Aspects of cyclodextrin host-guest complexes in mass spectrometry

Cancer is a widely spread disease leading to uncontrolled cellular replication that caused 9.6 million deaths worldwide in 2018. One approach in cancer treatment is inhibiting the replication process by the administration of organometallic compounds that bind to DNA. Cisplatin is one of the most prominent organometallic compounds that reached clinical approval. However, it suffers from severe side effects (e.g., nephrotoxicity) and causes the development of resistance. Various other metallorganic drugs have been evaluated for their potential in cancer treatment. Thereof, titanocene dichloride had entered clinical trials, but showed only low patient effcacy. Titanocene dichloride is a representative of the class of the bent metallocene dihalides that comprise a tetrahedral structure with two cyclopentadienyl and two halogenide ligands and a metal ion as central atom. Hydrolysis of the halogenide ligands is a crucial step in the activation of the metallocene, allowing for the interaction with its biological target. Unfortunately, extensive hydrolysis of the halogenide and the cyclopentadienyl ligands is detected for titanocene in aqueous environment at physiological conditions, leading to its inactivation. One approach for increasing the hydrolytic stability of titanocene is its inclusion within the cavity of a macrocyclic host structure. Cyclodextrins are such macrocyclic compounds composed of six to eight 1,4-linked α-D-glucopyranose units that are considered nontoxic upon oral administration. Therefore, several aspects of cyclodextrin host-guest complexes in mass spectrometry have been investigated and are discussed in this thesis. In the first section, the mass spectrometric behavior of cyclodextrins is discussed. The central part of this project was the elucidation of the fragmentation mechanism underlying the decomposition of protonated cyclodextrins. Linearization of the macrocyclic structure upon charge-induced cleavage of a glycosidic bond has been revealed as the initial dissociation step. Further decomposition of the linearized structure is characterized by neutral loss of glucose subunits. This dissociation step has been stated to occur upon charge-remote cleavage of other glycosidic bonds, leading to the elimination of a zwitterionic moiety which is potentially internally rearranged. In the second section, the focus is laid on the interaction between titanocene and cyclodextrins elucidated from mass spectrometric experiments. The obtained data indicated the formation of covalent bonds between titanium and the hydroxy groups at the rim of cyclodextrins rather than the formation of an inclusion complex. Consequently, improvement of the hydrolytic stability of titanocene at physiological pH was not obtained by the interaction of titanocene with cyclodextrins. In-source fragmentation has been found to contribute considerably to the ions detected in full scan mass spectrometry. Therefore, the effect of instrumental parameters on the quality of the obtained full scan mass spectra has been evaluated. While the capillary voltage showed only minor effects, proper adjustment of the capillary temperature and the tube lens voltage signifcantly improved the quality of the obtained data. In conclusion, diverse aspects of cyclodextrin host-guest complexes have been successfully investigated using mass spectrometry showing the potential of this analytical technique for various applications

Emotional Reactions to the Perception of Risk in the Pompeii Archaeological Park

The assessment of perceived risk by people is extremely important for safety and security management. Each person is based on the opinion of others to make a choice and the Internet represents the place where these opinions are mostly researched, found and reviewed. Social networks have a decisive impact: 92% of consumers say they have more trust in social media reviews than in any other form of advertising. For this reason, Opinion Mining and Sentiment Analysis have found interesting applications in the most diverse context, among which the most innovative is certainly represented by public safety and security. Security managers can use the perceptions expressed by people to discover the unexpected and potential weaknesses of a controlled environment or otherwise the risk and security perception of people that sometimes can be very different from real level of risk and security of a given site. Since the perceptions are the result of mostly unconscious elaborations, it is necessary to go deeper and to search for the emotions, triggered by the sensorial stimuli, that determine them. The objective of this paper is to study the perception of risk within the Pompeii Archaeological Park, giving emphasis to the emotional components, using the semantic analysis of the textual contents present in Twitter.Peer reviewe

Polarization reconfigurable patch antenna for compact and low cost UHF RFID reader

This paper presents a patch antenna designed for Ultra High Frequency (UHF) Radio Frequency IDentification (RFID) reader including a reconfigurable feeding for achieving polarization agility. The switchable polarization improves the polarization efficiency in comparison with standard circular polarized antenna solutions. CMOS switches are used in the reconfigurable feeding network for enabling higher power transmission and uncomplicated control with respect to solutions involving varactors and PIN diodes. Moreover, the designed patch antenna and ground planes have reduced size, for best integration of the reader in the required application. The combination of antenna and reconfigurable feeding network has been tested through simulations, showing good performance over the EU RFID frequency band (865-868 MHz). Due to its flexible and inexpensive structure, the proposed reconfigurable feeding system is a promising alternative to standard circular polarized reader antenna approaches

