Balancing risks and rewards of alternate strategies in the seaward extent, duration and timing of fjord use in contemporary anadromy of brown trout (Salmo trutta)

BACKGROUND

Anadromy comprises a successful life-cycle adaptation for salmonids, with marine migration providing improved feeding opportunities and thus improved growth. These rewards are balanced against costs from increased energy expenditure and mortality risk. Anthropogenic-induced environmental changes that reduce benefits and/or increase costs of migration e.g., aquaculture and hydropower, may therefore result in adaptations disfavouring anadromy. We tagged brown trout (Salmo trutta) smolts (N = 175) and veteran migrants (N = 342), from five adjacent riverine populations located in Sognefjorden, the longest Norwegian fjord-system supporting anadromous brown trout populations (209 km). Over four years, 138 acoustic telemetry receivers were deployed to track migrations of tagged individuals from freshwater and throughout Sognefjorden. Detected movements were used to fit migration models and multi-state mark-recapture models of survival and movement for each life-stage. Seaward migration distance was modelled to examine the fitness consequences from alternate migration strategies, with these models used to simulate the extent of fjord-use by individuals and accompanying growth, fecundity and survival consequences. We compared these findings with mark-recapture data collected prior to aquaculture and hydropower development.

RESULTS

The telemetry data revealed that the outermost-fjord region was utilised by all populations albeit by few individuals. However, historical recaptures were located at a greater distance from the river mouth (87.7 ± 70.3 km), when compared to maximum migration distances of present-day counterparts (58.6 ± 54.9 km). River of origin influenced observed migratory behaviour and differential survival was estimated for each population and life-stage. The simulations based on telemetry-data models revealed a 30% and 23% difference in survival among populations for smolts and veteran migrants, respectively. At the individual-level, a long-distance migration strategy was rewarded with enhanced fecundity. However, the main contribution to population-level fecundity was overwhelmingly derived from middle-distance migrants, due to higher mortality rates and limited numbers of long-distant migrants.

CONCLUSIONS

We conclude that present-day anadromy is precarious, but potential risk varies considerably between life-stages and populations, even within a single fjord system. Our findings suggest that selection for extended migration is under pressure, we therefore stress the importance of monitoring and management actions to secure genetic variation pertinent to preserve fitness gains of anadromy.

Life cycle assessment of roads: Exploring research trends and harmonization challenges

The transparency, heterogeneity and hypotheses considered in the calculation of the environmental impacts of roads are still barriers to the identification of low-carbon solutions. To overcome this problem, this study presents an analysis of 94 papers obtained in a systematic literature review of the Scopus, Science Direct, Mendeley, Springer Link, and Web of Science databases. From a total of 417 road case studies, only 18% were found to be fully transparent, reproducible, and likely to present reliable results. The road design parameters of the speed limit were provided in 11% of the cases, and the average annual daily traffic data were provided in 42%. Limited data were found for the dimensions of road elements such as the number (77%) and width of lanes (33%), shoulders (15%), footpaths (5%), berms (1%) and foreslope (4%). The source of the life cycle inventory was presented in 57% of the case studies, impact assessment method was indicated in 22%, and the software utilized was listed in 50%. A lack of information was noted in the description of the types of materials employed in road projects. In addition, the large heterogeneity in the definitions of the functional unit, system boundary and in the reference study period of repair, replacement, rehabilitation or end-of-life for both flexible and rigid pavement does not support the identification of the most environmentally friendly solutions. Based on the results of the analysis, several recommendations for design parameters and life cycle assessment aspects are proposed to support a harmonized calculation of the environmental impacts of road projects.

Patterns of anaphylaxis after diagnostic workup: A follow-up study of 226 patients with suspected anaphylaxis

BACKGROUND

Most published studies on anaphylaxis are retrospective or register based. Data on subsequent diagnostic workup are sparse. We aimed to characterize patients seen with suspected anaphylaxis at the emergency care setting (ECS), after subsequent diagnostic workup at our Allergy Center (AC).

METHODS

Prospective study including patients from the ECS, Odense University Hospital, during May 2013-April 2014. Possible anaphylaxis cases were daily identified based on a broad search profile including history and symptoms in patient records, diagnostic codes and pharmacological treatments. At the AC, all patients were evaluated according to international guidelines.

RESULTS

Among 226 patients with suspected anaphylaxis, the diagnosis was confirmed in 124 (54.9%) after diagnostic workup; 118 of the 124 fulfilled WAO/EAACI criteria of anaphylaxis at the ECS, while six were found among 46 patients with clinical suspicion but not fulfilling the WAO/EAACI criteria at the ECS. The estimated incidence rate of anaphylaxis was 26 cases per 100 000 person-years and the one-year period prevalence was 0.04%. The most common elicitor was drugs (41.1%) followed by venom (27.4%) and food (20.6%). In 13 patients (10.5%), no elicitor could be identified. Mastocytosis was diagnosed in 7.7% of adult patients and was significantly associated with severe anaphylaxis. Atopic diseases were significantly associated only with food-induced anaphylaxis. Cofactors were present in 58.1% and were significantly associated with severe anaphylaxis.

