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Maixner W, Fillingim R, Sigurdsson A, Kincaid S, Silva S. Sensitivity of patients with painful temporomandibular disorders to experimentally evoked pain: evidence for altered temporal summation of pain. Pain 1998; 76:71-81. [PMID: 9696460 DOI: 10.1016/s0304-3959(98)00028-1] [Citation(s) in RCA: 275] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Temporomandibular disorders (TMD) represent a group of chronic painful conditions involving the muscles of mastication and the temporomandibular joint. Several studies have reported that TMD is associated with enhanced sensitivity to experimental pain. Twenty-three TMD subjects and 24 pain-free matched control subjects participated in a set of studies which were designed to evaluate whether the temporal integrative aspects of thermal pain perception are altered in TMD patients compared with control subjects. Specifically, we have examined in both TMD patients and in age- and gender-matched control subjects: (1) the time-course and magnitude of perceived pain evoked by the application of sustained 7-s noxious thermal stimuli (45-48 degrees C) to the face and forearm, (2) the central summation of C-fiber-mediated pain produced by applying brief trains of noxious heat pulses to the skin overlying the ventral aspect of the right palm and (3) the ability to discriminate small increments in noxious heat applied to facial and volar forearm skin. Data collected from these studies indicate that TMD patients show enhanced temporal integration of thermal pain compared with control subjects. TMD patients show greater thermal C-fiber-mediated temporal summation than pain-free subjects and they report a greater magnitude of sustained noxious heat pulses applied to either the face or the forearm than control subjects. In contrast to these findings, TMD and pain-free subjects are equally able to discriminate and detect small increments of heat applied to noxious adapting temperatures. These findings suggest that the augmented temporal integration of noxious stimuli may result from alterations in central nervous system processes which contribute to the enhanced pain sensitivity observed in TMD patients.
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275 |
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Freimer NB, Reus VI, Escamilla MA, McInnes LA, Spesny M, Leon P, Service SK, Smith LB, Silva S, Rojas E, Gallegos A, Meza L, Fournier E, Baharloo S, Blankenship K, Tyler DJ, Batki S, Vinogradov S, Weissenbach J, Barondes SH, Sandkuijl LA. Genetic mapping using haplotype, association and linkage methods suggests a locus for severe bipolar disorder (BPI) at 18q22-q23. Nat Genet 1996; 12:436-41. [PMID: 8630501 DOI: 10.1038/ng0496-436] [Citation(s) in RCA: 204] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Manic depressive illness, or bipolar disorder (BP), is characterized by episodes of elevated mood (mania) and depression. We designed a multistage study in the genetically isolated population of the Central Valley of Costa Rica to identify genes that promote susceptibility to severe BP (termed BPI), and screened the genome ot two Costa Rican BPI pedigrees (McInnes et al., submitted). We considered only individuals who fulfilled very stringent diagnostic criteria for BPI to be affected. The strongest evidence for a BPI locus was observed in 18q22-q23. We tested 16 additional markers in this region and seven yielded peak lod scores over 1.0. These suggestive lod scores were obtained over a far greater chromosomal length (about 40 cM) than in any other genome region. This localization is supported by marker haplotypes shared by 23 of 26 BPI affected individuals studied. Additionally, marker allele frequencies over portions of this region are significantly different in the patient sample from those of the general Costa Rican population. Finally, we performed an analysis which made use of both the evidence for linkage and for association in 18q23, and we observed significant lod scores for two markers in this region.
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Rodrigues CF, Silva S, Henriques M. Candida glabrata: a review of its features and resistance. Eur J Clin Microbiol Infect Dis 2013; 33:673-88. [PMID: 24249283 DOI: 10.1007/s10096-013-2009-3] [Citation(s) in RCA: 190] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2013] [Accepted: 10/22/2013] [Indexed: 11/30/2022]
Abstract
Candida species belong to the normal microbiota of the oral cavity and gastrointestinal and vaginal tracts, and are responsible for several clinical manifestations, from mucocutaneous overgrowth to bloodstream infections. Once believed to be non-pathogenic, Candida glabrata was rapidly blamable for many human diseases. Year after year, these pathological circumstances are more recurrent and problematic to treat, especially when patients reveal any level of immunosuppression. These difficulties arise from the capacity of C. glabrata to form biofilms and also from its high resistance to traditional antifungal therapies. Thus, this review intends to present an excerpt of the biology, epidemiology, and pathology of C. glabrata, and detail an approach to its resistance mechanisms based on studies carried out up to the present.
