Az intravazális volumenstátusz elemzése = Analysis of intravascular blood volume status

Kidolgoztunk egy pulzatilis fizikai modellt a humán artériás keringés vizsgálatára. A modellen mérhetők különböző pontokban a nyomások és az áramlás. Elemeztük az ICG-vel mért vértérfogat paraméterek (BV) és a PiCCO monitorral mért keringési változók közötti összefüggéseket. Szoros korrelációt tudtunk kimutatni a BV és a globális vég-diasztolés térfogat (GEDVI) között, ezért a vizsgálat további részében a GEDVI-t használtuk referenciaként. Megvizsgáltuk a perctérfogat- (CI) és a GEDVI mérés pontosságát. 30 betegen igazoltuk, hogy már 2 mérés átlaga is <5% hibát eredményez, ezért felhasználható tudományos célokra. A megfigyelés klinikai jelentősége az, hogy hemodinamikai mérések során nem kell kitenni a beteget felesleges folyadékterhelésnek. Elemeztük a CI-GEDVI összefüggés matematikai kapcsolódásának lehetőségét (n=122). Kimutattuk, hogy a CI-(MTt-DSt)-GEDVI kapcsolatban létezik egy matematikai kapcsolódás, ami azonban csak 3 összetevőjű modellben érvényesül. 2 paraméter kiragadása az összefüggésből téves következtetések levonására vezethet. Elemeztük, hogy az artériás nyomásgörbe mely paramétereiből lehet jó hatásfokkal következtetni a GEDVI-re (n=122). A parciális pulzusnyomás, a szisztolés csúcsnyomás görbülete, az augmentációs index, a szívfrekvencia valamint a kor bevonásával jó hatásfokkal meg lehetett becsülni a GEDVI értékét. Jelentős különbséget észleltünk férfiak (r=0,779) illetve nők között (r=0,530), melynek tisztázására további vizsgálatokra van szükség. | We have developed a pulsatile physical model to examine the human arterial circulation, enable us to measure pressure and flow in the different parts of the model. We have analyzed the relationship between blood volume parameters (BV) and the other components of circulation (n=26) using PiCCO monitoring technique. Strong correlation was found between BV and end-diastolic volume (GEDVI) therefore GEDVI was used as a reference in the latter part of the study. We have analyzed the precision of cardiac index (CI) and GEDVI measurements. It was proved (n=30) that the error is <5% - fulfilling the criterion of scientific precision -when the mean is calculated from 2 measurements. Any further repeated measurements may be unnecessary, and may contribute to volume overloading. The potential mathematical coupling between CI and GEDVI was analyzed (n=122). We could prove a mathematical coupling among CI-(MTt-DSt)-GEDVI but it works only in a 3-compartment model. Focusing only 2 parameters from this relationship may cause errors. We tried to calculate the GEDVI values from the different components of the arterial pressure curve (n=122). Putting the partial pulse pressure, the curve of the systolic peak pressure, the augmentation index, the heart rate and the age into an equation we could estimate GEDVI values with a good agreement. However, a significant difference was found between male (r=0.779) and female (r=0.530) patients, whose explanation needs further examination

Spin- és töltésdinamika szilárd testekben és nanoszerkezetekben = Spin and charge dynamics in solids and nanostructures

