Design and Preclinical Evaluation of a Novel Prostate-Specific Membrane Antigen Radioligand Modified with a Transthyretin Binder.

Transthyretin binders have previously been used to improve the pharmacokinetic properties of small-molecule drug conjugates and could, thus, be utilized for radiopharmaceuticals as an alternative to the widely explored "albumin binder concept". In this study, a novel PSMA ligand modified with a transthyretin-binding entity (TB-01) was synthesized and labeled with lutetium-177 to obtain [177Lu]Lu-PSMA-TB-01. A high and specific uptake of [177Lu]Lu-PSMA-TB-01 was found in PSMA-positive PC-3 PIP cells (69 ± 3% after 4 h incubation), while uptake in PSMA-negative PC-3 flu cells was negligible (<1%). In vitro binding studies showed a 174-fold stronger affinity of [177Lu]Lu-PSMA-TB-01 to transthyretin than to human serum albumin. Biodistribution studies in PC-3 PIP/flu tumor-bearing mice confirmed the enhanced blood retention of [177Lu]Lu-PSMA-TB-01 (16 ± 1% IA/g at 1 h p.i.), which translated to a high tumor uptake (69 ± 13% IA/g at 4 h p.i.) with only slow wash-out over time (31 ± 8% IA/g at 96 h p.i.), while accumulation in the PC-3 flu tumor and non-targeted normal tissue was reasonably low. Further optimization of the radioligand design would be necessary to fine-tune the biodistribution and enable its use for therapeutic purposes. This study was the first of this kind and could motivate the use of the "transthyretin binder concept" for the development of future radiopharmaceuticals.

Which roads lead to access? A global landscape of six COVID-19 vaccine innovation models.

BACKGROUND: Unequal and inequitable access to Covid-19 vaccines in low- and middle-income countries (L&MICs) was a major political, ethical and public health failure in the pandemic. However, vaccine developers' practices were not monolithic, but rather, took diverse approaches to supplying different countries, with important implications for global access. RESULTS: Using data on R&D investments, regulatory approvals, manufacturing and purchase agreements, and vaccine deliveries, we identified six distinct innovation models that apply across the 14 COVID-19 vaccines with more international presence from 2020-2022. "Western Early Arrivers" Pfizer/BioNTech and Moderna supplied the largest volumes quickly and prioritized high-income countries (HICs) from registration to vaccine delivery. "Western Latecomers" Janssen and Novavax supplied intermediate volumes later, also prioritizing HICs but with a greater proportion to L&MICs. "Major Chinese Developers" Sinopharm and Sinovac supplied intermediate volumes early, primarily to middle-income countries (MICs). "Russian Developer" Gamaleya completed development early but ultimately supplied small volumes, primarily to middle-income countries (MICs). "Cosmopolitan Developer" Oxford/AstraZeneca supplied large volumes early to HICs and MICs at the lowest prices. Finally, "Small MIC Developers" CanSino, Bharat Biotech, Medigen, Finlay Institute and the Center for Genetic Engineering and Biotechnology (CGEB), exported relatively small volumes to a few MICs. Low-income countries (LICs) were not targeted by any developer, and received far fewer doses, later, than any other income group. Almost all developers received public funding and other forms of support, but we found little evidence that such support was leveraged to expand global access. CONCLUSIONS: Each of the six innovation models has different implications for which countries get access to which vaccines, how quickly, and at which prices. Each offers different strengths and weaknesses for achieving equitable access. Our findings also suggest that Western firms had the greatest capacity to develop and deliver vaccines quickly during the pandemic, but such capacity is rapidly becoming more globally distributed with MICs playing a significant role, especially in supplying other MICs. Given the critical role of public support in enabling pandemic vaccine development and supply, governments have both the capacity and responsibility to craft international rules that will make responses to future pandemics more equitable and effective.

Occurrence of herpesvirus in fish.

