Engineering and Validation of a Peptide-Stabilized Poly(lactic-co-glycolic) Acid Nanoparticle for Targeted Delivery of a Vascular Disruptive Agent in Cancer Therapy.

Developing a biocompatible and biodegradable nanoparticle (NP) carrier that integrates drug-loading capability, active targeting, and imaging modality is extremely challenging. Herein, we report an NP with a core of poly(lactic-co-glycolic) acid (PLGA) chemically modified with the drug combretastatin A4 (CA4), a vascular disrupting agent (VDA) in clinical development for ovarian cancer (OvCA) therapy. The NP is stabilized with a short arginine-glycine-aspartic acid-phenylalanine x3 (RGDFFF) peptide via self-assembly of the peptide on the PLGA surface. Importantly, the use of our RGDFFF coating replaces the commonly used polyethylene glycol (PEG) polymer that itself often induces an unwanted immunogenic response. In addition, the RGD motif of the peptide is well-known to preferentially bind to αvß3 integrin that is implicated in tumor angiogenesis and is exploited as the NP's targeting component. The NP is enhanced with an optical imaging fluorophore label via chemical modification of the PLGA. The RGDFFF-CA4 NPs are synthesized using a nanoprecipitation method and are ∼75 ± 3.7 nm in diameter, where a peptide coating comprises a 2-3 nm outer layer. The NPs are serum stable for 72 h. In vitro studies using human umbilical cord vascular endothelial cells (HUVEC) confirmed the high uptake and biological activity of the RGDFFF-CA4 NP. NP uptake and viability reduction were demonstrated in OvCA cells grown in culture, and the NPs efficiently accumulated in tumors in a preclinical OvCA mouse model. The RGDFFF NP did not induce an inflammatory response when cultured with immune cells. Finally, the NP was efficiently taken up by patient-derived OvCA cells, suggesting a potential for future clinical applications.

False recognitions in short-term memory - Age-differences in neural activity.

While the knowledge on age-related differences in susceptibility to episodic false memories is extensive, little is known about this phenomenon in visual short-term memory (STM). Our previous behavioural research indicated that older adults are more confident of their erroneous STM recognitions than young adults. However, unlike in episodic memory, we did not find support for older adults' higher rate of false alarms. To further understand this specific age-difference, here we investigated its neural correlates. First, the pattern of behavioural results replicated the one from our previous experiment. Second, younger adults, when compared to older adults, exhibited higher false recognition-related activity of the visual cortex, the anterior cingulate cortex, the frontal operculum/insular cortex as well as regions within the anterior and dorsolateral prefrontal cortex. No age-differences were observed in hippocampal activity. Third, younger but not older adults presented higher activity in the anterior cingulate cortex and the frontal operculum/insular cortex for false recognitions when compared to highly confident correct rejections. Finally, frontal activity was influenced by both the individuals' performance and their metacognitive abilities. The results suggest that age-related differences in confidence of STM false recognitions may arise from age-differences in performance monitoring and uncertainty processing rather than in hippocampal-mediated binding.

Optical Spectra of Oligofurans: A Theoretical Approach to the Transition Energies, Reorganization Energies, and the Vibronic Activity.

There is experimental evidence of high vibronic activity that accompanies the allowed transition between the ground state and the lowest electronic singlet excited state of oligofurans that contain two, three, and four furan rings. The absorption and emission spectra of the three lowest oligofurans measured at liquid nitrogen temperature show distinct fine structures that are reproduced using the projection-based model of vibronic coupling (with Dushinsky rotation included) parameterized utilizing either Density Functional Theory (DFT, with several different exchange-correlation functionals) or ab initio (CC2) quantum chemistry calculations. Using as a reference the experimental data concerning the electronic absorption and fluorescence for the eight lowest oligofurans, we first analyzed the performance of the exchange-correlation functionals for the electronic transition energies and the reorganization energies. Subsequently, we used the best functionals alongside with the CC2 method to explore how the reorganization energies are distributed among the totally symmetric vibrations, identify the normal modes that dominate in the fine structures present in the absorption and emission bands, and trace their evolution with the increasing number of rings in the oligofuran series. Confrontation of the simulated spectra with the experiment allows for the verification of the performance of the selected DFT functionals and the CC2 method.

