Accounting for early rearing density effects on growth in the genetic evaluation of rainbow trout, Oncorhynchus mykiss.

In fish breeding, full-sib families are often kept in separate tanks until individuals are large enough to be tagged and pooled. This practice induces substantial environmental variation common to full sibs (VFS) in BW. We used multigeneration data on rainbow trout to investigate how variation among families in early rearing density affects BW at different ages and environments (fresh water and sea), and whether variance parameters and ranking of breeding candidates change when density is either excluded or included as a regression term in a multitrait animal model. Increasing density displayed a consistent negative relationship with full-sib tank-mean BW at the end of fry-stage when family sizes were equalized (r2 of linear regressions 11 to 31%). In 4 out of 6 year classes, the significant negative association between density and BW also remained through the family-tank period until tagging at 6 mo of age (r2=3 to 19%). In some year classes, early density had a carry-over effect on later BW means, reaching up to the age of >2 yr (after the second and third growing season). Yet, the association was generally weaker at later ages and varied from nonexistent to both significantly negative and positive (r2=0 to 6%). For each BW, the inclusion of early density in genetic model primarily captured the variance that was otherwise attributable to VFS. The reduction of VFS was most pronounced in tagging BW (21% difference between the models), where common environmental effects were moderately high (c2=0.18 in the model without density). For later BW traits, the difference in VFS was 6 to 8% (c2=0.04 to 0.05). The changes in genetic, residual, and phenotypic variances were generally small in the model, including density. Similarly, only a slight change in the heritability estimate of any BW was found (differences of h2 0.2 to 1.3% between models). Correlations between EBV obtained by the 2 models were highly positive in each BW trait (r range 0.94 to 1.00), indicating that ranking of the breeding candidates remained consistent, regardless of whether density was accounted for or not. Our findings highlight the importance of equalizing family sizes to decrease VFS in rainbow trout growth. If selection is practiced for EBV of BW recorded at an age of >2 yr, and equalization is done early enough, the effects induced by different initial density can be sufficiently corrected for by the common full-sib effect in models used for genetic evaluation.

Supermagnetosonic jets behind a collisionless quasiparallel shock.

The downstream region of a collisionless quasiparallel shock is structured containing bulk flows with high kinetic energy density from a previously unidentified source. We present Cluster multispacecraft measurements of this type of supermagnetosonic jet as well as of a weak secondary shock front within the sheath, that allow us to propose the following generation mechanism for the jets: The local curvature variations inherent to quasiparallel shocks can create fast, deflected jets accompanied by density variations in the downstream region. If the speed of the jet is super(magneto)sonic in the reference frame of the obstacle, a second shock front forms in the sheath closer to the obstacle. Our results can be applied to collisionless quasiparallel shocks in many plasma environments.

The loss of ions from Venus through the plasma wake.

Venus, unlike Earth, is an extremely dry planet although both began with similar masses, distances from the Sun, and presumably water inventories. The high deuterium-to-hydrogen ratio in the venusian atmosphere relative to Earth's also indicates that the atmosphere has undergone significantly different evolution over the age of the Solar System. Present-day thermal escape is low for all atmospheric species. However, hydrogen can escape by means of collisions with hot atoms from ionospheric photochemistry, and although the bulk of O and O2 are gravitationally bound, heavy ions have been observed to escape through interaction with the solar wind. Nevertheless, their relative rates of escape, spatial distribution, and composition could not be determined from these previous measurements. Here we report Venus Express measurements showing that the dominant escaping ions are O+, He+ and H+. The escaping ions leave Venus through the plasma sheet (a central portion of the plasma wake) and in a boundary layer of the induced magnetosphere. The escape rate ratios are Q(H+)/Q(O+) = 1.9; Q(He+)/Q(O+) = 0.07. The first of these implies that the escape of H+ and O+, together with the estimated escape of neutral hydrogen and oxygen, currently takes place near the stoichometric ratio corresponding to water.

Direct and indirect selection of visceral lipid weight, fillet weight, and fillet percentage in a rainbow trout breeding program.

