Development and validation of a specific questionnaire for evaluating the impact of gastrointestinal symptoms on the health-related quality of life of transplant patients

BACKGROUND

Transplant patients receiving immunosuppressant treatment suffer gastrointestinal symptoms (GIS) limiting their health-related quality of life (HRQOL) and causing dose redíuctions and discontinuations.

METHODS

This observational, multicenter, cross-sectional study aims to develop and validate a questionnaire for detecting and quantifying the impact of GIS on the HRQOL of patients with functioning organ transplants. We developed a pilot version of the questionnaire SIGIT-QOL (Impact of Gastrointestinal Symptoms on Quality Of Life) and then evaluated the feasibility, validity, and reliability. We consecutively recruited 274 solid organ transplant patients from 20 hospitals. Sociodemographic and clinical data were collected. Patients completed the SIGIT-QOL and Gastrointestinal Quality of Life Index-GIQLI- questionnaires.

RESULTS

Mean age was 52.7 (SD, 7.59) and 181 were male; 43.4% showed an episode of GIS since transplantation (3-12 months before). Of all patients, 95.3% completed the SIGIT-QOL. Mean time of completion was 6.49 minutes. Exploratory factorial analysis identified a 1-dimensional structure (42% of total variance). Internal consistency was high (Cronbach's alpha, 0.889). A significant association was found between the SGITI-QOL and the presence of GIS (P < .01). Finally, correlation coefficients between SIGIT-QOL and GIQLI were moderate-high except for Social Function.

CONCLUSION

The brief SIGIT-QOL questionnaire can detect and quantify the GIS and their impact on the HRQOL of solid organ transplant patients.

Cost-effectiveness analysis of timely dialysis referral after renal transplant failure in Spain

BACKGROUND

A cost-effectiveness analysis of timely dialysis referral after renal transplant failure was undertaken from the perspective of the Public Administration. The current Spanish situation, where all the patients undergoing graft function loss are referred back to dialysis in a late manner, was compared to an ideal scenario where all the patients are timely referred.

METHODS

A Markov model was developed in which six health states were defined: hemodialysis, peritoneal dialysis, kidney transplantation, late referral hemodialysis, late referral peritoneal dialysis and death. The model carried out a simulation of the progression of renal disease for a hypothetical cohort of 1,000 patients aged 40, who were observed in a lifetime temporal horizon of 45 years. In depth sensitivity analyses were performed in order to ensure the robustness of the results obtained.

RESULTS

Considering a discount rate of 3 %, timely referral showed an incremental cost of 211 €, compared to late referral. This cost increase was however a consequence of the incremental survival observed. The incremental effectiveness was 0.0087 quality-adjusted life years (QALY). When comparing both scenarios, an incremental cost-effectiveness ratio of 24,390 €/QALY was obtained, meaning that timely dialysis referral might be an efficient alternative if a willingness-to-pay threshold of 45,000 €/QALY is considered. This result proved to be independent of the proportion of late referral patients observed. The acceptance probability of timely referral was 61.90 %, while late referral was acceptable in 38.10 % of the simulations. If we however restrict the analysis to those situations not involving any loss of effectiveness, the acceptance probability of timely referral was 70.10 %, increasing twofold that of late referral (29.90 %).

CONCLUSIONS

Timely dialysis referral after graft function loss might be an efficient alternative in Spain, improving both patients' survival rates and health-related quality of life at an affordable cost. Spanish Public Health authorities might therefore promote the inclusion of specific recommendations for this group of patients within the existing clinical guidelines.

Phosphorylated S6K1 (Thr389) is a molecular adipose tissue marker of altered glucose tolerance

Molecular tissue markers of altered glucose metabolism will be useful as potential targets for antidiabetic drugs. S6K1 is a downstream signal of insulin action. We aimed to evaluate (pThr389)S6K1 and total S6K1 levels in human and rat fat depots as candidate markers of altered glucose metabolism. (pThr389)S6K1 and total S6K1 levels were measured using enzyme linked immune sorbent assay (ELISA) in 49 adipose tissue samples from subjects with morbid obesity and in 18 peri-renal white adipose tissue samples from rats. The effects of high glucose and rosiglitazone have been explored in human preadipocytes. (pThr389)S6K1/(total)S6K1 in subcutaneous adipose tissue was significantly increased subjects with Type 2 diabetes (0.78 ± 0.26 vs. 0.55 ± 0.14, P=.02) and associated with fasting glucose (r=0.46, P=.04) and glycated hemoglobin (r=0.63, P=.02) in SAT. Similar associations with fasting glucose (r=0.43, P=.03) and IRS1 (r=-0.41, P=.04) gene expression were found in visceral adipose tissue. In addition, rat experiments confirmed the higher (pThr389)S6K1/totalS6K1 levels in adipose tissue in association with obesity-associated metabolic disturbances. (pThr389)S6K1/totalS6K1 was validated using western blot in rat adipose tissue. Both ELISA and western blot data significantly correlated (r=0.85, P=.005). In human preadipocytes, high glucose medium led to increased (pThr389)S6K1/total S6K1 levels in comparison with normal glucose medium, which was significantly decreased under rosiglitazone administration. In conclusion, in human and rat adipose tissue, phosphorylated S6K1 is a marker for increased glucose levels.

