNF)-α, transforming growth factor (TGF)-β, and granulocyte-macrophage colony stimulating factor (GM-CSF). However, message was undetectable for IL-2, IL-4, IL-5, IL-9, IL-10, IL-12p40, IL-13, and interferon (IFN)-γ in the resting as well as the stimulated state. Stimulation of HIMEC and HUVEC with recombinant human (rh) IL-1β or rhTNF-α induced cell associated bioactive IL-1α but not IL-1β, as well as enhanced secretion of both IL-6 and IL-8. Furthermore, transcript levels for GM-CSF and TNF-α were enhanced by rhIL-1β or rhTNF-α in both cell types. Supernatants from Th1-like or Th0-like gluten reactive intestinal T cell clones derived from patients with coeliac disease elicited cytokine profiles in both HIMEC and HUVEC similar to those revealed after rhIL-1β or rhTNF-α stimulation.Conclusions—These data demonstrate that the intestinal microvascular endothelium may contribute to the cytokine network of the intestinal mucosa with the ability to respond to locally generated cytokines and to produce potent inflammatory mediators.

The Lake Roosevelt Monitoring/Data Collection Program resulted from a merger between the Lake Roosevelt Monitoring Program and the Lake Roosevelt Data Collection Project. This project will model biological responses to reservoir operations, evaluate the effects of releasing hatchery origin kokanee salmon and rainbow trout on the fishery, and evaluate the success of various stocking strategies. In 1996, limnological, reservoir operation, zooplankton, and tagging data were collected. Mean reservoir elevation, storage volume and water retention time were reduced in 1996 relative to the last five years. In 1996, Lake Roosevelt reached a yearly low of 1,227 feet above mean sea level in April, a yearly high of 1,289 feet in July, and a mean yearly reservoir elevation of 1,271.4 feet. Mean monthly water retention times in Lake Roosevelt during 1996 ranged from 15.7 days in May to 49.2 days in October. Average zooplankton densities and biomass were lower in 1996 than 1995. Daphnia spp. and total zooplankton densities peaked during the summer, whereas minimum densities occurred during the spring. Approximately 300,000 kokanee salmon and 400,000 rainbow trout were released into Lake Roosevelt in 1996. The authors estimated 195,628 angler trips to Lake Roosevelt during 1996 with an economic value of $7,629,492.

In previous studies we have observed that the nitric oxide synthase inhibitor L-NAME induces a profound deterioration of liver circulation in experimental endotoxemia. Using the same porcine model we now have evaluated the possibility of modulating these effects with the nitric oxide donor sodium nitroprusside. Infusion of endotoxin led to a gradual deterioration of hemodynamic parameters, including liver blood flow. The decreases in portal blood flow paralleled and matched the decreases in cardiac output, and no compensatory increase in hepatic arterial flow occurred. L-NAME had detrimental effects on hemodynamics, including the liver circulation. The latter effects could, however, partially be reversed by sodium nitroprusside. Hepatic arterial flow increased from 1.9 to 7.2 ml/kg/min, with a concomitant decrease in hepatic arterial resistance from 5,364 to 1,746 dyn s/cm5 kg. A control group exhibited no significant change in either flow or resistance. The response to sodium nitroprusside was rapid and vigorous, and probably largely due to relaxation of the hepatic arterioles, and not to abatement of intrahepatic edema or plugging of the sinusoids. Furthermore, we conclude that the endotoxin-induced dysfunction of the hepatic arterial buffer response may be due to a selective inhibition of vascular endothelial function.

