21 results on '"Żak P"'
Search Results
2. Traumatic Neuroma of the Hard Palate Mimicking a Small Salivary Gland Tumor—A Case Report
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Kamil Nelke, Maciej Janeczek, Edyta Pasicka, Krzysztof Żak, Marceli Łukaszewski, Jan Nienartowicz, Grzegorz Gogolewski, Irma Maag, Piotr Kuropka, and Maciej Dobrzyński
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hard palate ,traumatic neuroma ,minor salivary glands ,case report ,cyst ,tumors ,Biology (General) ,QH301-705.5 - Abstract
In the case of any pathologies arising in the hard palate, it is always important to exclude their possible odontogenic origins. Cone-beam computed tomography is mandatory. In cases where a possible non-teeth-related pathology is confirmed, each clinician should remember possible differential diagnostics. Many small salivary glands between the mucosa and bone are present in this palatal area. Both benign and malignant tumors arising from the small glands, and mucosa of the hard palate, might occur. The case presented here mimics a solid tumor because of the nodule consistency. Because of a healthy palatal mucosa without any erosions or irritations with firm attachment to the submucosal nodule, a possible malignant tumor of small salivary gland origins was suspected in this case. When the tumor diameter is small, an excisional biopsy is required to collect good and representative material for further histopathological evaluation. In most cases, bulky nodules present on the palate are hard on palpation, non-movable, and covered with healthy mucosa. Possible bone infiltrations with mucous membrane ulcerations could manifest a more expansive character of the lesion. In the presented case, an unusual occurrence of a traumatic neuroma without any past traumatic etiology of the palate was first differentiated from the occurrence of adenoid-cystic carcinoma (ACC), pleomorphic adenoma, other benign/malignant small gland tumors, or atypical, fibroma/schwannoma of the palate. This paper presents treatment options for this rare oral neural tumor occurrence in the palate and differential diagnosis between hard palate tumors in a 42-year-old male patient, furthermore highlighting the role of an excisional biopsy as a good source for a tissue sample.
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- 2024
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3. The Impact of the IL-10 Gene Polymorphism on mRNA Expression and IL-10 Serum Concentration in Polish Lupus Patients
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Agnieszka Żak-Gołąb, Paweł Cieślik, Urszula Siekiera, Dariusz Kuśmierz, Antoni Hrycek, and Michał Holecki
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IL-10 polymorphism ,mRNA expression ,IL-10 ,systemic lupus erythematosus ,Biology (General) ,QH301-705.5 ,Chemistry ,QD1-999 - Abstract
Systemic lupus erythematosus (SLE) is a complex autoimmune disease characterized by the production of autoantibodies against a lot of nuclear components. Despite many studies on the genetic background of this disease, the pathogenesis remains unclear. The aim of the study is to comprehensively evaluate the polymorphism of the IL-10 promoter gene, its mRNA expression, and the serum IL-10 concentration of SLE female patients and females age-matched controls. Analyzing the association between the level of the tested cytokine and the polymorphism genotype-1082; -819; -592, we found statistically higher serum IL-10 levels in SLE patients compared to in healthy controls (11.9 ± 2.2 pg/mL vs. 9.4 ± 1.7 pg/mL, accordingly; p < 0.0001). We did not find statistically significant differences in the gene polymorphism of IL-10 among SLE patients and controls. The most significant observation derived from our study is that IL-10 mRNA transcripts are upregulated in SLE patients compared to in healthy controls (p < 0.0001). According to our results, the presence of the IL-10 genetic polymorphism has no clinical significance for the development of SLE, and subsequent differences in mRNA and IL-10 concentration results from the influence of other factors which should be the subject of further research.