Circulating zonulin, a marker of intestinal permeability, is increased in association with obesity-associated insulin resistance

Zonulin is the only physiological mediator known to regulate intestinal permeability reversibly by modulating intercellular tight junctions. To investigate the relationship between intestinal permeability and obesity-associated metabolic disturbances in humans, we aimed to study circulating zonulin according to obesity and insulin resistance. Circulating zonulin (ELISA) was measured in 123 caucasian men in association with inflammatory and metabolic parameters (including minimal model-measured insulin sensitivity). Circulating zonulin increased with body mass index (BMI), waist to hip ratio (WHR), fasting insulin, fasting triglycerides, uric acid and IL-6, and negatively correlated with HDL-cholesterol and insulin sensitivity. In multiple regression analysis, insulin sensitivity (p = 0.002) contributed independently to circulating zonulin variance, after controlling for the effects of BMI, fasting triglycerides and age. When circulating IL-6 was added to this model, only BMI (p = 0.01) contributed independently to circulating zonulin variance. In conclusion, the relationship between insulin sensitivity and circulating zonulin might be mediated through the obesity-related circulating IL-6 increase.

O estatuto da medicalização e as interpretações de Ivan Illich e Michel Foucault como ferramentas conceituais para o estudo da desmedicalização

Analisa-se o termo medicalização nos estudos de Illich e Foucault, com vistas a oferecer ferramentas conceituais para o estudo dos movimentos contestatórios à medicalização. Illich aborda a hipertrofia da medicalização na modernidade, ressaltando o efeito de redução da autonomia dos sujeitos, sobretudo pelo fato de as instituições médicas assumirem a responsabilidade de cuidar da dor, transformando seu significado íntimo e pessoal em um problema técnico. Foucault aborda a medicalização a partir da noção de biopoder, e, quando trabalha a noção de governamentalidade, abre espaço para a análise das formas de resistência dos indivíduos ao exercício do poder. Ambos os trabalhos, que têm como preocupação propor formas de exercício da liberdade - apesar de Foucault o fazer de forma mais detalhada e diversificada - parecem apropriados para se pensar o processo atual de desmedicalização ou recusa do diagnóstico médico por parte de seus portadores ou familiares.

Determination of inflammatory biomarkers in patients with COPD: a comparison of different assays

Background

Chronic obstructive pulmonary disease (COPD) is an inflammatory pulmonary disorder with systemic inflammatory manifestations that are mediated by circulating acute-phase reactants. This study compared an enzyme-linked immunosorbent assay (ELISA) to a nephelometric technique for the measurement of serum C-reactive protein (CRP) and serum amyloid A (SAA) and investigated how the choice of assay influenced the estimation of inflammation in patients with stable COPD.

Methods

CRP and SAA concentrations measured by ELISA and nephelometry in 88 patients with COPD and 45 control subjects were used to evaluate the performance of these methods in a clinical setting.

Results

With both assays, the concentrations of CRP and SAA were higher in COPD patients than in controls after adjustment for age and sex. There was a moderate correlation between the values measured by ELISA and those measured by nephelometry (logCRP: r = 0.55, p < 0.001; logSAA: r = 0.40, p < 0.001). However, the concentrations of biomarkers determined by nephelometry were significantly higher than those obtained with ELISA for CRP (mean difference = 2.7 (9.4) mg/L) and SAA (mean difference = 0.31 (14.3) mg/L).

Conclusion

Although the serum CRP and SAA concentrations measured by ELISA and nephelometry correlated well in COPD patients, the ELISA values tended to be lower for CRP and SAA when compared with nephelometric measurements. International standardization of commercial kits is required before the predictive validity of inflammatory markers for patients with COPD can be effectively assessed in clinical practice.

Association between a common KCNJ11 polymorphism (rs5219) and new-onset posttransplant diabetes in patients treated with Tacrolimus

KCNJ11 polymorphisms have been linked to the risk of developing type 2 diabetes. Our aim was to define the contribution of KCNJ11 to new-onset diabetes after transplantation (NODAT) among patients treated with Tacrolimus (Tac). A total of 115 NODAT and 205 non-NODAT were genotyped for rs5219 (p.E23K). AA+AG genotypes were significantly associated with NODAT-risk (p=0.004; OR=2.10). The reported effect of this KCNJ11 polymorphism on insulin release by beta cells could explain this association.

Consensus document on the overlap phenotype COPD-asthma in COPD

INTRODUCTION

Although asthma and COPD are different pathologies, many patients share characteristics from both entities. These cases can have different evolutions and responses to treatment. Nevertheless, the evidence available is limited, and it is necessary to evaluate whether they represent a differential phenotype and provide recommendations about diagnosis and treatment, in addition to identifying possible gaps in our understanding of asthma and COPD.

METHODS

A nation-wide consensus of experts in COPD in two stages: 1) during an initial meeting, the topics to be dealt with were established and a first draft of statements was elaborated with a structured "brainstorming" method; 2) consensus was reached with two rounds of e-mails, using a Likert-type scale.

RESULTS

Consensus was reached about the existence of a differential clinical phenotype known as"Overlap Phenotype COPD-Asthma", whose diagnosis is made when 2 major criteria and 2 minor criteria are met. The major criteria include very positive bronchodilator test (increase in FEV(1) ≥ 15% and ≥ 400ml), eosinophilia in sputum and personal history of asthma. Minor criteria include high total IgE, personal history of atopy and positive bronchodilator test (increase in FEV(1) ≥ 12% and ≥ 200ml) on two or more occasions. The early use of individually-adjusted inhaled corticosteroids is recommended, and caution must be taken with their abrupt withdrawal. Meanwhile, in severe cases the use of triple therapy should be evaluated. Finally, there is an obvious lack of specific studies about the natural history and the treatment of these patients.

