97 results on '"Tzelepis G"'
Search Results
2. Thoracoabdominal motion in ankylosing spondylitis: association with standardised clinical measures and response to therapy
- Author
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Tzelepis, G E, Kalliakosta, G, Tzioufas, A G, Sfikakis, P P, Mandros, C, Boki, K A, Roussos, C, and Moutsopoulos, H M
- Published
- 2009
- Full Text
- View/download PDF
3. Role of activins in lung pathophysiology: S9.5
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Xirakia, C, Apostolou, E, Stavropoulos, A, Giaglis, S, Soundoulidis, A, Protopapadaki, E, Tzelepis, G, Andreakos, E, and Sideras, P
- Published
- 2008
4. Comparison of gastric air tonometry with standard saline tonometry
- Author
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Tzelepis, G., Kadas, V., Michalopoulos, A., and Geroulanos, S.
- Published
- 1996
- Full Text
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5. Mycophenolate mofetil for interstitial lung disease in scleroderma
- Author
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Plastiras, S. C., Vlachoyiannopoulos, P. G., and Tzelepis, G. E.
- Published
- 2006
6. Respiratory muscle performance with stretch-shortening cycle manoeuvres: maximal inspiratory pressure–flow curves
- Author
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Tzelepis, G. E., Zakynthinos, S., Mandros, C., Tzelepis, E., and Roussos, C.
- Published
- 2005
7. Absence of a hemidiaphragm: Mechanical implications
- Author
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McCool, F. D., Tzelepis, G. E., and Mead, J.
- Published
- 1991
- Full Text
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8. Morbid obesity and hypersomnolence in several members of an ancient royal family
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Michalopoulos, A, Tzelepis, G, and Geroulanos, S
- Published
- 2003
9. Pulmonary function and respiratory muscle strength in chronic heart failure: comparison between ischaemic and idiopathic dilated cardiomyopathy
- Author
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Daganou, M, Dimopoulou, I, Alivizatos, P A, and Tzelepis, G E
- Published
- 1999
10. PORTOPULMONARY HYPERTENSION AND SERUM ENDOTHELIN LEVELS IN PATIENTS WITH CIRRHOSIS
- Author
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Tsiakalos, A. P. Hatzis, G. Moyssakis, I. Karatzaferis, A. and Ziakas, P. D. Tzelepis, G. E.
- Published
- 2010
11. Thoracoabdominal motion in ankylosing spondylitis: association with standardised clinical measures and response to therapy
- Author
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Tzelepis, G. E. Kalliakosta, G. Tzioufas, A. G. Sfikakis, P. P. Mandros, C. Boki, K. A. Roussos, C. Moutsopoulos, H. M.
- Abstract
Objectives: To assess the relationship between thoracoabdominal motion during quiet breathing and standardised indices of disease severity in patients with ankylosing spondylitis (AS); also to evaluate whether thoracoabdominal motion improves after institution of biological agents in these patients. Methods: Displacement of the rib cage (RC) and abdomen (Abd) during quiet breathing in the sitting, standing and supine position were recorded by impedance plethysmography in 60 patients (mean (SD) age 41 (10) years, 56 men) and 21 healthy men (mean (SD) 36 (7) years). x-y plots of RC versus Abd displacement during quiet breathing were constructed, and the angle of the slope of the RC-Abd loop was calculated and averaged for five consecutive breaths. In 13 patients treated with anti-tumour necrosis factor alpha (TNF alpha), measurements were made before and at 3, 6 and 12 months after the start of treatment. Results: In the entire AS group, the angle of the slope of the RC-Abd loop correlated with Bath Ankylosing Spondylitis Functional Index (BASFI) in the sitting (R = -0.50, p
- Published
- 2009
12. The presence of anti-centromere antibodies may predict progression of estimated pulmonary arterial systolic pressure in systemic sclerosis
- Author
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Kampolis, C. Plastiras, S. C. Vlachoyiannopoulos, P. G. and Moyssakis, I. Tzelepis, G. E.
- Abstract
Objective: To define the risk factors associated with a relatively rapid increase in estimated pulmonary arterial systolic pressure (PASP) in patients with systemic sclerosis (SSc). Methods: SSc patients undergoing screening for pulmonary arterial hypertension (PAH) by echocardiography were identified and their charts were retrospectively reviewed. In all patients, we recorded PASP, pulmonary function, and clinical and laboratory data. PAH was defined as an estimated PASP40mmHg. In each patient, the PASP values with their corresponding time intervals were fitted to a linear function and the slope of the line was calculated. Results: Seventy-one patients with at least two echocardiographic studies each were analysed. In 16 (23%) patients, the rate of PASP progression was 2.5mmHg/year whereas in the remaining 55 (77%) patients the rate of progression was 2.5mmHg/year. In multiple logistic regression analysis, anti-centromere antibodies (ACA) (OR 8.75, CI 1.12-68.38, p=0.039) and age 50 years at diagnosis (OR 8.76, CI 1.28-60.14, p=0.027) were independently associated with a rise of PASP by 2.5mmHg/year. Baseline forced vital capacity (FVC) 70% (predicted), Raynaud’s duration preceding skin manifestations by 5 years, and fibrosis on lung computed tomography (CT) were not associated with a rapid rise of PASP (p0.05). Conclusions: Old age at diagnosis and ACA are associated with a relatively rapid rise of PASP estimated by echocardiography in SSc. Screening for PAH in these patients may, if followed by right heart catheterization, detect PAH at an earlier stage and guide therapeutic decisions.
- Published
- 2008
13. Occult connective tissue diseases mimicking idiopathic interstitial pneumonias
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Tzelepis, G. E. Toya, S. P. Moutsopoulos, H. M.
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respiratory tract diseases - Abstract
In patients with interstitial lung disease (ILD), the diagnosis of idiopathic interstitial pneumonia is usually made after excluding, among other conditions, connective tissue diseases (CTDs). Although in most patients with a CTD and respiratory symptoms, the systemic nature of the disease is obvious, the ILD-related manifestations in CTDs may often dominate the clinical picture or precede systemic findings and thus mimic idiopathic interstitial pneumonia. With the exception of systemic lupus erythematosus, all CTDs may imitate chronic idiopathic interstitial pneumonias. In this setting, clues to an underlying CTD may be entirely absent or include subtle findings from various systems, including skin, vascular and musculoskeletal system or internal organs. Since nonspecific interstitial pneumonia is a relatively frequent histological pattern in CTDs, biopsy reports of nonspecific interstitial pneumonia should also prompt a search for an underlying CTD. Ultimately, diagnosis of a CTD requires confirmation with immunological testing; interpretation of the various laboratory tests should always be carried out in conjunction with clinical findings. The present article reviews specific clinical aspects of connective tissue disease-related interstitial lung disease that may help differentiate it from idiopathic interstitial pneumonia, especially when interstitial lung disease is the predominant or sole manifestation of an occult connective tissue disease.
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- 2008
14. Diffuse lymphangiomatosis: Are there any clinical or therapeutic standards?
- Author
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Zisis, C. Spiliotopoulos, K. Patronis, M. Filippakis, G. Stratakos, G. Tzelepis, G. Bellenis, I.
- Published
- 2007
15. Candiduria in intensive care units: association with heavy colonization and candidaemia
- Author
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Toya, S. P. Schraufnagel, D. E. Tzelepis, G. E.
- Abstract
Candiduria is increasingly detected in intensive care unit (ICU) patients and often coexists with candidal colonization at other anatomical, sites. Studies involving surgical. and medical ICU patients have consistentty reported a relationship between candiduria and heavy colonization. This suggests that candiduria could be considered as a marker for heavy colonization. Risk factors that predispose to heavy colonization are generally similar to those predisposing to candidaemia. Candiduria in ICU patients is characterized by a high mortality, largely through a significant relationship with candidaemia, which in some patients may reach 50%. Therapeutic interventions should be strongly considered in the critically itt patient who presents with candiduria and concurrent clinical. risk factors predisposing to dissemination. (C) 2007 The Hospital Infection Society. Published by Elsevier Ltd. All rights reserved.
- Published
- 2007
16. Mycophenolate mofetil for interstitial lung disease in scleroderma
- Author
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Plastiras, S. C. Vlachoyiannopoulos, P. G. Tzelepis, G. E.
