67 research outputs found
Barrage formation is independent from heterokaryon incompatibility in Verticillium dahliae
Barrage formation has been traditionally used for the assessment of mycelial compatibility in many fungi and has often been assumed to represent a non-self recognition phenotype that is directly associated with vegetative incompatibility in these organisms. In this work, the optimal growth conditions for large-scale studies of barrage formation in the asexual fungus Verticillium dahliae were determined, and they were used for the analysis of a diverse collection comprising 69 isolates of V. dahliae and related species. Barrage formation was very frequent on a defined complete agar medium within V. dahliae and between species of the genus. However, it was not correlated with the classification of V. dahliae isolates into Vegetative Compatibility Groups (VCGs) (based on the standard method using complementary nit mutants), as it was recorded at high frequencies both within and between V. dahliae VCGs. The high overall frequency of barrage formation demonstrated the presence of a higher level of mycelial incompatibility in V. dahliae than heterokaryon incompatibility assessed by forcing complementary nit mutants to form heterokaryons under selective conditions. The possible association of barrage formation with morphological characteristics of the fungal colonies was investigated, and a negative correlation of frequency and intensity of barrages with the isolates’ capacity for pigment production was detected. Real-time quantitative PCR VCG discriminatio
High-Throughput Assessment and Genetic Investigation of Vegetative Compatibility in Verticillium dahliae
Classification of isolates into vegetative compatibility groups (VCGs) using nitrate-non-utilizing (nit) mutants has been widely used for the characterization of Verticillium dahliae populations. However, certain methodological limitations prevent its application on a large scale. Furthermore, systematic investigations into the genetics underlying complementation tests between nit mutants of fungal isolates (i.e. heterokaryon formation) are lacking for Verticillium species. In this work, a diverse collection of 27 V. dahliae isolates – including representatives of all VCGs, both mating types, and heterokaryon self-incompatible isolates – was employed for the development and optimization of (i) a protocol for the rapid generation of nit mutants of V. dahliae isolates using UV-irradiation and (ii) a reproducible high-throughput procedure for complementation tests between nit mutants in liquid cultures using 96-well microplates. The genetic analysis of selected heterokaryons demonstrated that the frequently encountered ‘weak’ cross-reactions between VCGs and their subgroups can be actually heterokaryotic, implying the absence of strict genetic barriers between VCGs. In conclusion, we provide in this work an optimized method for the high-throughput VCG assignment of V. dahliae populations and a genetic analysis of heterokaryons that may have serious implications for the interpretation of VCG classification data. These advancements in the available methodology and the genetic background of vegetative compatibility grouping may contribute to a better understanding of the population biology of V. dahliae and possibly other mitosporic fun
‘‘Cryptic’’ group-I introns in the nuclear SSU-rRNA gene of Verticillium dahliae
Group-I introns are widespread—though irregularly distributed—in eukaryotic organisms, and they have been extensively used for discrimination and phylogenetic analyses. Within the Verticillium genus, which comprises important phytopathogenic fungi, a group-I intron was previously identified in the SSU-rRNA (18S) gene of only V. longisporum. In this work, we aimed at elucidating the SSU-located intron distribution in V. dahliae and other Verticillium species, and the assessment of heterogeneity regarding intron content among rDNA repeats of fungal strains. Using conserved PCR primers for the amplification of the SSU gene, a structurally similar novel intron (sub-group IC1) was detected in only a few V. dahliae isolates. However, when intron-specific primers were used for the screening of a diverse collection of Verticillium isolates that originally failed to produce intron-containing SSU amplicons, most were found to contain one or both intron types, at variable rDNA repeat numbers. This marked heterogeneity was confirmed with qRT-PCR by testing rDNA copy numbers (varying from 39 to 70 copies per haploid genome) and intron copy ratios in selected isolates. Our results demonstrate that (a) IC1 group-I introns are not specific to V. longisporum within the Verticillium genus, (b) V. dahliae isolates of vegetative compatibility groups (VCGs) 4A and 6, which bear the novel intron at most of their rDNA repeats, are closely related, and (c) there is considerable intra-genomic heterogeneity for the presence or absence of introns among the ribosomal repeats. These findings underline that distributions of introns in the highly heterogeneous repetitive rDNA complex should always be verified with sensitive methods to avoid misleading conclusions for the phylogeny of fungi and other organisms
