Evelyn Ploetz, Ambrose, Benjamin , Barth, Anders , Börner, Richard , Erichson, Felix , Kapanidis, Achillefs N. , Kim, Harold D. , Levitus, Marcia , Lohman, Timothy M. , Mazumder, Abhishek , Rueda, David , Steffen, Fabio D. , Cordes, Thorben , Magennis, Steven W. , ו Lerner, Eitan . 2023. “A New Twist On Pife: Photoisomerisation-Related Fluorescence Enhancement”. Methods And Applications In Fluorescence, 12, 1, Pp. 012001. . Publisher's Versionתקציר
PIFE was first used as an acronym for protein-induced fluorescence enhancement, which refers to the increase in fluorescence observed upon the interaction of a fluorophore, such as a cyanine, with a protein. This fluorescence enhancement is due to changes in the rate of cis/trans photoisomerisation. It is clear now that this mechanism is generally applicable to interactions with any biomolecule. In this review, we propose that PIFE is thereby renamed according to its fundamental working principle as photoisomerisation-related fluorescence enhancement, keeping the PIFE acronym intact. We discuss the photochemistry of cyanine fluorophores, the mechanism of PIFE, its advantages and limitations, and recent approaches to turning PIFE into a quantitative assay. We provide an overview of its current applications to different biomolecules and discuss potential future uses, including the study of protein-protein interactions, protein-ligand interactions and conformational changes in biomolecules.
Ben Katz, Zaguri, Rachel , Edvardson, Simon , Maayan, Channa , Elpeleg, Orly , Lev, Shaya , Davidson, Elyad , Peters, Maximilian , Kfir-Erenfeld, Shlomit , Berger, Esther , Ghazalin, Shifa , Binshtok, Alexander M, ו Minke, Baruch . 2023. “Nociception And Pain In Humans Lacking A Functional Trpv1 Channel”. J Clin Invest, 133, 3. doi:10.1172/JCI153558. תקציר
BACKGROUNDChronic pain is a debilitating illness with currently limited therapy, in part due to difficulties in translating treatments derived from animal models to patients. The transient receptor potential vanilloid 1 (TRPV1) channel is associated with noxious heat detection and inflammatory pain, and reports of adverse effects in human trials have hindered extensive efforts in the clinical development of TRPV1 antagonists as novel pain relievers.METHODSWe examined 2 affected individuals (A1 and A2) carrying a homozygous missense mutation in TRPV1, rendering the channel nonfunctional. Biochemical and functional assays were used to analyze the mutant channel. To identify possible phenotypes of the affected individuals, we performed psychophysical and medical examinations.RESULTSWe demonstrated that diverse TRPV1 activators, acting at different sites of the channel protein, were unable to open the cloned mutant channel. This finding was not a consequence of impairment in the expression, cellular trafficking, or assembly of protein subunits. The affected individuals were insensitive to application of capsaicin to the mouth and skin and did not demonstrate aversive behavior toward capsaicin. Furthermore, quantitative sensory testing of A1 revealed an elevated heat-pain threshold but also, surprisingly, an elevated cold-pain threshold and extensive neurogenic inflammatory, flare, and pain responses following application of the TRPA1 channel activator mustard oil.CONCLUSIONOur study provides direct evidence in humans for pain-related functional changes linked to TRPV1, which is a prime target in the development of pain relievers.FUNDINGSupported by the Israel Science Foundation (368/19); Teva's National Network of Excellence in Neuroscience grant (no. 0394886) and Teva's National Network of Excellence in Neuroscience postdoctoral fellowship.
Directed self-assembly of block copolymers is evolving toward applications that are more defect-tolerant but still require high morphological control and could benefit from simple, inexpensive fabrication processes. Previously, we demonstrated that simply casting ultra-thin block copolymer films on topographically defined substrates leads to hierarchical structures with dual patterns in a controlled manner and unraveled the dependence of the local morphology on the topographic feature dimensions. In this article, we discuss the extreme of the ultraconfined thickness regime at the border of film dewetting. Additional non-bulk morphologies are observed at this extreme, which further elaborate the arsenal of dual patterns that could be obtained in coexistence with full placement control. It is shown that as the thickness confinement approaches its limit, lateral confinement imposed by the width of the plateaus becomes a critical factor influencing the local morphology.
