Papers by Susana Rodrigues
Clinical Pediatrics, 1994
Neurological Sciences, 2010
Tests of famous faces are used to study language and memory. Yet, the effect of stimulus properti... more Tests of famous faces are used to study language and memory. Yet, the effect of stimulus properties on performance has not been fully investigated. To identify factors influencing proper name retrieval and to probe stimulus-specific parameters within proper name lexicon, we analysed the results obtained by 300 healthy participants on a test of famous faces that includes 74 personalities. A factor analysis yielded five main factors that were characterized by language (national or foreign names), epoch of peak popularity (current, recent or past) and occupation (politicians, entertainment and sports) of the personalities. Multiple regression analysis showed that participants’ education, age and gender accounted for 10–32% of the variance in factor scores. These results indicate that there are variables of the stimulus and participants’ that must be taken into account in proper name testing and in designing tests aimed to differentiate age-associated difficulties from cognitive decline.
Marine Pollution Bulletin, 2009
Harmful Algae, 2008
Foodborne outbreaks attributed to marine biotoxins were first reported in Portugal in 1946. A reg... more Foodborne outbreaks attributed to marine biotoxins were first reported in Portugal in 1946. A regular monitoring programme was implemented in 1986 for PSP, in 1987 for DSP and in 1996 for ASP. The gradual introduction of HPLC methodologies for DSP and PSP allowed a better understanding of toxin biotransformation by bivalves, supplying more selective and sensitive data than mouse bioassays. A comprehensive exposure assessment from DSP toxins in bivalves from the whole coast was only obtained more recently with the introduction of LC-MS methodology. Data on maximum toxin levels found, geographic distribution, seasonality of toxin families, and frequency of samples above current regulatory limits is presented in order to review the data available on exposure assessment after two decades of monitoring. Contamination with DSP toxins was more severe in estuarine and offshore bivalves from the NW and in offshore Donax spp. from the SW and south coasts. DSP toxins were recurrent every year mainly between late spring/early autumn. PSP toxins appeared intermittently in some years between 1986 and 2006, predominantly in autumn. Bivalves from the entire coast were severely contaminated, although bivalves from the NW coast were affected more often. ASP toxins appeared between spring and autumn around the entire coast, but toxin levels rarely exceeded the regulatory limit. Azaspiracids occurred in trace levels below the regulatory limit. Yessotoxins and pectenotoxins occurred in bivalves but have no known effects on the consumers. Several intoxication outbreaks attributed to PSP and DSP occurred during the two decades of the monitoring programme. #
Toxicon, 2003
The swimming crab Polybius henslowii may play an important role in the movement of the amnesic sh... more The swimming crab Polybius henslowii may play an important role in the movement of the amnesic shellfish toxin, domoic acid (DA), through the marine food chain. High DA concentrations have been determined in crab samples harvested along the Portuguese coast during the summer of 2002, reaching a level of 323.1 mg DA/g crab tissue. Toxin distribution in the different crab organs showed levels as high as 571.6 mg DA/g in the visceral tissues. Levels of toxin 4 -12 times lower were detected in the remaining tissues. This crab might be a prominent vector of the toxin to higher trophic levels, including fishes, sea birds and even humans. In Portugal P. henslowii is commercialised during the summer in some local markets. DA concentrations were found close to the legal limit of 20 mg/g in samples purchased at Figueira da Foz market. The crabs are boiled prior to reaching the consumers. The cooking process was evaluated. Determination of toxin losses during the cooking process showed a toxin reduction higher than 50%. DA was determined by HPLC-UV and confirmed by spectra acquired with diode-array detector. q
Journal of Chromatography A, 2007
The presence of paralytic shellfish poisoning (PSP) toxins has not been recorded in the Portugues... more The presence of paralytic shellfish poisoning (PSP) toxins has not been recorded in the Portuguese coast since 1995. A bloom of Gymnodinium catenatum occurred in the NW coast of Portugal in the autumn of 2005, and PSP profiles were determined in several inshore and offshore shellfish species by HPLC after pre-column oxidation. Most of the species studied contained a complex toxin profile, typically representative of contamination by G. catenatum. However, clams such as Spisula solida contained mainly decarbamoyl toxins, while less extensive transformation was found in Scrobicularia plana. In vitro incubation of S. solida digestive glands with PSP standards revealed a rapid transformation of carbamate and N-sulfocarbamoyl toxins into their corresponding decarbamate analogues. After 24 h, less than 5% of the carbamate or N-sulfocarbamoyl toxins tested remained. After a 24 h in vitro incubation of S. plana digestive glands, no decarbamate analogues were detected. Artificial toxification of S. plana with cultures of G. catenatum revealed the conversion into decarbamoyl analogues progressed slowly: initially dcGTX2 + 3 and dcSTX accounted only for 5% of total non N-1 hydroxilated toxins, after 6 days these toxins accounted for 41% of the toxin composition. In vitro incubations of digestive glands from other commercial bivalves did not reveal production of decarbamoyl analogues over a 24 h period.