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Review |
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190 |
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Paulis WD, Silva S, Koes BW, van Middelkoop M. Overweight and obesity are associated with musculoskeletal complaints as early as childhood: a systematic review. Obes Rev 2014; 15:52-67. [PMID: 23941399 DOI: 10.1111/obr.12067] [Citation(s) in RCA: 154] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/10/2013] [Revised: 06/19/2013] [Accepted: 06/26/2013] [Indexed: 12/26/2022]
Abstract
In order to examine (i) the association between weight status and musculoskeletal complaints (MSC) in children, and (ii) whether overweight and obese children have a higher risk of developing MSC than normal-weight children Medline, Embase, Web of Science and Cochrane were searched (all years up to 2 January 2013) for observational studies studying direct associations between body mass index (or weight status) and MSC in children. Forty studies, together studying over one million children, were included. There was moderate quality of evidence that being overweight in childhood is positively associated with musculoskeletal pain (risk ratio [RR] 1.26; 95% confidence interval [CI]: 1.09-1.45). In addition, low quality of evidence was found for a positive association between overweight and low back pain (RR 1.42; 95% CI: 1.03-1.97) and between overweight and injuries and fractures (RR 1.08; 95% CI: 1.03-1.14). Although the risk of developing an injury was significantly higher for overweight than for normal-weight adolescents (RR: 2.41, 95% CI: 1.42 to 4.10), this evidence was of very low quality. Overweight and obesity are associated with musculoskeletal pain, injuries and fractures as early as childhood. More high-quality prospective cohort studies are needed to study the nature of this relationship.
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Review |
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Bernsten C, Björkman I, Caramona M, Crealey G, Frøkjaer B, Grundberger E, Gustafsson T, Henman M, Herborg H, Hughes C, McElnay J, Magner M, van Mil F, Schaeffer M, Silva S, Søndergaard B, Sturgess I, Tromp D, Vivero L, Winterstein A. Improving the well-being of elderly patients via community pharmacy-based provision of pharmaceutical care: a multicentre study in seven European countries. Drugs Aging 2001; 18:63-77. [PMID: 11232739 DOI: 10.2165/00002512-200118010-00005] [Citation(s) in RCA: 131] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
OBJECTIVE This study aimed to measure the outcomes of a harmonised, structured pharmaceutical care programme provided to elderly patients (> or =65 years of age) by community pharmacists in a multicentre international study performed in 7 European countries. DESIGN AND SETTING The study was a randomised, controlled, longitudinal, clinical trial with repeated measures performed over an 18-month period. A total of 104 intervention and 86 control pharmacy sites participated in the research and 1290 intervention patients and 1164 control patients were recruited into the study. MAIN OUTCOME MEASURES AND RESULTS A general decline in health-related quality of life over time was observed in the pooled data; however, significant improvements were achieved in patients involved in the pharmaceutical care programme in some countries. Intervention patients reported better control of their medical conditions as a result of the study and cost savings associated with pharmaceutical care provision were observed in most countries. The new structured service was well accepted by intervention patients and patient satisfaction with the services improved during the study. The pharmacists involved in providing pharmaceutical care had a positive opinion on the new approach, as did the majority of general practitioners surveyed. The positive effects appear to have been achieved via social and psychosocial aspects of the intervention, such as the increased support provided by community pharmacists, rather than via biomedical mechanisms. CONCLUSIONS This study is the first large-scale, multicentre study to investigate the effects of pharmaceutical care provision by community pharmacists to elderly patients. Future research methodology and implementation will be informed by the experience gained from this challenging trial.
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McInnes LA, Escamilla MA, Service SK, Reus VI, Leon P, Silva S, Rojas E, Spesny M, Baharloo S, Blankenship K, Peterson A, Tyler D, Shimayoshi N, Tobey C, Batki S, Vinogradov S, Meza L, Gallegos A, Fournier E, Smith LB, Barondes SH, Sandkuijl LA, Freimer NB. A complete genome screen for genes predisposing to severe bipolar disorder in two Costa Rican pedigrees. Proc Natl Acad Sci U S A 1996; 93:13060-5. [PMID: 8917544 PMCID: PMC24046 DOI: 10.1073/pnas.93.23.13060] [Citation(s) in RCA: 127] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Bipolar mood disorder (BP) is a debilitating syndrome characterized by episodes of mania and depression. We designed a multistage study to detect all major loci predisposing to severe BP (termed BP-I) in two pedigrees drawn from the Central Valley of Costa Rica, where the population is largely descended from a few founders in the 16th-18th centuries. We considered only individuals with BP-I as affected and screened the genome for linkage with 473 microsatellite markers. We used a model for linkage analysis that incorporated a high phenocopy rate and a conservative estimate of penetrance. Our goal in this study was not to establish definitive linkage but rather to detect all regions possibly harboring major genes for BP-I in these pedigrees. To facilitate this aim, we evaluated the degree to which markers that were informative in our data set provided coverage of each genome region; we estimate that at least 94% of the genome has been covered, at a predesignated threshold determined through prior linkage simulation analyses. We report here the results of our genome screen for BP-I loci and indicate several regions that merit further study, including segments in 18q, 18p, and 11p, in which suggestive lod scores were observed for two or more contiguous markers. Isolated lod scores that exceeded our thresholds in one or both families also occurred on chromosomes 1, 2, 3, 4, 5, 7, 13, 15, 16, and 17. Interesting regions highlighted in this genome screen will be followed up using linkage disequilibrium (LD) methods.