Introduction: Herpesviruses are common agents in animals of the aquatic environment. They infect many species of fish but only lead to disease in one or two species. Nevertheless, infected fish without clinical symptoms can actively transfer infectious agents to disease-susceptible species. The aim of the study was to identify and prove the natural presence of different herpesviruses. Material and Methods: Koi, Nile tilapia, grass carp, goldfish and crucian carp were infected with a herpesvirus isolate 99% identical to goldfish herpesvirus (GHV) or cyprinid herpesvirus 2 (CyHV-2) obtained from crucian carp. Before and after infection, samples were collected non-lethally at different time points from all five fish species to identify and evaluate the replication of viruses naturally infecting the fish as well as the CyHV-2 experimentally infecting them. Gill swabs and separated leukocytes were subjected to PCR and the results compared. Results: These samples yielded DNA of koi herpesvirus (KHV, also referred to as CyHV-3), GHV and a new herpesvirus. While Asian-lineage CyHV-3 DNA was detected in samples from crucian carp and goldfish, CyHV-2 DNA was found in samples from koi and tilapia. A new, hitherto unknown herpesvirus was identified in samples from grass carp, and was confirmed by nested PCR and sequence analysis. The survival rates were 5% for grass carp, 30% for tilapia, 55% for crucian carp, 70% for koi and 100% for goldfish at 20 days post infection. Evolutionary analyses were conducted and five clusters were visible: CyHV-1 (carp pox virus), CyHV-2 with sequences from koi and tilapia, CyHV-3 with sequences from crucian carp and goldfish, probable CyHV-4 from sichel and a newly discovered herpesvirus - CyHV-5 - from grass carp. Conclusion: The results obtained with the molecular tools as well as from the animal experiment demonstrated the pluripotency of aquatic herpesviruses to infect different fish species with and without visible clinical signs or mortality.

The presence of free palmitic acid modulates the effects of lutein on structural and dynamic properties of lipid membranes.

Free fatty acids, like palmitic acid (PA), and xanthophyll pigments, like lutein (LUT) are the natural membrane compounds in plants. To study the effect of PA on LUT and their organization, a model membrane of 1,2-dimyristoyl-sn-glycerol-3-phosphocholine (DMPC) enriched with 2 mol% PA and 1 mol% LUT was formed. Molecular mechanisms underlying the interaction between these two compounds were examined with application of molecular spectroscopy techniques, e.g., visible spectroscopy, electron paramagnetic resonance and Fourier transform infrared. We determined the monomeric/dimeric organization of LUT in the membrane. We proved that the presence of PA in the lipid phase facilitated and stabilized the formation of LUT structures in the membrane. Lutein with PA did not form strong molecular aggregates like H- and J-structures. We presented the simplified model membrane that could be a suitable representation of the physiological process of de-esterification of PA from LUT appearing in natural biomembranes in humans.

The revival of the psychedelic experience scale: Revealing its extended-mystical, visual, and distressing experiential spectrum with LSD and psilocybin studies.

BACKGROUND: Research with the Psychedelic Experience Questionnaire/Scale (PES) focuses on questions relating to mystical experience (Mystical Experience Questionnaire (MEQ)). The psychometric potential of the non-MEQ items of the PES remains largely unexplored. AIMS: We investigated whether the PES also yields subscales besides the MEQ30 subscales. METHODS: Data from 239 PES measurements (140 healthy participants) from six studies with moderate to high doses of lysergic acid diethylamide and/or psilocybin were included. New subscales (with items other than MEQ30) were created and validated as follows: (1) theoretical derivation of candidate items; (2) removal of items with rare experiences; (3) exploratory factor analysis; and (4) confirmatory factor analysis. Correlations of subscales within the PES and between the PES and the 5-Dimensional Altered States of Consciousness Scale (5D-ASC) were performed. In addition, a cluster analysis using all items (except rare experiences) was performed. RESULTS: The reliability of the four original factors of the MEQ30 was confirmed and four additional factors for the non-MEQ items were revealed: paradoxicality, connectedness, visual experience, and distressing experience. The first two additional factors were strongly correlated with the MEQ30 mystical subscale. Adding the new subscales to the MEQ30 subscales increased the explained variance with the 5D-ASC. The cluster analysis confirmed our main results and provided additional insights for future psychedelic psychometrics. CONCLUSION: The study yields a new validated 6-factor structure for extended mystical experience (MEQ40: MEQ30 + Paradoxicality + Connectedness) and covers psychedelic experience as a whole more comprehensively than has hitherto been possible within a single questionnaire (PES48). The entire PES (PES100) can also be used for further future psychedelic-psychometric research.

