Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 34
Filtrar
1.
Med Pr ; 75(1): 31-44, 2024 Mar 22.
Artículo en Polaco | MEDLINE | ID: mdl-38523499

RESUMEN

BACKGROUND: The work of a paramedic, is characterised by a high risk of injury. Ergonomic, psychological, and biomechanical factors are considered risk factors in the profession of emergency medical technicians. Ensuring ergonomic working conditions for emergency medical technicians is a priority and requires a thorough assessment both in the design process and during the operation of the ambulance, to provide a diagnosis of the current state and present necessary recommendations for modernization. Identifying stressors will enable the design of an ergonomic interior for the ambulance, ensuring comfort and reliability for members of the emergency medical team, thereby reducing the risk of injuries. MATERIAL AND METHODS: The authors of this article developed a comprehensive methodology for assessing the nuisances occurring during the paramedic's work, which required specialised preliminary research. The research included the measurement and analysis of the paramedic's movement kinematics during typical medical procedures, both at a standstill and while driving the ambulance. For the analysis of motion kinematics, a non-invasive method called myoMotion was employed, and the study was conducted in a Mercedes ambulance. RESULTS: This article contains preliminary results on the evaluation of movement kinematics. These demonstrated the necessity for the paramedic to adopt forced positions when performing medical procedures. The ranges of movement of the individual body parts of the paramedic deviated from accepted norms, resulting in musculoskeletal overload. CONCLUSIONS: The acquired knowledge forms the basis for a detailed analysis of tasks performed within each procedure from the perspective of the spatial structure of the ambulance, the arrangement of equipment and medical supplies, their accessibility during work, and the organization of work within the ambulance. Additional identification of musculoskeletal system stress, its sources, and the formulation of modification recommendations for the ambulance interior will enable ensuring the comfort and reliability of the work for emergency medical teams, thereby reducing the risk of injuries in the workplace. Med Pr Work Health Saf. 2024;75(1):31-44.


Asunto(s)
Servicios Médicos de Urgencia , Auxiliares de Urgencia , Humanos , Ambulancias , Paramédico , Reproducibilidad de los Resultados , Condiciones de Trabajo , Ergonomía , Servicios Médicos de Urgencia/métodos
2.
Int J Mol Sci ; 25(6)2024 Mar 11.
Artículo en Inglés | MEDLINE | ID: mdl-38542174

RESUMEN

The present study was designed to investigate the physical stability of three organic materials with similar chemical structures. The examined compounds revealed completely different crystallization tendencies in their supercooled liquid states and were classified into three distinct classes based on their tendency to crystallize. (S)-4-Benzyl-2-oxazolidinone easily crystallizes during cooling from the melt; (S)-4-Benzylthiazolidine-2-thione does not crystallize during cooling from the melt, but crystallizes easily during subsequent reheating above Tg; and (S)-4-Benzyloxazolidine-2-thione does not crystallize either during cooling from the melt or during reheating. Such different tendencies to crystallize are observed despite the very similar chemical structures of the compounds, which only differ in oxide or sulfur atoms in one of their rings. We also studied the isothermal crystallization kinetics of the materials that were shown to transform into a crystalline state. Molecular dynamics and thermal properties were thoroughly investigated using broadband dielectric spectroscopy, as well as conventional and temperature-modulated differential scanning calorimetry in the wide temperature range. It was found that all three glass formers have the same dynamic fragility (m = 93), calculated directly from dielectric structural relaxation times. This result verifies that dynamic fragility is not related to the tendency to crystallize. In addition, thermodynamic fragility predictions were also made using calorimetric data. It was found that the thermodynamic fragility evaluated based on the width of the glass transition, observed in the temperature dependence of heat capacity, correlates best with the tendency to crystallize.


Asunto(s)
Tionas , Cristalización/métodos , Transición de Fase , Temperatura , Termodinámica , Rastreo Diferencial de Calorimetría
3.
J Phys Chem B ; 127(42): 9102-9110, 2023 Oct 26.
Artículo en Inglés | MEDLINE | ID: mdl-37846653

RESUMEN

A series of four alcohols, n-propanol and its halogen (Cl, Br, and I) derivatives, were selected to study the effects of variation in polarity and halogen-driven interactions on the hydrogen bonding pattern and supramolecular structure by means of experimental and theoretical methods. It was demonstrated on both grounds that the average strength of H-bonds remains the same but dissociation enthalpy, the size of molecular nanoassemblies, as well as long-range correlations between dipoles vary with the molecular weight of halogen atom. Further molecular dynamics simulations indicated that it is connected to the variation in the molecular order introduced by specific halogen-based hydrogen bonds and halogen-halogen interactions. Our results also provided important experimental evidence supporting the assumption of the transient chain model on the molecular origin of the structural process in self-assembling alcohols.