MR spectroscopy differences between lipomatosis of nerve and neuromuscular choristoma: a potential adjunctive diagnostic tool.

OBJECTIVE: To describe differences between lipomatosis of nerve (LN) and neuromuscular choristoma (NMC) evaluated with MR spectroscopy (MRS). MATERIALS AND METHODS: Eight patients were included in this prospective pilot study: three patients with LNs and five with NMCs. Single voxel PRESS MRS of the tumors were acquired with 3 T MRI. MRS data were processed with LCModel version 6.3-1J using the internal "lipid-8" basis set. From individual lipid peak and water content measurements, total fatty acid molecules (TFAM), unsaturated fatty acid molecules (UFAM), and glycerol molecules (GM) were computed and analyzed, as well as ratios of UFAM/TFAM, TFAM/GM, and a fatty-acid chain-length index (CLI). RESULTS: The LN group included two men and one woman (average age 58.3 years); the NMC group included two men and three women (average age 20.4 years). Lipid composition analysis showed that LN had considerably more fat than NMC: TFAM: LN = 15.29 vs NMC = 7.14; UFAM: LN = 4.48 vs NMC = 2.63; GM: LN = 5.20 vs NMC = 1.02. Both tumors had a similar fraction of unsaturated fatty acids: UFAM/TFAM: LN = 0.29 vs NMC = 0.37. LN had the usual number of FA molecules/glycerol molecule, while NMC had considerably more: TFAM/GM: LN = 2.94 vs NMC = 6.98. Finally, average FA chains were longer in NMC: CLI: LN = 17.39 vs NMC = 22.55. CONCLUSION: Our analysis suggests measurable differences in the amount and composition of lipid in LN and NMC. While a larger, statistically powered study is needed, these initial findings may be helpful to properly diagnose ambiguous cases and thereby avoid surgical intervention such as biopsy.

Tripeptide-Stabilized Oil-in-Water Nanoemulsion of an Oleic Acids-Platinum(II) Conjugate as an Anticancer Nanomedicine.

We report a nanoemulsion (NE) which is stabilized by self-assembling tripeptide lysine-tyrosine-phenylalanine (KYF) and encapsulates an oleic acids-platinum conjugate formed using simple Pt (II) coordination chemistry. The KYF-Pt-NE is evaluated both in cultured ovarian cancer cells and in an in vivo preclinical cancer model and shows pH dependent Pt (II) release, which is low at physiological pH and enhanced at tumoral pH. The biological activity of KYF-Pt-NE, evaluated in multiple ovarian cancer cell lines, is significantly higher when compared to the analogous Pt (II) complex used in the clinic. Concurrently, the KYF-Pt-NE platform shows good compatibility with the immune system. Preliminary in vivo testing of KYF-Pt-NE with tumor bearing mice indicates efficient Pt (II) delivery to the tumor. Together, these results demonstrate the potential of peptide-stabilized nanoemulsions, specifically KYF-Pt-NE as an effective nanomedicine against cancer.

Adolescent nicotine exposure transiently increases high-affinity nicotinic receptors and modulates inhibitory synaptic transmission in rat medial prefrontal cortex.

