Fusarium wilt pandemic: current understanding and molecular perspectives

Plant diseases pose a severe threat to the food security of the global human population. One such disease is Fusarium wilt, which affects many plant species and causes up to 100% yield losses. Fusarium pathogen has high variability in its genetic constitution; therefore, it has evolved into different physiological races to infect different plant species spread across the different geographical regions of the world. The pathogen mainly affects plant roots, leading to colonizing and blocking vascular bundle cells, specifically xylem vessels. This blocking results in chlorosis, vascular discoloration, leaf wilting, shortening of plant, and, in severe cases, premature plant death. Due to the soil-borne nature of the wilt pathogen, neither agronomic nor plant protection measures effectively reduce the incidence of the disease. Therefore, the most cost-effective management strategy for Fusarium wilt is developing varieties resistant to a particular race of the fungus wilt prevalent in a given region. This strategy requires understanding the pathogen, its disease cycle, and epidemiology with climate-changing scenarios. Hence, in the review, we will discuss the pathogenic aspect and genetics of the Fusarium wilt, including molecular interventions for developing climate-smart wilt tolerant/resistant varieties of crops. Overall, this review will add to our knowledge for advancing the breeding of resistance against the wilt pandemic.

Drought stress in maize: stress perception to molecular response and strategies for its improvement

Given the future demand for food crops, increasing crop productivity in drought-prone rainfed areas has become essential. Drought-tolerant varieties are warranted to solve this problem in major crops, with drought tolerance as a high-priority trait for future research. Maize is one such crop affected by drought stress, which limits production, resulting in substantial economic losses. It became a more serious issue due to global climate change. The most drought sensitive among all stages of maize is the reproductive stages and the most important for overall maize production. The exact molecular basis of reproductive drought sensitivity remains unclear due to genes' complex regulation of drought stress. Understanding the molecular biology and signaling of the unexplored area of reproductive drought tolerance will provide an opportunity to develop climate-smart drought-tolerant next-generation maize cultivars. In recent decades, significant progress has been made in maize to understand the drought tolerance mechanism. However, improving maize drought tolerance through breeding is ineffective due to the complex nature and multigenic control of drought traits. With the help of advanced breeding techniques, molecular genetics, and a precision genome editing approach like CRISPR-Cas, candidate genes for drought-tolerant maize can be identified and targeted. This review summarizes the effects of drought stress on each growth stage of maize, potential genes, and transcription factors that determine drought tolerance. In addition, we discussed drought stress sensing, its molecular mechanisms, different approaches to developing drought-resistant maize varieties, and how molecular breeding and genome editing will help with the current unpredictable climate change.

European Position Paper on Rhinosinusitis and Nasal Polyps 2020

The European Position Paper on Rhinosinusitis and Nasal Polyps 2020 is the update of similar evidence based position papers published in 2005 and 2007 and 2012. The core objective of the EPOS2020 guideline is to provide revised, up-to-date and clear evidence-based recommendations and integrated care pathways in ARS and CRS. EPOS2020 provides an update on the literature published and studies undertaken in the eight years since the EPOS2012 position paper was published and addresses areas not extensively covered in EPOS2012 such as paediatric CRS and sinus surgery. EPOS2020 also involves new stakeholders, including pharmacists and patients, and addresses new target users who have become more involved in the management and treatment of rhinosinusitis since the publication of the last EPOS document, including pharmacists, nurses, specialised care givers and indeed patients themselves, who employ increasing self-management of their condition using over the counter treatments. The document provides suggestions for future research in this area and offers updated guidance for definitions and outcome measurements in research in different settings. EPOS2020 contains chapters on definitions and classification where we have defined a large number of terms and indicated preferred terms. A new classification of CRS into primary and secondary CRS and further division into localized and diffuse disease, based on anatomic distribution is proposed. There are extensive chapters on epidemiology and predisposing factors, inflammatory mechanisms, (differential) diagnosis of facial pain, allergic rhinitis, genetics, cystic fibrosis, aspirin exacerbated respiratory disease, immunodeficiencies, allergic fungal rhinosinusitis and the relationship between upper and lower airways. The chapters on paediatric acute and chronic rhinosinusitis are totally rewritten. All available evidence for the management of acute rhinosinusitis and chronic rhinosinusitis with or without nasal polyps in adults and children is systematically reviewed and integrated care pathways based on the evidence are proposed. Despite considerable increases in the amount of quality publications in recent years, a large number of practical clinical questions remain. It was agreed that the best way to address these was to conduct a Delphi exercise . The results have been integrated into the respective sections. Last but not least, advice for patients and pharmacists and a new list of research needs are included. The full document can be downloaded for free on the website of this journal: http://www.rhinologyjournal.com.