CONCLUSION

A broad search profile in the ECS and subsequent diagnostic workup is important for identification and classification of patients with anaphylaxis. Evaluation of comorbidities and cofactors is important.

Prospective evaluation of the diagnostic value of sensitive KIT D816V mutation analysis of blood in adults with suspected systemic mastocytosis

BACKGROUND

Sensitive KIT D816V mutation analysis of blood has been proposed to guide bone marrow (BM) investigation in suspected systemic mastocytosis (SM). The aim of this prospective study was for the first time to compare the D816V status of the "screening blood sample" used to guide BM biopsy in suspected SM to the outcome of the subsequent BM investigation.

METHODS

Fifty-eight adult patients with suspected SM were included. The outcome of sensitive KIT D816V analysis of blood was compared to the result of the BM investigation.

RESULTS

Screening blood samples from 44 of 58 patients tested D816V-positive. In 43 of these, SM was subsequently diagnosed in the BM investigation. One patient with a D816V-positive screening sample was diagnosed with monoclonal MC activation syndrome. Screening blood samples from 14 patients tested D816V-negative. SM was subsequently diagnosed in five of these, whereas nine patients did not fulfill any diagnostic SM criteria (excluding tryptase criterion). Of the 48 SM patients, 90% tested D816V-positive. Thirteen SM patients presented with Hymenoptera venom-induced anaphylaxis, no skin lesions, and baseline serum tryptase ≤20 ng/mL. Of these, 92% tested D816V-positive in the screening blood sample.

CONCLUSION

This prospective study demonstrates that a D816V-positive result in a screening blood sample identifies SM among patients with hymenoptera venom-induced anaphylaxis in whom the diagnosis would most probably have been missed, with potential severe implications. The observed false-negative screening results also underline that BM investigation is mandatory in all adult patients with clear signs of, or highly suspected SM, regardless of the KIT mutation status.

Proliferative Response of Human T Lymphocytes to Porcine Fetal Brain Cells

Intracerebral grafting of porcine fetal brain cells is a potential treatment of neurodegenerative disorders in humans. Although it is well known that the survival of fetal pig brain cells in the rat brain requires immunosuppression, the response of human T lymphocytes to fetal pig brain cells is unknown. Here we report on the proliferative response of human T lymphocytes to freshly isolated cells and 14-18 days cultured cells from 28- or 35-day-old porcine fetal brains. After 5 days of mixed lymphocyte-brain cell culture, we observed no or only minor T cell responses to the freshly isolated brain cells, while both CD4 cells and CD8 cells proliferated in response to the cultured brain cells. Pretreatment of the cultured brain cells with heat-inactivated human serum significantly reduced the proliferative T cell response. The data suggest that the porcine fetal brain contains cells that can stimulate the human cellular immune system, and that this stimulation may be reduced by pretreatment of the fetal pig brain cells with human serum.

Early lactation production, health, and welfare characteristics of cows selected for extended lactation

Some cows are able to achieve relatively high milk yields during extended lactations beyond 305 d in milk, and farmers may be able to use this potential by selecting the most suitable cows for an extended lactation. However, the decision to postpone insemination has to rely on information available in early lactation. The main objectives of this study were, therefore, to assess the association between the information available in early lactation and the relative milk production of cows on extended lactation, and to investigate if this information can be used to differentiate time of first insemination between cows. Data came from 4 Danish private herds practicing extended lactation in which some cows are selected to have a delayed time of planned first insemination. Average herd size varied from 93 to 157 cows, and milk yield varied from 7,842 to 12,315 kg of energy-corrected milk (ECM) per cow per year across herds. The analysis was based on 422 completed extended lactations (427 ± 87 d), and each lactation was assigned to 1 of 3 (low, medium, and high) milk performance groups (MPG) within parity group within herd based on a standardized lactation yield. For cows in the high MPG, peak ECM yield, and ECM yield at dry off were significantly greater, the relative reduction in milk yield between 60 and 305 d in milk was significantly smaller, and a smaller proportion had a body condition score (scale: 1-5) at dry off of 3.5 or greater compared with cows in low MPG. Previous lactation days in milk at peak ECM yield and ECM yield at dry off were higher, the relative reduction in milk yield between 60 and 305 d in milk was smaller, and the number of inseminations per conception was higher for multiparous cows in high MPG compared with low. Current lactation ECM yield at second and third milk recording were greater for cows in high MPG compared with low. A principal component analysis indicated that variables related to fertility, diseases, and milk yield explained most of the total variation between primiparous cows, whereas variables related to milk yield, fertility, and days in milk at peak yield were the most dominating for multiparous cows. Our study indicated that milk yields in previous lactation and at second and third milk recording correlate well with milk production potential, and therefore, may be promising indicators when selecting the most suitable cows for extended lactation.