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research-article |
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127 |
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Jones AK, Cunningham VJ, Ha-Kawa S, Fujiwara T, Luthra SK, Silva S, Derbyshire S, Jones T. Changes in central opioid receptor binding in relation to inflammation and pain in patients with rheumatoid arthritis. BRITISH JOURNAL OF RHEUMATOLOGY 1994; 33:909-16. [PMID: 7921749 DOI: 10.1093/rheumatology/33.10.909] [Citation(s) in RCA: 126] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
A group of four patients with RA were examined to test the hypothesis that there is a change in the endogenous opioid system in the brain during inflammatory pain. Regional cerebral opioid receptor binding was quantified using the opioid receptor antagonist [11C] diprenorphine and positron emission tomography (PET). In the four patients studied in and out of pain, significant increases in [11C]diprenorphine binding were seen in association with a reduction in pain. Increases were seen in most of the areas of the brain that were sampled apart from the occipital cortex. Significant region-specific increases over and above the more generalized changes were also seen in the frontal, cingulate and temporal cortices in addition to the straight gyrus. These findings are consistent with the hypothesis that there are substantial increases in occupancy by endogenous opioid peptides during inflammatory pain.
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Monteiro DR, Gorup LF, Silva S, Negri M, de Camargo ER, Oliveira R, Barbosa DB, Henriques M. Silver colloidal nanoparticles: antifungal effect against adhered cells and biofilms of Candida albicans and Candida glabrata. BIOFOULING 2011; 27:711-9. [PMID: 21756192 DOI: 10.1080/08927014.2011.599101] [Citation(s) in RCA: 123] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
The aim of this study was to evaluate the effect of silver nanoparticles (SN) against Candida albicans and Candida glabrata adhered cells and biofilms. SN (average diameter 5 nm) were synthesized by silver nitrate reduction with sodium citrate and stabilized with ammonia. Minimal inhibitory concentration (MIC) tests were performed for C. albicans (n = 2) and C. glabrata (n = 2) grown in suspension following the Clinical Laboratory Standards Institute microbroth dilution method. SN were applied to adhered cells (2 h) or biofilms (48 h) and after 24 h of contact their effect was assessed by enumeration of colony forming units (CFUs) and quantification of total biomass (by crystal violet staining). The MIC results showed that SN were fungicidal against all strains tested at very low concentrations (0.4-3.3 μg ml(-1)). Furthermore, SN were more effective in reducing biofilm biomass when applied to adhered cells (2 h) than to pre-formed biofilms (48 h), with the exception of C. glabrata ATCC, which in both cases showed a reduction ∼90%. Regarding cell viability, SN were highly effective on adhered C. glabrata and respective biofilms. On C. albicans the effect was not so evident but there was also a reduction in the number of viable biofilm cells. In summary, SN may have the potential to be an effective alternative to conventional antifungal agents for future therapies in Candida-associated denture stomatitis.
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123 |
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Tsilimigras DI, Moris D, Hyer JM, Bagante F, Sahara K, Moro A, Paredes AZ, Mehta R, Ratti F, Marques HP, Silva S, Soubrane O, Lam V, Poultsides GA, Popescu I, Alexandrescu S, Martel G, Workneh A, Guglielmi A, Hugh T, Aldrighetti L, Endo I, Sasaki K, Rodarte AI, Aucejo FN, Pawlik TM. Hepatocellular carcinoma tumour burden score to stratify prognosis after resection. Br J Surg 2020; 107:854-864. [PMID: 32057105 DOI: 10.1002/bjs.11464] [Citation(s) in RCA: 91] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Revised: 10/23/2019] [Accepted: 11/15/2019] [Indexed: 01/27/2023]
Abstract
BACKGROUND Although the Barcelona Clinic Liver Cancer (BCLC) staging system has been largely adopted in clinical practice, recent studies have emphasized the need for further refinement and subclassification of this system. METHODS Patients who underwent hepatectomy with curative intent for BCLC-0, -A or -B hepatocellular carcinoma (HCC) between 2000 and 2017 were identified using a multi-institutional database. The tumour burden score (TBS) was calculated, and overall survival (OS) was examined in relation to TBS and BCLC stage. RESULTS Among 1053 patients, 63 (6·0 per cent) had BCLC-0, 826 (78·4 per cent) BCLC-A and 164 (15·6 per cent) had BCLC-B HCC. OS worsened incrementally with higher TBS (5-year OS 77·9, 61 and 39 per cent for low, medium and high TBS respectively; P < 0·001). No differences in OS were noted among patients with similar TBS, irrespective of BCLC stage (61·6 versus 58·9 per cent for BCLC-A/medium TBS versus BCLC-B/medium TBS, P = 0·930; 45 versus 13 per cent for BCLC-A/high TBS versus BCLC-B/high TBS, P = 0·175). Patients with BCLC-B HCC and a medium TBS had better OS than those with BCLC-A disease and a high TBS (58·9 versus 45 per cent; P = 0·005). On multivariable analysis, TBS remained associated with OS among patients with BCLC-A (medium TBS: hazard ratio (HR) 2·07, 95 per cent c.i. 1·42 to 3·02, P < 0·001; high TBS: HR 4·05, 2·40 to 6·82, P < 0·001) and BCLC-B (high TBS: HR 3·85, 2·03 to 7·30; P < 0·001) HCC. TBS could also stratify prognosis among patients in an external validation cohort (5-year OS 79, 51·2 and 28 per cent for low, medium and high TBS respectively; P = 0·010). CONCLUSION The prognosis of patients with HCC varied according to the BCLC stage but was largely dependent on the TBS.
