303 research outputs found

    Bisphosphonate-associated jaws osteonecrosis: an important complication of oncology treatment

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    Os bisfosfonatos são um grupo de medicamentos utilizados no tratamento de doenças malignas metastáticas e em outras doenças ósseas como osteoporose e doença de Paget. A despeito dos seus benefícios, uma importante complicação denominada de osteonecrose dos maxilares vem sendo observada nos pacientes usuários crônicos dos bisfosfonatos que se caracteriza clinicamente por exposições ósseas na região maxilofacial persistente, acompanhadas de osteomielite, geralmente sintomáticas e cujo tratamento é complexo. Este estudo tem por objetivo revisar a literatura sobre a osteonecrose associada ao uso dos bisfosfonatos, em especial, em oncologia, no período de 2003 a 2008. Serão apresentados e discutidos os fatores de risco, aspectos etiopatogênicos, clínicos, imagenológicos, terapêuticos e preventivos desta doença. Devido à dificuldade de tratamento da osteonecrose associada aos bisfosfonatos, o foco deve ser a prevenção, sendo o ideal a eliminação de quadros infecciosos orais antes da terapia com os bisfosfonatos ter sido iniciada e minimizar traumas em boca após o uso destes medicamentos.Bisphosphonates are drugs used in the treatment of malignant metastatic diseases and in other bone lesions such as osteoporosis and Paget´s disease. Besides their benefits, jaw osteonecrosis, an important side effect, has been observed in long-term users of these drugs. Jaw osteonecrosis is clinically characterized by prolonged maxillary and mandible bone exposure accompanied by osteomyelitis. These lesions are usually symptomatic and difficult to treat. This study has the objective of reviewing publications from 2003 to 2008 about bisphosphonate-associated jaw osteonecrosis, in particular in relation to oncology. Risk factors, and etiopathological, clinical, radiographic, therapeutic, and preventive aspects of this condition are presented and discussed. Due to the difficulty to treat this disease, the focus must be prevention, with the ideal therapy being the elimination of oral infections before treatment with bisphosphonates is initiated thereby attempting to minimize possible traumas to the mouth with the use of these medications

    Monophasic and Biphasic Electrical Stimulation Induces a Precardiac Differentiation in Progenitor Cells Isolated from Human Heart

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    Electrical stimulation (ES) of cells has been shown to induce a variety of responses, such as cytoskeleton rearrangements, migration, proliferation, and differentiation. In this study, we have investigated whether monophasic and biphasic pulsed ES could exert any effect on the proliferation and differentiation of human cardiac progenitor cells (hCPCs) isolated from human heart fragments. Cells were cultured under continuous exposure to monophasic or biphasic ES with fixed cycles for 1 or 3 days. Results indicate that neither stimulation protocol affected cell viability, while the cell shape became more elongated and reoriented more perpendicular to the electric field direction. Moreover, the biphasic ES clearly induced the upregulation of early cardiac transcription factors, MEF2D, GATA-4, and Nkx2.5, as well as the de novo expression of the late cardiac sarcomeric proteins, troponin T, cardiac alpha actinin, and SERCA 2a. Both treatments increased the expression of connexin 43 and its relocation to the cell membrane, but biphasic ES was faster and more effective. Finally, when hCPCs were exposed to both monophasic and biphasic ES, they expressed de novo the mRNA of the voltage-dependent calcium channel Cav 3.1(α(1G)) subunit, which is peculiar of the developing heart. Taken together, these results show that ES alone is able to set the conditions for early differentiation of adult hCPCs toward a cardiac phenotype