- Published
- 2006
17. A phase II study of the docetaxel-carboplatin chemotherapy regimen in advanced non-small-cell lung cancer
- Author
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Tsavaris, N Kosmas, C Skopelitis, E Gennatas, K Zorbala, A Papas, P Gouveris, P Antypas, G Rokana, S and Tzelepis, G
- Abstract
The efficacy of the docetaxel-carboplatin combination chemotherapy was studied in various phase II studies. Based on these data we aimed to test the regimen in previously untreated patients with advanced advanced non-stroking lung cancer (NSCLC) with docetaxel 80 mg/m(2) a standard dose of carboplatin at AUC = 5, in an attempt to define the efficacy and tolerability of the combination in an open-label phase II study. Patients with histologically confirmed advanced NSCLC stage IIIB and IV were candidates for the present study. Docetaxel was administered at 80 mg/m(2) over 1 h by intravenous (IV) infusion followed by carboplatin AUC = 5 in 30 min IV infusion, both on day 1, and recycled every 21 days. Sixty patients received 263 courses of therapy in total; 231/263 (88%) were administered according to the planned doses, and 48/60 (80%) patients received chemotherapy without decrement of the dose; 32/263 (12%) of the courses were administered with a 10%-30% dose reduction. Complete responses (CR) were seen in 5 patients (8.3%) and partial responses (PR) in 16 patients (26.7%) for an overall response rate of 35%. Median duration of response was 7.5 months [95% confidence interval (CI)-7.1-7.9], time to progression (TIP) 11.5 months (95% CI-8.2-14.8), median overall survival (OS) 15.0 months (95% CI-10.8-19.2). One-year survival was 61.7%. Toxicity was acceptable; it was calculated according to the administered cycles and was mainly neutropenia: grade 3, 9% and grade 4, 2%; anemia: grade 3, 8%; nausea and vomiting: grade 3, 8%. The outpatient regimen of docetaxel-carboplatin is effective with acceptable toxicity in patients with advanced NSCLC.
- Published
- 2005
18. A phase II study of the docetaxel-ifosfamide-carboplatin combination in advanced non-small-cell lung cancer
- Author
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Kosmas, C Tsavaris, N Koutras, A Makatsoris, T and Mylonakis, N Tzelepis, G Dimitrakopoulos, A Spyropoulos, K and Polyzos, A Karabelis, A Kalofonos, HP
- Abstract
Purpose: In the present phase II study we evaluated the docetaxel-ifosfamide-carboplatin (DICb) combination in the outpatient setting in patients with advanced non-small-cell lung cancer (NSCLC). Patients and Methods: Patients with advanced NSCLC ( stages IIIB/IV), WHO performance status ( PS) ! 2, and no prior chemotherapy were eligible. Chemotherapy drug doses were: docetaxel: 80 mg/m(2), ifosfamide: 3.5 g/m(2), and carboplatin at a target area under the curve of 5 ( based on Calvert’s formula), all on day 1, followed by prophylactic G-CSF. Results: Fourty patients were entered and all are evaluable for response and toxicity: median age: 64 ( 48 - 72); PS: 1 ( 0 - 1); gender: 29 males/11 females; stages: IIIB: 13 (33%), IV: 27 (67%). Metastatic sites at diagnosis included: lymph nodes: 25; bone: 7; liver: 4; brain: 5; lung nodules: 13; adrenals: 6. Responses were as follows: 22/ 40 [55%; 95% confidence interval (CI), 54 - 81%] evaluable patients responded: 4 complete responses, 18 partial responses, 11 had stable disease, and 7 had progressive disease. The median response duration was 7 months ( range 2 14 months), median time to progression 9 months ( range 2 - 18 months) and median overall survival 11 months ( range 3 - 46+ months). 1-year survival was 47.5%. Grade 3/4 toxicities included: neutropenia 28/40, with 12 developing grade 4 and 12% febrile neutropenia, thrombocytopenia grade 3: 3/40 and grade 4: 1/40, no grade 3 neuropathy, grade 1 CNS toxicity in 3, no renal toxicity, 8 grade 2 diarrhea and 4 grade 3 vomiting. Conclusion: In the present phase II study the DICb combination yielded important activity and good tolerability in advanced NSCLC. Copyright (C) 2005 S. Karger AG, Basel.
- Published
- 2005
19. Chest Wall Distortion in Patients with Flail Chest
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Tzelepis, G. E., McCool, F. D., and Hoppin, F. G., Jr.
- Published
- 1989
- Full Text
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20. Myocardial performance and aortic elasticity are impaired in patients with ankylosing spondylitis.
- Author
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Moyssakis, I., Gialafos, E., Vassiliou, V. A., Boki, K., Votteas, V., Sfikakis, P. P., and Tzelepis, G. E.
- Subjects
ANKYLOSING spondylitis ,MYOCARDIUM ,AORTA ,LEFT heart ventricle ,COMORBIDITY - Abstract
Objective: To measure aortic stiffness and global left ventricular (LV) function in patients with ankylosing spondylitis (AS) and no clinical evidence of heart disease. Methods: Fifty-seven consecutive patients with AS (54 males, three females, mean age 41.78±10.02 years) without clinical evidence of cardiac involvement and 78 healthy subjects (73 males, five females, mean age 39.92±9.11 years) underwent complete echocardiographic study. Aortic stiffness was determined non-invasively by aortic distensibility (AoD) and the global LV function was evaluated by the myocardial performance index (the Tei index). Results: AoD in patients with AS [(2.21±0.24)×10-6 cm2 dyn-1] was decreased compared to controls [(2.58±0.19) )×10-6 cm2 dyn-1, p<0.01], confirming that aortic stiffness is increased in AS. The LV Tei index was significantly increased in the patient group compared to the control group (0.392±0.031 vs. 0.370±0.034, p<0.01). The ejection fraction (EF) did not differ between the two groups (p>0.05). In multivariate linear regression analysis, AoD was significantly associated with the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) and LV isovolumic relaxation time (IVRT) whereas the LV Tei index was associated with BASDAI and the LV mass index. Conclusions: Patients with AS and no clinical evidence of cardiac disease have increased stiffness of the aorta and decreased global myocardial performance and both of these abnormal measurements correlate with disease activity. The abnormal Tei index may reflect an early manifestation of cardiac dysfunction in these patients. [ABSTRACT FROM AUTHOR]
- Published
- 2009
- Full Text
- View/download PDF
21. The presence of anti-centromere antibodies may predict progression of estimated pulmonary arterial systolic pressure in systemic sclerosis.
- Author
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Kampolis, C., Plastiras, S. C., Vlachoyiannopoulos, P. G., Moyssakis, I., and Tzelepis, G. E.
- Subjects
CENTROMERE ,CHROMOSOMES ,IMMUNOGLOBULINS ,HYPERTENSION ,BLOOD circulation disorders - Abstract
Objective: To define the risk factors associated with a relatively rapid increase in estimated pulmonary arterial systolic pressure (PASP) in patients with systemic sclerosis (SSc). Methods: SSc patients undergoing screening for pulmonary arterial hypertension (PAH) by echocardiography were identified and their charts were retrospectively reviewed. In all patients, we recorded PASP, pulmonary function, and clinical and laboratory data. PAH was defined as an estimated PASP≥40 mmHg. In each patient, the PASP values with their corresponding time intervals were fitted to a linear function and the slope of the line was calculated. Results: Seventy-one patients with at least two echocardiographic studies each were analysed. In 16 (23%) patients, the rate of PASP progression was ≥2.5 mmHg/year whereas in the remaining 55 (77%) patients the rate of progression was <2.5 mmHg/year. In multiple logistic regression analysis, anti-centromere antibodies (ACA) (OR 8.75, CI 1.12-68.38, p = 0.039) and age ≥50 years at diagnosis (OR 8.76, CI 1.28-60.14, p = 0.027) were independently associated with a rise of PASP by ≥2.5 mmHg/year. Baseline forced vital capacity (FVC) <70% (predicted), Raynaud's duration preceding skin manifestations by ≥5 years, and fibrosis on lung computed tomography (CT) were not associated with a rapid rise of PASP (p>0.05). Conclusions: Old age at diagnosis and ACA are associated with a relatively rapid rise of PASP estimated by echocardiography in SSc. Screening for PAH in these patients may, if followed by right heart catheterization, detect PAH at an earlier stage and guide therapeutic decisions. [ABSTRACT FROM AUTHOR]
- Published
- 2008
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22. P-43 Cardiac arrest after open heart surgery and interventional procedures
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Papadimitriou, L., Deligianni, M., Smyrli, A., Rellia, P., Kalogris, P., Anthi, A., Tzelepis, G., and Voudris, V.