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- 2024
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4. The Occurrence of a Rare Mandibular Retromolar Triangle Schwannoma and Its Differentiation from Other Rare and Atypical Oral Cavity Tumours
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Kamil Nelke, Maciej Janeczek, Edyta Pasicka, Krzysztof Żak, Szczepan Barnaś, Jan Nienartowicz, Grzegorz Gogolewski, Irma Maag, and Maciej Dobrzyński
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mandible ,schwannoma ,salivary gland ,pleomorphic adenoma ,neurilemoma ,Technology ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Biology (General) ,QH301-705.5 ,Physics ,QC1-999 ,Chemistry ,QD1-999 - Abstract
Cone-beam computed tomography (CBCT) remains the diagnostic modality of choice. The involvement of the cortical bone and adjacent teeth can be easily established via CBCT. Magnetic resonance can be helpful in the estimation of any other soft-tissue tumour spread within this anatomical area. The soft, hard-tissue, or mixed aetiology of tumours requires a differential diagnosis and accurate evaluation. If such pathologies arise, an adequate biopsy or incisional biopsy is essential to evaluate the type of tumour histopathologically. The occurrence of some neural tumours in the oral cavity is rare. Schwannomas (SCs), like some neuromas and other types of neural tumours, are rare and atypical. During clinical examination, a smooth, sponge-like, elastic mass could indicate other small salivary gland tumours rather than an oral neural tumour. Such pathologies of neural origins are quite rare and are uncommon findings in the oral cavity; therefore, their appearance may be conflated with other more typical benign or malignant tumours in the oral cavity. Establishing the status of bone via CBCT, the tooth involvement and the composition of the cortical bone may be helpful for establishing the best treatment of choice. The presented case report describes a rare schwannoma localised at the mandibular retromolar trigone.
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- 2024
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5. Modelling Crystalline α-Mg Phase Growth in an Amorphous Alloy Mg72Zn28
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Bartosz Opitek, Paweł L. Żak, Janusz Lelito, and Vincent Vignal
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amorphous structure ,crystallisation ,Mg72Zn28 alloy ,numerical methods ,metallic glass ,Technology ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Biology (General) ,QH301-705.5 ,Physics ,QC1-999 ,Chemistry ,QD1-999 - Abstract
A model of α-Mg grain growth in an amorphous Mg72Zn28 alloy matrix was developed together with numerical software. Its application enables tracking the growth process of the α-Mg phase in an amorphous alloy. The model was based on the diffusion-driven growth of α-Mg in an amorphous alloy under appropriate boundary conditions at an isothermal annealing temperature and taking into account the presence of a grain with an initial radius of 1 nm. The numerical model was based on a mathematical model of heat flow, described by the Fourier–Kirchhoff equation, and diffusion, described by Fick’s second law. The initial boundary conditions necessary to simulate grain growth in the amorphous phase were established. The results of the numerical simulation indicate grain growth with increasing isothermal annealing temperature and increasing isothermal annealing time.
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- 2024
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6. Regulation of otic neurosensory specification by Notch and Wnt signalling: insights from RNA-seq screenings in the embryonic chicken inner ear
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Magdalena Żak, Thea P. Støle, Vincent Plagnol, and Nicolas Daudet
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Notch signailing pathway ,Wnt/β-catenin signaling pathway ,RNA-seq-RNA sequencing ,prosensory specification ,inner ear development ,chicken embryo ,Biology (General) ,QH301-705.5 - Abstract
The Notch and Wnt signalling pathways play key roles in the formation of inner ear sensory organs, but little is known about their transcriptional effectors and targets in this context. Here, we perturbed Notch and Wnt activities in the embryonic chicken otic vesicle using pharmacological treatment or in ovo electroporation of plasmid DNA, and used RNA-Seq to analyse the resulting changes in gene expression. Compared to pharmacological treatments, in ovo electroporation changed the expression of fewer genes, a likely consequence of the variability and mosaicism of transfection. The pharmacological inhibition of Notch activity induced a rapid change in the expression of known effectors of this pathway and genes associated with neurogenesis, consistent with a switch towards an otic neurosensory fate. The Wnt datasets contained many genes associated with a neurosensory biological function, confirming the importance of this pathway for neurosensory specification in the otocyst. Finally, the results of a preliminary gain-of-function screening of selected transcription factors and Wnt signalling components suggest that the endogenous programs of otic neurosensory specification are very robust, and in general unaffected by the overexpression of a single factor. Altogether this work provides new insights into the effectors and candidate targets of the Notch and Wnt pathways in the early developing inner ear and could serve as a useful reference for future functional genomics experiments in the embryonic avian inner ear.
