Astrocytic ß-catenin signaling via TCF7L2 regulates synapse development and social behavior.

The Wnt/ß-catenin pathway contains multiple high-confidence risk genes that are linked to neurodevelopmental disorders, including autism spectrum disorder. However, its ubiquitous roles across brain cell types and developmental stages have made it challenging to define its impact on neural circuit development and behavior. Here, we show that TCF7L2, which is a key transcriptional effector of the Wnt/ß-catenin pathway, plays a cell-autonomous role in postnatal astrocyte maturation and impacts adult social behavior. TCF7L2 was the dominant Wnt effector that was expressed in both mouse and human astrocytes, with a peak during astrocyte maturation. The conditional knockout of Tcf7l2 in postnatal astrocytes led to an enlargement of astrocytes with defective tiling and gap junction coupling. These mice also exhibited an increase in the number of cortical excitatory and inhibitory synapses and a marked increase in social interaction by adulthood. These data reveal an astrocytic role for developmental Wnt/ß-catenin signaling in restricting excitatory synapse numbers and regulating adult social behavior.

Ethics of research engagement with Deaf people. A qualitative evidence synthesis.

In this article, we explore ethical issues of Deaf people's engagement in research. To focus on the perspectives of Deaf people, we investigated existing qualitative and mixed methods research within a qualitative evidence synthesis. Our synthesis is based on a systematic database search (Scopus, PubMed) and reference check of included papers which resulted in 27 eligible papers. We analyzed the data using thematic synthesis and developed 5 analytical themes. The results present research as a struggle for Deaf people and emphasize the need for changes regarding recognition of Deaf research in a cross-cultural context, maintaining equal and partner relations, and provision of accessible communication. Our research contributes to understanding what the ethical inclusion of Deaf people in research implies. It may also support the development of evidence-based normative recommendations and scientific cooperation between Deaf and hearing people.

Ratiometric pH-Responsive 19F Magnetic Resonance Imaging Contrast Agents Based on Hydrazone Switches.

Hydrazone-based molecular switches serve as efficient ratiometric pH-sensitive agents that can be tracked with 19F NMR/MRI and 1H NMR. Structural changes induced between pH 3 and 4 lead to signal appearance and disappearance at 1H and 19F NMR spectra allowing ratiometric pH measurements. The most pronounced are resonances of the CF3 group shifted by 1.8 ppm with 19F NMR and a hydrazone proton shifted by 2 ppm with 1H NMR.

19 F MRI Probes for Multimodal Imaging.

Magnetic resonance imaging (MRI) is one of the most powerful imaging tools today, capable of displaying superior soft-tissue contrast. This review discusses developments in the field of 19 F MRI multimodal probes in combination with optical fluorescence imaging (OFI), 1 H MRI, chemical exchange saturation transfer (CEST) MRI, ultrasonography (USG), X-ray computed tomography (CT), single photon emission tomography (SPECT), positron emission tomography (PET), and photoacoustic imaging (PAI). In each case, multimodal 19 F MRI probes compensate for the deficiency of individual techniques and offer improved sensitivity or accuracy of detection over unimodal counterparts. Strategies for designing 19 F MRI multimodal probes are described with respect to their structure, physicochemical properties, biocompatibility, and the quality of images.

Design Principles of Responsive Relaxometric 19F Contrast Agents: Evaluation from the Point of View of Relaxation Theory and Experimental Data.

19F magnetic resonance imaging (MRI) is a promising tool in medical diagnostics. An important class of 19F MRI contrast agents is based on paramagnetic resonance enhancement. This effect allows an improvement in sensitivity by increasing the number of scans per unit of time or facilitates the development of responsive contrast agents that are based on changes in relaxation rates as a detection principle. In this work, Bloch-Redfield-Wangsness relaxation theory was used to predict the relaxation properties of existing lanthanoid and transition metal complexes of fluoroorganic ligands and to evaluate several design strategies for responsive contrast agents. Electron-nucleus dipole-dipole, Curie relaxation, and contact interactions were included in the model. Potential significance of chemical shift anisotropy-anisotropic dipolar shielding cross-correlation was discussed. The calculated and experimental results were well aligned. The presented model, along with the optimized field-dependent values of electronic relaxation times, could be used for the preliminary selection of the optimal metal ion for applications in 19F MRI. The results indicate potential advantages of other metal ions in addition to Gd3+ particularly Cu2+, Mn2+, Ni2+, Fe3+, and other lanthanoids as a part of 19F contrast agents.

