33 research outputs found
Morphometric Relationship, Phylogenetic Correlation, and Character Evolution in the Species-Rich Genus Aphis (Hemiptera: Aphididae)
The species-rich genus Aphis consists of more than 500 species, many of them host-specific on a wide range of plants, yet very similar in general appearance due to convergence toward particular morphological types. Most species have been historically clustered into four main phenotypic groups (gossypii, craccivora, fabae, and spiraecola groups). To confirm the morphological hypotheses between these groups and to examine the characteristics that determine them, multivariate morphometric analyses were performed using 28 characters measured/counted from 40 species. To infer whether the morphological relationships are correlated with the genetic relationships, we compared the morphometric dataset with a phylogeny reconstructed from the combined dataset of three mtDNA and one nuclear DNA regions.Based on a comparison of morphological and molecular datasets, we confirmed morphological reduction or regression in the gossypii group unlike in related groups. Most morphological characteristics of the gossypii group were less variable than for the other groups. Due to these, the gossypii group could be morphologically well separated from the craccivora, fabae, and spiraecola groups. In addition, the correlation of the rates of evolution between morphological and DNA datasets was highly significant in their diversification.The morphological separation between the gossypii group and the other species-groups are congruent with their phylogenetic relationships. Analysis of trait evolution revealed that the morphological traits found to be significant based on the morphometric analyses were confidently correlated with the phylogeny. The dominant patterns of trait evolution resulting in increased rates of short branches and temporally later evolution are likely suitable for the modality of Aphis speciation because they have adapted species-specifically, rapidly, and more recently on many different host plants
A population genomics approach shows widespread geographical distribution of cryptic genomic forms of the symbiotic fungus Rhizophagus irregularis.
Arbuscular mycorrhizal fungi (AMF; phylum Gomeromycota) associate with plants forming one of the most successful microbe-plant associations. The fungi promote plant diversity and have a potentially important role in global agriculture. Plant growth depends on both inter- and intra-specific variation in AMF. It was recently reported that an unusually large number of AMF taxa have an intercontinental distribution, suggesting long-distance gene flow for many AMF species, facilitated by either long-distance natural dispersal mechanisms or human-assisted dispersal. However, the intercontinental distribution of AMF species has been questioned because the use of very low-resolution markers may be unsuitable to detect genetic differences among geographically separated AMF, as seen with some other fungi. This has been untestable because of the lack of population genomic data, with high resolution, for any AMF taxa. Here we use phylogenetics and population genomics to test for intra-specific variation in Rhizophagus irregularis, an AMF species for which genome sequence information already exists. We used ddRAD sequencing to obtain thousands of markers distributed across the genomes of 81 R. irregularis isolates and related species. Based on 6 888 variable positions, we observed significant genetic divergence into four main genetic groups within R. irregularis, highlighting that previous studies have not captured underlying genetic variation. Despite considerable genetic divergence, surprisingly, the variation could not be explained by geographical origin, thus also supporting the hypothesis for at least one AMF species of widely dispersed AMF genotypes at an intercontinental scale. Such information is crucial for understanding AMF ecology, and how these fungi can be used in an environmentally safe way in distant locations
Outcome of hospitalization for COVID-19 in patients with interstitial lung disease. An international multicenter study
Rationale: The impact of coronavirus disease (COVID-19) on patients with interstitial lung disease (ILD) has not been established.
Objectives: To assess outcomes in patients with ILD hospitalized for COVID-19 versus those without ILD in a contemporaneous age-, sex-, and comorbidity-matched population.
Methods: An international multicenter audit of patients with a prior diagnosis of ILD admitted to the hospital with COVID-19 between March 1 and May 1, 2020, was undertaken and compared with patients without ILD, obtained from the ISARIC4C (International Severe Acute Respiratory and Emerging Infection Consortium Coronavirus Clinical Characterisation Consortium) cohort, admitted with COVID-19 over the same period. The primary outcome was survival. Secondary analysis distinguished idiopathic pulmonary fibrosis from non–idiopathic pulmonary fibrosis ILD and used lung function to determine the greatest risks of death.
Measurements and Main Results: Data from 349 patients with ILD across Europe were included, of whom 161 were admitted to the hospital with laboratory or clinical evidence of COVID-19 and eligible for propensity score matching. Overall mortality was 49% (79/161) in patients with ILD with COVID-19. After matching, patients with ILD with COVID-19 had significantly poorer survival (hazard ratio [HR], 1.60; confidence interval, 1.17–2.18; P = 0.003) than age-, sex-, and comorbidity-matched controls without ILD. Patients with an FVC of <80% had an increased risk of death versus patients with FVC ≥80% (HR, 1.72; 1.05–2.83). Furthermore, obese patients with ILD had an elevated risk of death (HR, 2.27; 1.39−3.71).
