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1.
Artigo em Inglês | MEDLINE | ID: mdl-38477149

RESUMO

OBJECTIVE: This study aimed to externally and prospectively validate the International Ovarian Tumor Analysis (IOTA) Simple Rules (SRs), Logistic Regression model 2 (LR2) and Assessment of Different NEoplasias in the adneXa (ADNEX) in a Portuguese population, comparing them with operator subjective assessment (SA), Risk-of-Malignancy Index (RMI), as well as with each other. This study also aimed to retrospectively validate IOTA two-step strategy, using modified benign descriptors (MBDs) followed by the application of ADNEX in cases where MBDs were not applicable (MBDs + ADNEX). METHODS: In this multicenter diagnostic accuracy study, conducted between January 2016 and December 2021, three tertiary referral centers prospectively included consecutive patients with ultrasound diagnosis of at least one adnexal tumor who underwent surgery. All ultrasound assessments were performed by level II or III sonologists with IOTA certification. Patient clinical data and serum cancer antigen (CA125) levels were collected from the hospital databases. Each adnexal mass was classified as benign or malignant using SA, RMI, IOTA SRs, LR2 and ADNEX (with and without CA125). The reference standard was histopathological diagnosis. In the second phase, all adnexal tumors were retrospectively classified using the two-step strategy (MBDs + ADNEX). The sensitivity, specificity, positive (PPV) and negative predictive value (NPV), positive (LR+) and negative likelihood ratio (LR-) as well as overall accuracy were determined for SA, RMI, IOTA SRs, LR2, ADNEX and two-step strategy (MBDs + ADNEX). Receiver-operator characteristic curves were constructed and corresponding areas under the curve (AUC) determined for RMI, LR2 and ADNEX and two-step strategy (MBDs + ADNEX). The ADNEX calibration plots were constructed and estimated by LOESS smoother. RESULTS: Of the 571 included patients, 428 had benign disease, 42 borderline ovarian tumors, 93 primary invasive adnexal cancers and 8 metastatic tumors in adnexa (malignancy prevalence: 25.0%). The operator SA had an overall sensitivity of 97.9% and a specificity of 83.6% for distinguishing between benign and malignant lesions. RMI showed high specificity (95.6%) but very low sensitivity (58.7%), with an AUC of 0.913. The IOTA SRs were applicable in 80.0% of patients, with a sensitivity of 94.8% and a specificity of 98.6%. LR2 revealed a sensitivity of 84.6%, a specificity of 86.9% and an AUC of 0.939, at the malignancy risk cut-off of 10%. At the same cut-off, ADNEX with and without CA125 had a sensitivity of 95.8% and 98.6%, respectively, and a specificity of 82.5% and 79.7%, respectively. The AUC of ADNEX with vs. without CA125 was 0.962 vs. 0.960. The ADNEX model provided heterogeneous results in distinguishing between benign and different subtypes of malignancy, with the highest AUC (0.991) for discriminating benign masses from primary adnexal cancer stage II-IV, and the lowest AUC (0.696) for distinguishing primary adnexal cancer stage I and metastatic lesion in adnexa. The ADNEX calibration plots suggested an underestimation of the predicted risk in relation with the observed proportion of malignancies. The MBDs were applicable in 26.3% of cases (150/571 tumors, none of which were malignant). Similar to the ADNEX model applied in all patients, the two-step strategy using ADNEX in the second step only, with and without CA125, had an AUC of 0.964 and 0.961, respectively. CONCLUSIONS: Our results showed a good to excellent performance of the IOTA methods in the studied Portuguese population, outperforming RMI. ADNEX was superior in accuracy, but interpretation of its ability to distinguish malignant subtypes was fundamentally limited not only by sample size but also by large differences in the prevalence of tumor subtypes. The IOTA MBDs have been shown to be reliable in identifying benign disease. The two-step strategy based on the application of MBDs, followed by the ADNEX model if MBDs are not applicable, has proven to be suitable for daily practice circumventing the need to use electronic support in all patients. This article is protected by copyright. All rights reserved.

2.
Acta Biotheor ; 64(4): 311-325, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27770317

RESUMO

This article is devoted to the characterization of the basin of attraction of pattern solutions for some slow-fast reaction-diffusion systems with a symmetric property and an underlying oscillatory reaction part. We characterize some subsets of initial conditions that prevent the dynamical system to evolve asymptotically toward solutions which are homogeneous in space. We also perform numerical simulations that illustrate theoretical results and give rise to symmetric and non-symmetric pattern solutions. We obtain these last solutions by choosing particular random initial conditions.