The Participation of 3,3,3-Trichloro-1-nitroprop-1-ene in the [3 + 2] Cycloaddition Reaction with Selected Nitrile N-Oxides in the Light of the Experimental and MEDT Quantum Chemical Study.

The regioselective zw-type [3 + 2] cycloaddition (32CA) reactions of a series of aryl-substituted nitrile N-oxides (NOs) with trichloronitropropene (TNP) have been both experimentally and theoretically studied within the Molecular Electron Density Theory (MEDT). Zwitterionic NOs behave as moderate nucleophiles while TNP acts as a very strong electrophile in these polar 32CA reactions of forward electron density flux, which present moderate activation Gibbs free energies of 22.8-25.6 kcal·mol-1 and an exergonic character of 28.4 kcal·mol-1 that makes them irreversible and kinetically controlled. The most favorable reaction is that involving the most nucleophilic MeO-substituted NO. Despite Parr functions correctly predicting the experimental regioselectivity with the most favorable O-CCCl3 interaction, these reactions follow a two-stage one-step mechanism in which formation of the O-C(CCl3) bond takes place once the C-C(NO2) bond is already formed. The present MEDT concludes that the reactivity differences in the series of NOs come from their different nucleophilic activation and polar character of the reactions, rather than any mechanistic feature.

Oilseed rape (Brassica napus): the importance of aminopeptidases in germination under normal and heavy metals stress conditions.

BACKGROUND: Oilseed rape is one of the most important oilseed crops worldwide, crucial in the food and feed industries. Different environment and climatic conditions can influence its sustainable cultivation and crop yield. Aminopeptidases are crucial enzymes in many physiological processes in all organisms, including humans, so it is important to learn their behavior in food and feed sources. This study presents, for the first time, a detailed discussion on the importance of aminopeptidases, during the oilseed rape germination process, under standard and stress conditions. RESULTS: During the germination of oilseed rape under standard conditions, a significant increase in aminopeptidases activity toward N-terminal amino acids - phenylalanine (Phe), alanine (Ala), glycine (Gly), leucine (Leu), proline (Pro), methionine (Met) - was observed. The change was substrate specific, with the highest increase being observed for Gly (3.2-fold), followed by Ala (2.9-fold), Pro (2.5-fold), Met (1.5-fold), and Phe (1.3-fold). Generally, N-terminal Phe was preferentially cleaved. Germination under stress conditions, caused by several heavy metal ions (e.g. divalent copper, zinc, cadmium, and lead ions), negatively influenced the plants' growth and quality, but significantly enhanced the expression of genes encoding aminopeptidases (or potentially activated aminopeptidases precursors), which was related to the dramatic increase of their activity. CONCLUSIONS: The activity/concentration of aminopeptidases in plants is adjusted to the needs at each stage of development and stress factors occurrence. The most significant increase of activity toward N-terminal Gly and Pro proved the key role of aminopeptidases in the defense mechanisms, by supplying the plants with osmoprotectants and organic nitrogen. The results provide new concepts of oilseed rape growth and cultivation under different conditions. © 2021 Society of Chemical Industry.

MiRNAs in endometrioid endometrial cancer metastatic loci derived from positive lymph nodes.