    Schwartz - Zippelov teorem i neke njegove primjene

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    U ovom radu izložen je rezultat poznat pod nazivom Schwartz - Zippelova lema ili Schwartz - Zippelov teorem. Tema rada pripada pretežno algebri, ali ima značajne primjene u drugim matematičkim područjima kao što je na primjer teorija algoritama, te kombinatorika. Rad se sastoji od tri poglavlja. U uvodu je ukratko opisana tema i cilj rada. Prvo poglavlje sadrži kratku povijest nastanka teorema, različite oblike rezultata pojedinih autora, te kratki opis pojmova korištenih u samom radu. Drugo poglavlje sastoji se od iskaza i dokaza Schwartz - Zippelovog teorema, a u trećem poglavlju izložene su neke primjene tog teorema na probleme koji se mogu svesti na testiranje jednakosti polinoma. Takvi su, primjerice, problem postojanja savršenog sparivanja u grafu i ispitivanje svojstva asocijativnosti u grupoidu. Uz svaku primjenu navedeni su i prikladni primjeri.In this diploma thesis we present the result usually called the Schwartz-Zippel lemma or the Schwartz-Zippel theorem. The nature of this theorem is basically algebraic, but it has significant applications in other areas of mathematics, such as the theory of algorithms and combinatorial theory. The thesis consists of three chapters. The main theme and objective are briefly described in the introduction. The first chapter contains a short history of the theorem’s origins, various forms of the main results by different authors and some comments of basic concepts related to this topic. The statement and a proof of the Schwartz-Zippel theorem are given in the second chapter, together with the general outline of its applications. The third and final chapter consists of some applications to problems which can be reduced to polynomial identity testing, including the existence of a perfect matching in a graph and testing of the associativity property in a groupoi

    Hyponatremia influences the outcome of patients with acute-on-chronic liver failure: an analysis of the CANONIC study

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    INTRODUCTION: Hyponatremia is a marker of poor prognosis in patients with cirrhosis. This analysis aimed to assess if hyponatremia also has prognostic value in patients with acute-on-chronic liver failure (ACLF), a syndrome characterized by acute decompensation of cirrhosis, organ failure(s) and high short-term mortality. METHODS: We performed an analysis of the Chronic Liver Failure Consortium CANONIC database in 1,341 consecutive patients admitted to 29 European centers with acute decompensation of cirrhosis (including ascites, gastrointestinal bleeding, hepatic encephalopathy, or bacterial infections, or any combination of these), both with and without associated ACLF (301 and 1,040 respectively). RESULTS: Of the 301 patients with ACLF, 24.3% had hyponatremia at inclusion compared to 12.3% of 1,040 patients without ACLF (P <0.001). Model for end-stage liver disease, Child-Pugh and chronic liver failure-SOFA scores were significantly higher in patients with ACLF and hyponatremia compared to those without hyponatremia. The presence of hyponatremia (at inclusion or during hospitalization) was a predictive factor of survival both in patients with and without ACLF. The presence of hyponatremia and ACLF was found to have an independent effect on 90-day survival after adjusting for the potential confounders. Hyponatremia in non-ACLF patients nearly doubled the risk (hazard ratio (HR) 1.81 (1.33 to 2.47)) of dying at 90 days. However, when considering patients with both factors (ACLF and hyponatremia) the relative risk of dying at 90 days was significantly higher (HR 6.85 (3.85 to 12.19) than for patients without both factors. Patients with hyponatremia and ACLF had a three-month transplant-free survival of only 35.8% compared to 58.7% in those with ACLF without hyponatremia (P <0.001). CONCLUSIONS: The presence of hyponatremia is an independent predictive factor of survival in patients with ACLF. In cirrhosis, outcome of patients with ACLF is dependent on its association with hyponatremia

    Photo-induced second-order nonlinearity in stoichiometric silicon nitride waveguides