Adolescence is a critical developmental period during which most adult smokers initiate their habit. Adolescents are more vulnerable than adults to nicotine's long-term effects on addictive and cognitive behavior. We investigated whether adolescent nicotine exposure in rats modifies expression of nicotinic acetylcholine receptors (nAChRs) in medial prefrontal cortex (mPFC) in the short and/or long term, and whether this has functional consequences. Using receptor binding studies followed by immunoprecipitation of nAChR subunits, we showed that adolescent nicotine exposure, as compared with saline, caused an increase in mPFC nAChRs containing α4 or ß2 subunits (24 and 18%, respectively) 24 h after the last injection. Nicotine exposure in adulthood had no such effect. This increase was transient and was not observed 5 wk following either adolescent or adult nicotine exposure. In line with increased nAChRs expression 1 d after adolescent nicotine exposure, we observed a 34% increase in amplitude of nicotine-induced spontaneous inhibitory postsynaptic currents in layer II/III mPFC pyramidal neurons. These effects were transient and specific, and observed only acutely after adolescent nicotine exposure, but not after 5 wk, and no changes were observed in adult-exposed animals. The acute nicotine-induced increase in α4ß2-containing receptors in adolescents interferes with the normal developmental decrease (37%) of these receptors from early adolescence (postnatal day 34) to adulthood (postnatal day 104) in the mPFC. Together, this suggests that these receptors play a role in mediating the acute rewarding effects of nicotine and may underlie the increased sensitivity of adolescents to nicotine.

Accidental Morcellation of Uterine Leiomyosarcoma Influences Relapse Free Survival but Does Not Negatively Influence Overall Survival.

Background: Uterine leiomyosarcoma (LMS) is a rare entity amongst malignant gynaecological tumours and is mostly diagnosed after surgery for benign leiomyoma (LM) of the uterus. As minimal invasive surgery is widely used, the morcellation of LM and the uterus is rather common. As there is little known about the impact of the morcellation of LMS on local and distant metastases, as well as overall survival, we carried out a large-scale retrospective study. Methods: A total of 301 LMS cases from the German Clinical Competence Centre for Genital Sarcomas and Mixed Tumours were analysed. We distinguished morcellated and non-morcellated LMS from pT1 and >pT1 tumours. Fine−Gray competing risks regressions and cumulative incidence rates were computed for the time to local recurrence, distant metastases, and patient death. Results: The recurrence free interval in pT1 LMS was significantly lower in the morcellation group with a 2-year cumulative incidence rate of 49% vs. 26% in non-morcellated LMS (p = 0.001). No differences were seen in >pT1 tumours. Distant metastases were more frequently found in non-morcellated pT1 LMS compared to the morcellated cases (5-year cumulative incidence: 54% vs. 29%, p < 0.001). There was no significant difference in time to death between both groups neither in the pT1 stages nor in >pT1 disease. Subdistribution hazard ratios estimated by multivariable competing risks regressions for the morcellation of pT1 LMS were 2.11 for local recurrence (95% CI 1.41−3.16, p < 0.001) and 0.52 for distant metastases (95% CI 0.32−0.84, p = 0.008). Conclusions: Tumour morcellation is not associated with OS for pT1 tumours. The morcellation of pT1 LMS seems to prolong the time to distant metastases whereas local recurrence is more likely to occur after the morcellation of pT1 LMS.

Ticagrelor effectively inhibits platelet aggregation in comatose survivors of cardiac arrest undergoing primary percutaneous coronary intervention treated with mild therapeutic hypothermia.

BACKGROUND: Mild therapeutic hypothermia (MTH) is believed to reduce the effectiveness of antiplatelet drugs. Effective dual-antiplatelet therapy after percutaneous coronary intervention (PCI) is mandatory to avoid acute stent thrombosis. The effectiveness of ticagrelor in MTH-treated out-of-hospital cardiac arrest (OHCA) survivors is still a matter of debate. The aim of the study was to evaluate the impact of MTH on the platelet-inhibitory effect of ticagrelor in comatose survivors of OHCA treated with primary PCI. METHODS: Eighteen comatose survivors of OHCA with acute coronary syndrome undergoing immediate PCI treated with MTH were compared with 14 patients with uncomplicated primary myocardial infarction after PCI, matched for gender and age, in a prospective, single-center, observational study. Platelet aggregation was evaluated using VerifyNow P2Y12 point-of-care testing at 3 time points: admission (T0), during MTH (T1), and 48-72 h after rewarming (T2). RESULTS: Ticagrelor effectively inhibits platelet aggregation in OHCA patients subjected to MTH and in all patients in the control group. The effectiveness of ticagrelor did not differ between the MTH group and the control group (p = 0.581). In 2 cases in the MTH population, the platelet response to ticagrelor was inadequate, and in one of them it remained insufficient during the re-warming phase. There was no stent thrombosis in these patients. CONCLUSIONS: The present study confirmed the effectiveness of ticagrelor to inhibit platelets in myocardial infarction patients after OHCA treated with primary PCI undergoing hypothermia. The use of cooling was not associated with an increased risk of stent thrombosis.