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- 2023
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7. Biomechanical Analysis of the Impact of Transverse Connectors of Pedicle-Screw-Based Fixation on Thoracolumbar Compression Fracture
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Klaudia Szkoda-Poliszuk, Małgorzata Żak, Rafał Załuski, and Celina Pezowicz
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thoracolumbar spine ,fractures ,posterior spinal fixation system ,biomechanics ,transverse connectors ,Technology ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Biology (General) ,QH301-705.5 ,Physics ,QC1-999 ,Chemistry ,QD1-999 - Abstract
Contemporary clinical practice is progressively shifting towards percutaneous minimally invasive surgery. Conversely, the incorporation of transverse connectors in the design of spinal fixation systems is associated with more invasive open surgical procedures. The primary objective of this investigation was to evaluate the influence of transverse connectors in posterior spinal fixation system designs in cases involving vertebral compression fractures, specifically on selected mechanical parameters of the thoracolumbar spine in situations of instability. This research objective was achieved through a combination of experimental tests and numerical simulations. From the experimental tests conducted, critical mechanical parameters were ascertained, including the bending stiffness coefficient and energy dissipation. Numerical simulations were employed to determine additional parameters, such as the angular range of motion for individual spinal segments, intradiscal pressure within individual intervertebral discs, and stress distribution on the articular facets. Analyzing the impact of transverse connectors on the obtained results revealed that their inclusion in a fixation system results in a minor increase in stiffness and a decrease in mobility in comparison to fixation systems devoid of connectors. These findings create the potential for utilizing minimally invasive surgery as a viable alternative to open surgical procedures.
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- 2023
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8. Fresh–Frozen Allogenic Bone Graft Usage in Treatment of an Odontogenic Keratocyst in the Mandible
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Kamil Nelke, Klaudiusz Łuczak, Maciej Janeczek, Edyta Pasicka, Krzysztof Żak, Marceli Łukaszewski, Radosław Jadach, and Maciej Dobrzyński
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fresh–frozen bone ,allograft ,odotogenic keratocyst ,bone defect ,bone reconstruction ,Technology ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Biology (General) ,QH301-705.5 ,Physics ,QC1-999 ,Chemistry ,QD1-999 - Abstract
There are many cysts and tumors which might occur in the mandibular and maxillary bones. Their origin can be either odontogenic or non-odontogenic. One of the most common odontogenic cysts is the odontogenic keratocyst (OKC). Its nomenclature and classification have changed many times over years, from a tumor to, finally, a cyst. Nowadays, its treatment has not greatly changed, however, it is related to a potential recurrence rate more than any other cyst of odontogenic origins. OKC size, localization, and possible cortical expansion towards adjacent soft tissues might influence the scope of treatment and possible reoccurrence in time. Each case is quite individual, and after removal of the pathology in some cases there can be a necessity for either bone grafting or any other reconstruction method to restore proper bone continuity. The size and the placement of OKC might influence pathological fracture occurrence or inappropriate healing if the bone cavity after cyst removal is not properly treated. A good healing potential can be achieved with xenograft bone substitutes or allograft fresh–frozen bones. On rare occasions, a titanium plate is used to ensure mandibular stability. In the following case report, an atypical case of a large OKC treated with fresh–frozen bone grafts, supported with collagen barrier material in the anterior mandible with buccal cortical expansion, will be presented.
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- 2023
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9. Differences in motivation during the bench press movement with progressive loads using EEG analysis
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Adam Maszczyk, Paweł Dobrakowski, Marcin Żak, Paweł Gozdowski, Magdalena Krawczyk, Andrzej Małecki, Petr Stastny, and Tomasz Zajac
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eeg ,motivation ,bench press ,brain activity ,Sports medicine ,RC1200-1245 ,Biology (General) ,QH301-705.5 - Abstract
Considering our preliminary research with EEG analysis of the bench press in experienced powerlifters, we hypothesized that there would be significant differences in motivation between novice and elite powerlifters. Therefore the main objective of this study was to identify patterns of frontal alpha asymmetry (FAA) of the prime movers by alpha frequency band analysis (named as alpha motivation values) for each 35–100% one-repetition maximum (1RM) during the flat bench press. Ten novice powerlifters with no more than 2.5 years of resistance training experience and ten elite powerlifters with at least 7.5 years of training experience participated in the study. All participants were required to squat, bench press, and deadlift 100, 125, and 150% of their body mass, respectively. The athletes constituted a homogeneous group with respect to age (mean 22.3 ± 0.5 years). The EEG recordings were conducted using automatic headcups with 19 electrodes that were placed according to the International 10-20 Electrode Placement System. Signals from 8–12 Hz considering points F3 and F4 were analyzed. Furthermore, electromyographic (EMG) signals from the trapezius muscle were recorded. Before testing, moods and emotions of subjects were assessed to eliminate subjects with intense emotions. The results showed brain activity before, during and after cognitive and motor performance using electroencephalography (EEG). However, considering the still existing problems of movement artefacts during EEG measurements, eligible sports and exercises are limited to those that are relatively motionless during execution. Further studies are needed to confirm these preliminary results.
