Tropical and subtropical Asia's valued tree species under threat.

Tree diversity in Asia's tropical and subtropical forests is central to nature-based solutions. Species vulnerability to multiple threats, which affect provision of ecosystem services, is poorly understood. We conducted a region-wide, spatially explicit assessment of the vulnerability of 63 socioeconomically important tree species to overexploitation, fire, overgrazing, habitat conversion, and climate change. Trees were selected for assessment from national priority lists, and selections were validated by an expert network representing 20 countries. We used Maxent suitability modeling to predict species distribution ranges, freely accessible spatial data sets to map threat exposures, and functional traits to estimate threat sensitivities. Species-specific vulnerability maps were created as the product of exposure maps and sensitivity estimates. Based on vulnerability to current threats and climate change, we identified priority areas for conservation and restoration. Overall, 74% of the most important areas for conservation of these trees fell outside protected areas, and all species were severely threatened across an average of 47% of their native ranges. The most imminent threats were overexploitation and habitat conversion; populations were severely threatened by these factors in an average of 24% and 16% of their ranges, respectively. Our model predicted limited overall climate change impacts, although some study species were likely to lose over 15% of their habitat by 2050 due to climate change. We pinpointed specific natural areas in Borneo rain forests as hotspots for in situ conservation of forest genetic resources, more than 82% of which fell outside designated protected areas. We also identified degraded areas in Western Ghats, Indochina dry forests, and Sumatran rain forests as hotspots for restoration, where planting or assisted natural regeneration will help conserve these species, and croplands in southern India and Thailand as potentially important agroforestry options. Our results highlight the need for regionally coordinated action for effective conservation and restoration.

Especies de Árboles Valoradas y Amenazadas de Asia Tropical y Subtropical Resumen La diversidad de árboles en los bosques tropicales y subtropicales de Asia es un eje central para las soluciones basadas en la naturaleza. La vulnerabilidad de las especies ante las múltiples amenazas, las cuales afectan el suministro de servicios ambientales, es un tema poco comprendido. Realizamos una evaluación regional espacialmente explícita de la vulnerabilidad de 63 especies de árboles de importancia socioeconómica ante la sobreexplotación, incendios, sobrepastoreo, conversión del hábitat y cambio climático. Los árboles se seleccionaron para su evaluación a partir de listas nacionales de prioridades, y las selecciones fueron validadas por una red de expertos de 20 países. Usamos el modelado de idoneidad Maxent para predecir el rango de distribución de las especies, conjuntos de datos espaciales de libre acceso para mapear la exposición a las amenazas y rasgos funcionales para estimar la susceptibilidad a las amenazas. Con base en la vulnerabilidad a las amenazas actuales y al cambio climático, identificamos las áreas prioritarias para su conservación y restauración. En general, el 74% de las áreas más importantes para la conservación de estos árboles quedó fuera de las áreas protegidas y todas las especies estaban seriamente amenazadas en promedio en el 47% de su distribución nativa. Las amenazas más inminentes fueron la sobreexplotación y la conversión del hábitat; las poblaciones estuvieron seriamente amenazadas por estos factores en promedio en el 24% y 16% de su distribución, respectivamente. Nuestro modelo predijo un impacto general limitado del cambio climático, aunque algunas especies estudiadas tuvieron la probabilidad de perder más del 15% de su hábitat para el 2050 debido a este factor. Identificamos áreas naturales específicas en las selvas de Borneo como puntos calientes para la conservación in situ de los recursos genéticos forestales, más del 82% de los cuales estaban fuera de las áreas protegidas designadas. También identificamos áreas degradadas en los Ghats Occidentales, los bosques secos de Indochina y las selvas de Sumatra como puntos calientes para la restauración, en donde la siembra o la regeneración natural asistida ayudarán a conservar estas especies. Además, identificamos campos de cultivo al sur de India y Tailandia como potenciales opciones importantes de agrosilvicultura. Nuestros resultados resaltan la necesidad de acciones regionales coordinadas para la conservación y restauración efectivas.

18-kDa translocator protein ligand 18F-FEMPA: Biodistribution and uptake into atherosclerotic plaques in mice.