At the kokanee salmon hatcheries on Lake Roosevelt, constructed as partial mitigation for effects from Grand Coulee Dam, adult returns have been poor. The reason may be in the imprinting or in the smoltification. A study was initiated in 1992 to determine if there was a critical period for thyroxine induced alfactory imprinting in kokanee salmon; experiments were conducted on imprinting to morpholine and phenethyl alcohol. Other results showed that chemical imprinting coincided with elevated thyroxine levels in 1991 kokanee exposed to synthetic chemicals in 1992. In this report, imprinting experiments were repeated; results showed that imprinting occurred concomitant with elevated thyroxine levels in 1991 kokanee exposed to synthetic chemicals in 1992 and tested in 1994 as age 3 spawners. Imprinting also occurred at the same time as thyroxine peaks in 1992 kokanee exposed to synthetic chemicals in 1993 and tested as age 2 spawners. In both groups fish that had the highest whole body thyroxine content (swimup stage) also had the highest percentage of fish that were attracted to their exposure odor in behavioral tests. So, kokanee salmon imprinted to chemical cues during two sensitive periods during development, at the alevin/swimup and smolt stages. A field test was conductedmore » in Lake Roosevelt on coded wire tagged fish. Smoltification experiments were conducted from 1992 to 1994. Recommendations are made for the Lake Roosevelt kokanee hatcheries.« less

In 1987 the Northwest Power Planning Council amended the Columbia River Basin Fish and Wildlife Program, directing the Bonneville Power Administration (BPA) to fund, ``a baseline stream survey of tributaries located on the Coeur d`Alene Indian Reservation to compile information on improving spawning habitat, rearing habitat, and access to spawning tributaries for bull trout, cutthroat trout, and to evaluate the existing fish stocks. ff justified by the results of the survey, fund the design, construction and operation of a cutthroat and bull trout hatchery on the Coeur d`Alene Indian Reservation; necessary habitat improvement projects; and a three year monitoring program to evaluate the effectiveness of the hatchery and habitat improvement projects. If the baseline survey indicates a better alternative than construction of a fish hatchery, the Coeur d`Alene Tribe will submit an alternative plan for consideration in program amendment proceeding.`` This report contains the results of the third year of the study and the Coeur d`Alene Indian Tribes` preliminary recommendations for enhancing the cutthroat and bull trout fishery on the Coeur d`Alene Indian Reservation. These recommendations are based on study results from year three data and information obtained in the first two years of the study.

