Pork belly quality variation and its association with fatness level

Belly is a very popular pork cut composed of different layers of fat and muscle tissue. This work aims to investigate the effect of belly fatness on the morphological, mechanical (firmness) and compositional characteristics of fresh pork bellies and the distribution of the fat within the belly slice. A total of 182 bellies, selected to ensure variability of fatness, sexes and genotypes, were scanned by computed tomography (CT) to determine the fat content which, together with the genotype, led to the formation of 5 classes: F1 class below 26%, F2 class from 26% to 33.9%, and F3 class above 33.9% of fat content from common commercial crossbred pigs; F4 class with an average fatness of 47.3% from pure Duroc pigs; and last, F5 class with 62.6% average fat content from Iberian×Duroc pigs. The distribution of the fat in the central belly slice obtained by CT revealed important differences by region although the fat content was proportional to the overall fatness of the belly. Both belly weight and belly firmness increased with higher fatness. In bellies from common commercial pigs, an increase of SFA and MUFA and a decrease of PUFA as fatness increased was observed. This study highlights variations in belly characteristics among different fat classes, indicating considerable differences in the quality of bellies currently available in the market. This may influence producers and consumers acceptability such that fat content could be considered as a quality criterion to pre-classify bellies and better match the raw product with its final destination.

The effect of immunocastration of male and female Duroc pigs on the morphological, mechanical and compositional characteristics of pork belly

Pork belly is an important and heterogeneous cut, characterized by its fat content. Immunocastration is an alternative to surgical castration that can modify the composition of carcasses and cuts and it can affect at its processing. This work compares the morphological, mechanical and compositional characteristics of pork belly of (1) pure Duroc pigs from surgically castrated males (CM), entire females (EF) and immunocastrated females (IF), and (2) Duroc crossbreed pigs from immunocastrated males (IM) and entire males (EM). Two trials were carried out: Trial 1, in which 36 bellies were evaluated, 12 from each sexual type, CM, EF and IF; and Trial 2, where 30 bellies were used, 15 from each sexual type, IM and EM. Results show few differences in bellies from EF and IF, while those from CM were fatter and firmer and with lower polyunsaturated fat. Bellies from IM were longer and firmer than those from EM, and their skin was thinner. IM bellies had higher saturated and lower polyunsaturated fat than those from EM. To conclude, the sex of the pigs affects belly characteristics and this could be a criterion for determining the destination of the bellies in the cutting plant. Immunocastration of pure Duroc females had a lower effect on the belly characteristics when compared to those from entire females, but some differences could be found in the fat distribution. Immunocastration of Duroc crossbred males produces firmer and thicker bellies, with a thinner skin, that could be advantageous for slicing and further processing.

Classical Goldstone modes in long-range interacting systems

For a classical system with long-range interactions, a soft mode exists whenever a stationary state spontaneously breaks a continuous symmetry of the Hamiltonian. Besides that, if the corresponding coordinate associated to the symmetry breaking is periodic, then the same energy of the different stationary states and finite N thermal fluctuations result in a superdiffusive motion of the center of mass for total zero momentum, that tends to a normal diffusion for very long times. As examples of this, we provide a two-dimensional self-gravitating system, a free electron laser, and the Hamiltonian mean-field (HMF) model. For the latter, a detailed theory for the motion of the center of mass is given. We also discuss how the coupling of the soft mode to the mean-field motion of individual particles may lead to strong chaotic behavior for a finite particle number, as illustrated by the HMF model.

Co-extruded alginate as an alternative to collagen casings in the production of dry-fermented sausages: Impact of coating composition

The performance of co-extruded alginate coatings containing no extra additives (A), polyglycerol esters of fatty acids (EA), or pea protein (PA) was assessed as an alternative to collagen casings (C) for the manufacturing of dry-fermented sausages (fuet) with no inoculation of moulds and without a fermentation step (NMNF) and fuet inoculated with Penicillium candidum and fermented (MF). Stuffing into collagen casings resulted in slower sausage drying kinetics compared with alginate coating. No significant differences in a_w were observed among the studied casing types for NMNF and MF fuets and for the evolution of the technological and spoilage microorganisms. Fuets coated with A, EA, and PA showed lower pH values than fuets stuffed in collagen casings. No significant differences on sensory properties between casing types were observed. Therefore, alginate coatings would be a feasible alternative to collagen casing from a technological and safety point of view.

