Enzymatic degradation of biostatic materials based on polylactide

The paper presents the research results for enzymatic degradation of biodegradable materials in proteinase K. Polylactide and its composites containing a biostatic substance in the form of sulphanilic acid salt PHMG were tested as part of the research project. Three different concentrations of the biostatic substance were used: 0.2%, 0.6% and 1.0 % of the mass. The research results of differential scanning calorimetry (DSC) for the tested materials were compared both before and after the enzymatic degradation. Photographs obtained from a scanning electron microscope (SEM) and the analysis of the foil physical mass loss confirmed that these materials were susceptible to enzymes

Bacterial biofilm on PLA film and methods of its identification

This paper presents a brief characterization of bacterial biofilm, formed on polylactide, ecologically important biodegradable material. The concept of bacterial biofilm was explained, including the process of its formation as well as the structure and model of functioning in a biological environment. Three methods of its determination and documentation by spectrophotometric measurement, live/dead test using fluorescence microscope and surface structure analysis using scanning electron microscope were presented

New biodegradable polylactide material with antimicrobial properties

This study aimed to investigate the bactericidal, fungicidal and non-phytotoxic properties of vapor permeable polylactide films containing five different concentrations (in the range of 0.2–1.0%) of thiabendazole. All films showed bactericidal properties on Staphylococcus aureus and Escherichia coli. Thiabendazole introduced into polylactide affected the antifungal activity of the materials containing 0.8 and 1.0% thiabendazole. The films containing thiabendazole were characterized by increased permeability. The vapor permeability of the film increased with the increase of the biocide content in the composites. The new materials had no a negative effect on the growth and development of monocotyledonous and dicotyledonous plants. It has been shown that the presence of thiabendazole increases the water vapor permeability of polylactide films. The obtained materials are biodegradable and can be used in horticulture and agriculture to protect plants against pathogens. The use of films with biocide properties will reduce the use of plant protection products. This is particularly important due to the need to protect biodiversity in the ecosystem of agricultural soils

Growth of selected fungi on biodegradable films

This study presents the data summary on growth speed of selected species of fungi on some of biodegradable polymer materials. Growth speed was assessed on films composed of poly(lactide), poly(ε-caprolactone) and poly(hydroxybutyrate) after a month of incubation in 24oC. To assess growth of fungi optical microscopy on densitometric measurements were used. Through these analyses the best growth was confirmed for fungus: Chaetomium globosum (ATTC 6205) on a film made of poly(ε -caprolactone)

Biodiversity of bacteriophages: morphological and biological properties of a large group of phages isolated from urban sewage

A large scale analysis presented in this article focuses on biological and physiological variety of bacteriophages. A collection of 83 bacteriophages, isolated from urban sewage and able to propagate in cells of different bacterial hosts, has been obtained (60 infecting Escherichia coli, 10 infecting Pseudomonas aeruginosa, 4 infecting Salmonella enterica, 3 infecting Staphylococcus sciuri, and 6 infecting Enterococcus faecalis). High biological diversity of the collection is indicated by its characteristics, both morphological (electron microscopic analyses) and biological (host range, plaque size and morphology, growth at various temperatures, thermal inactivation, sensitivity to low and high pH, sensitivity to osmotic stress, survivability upon treatment with organic solvents and detergents), and further supported by hierarchical cluster analysis. By the end of the research no larger collection of phages from a single environmental source investigated by these means had been found. The finding was confirmed by whole genome analysis of 7 selected bacteriophages. Moreover, particular bacteriophages revealed unusual biological features, like the ability to form plaques at low temperature (4 °C), resist high temperature (62 °C or 95 °C) or survive in the presence of an organic solvents (ethanol, acetone, DMSO, chloroform) or detergent (SDS, CTAB, sarkosyl) making them potentially interesting in the context of biotechnological applications

Characterization of Bacteriophage vB-EcoS-95, Isolated From Urban Sewage and Revealing Extremely Rapid Lytic Development