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Silva SV, Pihlanto A, Malcata FX. Bioactive peptides in ovine and caprine cheeselike systems prepared with proteases from Cynara cardunculus. J Dairy Sci 2008; 89:3336-44. [PMID: 16899666 DOI: 10.3168/jds.s0022-0302(06)72370-0] [Citation(s) in RCA: 89] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The potential angiotensin-converting enzyme (ACE)-inhibitory and antioxidant activities of peptides in water-soluble extracts, obtained from raw and sterilized ovine and caprine cheeselike systems coagulated with enzymes from the plant Cynara cardunculus, were assessed. Prior to the assay, the 3,000-Da permeate from 45-d-old cheeselike systems was fractionated by tandem chromatographic techniques. Several peaks were obtained in each chromatogram, but only some were associated with ACE-inhibitory or antioxidant activity or both. Peptides Tyr-Gln-Glu-Pro, Val-Pro-Lys-Val-Lys, and Tyr-Gln-Glu-Pro-Val-Leu-Gly-Pro-* from beta-casein, as well as Arg-Pro-Lys and Arg-Pro-Lys-His-Pro-Ile-Lys-His-* from alpha(s1)-casein exhibited ACE-inhibitory activity. Peptides released upon cleavage of the peptide bond Leu190-Tyr191 (either in ovine or caprine beta-casein), and corresponding to the beta-casein sequence Tyr-Gln-Glu-Pro-*, possessed antioxidant activity.
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Research Support, Non-U.S. Gov't |
17 |
89 |
11
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Porrini M, Crovetti R, Testolin G, Silva S. Evaluation of satiety sensations and food intake after different preloads. Appetite 1995; 25:17-30. [PMID: 7495324 DOI: 10.1006/appe.1995.0038] [Citation(s) in RCA: 84] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The reproducibility of three questions, related to fullness, satiety and desire to eat, rated on an unmarked triangle was verified. In four sessions 12 volunteers ate pasta with tomato sauce (520 kcal) and were asked to rate the sensations felt. There was no difference in rating scores of the replications so the proposed questionnaire provides a stable measure of sensations related to satiety. Subsequently three satiety conditions were studied. Two foods, one rich in carbohydrate, pasta (baked macaroni) and the other in protein, polpette (meatballs), were used as loads at two calorie levels and as preload before an "ad libitum" meal. All the three questions proved useful in discriminating between the different satiety conditions. The food intake underlines the specificity of satiety: subjects, after eating a preload which previously had satiated them, ate other foods in different amounts depending on the kind of preload eaten. Food intake was significantly higher after the pasta preload, furthermore "fullness" and "satiety" ratings were significantly highest after the meatball preload, suggesting that in our experimental conditions, meatballs were more satiating than pasta. In conclusion, this study highlights the validity of using several quite different questions to study hunger and satiety, together with the actual food intake.
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30 |
84 |
12
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Monteiro DR, Silva S, Negri M, Gorup LF, de Camargo ER, Oliveira R, Barbosa DB, Henriques M. Silver nanoparticles: influence of stabilizing agent and diameter on antifungal activity against Candida albicans and Candida glabrata biofilms. Lett Appl Microbiol 2012; 54:383-91. [PMID: 22313289 DOI: 10.1111/j.1472-765x.2012.03219.x] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
AIM The purpose of this work was to evaluate the size-dependent antifungal activity of different silver nanoparticles (SN) colloidal suspensions against Candida albicans and Candida glabrata mature biofilms. METHODS AND RESULTS The research presented herein used SN of three different average sizes (5, 10 and 60 nm), which were synthesized by the reduction of silver nitrate through sodium citrate and which were stabilized with ammonia or polyvinylpyrrolidone. Minimal inhibitory concentration (MIC) assays were performed using the microdilution methodology. The antibiofilm activity of SN was determined by total biomass quantification (by crystal violet staining) and colony forming units enumeration. MIC results showed that all SN colloidal suspensions were fungicidal against the tested strains at very low concentrations (0·4-3·3 μg ml(-1) ). With regard to biomass quantification, SN colloidal suspensions were very effective only against C. glabrata biofilms, achieving biomass reductions around 90% at a silver concentration of 108 μg ml(-1) . In general, all SN suspensions promoted significant log(10) reduction of the mean number of cultivable biofilm cells after exposure to silver concentrations at or higher than 108 μg ml(-1) . Moreover, the results showed that the particle size and the type of stabilizing agent used did not interfere in the antifungal activity of SN against Candida biofilms. CONCLUSIONS This study suggests that SN have antifungal therapeutic potential, but further studies are still required namely regarding formulation and delivery means. SIGNIFICANCE AND IMPACT OF THE STUDY SN may contribute to the development of new strategies for the improvement of oral health and quality of life particularly of the complete denture wearers.