4.
J Phys Chem B ; 127(23): 5334-5340, 2023 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-37257018

RESUMEN

Dynamics and thermodynamics of molecular systems in the vicinity of the boundary between thermodynamically nonequilibrium glassy and metastable supercooled liquid states are still incompletely explored and their theoretical and simulation models are imperfect despite many previous efforts. Among them, the role of total system entropy, configurational entropy, and excess entropy in the temperature-pressure or temperature-density dependence of global molecular dynamics (MD) timescale relevant to the glass transition is an essential topic intensively studied for over half of a century. By exploiting a well-known simple ellipsoidal model recently successfully applied to simulate the supercooled liquid state and the glass transition, we gain a new insight into the different views on the relationship between entropy and relaxation dynamics of glass formers, showing the molecular grounds for the entropy scaling of global MD timescale. Our simulations in the anisotropic model of supercooled liquid, which involves only translational and rotational degrees of freedom, give evidence that the total system entropy is sufficient to scale global MD timescale. It complies with the scaling effect on relaxation dynamics exerted by the configurational entropy defined as the total entropy diminished by vibrational contributions, which was earlier discovered for measurement data collected near the glass transition. Moreover, we argue that such a scaling behavior is not possible to achieve by using the excess entropy that is in excess of the ideal gas entropy, which is contrary to the results earlier suggested within the framework of simple isotropic models of supercooled liquids. Thus, our findings also warn against an excessive reliance on isotropic models in theoretical interpretations of molecular phenomena, despite their simplicity and popularity, because they may reflect improperly various physicochemical properties of glass formers.

5.
Int J Mol Sci ; 23(17)2022 Aug 29.
Artículo en Inglés | MEDLINE | ID: mdl-36077212

RESUMEN

In this paper, we thoroughly investigated the physical stability of the anti-inflammatory drug etoricoxib, which has been reported earlier to be resistant to recrystallization in its glassy and supercooled states at ambient pressure. Our unique application of the standard refractometry technique showed that the supercooled liquid of the drug was able to recrystallize during isothermal experiments in atmospheric conditions. This enabled us to determine the crystallization onset timescale and nucleation energy barrier of etoricoxib for the first time. As the physical instability of etoricoxib requires working out an efficient method for improving the drug's resistance to recrystallization to maintain its amorphous form utility in potential pharmaceutical applications, we focused on finding a solution to this problem, and successfully achieved this purpose by preparing binary mixtures of etoricoxib with octaacetylmaltose. Our detailed thermal, refractometry, and molecular dynamics studies of the binary compositions near the glass transition revealed a peculiar behavior of the glass transition temperatures when changing the acetylated disaccharide concentration in the mixtures. Consequently, the anti-plasticization effect on the enhancement of physical stability could be excluded, and a key role for specific interactions in the improved resistance to recrystallization was expected. Invoking our previous results obtained for etoricoxib, the chemically similar drug celecoxib, and octaacetylmaltose, we formulated a hypothesis about the molecular mechanisms that may cause an impediment to crystal nuclei formation in the amorphous mixtures of etoricoxib with octaacetylmaltose. The most plausible scenario may rely on the formation of hydrogen-bonded heterodimers of the drug and excipient molecules, and the related drop in the population of the etoricoxib homodimers, which disables the nucleation. Nevertheless, this hypothesis requires further investigation. Additionally, we tested some widely discussed correlations between molecular mobility and crystallization properties, which turned out to be only partially satisfied for the examined mixtures. Our findings constitute not only a warning against manufacturing the amorphous form of pure etoricoxib, but also evidence for a promising outcome for the pharmaceutical application of the amorphous compositions with octaacetylmaltose.


