139 research outputs found

    1. Rola systemu varis i vision w nowoczesnej radioterapii

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    Planowanie leczenia przy użyciu systemów trójwymiarowych spowodowafo skomplikowanie technik napromieniania. Powstają coraz bardziej złożone aparaty do radioterapii wyposażane w asymetryczny kolimator, terapie kątowe, MLC i IMRT. Aby dokładnie odtworzyć parametry napromienianych pó1 przy tak dużej liczbie zmiennych należy bardzo uważnie przejrzeć i odczytać cala dokumentacje dołączona do karty chorego. Tradycyjna forma przygotowania dokumentów do napromieniania zawiera ryzyko, iż dane te mogą być żle odczytane i blednie wprowadzane na aparacie terapeutycznym. Doskonałym rozwiązaniem eliminującym ewentualne pomyłki jest system Varis. Wszystkie dane niezbędne do wykonania poprawnego napromieniania Są umieszczone w elektronicznej karcie pacjenta. Dane do niej Są wpisywane automatycznie z systemu planowania trójwymiarowego lub określane na symulatorze. Napromieniając chorego na aparacie terapeutycznym nie ma możliwości ustawienia aparatu w inny sposób niż zostało to zaplanowane. W systemie zintegrowanego zarządzania radioterapia Varis można dokładnie zaplanować nie tylko sposób leczenia, ale również godzinę, o której chory powinien zgłosić się na aparat terapeutyczny. System Varis pozwala także wykreować róiżnego rodzaju raporty dotyczące pacjentów na podstawie danych zgromadzonych na serwerach. Nierozerwalna Częścią Varisa jest system Vision. Pozwala on na kontrole i weryfikacje ułożenia pacjenta podczas terapii. Służą do tego zdjęcia z symulatora i wykonywane komputerowo zdjęcia weryfikacyjne. System Vision pozwala na bardzo precyzyjna obróbkę otrzymywanych obrazów. Systemy Varis i Vision eliminują lub korygują ewentualne błędy wynikające z niepoprawnego egzekwowania zaplanowanych parametrów fizycznych. Podczas sesji przedstawione zostaną własne doświadczenia Kliniki w stosowaniu wymienionego systemu

    148. Changes in lateral dimensions of irradiated volume and their impact on the accuracy of dose delivery during radiotherapy for head and neck cancer

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    AimTo assess changes in lateral dimensions of irradiated volume during head and neck cancer radiotherapy and their impact on dose delivery accuracy.Material and methodsLateral dimensions of irradiated volumes were measured in 5 predefined points using computed tomography, simulator and manually with calipers, prior to treatment and then bi-weekly. For each measurement reference point dose was calculated and verified using in vivo dosimetry. Early radiation reactions, patient's weight changes and the need to modify radiotherapy accessories were also assessed. All these parameters were analyzed in relation to tumor site and stage, treatment field size, radiation dose and the degree of radiation reactions.ResultsThe study included 33 head and neck cancer patients (24 men and 9 women) aged 24–77 (median 56). All patients were irradiated using the parallel opposed megavoltage fields ranging from 49 to 180 cm2 (median 121 cm2) to the dose of 44 to 80 Gy (median 66 Gy). Radiation reactions included mucositis (grade 3 – 1 patient, grade 2 – 17 patients, grade 1 – 13 patients) and dysphagia (grade 2 – 12 patients, grade 1 – 16 patients). The body mass changes during radiotherapy ranged from −18 to +4 kg (median −5 kg). In 1 patient radiotherapy accessories had to be modified three times during the treatment, in 6 – twice and in 10 – once. Lateral dimensions changes >5 mm occurred in all but one patient (range −37 to +16 mm). Theoretical doses calculated for changed dimensions varied from prescribed by −2.5% to +6% (median +2%). Differences larger than 5% were present in 4.8% of calculations. In vivo dose measurements (after introduction of necessary corrections) demonstrated difference from prescribed dose larger than 5% in 7.6% of measurements.ConclusionChanges in the lateral dimensions of irradiated volume during head and neck cancer radiotherapy may lead to some inaccuracies in delivered doses. Such situations may necessitate adequate corrections of dose calculations and modification of radiotherapy accessories during the course of treatment

    Identification and quantification of phenolic compounds in bambangan (Mangifera pajang Kort.) peels and their free radical scavenging activity.