We assessed whether visceral lipid weight, fillet weight, and percentage fillet from BW, 3 traits laborious to record, could be genetically improved by indirect selection on more easily measured traits in farmed rainbow trout. Visceral lipid is discarded as waste during slaughter, influencing production efficiency and production costs. Fillet weight and fillet percentage directly influence economic returns in trout production. The study comprised 3 steps. First, we assessed the degree to which selection on percentage of visceral weight from BW indirectly changes visceral lipid weight and the size of intestines and internal organs. The phenotypic analysis of weights of viscera, intestines, visceral lipid, liver, and gonads measured from 40 fish revealed that phenotypic selection against visceral weight was most strongly directed to visceral lipid, and to a lesser degree to intestines and gonads. Because genetic relationships among these traits were not established, it is not known whether indirect selection leads to genetic responses. Second, we examined whether direct selection for the fillet traits could be replaced by indirect selection on BW, eviscerated BW, visceral weight, visceral percentage, head volume, and relative head volume (head volume relative to BW). The selection index calculations based on the quantitative genetic parameters obtained from multigenerational pedigree data showed that genetic improvement of fillet percentage through direct selection (selection accuracy, r(TI) = 0.54) was equally efficient compared with indirect selection on visceral percentage ( r(TI) = 0.54). Genetic improvement of fillet weight through direct selection (r(TI) = 0.56) was always more efficient than indirect selection, yet indirect selection for eviscerated BW ( r(TI) = 0.50) was almost as efficient as direct selection. Third, the expected genetic responses to alternative selection indices showed that improved fillet percentage was mainly a result of a moderate decrease in visceral weight rather than of a major increase in absolute fillet weight. Moreover, fillet percentage is challenging to improve, even if it exhibits moderate heritability (h(2) = 0.29). This is because fillet percentage displays low phenotypic variation. In conclusion, fillet weight and fillet percentage can be increased by indirect selection against visceral percentage and for high eviscerated BW.

Plasma acceleration above martian magnetic anomalies.

Auroras are caused by accelerated charged particles precipitating along magnetic field lines into a planetary atmosphere, the auroral brightness being roughly proportional to the precipitating particle energy flux. The Analyzer of Space Plasma and Energetic Atoms experiment on the Mars Express spacecraft has made a detailed study of acceleration processes on the nightside of Mars. We observed accelerated electrons and ions in the deep nightside high-altitude region of Mars that map geographically to interface/cleft regions associated with martian crustal magnetization regions. By integrating electron and ion acceleration energy down to the upper atmosphere, we saw energy fluxes in the range of 1 to 50 milliwatts per square meter per second. These conditions are similar to those producing bright discrete auroras above Earth. Discrete auroras at Mars are therefore expected to be associated with plasma acceleration in diverging magnetic flux tubes above crustal magnetization regions, the auroras being distributed geographically in a complex pattern by the many multipole magnetic field lines extending into space.

Transcriptional analysis of LPS-stimulated activation of trout (Oncorhynchus mykiss) monocyte/macrophage cells in primary culture treated with cortisol.

Primary immune responses to pathogen invasion are mediated by the innate immune system in which tissue macrophages play a key role. During infectious processes glucocorticoids generally may function to dampen inflammatory responses. In this study, the ability of cortisol to directly modulate the transcriptional response of rainbow trout macrophages to the cellular activator lipopolysaccharide (LPS) was investigated. The results indicate that cortisol significantly inhibits the well-described LPS-dependent induction of the expression of TNF-alpha2, a pro-inflammatory cytokine. In order to further characterize the molecular effects of LPS and the immunomodulatory role of cortisol, the in vitro macrophage response to LPS in the absence or presence of 12-h cortisol exposure was analyzed utilizing a salmonid-specific microarray platform. Genes that were stimulated or inhibited with LPS plus cortisol fell into several major functional groups. The first, a general "response" group comprising genes within ontology classes including the response to external stimuli, stress, humoral immunity and apoptosis, exhibited a significant increase after LPS stimulation, whereas suppression of this response was observed in the presence of cortisol. LPS stimulated other genes in a second group involved in cell signalling and also genes in a third group involved in the activation of transcription. Categories activated with cortisol were mainly related to various aspects of metabolism (including protein biosynthesis, binding and transport of ions) and structural proteins (mainly cytoskeleton and microtubules). The immunomodulatory action of cortisol on LPS-stimulated macrophages therefore appears more complex than simply the antagonism of LPS-induced transcriptional responses.

Solar wind-induced atmospheric erosion at Mars: first results from ASPERA-3 on Mars Express.

The Analyzer of Space Plasma and Energetic Atoms (ASPERA) on board the Mars Express spacecraft found that solar wind plasma and accelerated ionospheric ions may be observed all the way down to the Mars Express pericenter of 270 kilometers above the dayside planetary surface. This is very deep in the ionosphere, implying direct exposure of the martian topside atmosphere to solar wind plasma forcing. The low-altitude penetration of solar wind plasma and the energization of ionospheric plasma may be due to solar wind irregularities or perturbations, to magnetic anomalies at Mars, or both.