INTRODUCTION: MicroRNAs (miRNAs) take part in tumorigenesis and show aberrant expression levels in cancerous tissues. We aimed to perform miRNA profiling of endometrioid endometrial cancer (EEC) metastatic loci derived from lymph nodes. Identification of aberrant miRNAs in positive lymph nodes could contribute to establishing new diagnostic markers and therapeutic targets. MATERIAL AND METHODS: During the screening phase of the study, we performed profiling of 754 human miRNAs in endometrioid endometrial cancer tissues, microdissected metastatic loci from lymph nodes and healthy lymph nodes (Taqman Array). Selection of candidate miRNAs and subsequent validation using quantitative reverse transcription polymerase chain reaction (qRT-PCR) in 50 tissue samples were performed. RESULTS: After the screening phase of the study, five miRNAs were selected (hsa-miR-18b, hsa-miR-148a-5p, hsa-miR-204, hsa-miR-424, hsa-miR-129-1-3p). Validation revealed that miRNA-204 and miRNA-424 were highly downregulated in metastatic tissues compared with endometrial cancer samples (hsa-miR-204-P = .0008; hsa-miR-424-P = .0001). Receiver operating characteristic curves, which were constructed to compare endometrioid endometrial cancer and positive endometrioid endometrial cancer lymph nodes yielded the following area under the curves (AUCs): hsa-miR-204-.802 (96% confidence interval CI 0.676-0.927), hsa-miR-424-.84 (95% CI 0.711-0.969). CONCLUSIONS: Compared with primary endometrioid endometrial cancer tissue, metastatic loci derived from positive lymph nodes are characterized by profound downregulation of miRNA-204 and miRNA-424.

Determination of silyl peroxides by ultra-performance liquid chromatography/electrospray ionisation mass spectrometry.

RATIONALE: Residual initiators in polymers are a concern in the case of products that come directly into contact with the human body or food. Due to low concentrations and difficulties in the sample preparation, highly sensitive and selective methods are required. METHODS: A series of bis-silyl- and alkyl-silyl peroxides were analysed by electrospray ionisation mass spectrometry (ESI-MS) on an ultra-performance liquid chromatography/time-of-flight (UPLC/TOF) instrument. Li, Na, K, and NH4 acetates were used to promote the formation of [M + Me]+ ions. The sample preparation involved only dissolution of the polymer sample in 0.1 mL of acetonitrile, followed by precipitation with 1 mL of water. A portion of 0.1-1 µL of the solution was then analysed without further treatment by UPLC/ESI-MS. RESULTS: Limits of detection (LODs) were in the range of 0.06-9 pmol, depending on the peroxide structure. On average, the signal intensity increased with the number of phenyl groups in a peroxide and decreased in the order Na > Li > K > NH4 . Peroxides that did not contain phenyl groups could not be detected. Collision-induced dissociation experiments can be used for structural investigations of alkyl-silyl peroxides. It was possible to detect 2 × 10-4 % (LOD = 7 × 10-5 %) of unreacted Ph3 SiOOt-Bu in the poly(methyl methacrylate) sample. CONCLUSIONS: The method is suitable for the analysis of trace peroxide initiators in polymers and for other purposes where LODs in the pmol range are required.

The influence of chosen fungicides on the activity of aminopeptidases in winter oilseed rape during pods development.

Cultivation of oilseed rape requires application of specific fungicides. Besides their protective role, they can potentially influence the expression and activity of crucial enzymes in the plant. Among the large number of enzymes expressed in plants, aminopeptidases play a key role in all crucial physiological processes during the whole life cycle (e.g. storage protein mobilization and thus supplying plant with needed amino acids, as well as plant aging, protection and defense responses). In the present paper, we evaluate for the first time, the influence of the treatment of winter oilseed rape with commercially available fungicides (Pictor 400 SC, Propulse 250 SE and Symetra 325 SC), on the activity of aminopeptidases expressed in each plant organ (flowers, leaves, stems and pods separately). Fungicides were applied once, at one of the three stages of oilseed rape development (BBCH 59-61, BBCH 63-65 and BBCH 67-69). The aminopeptidase activity was determined using six different amino acid p-nitroanilides as substrates. The results have shown, that in control plants, at the beginning of intensive pods development and seeds production, hydrophobic amino acids with bulky side chains (Phe, Leu) were preferentially hydrolysed. In control plants, the activity was ~3.5 times higher in stems and pods, compared to leaves. The treatment with all pesticides caused significant increase in aminopeptidases hydrolytic activity toward small amino acids Gly, Ala as well as proline, mostly in flowers and leaves. These amino acids are proven to be crucial in the mechanisms of delaying of plant aging, development of better resistance to stress and plant defense. It can be suggested, that studied fungicides enhance such mechanisms, by activating the expression of genes coding for aminopeptidases, which are active in hydrolysis of N-terminal amino acids such as Gly, Ala, Pro from storage peptides and proteins. Depending on fungicide, the major increase of aminopeptidase activity was observed after application at BBCH 67-69 (Pictor 400 SC and Symetra 325 SC) and BBCH 63-65 (Propulse 250 SE) stages of development. Our study revealed, that agrochemical treatment and time of application, influenced the expression and activity of aminopeptidases, even though they were not molecular targets of applied fungicides. Since aminopeptidases are widely distributed throughout all organisms and are crucial in many key physiological processes, it can be expected, that factors influencing their expression and activity in plants, can also influence these enzymes in other organisms, especially humans and other mammals.

