Brain metastases of choriocarcinoma: A report on two cases

Introduction. Gestational trophoblastic diseases (GTD) are a spectrum of tumors with a various of biological behavior and potential for metastases. It consists of hydatiform mole, invasive mole, choriocarcinoma and placental site trophoblastic tumor. Choriocarcinoma presents a very aggressive tumor with high malignant potential. Case report. We presented the two cases of choriocarcinoma with brain metastases. The first one was manifested by neurological deterioration as the first sign of metastasis, while the second patient had firstly metrorrhagia and in the further couse neurological disturbances that suggested the presence of brain tumor. In both cases we applied a combined treatment of surgery, chemotherapy and radiation therapy. Both patient survived with high quality of life. Conclusion. A successful outcome of brain metastases of choriocarcinoma was obtained by the use of a combined treatment of surgery, chemotherapy and radiation therapy. In cases of young women with brain metastases, gynecological malignancy should be always considered

Investigating the influence of hydrothermal treatment on oxygen functional groups in graphene oxide-based nanocomposites

Different hierarchical ordering of nanomaterials, either as individual components or in the form of nanocomposites, is one of the approaches used for the development of supercapacitors. In this work, the effect of hydrothermal treatment on oxygen functional groups of nanocomposites between graphene oxide (GO), 12-tungstophosphoric acid (WPA), and 3,4,9,10-perylenetetracarboxylic dianhydride (PTCDA) was examined. The mentioned materials were hydrothermally treated for 4, 8 and 12 hours at 180 °C in order to understand how interaction between the components is influencing development of surface chemistry. The results of Fourier-transform infrared spectroscopy (FTIR), Raman spectroscopy (Raman), and temperature-programmed desorption (TPD) are showing the surface and structural changes of GO (individually and in nanocomposite) as a result of hydrothermal treatment. Both FTIR and RAMAN confirm the presence of WPA and PTCDA. Additionally, it appears that hydrothermal treatment has no impact on the structural changes in PTCDA, which is consistent across various temperature conditions. TPD results indicate that prolonged hydrothermal treatment leads to a gradual increase of the number of functional groups of GO. However, the number of desorbed groups is influenced by the WPA and PTDCA components. This research offers new insights into GO, WPA, and PTCDA interactions which can have useful implications for development of electrochemical supercapacitors.Twenty-First Young Researchers’ Conference - Materials Science and Engineering: Program and the Book of Abstracts; November 29 – December 1, 2023, Belgrade, Serbi

Enhanced electrochemical detection of gallic acid using modified glassy carbon electrodes with Zn/Ga-dopped cobalt ferrite

In this study, solvothermally synthesized nanoparticles of cobalt ferrite (CoFe2O4, CFO) and Zn/Ga-dopped cobalt ferrite (Co0.5Zn0.5Fe2O4, CFO_Zn and CoFe1.5Ga0.5O4, CFO_Ga, respectively) with dihydrocaffeic acid (DHCA) as a surfactant were examined for electrochemical detection of gallic acid. Based on X-ray diffraction analysis, diffraction maxima of all samples correspond to the cubic spinel phase, while transmission electron microscopy showed that the nanoparticles are non-agglomerated, sphere-like with an average size of 5±1 nm. The presence of DHCA on the surface of nanoparticles was confirmed by Fourier Transform Infrared Spectroscopy (FTIR). For the purpose of electrochemical detection of gallic acid the modified glassy carbon electrode (m-GCE) was prepared from CFO, CFO_Zn and CFO_Ga nanoparticles. Initial tests have shown instability/disintegration of m-GCE in aqueous solutions, because of which samples were annealed at 450 °C in air. Cyclic voltammograms of all annealed samples showed good reversibility in the system [Fe(CN)6] 3-/4- . The most efficient electron transfer was achieved when the mass ratio between sample and Nafion® was 85:15, respectively. The best sensitivity to gallic acid (10-4 M, in Britton-Robinson buffer) was observed for CFO_Zn sample. Results are showing that by selective functionalization and surface modification of nanoparticles, it is possible to optimize the electrochemical properties suitable for sensing, which is the basis of this method and the goal of further research.Twenty-First Young Researchers’ Conference - Materials Science and Engineering: Program and the Book of Abstracts; November 29 – December 1, 2023, Belgrade, Serbi

Surface, structural and electric properties of ion beam irradiated graphene oxide papers