Investigations Using Albumin Binders to Modify the Tissue Distribution Profile of Radiopharmaceuticals Exemplified with Folate Radioconjugates.

Introducing an albumin-binding entity into otherwise short-lived radiopharmaceuticals can be an effective means to improve their pharmacokinetic properties due to enhanced blood residence time. In the current study, DOTA-derivatized albumin binders based on 4-(p-iodophenyl)butanoate (DOTA-ALB-1 and DOTA-ALB-3) and 5-(p-iodophenyl)pentanoate entities (DOTA-ALB-24 and DOTA-ALB-25) without and with a hydrophobic 4-(aminomethyl)benzoic acid (AMBA) linker unit, respectively, were synthesized and labeled with lutetium-177 for in vitro and in vivo comparison. Overall, [177Lu]Lu-DOTA-ALB-1 demonstrated ~3-fold stronger in vitro albumin-binding affinity and a longer blood residence time (T50%IA ~8 h) than [177Lu]Lu-DOTA-ALB-24 (T50%IA ~0.8 h). Introducing an AMBA linker enhanced the albumin-binding affinity, resulting in a T50%IA of ~24 h for [177Lu]Lu-DOTA-ALB-3 and ~2 h for [177Lu]Lu-DOTA-ALB-25. The same albumin binders without or with the AMBA linker were incorporated into 6R- and 6S-5-methyltetrahydrofolate-based DOTA-conjugates (177Lu-RedFols). Biodistribution studies in mice performed with both diastereoisomers of [177Lu]Lu-RedFol-1 and [177Lu]Lu-RedFol-3, which comprised the 4-(p-iodophenyl)butanoate moiety, demonstrated a slower accumulation in KB tumors than those of [177Lu]Lu-RedFol-24 and [177Lu]Lu-RedFol-25 with the 5-(p-iodophenyl)pentanoate entity. In all cases, the tumor uptake was high (30-45% IA/g) 24 h after injection. Both diastereoisomers of [177Lu]Lu-RedFol-1 and [177Lu]Lu-RedFol-3 demonstrated high blood retention (3.8-8.7% IA/g, 24 h p.i.) and a 2- to 4-fold lower kidney uptake than the corresponding diastereoisomers of [177Lu]Lu-RedFol-24 and [177Lu]Lu-RedFol-25, which were more rapidly cleared from the blood (<0.2% IA/g, 24 h after injection). Kidney retention of the 6S-diastereoisomers of all 177Lu-RedFols was consistently higher than that of the respective 6R-diastereoisomers, irrespective of the albumin binder and linker unit used. It was demonstrated that the blood clearance data obtained with 177Lu-DOTA-ALBs had predictive value for the blood retention times of the respective folate radioconjugates. The use of these albumin-binding entities without or with an AMBA linker may serve for fine-tuning the blood retention of folate radioconjugates and also other radiopharmaceuticals and, hence, optimize their tissue distribution profiles. Dosimetry estimations based on patient data obtained with one of the most promising folate radioconjugates will be crucial to identify the dose-limiting organ, which will allow for selecting the most suitable folate radioconjugate for therapeutic purposes.

Dual Action of Curcumin as an Anti- and Pro-Oxidant from a Biophysical Perspective.

Curcumin, a natural polyphenol widely used as a spice, colorant and food additive, has been shown to have therapeutic effects against different disorders, mostly due to its anti-oxidant properties. Curcumin also reduces the efficiency of melanin synthesis and affects cell membranes. However, curcumin can act as a pro-oxidant when blue light is applied, since upon illumination it can generate singlet oxygen. Our review aims to describe this dual role of curcumin from a biophysical perspective, bearing in mind its concentration, bioavailability-enhancing modifications and membrane interactions, as well as environmental conditions such as light. In low concentrations and without irradiation, curcumin shows positive effects and can be recommended as a beneficial food supplement. On the other hand, when used in excess or irradiated, curcumin can be toxic. Therefore, numerous attempts have been undertaken to test curcumin as a potential photosensitizer in photodynamic therapy (PDT). At that point, we underline that curcumin-based PDT is limited to the treatment of superficial tumors or skin and oral infections due to the weak penetration of blue light. Additionally, we conclude that an increase in curcumin bioavailability through the using nanocarriers, and therefore its concentration, as well as its topical use if skin is exposed to light, may be dangerous.

