Comparison of CT and PET-CT based planning of radiation therapy in locally advanced pancreatic carcinoma

Abstract Background To compare computed tomography (CT) with co-registered positron emission tomography-computed tomography (PET-CT) as the basis for delineating gross tumor volume (GTV) in unresectable, locally advanced pancreatic carcinoma (LAPC). Methods Fourteen patients with unresectable LAPC had both CT and PET images acquired. For each patient, two three-dimensional conformal plans were made using the CT and PET-CT fusion data sets. We analyzed differences in treatment plans and doses of radiation to primary tumors and critical organs. Results Changes in GTV delineation were necessary in 5 patients based on PET-CT information. In these patients, the average increase in GTV was 29.7%, due to the incorporation of additional lymph node metastases and extension of the primary tumor beyond that defined by CT. For all patients, the GTVCT versus GTVPET-CT was 92.5 ± 32.3 cm3 versus 104.5 ± 32.6 cm3 (p = 0.009). Toxicity analysis revealed no clinically significant differences between two plans with regard to doses to critical organs. Conclusion Co-registration of PET and CT information in unresectable LAPC may improve the delineation of GTV and theoretically reduce the likelihood of geographic misses.</p

Risk Factors Associated with Adverse Fetal Outcomes in Pregnancies Affected by Coronavirus Disease 2019 (COVID-19): A Secondary Analysis of the WAPM study on COVID-19

To evaluate the strength of association between maternal and pregnancy characteristics and the risk of adverse perinatal outcomes in pregnancies with laboratory confirmed COVID-19. Secondary analysis of a multinational, cohort study on all consecutive pregnant women with laboratory-confirmed COVID-19 from February 1, 2020 to April 30, 2020 from 73 centers from 22 different countries. A confirmed case of COVID-19 was defined as a positive result on real-time reverse-transcriptase-polymerase-chain-reaction (RT-PCR) assay of nasal and pharyngeal swab specimens. The primary outcome was a composite adverse fetal outcome, defined as the presence of either abortion (pregnancy loss before 22 weeks of gestations), stillbirth (intrauterine fetal death after 22 weeks of gestation), neonatal death (death of a live-born infant within the first 28 days of life), and perinatal death (either stillbirth or neonatal death). Logistic regression analysis was performed to evaluate parameters independently associated with the primary outcome. Logistic regression was reported as odds ratio (OR) with 95% confidence interval (CI). Mean gestational age at diagnosis was 30.6\ub19.5 weeks, with 8.0% of women being diagnosed in the first, 22.2% in the second and 69.8% in the third trimester of pregnancy. There were six miscarriage (2.3%), six intrauterine device (IUD) (2.3) and 5 (2.0%) neonatal deaths, with an overall rate of perinatal death of 4.2% (11/265), thus resulting into 17 cases experiencing and 226 not experiencing composite adverse fetal outcome. Neither stillbirths nor neonatal deaths had congenital anomalies found at antenatal or postnatal evaluation. Furthermore, none of the cases experiencing IUD had signs of impending demise at arterial or venous Doppler. Neonatal deaths were all considered as prematurity-related adverse events. Of the 250 live-born neonates, one (0.4%) was found positive at RT-PCR pharyngeal swabs performed after delivery. The mother was tested positive during the third trimester of pregnancy. The newborn was asymptomatic and had negative RT-PCR test after 14 days of life. At logistic regression analysis, gestational age at diagnosis (OR: 0.85, 95% CI 0.8-0.9 per week increase; p<0.001), birthweight (OR: 1.17, 95% CI 1.09-1.12.7 per 100 g decrease; p=0.012) and maternal ventilatory support, including either need for oxygen or CPAP (OR: 4.12, 95% CI 2.3-7.9; p=0.001) were independently associated with composite adverse fetal outcome. Early gestational age at infection, maternal ventilatory supports and low birthweight are the main determinants of adverse perinatal outcomes in fetuses with maternal COVID-19 infection. Conversely, the risk of vertical transmission seems negligible

Avrupa araştırma geliştirme programlarında uluslararası bilgi transferi: Türkiye örneği

International programmes, namely Framework Programmes 6, 7, and European Research Cooperation Agency (EUREKA), aim supporting national Small and Medium Scale Enterprises (SMEs) to subcontract their research needs to Research and Technological Development (RTD) performers. Main objective of this thesis is to measure level of success of knowledge transfer from RTD performers towards Turkish SMEs within the FP6, FP7 and EUREKA. The thesis proposes a model for knowledge transfer consisting of four stages: initiation, implementation, elaboration, and internalization. Extensive data is collected from sixty projects involved in these programmes via structured survey. The data is analyzed within the context of the proposed model via using the variables selected from the literature. Main findings show that the initiation stage is at a satisfactory level. The national SMEs continue learning from the international partners while they practice the knowledge they acquire, therefore, necessary support should be given to national SMEs to communicate as much as possible in order to receive as much knowledge as possible from their international partners, during implementation process. Level of absorptive capacity is indispensable for elaboration. Therefore, much effort is required to strengthen absorptive capacity of national SMEs. Internalization is the weakest stage. If internalization is not successfully achieved, it is hardly possible to sustain and systematize the knowledge. All stages are mutually exclusive. If the initiation is not based on real needs and expertise of the SMEs, implementation will fail. It will be difficult to elaborate on the knowledge; therefore, improvement of the knowledge will not be at expected level. Since the improvement will not be sustained, internalization of the knowledge will be less, which will undermine successful transfer.M.S. - Master of Scienc