Asunto(s)
Simulación de Dinámica Molecular , Vitrificación , Rastreo Diferencial de Calorimetría , Estabilidad de Medicamentos , Etoricoxib , Excipientes/química
6.
Front Pediatr ; 10: 839111, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35664873

RESUMEN

Objective: We aimed to assess BCG (Bacillus Calmette-Guérin) complications in patients with Inborn Errors of Immunity (IEI), according to the inherited disorders and associated immunological defects, as well as the different BCG substrains. Material: We studied adverse reactions to the locally-produced BCG Moreau vaccine, analyzed in patients with IEI diagnosed between 1980 and 2020 in the Department of Immunology, Children's Memorial Health Institute (CMHI), Warsaw. These results were compared with previously published studies. Results: Significantly fewer disseminated BCG infections (BCGosis) were found in 11 of 72 (15%) SCID (Severe Combined Immunodeficiency) NK (Natural Killer)-phenotype patients, when compared with the 119 out of 349 (34%) (p = 0.0012) patients with SCID with BCG in other countries. Significantly fewer deaths caused by BCGosis were observed (p = 0.0402). A significantly higher number of hematopoietic stem cell transplantations (HSCTs) were performed in the CMHI study (p = 0.00001). BCGosis was found in six patients with Mendelian susceptibility to mycobacterial diseases (MSMD). Other patients with IEI prone to BCG complications, such as CGD (Chronic Granulomatous Disease), showed no case of BCGosis. Conclusion: The BCG Moreau substrain vaccine, produced in Poland since 1955, showed genetic differences with its parental Brazilian substrain together with a superior clinical safety profile in comparison with the other BCG substrains, with no BCGosis in patients with IEI other than SCID and MSMD. Our data also confirmed significantly fewer cases of BCGosis and deaths caused by BCG infection in patients with SCID with this vaccine substrain. Finally, they confirmed the protecting role of NK cells, probably via their production of IFN-γ.

7.
Med Microbiol Immunol ; 210(5-6): 251-262, 2021 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-34338880

RESUMEN

The aim of this study was to compare the elimination of Bordetella pertussis clinical isolates, representing different genotypes in relation to alleles encoding virulence factors (MLST-multi-locus antigen sequence typing), MLVA type (multi-locus variable-number tandem repeat analysis) and PFGE group (pulsed-field gel electrophoresis) from the lungs of naive mice or mice were immunised with the commercial whole-cell pertussis vaccine, the acellular pertussis vaccine and the experimental whole-cell pertussis vaccine. Molecular data indicate that the resurgence of pertussis in populations with high vaccine coverage is associated with genomic adaptation of B. pertussis, to vaccine selection pressure. Pertactin-negative B. pertussis isolates were suspected to contribute to the reduced vaccine effectiveness. It was shown that one of the isolates used is PRN deficient. The mice were intranasally challenged with bacterial suspension containing approximately 5 × 10 7 CFU/ml B. pertussis. The immunogenicity of the tested vaccines against PT (pertussis toxin), PRN (pertactin), FHA (filamentous haemagglutinin) and FIM (fimbriae types 2 and 3) was examined. The commercial whole-cell and acellular pertussis vaccines induced an immunity effective at eliminating the genetically different B. pertussis isolates from the lungs. However, the elimination of the PRN-deficient isolate from the lungs of mice vaccinated with commercial vaccines was delayed as compared to the PRN ( +) isolate, suggesting phenotypic differences with the circulating isolates and vaccine strains. The most effective vaccine was the experimental vaccine with the composition identical to that of the strains used for infection.


Asunto(s)
Bordetella pertussis/inmunología , Vacuna contra la Tos Ferina/inmunología , Eficacia de las Vacunas , Tos Ferina/microbiología , Tos Ferina/prevención & control , Animales , Anticuerpos Antibacterianos/sangre , Carga Bacteriana , Bordetella pertussis/genética , Bordetella pertussis/crecimiento & desarrollo , Bordetella pertussis/aislamiento & purificación , Vacuna contra Difteria, Tétanos y Tos Ferina/inmunología , Vacunas contra Difteria, Tétanos y Tos Ferina Acelular/inmunología , Femenino , Perfil Genético , Inmunogenicidad Vacunal , Pulmón/microbiología , Ratones , Ratones Endogámicos BALB C , Tipificación de Secuencias Multilocus
8.
J Phys Chem Lett ; 12(8): 2142-2147, 2021 Mar 04.
Artículo en Inglés | MEDLINE | ID: mdl-33625856

RESUMEN

A series of five alcohols (3-methyl-2-butanol, 1-cyclopropylethanol, 1-cyclopentylethanol, 1-cyclohexylethanol, and 1-phenylethanol) was used to study the impact of the size of steric hindrance and its aromaticity on self-assembling phenomena in the liquid phase. In this Letter, we have explicitly shown that the phenyl ring exerts a much stronger effect on the self-organization of molecules via the O-H···O scheme than any other type of steric hindrance, leading to a significant decline in the size and concentration of the H-bonded clusters. Given the combination of calorimetric, dielectric, infrared, and diffraction studies, this phenomenon was ascribed to its additional proton-acceptor function for the competitive intermolecular O-H···π interactions. The consequence of this is a different packing of molecules on the short- and medium-range scale.