In 1991, we initiated studies to determine the critical period for thyroxine-induced olfactory imprinting in kokanee salmon. In our preliminary investigation we found that thyroxine [T{sub 4}] levels of Lake Whatcom stock, 1990 year class, kokanee were relatively high in eggs and alevins as compared to post-swimup fry, and peaked at hatch and swimup. Here we report on follow-up studies conducted in 1992 designed to determine if our initial results could be replicated. Additionally, in 1992, we initiated experiments to determine if kokanee could be imprinted to synthetic chemicals--morpholine and phenethyl alcohol--at different life stages. In 1991, whole body thyroxine content [T{sub 4}] was measured in 460 Lake Whatcom stock kokanee and 480 Lake Pend Orielle (Cabinet Gorge) stock kokanee to indicate the critical period for imprinting. Lots of 20 kokanee eggs, alevins and fry from both stocks, reared at the Spokane Tribal hatchery, were collected at weekly intervals from November 1991 to August 1992 and assayed for T{sub 4} content by radioimmunoassay. T{sub 4} levels were monitored in Lake Whatcom stock, 1991 year class fish, from eyed egg (33 days post-fertilization) to fry (248 days post-fertilization) stages. T{sub 4} concentration ({+-} SEM) in eggs was 6.7 {+-} 1.3 rig/g more » body weight. T{sub 4} peaked on the day of hatch at 13.1 {+-} 2.5 ng/g body weight, then declined to 10.3 {+-} 1.1 ng/g body weight in recently post-hatch alevins. T{sub 4} peaked again at 22.1 {+-} 5.2 ng/g body weight during swimup, then steadily decreased to about 1.0 ng/g body weight in 176-248 day old fry. T{sub 4} levels were monitored in Lake Pend Orielle stock, 1991 year class, fish from the day of fertilization (day 0) to 225 days post-fertilization. T{sub 4} content of eggs was 9.5 {+-} 1.7 ng/g body weight and peaked on the day of hatch (day 53 post-fertilization) at 24.2 {+-} 4.5 ng/g body weight. After declining to 13.0 {+-} 2.9 ng/g body weight on day 81 post-fertilization, T{sub 4} peaked a second time during swimup (88-95 days post-fertilization) at 24.3 {+-} 3.8 ng/g body weight. After swimup, T{sub 4} concentration steadily declined to about 0.6 ng/g body weight in 225 day old post-fertilization fry. Thus, results of our 1992 investigations were consistent with our preliminary 1991 study. In all cases: (1) T{sub 4} concentration was relatively high in eggs and alevins as compared to older fry; and (2) T{sub 4} peaks occurred at hatch and swimup. Blood serum T{sub 4} concentration was measured in 9 month to 21 month-old Lake Whatcom stock, 1990 year class, kokanee from July 1991 to August 1992. T{sub 4} concentrations were low in summer, peaked slightly in October, were low in early winter, then peaked several times between January and May 1992. Thus, the 1990 year class Lake Whatcom kokanee evidenced high T{sub 4} activity from egg to swimup stages in their first year and in the winter and spring of their second year of life. The fish appeared to undergo smolt transformation between 16-18 months old. In 1992, Lake Whatcom (1991 cohort) kokanee were exposed to synthetic chemicals--1,072,000 to morpholine and 1,117,000 to phenethyl alcohol--at different life history stages: (1) eye to hatch; (2) hatch; (3) hatch to swimup; (4) swimup; and (5) post-swimup fry (in February, March, April and May-June). Additionally, Lake Whatcom (1990 cohort) kokanee were exposed to synthetic chemicals--36,000 to morpholine and 51,600 to phenethyl alcohol--at age 16-18 months. Most of these fish were marked and released in Lake Roosevelt in July and August 1992 as part of a field test. A portion of the fish from each group was retained at the Spokane Tribal hatchery until August-October 1993, when behavioral tests will be conducted to determine if the fish imprinted to their exposure odor. « less

Previous investigations have determined that thyroid hormone surges activate olfactory imprinting in anadromous salmonid smolts. The mechanism of action appears to require binding of thyroid hormones to receptors in brain cell nuclei, which stimulates neuron differentiation and wires a pattern of neuron circuitry that allows for the permanent storage of the imprinted olfactory memory. In this study, thyroxine concentrations [T{sub 4}] were measured in 487 Lake Whatcom stock and 70 Lake Roosevelt stock Kokanee salmon to indicate the critical period for imprinting. Eggs, alevins and fry, reared at the Spokane Indian Kokanee Hatchery, were collected from January through August 1991. Sampled fish were flash frozen on dry ice and stored at {minus}80{degrees}C until T{sub 4} was extracted and concentrations determined by radioimmunassay. Mean concentration {+-} SEM of 10--20 individual fish (assayed in duplicate) were determined for each time period. T{sub 4} concentration peaked on the day of hatch at 16.8 ng/g body weight and again at swim-up at 16.0 {+-} 4.7 ng/g body weight. T{sub 4} concentration was 12.5 to 12.9 ng/g body weight in eggs, 7.1 to 15.2 ng/g body weight in. alevins, 4.5 to 11.4 ng/g body weight in 42 to 105 day old fry and 0.1 tomore » 2.9 ng/g body weight in 112 to 185 day old fry. T{sub 4} concentrations were highest in eggs at 13.3 {+-} 2.8 ng/g body weight, then steadily decreased to 0.1 {+-} 0.1 ng/g body weight in older fry. Fry were released in Lake Roosevelt tributaries in July and August 1991, at about 170--180 days post hatching, in order to imprint them to those sites. The results of this study indicate that the time of release was not appropriate for imprinting. If T{sub 4} levels are an accurate guide for imprinting in kokanee, our results suggest that the critical period for imprinting in kokanee is at hatching or swim-up stages.« less