המטרה : לבחון את תפיסותיהם של אנשי מקצועות הטיפול המטפלים בילדים שעברו התעללות מינית כלפי מושג האהבה בסביבתם של ילדים אלה. הנבדקים : אנשי מקצוע העובדים עם ילדים שנפלו קורבן להתעללות מינית במרכזים שונים לשלום הילד בארצות הברית. שיטת מחקר : הנבדקים השתתפו במחקר איכותני, שבמסגרתו נערכו חמש קבוצות מיקוד. מן הממצאים ניתוח הדיונים בקבוצות המיקוד הצביע על קיומם של שלושה היבטים שנקשרו לתפיסותיהם של אנשי המקצוע כלפי מושג האהבה במשפחות שבהן קיימת התעללות מינית: תפיסות הנוגעות לאהבה הורית; תפיסות המתייחסות לאהבת הילד את ההורה; ותפיסות הנוגעות לאהבה בין האחאים. הנבדקים הכירו בקיומה של אהבה הורית במקרים שבהם טיפלו, אך ראו אותה בצורה אמביוולנטית, ובדרך כלל כתוקפנית ולא סתגלנית. לעומת זאת, הם נטו לתפוס את הילדים כבעלי יכולת רבה מאד להביע ולהרגיש אהבה אמיתית וכנה. כמו כן, אנשי המקצוע שהשתתפו במחקר גם הכירו את המנגנונים המאפשרים לילדים לאהוב גם את ההורה הפוגע וגם את ההורה שלא, ואת הבעות האהבה המורכבות של האחאים, גם במקרים שבהם אחד האחים התעלל מינית באחרים. לבסוף, נמצא שחלק מן המשתתפים ראו בילדים שחוו התעללות מינית כבעלי תחושת סוכנות המאפשרת להם לקבל החלטות הקשורות לאהבה ולדאגה בצורה מודעת. ממצאי המחקר מאירים את הצורך לקדם את השיח על אהב ומשמעויותיה במקרים טיפוליים של התעללות מינית בתוך המשפחה, שכן ההכרה במורכבותם של קשרי האהבה יכולה להעצים את הילד הנפגע ולתמוך בצורך שלהם להאמין באהבת ההורה.
Recent work highlights that identification of present bias using task-completion data is problematic. In this note, we add to the literature in two ways. First, whereas prior work considers single-deadline tasks, we consider tasks for which there is a series of deadlines, with incremental penalties for missing each deadline. Second, we also consider identification of forgetting from the same type of data. Using numerical examples, we demonstrate that identification of present bias is still problematic even when there are multiple deadlines. Identification of forgetting perhaps holds more promise theoretically, although in practice we suspect it too is problematic.
Trevor DeMourdant, Rajkovic, Christian J, Tracz, Jovanna A, Perdomo-Pantoja, Alexander , Judy, Brendan F, Hernandez, Vaughn N, Lin, Jessica , Lazzari, Julianna L, Dikeman, Dustin A, Archer, Nathan K, Davis, Kimberly M, Gordon, Oren , ו Witham, Timothy F. 2023. “A Novel Rodent Model Of Chronic Spinal Implant-Associated Infection”. The Spine Journal: Official Journal Of The North American Spine Society, 23, Pp. 1389–1399. doi:10.1016/j.spinee.2023.05.014. תקציר
BACKGROUND CONTEXT: Bacterial infection of spinal instrumentation is a significant challenge in spinal fusion surgery. Although the intraoperative local application of powdered vancomycin is common practice for mitigating infection, the antimicrobial effects of this route of administration are short-lived. Therefore, novel antibiotic-loaded bone grafts as well as a reliable animal model to permit the testing of such therapies are needed to improve the efficacy of infection reduction practices in spinal fusion surgery. PURPOSE: This study aims to establish a clinically relevant rat model of spinal implant-associated infection to permit the evaluation of antimicrobial bone graft materials used in spinal fusion. STUDY DESIGN: Rodent study of chronic spinal implant-associated infection. METHODS: Instrumentation anchored in and spanning the vertebral bodies of L4 and L5 was inoculated with bioluminescent methicillin-resistant Staphylococcus aureus bacteria (MRSA). Infection was monitored using an in vivo imaging system (IVIS) for 8 weeks. Spines were harvested and evaluated histologically, and colony-forming units (CFUs) were quantified in harvested implants and spinal tissue. RESULTS: Postsurgical analysis of bacterial infection in vivo demonstrated stratification between MRSA and phosphate-buffered saline (PBS) control groups during the first 4 weeks of the 8-week infection period, indicating the successful establishment of acute infection. Over the 8-week chronic infection period, groups inoculated with 1 × 105 MRSA CFU and 1 × 106 MRSA CFU demonstrated significantly higher bioluminescence than groups inoculated with PBS control (p = 0.009 and p = 0.041 respectively). Histological examination at 8 weeks postimplantation revealed the presence of abscesses localized to implant placement in all MRSA inoculation groups, with the most pervasive abscess formation in samples inoculated with 1 × 105 MRSA CFU and 1 × 106 MRSA CFU. Quantification of CFU plated from harvested spinal tissue at 8 weeks post-implantation revealed the 1 × 105 MRSA CFU inoculation group as the only group with a significantly greater average CFU count compared to PBS control (p = 0.017). Further, CFU quantification from harvested spinal tissue was greater than CFU quantification from harvested implants across all inoculation groups. CONCLUSION: Our model demonstrated that the inoculation dosage of 1 × 105 MRSA CFU exhibited the most robust chronic infection within instrumented vertebral bodies. This dosage had the greatest difference in bioluminescence signal from control (p < 0.01), the lowest mortality (0% compared to 50% for samples inoculated with 1 × 106 MRSA CFU), and a significantly higher amount of CFUs from harvested spine samples than CFUs from control harvested spine samples. Further, histological analysis confirmed the reliability of this novel rodent model of implanted-associated infection to establish infection and biofilm formation of MRSA for all inoculation groups. CLINICAL SIGNIFICANCE: This model is intended to simulate the infection of instrumentation used in spinal fusion surgeries concerning implant locality and material. This model may evaluate potential antimicrobial and osteogenic biomaterials and investigate the relationship between implant-associated infection and failed fusion.