The effects of sustained aerobic swimming on osmoregulatory pathways in Atlantic salmon Salmo salar smolts

Atlantic salmon Salmo salar smolts were exposed to one of the four different aerobic exercise regimens for 10 weeks followed by a 1 week final smoltification period in fresh water and a subsequent eight-day seawater transfer period. Samples of gill and intestinal tissue were taken at each time point and gene expression was used to assess the effects of exercise training on both branchial and intestinal osmoregulatory pathways. Real-time polymerase chain reaction (PCR) analysis revealed that exercise training up-regulated the expression of seawater relevant genes in the gills of S. salar smolts, including Na(+) , K(+) ATPase (nka) subunit α1b, the Na(+) , K(+) , 2 Cl(-) co-transporter (nkcc1) and cftr channel. These findings suggest that aerobic exercise stimulates expression of seawater ion transport pathways that may act to shift the seawater transfer window for S. salar smolts. Aerobic exercise also appeared to stimulate freshwater ion uptake mechanisms probably associated with an osmorespiratory compromise related to increased exercise. No differences were observed in plasma Na(+) and Cl(-) concentrations as a consequence of exercise treatment, but plasma Na(+) was lower during the final smoltification period in all treatments. No effects of exercise were observed for intestinal nkcc2, nor the Mg(2+) transporters slc41a2 and transient receptor protein M7 (trpm7); however, expression of both Mg(2+) transporters was affected by salinity transfer suggesting a dynamic role in Mg(2+) homeostasis in fishes.

Long-term hypo-osmoregulatory capacity in downstream migrating Atlantic salmon Salmo salar L. smolts

The duration of hypo-osmoregulatory capacity in downstream migrating Atlantic salmon Salmo salar L smolts previously stocked as startfed young-of-the year (YOY) parr was tested in the River Dalåa from mid-May to late-June 1999. Hypo-osmoregulatory capacity, measured as plasma osmolality and chloride, was assessed after seawater (SW) challenge tests (168 h, salinity = 35). All S. salar exhibited sufficient hypo-osmoregulatory capacity at the initiation of downstream migration in mid-May. Migrating S. salar smolts caught in mid-May and retained in fresh water displayed no signs of de-smoltification as they maintained hypo-osmoregulatory capacity through June. This indicates a physiological smolt window that lasts a minimum of 6 weeks (330 degree days; D°) for hatchery-produced S. salar smolts stocked as YOY parr. Based on the observed river migration speeds, it can be assumed that the S. salar smolts entered SW 2-4 weeks after initiation of migration in the upper parts of the River Dalåa. Hence, based on smolt migration and SW tolerance, it is suggested that stocking of YOY parr is a viable enhancement strategy in the River Dalåa.

Proposed diagnostic algorithm for patients with suspected mastocytosis: a proposal of the European Competence Network on Mastocytosis

Mastocytosis is an emerging differential diagnosis in patients with more or less specific mediator-related symptoms. In some of these patients, typical skin lesions are found and the diagnosis of mastocytosis can be established. In other cases, however, skin lesions are absent, which represents a diagnostic challenge. In the light of this unmet need, we developed a diagnostic algorithm for patients with suspected mastocytosis. In adult patients with typical lesions of mastocytosis in the skin, a bone marrow (BM) biopsy should be considered, regardless of the basal serum tryptase concentration. In adults without skin lesions who suffer from mediator-related or other typical symptoms, the basal tryptase level is an important parameter. In those with a slightly increased tryptase level, additional investigations, including a sensitive KIT mutation analysis of blood leucocytes or measurement of urinary histamine metabolites, may be helpful. In adult patients in whom (i) KIT D816V is detected and/or (ii) the basal serum tryptase level is clearly increased (>25-30 ng/ml) and/or (iii) other clinical or laboratory features suggest the presence of 'occult' mastocytosis or another haematologic neoplasm, a BM investigation is recommended. In the absence of KIT D816V and other signs or symptoms of mastocytosis or another haematopoietic disease, no BM investigation is required, but the clinical course and tryptase levels are monitored in the follow-up. In paediatric patients, a BM investigation is usually not required, even if the tryptase level is increased. Although validation is required, it can be expected that the algorithm proposed herein will facilitate the management of patients with suspected mastocytosis and help avoid unnecessary referrals and investigations.

A rapid qPCR method for genetic sex identification of Salmo salar and Salmo trutta including simultaneous elucidation of interspecies hybrid paternity by high-resolution melt analysis

This study presents an improved duplex quantitative polymerase chain reaction (qPCR) method using the master sex-determining gene sdY as a marker for simultaneous genetic sex identification of salmonids of the Salmo genus and paternity elucidation for Salmo salar × Salmo trutta hybrids. This method will provide a new, simple and economical molecular tool for ecological studies of these species as well as for aquaculture purposes.