BACKGROUND: Radioligands of 18-kDa translocator protein (TSPO) expressed on activated macrophages are a potential approach for imaging of inflammation in atherosclerosis. We evaluated a novel TSPO-targeted tracer 18F-FEMPA for the detection of atherosclerotic plaque inflammation in mice. METHODS AND RESULTS: The distribution kinetics of 18F-FEMPA was evaluated by in vivo PET/CT imaging. 18F-FEMPA uptake was compared in atherosclerotic (LDLR-/-ApoB100/100, n = 10) and healthy mice (C57BL/6 N, n = 7) ex vivo at twenty minutes post-injection. Biodistribution was analyzed from harvested tissue samples, and aortas were sectioned for autoradiography. Aortas of LDLR-/-ApoB100/100 mice showed large, macrophage-rich atherosclerotic plaques. In vivo, 18F-FEMPA showed rapid blood clearance but no difference in aortic uptake between atherosclerotic and healthy mice. In the mice studied ex vivo at 20 minutes post-injection, quantification of radioactivity in the whole aorta showed 1.3-fold higher 18F-FEMPA accumulation in atherosclerotic than healthy mice (P = .028). Autoradiography showed higher tracer uptake in plaque areas with high macrophage content as compared with areas of no macrophages (count densities 190 ± 54 vs 40 ± 13 PSL/mm2, P < .001), but the uptake in the plaques was not higher than in the normal vessel wall (230 ± 78 PSL/mm2). In vitro blocking showed specific accumulation in mouse and human atherosclerotic plaques. Immunohistochemistry confirmed co-localization of TSPO and macrophages. CONCLUSIONS: 18F-FEMPA shows rapid blood clearance and uptake in the mouse aorta. Uptake in atherosclerotic plaques correlated with the amount of macrophages, but did not exceed that in the normal vessel wall.

Positron emission tomography imaging of the 18-kDa translocator protein (TSPO) with [18F]FEMPA in Alzheimer's disease patients and control subjects.

PURPOSE: Imaging of the 18-kDa translocator protein (TSPO) is a potential tool for examining microglial activation and neuroinflammation in early Alzheimer's disease (AD). [(18)F]FEMPA is a novel high-affinity second-generation TSPO radioligand that has displayed suitable pharmacokinetic properties in preclinical studies. The aims of this study were to quantify the binding of [(18)F]FEMPA to TSPO in AD patients and controls and to investigate whether higher [(18)F]FEMPA binding in AD patients than in controls could be detected in vivo. METHODS: Ten AD patients (five men, five women; age 66.9 ± 7.3 years; MMSE score 25.5 ± 2.5) and seven controls (three men, four women; age 63.7 ± 7.2 years, MMSE score 29.3 ± 1.0) were studied using [(18)F]FEMPA at Turku (13 subjects) and at Karolinska Institutet (4 subjects). The in vitro binding affinity for TSPO was assessed using PBR28 in a competition assay with [(3)H]PK11195 in seven controls and eight AD patients. Cortical and subcortical regions of interest were examined. Quantification was performed using a two-tissue compartment model (2TCM) and Logan graphical analysis (GA). The outcome measure was the total distribution volume (V T). Repeated measures analysis of variance was used to assess the effect of group and TSPO binding status on V T. RESULTS: Five AD patients and four controls were high-affinity binders (HABs). Three AD patients and three controls were mixed-affinity binders. V T estimated with Logan GA was significantly correlated with V T estimated with the 2TCM in both controls (r = 0.97) and AD patients (r = 0.98) and was selected for the final analysis. Significantly higher V T was found in the medial temporal cortex in AD patients than in controls (p = 0.044) if the TSPO binding status was entered as a covariate. If only HABs were included, significantly higher V T was found in the medial and lateral temporal cortex, posterior cingulate, caudate, putamen, thalamus and cerebellum in AD patients than in controls (p < 0.05). CONCLUSION: [(18)F]FEMPA seems to be a suitable radioligand for detecting increased TSPO binding in AD patients if their binding status is taken into account.

Differentiation between Staphylococcus aureus and coagulase-negative Staphylococcus species by real-time PCR including detection of methicillin resistants in comparison to conventional microbiology testing.