Structural and phylogenetic analysis of the rDNA intergenic spacer region of Verticillium dahliae
The nuclear ribosomal intergenic spacer (IGS) region was structurally analyzed and exploited for molecular discrimination and phylogenetic analysis of vegetative compatibility groups (VCGs) of Verticillium dahliae. A structural study of 201 available IGS sequences of the fungus was performed, and four classes of ubiquitous repetitive elements, organized in higher-order repetitive structures or composite blocks, were detected in a variable IGS subregion. This subregion was amplified from an international collection of 59 V. dahliae isolates covering all VCGs, together with nine representative V. albo-atrum and V. longisporum isolates, and sequenced. Structural and phylogenetic analyses of the sequences of this polymorphic IGS subregion were consistently informative and allowed the identification of two main lineages in V. dahliae, that is, clade I including VCGs 1A, 1B, 2A, 4B, and 3 and clade II containing VCGs 2B, 4A, and 6. Analysis of IGS sequences proved a highly suitable molecular tool for (a) rapid interspecific differentiation, (b) intraspecific discrimination among VCGs of V. dahliae, facilitating high-throughput VCG confirmation and prediction/profiling, and (c) phylogenetic analysis within and among V. dahliae VCGs
Unilateral hypertransparency on chest radiograph: the congenital Poland Syndrome
Unilateral hypertransparent hemithorax requires a particular diagnostic approach as it can be the result of diverse pulmonary diseases, including pneumothorax, large pulmonary embolus, unilateral large bullae, mucous plag, airway obstruction and contralateral pleural effusion. Congenital syndromes with chest wall abnormalities, are rare, but often underdiagnosed causes. Poland Syndrome consists of such a rare, congenital anomaly and is characterized by the absence of the pectoralis major muscle and upper limb ipsilateral abnormalities. We present a case of a patient with acute exacerbation of chronic obstructive pulmonary disease (COPD) and a unilateral hypertransparency on chest radiology, attributed to the underlying Poland Syndrome.
Jednostronnie jasne płuco na radiogramie klatki piersiowej — wrodzony zespół Polanda
Zwiększenie przejrzystości jednego płuca wymaga wdrożenia szczególnych procedur diagnostycznych, ponieważ przyczyną takiego stanu może być wiele różnorodnych chorób układu oddechowego, włączając odmę opłucnową, masywny zator płucny, duży jednostronny pęcherz rozedmowy, czop śluzowy, zamknięcie dużego oskrzela oraz płyn w przeciwległej jamie opłucnowej. Wrodzone zaburzenia budowy ściany klatki piersiowej należą do rzadkich, choć często niezdiagnozowanych przyczyn. Zespół Polanda należy do takich rzadkich wrodzonych anomalii i polega na niewykształceniu mięśnia piersiowego większego i nieprawidłowościach budowy kończyny górnej po tej samej stronie. W pracy przedstawiono przypadek chorego z zaostrzeniem przewlekłej obturacyjnej choroby płuc (POChP) i obrazem jednostronnie jasnego płuca na radiogramie klatki piersiowej, spowodowanym zespołem Polanda.Zwiększenie przejrzystości jednego płuca wymaga wdrożenia szczególnych procedur diagnostycznych, ponieważ przyczyną takiego stanu może być wiele różnorodnych chorób układu oddechowego, włączając odmę opłucnową, masywny zator płucny, duży jednostronny pęcherz rozedmowy, czop śluzowy, zamknięcie dużego oskrzela oraz płyn w przeciwległej jamie opłucnowej. Wrodzone zaburzenia budowy ściany klatki piersiowej należą do rzadkich, choć często niezdiagnozowanych przyczyn. Zespół Polanda należy do takich rzadkich wrodzonych anomalii i polega na niewykształceniu mięśnia piersiowego większego i nieprawidłowościach budowy kończyny górnej po tej samej stronie. W pracy przedstawiono przypadek chorego z zaostrzeniem przewlekłej obturacyjnej choroby płuc (POChP) i obrazem jednostronnie jasnego płuca na radiogramie klatki piersiowej, spowodowanym zespołem Polanda
Sequential treatment with teriparatide and strontium ranelate in a postmenopausal woman with atypical femoral fractures after long-term bisphosphonate administration
