Measurement of the specific and non-specific binding energies of Mg2+ to RNA.

Determining the non-specific and specific electrostatic contributions of magnesium binding to RNA is a challenging problem. We introduce a single-molecule method based on measuring the folding energy of a native RNA in magnesium and at its equivalent sodium concentration. The latter is defined so that the folding energy in sodium equals the non-specific electrostatic contribution in magnesium. The sodium equivalent can be estimated according to the empirical 100/1 rule (1 M NaCl is equivalent to 10 mM MgCl2), which is a good approximation for most RNAs. The method is applied to an RNA three-way junction (3WJ) that contains specific Mg2+ binding sites and misfolds into a double hairpin structure without binding sites. We mechanically pull the RNA with optical tweezers and use fluctuation theorems to determine the folding energies of the native and misfolded structures in magnesium (10 mM MgCl2) and at the equivalent sodium condition (1 M NaCl). While the free energies of the misfolded structure are equal in magnesium and sodium, they are not for the native structure, the difference being due to the specific binding energy of magnesium to the 3WJ, which equals ΔG≃ 10 kcal/mol. Besides stabilizing the 3WJ, Mg2+ also kinetically rescues it from the misfolded structure over timescales of tens of seconds in a force-dependent manner. The method should generally be applicable to determine the specific binding energies of divalent cations to other tertiary RNAs.

Folding Free Energy Determination of an RNA Three-Way Junction Using Fluctuation Theorems.

Nonequilibrium work relations and fluctuation theorems permit us to extract equilibrium information from nonequilibrium measurements. They find application in single-molecule pulling experiments where molecular free energies can be determined from irreversible work measurements by using unidirectional (e.g., Jarzynski's equality) and bidirectional (e.g., Crooks fluctuation theorem and Bennet's acceptance ratio (BAR)) methods. However, irreversibility and the finite number of pulls limit their applicability: the higher the dissipation, the larger the number of pulls necessary to estimate ΔG within a few kBT. Here, we revisit pulling experiments on an RNA three-way junction (3WJ) that exhibits significant dissipation and work-distribution long tails upon mechanical unfolding. While bidirectional methods are more predictive, unidirectional methods are strongly biased. We also consider a cyclic protocol that combines the forward and reverse work values to increase the statistics of the measurements. For a fixed total experimental time, faster pulling rates permit us to efficiently sample rare events and reduce the bias, compensating for the increased dissipation. This analysis provides a more stringent test of the fluctuation theorem in the large irreversibility regime.

The All4Children project to assess the initial implementation of the Integrated Model of Family Foster Care in Portugal: A description of the study protocol.

BACKGROUND: The All4Children project addresses the urgent need to transition from institutionalization to family-based care for out-of-home children in Portugal. Despite evidence highlighting the detrimental effects of institutionalization, only a small percentage of children (less than 4%) are currently placed in family foster care in the country. In response to European directives for deinstitutionalization, Portuguese legislation now prioritizes non-kinship family foster care as the preferred alternative for young children in need of care. To facilitate this transition, the Integrated Model of Family Foster Care (MIAF) was developed, offering a comprehensive framework covering the entire spectrum of family foster care. OBJECTIVE: This research aims to investigate the initial implementation stage of the MIAF to promote high-quality family foster care in Portugal. METHOD: The study will conduct a mixed-method and longitudinal research project in family foster care agencies across different regions of Portugal, focusing on evaluating the implementation and outcomes of the MIAF model using a multi-informant and multi-method approach. The participants will include caseworkers, children aged 0-9 years entering foster care, and their respective foster families enrolled in the MIAF program. Process evaluation will assess fidelity, feasibility, appropriateness, and acceptability of MIAF modules, while outcome evaluation will examine child safety, stability, well-being, as well as foster family well-being and quality of relational care. OUTCOMES: The insights gained from this research initiative will serve as a foundation for the ongoing enhancement of MIAF. Consequently, this project has the capacity to advance evidence-based child welfare practices by refining processes and strategies to better serve vulnerable children and youth. CONCLUSION: Facilitated by a multidisciplinary team, this project will contribute to advancing research in the field, enhancing practice, and informing policy during a pivotal stage of deinstitutionalization in Portugal.

