291 results on '"Ziegler, Christian"'
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252. Die selige und auf ewig währende Vermählung mit Christo wolten bey dem Eh-Jubileo des Hochgebornen Grafen und Herrn, Herrn Christian Ernst, des h. R. R. Grafen zu Stolberg, ... und der Hochgebornen Gräfin und Frau, Frau Sophie Charlotte, vermählten Reichs-Gräfin zu Stolberg, ... kindlich besingen ... unten benante Schulkinder auf dem Schlosse: Christian Friedrich Ziegler, Christian Carl Haberland, Christian Gottfried Jacobi, Christian Friedrich Hattorf, Johan Gottfried Hattorf, Christoph Friedrich Haberland, Christian Ernst Nicolai, Ernst August Hattorf, Christian Friedrich Lose. Christine Elisabeth Heinriette Losin, Heinritte Elisabeth Neuhausin, Sophia Catharina Jacobin, Louise Christiane Haberlandin, Dorothea Christiane Neuhausin, Elenore Friedericke Lohsin, Dorothea Friedericka Simonin, Anna Christina Jacobin, Christina Ferdinande Vesterlingen Louisa Augusta Neuhausin, Euphrosina Beata Jacobin, Sophia Heinrietta Christine Nicolain, Charlotta Christiane Simonin
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Haberland, Christian Carl, Jacobi, Christian Gottfried, Hattorf, Christian Friedrich, Hattorf, Johan Gottfried, Haberland, Christoph Friedrich, Nicolai, Christian Ernst, Hattorf, Ernst August, Lose, Christian Friedrich, Losin, Christine Elisabeth Heinriette, Neuhausin, Heinritte Elisabeth, Jacobin, Sophia Catharina, Haberlandin, Louise Christiane, Neuhausin, Dorothea Christiane, Lohsin, Elenore Friedericke, Simonin, Dorothea Friedericka, Jacobin, Anna Christina, Vesterlingen, Christina Ferdinande, Neuhausin, Louisa Augusta, Jacobin, Euphrosina Beata, Nicolain, Sophia Heinrietta Christine, Simonin, Charlotta Christiane, Ziegler, Christian Friedrich, Haberland, Christian Carl, Jacobi, Christian Gottfried, Hattorf, Christian Friedrich, Hattorf, Johan Gottfried, Haberland, Christoph Friedrich, Nicolai, Christian Ernst, Hattorf, Ernst August, Lose, Christian Friedrich, Losin, Christine Elisabeth Heinriette, Neuhausin, Heinritte Elisabeth, Jacobin, Sophia Catharina, Haberlandin, Louise Christiane, Neuhausin, Dorothea Christiane, Lohsin, Elenore Friedericke, Simonin, Dorothea Friedericka, Jacobin, Anna Christina, Vesterlingen, Christina Ferdinande, Neuhausin, Louisa Augusta, Jacobin, Euphrosina Beata, Nicolain, Sophia Heinrietta Christine, Simonin, Charlotta Christiane, and Ziegler, Christian Friedrich
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Autopsie nach Exemplar der ULB Sachsen-Anhalt, Vorlageform des Erscheinungsvermerks: Wernigerode, gedruckt bey J. G. Struck, Hof-Buchdrucker, den 31. März 1762.
253. Wehmüthige Anbetung der unveränderlichen Treue Gottes in Christo bey der Gruft Ihrer in ihrem 61ten Jahre 1770 den 26ten Julii selig vollendeten treuen Mutter Johanne Elisabeth Zieglern, geb. Herrnschmidten von ihren hinterlassenen tiefgebeugten Kindern Sophie Charlotte Zieglern, Samuel Siegfried Ziegler, Christian Friedrich Ziegler
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Ziegler, Sophie Charlotte, Ziegler, Samuel Siegfried, Ziegler, Christian Friedrich, Ziegler, Sophie Charlotte, Ziegler, Samuel Siegfried, and Ziegler, Christian Friedrich
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Autopsie nach Ex. der ULB Sachsen-Anhalt, Vorlageform des Erscheinungsvermerks: Wernigerode, gedruckt bey Joh. Ge Struck, Hochgr. Hof-Buchdrucker.
254. Proelivm Mavritio Dvci Saxoniae Victori Et Alberto Brandenbvrgico Ivxta Sivershvsam Fatale
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Ziegler, Christian Friedrich and Ziegler, Christian Friedrich
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In Memoriam Beneficii Mareschalliani Die V. Octobris MDCCLXXVIII. Carmine Celebrat M. Christianvs Fridericvs Ziegler. Mühlberga Misn., Vorlageform des Erscheinungsvermerks: Vitebergae, Excudit Adamus Christianus Charisius.
255. Die selige und auf ewig währende Vermählung mit Christo wolten bey dem Eh-Jubileo des Hochgebornen Grafen und Herrn, Herrn Christian Ernst, des h. R. R. Grafen zu Stolberg, ... und der Hochgebornen Gräfin und Frau, Frau Sophie Charlotte, vermählten Reichs-Gräfin zu Stolberg, ... kindlich besingen ... unten benante Schulkinder auf dem Schlosse: Christian Friedrich Ziegler, Christian Carl Haberland, Christian Gottfried Jacobi, Christian Friedrich Hattorf, Johan Gottfried Hattorf, Christoph Friedrich Haberland, Christian Ernst Nicolai, Ernst August Hattorf, Christian Friedrich Lose. Christine Elisabeth Heinriette Losin, Heinritte Elisabeth Neuhausin, Sophia Catharina Jacobin, Louise Christiane Haberlandin, Dorothea Christiane Neuhausin, Elenore Friedericke Lohsin, Dorothea Friedericka Simonin, Anna Christina Jacobin, Christina Ferdinande Vesterlingen Louisa Augusta Neuhausin, Euphrosina Beata Jacobin, Sophia Heinrietta Christine Nicolain, Charlotta Christiane Simonin
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Haberland, Christian Carl, Jacobi, Christian Gottfried, Hattorf, Christian Friedrich, Hattorf, Johan Gottfried, Haberland, Christoph Friedrich, Nicolai, Christian Ernst, Hattorf, Ernst August, Lose, Christian Friedrich, Losin, Christine Elisabeth Heinriette, Neuhausin, Heinritte Elisabeth, Jacobin, Sophia Catharina, Haberlandin, Louise Christiane, Neuhausin, Dorothea Christiane, Lohsin, Elenore Friedericke, Simonin, Dorothea Friedericka, Jacobin, Anna Christina, Vesterlingen, Christina Ferdinande, Neuhausin, Louisa Augusta, Jacobin, Euphrosina Beata, Nicolain, Sophia Heinrietta Christine, Simonin, Charlotta Christiane, Ziegler, Christian Friedrich, Haberland, Christian Carl, Jacobi, Christian Gottfried, Hattorf, Christian Friedrich, Hattorf, Johan Gottfried, Haberland, Christoph Friedrich, Nicolai, Christian Ernst, Hattorf, Ernst August, Lose, Christian Friedrich, Losin, Christine Elisabeth Heinriette, Neuhausin, Heinritte Elisabeth, Jacobin, Sophia Catharina, Haberlandin, Louise Christiane, Neuhausin, Dorothea Christiane, Lohsin, Elenore Friedericke, Simonin, Dorothea Friedericka, Jacobin, Anna Christina, Vesterlingen, Christina Ferdinande, Neuhausin, Louisa Augusta, Jacobin, Euphrosina Beata, Nicolain, Sophia Heinrietta Christine, Simonin, Charlotta Christiane, and Ziegler, Christian Friedrich
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Autopsie nach Exemplar der ULB Sachsen-Anhalt, Vorlageform des Erscheinungsvermerks: Wernigerode, gedruckt bey J. G. Struck, Hof-Buchdrucker, den 31. März 1762.
256. Wehmüthige Anbetung der unveränderlichen Treue Gottes in Christo bey der Gruft Ihrer in ihrem 61ten Jahre 1770 den 26ten Julii selig vollendeten treuen Mutter Johanne Elisabeth Zieglern, geb. Herrnschmidten von ihren hinterlassenen tiefgebeugten Kindern Sophie Charlotte Zieglern, Samuel Siegfried Ziegler, Christian Friedrich Ziegler
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Ziegler, Sophie Charlotte, Ziegler, Samuel Siegfried, Ziegler, Christian Friedrich, Ziegler, Sophie Charlotte, Ziegler, Samuel Siegfried, and Ziegler, Christian Friedrich
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Autopsie nach Ex. der ULB Sachsen-Anhalt, Vorlageform des Erscheinungsvermerks: Wernigerode, gedruckt bey Joh. Ge Struck, Hochgr. Hof-Buchdrucker.
257. Functional adaptation after femoral intertrochanteric valgus osteotomy in Legg–Calvé–Perthes disease.
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Wagner, Ferdinand, Weiß, Barbara, Holzapfel, Boris Michael, Ziegler, Christian Max, and Heimkes, Bernhard
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ADDUCTION , *OSTEOTOMY , *HIP joint , *PROGNOSIS , *PATIENT selection , *RANGE of motion of joints , *QUALITY of life - Abstract
Legg–Calvé–Perthes disease (LCPD) requires individualized treatment in order to regain a functional hip joint. In severe cases, in which a congruent joint cannot be achieved, other options are necessary in order to improve functionality and prevent early osteoarthritis. Therefore, we analysed the clinical and radiologic outcome of 28 patients after valgus osteotomy of the proximal femur (VOF). We examined the range of hip motion, functionality and health-related quality of life (HRQoL) via modified Harris Hip Score (mHHS) and Kidscreen-10. Radiographic analysis contained quantitative and qualitative measurements of hip morphology. In particular, we correlated the results with the change of the pelvic-femoral angle (PFA). PFA was defined as the angle between the anatomical diaphyseal line of the femur and a vertical line through the pelvis. The mean follow-up was 5.5 years. Patients showed high mHHS and good HRQoL postoperatively. An increase in ROM with an improvement of 30.5° abduction and 10.3° internal rotation was evident. PFA correlated with adduction contracture and improved significantly after surgery. In consideration of careful patient selection, VOF showed a positive effect on ROM, pain, HRQoL, radiographic congruence and outcome. We identified the age at surgery and an increasing adduction contracture—objectified by a decreased PFA—as a prognostic factor. [ABSTRACT FROM AUTHOR]
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- 2023
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258. Nanotechnologies for the biosciences.
