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Aluminium tolerance of different Paxillus involutus Fr. strains originating from polluted and nonpolluted sites
Maria Rudawska,Tomasz Leski
Acta Societatis Botanicorum Poloniae , 1998, DOI: 10.5586/asbp.1998.015
Abstract: The caps of the sporocarps of P. involutus originating from the polluted site (Luboń) and from the control site in Kórnik and Puszcza Nadnotecka accumulated high amounts of aluminium and revealed symptoms of bioconcentration. However in caps of the sporocarps from the control sites a lower amount of Al was accumulated than in caps from the polluted site (Luboń). A significantly lower concentration of Al was found in stems of sporocarps originating from the special control site in Puszcza Nadnotecka. Mycelia of 11 strains isolated from sporocarps collected at the polluted and control sites were cultivated on a liquid medium containing 100 mg L-1 Al. All strains showed high bioconcentration of Al despite of the place of origin. In a subsequent experiment 10 strains of P. involutus originating from polluted soil and 8 strains derived from the control sites were grown in agar media containing 10, 100, 500 and 1000 mg/L-1 of Al. The radial growth rates during culture, the final colony dry weight and the metal tolerance indices calculated on the basis of measured parameters were determined. P. involutus strains appeared to be very tolerant to the presence of Al in the medium and were able to grow even at the highest Al concentration. Increasing aluminium level in the medium to different extent influenced growth of tested strains, however the site of the origin did not influence the response of P. involutus to aluminium: among 18 strains tested, the most tolerant were selected both from the polluted and from the unpolluted sites. The results are discussed with reference to the high intraspecific variability of different physiological features of the ectomycorrhizal fungus P. involutus.
Molecular Characterization of Multidrug Resistant Hospital Isolates Using the Antimicrobial Resistance Determinant Microarray
Tomasz A. Leski, Gary J. Vora, Brian R. Barrows, Guillermo Pimentel, Brent L. House, Matilda Nicklasson, Momtaz Wasfy, Mohamed Abdel-Maksoud, Chris Rowe Taitt
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0069507
Abstract: Molecular methods that enable the detection of antimicrobial resistance determinants are critical surveillance tools that are necessary to aid in curbing the spread of antibiotic resistance. In this study, we describe the use of the Antimicrobial Resistance Determinant Microarray (ARDM) that targets 239 unique genes that confer resistance to 12 classes of antimicrobial compounds, quaternary amines and streptothricin for the determination of multidrug resistance (MDR) gene profiles. Fourteen reference MDR strains, which either were genome, sequenced or possessed well characterized drug resistance profiles were used to optimize detection algorithms and threshold criteria to ensure the microarray's effectiveness for unbiased characterization of antimicrobial resistance determinants in MDR strains. The subsequent testing of Acinetobacter baumannii, Escherichia coli and Klebsiella pneumoniae hospital isolates revealed the presence of several antibiotic resistance genes [e.g. belonging to TEM, SHV, OXA and CTX-M classes (and OXA and CTX-M subfamilies) of β-lactamases] and their assemblages which were confirmed by PCR and DNA sequence analysis. When combined with results from the reference strains, ~25% of the ARDM content was confirmed as effective for representing allelic content from both Gram-positive and –negative species. Taken together, the ARDM identified MDR assemblages containing six to 18 unique resistance genes in each strain tested, demonstrating its utility as a powerful tool for molecular epidemiological investigations of antimicrobial resistance in clinically relevant bacterial pathogens.