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    We report the observation of second-harmonic generation in stoichiometric silicon nitride waveguides grown via low-pressure chemical vapour deposition. Quasi-rectangular waveguides with a large cross section were used, with a height of 1 {\mu}m and various different widths, from 0.6 to 1.2 {\mu}m, and with various lengths from 22 to 74 mm. Using a mode-locked laser delivering 6-ps pulses at 1064 nm wavelength with a repetition rate of 20 MHz, 15% of the incoming power was coupled through the waveguide, making maximum average powers of up to 15 mW available in the waveguide. Second-harmonic output was observed with a delay of minutes to several hours after the initial turn-on of pump radiation, showing a fast growth rate between 104^{-4} to 102^{-2} s1^{-1}, with the shortest delay and highest growth rate at the highest input power. After this first, initial build-up, the second-harmonic became generated instantly with each new turn-on of the pump laser power. Phase matching was found to be present independent of the used waveguide width, although the latter changes the fundamental and second-harmonic phase velocities. We address the presence of a second-order nonlinearity and phase matching, involving an initial, power-dependent build-up, to the coherent photogalvanic effect. The effect, via the third-order nonlinearity and multiphoton absorption leads to a spatially patterned charge separation, which generates a spatially periodic, semi-permanent, DC-field-induced second-order susceptibility with a period that is appropriate for quasi-phase matching. The maximum measured second-harmonic conversion efficiency amounts to 0.4% in a waveguide with 0.9 x 1 {\mu}m2^2 cross section and 36 mm length, corresponding to 53 {\mu}W at 532 nm with 13 mW of IR input coupled into the waveguide. The according χ(2)\chi^{(2)} amounts to 3.7 pm/V, as retrieved from the measured conversion efficiency.Comment: 20 pages, 10 figure

    Isolated Third Cranial Nerve Palsy Leading to the Diagnosis of Disseminated Burkitt Lymphoma: A Case Report and Literature Review

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    Dysfunction of the third cranial nerve can result from lesions anywhere along its course between the midbrain and the orbit. Lymphoma is a rare cause of isolated oculomotor nerve palsy (OMP), with only 19 cases reported in the literature. We describe a case of an isolated OMP leading to the diagnosis of disseminated Burkitt lymphoma (BL)

    Prevalence of thyroid dysfunction in patients with diabetes mellitus

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    BACKGROUND: Diabetes mellitus (DM) and thyroid dysfunction (TD) are the two most common endocrine disorders in clinical practice. The unrecognized TD may adversely affect the metabolic control and add more risk to an already predisposing scenario for cardiovascular diseases. The objective of this study was to investigate the prevalence of TD in patients with type 1 and type 2 diabetes mellitus (T1DM and T2DM). METHODS: This is an observational cross-sectional study. Three hundred eighty-six (386) patients with T1DM or T2DM that regularly attended the outpatient clinic of the Diabetes unit, Hospital Universitário Pedro Ernesto, participated in the study. All patients underwent a clinical and laboratory evaluation. Thyroid dysfunction was classified as clinical hypothyroidism (C-Hypo) if TSH > 4.20 μUI/mL and FT4 < 0.93 ng/dL; Subclinical hypothyroidism (SC-Hypo) if TSH > 4.20 μUI/ml and FT4 ranged from 0.93 to 1.7 ng/dL; Subclinical hyperthyroidism (SC-Hyper) if TSH < 0.27 μUI/ml and FT4 in the normal range (0.93 and 1.7 ng/dL) and Clinical hyperthyroidism (C-Hyper) if TSH < 0.27 μUI/ml and FT4 > 1.7 μUI/mL. Autoimmunity were diagnosed when anti-TPO levels were greater than 34 IU/mL. The positive autoimmunity was not considered as a criterion of thyroid dysfunction. RESULTS: The prevalence of TD in all diabetic patients was 14,7%. In patients who had not or denied prior TD the frequency of TD was 13%. The most frequently TD was subclinical hypothyroidism, in 13% of patients with T1DM and in 12% of patients with T2DM. The prevalence of anti-TPO antibodies was 10.8%. Forty-four (11.2%) new cases of TD were diagnosed during the clinical evaluation. The forty-nine patients with prior TD, 50% with T1DM and 76% with T2DM were with normal TSH levels. CONCLUSIONS: We conclude that screening for thyroid disease among patients with diabetes mellitus should be routinely performed considering the prevalence of new cases diagnosed and the possible aggravation the classical risk factors such as hypertension and dyslipidemia, arising from an undiagnosed thyroid dysfunction

    MoD Tools: regulatory motif discovery in nucleotide sequences from co-regulated or homologous genes