In this paper, the physicochemical properties of nanocomposites of graphene oxide (GO) and cobalt ferrite nanoparticles CFO NPs (pristine and doped with zinc and gallium, CFO_Zn, CFO_Ga) were investigated. CFO, CFO_Zn and CFO_Ga NPs were synthesized using the solvothermal method with oleic acid (OA) as a surfactant. X-ray diffraction (XRD) confirmed the presence of pure ferrite phase while transmission electron microscopy (TEM) revealed spherical and non-agglomerated NPs with average size of 5±1 nm. Fourier transform infrared spectroscopy (FTIR) has confirmed bridging bidentate interaction between the oleic acid and the metal atoms on the surface of the NPs, while Raman spectroscopy results confirmed the incorporation of zinc and gallium in the spinel structure. Prior to preparation of nanocomposite with GO, an OA coating has been exchanged with dihydrocaffeic acid (DHCA). DHCA binds to surface of NPs through both covalent bridging bidentate interaction and catechol groups, as determined by FTIR. Nanocomposite has been obtained by adding CFO(_Zn/Ga) NPs to a GO suspension with nominal fractions of 5 to 15 wt.%, followed by homogenization and hydrothermal treatment (T=120 °C, t=3 h). TEM results revealed that the shape and size of NPs remain unchanged in nanocomposite, while FTIR results have shown that hydrogen bond is established between the functional groups of GO and DHCA. Electrochemical properties of individual components and nanocomposite were examined by cyclic voltammetry. The best electrochemical properties, in terms of the highest specific capacity, were shown by the composite which contains 15 wt.% CFO NPs.Nineteenth Young Researchers' Conference Materials Science and Engineering, December 1-3, 2021, Belgrade, Serbi

Electrochemical properties of composites of graphene oxide and cobalt ferrite doped with zink and gallium

The possibility of surface functionalization and formation of stable aqueous suspensions make graphene oxide (GO) suitable as base for composite materials, especially with nanoparticles. Cobalt ferrite (CFO) has attracted attention due to its unique properties such as large magnetic anisotropy, high coercivity, moderate saturation magnetization, excellent chemical stability, mechanical hardness, etc. This study presents the electrochemical properties of GO and CFO composites, as well as CFO doped with zinc (CFO_Zn) and gallium (CFO_Ga). Magnetic nanoparticles were synthesized using the solvothermal method, after which the oleic acid was exchanged with dihydrocaffeic acid to obtain the hydrophilic material. GO was synthesized using a modified Hummer's method. Composites of GO and magnetic nanoparticles were synthesized by the hydrothermal method (T = 120 °C, t = 3 h), with nominal fractions of 5 and 15 wt.% of magnetic nanoparticles. X-ray structural diffraction, as well as FTIR analysis, confirmed the complete oxidation of graphene layers. SEM and TEM images showed deposition of magnetic nanoparticles on GO layer with the different distribution density between 5 wt.% and 15 wt.% composites. Also, shape and size of magnetic nanoparticles remained unchanged. Based on FTIR analysis of hydrothermally treated GO and composites a partial reduction of epoxy groups was found along with hydrogen bond established between the components of the composite. The electrochemical charge storage of composites is mainly of pseudocapacitive nature, which originates from the oxidoreduction reactions of H+ ions from electrolytes and surface functional groups of GO. The best electrochemical properties, in terms of the highest specific capacity, were shown by the composite which contains 15 wt.% CFO, which value is 36.86 F g-1 at a polarization rate of 5 mV s-

Electrochemical properties of composites of graphene-oxide and cobalt-ferrite doped with zink and gallium

U ovom radu prikazana su elektrohemijska svojstva kompozita grafen-oksida i nanočestica kobalt-ferita, kao i kobalt-ferita dopiranog sa cinkom i galijumom. Grafen-oksid (GO) sintetisan je modifikovanom Hamerovom metodom. Magnetne nanočestice sintetisane su solvotermalnom metodom, nakon čega je izvršena izmena oleinske kiseline dihidrokofeinskom kiselinom sa ciljem dobijanja hidrofilnog materijala. Kompoziti grafen-oksida i magnetnih nanočestica sintetisani su hidrotermalnom metodom, prilikom čega je udeo magnetnih čestica bio 5 i 15 težinskih % u odnosu na grafen-oksid. Rezultati rendgeno-strukturne i FTIR analize potvrdili su potpunu oksidaciju grafenskih slojeva. SEM i TEM analize pokazale su depoziciju magnetnih nanočestica na sloju grafen-oksida, bez promene veličine ili oblika nanočestica. FTIR analiza hidrotemalno tretiranog grafen-oksida i kompozita pokazala je da dolazi do delimične redukcije epoksi grupa, kao i da se uspostavlja vodonična veza između komponenti kompozita. Ciklovoltamogrami pokazuju da su kompoziti stabilni pri brzinama polarizacije od 5 do 400 mV s-1, kao i da je njihov kapacitet pretežno pseudokapacitivne prirode. Pseudokapacitivnost potiče od oksidoredukcionih reakcija H+ jona iz elektrolita i površinskih funkcionalnih grupa grafen oksida. Na osnovu ciklovoltamograma izračunati su specifični kapaciteti svih kompozita, pri čemu je najveću vrednost pokazao kompozit CFO_GO_15% koja iznosi 36,86 F g-1 pri brzini polarizacije od 5 mV s-1.This paper presents the electrochemical properties of graphene-oxide composites and nanoparticles of cobalt-ferrite, as well as cobalt-ferrite doped with zinc and gallium. Graphene-oxide (GO) was synthesized by a modified Hummer's method. The magnetic nanoparticles were synthesized by the solvothermal method, after which the oleic acid was exchanged with dihydrocaffeic acid to obtain the hydrophilic material. Composites of graphene-oxide and magnetic nanoparticles were synthesized by the hydrothermal method, where the share of magnetic particles was 5 and 15 wt.% on graphene-oxide. The results of X-ray structural and FTIR analysis confirmed the complete oxidation of graphene layers. SEM and TEM analyzes showed deposition of magnetic nanoparticles on the graphene-oxide layer, without changing the size or shape of the nanoparticles. FTIR analysis of hydrothermally treated graphene oxide and composites showed that there is a partial reduction of epoxy groups, also a hydrogen bond is established between the components of the composite. Cyclic voltammograms show that the composites are stable at polarization rates of 5-400 mV s-1, and that their capacity is predominantly pseudocapacitive in nature. Pseudocapacitance originates from the oxidoreduction reactions of H+ ions from electrolytes and surface functional groups of graphene-oxide. Based on the cyclic voltammograms, the specific capacities of all composites were calculated and the highest value being shown by the CFO_GO_15% composite, which is 36.86 F g-1 at a polarization rate of 5 mV s-1

