Formation of intracellular vesicles within the Gram+ Lactococcus lactis induced by the overexpression of Caveolin-1ß.

BACKGROUND: Caveolae are invaginated plasma membrane domains of 50-100 nm in diameter involved in many important physiological functions in eukaryotic cells. They are composed of different proteins, including the membrane-embedded caveolins and the peripheric cavins. Caveolin-1 has already been expressed in various expression systems (E. coli, insect cells, Toxoplasma gondii, cell-free system), generating intracellular caveolin-enriched vesicles in E. coli, insect cells and T. gondii. These systems helped to understand the protein insertion within the membrane and its oligomerization. There is still need for fundamental insights into the formation of specific domains on membrane, the deformation of a biological membrane driven by caveolin-1, the organization of a caveolar coat, and the requirement of specific lipids and proteins during the process. The aim of this study was to test whether the heterologously expressed caveolin-1ß was able to induce the formation of intracellular vesicles within a Gram+ bacterium, Lactococcus lactis, since it displays a specific lipid composition different from E. coli and appears to emerge as a good alternative to E. coli for efficient overexpression of various membrane proteins. RESULTS: Recombinant bacteria transformed with the plasmid pNZ-HTC coding for the canine isoform of caveolin-1ß were shown to produce caveolin-1ß, in its functional oligomeric form, at a high expression level unexpected for an eukaryotic membrane protein. Electron microscopy revealed several intracellular vesicles from 30 to 60 nm, a size comparable to E. coli h-caveolae, beneath the plasma membrane of the overexpressing bacteria, showing that caveolin-1ß is sufficient to induce membrane vesiculation. Immunolabelling studies showed antibodies on such neo-formed intracellular vesicles, but none on plasma membrane. Density gradient fractionation allowed the correlation between detection of oligomers on Western blot and appearance of vesicles measurable by DLS, showing the requirement of caveolin-1ß oligomerization for vesicle formation. CONCLUSIONS: Lactococcus lactis cells can heterologously overexpress caveolin-1ß, generating caveolin-1ß enriched intracellular neo-formed vesicles. These vesicles might be useful for potential co-expression of membrane proteins of pharmaceutical interest for their simplified functional characterization.

Toward RGB LEDs based on rare earth-doped ZnO.

By using ZnO thin films doped with Ce, Tb or Eu, deposited via radiofrequency magnetron sputtering, we have developed monochromatic (blue, green and red, respectively) light emitting devices (LEDs). The rare earth ions introduced with doping rates lower than 2% exhibit narrow and intense emission peaks due to electronic transitions in relaxation processes induced after electrical excitation. This study proves zinc oxide to be a good host for these elements, its high conductivity and optical transparency in the visible range being as well exploited as top transparent electrode. After structural characterization of the different doped layers, a device structure with intense electroluminescence is presented, modeled, and electrically and optically characterized. The different emission spectra obtained are compared in a chromatic diagram, providing a reference for future works with similar devices. The results hereby presented demonstrate three operating monochromatic LEDs, as well as a combination of the three species into another one, with a simply-designed structure compatible with current Si technology and demonstrating an integrated red-green-blue emission.

Correlation between composition, microstructure, and emission properties in Nd-doped Si-rich Si oxynitride films: investigation into the nature of the sensitizer.