Establishment of vestibular schwannoma primary cell cultures obtained from cavitron ultrasonic surgical aspirator tissue material.

BACKGROUND: Vestibular schwannoma (VS) is a benign tumor arising from the Schwann cells of the eighth cranial nerve. The complexity in treatment is associated with unpredictable progression of this tumor. Some of the VS do not alter for years, while others rapidly increase in size. The mechanisms behind size progression are not well studied. Furthermore, despite several studies, there is no pharmacological treatment available for sporadic VS. Therefore, in vitro models are essential tools to study the cellular and molecular processes of VS. In addition, patient-derived cell cultures are important for substance screening to investigate pharmacological approaches in vitro. NEW METHOD: This study presents a simple and fast method for culturing VS cells from patient tissue material obtained using a cavitron ultrasonic surgical aspirator (CUSA). In addition, the cells were characterized based on the expression of schwannoma markers, growth properties and screened for fibroblast contamination. RESULT: We could show that CUSA obtained material is a suitable resource for isolation of VS primary cultures and enables real time analysis on living cells. COMPARISON WITH EXISTING METHODS: To date, only a few protocols are available for culturing VS cells from patient tissue material. A disadvantage of these methods is the relatively large amount of tissue needed to obtain the primary cells, which can be difficult, especially in small VS. By obtaining the cells from the CUSA, there is the possibility to establish a primary culture even with limited material. CONCLUSION: This approach could be particularly useful for testing substances that represent candidates for drug therapy of vestibular schwannoma.

Structural Impact of Selected Retinoids on Model Photoreceptor Membranes.

Photoreceptor membranes have a unique lipid composition. They contain a high level of polyunsaturated fatty acids including the most unsaturated fatty acid in nature, docosahexaenoic acid (22:6), and are enriched in phosphatidylethanolamines. The phospholipid composition and cholesterol content of the subcellular components of photoreceptor outer segments enables to divide photoreceptor membranes into three types: plasma membranes, young disc membranes, and old disc membranes. A high degree of lipid unsaturation, extended exposure to intensive irradiation, and high respiratory demands make these membranes sensitive to oxidative stress and lipid peroxidation. Moreover, all-trans retinal (AtRAL), which is a photoreactive product of visual pigment bleaching, accumulates transiently inside these membranes, where its concentration may reach a phototoxic level. An elevated concentration of AtRAL leads to accelerated formation and accumulation of bisretinoid condensation products such as A2E or AtRAL dimers. However, a possible structural impact of these retinoids on the photoreceptor-membrane properties has not yet been studied. In this work we focused just on this aspect. The changes induced by retinoids, although noticeable, seem not to be significant enough to be physiologically relevant. This is, however, an positive conclusion because it can be assumed that accumulation of AtRAL in photoreceptor membranes will not affect the transduction of visual signals and will not disturb the interaction of proteins engaged in this process.

Cr(vi) permanently binds to the lipid bilayer in an inverted hexagonal phase throughout the reduction process.

Cr(vi) is a harmful, carcinogenic agent with a high permeability rate throughout the lipid membranes. In an intracellular environment and during interactions with cellular membranes, it undergoes an instant reduction to lower oxidation states throughout radical states, recognized as the most dangerous factor for cells. The cellular membrane is the most visible cellular organelle in the interior and exterior of a cell. In this study, liposomes and non-lamellar inverted hexagonal phase lipid structures based on phosphoethanolamine (PE) were used as model cellular bilayers because of their simple composition, preparation procedure, and the many other properties of natural systems. The lipid membranes were subjected to 0.075 mM Cr(vi) for 15 min, after which the Cr content was removed via dialysis. This way, the remaining Cr content could be studied qualitatively and quantitatively. Using the combined XRF/XAS/EPR approach, we revealed that some Cr content (Cr(iii) and Cr(vi)) was still present in the samples even after long-term dialysis at a temperature significantly above the phase transition for the chosen liposome. The amount of bound Cr increased with increasing PE and -C[double bond, length as m-dash]C- bond content in lipid mixtures. Internal membrane order decreased in less fluid membranes, while in more liquified ones, internal order was only slightly changed after subjecting them to the Cr(vi) agent. The results suggest that the inverted hexagonal phase of lipid structures is much more sensitive to oxidation than the lamellar lipid phase, which can play an important role in the strong cytotoxicity of Cr(vi).