Decreased peripheral blood CD4+/CD25+ regulatory T cells in patients with alcoholic hepatitis.

BACKGROUND: Development of alcoholic hepatitis (AH) may be favored by the activation of the innate immune response. Recently, decreased numbers of circulating regulatory T cells (Tregs) have been reported in diseases associated with an immune activation status, but no studies have focused so far, in investigating the distribution of Tregs in chronic alcoholism and its potential association with liver disease. Here, we analyzed for the first time the frequency of peripheral blood (PB) Tregs and Treg subsets in AH and its relationship with the production of inflammatory cytokines by PB monocytes and dendritic cells (DCs). METHODS: PB samples from 25 male patients with AH were studied; in parallel, 15 male chronic alcoholic patients without liver disease (AWLD) and 17 male healthy donors were also studied, as controls. The distribution of CD4⁺CD25hiCD127-/lo Tregs and their maturation subsets (naïve, central memory, and peripheral memory Tregs) was analyzed by flow cytometry. Spontaneous and in vitro-stimulated production of inflammatory cytokines by PB monocytes and DCs was analyzed by flow cytometry at the cytoplasmic level. RESULTS: Patients with AH showed decreased (p < 0.05) numbers of PB CD4⁺CD25hiCD127-/lo Tregs at the expense of all maturation-associated subsets, while AWLD and healthy subjects showed a similar (p > 0.05) distribution of PB CD4⁺CD25hiCD127-/lo Tregs. Interestingly, significantly increased amounts of spontaneously produced inflammatory cytokines were found among circulating monocyte-derived DCs and monocytes from AH (and AWLD) patients in comparison with healthy donors. Conversely, the ability of these cell subsets to produce cytokines after in vitro stimulation was lower (p < 0.05) in AH versus the 2 control groups. CONCLUSIONS: PB CD4⁺CD25hiCD127-/lo Tregs are significantly decreased in patients with AH when compared to both healthy and AWLD; this may contribute to explain the more pronounced activation of the innate immune response observed in AH, as reflected by an increased secretion of inflammatory cytokines by PB DCs and monocytes, and could facilitate the development of liver disease.

Prevalence of hepatitis C virus infection in alcoholic patients: cohort study and systematic review.

AIMS: Prevalence of chronic hepatitis C virus (HCV) infection among alcoholics is thought to be higher than in the general population, although prevalence rates reported are quite variable. Our study is aimed to analyze HCV prevalence in a cohort of alcoholics and to perform a systematic review on this topic. PATIENTS AND METHODS: A total of 396 alcoholic patients consecutively referred to our Alcoholism Unit were included. HCV infection status and other clinical variables were recorded for each patient. Variables associated with HCV infection were analyzed by means of logistic regression. Additionally, we performed a systematic review focused on previous studies on this topic. RESULTS: Among our alcoholic patients, 14 of them (3.53%) had chronic HCV infection. Variables independently associated with HCV infection were female gender, injection drug use (IDU) and the presence of alcoholic liver disease (ALD). Twenty-four studies analyzing HCV prevalence in alcoholic patients were included in our systematic review, showing prevalence rates of HCV infection ranging from 2.1 to 51% and an average weighted prevalence of 16.32%. CONCLUSION: In our series, the prevalence rate of chronic HCV infection among alcoholic patients is lower than previously reported, which is probably explained by the relatively low number of patients with ALD or IDU in our sample. Prevalence rates previously published are quite different and the presence of ALD and/or IDU can act as confounding factors for HCV prevalence among alcoholics.

Cannabinoid receptor 1 gene is associated with alcohol dependence.

