524 research outputs found
Patient-Derived Pancreatic Ductal Adenocarcinoma Organoids: A Strategy for Precision Medicine and Therapy Improvement
Pancreatic cancer is the seventh leading cause of cancer related mortalities worldwide and incidences are increasing. The prognosis remains poor as the 5-year survival rate is below 10%. This can be partly explained by the silent progression of disease as most patients present with advanced disease at time of diagnosis. In turn, surgical resection, the only potential curative measure, is not possible in nearly 80% of cases due to the occurrence of distant metastasis and/or infiltration of major vessels in close proximity to the pancreas. In patients with localized but advanced disease, resectability can be achieved in some cases by initiation of a neoCTx. However, as neoCTx is commonly conducted by administering multi-drug treatments, severe side effects occur frequently, which require an adaption of drug doses administered.
In this study, we revealed the negative impact of these drug dose changes during neoCTx on the patients´ treatment outcome. R0 resections were significantly less frequently observed, and the N-status significantly impacted by the tumor regression grade, which in turn trended towards minor response in the cohort of patients that did not sustain full dose course prior surgery. In turn, treatment of LA PDAC could be improved by increasing the proportion of patients that undergo neoCTx without any changes of the treatment schedule. Patient-derived PDAC organoid could serve as an avatar of patients´ tumor disease on which optimal treatment protocols could be tested.
In this study, a large living PDAC PDO biobank successfully has been established from surgical resection specimens as well as EUS guided FNA samples. Subsequently, a new protocol for molecular subtyping of PDAC on organoids was established by assessing the expression level of KRT81 and CFTR, as a replacement for HNF1a, using IF staining. Strikingly, we observed identical PDAC subtypes in PDOs and their respective tissue of origin in nearly all cases. This observation allowed the assumption that PDOs could indeed be used as patient-individual avatars to identify treatment sensitivities and resistances, as they share fundamental molecular properties with the tissue they have been initiated from.
Extensive pharmacotyping was performed for many PDO lines by testing the response behavior to the multi-drug regimens FOLFIRINOX and Gem/Pac, as well as their respective single drug compounds. As a result, we observed diverse response patterns for each PDAC PDO line. A poor response to FOLFIRINOX did not necessarily imply a resistance to Gem/Pac. PDO pharmacotyping could guide treatment decision making in the foreseeable future. Moreover, when the non-efficient drug was removed, no changes of overall efficacy of treatment in PDOs was observed, implying that additional therapy improvements could be possible using this ex vivo model. This observation was true for both commonly used chemotherapy protocols, FOLFIRINOX and Gem/Pac and could result in less drug mediated side effects under (neo)adjuvant CTx without impacting treatment efficacy.
Yet, the main goal of this study was to assess if PDAC PDOs can be used to predict the neoCTx outcome of PDAC patients. All methods required to address this issue in a prospective clinical trial have been established as a protocol for PDAC PDOs initiation from minimal starting material has been established and subsequently improved resulting in take rates of up to 80%. To support this study, we successfully secured patient enrollment from a second clinical center, which will increase the number of recruited patients in the future. Unfortunately, at the time of writing this thesis, patient numbers were not sufficient to answer the question of the predictive value of PDAC PDOs in regard to the current standard of care
Training professors in ICT: Personal Learning Environments. A grounded theory research study
14 páginasThe objective of this study is to recommend a training plan for teachers in the Department of Nursing and Rehabilitation that develops the competencies necessary for the educational integration of information and communication technologies (ICTs) in teaching and learning processes. The study was conducted with qualitative tools, beginning with a questionnaire that identified ICT competencies. Professors were able to develop reflection processes regarding their pedagogical practice that resulted in designing learning strategies centred on the student with the support of ICTs. The competencies developed by the professors allowed them to continue exploring the pedagogical technological tools available, that is, taking into consideration the learning objectives that are expected to be reached in the courses and subjects suggested. Personal learning environments served as mediating factors in the development of the professors’ competencies and as a mechanism for continuing with the training process
First Impressions are More Important than Early Intervention Qualifying Broken Windows Theory in the Lab
Broken Windows: the metaphor has changed New York and Los Angeles. Yet it is far from undisputed whether the broken windows policy was causal for reducing crime. In a series of lab experiments we put two components of the theory to the test. We show that first impressions and early punishment of antisocial behaviour are independently and jointly causal for cooperativeness. The effect of good first impressions and of early vigilance cannot be explained with, but adds to, participants’ initial level of benevolence. Mere impression management is not strong enough to maintain cooperation. Cooperation stabilizes if good first impressions are combined with some risk of sanctions. Yet if we control for first impressions, early vigilance only has a small effect. The effect vanishes over time.