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- 2019
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10. Implementation of Demand Forecasting Module of ERP System in Mass Customization Industry—Case Studies
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Katarzyna Grobler-Dębska, Edyta Kucharska, Bartłomiej Żak, Jerzy Baranowski, and Adam Domagała
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ERP system ,ERP implementation ,historical demand ,demand forecasting method ,sales and operation planning ,mass customization production ,Technology ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Biology (General) ,QH301-705.5 ,Physics ,QC1-999 ,Chemistry ,QD1-999 - Abstract
Mass customization production is a manufacturing process in which mass-produced products are modified according to specific customer needs. An example of such production is furniture production, where multiple options options for various components or features are available. Demand forecasting in mass customization industry is a difficult task for organizations and is both crucial for their profits and for market penetration. Unfortunately, the currently available tools are focused on more standard demand forecasts, which lack interpretable representation of information relevant for mass customization products. This is especially relevant for ERP systems, which are the backbone of modern manufacturing. We propose a forecasting method adapted to the needs of mass customization by focusing on demand prediction—not on finished products, but on key intermediate goods. Moreover, we provide a method for determining such goods. As an additional consequence we provide an implementation strategy that reduces the risk and time consumption when implementing forecasting in ERP systems. All the results are implemented as appropriate functionalities of a IFS Application ERP system.
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- 2022
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11. Molecular Level Characterisation of the Surface of Carbohydrate-Functionalised Mesoporous silica Nanoparticles (MSN) as a Potential Targeted Drug Delivery System via High Resolution Magic Angle Spinning (HR-MAS) NMR Spectroscopy
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Karolina Krajewska, Anna M. Gołkowska, Maciej Nowak, Marta Kozakiewicz-Latała, Wojciech Pudło, Andrzej Żak, Bożena Karolewicz, Yaroslav Z. Khimyak, and Karol P. Nartowski
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mesoporous silica nanoparticles ,MSN ,porous materials ,functionalisation ,NMR ,HR-MAS NMR ,Biology (General) ,QH301-705.5 ,Chemistry ,QD1-999 - Abstract
Atomistic level characterisation of external surface species of mesoporous silica nanoparticles (MSN) poses a significant analytical challenge due to the inherently low content of grafted ligands. This study proposes the use of HR-MAS NMR spectroscopy for a molecular level characterisation of the external surface of carbohydrate-functionalised nanoparticles. MSN differing in size (32 nm, 106 nm, 220 nm) were synthesised using the sol-gel method. The synthesised materials displayed narrow particle size distribution (based on DLS and TEM results) and a hexagonal arrangement of the pores with a diameter of ca. 3 nm as investigated with PXRD and N2 physisorption. The surface of the obtained nanoparticles was functionalised with galactose and lactose using reductive amination as confirmed by FTIR and NMR techniques. The functionalisation of the particles surface did not alter the pore architecture, structure or morphology of the materials as confirmed with TEM imaging. HR-MAS NMR spectroscopy was used for the first time to investigate the structure of the functionalised MSN suspended in D2O. Furthermore, lactose was successfully attached to the silica without breaking the glycosidic bond. The results demonstrate that HR-MAS NMR can provide detailed structural information on the organic functionalities attached at the external surface of MSN within short experimental times.