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- 1996
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23. O-42 First year survival after successful CPR in the immediate postoperative period following open heart surgery
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Anthi, A., Karakatsani, A., Kriaras, I., Tzelepis, G., Palatianos, G., Papadimitriou, L., and Geroulanos, S.
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- 1996
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24. O-32 Antimicrobial protection in cardiac surgery patients undergoing open chest CPR
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Kriaras, I., Anthi, A., Michelopoulos, A., Karakatsani, A., Tzelepis, G., Papadimitriou, L., and Geroulanos, S.
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- 1996
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25. Transcriptomic and functional analyses on a Botrytis cinerea multidrug-resistant (MDR) strain provides new insights into the potential molecular mechanisms of MDR and fitness.
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Sofianos G, Piombo E, Dubey M, Karlsson M, Karaoglanidis G, and Tzelepis G
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- Pyrroles pharmacology, Gene Expression Regulation, Fungal drug effects, Fungal Proteins metabolism, Fungal Proteins genetics, Gene Expression Profiling, Drug Resistance, Multiple, Fungal genetics, Drug Resistance, Fungal genetics, Drug Resistance, Fungal drug effects, Genetic Fitness, Botrytis drug effects, Botrytis genetics, Botrytis pathogenicity, Transcriptome genetics, Fungicides, Industrial pharmacology, Dioxoles pharmacology
- Abstract
Botrytis cinerea is a notorious pathogen causing pre- and post-harvest spoilage in many economically important crops. Excessive application of site-specific fungicides to control the pathogen has led to the selection of strains possessing target site alterations associated with resistance to these fungicides and/or strains overexpressing efflux transporters associated with multidrug resistance (MDR). MDR in B. cinerea has been correlated with the overexpression of atrB and mfsM2, encoding an ATP-binding cassette (ABC) and a major facilitator superfamily (MFS) transporter, respectively. However, it remains unknown whether other transporters may also contribute to the MDR phenotype. In the current study, the transcriptome of a B. cinerea multidrug-resistant (MDR) field strain was analysed upon exposure to the fungicide fludioxonil, and compared to the B05.10 reference strain. The transcriptome of this field strain displayed significant differences as compared to B05.10, including genes involved in sugar membrane transport, toxin production and virulence. Among the induced genes in the field strain, even before exposure to fludioxonil, were several putatively encoding ABC and MFS transmembrane transporters. Overexpression of a highly induced MFS transporter gene in the B05.10 strain led to an increased tolerance to the fungicides fluopyram and boscalid, indicating an involvement in efflux transport of these compounds. Overall, the data from this study give insights towards better understanding the molecular mechanisms involved in MDR and fitness cost, contributing to the development of more efficient control strategies against this pathogen., (© 2024 The Author(s). Molecular Plant Pathology published by British Society for Plant Pathology and John Wiley & Sons Ltd.)
- Published
- 2024
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26. Verticillium longisporum phospholipase VlsPLA 2 is a virulence factor that targets host nuclei and modulates plant immunity.
- Author
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Rafiei V, Vélëz H, Piombo E, Dubey M, and Tzelepis G
- Subjects
- Virulence Factors metabolism, Phospholipases genetics, Phospholipases metabolism, Plant Immunity, Plant Diseases microbiology, Verticillium, Ascomycota, Arabidopsis microbiology
- Abstract
Phospholipase A
2 (PLA2 ) is a lipolytic enzyme that hydrolyses phospholipids in the cell membrane. In the present study, we investigated the role of secreted PLA2 (VlsPLA2 ) in Verticillium longisporum, a fungal phytopathogen that mostly infects plants belonging to the Brassicaceae family, causing severe annual yield loss worldwide. Expression of the VlsPLA2 gene, which encodes active PLA2 , is highly induced during the interaction of the fungus with the host plant Brassica napus. Heterologous expression of VlsPLA2 in Nicotiana benthamiana resulted in increased synthesis of certain phospholipids compared to plants in which enzymatically inactive PLA2 was expressed (VlsPLA2 ΔCD ). Moreover, VlsPLA2 suppresses the hypersensitive response triggered by the Cf4/Avr4 complex, thereby suppressing the chitin-induced reactive oxygen species burst. VlsPLA2 -overexpressing V. longisporum strains showed increased virulence in Arabidopsis plants, and transcriptomic analysis of this fungal strain revealed that the induction of the gene contributed to increased virulence. VlsPLA2 was initially localized to the host nucleus and then translocated to the chloroplasts at later time points. In addition, VlsPLA2 bound to the vesicle-associated membrane protein A (VAMPA) and was transported to the nuclear membrane. In the nucleus, VlsPLA2 caused major alterations in the expression levels of genes encoding transcription factors and subtilisin-like proteases, which play a role in plant immunity. In conclusion, our study showed that VlsPLA2 acts as a virulence factor, possibly by hydrolysing host nuclear envelope phospholipids, which, through a signal transduction cascade, may suppress basal plant immune responses., (© 2023 The Authors. Molecular Plant Pathology published by British Society for Plant Pathology and John Wiley & Sons Ltd.)- Published
- 2023
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27. Investigating the role of a putative endolysin-like candidate effector protein in Verticillium longisporum virulence.
- Author
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Rafiei V, Najafi Y, Vélëz H, and Tzelepis G
- Subjects
- Endopeptidases, Plant Diseases microbiology, Plants, Virulence, Ascomycota, Brassica napus, Verticillium genetics
- Abstract
Verticillium is a genus of ascomycete fungi that encompasses several plant pathogenic species, and cause severe annual yield losses on many economically important crops worldwide. One of the most important species in this genus, is V. longisporum, which causes disease mainly on plants in the Brassicaceae family. Genome analysis of V. longisporum strain VL1 revealed a number of candidate effector genes that may be associated with fungal virulence. One of these candidate effector-genes encodes a putative endolysin-like protein. Endolysins are hydrolytic enzymes that are secreted by bacteriophages and recently, they have been identified in fungal genomes as well. In this study, the potential role of this gene has been investigated in V. longisporum. Our data showed that this gene was highly induced in the fungus during Brassica napus infection and its overexpression significantly increased V. longisporum virulence, indicating an involvement in the fungal infection process., Competing Interests: Declaration of competing interest The authors declare that they have no conflict of interest., (Copyright © 2022 The Authors. Published by Elsevier Inc. All rights reserved.)
- Published
- 2022
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28. Root Transcriptional and Metabolic Dynamics Induced by the Plant Growth Promoting Rhizobacterium (PGPR) Bacillus subtilis Mbi600 on Cucumber Plants.
- Author
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Samaras A, Kamou N, Tzelepis G, Karamanoli K, Menkissoglu-Spiroudi U, and Karaoglanidis GS
- Abstract
Bacillus subtilis MBI600 is a commercialized plant growth-promoting bacterial species used as a biocontrol agent in many crops, controlling various plant pathogens via direct or indirect mechanisms. In the present study, a detailed transcriptomic analysis of cucumber roots upon response to the Bs MBI600 strain is provided. Differentially expressed genes (DEGs) analysis showed altered gene expression in more than 1000 genes at 24 and 48 h post-application of Bs MBI600. Bs MBI600 induces genes involved in ISR and SAR signaling. In addition, genes involved in phytohormone production and nutrient availability showed an upregulation pattern, justifying the plant growth promotion. Biocontrol ability of Bs MBI600 seems also to be related to the activation of defense-related genes, such as peroxidase, endo-1,3(4)-beta-glucanase, PR-4, and thaumatin-like. Moreover, KEGG enriched results showed that differentially expressed genes were classified into biocontrol-related pathways. To further investigate the plant's response to the presence of PGPR, a profile of polar metabolites of cucumber treated with Bs MBI600 was performed and compared to that of untreated plants. The results of the current study gave insights into the mechanisms deployed by this biocontrol agent to promote plant resistance, helping to understand the molecular interactions in this system.
- Published
- 2022
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29. A Verticillium longisporum pleiotropic drug transporter determines tolerance to the plant host β-pinene monoterpene.