Influence of surfactants and proteins on the properties of wet edible calcium alginate meat coatings

Calcium alginate structures are of interest as replacers for natural casings due to their high availability, biodegradability and low price. The aim of this paper is to study the effect of oil, surfactants and proteins (pea and collagen) on the water transfer, mechanical and microstructural properties of the wet calcium alginate films. The addition of oil and surfactants tended to reduce the water permeance and the weight loss rate, reaching values between those shown by natural and collagen artificial casings. The addition of proteins did not improve the adherence of the films and it decreased the maximum force of the film at puncture test, which was even lower with the presence of the surfactant E475. The TEM micrographs showed that the differences in mechanical properties are mainly related to the differences in the compaction of the microstructure. Wet alginate films with E475 are envisaged as a substitute of natural and collagen artificial casings in the stuffed meat products industry.

Formation and relaxation of quasistationary states in particle systems with power-law interactions

We explore the formation and relaxation of the so-called quasistationary states (QSS) for particle distributions in three dimensions interacting via an attractive radial pair potential V(r→∞)∼1/r^{γ} with γ>0, and either a soft core or hard core regularization at small r. In the first part of the paper, we generalize, for any spatial dimension d≥2, Chandrasekhar's approach for the case of gravity to obtain analytic estimates of the rate of collisional relaxation due to two-body collisions. The resultant relaxation rates indicate an essential qualitative difference depending on the integrability of the pair force at large distances: for γ>d-1, the rate diverges in the large particle number N (mean-field) limit, unless a sufficiently large soft core is present; for γ<d-1, on the other hand, the rate vanishes in the same limit even in the absence of any regularization. In the second part of the paper we compare our analytical predictions with the results of extensive parallel numerical simulations in d=3 performed with an appropriate modification of the gadget code, for a range of different exponents γ and soft cores leading to the formation of QSS. We find, just as for the previously well studied case of gravity (which we also revisit), excellent agreement between the parametric dependence of the observed relaxation times and our analytic predictions. Further, as in the case of gravity, we find that the results indicate that, when large impact factors dominate, the appropriate cutoff is the size of the system (rather than, for example, the mean interparticle distance). Our results provide strong evidence that the existence of QSS is robust only for long-range interactions with a large distance behavior γ<d-1; for γ≥d-1, the existence of such states will be conditioned strongly on the short-range properties of the interaction.

Active Packaging Applications for Food

The traditional role of food packaging is continuing to evolve in response to changing market needs. Current drivers such as consumer's demand for safer, "healthier," and higher-quality foods, ideally with a long shelf-life; the demand for convenient and transparent packaging, and the preference for more sustainable packaging materials, have led to the development of new packaging technologies, such as active packaging (AP). As defined in the European regulation (EC) No 450/2009, AP systems are designed to "deliberately incorporate components that would release or absorb substances into or from the packaged food or the environment surrounding the food." Active packaging materials are thereby "intended to extend the shelf-life or to maintain or improve the condition of packaged food." Although extensive research on AP technologies is being undertaken, many of these technologies have not yet been implemented successfully in commercial food packaging systems. Broad communication of their benefits in food product applications will facilitate the successful development and market introduction. In this review, an overview of AP technologies, such as antimicrobial, antioxidant or carbon dioxide-releasing systems, and systems absorbing oxygen, moisture or ethylene, is provided, and, in particular, scientific publications illustrating the benefits of such technologies for specific food products are reviewed. Furthermore, the challenges in applying such AP technologies to food systems and the anticipated direction of future developments are discussed. This review will provide food and packaging scientists with a thorough understanding of the benefits of AP technologies when applied to specific foods and hence can assist in accelerating commercial adoption.

Collisional relaxation in the inhomogeneous Hamiltonian mean-field model: Diffusion coefficients

Systems of particles with long-range interactions present two important processes: first, the formation of out-of-equilibrium quasistationary states (QSS) and, second, the collisional relaxation towards Maxwell-Boltzmann equilibrium in a much longer time scale. In this paper, we study the collisional relaxation in the Hamiltonian mean-field model using the appropriate kinetic equations for a system of N particles at order 1/N: the Landau equation when collective effects are neglected and the Lenard-Balescu equation when they are taken into account. We derive explicit expressions for the diffusion coefficients using both equations for any magnetization, and we obtain analytic expressions for highly clustered configurations. An important conclusion is that in this system collective effects are crucial in order to describe the relaxation dynamics. We compare the diffusion calculated with the kinetic equations with simulations set up to simulate the system with or without collective effects, obtaining a very good agreement between theory and simulations.

