Effect of selective breeding on collagen properties of Atlantic salmon (Salmo salar L.).

Collagen content and properties of skeletal muscle were studied among selected (FP) and unselected (WP) Atlantic salmon lines that were reared together to avoid any environmental effects. The FP group had significantly higher body weight at harvesting, softer texture and lower connective tissue yield compared with the WP group. The relative collagen fractions (acid, pepsin, insoluble) were similar, but the FP group had a greater abundance of amino acids involved in collagen triple helix conformation and stabilisation (Gly, Pro, Hyp and Hyl), whilst the Lys content was greater for the WP group, indicating a more aggregated collagen. The connective tissue denaturation temperature was lower for the FP group, coinciding with a lower degree of collagen self-assembly and intermolecular-crosslinks. It is concluded that selective breeding has resulted in lower connective tissue stability of Atlantic salmon fillets.

Enzyme-assisted extraction of κ/ι-hybrid carrageenan from Mastocarpus stellatus for obtaining bioactive ingredients and their application for edible active film development.

Two hydrolysates were obtained from dried Mastocarpus stellatus using alcalase. The phenolic content was partially removed from one of them. The phenolic-partially-removed hydrolysate (H) was found to be a potent angiotensin-I converting enzyme (ACE) inhibitor. However, the phenolic-containing hydrolysate (Hp) showed a higher Folin-reactive substance content and antioxidant capacity (reducing power and radical scavenging capacity). Hp was therefore selected for the development of antioxidant Mastocarpus carrageenan-based films. F-Hp0 (without the hydrolysate), F-Hp15 (with 15% hydrolysate) and F-Hp30 (with 30% hydrolysate) films were developed. κ/ι-hybrid carrageenan was the main film constituent and hydrolysate addition resulted in an increased sulfated proportion, higher protein content and higher number of hydrogen bonds. Therefore interactions between carrageenan helices, plasticizers and peptides in the film-forming solution were enhanced, especially in F-Hp15, and consequently the water vapour permeability (WVP) of the resulting film decreased. Nevertheless, F-Hp30 considerably improved the transparency, UV/Vis light barrier, water resistance and elongation at break (EAB). The presence of Hp increased both puncture force (F) and puncture elongation (E), but not tensile strength (TS) or Young's modulus (Y). The addition of an increased concentration of hydrolysate to the films led to a considerable increase in the Folin-reactive substance content and the antioxidant activity, especially the radical scavenging capacity.

Determination of alpha activity in solid samples by leaching or digestion.

The analysis of solid environmental samples by α-particle spectrometry generally involves processes requiring an initial treatment to destroy the complexes in the matrix, and dissolve the radionuclides of interest. This study compared the activities obtained for several natural radionuclides ((238)U, (234)U, (230)Th, (226)Ra, and (210)Po) in previously well-characterized materials, using two procedures: acid leaching and digestion in a microwave oven. The measured activities were in general very similar for the two procedures, with a strong statistical correlation between the two sets of values.

Collagen characteristics of farmed Atlantic salmon with firm and soft fillet texture.

The possible role of collagen in texture variations among Atlantic salmon (Salmo salar L.) grown under commercial conditions at a Norwegian farm was studied. The texture was determined instrumentally as the breaking strength, and collagen and its salt (SSC), acid (ASC), pepsin (PSC) and insoluble (IF) fractions were analysed in order to determine the collagen aggregation degree. The collagen solubility and its overall amino acid (AA) composition showed no correlation to the breaking strength, but a positive correlation was observed between the breaking strength and glycine (r=0.74) and alanine (r=0.87) contents of the PSC fraction. Salmon with high breaking strength had higher T(peak) (temperature of transition) and ΔH (enthalpy of transition), and the collagen seemed to have triple helix structures mainly stabilized by covalent associations as compared to salmon with low breaking strength. The glycosylation degree was also positively correlated to the breaking strength (r=0.88, p ≤ 0.05). It is concluded that firmness of salmon muscle was not related to the total amount of collagen in the muscle, but rather higher collagen stability.

TP53INP1 decreases pancreatic cancer cell migration by regulating SPARC expression.