- Author
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Rafiei V, Ruffino A, Persson Hodén K, Tornkvist A, Mozuraitis R, Dubey M, and Tzelepis G
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- Ascomycota, Bicyclic Monoterpenes, Monoterpenes, Plant Diseases, Pharmaceutical Preparations, Verticillium
- Abstract
Terpenes constitute a major part of secondary metabolites secreted by plants in the rhizosphere. However, their specific functions in fungal-plant interactions have not been investigated thoroughly. In this study we investigated the role of monoterpenes in interactions between oilseed rape (Brassica napus) and the soilborne pathogen Verticillium longisporum. We identified seven monoterpenes produced by B. napus, and production of α-pinene, β-pinene, 3-carene, and camphene was significantly increased upon fungal infection. Among them, β-pinene was chosen for further analysis. Transcriptome analysis of V. longisporum on exposure to β-pinene resulted in identification of two highly expressed pleotropic drug transporters paralog genes named VlAbcG1a and VlAbcG1b. Overexpression of VlAbcG1a in Saccharomyces cerevisiae increased tolerance to β-pinene, while deletion of the VlAbcG1a homologous gene in Verticillium dahliae resulted in mutants with increased sensitivity to certain monoterpenes. Furthermore, the VlAbcG1a overexpression strain displayed an increased tolerance to β-pinene and increased virulence in tomato plants. Data from this study give new insights into the roles of terpenes in plant-fungal pathogen interactions and the mechanisms fungi deploy to cope with the toxicity of these secondary metabolites., (© 2021 The Authors. Molecular Plant Pathology published by British Society for Plant Pathology and John Wiley & Sons Ltd.)
- Published
- 2022
- Full Text
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30. Rhizoctonia solani Infection Assay of Young Sugar Beet and Arabidopsis plantlets.
- Author
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Dölfors F, Holmquist L, Tzelepis G, and Dixelius C
- Abstract
Rhizoctonia solani is a soil-borne fungus, which rarely produces any spores in culture. Hence, all inoculation procedures are based on mycelia, often as a coat on cereal kernels, placed in close vicinity to the plant to be infected. In this protocol, an inoculation method is described where the fungus is first allowed to infest a perlite-maize flour substrate for 10 days, followed by thorough soil mixing to generate uniform fungal distribution. Pre-grown seedlings are then replanted in the infested soil. Plant materials can be harvested, five (sugar beet) and ten days ( Arabidopsis ) post infection, followed by a rapid cleaning step ahead of any nucleic acid preparation. Commercial DNA or RNA extraction kits can be used or, if higher DNA yield is required, a CTAB extraction method. Our purpose was to develop a reliable and reproducible protocol to determine the infection levels in planta upon infection with R. solani . This protocol is less laborious compared to previous ones, improves the consistency of plant infection, reproducibility between experiments, and suits both a root crop and Arabidopsis . Graphic abstract: Plant infection Inoculation of R. solani Preparation of inoculumPCR analysis Overview of the R. solani infection procedure., Competing Interests: Competing interestsThe authors declare no conflict of interest., (Copyright © 2022 The Authors; exclusive licensee Bio-protocol LLC.)
- Published
- 2022
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31. The Role of Glycoside Hydrolases in Phytopathogenic Fungi and Oomycetes Virulence.
- Author
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Rafiei V, Vélëz H, and Tzelepis G
- Subjects
- Cell Wall chemistry, Cell Wall metabolism, Cell Wall microbiology, Plant Cells microbiology, Virulence, Fungi enzymology, Fungi pathogenicity, Glycoside Hydrolases physiology, Oomycetes enzymology, Oomycetes pathogenicity, Plant Diseases microbiology
- Abstract
Phytopathogenic fungi need to secrete different hydrolytic enzymes to break down complex polysaccharides in the plant cell wall in order to enter the host and develop the disease. Fungi produce various types of cell wall degrading enzymes (CWDEs) during infection. Most of the characterized CWDEs belong to glycoside hydrolases (GHs). These enzymes hydrolyze glycosidic bonds and have been identified in many fungal species sequenced to date. Many studies have shown that CWDEs belong to several GH families and play significant roles in the invasion and pathogenicity of fungi and oomycetes during infection on the plant host, but their mode of function in virulence is not yet fully understood. Moreover, some of the CWDEs that belong to different GH families act as pathogen-associated molecular patterns (PAMPs), which trigger plant immune responses. In this review, we summarize the most important GHs that have been described in eukaryotic phytopathogens and are involved in the establishment of a successful infection.
- Published
- 2021
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32. Insights into the multitrophic interactions between the biocontrol agent Bacillus subtilis MBI 600, the pathogen Botrytis cinerea and their plant host.
- Author
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Samaras A, Karaoglanidis GS, and Tzelepis G
- Subjects
- Biological Control Agents pharmacology, Botrytis growth & development, Botrytis physiology, Cucumis sativus genetics, Cucumis sativus immunology, Mycelium drug effects, Mycelium growth & development, Mycelium physiology, Plant Diseases genetics, Plant Diseases immunology, Plant Diseases microbiology, Plant Proteins genetics, Plant Proteins immunology, Bacillus subtilis physiology, Botrytis drug effects, Crop Protection methods, Cucumis sativus microbiology, Plant Diseases prevention & control
- Abstract
Botrytis cinerea is a plant pathogen causing the gray mold disease in a plethora of host plants. The control of the disease is based mostly on chemical pesticides, which are responsible for environmental pollution, while they also pose risks for human health. Furthermore, B. cinerea resistant isolates have been identified against many fungicide groups, making the control of this disease challenging. The application of biocontrol agents can be a possible solution, but requires deep understanding of the molecular mechanisms in order to be effective. In this study, we investigated the multitrophic interactions between the biocontrol agent Bacillus subtilis MBI 600, a new commercialized biopesticide, the pathogen B. cinerea and their plant host. Our analysis showed that this biocontrol agent reduced B. cinerea mycelial growth in vitro, and was able to suppress the disease incidence on cucumber plants. Moreover, treatment with B. subtilis led to induction of genes involved in plant immunity. RNA-seq analysis of B. cinerea transcriptome upon exposure to bacterial secretome, showed that genes coding for MFS and ABC transporters were highly induced. Deletion of the Bcmfs1 MFS transporter gene, using a CRISP/Cas9 editing method, affected its virulence and the tolerance of B. cinerea to bacterial secondary metabolites. These findings suggest that specific detoxification transporters are involved in these interactions, with crucial role in different aspects of B. cinerea physiology., (Copyright © 2021 The Author(s). Published by Elsevier GmbH.. All rights reserved.)
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- 2021
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33. Plant mitochondria and chloroplasts are targeted by the Rhizoctonia solani RsCRP1 effector.
- Author
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Tzelepis G, Dölfors F, Holmquist L, and Dixelius C
- Subjects
- Beta vulgaris metabolism, Beta vulgaris microbiology, Chloroplasts microbiology, Mitochondria microbiology, Plant Diseases genetics, Plant Immunity, Plant Leaves metabolism, Plant Leaves microbiology, Seedlings metabolism, Seedlings microbiology, Nicotiana metabolism, Nicotiana microbiology, Beta vulgaris growth & development, Chloroplasts metabolism, Mitochondria metabolism, Plant Diseases microbiology, Rhizoctonia pathogenicity, Seedlings growth & development, Virulence Factors metabolism
- Abstract
The fungal species Rhizoctonia solani belongs to the Basidiomycota division and is a ubiquitous soil-borne pathogen. It is the main agent of the damping-off disease in seedlings and causes the root and crown rot disease in sugar beets. Plant pathogens deploy small secreted proteins, called effectors, to manipulate plant immunity in order to infect the host. Here, a gene (RsCRP1) encoded a putative effector cysteine-rich protein was cloned, expressed in Cercospora beticola and used for virulence assays. The RsCRP1 gene was highly induced upon the early-infection stage of sugar beet seedlings and disease was promoted. Confocal microscopy demonstrated localization to the chloroplasts and mitochondria upon transient expression of RsCRP1 in leaves of Nicotiana benthamiana. Further, this effector was unable to induce necrosis or to suppress hypersensitive response induced by the Avr4/Cf4 complex in N. benthamiana. Overall, these data indicate that RsCRP1 is a novel effector targeting distinct plant cell organelles in order to facilitate a successful infection at the early stages of the disease development., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.)
- Published
- 2021
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34. The RsRlpA Effector Is a Protease Inhibitor Promoting Rhizoctonia solani Virulence through Suppression of the Hypersensitive Response.