Rare earth (RE) ions doped in Si-based materials, compatible with Si technology, are promising compounds with regards to optical communication and energy conversion. In this article, we show the emission properties of Nd-doped Si-rich Si oxynitride (Nd-SRSON) films, and their dependence on the dangling bond density and the nature of the sensitizer. These films were prepared by reactive magnetron sputtering and post-annealing. The film composition, microstructure, and emission properties were investigated as a function of deposition parameters and annealing temperatures. Both Fourier transform infrared (FTIR) and ellipsometry spectroscopy measurements have confirmed that the sample composition (Si/N ratio) can be carefully tuned by varying the ratio of reactive nitrogen to argon in the sputtering plasma. Moreover, FTIR and x-ray photoelectron spectroscopy measurements demonstrate the existence of both nitrogen and oxygen dangling bonds (N· and O·) in as-deposited samples. These dangling bonds were passivated during annealing. Under non-resonant excitation at 488 nm, the films exhibit a significant photoluminescence (PL) signal from Nd3+ ions demonstrating the occurrence of an effective sensitization of Nd3+ ions in the host matrix. Both PL excitation and ellipsometry results (the energy band gap from new amorphous model) exclude the sensitization by an exciton with energy over the band gap, whereas the presence of Si agglomerates, at the atomic scale, have been identified as effective sensitizers towards Nd3+ ions. This work not only provides knowledge to optimize Si-based materials for favorable emission properties, but also, presents a universal methodology to investigate the nature of sensitizers for RE emitters. This allows one to find correlations between composition, microstructure, and emission properties.

Development of a Simple Hydroponic Assay to Study Vertical and Horizontal Resistance of Soybean and Pathotypes of Phytophthora sojae.

Phytophthora root rot, caused by Phytophthora sojae, is one of the most damaging diseases of soybean and the introgression of Rps (Resistance to P. sojae) genes into elite soybean lines is arguably the best way to manage this disease. Current bioassays to phenotype the gene-for-gene relationship are hampered with respect to reproducibility and long-term stability of isolates, and do not accurately predict horizontal resistance individually. The aim of our study was to investigate a new way of phenotyping P. sojae isolates and vertical and horizontal resistance in soybean that relies on zoospores inoculated directly into a hydroponic system. Inoculation of P. sojae isolates against a set of eight differentials accurately and reproducibly identified pathotypes over a period of two years. When applied to test vertical resistance of soybean lines with known and unknown Rps genes, the bioassay relied on plant dry weight to correctly identify all genes. In addition, simultaneous inoculations of three P. sojae isolates, collectively carrying eight major virulence factors against 64 soybean lines with known and unknown levels of horizontal resistance, separated the plants into five distinct groups of root rot, allowing the discrimination of lines with various degrees of partial resistance. Based on those results, this bioassay offers several advantages in facilitating efforts in breeding soybean for P. sojae resistance and in identifying virulence factors in P. sojae.

Structural and emission properties of Tb3+-doped nitrogen-rich silicon oxynitride films.

Terbium doped silicon oxynitride host matrix is suitable for various applications such as light emitters compatible with CMOS technology or frequency converter systems for photovoltaic cells. In this study, amorphous Tb3+ ion doped nitrogen-rich silicon oxynitride (NRSON) thin films were fabricated using a reactive magnetron co-sputtering method, with various N2 flows and annealing conditions, in order to study their structural and emission properties. Rutherford backscattering (RBS) measurements and refractive index values confirmed the silicon oxynitride nature of the films. An electron microscopy analysis conducted for different annealing temperatures (T A) was also performed up to 1200 °C. Transmission electron microscopy (TEM) images revealed two different sublayers. The top layer showed porosities coming from a degassing of oxygen during deposition and annealing, while in the region close to the substrate, a multilayer-like structure of SiO2 and Si3N4 phases appeared, involving a spinodal decomposition. Upon a 1200 °C annealing treatment, a significant density of Tb clusters was detected, indicating a higher thermal threshold of rare earth (RE) clusterization in comparison to the silicon oxide matrix. With an opposite variation of the N2 flow during the deposition, the nitrogen excess parameter (Nex) estimated by RBS measurements was introduced to investigate the Fourier transform infrared (FTIR) spectrum behavior and emission properties. Different vibration modes of the Si-N and Si-O bonds have been carefully identified from the FTIR spectra characterizing such host matrices, especially the 'out-of-phase' stretching vibration mode of the Si-O bond. The highest Tb3+ photoluminescence (PL) intensity was obtained by optimizing the N incorporation and the annealing conditions. In addition, according to these conditions, the integrated PL intensity variation confirmed that the silicon nitride-based host matrix had a higher thermal threshold of rare earth clusterization than its silicon oxide counterpart. Analysis of time-resolved PL intensity versus T A showed the impact of Tb clustering on decay times, in agreement with the TEM observations. Finally, PL and PL excitation (PLE) experiments and comparison of the related spectra between undoped and Tb-doped samples were carried out to investigate the impact of the band tails on the excitation mechanism of Tb3+ ions.