Tumor protein 53 induced nuclear protein 1 (TP53INP1) is a p53 target gene that induces cell growth arrest and apoptosis by modulating p53 transcriptional activity. TP53INP1 interacts physically with p53 and is a major player in the p53-driven oxidative stress response. Previously, we demonstrated that TP53INP1 is downregulated in an early stage of pancreatic cancerogenesis and when restored is able to suppress pancreatic tumor development. TP53INP1 downregulation in pancreas is associated with an oncogenic microRNA miR-155. In the present work, we studied the effects of TP53INP1 on cell migration. We found that TP53INP1 inactivation correlates with increased cell migration both in vivo and in vitro. The impact of TP53INP1 expression on cell migration was studied in different cellular contexts: mouse embryonic fibroblast and different pancreatic cancer cell lines. Its expression decreases cell migration by the transcriptional downregulation of secreted protein acidic and rich in cysteine (SPARC). SPARC is a matrix cellular protein, which governs diverse cellular functions and has a pivotal role in regulating cell-matrix interactions, cellular proliferation and migration. SPARC was also showed to be upregulated in normal pancreas and in pancreatic intraepithelial neoplasia lesions in a pancreatic adenocarcinoma mouse model only in the TP53INP1-deficient animals. This novel TP53INP1 activity on the regulation of SPARC expression could explain in part its tumor suppressor function in pancreatic adenocarcinoma by modulating cellular spreading during the metastatic process.

Alpha-particle emission probabilities in the decay of 240Pu.

Sources of enriched (240)Pu were prepared by vacuum evaporation on quartz substrates. High-resolution alpha-particle spectrometry of (240)Pu was performed with high statistical accuracy using silicon detectors and with low statistical accuracy using a bolometer. The alpha-particle emission probabilities of six transitions were derived from the spectra and compared with literature values. Additionally, some alpha-particle emission probabilities were derived from gamma-ray intensity measurements with a high-purity germanium detector. The alpha-particle emission probabilities of the three main transitions at 5168.1, 5123.6 and 5021.2 keV were derived from seven aggregate spectra analysed with five different fit functions and the results were compatible with evaluated data. Two additional weak peaks at 4863.5 and 4492.0 keV were fitted separately, using the exponential of a polynomial function to represent the underlying tailing of the larger peaks. The peak at 4655 keV could not be detected by alpha-particle spectrometry, while gamma-ray spectrometry confirms that its intensity is much lower than expected from literature.

Radioactive content of charcoal.

Coal and charcoal present similar physical and chemical characteristics. There is no standardized procedure to distinguish them. However, their differences in age and origin result in several differences in their natural radionuclide content. Moreover, charcoal can be contaminated with fallout. In this work, activity concentrations of (228)Th, (226)Ra, (40)K, and (137)Cs were determined in charcoal and coal samples in order to obtain evidence to distinguish the two kinds of sample.

An intercomparison of Monte Carlo codes used in gamma-ray spectrometry.

In an intercomparison exercise, the Monte Carlo codes most commonly used in gamma-ray spectrometry today were compared with each other in order to gauge the differences between them in terms of typical applications. No reference was made to experimental data; instead, the aim was to confront the codes with each other, as they were applied to the calculation of full-energy-peak and total efficiencies. Surprising differences between the results of different codes were revealed.

Multi-technique characterization of a nuclear bomb particle from the Palomares accident.

A January 1966 accident dispersed Pu and other nuclear bomb materials in the vicinity of Palomares, a village in southeastern Spain. Radioactive particles were identified in a soil sample collected in 1998 and analytical results obtained from one of the isolated particles are presented here. Isolation of the particle was performed using gamma-ray spectrometry and imaging plates. Scanning electron microscopy with X-ray microanalysis revealed the presence of U and Pu as well as Pb and Fe in the particle of approximately 10microm diameter. Radioisotopes of U, Pu, and Am were quantified using radiometric methods, inductively coupled plasma mass spectrometry and secondary ion mass spectrometry. The elevated (235)U/(238)U atom ratio indicates enriched U, and the Pu atom ratios are consistent with weapons-grade material. This work demonstrates that the analysis of individual particles provides information not available through bulk sample analysis.

Fast adaptive alpha-particle spectrum fitting algorithm based on genetically estimated initial parameters.

This work presents a high performance procedure for the unfolding of alpha particle spectra based on genetically estimated initial parameters. The process starts with the search for a globally optimized set of fitting parameters from a population of randomly generated solutions. The solution found with the genetic algorithm is then transferred to a Levenberg-Marquardt procedure in order to calculate the covariance matrix for the fit. The proposed method provides the set of final parameters and their associated standard deviation. Several fitted spectra demonstrate the effectiveness of the proposed method in searching for and finding initial conditions in a fast and automated process.

Study of inhomogeneities in sources prepared for alpha-particle spectrometry using scanning probe microscopy.