BACKGROUND: Alcohol dependence (AD) vulnerability is determined by a complex array of genetic factors. Given the potential role of endocannabinoid system in AD, polymorphisms within cannabinoid receptor 1 gene (CNR1) have been potentially associated with susceptibility to this disease. We thus aimed to examine the relationship between 3 allelic variants of CNR1 (rs6454674, rs1049353, and rs806368) and AD. METHODS: Genotyping of the aforementioned polymorphisms was carried out by PCR in 298 male alcoholics (187 of them with AD) and 155 healthy controls. Single-marker, haplotype, and interaction analysis were performed to analyze the influence of CNR1 gene on AD susceptibility. RESULTS: We found an association between CNR1 gene and AD after haplotype analysis. Alcoholic patients with TGT haplotype (corresponding to rs6454674-rs1049353-rs806368 polymorphisms in this order) were less prone to have AD (p = 0.017). Besides, alcoholics with a G/T substitution of the first marker (GGT haplotype) or a C/T substitution of the third marker (TGC haplotype) were more likely to develop AD (p = 0.006 and 0.004, respectively) and an interaction was found between the G allele of rs6454674 single nucleotide polymorphism (SNP) and the C allele of rs806368 SNP (p = 0.009). CONCLUSIONS: Our findings support previously reported associations of CNR1 with dependence to alcohol and other substances and emphasizes the relevance of endocannabinoid system in AD.

Molecular dynamics simulation of the spherical electrical double layer of a soft nanoparticle: effect of the surface charge and counterion valence.

Molecular dynamics simulations were performed to study the ion and water distribution around a spherical charged nanoparticle. A soft nanoparticle model was designed using a set of hydrophobic interaction sites distributed in six concentric spherical layers. In order to simulate the effect of charged functionalyzed groups on the nanoparticle surface, a set of charged sites were distributed in the outer layer. Four charged nanoparticle models, from a surface charge value of -0.035 C m(-2) to -0.28 C m(-2), were studied in NaCl and CaCl(2) salt solutions at 1 M and 0.1 M concentrations to evaluate the effect of the surface charge, counterion valence, and concentration of added salt. We obtain that Na(+) and Ca(2+) ions enter inside the soft nanoparticle. Monovalent ions are more accumulated inside the nanoparticle surface, whereas divalent ions are more accumulated just in the plane of the nanoparticle surface sites. The increasing of the the salt concentration has little effect on the internalization of counterions, but significantly reduces the number of water molecules that enter inside the nanoparticle. The manner of distributing the surface charge in the nanoparticle (uniformly over all surface sites or discretely over a limited set of randomly selected sites) considerably affects the distribution of counterions in the proximities of the nanoparticle surface.

Association of µ-opioid receptor (OPRM1) gene polymorphism with response to naltrexone in alcohol dependence: a systematic review and meta-analysis.

Previous studies have suggested that the effect of naltrexone in patients with alcohol dependence may be moderated by genetic factors. In particular, the possession of the G allele of the A118G polymorphism of the µ-opioid receptor gene (OPRM1) has been associated with a better response to naltrexone, although controversial results have been reported. The aim of this paper is to combine previous findings by means of a systematic review and a meta-analysis. We retrieved studies on the relationship between A118G polymorphism in OPRM1 gene and response to treatment with naltrexone in patients with alcohol dependence by means of electronic database search. A meta-analysis was conducted using a random-effects model. Calculations of odds ratio (OR) and their confidence intervals (CI) and tests for heterogeneity of the results have been performed. Six previous studies have analyzed the role of A118G polymorphism in response to naltrexone for alcohol dependence. After meta-analysis, we found that naltrexone-treated patients carrying the G allele had lower relapse rates than those who were homozygous for the A allele (OR: 2.02, 95% CI 1.26-3.22; P = 0.003). There were no differences in abstinence rates. Our results support the fact that the G allele of A118G polymorphism of OPRM1 moderates the effect of naltrexone in patients with alcohol dependence. This genetic marker may therefore identify a subgroup of individuals more likely to respond to this treatment.

[Monkeypox: description of two cases under follow-up in Buenos Aires]. / Viruela símica: descripción de dos casos en seguimiento en Buenos Aires.