Purification and concentration of infectious koi herpesvirus using steric exclusion chromatography.

Koi herpesvirus (KHV) is the causative agent of a koi herpesvirus disease (KHVD) inducing high mortality rates in common carp and koi (Cyprinus carpio). No widespread effective vaccination strategy has been implemented yet, which is partly due to side effects of the immunized fish. In this study, we present an evaluation of the purification of infectious KHV from host cell protein and DNA, using the steric exclusion chromatography. The method is related to conventional polyethylene glycol (PEG) precipitation implemented in a chromatographic set-up and has been applied for infectious virus particle purification with high recoveries and impurity removal. Here, we achieved a yield of up to 55% of infectious KHV by using 12% PEG (molecular weight of 6 kDa) at pH 7.0. The recoveries were higher when using chromatographic cellulose membranes with 3-5 µm pores in diameter instead of 1 µm. The losses were assumed to originate from dense KHV precipitates retained on the membranes. Additionally, the use of >0.6 M NaCl was shown to inactivate infectious KHV. In summary, we propose a first step towards a purification procedure for infectious KHV with a possible implementation in fish vaccine manufacturing.

Acute effects of MDMA and LSD co-administration in a double-blind placebo-controlled study in healthy participants.

There is renewed interest in the use of lysergic acid diethylamide (LSD) in psychiatric research and practice. Although acute subjective effects of LSD are mostly positive, negative subjective effects, including anxiety, may occur. The induction of overall positive acute subjective effects is desired in psychedelic-assisted therapy because positive acute experiences are associated with greater therapeutic long-term benefits. 3,4-Methylenedioxymethamphetamine (MDMA) produces marked positive subjective effects and is used recreationally with LSD, known as "candyflipping." The present study investigated whether the co-administration of MDMA can be used to augment acute subjective effects of LSD. We used a double-blind, randomized, placebo-controlled, crossover design with 24 healthy subjects (12 women, 12 men) to compare the co-administration of MDMA (100 mg) and LSD (100 µg) with MDMA and LSD administration alone and placebo. Outcome measures included subjective, autonomic, and endocrine effects and pharmacokinetics. MDMA co-administration with LSD did not change the quality of acute subjective effects compared with LSD alone. However, acute subjective effects lasted longer after LSD + MDMA co-administration compared with LSD and MDMA alone, consistent with higher plasma concentrations of LSD (Cmax and area under the curve) and a longer plasma elimination half-life of LSD when MDMA was co-administered. The LSD + MDMA combination increased blood pressure, heart rate, and pupil size more than LSD alone. Both MDMA alone and the LSD + MDMA combination increased oxytocin levels more than LSD alone. Overall, the co-administration of MDMA (100 mg) did not improve acute effects or the safety profile of LSD (100 µg). The combined use of MDMA and LSD is unlikely to provide relevant benefits over LSD alone in psychedelic-assisted therapy. Trial registration: ClinicalTrials.gov identifier: NCT04516902.

Acute effects of intravenous DMT in a randomized placebo-controlled study in healthy participants.

N,N-dimethyltryptamine (DMT) is distinct among classic serotonergic psychedelics because of its short-lasting effects when administered intravenously. Despite growing interest in the experimental and therapeutic use of intravenous DMT, data are lacking on its clinical pharmacology. We conducted a double-blind, randomized, placebo-controlled crossover trial in 27 healthy participants to test different intravenous DMT administration regimens: placebo, low infusion (0.6 mg/min), high infusion (1 mg/min), low bolus + low infusion (15 mg + 0.6 mg/min), and high bolus + high infusion (25 mg + 1 mg/min). Study sessions lasted for 5 h and were separated by at least 1 week. Participant's lifetime use of psychedelics was ≤20 times. Outcome measures included subjective, autonomic, and adverse effects, pharmacokinetics of DMT, and plasma levels of brain-derived neurotropic factor (BDNF) and oxytocin. Low (15 mg) and high (25 mg) DMT bolus doses rapidly induced very intense psychedelic effects that peaked within 2 min. DMT infusions (0.6 or 1 mg/min) without a bolus induced slowly increasing and dose-dependent psychedelic effects that reached plateaus after 30 min. Both bolus doses produced more negative subjective effects and anxiety than infusions. After stopping the infusion, all drug effects rapidly decreased and completely subsided within 15 min, consistent with a short early plasma elimination half-life (t1/2α) of 5.0-5.8 min, followed by longer late elimination (t1/2ß = 14-16 min) after 15-20 min. Subjective effects of DMT were stable from 30 to 90 min, despite further increasing plasma concentrations, thus indicating acute tolerance to continuous DMT administration. Intravenous DMT, particularly when administered as an infusion, is a promising tool for the controlled induction of a psychedelic state that can be tailored to the specific needs of patients and therapeutic sessions.Trial registration: ClinicalTrials.gov identifier: NCT04353024.