9.
J Chem Phys ; 154(6): 064701, 2021 Feb 14.
Artículo en Inglés | MEDLINE | ID: mdl-33588559

RESUMEN

Herein, we examined the effect of finite size and wettability on the structural dynamics and the molecular arrangement of the propylene carbonate derivative, (S)-(-)-4-methoxymethyl-1,3-dioxolan-2-one (assigned as s-methoxy-PC), incorporated into alumina and silica porous templates of pore diameters d = 4 nm-10 nm using Raman and broadband dielectric spectroscopy, differential scanning calorimetry, and x-ray diffraction. It was demonstrated that only subtle changes in the molecular organization and short-range order of confined s-methoxy-PC molecules were detected. Yet, a significant deviation of the structural dynamics and depression of the glass transition temperatures, Tg, was found for all confined samples with respect to the bulk material. Interestingly, these changes correlate with neither the finite size effects nor the interfacial energy but seem to vary with wettability, generally. Nevertheless, for s-methoxy-PC infiltrated into native (more hydrophilic) and modified (more hydrophobic) silica templates of the same nanochannel size (d = 4 nm), a change in the dynamics and Tg was negligible despite a significant variation in wettability. These results indicated that although wettability might be a suitable variable to predict alteration of the structural dynamics and depression of the glass transition temperature, other factors, i.e., surface roughness and the density packing, might also have a strong contribution to the observed confinement effects.

10.
Phys Chem Chem Phys ; 22(32): 17948-17959, 2020 Aug 28.
Artículo en Inglés | MEDLINE | ID: mdl-32747880

RESUMEN

In this work, we report the synthesis, unexpected glass-forming properties, molecular dynamics and conformational analysis of two thiacrown ethers: 6-methyl-2,3-dihydro-1,4-benzodithiine (1), with a six-membered heterocyclic ring, and macrocyclic 2,3-(4'-methylbenzo)-1,4-dithia-7-oxacyclononane (2). Based on the calorimetric studies, we showed that compound 1 is a viscous liquid at room temperature undergoing vitrification at 192 K. Compound 2 is a crystalline solid at room temperature characterized by a melting point at 331 K; however, it can be vitrified with ease after being melted by cooling down to 224 K. This gave us the unique possibility to analyze the dielectric response and to follow the molecular dynamics in supercooled liquid and glassy states for each thiacrown ether. Two relaxation processes were found for compound 1, which are structural α-relaxation, connected with the collective rotational motions of molecules in a liquid, and a low-temperature secondary γ-process, resulting from conformational changes in the heterocyclic ring. Beside these two relaxation processes, an additional intermolecular ß-process of JG type was detected in the case of compound 2. Finally, based on the analysis of the thermal evolution of the Kirkwood-Fröhlich factor, it has also been shown that thiacrown ethers may be characterized by a local ordering between neighboring molecules in the supercooled liquid state.

11.
Mol Pharm ; 17(8): 3087-3105, 2020 08 03.
Artículo en Inglés | MEDLINE | ID: mdl-32584584

RESUMEN

In this paper, we explore the strategy increasingly used to improve the bioavailability of poorly water-soluble crystalline drugs by formulating their amorphous solid dispersions. We focus on the potential application of a low molecular weight excipient octaacetyl-maltose (acMAL) to prepare physically stable amorphous solid dispersions with ibuprofen (IBU) aimed at enhancing water solubility of the drug compared to that of its crystalline counterpart. We thoroughly investigate global and local molecular dynamics, thermal properties, and physical stability of the IBU+acMAL binary systems by using broadband dielectric spectroscopy and differential scanning calorimetry as well as test their water solubility and dissolution rate. The obtained results are extensively discussed by analyzing several factors considered to affect the physical stability of amorphous systems, including those related to the global mobility, such as plasticization/antiplasticization effects, the activation energy, fragility parameter, and the number of dynamically correlated molecules as well as specific intermolecular interactions like hydrogen bonds, supporting the latter by density functional theory calculations. The observations made for the IBU+acMAL binary systems and drawn recommendations give a better insight into our understanding of molecular mechanisms governing the physical stability of amorphous solid dispersions.


