95 research outputs found
Técnicas de biopsia para el diagnóstico de lesiones mamarias no palpables
Facing a non-palpable mammary lesion requiring a diagnostic biopsy, consideration must be given to the most suitable guiding method for obtaining the latter. Three methods are employed at present: stereotaxy (basically in cases of microcalcifications), echography (above all in the nodules), and magnetic resonance (for lesions not made visible through the previous systems). The next step is to select the most suitable biopsy technique. The most classical and reliable technique is the surgical biopsy with prior marking using a metallic harpoon, but, besides its high cost, it has the drawback of being an aggressive technique for the diagnosis of a benign pathology. Numerous systems of puncture have been developed as alternatives. Puncture with a fine needle is technically simple to carry out and can provide good results in the mammary nodules, but the existence of positive and negative false results has progressively limited its use. As an alternative, the systems of biopsy with a broad needle have made it possible to obtain multiple cylinders with a high diagnostic reliability, above all in the case of mammary nodules. However, their use in microcalcifications continues to show negative false results. The arrival of systems of vacuum-assisted biopsy has made it possible to obtain cylinders of greater quality, above all in cases of microcalcifications. Finally, the systems of percutaneous resection biopsy by means of cannulas with a diameter of 22 mm make it possible to completely extract lesions of a size below that of the cannula, with a reliability similar to that of the surgical biopsy
Modular multilevel converter in electrified railway systems: applications of rail static frequency converters and rail power conditioners
The Modular Multilevel Converter (MMC) has become the most preferable multilevel converter topology for medium and high-power systems, due to the MMC's high reliability and redundancy. This paper focuses on MMC applications in electrified railway traction grids, namely, applications of rail static frequency converters and rail power conditioners. These applications provide a higher railway traction grid capacity and improve the power quality of the three-phase power grid. Simulation results of a case study are presented to show the features when using the MMC in electrified railway grids.This work has been supported by the Portuguese Foundation of Science and Technology (FCT), within the R&D Units Project Scope: UIDB/00319/2020 and PTDC/EEIEEE/28813/2017. The first author Mohamed Tanta is supported by FCT Ph.D. grant with a reference PD/BD/127815/2016
Evaluación de la mama contralateral mediante resonancia magnética en pacientes con diagnóstico reciente de cáncer mamario unilateral
Breast Magnetic Resonance (BMR) imaging is a useful tool in the evaluation of breast cancer before surgical treatment. BMR imaging plays an important role in the evaluation of the extension of the malignant lesions, and the study of multifocality and multicentricity. BMR may have a role in the detection of synchronous contralateral breast cancer that is occult to conventional imaging methods (mammography and ultrasonography). In this study we review 13 series of different authors in which they have used BMR in the evaluation of the contralateral breast in patients with newly diagnosed breast cancer. Two thousand five hundred and eleven patients were evaluated with BMR and 123 contralateral cancers, that were occult to conventional methods, were detected with this technique (4,9 %). Therefore, BMR imaging of the breast is useful as a complementary tool because of its high sensitivity in local staging of a breast cancer and its ability in the detection of synchronous contralateral breast cancer in patients with newly diagnosed breast cance
Axillary lymph node imaging in mRNA, vector-based, and mix-and-match COVID-19 vaccine recipients: ultrasound features
Objectives To assess ultrasound characteristics of ipsilateral axillary lymph nodes after two doses of four different COVID-19
vaccination protocols, to determine whether these parameters differed with age, and to describe how they changed on follow-up
imaging.
Methods A total of 247 volunteer employees from our center who had received two doses of COVID-19 vaccination were
recruited and followed prospectively. Axillary ultrasound of the ipsilateral vaccinated arm was performed the week after
receiving the second dose to analyze lymph node features (number, long-axis, cortical thickness, morphology, and vascular
imaging). Axillary lymphadenopathy resulting from four vaccination protocols—mRNA (BNT162b2, mRNA-1273),
ChAdOx1-S, and mix-and-match—was compared. Analysis was conducted using the Kruskal-Wallis test and post hoc analysis
with Bonferroni corrections. Nodal reactogenicity was evaluated for two age groups: young (< 45 years old) and middle-aged ( ≥
45 years old). All parameters were compared between both groups using an unpaired-sample Student t test. A p value < 0.05 was
considered statistically significant.
Results Significantly higher values for total number of visible nodes, cortical thickness, Bedi’s classification (p < 0.001), and
vascularity (p < 0.05) were observed in mRNA vaccine recipients compared to full ChAdOx1-S protocol recipients. Moreover,
mix-and-match protocol recipients showed greater nodal cortical thickness and higher Bedi’s classification than full ChAdOx1-S
recipients (p < 0.001). Analyses between age groups revealed greater cortical thickness, Bedi’s classification, and color Doppler
signal in younger patients (p < 0.05).
