121 research outputs found
Deciphering the role of the TRAIL pathway as potential tumor escape mechanism in ovarian cancer
TRAIL (Tumor necrosis factor (TNF)-related apoptosis-inducing ligand) induziert in einer Vielzahl von Tumorzellen Apoptose, nicht jedoch in gesunden Zellen. Deshalb werden TRAIL selbst, sowie agonistische Antikörper für die funktionellen TRAIL-Rezeptoren (TRAIL-R1 (DR4) und TRAIL-R2 (DR5)) gegenwärtig in präklinischen und klinischen Studien für die Behandlung von diversen Erkrankungen untersucht.
TRAIL ist im Mikroumfeld von Ovarialtumoren prävalent und wird mit verlängertem Überleben assoziiert. Mehr als zwei Drittel der Ovarialtumorpatientinnen haben einen gestörten TRAIL-Signalweg, ein wichtiges Faktum für Prognose und Therapiemöglichkeiten. Defekte im TRAIL-Signalweg beinhalten eine Reduzierung der funktionellen Rezeptoren DR4 und DR5 und/oder eine Überexpression der langen Isoform von c-FLIP (cellular Fas-associated death domain-like interleukin-1β-converting enzyme (FLICE)-like inhibitory protein, c-FLIPL).
Das Hauptziel meiner Doktorarbeit war Einblicke in die Deregulierung des TRAIL-Signalweges als potentiellen Tumor-Escape-Mechanismus beim Ovarialkarzinom zu erhalten. Im ersten Teil meiner Arbeit habe ich untersucht, ob eine Resistenz gegen TRAIL beim Ovarialkarzinom durch einen agonistischen anti-humanen DR5 monoklonalen Antikörper (AD5-10) aufgehoben werden kann. Ich konnte zeigen, dass die gemeinsame Anwendung von AD5-10 mit Carboplatin einen mehr als additiven Effekt in vitro hat. Dies könnte dadurch erklärt werden, dass Carboplatin die DR5-Expression an Ovarialkarzinomzellen, unabhängig von deren p53-Status, steigert. Eine Kombinationstherapie von AD5-10 mit Carboplatin eliminiert etablierte, platinresistente Ovarialtumore in vivo und reduziert deren Größe in mehr als 50 % der Mäuse (P=0.002) bis unter die Nachweisgrenze. Zusätzlich konnte ich zeigen, dass TRAIL und Natürliche Killerzellen (NK-Zellen) im Tumor-Mikroumfeld in sehr hohem Ausmaß vorhanden sind und der Abbau von NK-Zellen die antitumorale Aktivität von AD5-10 aufhebt. Zusammengefasst zeigen diese Daten, dass eine Kombination eines agonistischen monoklonalen anti-DR5 Antikörpers wie AD5-10 und Carboplatin eine vielversprechende Therapie für die Behandlung des Ovarialkarzinoms sein kann. Diese Ergebnisse zeigen auch die Interaktion zwischen einer Therapie, die die Apoptose-Kaskade in Gang setzt, und der Rolle des Immunsystems.
Im zweiten Teil meiner Arbeit habe ich mein Hauptaugenmerk auf die physiologische Rolle von c-FLIPL in der Ovarialkarzinomentstehung gelegt. Um auf diese Frage einzugehen, habe ich die Loss-of-Function-Methode, unter Verwendung von RNA Interferenz (RNAi) im Ovarialkarzinom in vitro und in vivo, angewendet. Es war mir möglich zu zeigen, dass durch die Unterdrückung von c-FLIPL die Sensitivität von menschlichen Ovarialkarzinomzellen für TRAIL-induzierte Apoptose erhöht und die Tumorentstehung in vivo gehemmt wird. Von besonderem Interesse war die Beobachtung, dass eine Reduzierung von c-FLIPL die Apoptoserate und die Proliferation in vivo senkt. Die Reduzierung von c-FLIPL verhinderte insbesondere die Invasion der Ovarialkarzinomzellen in die Peritonealhöhle, eine Beobachtung die auf die hohe Expression von TRAIL durch die NK-Zellen im Tumorstroma zurückzuführen sein könnte. Alles in allem zeigen diese Resultate, dass c-FLIPL die TRAIL-induzierte Apoptose in Ovarialkarzinomzellen wesentlich beeinflusst.