Predicting gaseous emissions from small-scale combustion of agricultural biomass fuels

A prediction model of gaseous emissions (CO, CO2, NOx, SO2 and HCl) from small-scale combustion of agricultural biomass fuels was developed in order to rapidly assess their potential to be burned in accordance to current environmental threshold values. The model was established based on calculation of thermodynamic equilibrium of reactive multicomponent systems using Gibbs free energy minimization. Since this method has been widely used to estimate the composition of the syngas from wood gasification, the model was first validated by comparing its prediction results with those of similar models from the literature. The model was then used to evaluate the main gas emissions from the combustion of four dedicated energy crops (short-rotation willow, reed canary grass, switchgrass and miscanthus) previously burned in a 29-kW boiler. The prediction values revealed good agreement with the experimental results. The model was particularly effective in estimating the influence of harvest season on SO2 emissions.

Nonequilibrium phase transition with gravitational-like interaction in a cloud of cold atoms

We propose to use a cloud of laser-cooled atoms in a quasi-two-dimensional trap to investigate a nonequilibrium collapse phase transition in the presence of a gravitational-like interaction. Using theoretical arguments and numerical simulations, we show that, like in two-dimensional gravity, a transition to a collapsed state occurs below a critical temperature. In addition and as a signature of the nonequilibrium nature of the system, persistent particle currents, dramatically increasing close to the phase transition, are observed.

Will climate change drive alien invasive plants into areas of high protection value? An improved model-based regional assessment to prioritise the management of invasions

Species distribution models (SDMs) studies suggest that, without control measures, the distribution of many alien invasive plant species (AIS) will increase under climate and land-use changes. Due to limited resources and large areas colonised by invaders, management and monitoring resources must be prioritised. Choices depend on the conservation value of the invaded areas and can be guided by SDM predictions. Here, we use a hierarchical SDM framework, complemented by connectivity analysis of AIS distributions, to evaluate current and future conflicts between AIS and high conservation value areas. We illustrate the framework with three Australian wattle (Acacia) species and patterns of conservation value in Northern Portugal. Results show that protected areas will likely suffer higher pressure from all three Acacia species under future climatic conditions. Due to this higher predicted conflict in protected areas, management might be prioritised for Acacia dealbata and Acacia melanoxylon. Connectivity of AIS suitable areas inside protected areas is currently lower than across the full study area, but this would change under future environmental conditions. Coupled SDM and connectivity analysis can support resource prioritisation for anticipation and monitoring of AIS impacts. However, further tests of this framework over a wide range of regions and organisms are still required before wide application.

Clinical outcome, fertility and uterine artery Doppler scans in women with obstetric bilateral internal iliac artery ligation or embolisation

The objective of our study was to report on the clinical outcome, fertility and uterine artery Doppler scans in patients with major postpartum haemorrhage, treated with bilateral internal iliac artery ligation or embolisation. We performed an observational analysis of successful bilateral internal iliac artery ligation or embolisation for postpartum haemorrhage in a tertiary hospital between 2001 and 2006. Clinical data and other medical/ surgical manoeuvres were recorded. Fertility data, menstrual cycle characteristics and uterine artery Doppler scans were assessed. Our success rate in bleeding control was 81%. Three patients got pregnant again 13, 16 and 23 months after the procedure. The one patient whose uterine artery was not identified in the Doppler scan was the only one who presented with secondary infertility. Three patients presented with secondary dysmenorrhoea. We concluded that internal iliac artery occlusion is an effective fertility-sparing procedure for postpartum haemorrhage. The absence of uterine revascularization could be a negative factor in future reproduction. Due to our limited sample size, larger studies are required to confirm these findings.