Pt(II)-PLGA Hybrid in a pH-Responsive Nanoparticle System Targeting Ovarian Cancer.

Platinum-based agents are the main treatment option in ovarian cancer (OC). Herein, we report a poly(lactic-co-glycolic acid) (PLGA) nanoparticle (NP) encapsulating platinum (II), which is targeted to a cell-spanning protein overexpressed in above 90% of late-stage OC, mucin 1 (MUC1). The NP is coated with phospholipid-DNA aptamers against MUC1 and a pH-sensitive PEG derivative containing an acid-labile hydrazone linkage. The pH-sensitive PEG serves as an off-on switch that provides shielding effects at the physiological pH and is shed at lower pH, thus exposing the MUC1 ligands. The pH-MUC1-Pt NPs are stable in the serum and display pH-dependent PEG cleavage and drug release. Moreover, the NPs effectively internalize in OC cells with higher accumulation at lower pH. The Pt (II) loading into the NP was accomplished via PLGA-Pt (II) coordination chemistry and was found to be 1.62 wt.%. In vitro screening using a panel of OC cell lines revealed that pH-MUC1-Pt NP has a greater effect in reducing cellular viability than carboplatin, a clinically relevant drug analogue. Biodistribution studies have demonstrated NP accumulation at tumor sites with effective Pt (II) delivery. Together, these results demonstrate a potential for pH-MUC1-Pt NP for the enhanced Pt (II) therapy of OC and other solid tumors currently treated with platinum agents.

Sutureless technique for repositioning and scleral fixation of the capsular bag-intraocular lens complex with permanent use of iris retractors.

A new sutureless technique used for repositioning and scleral fixation of the capsular bag-intraocular lens (IOL) complex in the surgical treatment of subluxated lenses is described. Iris retractors were used not only to induce a tent effect on the capsule but also to permanently fix the capsular bag to the sclera in this method, without the need to prepare scleral or conjunctival flaps. Surgery with the use of a capsular tension ring (CTR) and iris retractors, the ends of which were brought out through the sclera and cauterized, was performed in 7 eyes of 7 patients with moderate or severe subluxation of the crystalline lens. In all cases, simultaneous use of a CTR and iris retractors ensured good centration of the capsular bag-IOL complex. The method was safe and effective in fixing the capsule to the sclera in the case of significant damage to the ligamentous apparatus of the lens.

Gastrointestinal bleeding.

Gastrointestinal bleeding remains one of the most important emergencies in gastroenterology. Despite this, only about 100 abstracts concerning gastrointestinal bleeding (excluding bleeding complicating endoscopic procedures) were presented at this year's Digestive Disease Week (DDW; 7-10 May 2011; Chicago, Illinois, USA), accounting for less than 2% of all presented lectures and posters. It seems that the number of such abstracts has been decreasing over recent years. This may be due in part to the high level of medical care already achieved, especially in the areas of pharmacotherapy and endoscopic treatment of gastrointestinal bleeding. In this review of gastrointestinal bleeding, priority has been given to large epidemiological studies reflecting "real life," and abstracts dealing more or less directly with endoscopic management.

Antifungal action of the oxathiolone-fused chalcone derivative.