Monkeypox is an endemic disease in several African countries. In May 2022, an outbreak was reported in dozens of non-endemic countries. On July 23, 2022, the WHO Director-General declared this multinational outbreak a public health emergency of international concern. We report two cases of patients under follow-up in Buenos Aires, Argentina, between June and July 2022. Both were men who have sex with men, with the appearance of lesions in the genital area without a prodromal period. In both cases, treatment was carried out in the first instance with suspicion of sexually transmitted infections. We highlight the importance of considering this pathology as a differential diagnosis, taking into account the current epidemiological context.

La viruela símica es una enfermedad endémica en varios países de áfrica. En mayo de 2022 varios países donde la viruela símica no es endémica notificaron casos, incluyendo algunos países de las Américas. El 23 de julio de 2022, el Director General de la OMS declaró que este brote multinacional constituye una emergencia de salud pública de importancia internacional. Comunicamos dos casos de pacientes en seguimiento en la Ciudad de Buenos Aires, Argentina, entre junio y julio de 2022. Ambos eran hombres que tienen sexo con hombres, con aparición de lesiones en zona genital sin período prodrómico. En los dos casos se realizó tratamiento en primera instancia con sospecha de infecciones de transmisión sexual. Señalamos la importancia de considerar esta enfermedad como diagnóstico diferencial teniendo en cuenta el contexto epidemiológico actual.

Post-Adoption Help-Seeking in Portugal: A Comprehensive Study on Parental Difficulties and Help-Seeking Behaviors and Perceptions.

Effective psychological parenting interventions delivered to adoptive parents may prevent serious adjustment difficulties and promote a healthy functioning; however, less is known about adoptive parents' specific parental difficulties and help-seeking behaviors and perceptions, the understanding of which is deemed necessary to design well-informed interventions. This study aimed to describe parental difficulties, help-seeking behaviors, satisfaction with, and perceived barriers to seek, professional help, and acceptability of psychological parenting interventions among Portuguese adoptive parents. Comparisons with biological parents (Study 1) and between adoptive parents that requested adoption-specialized and non-specialized support (i.e., adoption-specialized vs. non-specialized help-seekers) (Study 2) were explored. A cross-sectional online survey was conducted. Participants were 471 adoptive and 552 biological parents of children aged under 18 years who were recruited through schools, adoption agencies, and social networks. They completed measures assessing parental difficulties, help-seeking behaviors, satisfaction with, and perceived barriers to seek, professional help, and acceptability of psychological parenting interventions. Comparison tests between the study groups, Pearson's correlations, analyses of covariance (ANCOVA) and multivariate logistic regressions (MLR) were performed. Parents' well-being and normative parenting challenges were the most frequent difficulties in both groups, but only associated with adoptive parents' help-seeking. Although difficulties related to a child's problems/parent-child relationship were more frequent among adoptive parents, adoption-related difficulties were rarely reported. Adoptive parents sought professional help more frequently, regardless of parental difficulties. Knowledge-related barriers to seeking help were the most frequent among adoptive parents. Adoption non-specialized help was less satisfactory. Acceptability of psychological parenting interventions was high, but dependent on parental difficulties. Implications for post-adoption services' development are discussed.

Genetic susceptibility to telomere shortening through the rs2293607 polymorphism is associated with a greater risk of alcohol use disorder.

Telomere shortening is usually considered a biomarker of ageing. Harmful alcohol use promotes accelerated biological ageing and alcohol use disorders (AUDs) are associated with short telomere length (TL). This study was conducted to examine the relationship of TL to AUD and determine whether single nucleotide polymorphisms (SNPs) in TERC and TERT modulate this association. For this purpose, we genotyped TERC SNPs rs2293607, rs12696304, and rs16847897 and TERT SNPs rs2735940, rs2736100, and rs2736098 in 308 male patients with AUD and 255 sex-matched healthy controls and measured TL in a subset of 99 patients and 99 controls paired by age and smoking status. Our results showed that the mean TL was shorter in patients with AUD than in controls. The area under the ROC curve was 0.70 (P < 0.001). The GG genotype of TERC rs2293607 was more common among patients with AUD than among controls (9.8% vs. 5.1%; P = 0.038). No difference was found for the other SNPs. Carriers of the GG genotype of rs2293607 had shorter telomeres than did allele A carriers. In conclusion, patients with AUD had shorter telomeres. Genetic susceptibility to telomere shortening through the rs2293607 SNP is associated with a greater risk of AUD.

