32 research outputs found
Antifungal activity of selected Malassezia indolic compounds detected in culture
Background: Malassezia yeasts produce bioactive indolic substances when grown on Lâtryptophan agar. A panel of these substances was tested against commensal and opportunistic fungi, the Minimum Inhibitory Concentration (MIC) was determined and the potential for in loco antifungal activity on the skin was assessed.
Materials and Methods: Eight indoles were included (malassezin, pityriacitrin, indirubin, indolo[3,2âb]carbazole, 6âformylindolo[3,2âb]carbazole, tryptanthrin, 6âhydroxymethylindolo[3,2âb]carbazole and 6âmethylindolo[3,2âb]carbazole) and were tested against 40 fungal strains [yeasts: Malassezia spp.(N = 9); Cryptococcus spp.(N = 10); Candida spp.(N = 7); Yarrowia lipolytica(N = 1); Exophialla dermatitidis (N = 2); moulds: Aspergillus spp.(N = 7); Fusarium spp.(N = 2); Rhizopus oryzae(N = 2)]. The concentration of 5/8 of the tested indoles on diseased skin was calculated from published data. KruskalâWallis and MannâWhitney U tests were employed for group susceptibility evaluation in 33 strains.
Results: The MIC range was 0.125â32 ÎŒg/mL, and the median log2MIC was four. Indirubin was the most potent antifungal agent and differed significantly from the others. The highest median MIC was found for FICZ.
Malassezia with Candida strains were more susceptible compared to Cryptococcus and Aspergillus, and this inhibitory activity was predicted to be valid also on human skin.
Conclusions: Malassezia yeasts produce indolic species that inhibit an array of clinically significant yeasts and moulds
No Evidence of Persisting Unrepaired Nuclear DNA Single Strand Breaks in Distinct Types of Cells in the Brain, Kidney, and Liver of Adult Mice after Continuous Eight-Week 50 Hz Magnetic Field Exposure with Flux Density of 0.1 mT or 1.0 mT
BACKGROUND: It has been hypothesized in the literature that exposure to extremely low frequency electromagnetic fields (50 or 60 Hz) may lead to human health effects such as childhood leukemia or brain tumors. In a previous study investigating multiple types of cells from brain and kidney of the mouse (Acta Neuropathologica 2004; 107: 257-264), we found increased unrepaired nuclear DNA single strand breaks (nDNA SSB) only in epithelial cells of the choroid plexus in the brain using autoradiographic methods after a continuous eight-week 50 Hz magnetic field (MF) exposure of adult mice with flux density of 1.5 mT. METHODS: In the present study we tested the hypothesis that MF exposure with lower flux densities (0.1 mT, i.e., the actual exposure limit for the population in most European countries, and 1.0 mT) shows similar results to those in the previous study. Experiments and data analysis were carried out in a similar way as in our previous study. RESULTS: Continuous eight-week 50 Hz MF exposure with 0.1 mT or 1.0 mT did not result in increased persisting unrepaired nDNA SSB in distinct types of cells in the brain, kidney, and liver of adult mice. MF exposure with 1.0 mT led to reduced unscheduled DNA synthesis (UDS) in epithelial cells in the choroid plexus of the fourth ventricle in the brain (EC-CP) and epithelial cells of the cortical collecting duct in the kidney, as well as to reduced mtDNA synthesis in neurons of the caudate nucleus in the brain and in EC-CP. CONCLUSION: No evidence was found for increased persisting unrepaired nDNA SSB in distinct types of cells in the brain, kidney, and liver of adult mice after continuous eight-week 50 Hz magnetic field exposure with flux density of 0.1 mT or 1.0 mT
Chemotherapy in conjoint aging-tumor systems: some simple models for addressing coupled aging-cancer dynamics
Background
In this paper we consider two approaches to examining the complex dynamics of conjoint aging-cancer cellular systems undergoing chemotherapeutic intervention. In particular, we focus on the effect of cells growing conjointly in a culture plate as a precursor to considering the larger multi-dimensional models of such systems. Tumor cell growth is considered from both the logistic and the Gompertzian case, while normal cell growth of fibroblasts (WI-38 human diploid fibroblasts) is considered as logistic only. Results
We demonstrate, in a simple approach, how the interdependency of different cell types in a tumor, together with specifications of for treatment, can lead to different evolutionary patterns for normal and tumor cells during a course of therapy. Conclusions
These results have significance for understanding appropriate pharmacotherapy for elderly patients who are also undergoing chemotherapy
Advanced keratinocyte skin cancer is a tumor with considerable disease burden and aggressiveness