Abstract P3-05-03: HER2-CONNECT® pathologist-assisted image analysis algorithm for HER2 IHC interpretation improves correlation with HER2 FISH results

Background: HER2 testing by immunohistochemistry (IHC) is prone to inter-observer variability and subjective interpretation. Pathologist-assisted digital image analysis is recommended in the CAP/ASCO guidelines to improve interpretive consistency. As a quality benchmark, HER2 IHC results should correlate with HER2 fluorescence in-situ hybridization (FISH) in >95% of positive and negative cases. HER2-CONNECT® (Visiopharm, Hoersholm Denmark) is a digital analysis algorithm that scores stained membrane interconnectivity rather than relying solely on staining of individual cells. As such, it can be thought of as a surrogate for the so-called “chickenwire” pattern characteristic of true HER2 positive tumors. In this study we applied HER2-CONNECT® analysis with pathologist quantitative interpretation (HC+PQI) to a set of breast tumors with known HER2 FISH status to assess concordance.

Design: Breast carcinoma tissue sections previously stained with HER2 IHC (HercepTest) and interpreted manually were retrospectively re-submitted for HC+PQI. These included core and excisional biopsies from primary and metastatic sites. Fixation times were documented within recommended guidelines. HER2 FISH (PathVysion) was performed on all cases. Using connectivity scores on a scale of 0 - 1.0 from the analyzed regions, a pathologist determined the overall% of HER2 positive tumor cells in the sample (since HER2-CONNECT reports connectivity, but not tumor cell quantitation) and reported a final score per CAP/ASCO guidelines (<10% = 1+, 10-30% = 2+, >30% = 3+).

Results: 190 cases comprised the analysis set, including 77 3+, 73 2+, and 40 0/1+ as scored in the original reports. 66 cases were HER2 FISH amplified (64/77, 83% of the original 3+ cases and 2/73, 2.7% of 2+ cases) and 6 cases were FISH equivocal. None of the 0/1+ cases were HER2 FISH amplified. Using HC+PQI, the new scores were 67 3+, 68 2+, and 55 1+. Correlation between HC+PQI and HER2 FISH was 95.5% (64/67) for 3+/amplified and 100% (55/55) for <2+/nonamplified (overall concordance 97.5%). Using FISH as the gold standard, the HC+PQI interpretation reduced the false positive rate from 13% (15/108) to 3% (4/108). 17 of 63 HER2 nonamplified samples originally scored 2+ were changed to 1+ on HC+PQI (i.e. reduction of FISH testing by 27% (17/63)).

Conclusions: Relative to the original report scores, HC+PQI improved correlation with HER2 FISH and reduced the overall number of 2+ results (potentially reducing the number of FISH tests required). These data also objectively highlight the importance of the “chickenwire” pattern in positive result interpretation for HER2.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P3-05-03.

Seawater tolerance and post-smolt migration of wild Atlantic salmon Salmo salar × brown trout S. trutta hybrid smolts

High levels of hybridization between Atlantic salmon Salmo salar and brown trout Salmo trutta have been reported in the River Driva. This study presents the underlying mechanisms of development of seawater (SW) tolerance and marine migration pattern for S. salar×S. trutta hybrids. Migrating S. salar×S. trutta hybrid smolts caught in the River Driva, Norway (a river containing Gyrodactylus salaris), displayed freshwater (FW) gill Na(+), K(+) -ATPase (NKA) activity levels of 11·8 µmol ADP mg protein h(-1), which were equal to or higher than activity levels observed in S. salar and S. trutta smolts. Following 4 days of SW exposure (salinity 32·3), enzyme activity remained high and plasma ion levels were maintained within the normal physiological range observed in S. salar smolts, indicating no signs of ion perturbations in S. salar×S. trutta hybrids. SW exposure induced an increase in NKA α1b-subunit mRNA levels with a concurrent decrease in α1a levels. Salmo salar×S. trutta post-smolts migrated rapidly through the fjord system, with increasing speed with distance from the river, as is often seen in S. salar smolts. The present findings suggest that S. salar×S. trutta smolts, as judged by the activity and transcription of the NKA system, regulation of plasma ion levels and migration speed more closely resemble S. salar than S. trutta.

Assessment of coronary artery disease using coronary computed tomography angiography in patients with aortic valve stenosis referred for surgical aortic valve replacement

BACKGROUND

In patients referred for aortic valve replacement (AVR) a pre-surgical assessment of coronary artery disease is mandatory to determine the possible need for additional coronary artery bypass grafting. The diagnostic accuracy of coronary computed tomography angiography (coronary CTA) was evaluated in patients with aortic valve stenosis referred for surgical AVR.

METHODS

Between March 2008 and March 2010 a total of 181 consecutive patients were included. All patients underwent pre-surgical coronary CTA (64- or 320-detector CT scanner) and invasive coronary angiography (ICA). The analyses were performed blinded to each other.

RESULTS

The mean ± SD age of the included patients was 71 ± 9 years and 59% were male. The prevalence of significant coronary artery stenosis >70% by ICA was 36%. Average heart rate during coronary CTA was 65 ± 16 b pm. In a patient based analysis 94% of the patients (171/181) were considered fully evaluable. Coronary CTA had a sensitivity of 68%, a specificity of 91%, a positive predictive value of 81%, and a negative predictive value of 83%. Advanced age, obstructive lung disease, NYHA function class III/IV, and high Agatston score were found to be significantly associated with disagreement between ICA and coronary CTA in univariate analysis.