AMG-148, an oxathiolone-fused chalcone derivative, exhibited in vitro antifungal activity against several strains of human pathogenic yeast, with minimum inhibitory concentration values within the range of 1-16 µg ml(-1) and a fungicidal effect was observed at higher concentrations. Presence of major drug-effluxing membrane proteins Cdr1p, Cdr2p or Mdr1p, did not affect substantially the fungistatic activity of this compound against clinical Candida albicans strains. Studies on the mode of action revealed that AMG-148 inhibited chitin and ß(1→3)glucan biosynthesis and was in vitro an inhibitor of ß(1→3)glucan synthase. Inhibition of chitin biosynthesis was responsible for fungistatic activity, while the fungicidal effect was a consequence of disturbance of ß(1→3)glucan synthase function. The chalcone derivative may be a useful lead compound for the development of novel antifungal agents.

[Vascular complications in transcatheter aortic valve implantation in IKEM]. / Cévní komplikace pri transkatetrové implantaci aortální chlopne v IKEM.

AIM: Retrograde transfemoral arterial approach is the most common technique of transcatheter aortic valve implantation. Diameter of available catheters is the limiting factor for percutaneous usage. We currently use 18 French third generation Medtronic Core Valve system. We retrospectively analyzed procedure related complications in our patient cohort. MATERIAL AND METHODS: Transcatheter aortic vale implantation with 18 French Medtronic Core Valve was performed in 35 patients (23 females, 12 males) in between 12/2008 and 7/2010. RESULTS: Mean age was 81.4 +/- 6.1 years (range 69-92), mean logistics EuroSCORE was 19.3 +/- 8.9% (range 8-42), mean aortic valve gradient 59.8 +/- 19.8 mm Hg (range 30-86 mm Hg (mean indexed aortic valve area 0.37 +/- 0.11 cm.

[Evaluation of dynamic cardiac troponin I concentrations and C-reactive protein in the monitoring of myocardial infarction in patients with repeated myocardial infarction]. / Ocena dynamiki stezen sercowej troponiny I oraz bialka C-reaktywnego w monitorowaniu zawalu miesnia sercowego u chorych z powtórnym zawalem.