Puncture site bleeding complications in patients with Clopidogrel hyper-response: Three case reports

Dual antiplatelet therapy (clopidogrel and acetylsalicylic acid) is a standard for the embolization of planned intracranial aneurysms with CNS stent due to the possibility of stent thrombus formation. All anti-aggregation drugs, including those listed, have bleeding as a side effect. Three patients with aneurysm had an elevated response to antiplatelet therapy with clopidogrel, which was confirmed by a multiplate test on the "VerifyNow" system. After reducing the dose of clopidogrel or after interrupting it, with the introduction of low molecular weight heparin for the duration of five days, aneurysms were successfully resolved by intracranial implantation of the stent. Perioperative angiograms and postoperative CT angiograms have verified hematomas at the place of punction of the femoral artery. Bleeding was resolved by the femoral artery suture by a vascular surgeon. All patients were discharged home without further complications and with dual antiplatelet therapy. By measuring the platelet function in vitro, the degree of inhibition of platelet activity achieved by the action of the drug can be assessed. A specific test can identify those patients who are highly responsive to the drug with increased platelet reactivity and the possibility of increased risk of bleeding. Our suggestion is to reduce the dosage of clopidogrel or to leave it out for 24 hours with preventive doses of low molecular weight heparin or to change the strategy of treatment of intracranial aneurysm, i.e. avoiding implantation of CNS stent

Germline Variants in Cancer Predisposition Genes in Pediatric Patients with Central Nervous System Tumors

Central nervous system (CNS) tumors comprise around 20% of childhood malignancies. Germline variants in cancer predisposition genes (CPGs) are found in approximately 10% of pediatric patients with CNS tumors. This study aimed to characterize variants in CPGs in pediatric patients with CNS tumors and correlate these findings with clinically relevant data. Genomic DNA was isolated from the peripheral blood of 51 pediatric patients and further analyzed by the next-generation sequencing approach. Bioinformatic analysis was done using an “in-house” gene list panel, which included 144 genes related to pediatric brain tumors, and the gene list panel Neoplasm (HP:0002664). Our study found that 27% of pediatric patients with CNS tumors have a germline variant in some of the known CPGs, like ALK, APC, CHEK2, ELP1, MLH1, MSH2, NF1, NF2 and TP53. This study represents the first comprehensive evaluation of germline variants in pediatric patients with CNS tumors in the Western Balkans region. Our results indicate the necessity of genomic research to reveal the genetic basis of pediatric CNS tumors, as well as to define targets for the application and development of innovative therapeutics that form the basis of the upcoming era of personalized medicine

Association between microRNAs 10b/21/34a and acute toxicity in glioblastoma patients treated with radiotherapy and temozolomide

A personalized approach to chemoradiation is important in reducing its potential side effects and identifying a group of patients prone to toxicity. MicroRNAs have been shown to have a predictive potential for radiotoxicity. The goal of the study was to test if levels of miRNA in peripheral blood mononuclear cells of glioblastoma patients are associated with toxicity and to identify the peak time point for toxicity. MicroRNA-10b/21/34a levels were measured in 43 patients with and without toxicity, at baseline, at the 15th, and at the 30th fraction by Real-Time quantitative Polymerase Chain Reaction. MicroRNA-10b/21 levels increased with toxicity grade (p = 0.014; p = 0.013); miR-21/34a levels were significantly different between patients with and without toxicity at the 15th fraction (p = 0.030; p = 0.045), while miR-34a levels significantly changed during treatment (p < 0.001). All three miRNAs showed a significantly high positive correlation with one another. MiR-34a might be considered as a predictive factor for toxicity due to its changes during treatment, and differences between the groups with and without toxicity; miR-10b might be used to predict toxicity; miR-10b/21 might be used for predicting the grade of toxicity in GB patients

Očna duplja, anatomija i neurohirurški pristup (The orbit: Anatomy and neurosurgical approaches) Authors: Ilija Nagulić and Mirjana Nagulić. Publisher: “Obeležja”, Belgrade, October 2011, 2 chapters, 202 pages, 46 illustrations and one table.

No abstract available