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Papers by Antonio Barbosa

Background: It has been demonstrated in many studies that quality of life can be improved after l... more Background: It has been demonstrated in many studies that quality of life can be improved after liver transplantation in patients with liver disease. Nevertherless quality of life improvement in specific groups of transplantated patients such as those with Familial Amyloid Polineuropathy hasn't yet been explored. The present study aimed to compare the change in quality of life following liver transplantation between patients with Familial Amyloid Polineuropathy (FAP) and patients with liver disease.

Objectives. We sought to investigate the improvement in quality of life (mental and physical comp... more Objectives. We sought to investigate the improvement in quality of life (mental and physical components) at 1 and 6 months after liver transplantation. Methods. A sample of liver transplant candidates (n ϭ 60), comprising consecutive patients attending outpatient clinics of a liver transplantation central unit (25% of the patients had familial amyloid polyneuropathy [FAP] and the remaining patents had chronic liver diseases), was assessed by means of the Short Form (SF)-36, Portuguesevalidated version, a self-rating questionnaire developed by the Medical Outcome Trust, to investigate certain primary aspects of quality of life, at 3 times: before, and at 1 and 6 months after transplantation. Results. We observed a significant improvement in quality of life (both mental and physical components) by 1 month after transplantation. Between the first month and the sixth month after transplantation, there also was an improvement in the quality of life (both mental and physical components), although only the physical components of quality of life was significantly improved. Conclusions. Our findings suggested that quality of life improved early after liver transplantation (1 month). Between the first and the sixth months, there only was a significant improvement in the physical quality of life.

Objectives. We sought to investigate the psychosocial determinants of quality of life at 6 months... more Objectives. We sought to investigate the psychosocial determinants of quality of life at 6 months after transplantation. Methods. A sample of liver transplant candidates (n ϭ 60), composed of consecutive patients (25% with familial amyloid polyneuropathy [FAP]) attending outpatient clinics was assessed in the pretransplant period using the Neo Five Factor Inventory, Hospital Anxiety and depression Scale (HADS), Brief COPE, and SF-36, a qualityof-life, self-rating questionnaire. Six months after transplantation, these patients were assessed by means of the SF-36. Results. Psychosocial predictors where found by means of multiple regression analysis. The physical component of quality of life at 6 months after transplantation was determined based upon coping strategies and physical quality of life in the pretransplant period (this model explained 32% of variance). The mental component at 6 months after transplantation was determined by depression in the pretransplant period and by clinical diagnoses of patients. Because FAP patients show a lower mental component of quality of life, this diagnosis explained 25% of the variance. Conclusions. Our findings suggested that coping strategies and depression measured in the pretransplant period are important determinants of quality of life at 6 months after liver transplantation. Address reprint requests to Dr Diogo Telles-Correia, Rua Sacadura Cabral n°55, 4°B, 1495 Cruz Quebrada-Dafundo,

Revista do Departamento de Psicologia. UFF, 2007

Objective: A protective layer of endothelial cells (EC) of host origin on the entire surface of b... more Objective: A protective layer of endothelial cells (EC) of host origin on the entire surface of bioprosthetic heart valves has never been reported. Current commercial bioprosthetic heart valves are commonly preserved in glutaraldehyde (GA) and are cytotoxic to host cells preventing spontaneous endothelialization. The aim of this study is to demonstrate the potential for in vivo endothelialization of heart valves

Psychology, Health & Medicine, 2011

Aims: To establish an alcohol-dependent drinker's clinical typology, based on patients atten... more Aims: To establish an alcohol-dependent drinker's clinical typology, based on patients attending the Alcoholism Unit of Santa Maria's General Hospital in Lisbon, Portugal. Methods: A multivariate statistical analysis was used to extract the typology solu- tion. Results: We obtained five factors: Anxiopathic, typifies anxious functioning; Heredopathic, congregates familiar and genetic influences on alcoholism; Thimopathic, typified by affective symptomatology; Sociopathic, characterized by disruptive behaviours under alcohol influence; and Adictopathic, isolates younger individuals who consume alcohol and other types of psychoactive substances. Conclusions: There are increasingly alcoholic polymorphic subtypes derived from the interactive complexity between genetic/family and psychosocial factors.