CONCLUSIONS

It is necessary to expand our knowledge about this phenotype in order to establish adequate guidelines and recommendations for its diagnosis and treatment.

Circulating lipopolysaccharide-binding protein (LBP) as a marker of obesity-related insulin resistance

OBJECTIVE

Lipopolysaccharide-binding protein (LBP) is a 65-kDa acute-phase protein present in blood at high concentrations, known to be derived from the liver. We aimed to gain insights into the association of circulating LBP with insulin resistance in humans and mice. METHODS, DESIGN AND MEASUREMENTS: We studied the cross-sectional (n=222) and weight loss-induced (n=34) associations of LBP (enzyme-linked immunosorbent assay) with inflammatory and metabolic parameters (including minimal model-measured insulin sensitivity), and the effects of high-fat diet (HFD), metformin and genetic insulin sensitization (glucagon-like peptide 1 receptor knockout model) in mice.

RESULTS

Circulating LBP concentration was significantly increased in subjects with type 2 diabetes and dramatically increased in subjects with morbid obesity. LBP was significantly associated with insulin sensitivity and different inflammatory markers and decreased after weight loss (22.2 ± 5.8 vs 16.2 ± 9.3 μg ml(-1), P<0.0001) in association with changes in body mass index and insulin sensitivity. Circulating LBP concentration was increased in HFD mice, whereas decreased in glucagon-like peptide 1 receptor knockout mice (significantly more insulin sensitive than wild-type mice) and after metformin administration.

CONCLUSION

LBP is an inflammatory marker associated with obesity-related insulin resistance.

Dielectric and molecular dynamics study of the secondary relaxations of poly(styrene-co-methylmethacrylate) copolymers: Influence of the molecular architecture

The effect of the structure of copolymers (random, alternate or diblock) on their dynamics has been studied by dielectric spectroscopy. Six copolymers of styrene and methyl methacrylate (three diblocks, one alternate and two random) have been studied. The results show that the sub- T (g) transitions of the diblock samples can be described by one asymmetric Havriliak-Negami (HN) function, while two are necessary for the rest of the copolymers (β and γ relaxations). The characteristic times of the sub- T (g) relaxations show an Arrhenius temperature dependence and there is a strong coupling of the α and β relaxations at high temperatures. The deconvolution of the merging relaxations has been made in the framework of the Williams Ansatz set out in terms of Havriliak-Negami distributions. Because the 2D (2)H-NMR results excluded any significant contribution from the rotation of the methoxy group of the methacrylate group around the C-OCH(3) bond, the γ relaxation may be assigned to the rotation of the methyl methacrylate group in a styrene-rich environment. The Molecular Dynamics simulations of a poly(methyl methacrylate) homopolymer and of the alternate copolymer are in qualitative agreement with the experimental results, although they predict smaller values for the activation energy of the sub- T (g) relaxations.

Cyclooxygenase-2 -765G>C polymorphism is associated with C-reactive protein levels in resistant smokers but not in chronic obstructive pulmonary disease patients

We sought to investigate whether the serum concentrations of several inflammatory biomarkers are related to the cyclooxygenase-2 (COX2) -765G>C polymorphism in chronic obstructive pulmonary disease (COPD) and a control group of non-COPD smokers. Serum inflammatory markers (CRP, SAA, CXCL8, and sICAM-1) were measured by ELISA in 144 patients with COPD and in 55 control subjects. Genomic DNA was extracted from peripheral blood leukocytes, and the COX2 -765G>C (rs20417) polymorphism was genotyped. After adjustment for age and active smoking, CRP and SAA concentrations were associated with the COX2 polymorphism in controls (p=0.041 and 0.014, respectively) but not in COPD patients. The CXCL8 and sICAM-1 concentrations were not associated with the COX2 polymorphism for either cases or controls. The results of the present study indicate that there is a relationship between the COX2 -765G>C polymorphism and the concentrations of CRP and SAA in non-COPD smokers and that this relationship does not exist in COPD patients.

Decreased STAMP2 expression in association with visceral adipose tissue dysfunction

CONTEXT

Six-transmembrane protein of prostate 2 (STAMP2) is a counter-regulator of inflammation and insulin resistance according to findings in mice. However, there have been contradictory reports in humans.

OBJECTIVE

We aimed to explore STAMP2 in association with inflammatory and metabolic status of human obesity.

DESIGN, PATIENTS, AND METHODS

STAMP2 gene expression was analyzed in adipose tissue samples (171 visceral and 67 sc depots) and during human preadipocyte differentiation. Human adipocytes were treated with macrophage-conditioned medium, TNF-α, and rosiglitazone.

RESULTS

In visceral adipose tissue, STAMP2 gene expression was significantly decreased in obese subjects, mainly in obese subjects with type 2 diabetes. STAMP2 gene expression and protein were significantly and inversely associated with obesity phenotype measures (body mass index, waist, hip, and fat mass) and obesity-associated metabolic disturbances (systolic blood pressure and fasting glucose). In addition, STAMP2 gene expression was positively associated with lipogenic (FASN, ACC1, SREBP1, THRSP14, TRα, and TRα1), CAV1, IRS1, GLUT4, and CD206 gene expression. In sc adipose tissue, STAMP2 gene expression was not associated with metabolic parameters. In both fat depots, STAMP2 gene expression in stromovascular cells was significantly higher than in mature adipocytes. STAMP2 gene expression was significantly increased during the differentiation process in parallel to adipogenic genes, being increased in preadipocytes derived from lean subjects. Macrophage-conditioned medium (25%) and TNF-α (100 ng/ml) administration increased whereas rosiglitazone (2 μM) decreased significantly STAMP2 gene expression in human differentiated adipocytes.