Analysis of raw hams using SELDI-TOF-MS to predict the final quality of dry-cured hams

The relationship between protein profiles of Gluteus medius (GM) muscles of raw hams obtained from 4 pure breed pigs (Duroc, Large White, Landrace, and Piétrain) with the final quality of the Semimembranosus and Biceps femoris muscles of dry-cured hams was investigated. As expected, Duroc hams showed higher levels of marbling and intramuscular fat content than the other breeds. Piétrain hams were the leanest and most conformed, and presented the lowest salt content in dry-cured hams. Even if differences in the quality traits (colour, water activity, texture, composition, intramuscular fat, and marbling) of dry-cured hams were observed among the studied breeds, only small differences in the sensory attributes were detected. Surface-enhanced laser desorption/ionisation time-of-flight mass spectrometry (SELDI-TOF-MS) was used to obtain the soluble protein profiles of GM muscles. Some associations between protein peaks obtained with SELDI-TOF-MS and quality traits, mainly colour (b*) and texture (F(0), Y(2), Y(90)) were observed. Candidate protein markers for the quality of processed dry-cured hams were identified.

Quasistationary states and the range of pair interactions

"Quasistationary" states are approximately time independent out of equilibrium states which have been observed in a variety of systems of particles interacting by long-range interactions. We investigate here the conditions of their occurrence for a generic pair interaction V(r→∞)~1/r(γ) with γ>0, in d>1 dimensions. We generalize analytic calculations known for gravity in d=3 to determine the scaling parametric dependences of their relaxation rates due to two-body collisions, and report extensive numerical simulations testing their validity. Our results lead to the conclusion that, for γ<d-1, the existence of quasistationary states is ensured by the large distance behavior of the interaction alone, while for γ>d-1 it is conditioned on the short distance properties of the interaction, requiring the presence of a sufficiently large soft core in the interaction potential.

Gravitational dynamics of an infinite shuffled lattice: early time evolution and universality of nonlinear correlations

In two recent papers, a detailed study has been presented of the out-of-equilibrium dynamics of an infinite system of self-gravitating points initially located on a randomly perturbed lattice. In this paper, we extend the treatment of the early time phase during which strong nonlinear correlations first develop, prior to the onset of "self-similar" scaling in the two-point correlation function. We establish more directly, using appropriate modifications of the numerical integration, that the development of these correlations can be well described by an approximation of the evolution in two phases: a first perturbative phase in which particle displacements are small compared to the lattice spacing, and a subsequent phase in which particles interact only with their nearest neighbors. For the range of initial amplitudes considered, we show that the first phase can be well approximated as a transformation of the perturbed lattice configuration into a Poisson distribution at the relevant scales. This appears to explain the universality of the spatial dependence of the asymptotic nonlinear clustering observed from both shuffled lattice and Poisson initial conditions.

Effects of 5-HT6 receptor antagonism and cholinesterase inhibition in models of cognitive impairment in the rat

BACKGROUND AND PURPOSE

The beneficial effect of 5-HT6 receptor antagonism in cognition remains controversial. This study has been undertaken to reassess the cognition enhancing properties of acute vs subchronic treatment with the selective 5-HT6 receptor antagonist SB-271046 in unimpaired rats, as well as against scopolamine (cholinergic-) or MK-801 (glutamatergic-mediated) deficits.

EXPERIMENTAL APPROACH

The Morris water maze was used, measuring behaviour acquisition and retention, and swim speed. Other behavioural measures included yawning and motor activity. SB-271046 was given acutely before each trial or subchronically for 7 days before the trials. The AChE inhibitor galanthamine was also used alone or in combination with SB-271046.

KEY RESULTS

Subchronic treatment with SB-271046 improved acquisition in the Morris water maze, while the acute treatment only improved retention. Neither acute nor subchronic SB-271046 treatment reversed scopolamine-induced learning deficits. MK-801 induced learning impairment associated with a behavioural syndrome, reversed by acute, but not subchronic, SB-271046 treatment. Interestingly, combined treatment with galanthamine and SB-271046 reversed the scopolamine- or MK-801-induced learning impairments. Subchronic treatment with SB-271046 did not modify motor activity or the increased number of yawns, a cholinergic-mediated behaviour, induced by single administration of SB-271046.

CONCLUSIONS AND IMPLICATIONS

These data suggest a potential therapeutic role of 5-HT6 receptor antagonists such as SB-271046, alone or in combination with galanthamine, in the treatment of cognitive dysfunction, such as those seen in Alzheimer's disease and schizophrenia.