MRI-Based Texture Analysis to Differentiate Sinonasal Squamous Cell Carcinoma from Inverted Papilloma

BACKGROUND AND PURPOSE

Because sinonasal inverted papilloma can harbor squamous cell carcinoma, differentiating these tumors is relevant. The objectives of this study were to determine whether MR imaging-based texture analysis can accurately classify cases of noncoexistent squamous cell carcinoma and inverted papilloma and to compare this classification performance with neuroradiologists' review.

MATERIALS AND METHODS

Adult patients who had inverted papilloma or squamous cell carcinoma resected were eligible (coexistent inverted papilloma and squamous cell carcinoma were excluded). Inclusion required tumor size of >1.5 cm and preoperative MR imaging with axial T1, axial T2, and axial T1 postcontrast sequences. Five well-established texture analysis algorithms were applied to an ROI from the largest tumor cross-section. For a training dataset, machine-learning algorithms were used to identify the most accurate model, and performance was also evaluated in a validation dataset. On the basis of 3 separate blinded reviews of the ROI, isolated tumor, and entire images, 2 neuroradiologists predicted tumor type in consensus.

RESULTS

The inverted papilloma (n = 24) and squamous cell carcinoma (n = 22) cohorts were matched for age and sex, while squamous cell carcinoma tumor volume was larger (P = .001). The best classification model achieved similar accuracies for training (17 squamous cell carcinomas, 16 inverted papillomas) and validation (7 squamous cell carcinomas, 6 inverted papillomas) datasets of 90.9% and 84.6%, respectively (P = .537). For the combined training and validation cohorts, the machine-learning accuracy (89.1%) was better than that of the neuroradiologists' ROI review (56.5%, P = .0004) but not significantly different from the neuroradiologists' review of the tumors (73.9%, P = .060) or entire images (87.0%, P = .748).

CONCLUSIONS

MR imaging-based texture analysis has the potential to differentiate squamous cell carcinoma from inverted papilloma and may, in the future, provide incremental information to the neuroradiologist.

The Impact of Middle Turbinate Concha Bullosa on the Severity of Inferior Turbinate Hypertrophy in Patients with a Deviated Nasal Septum

BACKGROUND AND PURPOSE

Inferior turbinate hypertrophy and concha bullosa often occur opposite the direction of nasal septal deviation. The objective of this retrospective study was to determine whether a concha bullosa impacts inferior turbinate hypertrophy in patients who have nasal septal deviation.

MATERIALS AND METHODS

The electronic medical record was used to identify sinus CT scans exhibiting nasal septal deviation for 100 adult subjects without and 100 subjects with unilateral middle turbinate concha bullosa. Exclusion criteria included previous sinonasal surgery, tumor, sinusitis, septal perforation, and craniofacial trauma. Nasal septal deviation was characterized in the coronal plane by distance from the midline (severity) and height from the nasal floor. Measurement differences between sides for inferior turbinate width (overall and bone), medial mucosa, and distance to the lateral nasal wall were calculated as inferior turbinate hypertrophy indicators.

RESULTS

The cohorts with and without concha bullosa were similarly matched for age, sex, and nasal septal deviation severity, though nasal septal deviation height was greater in the cohort with concha bullosa than in the cohort without concha bullosa (19.1 ± 4.3 mm versus 13.5 ± 4.1 mm, P < .001). Compensatory inferior turbinate hypertrophy was significantly greater in the cohort without concha bullosa than in the cohort with it as measured by side-to-side differences in turbinate overall width, bone width, and distance to the lateral nasal wall (P < .01), but not the medial mucosa. Multiple linear regression analyses found nasal septal deviation severity and height to be significant predictors of inferior turbinate hypertrophy with positive and negative relationships, respectively (P < .001).

CONCLUSIONS

Inferior turbinate hypertrophy is directly proportional to nasal septal deviation severity and inversely proportional to nasal septal deviation height. The effect of a concha bullosa on inferior turbinate hypertrophy is primarily mediated through influence on septal morphology, because the nasal septal deviation apex tends to be positioned more superior from the nasal floor in these patients.

Immunological profiling in chronic rhinosinusitis with nasal polyps reveals distinct VEGF and GM-CSF signatures during symptomatic exacerbations

BACKGROUND

The mechanisms and immune pathways associated with chronic rhinosinusitis (CRS) are not fully understood. Immunological changes during acute exacerbation of CRS may provide valuable clues to the pathogenesis and perpetuation of the disease.