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Ziegler, Christian
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NANOTECHNOLOGY , *HIGH technology , *ANALYTICAL chemistry , *BIOLOGY , *PERIODICALS , *SERIAL publications - Abstract
Editorial. Introduces the articles published in the August 2004 issue of the periodical "Analytical and Bioanalytical Chemistry". Developments in the nanotechnology affecting the analytical chemistry field; Importance of analyzing natural materials in understanding biological mechanisms.
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- 2004
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259. Electronic structure of KCa2Nb3O10 as envisaged by density functional theory and valence electron energy loss spectroscopy.
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Singh Virdi, Kulpreet, Kauffmann, Yaron, Ziegler, Christian, Ganter, Pirmin, Lotsch, Bettina V., Kaplan, Wayne D., Blaha, Peter, and Scheu, Christina
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ELECTRONIC structure , *DENSITY functional theory , *CONDUCTION electrons , *ELECTRON energy loss spectroscopy , *PEROVSKITE , *BAND gaps - Abstract
KCa2Nb3O10 is a layered Dion-Jacobson-type perovskite important for a number of applications such as photocatalysis and as a building block for heteronanostructures. Despite this, some of its central electronic properties such as the band gap and dielectric function are not well understood. In this report we have attempted to determine the band gap and understand the electronic structure of KCa2Nb3O10 using density functional theory. Simultaneously, the band gap and loss function have been determined experimentally using valence electron energy loss spectroscopy. The theoretical results indicate that KCa2Nb3O10 is a direct band gap semiconductor with a sparse density of states close to the onset of the conduction band. The calculated band gap value of 3.1 eV is in excellent agreement with the 3.2±0.1 eV measured experimentally. The loss functions computed and experimentally determined show good agreement up to 20 eV, but the theoretical peak positions at higher energy do not agree with the experimental electron energy loss spectrum. These transitions originate from K-3p, Ca-3p, and Nb-4p semicore states and their positions are not well described by Kohn-Sham eigenvalues. After a scissors shift of transitions due to these states by about 2.5 eV to higher energies we obtain good agreement with the experimental loss function and can thus explain the origin of all the features seen in the experimental electron energy loss spectrum. [ABSTRACT FROM AUTHOR]
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- 2013
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260. Sparsam stapeln und transportieren.
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Ziegler, Christian
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- 2015
261. Prolonged delivery of HIV-1 vaccine nanoparticles from hydrogels.
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Mietzner, Raphael, Barbey, Clara, Lehr, Heike, Ziegler, Christian E., Peterhoff, David, Wagner, Ralf, Goepferich, Achim, and Breunig, Miriam
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HIV , *VACCINE effectiveness , *SILICA nanoparticles , *MACROMONOMERS , *NANOPARTICLES - Abstract
[Display omitted] Immunization is a straightforward concept but remains for some pathogens like HIV-1 a challenge. Thus, new approaches towards increasing the efficacy of vaccines are required to turn the tide. There is increasing evidence that antigen exposure over several days to weeks induces a much stronger and more sustained immune response compared to traditional bolus injection, which usually leads to antigen elimination from the body within a couple of days. Therefore, we developed a poly(ethylene) glycol (PEG) hydrogel platform to investigate the principal feasibility of a sustained release of antigens to mimic natural infection kinetics. Eight-and four-armed PEG macromonomers of different MWs (10, 20, and 40 kDa) were end-group functionalized to allow for hydrogel formation via covalent cross-linking. An HIV-1 envelope (Env) antigen in its trimeric (Env tri) or monomeric (Env mono) form was applied. The soluble Env antigen was compared to a formulation of Env attached to silica nanoparticles (Env-SiNPs). The latter are known to have a higher immunogenicity compared to their soluble counterparts. Hydrogels were tunable regarding the rheological behavior allowing for different degradation times and release timeframes of Env-SiNPs over two to up to 50 days. Affinity measurements of the VCR01 antibody which specifically recognizes the CD4 binding site of Env, revealed that neither the integrity nor the functionality of Env mono -SiNPs (K d = 2.1 ± 0.9 nM) and Env tri -SiNPs (K d = 1.5 ± 1.3 nM), respectively, were impaired after release from the hydrogel (K d before release: 2.1 ± 0.1 and 7.8 ± 5.3 nM, respectively). Finally, soluble Env and Env-SiNPs which are two physico-chemically distinct compounds, were co-delivered and shown to be sequentially released from one hydrogel which could be beneficial in terms of heterologous immunization or single dose vaccination. In summary, this study presents a tunable, versatile applicable, and effective delivery platform that could improve vaccination effectiveness also for other infectious diseases than HIV-1. [ABSTRACT FROM AUTHOR]
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- 2024
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262. Exquisite sensitivity of adrenocortical carcinomas to induction of ferroptosis.
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Belavgeni, Alexia, Bornstein, Stefan R., von Mässenhausen, Anne, Tonnus, Wulf, Stumpf, Julian, Meyer, Claudia, Othmar, Evelyn, Latk, Markus, Kanczkowski, Waldemar, Kroiss, Matthias, Hantel, Constanze, Hugo, Christian, Fassnacht, Martin, Ziegler, Christian G., Schally, Andrew V., Krone, Nils P., and Linkermann, Andreas
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UNSATURATED fatty acids , *CELL death , *SOMATOTROPIN , *CARCINOMA , *GLUTATHIONE peroxidase - Abstract
Adrenocortical carcinomas (ACCs) are rare and highly malignant cancers associated with poor survival of patients. Currently, mitotane, a nonspecific derivative of the pesticide DDT (1,1-(dichlorobiphenyl)-2,2-dichloroethane), is used as the standard treatment, but its mechanism of action in ACCs remains elusive. Here we demonstrate that the human ACC NCI-H295R cell line is remarkably sensitive to induction of ferroptosis, while mitotane does not induce this iron-dependent mode of regulated necrosis. Supplementation with insulin, transferrin, and selenium (ITS) is commonly used to keep NCI-H295R cells in cell culture. We show that this supplementation prevents spontaneous ferroptosis, especially when it contains polyunsaturated fatty acids (PUFAs), such as linoleic acid. Inhibitors of apoptosis (zVAD, emricasan) do not prevent the mitotane-induced cell death but morphologically prevent membrane blebbing. The expression of glutathione peroxidase 4 (GPX4) in H295R cells, however, is significantly higher when compared to HT1080 fibrosarcoma cells, suggesting a role for ferroptosis. Direct inhibition of GPX4 in H295R cells led to high necrotic populations compared to control, while cotreatment with ferrostatin-1 (Fer-1) completely reverted ferroptosis. Interestingly, the analysis of public databases revealed that several key players of the ferroptosis pathway are hypermethylated and/or mutated in human ACCs. Finally, we also detected that growth hormone-releasing hormone (GHRH) antagonists, such as MIA602, kill H295R cells in a nonapoptotic manner. In summary, we found elevated expression of GPX4 and higher sensitivity to ferroptosis in ACCs. We hypothesize that instead of treatment with mitotane, human adrenocortical carcinomas may be much more sensitive to induction of ferroptosis. [ABSTRACT FROM AUTHOR]
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- 2019
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263. Case report: Incidentally discovered case of pheochromocytoma as a cause of long COVID-19 syndrome
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Christian G. Ziegler, Carina Riediger, Matthias Gruber, Carola Kunath, Martin Ullrich, Jens Pietzsch, Svenja Nölting, Timo Siepmann, Stefan R. Bornstein, Hanna Remde, Georgiana Constantinescu, University of Zurich, and Ziegler, Christian G
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2712 Endocrinology, Diabetes and Metabolism ,Endocrinology, Diabetes and Metabolism ,10265 Clinic for Endocrinology and Diabetology ,610 Medicine & health ,COVID - Abstract
Pheochromocytomas (PCCs) are rare but potentially lethal tumors that arise from the adrenal medulla. The clinical suspicion and diagnosis of PCC can be challenging due to the non-specific nature of signs and symptoms. In many patients, infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) could lead to long-term symptoms including fatigue, headaches, and cognitive dysfunction. Here, we present the case of a patient incidentally diagnosed with an adrenal mass that proved to be a PCC after imaging was performed due to persisting complaints after coronavirus disease 2019 (COVID-19) infection. A 37-year-old male patient was referred to our center because of a right-sided inhomogeneous adrenal mass, incidentally found during a computed tomographic scan of the thorax performed due to cough and dyspnea that persisted after COVID-19 infection. Other complaints that were present prior to COVID-19 infection included profuse sweating, dizziness, exhaustion with chronic fatigue, and concentration difficulties. The patient had no history of hypertension, his blood pressure was normal, and the 24-h ambulatory blood pressure monitoring confirmed normotension but with the absence of nocturnal dipping. Plasma normetanephrine was 5.7-fold above the upper limit (UL) of reference intervals (738 pg/ml, UL = 129 pg/ml), whereas plasma metanephrine and methoxytyramine were normal at 30 pg/ml (UL = 84 pg/ml) and
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- 2022
264. Functional Engineering of Perovskite Nanosheets: Impact of Lead Substitution on Exfoliation in the Solid Solution RbCa2- xPb xNb3O10.