For high-resolution alpha-particle spectrometry, sources of high quality must be prepared by methods giving the thinnest and most homogeneous deposit possible on a suitable support. Surface characteristics of several types of alpha-particle sources were studied using a scanning probe microscope. Major inhomogeneities were observed, which means that the materials and techniques used for thc preparation of sources must be improved.

The effect of energy losses in alpha-particle sources on the shape of peaks in spectra obtained with wide-angle geometry.

It has been shown that two main effects contribute to the tailing in the shapes of alpha-peaks measured with silicon detectors: the ionization loss in the source and the response of the detector. We studied the relative influence of both factors in measurements with small source-to-detector distances. The computer simulation code 'the stopping and range of ions in matter' has been used to obtain the energy spectra of a 226Ra source as a function of the source thickness. Results of the simulation are compared with experimental measurements.

Activity of (239 + 240)Pu and 238Pu in atmospheric deposits.

Radioactive concentrations of (239 + 240)Pu and 238Pu were determined in rainwater samples collected at Badajoz (in a semi-arid zone in the south-west of Spain) from 1992 to 1996. Total plutonium deposition (including dry and wet deposition) was investigated during dry and wet periods. Anomalously high depositions of (239 + 240)Pu ((6.8 +/- 0.4) mBq/m2) and 238Pu ((2.2 +/- 0.2)mBq/m2) were found in the second-half of 1995. The 238Pu/(239 + 240)Pu activity ratio (0.32 +/- 0.04) obtained for that sample was higher than in global fallout.

[Predictive capacity of 3 methods for estimating the maintenance dose of digoxin in elderly patients]. / Capacidad predictiva de tres métodos de cálculo de la dosis de mantenimiento de digoxina en ancianos.

PURPOSE: To evaluate three methods for digoxin dose adjustment in aged patients. METHODS: We determined the plasma digoxin levels that would be attained in 47 consecutive old patients with doses adjusted to the creatinin clearance (Clc) by means of three mathematical functions. RESULTS: Age: 79.1 +/- 6.1 years of age; Clc: 0.77 +/- 0.24 mL/kg of lean body weight and minute. Once the dose has been fitted to the digoxin pharmacokinetic parameters described in the bibliography, the drug levels would oscillate between 0.8 and 2.0 ng/mL in 85.1% of the patients, with a 95% confidence interval (95% CI) from 72.3% to 92.6%; in 0.0% of the patients the levels would be greater than 2 ng/mL (95% IC: 0.0% to 7.6%). The precision and the bias would be 0.40 ng/mL (95% IC: 0.33 to 0.46 ng/mL) and--0.08 ng/m (95% IC: -0.19 to 0.04 ng/mL), respectively. The drug level would not be associated with the Clc (coefficient of Clc in the regression line: -0.0003; P > 0.9). The results would be worse with the others two mathematical functions. CONCLUSION: The first of the above adjustment methods would lead to good results if digoxin has not been prescriped in order to control the cardiac frequency in the setting of auricular fibrillation.

Radioactivity in bottled mineral waters.

Consumption of bottled mineral water is a growing practice and is sometimes a necessity rather than a choice. In this work, a study of the radioactive content of a wide selection of commercial bottled mineral waters for human intake was carried out. The origins of the analyzed waters were very different, coming from various locations in France, Portugal and Spain. Their total alpha and beta activity concentrations were determined and also gamma spectrometry was used to detect some radionuclides. In some cases, the waters presented high values of the total alpha and beta activity concentrations surpassing the reference levels established by the CSN, the Spanish. Regulatory Organization. In these cases, a determination of uranium and 226Ra was also performed by using low-level liquid scintillation counting. The results revealed a strong correlation between radioactive content and dry residue, and lead one to conclude that high radioactive content is mainly related to the mineralization in waters of underground origin.

Familial adenomatous polyposis: identification of a new frameshift mutation of the APC gene in an Italian family.

Familial Adenomatous Polyposis (FAP) is a premalignant disease of the gastrointestinal tract inherited as an autosomal dominant trait assigned to chromosome 5q21. The 15 exons of the APC gene responsible for the defect were amplified from the DNA of one FAP patient. SSCP analysis of the amplified DNA revealed a variant conformer of exon 10. The sequencing of the cloned PCR product showed a 1 base insertion at position 1370, creating a stop codon four nucleotides downstream. SSCP analysis of 20 family members and nucleotide sequencing of exon 10 in three affected members confirmed the Mendelian inheritance of the mutant allele.