SEC Separation of Polysaccharides Using Macroporous Spherical Silica Gel as a Stationary Phase.

ABSTRACT: Meso- and macroporous spherical silica gels of pore sizes in the range of 60-1000 Å and 40-75 µm particle size were investigated as a stationary phase for the separation and purification of polysaccharides and poly(ethylene glycols) (PEGs) of various MWs using an aqueous mobile phase. Sephadex and Bio-Gel were used for comparison as the most common stationary phases for similar purposes. The separation of dextrans of a mean MW = 31 kDa from small molecules (NaCl) was possible with SiO2 with a pore size of 60-300 Å, but the observed efficiencies of a column of the same size were lower comparing with Sephadex or Bio-Gel. In the case of oxidized alginic acid only SiO2 of the 60 Å pore size was suitable, while Sephadex, Bio-Gel and other investigated silicas were not efficient. Sephadex and 300-1000 Å SiO2 offered the possibility of dividing dextrans with MW within the range of 1 MDa-10 kDa into fractions of various MWs, while Bio-Gel and 60 Å SiO2 were not suitable. The investigated silica gels strongly adsorbed PEGs of MW 2-20 kDa. The amount adsorbed decreased with the increase of pore size and they were not useful as a stationary phase for this class of polymers. An advantage of SiO2 of the investigated particle size was a very low back pressure comparing with Sephadex. A considerably lower price of silica offers time- and cost-efficient separation of polysaccharides.

Linear polymer separation using carbon-nanotube-modified centrifugal filter units.

The separation of linear polymers such as polysaccharides and polyethylene glycol was performed with modified commercial centrifugal filter units. The deposition of a 0.16-0.35 µm layer of modified carbon nanotubes prevented permeation of linear polymers of molecular weight higher than 20 000 Da through the membrane. It allowed facile purification of solution of 0.1 g of polymer samples from small molecules within 25 min by using a bench-top centrifuge. The structure of modified carbon nanotubes was optimized in order to achieve good adhesion to the low binding regenerated cellulose surface and low solubility in aqueous solutions after deposition. The best modification of carbon nanotubes was oxidation and subsequent amide formation of diethanolamine. Introduction of acetic acid groups using sodium chloroacetate worked equally well. The modified filter could be used multiple times without the decrease of the efficiency. The carbon nanotubes layer was stable in aqueous solutions in a pH range of 1-7. The proposed method provides a convenient way of purification of modified polymers in research areas such as drug delivery or macromolecular probes synthesis.

Enhanced electrospray ionization mass spectrometric detection of hexamethylene triperoxide diamine (HMTD) after oxidation to tetramethylene diperoxide diamine dialdehyde (TMDDD).