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    Phenolic compounds and antioxidant capacity of acidified methanolic extract prepared from fully ripe bambangan (Mangifera pajang K.) peel cultivated in Sarawak, Malaysia, were analyzed. The total phenolic content (98.3 mg GAE/g) of bambangan peel powder (BPP) was determined by the Folin-Ciocalteu method. BPP showed a strong potency of antioxidant activity and was consistent with that of BHT and vitamin C as confirmed by the DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging activity and FRAP (ferric-reducing antioxidant power) assays. Gallic acid, p-coumaric acid, ellagic acid, protocatechuic acid, and mangiferin were the major compounds among the 16 phenolics that have been identified and quantified in M. pajang peels with 20.9, 12.7, 7.3, 5.4, and 4.8 mg/g BPP, respectively. Peak identities were confirmed by comparing their retention times, UV-vis absorption spectra, and mass spectra with authentic standards. The 16 phenolic compounds identified in M. pajang K. using HPLC-DAD and TSQ-ESI-MS are reported here for the first time

    Determination of Total Polyphenol Content in Food with the Flow-Injection

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    U ovom radu predložena je modificirana automatizirana metoda ubrizgavanja u protok za određivanje sadržaja ukupnih polifenola u namirnicama bazirana na Folin-Ciocalteauovoj reakciji u 0,5 mol L-1 NaOH. Metoda omogućuje automatiziranu analizu različitih uzoraka brzinom protoka 55 uzoraka na sat uz upotrebu galne kiseline kao standarda. Primjenom predložene metode na konkretne uzorke (bijelo i crno vino, zeleni, indijski te čaj od lipe, metvice i kamilice i bistri voćni sokovi od crnog ribiza i višnje), određen je njihov “indeks ukupnih polifenola” s većom repetibilnošću za razliku od ranije objavljenih metoda, manje ovisno o razrjeđenju uzorka. U odnosu na “batch” metodu, ova je metoda visoko tolerantna prema najčešćim interferentima (SO2, reducirajući šećeri i askorbinska kiselina). Rezultati dobiveni predloženom metodom pokazali su relativno slaganje s onima dobivenim referentnom Folin-Ciocalteauovom metodom.This paper describes an optimised flow-injection method for the determination of total polyphenol in food based on the Folin-Ciocalteau reaction in 0.5 mol L-1 NaOH. The method allows different types of samples to be analysed automatically at a rate of 55 samples per hour by using gallic acid as standard. By applying the proposed method to real samples (white and red wines, green, Indian, lime-tree, mentha and chamomile teas, and blackberry and cherry juices), their total polyphenol indices were determined with a higher reproducibility than obtained by earlier methods, whatever the dilution used. This method is highly tolerant towards the most common interferences (SO2, reducing sugars, and ascorbic acid) associated with the batch method. The results obtained by the proposed method relatively agree with those obtained using the referent Folin-Ciocalteau method

    Glycyrrhizin Exerts Antioxidative Effects in H5N1 Influenza A Virus-Infected Cells and Inhibits Virus Replication and Pro-Inflammatory Gene Expression

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    Glycyrrhizin is known to exert antiviral and anti-inflammatory effects. Here, the effects of an approved parenteral glycyrrhizin preparation (Stronger Neo-Minophafen C) were investigated on highly pathogenic influenza A H5N1 virus replication, H5N1-induced apoptosis, and H5N1-induced pro-inflammatory responses in lung epithelial (A549) cells. Therapeutic glycyrrhizin concentrations substantially inhibited H5N1-induced expression of the pro-inflammatory molecules CXCL10, interleukin 6, CCL2, and CCL5 (effective glycyrrhizin concentrations 25 to 50 µg/ml) but interfered with H5N1 replication and H5N1-induced apoptosis to a lesser extent (effective glycyrrhizin concentrations 100 µg/ml or higher). Glycyrrhizin also diminished monocyte migration towards supernatants of H5N1-infected A549 cells. The mechanism by which glycyrrhizin interferes with H5N1 replication and H5N1-induced pro-inflammatory gene expression includes inhibition of H5N1-induced formation of reactive oxygen species and (in turn) reduced activation of NFκB, JNK, and p38, redox-sensitive signalling events known to be relevant for influenza A virus replication. Therefore, glycyrrhizin may complement the arsenal of potential drugs for the treatment of H5N1 disease

    Genotype and Growing Environment Interaction Shows a Positive Correlation between Substrates of Raffinose Family Oligosaccharides (RFO) Biosynthesis and Their Accumulation in Chickpea (Cicer arietinum L.) Seeds

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    To develop genetic improvement strategies to modulate raffinose family oligosaccharides (RFO) concentration in chickpea (Cicer arietinum L.) seeds, RFO and their precursor concentrations were analyzed in 171 chickpea genotypes from diverse geographical origins. The genotypes were grown in replicated trials over two years in the field (Patancheru, India) and in the greenhouse (Saskatoon, Canada). Analysis of variance revealed a significant impact of genotype, environment, and their interaction on RFO concentration in chickpea seeds. Total RFO concentration ranged from 1.58 to 5.31 mmol/100 g and from 2.11 to 5.83 mmol/100 g in desi and kabuli genotypes, respectively. Sucrose (0.60−3.59 g/100 g) and stachyose (0.18−2.38 g/ 100 g) were distinguished as the major soluble sugar and RFO, respectively. Correlation analysis revealed a significant positive correlation between substrate and product concentration in RFO biosynthesis. In chickpea seeds, raffinose, stachyose, and verbascose showed a moderate broad sense heritability (0.25−0.56), suggesting the use of a multilocation trials based approach in chickpea seed quality improvement programs
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