Wait times for diagnosis and treatment of lung cancer: a single-centre experience.

BACKGROUND: Multiple clinical practice guidelines recommend rapid evaluation of patients with suspected lung cancer. It is uncertain whether delays in diagnosis and management have a negative effect on outcomes. METHODS: This retrospective study included 551 patients diagnosed with lung cancer through the diagnostic assessment program at the Institut universitaire de cardiologie et de pneumologie de Québec between September 2013 and March 2015. Median wait times between initial referral, diagnosis, and first treatment were calculated and compared with recommended targets. Analyses were performed to evaluate for specific factors associated with longer wait times and for the effect of delays on the outcomes of progression-free survival (pfs), relapse-free survival (rfs) after primary surgical resection, and overall survival (os). RESULTS: Most patients were investigated and treated within recommended targets. Of the entire cohort, 379 patients were treated at our institution. Of those 379 patients, 311 (82%) were treated within recommended targets. In comparing patients within and outside target times, the only statistically significant difference was found in the distribution of treatment modalities: patients meeting targets were more likely to be treated with surgery or chemotherapy rather than with radiation. The pfs on first treatment modality was influenced by clinical stage, but not by time to therapy [hazard ratio (hr): 1.10; p = 0.65]. The os for the entire cohort was also influenced by stage, but not by delays (hr: 1.04; p = 0.87). For the 209 patients treated by surgery with curative intent, a significant reduction in rfs was associated with male sex and TNM stage, but not with delays (hr: 1.11; p = 0.83). The os after primary surgical resection was also associated with TNM stage, but not with delays (hr: 1.82; p = 0.43). CONCLUSIONS: Recommended targets for wait times in the investigation and treatment of lung cancer can be achieved within a diagnostic assessment program. Compared with radiation treatment, treatment with surgery or chemotherapy is more likely to be completed within targets. Delays in investigation and treatment do not appear to negatively affect the clinical outcomes of os, rfs, and pfs. Prospective studies are needed to evaluate whether efficient work-up and treatment influence other important variables, such as quality of life, cost of care, and access to therapies while performance status is adequate.

DNAJC13 p.Asn855Ser mutation screening in Parkinson's disease and pathologically confirmed Lewy body disease patients.

BACKGROUND: Recently, a novel mutation in exon 24 of DNAJC13 gene (p.Asn855Ser, rs387907571) has been reported to cause autosomal dominant Parkinson's disease (PD) in a multi-incident Mennonite family. METHODS: In the present study the mutation containing exon of the DNAJC13 gene has been sequenced in a Caucasian series consisting of 1938 patients with clinical PD and 838 with pathologically diagnosed Lewy body disease (LBD). RESULTS: Our sequence analysis did not identify any coding variants in exon 24 of DNAJC13. Two previously described variants in intron 23 (rs200204728 and rs2369796) were observed. CONCLUSION: Our results indicate that the region surrounding the DNAJC13 p.Asn855Ser substitution is highly conserved and mutations in this exon are not a common cause of PD or LBD among Caucasian populations.

Pericardiocentesis versus pericardiotomy for malignant pericardial effusion: a retrospective comparison.

