A comparison of the use of different swab materials for optimal diagnosis of amoebic gill disease (AGD) in Atlantic salmon (Salmo salar L.)

Routine gill swabbing is a non-destructive sampling method used for the downstream qPCR detection and quantitation of the pathogen Neoparamoeba perurans, a causative agent of amoebic gill disease (AGD). Three commercially available swabs were compared aiming their application for timelier AGD diagnosis (Calgiswab^® (calcium alginate fibre-tipped), Isohelix^® DNA buccal and cotton wool-tipped). Calcium alginate is soluble in most sodium salts, which potentially allows the total recovery of biological material, hence a better extraction of target organisms' DNA. Thus, this study consisted of (a) an in vitro assessment involving spiking of the swabs with known amounts of amoebae and additional assessment of retrieval efficiency of amoebae from agar plates; (b) in vivo testing by swabbing of gill arches (second, third and fourth) of AGD-infected fish. Both in vitro and in vivo experiments identified an enhanced amoeba retrieval with Calgiswab® and Isohelix® swabs in comparison with cotton swabs. Additionally, the third and fourth gill arches presented significantly higher amoebic loads compared to the second gill arch. Results suggest that limiting routine gill swabbing to one or two arches, instead of all, could likely lead to reduced stress-related effects incurred by handling and sampling and a timelier diagnosis of AGD.

Generation of Paramoeba perurans clonal cultures using flow cytometry and confirmation of virulence

Amoebic gill disease (AGD) in farmed Atlantic salmon is caused by the amoeba Paramoeba perurans. The recent establishment of in vitro culture techniques for P. perurans has provided a valuable tool for studying the parasite in detail. In this study, flow cytometry was used to generate clonal cultures from single-sorted amoeba, and these were used to successfully establish AGD in experimental Atlantic salmon. The clonal cultures displayed differences in virulence, based on gill scores. The P. perurans load on gills, determined by qPCR analysis, showed a positive relationship with gill score, and with clonal virulence, indicating that the ability of amoebae to proliferate and/or remain attached on gills may play a role in virulence. Gill scores based on gross signs and histopathological analysis were in agreement. No association between level of gill score and specific gill arch was observed. It was found that for fish with lower gill scores based on histopathological examination, gross examination and qPCR analysis of gills from the same fish were less successful in detecting lesions and amoebae, respectively.

Abstract P2-12-02: Characteristics of the BRCA mutation profile of a population of patients with triple negative breast cancer

Purpose: This study assessed the relation between age, family history (breast and/or ovarian cancer) and BRCA1 and BRCA2 mutations prevalence in a cohort of patients with triple-negative breast cancer (BC).

Methods: We identified in our database 218 patients (pts) with triple negative (TN) breast carcinoma (defined as <1% estrogen and progesterone and HER-2 not over expressed). All pts gave consent for BRCA1 and BRCA2 screening (HRM/sequencing of exons and intron-exon junctions and large rearrangement analysis). In this cohort, we noted family history of breast only, ovarian only or both breast and ovarian cancer.

We compared this cohort to 498 pts with a family history of breast cancer (non triple-negative tumors) and/or ovarian cancer that were also screened for BRCA1/2 mutations.

Results: In the TN cohort, 146 tests were realized, 72 are still on going. We identified 31 deleterious mutations (21.2%) in BRCA1 and 3 (2.1%) in BRCA2. In 100 cases (68.5%), we found no BRCA mutations and in 13 cases, we found Variants of Unknown Signification (VUS) (8.9%) (5 (3.4%) in BRCA1 and 8 (5.5%) in BRCA2).

Concerning family history, 74 pts belonged to families with a history of breast cancer only, 3 pts to families with ovarian cancer only and 10 pts to families with both breast and ovarian cancer. Fifty nine pts were screened on the basis of a TN tumor at age ≤ 50 years old with no other family history of breast or ovarian cancer. The mean age at first diagnosis for all the TN cohort tested is 45.4 ± 10.2 (min 26 - max 76). The mean age of patients for whom a mutation was identified is : 40.6 ± 8.7 for BRCA1 (min 29 - max 69), 45.7 ± 8.5 for BRCA2 (min 37 - max 54). The mean age of patients for whom no BRCA mutation was identified is 46.8 ±10.2 (min 26 - max 76). All patients studied were symptomatic.

In the “control cohort”, we identified 26 deleterious mutations (5.2%) in BRCA1 and 28 (5.6%) in BRCA2. In 408 cases (81.9%), we found no BRCA mutations and in 36 cases, we found Variants of Unknown Signification (VUS) (7.2%) (8 (1.6%) in BRCA1 and 28 (5.6%) in BRCA2).

We have in our region (Lorraine), a recurrent BRCA1 mutation with founder-effect (c.3481_3491del11 p.Glu1161Phe), the prevalence of which we evaluated in both cohorts.