Ich habe meine Arbeit durch die Verwendung eines etablierten, immunkompetenten Ovarialtumor-Modells ergänzt, welches freundlicherweise von einem Kooperationspartner zur Verfügung gestellt wurde. Durch die Anwendung dieses Modells erhielt ich allererste Einsichten in die Interaktion zwischen dem TRAIL-Signalweg und dem Ovarialkarzinom in einer immunkompetenten Situation. Ich konnte beobachten, dass DR5 in allen zehn tumorigenen MOSE (Mouse-Ovarial-Surface-Epithel)-Zelllinien weniger exprimiert wird als in normalen (nicht-tumorigenen) MOSE-Zellen. Rund 70 % der tumorigenen MOSE-Zelllinien waren resistent gegen TRAIL-induzierte Apoptose. In einem vorangegangenen Tierexperiment hat die Reduktion von Maus-DR5 die Entstehung von Aszites beschleunigt und die Lebensspanne der Mäuse verkürzt. Dies stimmt mit unseren früheren Beobachtungen, bezüglich der zentralen Rolle von TRAIL-Rezeptoren im menschlichen Ovarialkarzinom, überein.
Zusammenfassend zeigen die Ergebnisse meiner Dissertation, dass DR5 und c-FLIPL im Zusammenhang mit dem TRAIL-Signalweg eine fundamentale Rolle in der Pathogenese des Ovarialkarzinoms spielen und dass DR5 und c-FLIPL potentielle Ziele fĂĽr die Therapie des Ovarialkarzinoms darstellen.Tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) triggers apoptosis in a variety of tumor cells, but not in normal cells. Therefore, TRAIL and in particular agonistic antibodies to the functional TRAIL receptors TRAIL-R1 (DR4) and TRAIL-R2 (DR5) are currently being explored in pre-clinics and clinical trials for the treatment of various malignancies.
TRAIL is highly prevalent in ovarian tumor microenvironment and is being associated with prolonged survival. In addition, more than two third of ovarian cancer (OC) patients have a disturbed TRAIL signaling pathway, a fact important not only for prognosis, but also for future therapeutic options. Defects in the TRAIL pathway include a downregulation of TRAIL functional receptors DR4 and DR5, and/or an overexpression of the long isoform of caspase-8 inhibitor protein cellular Fas-associated death domain-like interleukin-1beta-converting enzyme (FLICE)-like inhibitory protein (c-FLIPL).
The central aim of my PhD thesis was to gain further insight into the deregulation of the TRAIL signaling axis as potential tumor escape mechanism in OC. In the first part of my PhD thesis I elucidated whether human OC resistance to TRAIL may be overcome by an agonistic anti-human DR5 monoclonal antibody (AD5-10). I identified that co-administration of AD5-10 with carboplatin exhibits more than an additive effect in vitro, which may be explained by the finding that carboplatin upregulates DR5 expression on OC cells irrespective of the p53 status. The combination therapy of AD5-10 with carboplatin eliminated large established platin resistant ovarian tumors in vivo, reducing tumor size to undetectable levels in more than 50% of mice (P=0.002). In addition, I found that TRAIL and natural killer (NK) cell expression are abundant in the tumor microenvironment, and that depletion of NK cells abolishes the antitumor activity of AD5-10. Taken together, these data show that a combination of agonistic anti-DR5 monoclonal antibody such as AD5-10 and carboplatin is a promising regimen for treatment of OC. These results also highlight the interplay between a therapy addressing the apoptosis cascade and the role of the immune system.
