Light and immunoelectronmicroscopic study of Hodgkin’s disease: Evidence of immunoglobulin synthesis by tumor cells

The direct immunoperoxidase technique with peroxidase-conjugated F(ab')2 fragments was used at the light and electron microscopic levels to identify intracytoplasmic immunoglobulin (CIg) components in malignant cells of Hodgkin's disease. In each of the 27 cases studied, Hodgkin and Reed-Sternberg cells contained either IgG or IgM, with both light chains often present simultaneously. The number of IgG-positive malignant cells was inversely related to changes in the lymphoid compartment, as defined by the Rye grading system. The evolution from lymphocytic predominance to lymphocytic depletion was paralleled by a decrease of IgM-positive cells and by a substantial increase (to exclusiveness) of IgG-containing cells. These immunoelectronmicroscopic studies disclosed definite morphologic evidence of CIg synthesis by Hodgkin, Reed-Sternberg and lacunar cells. The immunoglobulin components were also synthesized by lymphoid B cells at different levels of modulation. Immunoglobulin synthesis by malignant cells was localized in perinuclear zone, on free cytoplasmic ribosomes and profiles of rough endoplasmic reticulum. The results of this joint light and electron microscopic study support the view that Hodgkin, Reed-Sternberg and lacunar cells belong to the B-cell compartment within Hodgkin's disease.     

Extensive activation,tissue trafficking,turnover and functional impairment of NK cells in COVID-19 patients at disease onset associates with subsequent disease severity

The SARS-CoV-2 infection causes severe respiratory involvement (COVID-19) in 5–20% of patients through initial immune derangement, followed by intense cytokine production and vascular leakage. Evidence of immune involvement point to the participation of T, B, and NK cells in the lack of control of virus replication leading to COVID-19. NK cells contribute to early phases of virus control and to the regulation of adaptive responses. The precise mechanism of NK cell dysregulation is poorly understood, with little information on tissue margination or turnover. We investigated these aspects by multiparameter flow cytometry in a cohort of 28 patients hospitalized with early COVID-19.Relevant decreases in CD56^brightCD16+/- NK subsets were detected, with a shift of circulating NK cells toward more mature CD56^dimCD16+KIR+NKG2A+ and “memory” KIR+CD57+CD85j+ cells with increased inhibitory NKG2A and KIR molecules. Impaired cytotoxicity and IFN-γ production were associated with conserved expression of natural cytotoxicity receptors and perforin. Moreover, intense NK cell activation with increased HLA-DR and CD69 expression was associated with the circulation of CD69+CD103+ CXCR6+ tissue-resident NK cells and of CD34+DNAM-1^brightCXCR4+ inflammatory precursors to mature functional NK cells. Severe disease trajectories were directly associated with the proportion of CD34+DNAM-1^brightCXCR4+ precursors and inversely associated with the proportion of NKG2D+ and of CD103+ NK cells.Intense NK cell activation and trafficking to and from tissues occurs early in COVID-19, and is associated with subsequent disease progression, providing an insight into the mechanism of clinical deterioration. Strategies to positively manipulate tissue-resident NK cell responses may provide advantages to future therapeutic and vaccine approaches.     

Impact of neonatal hypoxia‐ischaemia on oligodendrocyte survival,maturation and myelinating potential

Hypoxic‐ischaemic episodes experienced at the perinatal period commonly lead to a development of neurological disabilities and cognitive impairments in neonates or later in childhood. Clinical symptoms often are associated with the observed alterations in white matter in the brains of diseased children, suggesting contribution of triggered oligodendrocyte/myelin pathology to the resulting disorders. To date, the processes initiated by perinatal asphyxia remain unclear, hampering the ability to develop preventions. To address the issue, the effects of temporal hypoxia‐ischaemia on survival, proliferation and the myelinating potential of oligodendrocytes were evaluated ex vivo using cultures of hippocampal organotypic slices and in vivo in rat model of perinatal asphyxia. The potential engagement of gelatinases in oligodendrocyte maturation was assessed as well. The results pointed to a significant decrease in the number of oligodendrocyte progenitor cells (OPCs), which is compensated for to a certain extent by the increased rate of OPC proliferation. Oligodendrocyte maturation seemed however to be significantly altered. An ultrastructural examination of selected brain regions performed several weeks after the insult showed however that the process of developing central nervous system myelination proceeds efficiently resulting in enwrapping the majority of axons in compact myelin. The increased angiogenesis in response to neonatal hypoxic‐ischaemic insult was also noticed. In conclusion, the study shows that hypoxic‐ischaemic episodes experienced during the most active period of nervous system development might be efficiently compensated for by the oligodendroglial cell response triggered by the insult. The main obstacle seems to be the inflammatory process modulating the local microenvironment.     