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- 2022
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12. A gradient of Wnt activity positions the neurosensory domains of the inner ear
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Magdalena Żak and Nicolas Daudet
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inner ear ,Wnt signalling ,sensory organ ,tissue patterning ,Medicine ,Science ,Biology (General) ,QH301-705.5 - Abstract
The auditory and vestibular organs of the inner ear and the neurons that innervate them originate from Sox2-positive and Notch-active neurosensory domains specified at early stages of otic development. Sox2 is initially present throughout the otic placode and otocyst, and then it becomes progressively restricted to a ventro-medial domain. Using gain- and loss-of-function approaches in the chicken otocyst, we show that these early changes in Sox2 expression are regulated in a dose-dependent manner by Wnt/beta-catenin signalling. Both high and very low levels of Wnt activity repress Sox2 and neurosensory competence. However, intermediate levels allow the maintenance of Sox2 expression and sensory organ formation. We propose that a dorso-ventral (high-to-low) gradient and wave of Wnt activity initiated at the dorsal rim of the otic placode progressively restricts Sox2 and Notch activity to the ventral half of the otocyst, thereby positioning the neurosensory competent domains in the inner ear.
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- 2021
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13. An optimized method for high quality DNA extraction from microalga Prototheca wickerhamii for genome sequencing
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Tomasz Jagielski, Jan Gawor, Zofia Bakuła, Karolina Zuchniewicz, Iwona Żak, and Robert Gromadka
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DNA extraction ,DNA isolation ,Genome sequencing ,Prototheca ,Plant culture ,SB1-1110 ,Biology (General) ,QH301-705.5 - Abstract
Abstract Background The complex cell wall structure of algae often precludes efficient extraction of their genetic material. The purpose of this study was to design a next-generation sequencing-suitable DNA isolation method for unicellular, achlorophyllous, yeast-like microalgae of the genus Prototheca, the only known plant pathogens of both humans and animals. The effectiveness of the newly proposed scheme was compared with five other, previously described methods, commonly used for DNA isolation from plants and/or yeasts, available either as laboratory-developed, in-house assays, based on liquid nitrogen grinding or different enzymatic digestion, or as commercially manufactured kits. Results All five, previously described, isolation assays yielded DNA concentrations lower than those obtained with the new method, averaging 16.15 ± 25.39 vs 74.2 ± 0.56 ng/µL, respectively. The new method was also superior in terms of DNA purity, as measured by A260/A280 (−0.41 ± 4.26 vs 2.02 ± 0.03), and A260/A230 (1.20 ± 1.12 vs 1.97 ± 0.07) ratios. Only the liquid nitrogen-based method yielded DNA of comparable quantity (60.96 ± 0.16 ng/µL) and quality (A260/A280 = 2.08 ± 0.02; A260/A230 = 2.23 ± 0.26). Still, the new method showed higher integrity, which was best illustrated upon electrophoretic analysis. Genomic DNA of Prototheca wickerhamii POL-1 strain isolated with the protocol herein proposed was successfully sequenced on the Illumina MiSeq platform. Conclusions A new method for DNA isolation from Prototheca algae is described. The method, whose protocol involves glass beads pulverization and cesium chloride (CsCl) density gradient centrifugation, was demonstrated superior over the other common assays in terms of DNA quantity and quality. The method is also the first to offer the possibility of preparation of DNA template suitable for whole genome sequencing of Prototheca spp.
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- 2017
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14. CdS Nanoplates Modification as a Platform for Synthesis of Blue-Emitting Nanoparticles
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Anna Lesiak, Mateusz Banski, Hanna Woznica, Andrzej Żak, Joanna Cabaj, and Artur Podhorodecki
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3-mercaptopropionic acid ,blue emitting quantum dots ,d-penicillamine ,ligand exchange ,CdS nanoplatelets ,phase transfer ,Biology (General) ,QH301-705.5 ,Chemistry ,QD1-999 - Abstract
In this paper, the study of surface modification of two-dimensional (2D), non-luminescent CdS nanoplates (NPLs) by thiol-containing ligands is presented. We show that a process of twophase transfers with appropriate ligand exchange transforms non-luminescent NPLs into spherical CdS nanoparticles (NPs) exhibiting a blue photoluminescence with exceptionally high quantum yield ~90%. In the process, transfer from inorganic solvent to water is performed, with appropriately selected ligand molecules and pH values (forward phase transfer), which produces NPs with modified size and shape. Then, in reverse phase transfer, NPs are transferred back to toluene due to surface modification by combined Cd (OL)2 and Cd (Ac)2. As a result, spherical NPs are formed (average diameter between 4 and 6 nm) with PL QY as high as 90%. This is unique for core only CdS NPs without inorganic shell.