Asunto(s)
Ibuprofeno/química , Maltosa/química , Acetilación/efectos de los fármacos , Rastreo Diferencial de Calorimetría/métodos , Química Farmacéutica/métodos , Cristalización/métodos , Estabilidad de Medicamentos , Excipientes/química , Simulación de Dinámica Molecular , Peso Molecular , Polímeros/química , Solubilidad/efectos de los fármacos
12.
BMC Infect Dis ; 20(1): 308, 2020 Apr 25.
Artículo en Inglés | MEDLINE | ID: mdl-32334517

RESUMEN

BACKGROUND: Diphtheria outbreaks occurred in endemic areas and imported and indigenous cases are reported in UE/EEA. Because of the high infectiveness and severity of the disease, early and accurate diagnosis of each suspected case is essential for the treatment and management of the case and close contacts. The aim of the study was to establish simple and rapid testing methods based on Loop-Mediated Isothermal Amplification (LAMP) assay for the detection of Corynebacterium diphtheriae and differentiation between toxigenic and non-toxigenic strains. METHODS: Corynebacterium diphtheriae and Corynebacterium ulcerans isolates from the National Institute of Public Health-National Institute of Hygiene collection were used for the development of LAMP assay for the diagnosis of diphtheria and nontoxigenic C. diphtheriae infections. Various colorimetric methods for visualization of results were investigated. Sensitivity and specificity of the assay were examined using a collection of DNA samples from various gram-positive and gram-negative bacteria. RESULTS: The LAMP assay for tox and dtxR genes was developed. The sensitivity and specificity of the assay were calculated as 100%. The detection limit was estimated as 1.42 pg/µl concentration of DNA template when the reaction was conducted for 60 min. However, the detection limit was lowered 10 times for every 10 min of reduction in the time of incubation during the reaction. Positive results were successfully detected colorimetrically using hydroxynaphthol blue, calcein, QuantiFluor, and lateral flow Milenia HybriDetect dipsticks. CONCLUSION: The assay developed in the study might be applied for point-of-care testing of diphtheria and other C. diphtheriae infections as well as for other infections caused by diphtheria-toxin producing Corynebacterium species. It is highly sensitive, specific, inexpensive, easy to use, and suitable for low-resource settings.


Asunto(s)
Colorimetría/métodos , Corynebacterium diphtheriae/genética , Difteria/microbiología , Técnicas de Amplificación de Ácido Nucleico/métodos , Proteínas Bacterianas/genética , Colorimetría/instrumentación , Corynebacterium diphtheriae/aislamiento & purificación , Proteínas de Unión al ADN/genética , Bacterias Gramnegativas/genética , Bacterias Grampositivas/genética , Humanos , Límite de Detección , Pruebas en el Punto de Atención
13.
J Clin Immunol ; 40(1): 138-146, 2020 01.
Artículo en Inglés | MEDLINE | ID: mdl-31749033

RESUMEN

OBJECTIVES: The aim of the study was to estimate the rate of adverse reactions to live BCG Moreau vaccine, manufactured by Biomed in Poland, in severe combined immunodeficiency (SCID) patients. MATERIAL: The profiles of 52 SCID patients vaccinated at birth with BCG, hospitalized in Children's Memorial Health Institute, Warsaw (CMHI), in the years 1980-2015 were compared with those of 349 BCG-vaccinated SCID patients from other countries analyzed by Beatriz E. Marciano et al. in a retrospective study (Marciano et al. J Allergy Clin Immunol. 2014;133(4):1134-1141). RESULTS: Significantly less disseminated BCG infections (10 out of 52 SCID, 19%) occurred in comparison with Marciano study-119 out of 349, 34% (p = 0.0028), with no death in patients treated with SCID anti-TB drug, except one in lethal condition. In our study, disseminated BCG infection was observed only in SCID with T-B+NK- phenotype and significantly lower NK cell counts (p = 0.0161). NK cells do not influence on the frequency of local BCG reaction. A significantly higher number of hematopoietic stem cells transplantations (HSCT) were performed in CMHI study (p = 0.0001). Anti-TB treatment with at least two medicines was provided. CONCLUSION: The BCG Moreau vaccine produced in Poland, with well-documented genetic characteristics, seems to be safer than other BCG substrains used in other regions of the world. Importantly, NK cells seem to play a role in protecting SCID patients against disseminated BCG complications, which NK- SCID patients are more prone to. HSCT and TB therapy could be relevant due to the patients' survival and the fact that they protect against BCG infection.


