Comparison of methods of differentiating between fresh and frozen–thawed fish or fillets

Freezing is an efficient way of storing fish. Objectively though, it is very hard to determine whether a fish has been previously frozen. Following an appraisal of various methods, we selected a physical determination (torrymeter), a physiological examination (eye lens) and three enzymatic assays (α‐glucosidase, β‐N‐acetylglucosaminidase and β‐hydroxyacyl‐CoA‐dehydrogenase) and applied them to three species: plaice (Pleuronectes platessa), whiting (Merlangus merlangus) and mackerel (Scomber scombrus). We also compared the results obtained following slow and rapid freezing and investigated how spoilage affects the torrymeter measurements and α‐glucosidase assay values. For whole fish the physical method using the torrymeter is a reliable indicator. For fish fillets we recommend the enzymatic method using the α‐glucosidase assay, which should be accompanied by measurement of the freshness to avoid confusing a frozen–thawed fish and a fish in an advanced stage of spoilage. The values noted for fresh and thawed whiting and plaice indicated cut‐off values of 0.15 for whiting and 0.5 for plaice, above which it can be asserted that the sample had been frozen. © 2002 Society of Chemical Industry     

Standards, Options, and Recommendations for the management of patients with malignant mesothelioma of the pleura. Fédération Nationale des Centres de Lutte Contre le Cancer

The "Standards, Options and Recommandations" (SOR), started in 1993, are a collaborative project between the Federation of the French Cancer Centres (FNCLCC), the 20 French Cancer Centres and specialists from French Public Universities, General Hospitals and Private Clinics. The main objective is the development of clinical practice guidelines to improve the quality of health care and outcomes for cancer patients. The methodology is based on literature review and critical appraisal by a multidisciplinary experts group, with feedback from specialists in cancer care delivery. The objectives are to develop a clinical practice guideline with definitions of Standards. Options and Recommendations for the clinical care of malignant pleural mesothelioma. Data have been identified by literature search using Medline (1966-June 1997) and personal references lists. The main criteria considered were incidence, risk factors, pronostic factors and efficacy of cancer treatment. Once the guideline was defined, the document was submitted to 40 independent reviewers for peer review, and to the medical committees of the 20 French Cancer Centres for review and agreement. The results are: 1) systematic assessment of (professional) exposure to asbestos is based on a standardized interrogatory, completed by specific consultation for professional disease; 2) diagnostic and clinical staging is based on multiple biopsies under thoracoscopy and thoracic scanner; 3) there is no indication for extemporaneous examination, immunocytochemistry should use cytokeratine, EMA, vimentine, ACE, Leu-M1; 4) clinical care: the recommended staging classification is the IMIG (International Mesothelioma Interest Group) classification; 5) validated, independent pronostic factors are stage of disease patient's functional status and histologic type (i.e. epithelial lesions are of better prognosis); 6) treatment is based on symptomatic and palliative treatment options. Anticancer treatments (surgery, chemotherapy, immunotherapy, radiotherapy) did not show significant improvement of survival. The inclusion of patients in clinical trials is recommended.     

Rheology of Zirconia Suspensions in a Nonpolar Organic Medium

Three dispersants (stearic acid, oleic acid, and poly(12-hydroxystearic acid)) are compared for their ability to produce low-viscosity suspensions of zirconia in kerosene. Rheological measurements and sediment packing density measurements show that poly(12-hydroxystearic acid) is a better dispersant than stearic acid or oleic acid; this is explained in terms of the longer tail of the poly(12-hydroxystearic acid) surfactant molecule. The amount of dispersant can be optimized to reduce viscosity and yield point of the suspension, and to eliminate thixotropic hysteresis. The use of a dispersion medium of lower viscosity than the dispersant makes it easy to detect when complete monolayer coverage has been achieved. The loss of pseudoplasticity, brought about by a higher degree of deflocculation, can be recovered by increasing the volume fraction of solids of a suspension and this is beneficial in the plastic forming of ceramics. Rheological measurements showed that these suspensions reach a "critical state" above a critical shear stress (τ_c). This critical state is described by several parameters, i.e., the Bingham yield stress (τ_b), the plastic viscosity (ν_Pl), and the critical shear rate (γ_c), which are dependent on the volume fraction of solids.     