Napjaink szilárdtestfizikai kutatásainak központi területét jelentik azok a kvantum-jelenségek, amelyekben az elektron töltése és spinje egyaránt lényeges szerepet játszik. A projekt keretében ilyen jelenségeket tanulmányoztunk hagyományos módszerekkel (ESR spektroszkópia, elektromos és mágneses mérések), valamint olyan új spektroszkópia eljárásokkal, melyek nanotechnológiai megoldásokat alkalmaznak (alagút- és pont-kontaktus-spektroszkópia, Andrejev-spektroszkópia). A kísérleti és elméleti módszerekkel vizsgált anyagcsaládok egzotikus alapállapottal rendelkező erősen anizotrop kölcsönható elektronrendszerek, mint például: i, szupravezető átalakulás közelében lévő kuprátok, ii., ritkaföldfém vegyületek nem-konvencionális sűrűséghullámai, illetve iii., átmeneti fém oxidok a kvantum kritikus pont tartományában. A legfontosabb új eredmények a versengő kölcsönhatású rendszerek fázisdiagramjára, az antiferromágneses anyagok spin-gerjesztéseinek közvetlen meghatározására, valamint ferromágneses anyagokban a töltéshordozók spin-polarizáltságának mérésére vonatkoznak. Ez utóbbi, az alapvetően új nanotechnológiai méréstechnika alkalmazása mellett, a modern kvantum elméletek nanoszerkezetekre történő kiterjesztését is igényelte. Az eredményeket nívós nemzetközi folyóiratokban közöltük. A 40 kiemelt publikáció között 6 db. Physical Review Letters és 27 db. Physical Review B cikk szerepel. | Electrons have spin and charge, and the quantum phenomena where both of these properties are relevant represent the hottest subjects in condensed matter research today. We investigated these features by bulk characterization methods (ESR spectroscopy, transport and magnetization measurements) supplemented with novel spectroscopic ones utilizing nanotechnology (tunneling-, point-contact, and Andreev-spectroscopy). Highly anisotropic interacting electron systems with exotic ground states have been studied both experimentally and theoretically. The prime examples are: i., cuprates in the vicinity of a superconducting transition, ii., rare-earth compounds with unconventional density waves and iii., transition metal oxides close to a quantum critical point. The most important new results deal with the determination of phase diagrams for systems of competing interactions, direct measurement of spin excitations in antiferromagtic structures, and determination of spin polarization of the charge carriers in ferromagnetic structures. The latter required novel nanoscale techniques, and the application of quantum theories for nanostructures. The results were published leading scientific journals. The top 40 publication include 6 Physical Review Letters and 27 Physical Review B papers

Novel Crizotinib–GnRH conjugates revealed the significance of lysosomal trapping in GnRH-based drug delivery systems

Several promising anti-cancer drug–GnRH (gonadotropin-releasing hormone) conjugates have been developed in the last two decades, although none of them have been approved for clinical use yet. Crizotinib is an effective multi-target kinase inhibitor, approved against anaplastic lymphoma kinase (ALK)- or ROS proto-oncogene 1 (ROS-1)-positive non-small cell lung carcinoma (NSCLC); however, its application is accompanied by serious side effects. In order to deliver crizotinib selectively into the tumor cells, we synthesized novel crizotinib analogues and conjugated them to a [d-Lys6]–GnRH-I targeting peptide. Our most prominent crizotinib–GnRH conjugates, the amide-bond-containing [d-Lys6(crizotinib*)]–GnRH-I and the ester-bond-containing [d-Lys6(MJ55*)]–GnRH-I, were able to bind to GnRH-receptor (GnRHR) and exert a potent c-Met kinase inhibitory effect. The efficacy of compounds was tested on the MET-amplified and GnRHR-expressing EBC-1 NSCLC cells. In vitro pharmacological profiling led to the conclusion that that crizotinib–GnRH conjugates are transported directly into lysosomes, where the membrane permeability of crizotinib is diminished. As a consequence of GnRHR-mediated endocytosis, GnRH-conjugated crizotinib bypasses its molecular targets—the ATP-binding site of RTKs— and is sequestered in the lysosomes. These results explained the lower efficacy of crizotinib–GnRH conjugates in EBC-1 cells, and led to the conclusion that drug escape from the lysosomes is a major challenge in the development of clinically relevant anti-cancer drug–GnRH conjugates

A conserved MTMR lipid phosphatase increasingly suppresses autophagy in brain neurons during aging