New insights into diffusion in 3D crowded media by Monte Carlo simulations: effect of size, mobility and spatial distribution of obstacles.

Particle diffusion in crowded media was studied through Monte Carlo simulations in 3D obstructed lattices. Three particular aspects affecting the diffusion, not extensively treated in a three-dimensional geometry, were analysed: the relative particle-obstacle size, the relative particle-obstacle mobility and the way of having the obstacles distributed in the simulation space (randomly or uniformly). The results are interpreted in terms of the parameters that characterize the time dependence of the diffusion coefficient: the anomalous diffusion exponent (α), the crossover time from anomalous to normal diffusion regimes (τ) and the long time diffusion coefficient (D*). Simulation results indicate that there are a more anomalous diffusion (smaller α) and a lower long time diffusion coefficient (D*) when obstacle concentration increases, and that, for a given total excluded volume and immobile obstacles, the anomalous diffusion effect is less important for bigger size obstacles. However, for the case of mobile obstacles, this size effect is inverted yielding values that are in qualitatively good agreement with in vitro experiments of protein diffusion in crowded media. These results underline that the pattern of the spatial partitioning of the obstacle excluded volume is a factor to be considered together with the value of the excluded volume itself.

A semi-grand canonical Monte Carlo simulation model for ion binding to ionizable surfaces: proton binding of carboxylated latex particles as a case study.

In this paper, we present a computer simulation study of the ion binding process at an ionizable surface using a semi-grand canonical Monte Carlo method that models the surface as a discrete distribution of charged and neutral functional groups in equilibrium with explicit ions modelled in the context of the primitive model. The parameters of the simulation model were tuned and checked by comparison with experimental titrations of carboxylated latex particles in the presence of different ionic strengths of monovalent ions. The titration of these particles was analysed by calculating the degree of dissociation of the latex functional groups vs. pH curves at different background salt concentrations. As the charge of the titrated surface changes during the simulation, a procedure to keep the electroneutrality of the system is required. Here, two approaches are used with the choice depending on the ion selected to maintain electroneutrality: counterion or coion procedures. We compare and discuss the difference between the procedures. The simulations also provided a microscopic description of the electrostatic double layer (EDL) structure as a function of pH and ionic strength. The results allow us to quantify the effect of the size of the background salt ions and of the surface functional groups on the degree of dissociation. The non-homogeneous structure of the EDL was revealed by plotting the counterion density profiles around charged and neutral surface functional groups.

Supplementation with Resveratrol, Piperine and Alpha-Tocopherol Decreases Chronic Inflammation in a Cluster of Older Adults with Metabolic Syndrome.

Metabolic Syndrome (MetS) is increasing worldwide regardless of culture, genetic, gender, and geographic differences. While multiple individual risk factors, such as obesity, hypertension, diabetes, and hyperlipidemia, can cause cardiovascular disease (CVD), it is the intercurrence of these risk factors that defines MetS as a cluster that creates an environment for atherosclerosis and other manifestations of CVD. Despite the advances in the knowledge and management of each of the components of MetS, there are two molecular biology processes, chronic inflammation and oxidative stress, which are still underdiagnosed and undertreated. In order to assess the effect of a dietary supplement on chronic inflammation in MetS, we conducted a clinical trial with volunteers receiving a formula composed of resveratrol, piperine and alpha tocopherol (FRAMINTROL®), together with their habitual treatment, for three months. The inflammatory state was evaluated by ultrasensitive C reactive protein (US CRP) and ferritin in plasma, and oxygen consumption and chemiluminescence in neutrophils. The results showed that ferritin decreased by 10% (p < 0.05), US-CRP by 33% (p < 0.0001), oxygen consumption by 55% (p < 0.0001), and spontaneous chemiluminiscence was by 25% (p < 0.005) after treatment. As far as we know, this is the first study showing a chronic inflammation decrease in MetS patients due to the administration of a biopower Resveratrol-piperine and alpha tocopherol dietary supplement together with conventional therapy.