Lung sounds in asbestos induced pulmonary disorders.

The aim of the study was to compare the lung sounds in patients with asbestos related pulmonary disorders with findings in high-resolution computed tomography (HRCT), and with lung function variables, in order to find out associations of acoustic changes with radiological fibrosis, emphysema or with pulmonary gas transfer functions. Sixty-four patients with asbestos-related pleural disease, with or without pulmonary disease, were studied. Lung sound recording and analysis was carried out with a computerized lung sound analyser, and HRCT of the chest, as well as forced spirometry and diffusing capacity measurement were performed. The fibrosis score correlated positively with the quartile frequencies of the power spectrum of lung sounds in inspiration (f50) and expiration (f50) and crackle count in inspiration, as well as negatively with diffusing capacity. When the patients with crackling sounds and significant fibrosis were excluded (n=18), emphysema correlated negatively with expiratory quartile frequencies of the power spectrum, with f25 and f50. Furthermore, diffusing capacity correlated with inspiratory f25 and forced expiratory volume in one second with inspiratory f50 when crackles and fibrosis were excluded. Changes in lung sounds were significantly associated with radiologically verified abnormalities and gas transfer of pulmonary tissue. High sound frequencies were associated with fibrotic changes of the lung while low sound frequencies with pulmonary emphysema. Acoustic analysis gives complementary clinical information for evaluation of asbestos-related pulmonary disorders.

Fibrosis of the lung and pleura and long-term exposure to wollastonite.

OBJECTIVES: The purpose of this study was to determine whether long-term exposure to wollastonite causes fibrosis of the lung and pleura in humans. METHODS: Forty-nine workers (mean exposure 25 years) in a Finnish limestone-wollastonite mine and mill were examined. Their work histories and symptoms of chronic bronchitis were recorded. The chest radiographs were classified according to the classification of the International Labour Office (1980); a radiographic follow-up from 1981 to 1990 was included. Spirometry and diffusion capacity were measured. Four workers underwent high-resolution computed tomography (HRCT) and bronchoalveolar lavage (BAL). Lung tissue specimens were available for 2 workers. Mineral fibers and asbestos bodies were analyzed from the BAL fluid and lung tissue specimens, which were also analyzed for lung fibrosis. RESULTS: Two workers (4%) had small irregular lung opacities (ILO 1/0), 1 worker (2%) ILO 0/1 of the s/t type. HRCT revealed no parenchymal fibrosis in the 2 workers with the ILO 1/0 classification. Of the 9 workers (18%) with pleural plaques, 5 had been exposed to asbestos. Multivariate logistic regression analyses revealed no association of plaques with the duration of wollastonite or asbestos exposure. Wollastonite fibers or bodies were not found in any of the 4 workers who underwent BAL, nor in either of the workers whose lung tissue specimens were available. CONCLUSIONS: No evidence was found that long-term exposure to wollastonite causes parenchymal fibrosis of the lung and pleura. Furthermore, the findings indicate that wollastonite fibers are poorly retained in human lungs.

Mutations, tissue accumulations, and serum levels of p53 in patients with occupational cancers from asbestos and silica exposure.

In order to determine the relationship between mutations, tissue accumulations, and serum levels of p53 in occupational cancers, we used denaturing gradient gel electrophoresis and DNA sequencing of exons 5-9 of the p53 gene, immunohistochemical analysis for tissue identification of mutant p53 protein, and enzyme-linked immunosorbent assay for serum levels of mutant p53 protein to examine for such alteration in a cohort of individuals with workplace exposure to asbestos or silica, and resultant lung cancers or mesotheliomas. DNA analysis detected mutations in 5 of 18 (28%) tumors, and tissue accumulations of protein were detected in 7 of 20 (35%) tumors; the agreement between mutational and immunohistochemical analyses was significant (kappa = 0.62, P = 0.002). Serum elevations of protein were detected in 4 of 11 (36%) cases with available serum samples; the agreement between tissue alterations and serum elevations was also significant (kappa = 0.71, P = 0.017). In addition, based on the analysis of banked samples, serum results tended to be consistent over time prior to the diagnosis of disease (positive predictive value = 0.67, negative predictive value = 0.83). These results suggest that serum levels of p53 are reasonably accurate in reflecting tissue alterations in p53 at the gene and/ or protein level and may be early biomarkers of disease risk.

