Transbronchial cryobiopsy followed by as-needed surgical lung biopsy versus immediate surgical lung biopsy for diagnosing interstitial lung disease (the COLD study): a randomised controlled trial.

BACKGROUND: An adequate diagnosis for interstitial lung disease (ILD) is important for clinical decision making and prognosis. In most patients with ILD, an accurate diagnosis can be made by clinical and radiological data assessment, but in a considerable proportion of patients, a lung biopsy is required. Surgical lung biopsy (SLB) is the most common method to obtain tissue, but it is associated with high morbidity and even mortality. More recently, transbronchial cryobiopsy has been introduced, with fewer adverse events but a lower diagnostic yield than SLB. The aim of this study is to compare two diagnostic strategies: a step-up strategy (transbronchial cryobiopsy, followed by SLB if the cryobiopsy is insufficiently informative) versus immediate SLB. METHODS: The COLD study was a multicentre, randomised controlled trial in six hospitals across the Netherlands. We included patients with ILD with an indication for lung biopsy as assessed by a multidisciplinary team discussion. Patients were randomly assigned in a 1:1 ratio to the step-up or immediate SLB strategy, with follow-up for 12 weeks from the initial procedure. Patients, clinicians, and pathologists were not masked to the study treatment. The primary endpoint was unexpected chest tube drainage, defined as requiring any chest tube after transbronchial cryobiopsy, or prolonged (>24 h) chest tube drainage after SLB. Secondary endpoints were diagnostic yield, in-hospital stay, pain, and serious adverse events. A modified intention-to-treat analysis was performed. This trial is registered with the Dutch Trial Register, NL7634, and is now closed. FINDINGS: Between April 8, 2019, and Oct 24, 2021, 122 patients with ILD were assessed for study participation; and 55 patients were randomly assigned to the step-up strategy (n=28) or immediate SLB (n=27); three patients from the immediate SLB group were excluded. Unexpected chest tube drainage occurred in three of 28 patients (11%; 95% CI 4-27%) in the step-up group, and the number of patients for whom the chest tube could not be removed within 24 h was 11 of 24 patients (46%; 95% CI 2-65%) in the SLB group, with an absolute risk reduction of 35% (11-56%; p=0·0058). In the step-up strategy, the multidisciplinary team diagnostic yield after transbronchial cryobiopsy alone was 82% (64-92%), which increased to 89% (73-96%) when subsequent SLB was performed after inconclusive transbronchial cryobiopsy. In the immediate surgery strategy, the multidisciplinary team diagnostic yield was 88% (69-97%). Total in-hospital stay was 1 day (IQR 1-1) in the step-up group versus 5 days (IQR 4-6) in the SLB group. One (4%) serious adverse event occurred in step-up strategy versus 12 (50%) in the immediate SLB strategy. INTERPRETATION: In ILD diagnosis, if lung tissue assessment is required, a diagnostic strategy starting with transbronchial cryobiopsy, followed by SLB when transbronchial cryobiopsy is inconclusive, appears to result in a significant reduction of patient burden and in-hospital stay with a similar diagnostic yield versus immediate SLB. FUNDING: Netherlands Organisation for Health Research and Development (ZonMW) and Amsterdam University Medical Centers.

A national multi centre pre-hospital ECPR stepped wedge study; design and rationale of the ON-SCENE study.

BACKGROUND: The likelihood of return of spontaneous circulation with conventional advanced life support is known to have an exponential decline and therefore neurological outcome after 20 min in patients with a cardiac arrest is poor. Initiation of venoarterial ExtraCorporeal Membrane Oxygenation (ECMO) during resuscitation might improve outcomes if used in time and in a selected patient category. However, previous studies have failed to significantly reduce the time from cardiac arrest to ECMO flow to less than 60 min. We hypothesize that the initiation of Extracorporeal Cardiopulmonary Resuscitation (ECPR) by a Helicopter Emergency Medical Services System (HEMS) will reduce the low flow time and improve outcomes in refractory Out of Hospital Cardiac Arrest (OHCA) patients. METHODS: The ON-SCENE study will use a non-randomised stepped wedge design to implement ECPR in patients with witnessed OHCA between the ages of 18-50 years old, with an initial presentation of shockable rhythm or pulseless electrical activity with a high suspicion of pulmonary embolism, lasting more than 20, but less than 45 min. Patients will be treated by the ambulance crew and HEMS with prehospital ECPR capabilities and will be compared with treatment by ambulance crew and HEMS without prehospital ECPR capabilities. The primary outcome measure will be survival at hospital discharge. The secondary outcome measure will be good neurological outcome defined as a cerebral performance categories scale score of 1 or 2 at 6 and 12 months. DISCUSSION: The ON-SCENE study focuses on initiating ECPR at the scene of OHCA using HEMS. The current in-hospital ECPR for OHCA obstacles encompassing low survival rates in refractory arrests, extended low-flow durations during transportation, and the critical time sensitivity of initiating ECPR, which could potentially be addressed through the implementation of the HEMS system. When successful, implementing on-scene ECPR could significantly enhance survival rates and minimize neurological impairment. TRIAL REGISTRATION: Clinicaltyrials.gov under NCT04620070, registration date 3 November 2020.