Functional interaction between 5-HT(6) receptors and hypothalamic-pituitary-adrenal axis: cognitive implications

The serotonin 5-HT(6) receptor has become a promising target for the treatment of neuropsychological diseases, such as affective disorders. Increasing evidence implicates stress and its effector system, the hypothalamic-pituitary-adrenal (HPA) axis, in the neurobiology of depression. In addition, there are important memory disturbances in stress-related psychiatric disorders that have been associated to an impairment of the HPA axis reactivity. The aim of the present work is to study the functional interactions between 5-HT(6) receptors and HPA axis. In a situation of increased HPA axis responsiveness (maternal separation, MS) no differences were found in the expression of 5-HT(6) gene in the hippocampus or frontal cortex, although serotonin levels were higher in the frontal cortex of MS rats. 5-HT(6) receptor mRNA expression increased significantly in the hippocampus in a situation of decreased glucocorticoid levels, such as adrenalectomy. Cognitive deficits associated to HPA dysfunction, such those found in the MS model, were fully reversed by administration of SB271046, a selective 5-HT(6) receptor antagonist. A chronic treatment with SB271046 did not modify CRF mRNA levels in the hypothalamus, but there was a higher glucocorticoid receptor density in the hippocampus compared to control. In contrast, in the frontal cortex, treatment with SB271046 induced a significant decrease in glucocorticoid receptor density. These data suggest that expression of 5-HT(6) receptors might be differentially regulated depending on levels of circulating adrenal corticoids. These results are discussed in terms of therapeutical approaches to the treatment of behavioral (depressive-like) and cognitive disturbances associated to an altered response to stress.

Use of antimicrobial biodegradable packaging to control Listeria monocytogenes during storage of cooked ham

The antimicrobial effect against L. monocytogenes of biodegradable films (alginate, zein and polyvinyl alcohol) containing enterocins was investigated. Survival of the pathogen was studied by means of challenge tests performed at 6 degrees C during 8 and 29 days, for air-packed and vacuum-packed sliced cooked ham, respectively. Air packaging was tested with two concentrations of enterocins (200 and 2000 AU/cm2). Control air-packed cooked ham showed an increase of L. monocytogenes from 10(4) to 10(7) CFU/g after 8 days. By contrast, packaging with antimicrobial films effectively slowed down the pathogen's growth, leading to final counts lower than in control lots. Air-packaging with alginate films containing 2000 AU/cm2 of enterocins effectively controlled L. monocytogenes for 8 days. An increase of only 1 log unit was observed in zein and polyvinyl alcohol lots at the same enterocin concentration. Vacuum packaging with films containing enterocins (2000 AU/cm2) also delayed the growth of the pathogen. No increase from inoculated levels was observed during 15 days in antimicrobial alginate films. After 29 days of storage, the lowest counts were obtained in samples packed with zein and alginate films containing enterocins, as well as with zein control films. The most effective treatment for controlling L. monocytogenes during 6 degrees C storage was vacuum-packaging of sliced cooked ham with alginate films containing 2000 AU/cm2 of enterocins. From the results obtained it can concluded that antimicrobial packaging can improve the safety of sliced cooked ham by delaying and reducing the growth of L. monocytogenes.

High-pressure processing and antimicrobial biodegradable packaging to control Listeria monocytogenes during storage of cooked ham

The efficiency of combining high-pressure processing (HPP) and active packaging technologies to control Listeria monocytogenes growth during the shelf life of artificially inoculated cooked ham was assessed. Three lots of cooked ham were prepared: control, packaging with alginate films, and packaging with antimicrobial alginate films containing enterocins. After packaging, half of the samples were pressurized. Sliced cooked ham stored at 6 degrees C experienced a quick growth of L. monocytogenes. Both antimicrobial packaging and pressurization delayed the growth of the pathogen. However, at 6 degrees C the combination of antimicrobial packaging and HPP was necessary to achieve a reduction of inoculated levels without recovery during 60 days of storage. Further storage at 6 degrees C of pressurized antimicrobial packed cooked ham resulted in L. monocytogenes levels below the detection limit (day 90). On the other hand, storage at 1 degrees C controlled the growth of the pathogen until day 39 in non-pressurized ham, while antimicrobial packaging and storage at 1 degrees C exerted a bacteriostatic effect for 60 days. All HPP lots stored at 1 degrees C led to counts <100CFU/g at day 60. Similar results were observed when combining both technologies. After a cold chain break no growth of L. monocytogenes was observed in pressurized ham packed with antimicrobial films, showing the efficiency of combining both technologies.

