18 research outputs found
Relevance of Positron-Emission Therapy for Optimization of Treatment of Advanced Hodgkin’s Lymphoma Using Intensive ЕАСОРР-14 Program
Aim. To evaluate the relevance of the positron-emission therapy (PET) for optimization of the therapy of advanced Hodgkin’s lymphoma (HL) using the intensive EACOPP-14 program.
Materials & Methods. 91 patients with advanced HL (IIX–IIE, III–IV) received the treatment according to the “ЛХМосква1-3” protocol over the period from November 2009 to February 2015, and then the treatment was analyzed. The median age was 29 years (range: 17–50); there were 42 men (46.3 %) and 49 (53.7 %) women. The treatment included 6 cycles of polychemotherapy according to the regimen ЕА(50)СОРР-14 ± radiation therapy. The radiation therapy was performed in 66 patients (72.5 %) after the completion of the chemotherapy. The cumulative focal dose was 30 Gy onto the areas of residual lesions and/or initially large tumor masses.
Results. PET performed during the initial HL diagnosing permited to identify new areas of neoplastic lesions without changes in staging and treatment scheme, as well as specify areas and field size of planned radiation consolidation. The paper confirms the prognostic value of the intermediate PET in patients with advanced HL during the intensive first-line chemotherapy. The intensive therapy at the beginning of the treatment program is associated with higher chances for survival for patients with extremely unfavorable prognosis. After completion of the drug therapy, negative PET findings had a higher prognostic value, than the positive ones. The analysis of the relevance of residual tumor dimensions in the PET negative group demonstrated that the relapses were more common, if the residual tumor was more than 4.5 cm (according to CT findings).
Conclusion. This study confirmed that it reasonable to discuss the discontinuation of the radiation therapy in patients with advanced HL, negative PET findings and small (< 2.5 cm) residual tumor after the intensive ЕАСОРР-14 program. This tactics permits avoiding a number of delayed complications
Dengue Virus Ensures Its Fusion in Late Endosomes Using Compartment-Specific Lipids
Many enveloped viruses invade cells via endocytosis and use different environmental factors as triggers for virus-endosome fusion that delivers viral genome into cytosol. Intriguingly, dengue virus (DEN), the most prevalent mosquito-borne virus that infects up to 100 million people each year, fuses only in late endosomes, while activation of DEN protein fusogen glycoprotein E is triggered already at pH characteristic for early endosomes. Are there any cofactors that time DEN fusion to virion entry into late endosomes? Here we show that DEN utilizes bis(monoacylglycero)phosphate, a lipid specific to late endosomes, as a co-factor for its endosomal acidification-dependent fusion machinery. Effective virus fusion to plasma- and intracellular- membranes, as well as to protein-free liposomes, requires the target membrane to contain anionic lipids such as bis(monoacylglycero)phosphate and phosphatidylserine. Anionic lipids act downstream of low-pH-dependent fusion stages and promote the advance from the earliest hemifusion intermediates to the fusion pore opening. To reach anionic lipid-enriched late endosomes, DEN travels through acidified early endosomes, but we found that low pH-dependent loss of fusogenic properties of DEN is relatively slow in the presence of anionic lipid-free target membranes. We propose that anionic lipid-dependence of DEN fusion machinery protects it against premature irreversible restructuring and inactivation and ensures viral fusion in late endosomes, where the virus encounters anionic lipids for the first time during entry. Currently there are neither vaccines nor effective therapies for DEN, and the essential role of the newly identified DEN-bis(monoacylglycero)phosphate interactions in viral genome escape from the endosome suggests a novel target for drug design
Regulation of ABCC6 trafficking and stability by a conserved C-terminal PDZ-like sequence
Mutations in the ABCC6 ABC-transporter are causative of pseudoxanthoma elasticum (PXE). The loss of functional ABCC6 protein in the basolateral membrane of the kidney and liver is putatively associated with altered secretion of a circulatory factor. As a result, systemic changes in elastic tissues are caused by progressive mineralization and degradation of elastic fibers. Premature arteriosclerosis, loss of skin and vascular tone, and a progressive loss of vision result from this ectopic mineralization. However, the identity of the circulatory factor and the specific role of ABCC6 in disease pathophysiology are not known. Though recessive loss-of-function alleles are associated with alterations in ABCC6 expression and function, the molecular pathologies associated with the majority of PXE-causing mutations are also not known. Sequence analysis of orthologous ABCC6 proteins indicates the C-terminal sequences are highly conserved and share high similarity to the PDZ sequences found in other ABCC subfamily members. Genetic testing of PXE patients suggests that at least one disease-causing mutation is located in a PDZ-like sequence at the extreme C-terminus of the ABCC6 protein. To evaluate the role of this C-terminal sequence in the biosynthesis and trafficking of ABCC6, a series of mutations were utilized to probe changes in ABCC6 biosynthesis, membrane stability and turnover. Removal of this PDZ-like sequence resulted in decreased steady-state ABCC6 levels, decreased cell surface expression and stability, and mislocalization of the ABCC6 protein in polarized cells. These data suggest that the conserved, PDZ-like sequence promotes the proper biosynthesis and trafficking of the ABCC6 protein. © 2014 Xue et al
Serum Metabolome and Lipidome Changes in Adult Patients with Primary Dengue Infection
10.1371/journal.pntd.0002373PLoS Neglected Tropical Diseases78
Dengue Virus Infection Perturbs Lipid Homeostasis in Infected Mosquito Cells
