1,721,192 research outputs found
A narrative review of genetic alterations in primary thyroid epithelial cancer
No full textThyroid carcinoma is the most frequent endocrine neoplasia. Different types of thyroid carcinoma are described: well-differentiated papillary thyroid carcinoma (PTC), poorly differentiated thyroid carcinoma (PDTC), follicular thyroid carcinoma (FTC), anaplastic thyroid carcinoma (ATC), and medullary thyroid carcinoma (MTC). MTC is inherited as an autosomal dominant trait in 25% of cases. The genetic landscape of thyroid carcinoma has been largely deciphered. In PTC, genetic alterations have been found in about 95% of tumors: BRAF mutations and RET rearrangements are the main genetic alterations. BRAF and RAS mutations have been confirmed to play an important role also in PDTC and ATC, together with TP53 mutations that are fundamental in tumor progression. It has also been clearly demonstrated that telomerase reverse transcriptase (TERT) promoter mutations and TP53 mutations are present with a high-frequency in more advanced tumors, frequently associated with other mutations, and their presence, especially if simultaneous, is a signature of aggressiveness. In MTC, next-generation sequencing confirmed that mutations in the RET gene are the most common molecular events followed by H-RAS and K-RAS mutations. The comprehensive knowledge of the genetic events responsible for thyroid tumorigenesis is important to better predict the biological behavior and better plan the therapeutic strategy for specific treatment of the malignancy based on its molecular profile
Power supply noise and immunity
No full textAn electronic transformer used to supply
low-voltage halogen lamps, was designed
by means of an HSPICE simulator.
The same simulator was used to predict
conducted emission and susceptibility
in order to verify the compliance with
VDE 0875 and IEC 801-5 regulations.
With respect to the other method based
on the equivalent noise generator, the
proposed technique allows a more accurate
prediction. This method also allows a
real-time checking of the effects that the
inserted filtering and protection
devices produce on the functional
behavior of the SMPS
Papillary thyroid microcarcinoma: Toward an active surveillance strategy
No full textIn the last decades, the incidence of thyroid cancer (TC) has m ore than doubled, but the disease-specific mortality rate was stable. To date, 30-40% of all TC is represented by papilla ry microcarcinomas (mPTC), an indolent tumor, that probably remained undiagnosed before routine ultrasound use. In 1993, Miyauchi was the first who hypothesized a conservative approach for low-risk mPTC and introduced the co ncept of active surveillance (AS) in its clinical management. The progression rate of mPTC during AS was low and delaying surgery did not impact the efficacy of treatment or outcome. Since then, several authors from all over the world have reported their experience of AS in mPTCs. As suggested by current guidelines, AS can be considered as an alternative to immediate surgery to avoid overtreatment in low-risk mPTC and may be the strategy to avoid complications from unnecessary surgery. In the last years, AS inclusion criteria have been extended to both bigger tumors and to younger/healthier patients. The adoption of AS should take into consideration not only tumor characteris tics but also patient psychological profiles and medical team expertise. Its safety and efficacy have been demonstrated in long-term outcome studies and in other types of tumors; however, skepticism in patients, families and physician s should be overcome by strong recommendations coming from scientific guidelines. This review analyses the seve ral and different experiences of AS and the potential obstacles in implementing it as a routine approach in mPTC pati ents
Characterization of three winding transformers for the reduction of switching mode power supply conducted emission
No full textThe paper focuses the attention on the modelling of transformers for the prediction of conducted emissions from SMPS. The transformer equivalent circuit component values are extracted by impedance measurements with proper load conditions. Beside a traditional two-winding transformer, also a three winding version is analysed: the third winding is used to realize a shield, in order to reduce the conducted emission. This is a quick and cheap way to realise the shield, without appreciably increase the production time. Finally, the simulation of a flyback SMPS, allows to evaluate the benefits obtained in using the shielded transformer. All simulations are experimentally validated showing a satisfactory agreement
Sporadic Medullary Thyroid Carcinoma: Towards a Precision Medicine
No full textMedullary thyroid carcinoma (MTC) is a neuroendocrine malignant tumor originating from parafollicular C-cells producing calcitonin. Most of cases (75%) are sporadic while the remaining (25%) are hereditary. In these latter cases medullary thyroid carcinoma can be associated (multiple endocrine neoplasia type IIA and IIB) or not (familial medullary thyroid carcinoma), with other endocrine diseases such as pheochromocytoma and/or hyperparathyroidism. RET gene point mutation is the main molecular alteration involved in MTC tumorigenesis, both in sporadic and in hereditary cases. Total thyroidectomy with prophylactic/therapeutic central compartment lymph nodes dissection is the initial treatment of choice. Further treatments are needed according to tumor burden and rate of progression. Surgical treatments and local therapies are advocated in the case of single or few local or distant metastasis and slow rate of progression. Conversely, systemic treatments should be initiated in cases with large metastatic and rapidly progressive disease. In this review, we discuss the details of systemic treatments in advanced and metastatic sporadic MTC, focusing on multikinase inhibitors, both those already used in clinical practice and under investigation, and on emerging treatments such as highly selective RET inhibitors and radionuclide therapy
Cabozantinib: An orphan drug for thyroid cancer
No full textIntroduction: Until recently, no therapeutic options were available for the treatment of advanced medullary thyroid cancer (MTC). Cabozantinib (XL184) is a novel tyrosine kinase inhibitor (TKI) that inhibits several tyrosine kinase receptors, in particular those coded by MET, VEGFR-2 and RET oncogenes that are considered to be involved in the pathogenesis of MTC.Areas covered: This article provides an overview of the phase I and III trials that demonstrated the efficacy of cabozantinib in two cohorts of advanced MTC patients who were naà ̄ve or previously treated with other TKIs. The benefits in terms of progression-free survival (PFS), overall survival (OS) and the demographic clinical and mutational status of the two cohorts of MTC patients are reported and discussed.Expert opinion: The possibility to have a therapeutic option for the treatment of patients with advanced and progressive MTC and, in particular, the evidence that the drug can be active also in those patients who already experienced disease progression while taking another TKI is a great opportunity as demonstrated in cases treated with cabozantinib after vandetanib such as the one reported in this paper
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Significant response of medullary thyroid cancer choroidal metastases to highly selective RET inhibitor selpercatinib: a case report
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