Toxicon, 2009
Portuguese bivalves are recurrently contaminated with okadaic acid (OA) and dinophysistoxin-2 (DT... more Portuguese bivalves are recurrently contaminated with okadaic acid (OA) and dinophysistoxin-2 (DTX2), found mainly in esterified forms. Throughout the years different conditions have been reported in the literature for releasing the parent toxins through an alkaline hydrolysis step, in order to simplify their detection by HPLC-FLD or LC-MS. In order to clearly understand toxin stability and reaction end-point the binominous temperature/time course and base concentration were studied using naturally contaminated bivalve samples. The results showed a strong temperature dependence of the reaction. At 60 C and 70 C the hydrolysis was fast, and 40 min were sufficient for maximal recovery of OA and DTX2, while at 40 C and 50 C it was only complete after 100 min and 60 min, respectively. At room temperature the reaction was slow and incomplete even after 2 h. Stability of OA and DTX2 in semi-purified bivalve matrix at 70 C for 2 h was demonstrated. Concentrations of sodium hydroxide lower than 2.5 M, corresponding to a final incubation concentration of 0.23 M, resulted in incomplete release of parent toxins, demonstrating that high concentrations are needed when taking into account the dilution in the supernatant extract.
Journal of Applied Toxicology, 2010
Contamination of shellfish from the Portuguese coast with diarrhetic shellfish poisoning (DSP) to... more Contamination of shellfish from the Portuguese coast with diarrhetic shellfish poisoning (DSP) toxins is a recurrent event, with most of the commercial bivalves contaminated with high percentages of esters of okadaic acid (OA) and dinophysistoxin-2 (DTX2). This report describes the quantification of DSP toxins in unhydrolysed and hydrolysed extracts of several cockle and mussel samples naturally contaminated and the evaluation of their cytotoxicity profiles in V79 cells. The quantification of the acyl esters in the shellfish samples involved the cleavage of the ester bond through alkaline hydrolysis and the release of the parent toxins OA and DTX2. Unhydrolysed and hydrolysed extracts were then analyzed by liquid chromatography (LC) coupled with mass spectrometry (MS) for the detection and quantification of DSP toxins. The cytotoxicity of the analysed extracts was evaluated using the MTT reduction assay and compared with the cytotoxicity presented by different concentrations of OA standard (1–100 nm). OA exhibited marked cytotoxic effects and decreased cell viability in a dose dependent mode, with an IC50 of 27 nm. The cytotoxicity pattern of unhydrolysed extracts was clearly dependent on the concentration of free toxins. Moreover, the cytotoxicity of the esterified toxins present was revealed after their conversion into free toxins by alkaline hydrolysis. For the hydrolysed extracts of cockles and mussels, the cytotoxicity presented was mainly related to the concentration of OA and DTX2. Copyright © 2010 John Wiley & Sons, Ltd.
Immunobiology, 2011
Defects in macrophage function have been implicated in the establishment of Crohn's disease (CD).... more Defects in macrophage function have been implicated in the establishment of Crohn's disease (CD). However, the response of macrophages from CD patients to live bacteria, particularly Mycobacterium avium subsp. paratuberculosis (MAP), has not been addressed. Considering MAP has long been associated to CD, our objective was to assess whether macrophages from CD patients showed impaired inflammatory response to infection by MAP comparing to M. avium subsp. avium (MA) and other live intestinal commensal bacteria. Human peripheral blood monocyte-derived macrophages were obtained from CD patients, ulcerative colitis (UC) patients and controls. Following in vitro infection with MAP, MA, Escherichia coli or Enterococcus faecalis, cytokine levels and cell surface receptor expression were evaluated at different time points. Macrophages from CD patients showed impaired TNF-␣ secretion in response to bacterial challenge, but augmented IL-23 secretion and preserved IL-12 secretion and CD-40 expression. In addition, CD macrophages showed low IL-10 secretion. Macrophages from IBD patients showed increased expression of TLR-2 and -4, unaffected by infection. Differences in cytokine secretion observed after bacterial challenge were not MAP-specific, as other bacteria (E. coli and MA) showed similar effects. Macrophages from UC patients showed a less compromised TNF-␣ synthesis in response to mycobacterial infection than CD macrophages, with increased constitutive IL-12 secretion, and preserved IL-10 secretion. The increased IL-23 levels in response to infection and decreased IL-10 production observed in macrophages from CD patients may contribute to the inflammatory exacerbation observed in those patients.
Journal of Crohns & Colitis, 2011
Liver abscesses are very rare complications of ulcerative colitis, with only nine cases described... more Liver abscesses are very rare complications of ulcerative colitis, with only nine cases described in the literature, to our knowledge. We report a case where a recurrence of liver abscess occurred in an ulcerative colitis patient, in two different hepatic lobes, which has not been previously described. The recurrence was in the caudate lobe having the cultures yielded Staphylococcus aureus. This is also the first case report of liver abscess in this location and caused by this microorganism in an ulcerative colitis patient. A review of the literature concerning liver abscesses involving ulcerative colitis patients is also provided.