Asunto(s)
Vacuna BCG/inmunología , Células Asesinas Naturales/inmunología , Inmunodeficiencia Combinada Grave/inmunología , Preescolar , Femenino , Trasplante de Células Madre Hematopoyéticas/métodos , Humanos , Lactante , Recién Nacido , Masculino , Polonia , Estudios Retrospectivos , Tuberculosis/inmunología , Vacunación/métodos
14.
Pol J Microbiol ; 68(2): 233-246, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31250594

RESUMEN

The aim of this study was to identify the potential vaccine antigens in Corynebacterium diphtheriae strains by in silico analysis of the amino acid variation in the 67-72p surface protein that is involved in the colonization and induction of epithelial cell apoptosis in the early stages of infection. The analysis of pili structural proteins involved in bacterial adherence to host cells and related to various types of infections was also performed. A polymerase chain reaction (PCR) was carried out to amplify the genes encoding the 67-72p protein and three pili structural proteins (SpaC, SpaI, SapD) and the products obtained were sequenced. The nucleotide sequences of the particular genes were translated into amino acid sequences, which were then matched among all the tested strains using bioinformatics tools. In the last step, the affinity of the tested proteins to major histocompatibility complex (MHC) classes I and II, and linear B-cell epitopes was analyzed. The variations in the nucleotide sequence of the 67-72p protein and pili structural proteins among C. diphtheriae strains isolated from various infections were noted. A transposition of the insertion sequence within the gene encoding the SpaC pili structural proteins was also detected. In addition, the bioinformatics analyses enabled the identification of epitopes for B-cells and T-cells in the conserved regions of the proteins, thus, demonstrating that these proteins could be used as antigens in the potential vaccine development. The results identified the most conserved regions in all tested proteins that are exposed on the surface of C. diphtheriae cells.The aim of this study was to identify the potential vaccine antigens in Corynebacterium diphtheriae strains by in silico analysis of the amino acid variation in the 67­72p surface protein that is involved in the colonization and induction of epithelial cell apoptosis in the early stages of infection. The analysis of pili structural proteins involved in bacterial adherence to host cells and related to various types of infections was also performed. A polymerase chain reaction (PCR) was carried out to amplify the genes encoding the 67­72p protein and three pili structural proteins (SpaC, SpaI, SapD) and the products obtained were sequenced. The nucleotide sequences of the particular genes were translated into amino acid sequences, which were then matched among all the tested strains using bioinformatics tools. In the last step, the affinity of the tested proteins to major histocompatibility complex (MHC) classes I and II, and linear B-cell epitopes was analyzed. The variations in the nucleotide sequence of the 67­72p protein and pili structural proteins among C. diphtheriae strains isolated from various infections were noted. A transposition of the insertion sequence within the gene encoding the SpaC pili structural proteins was also detected. In addition, the bioinformatics analyses enabled the identification of epitopes for B-cells and T-cells in the conserved regions of the proteins, thus, demonstrating that these proteins could be used as antigens in the potential vaccine development. The results identified the most conserved regions in all tested proteins that are exposed on the surface of C. diphtheriae cells.


Asunto(s)
Adhesinas Bacterianas/genética , Antígenos Bacterianos/genética , Corynebacterium diphtheriae/genética , Toxoide Diftérico/genética , Difteria/prevención & control , Variación Genética , Proteínas de la Membrana/genética , Adhesinas Bacterianas/inmunología , Antígenos Bacterianos/inmunología , Biología Computacional , Secuencia Conservada , Corynebacterium diphtheriae/inmunología , Toxoide Diftérico/inmunología , Epítopos de Linfocito B/genética , Epítopos de Linfocito B/inmunología , Epítopos de Linfocito T/genética , Epítopos de Linfocito T/inmunología , Antígenos de Histocompatibilidad Clase I/inmunología , Antígenos de Histocompatibilidad Clase II/inmunología , Proteínas de la Membrana/inmunología , Reacción en Cadena de la Polimerasa , Unión Proteica , Análisis de Secuencia de ADN
15.
Microbes Infect ; 21(3-4): 170-175, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-30580013

RESUMEN

The introduction of pertussis vaccination in the 1950s resulted in a significant decrease in the incidence of disease. However, since the 1990s many highly vaccinated countries have observed the re-emergence of the disease. One of the causes of this phenomenon might be related to the adaptation of Bordetella pertussis to vaccination. The purpose of the presented study was an investigation of the emergence and spread of vaccine antigen-deficient B. pertussis isolates in Poland and genomic characterization of the currently circulating pathogen population using PFGE, MLVA and MAST. The results revealed that all tested isolates expressed Ptx, FHA and ACT antigens but 15.4% (4/26) of isolates from 2010 to 2016 were Prn-deficient. Moreover, one TcfA-deficient isolate was collected in 2015. The genotyping showed a genetic distinction between the isolates circulating in 2010-2016 and isolates from previous periods. The majority of currently circulating isolates belonged to PFGE group IV (96.2%), type MT27 (73.1%), and carried ptxA1-ptxC2-ptxP3-prn2-tcfA2-fim2-1-fim3-1 alleles (61.5%). The unique genetic structure of the B. pertussis population in Poland has changed since 2010 and became similar to that observed in countries with aP vaccination. This could be a result of increasing use of aP vaccines (60% of primary vaccination in 2013) over wP vaccines, which have been broadly used for primary vaccination in Poland for decades.