UNLABELLED: Significant progress in diagnosis and treatment of heart attack led European Society of Cardiology (ESC) and American College of Cardiology (ACC) to develop in 2007 a document on contemporary criteria for diagnosis of fresh myocardial infarction. In the case of percutaneous coronary intervention (PCI) in patients with initially normal serum concentrations of biomarkers troponin increase above the 99th percentile upper limit of the reference points to the occurrence of myocardial necrosis dislodgement. Conventionally assumed that the increased levels of biomarkers of value in excess of 3 x 99th percentile upper reference requires identification of MI in conjunction with PCI. THE AIM OF THE STUDY: To evaluate the dynamic of troponin concentrations and C-reactive protein in patients with the second or subsequent myocardial infarction undergoing percutaneous coronary intervention (PCI) and comparing the results obtained with the results obtained in patients with first myocardial infarction, in patients undergoing elective coronary angiography and the healthy control group. MATERIAL AND METHODS: The study involved a total of 120 patients who entered in four groups: study group Z2 and three comparative groups: Z1, the NRA and C. Z2 study group consisted of patients admitted to hospital because of second or subsequent myocardial infarction. Z1 group consisted of patients with first myocardial infarction. Patients groups Z2 and Z1 underwent PCI. The group included people the NRA people with a history of previous myocardial infarction, who underwent elective coronary angiography and after noting the time of surgery of coronary arteries was performed in one PCI slot. Control group C consisted of healthy, free from recognized risk factors for heart attack, in which there were no previous episodes of acute heart. Patients groups Z2 and NRA received statins and ASA before hospitalization. The material in patients with suspected myocardial infarction (study group Z2 and Z1 and in the group NRA represented the blood clot, taken on at the time of notification to the patient to the hospital, between 6 and 9 h, in 16 h, 24 and 48 h hospitalization. In the control group C blood samples were taken at one time. In plasma the concentrations of cardiac troponin I (cTnl), and serum CRP. RESULTS: The dynamics of median concentrations of cTnl for the test group Z2 and control group Z1 are comparable. Median concentrations are very close to each other (with the exception of point 1) in any of the measuring points, there was no statistically significant differences. Between 6 and 9 time of infarction in group Z1 median concentrations were significantly higher than in Z2. Significant differences were found between the Z1 and Z2 group and the NRA in all. measuring points, at the time of admission, between 6 and 9 time, the 16th, 24th and 48 time of onset of stroke (point 0, p = 0.027, points 1, 2, 3, and 4 p = 0.0000). The reference group of people from the NRA who previously underwent selective coronary heart attack and surgery PCI, 7 patients were observed a slight increase in troponin I concentrations (usually between the 9th and 24th h hospitalisation), not exceeding three times the value of the decision, which permits the exclusion of myocardial. Median concentrations of CRP in 16 h, 24 and 48 h MI showed significant differences between the group and the NRA Z2 (section 2, p = 0.001, section 3 and 4--p < 0.001) and between the group and the NRA Z1 (section 2, p = 0.028, section 3 and 4--p < 0.001). Median values in the group Z2 versus Z1 showed similar dynamics in the time points 0, 1, 2 and 3. Higher median values in the fourth time point were observed in the group Z2. Median CRP at the time of admission to hospital was the highest in the group Z2 (2.65 mg/l), and reference groups Z1 and NRA was 2.25 mg/l and 2.35 mg/l. Median CRP in the groups Z2, Z1 and CRV were significantly higher against the group C (1.20 mg/l). In group C the lowest percentage observed in the results of CRP >3 mg/l (indicating the risk of ACS) of 16.7%. In the other groups this proportion was 30-40% and was highest in the group Z2. CONCLUSIONS: The concentration of cardiac troponin I in the first hours of the course of myocardial infarction (between 6 and 9 h) in patients who have made a second heart attack tends to lower its growth levels compared to people with first MI. It can be assumed that the myocardial inflammatory response to repeated defense system reduces the area of necrosis and less ejection from the troponin myocardial cells. In patients who underwent myocardial infarction in the past and were subjected to selective coronary angiography, and its treatment by PCI, troponin I, did not exceed three times the 99th percentile of the healthy population, suggesting that the proper emergency procedures cardiac surgeons performing PCI.

[Right ventricular dysfunction after left ventricular assist device implantation]. / Dysfunkce pravé komory po implantaci levostranné mechanické srdecní podpory.

OBJECTIVE: The frequency of long-term left ventricular assist device (LVAD) implantation is increasing. Acute right ventricular dysfunction or right ventricular failure after LVAD implantation has important influence on morbidity and mortality. The aim of our study was to assess the management of right ventricular dysfunction after LVAD implantation. METHODS: The study group comprised 21 patients with implanted HeartMate II LVAD since December, 2006 to April, 2009. We evaluated in retrospective fashion baseline parameters of cardiovascular and other organ systems before LVAD implantation, applied pharmacological and mechanical support for the right ventricle, and important clinical outcomes to the end ofJune, 2009. RESULTS: LVAD was implanted in 18 men and 3 women with mean age of 48.7 +/- 11.2 years. The most frequent diagnosis was dilatational cardiomyopathy (9 patients; 42.9%), and the most frequent indication for implantation was bridge-to-transplantation (19 patients; 90.4%). Pharmacological support of the right ventricle after LVAD implantation comprised dobutamine (21 patients; 100%), milrinone (21 patients; 100%), isoproterenol (1 patient; 4.8%), and levosimendan (5 patients; 23.8%). In 2 (9.5%) cases there was a need for repeated application of levosimendan during postoperative course. Inhalational nitric oxide was used in 14 (66.7%) patients. Despite extensive pharmacological support, 3 (14.3%) patients needed right ventricular assist device (RVAD) implantation. Most patients (9; 42.8%) survived to heart transplantation; in one (4.8%) case LVAD was successfuly explanted; 6 (28.6%) patients is living with LVAD; 5 (23.8%) patients died during LVAD support. CONCLUSION: After LVAD implantation there is a need for aggressive pharmacological, and in some cases mechanical, support of the right ventricular function to provide adequate blood flow to LVAD in order to minimize morbidity and mortality.