Ofek Vardi, Maroudas-Sklare, Naama , Kolodny, Yuval , Volosniev, Artem , Saragovi, Amijai , Galili, Nir , Ferrera, Stav , Ghazaryan, Areg , Yuran, Nir , Affek, Hagit P, Luz, Boaz , Goldsmith, Yonaton , Keren, Nir , Yochelis, Shira , Halevy, Itay , Lemeshko, Mikhail , ו Paltiel, Yossi . 2023. “Nuclear Spin Effects In Biological Processes”. Proceedings Of The National Academy Of Sciences, 120, Pp. e2300828120. doi:10.1073/pnas.2300828120. Publisher's Versionתקציר
Traditionally, nuclear spin is not considered to affect biological processes. Recently, this has changed as isotopic fractionation that deviates from classical mass dependence was reported both in vitro and in vivo. In these cases, the isotopic effect correlates with the nuclear magnetic spin. Here, we show nuclear spin effects using stable oxygen isotopes (16O, 17O, and 18O) in two separate setups: an artificial dioxygen production system and biological aquaporin channels in cells. We observe that oxygen dynamics in chiral environments (in particular its transport) depend on nuclear spin, suggesting future applications for controlled isotope separation to be used, for instance, in NMR. To demonstrate the mechanism behind our findings, we formulate theoretical models based on a nuclear-spin-enhanced switch between electronic spin states. Accounting for the role of nuclear spin in biology can provide insights into the role of quantum effects in living systems and help inspire the development of future biotechnology solutions.
This paper is aimed at comprehensively reviewing olfactory and gustatory disorders caused by SARS-CoV-2 in children and adults. An electronic and manual search was done on three databases: MEDLINE, Embase, and Web of Science. Inclusion criteria included publications written in English, involving humans in the age range of 0 to 99 years that were captured by a controlled vocabulary of thesaurus terms. Olfactory and gustatory disorders rates in COVID-19 ranged from 22% to 71.9% in adults and 16.6% to 25.8% in children. Olfactory and gustatory disorders might appear as the first symptom, and in adults might even be the only symptom (4.8% to 10%). Anosmia is the most common olfactory disorder and hypogeusia is the most common gustatory disorder. In 33% to 89% of cases, olfactory and gustatory disorders resolve spontaneously within a few weeks, coinciding with the resolution of other COVID-19 symptoms, both in adults and children. However, in some patients, olfactory and gustatory disorders persist beyond the resolution of other symptoms. Notably, children generally experience a swifter and more favorable recovery compared to adults. The precise pathogenesis underlying olfactory and gustatory disorders in the context of COVID-19 remains unclear and is likely multifactorial. Presently, no established treatment protocol exists for olfactory and gustatory disorders and current treatments reviewed lack robust evidence and are not readily available for clinical use. Olfactory training represents the only therapy currently recommended by international authorities. Pediatric practitioners and general dental practitioners should be aware of olfactory and gustatory disorders in both pediatric and adult populations, including their biologic mechanisms, treatment options, and recovery rates.
One of the most important properties of intrinsically disordered proteins is their ability to undergo liquid-liquid phase separation and form droplets. The Adenomatous Polyposis Coli (APC) protein is an IDP that plays a key role in Wnt signaling and mutations in Apc initiate cancer. APC forms droplets via its 20R domains and self-association domain (ASAD) and in the context of Axin. However, the mechanism involved is unknown. Here, we used peptides to study the molecular mechanism and regulation of APC droplet formation. We found that a peptide derived from the ASAD of APC-formed droplets. Peptide array screening showed that the ASAD bound other APC peptides corresponding to the 20R3 and 20R5 domains. We discovered that the 20R3/5 peptides also formed droplets by themselves and mapped specific residues within 20R3/5 that are necessary for droplet formation. When incubated together, the ASAD and 20R3/5 did not form droplets. Thus, the interaction of the ASAD with 20R3 and 20R5 may regulate the droplet formation as a means of regulating different cellular functions. Phosphorylation of 20R3 or 20R5 at specific residues prevented droplet formation of 20R3/5. Our results reveal that phosphorylation and the ability to undergo liquid-liquid phase separation, which are both important properties of intrinsically disordered proteins, are related to each other in APC. Phosphorylation inhibited the liquid-liquid phase separation of APC, acting as an ‘on-off’ switch for droplet formation. Phosphorylation may thus be a common mechanism regulating LLPS in intrinsically disordered proteins.