CONCLUSIONS

Decreased STAMP2 expression (mRNA and protein) might reflect visceral adipose dysfunction in subjects with obesity and type 2 diabetes.

[Robotic surgery: history and teaching impact]

CONTEXT

The purpose of this article is to review the history of robotic surgery, its impact on teaching as well as a description of historical and current robots used in the medical arena.

SUMMARY OF EVIDENCE

Although the history of robots dates back to 2000 years or more, the last two decades have seen an outstanding revolution in medicine, due to all the changes that robotic surgery has made in the way of performing, teaching and practicing surgery.

CONCLUSIONS

Robotic surgery has evolved into a complete and self-contained field, with enormous potential for future development. The results to date have shown that this technology is capable of providing good outcomes and quality care for patients.

Influence of the percentage of acetylation on the assembly of LbL multilayers of poly(acrylic acid) and chitosan

The Layer-by-Layer (LbL) self-assembly of polyelectrolyte multilayers (PEMs) formed by poly(acrylic acid) (PAA) and chitosan (CHI) of two different percentages of acetylation (AC) has been studied by dissipative quartz crystal microbalance (D-QCM) and ellipsometry. The results point out that the non-linear growth (exponential growth) of the films is not modified by the percentage of acetylation of the CHI (AC). The comparison of the thickness obtained by D-QCM and by ellipsometry has allowed us to calculate the water content of the films showing that the multilayers are highly hydrated. This agrees with the values of the complex shear modulus obtained from the analysis of D-QCM data that are in the MPa range, and show a transition from a viscous to mainly elastic behavior depending on the charge density of the CHI chains. The monomer surface density in each layer (obtained from the combination of ellipsometry and differential refractive index measurements) indicated that the mechanism of charge compensation depends on the percentage of acetylation of the CHI. It was found that the adsorption kinetics is a bimodal process with characteristic times that depend on the number and nature of each layer. The load capacity of the multilayers for a β-blocker, propranolol, was found to be higher for the lowest acetylation degree.

Influence of the molecular architecture on the adsorption onto solid surfaces: comb-like polymers

The processes of adsorption of grafted copolymers onto negatively charged surfaces were studied using a dissipative quartz crystal microbalance (D-QCM) and ellipsometry. The control parameters in the study of the adsorption are the existence or absence on the molecular architecture of grafted polyethyleneglycol (PEG) chains with different lengths and the chemical nature of the main chain, poly(allylamine) (PAH) or poly(L-lysine) (PLL). It was found out that the adsorption kinetics of the polymers showed a complex behavior. The total adsorbed amount depends on the architecture of the polymer chains (length of the PEG chains), on the polymer concentration and on the chemical nature of the main chain. The comparison of the thicknesses of the adsorbed layers obtained from D-QCM and from ellipsometry allowed calculation of the water content of the layers that is intimately related to the grafting length. The analysis of D-QCM results also provides information about the shear modulus of the layers, whose values have been found to be typical of a rubber-like polymer system. It is shown that the adsorption of polymers with a charged backbone is not driven exclusively by the electrostatic interactions, but the entropic contributions as a result of the trapping of water in the layer structure are of fundamental importance.

Pharmacogenetics of tacrolimus: ready for clinical translation?

Tacrolimus (Tac) exhibits an interindividual pharmacokinetic variability that affects the dose required to reach the target concentration in blood. Tac is metabolized by two enzymes of the cytochrome P450 family, CYP3A5 and CYP3A4. The effect of the CYP3A5 genotype on Tac bioavailability has been demonstrated, and the main determinant of this pharmacogenetic effect is a single-nucleotide polymorphism (SNP) in intron 3 of CYP3A5 (6986 A>G; SNP rs776746; also known as CYP3A5*3). The mean dose-adjusted blood Tac concentration was significantly higher among CYP3A5*3 homozygotes than that of carriers of the wild-type allele (CYP3A5*1). In a recent prospective study, a group of kidney transplant patients received a Tac dose either according to the CYP3A5 genotype (the adapted group) or according to the standard regimen (the control group). All patients received induction therapy with mycophenolate mofetil, corticosteroids, and either basiliximab or intravenous anti-thymocyte globulin. Patients in the adapted-dose group required 3–8 days (median 6 days) to reach the target range compared with 3–25 days (median 7 days) in the control group (P=0.001). The total number of dose modifications was also lower in the adapted-dose group. This study also suggested that the CYP3A5 genotype might contribute minimally to the reduction of early acute rejection. However, additional studies are necessary to determine whether the pharmacogenetic approach could help reduce the necessity for induction therapy and co-immunosuppressors.

Adsorption of conditioning polymers on solid substrates with different charge density

The adsorption processes of polymers that belong to two different families (neutral hydrophilic polymers and cationic polysaccharide polymers) onto solid surfaces with different charge density have been studied using dissipative quartz crystal microbalance (D-QCM) and ellipsometry. The polymers studied are very frequently used in the cosmetic industry as conditioning agents. The adsorption kinetics of the polymers involves at least two steps. The total adsorbed amount depends on the charge density of the surface for both types of polymers. The comparison of the adsorbed mass on each layer obtained from D-QCM and from ellipsometry has allowed calculating the water content of the layers that reaches high values for the polymers studied. The analysis of D-QCM results also provided information about the shear modulus of the layers, whose values have been found to be typical of a rubber-like polymer system. The main driving force of the adsorption was found to be the energy of the interactions between chains and surface.