Phase shifters design for Rotman lens based beamforming network scan range extension

The design of the phase management unit needed for extending the scan range of a 24 GHz array antenna system based on Rotman lens beamforming is presented. The developed phase management unit consists of both static and switchable reflective type phase shifters, whose particular arrangement, in combination with a Rotman lens, allows increasing the maximum steering beam angle by 100%. Finally, the proposed concept is validated through simulation including the complete beamforming network and antenna array system

Pineoblastoma in Adults: A Rare Case Successfully Treated with Multimodal Approach Including Craniospinal Irradiation Using Helical Tomotherapy

Pineoblastomas (PBs) are rare and aggressive malignancies of the pineal gland. They are more commonly diagnosed in children between 1-12 years old, and are very rarely diagnosed in adults. For this reason, evidence in literature for adults is scarce and mainly derives from the paediatric practice. For their clinical behaviour and embryonal histology, PBs are often grouped together with medulloblastomas in clinical trials. In this report, we describe an adult PB case who was treated at our institution. We reference the literature to explain the clinical reasoning behind our decision-making process. A 46-year-old male patient was referred to our institution in November 2015 with three months history of headache. Imaging confirmed localised disease of the pineal gland. He underwent surgery which was radical and clinically uncomplicated. Histology showed PB. He then received adjuvant craniospinal radiotherapy with a boost to the tumour bed followed by consolidation chemotherapy. After 36 months follow-up, he remains disease-free without significant toxicities. Surgery followed by craniospinal irradiation and consolidation chemotherapy can be a safe and effective treatment option in adult PBs

Potassium bicarbonate and D-ribose effects on A72 canine and HTB-126 human cancer cell line proliferation in vitro

<p>Abstract</p> <p>Background</p> <p>The synergic action of KHCO₃and D-ribose is tested on A72 and HTB-126 cell lines proliferation using K:D-Rib solution. Altered Na⁺/K⁺ATPase expression and activity were shown in patients with cancer. Studies in human epithelial-derived malignancies indicate that K⁺depletion also occurs, contributing to the increased intracellular Na⁺/K⁺ratio <abbrgrp><abbr bid="B1">1</abbr></abbrgrp>. D-ribose transformed to piruvate, enters into the Krebs's cycle and has a key role on energetic metabolism. The up-regulation of glycolysis in tumor cells is already well known and it is the rationale of F¹⁸-FDG PET diagnostic technique. D-ribose is synthesized by the non-oxidative transketolase PPP reaction.</p> <p>Results</p> <p>Results with different K:D-Rib concentrations show that MTT salt interferes with K:D-Rib solution and therefore this method is not reliable. The UV/VIS measurements show that K:D-Rib solutions reduce MTT salt to formazan in absence of cells. Cell proliferation has then been evaluated analysing the digital photos of the Giemsa stained cells with MCID™ software. At 5 mM K:D-Rib concentration, the cell growth arrests between 48 h and 72 h; in fact the cell number after 48 h is around the same with respect to the control after 72 h. In case of HTB-126 human cancer cells, the growth rate was valuated counting the splitting times during 48 days: control cells were split sixteen times while 5 mM treated cells eleven times. Most relevant, the clonogenic assay shows that nine colonies are formed in the control cells while only one is formed in the 5 mM and none in 10 mM treated cells.</p> <p>Conclusions</p> <p>The K:D-Rib solution has an antioxidant behaviour also at low concentrations. Incubation with 5 mM K:D-Rib solution on A72 cells shows a cytostatic effect at 5 mM, but it needs more than 24 h of incubation time to evidence this effect on cell proliferation. At the same concentration on human HTB-126 cells, K:D-Rib solution shows a clear replication slowing but the cytostatic effect at 10 mM K:D-Rib solution only. Results on A72 cells indicate the K⁺uptake could be determinant either to arrest or to slow down cell growth.</p

Frequency and Polarization Agile RFID Patch Antenna with Reduced Dimensions

This paper presents a frequency and polarization reconfigurable UHF RFID patch antenna based on a switchable feeding network. For best integration of the antenna, its size and ground plane are much smaller with respect to the canonical patch antenna design, however the proposed design is able to cover the EU and US frequency bands of the RFID standard. State-of-the-art CMOS switches are employed as key element for selecting the desired polarization and proper matching network. The switches provide also a simple solution for high power applications in contrast to concepts based on PIN diodes or varactors. Simulated results have shown good performance. Considering its flexible and inexpensive structure, the proposed system is a promising alternative to aperture tuning and circular polarized antenna approaches