Dengue virus causes ∼50–100 million infections per year and thus is considered one of the most aggressive arthropod-borne human pathogen worldwide. During its replication, dengue virus induces dramatic alterations in the intracellular membranes of infected cells. This phenomenon is observed both in human and vector-derived cells. Using high-resolution mass spectrometry of mosquito cells, we show that this membrane remodeling is directly linked to a unique lipid repertoire induced by dengue virus infection. Specifically, 15% of the metabolites detected were significantly different between DENV infected and uninfected cells while 85% of the metabolites detected were significantly different in isolated replication complex membranes. Furthermore, we demonstrate that intracellular lipid redistribution induced by the inhibition of fatty acid synthase, the rate-limiting enzyme in lipid biosynthesis, is sufficient for cell survival but is inhibitory to dengue virus replication. Lipids that have the capacity to destabilize and change the curvature of membranes as well as lipids that change the permeability of membranes are enriched in dengue virus infected cells. Several sphingolipids and other bioactive signaling molecules that are involved in controlling membrane fusion, fission, and trafficking as well as molecules that influence cytoskeletal reorganization are also up regulated during dengue infection. These observations shed light on the emerging role of lipids in shaping the membrane and protein environments during viral infections and suggest membrane-organizing principles that may influence virus-induced intracellular membrane architecture
The Membrane Fusion Step of Vaccinia Virus Entry Is Cooperatively Mediated by Multiple Viral Proteins and Host Cell Components
For many viruses, one or two proteins allow cell attachment and entry, which occurs through the plasma membrane or following endocytosis at low pH. In contrast, vaccinia virus (VACV) enters cells by both neutral and low pH routes; four proteins mediate cell attachment and twelve that are associated in a membrane complex and conserved in all poxviruses are dedicated to entry. The aim of the present study was to determine the roles of cellular and viral proteins in initial stages of entry, specifically fusion of the membranes of the mature virion and cell. For analysis of the role of cellular components, we used well characterized inhibitors and measured binding of a recombinant VACV virion containing Gaussia luciferase fused to a core protein; viral and cellular membrane lipid mixing with a self-quenching fluorescent probe in the virion membrane; and core entry with a recombinant VACV expressing firefly luciferase and electron microscopy. We determined that inhibitors of tyrosine protein kinases, dynamin GTPase and actin dynamics had little effect on binding of virions to cells but impaired membrane fusion, whereas partial cholesterol depletion and inhibitors of endosomal acidification and membrane blebbing had a severe effect at the later stage of core entry. To determine the role of viral proteins, virions lacking individual membrane components were purified from cells infected with members of a panel of ten conditional-lethal inducible mutants. Each of the entry protein-deficient virions had severely reduced infectivity and except for A28, L1 and L5 greatly impaired membrane fusion. In addition, a potent neutralizing L1 monoclonal antibody blocked entry at a post-membrane lipid-mixing step. Taken together, these results suggested a 2-step entry model and implicated an unprecedented number of viral proteins and cellular components involved in signaling and actin rearrangement for initiation of virus-cell membrane fusion during poxvirus entry
Spray printing of organic semiconducting single crystals
Single-crystal semiconductors have been at the forefront of scientific interest for more than 70 years, serving as the backbone of electronic devices. Inorganic single crystals are typically grown from a melt using time-consuming and energy-intensive processes. Organic semiconductor single crystals, however, can be grown using solution-based methods at room temperature in air, opening up the possibility of large-scale production of inexpensive electronics targeting applications ranging from field-effect transistors and light-emitting diodes to medical X-ray detectors. Here we demonstrate a low-cost, scalable spray-printing process to fabricate high-quality organic single crystals, based on various semiconducting small molecules on virtually any substrate by combining the advantages of antisolvent crystallization and solution shearing. The crystals’ size, shape and orientation are controlled by the sheer force generated by the spray droplets’ impact onto the antisolvent’s surface. This method demonstrates the feasibility of a spray-on single-crystal organic electronics
T cell–depleted cultured pediatric thymus tissue as a model for some aspects of human age-related thymus involution
A dynamic three-step mechanism drives the HIV-1 pre-fusion reaction
Little is known about the intermolecular dynamics and stoichiometry of the interactions of the human immunodeficiency virus type 1 (HIV-1) envelope (Env) protein with its receptors and co-receptors on the host cell surface. Here we analyze timeresolved HIV-1 Env interactions with T-cell surface glycoprotein CD4 (CD4) and C-C chemokine receptor type 5 (CCR5) or C-X-C chemokine receptor type 4 (CXCR4) on the surface of cells, by combining multicolor super-resolution localization microscopy (direct stochastic optical reconstruction microscopy) with fluorescence fluctuation spectroscopy imaging. Utilizing the primary isolate JR-FL and laboratory HXB2 strains, we reveal the time-resolved stoichiometry of CD4 and CCR5 or CXCR4 in the prefusion complex with HIV-1 Env. The HIV-1 Env pre-fusion dynamics for both R5- and X4-tropic strains consists of a three-step mechanism, which seems to differ in stoichiometry. Analyses with the monoclonal HIV-1-neutralizing antibody b12 indicate that the mechanism of inhibition differs between JR-FL and HXB2 Env. The molecular insights obtained here identify assemblies of HIV-1 Env with receptors and co-receptors as potential novel targets for inhibitor design
OBSERVATION OF A HIGH-ENERGY COSMIC-RAY FAMILY CAUSED BY A CENTAURO-TYPE NUCLEAR-INTERACTION IN THE JOINT EMULSION CHAMBER EXPERIMENT AT THE PAMIRS
1904167122623