Testing and Validation of High Density Resequencing Microarray for Broad Range Biothreat Agents Detection
Tomasz A. Leski, Baochuan Lin, Anthony P. Malanoski, Zheng Wang, Nina C. Long, Carolyn E. Meador, Brian Barrows, Sofi Ibrahim, Justin P. Hardick, Mohamed Aitichou, Joel M. Schnur, Clark Tibbetts, David A. Stenger
PLOS ONE , 2009, DOI: 10.1371/journal.pone.0006569
Abstract: Rapid and effective detection and identification of emerging microbiological threats and potential biowarfare agents is very challenging when using traditional culture-based methods. Contemporary molecular techniques, relying upon reverse transcription and/or polymerase chain reaction (RT-PCR/PCR) provide a rapid and effective alternative, however, such assays are generally designed and optimized to detect only a limited number of targets, and seldom are capable of differentiation among variants of detected targets. To meet these challenges, we have designed a broad-range resequencing pathogen microarray (RPM) for detection of tropical and emerging infectious agents (TEI) including biothreat agents: RPM-TEI v 1.0 (RPM-TEI). The scope of the RPM-TEI assay enables detection and differential identification of 84 types of pathogens and 13 toxin genes, including most of the class A, B and C select agents as defined by the Centers for Disease Control and Prevention (CDC, Atlanta, GA). Due to the high risks associated with handling these particular target pathogens, the sensitivity validation of the RPM-TEI has been performed using an innovative approach, in which synthetic DNA fragments are used as templates for testing the assay's limit of detection (LOD). Assay specificity and sensitivity was subsequently confirmed by testing with full-length genomic nucleic acids of selected agents. The LOD for a majority of the agents detected by RPM-TEI was determined to be at least 104 copies per test. Our results also show that the RPM-TEI assay not only detects and identifies agents, but is also able to differentiate near neighbors of the same agent types, such as closely related strains of filoviruses of the Ebola Zaire group, or the Machupo and Lassa arenaviruses. Furthermore, each RPM-TEI assay results in specimen-specific agent gene sequence information that can be used to assess pathogenicity, mutations, and virulence markers, results that are not generally available from multiplexed RT-PCR/PCR-based detection assays.
Leapfrog diagnostics: Demonstration of a broad spectrum pathogen identification platform in a resource-limited setting
Tomasz A Leski, Rashid Ansumana, Anthony P Malanoski, David H Jimmy, Umaru Bangura, Brian R Barrows, Morie Alpha, Bashiru M Koroma, Nina C Long, Abu J Sundufu, Alfred S Bockarie, Baochuan Lin, David A Stenger
Health Research Policy and Systems , 2012, DOI: 10.1186/1478-4505-10-22
Abstract: A laboratory for molecular diagnostics of infectious agents was established in Bo, Sierra Leone with a hybrid solar/diesel/battery system to ensure stable power supply and a satellite modem to enable efficient communication. An array of room temperature stabilization and refrigeration technologies for reliable transport and storage of reagents and biological samples were also tested to ensure sustainable laboratory supplies for diagnostic assays.The laboratory demonstrated its operational proficiency by conducting an investigation of a suspected avian influenza outbreak at a commercial poultry farm at Bo using broad range resequencing microarrays and real time RT-PCR. The results of the investigation excluded influenza viruses as a possible cause of the outbreak and indicated a link between the outbreak and the presence of Klebsiella pneumoniae.This study demonstrated that by application of a carefully selected set of technologies and sufficient personnel training, it is feasible to deploy and effectively use a broad-range infectious pathogen detection technology in a severely resource-limited setting.
Antimicrobial resistance of Klebsiella pneumoniae stool isolates circulating in Kenya
Abigael N. Ombogo,Chris Rowe Taitt,Christine Hulseberg,Daniel P. Erwin,Elizabeth A. Odundo,Gary J. Vora,Janet N. Ndonye,Judd L. Walson,Nancy C. Kipkemoi,Patricia B. Pavlinac,Ronald K. Kirera,Tomasz A. Leski
- , 2017, DOI: 10.1371/journal.pone.0178880
Abstract:
Intraspecific aluminium response in Suillus luteus (L.) s.f. gray., an ectomycorrhizal symbiont of scots pine
Tomasz Leski,Maria Rudawska,Barbara Kieliszewska-Rokicka
Acta Societatis Botanicorum Poloniae , 1995, DOI: 10.5586/asbp.1995.014
Abstract: Ten isolates of the ectomycorrhizal fungus Suillus luteus have been cultured on an aluminium containing growth medium in order to determine their in vitro aluminium tolerance. Five isolates originated from a site heavily polluted by acid rain with a high availability of aluminium in the soil. Five others were collected from a site free from direct pollution. Aluminium content in the sporocarps of S. luteus differed according to the site of origin and did not reveal symptoms of bioconcentration, although such phenomena were found when mycelium isolated from the sporocarps was submited to 100 mg/L Al in liquid culture. A clear relationship between Al accumulation in vitro and the site of origin of the isolate was not observed, although the highest amount of Al was found in the mycelium derived from the polluted soil. In a second experiment all isolates were grown in agar media containing 10, 100, 500 and 1000 mg/L-1 Al and the colony diameter during culture and the final colony dry weight determined. S. luteus appeared to be very tolerant to the presence of Al in the medium. Each of the parameters used to measure the metal tolerance of the fungus ranked the isolates in a slightly different order, but those originating from the polluted area showed some superiority over the others. In polluted soils this species seems to have been submitted to a selection for higher aluminium tolerance. The results are discussed with reference to the possibilities of transformating in vitro studies to situation in the forest ecosystem.