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- 2021
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15. Variability of Amyloid Propensity in Imperfect Repeats of CsgA Protein of Salmonella enterica and Escherichia coli
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Natalia Szulc, Marlena Gąsior-Głogowska, Jakub W. Wojciechowski, Monika Szefczyk, Andrzej M. Żak, Michał Burdukiewicz, and Malgorzata Kotulska
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functional amyloids ,curli ,aggregation ,biofilm ,ATR-FTIR ,FT-Raman ,Biology (General) ,QH301-705.5 ,Chemistry ,QD1-999 - Abstract
CsgA is an aggregating protein from bacterial biofilms, representing a class of functional amyloids. Its amyloid propensity is defined by five fragments (R1–R5) of the sequence, representing non-perfect repeats. Gate-keeper amino acid residues, specific to each fragment, define the fragment’s propensity for self-aggregation and aggregating characteristics of the whole protein. We study the self-aggregation and secondary structures of the repeat fragments of Salmonella enterica and Escherichia coli and comparatively analyze their potential effects on these proteins in a bacterial biofilm. Using bioinformatics predictors, ATR-FTIR and FT-Raman spectroscopy techniques, circular dichroism, and transmission electron microscopy, we confirmed self-aggregation of R1, R3, R5 fragments, as previously reported for Escherichia coli, however, with different temporal characteristics for each species. We also observed aggregation propensities of R4 fragment of Salmonella enterica that is different than that of Escherichia coli. Our studies showed that amyloid structures of CsgA repeats are more easily formed and more durable in Salmonella enterica than those in Escherichia coli.
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- 2021
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16. MixInYeast: A Multicenter Study on Mixed Yeast Infections
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Narda Medina, Juan Carlos Soto-Debrán, Danila Seidel, Isin Akyar, Hamid Badali, Aleksandra Barac, Stéphane Bretagne, Yasemin Cag, Carole Cassagne, Carmen Castro, Arunaloke Chakrabarti, Eric Dannaoui, Celia Cardozo, Julio Garcia-Rodriguez, Juliette Guitard, Petr Hamal, Martin Hoenigl, Tomasz Jagielski, Sadegh Khodavaisy, Giuliana Lo Cascio, María Carmen Martínez-Rubio, Joseph Meletiadis, Patricia Muñoz, Elżbieta Ochman, Teresa Peláez, Ana Perez-Ayala Balzola, Juergen Prattes, Emmanuel Roilides, Maite Ruíz-Pérez de Pipaón, Raphael Stauf, Jörg Steinmann, Ana Isabel Suárez-Barrenechea, Rocío Tejero, Laura Trovato, Lourdes Viñuela, Thanwa Wongsuk, Iwona Żak, Hossein Zarrinfar, Cornelia Lass-Flörl, Sevtap Arikan-Akdagli, Ana Alastruey-Izquierdo, and on behalf of MixInYeast Study Group from EFISG
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yeast ,chrome agar ,invasive candidiasis ,Candida ,mix infections ,polymicrobial infections ,Biology (General) ,QH301-705.5 - Abstract
Invasive candidiasis remains one of the most prevalent systemic mycoses, and several studies have documented the presence of mixed yeast (MY) infections. Here, we describe the epidemiology, clinical, and microbiological characteristics of MY infections causing invasive candidiasis in a multicenter prospective study. Thirty-four centers from 14 countries participated. Samples were collected in each center between April to September 2018, and they were sent to a reference center to confirm identification by sequencing methods and to perform antifungal susceptibility testing, according to the European Committee on Antimicrobial Susceptibility Testing (EUCAST). A total of 6895 yeast cultures were identified and MY occurred in 150 cases (2.2%). Europe accounted for the highest number of centers, with an overall MY rate of 4.2% (118 out of 2840 yeast cultures). Of 122 MY cases, the most frequent combinations were Candida albicans/C. glabrata (42, 34.4%), C. albicans/C. parapsilosis (17, 14%), and C. glabrata/C. tropicalis (8, 6.5%). All Candida isolates were susceptible to amphotericin B, 6.4% were fluconazole-resistant, and two isolates (1.6%) were echinocandin-resistant. Accurate identification of the species involved in MY infections is essential to guide treatment decisions.