Interaction of Whitefly Effector G4 with Tomato Proteins Impacts Whitefly Performance.

The phloem-feeding insect Bemisia tabaci is an important pest, responsible for the transmission of several crop-threatening virus species. While feeding, the insect secretes a cocktail of effectors to modulate plant defense responses. Here, we present a set of proteins identified in an artificial diet on which B. tabaci was salivating. We subsequently studied whether these candidate effectors can play a role in plant immune suppression. Effector G4 was the most robust suppressor of an induced- reactive oxygen species (ROS) response in Nicotiana benthamiana. In addition, G4 was able to suppress ROS production in Solanum lycopersicum (tomato) and Capsicum annuum (pepper). G4 localized predominantly in the endoplasmic reticulum in N. benthamiana leaves and colocalized with two identified target proteins in tomato: REF-like stress related protein 1 (RSP1) and meloidogyne-induced giant cell protein DB141 (MIPDB141). Silencing of MIPDB141 in tomato reduced whitefly fecundity up to 40%, demonstrating that the protein is involved in susceptibility to B. tabaci. Together, our data demonstrate that effector G4 impairs tomato immunity to whiteflies by interfering with ROS production and via an interaction with tomato susceptibility protein MIPDB141. [Formula: see text] Copyright © 2024 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.

Epidermal bladder cells as a herbivore defense mechanism.

The aerial surfaces of quinoa (Chenopodium quinoa) and common ice plant (Mesembryanthemum crystallinum) are covered with a layer of epidermal bladder cells (EBCs), which are modified non-glandular trichomes previously considered to be key to the extreme salt and drought tolerance of these plants. Here, however, we find that EBCs of these plants play only minor roles, if any, in abiotic stress tolerance and in fact are detrimental under conditions of water deficit. We report that EBCs instead function as deterrents to a broad range of generalist arthropod herbivores, through their combined function of forming both a chemical and a physical barrier, and they also serve a protective function against a phytopathogen. Our study overturns current models that link EBCs to salt and drought tolerance and assigns new functions to these structures that might provide novel possibilities for protecting crops from arthropod pests.

Optimal Dosing and Timing of High-Dose Corticosteroid Therapy in Hospitalized Patients With COVID-19: Study Protocol for a Retrospective Observational Multicenter Study (SELECT).

BACKGROUND: In hospitalized patients with COVID-19, the dosing and timing of corticosteroids vary widely. Low-dose dexamethasone therapy reduces mortality in patients requiring respiratory support, but it remains unclear how to treat patients when this therapy fails. In critically ill patients, high-dose corticosteroids are often administered as salvage late in the disease course, whereas earlier administration may be more beneficial in preventing disease progression. Previous research has revealed that increased levels of various biomarkers are associated with mortality, and whole blood transcriptome sequencing has the ability to identify host factors predisposing to critical illness in patients with COVID-19. OBJECTIVE: Our goal is to determine the most optimal dosing and timing of corticosteroid therapy and to provide a basis for personalized corticosteroid treatment regimens to reduce morbidity and mortality in hospitalized patients with COVID-19. METHODS: This is a retrospective, observational, multicenter study that includes adult patients who were hospitalized due to COVID-19 in the Netherlands. We will use the differences in therapeutic strategies between hospitals (per protocol high-dose corticosteroids or not) over time to determine whether high-dose corticosteroids have an effect on the following outcome measures: mechanical ventilation or high-flow nasal cannula therapy, in-hospital mortality, and 28-day survival. We will also explore biomarker profiles in serum and bronchoalveolar lavage fluid and use whole blood transcriptome analysis to determine factors that influence the relationship between high-dose corticosteroids and outcome. Existing databases that contain routinely collected electronic data during ward and intensive care admissions, as well as existing biobanks, will be used. We will apply longitudinal modeling appropriate for each data structure to answer the research questions at hand. RESULTS: As of April 2023, data have been collected for a total of 1500 patients, with data collection anticipated to be completed by December 2023. We expect the first results to be available in early 2024. CONCLUSIONS: This study protocol presents a strategy to investigate the effect of high-dose corticosteroids throughout the entire clinical course of hospitalized patients with COVID-19, from hospital admission to the ward or intensive care unit until hospital discharge. Moreover, our exploration of biomarker and gene expression profiles for targeted corticosteroid therapy represents a first step towards personalized COVID-19 corticosteroid treatment. TRIAL REGISTRATION: ClinicalTrials.gov NCT05403359; https://clinicaltrials.gov/ct2/show/NCT05403359. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/48183.