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Weber, Daniel, Duppel, Viola, Kamella, Claudia, Tuffy, Brian, Moudrakovski, Igor, Ziegler, Christian, Lotsch, Bettina V., Podjaski, Filip, Scheu, Christina, and Dennenwaldt, Teresa
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PEROVSKITE , *CHEMICAL peel , *TWO-dimensional materials (Nanotechnology) , *CRYSTAL structure , *IRRADIATION - Abstract
Tuning the chemical composition and structure for targeted functionality in two-dimensional (2D) nanosheets has become a major objective in the rapidly growing area of 2D materials. In the context of photocatalysis, both miniaturization and extending the light absorption of UV active photocatalysts are major assets. Here, we investigate the solid solution between two photocatalytic systems known from literature to evolve H2 from water/methanol under UV - RbCa2Nb3O10 ( Eg = 3.7 eV) - and visible light irradiation - RbPb2Nb3O10 ( Eg = 3.0 eV) - by synthesizing hypothetical RbCa2- xPb xNb3O10. While the calcium niobate can easily be exfoliated into individual nanosheets via cation-proton exchange and subsequent treatment with tetra- n-butylammonium hydroxide (TBAOH), the lead niobate barely yields nanosheets. Spectroscopic and microscopic analysis suggest that this is caused by volatilization of Pb during synthesis, leading to a local 3D linkage of RbPb2Nb3O10 perovskite units with Pb deficient units. On the one hand, this linkage progressively prevents exfoliation along with an increasing Pb content. On the other hand, introducing Pb into the perovskite blocks successively leads to bandgap narrowing, thus gradually enhancing the light harvesting capability of the solid solution. Finding a compromise between this narrowing of the bandgap and the possibility of exfoliation, visible light sensitized nanosheets can be engineered in good yield for an initial molar ratio of Ca:Pb ≥ 1:1. [ABSTRACT FROM AUTHOR]
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- 2017
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265. Modulation of pancreatic islets-stress axis by hypothalamic releasing hormones and 11β-hydroxysteroid dehydrogenase.
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Schmid, Janine, Ludwig, Barbara, Schally, Andrew V., Steffen, Anja, Ziegler, Christian G., Block, Norman L., Koutmani, Yassemi, Brendel, Mathias D., Karalis, Katia P., Simeonovic, Charmaine J., Licinio, Julio, Ehrhart-Bornstein, Monika, and Bornstein, Stefan R.
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CORTICOTROPIN releasing hormone , *GROWTH hormone releasing factor , *HYPOTHALAMIC-pituitary-adrenal axis , *MESSENGER RNA , *CELL proliferation - Abstract
Corticotropin-releasing hormone (CRH) and growth hormone-releasing hormone (GHRH), primarily characterized as neuroregulatots of the hypothalamic-pituitary-adrenal axis, directly influence tissue-specific receptor-systems for (RH and GHRH in the endocrine pancreas. Here, we demonstrate the expression of mRNA for (RH and CRH-receptor type 1 (CRHR1) and of protein for CRHR1 in rat and human pancreatic islets and rat insulinoma cells. Activation of CRHR1 and GHRH-receptor significantly increased cell proliferation and reduced cell apoptosis. (RH stimulated both cellular content and release of insulin in rat islet and insulinoma cells. At the ultrastructural level. CRHR1 stimulation revealed a more active metabolic state with enlarged mitochondria. Moreover, glucocorticoids that promote glucose production are balanced by both libhydroxysteroid dehydrogenase (11β-HSD) isoforms; 11β-HSDtype-i and 11β-HSD-type-2. We demonstrated expression of mRNA for 11β-HSD-1 and 11β-HSD-2 and protein for 11β-HSD-1 in rat and human pancreatic islets and insulinoma cells. Quantitative real-time PCR revealed that stimulation of CRHR1 and GHRHreceptor affects the metabolism of insulinoma cells by downregulating 11β-HSD-1 and up-regulating 11β-HSD-2. The 11~1-HSD enzyme activity was analyzed by measuring the production of cortisol from cortisone. Similarly, activation of CRHR1 resulted in reduced cortisol levels, indicating either decreased 11β-HSD-1 enzyme activity or increased 11β-HSD-2 enzyme activity; thus, activation of CRHR1 alters the glucocorticoid balance toward the inactive form. These data indicate that functional receptor systems for hypothalamic-releasing hormone agonists exist within the endocrine pancreas and influence synthesis of insulin and the pancreatic glucocorticoid shuttle. Agonists of CRHR1 and GHRH-receptor, therefore. may play an important role as novel therapeutic tools in the treatment of diabetes mellitus. [ABSTRACT FROM AUTHOR]
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- 2011
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266. Native and Oxidized Low-Density Lipoproteins Increase the Expression of the LDL Receptor and the LOX-1 Receptor, Respectively, in Arterial Endothelial Cells.
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Catar, Rusan, Chen, Lei, Zhao, Hongfan, Wu, Dashan, Kamhieh-Milz, Julian, Lücht, Christian, Zickler, Daniel, Krug, Alexander W., Ziegler, Christian G., Morawietz, Henning, and Witowski, Janusz
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ENDOTHELIAL cells , *VASCULAR endothelial cells , *CELL receptors , *AP-1 transcription factor , *TRANSCRIPTION factors , *LOW density lipoproteins , *MITOGEN-activated protein kinases , *LOW density lipoprotein receptors - Abstract
Atherosclerotic artery disease is the major cause of death and an immense burden on healthcare systems worldwide. The formation of atherosclerotic plaques is promoted by high levels of low-density lipoproteins (LDL) in the blood, especially in the oxidized form. Circulating LDL is taken up by conventional and non-classical endothelial cell receptors and deposited in the vessel wall. The exact mechanism of LDL interaction with vascular endothelial cells is not fully understood. Moreover, it appears to depend on the type and location of the vessel affected and the receptor involved. Here, we analyze how native LDL (nLDL) and oxidized LDL (oxLDL) modulate the expression of their receptors—classical LDLR and alternative LOX-1—in endothelial cells derived from human umbilical artery (HUAECs), used as an example of a medium-sized vessel, which is typically affected by atherosclerosis. Exposure of HUAECs to nLDL resulted in moderate nLDL uptake and gradual increase in LDLR, but not LOX-1, expression over 24 h. Conversely, exposure of HUAECs to oxLDL, led to significant accumulation of oxLDL and rapid induction of LOX-1, but not LDLR, within 7 h. These activation processes were associated with phosphorylation of protein kinases ERK1/2 and p38, followed by activation of the transcription factor AP-1 and its binding to the promoters of the respective receptor genes. Both nLDL-induced LDLR mRNA expression and oxLDL-induced LOX-1 mRNA expression were abolished by blocking ERK1/2, p-38 or AP-1. In addition, oxLDL, but not nLDL, was capable of inducing LOX-1 through the NF-κB-controlled pathway. These observations indicate that in arterial endothelial cells nLDL and oxLDL signal mainly via LDLR and LOX-1 receptors, respectively, and engage ERK1/2 and p38 kinases, and AP-1, as well as NF-κB transcription factors to exert feed-forward regulation and increase the expression of these receptors, which may perpetuate endothelial dysfunction in atherosclerosis. [ABSTRACT FROM AUTHOR]
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- 2022
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267. Influence of particle size selection methods on asphalt mixtures produced with lateritic aggregates.
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Cruz, Gabryelle Keith Avelino, de Medeiros Melo Neto, Osires, Arruda, Sonaly Mendes, de Figueiredo Lopes Lucena, Leda Christiane, Ziegler, Christian Rafael, and da Silva, Gustavo Correia Basto
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ASPHALT pavements , *ASPHALT , *MIXTURES , *PARTICLE analysis , *INFRASTRUCTURE (Economics) ,TROPICAL climate - Abstract
• The study evaluates the use of lateritic aggregates as an alternative to granitic aggregates. In addition to the study of this type of material, an analysis is carried out regarding the influence of particle size analysis methods on asphalt mixtures with these aggregates: • The research points out that the DAR technique was not efficient in estimating the permanent deformation and that the particle size selection methods did not interfere with the rigidity of the mixtures. • Mixtures with lateritic aggregates showed good performance regarding permanent deformation and resilience. However, greater susceptibility to the action of water, which limits the use of this material in regions with high rainfall. • Asphalt mixtures produced with lateritic aggregates are mainly indicated in countries with a tropical climate and low rainfall, such as the Northeast region of Brazil, where there is a significant presence of this material. The aggregates of asphalt mixtures provide resistance to most of the load applied to the pavement, so it is important to evaluate the physical and mechanical properties of the aggregates. In some regions of Brazil, the availability of traditional aggregates (granitic) is becoming scarce due to the rapid increase in infrastructure projects and the longer distance of deposit to the paving works. To address the above issues, we tried to find substitutes for granitic aggregates in asphalt mixtures. Laterite is a tropical or sub-tropical weathering product, abundant material in the North and Northeast of Brazil. The study aimed to evaluate the performance of asphalt mixtures produced with lateritic and granitic aggregates and verify the influence of National Department of Transport Infrastructure (DNIT), Bailey, and French particle size selection methods in the mixtures, through mechanical tests. The Dominant Aggregates Range (DAR) technique was used to evaluate the behavior of the mixtures in terms of permanent deformation. The asphalt mixtures were analyzed through dynamic modulus, flow number, fatigue test, resilience modulus, and Modified Lottman test. The analysis of the mixtures by the DAR method showed results that did not corroborate the results of the mechanical tests. However, all the analyzed mixtures showed good performance regarding permanent deformation, especially the mixtures with lateritic aggregates. The asphalt mixtures produced with lateritic aggregates present better mechanical performance, enabling their use mainly in countries with a tropical climate and low rainfall, such as the northeast region of Brazil. The French method showed equivalent mechanical performance and even superior to the DNIT method, commonly used in Brazil. [ABSTRACT FROM AUTHOR]
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- 2022
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268. Age-dependent regulation of chromaffin cell proliferation by growth factors, dehydroepiandrosterone (DHEA), and DHEA sulfate.
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Sicard, Flavie, Ehrhart-Bornstein, Monika, Corbeil, Denis, Sperber, Simone, Krug, Alexander W., Ziegler, Christian G., Rettori, Valeria, McCann, Samuel M., and Bornstein, Stefan R.