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- 2020
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17. Interspecies Outer Membrane Vesicles (OMVs) Modulate the Sensitivity of Pathogenic Bacteria and Pathogenic Yeasts to Cationic Peptides and Serum Complement
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Justyna Roszkowiak, Paweł Jajor, Grzegorz Guła, Jerzy Gubernator, Andrzej Żak, Zuzanna Drulis-Kawa, and Daria Augustyniak
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outer membrane vesicles (omvs) ,candida albicans ,antimicrobial peptides ,complement ,interspecies interactions ,inter-kingdom protection ,fungicidal activity ,fluconazole ,hyphae ,Biology (General) ,QH301-705.5 ,Chemistry ,QD1-999 - Abstract
The virulence of bacterial outer membrane vesicles (OMVs) contributes to innate microbial defense. Limited data report their role in interspecies reactions. There are no data about the relevance of OMVs in bacterial-yeast communication. We hypothesized that model Moraxella catarrhalis OMVs may orchestrate the susceptibility of pathogenic bacteria and yeasts to cationic peptides (polymyxin B) and serum complement. Using growth kinetic curve and time-kill assay we found that OMVs protect Candida albicans against polymyxin B-dependent fungicidal action in combination with fluconazole. We showed that OMVs preserve the virulent filamentous phenotype of yeasts in the presence of both antifungal drugs. We demonstrated that bacteria including Haemophilus influenza, Acinetobacter baumannii, and Pseudomonas aeruginosa coincubated with OMVs are protected against membrane targeting agents. The high susceptibility of OMV-associated bacteria to polymyxin B excluded the direct way of protection, suggesting rather the fusion mechanisms. High-performance liquid chromatography-ultraviolet spectroscopy (HPLC-UV) and zeta-potential measurement revealed a high sequestration capacity (up to 95%) of OMVs against model cationic peptide accompanied by an increase in surface electrical charge. We presented the first experimental evidence that bacterial OMVs by sequestering of cationic peptides may protect pathogenic yeast against combined action of antifungal drugs. Our findings identify OMVs as important inter-kingdom players.
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- 2019
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18. Shaping of inner ear sensory organs through antagonistic interactions between Notch signalling and Lmx1a
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Zoe F Mann, Héctor Gálvez, David Pedreno, Ziqi Chen, Elena Chrysostomou, Magdalena Żak, Miso Kang, Elachumee Canden, and Nicolas Daudet
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development ,notch ,inner ear ,Lmx1a ,lateral induction ,compartment boundaries ,Medicine ,Science ,Biology (General) ,QH301-705.5 - Abstract
The mechanisms of formation of the distinct sensory organs of the inner ear and the non-sensory domains that separate them are still unclear. Here, we show that several sensory patches arise by progressive segregation from a common prosensory domain in the embryonic chicken and mouse otocyst. This process is regulated by mutually antagonistic signals: Notch signalling and Lmx1a. Notch-mediated lateral induction promotes prosensory fate. Some of the early Notch-active cells, however, are normally diverted from this fate and increasing lateral induction produces misshapen or fused sensory organs in the chick. Conversely Lmx1a (or cLmx1b in the chick) allows sensory organ segregation by antagonizing lateral induction and promoting commitment to the non-sensory fate. Our findings highlight the dynamic nature of sensory patch formation and the labile character of the sensory-competent progenitors, which could have facilitated the emergence of new inner ear organs and their functional diversification in the course of evolution.
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- 2017
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19. Taxonomic and chemical assessment of exceptionally abundant rock mine biofilm
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Karolina Tomczyk-Żak, Paweł Szczesny, Robert Gromadka, and Urszula Zielenkiewicz
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Biodiversity ,Metagenomics ,Mine ,Biofilm ,Medicine ,Biology (General) ,QH301-705.5 - Abstract
Background An exceptionally thick biofilm covers walls of ancient gold and arsenic Złoty Stok mine (Poland) in the apparent absence of organic sources of energy. Methods and Results We have characterized this microbial community using culture-dependent and independent methods. We sequenced amplicons of the 16S rRNA gene obtained using generic primers and additional primers targeted at Archaea and Actinobacteria separately. Also, we have cultured numerous isolates from the biofilm on different media under aerobic and anaerobic conditions. We discovered very high biodiversity, and no single taxonomic group was dominant. The majority of almost 4,000 OTUs were classified above genus level indicating presence of novel species. Elemental analysis, performed using SEM-EDS and X-ray, of biofilm samples showed that carbon, sulphur and oxygen were not evenly distributed in the biofilm and that their presence is highly correlated. However, the distribution of arsenic and iron was more flat, and numerous intrusions of elemental silver and platinum were noted, indicating that microorganisms play a key role in releasing these elements from the rock. Conclusions Altogether, the picture obtained throughout this study shows a very rich, complex and interdependent system of rock biofilm. The chemical heterogeneity of biofilm is a likely explanation as to why this oligotrophic environment is capable of supporting such high microbial diversity.