Conclusions:

Among the TN cohort, mean age for BRCA1 mutation is lower than for BRCA2 (40.6 ± 8.7 vs 45.7 ± 8.5, non-significant results). By comparing BRCA mutation frequency between the 2 cohorts, we could conclude that:

- BRCA mutations are more frequent in the TN cohort : 23.3% vs 10.8% (p = 0.035)

- Among these, there are more BRCA1 mutations in the TN cohort : 21.2% vs 5.2% and less BRCA2 mutations : 2.1% vs 5.6% (p = 0.02)

Moreover, according to our preliminary results, this particular mutation seems to be more represented among the mutations of the TN cohort (3.5 folds) but we still have to test its impact concerning TN tumors.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P2-12-02.

Determinants of homocysteine-thiolactonase activity of the paraoxonase-1 (PON1) protein in humans

Homocysteine (Hcy)-thiolactonase (HTase) activity of the paraoxonase-1 (PON1) protein detoxifies Hcy-thiolactone in human blood and could thus delay the development of atherosclerosis. To gain insight into physiological role(s) of the PON1 protein, we studied HTase activities and PON1 genotypes in a group of 184 subjects, 32.6% of whom were healthy, 27.7% had angiographically proven coronary artery disease but did not have myocardial infarction (CAD), and 39.7% had myocardial infarction (MI). We found that the hydrolytic activities of the serum PON1 protein towards Hcy-thiolactone and the organophosphate paraoxon substrates were strongly correlated. PON1-192-RR and PON1-55-LL genotypes were associated with high HTase activity. HTase activity was negatively correlated with age (beta = -0.135, p =0.002), plasma total Hcy (in 192-QR subjects only; r = -0.46, p = 0.001), and positively correlated with total cholesterol (beta = 0.169, p<0.001), but not with HDL cholesterol. Mean HTase activities were similar in CAD subjects, MI subjects, and in healthy controls. However, the frequency of the PON1-192-RR genotype tended to be lower in CAD subjects than in controls (2% vs 10.0%, p = 0.057) and higher in MI subjects that in CAD subjects (10.9% vs 2.0%, p = 0.001). The R-allele was marginally associated with CAD (26.7% in controls vs 17.6% in CAD, p = 0.146) and significantly associated with MI (17.6% in CAD vs 31.5% in MI, p = 0.018). Multiple regression analysis suggests that PON1 genotype, total Hcy, total cholesterol, and age are major determinants of HTase activity in humans.

Models of risk and choice: challenge or danger

A dimensional model of perceived risk and a model of risk acceptance based on risk rates are proposed in this paper. In line with the proposed model of perceived risk, risk is a linear combination of the three basic dimensions of a risky situation: the amount and probability of loss and the amount of gain. It is assumed that psychological transformations are made on these dimensions. According to the model of acceptance, acceptance is judged by making a trade-off between perceived risk and the amount of gain. These models have been investigated in two experiments, in which risk judgments and acceptance rates for a set of descriptions of risky investments were collected from managers in Poland. The proposed dimensional model of perceived risk was compared to the distributional models of risk and to the risk models based on the expectation principle. The best fit was obtained for the proposed model. It was also found that perceived risk was useful in predicting acceptance rates. Better fits were obtained for the models of acceptance, based on perceived risk, than for the expected/weighted utility models, including bilinear models.

What Folklore Tells Us about Risk and Risk Taking: Cross-Cultural Comparisons of American, German, and Chinese Proverbs

Two studies attempted to discriminate between a situational-economic and a cultural explanation for the recently reported finding that Chinese from the People's Republic of China (PRC) are more risk-seeking than Americans. Both studies compared American and Chinese proverbs related to risk and risk-taking. The first study added Germany as a control group for its socioeconomic similarity to the United States but its closer resemblance to the PRC in its social safety-net and cultural collectivism. Members of each culture rated American, Chinese, and German risk-related proverbs, respectively, on implied advice (to take or avoid risk) and applicability to financial or social risks. Results were consistent with the cultural explanation of national differences in risk taking: (a) Chinese and German proverbs were judged to provide more risk-seeking advice than American proverbs; (b) American proverbs were judged less applicable to risks in the social domain than Chinese and German proverbs; (c) regardless of national origin of proverbs, Chinese perceived proverbs to advocate greater risk-seeking than American raters, but only for financial and not for social risks. Copyright 1998 Academic Press.

Perception and acceptance of technological and environmental risks: why are poor countries less concerned?

The research has been aimed at answering two questions: (1) What factors impact perception and acceptance of technological and environmental hazards? (2) Why are rich societies involved more in protecting their environment and health than poor societies? Data has been collected from representative samples of two countries--Poland and Sweden. The results indicate that (1) contrary to earlier findings, the inverse relations between perceived benefits and dangers of hazards has not been observed, (2) acceptance of a risk has been mostly influenced by perceived benefits, (3) rejection of a risk has been mostly influenced by its perceived harmful consequences. Concerning the second question, it has been found that: (1) perceived hazard's danger and benefit is not the only factor that impacts its acceptance, and (2) a broader economic context can impact acceptance (tolerance) of hazards. It has been found that being aware of high dangers and not very high benefits of hazardous activities, Poles still have accepted them. Thus, Poles seem to follow an old proverb: "When one does not have what one likes, one has to like what one has."