Tumor necrosis factor polymorphisms and alcoholic liver disease: a HuGE review and meta-analysis.

The association between alcoholic liver disease (ALD) and tumor necrosis factor-alpha gene (TNFA) polymorphisms has been analyzed in several studies, but results have been conflicting. The main purpose of this study was to integrate previous findings and explore whether these polymorphisms are associated with susceptibility to ALD. The authors surveyed studies on the relation between TNFA gene polymorphisms and ALD by means of an electronic database search. A meta-analysis was conducted in a random-effects model. The association between ALD and the -238G>A or -308G>A polymorphism of the TNFA gene has been analyzed in 11 studies. Concerning the -238G>A polymorphism, the authors found a significant association between possession of the A allele and risk of alcoholic liver cirrhosis (odds ratio = 1.47, 95% confidence interval: 1.05, 2.07). Meta-analysis of the relation between the -308G>A polymorphism and ALD did not show any significant association. Given the limited number of studies and the potential biases, more data are needed to confirm the association described for the -238A allele.

Common polymorphisms in interleukin genes (IL4, IL6, IL8 and IL12) are not associated with alcoholic liver disease or alcoholism in Spanish men.

BACKGROUND: Preliminary data suggest that polymorphisms in cytokine genes may be involved in the genetic predisposition to alcoholic liver cirrhosis or alcohol use disorders. We thus analyze the association between these diseases and the following polymorphisms: -33T>C IL4, -174 G>C IL6, -251 T>A IL8 and 1188 A>C IL12B. METHODS: 258 male alcoholics (161 without liver disease and 97 with liver cirrhosis) and 101 healthy controls were genotyped for the above mentioned polymorphisms. We examined the relationship between genotype and allele frequencies and the presence of disease, as well as the correlation with combinations of putative pro-inflammatory genotypes. Haplotypes were inferred using the expectation-maximization algorithm and haplotype frequencies were compared. RESULTS: We found no statistically significant association between any of these polymorphisms or the combinations of pro-inflammatory polymorphisms and the risk of alcoholic liver cirrhosis or alcohol abuse or dependence. Haplotype analysis of the IL4 and IL12B polymorphisms did not show any statistical relationship either. CONCLUSIONS: Our results do not support the hypothesis that the analyzed polymorphisms confer differences in alcoholic liver cirrhosis or alcohol use disorders susceptibility.

A functional polymorphism of the NFKB1 gene increases the risk for alcoholic liver cirrhosis in patients with alcohol dependence.

BACKGROUND: The genetic basis for the predisposition to alcoholic liver cirrhosis (ALC) remains unknown. Increasing evidence supports a role for the nuclear factor (NF)-kappaB, the NF-kappaB inhibitor alpha (NFKBIA), and the peroxisome proliferator-activated receptor (PPAR)-gamma in the pathogenesis of alcoholic liver disease, raising the possibility that common polymorphisms in genes encoding these molecules may confer susceptibility to ALC. The objective of this study was to analyze the relationship between common polymorphisms in NFKB1, NFKBIA, and PPARG2 genes and the presence of ALC. METHODS: A total of 258 male alcoholics (161 without liver disease and 97 with ALC) and 101 healthy controls were genotyped for the -94ins/delATTG NFKB1, 3'-UTR+126G>A NFKBIA, and 34C>G PPARG2 polymorphisms. The association of these genetic variants with ALC was tested in alcoholic patients with alcohol abuse and alcohol dependence. A logistic regression analysis was further performed to analyze the model of inheritance. RESULTS: We found an association between the presence of the deletion allele in NFKB1 polymorphism and ALC in patients with alcohol dependence. We found no association between NFKBIA and PPARG2 polymorphisms and the presence of ALC. CONCLUSIONS: The deletion allele of the -94ins/del NFKB1 polymorphism could be associated with a higher risk of developing ALC through an increase in inflammation, as supported by previous data.