OBJECTIVE

To characterize local and systemic immune responses associated with acute worsening of sinonasal symptoms during exacerbation in CRS with nasal polyps (CRSwNP) compared to controls.

METHODS

This was a non-interventional prospective study of individuals with CRSwNP and normal controls. Subjects underwent a baseline visit with collection of nasal secretions, nasal washes, and serum specimens. Within 3 days of acute worsening of sinonasal symptoms, subjects underwent a study visit, followed by a post-visit 2 weeks later. The sinonasal outcome test-22 (SNOT-22) scores and immunological parameters in the specimens were analysed using a novel, unsupervised learning method and by conventional univariate analysis.

RESULTS

Both CRSwNP patients and control subjects showed a significant increase in SNOT-22 scores during acute exacerbation. Increased nasal levels of IL-6, IL-5, and eosinophil major basic protein were observed in CRSwNP patients. A network analysis of serum specimens revealed changes in a set of immunological parameters, which are distinctly associated with CRSwNP but not with controls. In particular, systemic increases in VEGF and GM-CSF levels were notable and were validated by a conventional analysis.

CONCLUSIONS

CRSwNP patients demonstrate distinct immunological changes locally and systemically during acute exacerbation. Growth factors VEGF and GM-CSF may be involved in the immunopathogenesis of subjects with CRS and nasal polyps experiencing exacerbation.

Genome-Wide Scan for Copy Number Variation Association with Biomarker Quantitative Trait Loci in Aging

Biomarkers are emerging as important tools in the detection and monitoring of various diseases. A major limitation and challenge to effectively utilize biomarker signals is the limited understanding of factors contributing to their variance. As genetic variation is a major contributor to phenotypic variation, exploring genetic contributions is of great importance. Copy number variants (CNVs) offer an alternative genomic framework to understand contributions to phenotypic variance. A copy-number variation genome-wide association study was performed using 116 serum inflammatory biomarkers as quantitative trait in elderly normal controls to test the hypothesis that CNVs contribute to the phenotypic heterogeneity of serum biomarkers. Three chromosomal regions were associated with four biomarkers in trans. Transforming growth factor alpha (TG-alpha) serum levels were associated with CNV dosage at chr11:5,788 kb, soluble levels of receptor for advanced glycation endproducts (sRAGE) was associated with CNV dosage at chr8:40,183 kb and both thrombospondin-1 and tissue inhibitor of metalloproteinase 1 (TIMP-1) were associated with CNV dosage at chr11:18,961 kb. The CNV at chr11:5,788 kb harbors 2 olfactory genes and the introns of Tripartite motif-containing (TRIM) gene cluster TRIM5&22 while the CNV at chr11:18,961 includes the Mas-related G-protein coupled receptor member X1. These trans associations may identify novel relationships in the relevant pathways and suggest that genetic variation can contribute to biomarker levels. The detected trans-association between MRGPRX1 and thrombospondin-1/TIMP-1 could implicate a novel pathway between pain/itching and inflammation. Cataloguing all genetic variants with an effect on biomarkers will serve as a tool to interpret epidemiological studies and establish causal relationships through Mendelian randomization.

Radiation dose reduction in paranasal sinus CT using model-based iterative reconstruction

BACKGROUND AND PURPOSE

CT performed with Veo model-based iterative reconstruction has shown the potential for radiation-dose reduction. This study sought to determine whether Veo could reduce noise and improve the image quality of low-dose sinus CT.

MATERIALS AND METHODS

Twenty patients consented to participate and underwent low- and standard-dose sinus CT on the same day. Standard-dose CT was created with filtered back-projection (120 kV[peak], 210 mA, 0.4-second rotation, and 0.531 pitch). For low-dose CT, mA was decreased to 20 (the remaining parameters were unchanged), and images were generated with filtered back-projection and Veo. Standard- and low-dose datasets were reconstructed by using bone and soft-tissue algorithms, while the low-dose Veo reconstruction only had a standard kernel. Two blinded neuroradiologists independently evaluated the image quality of multiple osseous and soft-tissue craniofacial structures. Image noise was measured by using multiple regions of interest.

RESULTS

Eight women and 12 men (mean age, 63.3 years) participated. Volume CT dose indices were 2.9 mGy (low dose) and 31.6 mGy (standard dose), and mean dose-length products were 37.4 mGy-cm (low dose) and 406.1 mGy-cm (standard dose). Of all the imaging series, low-dose Veo demonstrated the least noise (P < .001). Compared with filtered back-projection low-dose CT using soft-tissue and bone algorithms, Veo had the best soft-tissue image quality but the poorest bone image quality (P < .001).