Asunto(s)
Antígenos Bacterianos/genética , Proteínas de la Membrana Bacteriana Externa/genética , Bordetella pertussis/genética , Bordetella pertussis/aislamiento & purificación , Vacuna contra la Tos Ferina/inmunología , Vacunación/métodos , Factores de Virulencia de Bordetella/genética , Tos Ferina/microbiología , Bordetella pertussis/inmunología , ADN Bacteriano/genética , Variación Genética/inmunología , Genoma Bacteriano/genética , Genotipo , Humanos , Polonia/epidemiología , Factores de Tiempo , Tos Ferina/epidemiología
16.
Arch Microbiol ; 200(9): 1407-1410, 2018 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-30182255

RESUMEN

Staphylococcus aureus subsp. anaerobius is an etiological agent of Morel's disease in small ruminants. The infection results in superficial abscesses located near lymph nodes. In the study, molecular analysis based on multilocus sequence typing (MLST) of seven housekeeping genes (arcC, aroE, glp, gmk, pta, tpi, yqiL) and random amplified polymorphic DNA (RAPD) was carried out on 19 S. aureus subsp. anaerobius strains isolated from two different goat herds from Poland. All of the 19 S. aureus subsp. anaerobius strains were found to belong to single MLST and RAPD types which support the high clonality level of this agent. However, the results obtained show clearly that the S. aureus subsp. anaerobius clone found in goats in Poland is different from those previously described. However, it is identical to the ATCC 38844 strain isolated from sheep in Spain, which has not been so far genotyped using MLST.


Asunto(s)
Enfermedades de las Cabras/microbiología , Cabras/microbiología , Infecciones Estafilocócicas/veterinaria , Staphylococcus aureus/genética , Staphylococcus aureus/aislamiento & purificación , Absceso/microbiología , Absceso/veterinaria , Animales , Genes Esenciales/genética , Genotipo , Tipificación de Secuencias Multilocus , Polonia , Técnica del ADN Polimorfo Amplificado Aleatorio , Infecciones Estafilocócicas/microbiología , Staphylococcus aureus/clasificación
17.
J Med Microbiol ; 66(6): 753-761, 2017 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-28598302

RESUMEN

PURPOSE: Despite the long history of pertussis vaccination and high vaccination coverage in Poland and many other developed countries, pertussis incidence rates have increased substantially, making whooping cough one of the most prevalent vaccine-preventable diseases. Among the factors potentially involved in pertussis resurgence, the adaptation of the Bordetella pertussis population to country-specific vaccine-induced immunity through selection of non-vaccine-type strains still needs detailed studies. METHODOLOGY: Multi-locus variable-number tandem repeat analysis (MLVA), also linked to MLST and PFGE profiling, was applied to trace the genetic changes in the B. pertussis population circulating in Poland in the period 1959-2013 versus country-specific vaccine strains. RESULTS: Generally, among 174 B. pertussis isolates, 31 MLVA types were detected, of which 11 were not described previously. The predominant MLVA types of recent isolates in Poland were different from those of the typical isolates circulating in other European countries. The MT27 type, currently predominant in Europe, was rarely seen and detected in only five isolates among all studied. The features of the vaccine strains used for production of the pertussis component of a national whole-cell diphtheria-tetanus-pertussis (DTP) vaccine, as studied by MLVA and MLST tools, were found to not match those observed in the currently circulating B. pertussis isolates in Poland. CONCLUSIONS: Differences traced by MLVA in relation to the MLST and PFGE profiling confirmed that the B. pertussis strain types currently observed elsewhere in Europe, even if appearing in Poland, were not able to successfully disseminate within a human population in Poland that has been vaccinated with a whole-cell pertussis vaccine not used in other countries.