BACKGROUND: Staphylococcus aureus has long been recognized as a major pathogen. Methicillin-resistant strains of S. aureus (MRSA) and methicillin-resistant strains of S. epidermidis (MRSE) are among the most prevalent multiresistant pathogens worldwide, frequently causing nosocomial and community-acquired infections. METHODS: In the present pilot study, we tested a polymerase chain reaction (PCR) method to quickly differentiate Staphylococci and identify the mecA gene in a clinical setting. RESULTS: Compared to the conventional microbiology testing the real-time PCR assay had a higher detection rate for both S. aureus and coagulase-negative Staphylococci (CoNS; 55 vs. 32 for S. aureus and 63 vs. 24 for CoNS). Hands-on time preparing DNA, carrying out the PCR, and evaluating results was less than 5 h. CONCLUSIONS: The assay is largely automated, easy to adapt, and has been shown to be rapid and reliable. Fast detection and differentiation of S. aureus, CoNS, and the mecA gene by means of this real-time PCR protocol may help expedite therapeutic decision-making and enable earlier adequate antibiotic treatment.

[(18)F]Fluoropyruvate: radiosynthesis and initial biological evaluation.

The radiosynthesis of [(18)F]fluoropyruvate was investigated using numerous precursors were synthesized from ethyl 2,2-diethoxy-3-hydroxypropanoate (5) containing different leaving groups: mesylate, tosylate, triflate, and nonaflate. These precursors were evaluated for [(18)F]fluoride incorporation with triflate being superior. The subsequent hydrolysis step was investigated, and an acidic hydrolysis was optimized. After establishing suitable purification and formulation methods, the [(18)F]fluoropyruvate could be isolated in ca. 50% d.c. yield. The [(18)F]fluoropyruvate was evaluated in vitro for its uptake into tumor cells using adenocarcinomic human alveolar basal epithelial cells (A549) and unfortunately showed an uptake of approximately 0.1% of the applied dose per 100,000 cells after 30 min. Initial pharmacokinetic properties were assessed in vivo using nude mice showed a high degree of bone uptake from defluorination, which will limit its potential as an imaging agent for metabolic processes.

Predictive Modeling of PROTAC Cell Permeability with Machine Learning.

Approaches for predicting proteolysis targeting chimera (PROTAC) cell permeability are of major interest to reduce resource-demanding synthesis and testing of low-permeable PROTACs. We report a comprehensive investigation of the scope and limitations of machine learning-based binary classification models developed using 17 simple descriptors for large and structurally diverse sets of cereblon (CRBN) and von Hippel-Lindau (VHL) PROTACs. For the VHL PROTAC set, kappa nearest neighbor and random forest models performed best and predicted the permeability of a blinded test set with >80% accuracy (k ≥ 0.57). Models retrained by combining the original training and the blinded test set performed equally well for a second blinded VHL set. However, models for CRBN PROTACs were less successful, mainly due to the imbalanced nature of the CRBN datasets. All descriptors contributed to the models, but size and lipophilicity were the most important. We conclude that properly trained machine learning models can be integrated as effective filters in the PROTAC design process.

Cyclobutane-bearing restricted anchoring residues enabled geometry-specific hydrocarbon peptide stapling.

Stapled peptides are regarded as the promising next-generation therapeutics because of their improved secondary structure, membrane permeability and metabolic stability as compared with the prototype linear peptides. Usually, stapled peptides are obtained by a hydrocarbon stapling technique, anchoring from paired olefin-terminated unnatural amino acids and the consequent ring-closing metathesis (RCM). To investigate the adaptability of the rigid cyclobutane structure in RCM and expand the chemical diversity of hydrocarbon peptide stapling, we herein described the rational design and efficient synthesis of cyclobutane-based conformationally constrained amino acids, termed (E)-1-amino-3-(but-3-en-1-yl)cyclobutane-1-carboxylic acid (E7) and (Z)-1-amino-3-(but-3-en-1-yl)cyclobutane-1-carboxylic acid (Z7). All four combinations including E7-E7, E7-Z7, Z7-Z7 and Z7-E7 were proven to be applicable in RCM-mediated peptide stapling to afford the corresponding geometry-specific stapled peptides. With the aid of the combined quantum and molecular mechanics, the E7-E7 combination was proven to be optimal in both the RCM reaction and helical stabilization. With the spike protein of SARS-CoV-2 as the target, a series of cyclobutane-bearing stapled peptides were obtained. Among them, E7-E7 geometry-specific stapled peptides indeed exhibit higher α-helicity and thus stronger biological activity than canonical hydrocarbon stapled peptides. We believe that this methodology possesses great potential to expand the scope of the existing peptide stapling strategy. These cyclobutane-bearing restricted anchoring residues served as effective supplements for the existing olefin-terminated unnatural amino acids and the resultant geometry-specific hydrocarbon peptide stapling provided more potential for peptide therapeutics.