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Research Support, Non-U.S. Gov't |
13 |
81 |
13
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Negri M, Silva S, Henriques M, Oliveira R. Insights into Candida tropicalis nosocomial infections and virulence factors. Eur J Clin Microbiol Infect Dis 2011; 31:1399-412. [PMID: 22037823 DOI: 10.1007/s10096-011-1455-z] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2011] [Accepted: 10/08/2011] [Indexed: 12/31/2022]
Abstract
Candida tropicalis is considered the first or the second non-Candida albicans Candida (NCAC) species most frequently isolated from candidosis, mainly in patients admitted in intensive care units (ICUs), especially with cancer, requiring prolonged catheterization, or receiving broad-spectrum antibiotics. The proportion of candiduria and candidemia caused by C. tropicalis varies widely with geographical area and patient group. Actually, in certain countries, C. tropicalis is more prevalent, even compared with C. albicans or other NCAC species. Although prophylactic treatments with fluconazole cause a decrease in the frequency of candidosis caused by C. tropicalis, it is increasingly showing a moderate level of fluconazole resistance. The propensity of C. tropicalis for dissemination and the high mortality associated with its infections might be strongly related to the potential of virulence factors exhibited by this species, such as adhesion to different host surfaces, biofilm formation, infection and dissemination, and enzymes secretion. Therefore, the aim of this review is to outline the present knowledge on all the above-mentioned C. tropicalis virulence traits.
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Review |
14 |
80 |
14
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Silva S, Basser PJ, Miranda PC. Elucidating the mechanisms and loci of neuronal excitation by transcranial magnetic stimulation using a finite element model of a cortical sulcus. Clin Neurophysiol 2008; 119:2405-13. [PMID: 18783986 DOI: 10.1016/j.clinph.2008.07.248] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2008] [Revised: 06/13/2008] [Accepted: 07/03/2008] [Indexed: 11/16/2022]
Abstract
OBJECTIVE This work aims to elucidate by what physical mechanisms and where stimulation occurs in the brain during transcranial magnetic stimulation (TMS), taking into account cortical geometry and tissue heterogeneity. METHODS An idealized computer model of TMS was developed, comprising a stimulation coil, a cortical sulcus, and surrounding tissues. The distribution of the induced electric field was computed, and estimates of the relevant parameters were generated to predict the locus and type of neurons stimulated during TMS, assuming three different stimulation mechanisms. RESULTS Tissue heterogeneity strongly affects the spatial distribution of the induced electric field and hence which stimulation mechanism is dominant and where it acts. Stimulation of neurons may occur in the gyrus, in the lip of the gyrus, and in the walls of the sulcus. The stimulated cells can be either pyramidal cells having medium to large caliber axons, or intracortical fibers of medium caliber. CONCLUSIONS The results highlight the influence of cortical folding on the action of magnetic and electric fields on cortical tissue. SIGNIFICANCE Tissue geometry and heterogeneity in electrical conductivity both must be taken into account to predict accurately stimulation loci and mechanism in TMS.
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Research Support, Non-U.S. Gov't |
17 |
79 |
15
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Ferreira IMPLVO, Silva S. Quantification of residual nitrite and nitrate in ham by reverse-phase high performance liquid chromatography/diode array detector. Talanta 2007; 74:1598-602. [PMID: 18371823 DOI: 10.1016/j.talanta.2007.10.004] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2007] [Revised: 09/05/2007] [Accepted: 10/03/2007] [Indexed: 10/22/2022]
Abstract
Nitrite and nitrate are used as additives in ham industry to provide colour, taste and protect against clostridia. The classical colorimetric methods widely used to determine nitrite and nitrate are laborious, suffer from matrix interferences and involve the use of toxic cadmium. The use of chromatography is potentially attractive since it is more rapid, sensitive, selective and provides reliable and accurate results. A rapid and cost-effective RP-HPLC method with diode array detector was optimized and validated for quantification of nitrites and nitrates in ham. The chromatographic separation was achieved using a HyPurity C18, 5 microm chromatographic column and gradient elution with 0.01 M n-octylamine and 5mM tetrabutylammonium hydrogenosulphate to pH 6.5. The determinations were performed in the linear range of 0.0125-10.0mg/L for nitrite and 0.0300-12.5 g/L for nitrate. The detection limits were 0.019 and 0.050 mg/kg, respectively. The reliability of the method in terms of precision and accuracy was evaluated. Coefficients of variation lower than 2.89% and 5.47% were obtained for nitrite and nitrate, respectively (n=6). Recoveries of residual nitrite/nitrate ranged between 93.6% and 104.3%. Analysis of cooked and dried ham samples was performed, and the results obtained were in agreement with reference procedures.