Conclusions Nodal parameters of Bedi’s classification and cortical thickness were more often increased in mRNA and mix-andmatch vaccine recipients when compared to ChAdOx1-S vaccine alone, especially in younger patients.
Key Points
• Hyperplastic lymphadenopathy was observed more frequently in mRNA and mix-and-match vaccine protocols compared to full
vector-based vaccination.
• Higher values for cortical thickness, Bedi’s classification, and color Doppler signal parameters were identified in younger
patients.
• Observed lymph node findings normalized in greater than 80% of patients by the third month following vaccination
Cáncer de mama durante el embarazo
As women in western countries delay childbearing, it has been hypothesized that the incidence of breast cancer diagnosed during pregnancy will increase. Breast carcinoma during pregnancy(BCP) put the health of the mother in conflict with that of the fetus. The aim is to give optimal treatment to the mother to maximise the chances of survival, whilst minimising the risk of harm of the fetus. Few breast surgeons or oncologist develop expertise in this area owing the rarity of the association. We report the epidemiology, pathology, clinical picture, therapeutic management and fetal outcome of pregnant women with breast cancer treated in our institutio
Técnicas de imagen para la valoración del estado ganglionar axilar en el cáncer de mama
The axillary lymph node status is the most important prognostic factor in breast cancer, and the axillary dissection as the gold standar for staging. It requires radical surgery, which is accompanied by importants postoperaive problems. Axillary lymph nodes can be imaged with a wide variety of available diagnostic radiological test (ultrasonography, mammography, computed tomography and magnetic resonance imaging). In these anatomic imaging, the limph nodes whit metastatic disease appear dense, enlarged or spiculated. Difficulties arise, not in visualization of the axillary lymph nodes, but in reliably separating normal from those involved with metastatic disease. Radionucleide studies and positron emisión tomography provide biochemical information, but are limited by resolution constrains
Metabolic Footprint, towards Understanding Type 2 Diabetes beyond Glycemia
Type 2 diabetes (T2D) heterogeneity is a major determinant of complications risk and treatment response. Using cluster analysis, we aimed to stratify glycemia within metabolic multidimensionality and extract pathophysiological insights out of metabolic profiling. We performed a cluster analysis to stratify 974 subjects (PREVADIAB2 cohort) with normoglycemia, prediabetes, or non-treated diabetes. The algorithm was informed by age, anthropometry, and metabolic milieu (glucose, insulin, C-peptide, and free fatty acid (FFA) levels during the oral glucose tolerance test OGTT). For cluster profiling, we additionally used indexes of metabolism mechanisms (e.g., tissue-specific insulin resistance, insulin clearance, and insulin secretion), non-alcoholic fatty liver disease (NAFLD), and glomerular filtration rate (GFR). We found prominent heterogeneity within two optimal clusters, mainly representing normometabolism (Cluster-I) or insulin resistance and NAFLD (Cluster-II), at higher granularity. This was illustrated by sub-clusters showing similar NAFLD prevalence but differentiated by glycemia, FFA, and GFR (Cluster-II). Sub-clusters with similar glycemia and FFA showed dissimilar insulin clearance and secretion (Cluster-I). This work reveals that T2D heterogeneity can be captured by a thorough metabolic milieu and mechanisms profiling-metabolic footprint. It is expected that deeper phenotyping and increased pathophysiology knowledge will allow to identify subject's multidimensional profile, predict their progression, and treat them towards precision medicine.publishersversionpublishe
Computer-Based Training in Math and Working Memory Improves Cognitive Skills and Academic Achievement in Primary School Children:Behavioral Results
Student academic achievement has been positively related to further development outcomes, such as the attainment of higher educational, employment, and socioeconomic aspirations. Among all the academic competences, mathematics has been identified as an essential skill in the field of international leadership as well as for those seeking positions in disciplines related to science, technology, and engineering. Given its positive consequences, studies have designed trainings to enhance children's mathematical skills. Additionally, the ability to regulate and control actions and cognitions, i.e., executive functions (EF), has been associated with school success, which has resulted in a strong effort to develop EF training programs to improve students' EF and academic achievement. The present study examined the efficacy of a school computer-based training composed of two components, namely, working memory and mathematics tasks. Among the advantages of using a computer-based training program is the ease with which it can be implemented in school settings and the ease by which the difficulty of the tasks can be adapted to fit the child's ability level. To test the effects of the training, children's cognitive skills (EF and IQ) and their school achievement (math and language grades and abilities) were evaluated. The results revealed a significant improvement in cognitive skills, such as non-verbal IQ and inhibition, and better school performance in math and reading among the children who participated in the training compared to those children who did not. Most of the improvements were related to training on WM tasks. These findings confirmed the efficacy of a computer-based training that combined WM and mathematics activities as part of the school routines based on the training's impact on children's academic competences and cognitive skills
Tratamiento conservador del cáncer de mama: valoración de los resultados
Introducción: La asociación de cirugía limitada y radioterapia es el tratamiento de elección para un gran número de mujeres con cáncer de mama; no obstante esta opción terapéutica va asociada a un número no despreciable de recidivas sobre la mama tratada (1-1,5% por año de seguimiento).