A molecular and epidemiological study on bladder cancer: p53 mutations, tobacco smoking, and occupational exposure to asbestos.

In this study, we found an unexpected association (crude odds ratio = 2.8; 95% confidence interval = 0.9-8.4) between definite work-related exposure to asbestos and carcinoma of the urinary bladder in a small group of patients (n = 28) initially recruited as referents for an epidemiological feasibility study on the occupational causes of lung cancer. We extended the study by using molecular methods to examine mutations in the p53 tumor suppressor gene in the same cases of bladder cancers. The same number of archival samples of transitional cell carcinoma, mainly of grade 3, were added to the analysis. We failed to show any association between occupational exposure to asbestos and p53 mutations among bladder cancer patients. We observed an increasing occurrence of p53 mutations in nonsmokers (5 of 17, 29%), former smokers (8 of 21, 38%), and current smokers (9 of 16, 56%) in that order; however, this was not statistically significant. The most prevalent type of mutation was G:C to A:T transition. Tumor grade was not associated with the frequency of mutations, but the higher stage (T3-T4) tumors appeared to have mutations more frequently than did the less invasive tumors (T1-T2).

Serum oncoproteins in asbestosis patients.

Using ELISAs, we determined the concentrations of transforming growth factor alpha (TGF-alpha), the extracellular domain of the erbB-2 receptor (erbB-2 ECD), and mutant p53 protein in stored serum samples of asbestosis patients with and without cancer and control subjects (without asbestosis or cancer). The percentage of individuals in these three groups with increased serum concentrations of TGF-alpha, erbB-2 ECD, and mutant p53, respectively, were: asbestosis patients with cancer, 36%, 16%, 19%; asbestosis patients without cancer, 38%, 19%, 6%; control subjects, 0%, 5%, 10%. Although differences in serum positivity for these oncoproteins were apparent among these groups, the differences did not achieve statistical significance (P > 0.05). In several of the cancer cases, increased concentrations of TGF-alpha, erbB-2 ECD, and mutant p53 were also detected in the stored serum samples collected years before the clinical diagnosis of disease.

Tumour necrosis factor-alpha (TNF-alpha) in patients who have asbestosis and develop cancer.

OBJECTIVES: Concentrations of tumour necrosis factor-alpha (TNF-alpha) were assayed by radioimmunoassay in serum samples collected between 1981 and 1987 from 111 patients with asbestosis who were at a high risk of cancer. Follow up of these patients until 1993 showed that 38 had developed cancer (27 lung, three mesotheliomas, and eight diverse malignancies). RESULTS: The mean serum concentrations of TNF-alpha given in fmol/100 microliters serum in all the cases with cancer (14.1) and the cases with lung cancer (13.6) were significantly higher (P < 0.05) than the mean concentrations in the exposed controls (10.5). A positive increase was considered to be any value that was > 2 SDs above the mean of the exposed controls. 22% (six of 27) of the cases with lung cancer were positive compared with 4% (three of 73) of the exposed controls, a significant difference (P < 0.001). The serum concentrations of TNF-alpha correlated moderately with cancer (r = 0.3), lung cancer (r = 0.3), and Neu oncoproteins and epidermal growth factor receptor (EGFR) (r = 0.3, 0.5 respectively). Also, there was a significant correlation between development of cancer and severity or progression of asbestosis. There was no correlation between the concentrations of TNF-alpha and severity or progression of asbestosis. CONCLUSIONS: These results showed high concentrations of TNF-alpha in the patients who had cancer. TNF-alpha may offer an auxiliary method in early diagnosis of cancers related to asbestosis.

The detection of increased amounts of the extracellular domain of the epidermal growth factor receptor in serum during carcinogenesis in asbestosis patients.

Overexpression of the epidermal growth factor receptor (EGFr) has been implicated in the pathogenesis of a wide variety of human malignancies and may be related to asbestos-induced carcinogenesis. Overexpression of the EGFr can be detected immunologically by quantitation of the extracellular domain (ECD) in the extracellular fluid in vitro and in serum in vivo. An enzyme-linked immunosorbent assay (ELISA) for the EGFr ECD was used to examine banked serum samples of 38 asbestosis patients who subsequently developed cancer, 72 age-sex-race-smoking-asbestos exposure matched asbestosis controls without cancer, and 20 age-sex-race-smoking matched nonasbestosis noncancer controls. The mean serum level for the EGFr ECD in the cancer cases (636 +/- 299 fmol/ml) was statistically significantly elevated (P < 0.05) in comparison to the mean level in the asbestosis controls (546 +/- 147 fmol/ml) or the nonasbestosis controls (336 +/- 228 fmol/ml). Defining a positive elevation of the serum EGFr ECD as any value more than 2 standard deviations above the nonasbestosis control mean, 7 (18%) of the cancer cases were positive compared to 4 (6%) of the asbestosis controls and one (5%) of the nonasbestosis controls. In addition, all of these cancer cases had positive serum samples prior to the time of disease diagnosis (average = 5.1 years). These results suggest that serum EGFr ECD may be elevated at an early stage of carcinogenesis in some asbestosis patients and that further prospective study of the utility of this biomarker is warranted.