NKG2D and its ligands: active factors in the outcome of solid organ transplantation?

The role of natural killer (NK) cells in solid organ transplantation is not well established, although several recent reports highlight the importance of the activating receptor NKG2D and its ligands in the development of rejection during transplantation. The human NKG2D ligands (MICA and MICB) are induced in allografts during acute and chronic rejection, and the presence of anti-MICA antibodies is correlated with a higher incidence of rejection. The binding of these ligands to its receptor NKG2D activates NK cells, enhances the functions of effectors, and allows NK cells to function as a bridge between innate and adaptive immunity associated with the transplantation. In fact, blockage of NKG2D with the anti-NKG2D monoclonal antibodies prolongs graft survival and prevents CD28-independent rejection in heart and skin allograft mouse models. Furthermore, the current immunosuppressive therapies can modulate the expression of NK cell receptors and consequently the effector functions of NK cells. That is particularly important during the first few months after transplantation, when the susceptibility to opportunistic viral infections is higher and NKG2D has an essential role. In this review, we analyze in detail the potential role of the NKG2D-activating receptor and its ligands in the immune responses during the outcome of solid organ transplantation. These findings open a new pathway for therapeutic intervention that can contribute to tolerance in solid organ transplantation.

Circulating omentin as a novel biomarker of endothelial dysfunction

Omentin is a novel soluble lectin expressed mainly in the stromal-vascular cells from visceral adipose tissue with vasodilator effect in isolated blood vessels. To gain insight in the relationship between obesity and cardiovascular risk factors, we aimed to explore the interaction among circulating omentin, metabolic parameters, and endothelial function. Circulating omentin (enzyme-linked immunosorbent assay) was studied in 248 white men (148 with normal glucose tolerance (NGT) and 100 with impaired glucose tolerance (IGT)). Insulin sensitivity was measured using the frequently sampled intravenous glucose tolerance test. Vascular reactivity was measured by high-resolution ultrasound of the brachial artery. Circulating omentin concentration was significantly increased in lean compared with overweight and obese subjects (53.7 ± 16.9 vs. 45.2 ± 16.8 and vs. 40.1 ± 15.5 ng/ml, P < 0.0001). Circulating omentin concentration correlated with age, BMI, waist-to-hip ratio (WHR), percentage of fat mass, systolic and diastolic blood pressure, endothelium-dependent and independent vasodilation (EDV and EIV), C-reactive protein, and interleukin-6 (IL-6). In IGT subjects, circulating omentin concentration also correlated with insulin sensitivity, although this association did not remain significant after controlling for BMI. In a multiple linear regression analysis, circulating omentin concentration (P = 0.01), systolic blood pressure (P = 0.04), and BMI (P = 0.04) contributed independently to EDV after controlling for age and C-reactive protein in IGT subjects. In NGT subjects, only circulating omentin concentration (P = 0.01) was significantly associated with EDV. In conclusion, circulating omentin concentration could be a useful marker of endothelial function.

Pharmacogenetics of tacrolimus after renal transplantation: analysis of polymorphisms in genes encoding 16 drug metabolizing enzymes

BACKGROUND

Tacrolimus (Tac) is an immunosuppressive drug used to prevent post-transplant (PT) organ rejection. Continuous Tac monitoring is necessary to adjust the dose and prevent toxicity or rejection. Tac is metabolized by cytochrome-P450 (CYP) enzymes, and variation at the CYP and other drug metabolizing enzymes could influence Tac bio-availability and dose requirements. Our aim was to define the effect of DNA variants at 16 drug metabolising enzymes on Tac dose in patients with kidney transplants.

METHODS

The REDINREN Pharmacogenetics Project was a multicenter study designed to evaluate the effect of DNA polymorphisms on Tac dose requirements. A total of 200 patients who received a first cadaveric kidney and Tac as primary immunosuppressive drug were genotyped for 96 DNA polymorphisms on 16 genes. Significant associations were further replicated in a second group of 200 patients. The Tac daily dose was adjusted to achieve a blood concentration of 10-15 ng/mL in the period 0-3 months PT, and 5-10 ng/mL thereafter. The dose of tacrolimus dose and blood concentrations were compared between genotypes at 1 week, 6 months, and 1 year PT.

RESULTS

The CYP3A5 genotype (SNP rs776746) was the strongest predictor of Tac dose requirements. Patients who were CYP3A5*3*3 (CYP3A5 non-expressors) received significantly higher Tac dose at 1 week, 6 months, and 1 year PT (p<0.0001). At 1 week, 41% of the CYP3A5 non-expressors achieved target blood concentrations compared to 26% of the CYP3A5 expressors (p=0.007). We also found a significant effect of CYP3A4 genotype (SNP rs2740574) on Tac dose requirements in patients who were CYP3A5 non-expressors. None of the other polymorphisms were related to Tac dose requirements or modified the effect of the CYP3A5 genotype.

CONCLUSIONS

rs776746 (CYP3A5) and rs2740574 (CYP3A4) were the only SNPs associated with Tac dosage. The genotyping of these polymorphisms could be a useful pharmacogenetic tool to determine the Tac dose immediately after transplantation.