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Validation Study |
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77 |
16
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Wang T, Hopkins D, Schmidt C, Silva S, Houghton R, Takita H, Repasky E, Reed SG. Identification of genes differentially over-expressed in lung squamous cell carcinoma using combination of cDNA subtraction and microarray analysis. Oncogene 2000; 19:1519-28. [PMID: 10734311 DOI: 10.1038/sj.onc.1203457] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
In order to develop effective vaccine products against human cancer, we are interested in identifying genes over-expressed in tumor cells. Through a combination of cDNA library subtraction and microarray technology, we identified seventeen genes preferentially expressed in lung squamous cell carcinoma, including four novel genes. To date, expression profiles of these genes were confirmed by Northern and/or real-time analysis, and several genes were also found to be expressed in head and neck squamous tumors. Thus, these combined methods represent a high throughput approach for identifying tumor specific genes. Furthermore, the report of characterization on these genes will allow them to be exploited for their diagnostic, prognostic, and therapeutic potentials including immunotherapy and antibody based anticancer therapy.
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25 |
77 |
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Bourbon M, Alves AC, Medeiros AM, Silva S, Soutar AK. Familial hypercholesterolaemia in Portugal. Atherosclerosis 2008; 196:633-42. [PMID: 17765246 DOI: 10.1016/j.atherosclerosis.2007.07.019] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/16/2007] [Revised: 06/19/2007] [Accepted: 07/11/2007] [Indexed: 11/22/2022]
Abstract
Familial hypercholesterolaemia (FH) is characterised clinically by an increased level of circulating LDL cholesterol that leads to lipid accumulation in tendons and arteries, premature atherosclerosis and increased risk of coronary heart disease (CHD). Although Portugal should have about 20,000 cases, this disease is severely under-diagnosed in our country, this being the first presentation of Portuguese data on FH. A total of 602 blood samples were collected from 184 index patients and 418 relatives from several centres throughout Portugal. Fifty-three different mutations were found in 83 index patients, 79 heterozygous and 4 with two defective LDLR alleles. Additionally, 4 putative alterations were found in 8 patients but were not considered mutations causing disease, mainly because they did not co-segregate with hypercholesterolaemia in the families. Three unrelated patients were found to be heterozygous for the APOB(3500) mutation and two unrelated patients were found to be heterozygous for a novel mutation in PCSK9, predicted to cause a single amino acid substitution, D374H. Cascade screening increased the number of FH patients identified genetically to 204. The newly identified FH patients are now receiving counselling and treatment based on the genetic diagnosis. The early identification of FH patients can increase their life expectancy and quality of life by preventing the development of premature CHD if patients receive appropriate pharmacological treatment.
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Stith BJ, Goalstone M, Silva S, Jaynes C. Inositol 1,4,5-trisphosphate mass changes from fertilization through first cleavage in Xenopus laevis. Mol Biol Cell 1993; 4:435-43. [PMID: 8507898 PMCID: PMC300944 DOI: 10.1091/mbc.4.4.435] [Citation(s) in RCA: 76] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
After fertilization in Xenopus laevis, inositol 1,4,5-trisphosphate (IP3) mass increased from 53 to 261 fmol/cell and returned to near basal by 10 min after insemination. IP3 was also elevated over control egg levels during first mitosis and first cleavage. Because IP3 levels and the fertilization calcium wave decline at about the same time and because calcium ionophore or pricking the egg increased IP3, the fertilization calcium wave may be due to calcium-induced IP3 production. In addition, the onset of sperm motility was associated with an increase, whereas the acrosomal reaction was accompanied by a decrease in IP3 mass. Combining our published data with this report, the first chronology of the levels of IP3 from the induction of meiosis (maturation) through fertilization and cleavage in one cellular system is summarized. These data suggest an in vivo dose response for IP3 and calcium release. A small (17 fmol/cell) IP3 change during the induction of meiosis may not be associated with a calcium change. Larger IP3 changes at cleavage (40 fmol/cell) and mitosis (125 fmol/cell) are associated with localized small calcium increases, whereas the largest IP3 change (208 fmol/cell) is associated with the large calcium increase at fertilization.
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research-article |
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76 |
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Costa EM, Silva S, Madureira AR, Cardelle-Cobas A, Tavaria FK, Pintado MM. A comprehensive study into the impact of a chitosan mouthwash upon oral microorganism's biofilm formation in vitro. Carbohydr Polym 2013; 101:1081-6. [PMID: 24299877 DOI: 10.1016/j.carbpol.2013.09.041] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2013] [Revised: 08/18/2013] [Accepted: 09/14/2013] [Indexed: 10/26/2022]
Abstract
Modern dentistry emphasizes the importance of dental plaque control to improve oral health. To that end the development of oral care formulations has been geared toward the incorporation of antiplaque agents that may play a crucial role in oral health maintenance. In later years the research into antiplaque agents has led to the discovery of compounds with significant capability to affect biofilm formation. Among these compounds was chitosan, a polysaccharide which showed great ability to interfere with Streptococcus mutans biofilm formation. As such the aim of this work was to incorporate chitosan into a mouthwash matrix and assess its effect upon biofilm formation of oral microorganisms. This assessment was performed via study of the impact the mouthwash upon microbial adherence, biofilm formation and mature biofilms. Additionally, the action of the chitosan mouthwash was compared with two commercially available mouthwashes. The results here obtained show that only the chitosan containing mouthwash was capable of interfering with all microorganisms' adherence, biofilm formation and mature biofilms while at the same time showing vastly superior activity than both commercial mouthwashes assayed. As such a chitosan mouthwash shows great potential as a natural and efficient alternative to traditional mouthwashes.