Increased incidence of lung and skin cancer in Finnish silicotic patients.

Cancer incidence during 1953 to 1991 in 811 Finnish silicotic patients diagnosed between 1936 and 1977 was evaluated. In comparison with the general population, excesses were observed for all cancers (standardized incidence ratio, 1.7 [95% confidence interval, 1.4 to 1.9]), all lung cancers (2.9 [2.4 to 3.5]), squamous cell lung cancers (3.3 [2.3 to 4.5]), and skin cancers: melanoma (3.0 [0.8 to 7.6]) and nonmelanoma (2.9 [1.2 to 6.1]). Confounding by tobacco smoking did not explain the lung cancer increment. The consistency of the association between silicosis and lung cancer across a large number of studies suggests that silicosis represents a direct or indirect lung cancer hazard. The skin cancer excess, a relatively novel finding, may be explained either by carcinogens in foundries, or silica-induced lowering of immunocompetence, which would lead to a more pronounced effect of solar ultraviolet radiation.

Pancreatic cancer in industrial branches and occupations in Finland.

An examination of the risk of pancreatic cancer associated with occupation, by industrial branch and job title, was undertaken in a nationwide case-referent study in Finland. The results are based on job history information from the next-of-kin of 625 incident cases of primary malignant exocrinic pancreatic neoplasms, and of 1,700 cancer referents (stomach, colon, and rectum). All cases and referents were between 40 and 74 years at diagnosis. The diagnoses were made in 1984-87, and both cases and referents were known to be dead by April 1, 1990. The source of the cases and referents was the Finnish Cancer Registry. Increases in risk of pancreatic cancer were suggested for a small number of industrial branches and job titles, including stone mining (odds ratio 3.7), cement and building materials (11.1), pharmacists and sales associates in pharmacies (12.9), male wood machinists (4.1), male gardeners (6.7), female textile workers (5.4), and male transport inspectors and supervisors (9.4). The exposures potentially implicated are discussed. In agreement with the overall results of epidemiologic studies conducted elsewhere, direct occupational determinants probably do not account for a substantial share of the etiology of pancreatic cancer, at least in conditions resembling Finnish working environments some 15-40 years ago.

Detection of increased amounts of the extracellular domain of the c-erbB-2 oncoprotein in serum during pulmonary carcinogenesis in humans.

Over-expression of the c-erbB-2 oncogene-encoded p185 protein product has been implicated in the pathogenesis of a wide variety of human malignancies, including lung cancer. Over-expression of p185 can be detected immunologically by quantification of the extracellular domain of p185 (c-erbB-2 oncopeptide) in extracellular fluid in vitro and in serum in vivo. An enzyme-linked immunosorbent assay (ELISA) for the c-erbB-2 oncopeptide was used to examine banked serum samples of 11 pneumoconiosis patients who subsequently developed lung cancer and serum samples from 11 hospital controls matched for age, sex, ethnic group and smoking as well as 55 unmatched general population controls. The mean serum level for the c-erbB-2 oncopeptide in human neu units/ml in the lung cancer cases (1,756 +/- 549 HNU/ml) was statistically significantly elevated (p < 0.001) in comparison to the mean level in the matched controls (976 +/- 488 HNU/ml) or the general population controls (888 +/- 655 HNU/ml). Defining a positive elevation of the serum c-erbB-2 oncopeptide as any value more than 2 standard deviations above the mean of the matched controls, 64% (7 of 11) of the lung cancer cases were positive compared to 0% (0 of 11) matched controls and 5% (3 of 55) of the unmatched controls. In addition, 4 of the 7 c-erbB-2 oncopeptide-positive cancer cases had positive serum samples prior to the time of disease diagnosis (average = 35 months). These results suggest that serum c-erbB-2 oncopeptide may be elevated at an early stage of pulmonary carcinogenesis and that further prospective study of the utility of this biomarker is warranted.