In vivo evaluation in cynomolgus monkey brain and metabolism of [¹8F]fluorodeprenyl: a new MAO-B pet radioligand.

In this study, we evaluated the in vivo characteristics of a new monoamine oxidase type B (MAO-B) radioligand, [¹8F]fluorodeprenyl, by positron emission tomography (PET) in two cynomolgus monkeys. The brain uptake of [¹8F]fluorodeprenyl was more than 7% (600% SUV) of the total injected radioactivity and similar to that of [¹¹C]deprenyl, an established MAO-B radioligand. The highest uptake was observed in the striatum, one of the MAO-B-rich regions, with a peak at approximately 2-3 min after injection, followed by lower uptake in the thalamus and the cortex and lowest uptake in the cerebellum. Brain uptake of [¹8F]fluorodeprenyl was largely inhibited by preadministration of the MAO-B inhibitor, L-deprenyl, whereas clorgyline, a MAO Type A blocker, had no significant inhibitory effect, thus demonstrating selectivity for MAO-B. [¹8F]Fluorodeprenyl showed relatively slow metabolism with the presence of two radiometabolite peaks with similar retention time as the labeled metabolites of [¹¹C]deprenyl. These results suggest that [¹8F]fluorodeprenyl is a potential PET radioligand for visualization of MAO-B activity.

Stereoselective synthesis of trans-fused iridoid lactones and their identification in the parasitoid wasp Alloxysta victrix, Part I: Dihydronepetalactones.

Starting from the enantiomers of limonene, all eight stereoisomers of trans-fused dihydronepetalactones were synthesized. Key compounds were pure stereoisomers of 1-acetoxymethyl-2-methyl-5-(2-hydroxy-1-methylethyl)-1-cyclopentene. The stereogenic center of limonene was retained at position 4a of the target compounds and used to stereoselectively control the introduction of the other chiral centers during the synthesis. Basically, this approach could also be used for the synthesis of enantiomerically pure trans-fused iridomyrmecins. Using synthetic reference samples, the combination of enantioselective gas chromatography and mass spectrometry revealed that volatiles released by the endohyperparasitoid wasp Alloxysta victrix contain the enantiomerically pure trans-fused (4R,4aR,7R,7aS)-dihydronepetalactone as a minor component, showing an unusual (R)-configured stereogenic center at position 7.

Stereoselective synthesis of trans-fused iridoid lactones and their identification in the parasitoid wasp Alloxysta victrix, Part II: Iridomyrmecins.

Following our earlier approach to the synthesis of dihydronepetalactones, all eight stereoisomers of trans-fused iridomyrmecins were synthesized starting from the enantiomers of limonene. Combined gas chromatography and mass spectrometry including enantioselective gas chromatography revealed that volatiles released by the endohyperparasitoid wasp Alloxysta victrix contain (4S,4aR,7S,7aR)-iridomyrmecin of 95-97% ee and stereochemically pure (4S,4aS,7R,7aS)-iridomyrmecin as a minor component.

Applications of the Columbus steerable guidewire.

The Columbus steerable guidewire (Rapid Medical, Israel) is a 0.014 inch guidewire with a remotely controlled deflectable tip intended for neuronavigational purposes. 1 The tip can be shaped by pulling or pushing the handle. Pulling the handle decreases the radius (from 4 mm to 2 mm) and curves the tip, while pushing the handle increases the curvature radius and straightens the tip until it bends in the opposite direction. The amount of deflection is at the discretion of the operator. Video 1 The response of the Columbus guidewire to rotational movements is inferior to that of standard wires, and the tip is very soft and malleable but brings great support when bent. We present two cases where the Columbus guidewire was used. In the first case, the Columbus enabled us to probe a posterior cerebral artery arising from a giant basilar tip aneurysm without wall contact. In the second case, the Columbus was used as a secondary wire to help cannulate the pericallosal artery in a patient with a recurrent anterior complex aneurysm; this subsequently permitted successful stent-assisted coiling of the aneurysm. neurintsurg;14/10/1045/V1F1V1Video 1.

