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1.
Int J Mol Sci ; 23(14)2022 Jul 18.
Article in English | MEDLINE | ID: mdl-35887247

ABSTRACT

Patients with muscle-invasive urothelial carcinoma achieving pathological complete response (pCR) upon neoadjuvant chemotherapy (NAC) have improved prognosis. Molecular subtypes of bladder cancer differ markedly regarding sensitivity to cisplatin-based chemotherapy and harbor FGFR treatment targets to various content. The objective of the present study was to evaluate whether preoperative assessment of molecular subtype as well as FGFR target gene expression is predictive for therapeutic outcome­rate of ypT0 status­to justify subsequent prospective validation within the "BladderBRIDGister". Formalin-fixed paraffin-embedded (FFPE) tissue specimens from transurethral bladder tumor resections (TUR) prior to neoadjuvant chemotherapy and corresponding radical cystectomy samples after chemotherapy of 36 patients were retrospectively collected. RNA from FFPE tissues were extracted by commercial kits, Relative gene expression of subtyping markers (e.g., KRT5, KRT20) and target genes (FGFR1, FGFR3) was analyzed by standardized RT-qPCR systems (STRATIFYER Molecular Pathology GmbH, Cologne). Spearman correlation, Kruskal−Wallis, Mann−Whitney and sensitivity/specificity tests were performed by JMP 9.0.0 (SAS software). The neoadjuvant cohort consisted of 36 patients (median age: 69, male 83% vs. female 17%) with 92% of patients being node-negative during radical cystectomy after 1 to 4 cycles of NAC. When comparing pretreatment with post-treatment samples, the median expression of KRT20 dropped most significantly from DCT 37.38 to 30.65, which compares with a 128-fold decrease. The reduction in gene expression was modest for other luminal marker genes (GATA3 6.8-fold, ERBB2 6.3-fold). In contrast, FGFR1 mRNA expression increased from 33.28 to 35.88 (~6.8-fold increase). Spearman correlation revealed positive association of pretreatment KRT20 mRNA levels with achieving pCR (r = 0.3072: p = 0.0684), whereas pretreatment FGFR1 mRNA was associated with resistance to chemotherapy (r = −0.6418: p < 0.0001). Hierarchical clustering identified luminal tumors of high KRT20 mRNA expression being associated with high pCR rate (10/16; 63%), while the double-negative subgroup with high FGFR1 expression did not respond with pCR (0/9; 0%). Molecular subtyping distinguishes patients with high probability of response from tumors as resistant to neoadjuvant chemotherapy. Targeting FGFR1 in less-differentiated bladder cancer subgroups may sensitize tumors for adopted treatments or subsequent chemotherapy.


Subject(s)
Carcinoma, Transitional Cell , Urinary Bladder Neoplasms , Aged , Carcinoma, Transitional Cell/drug therapy , Cisplatin/pharmacology , Cisplatin/therapeutic use , Female , Humans , Male , Muscles/metabolism , Neoadjuvant Therapy/adverse effects , Neoplasm Invasiveness , RNA, Messenger , Retrospective Studies , Urinary Bladder Neoplasms/drug therapy , Urinary Bladder Neoplasms/genetics , Urinary Bladder Neoplasms/pathology
2.
Dalton Trans ; 45(46): 18443-18446, 2016 Nov 22.
Article in English | MEDLINE | ID: mdl-27819712

ABSTRACT

An organic imidazolium salt of terephthalic acid has been utilized as a linker precursor for the synthesis of an aluminum-based metal organic framework (MOF) with MIL-53(ht) structure. This material shows the predicted porosity in terms of nitrogen and hydrogen sorption without exhibiting the breathing effect typical for MIL-53(Al) materials.

3.
Langmuir ; 31(45): 12382-9, 2015 Nov 17.
Article in English | MEDLINE | ID: mdl-26488156

ABSTRACT

The microporous zeolitic imidazolate framework ZIF-4 has been synthesized, and its ethylene/ethane and propylene/propane separation potentials have been evaluated by single-component adsorption isotherms and breakthrough experiments of the respective binary mixtures. In all experiments, a higher selectivity for the paraffin is observed that is manifested by a steeper equilibrium isotherm as well as a later breakthrough in the fixed-bed adsorber experiments. Microporous adsorbents with paraffin selectivity are rare but highly interesting for cyclic adsorption processes such as pressure-swing adsorption (PSA).

4.
Langmuir ; 29(27): 8592-600, 2013 Jul 09.
Article in English | MEDLINE | ID: mdl-23802617

ABSTRACT

Two types of metal-organic frameworks (MOFs) have been synthesized and evaluated in the separation of C2 and C3 olefins and paraffins. Whereas Co2(dhtp) (=Co-CPO-27 = Co-MOF-74) and Mg2(dhtp) show an adsorption selectivity for the olefins ethene and propene over the paraffins ethane and propane, the zeolitic imidazolate framework ZIF-8 behaves in the opposite way and preferentially adsorbs the alkane. Consequently, in breakthrough experiments, the olefins or paraffins, respectively, can be separated.


Subject(s)
Alkenes/chemistry , Organometallic Compounds/chemistry , Paraffin/chemistry , Zeolites/chemistry , Adsorption , Cobalt/chemistry , Ethane/chemistry , Ethylenes/chemistry , Models, Molecular , Organometallic Compounds/chemical synthesis , Propane/chemistry
5.
ACS Nano ; 5(6): 4658-69, 2011 Jun 28.
Article in English | MEDLINE | ID: mdl-21545143

ABSTRACT

The current work addresses the understanding of the stabilization of nanoparticles in suspension. Specifically, we study ZnO in ethanol for which the influence of particle size and reactant ratio as well as surface coverage on colloidal stability in dependence of the purification progress was investigated. The results revealed that the well-known ζ-potential determines not only the colloidal stability but also the surface coverage of acetate groups bound to the particle surface. The acetate groups act as molecular spacers between the nanoparticles and prevent agglomeration. Next to DLVO calculations based on the theory of Derjaguin, Landau, Verwey and Overbeek using a core-shell model we find that the stability is better understood in terms of dimensionless numbers which represent attractive forces as well as electrostatic repulsion, steric effects, transport properties, and particle concentration. Evaluating the colloidal stability in dependence of time by means of UV-vis absorption measurements a stability map for ZnO is derived. From this map it becomes clear that the dimensionless steric contribution to colloidal stability scales with a stability parameter including dimensionless repulsion and attraction as well as particle concentration and diffusivity of the particles according to a power law with an exponent of -0.5. Finally, we show that our approach is valid for other stabilizing molecules like cationic dendrons and is generally applicable for a wide range of other material systems within the limitations of vanishing van der Waals forces in refractive index matched situations, vanishing ζ-potential and systems without a stabilizing shell around the particle surface.


Subject(s)
Colloids/chemistry , Nanoparticles/chemistry , Nanotechnology/methods , Cations , Hydrogen-Ion Concentration , Models, Chemical , Particle Size , Quantum Dots , Semiconductors , Surface Properties , Temperature , Time Factors , Zinc Oxide/chemistry
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