CONCLUSIONS

Veo significantly reduces noise in low-dose sinus CT. Although this reduction improves soft-tissue evaluation, thin bone becomes less distinct.

Identification of bioneutralization epitopes of human follicle stimulating hormone in the regions 31-52 and 66-75 of its beta-subunit

The crucial role played by follicle stimulating hormone (FSH) in regulating both male and female reproduction and the possibilities of developing contraceptive methods for males by blocking the function of the hormone, makes it important to delineate the hormone-specific bioneutralization epitopes of human follicle stimulating hormone (hFSH) on its beta-subunit. Predictive methods were used to identify the potential surface-oriented regions of hFSH-beta. Peptides corresponding to these regions, i.e. 31-52, 66-75 and 86-95 hFSH-beta, were synthesized, anti-peptide antibodies were elicited in rabbits and the properties of these antisera to bind hFSH and neutralize its biological activity were assessed. Anti-31-52 hFSH-beta antisera bound hFSH specifically, whereas anti-66-75 and anti-86-95 hFSH-beta antisera did not show any detectable binding, proving the region 31-52 hFSH-beta to be a specific antigenic determinant of hFSH. The bioneutralizing abilities of the anti-peptide antibodies were assessed by measuring the hFSH-induced progesterone secretion by rat granulosa cells in vitro. Antibodies to 31-52 and 66-75 hFSH-beta neutralized the bioactivity of hFSH, but anti-86-95 hFSH-beta antibodies did not. Furthermore, the three linear peptides and two disulphide looped peptides of 31-52 hFSH-beta and 86-95 hFSH-beta were also subjected to the in-vitro granulosa cell assay. The linear peptides 31-52 hFSH-beta and 66-75 hFSH-beta and the cyclic 31-52 hFSH-beta disulphide loop peptide significantly inhibited the hFSH-induced progesterone secretion by rat granulosa cells, but the linear 86-95 hFSH-beta peptide and the corresponding cyclic disulphide loop peptide did not. The results clearly show that the regions 31-52 and 66-75 of hFSH-beta harbor bioneutralization epitopes of the hormone. The studies also indicate that cyclization of the linear 31-52 hFSH-beta peptide greatly enhances receptor recognition and that the region 66-75 hFSH-beta may also be involved in hormone-receptor interaction.

Studies on the delineation of the hormone-specific antigenic determinants of human follicle-stimulating hormone

Human follicle-stimulating hormone (hFSH) is a key hormone regulating both male and female reproduction. The present study attempts to delineate the hFSH-specific antigenic determinants on its beta-subunit. Predictive methods were used to identify the potential surface-oriented regions of hFSH-beta. Peptides corresponding to these regions, namely, 31-52, 66-75 and 86-95 hFSH-beta, were synthesized and conjugated to diphtheria toxoid. Antipeptide antibodies, elicited in rabbits by immunization with the conjugates, were screened for their ability to bind to hFSH-beta and hFSH. Anti-31-52 hFSH-beta antisera bound to both hFSH-beta and hFSH, whereas anti-66-75 and anti-86-95 hFSH-beta antisera did not show any detectable binding. Furthermore, screening of anti-hFSH antisera showed significant binding only to 31-52 hFSH-beta. These results identify the region 31-52 hFSH-beta as a hormone-specific antigenic determinant of hFSH.

Cosmogenic and nucleogenic isotopic changes in Mars: their rates and implications to the evolutionary history of Martian surface