BACKGROUND: Treatment of malignant pericardial effusion remains controversial, because no randomized controlled trials have been conducted to determine the best approach, and results of retrospective studies have been inconsistent. The objective of the present study was to compare pericardiocentesis and pericardiotomy with respect to efficacy for preventing recurrence, and to determine, for those two procedures, diagnostic yields, complication rates, and effects on survival. We also aimed to identify clinical and procedural factors that could predict effusion recurrence. METHODS: We retrospectively assessed 61 patients who underwent a procedure for treatment of a malignant pericardial effusion at the Institut universitaire de cardiologie et de pneumologie de Québec between February 2004 and September 2013. RESULTS: Pericardiocentesis was performed in 42 patients, and pericardiotomy, in 19 patients. The effusion recurrence rate was significantly higher in patients treated with pericardiocentesis than with pericardiotomy (31.0% vs. 5.3%, p = 0.046). The diagnostic yield of the procedures was not significantly different (92.9% vs. 86.7%, p = 0.6). The overall rate of complications was similar in the two groups, as was the median overall survival (2.4 months vs. 2.6 months, p = 0.5). In univariate analyses, the procedure type was the only predictor of recurrence that approached statistical significance. Age, sex, type of cancer, presence of effusion at the time of cancer diagnosis, prior chest irradiation, tamponade upon presentation, and total volume of fluid removed did not influence the recurrence rate. CONCLUSIONS: Compared with pericardiocentesis, pericardiotomy had higher success rate in preventing recurrence of malignant pericardial effusion, with similar diagnostic yields, complication rates, and overall survival.

[High flow nasal cannula in infants: Experience in a critical patient unit]. / Cánula nasal de alto flujo en lactantes: experiencia en una unidad de paciente crítico.

INTRODUCTION: The high flow nasal cannula (HFNC) is a method of respiratory support that is increasingly being used in paediatrics due to its results and safety. OBJECTIVE: To determine the efficacy of HFNC, as well as to evaluate the factors related to its failure and complications associated with its use in infants. PATIENTS AND METHOD: An analysis was performed on the demographic, clinical, blood gas, and radiological data, as well as the complications of patients connected to a HFNC in a critical care unit between June 2012 and September 2014. A comparison was made between the patients who failed and those who responded to HFNC. A failure was considered as the need for further respiratory support during the first 48hours of connection. The Kolmogorov Smirnov, Mann-Whitney U, chi squared and the Exact Fisher test were used, as well as correlations and a binary logistic regression model for P≤.05. RESULTS: The study included 109 patients, with a median age and weight: 1 month (0.2-20 months) and 3.7kg (2-10kg); 95 percentile: 3.7 months and 5.7kg, respectively. The most frequent diagnosis and radiological pattern was bronchiolitis (53.2%) and interstitial infiltration (56%). Around 70.6% responded. There was a significant difference between failure and response in the diagnosis (P=.013), radiography (P=018), connection context (P<.0001), pCO2 (median 40.7mmHg [15.4-67 mmHg] versus 47.3mmHg [28.6-71.3mmHg], P=.004) and hours on HFNC (median 60.75hrs [5-621.5 hrs] versus 10.5hrs [1-29 hrs], P<.0001). The OR of the PCO2 ≥ 55mmHg for failure was 2.97 (95% CI; 1.08-8.17; P=.035). No patient died and no complications were recorded. CONCLUSION: The percentage success observed was similar to that published. In this sample, the failure of HFNC was only associated with an initial pCO2 ≥ 55mmHg. On there being no complications reported as regards it use, it is considered safe, although a randomised, controlled, multicentre study is required to compare and contrast these results.

Emotional prosody recognition enhances and progressively complexifies from childhood to adolescence.