Ageing is driven by the progressive, lifelong accumulation of cellular damage. Autophagy (cellular self-eating) functions as a major cell clearance mechanism to degrade such damages, and its capacity declines with age. Despite its physiological and medical significance, it remains largely unknown why autophagy becomes incapable of effectively eliminating harmful cellular materials in many cells at advanced ages. Here we show that age-associated defects in autophagic degradation occur at both the early and late stages of the process. Furthermore, in the fruit fly Drosophila melanogaster , the myotubularin-related (MTMR) lipid phosphatase egg-derived tyrosine phosphatase (EDTP) known as an autophagy repressor gradually accumulates in brain neurons during the adult lifespan. The age-related increase in EDTP activity is associated with a growing DNA N 6 -adenine methylation at EDTP locus. MTMR14, the human counterpart of EDTP, also tends to accumulate with age in brain neurons. Thus, EDTP, and presumably MTMR14, promotes brain ageing by increasingly suppressing autophagy throughout adulthood. We propose that EDTP and MTMR14 phosphatases operate as endogenous pro-ageing factors setting the rate at which neurons age largely independently of environmental factors, and that autophagy is influenced by DNA N 6 -methyladenine levels in insects

The Potential Impact of Connexin 43 Expression on Bcl-2 Protein Level and Taxane Sensitivity in Head and Neck Cancers–In Vitro Studies

The poor prognosis of head and neck squamous cell carcinoma (HNSCC) is partly due to the lack of reliable predictive markers. Connexin 43 (Cx43) protein and its cell-communication channels have been assigned tumor suppressor functions while the anti-apoptotic Bcl-2 (B-cell lymphoma-2) protein has been associated with negative prognostic significance in cancer. This study aimed to test the role of Cx43 protein on Bcl-2 expression, tumor progression and response to taxane-based treatment in HNSCC. Human papillomavirus (HPV) negative HNSCC cell lines were tested for paclitaxel sensitivity through measuring apoptosis induction, cell viability and changes in Cx43 and Bcl-2 levels using flow cytometry, cell viability assay, immunocytochemistry and western blot. Inhibition of Cx43 expression using siRNA increased Bcl-2 protein levels in SCC25 (tongue squamous cell carcinoma) cells, while forced Cx43 expression reduced Bcl-2 levels and supported paclitaxel cytotoxicity in FaDu (hypopharynx squamous cell carcinoma) cells. In vitro results were in line with protein expression and clinicopathological features tested in tissue microarray samples of HNSCC patients. Our data demonstrate that elevated Cx43 and reduced Bcl-2 levels may indicate HNSCC sensitivity to taxane-based treatments. On the contrary, silencing of the Cx43 gene GJA1 (gap junction protein alpha-1) can result in increased Bcl-2 expression and reduced paclitaxel efficiency. Clinical tumor-based analysis also confirmed the inverse correlation between Cx43 and Bcl-2 expression.Published versio

Synthesis and Antiproliferative Activity of Novel Imipridone&ndash;Ferrocene Hybrids with Triazole and Alkyne Linkers

Imipridones, including ONC201, ONC206 and ONC212 (which are emblematic members of this class of compounds developed by Oncoceutics) constitute a novel class of anticancer agents, with promising results in clinical trials. With the aim of increasing the ROS (reactive oxygen species) responsivity of the synthesized molecules, a set of novel ferrocene&ndash;imipridone hybrids were designed and synthesized. Our strategy was motivated by the documented interplay between the imipridone-triggered activation of TRAIL (the tumor necrosis factor-related apoptosis-inducing ligand) and mitochondrial ClpP (Caseinolytic protease P) and the ROS-mediated effect of ferrocene-containing compounds. In order to obtain novel hybrids with multitarget characters, the ferrocene moiety was tethered to the imipridone scaffold through ethynylene and 1,2,3-triazolyl linkers by using Sonogashira coupling of Cu(I)- and Ru(II)-catalyzed azide&ndash;alkyne cycloadditions. The biological activities of the new hybrids were examined by using in vitro cell viability assays on four malignant cell lines (PANC-1, A2058, EBC-1 and Fadu), along with colony formation assays on the most resistant PANC-1 cell line. Several hybrids caused a significantly greater drop in the cell viability compared to ONC201, and two of them completely overcame the resistance, with IC50 values comparable to those produced by ONC201. The two most potent hybrids, but not ONC201, induced apoptosis/necrosis in PANC-1 and A2058 cells after 24 h of treatment

Novel Erlotinib–Chalcone Hybrids Diminish Resistance in Head and Neck Cancer by Inducing Multiple Cell Death Mechanisms