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Charova SN, Dölfors F, Holmquist L, Moschou PN, Dixelius C, and Tzelepis G
- Subjects
- Beta vulgaris drug effects, Beta vulgaris growth & development, Beta vulgaris microbiology, Plant Diseases microbiology, Soil Microbiology, Beta vulgaris immunology, Lipoprotein(a) pharmacology, Plant Diseases immunology, Plant Proteins pharmacology, Protease Inhibitors pharmacology, Rhizoctonia physiology, Virulence
- Abstract
Rhizoctonia solani (Rs) is a soil-borne pathogen with a broad host range. This pathogen incites a wide range of disease symptoms. Knowledge regarding its infection process is fragmented, a typical feature for basidiomycetes. In this study, we aimed at identifying potential fungal effectors and their function. From a group of 11 predicted single gene effectors, a rare lipoprotein A (RsRlpA), from a strain attacking sugar beet was analyzed. The RsRlpA gene was highly induced upon early-stage infection of sugar beet seedlings, and heterologous expression in Cercospora beticola demonstrated involvement in virulence. It was also able to suppress the hypersensitive response (HR) induced by the Avr4/Cf4 complex in transgenic Nicotiana benthamiana plants and functioned as an active protease inhibitor able to suppress Reactive Oxygen Species (ROS) burst. This effector contains a double-psi beta-barrel (DPBB) fold domain, and a conserved serine at position 120 in the DPBB fold domain was found to be crucial for HR suppression. Overall, R. solani seems to be capable of inducing an initial biotrophic stage upon infection, suppressing basal immune responses, followed by a switch to necrotrophic growth. However, regulatory mechanisms between the different lifestyles are still unknown.
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- 2020
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35. Dominance of Mating Type A1 and Indication of Epigenetic Effects During Early Stages of Mating in Phytophthora infestans .
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Tzelepis G, Hodén KP, Fogelqvist J, Åsman AKM, Vetukuri RR, and Dixelius C
- Abstract
The potato late blight pathogen Phytophthora infestans has both an asexual and a sexual mode of reproduction. In Scandinavia, the pathogen is reproducing sexually on a regular basis, whereas clonal lineages dominate in other geographical regions. This study aimed at elucidating events or key genes underlying this difference in sexual behavior. First, the transcriptomes of eight strains, known as either clonal or sexual, were compared during early stages of mating. Principal component analysis (PCA) divided the samples in two clusters A and B and a clear grouping of the mating samples together with the A1 mating type parents was observed. Induction of genes encoding DNA adenine N6-methylation (6mA) methyl-transferases clearly showed a bias toward the cluster A. In contrast, the Avrblb2 effector gene family was highly induced in most of the mating samples and was associated with cluster B in the PCA, similarly to genes coding for acetyl-transferases, which play an important role in RXLR modification prior to secretion. Avrblb2 knock-down strains displayed a reduction in virulence and oospore formation, suggesting a role during the mating process. In conclusion, a number of gene candidates important for the reproductive processes were revealed. The results suggest a possible epigenetic influence and involvement of specific RXLR effectors in mating-related processes., (Copyright © 2020 Tzelepis, Hodén, Fogelqvist, Åsman, Vetukuri and Dixelius.)
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- 2020
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36. A LysM effector protein from the basidiomycete Rhizoctonia solani contributes to virulence through suppression of chitin-triggered immunity.
- Author
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Dölfors F, Holmquist L, Dixelius C, and Tzelepis G
- Subjects
- Gene Expression genetics, Genome, Fungal genetics, Hyphae genetics, Plant Diseases microbiology, Plants microbiology, Basidiomycota genetics, Chitin genetics, Fungal Proteins genetics, Rhizoctonia genetics, Virulence genetics
- Abstract
Rhizoctonia solani is a fungal species that belongs to the fungal division Basidiomycota. It is a soil-borne pathogen that attacks a broad range of plant species and crops. Disease symptoms are commonly seen as damping off of seedlings and root rot, although it can infect plants at any developmental stage. Despite the severity of this disease, many aspects in R. solani infection biology remain unclear. Here we investigated the role of a LysM effector, previously predicted from the genome of a R. solani AG2-2IIIB strain that has sugar beet as a host. Gene expression analysis showed that RsLysM was highly induced upon sugar beet infection. When RsLysM was heterologously expressed in Cercospora beticola, necrotic lesion size and fungal colonization ability were increased, indicating a role in virulence. RsLysM displayed chitin-binding affinity and suppression of chitin-triggered immunity but could not protect hyphae from hydrolysis. Overall, this study is the first characterization of a LysM effector from Basidiomycota, suggesting that this necrotrophic fungal species relies on perturbation of chitin-triggered immunity to establish a successful infection.
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- 2019
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37. The immunophilin repertoire of Plasmodiophora brassicae and functional analysis of PbCYP3 cyclophilin.
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Singh K, Tzelepis G, Zouhar M, Ryšánek P, and Dixelius C
- Subjects
- Amino Acid Sequence, Brassica classification, Brassica parasitology, Cyclophilins classification, Cyclophilins metabolism, Gene Expression Profiling methods, Gene Expression Regulation, Host-Pathogen Interactions, Immunophilins metabolism, Phylogeny, Plant Diseases parasitology, Plant Roots parasitology, Plasmodiophorida metabolism, Plasmodiophorida physiology, Protozoan Proteins metabolism, Sequence Homology, Amino Acid, Spores, Protozoan genetics, Cyclophilins genetics, Immunophilins genetics, Plasmodiophorida genetics, Protozoan Proteins genetics
- Abstract
Plasmodiophora brassicae is a soil-borne pathogen that belongs to Rhizaria, an almost unexplored eukaryotic organism group. This pathogen requires a living host for growth and multiplication, which makes molecular analysis further complicated. To broaden our understanding of a plasmodiophorid such as P. brassicae, we here chose to study immunophilins, a group of proteins known to have various cellular functions, including involvement in plant defense and pathogen virulence. Searches in the P. brassicae genome resulted in 20 putative immunophilins comprising of 11 cyclophilins (CYPs), 7 FK506-binding proteins (FKBPs) and 2 parvulin-like proteins. RNAseq data showed that immunophilins were differentially regulated in enriched life stages such as germinating spores, maturing spores, and plasmodia, and infected Brassica hosts (B. rapa, B. napus and B. oleracea). PbCYP3 was highly induced in all studied life stages and during infection of all three Brassica hosts, and hence was selected for further analysis. PbCYP3 was heterologously expressed in Magnaporthe oryzae gene-inactivated ΔCyp1 strain. The new strain ΔCyp1+ overexpressing PbCYP3 showed increased virulence on rice compared to the ΔCyp1 strain. These results suggest that the predicted immunophilins and particularly PbCYP3 are activated during plant infection. M. oryzae is a well-studied fungal pathogen and could be a valuable tool for future functional studies of P. brassicae genes, particularly elucidating their role during various infection phases.
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- 2018
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38. Analysis of the hybrid genomes of two field isolates of the soil-borne fungal species Verticillium longisporum.
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Fogelqvist J, Tzelepis G, Bejai S, Ilbäck J, Schwelm A, and Dixelius C
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- Carbohydrate Metabolism, Evolution, Molecular, Fungal Proteins genetics, Genes, Mating Type, Fungal, Phylogeny, Polymorphism, Single Nucleotide, Soil Microbiology, Verticillium classification, Verticillium enzymology, Verticillium isolation & purification, Genome, Fungal, Verticillium genetics
- Abstract
Background: Brassica plant species are attacked by a number of pathogens; among them, the ones with a soil-borne lifestyle have become increasingly important. Verticillium stem stripe caused by Verticillium longisporum is one example. This fungal species is thought to be of a hybrid origin, having a genome composed of combinations of lineages denominated A and D. In this study we report the draft genomes of 2 V. longisporum field isolates sequenced using the Illumina technology. Genomic characterization and lineage composition, followed by selected gene analysis to facilitate the comprehension of its genomic features and potential effector categories were performed., Results: The draft genomes of 2 Verticillium longisporum single spore isolates (VL1 and VL2) have an estimated ungapped size of about 70 Mb. The total number of protein encoding genes identified in VL1 was 20,793, whereas 21,072 gene models were predicted in VL2. The predicted genome size, gene contents, including the gene families coding for carbohydrate active enzymes were almost double the numbers found in V. dahliae and V. albo-atrum. Single nucleotide polymorphisms (SNPs) were frequently distributed in the two genomes but the distribution of heterozygosity and depth was not independent. Further analysis of potential parental lineages suggests that the V. longisporum genome is composed of two parts, A1 and D1, where A1 is more ancient than the parental lineage genome D1, the latter being more closer related to V. dahliae. Presence of the mating-type genes MAT1-1-1 and MAT1-2-1 in the V. longisporum genomes were confirmed. However, the MAT genes in V. dahliae, V. albo-atrum and V. longisporum have experienced extensive nucleotide changes at least partly explaining the present asexual nature of these fungal species., Conclusions: The established draft genome of V. longisporum is comparatively large compared to other studied ascomycete fungi. Consequently, high numbers of genes were predicted in the two V. longisporum genomes, among them many secreted proteins and carbohydrate active enzyme (CAZy) encoding genes. The genome is composed of two parts, where one lineage is more ancient than the part being more closely related to V. dahliae. Dissimilar mating-type sequences were identified indicating possible ancient hybridization events.