BMC Psychiatry, 2010

Background: To investigate the validity and stability of a Portuguese version for the Screening f... more Background: To investigate the validity and stability of a Portuguese version for the Screening for Somatoform Symptoms-2 (SOMS-2) in primary care (PC) settings. Methods: An adapted version of the SOMS-2 was filled in by persons attending a PC unit. All medically unexplained symptoms were further ascertained in a clinical interview and by contacting the patient's physicians and examining medical records, attaining a final clinical symptom evaluation (FCSE). An interview yielded the diagnosis of Clinical Somatization (CS) and the diagnosis of current depressive and anxiety disorders. Results: From the eligible subjects, 167 agreed to participate and 34.1% of them were diagnosed with somatization. The correlation between the number of self-reported and FCSE symptoms was 0.63. After excluding symptoms with low frequency, low discriminative power and not correlated with the overall scale, 29 were retained in the final version. A cut-off of 4 symptoms gave a sensitivity of 86.0% and a specificity of 95.5% on the FCSE and 56.1% and 93.6% at selfreport. Stability in the number of symptoms after 6 months was good (k = 0.57).

BMC Gastroenterology, 2009

Bioorganic & Medicinal Chemistry Letters, 2006

A new class of benzimidazolone p38 MAP kinase inhibitors was discovered through high-throughput s... more A new class of benzimidazolone p38 MAP kinase inhibitors was discovered through high-throughput screening. X-ray crystallographic data of the lead molecule with p38 were used to design analogues with improved binding affinity and potency in a cell assay of LPS-induced TNFalpha production. Herein, we report the SAR of this new class of p38 inhibitors.

Annals of the New York Academy of Sciences, 2009

were the two predictors for alexithymia in SLE patients. The present findings showed that alexith... more were the two predictors for alexithymia in SLE patients. The present findings showed that alexithymia may play an important role in SLE patients. The difficulty in the management of emotions may lead to psychological distress and instability affecting the patient's quality of life, a relevant finding for the psychological, psychiatric, and clinical intervention and approach.

Fuel, 2011

This paper reports an electroanalytical method developed for tert-butylhydroquinone (TBHQ) determ... more This paper reports an electroanalytical method developed for tert-butylhydroquinone (TBHQ) determination in biodiesel in the presence of surfactant Triton X-100 (T-100). T-100 was shown to improve the electroanalytical signal and its use was decisive for direct analysis of TBHQ in biodiesel, only requiring previous dilution of biodiesel samples in methanol. Several parameters were studied and optimized for the development of

Talanta, 2010

A biosensor based on alfalfa sprout (Medicago sativa) homogenate as a source of peroxidase is pro... more A biosensor based on alfalfa sprout (Medicago sativa) homogenate as a source of peroxidase is proposed for the determination of thiodicarb by square-wave voltammetry. This enzyme was immobilized in self-assembled monolayers of l-cysteine on a gold electrode. Several parameters were investigated to evaluate the optimum conditions for operation of the biosensor. The analytical curve was linear for thiodicarb concentrations of 2.27 x 10(-6) to 4.40 x 10(-5) mol L(-1) with a detection limit of 5.75 x 10(-7) mol L(-1). The lifetime of the Au-alfalfa sprout-SAMs was 20 days (at least 220 determinations). The average recovery of thiodicarb from samples of vegetable extracts ranged from 99.02 to 101.04%. The results obtained for thiodicarb in vegetable extracts using the proposed method are in close agreement with those using a high performance liquid chromatography procedure at the 95% confidence level.

Sensors and Actuators B: Chemical, 2011

This study focuses on the development and evaluation of a new biosensor for the determination of ... more This study focuses on the development and evaluation of a new biosensor for the determination of the pesticide methomyl, based on enzyme inhibition. Laccase (LAC) obtained from a genetically modified fungus (Aspergillus oryzae) was successfully immobilized in a new supported ionic liquid phase (SILP) based on platinum nanoparticles and the 1-butyl-3-methylimidazolium tetrafluoroborate ionic liquid (Pt-BMI·BF 4 ) supported in montmorillonite, and subsequently applied in the construction of the biosensor. The process of inhibition by methomyl carbamate was performed using dopamine as a phenolic substrate to obtain the base signal. All measurements for the optimization and application of the biosensor were performed by square-wave voltammetry, and the best experimental conditions were obtained in acetate buffer solution (0.1 mol L −1 , pH 5.5), with 0.5 units of enzyme and voltammetric parameters: 60 Hz of frequency, 100 mV of pulse amplitude and 8 mV of scan increment. The determination of methomyl in carrot and tomato samples using the proposed biosensor showed results consistent with those obtained by HPLC, verifying that the method developed can be used for the quantification of this pesticide.