Asunto(s)
Bordetella pertussis/genética , Repeticiones de Minisatélite , Tipificación de Secuencias Multilocus , Tos Ferina/epidemiología , Bordetella pertussis/clasificación , Bordetella pertussis/aislamiento & purificación , ADN Bacteriano/genética , Electroforesis en Gel de Campo Pulsado , Europa (Continente)/epidemiología , Variación Genética , Genotipo , Humanos , Vacuna contra la Tos Ferina/administración & dosificación , Vacuna contra la Tos Ferina/inmunología , Polonia/epidemiología , Vacunación , Tos Ferina/microbiología
18.
Postepy Hig Med Dosw (Online) ; 70(0): 1259-1266, 2016 Dec 21.
Artículo en Inglés | MEDLINE | ID: mdl-28026828

RESUMEN

Tuberculosis was, and still is, one of the main causes of morbidity and mortality in the world. Thus it still remains a public health priority. Nonetheless, without a newly developed vaccine, it is rather unlikely to be easily resolved. The only available vaccine against tuberculosis (BCG) has been used for nearly 100 years. Currently a variety of BCG substrains are used by many manufacturers in the world. All these substrains were obtained from a single parental strain of Mycobacterium bovis. Attempts to explain the complete mechanisms of attenuation, as well as tracing the microevolution resulting from the different distribution time and conditions of production of BCG vaccines in the different parts of the world, might explain the differences in the observed efficacy of vaccines produced with different substrains. The most important marker associated with attenuation of virulent M. bovis is the loss of the RD1 region observed in all BCG substrains. Among other attenuation markers, still not completely identified, accumulation of SNP mutations seems to be an important one. The different number of passages and culture conditions of the parental vaccine strain have led to there being about 50 different sister vaccine BCG substrains throughout the world. Among them, there are "early strains", distributed until 1927, and "later strains" with the RD2 deletion obtained during 1927­1961. It has also been found that 22 regions containing 52 genes were lost during the distribution of sister substrains during the period 1924­1966. Genetic differences due to selection pressure, revealing specific microevolutionary traits, may explain the variability in immunogenicity and residual virulence of each vaccine BCG substrain.


Asunto(s)
Vacuna BCG/genética , Mycobacterium bovis/genética , Mycobacterium tuberculosis/genética , Tuberculosis/microbiología , Tuberculosis/prevención & control , Vacuna BCG/clasificación , Vacuna BCG/inmunología , Genoma Bacteriano/genética , Humanos , Mycobacterium bovis/clasificación , Mycobacterium tuberculosis/clasificación , Virulencia/genética
19.
Adv Drug Deliv Rev ; 100: 158-82, 2016 05 01.
Artículo en Inglés | MEDLINE | ID: mdl-26705851

RESUMEN

In recent years, there is a growing interest in improving the physicochemical stability of amorphous pharmaceutical solids due to their very promising applications to manufacture medicines characterized by a better water solubility, and consequently by a higher dissolution rate than those of their crystalline counterparts. In this review article, we show that the molecular mobility investigated both in the supercooled liquid and glassy states is the crucial factor required to understand molecular mechanisms that govern the physical stability of amorphous drugs. We demonstrate that pharmaceuticals can be thoroughly examined by means of the broadband dielectric spectroscopy, which is a very useful experimental technique to explore different relaxation processes and crystallization kinetics as well. Such studies conducted in the wide temperature and pressure ranges provide data needed in searching correlations between properties of molecular dynamics and crystallization process, which are aimed at developing effective and efficient methods for stabilizing amorphous drugs.


Asunto(s)
Preparaciones Farmacéuticas , Cristalización , Cinética , Simulación de Dinámica Molecular , Solubilidad
20.
Sci Rep ; 5: 13998, 2015 Sep 14.
Artículo en Inglés | MEDLINE | ID: mdl-26365623

RESUMEN

To solve a long-standing problem of condensed matter physics with determining a proper description of the thermodynamic evolution of the time scale of molecular dynamics near the glass transition, we have extended the well-known Adam-Gibbs model to describe the temperature-volume dependence of structural relaxation times, τα(T, V). We also employ the thermodynamic scaling idea reflected in the density scaling power law, τα = f(T(-1)V(-γ)), recently acknowledged as a valid unifying concept in the glass transition physics, to differentiate between physically relevant and irrelevant attempts at formulating the temperature-volume representations of the Adam-Gibbs model. As a consequence, we determine a straightforward relation between the structural relaxation time τα and the configurational entropy SC, giving evidence that also SC(T, V) = g(T(-1)V(-γ)) with the exponent γ that enables to scale τα(T, V). This important findings have meaningful implications for the connection between thermodynamics and molecular dynamics near the glass transition, because it implies that τα can be scaled with SC.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...