In a 2013 study published in this Journal, Dacosta Byfield et al. used MediCare data to extract reliable estimations of the incidence (Iâ=â6.16) and prevalence (Pâ=â10.31) rates of advanced keratinocyte skin cancer (aKSC) per 100,000 US population. These data unmask a considerable disease burden of aKSC (tumor stagesââ„â3) compared to the corresponding projected SEER predictions in 2019 of all invasive cases (tumor stagesââ„â1). According to its incidence, aKSC ranks 19th out of 29 major SEER registered neoplasms and has an average disease duration of 1.67 years, which is the second shortest disease duration next only to pancreatic carcinoma. Furthermore, in support of the high disease aggressiveness of aKSC and using a calibration approach, we calculated a mortality estimate of 4.64 per 100,000 and a 5-year survival rate of 21.8% for this tumor, which corresponds to positions of 13th and 5th out of 29 cancers among the SEER tracked malignancies, respectively. Taken together, these data indicate a considerable disease burden and biologic aggressiveness of aKSC
Psoriasis and inflammatory bowel disease: links and risks
Christoforos Vlachos,1 Georgios Gaitanis,1 Konstantinos H Katsanos,2 Dimitrios K Christodoulou,2 Epameinondas Tsianos,2 Ioannis D Bassukas1 1Department of Skin and Venereal Diseases, 2Division of Gastroenterology, Faculty of Medicine, School of Health Sciences, University of Ioannina, Ioannina, Greece Abstract: Psoriasis and the spectrum of inflammatory bowel diseases (IBD) are chronic, inflammatory, organotropic conditions. The epidemiologic coexistence of these diseases is corroborated by findings at the level of disease, biogeography, and intrafamilial and intrapatient coincidence. The identification of shared susceptibility loci and DNA polymorphisms has confirmed this correlation at a genetic level. The pathogenesis of both diseases implicates the innate and adaptive segments of the immune system. Increased permeability of the epidermal barrier in skin and intestine underlies the augmented interaction of allergens and pathogens with inflammatory receptors of immune cells. The immune response between psoriasis and IBD is similar and comprises phagocytic, dendritic, and natural killer cell, along with a milieu of cytokines and antimicrobial peptides that stimulate T-cells. The interplay between dendritic cells and Th17 cells appears to be the core dysregulated immune pathway in all these conditions. The distinct similarities in the pathogenesis are also reflected in the wide overlapping of their therapeutic approaches. Small-molecule pharmacologic immunomodulators have been applied, and more recently, biologic treatments that target proinflammatory interleukins have been introduced or are currently being evaluated. However, the fact that some treatments are quite selective for either skin or gut conditions also highlights their crucial pathophysiologic differences. In the present review, a comprehensive comparison of risk factors, pathogenesis links, and therapeutic strategies for psoriasis and IBD is presented. Specific emphasis is placed on the role of the immune cell species and inflammatory mediators participating in the pathogenesis of these diseases. Keywords: psoriasis, inflammatory bowel disease, Crohn’s disease, ulcerative colitis, immune cells, inflammatio
Proof of concept for the clinical effects of oral rilzabrutinib, the first Bruton tyrosine kinase inhibitor for pemphigus vulgaris: the phase II BELIEVE study
BACKGROUND: Bruton tyrosine kinase (BTK) inhibition targets B-cell and other non-T-cell immune cells implicated in the pathophysiology of pemphigus, an autoimmune disease driven by anti-desmoglein autoantibodies. Rilzabrutinib is a new reversible, covalent BTK inhibitor demonstrating preclinical efficacy as monotherapy in canine pemphigus foliaceus. OBJECTIVES: To evaluate the efficacy and safety of oral rilzabrutinib in patients with pemphigus vulgaris in a multicentre, proof-of-concept, phase II trial. METHODS: Patients with Pemphigus Disease Area Index severity scores 8-45 received 12 weeks of oral rilzabrutinib 400-600 mg twice daily and 12 weeks of follow-up. Patients initially received between 0 and †0·5 mg kg-1 prednisone-equivalent corticosteroid (CS; i.e. 'low dose'), tapered after control of disease activity (CDA; no new lesions, existing lesions healing). The primary endpoints were CDA within 4 weeks on zero-to-low-dose CS and safety. RESULTS: In total, 27 patients with pemphigus vulgaris were included: nine newly diagnosed (33%) and 18 relapsing (67%); 11 had moderate disease (41%) and 16 moderate to severe (59%). The primary endpoint, CDA, was achieved in 14 patients (52%, 95% confidence interval 32-71): 11 using low-dose CS and three using no CS. Over 12 weeks of treatment, mean CS doses reduced from 20·0 to 11·8 mg per day for newly diagnosed patients and from 10·3 to 7·8 mg per day for relapsing patients. Six patients (22%) achieved complete response by week 24, including four (15%) by week 12. Treatment-related adverse events were mostly mild (grade 1 or 2); one patient experienced grade 3 cellulitis. CONCLUSIONS: Rilzabrutinib alone, or with much lower CS doses than usual, was safe, with rapid clinical activity in pemphigus vulgaris. These data suggest that BTK inhibition may be a promising treatment strategy and support further investigation of rilzabrutinib for the treatment of pemphigus