Conclusions: Patients with ILD are at increased risk of death from COVID-19, particularly those with poor lung function and obesity. Stringent precautions should be taken to avoid COVID-19 in patients with ILD
Amplification of a Cytochrome P450 Gene Is Associated with Resistance to Neonicotinoid Insecticides in the Aphid Myzus persicae
The aphid Myzus persicae is a globally significant crop pest that has evolved high levels of resistance to almost all classes of insecticide. To date, the neonicotinoids, an economically important class of insecticides that target nicotinic acetylcholine receptors (nAChRs), have remained an effective control measure; however, recent reports of resistance in M. persicae represent a threat to the long-term efficacy of this chemical class. In this study, the mechanisms underlying resistance to the neonicotinoid insecticides were investigated using biological, biochemical, and genomic approaches. Bioassays on a resistant M. persicae clone (5191A) suggested that P450-mediated detoxification plays a primary role in resistance, although additional mechanism(s) may also contribute. Microarray analysis, using an array populated with probes corresponding to all known detoxification genes in M. persicae, revealed constitutive over-expression (22-fold) of a single P450 gene (CYP6CY3); and quantitative PCR showed that the over-expression is due, at least in part, to gene amplification. This is the first report of a P450 gene amplification event associated with insecticide resistance in an agriculturally important insect pest. The microarray analysis also showed over-expression of several gene sequences that encode cuticular proteins (2-16-fold), and artificial feeding assays and in vivo penetration assays using radiolabeled insecticide provided direct evidence of a role for reduced cuticular penetration in neonicotinoid resistance. Conversely, receptor radioligand binding studies and nucleotide sequencing of nAChR subunit genes suggest that target-site changes are unlikely to contribute to resistance to neonicotinoid insecticides in M. persicae.Peer reviewedFinal Published versio
Sarcoidosis in a 65-year-old woman presenting with a lung mass and pericardial effusion: a case report
<p>Abstract</p> <p>Introduction</p> <p>Sarcoidosis is a multi-systemic disorder of unknown origin and most commonly affects the lungs. Diagnosis relies on the presence of non-caseating granulomas on histologic specimens. In high-resolution computed tomography, the most characteristic findings are peribronchovascular thickening, perilymphatic nodular distribution, and bilateral hilar adenopathy. Confluent nodular opacities or large masses are rare manifestations of the disease. It is well recognized that sarcoidosis can mimic infectious, malignant, and granulomatous conditions. Here, we report a case with a high initial index of suspicion for lung malignancy in terms of clinical, lung imaging, and endoscopic findings.</p> <p>Case presentation</p> <p>A 65-year-old Caucasian woman, lifelong non-smoker with an unremarkable medical history, presented with a 10-month history of progressive breathlessness, dry cough, fatigue, arthralgias, and mild weight loss. The only significant clinical finding was bilateral enlargement of auxiliary lymph nodes. High-resolution computed tomography revealed a soft tissue density mass at the right hilum which was surrounding and narrowing airways and vascular components, nodules with vascular distribution, enlarged mediastinal lymph nodes, and pericardial effusion. Our patient underwent a bronchoscopy, which revealed the presence of submucosal infiltration and narrowing of the right upper bronchus. Endobronchial biopsies showed non-caseating granulomas. As local sarcoid reactions with non-caseating granulomas can be observed near tumors, our patient underwent video-assisted thoracoscopy and surgical removal of an auxiliary lymph node, both of which confirmed the presence of non-caseating granulomas and the diagnosis of sarcoidosis. She was treated with steroids with improvement of clinical and imaging findings. However, while on a maintenance dose, she presented with a pleural effusion, which, after the diagnostic work-up, proved to be sarcoidosis-related. Treatment with initially high doses of steroids plus a steroid-sparing agent led to resolution of the effusion.</p> <p>Conclusions</p> <p>We report a case with a high initial index of suspicion for lung malignancy. Clinicians should always be aware that sarcoidosis enters the differential diagnosis of patients presenting with a lung mass that encases and narrows bronchial and vascular structures with associated pericardial effusion. Rarely, pleural effusion can be the presenting symptom of disease relapse despite maintenance treatment.</p
Development, growth, feeding and reproduction of Ceratomegilla undecimnotata, Hippodamia variegata and Coccinella septempunctata fed on the tobacco aphid, Myzus persicae nicotianae
The demographic parameters and the larval aphid consumption of the predatory coccinellids Hippodamia variegata (Goeze) and Ceratomegilla undecimnotata (Schneider) were examined at five constant temperatures (17, 20, 23, 26, and 29 A degrees C). The same parameters were determined for Coccinella septempunctata L. at 23 A degrees C. A red Myzus persicae nicotiannae Blackman clone reared on tobacco leaves was used as prey. Preimaginal development of H. variegata and C. undecimnotata ranged from 12.4 to 40.6 days and 14.4 to 48.5 days at 17 A degrees C to 29 A degrees C, respectively. The corresponding thermal summation constants were 211 and 256 DD (day-degrees). Total and mean daily larval consumption at 26 A degrees C were 84.2 and 8.7 aphids, for H. variegata and 129.1 and 9.4 aphids, for C. undecimnotata, respectively. At 23 A degrees C, the mean fecundity of H. variegata, C. undecimnotata and C. septempunctata was 882, 656 and 586 eggs, respectively. The duration of the oviposition periods was 47.6, 50.4 and 73.4 days, respectively. The demographic parameters calculated for H. variegata, C. undecimnotata and C. septempunctata, were as follows: intrinsic rate of increase (r (m)) 0.129, 0.084, and 0.061 female/female/day; mean generation time (T) 42.4, 59.1, and 69.3 days; net reproductive rate (R-o) 241.9, 142.7, 67.3 female/female; and population duplication time (DT) 5.4, 8.3, and 11. 4 days. Total aphid consumption by a pair of adult male and female was 2381 aphids in H. variegata and 3242 aphids in C. undecimnotata. The possible role of the three predator species as biocontrol agents is discussed
Thigh-length compression stockings and DVT after stroke
Controversy exists as to whether neoadjuvant chemotherapy improves survival in patients with invasive bladder cancer, despite randomised controlled trials of more than 3000 patients. We undertook a systematic review and meta-analysis to assess the effect of such treatment on survival in patients with this disease