This report recommends resident fish substitution projects to partially replace anadromous fish losses caused by construction of Grand Coulee and Chief Joseph Dams. These recommendations involve enhancing the resident fishery in the Pend Oreille River as a substitute for anadromous fish losses. In developing these recommendations we have intentionally attempted to minimize the impact upon the hydroelectric system and anadromous fish recovery plans. In this report we are recommending that the Northwest Power Planning Council direct Bonneville Power Administration to fund the proposed enhancement measures as resident fish substitution projects under the NPPC's Columbia Basin Fish and Wildlife Program. The Pend Oreille River, located in northeast Washington, was historically a free flowing river which supported anadromous steelhead trout and chinook salmon, and large resident cutthroat trout and bull trout. In 1939, Grand Coulee Dam eliminated the anadromous species from the river. In 1955, Box Canyon Dam was constructed, inundating resident trout habitat in the river and creating many back water and slough areas. By the late 1950's the fishery in the reservoir had changed from a quality trout fishery to a warm water fishery, supporting largemouth bass, yellow perch and rough fish (tenth, suckers, squawfish). The object of this studymore » was to examine the existing fishery, identify fishery improvement opportunities and recommend fishery enhancement projects. Three years of baseline data were collected from the Box Canyon portion of the Pend Oreille River to assess population dynamics, growth rates, feeding habits, behavior patterns and factors limiting the fishery. Fishery improvement opportunities were identified based on the results of these data. Relative abundance surveys in the reservoir resulted in the capture of 47,415 fish during the study. The most abundant species in the reservoir were yellow perch, composing 44% of the fish captured. The perch population in the river is stunted and therefore not popular with anglers. Pumpkinseed composed 16% of the total catch, followed by tenth (9%), largemouth bass (8%), mountain whitefish (6%), largescale sucker (5%), northern squawfish (4%) and longnose sucker (3%).« less

Metacercariae of five small flukes transmitted to humans, Opistorchis viverrini (family Opisthorchiidae), Centrocestus formosanus, Haplorchis pumilio, H. taichui and Stellantchasmus falcatus (family Heterophyidae), were found in fish from Laos. All metacercariae, recorded from Laos for the first time, are described in detail and figured with special attention to the armature of ventrogenital complex of heterophyid larvae. Fish Hampala macrolepitoda and Cyclo-cheilichthys repasson represent new second intermediate hosts for O. viverrini; Esomus longimana for C. formosanus; H. macrolepidota and E. longimana for H. pumilio, H. macrolepidota, H. dispar and Mystacoleucus marginatus for H. taichui , and Xenentodon concila for S. falcatus .

A study of the epidemiology of trematode infections was carried out in Vientiane province, Laos, comprising examination of snails, fish, cats, and human stools. Opisthorchis viverrini cercariae were found in the snail Bithynia siamensis goniomphalus (Bithyniidae) and Haplorchis taichui cercariae in Tarebia granifera (Thiaridae). O. viverrini metacercariae were recorded in the flesh of 7 species of cyprinid fish; metacercariae of the heterophyid fluke Haplorchis taichui were found in 4 species of cyprinid fish and those of H. pumilio in 2 species. Cats from the same localities were infected with O. viverrini and 4 species of heterophyid flukes, frequently as multiple infections. The highest prevalence of small fluke eggs in human stools was recorded in the 20-29 years age group, particularly in males (90.4%). Three-quarters of human infections were light (less than 1000 eggs/g), the highest value (2975 eggs/g) being recorded in the 10-14 years age group. Identification of small flukes excreted by Laotian patients after treatment with praziquantel in Czechoslovakia revealed more cases with H. taichui than with O. viverrini. The results confirmed the simultaneous occurrence of O. viverrini and intestinal heterophyid flukes in the area studied.