CONCLUSION

In patients with aortic valve stenosis referred for surgical AVR the diagnostic accuracy of coronary CTA to identify significant coronary artery disease is moderate. Coronary CTA may be used successfully in a subset of patients with low age, no chronic obstructive lung disease, NYHA function class<III and low coronary Agatston score.

Effects of production intensity and production strategies in commercial Atlantic salmon smolt (Salmo salar L.) production on subsequent performance in the early sea stage

A data set from commercial Atlantic salmon (Salmo salar L.) producers on production intensity and production strategies in smolt tanks (N = 63-94) was obtained during 1999-2006. The effects of production intensity on subsequent fish mortality and growth during the early sea phase (90 days) were examined by principal component analysis and subsequent generalized linear model analysis. Levels of accumulated metabolites (CO(2), total ammonia nitrogen and NH(3)), and information provided by producers (production density (kg fish m(3-1)), specific water use (l kg fish(-1) min(-1)) and oxygen drop (mg l(-1)) from tank inlet to tank outlet), were used as predictor variables. In addition, several other welfare relevant variables such as disease history, temperature during freshwater and sea stage; season (S1) or off-season (S0) smolt production; and the use of seawater addition during the freshwater stage were analyzed. No strong intensity effects on mortality or growth were found. CO(2) levels alone (P < 0.001, R(2) = 0.16), and in combination with specific water use (R(2) = 0.20), had the strongest effect on mortality. In both cases, mortality decreased with increasing density. For growth, the intensity model with the most support (R(2) = 0.17) was O(2) drop, density and their interaction effects, resulting in the best growth at low and high intensity, and poorer growth at intermediate levels. Documented viral disease outbreaks (infectious pancreatic necrosis and two cases of pancreas disease) in the sea phase resulted in significantly higher mortalities at 90 days compared with undiagnosed smolt groups, although mortalities were highly variable in both categories. The temperature difference between the freshwater stage and seawater had a small, but significant, effect on growth with the best growth in groups stocked to warmer seawater (P = 0.04, R(2) = 0.06). S0 and S1 smolt groups did not differ significantly in growth, but the mortality was significantly (P = 0.02) higher in S1 groups. Seawater addition as a categorical variable had no significant effects, but when analyzed within the seawater addition group, intermediate salinities (15-25 ppt) gave the best results on growth (p = 0.04, R(2) = 0.15). Production intensity had small explanatory power on subsequent seawater performance in the analyzed smolt groups. If anything, the analysis shows a beneficial effect of intensive production strategies on subsequent performance. Analysis of the various production strategies indicates better survival of S0 compared with S1 smolt groups, improved growth when stocked in seawater warmer than freshwater, and a negative effect of viral disease outbreaks on survival. The results clearly demonstrate the difficulty of extrapolating results from experimental work on fish welfare and production intensity variables to commercial production. On the other hand, the presented results may simply demonstrate that the traditional fish welfare criteria growth and mortality may not suffice to evaluate welfare consequences of suboptimal water quality or production strategies in the aquaculture industry.

Effect of nutritional status and sampling intensity on recovery after dorsal aorta cannulation in free-swimming Atlantic salmon (Salmo salar L.)

Recovery from implantation of a cannula in the dorsal aorta (DA) of Atlantic salmon (Salmo salar) was studied in relation to nutritional status and sampling intensity. The incentive for the study was the inconsistency between published reports and our own experience of recovery and longevity of fish exposed to this protocol. In two studies using starved fish, blood (0.3 ml) was sampled 0, 1 and 24 h after DA-cannulation, and thereafter at 48 and 72 h and thereafter once weekly for four weeks. In a third study using fed fish, four consecutive samples (0, 3, 6 and 12 h after a meal) were obtained twice a week over a four-week period. All fish displayed a sharp increase in pCO(2) and haematocrit (Hct) during surgery, followed by a marked raise in cortisol, glucose, sodium and potassium (1 h). pCO(2), pH and Hct approached baseline levels as early as the 1 h post-surgery sample, while this was not the case for cortisol and electrolytes before the 24 h post-surgery sample. Glucose did not display any significant changes post surgery. From then on, all variables displayed minor but non-significant (P > 0.05) changes indicating a steady state close to baseline values for unstressed fish. This pattern was independent of sampling procedure, i.e. repeated single or multiple samples and thus volume of blood removed. Nutritional status (fed vs. starved) did not affect post-surgical recovery pattern. Only K(+) and Hct displayed consistent and significant post-prandial patterns. We found marked differences between baseline level of cannulated fish and uncannulated control fish, in pH, K(+) and Hct indicating that cannulation may be the preferred method to obtain representative resting values in fish.

Developments in greenhouse gas emissions and net energy use in Danish agriculture - how to achieve substantial CO(2) reductions?