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CHROMAFFIN cells , *GROWTH factors , *DEHYDROEPIANDROSTERONE , *STEROID hormones , *ANDROGENS , *DEVELOPMENTAL neurobiology - Abstract
The adrenal gland comprises two endocrine tissues of distinct origin, the catecholamine-producing medulla and the steroid-producing cortex. The inner adrenocortical zone, which is in direct contact with the adrenomedullary chromaffin cells, produces dehydroepiandrostendione (DHEA) and DHEA sulfate (DHEAS). These two androgens exhibit potential effects on neurogenesis, neuronal survival, and neuronal stem cell proliferation. Unlike the closely related sympathetic neurons, chromaffin cells are able to proliferate throughout life. The aim of this study was to investigate the effect of DHEA and DHEAS on proliferation of bovine chromaffin cells from young and adult animals. We demonstrated that graded concentrations of leukemia inhibitory factor induced proliferation of chromaffin cells from young animals, whereas EGF had no effect. On the contrary, EGF increased the cell proliferation in cells from adult animals, whereas leukemia inhibitory factor was inactive. In both cases, DHEA decreased the proliferative effect induced by the growth factors. Surprisingly, DHEAS enhanced, in a dose-dependent-manner, the effect of growth factors on proliferation in cells from adult animals but not from young animals. Flutamide, ICI 182,780, and RU 486 had no effect on the action of DHEA or DHEAS on chromaffin cell proliferation. These data show that DHEA and its sulfated form, DHEAS, differentially regulate growth-factor-induced proliferation of bovine chromaffin cells. In addition, the sensitivity of chromaffin cells to different growth factors is age-dependent, Furthermore, these two androgens may act through a receptor other than the classical steroid receptors. [ABSTRACT FROM AUTHOR]
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- 2007
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269. GLP-1 and PYY for the treatment of obesity: a pilot study on the use of agonists and antagonists in diet-induced rats.
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Oertel M, Ziegler CG, Kohlhaas M, Nickel A, Kloock S, Maack C, Sequeira V, Fassnacht M, and Dischinger U
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Objective: Combination therapies with gut hormone analogs represent promising treatment strategies for obesity. This pilot study investigates the therapeutic potential of modulators of the glucagon-like peptide 1 (GLP-1) and neuropeptide Y (NPY) system using GLP-1 receptor agonists (semaglutide) and antagonists (exendin 9-39), as well as non-selective and NPY-Y2-receptor selective peptide tyrosine tyrosine (PYY) analogs (PYY3-36/NNC0165-0020 and NNC0165-1273) and an NPY-Y2 receptor antagonist (JNJ31020028)., Methods: High-fat diet (HFD)-induced obese rats were randomized into following treatment groups: group 1, nonselective PYY analog + semaglutide (n = 4); group 2, non-selective and NPY-Y2 receptor selective PYY analog + semaglutide (n = 2); group 3, GLP-1 receptor antagonist + NPY-Y2 receptor antagonist (n = 3); group 4, semaglutide (n = 5); and group 5, control (n = 5). Animals had free access to HFD and low-fat diet. Food intake, HFD preference and body weight were measured daily., Results: A combinatory treatment with a non-selective PYY analog and semaglutide led to a maximum body weight loss of 14.0 ± 4.9% vs 9.9 ± 1.5% with semaglutide alone. Group 2 showed a maximum weight loss of 20.5 ± 2.4%. While HFD preference was decreased in group 2, a strong increase in HFD preference was detected in group 3., Conclusions: PYY analogs (especially NPY-Y2 selective receptor agonists) could represent a promising therapeutic approach for obesity in combination with GLP-1 receptor agonists. Additionally, combined GLP-1 and PYY3-36 receptor agonists might have beneficial effects on food preference.
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- 2024
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270. Association of preclinical blood glucose with hospitalization rate and in-hospital mortality: A single-center retrospective cohort study.
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Kloock S, Skudelny D, Kranke P, Güder G, Weismann D, Fassnacht M, Ziegler CG, and Dischinger U
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Objective: Critical illness is often accompanied by elevated blood glucose, which generally correlates with increased morbidity and mortality. Prehospital blood glucose (PBG) level might be a useful and easy-to-perform tool for risk assessment in emergency medicine. This retrospective single-center cohort study was designed to analyze the association of prehospital glucose measurements with hospitalization rate and in-hospital mortality., Methods: Records of 970 patients admitted to a university hospital by an emergency physician were analyzed. Patients with a PBG ≥140 mg/dL (G1, n = 394, equal to 7.8 mmol/L) were compared with patients with a PBG <140 mg/dL (G2, n = 576). Multivariable logistic regression models were used to correct for age, prediagnosed diabetes, and sex., Results: Five hundred thirty-four patients (55%) were hospitalized. In comparison to normoglycemic patients, hyperglycemic patients were more likely to be hospitalized with an adjusted odds ratio (OR) of 1.48 (95% confidence interval [CI] 1.11-1.97), more likely to be admitted to the intensive care unit (ICU) with an adjusted OR of 1.74 (95% CI 1.31-2.31) and more likely to die in the hospital with an adjusted OR of 1.84 (95% CI 0.96-3.53). Hospitalized hyperglycemic patients had a median length of stay of 6.0 days (interquartile range [IQR] 8.0) compared to 3.0 days (IQR 6.0) in the normoglycemic group ( P < 0.001). In the subgroup analysis of cases without known diabetes, patients with PBG ≥140 mg/dL were more likely to be hospitalized with an adjusted OR of 1.49 (95% CI 1.10-2.03) and more likely to be admitted to ICU/intermediate care with an adjusted OR of 1.80 (95% CI 1.32-2.45), compared to normoglycemic patients., Conclusion: Elevated PBG ≥140 mg/dL was associated with a higher hospitalization risk, a longer length of stay, and a higher mortality risk and may therefore be included in risk assessment scores., Competing Interests: The authors declared no conflict of interest., (© 2024 The Authors. Journal of the American College of Emergency Physicians Open published by Wiley Periodicals LLC on behalf of American College of Emergency Physicians.)
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- 2024
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271. Muscle forces acting on the greater trochanter lead to a dorsal warping of the apophyseal growth plate.
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Ziegler CM, Wagner F, Alleborn K, Geith T, Holzapfel BM, and Heimkes B
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- Child, Adult, Adolescent, Humans, Biomechanical Phenomena, Femur diagnostic imaging, Femur physiology, Muscles, Growth Plate diagnostic imaging, Hip Joint anatomy & histology
- Abstract
The apophyseal growth plate of the greater trochanter, unlike most other growth plates of the human body, exhibits a curved morphology that results in a divergent pattern resembling an open crocodile mouth on plain antero-posterior radiographs. To quantify the angular alignment of the growth plate and to draw conclusions about the function of the muscles surrounding it, we analyzed 57 MRI images of 51 children and adolescents aged 3-17 years and of six adults aged 18-52 years. We measured the angulation of the plate relative to the horizontal plane (AY angle) and the trajectories of the muscles attaching to the greater trochanter of the proximal femur. From anterior to posterior, the AY angle shows a decrease of 33.44°. In the anterior third, the cartilage is angled at a mean of 51.64°, and in the posterior third, the mean angulation is 18.6°. This indicates that the cartilage in the anterior region of the greater trochanteric apophysis is subject to more vertically oriented force vectors compared to the posterior region, as the growth plates align perpendicular to the force vectors acting on them. Combining the measured muscle trajectories with the physiological cross-sectional areas (PCSA) available from the literature revealed that, in addition to the known internal and external lateral traction ligament systems, a third, dorsally located traction ligament system exists that may be responsible for the dorsal deformation of the AY angle., (© 2023 The Authors. Journal of Anatomy published by John Wiley & Sons Ltd on behalf of Anatomical Society.)
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- 2024
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272. Improving susceptibility of neuroendocrine tumors to radionuclide therapies: personalized approaches towards complementary treatments.
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Richter S, Steenblock C, Fischer A, Lemm S, Ziegler CG, Bechmann N, Nölting S, Pietzsch J, and Ullrich M
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- Humans, 3-Iodobenzylguanidine, Quality of Life, Octreotide, Radioisotopes therapeutic use, Neuroendocrine Tumors radiotherapy, Neuroendocrine Tumors metabolism, Carcinoma, Neuroendocrine drug therapy
- Abstract
Radionuclide therapies are an important tool for the management of patients with neuroendocrine neoplasms (NENs). Especially [
131 I]MIBG and [177 Lu]Lu-DOTA-TATE are routinely used for the treatment of a subset of NENs, including pheochromocytomas, paragangliomas and gastroenteropancreatic tumors. Some patients suffering from other forms of NENs, such as medullary thyroid carcinoma or neuroblastoma, were shown to respond to radionuclide therapy; however, no general recommendations exist. Although [131 I]MIBG and [177 Lu]Lu-DOTA-TATE can delay disease progression and improve quality of life, complete remissions are achieved rarely. Hence, better individually tailored combination regimes are required. This review summarizes currently applied radionuclide therapies in the context of NENs and informs about recent advances in the development of theranostic agents that might enable targeting subgroups of NENs that previously did not respond to [131 I]MIBG or [177 Lu]Lu-DOTA-TATE. Moreover, molecular pathways involved in NEN tumorigenesis and progression that mediate features of radioresistance and are particularly related to the stemness of cancer cells are discussed. Pharmacological inhibition of such pathways might result in radiosensitization or general complementary antitumor effects in patients with certain genetic, transcriptomic, or metabolic characteristics. Finally, we provide an overview of approved targeted agents that might be beneficial in combination with radionuclide therapies in the context of a personalized molecular profiling approach., Competing Interests: Competing Interests: The authors have declared that no competing interest exists., (© The author(s).)- Published
- 2024
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273. Intrainstitutional Changes of the Treatment of Supracondylar Humerus Fracture in Children over a Period of 9 Years.