RATIONALE: Hexamethylene triperoxide diamine (HMTD) is one of the peroxide-based explosives that are difficult to detect using standard analytical methodologies. METHODS: It was analyzed by electrospray ionization mass spectrometry (ESI-MS) on a UPLC-TOF instrument. Alkali metal salts were used to promote the formation of ions. RESULTS: In the full scan positive ion mode a 3 ng (13 pmol) limit of detection was achieved if [HMTD + Me](+) ions (Me = Li, Na, K) were detected. It was found that HMTD easily undergoes oxidation to tetramethylene diperoxide diamine dialdehyde (TMDDD) in the source as well as in the samples. TMDDD can be detected as [TMDDD + Me](+) ions, but better ionization efficiency leads to the detection limit of TMDDD at the 2 pg (0.01 pmol) level. In butyl acetate the yield of oxidation of HMTD to TMDDD reaches 25% within 20 min at 120 °C, which offers a simple way of improving the detection limit of HMTD by two orders of magnitude. CONCLUSIONS: A simple procedure of detection of HMTD that matches the most sensitive methods available was developed. It uses standard equipment available in many laboratories. It was shown that the frequently reported [HMTD-H](+) cation observed by various authors was in fact a misinterpretation of the results, and should be attributed to [TMDDD + H](+).

CD44 expression in curettage and postoperative specimens of endometrial cancer.

BACKGROUND: Adhesive molecules like CD44 are well defined key players in the metastatic cascade in many cancers, including endometrial cancer. They could play a role of markers of invasion, metastasis and prognostic factors. AIM OF THE STUDY: The aim of the study is to assess a possible role of the CD44 as a marker of invasion in endometrial cancer, both at the moment of preoperative workup and final staging. MATERIALS AND METHODS: Available for analysis were archival specimens of 51 patients who had underwent curettage and surgery between 2002 and 2007. An immunohistochemical study for CD44 expression was performed in curettage and postoperative specimens. Normal endometrium of 20 randomly chosen patients was used as a control group. RESULTS: In endometrial cancer the expression of CD44 was significantly more intensive than in normal endometrium. In postoperative specimens, the CD44 expression was weaker in serous than in endometrioid cancer. There was no significant correlation between the adhesion molecule expression and clinicopathological features: grade,depth of invasion, cervical involvement, serosal and adnexal involvement, lymph-vascular space involvement, lymph node and distant metastases nor FIGO stage. CONCLUSIONS: An increased expression of CD44 in endometrial cancer suggests its possible role in pathogenesis of this disease, however, it doesn't seem to be crucial. Different expression of the CD44 in endometrioid and papillary-serous type may reflect different pathogenesis of these types of cancer. No statistically proved relation between the investigated molecule expression and clinicopathological parameters suggests scepticism about its use in diagnostic process of endometrial cancer.

Truthfulness as the basis for ethical safeguards in deceptive research: An interview study with researchers.

Ethical safeguards such as debriefing are often recommended or required for research studies in which participants are deceived. However, existing guidance on these safeguards seems insufficiently coherent and precise, which may be associated with their suboptimal implementation in practice. This study aimed to contribute to a more coherent and precise framework of ethical safeguards in deceptive studies through semi-structured interviews with a diverse sample of 24 researchers who had significant experience with deception. Interviewees discussed which ethical safeguards they implemented and how, as well as their relation to the notion of truthfulness (i.e., the intentional communication of true information). Moreover, interviewees provided a variety of reasons for and against implementing these safeguards, as well as how these reasons varied with the particular context of a study. Overall, the current study contributes to a more coherent and precise understanding of ethical safeguards in deceptive research that could be useful for guiding researchers and ethics reviewers in their ethical decision-making, although certain imprecisions and incoherent aspects remain in need of further investigation and normative reflection.

Tuning the pH of Activation of Fluorinated Hydrazone-Based Switches─A Pathway to Versatile 19F Magnetic Resonance Imaging Contrast Agents.

Molecular switches have become an area of great interest in recent years. They are explored as high-density data storage and organic diodes in molecular electronics as well as chemosensors due to their ability to undergo a transition between well-defined structures under the action of external stimuli. One of the types of such switches is hydrazones. They work by changing the configuration from E to Z under the influence of pH or light. The change in configuration is accompanied by a change in the absorption band and changes in the nuclear magnetic resonance (NMR) spectrum. In this publication, the structure-property relationship of fluorinated hydrazone switches was established. A linear relationship between the Hammett substituent constants and the pH where the switching occurs was found. Introduction of strong electron-donating groups allowed obtaining a hydrazone switch of pKa = 6 suitable for application in 19F MRI as contrast agents.