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    Understanding the complex mechanisms regulating gene expression at the transcriptional and post-transcriptional levels is one of the greatest challenges of the post-genomic era. The MoD (MOtif Discovery) Tools web server comprises a set of tools for the discovery of novel conserved sequence and structure motifs in nucleotide sequences, motifs that in turn are good candidates for regulatory activity. The server includes the following programs: Weeder, for the discovery of conserved transcription factor binding sites (TFBSs) in nucleotide sequences from co-regulated genes; WeederH, for the discovery of conserved TFBSs and distal regulatory modules in sequences from homologous genes; RNAProfile, for the discovery of conserved secondary structure motifs in unaligned RNA sequences whose secondary structure is not known. In this way, a given gene can be compared with other co-regulated genes or with its homologs, or its mRNA can be analyzed for conserved motifs regulating its post-transcriptional fate. The web server thus provides researchers with different strategies and methods to investigate the regulation of gene expression, at both the transcriptional and post-transcriptional levels. Available at and

    Analyzing immune cell infiltration of cancer spheroids in a 3D cell culture platform

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    The adoption of in vitro 3D cell culture models as a bridge between conventional 2D cell culture models and the complex in vivo animal models has been increasing. A carefully designed 3D model can run biological assays with animal model-like complexities but with the simplicity and affordability of traditional cell culture. For example, traditional 2D and transwell assays of immune cell infiltration efficiency are unrealistic, as cell migration is gravity-driven. AIM 3D cell culture chips offer a more realistic immune cell infiltration model by compartmentalizing immune cells and cancer spheroids in parallel channels. The chips consist of a 3D hydrogel channel and two flanking media channels. Cancer spheroids are cultured within the hydrogel channel while immune cells are seeded in one of the media channels. The seeded immune cells are required to actively invade and seek out target cancer cells in 3D hydrogel in AIM chips before they can infiltrate the cancer spheroids. This is a process similar to immune cell infiltration in vivo. By utilizing high content confocal imaging, fluorescent-labeled immune cells that migrate into the 3D hydrogel can be visualized and quantified. This assay, in combination with adoptive T cell therapy or immune checkpoint blockade, can determine the roles of tumor infiltrated lymphocytes in immunotherapy through quantifying the live: dead ratio of cancer spheroids in the chips. This is particularly useful as a quality control tool for cellular adoptive immunotherapy where the infiltration efficiency and tumoricidal activity of engineered immune cells can be accessed in vitro. In summary, AIM 3D cell culture chips create a more physiologically relevant 3D microenvironment for visualizing immune cell infiltration of cancer spheroids

    TRPA1 Is Expressed in Central But Not in Peripheral Glia

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    TRPA1 are cation channels expressed in sensory neurons and in several other cell types. This channel is specifically activated by ally isothiocyanate (AITC), the pungent component of mustard oil, as well as by other electrophilic compounds. Although TRPA1 expression in central glia has been reported, its subcellular localization and its expression in peripheral glia have not been investigated before. In this paper we report the molecular and functional expression of TRPA1 in rat cortical astrocytes. Real-time RT-PCR identified low but significant amounts of TRPA1 mRNA in cortical astrocytes while no signal was seen in peripheral glia isolated from dorsal root ganglia (DRG) or in a glial cell line (DITNC-1). Calcium imaging showed AITC-induced signals in astro-cytes while no response in peripheral glia. AITC induced calcium signals in astrocytes in the presence and in the absence of extracellular calcium, suggesting an intracellular localization of TRPA1 channels. Whole cell electrophysiological recordings were performed in astrocytes, in peripheral glia and in DITNC-1 cells transfected with TRPA1 during AITC application. In TRPA1-transfected DITNC-1 cells typical TRPA1 currents were recorded with a reversal potential near 0 mV, consistent with the opening of a non-selective cation channel. No such currents were recorded in untransfected DITNC-1 cells, in astrocytes and in peripheral glial cells, where even high concentrations of AITC (up to 10 mM) induced no significant outward current. In astrocytes AITC transiently induced an outward rectifying current with the reversal potential near ?90 mV, consistent with K channel activation, likely activated by intracellular release of calcium. Our results suggest that TRPA1 channels are molecularly and functionally expressed in calcium-containing organelles of rat cortical astrocytes, with no expression in the plasma membrane
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