Decreased serum creatinine concentration is associated with short telomeres of adipose tissue cells

Decreased serum creatinine concentration has been recently described to constitute a new risk factor of type 2 diabetes. Increased free radicals have been consistently associated with decreased serum creatinine and with cellular senescence. Telomere length is considered as a biological marker for senescence. We aimed to study the association of telomere length with serum creatinine. Telomere length of subcutaneous adipose tissue cells was measured in a sample of obese and nonobese subjects (n = 49). Telomere length of subcutaneous adipose tissue cells was positively associated with serum creatinine (r = 0.40, P = 0.004), i.e., the lower the telomere length, the lower the serum creatinine, but not with glomerular filtration rate (GFR). In addition, telomere length was negatively associated with BMI (r = -0.45, P = 0.001) and systolic blood pressure (r = -0.41, P = 0.003). In a multiple linear regression analysis, BMI (P = 0.005), systolic blood pressure (P = 0.01) and telomere length (P = 0.03) independently contributed to 37% of serum creatinine variance after controlling for sex and age. In conclusion, the association of serum creatinine with a marker of cellular senescence suggests an underlying mechanism influencing both decreased serum creatinine and increased risk of type 2 diabetes.

pH-induced changes in the fabrication of multilayers of poly(acrylic acid) and chitosan: fabrication, properties, and tests as a drug storage and delivery system

Multilayers of poly(acrylic acid), PAA, and chitosan, CHI, have been built by the layer-by-layer (LbL) method from aqueous solutions at different pH values and analyzed by the dissipative quartz crystal microbalance (D-QCM) and ellipsometry. The results showed that under all of the assembly conditions considered the growth of the films is nonlinear. The thickness of the PAA layers increases as the pH of the assembling solutions decreases, whereas the adsorption of CHI is almost unaffected by the pH conditions. The comparison of the thickness obtained by D-QCM and by ellipsometry has allowed us to calculate the water content of the films, showing that the multilayers are highly hydrated, with an average water content higher than 20%. The analysis of D-QCM data has provided high-frequency values of the complex shear modulus that are in the megapascal range and shows a transition from mainly viscous to mainly elastic behavior for the added PAA layers, depending on the pH. The monomer surface density in each layer (obtained from the combination of ellipsometry and differential refractive index measurements) indicated that the monomer density depends on the assembly conditions. It was found that the adsorption kinetics is a bimodal process, with characteristic times that depend on the number and nature of the layers. Finally, the possibility of using of these multilayers as a drug storage and delivery system has been evaluated.

Metilfenidato e aprimoramento cognitivo farmacológico: representações sociais de universitários

O artigo tem por objetivo apresentar o resultado da investigação das representações sociais de 20 estudantes universitários sobre o uso de metilfenidato para aprimorar o desempenho cognitivo em pessoas saudáveis. Nesta pesquisa qualitativa, de cunho exploratório, 20 universitários entre 18 e 25 anos, oriundos de cursos das áreas de saúde e humanas, foram distribuídos em três grupos focais para debater sobre o Aprimoramento Cognitivo Farmacológico. A análise dos dados revelou que entre esses estudantes houve uma maior tolerância aos métodos que alteram a neurobiologia a favor do ideal social de melhoria da performance das pessoas. Contudo, os entrevistados expressaram grande preocupação com a possibilidade de este procedimento vir a intensificar injustiças e desigualdades entre as pessoas, principalmente nas sociedades em que já existem significativas diferenças sociais. Assim, apesar de o tema ser pouco estudado no Brasil, a análise dos dados da presente investigação sugere que o Aprimoramento Cognitivo Farmacológico é um assunto atual e relevante. Não apenas por esta prática estar relacionada à construção e manutenção da subjetividade dos indivíduos em uma sociedade que prioriza a melhoria da performance cognitiva, mas também pelo risco de esta interferir em questões de igualdade e justiça social.

Fluid to soft-glass transition in a quasi-2D system: thermodynamic and rheological evidences for a Langmuir monolayer

We report an experimental study that points out the existence of a fluid to soft-glass transition in Langmuir polymer monolayers of poly(methyl methacrylate) (PMMA), for which the water/air interface behaves as a poor-solvent. The temperature dependence of surface pressure vs. surface area equilibrium isotherms shows a glass-like transition temperature at T(g,2D)≈ 298 K, significantly lower than the value for bulk PMMA (T(g,bulk)≈ 378 K). The plot of the film thickness h vs. temperature shows a sharp change of slope at about the same temperature, 298 K, which is a typical hallmark of a glass transition in thin polymer films [J. L. Keddie, R. A. L. Jones, R. A. Cory, Europhys. Lett., 1996, 27, 59-64]. Furthermore, slightly above T(g,2D), the temperature dependence of the dilational viscosity does not follow an Arrhenius law, but instead can be described by a Vogel-Fulcher-Tamman equation with parameters that are typical of a fragile glass. Not only the qualitative behavior of three distinct equilibrium and dynamic properties, but also the quantitative agreement of the values of T(g) obtained, are a strong evidence of the existence of a fluid to soft-glass transition in this quasi-2D system.