Two black hole initial data
Szymon Leski
Physics , 2005, DOI: 10.1103/PhysRevD.71.124018
Abstract: Misner initial data are a standard example of time-symmetric initial data with two apparent horizons. Compact formulae describing such data are presented in the cases of equal or non-equal masses (i.e. isometric or non-isometric horizons). The interaction energy in the "Schwarzschild + test particle" limit of the Misner data is analyzed.
“Syndrome of Contractures” According to Prof. Hans Mau; Problems of Shanks, Knees, Hips, Pelvis and Spine; Children, Adolescents, Adults, Diagnosis, Treatment  [PDF]
Karski Tomasz, Karski Jacek, Domaga？a Marian
Surgical Science (SS) , 2019, DOI: 10.4236/ss.2019.101004
Abstract: The problems of movement apparatus in children, youth and even adolescents aren’t connected with “a weakness of muscles” but with a shortening of muscles, tendons, and capsules which in orthopaedic literature is called “contracture” [1] [2] [3] [4]. The older way of thinking about the problem was based on the conviction that “weak muscles” cause and make problems; we, however, present on many examples that “restriction of movements” doing by shortening of soft tissues makes contracture and incorrect position of joints, body parts, the serious and frequent clinical problems.
Proteome analysis of Norway maple (Acer platanoides L.) seeds dormancy breaking and germination: influence of abscisic and gibberellic acids
Tomasz A Paw？owski
BMC Plant Biology , 2009, DOI: 10.1186/1471-2229-9-48
Abstract: A proteomic approach was used to analyse the mechanism of dormancy breaking in Norway maple seeds caused by cold stratification, and the participation of the abscisic (ABA) and gibberellic (GA) acids. Forty-four proteins showing significant changes were identified by mass spectrometry. Of these, eight spots were identified as water-responsive, 18 spots were ABA- and nine GA-responsive and nine spots were regulated by both hormones. The classification of proteins showed that most of the proteins associated with dormancy breaking in water were involved in protein destination. Most of the ABA- and GA-responsive proteins were involved in protein destination and energy metabolism.In this study, ABA was found to mostly down-regulate proteins whereas GA up-regulated proteins abundance. Most of the changes were observed at the end of stratification in the germinated seeds. This is the most active period of dormancy breaking when seeds pass from the quiescent state to germination. Seed dormancy breaking involves proteins of various processes but the proteasome proteins, S-adenosylmethionine synthetase, glycine-rich RNA binding protein, ABI3-interacting protein 1, EF-2 and adenosylhomocysteinase are of particular importance. The effect of exogenously applied hormones was not a determining factor for total inhibition (ABA) or stimulation (GA) of Norway maple seed dormancy breaking and germination but proteomic data has proven these hormones play a role.Seeds of many plant species enter a period of dormancy when they fail to germinate under favourable conditions. Seed dormancy is controlled by the physiological or structural properties of a seed and external conditions. It is induced as a part of the genetic program of seed development and maturation. Dormancy can be caused by the maternally derived seed covering structures or by embryonic factors, acting individually or in combination [1,2]. In the majority of species with dormancy located in the fully developed mature embryo,
Weryfikacja modelu stateczno ci drzew na terenach zalewowych na przyk adzie d bu Quercus robur L., sosny Pinus sylvestris L. i olchy Alnus glutinosa (L.) Gaertn
Tomasz Ka u a
Forest Research Papers , 2012, DOI: 10.2478/v10111-012-0013-5
Abstract: A tree's geometrical characteristics (diameter, trunk height, vertical and horizontal extent of roots) and the soil's geotechnical properties (type and state of soil) determine the critical force required to cause uprooting. This article presents a method for the estimation of the critical force causing uprooting of a tree during high winds and flooding in riparian forests. The model was tested for forest stands of black alder, Scots pine and pedunculate oak. The force required to pull up various trees was measured, and results used as the basis for formulation and verification of a theoretical model describing the critical threshold value for uprooting.
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