We present calculations of rates of production of several nuclides in the Martian atmosphere and in the regolith due to nuclear interactions of cosmic ray and radiogenic particles and consider their implications to the evolutionary history of Mars. Nuclides selected are those which, considering their chemical properties, may be useful as tracers for delineating the past histories of the Martian atmosphere and regolith. Calculations are presented for different assumed atmospheric pressures. The regolith production rates for the present thin Martian atmosphere (approximately 20 g cm-2) are expected to be fairly robust because they are based primarily on observed cosmogenic effects in the Moon, for which semiempirical estimates of nuclide production rates have been provided earlier by Reedy (1981). Uncertainties which arise in the calculations of nuclide production rates for an earlier hypothetical Martian atmosphere of approximately 300-500 g cm-2 thickness are discussed. Compared to cosmic ray production rates, the nucleogenic production rates are smaller by several orders of magnitude. However, the nucleogenic production extends to much deeper levels, whereas the cosmogenic production is essentially confined to the top 750-1000 g cm-2 depth. Important examples of nucleogenic production are discussed. Isotopes of neon and argon appear to be very promising for delineating relative magnitudes of a number of planetary processes related to the temporal changes in the thickness of the atmosphere, as well as their release from the regolith. However, quantification of the processes would require higher-precision isotopic data for the atmosphere and also direct measurements of isotopic ratios in the Martian regolith, along with supplementary information on changes in the isotopic compositions of hydrogen, carbon, and nitrogen, which are affected by a variety of mechanisms of escape of gases from the atmosphere. Cosmogenic effects are minimal in these cases. We show that although we can at present draw but limited inferences, the planet Mars presents a unique opportunity to use cosmogenic nuclides as tools to delineate the evolutionary history of the planet as a whole, as well as its regolith and the atmosphere. This arises because of two factors: minimal degassing of the planet, and a fairly intense chemical weathering history of the upper surface. Consequently, an appreciable fraction of some of the isotopes of volatile elements is contributed by nuclear reactions.

The esterification of fatty acids by Staphylococcus aureus fatty acid modifying enzyme (FAME) and its inhibition by glycerides

Fifty-five randomly selected Staphylococcus aureus strains were examined for fatty acid modifying enzyme (FAME) production. Of these, 20.4% did not elaborate the enzyme. Amongst the remaining strains, the lowest level produced in culture was 0.1 unit/10(9) cocci and the maximum was 2.01 U/10(9) cocci; the median level was 0.4 U/10(9) cocci. In a series of straight-chain saturated fatty acids with 11-24 carbons, all could be esterified by FAME. However, those with 15-19 carbons were generally better substrates than the others. For a particular chain length, the unsaturated forms were better substrates than the saturated form. Triglycerides with unsaturated fatty acid side chains were potent inhibitors of FAME. Diglycerides were almost as active as triglycerides, but monoglycerides were much less inhibitory. FAME was purified by gel filtration followed by hydrophobic interaction chromatography on hexyl agarose. FAME and lipase may have a role in determining the survival of S. aureus in lesions.

Does communication between investigators improve the conduct of the multicentre study?

Meetings between investigators participating in multicentre clinical trials are rarely held. Evidence is presented from a computerised system of multicentre trial management that there are advantages to both physicians and companies in improving communication and holding regular meetings.

Survival and mutagenic effects of 5-azacytidine in Escherichia coli

Survival and mutagenesis caused by 5-azacytidine was studied in Escherichia coli. Survival was partially lexA- and recA-dependent and was decreased by the presence of a DNA (cytosine-5)methyltransferase. The dcm, MspI, and EcoRII methyltransferase genes all decreased survival. There was no direct relationship between amount of methylase enzyme present and cell survival, but only plasmids containing a methylase gene sensitized cells to 5-azacytidine. Survival was not affected by uvrA, uvrB or umuCD mutations. Induction of sulA::lacZ fusions by 5-azacytidine was inhibited in strains containing elevated levels of DNA methylase. Cells resistant to 5-azacytidine when they contained a plasmid specifying the EcoRII methylase were sensitive if the plasmid specified the complete EcoRII restriction-modification system. The mechanism of cell death in these situations is therefore different. Mutation of the rpoB gene by 5-azacytidine was studied. The mutation rate was decreased by the presence of recA and lexA mutations. Mutation in umuCD had little effect on the mutation rate. The recA430 mutation, which does not support SOS-dependent mutagenesis induced by UV light, does support 5-azacytidine induced mutagenesis. The presence of DNA (cytosine-5)methyltransferase had no effect on the mutation rate caused by 5-azacytidine treatment. The mutagenic and lethal lesions caused by 5-azacytidine in the absence of methylase therefore differ from the lethal lesions that occur in the presence of methylase. The former could be due to the opening of the 5-azacytosine ring in DNA. Cell death in the presence of methylase could be due to tight binding of methylase to azacytosine containing DNA as well as inhibition of induction of the SOS response.

Cosmic-Ray Record in Solar System Matter

The energetic nuclei in cosmic rays interact with meteoroids, the moon, planets, and other solar system matter. The nuclides and heavy nuclei tracks produced by the cosmic-ray particles in these targets contain a wealth of information about the history of the objects and temporal and spatial variations in the particle fluxes. Most lunar samples and meny meteorites have complex histories of cosmicray exposure from erosion, gardening, fragmentation, orbital changes, and other processes. There appear to be variations in the past fluxes of solar particles, and possibly also galactic cosmic rays, on time scales of 10(4) to 10(7) years.