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- 2018
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39. Detection of Verticillium species in Swedish soils using real-time PCR.
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Tzelepis G, Bejai S, Sattar MN, Schwelm A, Ilbäck J, Fogelqvist J, and Dixelius C
- Subjects
- DNA Primers genetics, Plant Diseases microbiology, Real-Time Polymerase Chain Reaction, Soil chemistry, Soil Microbiology, Sweden, Verticillium classification, Brassicaceae microbiology, DNA, Fungal genetics, Verticillium genetics, Verticillium isolation & purification
- Abstract
Verticillium species are soilborne plant pathogens, responsible for big yield losses worldwide. Here, we report improved procedures to generate DNA from Verticillium species imbedded in farm soils. Using new genomic sequence information, primers for V. dahliae, V. albo-atrum, V. tricorpus, and V. longisporum were designed. In a survey of 429 samples from intensively farmed soil of two Swedish regions, only V. dahliae and V. longisporum were identified. A bias towards V. longisporum (40%) was seen in the south, whereas V. dahliae was more frequent in the western region (19%). Analyses of soil and leaf samples from 20 sugar beet fields, where foliar wilting had been observed, revealed V. dahliae DNA in all leaf and soil samples and V. longisporum in 18 soil samples, illustrating host choice and longevity of the V. longisporum microsclerotia. This study demonstrates the applicability of new molecular diagnostic tools that are important for growers of variable crops.
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- 2017
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40. Deglycosylating enzymes acting on N-glycans in fungi: Insights from a genome survey.
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Tzelepis G, Karlsson M, and Suzuki T
- Subjects
- Fungi chemistry, Mannosyl-Glycoprotein Endo-beta-N-Acetylglucosaminidase chemistry, Peptide-N4-(N-acetyl-beta-glucosaminyl) Asparagine Amidase chemistry, Peptide-N4-(N-acetyl-beta-glucosaminyl) Asparagine Amidase genetics, Polysaccharides chemistry, Protein Processing, Post-Translational genetics, Fungi enzymology, Genome, Fungal, Glycosylation, Polysaccharides metabolism
- Abstract
Background: N-Glycosylation, one of the most prominent post-translational modifications of proteins, is found in all domains of life, i.e. eukaryotes, bacteria and archaea, and has been shown to play a crucial role in modulating the physicochemical/physiological properties of carrier proteins. Deglycosylating enzymes that act on N-glycans are widely used in analyzing the structures/functions of N-glycans. Fungi are known to produce various deglycosylating enzymes, some of which are fungi-specific. While such enzymes likely are biologically relevant in fungal biology, their properties as well as their functions have not been explored in detail., Scope of Review: In this review, we summarize the current knowledge of fungal deglycosylating enzymes and discuss their biological significance., Major Conclusions: As of this writing, five types of deglycosylating enzymes that act on N-glycans are known to occur in fungi; (1) the cytosolic peptide: N-glycanase (PNGase), (2) the acidic PNGase, (3) the glycoside hydrolase family (GH) 85 endo-β-N-acetylglucosaminidase (ENGase), (4) the GH18 cytosolic ENGase, and (5) the GH18 secreted ENGase. Interestingly, genome surveys indicate that the loss of cytosolic PNGase activity in certain fungi coincide with the occurrence of GH18 cytosolic ENGase, implying that the GH18 ENGase serves to replace the deglycosylation function of the cytosolic PNGase in those filamentous ascomycete fungi., General Significance: Our review concludes that fungi promise to be valuable organisms for developing an understanding of the biological functions of PNGases/ENGases., (Copyright © 2017 Elsevier B.V. All rights reserved.)
- Published
- 2017
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41. Investigating the compatibility of the biocontrol agent Clonostachys rosea IK726 with prodigiosin-producing Serratia rubidaea S55 and phenazine-producing Pseudomonas chlororaphis ToZa7.
- Author
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Kamou NN, Dubey M, Tzelepis G, Menexes G, Papadakis EN, Karlsson M, Lagopodi AL, and Jensen DF
- Subjects
- ATP-Binding Cassette Transporters genetics, Gene Expression Regulation, Fungal, Hypocreales genetics, Solanum lycopersicum microbiology, Plant Diseases microbiology, Plant Roots microbiology, Pseudomonas genetics, Fusarium physiology, Hypocreales physiology, Microbial Interactions physiology, Plant Diseases prevention & control, Pseudomonas physiology, Serratia physiology
- Abstract
This study was carried out to assess the compatibility of the biocontrol fungus Clonostachys rosea IK726 with the phenazine-producing Pseudomonas chlororaphis ToZa7 or with the prodigiosin-producing Serratia rubidaea S55 against Fusarium oxysporum f. sp. radicis-lycopersici. The pathogen was inhibited by both strains in vitro, whereas C. rosea displayed high tolerance to S. rubidaea but not to P. chlororaphis. We hypothesized that this could be attributed to the ATP-binding cassette (ABC) proteins. The results of the reverse transcription quantitative PCR showed an induction of seven genes (abcB1, abcB20, abcB26, abcC12, abcC12, abcG8 and abcG25) from subfamilies B, C and G. In planta experiments showed a significant reduction in foot and root rot on tomato plants inoculated with C. rosea and P. chlororaphis. This study demonstrates the potential for combining different biocontrol agents and suggests an involvement of ABC transporters in secondary metabolite tolerance in C. rosea.
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- 2016
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42. Genome analysis of the sugar beet pathogen Rhizoctonia solani AG2-2IIIB revealed high numbers in secreted proteins and cell wall degrading enzymes.
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Wibberg D, Andersson L, Tzelepis G, Rupp O, Blom J, Jelonek L, Pühler A, Fogelqvist J, Varrelmann M, Schlüter A, and Dixelius C
- Subjects
- Chromosome Mapping, Comparative Genomic Hybridization, Plant Diseases microbiology, Rhizoctonia enzymology, Sequence Analysis, DNA, Beta vulgaris microbiology, Expressed Sequence Tags, Genome, Fungal, Rhizoctonia genetics
- Abstract
Background: Sugar beet (Beta vulgaris) is a crop cultivated for its high content in sugar, but it is vulnerable to many soil-borne pathogens. One of them is the basidiomycete Rhizoctonia solani. This fungal species has a compatibility system regulating hyphal fusions (anastomosis). Consequently, R. solani species are categorized in anastomosis groups (AGs). AG2-2IIIB isolates are most aggressive on sugar beet. In the present study, we report on the draft genome of R. solani AG2-2IIIB using the Illumina technology. Genome analysis, interpretation and comparative genomics of five sequenced R. solani isolates were carried out., Results: The draft genome of R. solani AG2-2IIIB has an estimated size of 56.02 Mb. In addition, two normalized EST libraries were sequenced. In total 20,790 of 21,980 AG2-2IIIB isotigs (transcript isoforms) were mapped on the genome with more than 95 % sequence identity. The genome of R. solani AG2-2IIIB was predicted to harbor 11,897 genes and 4908 were found to be isolate-specific. R. solani AG2-2IIIB was predicted to contain 1142 putatively secreted proteins and 473 of them were found to be unique for this isolate. The R. solani AG2-2IIIB genome encodes a high number of carbohydrate active enzymes. The highest numbers were observed for the polysaccharide lyases family 1 (PL-1), glycoside hydrolase family 43 (GH-43) and carbohydrate estarase family 12 (CE-12). Transcription analysis of selected genes representing different enzyme clades revealed a mixed pattern of up- and down-regulation six days after infection on sugar beets featuring variable levels of resistance compared to mycelia of the fungus grown in vitro., Conclusions: The established R. solani AG2-2IIIB genome and EST sequences provide important information on the gene content, gene structure and transcriptional activity for this sugar beet pathogen. The enriched genomic platform provides an important platform to enhance our understanding of R. solani biology.
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- 2016
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43. Identifying glycoside hydrolase family 18 genes in the mycoparasitic fungal species Clonostachys rosea.