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Wagner F, Boeriu A, Eberz P, Weigert A, Holzapfel BM, Böcker W, Hubertus J, Muensterer O, Bergmann F, and Ziegler CM
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To assess changes in treatment modalities for supracondylar humerus fractures (SCHFs) at a large pediatric university hospital, we analyzed patient data from 2014 to 2022. A total of 233 SCHFs treated surgically at our hospital were included. To evaluate postoperative outcome and quality of life, DASH and EuroQol-5D-Y questionnaires were sent to patients. In addition to a significant fluctuation in fracture severity, we found an increase in training interventions (more surgeries were performed by trainees) and a significant decrease in surgery times after 2016. From 2020, there was a significant shift in the type of surgical method away from closed reduction with elastic stable intramedullary nailing (ESIN) and towards closed reduction and crossed K-wire osteosynthesis (CRK). Surgeries performed in the morning and evening hours increased, while those performed in the afternoon and after midnight decreased. After a mean follow-up of 4 years, there was no difference in elbow function between ESIN and open reduction and K-wires (ORK). Treatment with ESIN was equivalent to ORK in terms of function, at least in the medium-term follow-up. In summary, the combination of shifting treatment from SCHF to daytime hours, increasing trainee participation and using cross K-wire fixation instead of ESIN had no negative impact on surgery times. In our setting, these measures have reduced resource utilization and increased efficiency without compromising patient care.
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- 2023
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274. Obesity and its comorbidities, current treatment options and future perspectives: Challenging bariatric surgery?
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Kloock S, Ziegler CG, and Dischinger U
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- Humans, Obesity epidemiology, Obesity surgery, Comorbidity, Incretins, Weight Loss, Diabetes Mellitus, Type 2 drug therapy, Diabetes Mellitus, Type 2 epidemiology, Diabetes Mellitus, Type 2 surgery, Bariatric Surgery
- Abstract
Obesity and its comorbidities, including type 2 diabetes mellitus, cardiovascular disease, heart failure and non-alcoholic liver disease are a major health and economic burden with steadily increasing numbers worldwide. The need for effective pharmacological treatment options is strong, but, until recently, only few drugs have proven sufficient efficacy and safety. This article provides a comprehensive overview of obesity and its comorbidities, with a special focus on organ-specific pathomechanisms. Bariatric surgery as the so far most-effective therapeutic strategy, current pharmacological treatment options and future treatment strategies will be discussed. An increasing knowledge about the gut-brain axis and especially the identification and physiology of incretins unfolds a high number of potential drug candidates with impressive weight-reducing potential. Future multi-modal therapeutic concepts in obesity treatment may surpass the effectivity of bariatric surgery not only with regard to weight loss, but also to associated comorbidities., Competing Interests: Declaration of Competing Interest The authors declare that there are no conflicts of interest., (Copyright © 2023 The Author(s). Published by Elsevier Inc. All rights reserved.)
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- 2023
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275. Metastatic Pheochromocytoma and Paraganglioma: Somatostatin Receptor 2 Expression, Genetics, and Therapeutic Responses.
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Fischer A, Kloos S, Maccio U, Friemel J, Remde H, Fassnacht M, Pamporaki C, Eisenhofer G, Timmers HJLM, Robledo M, Fliedner SMJ, Wang K, Maurer J, Reul A, Zitzmann K, Bechmann N, Žygienė G, Richter S, Hantel C, Vetter D, Lehmann K, Mohr H, Pellegata NS, Ullrich M, Pietzsch J, Ziegler CG, Bornstein SR, Kroiss M, Reincke M, Pacak K, Grossman AB, Beuschlein F, and Nölting S
- Subjects
- Humans, Receptors, Somatostatin genetics, Receptors, Somatostatin metabolism, Retrospective Studies, Succinate Dehydrogenase genetics, Succinate Dehydrogenase metabolism, Adrenal Gland Neoplasms genetics, Adrenal Gland Neoplasms therapy, Adrenal Gland Neoplasms metabolism, Neoplasms, Second Primary, Paraganglioma genetics, Paraganglioma therapy, Paraganglioma metabolism, Pheochromocytoma genetics, Pheochromocytoma therapy, Pheochromocytoma metabolism
- Abstract
Context: Pheochromocytomas and paragangliomas (PPGLs) with pathogenic mutations in the succinate dehydrogenase subunit B (SDHB) are associated with a high metastatic risk. Somatostatin receptor 2 (SSTR2)-dependent imaging is the most sensitive imaging modality for SDHB-related PPGLs, suggesting that SSTR2 expression is a significant cell surface therapeutic biomarker of such tumors., Objective: Exploration of the relationship between SSTR2 immunoreactivity and SDHB immunoreactivity, mutational status, and clinical behavior of PPGLs. Evaluation of SSTR-based therapies in metastatic PPGLs., Methods: Retrospective analysis of a multicenter cohort of PPGLs at 6 specialized Endocrine Tumor Centers in Germany, The Netherlands, and Switzerland. Patients with PPGLs participating in the ENSAT registry were included. Clinical data were extracted from medical records, and immunohistochemistry (IHC) for SDHB and SSTR2 was performed in patients with available tumor tissue. Immunoreactivity of SSTR2 was investigated using Volante scores. The main outcome measure was the association of SSTR2 IHC positivity with genetic and clinical-pathological features of PPGLs., Results: Of 202 patients with PPGLs, 50% were SSTR2 positive. SSTR2 positivity was significantly associated with SDHB- and SDHx-related PPGLs, with the strongest SSTR2 staining intensity in SDHB-related PPGLs (P = .01). Moreover, SSTR2 expression was significantly associated with metastatic disease independent of SDHB/SDHx mutation status (P < .001). In metastatic PPGLs, the disease control rate with first-line SSTR-based radionuclide therapy was 67% (n = 22, n = 11 SDHx), and with first-line "cold" somatostatin analogs 100% (n = 6, n = 3 SDHx)., Conclusion: SSTR2 expression was independently associated with SDHB/SDHx mutations and metastatic disease. We confirm a high disease control rate of somatostatin receptor-based therapies in metastatic PPGLs., (© The Author(s) 2023. Published by Oxford University Press on behalf of the Endocrine Society.)
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- 2023
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276. Encapsulation of Pioglitazone into Polymer-Nanoparticles for Potential Treatment of Atherosclerotic Diseases.
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Groner J, Tognazzi M, Walter M, Fleischmann D, Mietzner R, Ziegler CE, Goepferich AM, and Breunig M
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- Humans, Pioglitazone pharmacology, Pioglitazone therapeutic use, Polymers pharmacology, Macrophages, Atherosclerosis drug therapy, Atherosclerosis genetics, Atherosclerosis metabolism, Nanoparticles
- Abstract
Atherosclerosis is one of the most urgent global health subjects, causes millions of deaths worldwide, and is associated with enormous healthcare costs. Macrophages are the root cause for inflammatory onset and progression of the disease but are not addressed by conventional therapy. Therefore, we used pioglitazone, which is a drug initially used for diabetes therapies, but at the same time has great potential regarding the mitigation of inflammation. As yet, this potential of pioglitazone cannot be exploited, as drug concentrations at the target site in vivo are not sufficient. To overcome this shortcoming, we established PEG-PLA/PLGA-based nanoparticles loaded with pioglitazone and tested them in vitro. Encapsulation of the drug was analyzed by HPLC and revealed an outstanding encapsulation efficiency of 59% into the nanoparticles, which were 85 nm in size and had a PDI of 0.17. Further, uptake of our loaded nanoparticles in THP-1 macrophages was comparable to the uptake of unloaded nanoparticles. On the mRNA level, pioglitazone-loaded nanoparticles were superior to the free drug by 32% in increasing the expression of the targeted receptor PPAR-γ. Thereby the inflammatory response in macrophages was ameliorated. In this study, we take the first step toward an anti-inflammatory, causal antiatherosclerotic therapy, using the potential of the already established drug pioglitazone, and enable it to enrich at the target site by using nanoparticles. An additional crucial feature of our nanoparticle platform is the versatile modifiability of ligands and ligand density, to achieve an optimal active targeting effect in the future.
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- 2023
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277. Femur reconstruction in 3D ultrasound for orthopedic surgery planning.
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Gebhardt C, Göttling L, Buchberger L, Ziegler C, Endres F, Wuermeling Q, Holzapfel BM, Wein W, Wagner F, and Zettinig O
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- Humans, Child, Radiography, Femur diagnostic imaging, Femur surgery, Osteotomy, Imaging, Three-Dimensional methods, Image Processing, Computer-Assisted
- Abstract
Purpose: Derotation varisation osteotomy of the proximal femur in pediatric patients usually relies on 2-dimensional X-ray imaging, as CT and MRI still are disadvantageous when applied in small children either due to a high radiation exposure or the need of anesthesia. This work presents a radiation-free non-invasive tool to 3D-reconstruct the femur surface and measure relevant angles for orthopedic diagnosis and surgery planning from 3D ultrasound scans instead., Methods: Multiple tracked ultrasound recordings are segmented, registered and reconstructed to a 3D femur model allowing for manual measurements of caput-collum-diaphyseal (CCD) and femoral anteversion (FA) angles. Novel contributions include the design of a dedicated phantom model to mimic the application ex vivo, an iterative registration scheme to overcome movements of a relative tracker only attached to the skin, and a technique to obtain the angle measurements., Results: We obtained sub-millimetric surface reconstruction accuracy from 3D ultrasound on a custom 3D-printed phantom model. On a pre-clinical pediatric patient cohort, angular measurement errors were [Formula: see text] and eventually [Formula: see text] for CCD and FA angles, respectively, both within the clinically acceptable range. To obtain these results, multiple refinements of the acquisition protocol were necessary, ultimately reaching success rates of up to 67% for achieving sufficient surface coverage and femur reconstructions that allow for geometric measurements., Conclusion: Given sufficient surface coverage of the femur, clinically acceptable characterization of femoral anatomy is feasible from non-invasive 3D ultrasound. The acquisition protocol requires leg repositioning, which can be overcome using the presented algorithm. In the future, improvements of the image processing pipeline and more extensive surface reconstruction error assessments could enable more personalized orthopedic surgery planning using cutting templates., (© 2023. CARS.)
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- 2023
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278. Combined structural analysis and cathodoluminescence investigations of single Pr 3+ -doped Ca 2 Nb 3 O 10 nanosheets.