Assuntos
Simulação por Computador , Matemática , Modelos Teóricos , Análise Numérica Assistida por Computador , Difusão , Cinética
3.
Drug Alcohol Depend ; 223: 108706, 2021 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-33901753

RESUMO

BACKGROUND: Substance use-related stigma is a significant barrier to care among persons who use drugs (PWUD). Less is known regarding how intersectional identities, like gender, shape experiences of substance use-related stigma. We sought to answer the following question: Do men or women PWUD experience more drug use stigma? METHODS: Data were drawn from a systematic review of the global, peer-reviewed scientific literature on substance use-related stigma conducted through 2017 and guided by the Stigma and Substance Use Process Model and PRISMA guidelines. Articles were included in the present analysis if they either qualitatively illustrated themes related to the gendered nature of drug use-related stigma, or quantitatively tested the moderating effect of gender on drug use-related stigma. RESULTS: Of the 75 studies included, 40 (53 %) were quantitative and 35 (47 %) were qualitative. Of the quantitative articles, 22 (55 %) found no association between gender and drug use-related stigma, 4 (10 %) identified women who use drugs (WWUD) were more stigmatized, and 2 (5 %) determined men who use drugs (MWUD) were more stigmatized. In contrast, nearly all (34; 97 %) of the qualitative articles demonstrated WWUD experienced greater levels of drug use-related stigma. CONCLUSION: The quantitative literature is equivocal regarding the influence of gender on drug use-related stigma, but the qualitative literature more clearly demonstrates WWUD experience greater levels of stigma. The use of validated drug use-related stigma measures and the tailoring of stigma scales to WWUD are needed to understand the role of stigma in heightening the disproportionate harms experienced by WWUD.


Assuntos
Preparações Farmacêuticas , Transtornos Relacionados ao Uso de Substâncias , Feminino , Identidade de Gênero , Humanos , Masculino , Estigma Social , Transtornos Relacionados ao Uso de Substâncias/epidemiologia
4.
Ann Hum Biol ; 37(1): 86-107, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-19939195

RESUMO

BACKGROUND: Gene flow among human populations is generally interpreted in terms of complex patterns, with the observed gene frequencies being the consequence of the entire genetic and demographic histories of the population. AIMS: This study performs a high-resolution analysis of the Y-chromosome haplogroup E in Western Andalusians (Huelva province). The genetic information presented here provides new insights into migration processes that took place throughout the Mediterranean space and tries to evaluate its impact on the current genetic composition of the most southwestern population of Spain. SUBJECTS AND METHODS: 167 unrelated males were previously typed for the presence/absence of the Y-chromosome Alu polymorphism (YAP). The group of YAP (+) Andalusians was genotyped for 16 Y-SNPs and also characterized for 16 Y-STR loci. RESULTS: The distribution of E-M81 haplogroup, a Berber marker, was found at a frequency of 3% in our sample. The distribution of M81 frequencies in Iberia seems to be not concordant with the regions where Islamic rule was most intense and long-lasting. The study also showed that most of M78 derived allele (6.6%) led to the V13* subhaplogroup. We also found the most basal and rare paragroup M78* and others with V12 and V65 mutations. The lineage defined by M34 mutation, which is quite frequent in Jews, was detected as well. CONCLUSIONS: The haplogroup E among Western Andalusians revealed a complex admixture of genetic markers from the Mediterranean space, with interesting signatures of populations from the Middle East and the Balkan Peninsula and a surprisingly low influence by Berber populations compared to other areas of the Iberian Peninsula.


Assuntos
Cromossomos Humanos Y/genética , Genética Populacional , Haplótipos , Marcadores Genéticos , Humanos , Masculino , Polimorfismo de Nucleotídeo Único , Espanha/etnologia
5.
Ann Hum Genet ; 73(2): 184-95, 2009 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19133940