In the second part of my PhD thesis I focused on the physiological role of c-FLIPL in OC progression. To address this question, a loss of function approach was applied utilizing RNA interference (RNAi) in OC in vitro and in vivo. I was able to demonstrate that suppression of c-FLIPL enhanced sensitivity of human OC cells to TRAIL-mediated apoptosis and significantly decreased tumor development in vivo. Interestingly, I observed that downregulation of c-FLIPL decreased the rate of apoptosis and proliferation in vivo. The knockdown of c-FLIPL particularly inhibited the invasion of OC cells into the peritoneal cavity, which might be due to the high expression of TRAIL by NK cells in the tumor-stroma. Altogether, these results indicate that c-FLIPL regulates TRAIL-induced apoptosis in OC cells.
I complemented my work by utilizing an established syngeneic ovarian tumor model kindly provided by a collaboration partner, and obtained some very first insights into the interplay between the TRAIL pathway and OC in the immunocompetent situation. I observed that DR5 expression is reduced in all ten transformed mouse ovarian surface epithelial (MOSE) cell lines when compared to normal (non-tumorigenic) MOSE cells. About 70% of tumorigenic MOSE cell lines were resistant to TRAIL-induced apoptosis. In a preliminary animal experiment, the downregulation of mouse DR5 accelerated the development of ascites and decreased mouse life span, which is in line with previous observations that TRAIL receptors play a key role in human OC.
In conclusion, the data generated in the course of my PhD thesis indicate that DR5 and c-FLIPL, in the context of the TRAIL signaling pathway, play a fundamental role in OC pathogenesis and thus are potential targets for future OC therapy
IT Students Project Group Work in the Day of COVID-19: Understanding the Impact and Attitudes
COVID-19 pandemic has resulted in disruptive impacts on teaching and learning experience around the world. In a particular context of project-based courses, where students need to interact and collaborate frequently, there appears additional challenges in implementing and learning from projects. Understanding the impact of COVID-19 on project-based courses does not only provide recommendations for preparing such courses in post-pandemic eras, but also has some implications for physical IT projects in industry. We investigated 30 student teams in Spring semester 2020, when COVID-19 measures were applied in the middle of the course. We adopted a mixed-method approach; a bottom-up analysis with a thematic analysis, and a top-down approach with attribution theory. We found that COVID19 measures introduced as external attributions to the course had direct and sudden impact manifestations on individual level, which leads to internal attributions, such as lack of motivation, lack of commitment, realization of usefulness of some online tools, and mental struggle. This creates an indirect impact on team, process and product factors in the course
The Sonographic Measurement of the Inferior Vena Cava Diameter versus the Central Venous Pressure in Assessing Fluid Responsiveness in Patients after Coronary Artery Bypass Graft Surgery
Background: Fluid status assessment and management post coronary artery bypass grafting (CABG) is a clinical challenge. The study aimed to establish whether central venous pressure (CVP) and ultrasound measures of respiratory variability of inferior vena cava (IVC) diameter might predict fluid responsiveness in mechanically ventilated patients after CABG.
Methods: This comparative study included 200 consecutive adult patients who underwent elective CABG. We recorded the following parameters: heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP), central venous pressure (CVP), inferior vena cava maximum (IVCmax), and minimum (IVCmin) diameters, left ventricular ejection fraction (LVEF), and velocity-time integral in the left ventricular outflow tract (VTI-LVOT).
Results: The age of the patients ranged from 45 to 71 years, and 147 were males (73.5%). Patients were grouped into fluid responders (n= 135), defined as stroke volume variation (SVV) of 15% or greater following fluid bolus administration, and fluid non-responders (n= 65), defined SVV of less than 15% following fluid bolus administration. There was no statistically significant difference between the groups regarding their CVP, maximum and minimum IVC diameters, inferior vena cava distensibility index (IVC-DI), and other markers of fluid responsiveness (p-value 0.47, 0.34, 0.59, and 0.64, respectively). There was a significant difference in SVV between fluid responders (18.33±2.767) and non-responders (10.95±1.940) (p-value <0.001).