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Changizi R, Zaefferer S, Ziegler C, Romaka V, Lotsch BV, and Scheu C
- Abstract
Due to the novel properties of both 2D materials and rare-earth elements, developing 2D rare-earth nanomaterials has a growing interest in research. To produce the most efficient rare-earth nanosheets, it is essential to find out the correlation between chemical composition, atomic structure and luminescent properties of individual sheets. In this study, 2D nanosheets exfoliated from Pr
3+ -doped KCa2 Nb3 O10 particles with different Pr concentrations were investigated. Energy dispersive X-ray spectroscopy analysis indicates that the nanosheets contain Ca, Nb and O and a varying Pr content between 0.9 and 1.8 at%. K was completely removed after exfoliation. The crystal structure is monoclinic as in the bulk. The thinnest nanosheets are 3 nm corresponding to one triple perovskite-type layer with Nb on the B sites and Ca on the A sites, surrounded by charge compensating TBA+ molecules. Thicker nanosheets of 12 nm thickness (and above) were observed too by transmission electron microscopy with the same chemical composition. This indicates that several perovskite-type triple layers remain stacked similar to the bulk. Luminescent properties of individual 2D nanosheets were studied using a cathodoluminescence spectrometer revealing additional transitions in the visible region in comparison to the spectra of different bulk phases., (© 2023. The Author(s).)- Published
- 2023
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279. Injectable Anhydrous Poly(ethylene glycol) Polymer Liquids Form Protein Depot for Extended Controlled Release Applications Via Rapid In Situ Gelation.
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Ziegler CE, Graf M, Nagaoka M, Groner J, Mietzner R, Breunig M, and Goepferich AM
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- Delayed-Action Preparations, Hydrogels, Drug Delivery Systems, Proteins, Polyethylene Glycols, Polymers
- Abstract
Water-free preparation of protein delivery systems has the potential to overcome the limitations of hydrogel depot systems such as off-target reactions, functional group hydrolysis, and limited loading capacity. However, a major roadblock in the development and use of these systems is administration as implantation is often required. In this study, we developed a biodegradable and water-free injectable protein delivery system via inverse electron demand Diels-Alder reaction between norbornene- and tetrazine-functionalized four-armed poly(ethylene glycol) macromonomers. 1:1 mixtures of these precursors gelled rapidly in situ, taking less than 11 s to reach their gelation point. Methyl substitution of tetrazine slowed the gelation time and increased the cross-linking density, whereas oxygen incorporation into norbornene changed the mechanical properties. Introduction of hydrolytically cleavable groups enabled biodegradability. Using phenyl carbamate and phenyl carbonate ester groups, we could tune the stability. Controlled release of the protein surrogate glucose oxidase was achieved over a period of 500 days. The novel preparation method presented here is a promising step toward the development of water-free injectable protein depots for controlled drug delivery.
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- 2023
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280. Epigenetic drugs in somatostatin type 2 receptor radionuclide theranostics and radiation transcriptomics in mouse pheochromocytoma models.
- Author
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Ullrich M, Richter S, Liers J, Drukewitz S, Friedemann M, Kotzerke J, Ziegler CG, Nölting S, Kopka K, and Pietzsch J
- Subjects
- Mice, Animals, Precision Medicine, Transcriptome, Neoplasm Recurrence, Local drug therapy, Radioisotopes metabolism, Somatostatin, Octreotide therapeutic use, Receptors, Somatostatin genetics, Receptors, Somatostatin metabolism, Epigenesis, Genetic, Pheochromocytoma drug therapy, Pheochromocytoma genetics, Pheochromocytoma radiotherapy, Adrenal Gland Neoplasms, Neuroendocrine Tumors pathology
- Abstract
Pheochromocytomas and paragangliomas (PCCs/PGLs) are catecholamine-producing tumors. In inoperable and metastatic cases, somatostatin type 2 receptor (SSTR2) expression allows for peptide receptor radionuclide therapy with [
177 Lu]Lu-DOTA-TATE. Insufficient receptor levels, however, limit treatment efficacy. This study evaluates whether the epigenetic drugs valproic acid (VPA) and 5 -Aza- 2' -deoxycytidine (DAC) modulate SSTR2 levels and sensitivity to [177 Lu]Lu-DOTA-TATE in two mouse PCC models (MPC and MTT). Methods: Drug-effects on Sstr2 /SSTR2 were investigated in terms of promoter methylation, mRNA and protein levels, and radiotracer binding. Radiotracer uptake was measured in subcutaneous allografts in mice using PET and SPECT imaging. Tumor growth and gene expression (RNAseq) were characterized after drug treatments. Results: DAC alone and in combination with VPA increased SSTR2 levels along with radiotracer uptake in vitro in MPC ( high- SSTR2) and MTT cells ( low- SSTR2). MTT but not MPC allografts responded to DAC and VPA combination with significantly elevated radiotracer uptake, although activity concentrations remained far below those in MPC tumors. In both models, combination of DAC, VPA and [177 Lu]Lu-DOTA-TATE was associated with additive effects on tumor growth delay and specific transcriptional responses in gene sets involved in cancer and treatment resistance. Effects of epigenetic drugs were unrelated to CpG island methylation of the Sstr2 promoter. Conclusion: This study demonstrates that SSTR2 induction in mouse pheochromocytoma models has some therapeutic benefit that occurs via yet unknown mechanisms. Transcriptional changes in tumor allografts associated with epigenetic treatment and [177 Lu]Lu-DOTA-TATE provide first insights into genetic responses of PCCs/PGLs, potentially useful for developing additional strategies to prevent tumor recurrence., Competing Interests: Competing Interests: The authors have declared that no competing interest exists., (© The author(s).)- Published
- 2023
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281. Investigation of the Impact of Hydrolytically Cleavable Groups on the Stability of Poly(ethylene glycol) Based Hydrogels Cross-Linked via the Inverse Electron Demand Diels-Alder (iEDDA) Reaction.
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Ziegler CE, Graf M, Nagaoka M, and Goepferich AM
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- Cycloaddition Reaction, Delayed-Action Preparations chemistry, Polyethylene Glycols chemistry, Norbornanes, Biocompatible Materials, Polymers, Esters, Electrons, Hydrogels chemistry
- Abstract
Eight-armed poly(ethylene glycol) (PEG) hydrogels cross-linked via inverse electron demand Diels-Alder reaction between norbornene and tetrazine groups are promising materials for long-term protein delivery. While a controlled release over 265 days is achieved for 15% w/v hydrogels in the previous study, the material shows high stability over 500 days despite having cleavable ester linkages between the PEG macromonomers and their functionalities. In this study, the hydrolyzable ester linkers in the PEG-norbornene precursor structure are exchanged to reduce the degradation time. To this end, 3,6-epoxy-1,2,3,6-tetrahydrophthalimide, phenyl carbamate, carbonate ester, and phenyl carbonate ester are introduced as degradable functional groups. Oscillatory shear experiments reveal that they are not affected the in situ gelation. All hydrogel types have gel points of less than 20 s even at a low polymer concentration of 5% w/v. Hydrogels with varying polymer concentrations have similar mesh sizes, all of which fell in the range of 4-12 nm. The inclusion of phenyl carbonate ester accelerates degradation considerably, with complete dissolution of 15% w/v hydrogels after 302 days of incubation in phosphate buffer (pH 7.4). Controlled release of 150 kDa fluorescein isothiocyanate-dextran over a period of at least 150 days is achieved with 15% w/v hydrogels., (© 2022 The Authors. Macromolecular Bioscience published by Wiley-VCH GmbH.)
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- 2022
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282. Case report: Incidentally discovered case of pheochromocytoma as a cause of long COVID-19 syndrome.
- Author
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Ziegler CG, Riediger C, Gruber M, Kunath C, Ullrich M, Pietzsch J, Nölting S, Siepmann T, Bornstein SR, Remde H, and Constantinescu G
- Subjects
- Adult, Blood Pressure Monitoring, Ambulatory, Dizziness complications, Humans, Male, Metanephrine, Normetanephrine, Phenoxybenzamine, SARS-CoV-2, Post-Acute COVID-19 Syndrome, Adrenal Gland Neoplasms complications, Adrenal Gland Neoplasms diagnosis, Adrenal Gland Neoplasms surgery, COVID-19 complications, Hypertension complications, Pheochromocytoma complications, Pheochromocytoma diagnosis, Pheochromocytoma surgery
- Abstract
Pheochromocytomas (PCCs) are rare but potentially lethal tumors that arise from the adrenal medulla. The clinical suspicion and diagnosis of PCC can be challenging due to the non-specific nature of signs and symptoms. In many patients, infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) could lead to long-term symptoms including fatigue, headaches, and cognitive dysfunction. Here, we present the case of a patient incidentally diagnosed with an adrenal mass that proved to be a PCC after imaging was performed due to persisting complaints after coronavirus disease 2019 (COVID-19) infection. A 37-year-old male patient was referred to our center because of a right-sided inhomogeneous adrenal mass, incidentally found during a computed tomographic scan of the thorax performed due to cough and dyspnea that persisted after COVID-19 infection. Other complaints that were present prior to COVID-19 infection included profuse sweating, dizziness, exhaustion with chronic fatigue, and concentration difficulties. The patient had no history of hypertension, his blood pressure was normal, and the 24-h ambulatory blood pressure monitoring confirmed normotension but with the absence of nocturnal dipping. Plasma normetanephrine was 5.7-fold above the upper limit (UL) of reference intervals (738 pg/ml, UL = 129 pg/ml), whereas plasma metanephrine and methoxytyramine were normal at 30 pg/ml (UL = 84 pg/ml) and <4 pg/ml (UL = 16 pg/ml), respectively. Preoperative preparation with phenoxybenzamine was initiated, and a 4-cm tumor was surgically resected. Profuse sweating as well as dizziness was resolved after adrenalectomy pointing toward PCC and not COVID-19-associated patient concerns. Altogether, this case illustrates the difficulties in recognizing the possibility of PCC due to the non-specific nature of signs and symptoms of the tumor, which in this case did not include hypertension and coincided with some of the symptoms of long COVID-19., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Ziegler, Riediger, Gruber, Kunath, Ullrich, Pietzsch, Nölting, Siepmann, Bornstein, Remde and Constantinescu.)