Emotional prosody results from the dynamic variation of language's acoustic non-verbal aspects that allow people to convey and recognize emotions. The goal of this paper is to understand how this recognition develops from childhood to adolescence. We also aim to investigate how the ability to perceive multiple emotions in the voice matures over time. We tested 133 children and adolescents, aged between 6 and 17 years old, exposed to 4 kinds of linguistically meaningless emotional (anger, fear, happiness, and sadness) and neutral stimuli. Participants were asked to judge the type and intensity of perceived emotion on continuous scales, without a forced choice task. As predicted, a general linear mixed model analysis revealed a significant interaction effect between age and emotion. The ability to recognize emotions significantly increased with age for both emotional and neutral vocalizations. Girls recognized anger better than boys, who instead confused fear with neutral prosody more than girls. Across all ages, only marginally significant differences were found between anger, happiness, and neutral compared to sadness, which was more difficult to recognize. Finally, as age increased, participants were significantly more likely to attribute multiple emotions to emotional prosody, showing that the representation of emotional content becomes increasingly complex. The ability to identify basic emotions in prosody from linguistically meaningless stimuli develops from childhood to adolescence. Interestingly, this maturation was not only evidenced in the accuracy of emotion detection, but also in a complexification of emotion attribution in prosody.

MAST3: a novel IBD risk factor that modulates TLR4 signaling.

Inflammatory bowel disease (IBD) is a chronic disorder caused by multiple factors in a genetically susceptible host. Significant advances in the study of genetic susceptibility have highlighted the importance of the innate immune system in this disease. We previously completed a genome-wide linkage study and found a significant locus (IBD6) on chromosome 19p. We were interested in identifying the causal variant in IBD6. We performed a two-stage association mapping study. In stage 1, 1530 single-nucleotide polymorphisms (SNPs) were selected from the HapMap database and genotyped in 761 patients with IBD. Among the SNPs that passed the threshold for replication, 26 were successfully genotyped in 754 additional patients (stage 2). One intronic variant, rs273506, located in the microtubule-associated serine/threonine-protein kinase gene-3 (MAST3), was found to be associated in both stages (pooled P=1.8 x 10(-4)). We identified four MAST3 coding variants, including a non-synonymous SNP rs8108738, correlated to rs273506 and associated with IBD. To test whether MAST3 was expressed in cells of interest, we performed expression assays, which showed abundant expression of MAST3 in antigen-presenting cells and in lymphocytes. The knockdown of MAST3 specifically decreased Toll-like receptor-4-dependent NF-kappaB activity. Our findings are additional proofs of the pivotal role played by modulators of NF-kappaB activity in IBD pathogenesis.

[Evolution of the blood products distribution in France - detailed analysis in a regional blood transfusion centre]. / Evolution de la distribution des produits sanguins labiles en France - analyse détaillée au sein d'un Etablissement français du sang interrégional.

OBJECTIVE: The present increase of blood products distribution raises some adaptation questions. To understand this evolution, it is necessary to assure patients needs satisfaction. STUDY DESIGN: The study focuses on years 1997 to 2007. All blood products and hospitals are taken into account. The possible impact of size and clinical specialties is analyzed for the main hospitals. RESULTS: The evolution varies according to blood product: continuous drop for autologous red cells and plasmas, drop and rise for homologous red cells and platelets with a turnaround in 2001-2002, reverse and more chaotic movement for homologous plasmas. These movements are the result of public hospitals, with an upsurge of the medium sized ones. Private hospitals go down for all blood products, with a concentration on the larger ones. Surgical hospitals fall from 3 to 4% for all blood products, while medical ones rise of 3% for homologous red cells, 27% for platelets and fall of 10% for homologous plasmas. Private mixed hospitals fall for all blood products, while public ones rise for homologous red cells and platelets. CONCLUSION: Evolution understanding of blood products distribution requires precisions about the kind of products and the hospitals status and specialties: medical, surgical, even obstetrical or urgency-related. The present trend is a rise for public hospitals and medical specialties, which are both the largest. Blood transfusion needs will thus go on rising in the years to come.

[Influence of lipids on ice formation during the freezing of cryoprotective medium].