AbstrAct ObJEctIVE: Despite the existence of numerous case series, no evidenced-based medical management for atypical fractures associated with bisphosphonate (bP) treatment has been established. DEsIGN: We report the outcome of teriparatide (trP) administration followed by strontium ranelate (sr) in a woman with a complete and an incomplete contralateral atypical fracture of the femoral diaphysis (AFF) associated with bP treatment. the spontaneous complete AFF was managed with intramedullary nailing, discontinuation of bP and initiation trP. rEsULts: Eleven months later, she suffered a contralateral incomplete AFF. At the completion of the trP treatment, she had only slight discomfort in the femur with the incomplete AFF. bMD testing revealed increase of 7.61% at the lumbar spine (Ls) and 0.8% at the hip. Following trP, 1-year sr treatment resulted in further bMD increase of 9.2% at the Ls and 1.4% in the hip, while she does not report any pain. bone markers remain within the normal range. cONcLUsION: Our case indicates that sequential therapy with trP and sr in cases of AFF might be a rational treatment option. However, there is a need for additional information concerning the effect of trP and sr, given alone or sequentially, in these patients in order to incorporate these drugs into the management of AFF
A fatal case of recurrent amiodarone-induced thyrotoxicosis after percutaneous tracheotomy: a case report
<p>Abstract</p> <p>Background</p> <p>Amiodarone is a widely used antiarrythmic drug, which may produce secondary effects on the thyroid. In 14–18% of amiodarone-treated patients, there is overt thyroid dysfunction, usually in the form of amiodarone-induced thyrotoxicosis, which can be difficult to manage with standard medical treatment.</p> <p>Case presentation</p> <p>Presented is the case of a 65-year-old man, under chronic treatment of atrial fibrillation with amiodarone, who was admitted to the Intensive Care Unit with acute cardio-respiratory failure and fever. He was recently hospitalized with respiratory distress, attributed to amiodarone-induced pulmonary fibrosis. Clinical and laboratory investigation revealed thyrotoxicosis due to amiodarone treatment. He was begun on thionamide, prednisone and beta-blockers. After a short term improvement of his clinical status the patient underwent percutaneous tracheotomy due to weaning failure from mechanical ventilation, which led to the development of recurrent thyrotoxicosis, unresponsive to medical treatment. Finally, the patient developed multiple organ failure and died, seven days later.</p> <p>Conclusion</p> <p>We suggest that percutaneous tracheotomy could precipitate a thyrotoxic crisis, particularly in non-euthyroid patients suffering from concurrent severe illness and should be performed only in parallel with emergency thyroid surgery, when indicated.</p
Relation of tricuspid annular displacement and tissue Doppler imaging velocities with duration of weaning in mechanically ventilated patients with acute pulmonary edema
<p>Abstract</p> <p>Background</p> <p>Liberation from the ventilator is a difficult task, whereas early echocardiographic indices of weaning readiness are still lacking. The aim of this study was to test whether tricuspid annular plane systolic excursion (TAPSE) and right ventricular (RV) systolic (Sm) and diastolic (Em & Am) tissue Doppler imaging (TDI) velocities are related with duration of weaning in mechanically ventilated patients with acute respiratory failure due to acute pulmonary edema (APE).</p> <p>Methods</p> <p>Detailed quantification of left and right ventricular systolic and diastolic function was performed at admission to the Intensive Care Unit by Doppler echocardiography, in a cohort of 32 mechanically ventilated patients with APE. TAPSE and RV TDI velocities were compared between patients with and without prolonged weaning (≥ or < 7 days from the first weaning trial respectively), whereas their association with duration of ventilation and left ventricular (LV) echo-derived indices was tested with multivariate linear and logistic regression analysis.</p> <p>Results</p> <p>Patients with prolonged weaning (n = 12) had decreased TAPSE (14.59 ± 1.56 vs 19.13 ± 2.59 mm), Sm (8.68 ± 0.94 vs 11.62 ± 1.77 cm/sec) and Em/Am ratio (0.98 ± 0.80 vs 2.62 ± 0.67, p <0.001 for all comparisons) and increased Ε/e' (11.31 ± 1.02 vs 8.98 ± 1.70, p <0.001) compared with subjects without prolonged weaning (n = 20). Logistic regression analysis revealed that TAPSE (R<sup>2 </sup>= 0.53, beta slope = 0.76, p < 0.001), Sm (R<sup>2 </sup>= 0.52, beta = 0.75, p < 0.001) and Em/Am (R<sup>2 </sup>= 0.57, beta = 0.32, p < 0.001) can predict length of weaning ≥ 7 days. The above measures were also proven to correlate significantly with Ε/e' (r = -0.83 for TAPSE, r = -0.87 for Sm and r = -0.79 for Em/Am, p < 0.001 for all comparisons).</p> <p>Conclusions</p> <p>We suggest that in mechanically ventilated patients with APE, low TAPSE and RV TDI velocities upon admission are associated with delayed liberation from mechanical ventilation, probably due to more severe LV heart failure.</p
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