- Published
- 2022
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283. Personalized drug testing in human pheochromocytoma/paraganglioma primary cultures.
- Author
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Wang K, Schütze I, Gulde S, Bechmann N, Richter S, Helm J, Lauseker M, Maurer J, Reul A, Spoettl G, Klink B, William D, Knösel T, Friemel J, Bihl M, Weber A, Fankhauser M, Schober L, Vetter D, Broglie Däppen M, Ziegler CG, Ullrich M, Pietzsch J, Bornstein SR, Lottspeich C, Kroiss M, Fassnacht M, Wenter VUJ, Ladurner R, Hantel C, Reincke M, Eisenhofer G, Grossman AB, Pacak K, Beuschlein F, Auernhammer CJ, Pellegata NS, and Nölting S
- Subjects
- Animals, Everolimus therapeutic use, Humans, Mice, Zoledronic Acid therapeutic use, Adrenal Gland Neoplasms drug therapy, Adrenal Gland Neoplasms genetics, Adrenal Gland Neoplasms metabolism, Antineoplastic Agents pharmacology, Antineoplastic Agents therapeutic use, Paraganglioma drug therapy, Paraganglioma genetics, Paraganglioma pathology, Pheochromocytoma drug therapy, Pheochromocytoma genetics, Pheochromocytoma metabolism
- Abstract
Aggressive pheochromocytomas and paragangliomas (PPGLs) are difficult to treat, and molecular targeting is being increasingly considered, but with variable results. This study investigates established and novel molecular-targeted drugs and chemotherapeutic agents for the treatment of PPGLs in human primary cultures and murine cell line spheroids. In PPGLs from 33 patients, including 7 metastatic PPGLs, we identified germline or somatic driver mutations in 79% of cases, allowing us to assess potential differences in drug responsivity between pseudohypoxia-associated cluster 1-related (n = 10) and kinase signaling-associated cluster 2-related (n = 14) PPGL primary cultures. Single anti-cancer drugs were either more effective in cluster 1 (cabozantinib, selpercatinib, and 5-FU) or similarly effective in both clusters (everolimus, sunitinib, alpelisib, trametinib, niraparib, entinostat, gemcitabine, AR-A014418, and high-dose zoledronic acid). High-dose estrogen and low-dose zoledronic acid were the only single substances more effective in cluster 2. Neither cluster 1- nor cluster 2-related patient primary cultures responded to HIF-2a inhibitors, temozolomide, dabrafenib, or octreotide. We showed particular efficacy of targeted combination treatments (cabozantinib/everolimus, alpelisib/everolimus, alpelisib/trametinib) in both clusters, with higher efficacy of some targeted combinations in cluster 2 and overall synergistic effects (cabozantinib/everolimus, alpelisib/trametinib) or synergistic effects in cluster 2 (alpelisib/everolimus). Cabozantinib/everolimus combination therapy, gemcitabine, and high-dose zoledronic acid appear to be promising treatment options with particularly high efficacy in SDHB-mutant and metastatic tumors. In conclusion, only minor differences regarding drug responsivity were found between cluster 1 and cluster 2: some single anti-cancer drugs were more effective in cluster 1 and some targeted combination treatments were more effective in cluster 2.
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- 2022
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284. Clinical examination and patients' history are not suitable for neonatal hip screening.
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Ziegler CM, Ertl KM, Delius M, Foerster KM, Crispin A, Wagner F, and Heimkes B
- Abstract
Purpose: To assess the percentage of missed developmental dysplasia of the hip, which escape the German criteria for newborn hip high-risk screening, we analyzed our data gained from the general neonatal sonographic hip screening performed at our department. The aim of the study was to determine the number of potentially belatedly treated developmental dysplasia of the hip., Methods: The data from 1145 standardized newborn hip ultrasound examinations according to the Graf technique were analyzed retrospectively comparing findings for general neonatal sonographic hip screening and high-risk screening subgroups., Results: We diagnosed developmental dysplasia of the hip in 18 of the 1145 newborns via ultrasound. A total of 10 out of 18 developmental dysplasia of the hip would have been missed by high-risk screening, which corresponds to a proportion of 55.6% false-negative results. The sensitivity of high-risk screening was only 44.4% and specificity, 78.3%. The positive predictive value was 3.2%. Family history as a screening criterion yielded false-negative results in 77.8% and false-positive results in 16.8%. In all, 83.3% of the children who were born with developmental dysplasia of the hip but not from breech position as a risk factor were false negative. The clinical examination was false negative in 88.9% and false positive in 0.6%., Conclusion: High-risk screening detected less than every second developmental dysplasia of the hip, rendering the first month as the most effective treatment window unavailable for inapparent dysplastic hips, potentially resulting in the need for more invasive treatment. Due to the high sensitivity of ultrasound in the detection of developmental dysplasia of the hip, we recommend to replace the current German high-risk screening guidelines with a general newborn screening for all neonates using Graf ultrasound in the first week of life., Level of Evidence: Level II., Competing Interests: Declaration of conflicting interests: The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article., (© The Author(s) 2022.)
- Published
- 2022
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285. In Situ Forming iEDDA Hydrogels with Tunable Gelation Time Release High-Molecular Weight Proteins in a Controlled Manner over an Extended Time.
- Author
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Ziegler CE, Graf M, Nagaoka M, Lehr H, and Goepferich AM
- Subjects
- Molecular Weight, Polyethylene Glycols, Proteins, Electrons, Hydrogels
- Abstract
Off-target interactions between reactive hydrogel moieties and drug cargo as well as slow reaction kinetics and the absence of controlled protein release over an extended period of time are major drawbacks of chemically cross-linked hydrogels for biomedical applications. In this study, the inverse electron demand Diels-Alder (iEDDA) reaction between norbornene- and tetrazine-functionalized eight-armed poly(ethylene glycol) (PEG) macromonomers was used to overcome these obstacles. Oscillatory shear experiments revealed that the gel point of a 15% (w/v) eight-armed PEG hydrogel with a molecular weight of 10 kDa was less than 15 s, suggesting the potential for fast in situ gelation. However, the high-speed reaction kinetics result in a risk of premature gel formation that complicates the injection process. Therefore, we investigated the effect of polymer concentration, temperature, and chemical structure on the gelation time. The cross-linking reaction was further characterized regarding bioorthogonality. Only 11% of the model protein lysozyme was found to be PEGylated by the iEDDA reaction, whereas 51% interacted with the classical Diels-Alder reaction. After determination of the mesh size, fluorescein isothiocyanate-dextran was used to examine the release behavior of the hydrogels. When glucose oxidase was embedded into 15% (w/v) hydrogels, a controlled release over more than 250 days was achieved. Overall, the PEG-based hydrogels cross-linked via the fast iEDDA reaction represent a promising material for the long-term administration of biologics.
- Published
- 2021
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286. Hydrogel microspheres evading alveolar macrophages for sustained pulmonary protein delivery.
- Author
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Graf M, Ziegler CE, Gregoritza M, and Goepferich AM
- Subjects
- Administration, Inhalation, Animals, Cell Line, Delayed-Action Preparations administration & dosage, Delayed-Action Preparations chemistry, Hydrogels chemistry, Lung metabolism, Macrophages, Alveolar drug effects, Macrophages, Alveolar metabolism, Mice, Muramidase chemistry, Phagocytosis, Polyethylene Glycols chemistry, Propane administration & dosage, Propane analogs & derivatives, Propane chemistry, Propane radiation effects, Serum Albumin, Bovine chemistry, Ultraviolet Rays, Hydrogels administration & dosage, Microspheres, Muramidase administration & dosage, Polyethylene Glycols administration & dosage, Serum Albumin, Bovine administration & dosage
- Abstract
Pulmonary delivery is a highly attractive alternative to injections for biologics such as therapeutic proteins. However, bioavailabilities generally suffer from the presence of phagocytic cells that clear particulate matter entering the lung. In this study, microgel particles were developed using an all-aqueous two-phase system approach and evaluated for their efficacy as an inhalable controlled release system. Norbornene- and thiol-modified four- and eight-armed poly (ethylene glycol) with an average molecular mass of 10,000 Da were prepared as macromonomers for microgel formation. Emulsions of precursor solution droplets containing macromonomers and Irgacure 2959 as photocatalyst were prepared in a dextran solution. Irradiation with UV light was used to covalently crosslink the droplets by triggering the thiol-ene reaction. The resulting microgels were processed to dry powder inhaler formulations, and respirable aerodynamic sizes were assessed in vitro. Microgels were loaded with the model proteins lysozyme and bovine serum albumin, with encapsulation efficiencies of 51.5% and 73.6%, respectively. Depending on the macromonomer type, protein-loaded microgels released their cargo over a 6-14 day period. In an MTT assay, the particles did not show significant cytotoxicity, and their recognition by alveolar macrophages was considerably lower than for polystyrene control particles. This makes the microgels a promising pulmonary delivery system for proteins and other biologics., (Copyright © 2019 Elsevier B.V. All rights reserved.)
- Published
- 2019
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287. The long non-coding RNA LINC00941 and SPRR5 are novel regulators of human epidermal homeostasis.
- Author
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Ziegler C, Graf J, Faderl S, Schedlbauer J, Strieder N, Förstl B, Spang R, Bruckmann A, Merkl R, Hombach S, and Kretz M
- Subjects
- Cell Differentiation genetics, Cornified Envelope Proline-Rich Proteins metabolism, Gene Knockout Techniques, Humans, Keratinocytes cytology, Keratinocytes metabolism, Transcription, Genetic, Cornified Envelope Proline-Rich Proteins genetics, Epidermal Cells metabolism, Epidermis metabolism, Homeostasis, RNA, Long Noncoding genetics
- Abstract
Several long non-coding RNAs (lncRNAs) act as regulators of cellular homeostasis; however, few of these molecules were functionally characterized in a mature human tissue environment. Here, we report that the lncRNA LINC00941 is a crucial regulator of human epidermal homeostasis. LINC00941 is enriched in progenitor keratinocytes and acts as a repressor of keratinocyte differentiation. Furthermore, LINC00941 represses SPRR5, a previously uncharacterized molecule, which functions as an essential positive regulator of keratinocyte differentiation. Interestingly, 54.8% of genes repressed in SPRR5-deficient epidermal tissue are induced in LINC00941-depleted organotypic epidermis, suggesting a common mode of action for both molecules., (© 2019 The Authors.)