What function for human lithostathine?: structural investigations by three-dimensional structure modeling and high-resolution NMR spectroscopy

Human lithostathine is a 144-residue protein, expressed in variousorgans and pathologies. Several biological functions have beenproposed for this protein. Among others, inhibition of nucleationand growth of CaCO₃ crystals in the pancreas and bacterial aggregationhas retained attention, because lithostathine presents highsequence similarities with calcium-dependent (or C-type) lectins.To study its structure-function relationship and compare itwith that of C-type lectins, we have built a model for lithostathine.This model is derived from the only two C-type lectins of knownstructures: rat mannose binding protein and human E-selectin.An original strategy, inspired by that proposed by Havel andSnow, was designed for model building. We have undertaken NMRstudies on the natural protein. Although complete structuredetermination has not yet been achieved, the NMR studies didconfirm the main characteristics of the model. From analysisof the proposed model, we concluded that lithostathine is notexpected to present sugar- or calcium-binding properties. Therefore,the mechanisms of bacterial aggregation and inhibition of CaCO₃nucleation and growth have not yet been elucidated.     

Compromised Biomechanical Properties,Cell–Cell Adhesion and Nanotubes Communication in Cardiac Fibroblasts Carrying the Lamin A/C D192G Mutation

Clinical effects induced by arrhythmogenic cardiomyopathy (ACM) originate from a large spectrum of genetic variations, including the missense mutation of the lamin A/C gene (LMNA), LMNA D192G. The aim of our study was to investigate the biophysical and biomechanical impact of the LMNA D192G mutation on neonatal rat ventricular fibroblasts (NRVF). The main findings in mutated NRVFs were: (i) cytoskeleton disorganization (actin and intermediate filaments); (ii) decreased elasticity of NRVFs; (iii) altered cell–cell adhesion properties, that highlighted a strong effect on cellular communication, in particular on tunneling nanotubes (TNTs). In mutant-expressing fibroblasts, these nanotubes were weakened with altered mechanical properties as shown by atomic force microscopy (AFM) and optical tweezers. These outcomes complement prior investigations on LMNA mutant cardiomyocytes and suggest that the LMNA D192G mutation impacts the biomechanical properties of both cardiomyocytes and cardiac fibroblasts. These observations could explain how this mutation influences cardiac biomechanical pathology and the severity of ACM in LMNA-cardiomyopathy.     

Alanine minimises hepatocyte injury after ischemia-reperfusion in an <i>ex vivo</i> rat liver model

Ischemia-reperfusion injury is a determinant in liver injury occurring during surgery, ischemic states and multiple organ failure. The pre-existing nutritional status of the liver, i.e., fasting, might contribute to the extent of tissue injury. This study investigated whether alanine, an amino acid precursor of glucose, could protect ex vivo perfused livers of fasting rats from reperfusion injury. The portal vein was cannulated, the liver removed and perfused in a closed ex vivo system. Isolated livers were perfused either with glucose 1 g/L and 10 g/L, or with equal concentrations of alanine (n = 10 in each group). The experiment consisted of perfusion for 15 min, ischemia for 60 min, and reoxygenation during 60 min. Enzymes, glucose, lactate and bilirubin were analysed in perfusate samples. The proportion of glycogen as well as activation of caspase 3 was determined in biopsies. Alanine at a concentration of 10 g/L attenuated enzymes release in the perfusate during reoxygenation when compared to glucose-treated groups. Lactate level in the perfusate was lowest in alanine groups. Ischemia-reperfusion and mainly alanine activated apoptosis, specifically in Kupffer and endothelial cells. Alanine presents a protective effect on normothermic ischemia-reperfusion injury of the fasting rat liver when compared to glucose     

Pressure-infiltration processing of reinforced aluminum

Pressure infiltration of liquid metal is one of the most important processing routes for the production of aluminum-matrix composites having a self-supporting reinforcement phase. This article briefly examines the physical phenomena governing infiltration processes, to present practical guidelines derived from their analysis for optimization of the process and the materials produced. Engineering aspects that are pertinent to infiltration techniques, including preform preparation, process configurations, flow control, and innovative processes, are summarized.