In vitro spheroid model of placental vasculogenesis: does it work?

Placental vascular development begins very early in pregnancy and is characterized by construction of a primitive vascular network in a low-oxygen environment. In vitro three-component assays of this process are scarce. In this study, a complex three-dimensional spheroid model for in vitro studies of placental vasculogenesis with regard to cell-cell interactions between cytotrophoblasts (CTs), villous stromal cells and endothelial precursor cells was established. Microscopic and immunohistochemical analyses of the spheroids showed structural and differentiation patterns resembling the structure and differentiation of early placental chorionic villous tissue (in regard to the expression of multiple markers cytokeratin-7, vimentin, CD34, CD31). The authenticity of this model to in vivo events allowed investigation of placental vascular development and trophoblast invasion under physiological and pathological conditions. Particularly enhanced spheroidal expression of SDF-1alpha and its receptor CXCR4, the major chemokine system in embryonic vasculogenesis, in a low-oxygen environment was detected. In addition, our model confirmed previously described invasive phenotype of trophoblasts through collagen under low- (physiologic), but not high- (pathologic) oxygen concentrations. Therefore, the three-dimensional spheroid model consisting of major placental cell types proved to be an appropriate system to investigate early placental vessel development under both physiological and pathological conditions.

A Tripeptide-Stabilized Nanoemulsion of Oleic Acid.

We describe a method to produce a nanoemulsion composed of an oleic acids-Pt(II) core and a lysine-tyrosine-phenylalanine (KYF) coating (KYF-Pt-NE). The KYF-Pt-NE encapsulates Pt(II) at 10 wt. %, has a diameter of 107 ± 27 nm and a negative surface charge. The KYF-Pt-NE is stable in water and in serum, and is biologically active. The conjugation of a fluorophore to KYF allows the synthesis of a fluorescent nanoemulsion that is suitable for biological imaging. The synthesis of the nanoemulsion is performed in an aqueous environment, and the KYF-Pt-NE forms via self-assembly of a short KYF peptide and an oleic acids-platinum(II) conjugate. The self-assembly process depends on the temperature of the solution, the molar ratio of the substrates, and the flow rate of the substrate addition. Crucial steps include maintaining the optimal stirring rate during the synthesis, permitting sufficient time for self-assembly, and pre-concentrating the nanoemulsion gradually in a centrifugal concentrator.

Determination of In Vitro Membrane Permeability by Analysis of Intracellular and Extracellular Fluorescein Signals in Renal Cells.

BACKGROUND/AIM: The structural integrity of the eukaryotic cytoplasmic membrane is of crucial importance for its cell biological function and thus for the survival of the cell. Physical and chemical noxae can interact in various ways with components of the cytoplasmic membrane, influence its permeability and thus mediate toxic effects. In the study presented, changes in membrane permeability were quantified by intracellular accumulation of a fluorescent dye and by the release of the fluorescent dye from dye-loaded cells. MATERIALS AND METHODS: Non-malignant (RC-124) and malignant (786-O, Caki-1) renal cells were permeabilized with different concentrations of Triton X-100. The permeability of the membrane was determined at the single-cell level by the uptake of the dye into the cell inner by flow cytometry. In addition, a fluorescence plate reader was used to detect and quantify the release of the dye into the cell culture supernatant. RESULTS: Both malignant and non-malignant cells showed a dose-dependent alteration of membrane permeability after treatment with Triton X-100. In the presence of the fluorescent dye, significantly more dye was introduced into the permeabilized cells compared to control incubations. Vice versa, Triton X-100-treated and dye-loaded cells released significantly more dye into the cell culture supernatant. CONCLUSION: The combination of measurement of intracellular accumulated and extracellular released dye can quantifiably detect changes in membrane permeability due to cell-membrane damage. The combination of two different measurement methods offers additional value in reliable detection of membrane-damaging, potentially toxic influences.