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- 2019
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288. The underused hip in ipsilaterally orthotics-dependent children.
- Author
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Sallam A, Ziegler CM, Jansson V, and Heimkes B
- Abstract
Background: The aim of this investigation is the development of primarily healthy hips in children who have required orthoses/protheses over the long term due to ipsilateral distally located deformities of the leg. These children show ipsilateral in-toeing gait and Duchenne's limping followed by a coxa valga antetorta and facultative hip decentration. A practical question is whether these hips are in danger of decompensation. An additional theoretical question is how the external shape and internal architecture changes if a primarily healthy hip is underused., Methods: Ten children with healthy hips who are unilaterally long-term orthotics/prosthetics-dependent agreed to undergo an instrumental gait analysis. The results were analyzed and correlated with clinical findings, a common activity score and planimetric radiographic data., Results: The intra-individual comparison revealed a number of significant changes in the hip of the deformed leg (p < 0.05). Clinically, the internal rotation was increased (15° ± 4.2°), while the external rotation was diminished (13° ± 1.3°). Radiologically, the projected caput-collum-diaphyseal angle, the lesser trochanter to articular surface distance and the head-shaft angle were increased by 11.1° ± 15.4°, 5.8 ± 4.2 mm and 11.9° ± 0.6°, respectively. Both the Sharp and acetabular angles were increased, the former by 3.6° ± 0.6° and the latter by 3.2° ± 0.6°. Kinetic gait analysis showed increased stride length (6.8 ± 3.7 cm), shortened stance phase (6.6 ± 1.6 %) and reduced forces transmitted to the ground (92.2 ± 34.3 N). The kinematic analysis showed increased hip abduction (14.0° ± 8.2°), while the pelvic obliquity was not significantly changed (0.01° ± 0.01°)., Conclusions: Duchenne's limp and lack of weight-bearing stress are the decisive pathogenic factors of the underused coxa valga and acetabular dysplasia. These changes follow the mechanobiological concept of "function modifies design", which means function influences external shape and internal architecture of bones and joints. As a practical consequence we recommend that one pelvic radiograph be performed as a precaution at the end of puberty of children with these conditions., Level of Evidence: Level II retrospective study.
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- 2015
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289. In vivo fluorescence imaging and urinary monoamines as surrogate biomarkers of disease progression in a mouse model of pheochromocytoma.
- Author
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Ullrich M, Bergmann R, Peitzsch M, Cartellieri M, Qin N, Ehrhart-Bornstein M, Block NL, Schally AV, Pietzsch J, Eisenhofer G, Bornstein SR, and Ziegler CG
- Subjects
- Adrenal Gland Neoplasms pathology, Adrenal Gland Neoplasms urine, Animals, Cell Line, Tumor, Disease Models, Animal, Disease Progression, Female, HEK293 Cells, Humans, Male, Mice, Mice, Nude, Pheochromocytoma pathology, Pheochromocytoma urine, Urinalysis, Adrenal Gland Neoplasms diagnosis, Amines urine, Biomarkers, Tumor urine, Optical Imaging methods, Pheochromocytoma diagnosis
- Abstract
Pheochromocytoma (PHEO) is a rare but potentially lethal neuroendocrine tumor arising from catecholamine-producing chromaffin cells. Especially for metastatic PHEO, the availability of animal models is essential for developing novel therapies. For evaluating therapeutic outcome in rodent PHEO models, reliable quantification of multiple organ lesions depends on dedicated small-animal in vivo imaging, which is still challenging and only available at specialized research facilities. Here, we investigated whether whole-body fluorescence imaging and monitoring of urinary free monoamines provide suitable parameters for measuring tumor progression in a murine allograft model of PHEO. We generated an mCherry-expressing mouse PHEO cell line by lentiviral gene transfer. These cells were injected subcutaneously into nude mice to perform whole-body fluorescence imaging of tumor development. Urinary free monoamines were measured by liquid chromatography with tandem mass spectrometry. Tumor fluorescence intensity and urinary outputs of monoamines showed tumor growth-dependent increases (P < .001) over the 30 days of monitoring post-tumor engraftment. Concomitantly, systolic blood pressure was increased significantly during tumor growth. Tumor volume correlated significantly (P < .001) and strongly with tumor fluorescence intensity (rs = 0.946), and urinary outputs of dopamine (rs = 0.952), methoxytyramine (rs = 0.947), norepinephrine (rs = 0.756), and normetanephrine (rs = 0.949). Dopamine and methoxytyramine outputs allowed for detection of lesions at diameters below 2.3 mm. Our results demonstrate that mouse pheochromocytoma (MPC)-mCherry cell tumors are functionally similar to human PHEO. Both tumor fluorescence intensity and urinary outputs of free monoamines provide precise parameters of tumor progression in this sc mouse model of PHEO. This animal model will allow for testing new treatment strategies for chromaffin cell tumors.
- Published
- 2014
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290. Agonist of growth hormone-releasing hormone as a potential effector for survival and proliferation of pancreatic islets.
- Author
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Ludwig B, Ziegler CG, Schally AV, Richter C, Steffen A, Jabs N, Funk RH, Brendel MD, Block NL, Ehrhart-Bornstein M, and Bornstein SR
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- Animals, Apoptosis, Cell Proliferation, Glucose metabolism, Glucose Tolerance Test, Growth Hormone metabolism, Growth Hormone-Releasing Hormone metabolism, Hormones metabolism, Human Growth Hormone metabolism, Humans, Insulin biosynthesis, Insulin metabolism, Insulin-Secreting Cells metabolism, Insulin-Secreting Cells physiology, Insulinoma surgery, Islets of Langerhans surgery, Male, Mice, Mice, Inbred NOD, Mice, SCID, Rats, Rats, Wistar, Islets of Langerhans metabolism, Islets of Langerhans physiology
- Abstract
Therapeutic strategies for transplantation of pancreatic islet cells are urgently needed to expand beta-cell mass by stimulating islet cell proliferation and/or prolonging islet cell survival. Control of the islets by different growth factors provides a potential venue for augmenting beta-cell mass. In the present study, we show the expression of the biologically active splice variant-1 (SV-1) of growth hormone-releasing hormone (GHRH) receptor in rat insulinoma (INS-1) cells as well as in rat and human pancreatic islets. In studies in vitro of INS-1 cells, the GHRH agonist JI-36 caused a significant increase in cell proliferation and a reduction of cell apoptosis. JI-36 increased islet size and glucose-stimulated insulin secretion in isolated rat islets after 48-72 h. At the ultrastructural level, INS-1 cells treated with agonist JI-36 revealed a metabolic active stimulation state with increased cytoplasm. Coincubation with the GHRH antagonist MIA-602 reversed the actions of the agonist JI-36, indicating the specificity of this agonist. In vivo, the function of pancreatic islets was assessed by transplantation of rat islets under the kidney capsule of streptozotocin-induced diabetic non-obese diabetic-severe combined immunodeficiency (NOD-SCID) mice. Islets treated with GHRH agonist JI-36 were able to achieve normoglycemia earlier and more consistently than untreated islets. Furthermore, in contrast to diabetic animals transplanted with untreated islets, insulin response to an i.p. glucose tolerance test (IPGTT) in animals receiving islets treated with agonist Jl-36 was comparable to that of normal healthy mice. In conclusion, our study provides evidence that agonists of GHRH represent a promising pharmacological therapy aimed at promoting islet graft growth and proliferation in diabetic patients.
- Published
- 2010
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291. Rabbit anti T-lymphocyte globulin induces apoptosis in peripheral blood mononuclear cell compartments and leukemia cells, while hematopoetic stem cells are apoptosis resistant.
- Author
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Grüllich C, Ziegler C, and Finke J
- Subjects
- Animals, Antilymphocyte Serum therapeutic use, B-Lymphocytes, Cells, Cultured, Graft vs Host Disease drug therapy, Humans, Leukemia, Lymphocytic, Chronic, B-Cell, Leukemia, Myeloid, Acute, Monocytes, Precursor Cell Lymphoblastic Leukemia-Lymphoma, Rabbits, T-Lymphocytes, Antilymphocyte Serum pharmacology, Apoptosis drug effects, Graft vs Host Disease prevention & control, Hematopoietic Stem Cells cytology, Leukemia pathology, Leukocytes, Mononuclear cytology
- Abstract
Polyclonal anti-T-lymphocyte globulins (ATG) are used in allogeneic stem cell transplantation (SCT) for the prophylaxis of graft versus host disease (GVHD) by in vivo T cell depletion. In this study we investigated the complement independent induction of apoptosis by rabbit ATG in peripheral blood mononuclear cell (PBMNC) compartments and hematopoetic stem cells (HSC). We also detected antileukemic activity of ATG by measuring apoptosis in myeloid and lymphatic leukemia cell lines and primary leukemia cells. We found ATG to induce apoptosis in T-lymphocytes (CD4(+), CD8+), B-lymphocytes (CD20+), natural killer (NK)-cells (CD56(+)), and monocytes (CD14(+)). HSC, in contrast, were apoptosis resistant and could be growth stimulated by low-dose ATG in the presence of bystander cells. The human leukemia cell lines Jurkat, Daudi, DG-75 (lymphoblastic), and K562, HL-60, KG1, and U937 (myeloblastic) underwent ATG-induced apoptosis, whereas the NK-cell line YT was resistant. Primary leukemia cells from 6 investigated patients with acute lymphoblastic leukemia, 9 of 10 patients with chronic lymphocytic leukemia, and 4 of 8 patients with acute myeloblastic leukemia underwent ATG-induced apoptosis. We conclude apoptosis induction in all PBMNC compartments contributes to GVHD prophylaxis. ATG might support engraftment. Finally, antileukemic activity of ATG could positively influence the transplantation outcome.
- Published
- 2009
- Full Text
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