Informed Consent and Debriefing When Deceiving Participants: A Systematic Review of Research Ethics Guidelines.

Informed consent and debriefing of research participants in studies that use deception are ethical safeguards for which existing scholarly work on their implementation remains variable and insufficiently clear. A systematic review of research ethics guidelines was conducted to sketch a picture of whether, why and how informed consent and debriefing are recommended when using deception. Documents roughly agreed on several general principles, but varied significantly in the specifics of why and whether these safeguards are necessary, in which conditions and how they should be implemented. Various aspects that appear in the literature could not be found in the guidelines. In our review, guidance was integrated and showed a variation of implementation strategies that could help in contextualizing these safeguards.

Hydrazone Molecular Switches with Paramagnetic Center as 19F Magnetic Resonance Imaging Relaxation Enhancement Agents for pH Imaging.

The design and synthesis of hydrazone-based switches with a CF3 reporting group for 19F pH imaging using relaxation rate changes were described. A paramagnetic center was introduced into the hydrazone molecular switch scaffold by substitution of an ethyl functional group with a paramagnetic complex. The mechanism of activation relies on a gradual increase in T1 and T2 magnetic resonance imaging (MRI) relaxation times as pH decreases due to E/Z isomerization, which results in a change in the distance between fluorine atoms and the paramagnetic center. Among the three possible variants of the ligand, the meta isomer was found to offer the highest potential changes in relaxation rates due to the significant paramagnetic relaxation enhancement (PRE) effect and a stable position of the 19F signal, allowing for the tracking of a single narrow 19F resonance for imaging purposes. The selection of the most suitable Gd(III) paramagnetic ion for complexation was conducted by theoretical calculations based on the Bloch-Redfield-Wangsness (BRW) theory, taking into account the electron-nucleus dipole-dipole and Curie interactions only. The results were verified experimentally, confirming the accuracy of theoretical predictions, good solubility, and stability of the agents in water and the reversible transition between E and Z-H+ isomers. The results demonstrate the potential of this approach for pH imaging using relaxation rate changes instead of chemical shift.

Assessing the acceptability of individual studies that use deception: A systematic review of normative guidance documents.

Research participants are often deceived for methodological reasons. However, assessing the ethical acceptability of an individual study that uses deception is not straightforward. The academic literature is scattered on the subject and several aspects of the acceptability assessment are only scarcely addressed, which parallels reports of inconsistent ethics review. Therefore, we aimed to investigate where normative guidance documents agree and disagree about this assessment. A PRISMA-Ethics-guided systematic review of normative guidance documents that discuss deception of research participants was conducted. Our search strategy resulted in 55 documents that were subsequently analyzed through abductive thematic analysis. While guidance documents mention little about specific risks and opportunities of deception, our analysis describes a rich picture of the thresholds for acceptability of the risks and benefits of deception and their integration, the comparison with the risk-benefit analysis of alternative non-deceptive methods, and the bodies of people who are positioned to do the review. Our review reveals an agreement on the general process of assessing the acceptability of studies that use deception, although significant variability remains in the details and several topics are largely or completely unaddressed in guidance documents.

Vertex Deletion into Bipartite Permutation Graphs.

A permutation graph can be defined as an intersection graph of segments whose endpoints lie on two parallel lines ℓ 1 and ℓ 2 , one on each. A bipartite permutation graph is a permutation graph which is bipartite. In this paper we study the parameterized complexity of the bipartite permutation vertex deletion problem, which asks, for a given n-vertex graph, whether we can remove at most k vertices to obtain a bipartite permutation graph. This problem is NP -complete by the classical result of Lewis and Yannakakis [20]. We analyze the structure of the so-called almost bipartite permutation graphs which may contain holes (large induced cycles) in contrast to bipartite permutation graphs. We exploit the structural properties of the shortest hole in a such graph. We use it to obtain an algorithm for the bipartite permutation vertex deletion problem with running time O ( 9 k · n 9 ) , and also give a polynomial-time 9-approximation algorithm.