Comparative acute effects of mescaline, lysergic acid diethylamide, and psilocybin in a randomized, double-blind, placebo-controlled cross-over study in healthy participants.

Mescaline, lysergic acid diethylamide (LSD), and psilocybin are classic serotonergic psychedelics. A valid, direct comparison of the effects of these substances is lacking. The main goal of the present study was to investigate potential pharmacological, physiological and phenomenological differences at psychoactive-equivalent doses of mescaline, LSD, and psilocybin. The present study used a randomized, double-blind, placebo-controlled, cross-over design to compare the acute subjective effects, autonomic effects, and pharmacokinetics of typically used, moderate to high doses of mescaline (300 and 500 mg), LSD (100 µg), and psilocybin (20 mg) in 32 healthy participants. A mescaline dose of 300 mg was used in the first 16 participants and 500 mg was used in the subsequent 16 participants. Acute subjective effects of 500 mg mescaline, LSD, and psilocybin were comparable across various psychometric scales. Autonomic effects of 500 mg mescaline, LSD, and psilocybin were moderate, with psilocybin causing a higher increase in diastolic blood pressure compared with LSD, and LSD showing a trend toward an increase in heart rate compared with psilocybin. The tolerability of mescaline, LSD, and psilocybin was comparable, with mescaline at both doses inducing slightly more subacute adverse effects (12-24 h) than LSD and psilocybin. Clear distinctions were seen in the duration of action between the three substances. Mescaline had the longest effect duration (mean: 11.1 h), followed by LSD (mean: 8.2 h), and psilocybin (mean: 4.9 h). Plasma elimination half-lives of mescaline and LSD were similar (approximately 3.5 h). The longer effect duration of mescaline compared with LSD was due to the longer time to reach maximal plasma concentrations and related peak effects. Mescaline and LSD, but not psilocybin, enhanced circulating oxytocin. None of the substances altered plasma brain-derived neurotrophic factor concentrations. In conclusion, the present study found no evidence of qualitative differences in altered states of consciousness that were induced by equally strong doses of mescaline, LSD, and psilocybin. The results indicate that any differences in the pharmacological profiles of mescaline, LSD, and psilocybin do not translate into relevant differences in the subjective experience. ClinicalTrials.gov identifier: NCT04227756.

Spontaneous activity of specific C-nociceptor subtypes from diabetic patients and mice: Involvement of reactive dicarbonyl compounds and (sensitized) transient receptor potential channel A1.

BACKGROUND: Diabetic metabolism causes changes of the chemical milieu including accumulation of reactive carbonyl species, for example, methylglyoxal (MGO). MGO activates chemosensitive TRPA1 on nociceptors, but the contribution to neuronal pathophysiology causing pain and hyperalgesia in diabetic neuropathy is not fully understood. METHODS: We employed single-nerve-fiber recordings in type 2 diabetes patients with (spDN) and without cutaneous pain (DN) and in streptozotocin-diabetic and healthy mice. In mice, we measured Ca++ transients in cultured DRG neurons and stimulated CGRP release from hairy skin. RESULTS: In diabetic patients, we recorded a large proportion of pathologically altered nerve C-fibers (79%). In spDN patients we found a higher percentage (72%) of spontaneously active C-nociceptors than in DN patients (15%). The proportion of spontaneous activity was highest among pathological fibers with mechanoinsensitive fiber properties which are particularly sensitive to MGO in contrast to mechanosensitive fibers. Mouse polymodal nociceptors, in contrast to purely mechanosensitive C-fibers, showed highest prevalence of TRPA1-related chemosensitivity. In diabetic mice about 37% of polymodal nociceptors developed spontaneous activity and exhibited significantly greater MGO responses, indicating sensitized TRPA1 receptors. Low-threshold mechanosensitive Aδ-fibers were vigorously activated by MGO but independently of TRPA1 activation. INTERPRETATION: Our translational findings suggest that TRPA1-expressing C-nociceptors, which in human correspond to mechanoinsensitive and in mice to polymodal nociceptors, are especially vulnerable to develop spontaneous activity. Those two different nociceptor classes might share the functional role as dicarbonyl-sensitive chemosensors and represent the critical nociceptor population that support the development of pain and hyperalgesia in diabetic neuropathy.