In the Northwest Power Planning Council's 1987 Columbia River Basin Fish and Wildlife Program (NPPC 1987), the Council directed the Bonneville Power Administration (BPA) to construct two kokanee salmon (Oncorhynchus nerka) hatcheries as partial mitigation for the loss of anadromous salmon and steelhead incurred by construction of Grand Coulee Dam [Section 903 (g)(l)(C)]. The hatcheries will produce kokanee salmon for outplanting into Lake Roosevelt as well as rainbow trout (Oncorhynchus mykiss) for the Lake Roosevelt net-pen program. In section 903 (g)(l)(E), the Council also directed BPA to fund a monitoring program to evaluate the effectiveness of the kokanee hatcheries. The monitoring program included the following components: (1) a year-round, reservoir-wide, creel survey to determine angler use, catch rates and composition, and growth and condition of fish; (2) assessment of kokanee, rainbow, and walleye (Stizostedion vitreum) feeding habits and densities of their preferred prey, and; (3) a mark and recapture study designed to assess the effectiveness of different locations where hatchery-raised kokanee and net pen reared rainbow trout are released. The above measures were adopted by the Council based on a management plan, developed by the Upper Columbia United Tribes Fisheries Center, Spokane Indian Tribe, Colville Confederated Tribes, Washington Department ofmore » Wildlife, and National Park Service, that examined the feasibility of restoring and enhancing Lake Roosevelt fisheries (Scholz et al. 1986). In July 1988, BPA entered into a contract with the Spokane Indian Tribe to initiate the monitoring program. The projected duration of the monitoring program is through 1995. This report contains the results of the monitoring program from August 1988 to December 1989.« less

The body surface of an immature female Gnathostoma spinigerum found for the first time in the definitive host (Felis catus f. domestica) in Laos was studied using a scanning electron microscope. All types of cuticular spines, which are one of the most important features for species identification of gnathostomid nematodes, together with their spatial arrangement, are described and figured.

A taxonomic study of Proteocephalus species parasitizing cyprinid fishes in North America, namely Proteocephalus ptychocheilus Faust, 1920 and Proteocephalus cobraeformis Haderlie, 1953, has demonstrated their conspecificity with Proteocephalus torulosus (Batsch, 1786), a common parasite of cypriniform fishes (Cyprinidae and Cobitidae) in the Palaearctic Region. Proteocephalus ptychocheilus and P. cobraeformis are considered junior synonyms of P. torulosus.

The concentrations of cadmium (Cd), strontium (Sr) and uranium (U) were determined in whole eviscerated rainbow trout (Salmo gairdneri), trout liver, and water samples collected from a small stream receiving uranium mine discharge in northeast Washington state during high and low flow periods. Average water concentrations of Cd, Sr, and U downstream of the mine discharge increased 15, 5, and 100-fold, respectively. Cadmium levels increased in fish and liver samples during both sample periods. The weighted average fish concentration was eleven times higher than that for the control stream. There was no increase in fish and liver Sr levels below the mine discharge during either sample period. Increases in uranium concentrations were detected only in the fish where the weighted average low flow value was 15 times higher than the control stream value.

To test the olfactory hypothesis of salmon homing, fingerling coho salmon (Oncorhynchus kisutch) were exposed to low concentrations of an odorous synthetic chemical, morpholine during presmolt and smolting periods. Equal numbers of these fish were not exposed (controls). Both groups were stocked directly into Lake Michigan near Oak Creek, South Milwaukee Wisconsin. Another paired group of exposed and unexposed fish was released 13 km north of Oak Creek. During the adult spawning migration 18 mo later, morpholine was dripped into Oak Creek and the returning salmon were censused.For four experiments over 2 consecutive yr, the number of exposed and unexposed fish captured at the artificially scented stream were, 216 vs. 28, 437 vs. 49, 647 vs. 65, and 439 vs. 55. These differences were highly significant (P .05). These results confirm the existence of odor imprinting and long-term olfactory memory in coho salmon, It is possible that this mechanism is also used in the natural imprinting situation.