Microchemical Journal, 2011

In this paper we present a new electroanalytical method for determination of ceftiofur based on t... more In this paper we present a new electroanalytical method for determination of ceftiofur based on the hydrolysis of this antibiotic in 0.04 mol L −1 Britton-Robinson buffer at pH 10 and 60°C for 60 min (reduction peak at −0.70 V). Conditions were optimized for complete hydrolysis and quantitative determination of ceftiofur in milk. The method can be successfully used for determination of the antibiotic directly from samples of fluid milk and powder milk spiked to concentrations of 6.0 × 10 −8 , 8.0×10 −8 , and 10× 10 −8 mol L −1 , respectively. Recovery test ranged from 98.28% to 100.83%. The limits of detection and quantification were 3.73× 10 −10 and 1.24× 10 −9 mol L −1 , respectively. The method has the advantage of eliminating interference from proteins present in the sample, thus obviating the need for exhaustive extraction, which often renders other procedures unfeasible in terms of time and reagent cost. In addition, waste generation was found to be lower than in other methods.

Journal of Applied Electrochemistry, 2011

A simple electroanalytical method was developed to determine the antibiotic ceftiofur (CF) in mil... more A simple electroanalytical method was developed to determine the antibiotic ceftiofur (CF) in milk. The method is based on the adsorptive accumulation of the drug on a hanging mercury-drop electrode (HMDE) and the accompanying initiation of a negative square wave, which yielded well-defined cathodic peaks at -0.60 V (1C) and -0.91 V (2C) vs. Ag/AgCl. Calibration graphs were constructed and statistical parameters were evaluated. At pH 2.5, the square-wave voltammetry method revealed linearity from 52.4 to 524 ng mL -1 (r = 0.997), which is in accordance with the tolerance level of 100 ng mL -1 for CF as a residue in bovine milk established by the Food and Drug Administration (FDA) and the European Union. The limits of detection and quantification were 1.86 and 6.20 ng mL -1 , respectively. The method was tested to determine CF in spiked milk samples using HPLC as reference method.

Enzyme and Microbial Technology, 2010

A novel pequi fruit (Caryocar brasiliense Camb.) homogenate source of polyphenol oxidase was obta... more A novel pequi fruit (Caryocar brasiliense Camb.) homogenate source of polyphenol oxidase was obtained and immobilized in chitosan crosslinked with cyanuric chloride (CHcych-PPO). A biosensor was developed and used for the square-wave voltammetric determination of thiodicarb. Several parameters were investigated to evaluate the performance of this biosensor in the presence of hydroquinone and thiodicarb. The best response was obtained using 70:20:10% (w/w/w) of graphite powder:Nujol:CHcych-PPO, 250 U mL −1 of PPO and phosphate buffer solution (0.1 M; pH 7.0) with frequency, pulse amplitude and scan increment of 10 Hz, 150 mV, and 15 mV, respectively. Under optimized operational conditions the thiodicarb concentration was linear in the range of 3.75 × 10 −7 to 2.23 × 10 −6 M with a detection limit of 1.58 × 10 −7 M. The biosensor was applied in the determination of thiodicarb in fresh fruit and vegetable samples and the results compared with those obtained using high-performance liquid chromatography.

Environmental Research, 2010

Riverine populations of the Brazilian Amazon depend on fish for their principal source of protein... more Riverine populations of the Brazilian Amazon depend on fish for their principal source of protein, which changes in availability with seasonal fluctuations in the aquatic ecosystem. We report seasonal (high and low waters) and interannual changes in total mercury and methylmercury concentrations in hair of subsistence fish-eaters from a traditional riverine village on the banks of the Rio Tapajó s in the Brazilian Amazonia. Retrospective exposure assessment was conducted from hair concentrations in segments representative of 2 years. A total of 32 mothers and their 51 children were studied. They reported high fish consumption (4-14 times a week). Ranges of total mercury and methylmercury concentrations in hair were 1.0-51.0 and 0.5-41.4 mg g À 1 , with means of 12.4 and 10.2 mg g À 1 , respectively. The relative mean value for methylmercury was 80%. There was a significant correlation between mothers and children for both total-Hg (r ¼ 0.4826; P ¼0.003) and methyl-Hg (r ¼ 0.5214; P ¼ 0.004). Mercury concentrations along hair strands of individuals showed significant variation coinciding with seasonal high and low waters. The changes in the aquatic environment impacted fish species availability, which is reflected in the total and MeHg concentrations in hair.