Arguments for biodiversity conservation: factors influencing their observed effectiveness in European case studies

Making a strong case for biodiversity protection is central to meeting the biodiversity targets in international agreements such as the CBD and achieving the UN Sustainable Development Goals. Effective arguments are needed to convince diverse actors that protection is worthwhile, and can play a crucial role in closing the implementation gap between biodiversity policy targets and outcomes. Drawing on a database of arguments from 11 European case studies, along with additional interview and case study material from all 13 case studies of the BESAFE project, we analysed relationships between potential and observed effectiveness of arguments. Our results show that strong logic, robustness, and timing of arguments are necessary but not sufficient conditions for arguments to be effective. We find that use of multiple and diverse arguments can enhance effectiveness by broadening the appeal to wider audiences, especially when arguments are repeated and refined through constructive dialogue. We discuss the role of framing, bundling and tailoring arguments to audiences in increasing effectiveness. Our results provide further support for the current shift towards recognition of value pluralism in biodiversity science and decision-making. We hope our results will help to demonstrate more convincingly the value of biodiversity to stakeholders in decision processes and thus build better cases for its conservation.     

How does biodiversity conservation argumentation generate effects in policy cycles?

Arguments in the formulation, implementation and evaluation of biodiversity policy frame conservation in a range of ways and express interests that can be conflicting. Policy processes are cyclic and iterative by nature and as policies are constantly reformulated, argumentation has an important role at each policy stage. In this paper, we utilise the policy cycle model to shed light on biodiversity-related policy processes and the ways in which argumentation generates effects at different stages of these processes. The paper first draws on literature and the theory-driven assumptions are then illustrated with insights from four European case studies on different policy processes in which biodiversity conservation plays a role. The analysis shows that argumentation tends to evolve over the course of the policy cycle, and framing has a key role across the different policy stages. It is concluded that the ways in which arguments persist, accumulate, diffuse, and replace old arguments, should be the target of increased attention in policy analysis.     

β-N-Acetylglucosaminidase MthNAG from Myceliophthora thermophila C1, a thermostable enzyme for production of N-acetylglucosamine from chitin

Applied Microbiology and Biotechnology - Thermostable enzymes are a promising alternative for chemical catalysts currently used for the production of N-acetylglucosamine (GlcNAc) from chitin. In...     

Cadmium effect on hydrogen peroxide, gluthatione and phytochelatins levels in potato tuber

Short-term treatment of potato tuber (Solanum tuberosum L.) dises with CdCl₂ (1mM) induced an oxidative stress, manifested by higher levels of H₂O₂, and activated the synthesis of phytochclatins ((γ-Glu-Cys)_n-Gly): PC₂, PC₃ and PC₄. If in the tissues with a lower GSH level, the oxidative stress was induced by treatment with 3-aminotriazol (AT), or with AT and H₂O₂, the elevation of H₂O₂ and GSH levels and then some accumulation of thiols, including PC₂, PC₃ and PC₄, were observed. However, this increase of PC concentration was considerably lower when compared with the effects brought about by Cd⁺² treatment. If such a procedure of evoking subsequent moderate oxidative stress in tissues preceded Cd-treatment, a marked limitation of PC synthesis was observed. The presented results support the role of H₂O₂ as the second messenger in activating GSH synthesis and thus suggest a possibility of redox type regulation mechanism of PCs synthesis.