Intraspecific variation for host immune activation by the spider mite Tetranychus evansi.

Many parasites can interfere with their host's defences to maximize their fitness. Here, we investigated if there is heritable variation in the spider mite Tetranychus evansi for traits associated with how they interact with their host plant. We also determined if this variation correlates with mite fecundity. Tetranychus evansi can interfere with jasmonate (JA) defences which are the main determinant of anti-herbivore immunity in plants. We investigated (i) variation in fecundity in the presence and absence of JA defences, making use of a wild-type tomato cultivar and a JA-deficient mutant (defenseless-1), and (ii) variation in the induction of JA defences, in four T. evansi field populations and 59 inbred lines created from an outbred population originating from controlled crosses of the four field populations. We observed a strong positive genetic correlation between fecundity in the presence (on wild-type) and the absence of JA defences (on defenseless-1). However, fecundity did not correlate with the magnitude of induced JA defences in wild-type plants. Our results suggest that the performance of the specialist T. evansi is not related to their ability to manipulate plant defences, either because all lines can adequately reduce levels of defences, or because they are resistant to them.

Recovery after admission with COVID-19 pneumonia - A follow-up study.

INTRODUCTION: We performed this study to describe clinical, radiological and pulmonary function outcomes of patients with COVID-19 pneumonia 1 year after discharge from hospital. METHODS: This is a prospective longitudinal study on patients admitted with COVID-19 pneumonia in March and April 2020. 162 patients were classified as moderate, severe or critical. Symptoms and pulmonary function were assessed at 3 months and 1 year after discharge. Chest CT scans were made during hospital admission, at 3 months and, in case of persistent radiological abnormalities, after 1 year. RESULTS: 54% of patients reported full recovery of their pre-illness fitness after 1 year. 53% still reported exertional dyspnoea, independent of illness severity. DLCOc < 80% after 1 year was found in 74% of critical, 50% of severe and 38% of moderate cases. For KCOc<80%, no between-group difference was found. Restriction (TLC<80%) was found in 28% of critical, 5% of severe, and 13% of moderate cases. At baseline, chest CT score was significantly higher for the critical illness group, but after 1 year, there was no significant difference. Most resolution of abnormalities occurred before 3 months. A high prevalence of fibrotic lesions (24%) and subpleural banding (27%) was found. CONCLUSION/CLINICAL IMPLICATION: A large proportion of patients experience consequences of COVID-19 pneumonia one year after discharge, irrespective of initial disease severity. Follow-up of patients admitted with COVID-19 is therefore warranted. An evaluation of symptoms, pulmonary function and radiology three months after discharge can discriminate between patients with early complete recovery and those with persistent abnormalities.

Intradiol ring cleavage dioxygenases from herbivorous spider mites as a new detoxification enzyme family in animals.