The influence of lipids on ice formation during the freezing of cryoprotective medium for the semen of rainbow trout has been studied by the cryomicroscopy technique. It was shown that the lipids extracted from marine vertebrates and liposomes from the lipids of trout sperm effectively inhibit the ice formation in cryoprotective solutions during freezing, fundamentally changing the form and size of ice crystals. At high concentrations of lipids, either the crystallization does not occur in the cryoprotective medium or, even if ice crystals are formed, they have a broken shape and blurred borders. The addition of egg yolk sligthly increases the size and essentially changes the shape of ice crystals during the freezing of solution.

[Early and later intrahepatic cholestasis of pregnancy (ICP): Study of adverse pregnancy outcomes]. / Cholestases intrahepatiques gravidiques (CIG) précoces et tardives : étude des complications materno-fœtales.

OBJECTIVE: To compare the risk for adverse pregnancy and fetal outcomes in early or late-onset intrahepatic cholestasis of pregnancy (ICP). METHODS: In a retrospective and unicentric analysis, data were collected for all women with ICP (serum bile acid level over 8mol/L) between June 1, 2008 and January 1, 2015. Patients were divided in early-onset ICP (pregnancy duration at diagnosis<33 weeks) and late-onset ICP (pregnancy duration at diagnosis≥33 weeks). The frequency of adverse pregnancy and fetal outcomes was assessed. RESULTS: Among 138 eligible women, 40 were in the early-onset group and 98 in the late-onset group. Adverse pregnancy or fetal outcomes affected significantly more patients in early-onset ICP group (45% versus 17.3%, P<0.05). Threatened preterm birth (30% versus 10.0%, P<0.05) was significantly increased in early-onset ICP group. Prematurity was higher in early-onset group (40.0% versus 28.0%, P=0.23). Early-onset and severe ICP were not significantly linked (P=0.16). CONCLUSION: Early-onset ICP diagnosed before 33 Weeks is associated with adverse pregnancy outcomes, particularly threatened preterm birth.

The nitrogen concentration effect on Ce doped SiOxNy emission: towards optimized Ce3+ for LED applications.

Ce-Doped SiOxNy films are deposited by magnetron reactive sputtering from a CeO2 target under a nitrogen reactive gas atmosphere. Visible photoluminescence measurements regarding the nitrogen gas flow reveal a large emission band centered at 450 nm for a sample deposited under a 2 sccm flow. Special attention is paid to the origin of such an emission at high nitrogen concentration. Different emitting centers are suggested in Ce doped SiOxNy films (e.g. band tails, CeO2, Ce clusters, Ce3+ ions), with different activation scenarios to explain the luminescence. X-ray photoelectron spectroscopy (XPS) reveals the exclusive presence of Ce3+ ions whatever the nitrogen or Ce concentrations, while transmission electron microscopy (TEM) shows no clusters or silicates upon high temperature annealing. With the help of photoluminescence excitation spectroscopy (PLE), a wide excitation range from 250 nm up to 400 nm is revealed and various excitations of Ce3+ ions are proposed involving direct or indirect mechanisms. Nitrogen concentration plays an important role in Ce3+ emission by modifying Ce surroundings, reducing the Si phase volume in SiOxNy and causing a nephelauxetic effect. Taking into account the optimized nitrogen growth parameters, the Ce concentration is analyzed as a new parameter. Under UV excitation, a strong emission is visible to the naked eye with high Ce3+ concentration (6 at%). No saturation of the photoluminescence intensity is observed, confirming again the lack of Ce cluster or silicate phase formation due to the nitrogen presence.

Real-world benefit of nivolumab in a Canadian non-small-cell lung cancer cohort.