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Tzelepis G, Dubey M, Jensen DF, and Karlsson M
- Subjects
- Botrytis growth & development, Chitin metabolism, Cluster Analysis, DNA, Fungal chemistry, DNA, Fungal genetics, Gene Deletion, Gene Expression Profiling, Genetic Variation, Glycoside Hydrolases classification, Hypocreales drug effects, Hypocreales growth & development, Microbial Interactions, Molecular Sequence Data, Phylogeny, Rhizoctonia growth & development, Sequence Analysis, DNA, Sequence Homology, Genome, Fungal, Glycoside Hydrolases genetics, Hypocreales enzymology, Hypocreales genetics
- Abstract
Clonostachysrosea is a mycoparasitic fungal species that is an efficient biocontrol agent against many plant diseases. During mycoparasitic interactions, one of the most crucial steps is the hydrolysis of the prey's fungal cell wall, which mainly consists of glucans, glycoproteins and chitin. Chitinases are hydrolytic enzymes responsible for chitin degradation and it is suggested that they play an important role in fungal-fungal interactions. Fungal chitinases belong exclusively to the glycoside hydrolase (GH) family 18.These GH18 proteins are categorized into three distinct phylogenetic groups (A, B and C), subdivided into several subgroups. In this study, we identified 14 GH18 genes in the C. rosea genome, which is remarkably low compared with the high numbers found in mycoparasitic Trichoderma species. Phylogenetic analysis revealed that C. rosea contains eight genes in group A, two genes in group B, two genes in group C, one gene encoding a putative ENGase (endo-β-N-acetylglucosaminidase) and the ech37 gene, which is of bacterial origin. Gene expression analysis showed that only two genes had higher transcription levels during fungal-fungal interactions, while eight out of 14 GH18 genes were triggered by chitin. Furthermore, deletion of the C group chiC2 gene decreased the growth inhibitory activity of C. rosea culture filtrates against Botrytis cinerea and Rhizoctonia solani, although the biocontrol ability of C. rosea against B. cinerea was not affected. In addition, a potential role of the CHIC2 chitinase in the sporulation process was revealed. These results provide new information about the role of GH18 proteins in mycoparasitic interactions.
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- 2015
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44. Endo-β-N-acetylglucosamidases (ENGases) in the fungus Trichoderma atroviride: possible involvement of the filamentous fungi-specific cytosolic ENGase in the ERAD process.
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Tzelepis G, Hosomi A, Hossain TJ, Hirayama H, Dubey M, Jensen DF, Suzuki T, and Karlsson M
- Subjects
- Acetylglucosaminidase genetics, Amino Acid Sequence, Cytosol metabolism, Fungal Proteins genetics, Genome, Fungal, Glycosylation, Molecular Sequence Data, Recombinant Proteins genetics, Recombinant Proteins metabolism, Saccharomyces cerevisiae genetics, Saccharomyces cerevisiae metabolism, Sequence Homology, Amino Acid, Trichoderma genetics, Acetylglucosaminidase metabolism, Endoplasmic Reticulum-Associated Degradation genetics, Fungal Proteins metabolism, Trichoderma metabolism
- Abstract
N-Glycosylation is an important post-translational modification of proteins, which mainly occurs in the endoplasmic reticulum (ER). Glycoproteins that are unable to fold properly are exported to the cytosol for degradation by a cellular system called ER-associated degradation (ERAD). Once misfolded glycoproteins are exported to the cytosol, they are subjected to deglycosylation by peptide:N-glycanase (PNGase) to facilitate the efficient degradation of misfolded proteins by the proteasome. Interestingly, the ortholog of PNGase in some filamentous fungi was found to be an inactive deglycosylating enzyme. On the other hand, it has been shown that in filamentous fungi genomes, usually two different fungi-specific endo-β-N-acetylglucosamidases (ENGases) can be found; one is predicted to be localized in the cytosol and the other to have a signal sequence, while the functional importance of these enzymes remains to be clarified. In this study the ENGases of the filamentous fungus Trichoderma atroviride was characterized. By heterologous expression of the ENGases Eng18A and Eng18B in Saccharomyces cerevisiae, it was found that both ENGases are active deglycosylating enzymes. Interestingly, only Eng18B was able to enhance the efficient degradation of the RTL protein, a PNGase-dependent ERAD substrate, implying the involvement of this enzyme in the ERAD process. These results indicate that T. atroviride Eng18B may deglycosylate misfolded glycoproteins, substituting the function of the cytoplasmic PNGase in the ERAD process., (Copyright © 2014 Elsevier Inc. All rights reserved.)
- Published
- 2014
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45. Coexistence and expression profiles of two alternative splice variants of the pheromone receptor gene pre‑1 in Neurospora crassa.
- Author
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Strandberg R, Tzelepis G, Johannesson H, and Karlsson M
- Subjects
- Exons, Introns, Neurospora crassa metabolism, Transcriptome, Ubiquitination, Alternative Splicing, Fungal Proteins genetics, Neurospora crassa genetics, Receptors, Pheromone genetics
- Abstract
In this study, we show that two splice variants of the pheromone receptor gene (pre-1) transcript coexist in vegetative and reproductive tissues of the filamentous ascomycete fungus Neurospora crassa. The two splice variants differ by intron retention of the last intron, which is predicted to result in a premature stop codon and loss of 322 amino acids in the C-terminal cytosolic region of PRE-1. Using quantitative PCR, we show that expression of the variants is influenced by mating type (mat), with a higher proportion of intron-spliced transcripts in a mat A strain and a higher proportion of the intron-retained variant in a mat a strain. The intron-retained PRE-1 variant is predicted to lack 6 ubiquitination sites that may influence receptor function. In conclusion, N. crassa produce two pre-1 splice variants that display different transcription profiles.
- Published
- 2013
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46. IL-28A (IFN-λ2) modulates lung DC function to promote Th1 immune skewing and suppress allergic airway disease.
- Author
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Koltsida O, Hausding M, Stavropoulos A, Koch S, Tzelepis G, Ubel C, Kotenko SV, Sideras P, Lehr HA, Tepe M, Klucher KM, Doyle SE, Neurath MF, Finotto S, and Andreakos E
- Subjects
- Animals, Asthma pathology, Asthma therapy, CD11c Antigen metabolism, Cytokines genetics, Down-Regulation, Lung cytology, Lung immunology, Mice, OX40 Ligand metabolism, Recombinant Proteins genetics, Recombinant Proteins metabolism, Recombinant Proteins pharmacology, Th1 Cells cytology, Th1 Cells metabolism, Th17 Cells immunology, Th17 Cells metabolism, Th2 Cells immunology, Th2 Cells metabolism, Asthma immunology, Cytokines metabolism, Dendritic Cells immunology, Th1 Cells immunology
- Abstract
IL-28 (IFN-λ) cytokines exhibit potent antiviral and antitumor function but their full spectrum of activities remains largely unknown. Recently, IL-28 cytokine family members were found to be profoundly down-regulated in allergic asthma. We now reveal a novel role of IL-28 cytokines in inducing type 1 immunity and protection from allergic airway disease. Treatment of wild-type mice with recombinant or adenovirally expressed IL-28A ameliorated allergic airway disease, suppressed Th2 and Th17 responses and induced IFN-γ. Moreover, abrogation of endogenous IL-28 cytokine function in IL-28Rα(-/-) mice exacerbated allergic airway inflammation by augmenting Th2 and Th17 responses, and IgE levels. Central to IL-28A immunoregulatory activity was its capacity to modulate lung CD11c(+) dendritic cell (DC) function to down-regulate OX40L, up-regulate IL-12p70 and promote Th1 differentiation. Consistently, IL-28A-mediated protection was absent in IFN-γ(-/-) mice or after IL-12 neutralization and could be adoptively transferred by IL-28A-treated CD11c(+) cells. These data demonstrate a critical role of IL-28 cytokines in controlling T cell responses in vivo through the modulation of lung CD11c(+) DC function in experimental allergic asthma., (Copyright © 2011 EMBO Molecular Medicine.)
- Published
- 2011
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47. Prevalence and outcome of pulmonary fibrosis in microscopic polyangiitis.