Journal of Crohns & Colitis, 2010
a v a i l a b l e a t w w w . s c i e n c e d i r e c t . c o m Journal of Crohn's and Colitis (2... more a v a i l a b l e a t w w w . s c i e n c e d i r e c t . c o m Journal of Crohn's and Colitis (2009) 4, 301-311 Abstract Contemplating the multifactorial nature of Crohn's disease (CD), the purpose of this study was to compare two neighbouring CD populations from different nations and examine how clinical characteristics of patients can influence therapeutic strategies and consequently different surgical events in routine clinical practice. Cross-sectional study based on data of an on-line registry of patients with CD in northern Portugal and Galicia. Of the 1238 patients, all with five or more years of disease, 568 (46%) were male and 670 (54%) female. The Portuguese and Galician populations were similar regarding Montreal categories, age at diagnosis, and years of follow-up. Galician B2 patients were associated with immunosuppression (OR 3.6; CI 2.2-6.1) and biologic treatment (OR 1.8; CI 1.0-3.1). In both populations ileocolonic disease was associated with immunosuppression and biologic treatment and the penetrating group was linked to immunosuppression. In the north of Portugal 47% and 16% of patients, and in Galicia 63% and 33%, were treated with immunosuppressants and biologic treatment, respectively. In the north of Portugal 44% of patients classified as stricturing behavior were operated without immunomodulation, in contrast to 12% in Galicia. In the latter it was possible to maintain 16% of B2 patients and 40% of B3 patients without surgery with adequate immunosuppression and/or biologic treatment. The delta of surgeries in B2 patients was 8% and in B3 26%. Conclusions: Stratifying patients according to the Montreal classification identified similar clinical patterns in disparate geographic populations, and revealed that differing medical therapeutic practices may influence the occurrence of surgical events.
Inflammatory Bowel Diseases, 2009
Background:Clinical and therapeutic patterns of ulcerative colitis (UC) are variable in different... more Background:Clinical and therapeutic patterns of ulcerative colitis (UC) are variable in different world regions. The purpose of this study was to examine two close independent southern European UC populations from 2 bordering countries and observe how demographic and clinical characteristics of patients can influence the severity of UC.Clinical and therapeutic patterns of ulcerative colitis (UC) are variable in different world regions. The purpose of this study was to examine two close independent southern European UC populations from 2 bordering countries and observe how demographic and clinical characteristics of patients can influence the severity of UC.Methods:A cross-sectional study was conducted during a 15-month period (September 2005 to December 2006) based on data of 2 Web registries of UC patients. Patients were stratified according to the Montreal Classification and disease severity was defined by the type of treatment taken.A cross-sectional study was conducted during a 15-month period (September 2005 to December 2006) based on data of 2 Web registries of UC patients. Patients were stratified according to the Montreal Classification and disease severity was defined by the type of treatment taken.Results:A total of 1549 UC patients were included, 1008 (65%) from northern Portugal and 541 (35%) from Galicia (northwest Spain). A female predominance (57%) was observed in Portuguese patients (P < 0.001). The median age at diagnosis was 35 years and median years of disease was 7. The majority of patients (53%) were treated only with mesalamine, while 15% had taken immunosuppressant drugs, and 3% biologic treatment. Most patients in both groups were not at risk for aggressive therapy. Extensive colitis was a predictive risk factor for immunosuppression in northern Portugal and Galicia (odds ratio [OR] 2.737, 95% confidence interval [CI]: 1.846–4.058; OR 5.799, 95% CI: 3.433–9.795, respectively) and biologic treatment in Galicia (OR 6.329, 95% CI: 2.641–15.166). Younger patients presented a severe course at onset with more frequent use of immunosuppressors in both countries.A total of 1549 UC patients were included, 1008 (65%) from northern Portugal and 541 (35%) from Galicia (northwest Spain). A female predominance (57%) was observed in Portuguese patients (P < 0.001). The median age at diagnosis was 35 years and median years of disease was 7. The majority of patients (53%) were treated only with mesalamine, while 15% had taken immunosuppressant drugs, and 3% biologic treatment. Most patients in both groups were not at risk for aggressive therapy. Extensive colitis was a predictive risk factor for immunosuppression in northern Portugal and Galicia (odds ratio [OR] 2.737, 95% confidence interval [CI]: 1.846–4.058; OR 5.799, 95% CI: 3.433–9.795, respectively) and biologic treatment in Galicia (OR 6.329, 95% CI: 2.641–15.166). Younger patients presented a severe course at onset with more frequent use of immunosuppressors in both countries.Conclusions:In a large population of UC patients from two independent southern European countries, most patients did not require aggressive therapy, but extensive colitis was a clear risk factor for more severe disease. (Inflamm Bowel Dis 2010)In a large population of UC patients from two independent southern European countries, most patients did not require aggressive therapy, but extensive colitis was a clear risk factor for more severe disease. (Inflamm Bowel Dis 2010)
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Papers by Susana Rodrigues