Linker-Dependent Folding Rationalizes PROTAC Cell Permeability.

Proteolysis-targeting chimeras (PROTACs) must be cell permeable to reach their target proteins. This is challenging as the bivalent structure of PROTACs puts them in chemical space at, or beyond, the outer limits of oral druggable space. We used NMR spectroscopy and molecular dynamics (MD) simulations independently to gain insights into the origin of the differences in cell permeability displayed by three flexible cereblon PROTACs having closely related structures. Both methods revealed that the propensity of the PROTACs to adopt folded conformations with a low solvent-accessible 3D polar surface area in an apolar environment is correlated to high cell permeability. The chemical nature and the flexibility of the linker were essential for the PROTACs to populate folded conformations stabilized by intramolecular hydrogen bonds, π-π interactions, and van der Waals interactions. We conclude that MD simulations may be used for the prospective ranking of cell permeability in the design of cereblon PROTACs.

Leadership in a time of crisis: Lessons learned from a pandemic.

The current COVID-19 pandemic is testing political leaders and healthcare systems worldwide, exposing deficits in crisis communication, leadership, preparedness and flexibility. Extraordinary situations abound, with global supply chains suddenly failing, media communicating contradictory information, and politics playing an increasingly bigger role in shaping each country's response to the crisis. The pandemic threatens not just our health but also our economy, liberty, and privacy. It challenges the speed at which we work, the quality of our research, and the effectiveness of communication within the scientific community. It can impose ethical dilemmas and emotional stress on healthcare workers. Nevertheless, the pandemic also provides an opportunity for healthcare organizations, leaders, and researchers to learn from their mistakes and to place their countries and institutions in a better position to face future challenges.

In vitro and in vivo characterization of novel 18F-labeled bombesin analogues for targeting GRPR-positive tumors.

The gastrin-releasing peptide receptor (GRPR) is overexpressed on a number of human tumors and has been targeted with radiolabeled bombesin analogues for the diagnosis and therapy of these cancers. Seven bombesin analogues containing various linkers and peptide sequences were designed, synthesized, radiolabeled with (18)F, and characterized in vitro and in vivo as potential PET imaging agents. Binding studies displayed nanomolar binding affinities toward human GRPR for all synthesized bombesin analogues. Two high-affinity peptide candidates 6b (K(i) = 0.7 nM) and 7b (K(i) = 0.1 nM) were chosen for further in vivo evaluation. Both tracers revealed specific uptake in GRPR-expressing PC-3 tumors and the pancreas. Compared to [(18)F]6b, compound [(18)F]7b was characterized by superior tumor uptake, higher specificity of tracer uptake, and more favorable tumor-to-nontarget ratios. In vivo PET imaging allowed for the visualization of PC-3 tumor in nude mice suggesting that [(18)F]7b is a promising PET tracer candidate for the diagnosis of GRPR-positive tumors in humans.

Real-time polymerase chain-reaction detection of pathogens is feasible to supplement the diagnostic sequence for urinary tract infections.

OBJECTIVE: To evaluate, in a prospective pilot study, the feasibility of identifying pathogens in urine using real-time polymerase chain reaction (PCR), and to compare the results with the conventional urine culture-based procedures. PATIENTS AND METHODS: Severe urinary tract infections (UTIs) are frequent in critically ill patients in the intensive-care unit (ICU) and in outpatients, and thus the reliable and fast identification of the bacteria is mandatory, but routine urine culture is time-consuming and the therapeutic regimen is often calculated and not culture-based. The study included 301 prospectively collected urine samples from 189 patients with suspected UTI, based in a university hospital in 2005, and included outpatients and those in the ICU. Urine culture with Cled-, MacConkey- and malt extract agar of all samples was followed by microbiological identification of the pathogens in 98 samples with visible growth. In parallel, all samples were assessed using qualitative real-time PCR-based DNA detection and identification by labelled hybridization probes. RESULTS: In all, 15 dipstick culture-negative samples showed positive pathogen DNA identification by PCR. By contrast, 17 PCR-negative samples showed detectable pathogens by culture, of which 10 were not detectable on PCR because the identified pathogens were not represented in the probe panel. The sensitivity and specificity for detecting contaminated samples was 0.90 and 0.87, respectively. Overall, 95% of the mono-infection pathogens and 57% of the multiple-infection pathogens were detected concordantly with both methods. CONCLUSION: In this prospective pilot study PCR-based identification of pathogens was feasible for supplementing conventional culture methods for the diagnosis of UTI. The main advantage is the time saved in identifying the pathogens. The limited pathogen detection in multiple-infection-samples by PCR might be explained by competitive PCR amplification conditions.