Material y Métodos: Se analizan 641 casos de mujeres con cáncer de mama, tratados mediante cirugía conservadora de la mama y radioterapia y seguidos durante una media de 50 meses.
La técnica consistió preferentemente en la practica de una Resección Segmentaria de mama con vaciamiento axilar, al menos de los niveles I y II (excepto en los CIS a partir de 1997), complementada con la administración de Radioterapia (45-50 Gy sobre la mama y una sobreimpresión de 15-20 Gy).
Resultados: La edad media fue de 52.3 años, con extremos en 21 y 82 años El tamaño medio tumoral fue pT: 1,7 cm y el 63,1% de los casos correspondieron a tumores pT1. En 41 casos no se realizó vaciamiento axilar (35 CIS y 6 pT1mic). En 4 casos existió afectación puntual de bordes (componente intraductal) que fueron sometidos a sobreimpresión radioterápica con 20Gy.
Tras un seguimiento medio de 50 meses, el 91,4% están libres de enfermedad y en 12 casos (1,9%) se desconocía su estado. Se han producido 13 recidivas (2%) a nivel mamario (2 de ellas en un cuadrante distinto).
Conclusiones: El estado de los bordes de resección en un factor fundamental en la cirugía conservadora del cáncer de mama. La resección del tumor debe ser suficientemente amplia e incluir el segmento mamario asiento del tumor, para asegurar un alto índice de control local, sin comprometer el resultado cosmético. El estudio histológico de los bordes de resección permite reducir significativamente la necesidad de una segunda cirugía.Introduction: Conservative surgery combined with radiotherapy is an effective treatment in many cases of breast cancer. Nevertheless this therapy is associated with a not inconsiderable number of recurrences in the remaining breast after excision (1-1.5% recurrences per year of follow-up).
Material and Methods: We reviewed 641 cases of breast cancer (age average was 52.3 years (21-82) and tumour size average 1.7 cm, 3% corresponded to pT1 tumours) treated with conservative surgery combined with radiotherapy, average follow-up of 50 months.
The technique consisted of segmentectomy and at least level I-II axilary dissection (excluding in situ carcinoma diagnosed since 1997, in which lymphadenectomy was not performed). Adjuvant radiotherapy was also indicated (giving a dose of 45-50 Gy to the breast, and another 15-20 Gy dose was given to tumour size).
Results: In 41 cases lymphadenectomy was not performed (35 cases of Tis, and 6 pTmic). In 4 cases, 20 Gy radiotherapy was administered to the tumour excision site because of in situ carcinoma disease in the margins.
During follow-up of 50 months, 91.4% of the patients were disease- free; in 12 cases we are not informed of the present status. 13 recurrences (2%) have been found, two of which were in a different quadrant.
Conclusions: The status of the surgical margins is an important factor in the practice of conservative surgery. Tumour excision must be broad enough and must include the whole segment in which the tumour is located to obtain local control of the disease, maintaining an acceptable cosmetic appearance. The intraoperative study of specimen margins permits the reduction of cases in which a second operation is needed
Modification of the activity of an \u3b1-amylase from Bacillus licheniformis by several surfactants
The influence of different commercial surfactants on the enzymatic
activity of a commercial \u3b1-amylase from Bacillus licheniformis
(Termamyl 300 L) has been studied. As non-ionic surfactants, alkyl
polyglycosides (Glucopon\uae 215, Glucopon\uae 600 and
Glucopon\uae 650) were studied, as were fatty alcohol ethoxylates
(Findet 1214N/23 and Findet 10/15), and nonyl phenol ethoxylate (Findet
9Q/21.5NF). Also, an anionic surfactant, linear alkyl benzene sulfonate
(LAS) was assayed. In general, none of the non-ionic surfactants
studied, except Findet 10/15, vary substantially the enzymatic
activity. Findet 10/15 has the strongest hydrophobic character and
reduces the enzymatic activity more significantly the greater its
concentration. Regarding LAS, this surfactant significantly depressed
enzymatic activity, presumably due to the electrostatic interactions
caused by its anionic character
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