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- 2017
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20. Welding Capabilities of Nanostructured Carbide-Free Bainite: Review of Welding Methods, Materials, Problems, and Perspectives
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Aleksandra Królicka, Andrzej Ambroziak, and Andrzej Żak
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nanobainite ,NB ,CFB ,high-carbon steels ,high-strength steels ,Si-rich steels ,welding ,HAZ ,fusion zone ,Technology ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Biology (General) ,QH301-705.5 ,Physics ,QC1-999 ,Chemistry ,QD1-999 - Abstract
This article presents state-of-the-art welding methods and the weldability aspect of steels, particularly high-carbon nanobainitic (NB) steels, without carbide precipitates (CFB—carbide-free bainite). On the basis of research conducted to date, all welding methods with parameters and weld metals for NB CFB are presented. It was found that the process parameters significantly affected the mechanical properties of the welds, which were determined primarily by the properties of the low-temperature heat-affected zone. The microstructures of welded joints in the heat-affected and fusion zones are also described. The general requirements for welding processes, as well as problems and perspectives for further research, are presented.
- Published
- 2019
- Full Text
- View/download PDF
21. Examining the Genetic Background of Porcine Muscle Growth and Development Based on Transcriptome and miRNAome Data
- Author
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Katarzyna Ropka-Molik, Klaudia Pawlina-Tyszko, Kacper Żukowski, Katarzyna Piórkowska, Grzegorz Żak, Artur Gurgul, Natalia Derebecka, and Joanna Wesoły
- Subjects
RNA-seq ,miRNA ,pig ,next-generation sequencing (NGS) ,transcript analysis ,muscle ,Biology (General) ,QH301-705.5 ,Chemistry ,QD1-999 - Abstract
Recently, selection in pigs has been focused on improving the lean meat content in carcasses; this focus has been most evident in breeds constituting a paternal component in breeding. Such sire-breeds are used to improve the meat quantity of cross-breed pig lines. However, even in one breed, a significant variation in the meatiness level can be observed. In the present study, the comprehensive analysis of genes and microRNA expression profiles in porcine muscle tissue was applied to identify the genetic background of meat content. The comparison was performed between whole gene expression and miRNA profiles of muscle tissue collected from two sire-line pig breeds (Pietrain, Hampshire). The RNA-seq approach allowed the identification of 627 and 416 differentially expressed genes (DEGs) between pig groups differing in terms of loin weight between Pietrain and Hampshire breeds, respectively. The comparison of miRNA profiles showed differential expression of 57 microRNAs for Hampshire and 34 miRNAs for Pietrain pigs. Next, 43 genes and 18 miRNAs were selected as differentially expressed in both breeds and potentially related to muscle development. According to Gene Ontology analysis, identified DEGs and microRNAs were involved in the regulation of the cell cycle, fatty acid biosynthesis and regulation of the actin cytoskeleton. The most deregulated pathways dependent on muscle mass were the Hippo signalling pathway connected with the TGF-β signalling pathway and controlling organ size via the regulation of ubiquitin-mediated proteolysis, cell proliferation and apoptosis. The identified target genes were also involved in pathways such as the FoxO signalling pathway, signalling pathways regulating pluripotency of stem cells and the PI3K-Akt signalling pathway. The obtained results indicate molecular mechanisms controlling porcine muscle growth and development. Identified genes (SOX2, SIRT1, KLF4, PAX6 and genes belonging to the transforming growth factor beta superfamily) could be considered candidate genes for determining muscle mass in pigs.
- Published
- 2018
- Full Text
- View/download PDF
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