Determinants of persistent Salmonella infections.

Persistent bacterial infections constitute an enormous challenge for public health. Amongst infections with other bacteria, infections with typhoidal and nontyphoidal Salmonella enterica serovars can result in long-term infections of the human and animal host. Persistent infections that are asymptomatic are difficult to identify and thus can serve as a silent reservoir for transmission. Symptomatic persistent infections are often difficult to treat as they harbor a combination of antibiotic-tolerant and antibiotic-resistant bacteria and boost the spread of genetic antibiotic resistance. In the last couple of years, the field has made some major progress in understanding the role of persisters, their reservoirs as well as their interplay with host factors in persistent Salmonella infections.

The Role of Singlet Oxygen in Photoreactivity and Phototoxicity of Curcumin.

Curcumin is a plant-derived yellow-orange compound widely used as a spice, dye and food additive. It is also believed to have therapeutic effects against different disorders. On the other hand, there are data showing its phototoxicity against bacteria, fungi and various mammalian cells. Since the mechanism of its phototoxic action is not fully understood, we investigated here the phototoxic potential of curcumin in liposomal model membranes and in HaCaT cells. First, detection of singlet oxygen (1 O2 ) luminescence proved that curcumin generates 1 O2 upon blue light irradiation in organic solvent and in liposomes. Then, HPLC-EC(Hg) measurements revealed that liposomal and cellular cholesterol is oxidized by 1 O2 photogenerated by curcumin. Enrichment of liposome membranes with curcumin significantly increased the oxygen photo-consumption rate compared to the control liposomes as determined by EPR oximetry. Cytotoxicity measurements, mitochondrial membrane potential analyses and protein hydroperoxides detection confirmed strong phototoxic effects of curcumin in irradiated HaCaT cells. These data show that since curcumin is advertised as a valuable dietary supplement, or a component of cosmetics for topical use, caution should be recommended especially when skin is exposed to light.

Pharmacokinetics and Pharmacodynamics of Oral Psilocybin Administration in Healthy Participants.

Psilocybin is being investigated as a potential treatment for psychiatric and neurological disorders. Only a few studies have evaluated the pharmacokinetics (PKs) of psilocybin and have used body weight-adjusted dosing. Data on PKs and the PK-pharmacodynamic (PD) relationship of fixed doses that are commonly used are unavailable. The present study characterized the PKs and PK-PD relationship of 15, 25, and 30 mg of orally administered psilocybin in 28, 23, and 28 healthy subjects, respectively. Plasma levels of unconjugated psilocin (the psychoactive metabolite of psilocybin) and corresponding subjective effects were repeatedly assessed up to 24 hours. PK parameters were determined using compartmental modeling. Concentration-subjective effect relationships were described using PK-PD modeling. Mean (95% confidence interval) maximal psilocin concentrations were 11 ng/mL (10-13), 17 ng/mL (16-19), and 21 ng/mL (19-24) after the administration of 15, 25, and 30 mg psilocybin, respectively. Maximal concentrations were reached after an average of 2 hours. Elimination half-lives were 1.8 hours (1.7-2.0), 1.4 hours (1.2-1.7), and 1.8 hours (1.6-1.9) for 15, 25, and 30 mg psilocybin, respectively. Mean (± SD) durations of subjective effects were 5.6 ± 2.2 hours, 5.5 ± 1.6 hours, and 6.4 ± 2.2 hours, and maximal effects ("any drug" effects) were 58% ± 25%, 73% ± 27%, and 80% ± 18% after 15, 25, and 30 mg psilocybin, respectively. Psilocin exhibited dose-proportional PKs. The duration and intensity of subjective effects were dose-dependent. Body weight did not influence pharmacokinetics or the response to psilocybin. These data may serve as a reference for future clinical trials.