Vibronic effects in the 1(1)B(u)(1(1)B(2)) excited singlet states of oligothiophenes. fluorescence study of the 1(1)A(g)(1(1)A(1)) <-- 1(1)B(u)(1(1)B(2)) transition in terms of DFT, TDDFT, and CASSCF methods.

A combined DFT/TDDFT approach has been applied for calculating the Huang-Rhys (HR) parameters along the totally symmetric normal coordinates for the 1(1)A(g)(1(1)A(1)) <--1(1)B(u) (1(1)B(2)) electronic transition in a series of oligothiophenes containing from 2 to 6 thiophene rings. The calculations required optimized molecular geometries for both the ground state and the excited molecular state. The excited state geometry optimization was carried out by means of the time-dependent density functional theory (TDDFT) based methodology implemented in the Turbomole 5.9 (1) package of programs. The results for the three smallest oligothiophenes were verified by generating the theoretical vibronic structures and comparing them with the high-resolution fluorescence spectra measured for matrix-isolated molecules. For bithiophene a comparison was also made of the theoretical results obtained for different basis sets and the most popular exchange-correlation functionals. The best results were then confronted with the HR parameters based on the molecular geometries calculated at the CASSCF level of theory. The results obtained within the DFT/TDDFT approach are in very good agreement with the available experimental data for bithiophene, terthiophene, and quaterthiophene molecules.

Increased risk profile in the treatment of patients with symptomatic degenerative aortic valve stenosis over the last 10 years.

INTRODUCTION: Currently, Cardiology Centres are overfilled with patients with degenerative aortic valve stenosis (DAS), usually eldery, with severe concommittant comorbidities, who are referred for further decisions and possible intervention. AIM: To evaluate changes in the risk profile of patients with severe DAS admitted to the cardiology department a decade ago compared with patients currently being admitted. MATERIAL AND METHODS: We retrospectively evaluated all patients admitted with confirmed severe DAS, hospitalized during 2005-2006 (group I: 140 patients) and in 2016 (group II: 152 patients), admitted for aortic valve intervention. A standard transthoracic echocardiogram, cardiovascular symptom and risk factor distribution, perioperative risk with the logistic EuroSCORE II and STS mortality scores were obtained. RESULTS: Patients in group II were significantly older (p < 0.001), had more cardiovascular risk factors, and more often presented with atrial fibrillation (27% vs. 11.4%, p = 0.001), renal impairment (34.9% vs. 22.8%; p = 0.024), severe lung disease (17.1% vs. 2.1%, p < 0.001), and extracardiac arteriopathy (40.1% vs. 17.8%, p < 0.001). The aortic valve area (AVA) (p = 0.356), mean-transvalvular pressure gradient (p = 0.215), and left ventricular ejection fraction (p = 0.768) were similar in both groups. However, the prevalence of pulmonary hypertension, severe mitral regurgitation, and low-flow, low-gradient DAS were 3.1-, 8.4- and 1.84-fold more frequent in group II than group I. The percentages of subjects with EuroSCORE II and STS scores ≥ 4% in 2005-2006 were 7.1% and 6.4%, as compared to 27% and 26.3% in 2016 (both p < 0.001). 22% of patients in 2016, as compared to 31% in 2005/2006, were considered ineligible for DAS intervention. CONCLUSIONS: In just a decade, the risk profile of patients admitted with DAS has increased hugely, mainly due to older age, accumulation of comorbidities and more advanced disease at presentation. Although transcatheter aortic valve intervention has expanded the indications for intervention in high-risk patients, the number of patients disqualified from interventional treatment remains high.