Morphological, biological, and genetic characteristics of a virulent Siphoviridae phage, named vB-EcoS-95, is reported. This phage was isolated from urban sewage. It was found to infect some Escherichia coli strains giving clear plaques. The genome of this phage is composed of 50,910 bp and contains 89 ORFs. Importantly, none of the predicted ORFs shows any similarity with known pathogenic factors that would prevent its use in medicine. Genome sequence analysis of vB-EcoS-95 revealed 74% similarity to genomic sequence of Shigella phage pSf-1. Compared to pSf-1, phage vb-EcoS-95 does not infect Shigella strains and has an efficient bacteriolytic activity against some E. coli strains. One-step growth analysis revealed that this phage has a very short latent period (4 min), and average burst size of 115 plaque forming units per cell, which points to its high infectivity of host cells and strong lytic activity. The bacteriolytic effect of vB-EcoS-95 was tested also on biofilm-producing strains. These results indicate that vB-EcoS-95 is a newly discovered E. coli phage that may be potentially used to control the formation of biofilms

Very late relapse of ALL after 14 years: treatment with CAR-T cells

Not require

Changing risk factors in childhood acute lymphoblastic leukemia: experience from Kujawsko-Pomorski region 1976–2018

Introduction: Acute lymphoblastic leukemia (ALL) is the most common malignancy in children. Risk factors in childhood ALL have changed during recent decades, mostly due to treatment personalization. The aim of this study was to analyze therapy results and prognostic factors in childhood ALL in the Kujawsko-Pomorski region of Poland between 1976 and 2018. Material and methods: Data from 495 patients (0–18 years old) diagnosed with ALL from the Kujawsko-Pomorski region between 1976 and 2018 was analyzed. Prognostic factors were analyzed separately in specific therapeutic groups, which were defined by several therapy protocols. Results: Prognostic factors have changed over the course of consecutive therapeutic periods. Between 1976 and 1988 (the first and second therapeutic protocols), central nervous system involvement was the most important risk factor. During the third therapeutic period, an unsatisfactory treatment response on days 8 and 14 was related to a poor outcome. In 1995–2002, the risk factors were hepatomegaly, splenomegaly, lymph nodes involvement, and unsatisfactory therapy response on days 15 and 33. Between 2002 and 2011, immunophenotype other than ‘common’ and hemoglobin level at diagnosis were the risk factors, and a lack of BCR-ABL aberration was related to better therapy results. During the final analyzed period (2011–2018), failure to achieve remission on day 33 was a risk factor, and patients classified as non-high risk group and those aged <6 years had better outcomes. Conclusions: The changing profile of risk factors in ALL has reflected progress in ALL therapy, with the gradual elimination of factors related to poor outcomes, mostly due to modifications in treatment and the development of diagnostic methods as well as therapy monitoring

High risk of invasive fungal disease in children undergoing hematopoietic cell transplantation or complex anticancer therapy: the adverse role of post-transplant CMV replication

Introduction: We analyzed the epidemiology and outcomes of treatment of invasive fungal disease (IFD) in children during anticancer therapy (PHO, pediatric hematology and oncology) or after hematopoietic cell transplantation (HCT) over a period of eight consecutive years in a single-center study. Material and methods: Overall, a total of 254 HCTs were performed, and 415 children were newly diagnosed for malignancy. Incidence, epidemiology and outcome of IFD were analyzed. Results: The cumulative incidence of any IFD was 32.6% in allo-HCT, 22.2% in PHO, and 6.0% in auto-HCT patients. The incidence of proven +probable IFD was 12.6%, 10.4%, and 6.0%, respectively. As many as 77.0% HCT and 67.4% PHO of fungal episodes occurred in acute leukemia patients: the highest incidence of any IFD was observed for acute lymphoblastic leukemia (29.3% in HCT; 40.5% in PHO) and for acute myeloblastic leukemia (51.1% in HCT; 65.0% in PHO) patients. There were no significant differences in the incidence of fungal infections in both allo-HCT and PHO patients between the 2-year periods. Factors contributing to an increased risk of IFD in allo-HCT patients were: CMV replication, and acute and chronic graft-versus-host disease (GvHD). Survival from IFD was 91.9% in PHO, and 78.1% in HCT patients. Fungal pneumonia in HCT patients resolved in 62.9%, while in PHO patients it resolved in 93.5%. Conclusions: The risk of IFD in allo-HCT patients is much higher than in auto-HSCT and PHO patients. The outcome of IFD is better in PHO and auto-HCT than in allo-HCT settings