Ketanserin Reverses the Acute Response to LSD in a Randomized, Double-Blind, Placebo-Controlled, Crossover Study in Healthy Participants.

BACKGROUND: Lysergic acid diethylamide (LSD) is currently being investigated in psychedelic-assisted therapy. LSD has a long duration of acute action of 8-11 hours. It produces its acute psychedelic effects via stimulation of the serotonin 5-hydroxytryptamine-2A (HT2A) receptor. Administration of the 5-HT2A antagonist ketanserin before LSD almost fully blocks the acute subjective response to LSD. However, unclear is whether ketanserin can also reverse the effects of LSD when administered after LSD. METHODS: We used a double-blind, randomized, placebo-controlled, crossover design in 24 healthy participants who underwent two 14-hour sessions and received ketanserin (40 mg p.o.) or placebo 1 hour after LSD (100 µg p.o.). Outcome measures included subjective effects, autonomic effects, acute adverse effects, plasma brain-derived neurotrophic factor levels, and pharmacokinetics up to 12 hours. RESULTS: Ketanserin reversed the acute response to LSD, thereby significantly reducing the duration of subjective effects from 8.5 hours with placebo to 3.5 hours. Ketanserin also reversed LSD-induced alterations of mind, including visual and acoustic alterations and ego dissolution. Ketanserin reduced adverse cardiovascular effects and mydriasis that were associated with LSD but had no effects on elevations of brain-derived neurotrophic factor levels. Ketanserin did not alter the pharmacokinetics of LSD. CONCLUSIONS: These findings are consistent with an interaction between ketanserin and LSD and the view that LSD produces its psychedelic effects only when occupying 5-HT2A receptors. Ketanserin can effectively be used as a planned or rescue option to shorten and attenuate the LSD experience in humans in research and LSD-assisted therapy. TRIAL REGISTRY: ClinicalTrials.gov (NCT04558294).

Neuropsychological Assessment of Cognitive Impairment in Kidney Transplantation (NAsKiT) and its related risk factors: a study protocol.

BACKGROUND: Association of cognitive impairment with chronic kidney disease has been reported over the last decade. Individuals show better cognitive performance after kidney transplantation than individuals on dialysis but are more likely to be affected by cognitive impairment than age-matched comparison groups. Better knowledge of the prevalence as well as course and profile of cognitive impairment is important for the design of future studies assessing the clinical impact of cognitive impairment and developing management strategies. The goal of our study is to examine the extent of cognitive impairment before and after transplantation and to derive a distinct profile of cognitive function using standard neurocognitive tests. Furthermore, we aim to assess whether transplantation per se leads to an improvement in cognitive performance. METHODS: We are conducting a prospective single-center cohort study involving 100 kidney transplant individuals. Individuals who are wait-listed to receive a kidney transplantation or have already received one will be included in this study. Individuals will undergo a battery of detailed neurocognitive tests at baseline (in part before surgery), and then 3 and 12 months afterwards. Furthermore, the enrolled patients will complete a validated German version of the Cognitive Failure Questionnaire for self-assessment (s-CFQ) as well as the Hospital Anxiety and Depression Scale -Deutsche (HADS-D), a self-report screening instrument with two scales that capture anxiety and depression. In addition, a hair sample will be taken at each measurement time point for the determination of hair cortisol levels as a parameter for the cumulative hypothalamic-pituitary-adrenocortical axis activity over the previous three months. The primary outcome measure will be (a) the effect of kidney transplantation on the cognitive performance up to 12 months after transplantation and (b) the course of cognitive performance following kidney transplantation over time. DISCUSSION: The results of our study have potentially important implications for the prevention and treatment of cognitive impairment in kidney transplant individuals. By increasing our knowledge of the neurocognitive profile and assigning the corresponding deficits, it might be possible to create an individualized training program to positively impact cognitive deficits in kidney transplant patients.