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Research Support, Non-U.S. Gov't |
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68 |
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Silva S, Filipe MI, Pinho A. Variants of intestinal metaplasia in the evolution of chronic atrophic gastritis and gastric ulcer. A follow up study. Gut 1990; 31:1097-104. [PMID: 2083854 PMCID: PMC1378731 DOI: 10.1136/gut.31.10.1097] [Citation(s) in RCA: 68] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
A follow up study with biopsy was initiated in 1982 to define the relations between variants of intestinal metaplasia and the evolution of chronic atrophic gastritis and gastric ulcer. All patients (58 with chronic atrophic gastritis and 66 with gastric ulcer) had intestinal metaplasia at the start of the study. In the six year period to 1988 a total of 241 biopsies were performed on the patients with chronic atrophic gastritis and 243 on the patients with gastric ulcer. Initially, 81% of the patients with chronic atrophic gastritis presented with type I intestinal metaplasia and 14% with type III intestinal metaplasia. During follow up type I was predominant, often associated with grades 2 and 3 active disease (81%) and 45% of these patients reverted to a non-intestinal metaplasia status by the third year of follow up. In contrast, type III metaplasia was more common in the absence of appreciable inflammation (78% of biopsy specimens), being persistent in five of seven patients in the third year of follow up, and was found to be associated with dysplasia in three of these patients. Similarly, the initial biopsy specimen showed type I metaplasia in most patients with gastric ulcer (82%) and type III in only 4%. Type I metaplasia was also predominant in these patients (80%), particularly in active disease (68%), gradually regressing with healing. In contrast, type III was associated with delayed ulcer healing and reactivation (75%; six of eight patients). We conclude that (a) type I is a short term reactive process which regresses with healing; (b) type III is related to prolonged injury and chronicity and may regress or progress to dysplasia; (c) persistent and more immature forms of metaplasia may carry an increased risk of malignancy.
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Silva S, Sepodes B, Rocha J, Direito R, Fernandes A, Brites D, Freitas M, Fernandes E, Bronze MR, Figueira ME. Protective effects of hydroxytyrosol-supplemented refined olive oil in animal models of acute inflammation and rheumatoid arthritis. J Nutr Biochem 2014; 26:360-8. [PMID: 25620693 DOI: 10.1016/j.jnutbio.2014.11.011] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2014] [Revised: 10/25/2014] [Accepted: 11/18/2014] [Indexed: 11/19/2022]
Abstract
Virgin olive oil is the primary source of fat in the Mediterranean diet, and its beneficial health effects have been related with oleic acid and phenolic compounds content. Hydroxytyrosol, a typical virgin olive oil phenolic compound, has beneficial antioxidant and anti-inflammatory properties as previously reported. The aim of this study was to evaluate the effect of hydroxytyrosol-supplemented refined olive oil at 0.5 and 5 mg/kg in a rodent model of rheumatoid arthritis. Rheumatoid arthritis was induced by intradermic administration, in male Wistar rats, of Freund's adjuvant with collagen type II on days 1 and 21. Hydroxytyrosol-supplemented refined olive oils were administrated by gavage from day 23 until day 35. The treatment at 5-mg/kg dose significantly decreased paw edema (P<.01), histological damage, cyclooxygenase-2 and inducible nitric oxide synthase expression, and markedly reduced the degree of bone resorption, soft tissue swelling and osteophyte formation, improving articular function in treated animals. Acute inflammation, induced by carrageenan, was also evaluated for hydroxytyrosol-supplemented refined olive oils at 0.5 and 5 mg/kg. Both doses significantly reduced paw edema (P<.001). Our results suggest that the supplementation of refined olive oil with hydroxytyrosol may be advantageous in rheumatoid arthritis with significant impact not only on chronic inflammation but also on acute inflammatory processes.