BACKGROUND: Generalist herbivores such as the two-spotted spider mite Tetranychus urticae thrive on a wide variety of plants and can rapidly adapt to novel hosts. What traits enable polyphagous herbivores to cope with the diversity of secondary metabolites in their variable plant diet is unclear. Genome sequencing of T. urticae revealed the presence of 17 genes that code for secreted proteins with strong homology to "intradiol ring cleavage dioxygenases (DOGs)" from bacteria and fungi, and phylogenetic analyses show that they have been acquired by horizontal gene transfer from fungi. In bacteria and fungi, DOGs have been well characterized and cleave aromatic rings in catecholic compounds between adjacent hydroxyl groups. Such compounds are found in high amounts in solanaceous plants like tomato, where they protect against herbivory. To better understand the role of this gene family in spider mites, we used a multi-disciplinary approach to functionally characterize the various T. urticae DOG genes. RESULTS: We confirmed that DOG genes were present in the T. urticae genome and performed a phylogenetic reconstruction using transcriptomic and genomic data to advance our understanding of the evolutionary history of spider mite DOG genes. We found that DOG expression differed between mites from different plant hosts and was induced in response to jasmonic acid defense signaling. In consonance with a presumed role in detoxification, expression was localized in the mite's gut region. Silencing selected DOGs expression by dsRNA injection reduced the mites' survival rate on tomato, further supporting a role in mitigating the plant defense response. Recombinant purified DOGs displayed a broad substrate promiscuity, cleaving a surprisingly wide array of aromatic plant metabolites, greatly exceeding the metabolic capacity of previously characterized microbial DOGs. CONCLUSION: Our findings suggest that the laterally acquired spider mite DOGs function as detoxification enzymes in the gut, disarming plant metabolites before they reach toxic levels. We provide experimental evidence to support the hypothesis that this proliferated gene family in T. urticae is causally linked to its ability to feed on an extremely wide range of host plants.

Regional Impact of COVID-19-Associated Pulmonary Aspergillosis (CAPA) during the First Wave.

BACKGROUND: Critically ill COVID-19 patients have proven to be at risk for developing invasive fungal infections. However, the incidence and impact of possible/probable COVID-19-associated pulmonary aspergillosis (CAPA) in severe COVID-19 patients varies between cohorts. We aimed to assess the incidence, risk factors, and clinical outcome of invasive pulmonary aspergillosis in a regional cohort of COVID-19 intensive care patients. METHODS: We performed a regional, multicentre, retrospective cohort study in the intensive care units (ICUs) in North Brabant, The Netherlands. We included adult patients with rt-PCR-confirmed SARS-CoV-2 infection (COVID-19), requiring mechanical ventilation for acute respiratory distress syndrome. Demographics, clinical course, biomarker value, and treatment outcomes were compared between the groups with possible/probable CAPA from the main study centre and the regional centres, and without signs of CAPA from the main study centre as controls. The primary aim was to assess the regional impact of possible/probable CAPA in COVID-19 ICU patients, measured as all-cause mortality at 30 days after ICU admission. Secondary outcomes were risk factors for developing CAPA, based on underlying host factors and to identify the value of the mycological arguments for the diagnosing of CAPA. RESULTS: Between 1 March and 30 April 2020, we included 123 patients with severe COVID-19: 29 patients (30.9%) in the main ICU with possible/probable CAPA, and 65 (69.1%) with no signs of CAPA; 29 patients in the regional ICUs with signs of CAPA. Patients' characteristics and risk factors did not differ for CAPA and non-CAPA patients. Patients with COPD and/or chronic steroid medication developed CAPA more frequently, although this was not statistically significant. CAPA patients were admitted to the ICU earlier, had lower PF-ratios, and more often required renal replacement therapy. All-cause 30-day mortality was significantly higher in mechanically ventilated COVID-19 patients with possible/probable CAPA 39.7% (23/58) compared to patients without evidence for CAPA 16.9% (11/65) (OR 3.2 [95% CI 1.4-7.4] p = 0.005). CONCLUSION: The high incidence of possible and probable CAPA in critically ill COVID-19 patients is alarming. The increase in 30-day mortality in CAPA highlights the need for active surveillance and management strategies in critically ill COVID-19 patients.

Enhanced top-down control of herbivore population growth on plants with impaired defences.

Herbivore densities can be regulated by bottom-up and top-down forces such as plant defences and natural enemies, respectively. These forces can interact with each other to increase plant protection against herbivores; however, how much complementarity exists between bottom-up and top-down forces still remains to be fully elucidated. Particularly, because plant defences can hinder natural enemies, how these interactions affect herbivore performance and dynamics remains elusive.To address this topic, we performed laboratory and greenhouse bioassays with herbivorous mite pests and predatory mites on mutant tomato plants that lack defensive hairs on stems and leaves. Particularly, we investigated the behaviour and population dynamics of different phytophagous mite species in the absence and presence of predatory mites.We show that predatory mites do not only perform better on tomatoes lacking defensive hairs but also that they can suppress herbivore densities better and faster on these hairless plants. Hence, top-down control of herbivores by natural enemies more than compensated the reduced bottom-up herbivore control by plant defences.Our results lead to the counter-intuitive insight that removing, instead of introducing, plant defence traits can result in superior protection against important pests through biological control. Read the free Plain Language Summary for this article on the Journal blog.