Aminogenesis control in fermented sausages manufactured with pressurized meat batter and starter culture

The application of high hydrostatic pressure (200MPa) to meat batter just before sausage fermentation and the inoculation of starter culture were studied to improve the safety and quality of traditional Spanish fermented sausages (fuet and chorizo). Higher amounts of biogenic amines were formed in chorizo than in fuet. Without interfering with the ripening performance in terms of acidification, drying and proteolysis, hydrostatic pressure prevented enterobacteria growth but did not affect Gram-positive bacteria significantly. Subsequently, a strong inhibition of diamine (putrescine and cadaverine) accumulation was observed, but that of tyramine was not affected. The inoculated decarboxylase-negative strains, selected from indigenous bacteria of traditional sausages, were resistant to the HHP treatment, being able to lead the fermentation process, prevent enterococci development and significantly reduce enterobacteria counts. In sausages manufactured with either non-pressurized or pressurized meat batter, starter culture was the most protective measure against the accumulation of tyramine and both diamines.

Starter cultures and high-pressure processing to improve the hygiene and safety of slightly fermented sausages

The effectiveness of selected starter cultures and high hydrostatic pressure after ripening was evaluated to improve the safety and quality of slightly fermented sausages. Inhibition of common foodborne pathogens, spoilage bacteria, and biogenic amine content was studied. Random amplification of polymorphic DNA and plasmid profiles were used to monitor the competitiveness of the starter cultures during fermentation and ripening. Lactobacillus sakei CTC6626 and Staphylococcus xylosus CTC6013 dominated L. sakei CTC6469 and S. xylosus CTC6169 independently of the product assayed. Starter cultures were able to control the growth of Listeria monocytogenes, Enterobacteriaceae, Enterococcus, and the biogenic amine content. A pH decrease below 5.3 at the seventh day of fermentation was crucial. Salmonella spp. counts decreased significantly during ripening independently of the use of starter culture and product. High hydrostatic pressure treatment was necessary to ensure absence of Salmonella spp. in final products.

Gravitational evolution of a perturbed lattice and its fluid limit

We apply a simple linearization, well known in solid state physics, to approximate the evolution at early times of cosmological N-body simulations of gravity. In the limit that the initial perturbations, applied to an infinite perfect lattice, are at wavelengths much greater than the lattice spacing l, the evolution is exactly that of a pressureless self-gravitating fluid treated in the analogous (Lagrangian) linearization, with the Zeldovich approximation as a subclass of asymptotic solutions. Our less restricted approximation allows one to trace the evolution of the discrete distribution until the time when particles approach one another (i.e., "shell crossing"). We calculate modifications of the fluid evolution, explicitly dependent on l, i.e., discreteness effects in the N-body simulations. We note that these effects become increasingly important as the initial redshift is increased at fixed l.

PAIR as percutaneous treatment of hydatid liver cysts

Hydatid disease of the liver remains an important and challenging problem in rural areas; although, surgery is considered the treatment of choice, percutaneous treatment of hydatid cysts is relatively new, and the data related to it are limited. The purpose of the study was to present the results of percutaneous treatment of liver hydatid cysts. Thirty-four patients (13 male and 21 female), ranging in age between 14 and 80 years, with 55 liver hydatid cysts underwent percutaneous treatment with albendazole prophylaxis. Cysts were treated with a one-stage procedure that consisted of puncture of the cysts under guidance with computed tomography, aspiration of fluid, injection of hypertonic saline solution as scolicidal agent and reaspiration. Follow-up examinations showed progressive reduction and solidification of the cysts. The mean reduction in volume was 72%. No mortality, abdominal dissemination, or tract seeding occurred. Minor complications were urticaria with pruritus in two patients. One patient had a subcapusular hematoma without problem. Hospitalization courses varied from ambulatory procedures to 15 days of in-patient, mean hospital stay was 1.82 days. The results of percutaneous liver hydatid cyst treatment, indicating that the procedure is efficient and safe and offers complete cure in selected patients with a short hospitalization and that this technique should be considered an alternative to surgery.

[The genogram in the evaluation of natural family vital cycle and its dislocations]

OBJECTIVES

To evaluate whether the reading of the genogram allows the stages of the family vital cycle (FVC) and the map of relationships to be identified; and to study how it can be used to find the FVC and its dislocations, and family relationships.

DESIGN

Descriptive crossover study.