Cost and mortality prediction using polymerase chain reaction pathogen detection in sepsis: evidence from three observational trials.

INTRODUCTION: Delays in adequate antimicrobial treatment contribute to high cost and mortality in sepsis. Polymerase chain reaction (PCR) assays are used alongside conventional cultures to accelerate the identification of microorganisms. We analyze the impact on medical outcomes and healthcare costs if improved adequacy of antimicrobial therapy is achieved by providing immediate coverage after positive PCR reports. METHODS: A mathematical prediction model describes the impact of PCR-based rapid adjustment of antimicrobial treatment. The model is applied to predict cost and medical outcomes for 221 sepsis episodes of 189 post-surgical and intensive care unit (ICU) sepsis patients with available PCR data from a prospective, observational trial of a multiplex PCR assay in five hospitals. While this trial demonstrated reduction of inadequate treatment days, data on outcomes associated with reduced inadequate initial antimicrobial treatment had to be obtained from two other, bigger, studies which involved 1,147 (thereof 316 inadequately treated) medical or surgical ICU patients. Our results are reported with the (5% to 95%) percentile ranges from Monte Carlo simulation in which the input parameters were randomly and independently varied according to their statistical characterization in the three underlying studies. The model allows predictions also for different patient groups or PCR assays. RESULTS: A total of 13.1% of PCR tests enabled earlier adequate treatment. We predict that cost for PCR testing (300 €/test) can be fully recovered for patients above 717 € (605 € to 1,710 €) daily treatment cost. A 2.6% (2.0 to 3.2%) absolute reduction of mortality is expected. Cost per incremental survivor calculates to 11,477 € (9,321 € to 14,977 €) and incremental cost-effectiveness ratio to 3,107 € (2,523 € to 4,055 €) per quality-adjusted life-year. Generally, for ICU patients with >25% incidence of inadequate empiric antimicrobial treatment, and at least 15% with a positive blood culture, PCR represents a cost-neutral adjunct method. CONCLUSIONS: Rapid PCR identification of microorganisms has the potential to become a cost-effective component for managing sepsis. The prediction model tested with data from three observational trials should be utilized as a framework to deepen insights when integrating more complementary data associated with utilization of molecular assays in the management of sepsis.

[Microbiological point of care tests]. / Point-of-Care-Monitoring - Mikrobiologische POC-Diagnostik.

It is well known that the early initiation of a specific antiinfective therapy is crucial to reduce the mortality in severe infection. Procedures culturing pathogens are the diagnostic gold standard in such diseases. However, these methods yield results earliest between 24 to 48 hours. Therefore, severe infections such as sepsis need to be treated with an empirical antimicrobial therapy, which is ineffective in an unknown fraction of these patients. Today's microbiological point of care tests are pathogen specific and therefore not appropriate for an infection with a variety of possible pathogens. Molecular nucleic acid diagnostics such as polymerase chain reaction (PCR) allow the identification of pathogens and resistances. These methods are used routinely to speed up the analysis of positive blood cultures. The newest PCR based system allows the identification of the 25 most frequent sepsis pathogens by PCR in parallel without previous culture in less than 6 hours. Thereby, these systems might shorten the time of possibly insufficient antiinfective therapy. However, these extensive tools are not suitable as point of care diagnostics. Miniaturization and automating of the nucleic acid based method is pending, as well as an increase of detectable pathogens and resistance genes by these methods. It is assumed that molecular PCR techniques will have an increasing impact on microbiological diagnostics in the future.