Life stage-dependent genetic traits as drivers of plant-herbivore interactions.

In recent decades, we have come to understand in great detail the mechanisms that allow plants and herbivorous arthropods to withstand each other. Research into these interactions often focuses on specific life stages of plants and animals, often for pragmatic reasons. Yet it is well known that the lifecycles of plants and herbivores are accompanied by niche shifts that can change their interactions. The occurrence of changes in the defensive regulatory and metabolic networks of plants during their development as driver of plant-herbivore interactions is mainly inferred from behavioral patterns, but there is increasingly molecular-mechanistic data to support the causality. In particular, understanding the molecular-mechanistic signatures of ontogenetic niche shifts, and their genetic basis, may prove to be critical for the design of knowledge-based crop protection strategies.

Spotlight on the Roles of Whitefly Effectors in Insect-Plant Interactions.

The Bemisia tabaci species complex (whitefly) causes enormous agricultural losses. These phloem-feeding insects induce feeding damage and transmit a wide range of dangerous plant viruses. Whiteflies colonize a broad range of plant species that appear to be poorly defended against these insects. Substantial research has begun to unravel how phloem feeders modulate plant processes, such as defense pathways, and the central roles of effector proteins, which are deposited into the plant along with the saliva during feeding. Here, we review the current literature on whitefly effectors in light of what is known about the effectors of phloem-feeding insects in general. Further analysis of these effectors may improve our understanding of how these insects establish compatible interactions with plants, whereas the subsequent identification of plant defense processes could lead to improved crop resistance to insects. We focus on the core concepts that define the effectors of phloem-feeding insects, such as the criteria used to identify candidate effectors in sequence-mining pipelines and screens used to analyze the potential roles of these effectors and their targets in planta. We discuss aspects of whitefly effector research that require further exploration, including where effectors localize when injected into plant tissues, whether the effectors target plant processes beyond defense pathways, and the properties of effectors in other insect excretions such as honeydew. Finally, we provide an overview of open issues and how they might be addressed.

Genome streamlining in a minute herbivore that manipulates its host plant.

The tomato russet mite, Aculops lycopersici, is among the smallest animals on earth. It is a worldwide pest on tomato and can potently suppress the host's natural resistance. We sequenced its genome, the first of an eriophyoid, and explored whether there are genomic features associated with the mite's minute size and lifestyle. At only 32.5 Mb, the genome is the smallest yet reported for any arthropod and, reminiscent of microbial eukaryotes, exceptionally streamlined. It has few transposable elements, tiny intergenic regions, and is remarkably intron-poor, as more than 80% of coding genes are intronless. Furthermore, in accordance with ecological specialization theory, this defense-suppressing herbivore has extremely reduced environmental response gene families such as those involved in chemoreception and detoxification. Other losses associate with this species' highly derived body plan. Our findings accelerate the understanding of evolutionary forces underpinning metazoan life at the limits of small physical and genome size.

Arthropods are a group of invertebrates that include insects ­ such as flies or beetles ­ arachnids ­ like spiders or scorpions ­ and crustaceans ­ including shrimp and woodlice. One of the tiniest species of arthropods, measuring less than 0.2 millimeters, is the tomato russet mite Aculops lycopersici. This arachnid is among the smallest animals on Earth, even smaller than some single-celled organisms, and only has four legs, unlike other arachnids. It is a major pest on tomato plants, which are toxic to many other animals, and it feeds on the top cell layer of the stems and leaves. Tomato growers need a way to identify and treat tomato russet mite infestations, but this tiny species remains something of a mystery. One way to tackle this pest may be to take a closer look at its genome, as this could reveal what genes the mite uses to detoxify its diet. Examining the mite's genome could also reveal information about how evolution handles creatures becoming smaller. An area of particular interest is the overall size of its genome. Not all of the DNA in a genome is part of genes that code for proteins; there are also sections of so-called 'non-coding' DNA. These sequences play important roles in controlling how and when cells use their genes. In the human genome, for example, just 1% of the DNA codes for protein. In fact, most human protein-coding genes are interrupted by sequences of non-coding DNA, called introns. Here, Greenhalgh, Dermauw et al. sequence the entire tomato russet mite genome and reveal that not only is the mite's body size miniature: these tiny animals have the smallest arthropod genome reported to date, almost a hundred times smaller than the human genome. Part of this genetic miniaturization seems to be down to massive loss of non-coding DNA. Around 40% of the mite genome codes for protein, and 80% of its protein coding genes contain no introns. The rest of the miniaturization involves loss of genes themselves. The mites have lost some of the genes that determine body structure, which could explain why they have fewer legs than other arachnids. Additionally, they only carry a small set of genes involved in sensing chemicals and clearing toxins, which could explain why they are mostly found on tomato plants. Greenhalgh, Dermauw et al.'s findings shed light on what may happen to the genome at the extremes of size evolution. Sequencing the genomes of other mites could reveal when in evolutionary history this genetic miniaturization occurred. Furthermore, a better understanding of the tomato russet mite genome could lead to the development of methods to detect the infestation of plants earlier and be highly beneficial for tomato agriculture.