SETTING

Primary Care. Health Centres at Almanjayar and Cartuja (Granada). Patients and other participants. 499 genograms performed and analysed by Primary Care doctors.

INTERVENTIONS

Reading of the genograms by two doctors who had not participated in taking them, to establish whether the FVC stages and the map of relationships could be identified, and the cycle and its dislocations classified.

RESULTS

The reading of the genogram enabled the stages of the FVC to be identified in 96% of cases. 66% of the genograms had the map of relationships correctly drawn. We found that 30% of families were at the fourth stage, 22% in II-B and 19% in II-A. 43% of the genograms contributed data on family relationships. Dislocations in the FVC were evident in 16.6%.

CONCLUSIONS

When the genogram is well-constructed, we consider it a good tool for classifying families into the appropriate stage of the FVC, evaluating the role of family interactions throughout the cycle and discovering disruptions in the FVC.

[Correlation of flow and static cytometry; their application to the study of anaplastic lymphomas]

PURPOSE

DNA study by cytometric methods is one of the prognosis factors considered in malignant tumours. Flow cytometry (FCM) was the most frequently used techniques in cell suspensions. Image cytometry (ICM) was also applied in cellular smears and it is possible to measure the results with an Image Analyzer, which supposes a substancial advantage over DNA studies. To confirm the results and correlation of the two techniques a controversial subtype of lymphoid tumour was selected: Anaplastic large cell lymphoma (ALCL).

MATERIAL AND METHODS

Fifty four cases of ALCL (23 classical type and 31 ACL-Hodgkin related) were studied. Cytometry was performed in paraffin-embedded tissues previously dewaxed, rehydrated and minced. FCM was done in suspensions incubated with ribonuclease A and stained with propidium iodide in an EPICS-C flow cytometer. ICM study was performed in Feulgen-stained smears and measured by an Image Analyzer CAS-200.

RESULTS

All cases were aneuploid. ALCL were 30.5% hypodiploid (HpD) and 69.5% hyperdiploid (HrD) by FCM; 43.5% HpD and 56.5% HrD by ICM. ALCL-HR were 58% HpD and 42% HrD by FCM; 68% HpD and 32% HrD by ICM. There was a lack of correlation of 22% between both methods but it was not statistically significant.

CONCLUSIONS

We can conclude the obtained results by FCM and ICM are almost similar.

[Value of protein 53 expression in lymphoma. Its correlation with genetic mutations]

PURPOSE

p53 is a tumour suppressor gene encoding a nuclear phosphoprotein that plays an important role in the control of normal cell proliferation. We have tried to establish the value of expression of the p53 protein in malignant lymphomas and its correlation with the presence of structural gene abnormalities.

MATERIAL AND METHODS

230 cases of lymphomas (11 Hodgkin's disease and 219 non-Hodgkin's) were studied by immunohistochemistry using an anti-p53 monoclonal antibody (DO-7, DAKO). Sections were heated by pressure cooker in 0.01 M sodium citrate buffer pH 6 as a method for antigen unmasking. The quantification of levels of nuclear p53 protein were measured with an Image Analyzer (CAS-200, Becton-Dickinson S.A.). We have also searched for mutations in a series of 94 lymphomas using polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) analysis in exons 5 to 9 of the p53 gene and the sample showing abnormal pattern were sequenced.

RESULTS

p53 immunoreactivity has been detected in 82.6% of cases. The percentage of positive cells varies in a wide range which was divided into 0% (17.39%), less than 5% (57.39%), between 5-10% (13.91%) and more than 10% (11.30%). In all lymphoma subtypes, we have found the majority of cases show levels less than 10% and few more than 10%. We found abnormal bands in 9 of 94 lymphomas with different diagnosis (1 ALCL, 1 T-LNH, 2 B-LNH, 2 centroblastic, 1 lymphoblastic and 2 MALT). Two cases resulted to be a silent base change which not alter the function of the p53 protein and represent a common polymorphism. Seven cases showed single base pair missense mutations in all of them. Mutations in codons 179, 248 and 273 correspond to some of the typical hotspots described in p53 gene.

CONCLUSIONS

p53 expression, is a frequent finding in malignant lymphomas, is variable and relates to histological subtype. The results suggest that positive immunocytochemistry cannot be used to determine which tumours have mutations of p53 because the existence of cases with discrepancies between overexpression of the protein and presence of mutations.