Freezing transition and interaction potential in monolayers of microparticles at fluid interfaces

The structure and the interaction potential of monolayers of charged polystyrene microparticles at fluid interfaces have been studied by optical microscopy. Microparticles of different sizes have been studied over a broad range of surface particle densities. The structural characterization is based on the analysis of images obtained by digital optical microscopy. From the experimental images, radial distribution functions, hexagonal bond order correlation functions, and temporal orientational correlation functions have been calculated for different monolayer states at both the air/water and oil/water interfaces. The interaction potential has been calculated from the structure factor using integral equations within the hypernetted chain closure relationship. For particles trapped at the oil-water interface, it was found that, upon increasing the surface coverage, a freezing transition occurs, that leads to the formation of a 2D crystalline structure. We have studied the freezing densities of particle monolayers at the oil/water interface and compared them with Monte Carlo simulation results reported by H. Löwen. In contrast, at the air-water interface, freezing is inhibited due to the formation of particle aggregates.

Imagens cerebrais e o caso da síndrome da fadiga crônica

Este artigo analisa o uso de neuroimageamento nas pesquisas da síndrome da fadiga crônica. Revisam-se alguns dos estudos publicados sobre o assunto na década de 1990 e analisa-se um ponto específico desses estudo, que é a busca de alterações na ativação cerebral ou outros tipos de anormalidade que possam fornecer um padrão para diagnóstico e tratamento da doença. Analisa-se o entendimento da síndrome da fadiga crônica como uma doença reduzida aos achados cerebrais, argumentando em favor de uma visão mais ampliada da doença, que leve em conta os elementos psicossociais da vida do paciente em detrimento de explicações reduzidas ao somático.

Erythropoietin resistance as surrogate marker of graft and patient survival in renal transplantation: 3-year prospective multicenter study

BACKGROUND

Some transplant recipients demonstrate an inadequate response to erythropoiesis-stimulating agents, or so-called erythropoietin (Epo) resistance. The cause is multifactorial. Resistance to EPO may entail a poor prognosis for the graft and the patient, although results in the literature are inconsistent, and long-term follow-up is lacking.

OBJECTIVE

To evaluate whether the presence of Epo resistance at the beginning of the study was a predictive factor for graft and patient survival.

MATERIALS AND METHODS

From 482 renal transplant recipients (Kidney Disease Outcomes Quality Initiative stage 3-4T) receiving Epo-stimulating agents in the Anemia and Renal Transplantation in Spain study, 101 were selected for the present study. Erythropoietin resistance was defined as a ratio of weekly Epo dosage/hemoglobin concentration>486,94 U/g/dL with a hemoglobin/<11 g/dL. Darbepoetin dosage was calculated in Epo equivalent units, with a 1:200 conversion factor. Patients were grouped as Epo-resistant (ER+) or not Epo-resistant (ER-), to assess whether Epo resistance was predictive of patient and graft survival.

RESULTS

There were no differences in demographic data between the 2 groups except for a higher incidence of vascular, interstitial, and diabetes-related causes of chronic renal failure in the ER+ group. At 3 years posttransplantation, graft survival was 33% in the ER+ group vs 58% in the ER- group (P=.06), and patient survival was 52% in the ER+ group vs 88% in the ER- group (P=.008). Using a Cox regression model, at 3 years, the relative risk of graft failure was 1.96 in the ER+ group (95% CI, 0.93-3.12; P=.07), and of patient death was 3.9 (95% confidence interval, 1.30-11.63; P=.01).

CONCLUSION

Erythropoietin resistance is an independent risk factor for death after renal transplantation.

KCNQ1 gene variants and risk of new-onset diabetes in tacrolimus-treated renal-transplanted patients

Recent genome-wide association studies identified single-nucleotide polymorphisms (SNPs) in the gene encoding the pore-forming subunit of the voltage-gated K+ channel (KCNQ1) as a risk factor for type 2 diabetes. Tacrolimus (Tac) increased the risk of new-onset diabetes after transplantation (NODAT). The aim of this study was to analyze the association between KCNQ1 variants and the risk for NODAT in kidney-transplanted patients who received Tac as primary immunosuppressor. We genotyped three common KCNQ1 SNPs in 145 Spanish patients who received a cadaveric kidney graft and developed NODAT in the first-year post-transplant (the NODAT group), and 260 patients who remained non-diabetics (non-NODAT). In addition, we searched for DNA variants in the whole KCNQ1 coding exons in these patients. SNP rs2237895 (genotype CC) was associated with an increased risk for NODAT in our population (p = 0.008; OR = 1.83, 95% CI = 1.14-2.93), independently of other risk factors as body mass index, recipient age, or tacrolimus dosage. Other KCNQ1 variants were not associated with NODAT in our patients. Our work supported a role for KCNQ1 gene variants as determinants of the risk of developing NODAT among Tac-treated patients.

Proadipogenic effects of lactoferrin in human subcutaneous and visceral preadipocytes

Lactoferrin has been associated with insulin sensitivity in vivo and in vitro studies. We aimed to test the effects of lactoferrin on human subcutaneous and visceral preadipocytes. Human subcutaneous and visceral preadipocytes were cultured with increasing lactoferrin (hLf, 0.1, 1, 10 μM) under differentiation conditions. The effects of lactoferrin on adipogenesis were studied through the expression of different adipogenic and inflammatory markers, AMPK activation and Retinoblastoma 1 (RB1) activity. The response to insulin was evaluated through (Ser473)AKT phosphorylation. In both subcutaneous and visceral preadipocytes, lactoferrin (1 and 10 μM) increased adipogenic gene expressions and protein levels (fatty acid synthase, PPARγ, FABP4, ADIPOQ, ACC and STAMP2) and decreased inflammatory markers (IL8, IL6 and MCP1) dose-dependently in parallel to increased insulin-induced (Ser473)AKT phosphorylation. In addition to these adipogenic effects, lactoferrin decreased significantly AMPK activity (reducing (pThr172)AMPK and (pSer79)ACC) and RB1 activity (increasing the (pser807/811)RB1/RB1 ratio). In conclusion, these results suggest that lactoferrin promotes adipogenesis in human adipocytes by enhancing insulin signaling and inhibiting RB1 and AMPK activities.