An Active Form of Sphingosine Kinase-1 Is Released in the Extracellular Medium as Component of Membrane Vesicles Shed by Two Human Tumor Cell Lines

Expression of sphingosine kinase-1 (SphK-1) correlates with a poor survival rate of tumor patients. This effect is probably due to the ability of SphK-1 to be released into the extracellular medium where it catalyzes the biosynthesis of sphingosine-1-phosphate (S1P), a signaling molecule endowed with profound proangiogenic effects. SphK-1 is a leaderless protein which is secreted by an unconventional mechanism. In this paper, we will show that in human hepatocarcinoma Sk-Hep1 cells, extracellular signaling is followed by targeting the enzyme to the cell surface and parallels targeting of FGF-2 to the budding vesicles. We will also show that SphK-1 is present in a catalitycally active form in vesicles shed by SK-Hep1 and human breast carcinoma 8701-BC cells. The enzyme substrate sphingosine is present in shed vesicles where it is produced by neutral ceramidase. Shed vesicles are therefore a site for S1P production in the extracellular medium and conceivably also within host cell following vesicle endocytosis

Antimicrobial Activity of Lactoferrin-Related Peptides and Applications in Human and Veterinary Medicine

Antimicrobial peptides (AMPs) represent a vast array of molecules produced by virtually all living organisms as natural barriers against infection. Among AMP sources, an interesting class regards the food-derived bioactive agents. The whey protein lactoferrin (Lf) is an iron-binding glycoprotein that plays a significant role in the innate immune system, and is considered as an important host defense molecule. In search for novel antimicrobial agents, Lf offers a new source with potential pharmaceutical applications. The Lf-derived peptides Lf(1–11), lactoferricin (Lfcin) and lactoferrampin exhibit interesting and more potent antimicrobial actions than intact protein. Particularly, Lfcin has demonstrated strong antibacterial, anti-fungal and antiparasitic activity with promising applications both in human and veterinary diseases (from ocular infections to osteo-articular, gastrointestinal and dermatological diseases)

LPS-induced IL-8 activation in human intestinal epithelial cells is accompanied by specific histone H3 acetylation and methylation changes

<p>Abstract</p> <p>Background</p> <p>The release of LPS by bacteria stimulates both immune and specific epithelial cell types to release inflammatory mediators. It is known that LPS induces the release of IL-8 by intestinal mucosal cells. Because it is now emerging that bacteria may induce alteration of epigenetic patterns in host cells, we have investigated whether LPS-induced IL-8 activation in human intestinal epithelial cells involves changes of histone modifications and/or DNA methylation at IL-8 gene regulatory region.</p> <p>Results</p> <p>RT-PCR analysis showed that IL-8 mRNA levels rapidly increase after exposure of HT-29 cells to LPS. DNA demethylating agents had no effects on IL-8 expression, suggesting that DNA methylation was not involved in IL-8 gene regulation. Consistently we found that 5 CpG sites located around IL-8 transcription start site (-83, -7, +73, +119, +191) were unmethylated on both lower and upper strand either in LPS treated or in untreated HT-29 cells, as well as in normal intestinal mucosa.</p> <p>Conversely, pretreatment of HT-29 cells with deacetylase inhibitors strengthened the LPS-mediated IL-8 activation. Inhibitors of histone deacetylases could induce IL-8 mRNA expression also in the absence of LPS, suggesting that chromatin modifications could be involved in IL-8 gene regulation. Chromatin immunoprecipitation analyses showed that, concurrently with IL-8 activation, transient specific changes in H3 acetylation and H3K4, H3K9 and H3K27 methylation occurred at IL-8 gene promoter during LPS stimulation. Changes of H3-acetyl, H3K4me2 and H3K9me2 levels occurred early, transiently and corresponded to transcriptional activity, while changes of H3K27me3 levels at IL-8 gene occurred later and were long lasting.</p> <p>Conclusion</p> <p>The results showed that specific chromatin modifications occurring at IL-8 gene, including histone H3 acetylation and methylation, mark LPS-mediated IL-8 activation in intestinal epithelial cells while it is unlikely that DNA methylation of IL-8 promoter is directly involved in IL-8 gene regulation in these cells.</p