Greenhouse gas (GHG) emissions from agriculture are a significant contributor to total Danish emissions. Consequently, much effort is currently given to the exploration of potential strategies to reduce agricultural emissions. This paper presents results from a study estimating agricultural GHG emissions in the form of methane, nitrous oxide and carbon dioxide (including carbon sources and sinks, and the impact of energy consumption/bioenergy production) from Danish agriculture in the years 1990-2010. An analysis of possible measures to reduce the GHG emissions indicated that a 50-70% reduction of agricultural emissions by 2050 relative to 1990 is achievable, including mitigation measures in relation to the handling of manure and fertilisers, optimization of animal feeding, cropping practices, and land use changes with more organic farming, afforestation and energy crops. In addition, the bioenergy production may be increased significantly without reducing the food production, whereby Danish agriculture could achieve a positive energy balance.

Lack of arterial PO2 downregulation in Atlantic salmon (Salmo salar L.) during long-term normoxia and hyperoxia

Regulation of arterial partial pressure of O2 (PaO2) in Atlantic salmon (Salmo salar) was investigated during resting conditions in normoxic and hyperoxic water. Dorsal aorta cannulated adult Atlantic salmon (1.2-1.6 kg, n=8) were exposed to 2 week sequential periods of normoxia [16.7±1.1 kPa (mean±SD)] and hyperoxia (34.1±4.9 kPa) in individual tanks containing seawater (33.7±0.2 ppt) at stable temperature conditions (8.7±0.7°C) and a light regime of L:D=12:12. Tank design and sampling procedures were optimized to provide suitable shelter and current for the fish, and to allow repeated, undisturbed sampling of blood from free-swimming fish. Fish were sampled regularly through the experimental period. PwO2, PaO2, blood ion composition (Na+, K+, Cl-), acid-base status (pH, PCO2, HCO3-), haematocrit and glucose were measured. The most frequently observed PaO2 values were in the range of 60-80% of PwO2, both during normoxia and hyperoxia, and PaO2 values were significantly lower during normoxia than during hyperoxia. Blood pH, PCO2 and HCO3- were significantly elevated during hyperoxia, while, Na+, Cl- and Hct were significantly lower. K+ and glucose showed no significant differences. This study demonstrates a lack PaO2 regulation in Atlantic salmon to low partial pressures, in contrast to previous reports for many aquatic gill breathing animals. Both during normoxia and hyperoxia, PaO2 reflects PwO2, and alterations in external PO2 consequently result in proportional arterial PO2 changes. Physiological adaptation to hyperoxia, as illustrated by changes in several blood parameters, does not include down-regulation of PaO2 in Atlantic salmon. The lack of PaO2 regulation may make Atlantic salmon vulnerable to the oxidative stress caused by increased free radical formation in hyperoxic conditions.

Seawater tolerance in Atlantic salmon, Salmo salar L., brown trout, Salmo trutta L., and S. salar × S. trutta hybrids smolt

High levels of hybridization between Atlantic salmon (Salmo salar) and brown trout (Salmo trutta) have been reported in the Gyrodactylus salaris infected Rivers Vefsna and Driva in Norway. The survival and behaviour during the sea phase of such hybrids is unknown. The reported work documents ionoregulatory status after 24 h seawater challenge tests (24hSW) and gill Na+/K+-ATPase (NKA) activity of migrating wild smolts of Atlantic salmon, brown trout and hybrids at two sampling dates during the 2006 smolt run in River Driva. Salmon, trout and hybrids contributed to 27, 52 and 21% of the catches, respectively. The large contribution of hybrids suggests both a high hybridization rate and a high survival rate from fry to smolt. Both salmon and hybrids had a well-developed seawater tolerance at the time of downstream migration, revealed by small ionoregulatory effects and no or low mortality rates during the 24hSW tests. The trout were not fully adapted to seawater, and high mortality rates were observed (71 and 92%) during the 24hSW tests. The NKA activity was not significantly different between salmon and hybrids. Most of the hybrids were physiologically capable of direct entry to full strength seawater. The incomplete seawater tolerance in trout compared to salmon corresponds well with differences in life-history patterns between these two species. The life history strategy of the hybrids during the sea phase is not known, and further investigations on the marine behaviour and survival is needed to evaluate the role of hybrids in the risk of spreading G. salaris to nearby river systems.

Cost variation in diabetes care delivered in English hospitals

AIMS

We analysed the in-hospital costs of diabetic patients admitted to English hospitals and aimed to assess what proportions of cost variation are explained by patient and hospital characteristics.

METHODS

We used Hospital Episode Statistics and reference costs for all patients admitted to diabetes care for all English hospitals for the financial year 2005/2006. Our sample included 31 371 patients admitted to 148 hospitals. We applied a multi-level approach. We analysed the relationship between patient costs and patient characteristics. We estimated the average cost of being treated in each hospital after controlling for patient characteristics. In addition, we explored why these average costs vary across hospitals.

RESULTS

Much of the variation in the costs of controlling diabetes was driven by the Healthcare Resource Group to which the patient was allocated, but costs were also higher for patients who were transferred between hospitals, suffered infections and other complications, or for those who died in hospital. Even so, approximately 8-9% of the variation in costs was related to the hospital in which the patient was treated, with geographical variation in factor prices being the prime reason for this variation. The volume of patients, and the number and diversity of specialties involved in caring for diabetic patients did not explain the variation in the cost of treating diabetic patients across hospitals.