Genetic association between -93A/G polymorphism in the Fyn kinase gene and alcohol dependence in Spanish men.

BACKGROUND: Fyn tyrosine kinase is a member of the Scr family that phosphorylates the NR2A and NR2B subunits of the NMDA receptors reducing the inhibitory effects of ethanol and therefore may regulate the individual sensitivity to ethanol. OBJECTIVES: To investigate whether there is any relationship between the polymorphism at position -93 of the Fyn kinase gene and the susceptibility to develop alcoholism. METHODS: We studied the distribution of genotypes and alleles of the polymorphism -93A/G (137346 T/C) in the 5' UTR region of the fyn gene in 207 male heavy drinkers (119 with alcohol dependence and 88 with alcohol abuse) and 100 control subjects from Castilla y León (Spain). RESULTS: The frequency of G allele carriers was higher in alcohol dependents than in alcohol abusers (47.9% vs 30.6%; p=0.015; OR=2.077; 95% CI 1.165-3.704). CONCLUSION: Our results show that the -93G allele of Fyn kinase gene is associated with higher risk to develop alcohol dependence in Spanish men.

Effect of sol-gel confinement on the structural dynamics of the enzyme bovine Cu,Zn superoxide dismutase.

Immobilization of proteins in sol-gel glasses has allowed the development of a new generation of robust and sensitive analytical devices as well as contributes to the investigation of the effect of molecular confinement on the structure of proteins. The immobilized protein usually preserves its structural integrity and functionality, while interactions with the matrix and its surface seem to contribute to alter its dynamics and stability. With the aim of better understanding the nature of such interactions, we have encapsulated the enzyme bovine Cu,Zn superoxide dismutase (BSOD), negatively charged at physiological pH, in a sol-gel matrix and the photophysical properties of its single tyrosine have been determined using both steady-state and time-resolved fluorescence techniques. Fluorescence spectra, quenching experiments, fluorescence lifetimes, and anisotropy measurements indicate that immobilization does not lead to any major conformational change, at least in the region of protein where the tyrosine residue is located. In addition, fluorescence anisotropy decays recorded above and below the isoelectric point of the protein indicate that, at neutral pH, well above its isoelectric point, the entrapped BSOD freely rotates within the matrix pore, but showing a different rotational behavior as compared with that in the bulk aqueous solution. However, below the isoelectric point, the global motion of the protein is totally hindered upon entrapment. Electrostatic interactions with the gel matrix, changes in water viscosity, and protein-to-pore size ratio are discussed as possible factors responsible for this behavior.

A new genetic variant involved in genetic susceptibility to alcoholic liver cirrhosis: -330T>G polymorphism of the interleukin-2 gene.

OBJECTIVE: Genetic factors may determine susceptibility to develop alcoholic liver cirrhosis, although it remains uncertain why only a minority of alcoholics suffers from this disease. A decrease in serum levels of interleukin-2 (IL-2) is usually found in alcoholic cirrhotics. In this study we examined the relationship between the -330T>G IL-2 gene (IL2) polymorphism and alcoholic liver cirrhosis. METHODS: Genotyping of the aforementioned polymorphism was done by polymerase chain reaction and digestion with restriction enzymes in 257 male alcoholics (161 without liver disease and 96 with alcoholic liver cirrhosis) and 101 healthy controls. A logistic regression analysis was performed to adjust for potential confounders and to analyze the model of inheritance. RESULTS: We found an association between the -330T>G IL2 polymorphism and alcoholic liver cirrhosis: the frequency of the allele T carriers (genotype TT and GT) was significantly higher in alcoholics with cirrhosis (96.9%) than in those without liver disease (89.4%, P=0.043). CONCLUSION: We report for the first time that the possession of the -330T allele of the IL2 is associated with a higher risk of developing alcoholic liver cirrhosis and this fact may favor the progression of alcoholic liver disease.