Background: Nivolumab was the first immuno-oncology agent available for the treatment of lung cancer in Canada. In the present study, we evaluated the real-world benefit of nivolumab in Canadian patients with lung cancer. Methods: Patients included in the cohort were identified from a registry of patients treated through expanded access to nivolumab before and after Health Canada approval. Demographics were collected from the application forms. Outcome data for the duration of treatment and survival were collected retrospectively. Results: In contrast to the randomized clinical trial populations, our study cohort included patients who were older (median age: 66 years; range: 36-92 years) and who had an Eastern Cooperative Oncology Group performance status of 2 (8.9%). Despite the poorer-prognosis cohort, median overall survival was 12.0 months, which is comparable to the survival demonstrated in the randomized phase iii trials of nivolumab in lung cancer. Median time to treatment discontinuation was 3.45 months and was similar for all patient subgroups, including poorer-prognosis groups such as those with a performance status of 2, those 75 years of age and older, and those with brain metastases. Conclusions: Nivolumab given in a real-world clinical setting was associated with results similar to those reported in the phase iii clinical trial setting.

Rhythmic entrainment as a musical affect induction mechanism.

One especially important feature of metrical music is that it contains periodicities that listeners' bodily rhythms can adapt to. Recent psychological frameworks have introduced the notion of rhythmic entrainment, among other mechanisms, as an emotion induction principle. In this review paper, we discuss rhythmic entrainment as an affect induction mechanism by differentiating four levels of entrainment in humans-perceptual, autonomic physiological, motor, and social-all of which could contribute to a subjective feeling component. We review the theoretical and empirical literature on rhythmic entrainment to music that supports the existence of these different levels of entrainment by describing the phenomena and characterizing the associated underlying brain processes. The goal of this review is to present the theoretical implications and empirical findings about rhythmic entrainment as an important principle at the basis of affect induction via music, since it rests upon the temporal dimension of music, which is a specificity of music as an affective stimulus.

Cryobanking of fish somatic cells: optimizations of fin explant culture and fin cell cryopreservation.

When gametes or embryos are not available, somatic cells should be considered for fish genome cryobanking of valuable or endangered fish. The objective of this work was to develop a method for fin explant culture with an assessed reliability, and to assess fin cells ability to cryopreservation. Anal fins from goldfish (Carassius auratus) were minced and gently loosened with collagenase before explants were plated at 20 degrees C in L-15 medium supplemented with fetal bovine serum and pH buffering additives. Quantification of cell-donor explants per fin rated the culture success. Cells were successfully obtained from every cultured anal fin (mean = 65% cell-donor explant per fin). All other fin types were suitable except the dorsal fin. Explant plating could be deferred 3 days from fin collecting. Fins from seven other fish species were successfully cultured with the method. After 2-3 weeks, sub-confluent fin cells from goldfish were cryopreserved. Cryopreservation with dimethyl sulfoxide and sucrose at a slow freezing rate allowed the recovery of half the goldfish fin cells. Cells displayed the same viability as fresh ones. 1,2-propanediol was unsuitable when a fast freezing rate was used. The procedure could now be considered for cryobanking with only minimal adaptation to each new species.

Hydrostatic pressure effects on eel mitochondrial functioning and membrane fluidity.

Aerobic metabolism which is required for long swimming activities during the eel's spawning migration at depth, is a potential target for pressure effects due to its components located in the inner mitochondrial membrane (respiratory chain and oxidative phosphorylation). Previous studies have evidenced that eels are able to acclimatize to pressure through membrane fluidity adjustment. However these studies were performed on the premigratory stage (yellow stage), which never encounters high pressure. Metamorphosis (silvering) seems to preadapt eels (at the silver stage) to most of the environmental changes they will encounter during migration. Is it also true for pressure resistance? This study shows that yellow eels exhibit a higher pressure sensitivity than silver eels (compression effects). The acclimatization period (21 days at 10.1 MPa) cancels the differences in pressure sensitivity and in aerobic metabolism observed at 0.1 MPa between the two stages. The mechanisms, which take place in yellow eels during acclimatization to high pressure, appear to be already present in silver eels before pressure exposure. Indeed at 0.1 MPa, silver eels exhibit higher membrane fluidity and proportions of membrane polyunsaturated fatty acids. Metamorphosis, by improving membrane fluidity, seems to allow silver eels to cope with hydrostatic pressure without spending energy in acclimatization processes.