CONCLUSIONS

Healthcare Resource Groups and diagnostic markers are significant patient-related cost drivers in diabetes care. Costs are not lower in hospitals with a high volume of patients and where diabetes care is concentrated in few specialties.

Characterization of a porcine variable number tandem repeat sequence specific for the glucosephosphate isomerase locus

A variable number of tandem repeat from a porcine glucosephosphate isomerase intron has been isolated and sequenced. The repeat has a unit size of 39 bp, is highly conserved and is present in at least 14 copies. Flanking sequences show a sequence periodicity of 53-54 bp and some sequence homology to the 39 bp repeat. A considerable part of the genomic DNA has been lost during subcloning and is considered to be deletion prone or refractory to propagation in E. coli. The tandem repeat is locus specific and detects at least six alleles in BamHI digested porcine DNA. No homology to other tandem repeat sequences has been found.

DNA sequence of the skeletal muscle calcium release channel cDNA and verification of the Arg615----Cys615 mutation, associated with porcine malignant hyperthermia, in Norwegian landrace pigs

Porcine calcium release channel (CRC) cDNA from skeletal muscle has been cloned and sequenced. The deduced amino acid sequence showed 97% identity to the corresponding rabbit and human sequences. Using oligonucleotide primers based on the nucleotide sequence, CRC cDNA fragments from seven pigs representing HALNN, HALNn and HALnn genotypes have been amplified. Sequencing and restriction digestion of the amplified cDNA confirm that the reported C----T mutation, which gives rise to Arg615----Cys615 change in the calcium release channel, is associated with the halothane sensitive allele in Norwegian Landrace pigs. The mutation may alter the reactivity of a neighbouring serine residue which is potentially phosphorylated.

Isolation and sequencing of porcine lipoprotein lipase cDNA and its use in multiallelic restriction fragment length polymorphism detection

Porcine lipoprotein lipase (LPL) cDNA has been cloned and sequenced. The deduced amino acid sequence shows a high degree of identity to LPL from other species, and contains the Ser/His/Asp triade characteristic of serine proteases and esterases. A repetitive element is present in the 3'-untranslated region of the cDNA. A partial cDNA covering the coding region of LPL detects three restriction fragment length polymorphisms with HindIII. This represents the first marker assigned to porcine chromosome 14.

Fecundity, 17beta-estradiol concentrations and expression of vitellogenin and estrogen receptor genes throughout the ovarian cycle in female Eastern mosquitofish from three lakes in Florida

Previous studies of Eastern mosquitofish in contaminated Lake Apopka, Florida, have documented reduced sperm count and sexual behaviour in males but increased fecundity and liver weight in females, compared to nearby reference lakes. Liver weight can be an indicator of vitellogenin (Vtg) synthesis in fish, such as the mosquitofish. It was therefore hypothesized that estrogenic organochlorine pesticides, present at elevated concentrations in animals from Lake Apopka, could cause the reproductive disorders in males, as well as increase female fecundity. We initiated a test of this hypothesis by examining the relationship between 17beta-estradiol (E2) tissue concentrations, hepatic estrogen receptor alpha (ERalpha) and Vtg A, B and C gene expression and fecundity in sexually mature female Eastern mosquitofish from Lake Apopka and two reference lakes, Lake Woodruff and Lake Orange. We observed that female Eastern mosquitofish from one site in contaminated Lake Apopka produced fewer but bigger embryos than females from the other Lake Apopka site and two reference sites. However, female E2 concentrations and hepatic ERalpha and Vtg A, B and C gene expression showed no overall differences among the four sites, and it is therefore unlikely that the differences in fecundity were caused by estrogenic EDCs. In addition, we observed no induction of any of the three Vtg genes in male Eastern mosquitofish at the two Lake Apopka sites. Based on the well-documented high sensitivity of Vtg induction as a biomarker of xenoestrogen exposure, the evidence from the present study does not support the hypothesis that estrogenic EDCs are affecting reproduction in Eastern mosquitofish living in Lake Apopka. Our experimental design tested specifically for effects mediated via the ER, and e.g. antiandrogenic DDT metabolites might still be of importance for mosquitofish reproduction in Lake Apopka.

Effects of grazing system on production and parasitism of dairy breed heifers and steers grazing wet marginal grasslands