- Author
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Tzelepis GE, Kokosi M, Tzioufas A, Toya SP, Boki KA, Zormpala A, and Moutsopoulos HM
- Subjects
- Antibodies, Antineutrophil Cytoplasmic analysis, Female, Follow-Up Studies, Glomerulonephritis diagnosis, Glomerulonephritis mortality, Hemoptysis diagnosis, Humans, Male, Microscopic Polyangiitis diagnosis, Microscopic Polyangiitis mortality, Middle Aged, Prevalence, Prognosis, Pulmonary Fibrosis diagnostic imaging, Pulmonary Fibrosis mortality, Radiography, Treatment Outcome, Microscopic Polyangiitis epidemiology, Pulmonary Fibrosis epidemiology
- Abstract
We sought to determine the type of pulmonary involvement in microscopic polyangiitis (MPA), primarily focusing on pulmonary fibrosis (PF), its prevalence, temporal relationship with other disease manifestations and outcome. 33 patients (16 males) with biopsy proven perinuclear anti-neutrophilic cytoplasmic antibody-positive MPA (age 63.5 yrs) participated in the study. Pulmonary involvement was assessed using standard methods, including radiographic imaging (chest radiographs and high-resolution computed tomography), pulmonary function testing, bronchoscopy and bronchoalveolar lavage, and, if indicated, lung biopsy. All-cause mortality was analysed by the Kaplan-Meier method and was compared between MPA patients with and without PF. At the time of diagnosis, renal involvement was detected in all patients, with renal biopsies being consistent with segmental necrotising glomerulonephritis in all patients. The most common respiratory symptom was haemoptysis, which was found in nine (27%) patients. PF was present in 12 (36%) patients at the time of diagnosis, whereas one patient developed PF while on therapy approximately 10 yrs after disease diagnosis. In seven patients with PF, respiratory symptoms related to fibrosis preceded other disease manifestations by a median (range) period of 13 (5-120) months. Patients were followed up for a period of 38+/-30 months. Presence of PF was associated with increased mortality (p = 0.02), with six deaths occurring in the fibrotic group and one in the nonfibrotic group. In the fibrotic group most deaths were related to PF. PF occurs frequently in MPA, may precede other disease manifestations by a variable length of time and has a poor prognosis.
- Published
- 2010
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48. First Report of Penicillium glabrum Causing Fruit Rot of Pomegranate (Punica granatum) in Greece.
- Author
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Bardas GA, Tzelepis GD, Lotos L, and Karaoglanidis GS
- Abstract
During September and October of 2008 in the region of Larisa (central Greece), postharvest fruit rot was observed on pomegranate (cv. Kapmaditika), which is rapidly increasing in production in Greece, causing losses of 10 to 20% after 2 months of cold storage (5 to 6°C). Infected fruits showed green conidiophores in the calyx area, while internal symptoms consisted of soft, brown tissue that became covered with green mycelium and conidiophores. To isolate the casual agent, conidia and conidiophores were scraped aseptically from the internal fruit rot, suspended in sterile water, and streaked onto potato dextrose agar (PDA). Single hyphal tips were then transferred to new PDA plates. A fungus consistently isolated from the infected tissues was identified as Penicillium glabrum (Wehmer) Westling on the basis of morphological criteria, with conidiophores smooth or finely roughened and conidia in compact columns, glubose to subglubose, approximately 3.0 μm, with walls somewhat echinulate (1). The identification was confirmed by sequencing the internal transcribed spacer (ITS) region spanning ITS1, 5.8S, and ITS2 of the ribosomal DNA (2). The nucleotide sequence was submitted to GenBank (Accession No. FN313540). The pathogenicity of the isolated fungus was tested on five mature pomegranate fruit (cv. Kampaditika) after being surface sterilized with 5% sodium hypochlorite. A plug (5 mm in diameter) obtained from the margins of a P. glabrum colony was transferred to wounds (3 × 3 mm) made with a scalpel in the surface of fruit. Fruit inoculated with sterile PDA plugs served as controls. Fruit were incubated at 22°C and 80% relative humidity in the dark. Extensive decay, similar to that observed on diseased fruit in the field, was observed on the inoculated fruit 7 days after inoculation, whereas control fruit showed no decay. The pathogen was reisolated from inoculated fruit but not from the noninoculated fruit. To our knowledge, this is the first report of P. glabrum causing postharvest fruit rot of pomegranates in Greece. References: (1) C. Thom and K. B. Raper. Page 176 in: A Manual of the Penicillia. Williams and Wilkins, Baltimore, 1949. (2) T. J. White et al. Page 315 in: PCR Protocols: A Guide to Methods and Applications. Academic Press, San Diego, 1990.
- Published
- 2009
- Full Text
- View/download PDF
49. First Report of Botrytis cinerea Causing Gray Mold of Pomegranate (Punica granatum) in Greece.
- Author
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Bardas GA, Tzelepis GD, Lotos L, and Karaoglanidis GS
- Abstract
Pomegranate is rapidly increasing in production in Greece. During August of 2008 in the region of Larisa (central Greece), preharvest fruit rot was observed on pomegranate (cv. Kapmaditika) that caused losses estimated at 10%. Symptoms first appeared as small spots on the fruits that later increased in size and developed into expanded, dark brown lesions. Internally, tissues were soft and brown with gray mycelia and conidiophores observed. Affected fruits decayed completely during 2 months of storage (5 to 6°C), causing yield losses of up to 20%. To isolate the casual agent, conidia and conidiophores were scraped aseptically from the internal tissues, suspended in sterile water, and streaked onto the surface of potato dextrose agar (PDA). Single hyphal tips were transferred to PDA, and the isolated fungus was identified as Botrytis cinerea Pers.:Fr. on the basis of morphological characteristics (2). B. cinerea was consistently isolated from symptomatic tissues. Colonies of B. cinerea on PDA were at first colorless and became gray to brown with the development of lemon-shaped conidia (average 7.5 × 9 μm). Sclerotia were black and varied in size (1.4 to 4.5 × 1.5 to 2.7 mm) and shape (2). Pathogenicity of the isolated fungus was tested by wound inoculating five mature pomegranate fruits (cv. Kampaditika) after surface sterilization with 5% sodium hypochlorite. Plugs of the fungus (5 mm in diameter) obtained from the colony margins were transferred onto a 3- × 3-mm wound on the surface of sterilized fruit. Sterile PDA plugs were used to inoculate five control pomegranate fruits. Fruit were incubated at 22°C and 80% relative humidity in the dark. Extensive decay, similar to that observed on diseased fruits in the field, was observed on inoculated fruits 7 days after inoculation, whereas control fruits showed no decay. The pathogen was reisolated from internal rotten tissues of inoculated fruit, but not from the noninoculated control fruits. Fruit rot of pomegranate caused by B. cinerea has been reported previously in the United States (1) and China (3). However, to our knowledge, this is the first report of B. cinerea causing gray mold of pomegranate in Greece. References: (1) A. M. French. California Plant Disease Host Index. Calif. Dept. Food Agric., Sacramento, 1989. (2) W. B. Hewitt. Compendium of Grape Diseases. American Phytopathological Society, 1994. (3) Z. Zhang. Flora Fungorum Sinicorum 26:277, 2006.
- Published
- 2009
- Full Text
- View/download PDF
50. Occult connective tissue diseases mimicking idiopathic interstitial pneumonias.
- Author
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Tzelepis GE, Toya SP, and Moutsopoulos HM
- Subjects
- Autoantibodies chemistry, Biopsy, Chemistry, Clinical, Diagnosis, Differential, Humans, Lung pathology, Lupus Erythematosus, Systemic diagnosis, Models, Biological, Physical Examination, Connective Tissue Diseases diagnosis, Lung Diseases, Interstitial diagnosis, Pneumonia diagnosis, Pulmonary Fibrosis diagnosis, Pulmonary Medicine methods
- Abstract
In patients with interstitial lung disease (ILD), the diagnosis of idiopathic interstitial pneumonia is usually made after excluding, among other conditions, connective tissue diseases (CTDs). Although in most patients with a CTD and respiratory symptoms, the systemic nature of the disease is obvious, the ILD-related manifestations in CTDs may often dominate the clinical picture or precede systemic findings and thus mimic idiopathic interstitial pneumonia. With the exception of systemic lupus erythematosus, all CTDs may imitate chronic idiopathic interstitial pneumonias. In this setting, clues to an underlying CTD may be entirely absent or include subtle findings from various systems, including skin, vascular and musculoskeletal system or internal organs. Since nonspecific interstitial pneumonia is a relatively frequent histological pattern in CTDs, biopsy reports of nonspecific interstitial pneumonia should also prompt a search for an underlying CTD. Ultimately, diagnosis of a CTD requires confirmation with immunological testing; interpretation of the various laboratory tests should always be carried out in conjunction with clinical findings. The present article reviews specific clinical aspects of connective tissue disease-related interstitial lung disease that may help differentiate it from idiopathic interstitial pneumonia, especially when interstitial lung disease is the predominant or sole manifestation of an occult connective tissue disease.
- Published
- 2008
- Full Text
- View/download PDF
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