The Importance of Directly Derived Information in the Basketball Jump Shot. A Comparison of Changed Visual Conditions from Different Shooting Spots
The basketball jump shot as a movement, allowing visual feedback based corrections, can be considered as a generalized or a specialized motor skill. The purpose of this study is to look into the connection between visual perception and the specialization of a motor skill. Therefore, six male basketball players were asked to perform jump shots under different viewing conditions from their favourite spot (sweet spot) and a second, middle-distance spot. The question was, if performance is affected by the changed visual conditions and whether the shooting spot plays a role in a potentially change in performance. The different visual conditions were first, a regular basketball hoop with no adjustment, second a regular basketball hoop with a covered backboard, and third a regular basketball hoop with a covered rim. Between the different visual conditions, performance did not differ significantly, neither from the sweet spot, nor from the neutral defined spot. However, players showed a significantly better performance from sweet spot than from the neutral spot under regular viewing conditions
Prolonged Pediatric Extracorporeal Membrane Oxygenation Support with Cardiopulmonary Failure in Juvenile Myelomonocytic Leukemia
We report a case of a child survival after extracorporeal membrane oxygenation (ECMO) support of 25 days for cardiopulmonary failure and septic shock in the context of juvenile myelomonocytic leukemia (JMML). ECMO support is still a matter of debate for the management of septic patients with malignancy. However, these patients are at increased risk for early death secondary to pulmonary complications due to leukostasis, direct pulmonary infiltration with WBC, and systemic inflammatory response syndrome following malignant cell lysis. Despite the high risk of complications, ECMO support must be discussed as part of management, providing better outcome in this group of patients
G-protein betagamma-complex is crucial for efficient signal amplification in vision
A fundamental question of cell signaling biology is how faint external signals produce robust physiological responses. One universal mechanism relies on signal amplification via intracellular cascades mediated by heterotrimeric G-proteins. This high amplification system allows retinal rod photoreceptors to detect single photons of light. While much is now known about the role of the α-subunit of the rod-specific G-protein transducin in phototransduction, the physiological function of the auxiliary βγ-complex in this process remains a mystery. Here we show that elimination of the transducin γ-subunit drastically reduces signal amplification in intact mouse rods. The consequence is a striking decline in rod visual sensitivity and severe impairment of nocturnal vision. Our findings demonstrate that transducin βγ-complex controls signal amplification of the rod phototransduction cascade and is critical for the ability of rod photoreceptors to function in low light conditions
Diets with corn oil and/or low protein increase acute acetaminophen hepatotoxicity compared to diets with beef tallow in a rat model
It has been reported that dietary polyunsaturated fats (PUFA) increase liver injury in response to ethanol feeding. We tested the hypothesis that diets rich in linoleic acid (18:2n-6) would affect acute liver injury after acetaminophen injection and that protein restriction might exacerbate the liver injury. We examined effects of feeding diets with either 15% (wt/wt) corn oil or 14% beef tallow and 1% corn oil for six weeks with either 6 or 20 g/100 g protein on acute hepatotoxicity. After the feeding period, liver injury was induced by injecting either with 600 mg/kg body weight acetaminophen suspended in gum arabic-based vehicle, or with vehicle alone during fasting status. Samples of liver and plasma were taken for analyses of hepatic glutathione (GSH) levels and liver-specific enzymes [(Glutamate-pyruvate transaminase (GPT) and glutamate-oxaloacetate transaminase (GOT)], respectively. Whereas GSH level was significantly lower in only group fed 15% corn oil with 6 g/100 g protein among acetaminophen-treated groups, activities of GPT and GOT were significantly elevated in all groups except the one fed beef tallow with 20 g/100 g protein, suggesting low protein might exacerbate drug-induced hepatotoxicity. The feeding regimens changed the ratio of 18:2n-6 to oleic acid (18:1n-9) in total liver lipids approximately five-fold, and produced modest changes in arachidonic acid (20:4n-6). We conclude that diets with high 18:2n-6 promote acetaminophen-induced liver injury compared to diets with more saturated fatty acids (SFA). In addition, protein restriction appeared to exacerbate the liver injury
Zinc deficiency decreased cell viability both in endothelial EA.hy926 cells and mouse aortic culture ex vivo and its implication for anti-atherosclerosis
Zinc plays a protective role in anti-atherosclerosis but the clear mechanism has not been proposed yet. In the present study, we evaluated whether zinc modulates atherosclerotic markers, VACM-1 and ICAM-1 and cell viability both in endothelial cells in vitro and mouse aortic cell viability ex vivo. In study 1, as in vitro model, endothelial EA.hy926 cells were treated with TNFα for 5 hours for inducing oxidative stress, and then treated with Zn-adequacy (15 µM Zn) or Zn-deficiency (0 µM Zn) for 6 hours. Pro-atherosclerosis factors, VCAM-1 and ICAM-1 mRNA expression and cell viability was measured. In study 2, as ex vivo model, mouse aorta ring was used. Mourse aorta was removed and cut in ring then, cultured in a 96-well plate. Aortic ring was treated with various TNFα (0-30 mg/ml) and intracellular zinc chelator, N, N, N', N', -tetrakis (2-pyridylmethyl) ethylenediamine (TPEN, 0-30 µM) for cellular zinc depletion for 2 days and then cell viability was measured. The results showed that in in vitro study, Zn-adequate group induced more VCAM-1 & ICAM-1 mRNA expression than Zn-deficient group during 6-hour zinc treatment post-5 hour TNF-α treatment, unexpectedly. These results might be cautiously interpreted that zinc would biologically induce the early expression of anti-oxidative stress through the increased adhesion molecule expression for reducing atherosclerotic action, particularly under the present 6-hour zinc treatment. In ex vivo, mouse aortic ring cell viability was decreased as TNF-α and TPEN levels increased, which suggests that mouse aortic blood vessel cell viability was decreased, when oxidative stress increases and cellular zinc level decreases. Taken together, it can be suggested that zinc may have a protective role in anti-atherosclerosis by cell viability in endothelial cells and aorta tissue. Further study is needed to clarify how pro-atherosclerosis molecule expression is modulated by zinc
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