Production and endoparasitism of first grazing season Holstein heifers and steers were investigated over two grazing seasons. Studies were conducted on low-lying peaty soil. In year 2000, 40 animals were included in a 2×2 factorial, replicated experiment with two sexes (steers v. heifers) and two stocking rates (SR): normal v. low (840 v. 420 kg live weight per ha at turn-out) in a set stocking grazing system. Mean grass heights over the entire season were 6·3±4·8 cm (mean±s.d.) at normal SR and 9·8±6·1 cm at low SR. Mean daily live-weight gain during grazing was significantly (P<0·001) lower at normal SR (256±147 g) compared with low (468±142 g) but sex did not significantly affect the daily gain. Serum pepsinogen levels, indicating uptake of gastric nematodes, were higher at normal SR and consistently higher in steers compared with heifers, although not significantly. In 2001 the experiment included 80 animals in a 2×2 factorial experiment with two sexes (steers v. heifers), two grazing systems (set stocking and two-paddock rotation) and four replicates. Pasture quality was low, 570 g digestible organic matter per kg organic matter and 139 g crude protein per kg dry matter on average, independent of grazing system. Mean daily live-weight gain was not significantly affected by grazing system. A tendency (P=0·07) to lower daily gain for the heifers than for steers was observed (427±161 g v. 474±138 g). Lower levels of pasture contamination with parasites were observed in the paddocks without grazing up to mid July but otherwise rotation did not prevent parasite infections. It is concluded that first grazing season steers and heifers have the same potential for growth when grazing marginal areas with low pasture quality. Set stocking or the two-paddock rotation scheme did not affect productivity or level of parasite infection at the end of season. Parasite infections became a problem at high SR. SR is an important factor for both daily live-weight gain per animal and total production per ha. However, due to the very heterogeneous structure of marginal areas there is a need for other indicators than kg live weight per ha at turn-out in order to define a clear relationship between stocking rate and production.

Effects of hypo- and hyperoxia on transcription levels of five stress genes and the glutathione system in liver of Atlantic cod Gadus morhua

The transcript levels of three genes coding for antioxidants, Cu/Zn superoxide dismutase (SOD), catalase and phospholipid hydroperoxide glutathione peroxidase (GSH-Px), and those of two stress proteins,metallothionein (MT) and CYP1A, were examined with real-time quantitative (q)RT-PCR in hepatic tissue of Atlantic cod exposed to 46% (hypoxia), 76%(normoxia) and 145% (hyperoxia) O2 saturation (tank outlet). To evaluate the oxidative stress state, the levels of total glutathione (tGSH),reduced glutathione (GSH) and oxidized glutathione (GSSG) and subsequently the oxidative stress index (OSI), were determined in the same tissue samples. The transcript level of GSH-Px was significantly upregulated in fish exposed to hyperoxia, and significantly downregulated in fish exposed to hypoxia,compared to the normoxia group. Significant downregulation was also found for SOD and CYP1A transcriptional levels in fish exposed to hypoxia. The transcript levels of catalase and MT did not change in liver of cod exposed to suboptimal oxygen levels. No significant differences were seen between the groups for tGSH, GSH, GSSG or OSI. Prolonged exposure to unfavourable oxygen saturation levels did not alter the OSI, indicating that the antioxidant glutathione system is maintained at an unchanged level in liver of the examined cod.

mRNA expression of antioxidant enzymes (SOD, CAT and GSH-Px) and lipid peroxidative stress in liver of Atlantic salmon (Salmo salar) exposed to hyperoxic water during smoltification

The mRNA levels of three antioxidant genes, Cu/Zn superoxide dismutase (SOD), catalase (CAT) and phospholipid hydroperoxide glutathione peroxidase (GSH-Px), were quantified with real-time qRT-PCR in liver of Atlantic salmon Salmo salar exposed to 80% (normoxia), 105% and 130% O2 saturation for 54 days. The salmon were then translocated and exposed to 90% and 130% O2 saturation for additional 72 days during smoltification. TBARS and vitamin E levels in liver and the levels of oxidized glutathione (GSSG), total glutathione (GSH) and the resulting oxidative stress index (OSI) in blood were quantified as traditional oxidative stress markers. No significant mean normalized expression (MNE) differences of SOD, CAT or GSH-Px were found in liver after hyperoxia exposure at the two sampling times. Significantly decreased OSI was found in smolt exposed to 130% O2 saturation after 126 days (n = 18, P < 0.0001), indicating hyperoxia-induced oxidative stress. No effects were seen on growth, or on the levels of thiobarbituric reactive substances (TBARS) and vitamin E in liver after the exposure experiment. Overall, the mRNA expression of SOD, CAT and GSH-Px in liver related poorly with the hyperoxic exposure regimes, and more knowledge are needed before the expressed levels of these antioxidant genes can be applied as biomarkers of hyperoxia in Atlantic salmon.

Monitoring transfusion practice--a computerized procedure

As the description of transfusion practice over time requires the handling of massive amounts of data, and because the majority of records have until now been paper-based, little is known about the epidemiology of blood transfusion. Furthermore, most previous studies have collected data manually from patient records or from computerized registers created solely for study purposes. We describe a procedure for monitoring transfusion practices based exclusively upon the collection of data from the existing computerized registers. During the calendar years 1997 and 1998, more than 750 000 data records were collected from the blood transfusion registers, diagnosis and procedure registers, and clinical biochemistry registers at two university hospitals. Linking of the data required a unique and consistent identification of all data records. This was made possible by the national Personal Identification Number. In this way more than 98% of all transfusions could be identified and approximately 95% (77 950) could be connected to a principal diagnosis. The described procedure creates new opportunities for studies of transfusion practices both on a large scale and in richness of detail, and we propose to establish a network where transfusion practices data are available and comparable for individual departments, hospitals, whole regions, and possibly nations.