Conclusion: Neither CVP nor sonographic measures of IVC diameter respiratory variability provided an accurate method to distinguish between fluid responders and non-responders in the early postoperative period after CABG
Simple 1-D Convolutional Networks for Resting-State fMRI Based Classification in Autism
Deep learning methods are increasingly being used with neuroimaging data like
structural and function magnetic resonance imaging (MRI) to predict the
diagnosis of neuropsychiatric and neurological disorders. For psychiatric
disorders in particular, it is believed that one of the most promising modality
is the resting-state functional MRI (rsfMRI), which captures the intrinsic
connectivity between regions in the brain. Because rsfMRI data points are
inherently high-dimensional (~1M), it is impossible to process the entire input
in its raw form. In this paper, we propose a very simple transformation of the
rsfMRI images that captures all of the temporal dynamics of the signal but
sub-samples its spatial extent. As a result, we use a very simple 1-D
convolutional network which is fast to train, requires minimal preprocessing
and performs at par with the state-of-the-art on the classification of Autism
spectrum disorders.Comment: accepted for publication in IJCNN 201
Effets de la coopération sur le développement de la situation de la femme rurale: Cas des coopératives du groupement d’intérêt économique Tizargane à la province de Tiznit
Cooperatives are perceived as a social-based business model. They have the effect of creating social value, generating wealth, promoting employment and contributing to the country's socio-economic development. The membership rate of the active population in the cooperative turns around 4% according to the database of the office of development and cooperation.
This study aims at revealing the contribution of the Moroccan cooperatives in the improvement of the situation of rural women at the decision-making and socio-economic levels.
Therefore, we opt for a quantitative approach, which is conducted on a sample of about 70 women members of the TIZARGANE group of cooperatives in the province of Tiznit. As a result, the membership in the cooperative work has had positive effects in terms of women's empowerment and improvement of their living conditions.Les coopératives sont considérées comme un modèle d’entreprise à base sociale. Elles ont pour effet la création de la valeur sociale et de la richesse, la promotion de l’emploi et la contribution au développement socio-économique du pays. Le taux d’adhésion des populations actives à la coopérative tourne autour de 4% selon les données de l’Office de Développement et de la Coopération (ODCO).
Ce travail de recherche vise à montrer l’apport des coopératives marocaines dans le développement de la situation des femmes rurales aux niveaux décisionnel et socio-économique.
A cet effet, nous optons dans cette étude pour une démarche quantitative, menée auprès d’un échantillon d’environ 70 femmes membres du groupement TIZARGANE des coopératives de la province de Tiznit. Par conséquent, il en découle que l’adhésion au travail coopératif a eu des effets positifs en matière d’autonomisation de la femme et d’amélioration de ses conditions de vie
In vitro production of steroidal saponin, total phenols and antioxidant activity in callus suspension culture of Paris polyphylla Smith: an important Himalayan medicinal plant
Paris polyphylla Smith (Melanthiaceae) family, which is native to the Himalayan region, has received a lot of attention recently due to its extensive history of usage in traditional medicine. The production of steroidal saponin from callus suspension cultures of P. polyphylla was observed in the current study. The current study attempted to develop a P. polyphylla plant callus suspension culture through optimization of cultivation technique for callus suspension, quantification of total phenolic components and estimation of the extract’s antioxidant activity. A light-yellow callus was formed within six weeks of cultivating rhizomes on Murashige and Skoog (MS) media supplemented with Thidiazuron (TDZ). Furthermore, the effect of TDZ, Methyl Jasmonate (MeJA), and Yeast Extract (YE) on callus growth, steroidal saponin (dioscin and diosgenin), total phenolic content, total flavonoids, total