In a search for novel therapeutic options for head and neck squamous cell carcinomas (HNSCCs) generally treated with limited therapeutic success, we synthesized a series of novel erlotinib–chalcone molecular hybrids with 1,2,3-triazole and alkyne linkers and evaluated them for their anticancer activity on Fadu, Detroit 562 and SCC-25 HNSCC cell lines. Time- and dose-dependent cell viability measurements disclosed a significantly increased efficiency of the hybrids compared to the 1:1 combination of erlotinib and a reference chalcone. The clonogenic assay demonstrated that hybrids eradicate HNSCC cells in low micromolar concentrations. Experiments focusing on potential molecular targets indicate that the hybrids trigger the anticancer effect by a complementary mechanism of action that is independent of the canonical targets of their molecular fragments. Confocal microscopic imaging and real-time apoptosis/necrosis detection assay pointed to slightly different cell death mechanisms induced by the most prominent triazole- and alkyne-tethered hybrids (6a and 13, respectively). While 6a featured the lowest IC50 values on each of the three HNSCC cell lines, in Detroit 562 cells, this hybrid induced necrosis more markedly compared to 13. The therapeutic potential indicated by the observed anticancer efficacy of our selected hybrid molecules validates the concept of development and justifies further investigation to reveal the underlying mechanism of action

Novel Erlotinib&ndash;Chalcone Hybrids Diminish Resistance in Head and Neck Cancer by Inducing Multiple Cell Death Mechanisms

In a search for novel therapeutic options for head and neck squamous cell carcinomas (HNSCCs) generally treated with limited therapeutic success, we synthesized a series of novel erlotinib&ndash;chalcone molecular hybrids with 1,2,3-triazole and alkyne linkers and evaluated them for their anticancer activity on Fadu, Detroit 562 and SCC-25 HNSCC cell lines. Time- and dose-dependent cell viability measurements disclosed a significantly increased efficiency of the hybrids compared to the 1:1 combination of erlotinib and a reference chalcone. The clonogenic assay demonstrated that hybrids eradicate HNSCC cells in low micromolar concentrations. Experiments focusing on potential molecular targets indicate that the hybrids trigger the anticancer effect by a complementary mechanism of action that is independent of the canonical targets of their molecular fragments. Confocal microscopic imaging and real-time apoptosis/necrosis detection assay pointed to slightly different cell death mechanisms induced by the most prominent triazole- and alkyne-tethered hybrids (6a and 13, respectively). While 6a featured the lowest IC50 values on each of the three HNSCC cell lines, in Detroit 562 cells, this hybrid induced necrosis more markedly compared to 13. The therapeutic potential indicated by the observed anticancer efficacy of our selected hybrid molecules validates the concept of development and justifies further investigation to reveal the underlying mechanism of action

Protein Kinase D3 (PKD3) Requires Hsp90 for Stability and Promotion of Prostate Cancer Cell Migration

Prostate cancer metastasis is a significant cause of mortality in men. PKD3 facilitates tumor growth and metastasis, however, its regulation is largely unclear. The Hsp90 chaperone stabilizes an array of signaling client proteins, thus is an enabler of the malignant phenotype. Here, using different prostate cancer cell lines, we report that Hsp90 ensures PKD3 conformational stability and function to promote cancer cell migration. We found that pharmacological inhibition of either PKDs or Hsp90 dose-dependently abrogated the migration of DU145 and PC3 metastatic prostate cancer cells. Hsp90 inhibition by ganetespib caused a dose-dependent depletion of PKD2, PKD3, and Akt, which are all involved in metastasis formation. Proximity ligation assay and immunoprecipitation experiments demonstrated a physical interaction between Hsp90 and PKD3. Inhibition of the chaperone–client interaction induced misfolding and proteasomal degradation of PKD3. PKD3 siRNA combined with ganetespib treatment demonstrated a specific involvement of PKD3 in DU145 and PC3 cell migration, which was entirely dependent on Hsp90. Finally, ectopic expression of PKD3 enhanced migration of non-metastatic LNCaP cells in an Hsp90-dependent manner. Altogether, our findings identify PKD3 as an Hsp90 client and uncover a potential mechanism of Hsp90 in prostate cancer metastasis. The molecular interaction revealed here may regulate other biological and pathological functions