OPDA and ABA accumulation in Pb-stressed Zygophyllum fabago can be primed by salicylic acid and coincides with organ-specific differences in accumulation of phenolics.

Salicylic acid (SA) is a well-known priming agent that is widely used to protect plants against stressing agents, including heavy metals as Pb. A better understanding of the mechanisms that enable plants to counteract Pb toxicity would help to select strategies for land reclamation programs. Here we used a metallicolous population of Zygophyllum fabago to assess the extent to which SA pretreatment modulates Pb-induced changes in phenol metabolism and stress-related phytohormone levels in roots and leaves. Our data revealed that accumulation of different phytohormones, lignin, soluble and wall-bound phenolics as well as peroxidase (PRX) activity in Pb-stressed plants differed after SA-pretreatment. Exposure to Pb led to the induction of soluble and cell wall-bound PRX activities, particularly those involved in the oxidation of coniferyl alcohol and ferulic acid, while pretreatment with SA reduced the Pb-induced stimulation of PRX activities in roots but increased them in leaves. SA-treatment by itself induced accumulation of ABA and the JA-precursor 12-oxo-phytodienoic acid (OPDA) in the roots. Pb in turn inhibited these SA-induced effects with the exception of OPDA accumulation that was primed by the pretreatment. The SA treatment also induced accumulation of OPDA in leaves but suppressed the accumulation of JA-Ile although with relatively small absolute changes. Notably, Pb-induced accumulation of ABA was primed in the leaves of SA-pretreated plants. Together our data suggest that priming of OPDA accumulation in the roots and of ABA in the leaves by SA-pretreatment may play important regulatory roles, possibly via regulating PRX activities, for Pb stress in plants.

Juvenile Spider Mites Induce Salicylate Defenses, but Not Jasmonate Defenses, Unlike Adults.

When plants detect herbivores they strengthen their defenses. As a consequence, some herbivores evolved the means to suppress these defenses. Research on induction and suppression of plant defenses usually makes use of particular life stages of herbivores. Yet many herbivorous arthropods go through development cycles in which their successive stages have different characteristics and lifestyles. Here we investigated the interaction between tomato defenses and different herbivore developmental stages using two herbivorous spider mites, i.e., Tetranychus urticae of which the adult females induce defenses and T. evansi of which the adult females suppress defenses in Solanum lycopersicum (tomato). First, we monitored egg-to-adult developmental time on tomato wild type (WT) and the mutant defenseless-1 (def-1, unable to produce jasmonate-(JA)-defenses). Then we assessed expression of salivary effector genes (effector 28, 84, SHOT2b, and SHOT3b) in the consecutive spider mite life stages as well as adult males and females. Finally, we assessed the extent to which tomato plants upregulate JA- and salicylate-(SA)-defenses in response to the consecutive mite developmental stages and to the two sexes. The consecutive juvenile mite stages did not induce JA defenses and, accordingly, egg-to-adult development on WT and def-1 did not differ for either mite species. Their eggs however appeared to suppress the SA-response. In contrast, all the consecutive feeding stages upregulated SA-defenses with the strongest induction by T. urticae larvae. Expression of effector genes was higher in the later developmental stages. Comparing expression in adult males and females revealed a striking pattern: while expression of effector 84 and SHOT3b was higher in T. urticae females than in males, this was the opposite for T. evansi. We also observed T. urticae females to upregulate tomato defenses, while T. evansi females did not. In addition, of both species also the males did not upregulate defenses. Hence, we argue that mite ontogenetic niche shifts and stage-specific composition of salivary secreted proteins probably together determine the course and efficiency of induced tomato defenses.