tannin, and total antioxidant activity was also measured. The medium containing 0.5 μM TDZ depicted the maximum callus biomass (2.98 g fresh weight). Significantly high phenolic and tannin content was observed in the MS medium containing 50 μM MeJA, whereas, no significant increase was observed in total tannin production in any treatment. Three in vitro assays, DPPH (2,2-diphenyl-1-picrylhydrazyl), ABTS (2,2′-azino-bis (3-ethylbenzothiazoline- 6-sulfonic acid)) and FRAP (ferric ion reducing antioxidant potential) and FC (Folin-Ciocalteu), were used to assess antioxidant potential of callus. Maximum antioxidant analysis reported in 1.0 μM TDZ (6.89 mM AAE/100 g) containing medium followed by 50 μM MeJA (6.44 mM AAE/100 g). The HPLC analysis showed a high presence of dioscin and diosgenin (5.43% and 21.09%, respectively) compared to the wild sample (2.56% and 15.05%, respectively). According to the results, callus produced on media supplemented with 50 μM MeJA have significant phenolic contents and elevated antioxidant activity; nevertheless, callus growth was greater in the presence of 0.5 μM TDZ. The findings of the current study have commercial implications since greater biomass production will result in active phytochemicals that the pharmaceutical and nutraceutical sectors are in need desperately
Generative AI in Undergraduate Information Technology Education -- Insights from nine courses
The increasing use of digital teaching and emerging technologies,
particularly AI-based tools, such as ChatGPT, is presenting an inevitable and
significant impact on higher education. The capability of processing and
generating text could bring change to several areas, such as learning
assessments or learning experiences. Besides the negative impact, i.e exam
cheating, we also see a positive side that ChatGPT can bring to education. This
research article aims to contribute to the current debate on ChatGPT by
systematic reflection and experience reported from nine bachelor IT courses at
a Norwegian university. We conducted inductive empirical research with
reflective notes and focused groups of lecturers from nine different IT
courses. The findings were thematically organized with numerous use cases in
teaching IT subjects. Our discussion highlights the disruptive implications of
AI assistant usage in higher education and emphasizes the need for educators to
shape this transformation
Value of Immunological Biomarkers in Early Prediction of Bacillus Calmette-Guerin Failure in High-Risk Non-muscle-invasive Bladder Cancer
Objectives To investigate the predictive value of different immunological markers on treatment outcomes after bacillus Calmette-Guerin (BCG) induction in high-risk non-muscle-invasive bladder cancer (NMIBC).
Patients and Methods Patients who underwent transurethral resection of bladder tumors for NMIBC were assessed for study eligibility. Urine and blood samples were taken from patients at baseline (immediately before the first dose of induction). Urine samples were evaluated for interleukin (IL)-6, IL-8, IL-10, IL-11, and interferon- Îł by solid-phase enzyme-linked immunosorbent assay (ELISA). Blood samples were evaluated for epidermal growth factor receptor (EGFR) and human epidermal growth factor receptor-2 (HER2) using quantitative reverse transcriptase-polymerase chain reaction analysis. Each marker was assessed in relation to tumor recurrence.
Results Between June 2016 and December 2019, 160 patients were included. Tumor recurrence occurred in 47 (29.38%) patients over a median (IQR) follow-up of 24 (12: 49) months. Using univariate analysis, the following urinary cytokines were associated with higher recurrence: urinary IL-6, 8, 10, 11, and interferon-Îł. Also, serum EGFR and HER2 were associated with higher recurrence. On multivariate Cox regression analysis, significant variables include HER2 [HR (95%CI): 2.675 (1.367-5.233), p= 0.004], and IL-11 [HR (95%CI): 0.889 (0.825-0.957), p= 0.002].
Conclusions Serum HER2 and urinary IL-11 could be applied in clinical practice to predict BCG failure in patients with high-risk NMIBC, so those patients could be offered other modalities (radical cystectomy) early with better survival. Further studies are recommended to establish their exact role
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