Cultura somática, neurociências e subjetividade contemporânea

O artigo apresenta as características da cultura somática emergente nas sociedades industrializadas do Ocidente, analisando dois de seus desdobramentos diretos e indiretos no campo da psicologia: (a) a formação de modalidades de subjetividade somática, diferentes das encontradas na cultura burguesa da intimidade; (b) a ascensão de pesquisas neurocientíficas utilizando imageamento do cérebro para o estudo do comportamento humano. Apresenta-se a ideia de sujeito cerebral como um dos conceitos utilizados para compreender tanto as modificações nas formas subjetivas da contemporaneidade quanto o privilégio das pesquisas cerebrais na explicação dos transtornos mentais, comportamentos e ações humanas. Analisa-se a utilização das imagens cerebrais e as novas questões que essas tecnologias impõem ao campo da Psicologia, que se vê confrontada com um acirrado processo de biologização da mente.

Circulating osteocalcin concentrations are associated with parameters of liver fat infiltration and increase in parallel to decreased liver enzymes after weight loss

SUMMARY

The expression of liver genes was associated with insulin action in osteocalcin knockout mice. Our findings suggest that osteocalcin may play a role in the development of insulin resistance-associated fatty liver disease.

INTRODUCTION

The expression of insulin target genes was decreased in the liver of mice lacking osteocalcin. We aimed to explore the association of liver enzymes with osteocalcin.

METHODS

The associations were evaluated in a cross-sectional study (266 men) and following weight loss in 28 obese subjects (nine male, 19 females).

RESULTS

In the cross-sectional study, circulating osteocalcin concentration was negatively associated with alanine transaminase (ALT) (p = 0.002) and aspartate transaminase (AST) levels (p = 0.008). These associations were especially significant in non-obese subjects (n = 191). In a multiple linear regression analysis, age (p = 0.008), insulin sensitivity (p = 0.001), and osteocalcin (p = 0.04) independently contributed to 22% of ALT variance in these latter subjects. In the weight loss study, the increase in circulating osteocalcin concentration (+70.6 ± 29.3 vs. +32 ± 13.5%, p = 0.021) was significantly greater in subjects with the highest decrease in ALT levels, despite similar baseline BMI, insulin resistance and degree of weight loss than remaining subjects. In fact, the change in ALT levels were linearly associated with those of osteocalcin (r = -0.55, p = 0.003).

CONCLUSIONS

In summary, our findings suggest a bone-liver axis in which osteocalcin might be the active regulator.

Effectiveness of a cognitive orientation program with and without nicotine replacement therapy in stopping smoking in hospitalised patients

INTRODUCTION

We analysed the effectiveness of a high intensity behavioural-cognitive intervention compared to minimal intervention started during a hospital stay, to see if the combination of nicotine replacement therapy (NRT) can increase the quitting rate at 12 months of follow up.

METHOD

A total of 2560 active smokers were studied during their hospital stay. Of these, 717 smokers refused to enter the study and after a minimal intervention they were asked if we could telephone them after one year to ask if they still smoked. The remaining 1843 smokers who received high intensity cognitive therapy were randomised to receive or not receive NRT. The follow up after discharge was carried out by outpatient visits or with telephone sessions.

RESULTS

At one year of follow up, 7% of those who declined to enter the study had stopped smoking compared to 27% of those who entered the study (p<0.001). There were significant differences between the group that only had behavioural therapy (21% stopped) compared to the group that also had NRT (33% stopped; p=0.002). In this latter group there were significant differences (p=0.03) between those who had follow up in clinics (39% stopped) compared to those who were followed up telephone sessions (30%). In the multivariate analysis, the predictors of quitting at 12 months were: to have used NRT (OR 12.2; 95% CI, 5.2-32; p=0.002) and a higher score in the Richmond Test (OR 10.1; 95% CI, 3.9-24.2; p=0.01).

CONCLUSIONS

A cognitive type intervention started on smokers when admitted to hospital increases quitting rates at 12 months, compared to a minimal intervention, and these rates increase even more significantly if NRT is added.

A ritalina no Brasil: produções, discursos e práticas

O objetivo do artigo é apresentar uma pesquisa em andamento sobre as representações sociais da ritalina no Brasil entre 1998 e 2008. Nesse período, houve um incremento considerável do uso da medicação e sua expansão para outros fins além dos terapêuticos. A ritalina tem sido usada tanto para o tratamento de patologias da atenção como para melhoria de funções cognitivas em pessoas saudáveis. A pesquisa se desdobra em dois campos de investigação, com metodologias diferenciadas. O primeiro campo investiga as publicações brasileiras, científicas e em mídia popular, sobre a ritalina, analisando os argumentos que justificam seu uso e a difusão dos resultados científicos para o público leigo nos jornais de grande circulação. O segundo campo de investigação usa a metodologia de grupos focais para explorar as representações sociais de universitários, pais de universitários e profissionais de saúde, acerca do uso da ritalina para o aprimoramento do desempenho cognitivo.