Late histopathologic characteristics of critically ill COVID-19 patients: Different phenotypes without evidence of invasive aspergillosis, a case series.

PURPOSE: Pathological data of critical ill COVID-19 patients is essential in the search for optimal treatment options. MATERIAL AND METHODS: We performed postmortem needle core lung biopsies in seven patients with COVID-19 related ARDS. Clinical, radiological and microbiological characteristics are reported together with histopathological findings. MEASUREMENT AND MAIN RESULTS: Patients age ranged from 58 to 83 years, five males and two females were included. Time from hospital admission to death ranged from 12 to 36 days, with a mean of 20 ventilated days. ICU stay was complicated by pulmonary embolism in five patients and positive galactomannan on bronchoalveolar lavage fluid in six patients, suggesting COVID-19 associated pulmonary aspergillosis. Chest CT in all patients showed ground glass opacities, commonly progressing to nondependent consolidations. We observed four distinct histopathological patterns: acute fibrinous and organizing pneumonia, diffuse alveolar damage, fibrosis and, in four out of seven patients an organizing pneumonia. None of the biopsy specimens showed any signs of invasive aspergillosis. CONCLUSIONS: In this case series common late histopathology in critically ill COVID patients is not classic DAD but heterogeneous with predominant pattern of organizing pneumonia. Postmortem biopsy investigations in critically COVID-19 patients with probable COVID-19 associated pulmonary aspergillosis obtained no evidence for invasive aspergillosis.

Spider Mites Cause More Damage to Tomato in the Dark When Induced Defenses Are Lower.

Plants have evolved robust mechanisms to cope with incidental variation (e.g. herbivory) and periodical variation (e.g. light/darkness during the day-night cycle) in their environment. It has been shown that a plant's susceptibility to pathogens can vary during its day-night cycle. We demonstrated earlier that the spider mite Tetranychus urticae induces jasmonate- and salicylate-mediated defenses in tomato plants while the spider mite T. evansi suppresses these defenses probably by secreting salivary effector proteins. Here we compared induction/suppression of plant defenses; the expression of mite-effector genes and the amount of damage due to mite feeding during the day and during the night. T. urticae feeding upregulated the expression of jasmonate and salicylate marker-genes albeit significantly higher under light than under darkness. Some of these marker-genes were also upregulated by T. evansi-feeding albeit to much lower levels than by T. urticae-feeding. The expression of effector 28 was not affected by light or darkness in either mite species. However, the expression of effector 84 was considerably higher under light, especially for T. evansi. Finally, while T. evansi produced overall more feeding damage than T. urticae both mites produced consistently more damage during the dark phase than under light. Our results suggest that induced defenses are subject to diurnal variation possibly causing tomatoes to incur more damage due to mite-feeding during the dark phase. We speculate that mites, but especially T. evansi, may relax effector production during the dark phase because under these conditions the plant's ability to upregulate defenses is reduced.

Tetranychus evansi spider mite populations suppress tomato defenses to varying degrees.

Plant defense suppression is an offensive strategy of herbivores, in which they manipulate plant physiological processes to increase their performance. Paradoxically, defense suppression does not always benefit the defense-suppressing herbivores, because lowered plant defenses can also enhance the performance of competing herbivores and can expose herbivores to increased predation. Suppression of plant defense may therefore entail considerable ecological costs depending on the presence of competitors and natural enemies in a community. Hence, we hypothesize that the optimal magnitude of suppression differs among locations. To investigate this, we studied defense suppression across populations of Tetranychus evansi spider mites, a herbivore from South America that is an invasive pest of solanaceous plants including cultivated tomato, Solanum lycopersicum, in other parts of the world. We measured the level of expression of defense marker genes in tomato plants after infestation with mites from eleven different T. evansi populations. These populations were chosen across a range of native (South American) and non-native (other continents) environments and from different host plant species. We found significant variation at three out of four defense marker genes, demonstrating that T. evansi populations suppress jasmonic acid- and salicylic acid-dependent plant signaling pathways to varying degrees. While we found no indication that this variation in defense suppression was explained by differences in host plant species, invasive populations tended to suppress plant defense to a smaller extent than native populations. This may reflect either the genetic lineage of T. evansi-as all invasive populations we studied belong to one linage and both native populations to another-or the absence of specialized natural enemies in invasive T. evansi populations.