RESUMO

Inbreeding patterns over the past two centuries have been studied more extensively in Spain and Italy than anywhere else in Europe. Consanguinity studies in mainland Spain have shown that populations settled along the Cantabrian cornice share inbreeding patterns that distinguish them from other populations further south. A visual representation of spatial variations of two key inbreeding variables is presented here for the first time via contour maps. This paper also analyzes time trends of mean inbreeding coefficients for X-linked (F(x)) and autosomal genes (F) (1862-1995) together with variations in F(x)/F ratios in Guipúzcoa, the most autochthonous Spanish Basque province. Because close cousin marriages are a mark of identity of the study population, we evaluated the contribution of uncle-niece/aunt-nephew (M12) and first cousin (M22) marriages to F(x) and F values and compared the frequencies of M12 and M22 pedigree subtypes and their corresponding F(x)/F ratios to those found in other Spanish populations. The mean Fx and F inbreeding levels in Guipúzcoa for the 134-year period analyzed were 1.51 x 10(-3) and 1.04 x 10(-3), respectively, and the F(x)/F ratio was seen to be very stable over time. Our findings show that major similarities exist for close consanguineous marriage subtypes between Basque and non-Basque Spanish populations, despite significant geographic variability in terms of first cousin pedigrees. The distortion seems to be caused by Guipúzcoa. The F(x)/F ratios for first cousins in Spanish populations were higher than expected (1.25), with values ranging from 1.34 to 1.48. The findings of the present study may be useful for advancing knowledge on the effects of the interaction between biology and culture and for exploring associations between mating patterns and the prevalence of certain diseases.


Assuntos
Consanguinidade , Genes Ligados ao Cromossomo X , Genes , Genética Populacional , Cromossomos , Cultura , Feminino , Humanos , Masculino , Casamento , Espanha
6.
Math Biosci ; 295: 48-54, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-29104133

RESUMO

Geometrical Singular Perturbation Theory has been successful to investigate a broad range of biological problems with different time scales. The aim of this paper is to apply this theory to a predator-prey model of modified Leslie-Gower type for which we consider that prey reproduces mush faster than predator. This naturally leads to introduce a small parameter ϵ which gives rise to a slow-fast system. This system has a special folded singularity which has not been analyzed in the classical work [15]. We use the blow-up technique to visualize the behavior near this fold point P. Outside of this region the dynamics are given by classical regular and singular perturbation theory. This allows to quantify geometrically the attractive limit-cycle with an error of O(ϵ) and shows that it exhibits the canard phenomenon while crossing P.


Assuntos
Modelos Biológicos , Comportamento Predatório , Animais , Cadeia Alimentar , Conceitos Matemáticos , Dinâmica Populacional
8.
Hum Biol ; 78(6): 663-79, 2006 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-17564246

RESUMO

An understanding of population relationships in the Mediterranean region is crucial to the reconstruction of recent human evolution. Andalusia, the most southern region of Spain, has been continuously and densely occupied since ancient times and has a rich history of contacts with many different Mediterranean populations. Thus, to understand the Mediterranean peopling process, investigators should analyze the population relationships between the Iberian peninsula and northern Africa based on an assessment of genetic diversity that takes Andalusia into consideration. The aim of this study was to address the extent of genetic variation in the Iberian peninsula between its geographic extremes (Huelva and the Basque area) and to explain the intensity of the phylogenetic relationships between Andalusians and other neighboring populations, such as those from North Africa. We present, for the first time, results on allotype markers (GM and KM) of human immunoglobulins in the Andalusian population from Huelva. The most frequent GM haplotypes in Andalusia correspond to those that are also the most common in Europe. A sub-Saharan haplotype was found at a relatively high frequency compared to other Iberian samples, and a North Asian marker did not reach polymorphic frequencies in the study sample. A hierarchical cluster analysis based on the first two principal components (94.1% of the total genetic variance) revealed an interesting geographic structure for the 49 populations selected from the literature. The Huelva sample showed a central position in the multivariate space--despite being geographically located at one of the extremes of the Mediterranean basin--and clustered with most Western European populations. Western Europe and Eastern Europe (the latter group paradoxically including Italy and the major islands of the western Mediterranean) were differentiated. North African populations were grouped in two clusters that did not separate either Arabs and Berbers or their present-day countries. Analysis of immunoglobulin allotype markers shows that gene flow among human populations should generally be interpreted in terms of complex patterns, with the observed frequencies being the consequence of the entire genetic and demographic history of the population. Single historical events rarely determine gene frequencies in large human populations. Analysis of the GM system has shown that the Andalusian population from Huelva, as a result of its complex history, is not simply an outstanding part of the Mediterranean world but rather the genetic center of gravity of that world.


Assuntos
Frequência do Gene , Variação Genética/genética , Genética Populacional/estatística & dados numéricos , Alótipos Gm de Imunoglobulina/genética , Alótipos Km de Imunoglobulina/genética , África do Norte , População Negra , Análise por Conglomerados , Marcadores Genéticos , Geografia , Humanos , Imunoglobulinas/genética , Região do Mediterrâneo , Fenótipo , Filogenia , Polimorfismo Genético , Espanha , População Branca
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