On the co-absence of input terms in higher order neuron representation of boolean functions

Due to copyright restrictions, the access to the full text of this article is only available via subscription.Boolean functions (BFs) can be represented by using polynomial functions when −1 and +1 are used represent True and False respectively. The coefficients of the representing polynomial can be obtained by exact interpolation given the truth table of the BF. A more parsimonious representation can be obtained with so called polynomial sign representation, where the exact interpolation is relaxed to allow the sign of the polynomial function to represent the BF value of True or False. This corresponds exactly to the higher order neuron or sigma-pi unit model of biological neurons. It is of interest to know what is the minimal set of monomials or input lines that is sufficient to represent a BF. In this study, we approach the problem by investigating the (small) subsets of monomials that cannot be absent as a whole from the representation of a given BF. With numerical investigations, we study low dimensional BFs and introduce a graph representation to visually describe the behavior of the two-element monomial subsets as to whether they cannot be absent from any sign representation. Finally, we prove that for any n-variable BF, any three-element monomial set cannot be absent as a whole if and only if all the pairs from that set has the same property. The results and direction taken in the study may lead to more efficient algorithms for finding higher order neuron representations with close-to-minimal input terms for Boolean functions

Incidental detection of a vertebral body hemangioma on three-phase bone scintigraphy

WOS: 000083936200028PubMed ID: 10595494

Tc-99M tetrofosmin scintigraphy in acute leukaemia: the relationship between marrow uptake of tetrofosmin and P-glycoprotein and chemotherapy response

WOS: 000223478200004PubMed ID: 15266171Background The non-invasive detection of P-glycoprotein (Pgp) and multidrug resistance related proteins in vivo, will represent the greatest challenge in overcoming multidrug resistance. Although Tc-99m tetrofosmin has been used previously as a myocardial perfusion agent, it is now also being used in the imaging of various tumours. In the current study, Tc-99m tetrofosmin was used in the investigation of acute leukaemia. Aim To show the uptake pattern of Tc-99m tetrofosmin in the bone marrow of patients with acute leukaemia, and to ascertain the relationship between Tc-99m tetrofosmin uptake and the level of Pgp expression and their relation to the response to chemotherapy. In addition, CD95, which is an indicator of apoptosis (programmed cell death), has also been assessed. Materials and methods Pgp and CD95 were detected by using flow cytometry. Of the 27 acute leukaemia patients assessed, nine had previously received chemotherapy, and 18 had had an initial diagnosis. All patients had undergone Tc-99m tetrofosmin scintigraphy, and their Pgp and CD95 levels had been determined. The same parameters were studied again for 14 patients. The responses to chemotherapy were assessed by patients' clinicians. A control group of 37 patients without bone marrow pathology was also studied in order to provide comparisons for the scintigraphy results. The control images were assessed only qualitatively. Results In leukaemia patients the uptake of Tc-99m tetrofosmin into bone marrow was found to be considerably higher than in control patients (P = 0.000). An analysis of the relationship between Pgp, CD95, and the qualitative and quantitative tetrofosmin uptake ratios (URs) showed that there was an inverse correlation only between Pgp and the quantitative uptake ratio (P = 0.016, r = -0.461). When the patients were grouped as 'good' and 'poor', as related to the chemotherapy response, there were no meaningful differences between these two groups regarding Pgp, CD95 and tetrofosmin URs (P > 0.05). By evaluating the scintigraphic findings of the 'repeated' 14 patients, we showed that if the Tc-99m tetrofosmin UR in the second imaging test was reduced by > 0.08, the response to chemotherapy tended to be good. This method, based on follow-up scanning with tetrofosmin, showed a sensitivity of 83% and a specificity of 62% in the prediction of a 'good' response, if a decrease of 0.08 was taken into consideration. Conclusion In this study, patients with acute leukaemia showed significant uptake of tetrofosmin into the bone marrow. The addition of basal and repeated Tc-99m tetrofosmin scintigraphy to the management protocol for leukaemia could lead to the preferential determination of responses to chemotherapy, by evaluating whole bone marrow non-invasively. This method seems promising, but it needs further support from various similar investigations comprising more patients in order to confirm our results. (C) 2004 Lippincott Williams Wilkins

Natural phenolics as potential adjuvants in chemotherapy.

The first aim of this thesis was to study the scavenging and antioxidant properties of some selected compounds. The second aim was to evaluate their possible cytotoxic and cytoprotective effects against doxorubicin induced injury to neonatal rat cardiomyocytes (CMC) using the parameters of cellular damage. Test compounds - rosmarinic, chlorogenic, caffeic acids, silydianin, silychristin, dehydrosilybin, baicalein, kaempferol, luteolin, quercetin, with the exception of sibylline and apigenin - were capable of scavenging 2,2-diphenyl-1-picrylhydrazyl radical and their reducing capacities were demonstrated by cyclic voltammetry. In regard to demonstrated antioxidative properties all test compounds showed also the ability to inhibit doxorubicin-iron induced lipid peroxidation of microsomal and mitochondrial heart membranes. The parameters demonstrated no cytotoxicity of the test compounds on neonatal rat CMC. Conversely, the stabilisation effect of the test compounds on CMC was noted. The same parameters of cellular damage were used to assess cytoprotective effect of the test compounds against doxorubicin-induced injury to CMC. The observed cytoprotective effects of the majority of the test compounds were more effective that the effects of the dexrazoxane used as a positive control.Available from STL Prague, CZ / NTK - National Technical LibrarySIGLECZCzech Republi