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Journal Article |
11 |
64 |
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Silva S, Filipe MI. Intestinal metaplasia and its variants in the gastric mucosa of Portuguese subjects: a comparative analysis of biopsy and gastrectomy material. Hum Pathol 1986; 17:988-95. [PMID: 3759069 DOI: 10.1016/s0046-8177(86)80082-x] [Citation(s) in RCA: 60] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The incidence and prevalence of intestinal metaplasia (IM) of three types were investigated in 1,041 endoscopic biopsy specimens collected from patients with gastric abnormalities in 1981 and 1982. Intestinal metaplasia was classified as type I (complete), type II (incomplete, sulfomucin-negative), or type III (incomplete, sulfomucin-positive). Intestinal metaplasia, found in 244 biopsy specimens (23%), was prevalent in gastric carcinoma (65%), compared with the incidence of 18.4 per cent in benign conditions. The sulfomucin-negative types I and II were more common than type III and were present in both benign conditions (98 per cent) and carcinoma (64 per cent). In contrast, type III IM was seen in only 12 per cent of IM-positive biopsy specimens, 90 per cent of which (26 of 29) were from patients with carcinoma. The high specificity of type III IM (98 per cent) might be acceptable for screening purposes, but its sensitivity of 36 per cent for gastric carcinoma is low. Two main factors would seem to account for the low sensitivity, as shown in the comparative analysis of IM types in gastrectomy specimens and the previous biopsy specimens from 93 patients: 1) sampling and 2) the association of type III IM with gastric carcinoma of the intestinal type but not with diffuse gastric carcinoma. The data thus confirm a significant relation between incomplete sulfomucin-secreting IM (type III) and gastric carcinoma of the intestinal type (P less than 0.001). This variant of IM should be considered a risk factor, and its presence in a biopsy specimen should prompt close surveillance.
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Comparative Study |
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Silva S, Costa EM, Mendes M, Morais RM, Calhau C, Pintado MM. Antimicrobial, antiadhesive and antibiofilm activity of an ethanolic, anthocyanin-rich blueberry extract purified by solid phase extraction. J Appl Microbiol 2016; 121:693-703. [PMID: 27349348 DOI: 10.1111/jam.13215] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2016] [Revised: 06/21/2016] [Accepted: 06/26/2016] [Indexed: 01/28/2023]
Abstract
AIMS The present work aimed to characterize the impact of an anthocyanin-rich blueberry extract upon the growth, adhesion and biofilm formation of several pathogens including some multiresistant bacteria. METHODS AND RESULTS A group comprised of reference strains and clinical multiresistant isolates of Pseudomonas aeruginosa, Escherichia coli, Proteus mirabilis, Acinetobacter baumannii and Staphylococcus aureus, were used to screen for antimicrobial activity. Microbial growth was determined through the measurement of the optical density while adhesion and biofilm formation was determined using the standard crystal violet staining procedure. The results showed that, while blueberry extract was only effective in hindering the growth of Staph. aureus and E. coli, it was capable of significantly inhibiting biofilm formation and bacterial adhesion for all micro-organisms tested. CONCLUSIONS The extract demonstrated a considerable potential as a natural, alternative antimicrobial capable of either interfering with microbial growth or hamper the adhesion to surfaces, with Staph. aureus proving to be the most susceptible micro-organism. SIGNIFICANCE AND IMPACT OF THE STUDY The overall study demonstrates the potential of anthocyanin extracts as natural effective alternative antimicrobial agents. Additionally, the extract's capacity to reduce adhesion without reducing bacterial growth reduces the likeliness of resistance development while reducing the probability of infection.
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Journal Article |
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54 |
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Robertson K, Fiscus S, Kapoor C, Robertson W, Schneider G, Shepard R, Howe L, Silva S, Hall C. CSF, plasma viral load and HIV associated dementia. J Neurovirol 1998; 4:90-4. [PMID: 9531015 DOI: 10.3109/13550289809113485] [Citation(s) in RCA: 52] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Plasma viral burden has proven valuable in predicting the future course of systemic HIV related disease and the response to treatment. It is not known whether plasma or cerebrospinal fluid (CSF) viral burden can be used to predict onset of or response to treatment of nervous system disease. We propose a model of viral load mediated neurotoxicity underlying peripheral and central HIV associated neurological disease. The objective of this preliminary study was to assess the relationship of HIV associated neurological disease to quantitative viral load in plasma and CSF. 47 subjects (HIV- = 10, HIV+ = 37) participated in the study. Plasma and CSF samples were collected within a 3 h window. RT-PCR (Roche Amplicor Monitor) was utilized to assess HIV-1 RNA viral load in both plasma and cell free (centrifuged) CSF. Subjects underwent concurrent comprehensive neurological and neuropsychological evaluations. In general, systemic viral load, as measured in plasma, was greater than that found in cell free CSF. Cell free CSF HIV RNA viral load was significantly correlated with neurological dysfunction, whereas plasma viral load was not. The sole subject with an elevated CSF viral load (> 5 Log 10), had HIV associated dementia (HAD) on clinical examination.
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Silva SV, Soares AT, Batista AM, Almeida FC, Nunes JF, Peixoto CA, Guerra MMP. In Vitro and In Vivo Evaluation of Ram Sperm Frozen in Tris Egg-yolk and Supplemented with Superoxide Dismutase and Reduced Glutathione. Reprod Domest Anim 2011; 46:874-81. [DOI: 10.1111/j.1439-0531.2011.01758.x] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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